UNIVERSITI KUALA LUMPUR

ROYAL COLLEGE OF MEDICINE PERAK

SPECIAL STUDY MODULE (SSM)

A cross-sectional study on the anatomical variations of the superficial veins of the upper limb among the preclinical medical

students in UniKL-RCMP

Group members : HANAFI BIN ABDUL HAMID

: AMIR AFIF BIN SUHAIMI

: MUHAMMAD NAZMI BIN NOOH

: MUHAMAD AFIF IKHWAN BIN MOHD FUAT

Group number : GROUP NUMBER FIVE (5)

Supervisor : Dr. SAN SAN THWIN*

Co-Supervisor : Dr. MYINT MYINT SOE**

Department : *Department of Anatomy Universiti Kuala Lumpur Royal College of

Medicine Perak

** Department of Public Health Universiti Kuala Lumpur Royal College

of Medicine Perak

Date : 23rd November 2009

Table of Content pages

a) Abstract 3

b) Introduction 4-5

c) Objectives 6

d) Hypothesis 7

e) Methodology 8-11

f) Result 12-17

g) Discussion 18-19

h) Conclusion 19

i) References 19

j) Acknowledgment 20

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STUDIES ON VARIATIONS OF SUPERFICIAL VEINS OF UPPER LIMB

HANAFI B. ABDUL HAMID, AMIR AFIF B.SUHAIMI, MUHAMAD NAZMI B.NOOH, MUHAMAD AFIF IKHWAN B.MOHD FUAT

Department of Anatomy Universiti Kuala Lumpur Royal College of Medicine Perak

ABSTRACT

Objectives

The aim of the study was to observe and describe the distribution of anatomical variations of the

superficial veins of the upper limb among preclinical medical students in UniKL-RCMP.

Methods

Our sample was composed of 180 preclinical medical students of UniKL-RCMP aged from 18 to

27 years old. We had applied the tourniquet or blood pressure cuff applied around the right and

left arm of the respondent and we asked him/her to perform repeated flexion and extension of

forearm to help distend the veins. The pattern of the veins seen had been drawn onto a survey

form.

Result

Based on our analysis, the commonest type of anastomosis seen is Y type with 52.2% on the

right cubital fossa and 50.6% on the left cubital fossa. H type of anastomosis observed is 25% on

the right and 20.6% on the left cubital fossa. I type/no anastomosis was observed in 22.8% and

28.9% on the right and left cubital fossa respectively.

Conclusion

In our study of variation of anastomosis of superficial veins of upper limb, we found that the

majority of our subjects, from 50.6% to 52.2% have Y type of anastomosis on both left and right

cubital fossa respectively, followed by H type of anastomosis from 20.6% to 25.0% on both left

and right cubital fossa respectively. I type or no anastomosis was found in 22.8% to 28.9% on

right and left cubital fossa respectively.

Keywords

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Superficial veins, right upper limb, left upper limb, Y type, H type, no anastomosis, cubital fossa.

INTRODUCTION

Venous drainage of the upper limb can be classified as superficial and deep veins. Superficial

veins of upper limb are located in the superficial fascia of the upper limb. They are mainly

composed of cephalic vein and basilic vein. The cephalic vein lies on the lateral side of biceps

brachii, drains into axillary vein on infraclavicular fossa. The basilic vein lies on the medial side

of biceps brachii, drains into axillary vein together with venae comitantes in the deep fascia.

There are some variations of the superficial veins in the cubital fossa, either the presence of

median cubital vein (H type) or median antebrachial vein (Y type) or the I type when no

anastomoses. In this study, we observed the variations of superficial veins of cubital fossa on

both side.

The superficial veins are clinically important and are used for venipuncture for blood collection

and blood donation, as well as for health screening and testing, intravenous transfusion for the

emergency treatment of hypovolemic shock. The median basilic vein or basilic vein is commonly

used in central venous catheterization, and the basilic vein and cephalic vein can be used for

arteriovenous fistula (brachiobasilic or brachiocephalic fistula) for the hemodialysis purpose.

The arteriovenous shunting between cephalic vein and radial artery is recommended conduit

bypass (pre-bypass) of the upper limb to increase the diameter and strengthen the venous wall in

bypass surgery of lower extremities.

While there is much clinical relevance associated with the superficial veins of the cubital fossa,

no published literature is found on the anatomical variations of superficial veins of the upper

limb among Malaysian population. Thus, this study attempts to examine and describe the pattern,

branches and variations of the superficial veins of both upper limbs of the cubital fossa among

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the preclinical students of the medical degree program of UniKL-Royal college of Medicine

Perak.

