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Year : 2020  |  Volume : 7  |  Issue : 2  |  Page : 201-203

Successful endovascular exclusion of an isolated iliac artery aneurysm causing “May–Thurner effect”

1 Department of Vascular Surgery, Liverpool Hospital; South Western Sydney Clinical School, Liverpool, NSW, Australia
2 Department of Vascular Surgery, Liverpool Hospital, Liverpool, NSW, Australia

Date of Submission09-Jan-2020
Date of Acceptance20-Jan-2020
Date of Web Publication17-Jun-2020

Correspondence Address:
Dr. Nicolas Ramly
Department of Vascular Surgery, Liverpool Hospital; South Western Sydney Clinical School, Liverpool, NSW
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijves.ijves_3_20

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May–Thurner syndrome is a well-recognized entity, often described as the right common iliac artery (CIA) compression of the left common iliac vein (CIV), however, other configurations are possible. It is often associated with lower limb edema, recurrent varicose veins, and unprovoked deep femoral vein thrombosis. Herein, we present an unusual case where aneurysmal dilation of the right CIA resulted in the compression of the bilateral CIVs resulting in a bilateral May–Thurner effect. The management of this patient and the pathophysiology of May–Thurner syndrome are also discussed.

Keywords: Iliac vein compression, May-Thurner syndrome, venous compression syndrome

How to cite this article:
Ramly N, Singla A, Iliopoulos J. Successful endovascular exclusion of an isolated iliac artery aneurysm causing “May–Thurner effect”. Indian J Vasc Endovasc Surg 2020;7:201-3

How to cite this URL:
Ramly N, Singla A, Iliopoulos J. Successful endovascular exclusion of an isolated iliac artery aneurysm causing “May–Thurner effect”. Indian J Vasc Endovasc Surg [serial online] 2020 [cited 2021 Sep 27];7:201-3. Available from:

  Introduction Top

Solitary iliac artery (IA) aneurysms are a rare entity with an incidence of <0.1%.[1] Diagnosis can be challenging and is often delayed as many patients are asymptomatic or present with nonspecific symptoms. Symptoms may arise from impending rupture causing pain, thromboembolism causing distal ischemia, or compression of adjacent structures.[1],[2] We report an uncommon presentation of a large isolated right common IA (CIA) aneurysm presenting with bilateral lower limb edema.

  Case Report Top

A 64-year-old male presented to the emergency department with significant lower pitting edema which had developed over 3 months. The patient did not report any significant medical history and did not take any regular medications. He was an ex-smoker and had a history of heavy alcohol use.

Examination revealed a distended abdomen with a reducible umbilical hernia and no other palpable masses. No power or sensory deficits were noted in the lower limbs. Bilateral pitting edema to the level of the ankles was present. The patient's relevant blood work is demonstrated in [Table 1].
Table 1: Pathology results

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Computerized tomography demonstrated a fusiform aneurysm of the right CIA, measuring 6 cm in maximal transverse dimension, causing compression of both common iliac veins (CIVs) [Figure 1] and [Figure 2]. Evidence of hepatic cirrhosis was noted; a patent but dilated portal vein (19 mm diameter), paraesophageal and upper abdominal varices, and recanalization and dilatation of the paraumbilical vein. No hepatic lesions were identified. No ascites was present. No venous thrombosis of the iliac vessels or their tributaries was present.
Figure 1: Computerized tomography demonstrating the compression of the common iliac veins by the aneurysmal right common iliac artery

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Figure 2: Angiogram demonstrating the right common iliac artery aneurism

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The provisional diagnosis was aneurysmal compression of iliac veins causing a “May–Thurner effect.” Differentials include hypoalbuminemia secondary to cirrhosis and cardiac failure.

The patient's Child–Pugh score was calculated to be 7 (child class B), which carries a 30% perioperative mortality for abdominal surgery.[3] As the patient was hemodynamically stable and in a monitored environment, his cirrhosis was investigated first. He was diagnosed with alcoholic steatohepatitis. A gastroscopy was done, and Grade II varices were noted, and no intervention was required.

The patient subsequently underwent successful endovascular repair under a general anesthetic using an iliac branched device to preserve the right internal IA flow. Under general anesthetic, percutaneous access was obtained with ProGlide closure devices. A Zenith Cook off-the-shelf iliac branched device (12 cm × 61 cm × 58 cm) was first placed through the right side, with a covered stent (Fluency, BARD) for bridging into the internal IA. This was supported by an uncovered bare metal stent (LifeStent, BARD). This was followed by the placement of standard Zenith Cook Alpha graft with suprarenal graft fixation (30 mm × 70 mm main body, left iliac limb – 24 mm × 93 mm Zenith alpha limb, and right-sided bridging limb – 20 mm × 42 mm). The patient's postoperative angiogram is demonstrated in [Figure 3]. The patient was given intraoperative heparin to maintain ACT >250 throughout the case. Perioperatively, hematological management involved 10 mg Vitamin K before the operation, 1 unit of fresh frozen plasma, and 1 unit of pooled platelets postoperatively.
Figure 3: Angiogram demonstrating the aortoiliac arteries postintervention

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Postoperatively, the patient recovered well. His bilateral lower limb edema improved significantly post exclusion of the aneurysm. He was discharged on the 6th postoperative day. Follow-up was organized with both the vascular surgery team as well as the gastroenterology team.

