Chapter 74

Cesarean Birth: Surgical Techniques Grainger S. Lanneau, Patrick Muffley and Everett F. Magann Main Menu Table Of Contents

Grainger S. Lanneau, Jr, MD

Clinical Instructor, Departments of Family Practice/Ob/Gyn, Puget Sound Family Practice Residency,

Bremerton, Washington, Ob/Gyn Residency, Madigan Army Medical Center, Tacoma, Washington, Staff,

Department of Ob/Gyn, Naval Hospital Bremerton, BREMERTON Washington (Vol 2, Chaps 74, 75)

Patrick Muffley, MD

(Vol 2, Chaps 74, 75)

Everett F. Magann, MD

Professor, Department of Obstetrics & Gynecology, University of Western Australia, Perth Australia, Head,

Department of Labor & Delivery, King Edward Memorial Hospital, Perth, Australia (Vol 2, Chaps 74, 75, 97)

Table of Content:

HISTORY

EPIDEMIOLOGY

INDICATIONS

TECHNIQUE

SPECIAL SITUATIONS

COMPLICATIONS

CONCLUSION

REFERENCES

A cesarean section is the delivery of a fetus through an abdominal and uterine incision;

technically, it is a laparotomy followed by a hysterotomy.1 This definition considers only

the location of the fetus and not whether the fetus is delivered alive or dead. Over the

past two decades, cesarean delivery has become more commonly used in the United

States, and this increase has generated a number of controversial issues, including what

constitutes a suitable indication, what is proper technique, and what is the correct terminology to describe the operation known as cesarean section.

Legends and myths about the abdominal delivery of an infant appear in many cultures.

One of the earliest Greek myths include the birth of Aesculapius, who according to

legend, was cut from his mother's abdomen by Apollo, Bacchus, and Jupiter.2 Legend

holds that Julius Caesar was also delivered abdominally. Because very few neonates

would have survived an open laparotomy in those times, his mother's survival well into

adult life makes the story highly unlikely. It is the birth of Caesar that some authors

have attributed to the origin of the term cesarean delivery.1,3 Another possible source

for the term is the Latin verb caedare, meaning to cut, or the term for the children who

were born by postmortem cesarean sections, who were called caesones. The Roman

law Lex Regis, which dates from 600 BC, required that infants be delivered abdominally

after maternal death to facilitate separate burial; this has also been proposed as the

origin of the term. The specific law in question was called the Lex Cesare.4,5

HISTORY

Historic records that elude to the performance of cesarean section date back as far as

the second and fifth centuries BC and seem to imply that the outcome for both mother

and child were favorable.1 The earliest authenticated report of a child who survived

cesarean birth is a document describing the birth of Gorgias in Sicily in approximately

508 BC.4 There are no other accurate descriptions of the performance of a cesarean section or the immediate outcome of the mother or the neonate until 1610.1

Gabert and Bey assessed the evolution of the cesarean section by dividing its

development into three eras: before 1500, between 1500 and 1877, and from 1878

until the present.1Before 1500, references to cesarean section are often clouded in

mystery and misinformation, although some religious texts lead us to believe that cesarean sections were performed with the survival of both the mother and the infant.

After 1500, the available literature describing delivery by cesarean section and the

success of the operation is more plentiful. In 1500, Nufer is reported to have performed

the first successful modern cesarean section, with both the mother and infant surviving.

The authenticity of this report is doubtful, because it was not documented until 82 years

after the operation was performed. In his book Treatise on Caesarean Section published

in 1581, Roussett advised that the cesarean operation be performed on a living woman;

as such, he was the first physician to do so.4 In 1610, Trautmann performed a well-

documented cesarean section in Wittenberg. Unfortunately, the patient died from

infectious complications on postoperative day 25. In 1692, a patient who had died 14

years after delivering a child by cesarean section underwent autopsy. The accuracy of the claimed cesarean section was validated by finding a well-healed scar on her uterus.

During this time period, the cesarean operation remained crude at best. The abdominal

incision was made lateral to the rectus muscles, and the uterus was incised at

whichever portion was accessible through the laparotomy incision. The uterine

musculature was not reapproximated, and the patient had to be physically restrained during the procedure because anesthesia was not available.1

By the modern era of cesarean section (1878 to present), several modifications were

being made in the cesarean operation. The Porro operation was instituted and became

popular in the United States and England as it became evident that this procedure was

associated with decreased maternal mortality. The operation consisted of a laparotomy

and hysterotomy followed by supracervical hysterectomy and bilateral salpingo-

oophorectomy. The rationale behind this radical cesarean section was that with removal

of the uterus and adnexa, the rates of uterine infection, sepsis, and hemorrhage would

decrease.1,4 Sterility and premature menopause were unfortunate side effects of the Porro procedure.

The first step toward the cesarean operation as it is currently performed was described

by Sanger.6,6A He proposed a procedure that was much less radical and designed to

conserve fertility. His operation did not involve hysterectomy and adnexectomy but

instead consisted of removing the peritoneum from a portion of the anterior uterine wall

and performing a 2-cm-wide wedge resection of the anterior uterine wall. The wedge

was cut so that a thick edge of myometrium was adjacent to the peritoneum and a thin

edge was adjacent to the endometrial cavity. These modifications allowed the serosal

edges to be incorporated into the closure with interrupted silk sutures.1,4 The technique

was further improved on by Garrigues, who did not resect the myometrium but instead

simply closed the uterine incision. Other modifications included not dissecting the

uterine serosa from the uterus and the introduction of silver wire to approximate the myometrium in addition to the interrupted silk sutures on the serosal surface.1

Operative techniques continued to improve during the 18th and 19th centuries.

Cesarean section became a safer operation that could be used at an earlier stage in

difficult labors, and a number of perioperative and intraoperative modifications

emerged. The bladder and the rectum were emptied preoperatively, with catheters and

enemas, respectively, to decrease the volume of these organs in the operative field,

thereby reducing the risk of injury during the surgical procedure. Preoperative

antimicrobial preparation was introduced by Lister in 1876 and included shaving the

operative area and applying antiseptic solutions to the operative field. Vaginal douching was also introduced and routinely performed before performing cesarean deliveries.1

The technique of laparotomy and site of hysterotomy incision were vigorously debated

and modified. Abdominal incisions were made to the right or left of the rectus muscles

or in the midline along the linea nigra. The uterine incision was made vertically in the

midline, obliquely, transversely through the contractile myometrium, laterally 7.2 to 10 cm from the fundus, or on the posterior aspect of the uterus.1

The first report of uterine closure was not until 1769. A number of suture materials were

used to close the uterus, including silver wire, silk, and catgut. Uterine closure was

associated with decreased perioperative blood loss. Early surgeons often sutured the

uterine incision to the anterior abdominal wall to encourage adhesion formation to reinforce the uterus and allow it to tolerate future gestations.1

Closure of the abdominal incision slowly evolved from choosing to leave the wound open

and apply only bandages to allow healing by secondary intention to full closure of the

abdominal wall. However, the proponents of abdominal closure were in disagreement

regarding which layers required reapproximation. Many closed only the skin, whereas others closed all layers. Drainage of the surgical site was also introduced.

Johnson first described a lower segment uterine incision in 1786.1 In 1908, Selheim

suggested that a uterine incision made in the lower uterine segment rather than the

contractile segment of the myometrium would decrease blood loss at surgery and

decrease blood loss in the event of uterine dehiscence.1,4

The development of the modern cesarean operation has not been a recent

accomplishment but instead represents a series of innovations over many centuries of

trial and error. Many aspects of the operation as it is commonly performed today are

not based on randomized trial or techniques that have been proven to be superior by

rigorous study, but instead are the culmination of many years of trial and error.

