The nutcracker syndrome: Its role in the pelvic venous disorders

Background: Symptoms of pelvic venous congestion (chronic pelvic pain, dyspareunia, dysuria, and dysmenorrhea) have been attributed to massive gonadal reflux. However, obstruction of the gonadal outflow may produce similar symptoms. Mesoaortic compression of the left renal vein (nutcracker syndrome) produces both obstruction and reflux, resulting in symptoms of pelvic congestion. We describe the diagnosis and management of nine patients studied in our institutions. Materials and Methods: From a group of 51 female patients with pelvic congestion symptoms studied at our institutions, there were nine patients with symptoms of pelvic congestion, microscopic hematuria, and left-sided flank pain. The diagnosis of the nutcracker syndrome was suspected based on clinical examination, Doppler scan, duplex ultrasound scan, computed tomography scan, and magnetic resonance imaging. The diagnosis was confirmed by retrograde cine-video-angiography with renocaval gradient determination and catheterization of both internal iliac venous systems. All patients had a renocaval pressure gradient >4 mm Hg (normal, 0-1 mm Hg). Renal compression was relieved by external stent (ES) in two patients, internal stent (IS) in one patient, and gonadocaval bypass (GCB) in three. GCB was preceded by coil embolization of internal iliac vein tributaries connecting with lower-extremity varicose veins in three patients. Three patients deferred surgery and are under observation. Mean follow-up time was 36 months (range, 12-72 months). Results: Hematuria disappeared postoperatively in all patients. ES and IS normalized the renocaval gradient and resulted in significant alleviation of symptoms (90% improvement on a scale of 0-10 where 0 = no improvement and 10 = greatest improvement). Two patients with GCB had a residual gradient of 3 mm Hg. The third patient normalized the gradient. In this group, improvement of symptoms was 60%. Patients awaiting surgery are being treated conservatively (elastic stockings, hormones, and pelvic compression). They have shown only moderate improvement. Conclusion: The nutcracker syndrome should be considered in women with symptoms of pelvic venous congestion and hematuria. The diagnosis is suspected by compression of the left renal vein on magnetic resonance imaging or computed tomography scan and confirmed by retrograde cine-video-angiography with determination of the renocaval gradient. Internal and external renal stenting as well as gonadocaval bypass are effective methods of treatment of the nutcracker syndrome. IS and ES were accompanied by better results than GCB. Surgical and radiologie interventional methods should be guided by the clinical, radiologic, and hemodynamic findings.