  Discussion Top

Isolated CIA aneurysms are a rare phenomenon estimated to affect <0.1% of the general population.[1] The most prevalent definition of an IA aneurysm is a dilatation of the vessel to more than 1.5 times its normal diameter.[2] Of the IAs, the common iliac is the most often affected (70%), followed by the internal iliac (20%) and the external iliac (10%).[4]

Choice of repair

The European Society for Vascular Surgery guidelines for the management of abdominal aortoiliac aneurysms[2] suggest that elective repair be considered once a CIA aneurysm has reached a size of 3.5 cm. Operative management includes open surgical repair using interposition grafting and excision, surgical ligation with extra-anatomic bypass (femoral-femoral crossover), or several endovascular options often in conjunction with an infrarenal aortic graft including:

  • Iliac branched devices for the preservation of internal IA flow
  • Internal IA embolization (Amplatzer plug and coil) with extension into external IA
  • Bell-bottom (flared) iliac limbs
  • Sandwich iliac stents.

The choice of repair is dictated by patient comorbidities, device availability, and anatomical suitability. This patient underwent a successful endovascular aortic and iliac branched graft repair, allowing us to preserve the flow for his internal IA. This was not technically challenging and allowed exclusion of flow to his aneurysm. Given his comorbidities and his recently diagnosed cirrhosis, open surgical repair was relatively contraindicated. The other endovascular option for this patient of extension into the external IA was though have greater morbidity and offered no advantage in respect to technical success.

Treatment of “May–Thurner” effect

May–Thurner syndrome is a well-recognized entity, often described as right IA compression of left IV, however, other configurations are possible. It is often associated with lower limb edema, recurrent varicose veins, and unprovoked deep femoral vein thrombosis.

The classic pathophysiological cause for “May–Thurner” has been attributed to direct mechanical compression and pulsatile vibratory pressure from the right CIA, leading to repetitive microtrauma and subsequent endothelial injury of the vein, resulting in the formation of intraluminal spurs, and impeding venous outflow.[5] Treatment of this condition is often through endovenous stent placement, and less commonly, arterial transection and reconstruction.[5],[6]

This patient had an uncommon variation not previously described in the literature to our knowledge; pathological bilateral CIV compression between the right aneurysmal CIA and lumbar vertebrae. Of interest, there was a significant improvement in the lower limb swelling following endovascular exclusion of the aneurysm without the introduction of any diuretics or significant improvement of his serum albumin levels.

Endovascular exclusion does not remove the compressive effect of the aneurysm and does not treat endovenous pathology. It does however significantly reduce transmitted arterial pulsation. This suggests that cyclical arterial pulsation may be of pathophysiological significance in May–Thurner syndrome and should be further investigated.

  Conclusion Top

This case highlights an unusual presentation of May–Thurner syndrome in a patient presenting with large isolated CIA aneurysm. Successful treatment with endovascular occlusion led to the resolution of symptoms while preserving the internal IA flow.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Chaer RA, Barbato JE, Lin SC, Zenati M, Kent KC, McKinsey JF. Isolated iliac artery aneurysms: A contemporary comparison of endovascular and open repair. J Vasc Surg 2008;47:708-13.  Back to cited text no. 1
Wanhainen A, Verzini F, Van Herzeele I, Allaire E, Bown M, Cohnert T, et al. Editor's choice – European Society for Vascular Surgery (ESVS) 2019 clinical practice guidelines on the management of abdominal aorto-iliac artery aneurysms. Eur J Vasc Endovasc Surg 2019;57:8-93.  Back to cited text no. 2
Tsoris A, Marlar CA. Use of the Child Pugh score in liver disease. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2019. Available from: [Last updated on 2019 May 28].  Back to cited text no. 3
Krupski WC, Selzman CH, Floridia R, Strecker PK, Nehler MR, Whitehill TA. Contemporary management of isolated iliac aneurysms. J Vasc Surg 1998;28:1-13.  Back to cited text no. 4
Butros SR, Liu R, Oliveira GR, Ganguli S, Kalva S. Venous compression syndromes: Clinical features, imaging findings and management. Br J Radiol 2013;86:20130284.  Back to cited text no. 5
Harbin MM, Lutsey PL. May-Thurner syndrome: History of understanding and need for defining population prevalence. J Thromb Haemost 2019. doi: 10.1111/jth.14707. [Epub ahead of print].  Back to cited text no. 6


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1]


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