EPIDEMIOLOGY

In 1965, the total cesarean rate in the United State was 4.5%.7 By 1988, the cesarean

rate had increased to an all-time high of 24.7% and accounted for more than 965,000

live births that year. The cesarean rate continues to fluctuate and was 24.49% in

2001.8 The high incidence of cesarean delivery has caused a great deal of debate over

the past several years among health care providers, third-party payers, and health

policy developers. The questions debated include what is an appropriate cesarean rate,

are cesareans necessary for optimal patient care, and how should the cost of abdominal

delivery be addressed (Fig. 1)?

Fig. 1. Total and primary cesarean rate and VBAC rate in the

United States from 1989 to 2001. (Macdormon MF: Annual

Summary of Vital Statistics, Pediatrics 110:1037–1052, 2002.)

The vaginal birth after cesarean (VBAC) rate in 1985 rate was 6.6 per 100 deliveries by

women with a previous cesarean section. The VBAC rate increased 33% between 1991

and 1996 (from 21.3 to 28.3 per 100 births to women with a previous cesarean) but

then decreased 17% between 1996 and 1999 (to 23.4 per 100 births). The dramatic

increase in VBAC rates between 1991 and 1996, followed by its subsequent decrease,

was experienced by women of all ages and for each major race/ethnicity group. The

VBAC rate in 1993 had increased to 25.4 per 100 deliveries by previous cesarean

patients.9 These increases in the cesarean section rate were the impetus for a number

of investigators to assess the causes of these trends and to search for possible methods

to decrease the cesarean birth rate.8 The Healthy People 2000 Work Group

recommended a target national cesarean delivery rate of 15% for the year 2000

(including the specific targets of 12% for primary [first time] cesarean deliveries and

65% for repeat cesarean deliveries among women who had a previous cesarean

delivery); it is evident that this goal was not met. A Department of Health and Human

Services expert working group on cesarean delivery rates, which included ACOG

representatives, discussed the Healthy People 2010 objectives and developed evidence-

based cesarean delivery rate goals for the year 2010. The National Center for Health

Statistics (NCHS) has determined the cesarean delivery rates for two major categories

of patients from 1996 birth certificate data. Target cesarean delivery rates determined

by the expert working group were based on the 25th and 75th percentiles of state

ranking for these two categories. Targets for the two major categories should be set at

the 25th percentile for primary cesarean delivery rates and the 75th percentile for VBAC

rates. The task force has adopted 1996 rates to be consistent with NCHS and the expert working group rates, but uses 1997 national vital statistics elsewhere in this report.

The expert working group proposes the following cesarean delivery rate benchmarks:

nulliparous women at 37 weeks of gestation or greater with single fetuses with vertex

presentations, the national 1996 cesarean delivery rate for this group was 17.9%; the expert working group goal at the 25th percentile for this group is 15.5%.

Multiparous women with one previous low-transverse cesarean delivery at 37 weeks of

gestation or greater with singleton fetuses with vertex presentations: The national 1996

VBAC rate for this group was 30.3%; the expert working group goal at the 75th percentile is 37%.

Cesarean section and VBAC rates differ among geographic regions, demographic

populations, and third-party payer sources. For example the cesarean section rate

continues to be highest in the southern and northeastern United States compared with

the West and the Midwest. Conversely, the VBAC rates tend to be lowest in the southern and northeastern regions of the United States8,9 (Figs. 2A and 2B).

Fig. 2. A. State ranking of cesarean delivery rates

in the United States in 1997 (Ventura SJ, Martin

JA, Curtin SC et al: Births: Final data for 1997.

Natl Vital Stat Rep 47:1–84, 1999). B. State

ranking of VBAC rates in the United States in

1997. VBAC indicates vaginal birth after cesarean

delivery. (Ventura SJ, Martin JA, Curtin SC et al:

Births: Final data for 1997. Natl Vital Stat Rep

47:1–84, 1999.)

Fig. 2. Continued.

The rate of cesarean delivery was also increased in women older than age 35 years, in

hospitals with more than 500 beds, in for-profit hospitals, and in patients with private

insurance.10 The cesarean section rate in the United States, when compared with that in

other developed countries, is the among the highest in the world.10,11

Several authors have examined the incidence of cesarean section by indication. An

analysis of cesarean deliveries at the University of Vermont by Pollard and Capeless

revealed the that the total cesarean section rate was 14.4% and the primary cesarean section rate was 11.4%.12

Abnormal presentation and dystocia were the major indications for cesarean delivery. A

much smaller proportion was performed for nonreassuring fetal surveillance, failed induction, and 25% for other indications.

Repeat cesarean deliveries account for a large percentage (37%) of the cesarean

sections in the United States.9 It is believed that through both patient and health care

provider education, the number of repeat cesarean sections can be reduced. VBAC

success rates in excess of 70% have been reported in diverse populations with the

implementation of an aggressive VBAC policy. Strategies to improve VBAC rates might

include educating women about the risks for complications and benefits of VBAC,

ensuring careful selection of VBAC candidates, developing guidelines for management of

labor, and educating health care providers about reducing VBAC risks.5 Further work is

required to encourage patients and physicians to accept this alternative to repeat

cesarean delivery. The indications, contraindications, and predictors of success for VBAC

are discussed later in this chapter.

The diagnosis of dystocia is another important contributor to the high rate of cesarean

delivery. In 1995, Pollard and Capeless found that more than 35% of cesarean sections

in their institution were performed for either arrest of dilation or arrest of

descent.12 Diagnoses such as dystocia, cephalopelvic disproportion, and failure to

progress are unacceptably vague and do not reflect the true reason why the labor is not

progressing as anticipated. An accurate recording of the reason that labor has not

progressed should include the adequacy of the maternal pelvis, the fetal size and

position, and strength and frequency of the uterine contractions. To more thoroughly

evaluate the cause of the dystocia, an attempt to achieve active-phase labor should be

undertaken. It is important to note that a primary cesarean section for dystocia occurs

primarily in first labors, it is a relatively uncommon event in parous patients,13 and also

that the majority of repeat cesarean operations result from primary cesarean deliveries

for dystocia.13 Therefore, the thorough evaluation of patients with evidence of dystocia

in labor and the exhaustive search for the underlying cause, with reasonable attempts to alleviate correctable problems, could significantly impact the cesarean section rate.

