Understanding the patterns of superficial veins in cubital region: a cross-sectional study from Gulf Arab Populations

Introduction

Methods

Procedure for examining the venous patterns

The venous patterns of 139 males and 27 females were recorded following a standard protocol described by Vucinic et al., 2016.³ In brief, a tourniquet was placed approximately 10 cm proximal to the elbow crease for about 3 to 5 minutes with repeated clenching and unclenching of their fists until the superficial veins were dilated and palpable for observation. Once the veins were dilated and palpable, the investigators collected the data and recorded the observed venous pattern following a standard classification as described by Vucinic et al., 2016.³ In brief. This classification ( Figure 1) described nine types of venous patterns in the cubital region as follows:

Figure 1. Showing 9 different types of venous patterns of the cubital region.

C: Cephalic vein; B: Basilic vein; MCV: median cephalic vein; MBV: median basilic vein; MAV: median antebrachial vein; MCuV: median cubital vein.

Type 1 presenting “M” shaped pattern, in which the median antebrachial vein continues with the two terminal branches of the median cephalic and median basilic vein, which connects the cephalic and the basilic vein, respectively.

Type 2 presenting “N” shaped pattern, in which the median antebrachial vein ends into median cubital vein.

Type 3 presenting more or less similar to “M shaped pattern”.

Type 4 presenting a modified “N shaped pattern,” in which, median antebrachial vein ends in the basilic vein.

Type 5 presenting modified “M shaped pattern”, in which, one or two veins end either in median cephalic or median basilic vein.

Type 6 presents the cephalic and basilic veins with no communication between them, and the median antebrachial vein opens into either the basilic or cephalic vein.

Type 7 presents two median cubital veins above and below the crease of the elbow, with the median antebrachial vein opening into the medial cubital vein or basilic vein.

Type 8 presents with a cephalic vein running supermedially as the median cubital vein with no proximal cephalic vein.

Type 9 presenting “M shaped pattern” with a doubled brachial cephalic vein.

Results

The age of the volunteers who participated in this study was in the range of 17–27 years. The mean age of the participants was 20 ± 2.17. Of the total participants, the majority were male (83.73%), with a lower number of females (16.27%) ( Figure 2). Of these 139 males, 55 were from Bahrain, 58 were from Saudi Arabia, and 26 were from Kuwait. Of the 27 females, 8 were from Bahrain, 13 from Saudi Arabia, and 6 from Kuwait ( Figure 3, Tables 1 and 2).

Figure 2. Pie Chart showing the percentage of male and female participants of the study.

Figure 3. Number of male and female participants from different Gulf Arab populations.

Type 1 was identified in 40 right (28 males +12 females) and 40 cubital regions (34 males and 6 females). Eighty cubital regions exhibited this venous pattern. No significant differences were noted between the sexes (p = 0.109) or laterality (p = 1).

Type 2 was identified in nine right and seven left cubital regions of males with 0% females. Sixteen cubital regions exhibited this pattern. Statistically significant differences were noted between the sexes (p = 0). However, no statistically significant differences were noted in laterality (p = 0.608).

Type 3 was identified in 23 right cubital regions (22 males and 1 female) and 25 left cubital regions (23 males and 2 females). A total of 48 cubital regions exhibited this venous pattern. Statistically significant differences were noted between sexes (p = 0.005). However, no statistically significant differences were noted in laterality (p = 0.755).

Type 4 was identified in 17 right cubital regions (13 males and 4 females) and 14 left cubital regions (12 males and 2 females). A total of 31 cubital regions exhibited this venous pattern. No significant differences were noted between the sexes (p = 0.646) or laterality (p = 0.571).

Type 5 was identified in 16 right (16 males +0 females) and 12 left cubital regions (12 males and 0 females). A total of 28 cubital regions exhibited this venous pattern. Statistically significant differences were noted between the sexes (p = 0). However, no statistically significant differences were noted in laterality (p = 0.429).

Type 6 was identified in 48 right cubital regions (40 males and 8 females) and 49 left cubital regions (37 males and 12 females). In total, 97 cubital regions exhibited this venous pattern. No significant differences were noted between the sexes (p = 0.188) or laterality (p = 0.904).

Type 7 was identified in only 1 male patient. Statistically significant differences were noted between the sexes (p = 0). However, no statistically significant differences were noted in laterality (p = 0.316).

Type 8 was identified in five right cubital regions (three males and two females) and five left cubital regions (three males and two females). Ten cubital regions exhibited this pattern. No significant differences were noted between the sexes (p = 0.153) or laterality (p = 1).

Type 9 was identified in 8 right cubital regions (8 males and 0 females) and 13 left cubital regions (10 males and 3 females). A total of 21 cubital regions exhibited this venous pattern. No significant differences were noted between the sexes (p = 0.79) or laterality (p = 0.259).

