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47 Complications of Bariatric SurgeryRobert F. Poirier

Premature death from obesity now rivals the mortality rates related to smoking, with more than 300,000 deaths attribut-able to obesity per year.4

Bariatric surgery is the most effective and durable treatment to achieve weight loss and its associated comorbidity. Five-year mortality is reduced 89% in severely obese patients who undergo weight loss surgery.5,6 Fifteen-year survival increases by one third in patients who undergo bariatric surgery in com-parison with those who do not. New laparoscopic surgical techniques have contributed to the growing demand for and acceptance of bariatric surgery. Approximately 4925 bariatric procedures were performed in 1990, as compared with an estimated 220,000 in 2008. Bariatric surgery is now the second most common abdominal operation in the United States.

Women are more likely than men to choose bariatric surgery. It is estimated that men make up 36% of the morbidly obese population in the United States, although they account for less than 20% of patients choosing weight loss surgery each year. The typical demographic profile of a bariatric surgery patient is a woman 35 to 49 years of age with private insurance who belongs to a higher socioeconomic class.

Recent trends suggest that higher-risk, older patients are undergoing bariatric procedures with greater frequency; sur-prisingly, they demonstrate postoperative morbidity and mor-tality rates similar to those in the general population.7 Rates of perioperative complications, reoperation, hospital readmis-sion, and emergency department (ED) visits have been falling. The rates for these indicators are highest with gastric bypass followed by sleeve gastrectomy and lowest for laparoscopic adjustable gastric banding (LAGB).8 Overall, in-hospital mor-tality rates are between 0.05% and 0.2%, and 30-day mortality rates have been reported to range between 0.05% and 2%.

Complications of bariatric surgery are common and are generally initially treated in the ED. Up to 20% of patients are admitted for a postoperative complication within 1 year of the bariatric procedure; this rate increases to 40% within 3 years. The potential postoperative complications of the various bariatric procedures have predictable timing and clini-cal manifestations.9

TYPES OF BARIATRIC SURGERY:  ROUX-EN-Y AND GASTRIC BANDING

The two most common types of bariatric surgery in the United States are the Roux-en-Y gastric bypass (RYGBP) (54%) and adjustable gastric banding (39%). Adjustable gastric banding

• LaparoscopicRoux-en-YgastricbypassisthemostcommonlyperformedbariatricprocedureintheUnitedStates.

• Pulmonaryembolism(30%to40%)isthemostcommoncauseofdeathafterbariatricsurgery,followedbycardiacevents(25%)andanastomoticleaks(20%).Dumpingsyndrome,woundinfections,strictures,andstomalulcerationsarecommoncomplications.

• Acutegastricdistentionisararebutpotentiallydeadlyearlypostoperativecomplicationthatrequiresdecompression.

• Anasogastrictubecouldperforatethepouchsiteinpatientswhohaverecentlyundergonesurgery.

• Abdominalpainwithoutvomitingintheearlypostoperativeweeksmightrepresentasmallbowelobstructionorinternalhernia.

• Laparoscopicadjustablegastricbanding(LAGB)isthemostcommonlyperformedbariatricprocedureinEuropeandisbecomingmorecommonintheUnitedStates.

• AcuteanteriororposteriorgastricbandslippageisthemostcommoncomplicationofLAGBrequiringemergencytreatment(banddeflation).

• LAGBhasthelowestmorbidityandmortalityofallcurrentlyperformedbariatricprocedures.

KEY POINTS

EPIDEMIOLOGY

The prevalence of morbid obesity has risen more than fourfold since 1986.1 Currently, 1.7 billion people worldwide are con-sidered obese and approximately 60% of the U.S. population is overweight. In excess of 100 billion dollars is spent annu-ally on obesity health care–related costs.

To be considered morbidly obese, one must have either a body mass index (BMI) greater than 40 kg/m2 or a BMI of 35 to 40 kg/m2 with comorbid conditions.2 More than 15 million Americans currently have BMI levels that make them eligible for bariatric surgery.3 In the United States only about 1% of eligible patients undergo bariatric surgery.