Fetal malpresentation currently accounts for approximately 3% to 4% of cesarean

sections in the United States.13 Because of the International Term Breech Trial,

cesarean section is routinely offered to nonvertex infants. Because of these changes,

external cephalic version has emerged as a realistic means of correcting fetal

malpresentations prior to labor and therefore avoiding an unnecessary abdominal

delivery.14,15,16 The ACOG defines dystocia as difficult labor or childbirth resulting

from abnormalities involving the cervix and uterus, the fetus, the maternal pelvis, or combinations of these factors.17

Fetal intolerance of labor contributes minimally to the overall cesarean rate. However,

the cesarean section rate has increased with the widespread use of electronic fetal

monitoring.18,19,20,21,22 The use of centralized fetal monitoring increases the cesarean

rate even more.23 Because of the well-documented low specificity of a nonreassuring

fetal heart rate pattern, further assessment by other diagnostic means should be

undertaken in all but the most pressing cases. Fetal heart rate acceleration with scalp

stimulation or a normal scalp pH in the fetus with repetitive late decelerations is

reassuring of fetal well being. Scalp pH, which is time consuming and may be difficult to

obtain, may be replaced by a newer technology. Fetal pulse-oximetry is currently used

in Europe but has failed to become a standard of care in this country pending a more

thorough evaluation of its benefit.24

A number of other programs have been implemented at various institutions in an

attempt to reduce the cesarean section rate. A labor-adjusted cesarean rate has been

proposed as a more accurate indicator of the appropriateness of the rate of cesarean

section than raw numbers and rates.25 This labor-adjusted rate excludes patients who

are determined not to be candidates for vaginal delivery by a reasonable

physician standard. For example, excluded patients would include women with a history

of classical cesarean section, proven pelvic inadequacy, invasive cervical malignancy,

suspected ruptured uterus before labor, maternal disease that may be life-threatening

because of the physiologic changes involved in labor, macrosomia, macrocephaly, funic

presentation, monoamniotic twins, and nonreassuring fetal heart rate on antenatal

surveillance. In one population in which the labor-adjusted rate was studied, the

adjusted cesarean rate was almost one third of the raw cesarean rate.

Peer review committees have also been established in many hospitals to evaluate

cesarean section indications and rates.25 Although the institution of a peer review

process for cesarean deliveries has not been shown to significantly decrease the

cesarean section rate, it remains an excellent method of evaluating and adjusting

medical practice within a hospital community.

INDICATIONS

Indications for cesarean delivery vary depending on the clinical situation, resources

available for patient care, and individual physician management techniques. There are no

definitive algorithms available to the practicing obstetrician to direct when an abdominal

delivery will benefit the mother and/or the fetus in every clinical situation. The decision to

perform an abdominal delivery remains a joint judgment between the physician and

patient after carefully weighing the pros and cons of a cesarean delivery versus continued labor and/or operative or spontaneous vaginal delivery.

Primary Cesarean Section and Repeat Cesarean Section

Primary cesarean section is the delivery of the fetus through the maternal abdomen in a

gravida who has not previously undergone a cesarean delivery. Repeat cesarean section

refers to the gravid who refuses trial of labor or who is not a candidate for vaginal

delivery. Common indications for repeat cesarean deliveries include complete placenta

previa, breech presentation, fetal lie other than longitudinal after failed external cephalic

version, nonreassuring fetal assessment that cannot be further evaluated, clinically

proven inadequate maternal pelvis, and severe preeclampsia hemolysis, elevated liver

enzymes, and thrombocytopenia (HELLP) syndrome that is clinically worsening and is

remote from delivery, cervical cancer, obstructing fibroid, and acquired immune

deficiency. Indications for cesarean delivery can be divided into indications that are of

benefit to the mother, the fetus, or both.

Indications for cesarean delivery for maternal benefit include any situation in which it is

inadvisable to continue to strive for a vaginal delivery out of concern for maternal

outcome. In these situations, the gravida undergoes a major abdominal operation for indications that are likely to decrease her risk for morbidity and/or mortality.

In contrast, when a cesarean section is performed for fetal indications, the mother is

undergoing major abdominal surgery when there is no immediate benefit to her but there

is potential benefit to the neonate. In these situations, fetal health would be

compromised if further efforts toward vaginal delivery are pursued. Indications for

abdominal delivery that fall into this classification include delivery of a nonvertex infant or

nonreassuring fetal assessment. When counseling the patient before cesarean section

regarding the risks and benefits of abdominal delivery, the possibility of morbidity and

mortality must be discussed. This point is no less important when counseling for a repeat cesarean delivery.

Before performing an elective repeat cesarean delivery, several considerations must be

addressed. In 1995, the ACOG Committee on Quality Assessment published a criteria set

outlining these considerations. The committee suggested that the type of previous

uterine incision should be documented from the previous operative notes, the risks and

benefits of VBAC should be thoroughly discussed with the patient and documented in the

chart, the risks and benefits of repeat cesarean delivery should be thoroughly discussed

with the patient and documented in the chart, and fetal maturity should be verified and

documented.26 Fetal lung maturity may be assumed if any of the following criteria are

met: fetal heart tones have been documented for 20 weeks by a DeLee fetoscope or for

30 weeks by Doppler, it has been 36 weeks since a documented positive pregnancy test

(serum or urine) by a reliable laboratory, ultrasound measurement of fetal crown–rump

length performed between 6 and 11 weeks is consistent with a gestational age of 39

weeks or more, or ultrasonographic fetal biometry obtained between 12 and 20 weeks

gestation agrees with historic and physical examination assessment and supports a

gestational age of 39 weeks or more.27 If these criteria are not met, an elective cesarean

section may not be performed without documentation of fetal lung maturity by

amniocentesis or awaiting the onset of spontaneous labor. Cesarean section for maternal

or fetal indications or in the event of spontaneous labor when tocolysis is no longer

indicated may be performed without meeting these criteria.

TECHNIQUE

As noted in the historical review at the beginning of this chapter, the cesarean operation has

undergone a number of technical changes as the procedure has evolved. Many different

practitioners extol the benefits of various techniques of skin incision, uterine incision,

uterine closure, and many other technical aspects of the operation. However, there are

relatively few randomized trials to support many of the commonly used techniques in performing a cesarean section.28

Preoperative Evaluation

The preoperative assessment should include a full history and physical examination, past

medical and surgical history, current medications, drug allergies, and indication for cesarean

section. In the uncomplicated patient, no preoperative laboratory investigation is needed

except for the routine labor and delivery admission laboratory values. Rarely will chest x-ray

films and electrocardiograms be indicated unless there is a history of significant maternal

medical disease. In instances in which these studies are indicated, preoperative consultation

with an anesthesiologist, cardiologist, or both should be considered.

Abdominal Preparation

Although abdominal preparation and shaving the maternal abdomen the night before the

procedure have been the norm in the past, there are little data to support the use of night-

before preparations. There is evidence that any abdominal shave performed should be

performed in the operating room just before applying the antibacterial preparations and not

the night before. Shaving the patient the night before surgery actually increases the

bacterial count on the maternal abdomen.29 Shaving should be performed only to remove

the hair that will physically interfere with the operation itself. There is no reason to shave

most patients. Placing the patient in the left lateral tilt position using either a hip wedge or

an operative table with lateral tilt capability will help avoid uterine compression of the

inferior vena cava, which can cause fetal bradycardia during preparation for and

performance of the cesarean section. Before the abdominal preparation and draping of the

patient, a Foley catheter should be placed to allow the bladder to drain during the operation

so that urinary output can be evaluated intraoperatively and the presence of the bladder in the operative field can be minimized.

Skin Incision

A number of skin incisions have been used in abdominal deliveries. The most frequently

used type of skin incision in the United States is the Pfannenstiel incision; the midline

vertical incision is the next most common (Fig. 3). Other skin incisions used include the

Maylard, Cherney, right paramedian, and the low transverse. In general, the skin incision

should be determined by the physician based on maternal body habitus, clinical situation,

time available to deliver the infant, and skill of the surgeon. Midline vertical incisions are

generally more hemostatic and require less dissection; therefore, less time from incision to

birth than transverse incisions. Transverse incisions fall along the lines of expression of the

anterior abdominal wall and therefore should create less pronounced scarring and risk of dehiscence. Transverse incisions have also been associated with less postoperative pain.

