Diagnosis and Surgical Treatment of Nutcracker Syndrome: A Single-Center Experience

Abstract

Conclusion: Left renal vein transposition is an efficient surgical treatment for nutcracker syndrome. In some cases however pelvic pain remains following left renal vein transposition. Summary: The nutcracker syndrome is an unusual problem where the left renal vein is narrowed as it passes between an angle formed between the abdominal aorta and the superior mesenteric artery. This narrowing of the left renal vein can lead to increase venous pressure within the renal circulation and promote development of varices of the renal pelvis and ureter with resulting hematuria. Other symptoms associated with nutcracker syndrome include orthostatic proteinuria, flank pain, left-sided varicocele, pelvic congestion, and chronic fatigue. The authors retrospectively reviewed 23 patients with the diagnosis of nutcracker syndrome treated at their institution from July 1998 to July 2007. Nutcracker syndrome was suspected based on the combination of clinical examination, ultrasound, CT imaging, and MRI imaging. Hematuria was the most common presenting symptom (21 of 23 patients). One patient presented with orthostatic proteinuria and 1 with pelvic congestion syndrome. No patient had renal function deterioration and 13 of 23 undergoing cystoscopy had bleeding noted from the left ureteral orifice. Only 7 underwent transposition of the left renal vein with the indication of transposition being recurrent gross hematuria in 6 patients and persistent orthostatic proteinuria in 1 patient. Sixteen patients who had more mild symptoms were followed without operation. Patients with microscopic hematuria or intermittent short periods of painless gross hematuria were followed closely without treatment. Patients with flank or abdominal pain were treated with low-dose aspirin treatment. Four women with pelvic congestion syndrome were treated with medroxyprogesterone acetate. Patients undergoing left renal vein transposition did so through a mid-line abdominal incision with mobilization of the left colon and small bowel to give access to the retroperitoneum. The inferior adrenal vein, ovarian/testicular vein, and the lumbar vein draining into the left renal vein were ligated and transected. The left renal vein was excised with the small rim of vena cava and injected with heparin. Reanastomosis was then performed to a more caudad portion of the inferior vena cava. All 7 patients treated with renal vein transposition had normal pre-operative creatinine levels with no increase following renal vein transposition. Hematuria and proteinuria ceased spontaneously 5 to 14 days following surgery with no clinical relapses. Of the 16 patients treated conservatively, clinical improvement occurred in 11 with total relief of symptoms in 2 patients and partial relief in 9 patients. There was no relief of symptoms in 5 patients following a mean follow-up of 41.2 months. Comment: The pressure gradient between the left renal vein near the renal hilum is normally between 0 and 1 mmHg (J Urology 1982; 127: 1070-1071). An elevated gradient of more than 3 mmHg between the left renal vein and the vena cava is used as a criteria to diagnose nutcracker syndrome. All patients in this series had such a gradient. The study indicates that left renal vein transposition works well to alleviate symptoms in patients with nutcracker syndrome and elevated renal vein IVC pressure gradients. Equally important is that patients with mild symptoms do well treated conservatively. It would appear reasonable to reserve surgical treatment of nutcracker syndrome to those patients with recurrent gross hematuria or persistent orthostatic proteinuria who are not responsive to conservative management. The authors also point out that children and adolescents can have nutcracker syndrome that will frequently resolve as the child matures into adulthood. Surgical treatment of nutcracker syndrome in children and adolescents therefore, in most cases, should be avoided.