Douglas Smoot Lewis MD, Presenter: Nothing to Disclose

Lars J. Grimm MD, Abstract Co-Author: Advisory Board, Medscape, LLC

Charles Yoon Kim MD, Abstract Co-Author: Consultant, CareFusion Corporation Research Grant, Galil Medical Ltd Consultant, Kimberly-Clark Corporation Consultant, Cryolife, Inc

While numerous etiologies for varicocele formation have been proposed, none have been well-proven. The purpose of this study was to determine the contribution of left renal vein compression in patients with varicocele. 

Using a radiology report search engine, all contrast-enhanced CT scans and ultrasound examinations performed at our institution over the past 10 years with a diagnosis of varicocele were identified. Patients were included only if they had a concurrent contrast-enhanced CT scan. Analysis was performed on 101 male patients (mean age 50.3 years). On CT, the left renal vein (LRV) was analyzed for greater than 50% compression by the SMA (nutcracker morphology) or any other structures. As a control group, 99 asymptomatic patients undergoing contrast-enhanced CT as potential renal transplant donors were analyzed.

A varicocele was identified on the left in 68 patients, right in 9 patients, and bilaterally in 24 patients. Compression of the left renal vein was identified significantly more commonly in patients with a left varicocele (78%) compared to patients with a right (13%, p<0.001) or bilateral (42%, p=0.002) varicocele. 64% of left renal vein compressions were due to nutcracker morphology and 36% were due to a retroperitoneal lymph node, most commonly due to pancreatic or renal cell carcinoma. In total, LRV compression by a lymph node was found in 30% of left-sided varicoceles. Excluding patients with retroperitoneal lymphadenopathy, the prevalence of nutcracker morphology was significantly higher for patients with left-sided varicocele (69%) compared to the control group (27%, p<0.001), whereas the prevalence of nutcracker morphology in patients with right (13%) or bilateral (33%) varicocele was similar to controls.

Left renal vein compression by the SMA or a mass was significantly more common in isolated left-sided varicoceles compared to right-sided and bilateral varicoceles in this predominantly adult population. Furthermore, nutcracker phenomenon was identified significantly more commonly in patients with a left-sided varicocele compared to an asymptomatic control group. 

Both nutcracker morphology and malignant lymph nodes are significantly associated with isolated left-sided varicoceles, suggesting that attention on imaging is likely warranted. 

Lewis, D, Grimm, L, Kim, C, Left Renal Vein Compression as Cause for Varicocele: Prevalence and Associated Findings on Contrast-enhanced CT.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019327.html