Fig. 3. Abdominal incisions. A. Pfannenstiel incision

should be made in a curvilinear fashion

approximately 2 cm above the pubic

symphysis. B.Joel-Cohen incision should be made

in a linear fashion approximately 2 to 3 cm above

the traditional placement of the Pfannenstiel

incision. C.Midline vertical incision should be made

in the midline and extend from just below the

umbilicus to just above the symphysis pubis and

may be continued around the umbilicus if more

exposure is necessary. D. Wiser (right

paramedian) incision should be made several cm

to the right side of the umbilicus and somewhat

higher than the normal midline vertical incision.

TRANSVERSE INCISIONS

Although transverse incisions are commonly performed because of the widely held belief

that there is a decreased incidence of wound dehiscence and incisional hernia and greater

cosmetic appeal, more recent studies have not supported this belief and point to infection as

the greatest risk for dehiscence regardless of incision type.30,31,32 The Pfannenstiel incision is

made transversely in the maternal abdomen approximately 3 cm above the symphysis pubis

and is curvilinear, with the lateral apices of the incision smiling up toward the anterior

superior iliac spines (see Fig. 3). This incision is performed sharply to the level of the

anterior rectus fascia. The anterior rectus fascia is then sharply incised with the scalpel in a

transverse manner in the midline to expose the belly of the rectus muscle on either side of

the midline. At this time, the incision in the anterior rectus fascia may be extended laterally using either the scalpel or the Mayo scissors.

Care must be taken not to cut the underlying rectus muscles. This may be accomplished by

placing the Mayo scissors, with the tip up, underneath the fascia, and then sliding the

scissors laterally along the length of the proposed fascial incision, opening the blades of the

scissors at the proposed apex of the incision and withdrawing the scissors before closing the

blades. At this point, the Mayo scissors can be used to extend the fascial incision laterally by

merely pushing the blades of the scissors against the fascia. Care should be taken to avoid

the transverse oblique muscle when incising the fascia. After the fascia is incised, the

anterior rectus fascia can then be dissected from the underlying rectus muscles in both the

cephalad and caudad directions. This is accomplished by grasping the cut edges of the fascia

with a pair of strait Kocher clamps and using a combination of blunt and sharp dissection to

free the muscle from the overlying fascia. This dissection allows the rectus muscles to be

retracted laterally without being cut. During this dissection, care must be taken to identify

and ligate or electrocoagulate the perforating vessels between the rectus muscles and the

anterior fascia; this can be performed at entry, or in the event of an emergency cesarean

delivery, at the time of closure. The posterior sheath consists of the fascia of the

transversalis muscle and is closely opposed to the peritoneum. These tissues may be incised

in either a longitudinal and transverse manner. Regardless of which manner is chosen, the

entry point should be high in the operative field to avoid injury to the maternal bladder.

Sharpening of the peritoneum may be performed by elevating the peritoneal membrane

between two hemostats, palpating the opposing pieces of membrane for evidence of

entrapped bowel, and making circumcision with a scalpel or by bluntly introducing a finger

through the peritoneum at the level of the umbilicus. Once the peritoneal cavity is entered,

the peritoneal incision is extended using Metzenbaum scissors to maximize surgical

exposure, with care being taken to avoid inadvertent damage to the bladder or to any bowel or omentum that may be adherent to the anterior abdominal wall.

The Maylard and Cherney incisions differ from the Pfannenstiel incision in the manner in

which the anterior rectus sheath and the rectus muscles are approached. With the Maylard

incision, once the anterior rectus sheath is incised in a transverse fashion, the fascia is not

dissected free from the underlying rectus muscles; instead, the inferior epigastric arteries

are identified and ligated, and the rectus muscles are incised, usually with electrocautery to

minimize bleeding. The posterior rectus sheath and the peritoneum are then incised in a

transverse fashion.

The Cherney incision is performed in the same manner as the Pfannenstiel and the Maylard

incisions except that the rectus fascia is not entered; instead, the rectus muscles are cut

free from the symphysis pubis at their tendinous insertion and reflected superiorly. There are few if any indications for the use of this type of incision for an abdominal delivery.

The Joel-Cohen incision is performed in a transverse manner several cm above the location

of a Pfannenstiel incision and is linear, not curvilinear. The fascia is not dissected off of the

rectus muscles, and the peritoneum is entered transversely, as in the Maylard incision. An

advantages of this type of incision include decreased operating time, however there are no maternal or fetal advantages other than speed.33,34

In the moderately obese patient, a variation of the Pfannenstiel incision is performed several

cm higher than the true Pfannenstiel to avoid placing the incision in the fold created by the

abdominal pannus and thereby decreasing the rate of wound complications.

VERTICAL INCISIONS

Historically, the midline vertical skin incision has been the preferred incision for cesarean

section because of the speed and ease of entry into the peritoneal cavity. The decreased

dissection that is required reduces intraoperative blood loss. Vertical incisions remain useful

in situations such as cesarean section for fetal bradycardia and in the morbidly obese

patient in whom a transverse incision may not allow for adequate exposure of the operative

field. The incision is performed vertically from just below the umbilicus and extended to just

above the symphysis pubis and can easily be extended around the umbilicus if exposure of

the upper abdomen is required. When making a midline vertical incision, it is important to

remember that the linea nigra may not represent the true midline. The incision is carried

sharply down to the level of the rectus sheath, which is then incised sharply with the scalpel

in a vertical direction. This incision may be completed with the scalpel or by using the Mayo

scissors. The fascial edge closest to the midline is then grasped with a pair of Kocher

clamps, and sharp and blunt dissections are used to separate the rectus muscles from the

overlying fascia. The rectus muscles are then separated in the midline, and the peritoneum is entered vertically as described previously.

A right paramedian incision is useful in the morbidly obese patient in whom the abdominal

pannus is grossly displaced when the patient is placed in the left lateral tilt position.

Advantages of this incision are that once the skin has been incised, an incision that is

continued perpendicular toward the floor of the operating room will incise the fascia

approximately in the midline of the patient, resulting in better exposure for the delivery of

the infant.

Repeat cesarean delivery account for the majority of cesareans. In patients undergoing

repeat cesarean delivery, the abdominal scar may be revised at the time of repeat

operation. In the case of an emergency cesarean section, any scar revision should be

performed at the time of abdominal closure and not at entry. It is also important to

remember that the choice of skin incision should be that which the primary surgeon believes

will be most beneficial for the present operation and should not be dictated by the location of a previous scar.

Uterine Incisions

There are three standard uterine incisions that can be performed for delivery of the fetus:

low transverse, low vertical, and classical (Fig. 4). The specific type of uterine incision

should be determined by the primary surgeon at the time of the operation based on gestational age and lie of the fetus and any uterine anomalies.

Fig. 4. Uterine incisions. A. Low-transverse uterine incision should be made through the

thin, noncontractile portion of the lower uterine segment in a curvilinear fashion. Also

pictured is a low-vertical incision, which is made through the noncontractile lower uterine

segment in a vertical fashion. B. J-extension of the low-transverse incision. When

additional exposure to the uterine cavity is required to deliver the fetus, the low-transverse

incision can be extended laterally and cephalad to increase the length of the incision

without endangering the uterine arteries. C. Another option in this situation is to use a T-

extension in the midline. D. The classical uterine incision is made through the contractile

portion of the myometrium above the bladder reflection.

