The Journey and Barriers to Treatment of Patients with Renal Nutcracker Syndrome

Renal autotransplant as a definitive treatment for nutcracker syndrome: A multicenter retrospective study

OBJECTIVE

Nutcracker syndrome is a rare condition that involves mechanical compression of the left renal vein, leading to chronic and debilitating left flank pain. The etiology of the pain is misdiagnosed frequently, and patients usually require long-term opioid use to manage their pain. Multiple therapeutic options for nutcracker syndrome have been described in the literature but the reports are limited by small numbers of patients, and the lack of convincing data demonstrating consistently improved outcomes. Here we report the largest series to date of patients undergoing renal autotransplantation for the treatment of nutcracker syndrome.

METHODS

We performed a multicenter retrospective cohort review of patients 105 patients with nutcracker syndrome who underwent renal autotransplantation as a primary or salvage therapy.

RESULTS

During the overall study period, 93.1% of patients treated with autotransplantation had durable, complete flank pain relief at 12 months with both open and robotic surgical approach. After autotransplantation, a statistically significant decrease in the percentage of patients using opioids from 48.6% to 17.0% was demonstrated at 12 months. In those patients using opioids before autotransplantation, a statistically significant decrease in morphine milligram equivalents was demonstrated from an alarming 68.9 ± 15.0 per day to 25.0 ± 11.02 morphine milligram equivalents per day.

CONCLUSIONS

Our findings suggest that renal autotransplantation, as a primary treatment or a salvage treatment, in patients with nutcracker syndrome provides durable pain relief and a marked decrease in chronic opioid use regardless of surgical approach.

Patient-Reported Outcomes for Robot-Assisted Laparoscopic Extravascular Renal Vein Stent Placements for Nutcracker Syndrome

Introduction: Nutcracker phenomenon is the compression of the left renal vein between the superior mesenteric artery (SMA) and the abdominal aorta. Nutcracker syndrome refers to the presence of nutcracker phenomenon with symptoms. Between 2016 and 2022, we performed 18 robot-assisted laparoscopic extravascular renal vein stent (RALERVS) placements. We sought to assess patient-reported outcomes of RALERVS placement by a single institution. Methods: We performed a single-center retrospective review of 18 patients with a minimum of 3 months follow-up. Symptoms were assessed utilizing a questionnaire conducted with a 5-point Likert scale at a minimum of 3 months postoperatively. Five on the Likert scale was severe while 1 was none. Primary study outcomes compared pre- and postoperative patient-reported symptom scores. Results: Twelve out of 18 patients responded to the survey. The average length of time from date of operation to completion of survey was 2.6 years. Average age of the cohort was 36 years with a mean BMI of 19.4 kg/m2. There was only one man. Mean operative time was 137 minutes and mean estimated blood loss was 12 mL. Mean preoperative SMA angle was 19° and mean postoperative SMA angle was 36°. Patients reported that flank pain, abdominal pain, nausea, headaches, back pain, pelvic pain, and early satiety improved (p < 0.05). Ten of 12 respondents would recommend RALERVS for nutcracker syndrome. Conclusion: RALERVS demonstrates an effective treatment for nutcracker syndrome. Patients reported improved symptoms at 3 months postoperatively across multiple domains. Further studies need to be conducted to assess long-term durability of the extravascular renal vein graft.