Treatment of Nutcracker Syndrome with Left Renal Vein Transposition and Endovascular Stenting.

BACKGROUND: Nutcracker syndrome is a rare condition that occurs as a result of the entrapment of the left renal vein (LRV) between the aorta and the superior mesenteric artery. It is typically associated with symptoms such as left flank pain, hematuria, proteinuria, and pelvic congestion. The current treatment approach may be conservative in the presence of tolerable symptoms, and surgical or hybrid and stenting procedures in the order of priority in the presence of intolerable symptoms. The aim of this study is to review our experiences to evaluate the results of both methods in this series in which we have a greater tendency toward surgery instead of stenting. METHODS: The clinical data of consecutive patients with nutcracker syndrome who underwent LRV transposition and LRV stenting between July 2019 and October 2023 were retrospectively reviewed. The patients were divided into 2 groups based on the methods of treatment: surgical and stenting. For procedure selection, LRV transposition was primarily recommended, with stenting offered to those who declined. Primary end points were morbidity and mortality. Secondary end points included late complications, patency, freedom from reintervention, and resolution of symptoms. Standard basic statistics and survival analysis methods were employed. RESULTS: Nineteen patients with nutcracker syndrome (female: 100%) were treated with LRV stentings (n = 5) and LRV transposition (n = 14). The mean age was 24 (20-27, interquartile range [IQR]) years. The mean follow-up was 23 (9-32, IQR) months. There were no major complications and mortality after both procedures. The most frequent sign and symptom associated with LRV entrapment were left flank pain 100% (n = 19), proteinuria 88% (n = 15), and hematuria 47% (n = 9). The mean peak velocity ratio on Doppler ultrasound was 6.13 (6-6.44, IQR). Aortomesenteric angle, beak angle (beak sign), and mean diameter ratio on computed tomography were 26° (22.6-28.5, IQR), 25° (23.9-28, IQR), and 5.3 (5-6, IQR), respectively. Venous pressure measurements were only used to confirm the diagnosis in 5 patients in the stenting group. The measured renocaval gradient was 4 (3.9-4.4, IQR) mm Hg. After both procedures, the classical symptoms, including left flank pain, proteinuria, and hematuria, resolved in 89.5% (n = 17), 57.8% (n = 11), and 82.3% (n = 15) of the cases, respectively. A total of 4 patients required reintervention, 3 patients after LRV transposition (occlusion, n = 2; stenosis, n = 1), and 1 patient after stenting (occlusion, n = 1). The 1-year and 3-year primary patency for the 19 patients was 87% and 80%, respectively. Three-year primary-assisted patency was 100%. Similarly, the 1-year and 3-year freedom from reintervention rate was 83% and 72%, respectively. Additionally, the 1-year and 3-year primary patency for the surgical group was 91% and 81%, respectively, and the 1-year and 3-year primary patency for the stenting group was 75%. CONCLUSIONS: Nutcracker syndrome should be kept in mind in cases where flank pain and hematuria cannot be associated with kidney diseases. Radiographic evidence must be accompanied by serious symptoms to initiate the treatment of nutcracker syndrome with LRV transposition and endovascular stenting procedures. Both procedures, along with their respective advantages and disadvantages, can be preferred as primary treatments for nutcracker syndrome. Our study demonstrates that both procedures can be safely and effectively performed, yielding good outcomes.

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.

Síndrome de cascanueces: una causa infrecuente de hematuria / Nutcracker Syndrome: a Rare Cause of Hematuria

La hematuria en pediatría responde habitualmente a etiologías benignas. Una causa poco frecuente es el síndrome de cascanueces, que se define como la compresión de la vena renal izquierda entre la aorta y la arteria mesentérica superior, que deriva en una presión elevada en la vena renal izquierda con el desarrollo de venas colaterales y dilataciones varicosas. La prevalencia de este síndrome se desconoce. Cuando es sintomático ocasiona hematuria, proteinuria y dolor pélvico crónico. En la pubertad, el crecimiento rápido y el desarrollo de los cuerpos vertebrales pueden producir un estrechamiento del ángulo entre la aorta y la arteria mesentérica superior. Se describe el caso de una adolescente con diagnóstico de carcinoma mucoepitelial metastásico óseo múltiple que presenta hematuria anemizante. Se arribó al diagnóstico de síndrome de cascanueces y se discutieron las opciones de tratamiento. Finalmente, con el uso de realce del calzado para corrección de la escoliosis, se atenuó significativamente la hematuria. (AU)

In pediatrics, hematuria usually responds to benign etiologies. A rare cause is nutcracker syndrome, defined as compression of the left renal vein between the aorta and the superior mesenteric artery, resulting in elevated pressure in the left renal vein with the development of collateral veins and varicose dilatation. The prevalence of this syndrome is unknown. When symptomatic, it causes hematuria, proteinuria, and chronic pelvic pain. At puberty, the rapid growth and development of the vertebral bodies can produce a narrowing of the angle between the aorta and the superior mesenteric artery.We describe the case of a teenage girl diagnosed with multiple metastatic mucoepithelial carcinoma of bone who presented anemia-producing hematuria. The diagnosis of nutcracker syndrome was arrived at with consideration of the therapeutic options. Finally, with shoe enhancement for scoliosis correction, hematuria was significantly lessened. (AU)

Nutcracker Syndrome: Challenges in Diagnosis and Surgical Treatment.

