RIGHT-SIDED MAY–THURNER SYNDROME CAUSED BY AN ABERRANT RIGHT COMMON ILIAC ARTERY, MANAGED BY VENOPLASTY AND OVERLAPPING STENT PLACEMENT: A CASE REPORT

Abstract

Background: May–Thurner syndrome (MTS) classically denotes compression of the left common iliac vein (LCIV) between the overlying right common iliac artery (RCIA) and the fifth lumbar vertebral body, producing left-sided venous outflow obstruction, deep vein thrombosis (DVT) and chronic venous insufficiency [1,2]. Compression of the right common iliac vein (RCIV) is uncommon, and the published experience is confined to isolated reports and small series [3,4]. Case presentation: A 37-year-old man presented in July 2025 with mild swelling and pain of the right lower limb and dilated abdominal wall veins, two years after an ipsilateral iliofemoral DVT that had been treated with retrievable inferior vena cava (IVC) filter placement and mechanical thromboaspiration, followed by six months of anticoagulation. Thrombophilia screening had been negative. He was CEAP clinical class C3 at presentation. Duplex ultrasound demonstrated a severely stenotic right external iliac vein, echogenic webs and strands within a partially recanalised superficial femoral vein, and extensive abdominal wall collaterals. Computed tomography venography (CTV) showed the right common iliac vein flattened to an anteroposterior diameter of 2 mm against a 12 mm reference segment, with a preserved transverse diameter of 13 mm — an estimated 82% cross-sectional area reduction — where an aberrantly coursing RCIA crossed anterior to it and compressed it against the vertebral body. The IVC was normally positioned. Catheter venography via right popliteal access confirmed an occluded right iliac venous segment with cross-pelvic collateral drainage. The occlusion was crossed with a coaxial hydrophilic 0.035-inch guidewire and 4 Fr angled catheter, dilated with 6 × 150 mm and 10 × 100 mm balloons, and treated with overlapping 14 × 100 mm and 14 × 80 mm self-expanding nitinol stents. Completion venography showed brisk in-line flow into the IVC. The procedure was uncomplicated. Outcome: Duplex ultrasound on the first postoperative day and at eight weeks confirmed stent patency with continuous low-velocity flow, and the presenting symptoms resolved on clinical assessment. Conclusions: Right-sided May–Thurner syndrome may arise from an aberrant right common iliac artery in the presence of an otherwise normal infrarenal venous anatomy, without a left-sided IVC. Iliac vein compression should be considered in unexplained or recurrent right iliofemoral venous obstruction, and endovascular recanalisation with stenting is an effective treatment. This report is presented in accordance with the CARE guidelines [5].