Monocentric prospective study to valid multidisciplinary diagnostic and therapeutic approach for Nutcracker syndrome

Background: Nutcracker syndrome (NCS) is defined as left renal vein (LRV) compression by the superior mesenteric artery. NCS diagnosis is rendered complex by confounding symptoms. The study objective was to perform a prospective observational analysis of the diagnostic and therapeutic criteria of the patients with suspected NCS. When NCS diagnosis was confirmed, transposition of the LRV was carried out by mini-invasive robotic surgery (MIRS). Method: All patients addressed to the vascular surgery department for suspicion of NCS between January 2022 and June 2023 were included in the study. Patients were subsequently assessed by means of a computed tomography scan, dynamic duplex ultrasound and phlebography associated with an occlusion test of the left gonadic vein (LGV). Diagnostic criteria included aorto-mesenteric angle, LGV diameter and reflux, velocity ratios and diameters and the reno-caval gradient. Result: Thirty two patients aged 37 ± 14 years had suspicion of NCS. Twenty presented an aorto-mesenteric angle below 20°, twenty three had a LGV diameter greater than 5 mm and twenty two of the latter patients also had LGV reflux. A significant reno-caval gradient greater than 5 mmHg was found in ten cases, thereby consolidating NCS diagnosis. Overall, thirteen patients neither presented NCS or pelvic varicosities; eight had pelvic congestion syndrome without NCS and were successfully treated by embolization. Eleven patients with confirmed NCS underwent LRV transposition in the inferior vena cava (IVC). Eight of the latter patients received a complementary pelvic varicosity embolization 2 days later. Two months post-operation 100% of transposed LRV were permeable as assessed by duplex ultrasound controls and all of these patients reported an improvement of symptoms. Conclusion: An innovative multidisciplinary decisional algorithm establishes certitude in NCS diagnosis which can subsequently be treated radically by MIRS.