Historically, the creation of a bladder flap was advocated before making any uterine

incisions. More recently, randomized controlled trials have noted that the omission of the

bladder flap provides short term advantages such as reduction of operating time and

incision-delivery interval, reduced blood loss and need for analgesics. Long-term effects

remain to be evaluated.35 When developing a bladder flap, a segment of loose areolar

peritoneum can be visualized at the area where the bladder is adjacent to the lower uterine

segment. The peritoneum is grasped with a pair of forceps, elevated, and then incised

transversely with Metzenbaum scissors, with care being taken not to extend the incision

laterally into the vascular broad ligament. Next, the inferior portion of the incision is

elevated, and careful blunt and sharp dissection is used to separate the posterior wall of the

bladder from the lower uterine segment. This dissection serves two purposes: it allows

better access to the lower uterine segment and it allows the bladder to be retracted out of

the operative field. Before making the uterine incision, the surgeon should also identify the

round ligaments to properly orient the degree of dextrorotation of the uterus and to

evaluate for the presence of any myomas or other malformations that might affect the choice and/or placement of the incision.

The standard low-segment transverse incision accounts for 90% of all uterine incisions.28 It

is initiated sharply in the lower uterine segment, perpendicular to the long axis of the

uterus. This incision is made sharply with the scalpel in the midline and performed down to

the level of the fetal membranes, with care being made not to incise the membranes. This

incision is then extended laterally using either blunt dissection with the fingers or bandage

scissors (Fig. 5). There was thought to be no difference between the two methods in amount

of blood lost or in the rate of extension of the incision into the lateral uterine vessels when

they were compared and correlated by the stage of labor.36 However, a recent investigation

revealed a greater risk of subsequent blood transfusion in woman whose incision was

extended sharply compared to those extended bluntly.37 When blunt dissection is used, an

upward curve of the incision may be created by the surgeons placing their thumbs on the

patient's anterior superior iliac spines and index fingers in the uterine incision. By keeping

the hand in this position, the incision is pulled open in an arc.

Fig. 5. Extension of the lower uterine incision

may be accomplished either by inserting fingers

into the uterine cavity and bluntly stretching the

myometrial incision in a curvilinear fashion or by

sharply cutting the lower uterine segment with

bandage scissors. When the uterus has a poorly

developed lower uterine segment, using bandage

scissors is often preferable.

Intentional extension of the low-transverse incision is necessary in 1% to 2% of

cases.38 Typically, the extension of the low transverse incision is performed by creating a

low vertical incision in the midline, T-ing the uterine incision, or creating a vertical incision

at the lateral aspect of the uterine incision, a J-extension. These extensions are commonly

performed for malpresentations, poorly developed lower uterine segment, or deep

transverse arrest.38 When performed, extensions of the low-transverse incision are

associated with increased incidence of maternal blood loss, broad ligament hematoma, and

uterine artery laceration compared with low-segment transverse incisions that do not require extension.

The low-vertical uterine incision is made parallel to the longitudinal axis of the uterus in the

midline, with care being taken to remain below the contractile portion of the uterus and

within the thin lower uterine segment. Other than the direction of the incision, technical

aspects are carried out as described for the low-transverse uterine incision. Studies have

shown that there is no increased risk of uterine rupture in patients with this type of incision

compared with the low-segment transverse incision as long as the incision remains primarily in the thin lower uterine segment.39

A classical uterine incision is made by incising the uterus parallel to the longitudinal axis of

the uterus through the contractile portion of the

myometrium. Indications for classical uterine

incision include situations in which the lower uterine

segment is not adequately developed to

accommodate a low-transverse or a low vertical

incision; cases of abnormal fetal lie such as back-

down transverse lie, in which the low-transverse or

low-vertical incision will not allow the operator

adequate access to the fetus for manipulation and

delivery, or when myomas or uterine abnormalities

distort the uterus in such a way as to make a low

transverse incision inadvisable.

Delivery of the Fetus

After the uterine incision has been made, the fetal membranes, if still intact, are ruptured

with an Allis clamp. If the fetus is in a noncephalic presentation, leaving the membranes

intact until the fetal feet or head can be moved into the uterine incision will increase the

ease of delivery. When the fetus is in a cephalic presentation, delivery is performed by the

surgeons placing their dominant hand into the uterine cavity and elevating the fetal head

into the uterine incision (Fig. 6). If the fetus is not in an occiput anterior position, rotating

the head into this position will allow the fetal neck to extend around the upper portion of the

incised myometrium and more closely mimic the cardinal movements of vaginal delivery.

When the fetal head is impacted in the maternal pelvis, such as in deep transverse arrest,

there are a number of options to assist with delivery of the fetal head. The surgeon can

place a hand in the lower uterine segment in the standard fashion to cup and then

disengage the fetal head. Care must be taken by the surgeon not to flex the wrist, because

this often causes extension of the uterine incision caudally toward the bladder and vagina. If

this does not work, an assistant can place a sterile, gloved hand into the vagina from the

introitus and disengage the fetal head from below (Fig. 7). Another option is for the surgeon

to the dominant hand between the lower uterine segment and the reflected bladder and

attempt to disengage the head by cupping it through the lower uterine segment. It is our

experience that care must be taken with this maneuver to ensure that the bladder is not damaged by inadvertent blunt cystotomy.

Fig. 6. Extraction of the fetal head. The

surgeon's dominant hand is placed into the

uterine incision so that the back of the hand is

against the inside of the lower uterine segment

and the fingers cup the fetal head. Firm, gentle

traction is used to elevate the fetal head toward

the incision. The fetal head may then be rotated

to an occiput anterior position and delivered

through the uterine incision with the assistance of fundal pressure.

Fig. 7. Disimpaction of the fetal head. When the fetal

head has descended so far into the vagina that extraction

of the fetal head is difficult, having an assistant place a

gloved hand into the vagina and elevate the fetal head

from below can increase the ease of delivery and

decrease the trauma to the lower uterine segment and

vagina.

Once the fetal head is at the uterine incision, mild fundal pressure by the first assistant will

encourage the expulsion of the fetal head from the uterus. At this point, the nares and

mouth of the fetus should be suctioned and, after checking for and reducing any nuchal

cord, the fetal body is delivered by standard maneuvers as in a vaginal delivery. After the

infant is delivered, the cord is doubly clamped and cut, and the infant is handed to the

personnel who have been assigned to care for the newborn. It is important to remember

that if the newborn requires resuscitation, the obstetrician is responsible for its care as well

as the care of the mother. Qualified personnel should be available to assume care of the newborn.

Attention is now turned to the delivery of the placenta. The delivery of the placenta may be

accomplished either by manual extraction or by awaiting spontaneous delivery. Spontaneous

delivery of the placenta, when assisted with uterine massage and gentle traction on the

umbilical cord, is associated with a lower rate of postpartum endomyometritis and maternal

blood loss compared with manual extraction.40,41,42 Once the placenta has been delivered,

the uterus may be either exteriorized or left in situ to be repaired. Blood loss is not

significantly different with either method.42 Exteriorization of the uterus does allow for better

visualization of the adnexal structures and increases the ease with which tubal ligation can

be performed.

Fig. 8. Single-layer repair of the low-transverse uterine incision. To

obtain optimal hemostasis of the incision in a single layer, the surgeon

should be careful to include all layers of incised myometrium while

taking care to avoid including excess decidua and serosa.

Uterine closure may be performed with either a single- or double-layer closure technique.