Morbid obesity promotes the development of diabetes mel-litus, hypertension, dyslipidemia, cardiovascular disease, gas-troesophageal reflux, asthma, and obstructive sleep apnea.

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continues to rapidly gain in popularity since initial federal approval in 2001.7

Caloric restriction and malabsorption are the principal means of weight loss. In the United States, weight loss pro-cedures that combine both restrictive and malabsorptive components are the most popular. RYGBP, biliopancreatic diversion (BPD), and BPD with duodenal switch are examples of techniques that involve both malabsorption and restriction. In Europe, the preference is for purely restrictive bariatric procedures.

MALABSORPTIONSurgical techniques that induce malabsorption were the first attempted. Malabsorptive techniques were thought to be the most effective method of achieving rapid and sustained weight loss. Surgeons initially connected the proximal jejunum to a distal portion of the ileum or ascending colon in a procedure known as jejunoileal bypass (Fig. 47.1). This technique resulted in severe diarrhea, dangerous metabolic derangements, arthropathy, renal calculi, gallstones, liver disease, and short bowel syndrome. Gastric bypass has been shown to be a more effective malabsorptive procedure with fewer side effects than those associated with jejunoileal bypass. Malabsorptive procedures still in current use include laparoscopic RYGBP, BPD, duodenal switch, and isolated intestinal bypass.

Fig. 47.1 Jejunoileal bypass.

Stomach

Small intestine(bypassed)excludedsegment

Colon

Proximaljejunum

Distalileum

Fig. 47.2 Roux-en-Y gastric bypass.

Reduced-sizegastric pouch

Biliopancreaticlimb (duodenum)

Commonlimb

Bypassedportion ofstomach

Roux limb

RESTRICTIONPurely restrictive procedures are less effective than malab-sorptive techniques.6 Restrictive surgeries act by reducing oral intake through induction of early satiety. However, some areas of the stomach easily dilate over time, which causes gradual increases in perceived hunger and subsequent food intake. Restrictive procedures are more successful when the lesser-curve gastric pouch is 15 mL or smaller.4 Restrictive weight loss procedures such as vertical banded gastroplasty and isolated partial gastrectomy (sleeve gastrectomy) have fallen out of favor. LAGB is the most common, poses the least risk, and is the most effective restrictive technique currently performed.10

ROUX-EN-Y GASTRIC BYPASSThe RYGBP procedure creates a gastric pouch from the proxi-mal portion of the lesser curvature of the stomach that can hold about 15 to 30 mL of fluid and food (Fig. 47.2). A portion of the distal end of the small bowel is connected to this pouch to create a concurrent malabsorptive process. His-torically, RYGBP was an open procedure, but currently the majority are performed laparoscopically.

Early postoperative complications of RYGBP include obstruction of the bypassed small bowel segment, obstruction of the Roux limb, anastomotic leak, and gastrointestinal (GI) or intraperitoneal bleeding. Pulmonary embolism, a rare post-operative complication, remains the most common cause of postoperative death, followed by complications resulting from anastomotic leaks. Other complications include pneumonia, myocardial infarction, renal failure secondary to rhabdomy-olysis, and nutritional deficiencies.

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properly, use acid suppression medication, and eat small fre-quent meals reduces the incidence of GERD.

Diarrhea with malodorous flatulence may result from a short Roux limb and usually resolves spontaneously. Persis-tent diarrhea after weight stabilization, however, should raise suspicion of bacterial overgrowth in the bypassed tract.

Dumping syndrome consisting of abdominal cramping, nausea, vomiting, and diarrhea can be seen immediately post-operatively and may last up to 12 to 18 months. Noncompli-ance with diet is the most common and preventable cause. Treatment includes rehydration, electrolyte correction, and education of the patient regarding diet.