There are two methods which can be employed to do this research. The first method is to apply a

blood pressure cuff or tourniquet at the right and left arm of the respondents. Then, they are

asked to perform repeated flexion and extension simultaneously to make the vein become

prominent. After that, the pattern of the anastomosis is drawn onto a blank form. The second

method is by dissecting cadavers at autopsy and observing the pattern of the superficial veins of

upper limb. This technique had been done by Ryszard Jasiński and Elżbieta Poradnik in their

research using 40 dead bodies.

Since as medical students conducting an elective research project in a short period of time, and

without access to the required number of cadavers to dissect, we have chosen to do the first

method of applying tourniquet and mapping the visualized superficial veins and their

anastomoses.

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OBJECTIVES

Main objective:

To observe and describe the distribution of anatomical variations of the superficial veins of the

upper limb among preclinical medical students in UniKL-RCMP

Specific objectives:

1. To describe the study population by socio-demographic characteristics; age, gender and

ethnicity

2. To describe the study population by the presence or absence of the following superficial

veins; basilic vein, median basilic vein, cephalic vein, median cephalic vein, median vein,

and the median cubital vein of forearm

3. To describe the distribution of type of anastomosis observed between superficial veins of

the cubital fossa whether Y type, H type or absence of anastomosis.

4. To describe the study population by sets of venous pattern; Y type on both right and left

arm (YY), H type on both right and left arm (HH), no anastomosis on both right and left

arm (II), and mixture of venous pattern (YH, YI, IY, HY, HI, IH).

5. To explore relationship between type of anastomosis and socio demographic variables

such as gender and ethnicity.

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Hypotheses:

In exploring association; the type of anastomosis either H, Y and I type will be the dependent variable and independent variable will be like socio demographic variables, gender and ethnicity.

Hypothesis:

Question 1: Is there any association between type of anastomosis and gender?

H0: There is no association between type of anastomosis and gender

H1: There is an association between type of anastomosis and gender

Question 2: Is there any association between type of anastomosis and ethnicity?

H0: There is no association between type of anastomosis and ethnicity

H1: There is an association between type of anastomosis and ethnicity

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METHODOLOGY

Study design

The study is designed as a descriptive cross-sectional survey involving a simple examination of

the superficial veins of cubital fossa among preclinical students of UniKL-RCMP.

Study field

The study was conducted in UniKL-Royal College of Medicine Perak starting from 2nd

November till 20th November 2009.

Sample size and sampling procedure.

For sample size calculation, the estimated prevalence of H type of anastomosis is 50 percent and

if the worst acceptable prevalence at 95% confidence interval is set at 40 percent, the minimum

required sample size is 96. To do a subgroup analysis by other variables we have doubled the

required sample size and have decided to study a sample size of 192.

Since the total number of students registered in the current preclinical years is 194, we chosen all

preclinical students into the study to fulfill our sample size requirement.

Inclusion criteria

All Phase 1A and Phase 1B students currently registered in the Medical Degree Program of

UniKL-RCMP who give their consent to participate are taken into the study.

Exclusion criteria

All preclinical medical students who could not be reached and contacted to participate are not

included without any exclusion criteria.

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Study variables and operational definition

The study variables are as follows;1. Socio demographic variables

Age

Gender

Ethnicity

2. Presence or absence of superficial veins of cubital fossa

Basilic vein

Cephalic vein

Median Basilic vein

Median Cephalic vein

Median vein

Medial Cubital vein

3. Type of anastomosis of superficial veins

H type

Y type

I type / absence of anastomosis

Type of study variables, definition and measurement scale

Study Variable Type Operational Definition Scale

Socio-demographic

Variable

1. Age

2. Gender

3. Ethnicity

Qualitative / numerical

Qualitative /

categorical

Age in completed years as stated by respondent

Gender as stated by respondent

Ethnicity as stated by respondent

Numeric continous age in completed years last birthdayNominal

Male Female

Nomimal Malay Chinese Indian

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Qualitative / categorical

Superficial Vein

1. Basilic vein2. Cephalic

vein 3. Median

basilic vein4. Median

cephalic vein

5. Median vein6. Median

cubital vein

Qualitative /

categorical

Presence or absence as

observed under

examination

Nominal Present Absent

Type of

Anastomosis

1. H type2. Y type3. I type

Qualitative /

categorical

Type of anastomoses

observe under examination

Nominal

H type : Yes : No

Y type : Yes : No

I type : Yes : No

Method of data collection and data collection instrument

Data had been collected from interview with the respondents to obtain the necessary socio-

demographic information on age, gender and ethnicity. A simple examination had been

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performed to observe and to draw the visualized superficial veins of the upper limb on both

sides.

A data collection form given in Appendix 1 had been used to record the necessary socio-

demographic data and to map the observed pattern of superficial veins of upper limb on right and

left sides.

Technique of examination of superficial veins.

