Pathogenesis and management of superficial venous aneurysms through a case of thrombosed large great saphenous vein aneurysm

Introduction

The term aneurysm is classically used when referring to arterial aneurysms; however, venous aneurysms (VA) though uncommon are known to occur. Involvement of the deep venous system is far more common than the superficial venous system in the lower limbs. Incidence of superficial venous aneurysms (SVA) has been estimated to be around 0.1%. ¹ Here, we present a rare case of thrombosed GSV aneurysm and its management along with a brief review of literature on SVA. Informed written consent to publish this case report and images was obtained from the patient.

Case report

A 27-year-old gentleman presented with complaints of swelling over his right lower thigh for 13 years. Swelling was asymptomatic initially and reducible on manual manipulation and thus was ignored by the patient. Insidious and gradually progressive aching pain developed over the swelling two months prior to presentation. The swelling became irreducible and grew to a size of approximately 6 × 6 cm at presentation. He also developed multiple varicosities over the medial aspect of his right thigh at the same time. He denied any history of trauma and smoking. He was of average build and had no associated comorbidities. On examination, a tender and firm swelling with increased overlying skin temperature was present. No palpable thrill or dilated veins were present over the swelling (Figure 1).

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Figure 1.

Preoperative image of the venous aneurysm on the medial aspect of the right thigh.

Ultrasound venous Doppler revealed a thrombosed aneurysm directly communicating with the great saphenous vein (GSV). Tortuosity of GSV and short saphenous vein was present at mid leg level. Right saphenofemoral junction and perforators were incompetent (Figure 2(a) and (b)). No evidence of deep vein thrombosis (DVT) was noted. Low-molecular weight heparin was started preoperatively as a prophylaxis for DVT and was stopped after surgery. Surgical excision was planned under spinal anaesthesia in view of pain and aesthetic reasons. An elliptical incision was created over the swelling and extended down. Thrombosed superficial aneurysmal vein was excised along with few large varicosities at distal continuation of GSV and proximal continuation of GSV was ligated. Hemostasis was achieved. Subcutaneous tissue was closed with vicryl 2–0 and skin closed with monocryl 3–0 simple interrupted sutures (Figure 3). The patient tolerated the procedure well and was discharged home on postoperative day 1 with elastic compression bandages and advised for limb elevation to conservatively manage varicose veins and to prevent swelling. Follow-up visits after first and third week and repeat venous Doppler did not reveal any thrombus. Histopathological examination of the excised tissue was consistent with VA with intraluminal thrombus. The medial wall of the aneurysm was thickened and showed decreased smooth muscle tissue.

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Figure 2.

USG venous Doppler done for preoperative evaluation: (a) venous Doppler of the aneurysm; (b) showing the incompetence of the right saphenofemoral junction (black arrow).

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Figure 3.

Intraoperative images: (a) thrombosed venous aneurysm seen along with distal feeding GSV (black arrow). Distal varicose veins have been shown with a green arrow; (b) visible raw area after dissection of the aneurysm; (c) excised venous aneurysm specimen along with varicosities seen inferiorly (black arrow).

Discussion

VA is defined as a venous dilation that communicates with a main venous structure by a single channel, and it must have no association with an arteriovenous communication or a pseudoaneurysm. ² Primary VA differs from secondary VA. Primary aneurysm generally occurs in children and can appear in any part of the body, while secondary aneurysms are generally associated with trauma, inflammation or could be degenerative and usually present in adulthood.^3,4 It has been suggested that both primary and secondary mechanisms may be involved together ⁵ which seems to be a plausible explanation in our case.

In the early 1960s, Schatz and Fine ³ described the mechanism underlying VA and suggested that venous remodelling termed as endophlebohypertrophy and endophlebosclerosis plays important roles similar to atherosclerosis in arterial aneurysms. Histopathologically, an aneurysmal portion shows thinning of the vessel wall due to loss of smooth muscles and disruption of elastic fibres and replacement with fibrous tissue.^4,5 Fragmentation of elastic lamina has been observed in both arterial and venous aneurysms. This is in contrast to varicose veins where smooth muscle tissue is increased and the vessel is thickened. This finding was also confirmed in our case as well. Pascarella et al. ¹ have described superficial venous aneurysms (SVA) of the leg to occur due to reflux from incompetent valves leading to pulsatility and turbulency of blood flow. Since obese individuals have higher intraabdominal pressure compared to normal weight individuals, which tends to increase the reflux, VA has been linked to higher body mass index ¹ (BMI is defined as the body mass divided by the square of the body height).

Irwin et al. ⁶ made an interesting observation that there is an absence of literature having venous and arterial aneurysms in the same individual suggesting different pathogenesis. Gomez et al. ⁷ showed that arterial aneurysms and varicose veins may work through a common molecular regulatory pathway. This pathway involves the regulatory role of hydrogen sulphide on prostaglandin E2 synthesis which in turn regulates the synthesis of matrix metalloproteinases (MMP). It would be interesting to see if this holds for VA as well. A novel study by Irwin et al. ⁶ found increased expression of MMP 2, 9 and 13 in endothelial and smooth muscle cells of VA and varicose veins compared to normal veins. This finding may correspond to disruption of elastic fibres seen on histopathology as MMP’s are involved in collagen degradation.

GSV aneurysms have been classically divided into four types based on their location. ¹ Type I aneurysms (most common) are located in the proximal third of the saphenous vein. Type II aneurysms occur in the shaft of the saphenous vein in the distal third of the thigh. Type III superficial saphenous VA refers to the occurrence of types I and II in the same lower extremity. SVA of the short saphenous system is classified as type IV (least common). Our case describes a type II aneurysm. Aneurysms of saphenous veins are usually painless and generally present as swelling in the inguinal region ⁵ (Type I). They are often confused with inguinal hernias on clinical examination. They have been observed to occur both in the presence and absence of varicose veins. ⁵ Incidence of thrombosis leading to DVT or pulmonary embolism is extremely rare with SVA (only five cases reported previously).^2,8–10 The role of anticoagulation in SVA is yet to be explored and remains a matter of debate.

Venous Doppler has been considered as the imaging modality of choice ⁴ as it provides sufficient details regarding diagnosis and surgical anatomy of VA. MR venography or CT venography is required in exceptional cases when aneurysms are deep seated or diagnosis is unclear on venous Doppler. Majority of SVA are asymptomatic, and surgical excision is mainly performed for cosmesis, pain, oedema or compressive symptoms. ¹¹ The significance of thrombus in SVA is unknown, and therefore per se may not be an indication for surgery without the symptoms of DVT or PE. It is best to observe small SVA with repeated follow-up Doppler. Sclerotherapy and endovascular ablation ¹² have also been suggested as possible treatment options. Only three case reports describing treatment with foam/liquid sclerotherapy exist in the literature.^4,13,14 Experience with both these techniques is extremely limited, and more research is needed to determine their efficacy in the treatment of VA.

Conclusion

Occurrence of superficial saphenous VA is uncommon, and current data are limited to isolated case reports. They are usually painless and very rarely cause thromboembolism. Venous Doppler should be the first-line investigation in such cases. Surgical treatment is done mainly for symptomatic relief or aesthetic reasons. More studies are warranted to better understand its pathogenesis, to guide optimal time for intervention and to establish the role of anticoagulation in such patients.