Constipation may result from decreased fiber intake.Cholelithiasis may develop during the period of initial rapid

weight loss. Biliary colic and cholecystitis are high on the differential diagnosis list for abdominal pain in patients with ongoing reductions in weight. Prophylactic cholecystectomy was often performed during open RYGBP. The transition to laparoscopic surgery for most RYGBP procedures has led to a decrease in prophylactic cholecystectomy and thus an increase in cholelithiasis rates.

Bleeding may occur at any anastomotic site but is most common and dangerous in the gastrojejunostomy area. It often results in melena, hematemesis, hematochezia, or hypotension (or any combination of these findings) secondary to upper GI bleeding. Upper endoscopy is the most reliable way to confirm blood loss from this site. Bleeding at other anastomotic sites (jejunojejunostomy and the transected gastric remnant) is usually self-limited and managed nonoperatively.11 Stomal ulcers can occur 2 to 4 months after surgery and are identified by endoscopy. Many can be treated on an outpatient basis with proton pump inhibitors or sucralfate.

LAPAROSCOPIC ADJUSTABLE  GASTRIC BANDINGThe LAP-BAND (Allergan, Inc., Irvine, CA) is an adjustable device that is laparoscopically secured around the upper portion of the stomach (Fig. 47.3). The band is connected by a tube to a port implanted under the skin. Surgeons may adjust the extent of constriction (restriction) of the LAP-BAND by injecting saline into the subcutaneous port. Increased restric-tion limits food intake; adjustments can be made in response to adverse symptoms or patient preference, thereby allowing some control over the weight loss process. Operative risks for LAGB are less than those for RYGBP.

In 2007 the Food and Drug Administration (FDA) approved a second gastric banding device called the Realize Adjustable Gastric Band. The Heliogast and Midband adjustable gastric bands are available only outside the United States and have not been approved by the FDA. All gastric banding devices work similarly. In 2011 the U.S. FDA approved expanding the use of gastric banding surgery for an additional 27 million American patients with mild obesity (BMI of 30 to 35 kg/m2) who have one obesity-related health condition (e.g., hyperten-sion, diabetes mellitus).

ComplicationsLAGB is generally performed as outpatient surgery. Immedi-ate postoperative vomiting is usually caused by gastric wall edema under the band. Inflation of the band during surgery increases the likelihood of gastric wall edema. IV hydration is required until the edema subsides. Maintenance of nothing

Late complications generally involve both anatomic and systemic complications. Anatomic complications include esophageal reflux, chronic abdominal pain, internal hernias, ulcers, stricture, stenosis, and bowel obstruction. Systemic complications are manifested mostly as nutritional deficien-cies.11 Clinical manifestations include anemia (iron defi-ciency), osteopenic fractures (calcium deficiency), fatigue and lower extremity edema (protein-calorie malnutrition), chronic pain and proximal muscle weakness (vitamin D deficiency), visual deficits (vitamin A deficiency), and vague neurologic symptoms (thiamine, folate, and vitamin B12 deficiencies).

Complications of Open versus Laparoscopic ProceduresWound infections and incisional hernias are more common with open bariatric procedures (7% and 9%, respectively) than with laparoscopic procedures (3% and 0.5%, respectively). Patients who have undergone laparoscopic gastric bypass have a slightly higher rate of small bowel obstruction, anastomotic stomal stenosis, internal hernias, and GI hemorrhage. Pulmo-nary embolism, pneumonia, and anastomotic leaks have similar incidences after both open and laparoscopic proce-dures. Stomal stenosis manifested as postprandial epigastric pain and vomiting of undigested food is thought to be more common after laparoscopic RYGBP because a mechanical stapler is used instead of the hand-sewn methods with open RYGBP. Endoscopy often both diagnoses and treats this complication.

Specific Clinical PresentationsPersistent, severe vomiting can be caused by anastomotic strictures. Strictures can usually be treated by endoscopic balloon dilation but occasionally require surgical revision. Some episodes of nausea and vomiting are common during the immediate postoperative period, but if the vomiting per-sists, an anastomotic stricture may have formed.