Single-layer closure using a running locking stitch (Fig. 8) has been shown to be associated

with decreased operative time and fewer additional hemostatic sutures. A large Canadian

study found a four-fold increase in the risk of uterine rupture in woman who had a single layer closure in their previous pregnancy.43,44,45,46,47

Chromic catgut has been the suture of choice for closure of the uterine incision by many

obstetricians for a number of years. However, the use of a synthetic absorbable suture, such

as polyglycolic acid or polyglactin, has several advantages over the use of catgut. The

method of absorption of catgut suture is by phagocytosis, and this results in significantly

more inflammation than the absorption of synthetic sutures by hydrolysis.48 The decreased

inflammation associated with synthetic absorbable sutures, as well as the increased time interval to the loss of suture strength, are both advantageous in this situation.

After the uterus is closed and has been returned to the peritoneal cavity, irrigation can be

employed. Routine irrigation in low-risk populations does not reduce intrapartum or

postpartum maternal morbidity.49 Next, attention should be turned to ensuring that the

operative field is hemostatic, with special attention given to the uterine incision and bladder

flap, if these have been previously placed on tension because of exteriorization of the

uterus, and to the rectus muscles. Hemostasis may be achieved by either suture ligation or

electrocoagulation of bleeding points. There is no advantage to closure of the visceral or

parietal peritoneum. When repaired with suture, the peritoneum undergoes more

inflammation and scarring in animal models.50 Operating time and postoperative analgesia

requirements are reduced in patients who do not undergo closure of the visceral and parietal

peritoneum. There is also a decrease in adhesions found at repeat operation when the visceral and parietal peritoneum is not closed.51

Fascial closure in a Pfannenstiel incision is performed in a single layer with a synthetic

absorbable suture. In patients who have undergone more than one laparotomy through the

same scar, or in patients who are at increased risk for fascial separation or dehiscence such

as diabetic patients or patients who are on chronic corticosteroids, the use of a synthetic

delayed absorbable suture such as polydioxanone may be preferable because of its ability to

maintain suture strength for a longer period of time.52 For the closure of a vertical fascial

incision, a continuous running delayed absorbable suture has been shown to be as effective

as the Smead-Jones closure and to reduce operating time without increasing morbidity.

Whenever sutures are placed within the fascia, it is important to remember that a 10-mm

zone of collagenolysis occurs surrounding the incision; therefore, sutures should be placed

more than 1 cm from the fascial edge to achieve maximal wound strength.53

The subcutaneous tissue may be closed with an absorbable suture or simply reapproximated

by closure of the skin. Closing this layer has not been associated with decreased rates of

superficial wound disruption in several studies.54 Skin closure may be accomplished by

either a subcuticular stitch or staples. Subcuticular stitch has been associated with less

immediate postoperative pain and more cosmetically appealing at 6 weeks when compared to the stapling device.55

Postoperative Care

There is little literature to support any specific postoperative regimen in postcesarean

patients; however, common sense and extrapolation of data from other postlaparotomy

patients allow for the development of a rational plan of care. Most cesarean sections are

relatively uncomplicated, and in these patients, care should be similar to that given after a vaginal delivery.

In the first hour after cesarean section, the patient should be monitored closely in a

recovery area where urine output, pulse, blood pressure, respirations, and any evidence of

bleeding can be closely observed; if the patient remains stable and without complication, she may then be transferred to the postpartum ward.

Once any nausea and vomiting has abated, the patient should be encouraged to take fluids

orally. This may be followed by oral intake of solid food as soon as the patient feels that she

is ready; this should occur no later than the first postoperative day. Early institution of

feeding in the postsurgical patient with minimal intraoperative bowel manipulation does not

increase the incidence of postoperative ileus.56

Early ambulation should also be encouraged. Getting the patient out of bed as soon as

regional anesthesia has worn off or as soon as she has recovered from general anesthesia

will decrease the incidence of pulmonary complications such as atelectasis and pneumonia

and the incidence of thrombotic complications. This will also facilitate the removal of bladder

catheters, therefore decreasing the incidence of catheter-associated urinary tract infections.

In the uncomplicated patient with adequate urine output, the catheter should be removed

no later than the first postoperative day. Encouragement of deep breathing and coughing

with the use of incentive spirometry will also help prevent collapse of alveoli in the lung and resulting infection.

Routine laboratory studies are probably unnecessary in most postcesarean patients who

have no unexpected symptoms. However, a single hemoglobin determination on

postoperative day one or two is probably reasonable to screen for significant anemia. Most

postpartum patients with asymptomatic anemia respond well to oral iron therapy.

The wound should be cared for in the standard manner, with occlusive dressings removed

on the first postoperative day and the wound examined daily during the hospitalization for

evidence of infection, seroma, or hematoma. Skin staples can be removed on the second or

third postoperative day with Pfannenstiel incisions and at the fifth to seventh postoperative

day with vertical incisions. The placement of SteriStrips after staple removal may help maintain skin edge approximation with earlier removal.

The patient may be discharged when she is able to care for herself and her newborn. Many

patients are ready to leave the hospital by postoperative day two or three. Discharge

instructions should include patient education concerning expectations on activity level,

lochia, breastfeeding or milk suppression, contraception, and newborn care.

SPECIAL SITUATIONS

Vaginal Birth After Cesarean Section

VBAC has become less common in the United States, and between 1996 and 1999 the rate

decreased by 17 % to 23.4 %.7 The VBAC rate is defined as the number of vaginal births

to women with a previous cesarean section per 100 deliveries to women who had a

previous cesarean delivery. In 1999, the United States VBAC rate was 23.4.7 Since the

early 1980s, a number of reports have shown that vaginal delivery after a previous low-

transverse or low-vertical cesarean section is safe for both the mother and the

fetus.39,60,61 However, more recently the safety of VBAC has come under closer scrutiny.

Despite literature supporting the practice, most generated in university and tertiary-level

centers, there have been no randomized trials to prove that maternal and fetal outcomes

are improved by VBAC over repeat cesarean section. There have even been reports to

indicate that there are maternal and infant complications associated with an unsuccessful trial of labor.57,58,59 These facts demonstrate the need for a continued study in this area.

In properly selected patients, the success rate for trial of labor is between 60% and

80%,60,62,63,64 which is not grossly different from the vaginal delivery rate of the entire

obstetric population in the United States in recent years. A successful trial of labor is less

likely in patients who have not had a previous vaginal delivery, have a history of

dysfunctional labor, have nonreassuring fetal surveillance, undergo induction of labor, have

a fetus with evidence of intrauterine growth restriction, or have fetal–pelvic disproportion.65

Several authors have attempted to predict which patients are more likely to undergo

successful VBAC by various historic parameters and the physical examination at the time

of admission for delivery. Jakobi and colleagues66 found that previous cesarean section

performed for a nonrepetitive indication such as breech presentation, history of a previous

successful VBAC, station of −1 or more, unruptured membranes at admission, and dilation

of 4 cm or more at admission were all positively correlated with increased likelihood of

successful VBAC. A history of previous cesarean section for arrest of labor was significantly

associated with an increased risk of unsuccessful trial of labor. Using these criteria

retrospectively, the authors would have correctly predicted the success of a trial of labor in

more than 94% of candidates but would have correctly predicted failure of trial of labor in

only 33.3% of candidates.