1) First, the tourniquet or blood pressure cuff applied around the right and left arm of the

respondent. Then, we asked him/her to perform repeated flexion and extension of

forearm to help distend the veins.

2) When the superficial veins become prominent and visible, we sketch a drawing of

superficial veins, the branching and type of anastomosis seen on the data collection

sheet as shown in appendix 1.

Statistical Tests

All information collected are coded and entered into computer and analyzed using SPSS

software version 15.0. Data had been cleaned and checked before analysis.

A univariate analysis was done to describe the study population in percentage and proportion by

socio-demographic composition, and to describe the presence or absence of superficial veins and

type of anastomosis seen.

A bivariate cross tabulation had been done to explore possible association between the type of

variations seen in superficial veins and socio-demographic variables. A Chi Square test has been

performed to determine statistical significance of any association found.

RESULT

The respond rate of a total of 194 preclinical medical students, all those who could be reached a total of 180 and consented to participate were included in study with a response rate of 92%. The remaining 14 students could not be reached even after three attempt of home visit to their residential homes, could not be included in the study.

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The results of the study were based on the analysis of 180 preclinical medical students of the UniKL Royal College of Medicine Perak.

Socio Demographic Characteristic

The mean age of the study population is 20.11 years with a standard deviation of 1.56 years, and ranging between 18 to 27 years.

Figure 1 shows the percentage distribution of the study population by gender. From 180 students of our sample, 128 of them are female with percentage of 71%, and 52 of them are male with percentage of 29%.

Figure 1. Study Population by gender distribution.

Figure 2 shows the percentage distribution of the study population by ethnicity. Malays comprise the highest population with 153 students (85%), followed by Indians with 19 students (10.6%) and Chinese with 8 students (10.6%).

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Figure 2. Study Population by Ethnicity Distribution

Superficial Veins on Upper Limbs

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Our finding on analysis of the study population by the presence of the following superficial veins; basilic vein, median basilic vein, cephalic vein, median cephalic vein, median vein, and the median cubital vein of forearm is shown in figure 3.

Figure 3 shows the percentages of the study population by presence of superficial veins on right and left upper limbs. On the right upper limb, the basilic and cephalic veins are observed in 99.4% and 98.3% of subjects. The median basilic, median cephalic, and median veins are observed in 52.2% subjects and the median cubital vein is seen in 25% subjects only.

On the left upper limb, the basilic and cephalic veins are observed in 98.9% and 98.3% of subjects. The median basilic, median cephalic, median veins are observed in 50.6% of subjects. The median cubital vein is observed in 21.1% subjects only.

Figure 3 Study Population by presence of Superficial Veins on Right and Left Upper Limbs

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Types of Anastomosis of Superficial veins of the Cubital Fossa

The results of analysis by types of anastomosis observed between superficial veins of the cubital fossa whether Y type, H type or absence of anastomosis/I type is shown in figure 4.

The commonest type of anastomosis seen is Y type with 52.2% on the right cubital fossa and 51.1% on the left cubital fossa. H types of anastomosis observed is 25% of subjects on the right cubital fossa and in 20.6% of subjects on the left cubital fossa. I type/no anastomosis was observed in 22.8% and 28.9% on the right and left cubital fossa respectively.

Figure 4 Types of Anastomosis of Superficial Veins Observed in Right and Left Cubital Fossa of Upper Limb

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The result analyzed by sets of venous pattern; Y type on both right and left arm (YY), H type on both right and left arm (HH), no anastomosis on both right and left arm (II), and mixture of venous pattern (YH, YI, IY, HY, HI, IH) is shown in figure 5.

The commonest set of venous pattern seen is the mixture of venous pattern (YH, YI, IY, HY, HI, IH) with 46.67%. The YY set of venous pattern was observed in 32.2% of subjects, HH set of venous pattern was observed in 7.8% and II set of venous pattern was observed in 13.3%.

Figure 5 Study Population by Set of Venous Pattern.

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Relationship between type of anastomosis and socio demographic variables.

According to our objective no 5, we have attempted to explore relationship between type of anastomosis of the superficial vein and socio demographic variables, by doing cross tabulations and Chi-Square tests of significance.

Gender and Y type on right cubital fossa, p = 0.010

Gender and Y type on left cubital fossa, p = 0.426

Gender and H type on right cubital fossa, p = 1.000

Gender and H type on left cubital fossa, p = 0.347

Gender and I type on right cubital fossa, p = 0.002

Gender and I type on left cubital fossa, p = 0.068

Ethnicity and Y type on right cubital fossa, p = 0.480

Ethnicity and Y type on left cubital fossa, p = 0.731

Ethnicity and H type on right cubital fossa, p = 0.628

Ethnicity and H type on left cubital fossa, p = 0.847

Ethnicity and I type on right cubital fossa, p = 0.741

Ethnicity and I type on left cubital fossa, p = 0.398

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DISCUSSION

Most of the students in our population have Basilic and Cephalic Veins because they are the easily found. The previous study done by Berry et al showed that, the frequency of people having Basilic Vein is smaller compared to those of the Cephalic Vein.