Obstruction of the Roux limb requires percutaneous decom-pression. Patients with such an obstruction experience nausea, vomiting, abdominal pain, and distention. Diagnosis may require computed tomography (CT).

The occurrence of acute fever and tachycardia within weeks of a Roux-en-Y procedure suggests an anastomotic leak with or without abscess formation. The symptoms are often subtle but can include dyspnea, unexplained sepsis, changes in mental status, and restlessness. Peritoneal signs are often lacking. Because abdominal examination of morbidly obese patients is unreliable, the diagnosis is best accomplished through imaging studies. CT of the abdomen and pelvis with oral and intravenous (IV) administration of a contrast agent is the modality of choice. If the patient is unable to undergo CT because of the weight limitations of the CT table, an upper GI radiographic series should be obtained. The false-negative rate is high (up to 44%) with CT and other imaging studies for the evaluation of anastomotic leaks. Laparoscopy should be considered in cases of negative imaging but high pretest probability of an anastomotic leak.12,13

Esophageal reflux occurs infrequently after this procedure but may represent damage to the lower esophageal sphincter or impaired gastric emptying secondary to a distal obstruc-tion. Overfilling of the pouch, operative vagal nerve injury, or stomal stricture can lead to gastroesophageal reflux disease (GERD). Educating patients to avoid overeating, chew food

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patient should know this volume of saline, but if not, one can aspirate all the saline in the reservoir. Fluoroscopy or ultra-sound may be required if the port cannot be accessed easily. A GI swallow study and surgical consultation should be obtained after any band deflation. Symptoms should resolve over a couple of days after deflation. Surgery is often required to definitively repair gastric band slippage.

Gastric stoma obstruction by food, swelling, or hematoma can be an early or late complication. Partial obstruction can be treated conservatively with hydration and NPO status. Complete obstruction often requires band deflation and surgery to reposition the band.

Band erosion can occur in up to 4% of patients over time. The band can erode and migrate silently into the stomach. Peritonitis is often absent, but GI bleeding and bowel obstruc-tion can occur. Port site infections may be the first sign of band erosion, and endoscopy is the best method to diagnose band erosion. Upper GI studies and CT scans can assist in making the diagnosis as well. Removal of the band and repair of the stomach are required.

Gastric injury as a result of stomach perforation occurs rarely. One to 2 days following band placement an acute abdomen may develop. IV fluids, broad-spectrum antibiotics, NPO status, and surgical consultation with subsequent repair of the stomach are required.

Gastric necrosis of the stomach wall is a late complication that often results from ischemia caused by a combination of gastric prolapse—the part of the stomach below the band herniates up through the device (Fig. 47.4) and pressure from the band. Patients appear ill, with an acute abdomen. Upper GI studies or CT scans show an overly distended gastric pouch. Patients require emergency surgery to remove the band and repair the stomach wall.

Esophageal and gastric pouch dilation occurs when the band is too tight or patients are not compliant with their diet. The symptoms are similar to those seen with gastric slippage. Upper GI contrast studies make the diagnosis. Treatment is

by mouth (NPO) and IV steroids are thought to increase the resolution rate.

Immediate postoperative vomiting or dysphagia may also be due to gastroesophageal obstruction caused by proximal band slippage (1% to 3%). Gastric dilation and food intoler-ance may develop. Gastric necrosis and perforation may result from band migration at any time. A GI swallow study using fluoroscopy is the preferred method of diagnosing band migration, but a two-view upper GI contrast study or abdomi-nal radiograph may capture the position of the radiolucent band. An abdominal CT scan may also demonstrate move-ment of the band. Band slippage is the most common LAGB complication occurring early to late in the postoperative period. Band slippage rates are decreasing, however, with new placement techniques.

Any patient with signs of obstruction after LAGB should undergo immediate deflation of the band. Emergency physi-cians can deflate an adjustable gastric band by accessing the subcutaneous anterior abdominal port (see Fig. 47.3). A non-coring Huber needle should be used to remove the amount of saline injected during the previous two adjustments. The

Fig. 47.4 Gastric prolapse.