Flamm and Geiger67 examined similar data to develop a scoring system in an attempt to

predict the success of trial of labor. These authors found that maternal age younger than

40 years, indication other than failure to progress, cervical effacement of more than 75%

on admission, and cervical dilation of more than 4 cm at admission were all significantly

correlated with increased success of trial of labor. When these factors were weighted and

placed in a scoring system in an attempt to predict the success of attempted VBAC, the

authors found that as the number of these factors increased, the likelihood of successful

trial of labor increased. Patients with only one or two of these characteristics had a 49% to

59% success rate, whereas patients with four or more of these characteristics had a

greater than 90% success rate. The ability to more accurately predict the likely success of

trial of labor is clinically useful, because there is increased maternal morbidity is associated

with a failed trial of labor.68 These women have an increased risk of operative injury, infectious morbidity, and uterine rupture.

Morbidity associated with VBAC has been well established. Uterine rupture occurs in

approximately .3% to 1.5% of trials of labor with a low-transverse scar.69,70,71 The uterine

rupture rate is 1% to 7% with a low-segment vertical scar. The incidence of uterine

rupture may be increased in patients with a previous single-layer closure.72,36 However, in

patients with a previous classic uterine incision, the risk of uterine rupture may be as high

as 9%, with one third of these occurring before the onset of clinical labor.74 In patients for

whom documentation of the type of previous uterine incision is not available, there is no

increased risk of uterine rupture.73 More than one previous low-segment uterine incision is

not a contraindication to trial of labor.75

In the event of uterine rupture, fetal mortality and morbidity is excessive. When a classic

uterine incision ruptures, the fetal mortality is in excess of 50%, compared with 12% in the event of rupture of a prior low transverse incision.76

In evaluating a patient as a candidate for trial of labor, it is important to consider the

patient's history and physical examination, the patient's wishes concerning elective repeat

cesarean section versus trial of labor after appropriate counseling, and the environment

where the trial of labor is to be performed. Most studies that established the safety of

VBAC were conducted in tertiary care centers or teaching institutions.75 The availability of

operating room staff and anesthesia support in the event of uterine rupture or

nonreassuring fetal monitoring in these settings may vary considerably in private and small community hospitals.

After the patient has been appropriately counseled and has consented to a trial of labor,

labor management should not significantly differ from the management of a patient with

an unscarred uterus. Cervical ripening, oxytocin augmentation,73,77 and regional anesthesia78,79,80,81 may be used as clinically indicated with close monitoring of the patient.

Population-based studies have demonstrated the increased morbidity (uterine rupture

rates of 24.5/1000) associated with the use of prostaglandin cervical ripening agents in a

scarred uterus. This prompted ACOG to release a committee opinion discouraging their use

for the purpose of induction during VBAC attempts.82,83

Perimortem Cesarean Section

One of the first indications for cesarean section was for the delivery of the fetus in the case

of maternal death. Currently, the performance of a rapid cesarean delivery in the event of

sudden maternal cardiac arrest can be lifesaving for the fetus. In the event of maternal

cardiac arrest with a viable fetus, cesarean section should be initiated within 4 minutes of

cardiac arrest, with the goal of delivering the fetus within 5 minutes of onset of cardiac

arrest. This has been shown to allow neurologically intact survival of all infants

delivered.84Delivery after 5 minutes have elapsed results in increasing neurologic sequelae

in surviving infants but may still be beneficial to the majority of infants up until 15 minutes

after cardiac arrest. However, the goal should always be delivery of the neonate within 5

minutes of the loss of maternal cardiac function. Immediate abdominal delivery

accomplishes two goals in this setting: the removal of the fetus from what has become an

extremely hostile uterine environment and the increase of maternal blood return to the

heart by relieving uterine pressure on the maternal inferior vena cava. The perimortem

operation should be performed only when the fetus is suspected to be clinically viable. This

procedure should benefit both the mother and the fetus. As with any cardiac resuscitation

situation, the likelihood of good maternal and fetal outcome decreases with increased

interval to delivery time and increased time to the return of spontaneous circulation.85,86 It

is important to remember that the performance of a perimortem cesarean delivery outside

of an operating room under nonsterile conditions is not likely to negatively impact

maternal survival, because survival to discharge after a witnessed, in-hospital, cardiac

arrest is only 3%.87 Performance of this operation on a patient who is unstable but not in

cardiac arrest should never be undertaken, because maternal well-being always takes

precedence over fetal well-being.

COMPLICATIONS

Maternal Mortality

As anesthesia and operative techniques have improved, cesarean section has become an

increasingly safe and common procedure; however, the obstetrician must always bear in

mind that the abdominal delivery of an infant is still a major operative procedure and can be associated with significant mortality and morbidity.

Maternal mortality after cesarean section has been estimated to be between 5.81 and 6.1

per 100,000 procedures.88,89 Between 20% and 50% of these deaths are attributable to

the cesarean delivery, with the remainder being the result of complications that led to the cesarean section.

In general, the complications associated with cesarean section are similar to those

observed after any laparotomy, with the exception of an increased incidence of

endomyometritis. Complications may be divided into those encountered intraoperatively

and those encountered postoperatively.

Common intraoperative complications include uterine hemorrhage and injury to either the

urinary or gastrointestinal tract. Uterine hemorrhage can be caused by atony, lacerations,

or retained placenta. Because the uterus usually can be examined at the time of cesarean

delivery, determining which of these entities is the cause of the hemorrhage is not as

difficult as it is when hemorrhage occurs after a vaginal delivery. Uterine atony continues

to be the major cause of hysterectomy at the time of cesarean section.90,91 Having a

rational, well-thought-out approach in dealing with potential uterine atony will allow the

obstetrician to address this complication in an effective and timely manner. The first step

should be to repair the uterine incision. The first assistant should pull the uterine fundus

toward the patient's head during this repair to place the uterine arteries on tension and

thereby decrease blood flow to the uterus. Exterioration of the uterus for repair is

commonly advocated to facilitate exposure and place the uterine arteries on stretch.

Magann and colleagues at the University of Mississippi have recommended in situ closure

to minimize the trauma to the adnexa and shorten the operative time. The optimal site of

uterine closure remains unknown. As uterine repair is being performed, oxytocin (40 U/L

normal saline) should be rapidly administered intravenously to encourage myometrial

contraction. If bleeding persists, bimanual pressure is applied to the uterus, and the uterus

is vigorously massaged. If hemorrhage has not abated at this time, .25 mg of 25-methyl

prostaglandin F2a (Hemabate) is injected intramuscularly or directly into the uterus. This

may be repeated every 15 minutes as needed up to eight doses. Hemabate should not be

used in patients with asthma. Methergine .20 mg injected intramuscularly can also be used

in nonhypertensive patients. Misoprostol 800 to 1000 microgram should be considered

early and rectally administered. During this process, attention should be given to the

patient's hemodynamic status; blood loss can be rapid and excessive because blood flow to

the gravid term uterus is approximately 700 mL per minute. Fluid resuscitation and blood

transfusion should be instituted as clinically indicated. If manual compression of the uterus

and medical intervention are unsuccessful, uterine artery ligation should be performed

bilaterally, with sutures placed to obliterate both the ascending uterine artery at the level

of the lower uterine segment and its anastomosis with the ovarian artery at the uterine

cornua (Fig. 9). This will control bleeding from an atonic uterus in 75% of

cases.92 Localization of the uterine artery can be facilitated by careful palpation of its

course along the lateral edge of the uterus. The surgeon should then pull the engorged

uterine veins laterally into the broad ligament and away from the operative field to avoid

laceration of these veins during suture placement. Isolating the uterine artery with a

Babcock clamp is often helpful in these cases. Care should be taken to avoid incorporating

the ureter in the ligature. In cases that do not respond to bilateral uterine artery ligation,

bilateral hypogastric artery ligation is no longer recommended because it is successful in

less than 50% of patients and training opportunities are not readily available, thus an

experienced operator is unlikely. A new surgical technique introduced, the B Lynch has

proven very successful in preventing subsequent hysterectomy (Fig. 10). In patients who

do not respond to these management strategies, hysterectomy is appropriate and life-saving.93

Fig. 9. O'Leary stitch (uterine artery ligation). While

placing the broad ligament on traction to displace the

uterine veins laterally, the uterine artery is palpated and

isolated. A suture is then placed below the laceration to

the uterine artery to incorporate the artery with the

myometrium. If necessary, a second stitch may be

placed above the incision in the same manner.

