K.E.M. Radiology
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Department of Radiology
Seth G.S. Medical College and K.E.M. Hospital, Mumbai , India
Introduction:
Named after Robert May and Karl Thurner (1), May Thurner Syndrome (MTS) is one of the vascular compression syndromes which refers to compression of the left common iliac vein (CIV) by the common iliac artery (CIA) over the 5th lumbar vertebra (1). The most common clinical presentation of MTS is left lower limb pain and swelling, varicosities, deep vein thrombosis or venous ulcers. Rarely, it can cause dilatation and reflux into the pelvic veins resulting in pelvic congestion syndrome(PCS).
PCS is a common cause of chronic pelvic pain - defined as intermittent or constant pain, lasting for 3 to 6 months, present in the pelvic or abdominal region, occurring throughout the menstrual cycle, and without any association with pregnancy (2).
Although the aetiology of PCS still remains unclear, it may result from a combination of factors including genetic predisposition, anatomical abnormalities, hormonal factors, damage to the vein wall, valve dysfunction, reverse blood flow, hypertension and dilatation (3).
Here we present a patient with chronic pelvic pain with May Thurner Syndrome managed by endovascular stenting of the left CIV in the first sitting followed by ovarian vein embolisation planned at a second session.
Case presentation:
A 34 year old multiparous woman was referred to our department with chief complaints of vague intermittent pain in abdomen, non cyclic in nature since five months. She also complained of intermittent pain and swelling of left lower limb since one year. She denied history of current or prior DVT, pulmonary embolus, or anticoagulation therapy.She had past history of LSCS in 2019. There were no other co-mobidities. She had already undergone an Ultrasound examination of the abdomen and pelvis prior to visiting us. This was reported as having no significant abnormality. On CT venography, it was noticed that the left CIV is compressed by the right CIA with reformation of the internal and external iliac veins via collaterals due to chronic thrombosis of left CIV. (Fig 1 and 2). There were multiple pelvic and parametrial and ascending lumbar collaterals. Preprocedure colour Doppler screening of left lower limb revealed no abnormality. Thus a diagnosis of May Thurner Syndrome was made and the patient was planned for endovascular management.
Figure 1, 2
Axial CT Venography showing compression of left CIV by right CIA.(left)
Axial CT Venography showing parauterine varices.(right)
Interventional technique:
Percutaneous left common femoral vein access was obtained with a 6 Fr sheath under ultrasound guidance, and iliocaval venography was performed (Video 1).
Initial images revealed pelvic collateralization with crossover to the right iliac system as well as the ascending lumbar collaterals.
These findings were consistent with high-grade outflow stenosis or occlusion of the left CIV. Intravascular ultrasound could not be performed due to technical issues. A attempt to navigate the iliac occlusion from the ipsilateral common femoral route was unsuccessful. Hence, MPA catheter was used to engage the confluence of left CIV with IVC from the right jugular route (Fig 3).

Video 1 Iliocaval venography from left femoral access.
Fig. 3 DSA image showing contrast run through MPA catheter via right jugular access.
Using a MPA catheter tip as a guide under roadmap, a terumo glidewire wire was negotiated from the ipsilateral common femoral route into the IVC. ( Fig 4, Video 2). The length of the obstructed segment of the left common iliac vein was calibrated using a pigtail marker catheter by performing venograms from the femoral and jugular routes (Fig 5).

Fig 4: (top left) Image showing glidewire with the H1 catheter having been successfully negotiated into the IVC from the left femoral access.
Fig 5: (top right) DSA image showing the use of a marker pigtail catheter to identify the length of the obstructed segment of the left CIV
Video 2 (bottom) : Iliocaval venography from right jugular access.
Predilatation was done with a 12mm x 40mm balloon (Video 3). A 14mm X 120mm ABRE self expanding stent was deployed across the left CIV (Video 4, Fig 6).


Video 3 : Top left Predilatation with 12mm X 40mm balloon.
video 4 Top right Deployment of 14mm X 120mm ABRE self expanding stent across left CIV.
Fig 6 bottom Radiograph showing a stent in left CIV.
Completion venography demonstrated a widely patent iliac venous system with brisk antegrade flow into the IVC and significant reduction of pelvic venous collaterals (Video 5). Post procedure, Inj Heparin 5000IU TDS was administered for 24 hours. Thereafter, she was started with Warfarin 5mg OD and discharge was planned once her INR reached a value of 3.5. She was advised to continue warfarin for six months. Post procedure CT shows the stent in situ with a patent left CIV (Fig 7). There is significant reduction in the periuterine venous plexus (Fig 8).

Video 5 Iliocaval venography post procedure showing patent left CIV with brisk antegrade flow in the IVC.
Fig 7 Axial CT Venography post procedure showing stent in left CIV with patent lumen.
Fig 8 Axial CT venography showing reduction in parauterine pelvic varices post procedure.
CFV access on both sides and right IJV access was achieved and a venogram from the left CFV showed slow antegrade flow across the left CIV stent with multiple large left to right internal iliac vein pelvic collaterals. (Video 6, Video 7). Through the Jugular route a 7 Fr x 90 cm long sheath was introduced into IVC. The pelvic collaterals were selectively cannulated using a 5F MPA catheter and embolised using multiple pushable and detachable coils (FIG 9). Post coiling there was significantly reduced flow across these collaterals. (Video 8),


Video 6 Venogram from the left common femoral vein showing large left to right pelvic collaterals along the left internal iliac vein.
Video 7 Venogram from the left internal iliac vein showing large left to right pelvic collaterals.
Fig 9 Coils deployed in the left internal iliac vein collaterals.

Video 8 Post coiling venogram showing significantly reduced flow across the pelvic collaterals.
The left ovarian vein venogram showed reflux into a large ovarian vein and collaterals as well as into the parametrial collaterals, as also into a dilated right ovarian vein (Video 9). Bernstein balloon occlusion catheter navigated into left ovarian vein. A Progreat (2.4 Fr) microcatheter was inserted coaxially through the occlusion catheter and the left ovarian vein was embolised using foam sclerosant (2 cc Setrol, 1 cc Lipiodol, 7 cc air), after inflating the balloon proximally. Controlled foam sclerosant injection was done from microcatheter as well as balloon occlusion catheter. (Video 10). A detachable coil was deployed in the proximal ovarian vein through the inflated balloon occlusion catheter after foam sclerotherapy.


Video 9 : Left ovarian venogram showing a large left ovarian vein with collaterals, parametrial collaterals and reflux into the right ovarian vein.
Video 10 : Foam sclerotherapy of the left ovarian vein.
Post embolisation, there was no reflux in the left ovarian vein. (Video 11)
Venogram from the left CFV showed improved antegrade flow across the left CIV stent with significantly reduced flow in the pelvic collaterals. (Video 12)


Video 11 : Post embolisation venogram showing no flow in the left ovarian vein.
Video 12 : Venogram from both common femoral veins showing significantly reduced collaterals and good antegrade flow in the left CIV stent.