Gastricband

Prolapsedsegment

of stomach

Fig. 47.3 Laparoscopic adjustable gastric banding.

Gastricband

Smallstomach

pouch

Largerstomachportion

Esophagus

Band unfilled Band filled(5 mL saline)

Subcutaneousreservoir

(port)

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biliopancreatic diversion–duodenal switch (BPD-DS) proce-dure. It is considered an improvement on BPD alone because the length of the small intestine is increased to 100 cm, which allows better absorption of nutrients.

A linear (sleeve) gastrectomy in which a restrictive pouch of the lesser curvature is left is also performed during the duodenal switch. BPD-DS with sleeve gastrectomy allows gastric emptying to be somewhat regulated through preserva-tion of a functioning pylorus. The risk for dumping syndrome is subsequently reduced.

Some surgeons prefer to perform only a sleeve gastrectomy in high-risk patients (Fig. 47.7). This simple restrictive pro-cedure avoids intestinal bypass and anastomoses of the GI tract. Side effects such as nutritional deficiencies are rare because only mild malabsorption results from sleeve gastrec-tomy alone.

band deflation and close follow-up with the bariatric physi-cian. Prolonged dilation can result in chronic esophageal dys-motility, severe achalasia, and GERD, which is not always reversible (13%) with band deflation and removal.14

Device malfunction can cause port infections, tube leakage, tube disconnection, and skin ulceration. Plain radiographs, abdominal CT scans, and upper endoscopy may all aid in the diagnosis of gastric erosion and device malfunction.

Recent controversies have arisen regarding the long-term complications of gastric banding. Few long-term studies have been performed, but a recent 14-year study (1995 to 2009) of gastric band surgery showed high complication and reopera-tion rates. Reoperation because of complications was reported to occur in 30% of patients, band removal was needed in 12%, and weight regain began after 5 years of follow-up.15 Still, gastric banding has been shown to have a lower mortality rate than other bariatric surgeries, is less invasive, and is reversible.

BILIOPANCREATIC DIVERSIONBPD is popular in Italy (Fig. 47.5). The procedure involves a distal gastrectomy that leaves a 250-mL stomach capacity with a drastic intestinal bypass. Half of the jejunum and ileum are disconnected and reconnected near the terminal ileum. This procedure is particularly effective for severely obese patients (BMI > 50 kg/m2), in whom it causes significant weight loss and reduced morbidity. Less bacterial overgrowth occurs in the bypassed intestine because it is continuously exposed to bile and pancreatic enzymes. Serious complica-tions can result, however, particularly the metabolic abnor-malities and nutritional deficiencies seen after aggressive malabsorptive procedures. Hepatic dysfunction can develop in 2% of patients undergoing BPD.

DUODENAL SWITCH AND SLEEVE GASTRECTOMYThe duodenal switch procedure is similar to BPD, but the jejunum is connected to the proximal duodenum rather than the ileum (Fig. 47.6). This operation is also known as the

Fig. 47.5 Biliopancreatic diversion.

Removed portionof stomach

Stomachpouch

Small intestineattached tostomach pouch

Foodpassage

Colon

Commonbile duct

Fig. 47.6 Duodenal switch.

Commonbile duct

Proximalduodenum

Colon

Stomachpouch

Resectedstomach

Biliopancreaticlimb

Common channel(100 cm)

Alimentary limb

Fig. 47.7 Sleeve gastrectomy.

Newstomach pouch(gastric sleeve)

Resectedstomach

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a Roux-en-Y procedure usually requires surgical intervention or percutaneous drainage.