Fig. 10. Use a 70- to 80-mm round-bodied hand needle with

mounted number-2 plain or chromic catgut. With the bladder

displaced inferiorly, the first stitch is placed 3 cm below the lower

cesarean incision on the patient's left side and threaded through the

uterine cavity to emerge 3 cm above the upper incision margins,

approximately 4 cm from the lateral border of the uterus. Now, carry

the suture on the outside of the uterus over the top and to the

posterior side. The suture should be more or less vertical and lying

approximately 4 cm from the cornua. It does not tend to slip laterally

toward the broad ligament because the uterus has been compressed

and the suture milked through, ensuring that proper placement is

achieved and maintained. The suture is placed exactly the same way

as it was on the left side; that is, 3 cm above the incision, 4 cm from the lateral side of

the uterus through the top of the incision, into the uterine cavity, and then again back

through 3 cm below the incision.

In cases of hemorrhage not caused by uterine atony, careful exploration of the uterus for

possible retained placental fragments and exploration of the operative field for

unrecognized lacerations should be performed. Placental fragments may be removed

manually or may require the use of a sharp curette. Areas of placental adherence should

be examined for evidence of placenta accreta. Genital tract lacerations should be identified, isolated, and closed in a hemostatic manner.

Urinary Tract Injuries

Injury to the urinary tract is a relatively rare complication of cesarean delivery. The

incidences of bladder and ureteral injury are .3% and .1%, respectively.94 Bladder injuries

are more common with the use of Pfannenstiel incision and history of previous cesarean

section. The most common site for bladder injury during cesarean delivery is at the dome

of the bladder. Laceration of the bladder should be evaluated by first ensuring that the

trigone and ureters are not involved. This may be accomplished by direct visualization of

the ureters through a cystotomy incision. If the trigone is not involved and the ureters are

functioning, the cystotomy can be closed in two layers. Whenever there is a possibility of

inadvertent cystotomy at the time of cesarean section, this can be evaluated by distending

the bladder with sterile milk through the Foley catheter and observing the operative field

for the appearance of the milk.

Ureteral injury is less common than injury to the bladder. If there is concern during the

operative procedure that the ureter has been compromised, the abdomen should not be

closed until this possibility has been thoroughly evaluated and excluded or the injury has

been identified and corrected. Evaluation of the ureters can be performed by performing a

cystotomy in the dome of the bladder and passing an 8-French ureteral stent retrograde

through the ureter to the kidney. If ureteral stents are not immediately available, most

labor and delivery suites have 8-French pediatric feeding tubes on the neonatal

resuscitation cart, and these can be used instead. Another method of evaluating ureteral

integrity is to inject 5 to 10 mL of indigo carmine intravenously and observe for the

appearance of the dye at the ureteral orifice. Simply observing the appearance of the dye

in the Foley catheter is inadequate to evaluate ureteral patency, because this only

guarantees the patency of one ureter. Repair of ureteral injuries is performed as indicated

by the level of the injury. Ureteroureteral anastomosis or ureteral reimplantation with the

placement of ureteral stents is the standard. Some minor injuries may be managed by the

placement of ureteral catheters alone. Consultation intraoperatively with the appropriate

specialist is warranted.

Gastrointestinal Tract Injury

Injury to the bowel at the time of cesarean section is exceedingly rare. An incidence of less

than .1% has been reported.95 This low incidence is caused by the displacement of the

bowel out of the operative field by the enlarged, gravid uterus. The risk of bowel injury is

increased in patients with previous abdominal surgery or intraabdominal adhesions. Injury

is usually obvious because of the appearance of bowel contents in the surgical field. These

injuries should be quickly identified and isolated to minimize contamination of the

peritoneal cavity. Injury to the small bowel can be primarily repaired with a two-layer

closure using silk or delayed absorbable suture. The closure should be performed at 90

degrees to the bowel lumen to decrease its constriction. Larger lacerations of the small

bowel or multiple lacerations may require resection of a length of bowel. Injuries to the

large bowel must be carefully evaluated. In the patient who has not had bowel

preparation, large bowel lacerations of less than 1 cm may be primarily

repaired.96 Colostomy is indicated for more extensive large bowel injury with fecal

contamination. Broad-spectrum antibiotics should be administered in cases of large bowel injury.

Wound Infections

By definition, any cesarean section is a clean, contaminated operation. Wound infections

occur at a rate of approximately 7% after cesarean section when prophylactic antibiotics

are not given;94 this incidence is reduced to 2% with the use of prophylactic

antibiotics.97 Wound infections that occur after cesarean section include endomyometritis,

pelvic abscess, incisional abscess, and wound cellulitis. The antibiotic of choice for each

infection depends on the location of the infection and the suspected pathogen. Antibiotic

therapy should be instituted empirically and adjusted as needed based on culture results.

For pelvic abscesses, broad-spectrum antibiotics including anaerobic coverage are

required; for superficial wound infections, simply opening the incision and draining the

infectious source usually alleviates the problem in patients who do not have signs of

systemic infection. Superficial wound cellulitis can usually be treated using penicillinase-resistant penicillin.

Endomyometritis

Endomyometritis complicates up to 80% of cesarean sections performed after the

membranes have been ruptured for more than 6 hours in patients who are not

administered antibiotic prophylaxis98 and 30% in patients with intact membranes. The

incidence has been shown to be high in patient populations of lower socioeconomic

status,99 in patients that have had six or more vaginal examinations during labor, and in

patients with longer duration of rupture of membranes.100 The rate of uterine infection can

be reduced to 5% or less with the use of prophylactic antibiotics given at the time of cord

clamp.101 A single dose of a first-generation cephalosporin is relatively inexpensive and

effectively decreases the infection rate.

CONCLUSION

Over the past several decades the incidence of cesarean delivery has increased dramatically.

Although the operation continues to become safer, the incidence of maternal mortality and

morbidity is still higher than that of a vaginal delivery. Continued efforts on the part of the

obstetrician must be made to ensure that cesarean deliveries are not performed for

inappropriate indications and that every effort is made to allow the patient to deliver

vaginally when fetal and maternal status are reassuring. Recently, serious debate has arisen

over the autonomy of the patient and the ability to request an elective cesarean section. The

arguments on both sides of the issue are provocative and center on the low morbidity of

cesarean delivery compared with vaginal delivery. Proponents of elective cesarean delivery

point to the possibility of pelvic floor dysfunction leading to future urinary and fecal

incontinence. This could be a Pandora's box. We should continue to respect our patients'

autonomy while at the same time heed to our creed, first do no harm. Continuing research

is required to more appropriately evaluate the techniques of the cesarean operation and the

safety of elective primary cesarean delivery.

References

1. Gabert HA, Bey M: History and development of cesarean operation. Obstet Gynecol Clin

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