Overall, no statistically significant differences were found among the Bahraini-Saudi, Bahraini – Kuwaiti, and Saudi-Kuwaiti populations (p > 0.05). Our findings on the various venous patterns have been compared with other studies available in the literature ( Table 3).

Discussion

The structural and visual differences observed in the superficial venous patterns of the cubital region are driven by many factors, including biological and environmental factors such as embryological development, genetic predisposition, body composition, and demographic differences.⁷ During embryogenesis, veins of the upper limb originate as a capillary network and undergo a series of changes. During this remodeling process, many veins enlarge to form the main veins, while others regress. Any deviations during this normal process of regression and enlargement would present variant types of superficial veins that are largely determined by genetics, which dictate the specific branching pattern, size, and anastomoses of vascular networks.⁷

The current study conducted on superficial veins of the cubital region in the Gulf Arab population reported that the type 6 venous pattern (29.2%) was the most common, followed by the type 1 venous pattern (24.09%) in both males-females and on the right-left side. The occurrence of all other venous pattern types was significantly lower than that of these two types. Of all the types reported, type 7 was the rarest, reported in only one cubital region in the male and on the left side.

Our literature search concluded that there was only one study conducted in a Gulf Arab population from the eastern province of Saudi Arabia,¹³ which reported only four types of venous patterns following the classification described by Lee et al.¹⁶ This classification is entirely different from criterion³ we followed in our study, which makes our study of its first kind in reporting the detailed superficial venous patterns of the cubital region. According to their study³ and classification, type 2 was the most common (52.2%), followed by type 1 (32.4%). There are three studies available in the literature that report superficial venous patterns of the cubital region in Pan-Arab populations. A study from a Jordanian population following the classification proposed by Del Sol et al.⁴ reported that the type 2 pattern was the most common pattern followed by type 1.¹⁷ Another study from the Iraqi population reported an M-shaped pattern (type 1) as the most common pattern followed by type 2 as per the classification we followed in our study.¹⁸ A study from the Egyptian population revealed an N-shaped pattern (type 2) as the most common venous pattern.¹⁹ These findings are contrary to our results, and this could be due to the variation in the pool of the populations studied.⁷

A study from the Malaysian population⁵ reported six venous patterns in 532 cubital regions. The most common type reported in their study was type 2 with an N-shaped arrangement (68%) in 362 cubital regions, followed by an M-shaped arrangement in 86 cubital regions (16.2%). Studies from Polish, Japanese, Nigerian, and Iranian populations also followed the same trend, reporting more N-shaped venous patterns.^6,8,9,11 However, studies from Serbian, Indian, Sudanese, and Sri Lankan populations presented more M-shaped (type 1) venous patterns than the N-shaped arrangement.^3,7,14,15 These venous patterns reported from different populations follow a standard anatomy textbook description of type 2 being the most common, wherein the cephalic vein gives off the median cubital vein, which passes upward and medially to join the basilic vein. However, our study does not support this view, as type 6 is the most common. A study from the Ethiopian population¹⁰ conducted on 800 cubital regions presented a different scenario of type 1 being the commonest than the type 2. Contrary to this, another study from the Ethiopian population with more or less the same sample revealed type 2 being the most common one than type 1.¹² These variations observed from the same populations or comparing them with different populations are highly debatable in the clinical context, as these venous patterns depend on the hydration status, gender, genetic predisposition, age, and thickness of the subcutaneous fatty layer of the individuals.³ A thorough understanding of all the reported venous patterns and their predominance are crucial for healthcare workers, medical lab technicians, and phlebologists to improve their venipuncture practice and to avoid any procedural complications.² It is essential to spot and accurately identify the basilic vein and median cubital vein, particularly during the procedures of dialysis and venipuncture²⁰ and bearing the fundamental knowledge of variant venous patterns reported in our study and other comprehensive studies^3,21 would avoid any pressing challenges associated with these clinical procedures.

This study has several limitations. First, we did not obtain an equal number of subjects of either sex. Second, we did not correlate venous patterns with anthropometric variables such as height, weight, or body mass index (BMI). In the future, it may be worth examining these parameters to gain a more comprehensive understanding of the venous anatomy and to synthesize contemporary data about fundamental knowledge of the superficial veins of the cubital region, as these veins hold the highest value in diagnostic, therapeutic, and surgical procedures.

In conclusion, our study observed that the type 6 being the commonest venous pattern followed by the type 1 in the cubital regions of both males and females. These observations are unique and inconsistent with the findings of earlier studies.

Ethical approval

This study was approved by the Research & Ethics Committee (REC) of the College of Medicine & Health Sciences (CMHS), Arabian Gulf University (AGU) (Approval no: E41-PI-06-26).