PROCEDURE-SPECIFIC COMPLICATIONSBox 47.1 lists the most common GI complications of bariatric surgery.12

Anastomotic (Staple Line) LeakAnastomotic leaks most often occur in the immediate postop-erative period, although some leaks are not apparent until weeks after surgery. GI leaks are one of the most serious and potentially deadly complications of gastric bypass surgery. The incidence is up to 6% in patients after first procedures, but it rises 5-fold to 10-fold in patients who undergo revision of the initial procedure. Leaks are difficult to diagnose because of initial nonspecific signs and symptoms: low-grade fever, abdominal tenderness, tachypnea and respiratory insuffi-ciency, tachycardia, left shoulder pain, anxiety, and a feeling of impending doom. An upper GI radiographic series or abdominal CT scan sometimes confirms the diagnosis by demonstrating extravasation of the oral contrast agent (Gas-trografin). However, an upper GI series or CT scan often misses the leak. Many bariatric surgeons question the need for confirmatory studies and believe that patients should be taken to the operating room for laparoscopic examination when tachycardia greater than 120 beats/min and symptoms indicative of a leak are present.17 The most common site of the leak is the gastrojejunostomy anastomosis. Interventional or surgical management is required. Early antibiotic therapy is recommended.

Acute Gastric DistentionAcute gastric distention is a rare, potentially deadly, early postoperative complication. Patients may have pain, nausea, vomiting, abdominal distention, bloating, hiccups, tachycar-dia, shortness of breath, or referred left shoulder pain. Abdominal plain films or abdominal CT scans usually dem-onstrate a large air-fluid level in a dilated stomach. Obstruc-tion or edema at the enteroenterostomy site is often the cause of this complication and is best evaluated by CT. Treatment includes percutaneous fine-needle decompression, drainage

COMPLICATIONS OF BARIATRIC SURGERY

GENERAL COMPLICATIONSSerious complication rates are lower in hospitals with a high volume of bariatric surgery procedures.16

Pulmonary EmbolismPulmonary embolism is the leading cause of death after bar-iatric surgery. Although the postoperative incidence of deep vein thrombosis (DVT) and pulmonary embolism is only 2%, almost one third of affected patients die. The incidence of DVT and pulmonary embolism has not diminished despite the use of pneumatic compression stockings, low-molecular-weight heparin, and various other prophylactic measures. Early postoperative ambulation may be the most important preventive measure in the bariatric population. Lower extrem-ity duplex Doppler ultrasonography for DVT and helical pulmonary CT scanning for pulmonary embolism are the pre-ferred diagnostic studies. If weight limitations prevent perfor-mance of a CT scan, ventilation-perfusion scintigraphy should be considered.

Wound Infections, Seromas, and DehiscenceWound infections occur in 10% to 15% of patients undergoing open procedures and in 3% to 4% of those treated by laparo-scopic techniques. Seromas commonly occur in up to 40% of patients. Although the wound infections may appear superficial, deep extensions may be present in the morbidly obese. Patients with wound infections and fever should undergo contrast-enhanced CT of the abdomen to exclude deep infections.

Intraperitoneal Fluid Collections and PeritonitisIntraperitoneal fluid collections, abscesses, and peritonitis occur in less than 2% of patients undergoing bariatric pro-cedures. Anastomotic leaks are the most common cause of fluid collections in the early postoperative period. Clinical signs are often subtle, and the diagnosis cannot be made by physical examination alone. Patients may have low-grade fevers, tachycardia, and mild tachypnea. Early surgical con-sultation should be obtained to facilitate the most efficient evaluation and treatment because life-threatening sepsis may ensue. The poor cardiopulmonary reserve of morbidly obese patients may allow rapid clinical deterioration. Some institu-tions advocate CT-guided aspiration during initial imaging.

Incisional HerniaIncisional hernias occur in up to 9% of patients after open RYGBP. Rarely are incisional hernias seen in those who undergo laparoscopic procedures. Physical examination alone confirms the diagnosis.

