Unilateral Double Great Saphenous Vein: A Clinically Significant Case Report.

Great saphenous vein (GSV) is the longest vein in the body originating from the dorsum of the foot at medial malleolus to the level of groin skin crease. It is one among the clinically significant superficial veins of the lower limb. Double or duplication of GSV is considered to be one of its rarest variant forms, which might be often mistaken with the accessory saphenous vein. The overall incidence of duplicated GSV is reported to be 1%. We report herein, a unilateral duplication of GSV with its morphological and clinical perspectives. The major clinical complication that is often encountered from its duplication is recurrent incompetence of the GSV, which predisposes varicosity. Therefore, a thorough knowledge of venous anatomy is important for clinicians and sonographers.

INTRODUCTION

The great (long) saphenous vein (GSV) is a superficial vein representing preaxial vein of the lower limb. It begins in the medial marginal vein of the foot and ends in the femoral vein below the inguinal ligament. During its course, it ascends in front of the tibial malleolus and obliquely crosses the lower part of the medial surface of the tibia to its medial border and ascends to the knee. It reaches the saphenous opening in the thigh and drains into the femoral vein.[1]

GSV is known to show aberrant formation, termination, and various patterns of tributaries. However, its complete duplicating morphology is hardly ever reported to the best of our knowledge.

Accessory GSV and double GSV are often misinterpreted as synonyms. While accessory saphenous vein is generally smaller in size, the two veins of duplicate GSV will have the same caliber.[2] The present case report describes a rare morphological variation of GSV, as a unilateral duplication throughout its extent.

Incompetency of valves of GSV marks the common cause of varicosity. To achieve increasing success and efficacy of surgical treatments and in decreasing the recurrence rates of varicosity, the knowledge and identification of anatomical variations of veins of the limbs are obligatory to the clinicians.

CASE REPORT

During routine cadaveric dissection for undergraduate medical students, we observed a case of double GSV on the right lower limb in a male cadaver aged about 60 years. The origin of the main GSV was normal from the dorsal venous arch of the foot, whereas its duplicate vessel was found to be formed by the union of medial end of dorsal venous arch with the dorsal metatarsal vein which was draining the great and second toes [Figure 1a]. Main GSV had a normal course as it ran upward in front of the medial malleolus, along the medial side of the leg. The duplicate GSV was accompanying the main GSV laterally and had a similar course as that of the main GSV. Main GSV received the superficial external pudendal and superficial epigastric veins and united with the duplicated GSV, which received the superficial circumflex iliac vein before its union with the main GSV [Figure 1b] and both of them drained into the femoral vein after passing through the saphenous opening.

Figure 1

(a) Dissection of dorsum of the right foot and medial side of the leg showing the origin of main and duplicate great saphenous veins. (b) Dissection of front of the thigh showing termination of main and duplicate great saphenous vein into femoral vein. SA = Sartorius, RF = Rectus femoris, AL = Adductor longus muscles

DISCUSSION

The venous system is considered to be more variable than the arterial system. The arrangement of venous drainage of the lower limb may vary from subject to subject and even from limb to limb.[3]

The GSV, a clinically significant superficial vein of the lower limb, is a readily accessible vein. Due to the presence of enough distance between its tributaries and perforating veins, usable length of it can be harvested for vascular implantation purposes. Since its wall contains a significant amount of muscular and elastic fiber content than any other superficial vein, it is commonly used for coronary arterial bypass.[4]

Variant form in its formation, course, and tributary pattern is widely reported. However, reports on duplicate GSV are very uncommon as its occurrence rate is estimated to be 1%. Moreover, when duplication persists, it is reported that both GSVs lie in the same plane.[5]

GSV, with its variant formation, reported as a continuation of the dorsal venous arch at the proximal part of metatarsal bones in 70% of cases and in the remaining cases, it arises as a continuation of the first common metatarsal vein of the medial side of the great toe.[6]

Based on its relation with the femoral vein, duplication of GSV can be categorized into 3 types. They are duplication with a common junction, duplication with separate junctions, and insular duplication with a common junction.[7]

Duplicated GSV can be found below or above the knee. A case of duplicated GSV with the same origin and course as that of main GSV and with multiple intercommunications at mid-calf and mid-thigh levels has been reported by Waseem and Roger.[8]

Nakhate et al.[9] reported a unilateral duplicated GSV below the knee at the level of medial condyle of tibia with the eventual reunion of both to form a single saphenous vein with eventual termination into femoral vein.

GSV has a great clinical importance, as it is a vein of choice for the grafts in peripheric vascular surgery in the treatment of cerebrovascular diseases.[1011] Recurrent incompetence of the GSV is the most common predisposing factor of the persistence of duplicated GSV.[12]

Conservative approach, ultrasound-guided sclerotherapy, and junction ligation with or without vein stripping are the treatment options for varicose veins.[13] Expertize in venous anatomy and its atypical variant forms are necessary for interventional treatment modalities. Surgical or lesser invasive procedures might result in incomplete sephanofemoral junction surgery if important anatomical variations are not recognized.[1314]

CONCLUSION

Presence of rare and clinically essential variant form of GSV and its duplication should be known to clinicians, radiologists, and phlebotomists. Varicosity is one of the most significant clinical pose of superficial veins of the lower limb, its recurrence even after stripping or sclerotherapy procedure warrants the need of a meticulous look for the presence of double GSV.

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Conflicts of interest

There are no conflicts of interest.