Imaging of venous compression syndromes

Abstract

Venous compression syndromes are a unique group of disorders characterized by anatomical extrinsic venous compression, typically in young and otherwise healthy individuals. While uncommon, they may cause serious complications including pain, swelling, deep venous thrombosis (DVT), pulmonary embolism, and post-thrombotic syndrome. The major disease entities are May-Thurner syndrome (MTS), variant iliac vein compression syndrome (IVCS), venous thoracic outlet syndrome (VTOS)/Paget-Schroetter syndrome, nutcracker syndrome (NCS), and popliteal venous compression (PVC). In this article, we review the key clinical features, multimodality imaging findings, and treatment options of these disorders. Emphasis is placed on the growing role of noninvasive imaging options such as magnetic resonance venography (MRV) in facilitating early and accurate diagnosis and tailored intervention.

Keywords: May-Thurner syndrome (MTS); Venous compression; magnetic resonance venography (MRV); nutcracker syndrome (NCS); thoracic outlet syndrome (TOS).

Figure 1

May-Thurner and nutcracker syndromes. A 31-year-old woman with pelvic pain increasing over 2 months. Grayscale pelvic ultrasound image (A) shows multiple tubular hypoechoic structures (arrows) adjacent to the uterus, suspicious for varices. Contrast-enhanced MR (B-E) confirms the pelvic varices (B, arrows) and demonstrates marked compression of the left common iliac vein (C, arrow) by the right common iliac artery (C, bent arrow), consistent with May-Thurner anatomy. There is also compression of the left renal vein (D, arrow) between the abdominal aorta (D, bent arrow) and superior mesenteric artery (D, asterisk), consistent with nutcracker left renal vein anatomy. Note also the reflux of contrast into a dilated left gonadal (ovarian) vein (C, asterisk and E, arrow). Conventional venography (F,G) was subsequently performed confirming extrinsic compression on the left common iliac vein (F, arrow) with multiple cross-pelvic collaterals. The left gonadal vein is dilated (G, arrow), and there is mild narrowing of the left renal vein. The patient underwent stenting of the left common iliac vein and gonadal vein coil embolization with decrease in pelvic varices on follow-up ultrasound.

Figure 2

Variant iliac vein compression syndrome. A 63-year-old man with left retinal embolic stroke and patent foramen ovale. MRV was requested to evaluate for May-Thurner anatomy. Contrast-enhanced MR images (A,B) demonstrate marked compression of the left common iliac vein (A, arrow) by the left common iliac artery (A, asterisk) and milder compression of the right common iliac vein (A, bent arrow) by the right common iliac artery (A, double asterisks). There are multiple pelvic collaterals (B, arrows), raising suspicion for hemodynamically significant compression. MRV, magnetic resonance venography.

Figure 3

Extrinsic iliac vein compression from lymphadenopathy. A 46-year-old woman with right leg pain and swelling and history of strokes. Ultrasound images of the bilateral lower extremity deep veins with Doppler (A,B) demonstrate no evidence of thrombus. However, the right common femoral venous waveform (A) is abnormal, more continuous than expected with lack of augmentation response compared to the opposite side (B, arrow). These findings raise concern for a more proximal extrinsic venous compression. Non-contrast MR (C,D) was then performed, showing inferior vena cava (IVC) compression (C, arrow) between enlarged retroperitoneal lymph nodes (asterisks). Time-of-flight imaging reveals a signal void in the IVC, indicating partial reversal of flow/transient venous reflux. Subsequent CT-guided biopsy of the retroperitoneal lymphadenopathy revealed metastatic disease from an occult urothelial carcinoma.

Figure 4

Venous thoracic outlet/Paget-Schroetter syndrome. A 15-year-old girl, occasional weightlifter, and previous oral contraceptive user, with 1 week of right arm pain. Ultrasound image of the right upper extremity veins with Doppler (A) shows extensive occlusive thrombus (arrow), which extended from the right subclavian vein to the right brachial vein and into multiple superficial veins. Contrast-enhanced MR image (B) shows expansion of the right subclavian and axillary veins with low signal intensity material representing thrombus (arrow). There is also thrombus within superficial veins. Conventional right upper extremity venography (C) confirms extensive right upper extremity deep venous thrombus (arrow) with collaterals. The patient underwent catheter-directed thrombolysis of the clot followed by transaxillary first right rib resection to decompress the thoracic outlet.

Figure 5

Nutcracker phenomenon. A 85-year-old woman with chest pain, elevated troponin, and a history of fibromuscular dysplasia undergoing CTA to exclude significant coronary stenosis or aortic dissection. Axial CTA image (A) demonstrates focal abrupt narrowing (arrow) of the left renal vein as it passes between the abdominal aorta and SMA, consistent with nutcracker anatomy. Axial (B) and coronal MIP-reformatted (C) CTA images show dense and likely refluxed contrast within a dilated left gonadal vein (arrow) on this arterial phase acquisition. Although the presence of collaterals should raise concern for hemodynamic significance, the patient had no symptoms attributable to these presumed incidental findings, which had been stable on review of a remote prior scan. Therefore, no further management was pursued. SMA, superior mesenteric artery.

Figure 6

Popliteal venous compression. A 38-year-old man with left leg heaviness and intermittent cramping. MR was requested to evaluate for popliteal artery entrapment. Initial contrast-enhanced MR image (A) shows a widely left patent popliteal vein (arrow) and popliteal artery (bent arrow), adjacent to the medial head of gastrocnemius muscle (asterisk). Subsequent contrast-enhanced MR image performed with plantar flexion provocative maneuver (B) now shows a slit-like left popliteal vein (arrow) compressed against the gastrocnemius (asterisk). The left popliteal artery (bent arrow) remains widely patent.