GallstonesThe incidence of cholelithiasis is 1% to 3% after bariatric surgery. Rapid weight loss is known to promote the forma-tion of gallstones, and most surgeons perform prophylactic cholecystectomy in patients with known cholelithiasis. The distorted anatomy after gastric bypass often precludes successful endoscopic retrograde cholangiopancreatography. Symptomatic biliary disease in patients who have undergone

BOX 47.1 Top 10 Complications of Bariatric Surgery

1. Dumpingsyndrome2. Vitaminandmineraldeficiencies3. Nauseaandvomiting4. Staplelinefailure5. Infection6. Bowelobstructionandanastomoticstenosis7. Gastricandstomalulceration8. Bleeding9. Iatrogenicsplenicinjury

10. Perioperativedeath(pulmonaryembolism,sepsis,myo-cardialinfarction)

From Abell TL, Minocha A. Gastrointestinal complications of bariatricsurgery:diagnosisandtherapy.AmJMedSci2006;331:214-8.

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via a gastrectomy tube, or surgery for cases of recurrence or rupture. A nasogastric tube should not be used because of possible perforation.

PATIENT TEACHING TIPS

The American Society for Bariatric Surgery’s website hasexcellenteducationalresources(www.asbs.org).

Thepatientshouldreturntothehospitalifnausea,vomiting,orafastheartratedevelops.

Bloodglucose levelscanfluctuatewidelyafterweight losssurgeryandrequireclosemonitoring.

Patients must adhere strictly to the postoperative dietinstructionstopreventpotentialcomplications.

Stomal Stenosis and Anastomotic StricturesThe incidence of anastomotic strictures occurring at the gas-trojejunostomy site varies from 2% to 11%. Patients often have progressive postprandial, epigastric pain and vomiting. Patients are initially unable to tolerate solid foods, with char-acteristic progression to poor tolerance of liquids over time. Findings on plain radiography and CT of the abdomen are usually unremarkable. Upper endoscopy both diagnoses and treats this condition. Repeated endoscopic balloon dilation of the stricture is often required. Fluoroscopically guided balloon dilation is an alternative treatment.

Stomal UlcerationStomal ulceration causes severe dyspepsia, burning retroster-nal pain, and vomiting. Abdominal plain films, CT scans, and other upper GI radiographic studies are not useful in diagnos-ing this complication. Endoscopy is the diagnostic modality of choice. Proton pump inhibitors treat stomal ulceration, and antibiotics are prescribed if the patient is found to have coin-fection with Helicobacter pylori.

Small Bowel Obstruction and Internal HerniaAbdominal pain without vomiting in the early postoperative weeks might represent small bowel obstruction or an internal hernia. Small bowel obstructions and internal hernias are difficult to differentiate and have a combined incidence of 5% within the first postoperative month. Small bowel obstruc-tions are more common after open bariatric surgery because of adhesion formation; internal hernias are more common after laparoscopic surgery. The Roux limb or pancreaticobili-ary limb may herniate through the potential spaces created during surgery. Patients have nonspecific symptoms, includ-ing abdominal cramping, periumbilical pain, and nausea. Vomiting is uncommon because only minimal secretions are present in the small gastric pouch. Abdominal plain films are nondiagnostic because dilated loops of bowel are not com-monly seen. Upper GI studies and abdominal CT are often unable to distinguish between obstruction and hernia. Sur-geons may perform laparoscopy early to prevent potential bowel strangulation.

Dumping SyndromeDumping syndrome occurs in almost half of patients under-going gastric bypass. Typical symptoms are bloating, abdomi-nal cramping, nausea, diaphoresis, and lightheadedness; the symptoms are more pronounced after eating food with high concentrations of refined sugar. The effects are self-limited and diminish as patients becomes more selective with their diet.

DISPOSITION

Patients who go to the ED because of systemic or GI symp-toms after bariatric surgery often have a postoperative com-plication that mandates hospital admission. They generally need CT, an upper GI radiographic series, endoscopy, or any combination of these imaging modalities. Discharge should be considered only for patients who have been evaluated in consultation with a surgeon or gastroenterologist (or both), who have stable vital signs and minimal pain, and who can easily tolerate oral fluids.

SUGGESTED READINGSEdwards ED, Jacob BP, Gagner M, et al. Presentation and management of common

post–weight loss surgery problems in the emergency department. Ann Emerg Med 2006;47:160-6.