From the results, the first hypothesis is accepted for certain conditions; there are possible associations between gender with Y-type of anastomosis and absent of anastomosis (I-type) in right cubital fossa.

Frequency of male students to have Y-type pattern of anastomosis is higher than female students. Y-type anastomosis characterizes the individual with strong body build and with average length of limbs5 especially in male students. Thus, according to χ2-test, the p-value for possible association between genders with Y-type anastomosis on the right cubital fossa is significant (p-value=0.010, <0.050). Most of the female students came with absent of anastomosis or I-type anastomosis in right cubital fossa compared to the male students, with significant p-value (p-value=0.002, <0.050). This means that there is possible association between genders with absent (I-type) of anastomosis in right cubital fossa. For H-type anastomosis in right cubital fossa, the p-value is not significant (p-value=0.628, >0.050) because the probability for male and female students having H-type anastomosis on right cubital fossa is equal. Thus, there is no possible association between genders with H-type pattern of anastomosis on right cubital fossa.

There are no possible associations for all type of anastomosis in left cubital fossa because all the p-values are not significant (all p-values more than 0.050) according to gender.

There are no possible associations between ethnicity with pattern of anastomosis in both cubital fossae. We cannot associate all type of anastomoses with ethnicity because there is biased in Malay ethnic compared to Chinese and Indian. Thus, all the p-values derived from χ 2-test are not significant (more than 0.050).

From this study, we can conclude that, there are associations between genders for Y-type and absent type (I-type) of anastomosis in right cubital fossa; and the relationship between ethnicity with pattern of venous anastomosis is not relevant. This is a limitation in our study, which can be improved by modify the sample population which represents the population in Malaysia.

According to the previous study done by Berry et al 8, showed that the frequency of H-type anastomosis is the highest followed by Y-type pattern and absent (I-type) of anastomosis. Compared to the present study, the frequency of Y-type pattern is the highest followed by absent (I-type) of anastomosis and H-type venous pattern.

The similar study done by Jasinski et al stated that, there are 4 different venous sets of both Cubital Fossae (Y-Y, H-H, I-I and mixture of venous sets). The highest frequency is H-H type, followed by Y-Y type, mix type and I-I type. The present study showed that the highest

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frequency is mix type, followed by Y-Y type, I-I type and H-H type. The difference in frequency of the present study and the study done by Jasinski et al, is believed to be due to the sample size and gender in particular population. Jasinski et al study use 40 respondents as sample size which all of them are males deceased from diseases of cardiovascular and nervous systems5.

CONCLUSION

In our study of variation of anastomosis of superficial veins of upper limb, we found that the

majority of our subjects, from 50.6% to 52.2% have Y type of anastomosis on both left and right

cubital fossa respectively, followed by H type of anastomosis from 20.6% to 25.0% on both left

and right cubital fossa respectively. I type or no anastomosis was found in 22.8% to 28.9% on

right and left cubital fossa respectively.

REFERENCES

1. Snell R.S: Clinical Anatomy by Regions, 8th ed. Lippincott William & Wilkins, 2008

2. Fitzgerald J.T, et al. (February 2004) Outcomes of Upper Arm Arteriovenous Fistulas for Maintenance Hemodialysis Access. Archive of Surgery, 139(2), page 201

3.Stefanov G, et al. (2007) Arterialized cephalic vein as a femoropopliteal bypass graft: A case report. International Journal of Angiology, 16(4), page 146-148

4.Kouji (K) Y, et al. (2008) Cubital fossa venipuncture sites based on anatomical variations and relationships of cutaneous veins and nerve. Journal of Clinical anatomy (New York), 21(4), page 307-313

5.Jasiński R, et al. (2003) Superficial venous anastomosis in the human upper extremity — a post-mortem study. Folia Morphol., 62(3), page 191-199

6. Netter F.H: Atlas of Human Anatomy, 4th ed. Saunders, 2006

7. Drake R.L, Vogl W, Mitchell A.W.M: Gray’s Anatomy for Students, Elsevier Churchill Livingstone, 2005

8. Berry R.J.A., and H.A.S. Newton (1908): A Study of Superficial Veins.

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ACKNOWLEDGEMENT

We thank to our supervisor, Dr. San San Thwin and our co-supervisor Dr. Myint Myint Soe for

their invaluable assistance, guidance and advice throughout the elective period. We also thank to

our friends who had helping us to collect the data and also to all the volunteers who cooperated

and helped us in this project.

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