Ellison SR, Ellison SD. Bariatric surgery: a review of the available procedures and complications for the emergency physician. J Emerg Med 2008;34:21-32.

Tanner BD, Allen JW. Complications of bariatric surgery: implications for the covering physician. Am Surg 2009;75:103-12.

Trus TL, Pope GD, Finlayson RG. National trends in utilization and outcomes of bariatric surgery. Surg Endosc 2005;19:616-20.

REFERENCES

References can be found on Expert Consult @ www.expertconsult.com.

Consultthebariatricsurgeonorgastroenterologist(ifendos-copy is required)early forpatientswhohavepreviouslyundergonebariatricsurgery.

Donotplaceanasogastrictubeinpatientswhohaveunder-gonegastricbypasswithoutconsultation from thebar-iatricsurgeon.Blindplacementofsuchatubemayresultinperforationofthepouchsite,particularlyintheimmedi-atepostoperativeperiod.

Laparoscopy is often required for definitive diagnosis ofinternalherniasandanastomoticleaks.

Smallgastricpoucheslimittheamountoforalcontrastagentthat patients can ingest for a computed tomographyscan. If contrast is required, patients should be told tosip as much contrast agent as they feel comfortabletakingovera3-hourperiodbeforeimaging.Thescanisthen performed, regardless of the amount of contrastingested.12

TIPS AND TRICKS

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REFERENCES1. Sturm R. Increases in clinically severe obesity in the United States, 1986-2000.

Arch Intern Med 2003;163:2146-8.2. Gastrointestinal surgery for severe obesity: proceedings of a National Institutes of

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3. American Society for Metabolic and Bariatric Surgery (ASMBS) 2009 fact sheet. Available at www.asmbs.org.

4. Crookes PF. Surgical treatment of morbid obesity. Annu Rev Med 2006;57:243-64.

5. Christou NV, Sampalis JS, Liberman M, et al. Surgery decreases long-term mortality, morbidity, and health care use in morbidly obese patients. Ann Surg 2004;240:416-23.

6. Buchwald H, Avidor Y, Braunwald E, et al. Bariatric surgery: a systematic review and meta-analysis. JAMA 2004;292:1724-37.

7. Santry HP, Gillen DI, Lauderdale DS. Trends in bariatric surgical procedures. JAMA 2005;294:1909-24.

8. Birkmeyer NJ, Dimick JB, Share D. Hospital complication rates with bariatric surgery in Michigan. JAMA 2010;304:435-42.

9. Zingmond DS, McGory ML, Ko CY. Hospitalization before and after gastric bypass surgery. JAMA 2005;294:1918-24.

10. Kelly J, Tarnoff M, Shikora S, et al. Best practice recommendations for surgical care in weight loss surgery. Obes Res 2005;13:227-33.

11. Edwards ED, Jacob BP, Gagner M, et al. Presentation and management of common post–weight loss surgery problems in the emergency department. Ann Emerg Med 2006;47:160-6.

12. Abell TL, Minocha A. Gastrointestinal complications of bariatric surgery: diagnosis and therapy. Am J Med Sci 2006;331:214-8.

13. Monkhouse SJW, Morgan JDT, Norton SA. Complications of bariatric surgery: presentation and emergency management—a review. Ann R Col Surg Engl 2009;91:280-6.

14. Naef M, Wolfgang WG, Naef U, et al. Esophageal dysmotility disorders after laparoscopic gastric banding—an underestimated complication. Ann Surg 2011;253:285-90.

15. Stroh C, Hohmann U, Schramm H, et al. Fourteen-year long-term results after gastric banding. J Obes 2011;2011:128451.

16. Birkmeyer NJO, Dimick JB, Share D, et al. Hospital complication rates with bariatric surgery in Michigan. JAMA 2010;304:435-42.

17. Tanner BD, Allen JW. Complications of bariatric surgery: implications for the covering physician. Am Surg 2009;75:103-12.