BACKGROUND: Nutcracker syndrome (NCS) is an uncommon syndrome that presents with signs and symptoms caused by compression of the left renal vein (LRV), whereas 'nutcracker phenomenon' is solely used to refer to the anatomical configuration without clinical symptoms. Treatment for NCS may include nonoperative management, open surgical intervention, and in some instances endovascular stenting. We present a single-center retrospective case series of patients who presented with NCS managed with open surgical interventions. METHODS: A single-center, retrospective review of patients managed from 2010-2021. We diagnosed NCS via a thorough clinical examination and additional cross-sectional imaging studies including magnetic resonance venography and/or computed tomography venography. For further confirmation of the diagnosis, duplex ultrasound was frequently combined with contrast venography. RESULTS: Thirty eight patients were included in our study from 2010-2021. Twenty one (55.3%) patients presented with symptoms including flank pain, abdominal pain, hematuria, and fatigue. The remaining 17 (44.7%) patients had nutcracker phenomenon. Within the group of patients diagnosed with NCS, 11 patients underwent LRV transposition. Symptoms related to NCS improved in 10 patients. Hematuria in 1 patient did not improve. CONCLUSIONS: Transposition of the LRV is an effective treatment for NCS. Nonoperative management is an option for those patients experiencing less severe or nonspecific clinical symptoms.

Robotic-assisted combined transposition of left renal vein and gonadal vein as a novel treatment option for renal nutcracker syndrome: A case report.

RATIONALE: Renal nutcracker syndrome is a rare phenomenon that often causes various disability symptoms. The treatment protocol has been explored for a long time, but no consensus has been reached. PATIENT CONCERNS: Here, we report the case of a 19-year-old male suffering with nutcracker syndrome, including left-sided flank pain and intermittent gross hematuria. DIAGNOSES: The patient was diagnosed with renal nutcracker syndrome, and the pressure gradient between the left renal vein and inferior vena cava was >5 mm Hg. INTERVENTIONS: The patient underwentrobotic-assisted combined transposition of left renal vein and gonadal vein. OUTCOMES: Flank pain and gross hematuria ceased spontaneously after surgery without occurrence. LESSONS: Robotic-assisted combined transposition of the left renal vein and gonadal vein is a safe and promising option for this condition.

Laparoscopic placement of left renal vein extravascular stenting in treatment of nutcracker syndrome: Techniques and long-term outcomes.

OBJECTIVES: We aimed to assess the feasibility and efficacy of laparoscopic extravascular stent in treatment of nutcracker syndrome by transperitoneal or retroperitoneal approach. METHODS: Seventy-six patients with nutcracker syndrome were retrospectively enrolled from a tertiary referral center, and underwent transperitoneal (63 patients) or retroperitoneal (13 patients) laparoscopic extravascular stent from March 2011 to December 2020. Surgical parameters, complications, imaging and clinical outcomes were collected and analyzed. RESULTS: All procedures were successfully carried out without open conversion. The median operation time, estimated blood loss, and postoperative hospital day were 120 (interquartile range [IQR]: 90-144) min, 20 (IQR: 10-30) ml, and 7 (IQR: 6-9) days. At a median follow-up of 52 (range: 9-127) months, 60 (79%) patients had complete symptom resolution, 14 (18%) patients had significant symptom improvement, and 2 (3%) patients reported no symptom improvement. Ninety-four percent (50/53) of hematuria, 91% (30/33) of proteinuria, and 89% (25/28) of flank/abdominal pain resolved after extravascular LRV stenting. No significant differences were detected in surgery parameters and recovery rates of clinical symptoms between two approaches (each p > 0.05). However, patients with transperitoneal approach need longer to achieve complete recovery compared with retroperitoneal approach (8.7 vs. 1.5 months, p = 0.016). CONCLUSIONS: Laparoscopic extravascular stent performed either transperitoneally or retroperitoneally is a feasible and effective option in treatment of nutcracker syndrome. Retroperitoneal laparoscopic extravascular stent required shorter time to achieve complete recovery, which should be considered whenever possible in surgical decision-making.

SUCCESSFUL RESOLUTION OF NUTCRACKER SYNDROME WITH 3D PRINTED PEEK EXTRAVASCULAR STENT IN AN ADOLESCENT BOY.

Three-dimensional printed polyetheretherketone (PEEK) extravascular stent was applied to treat a 14-year-old boy with nutcracker syndrome. Digital subtraction angiography revealed a segment of the left renal vein (LRV) with reduced contrast filling immediately before its inflow into the inferior vena cava, and high-pressure gradient. The three-dimensional reconstruction model demonstrated that the LRV and the duodenum were contracted at the aortomesenteric angle, resulting in LRV compression from the abnormal high-level duodenal compartment. When duodenum courses between the abdominal aorta and superior mesenteric artery (duodenal interposition), the LRV entrapment occurs even at <90 aortomesenteric degrees. Three-dimensional printed PEEK extravascular stent was chosen to elevate the superior mesenteric artery and lower the duodenum position, thus relieving LRV compression. This extravascular application has significant advantages over open surgery, endovascular stenting and artificial vessel procedures with expanded polytetrafluoroethylene. It provides better cellular vitality by ensuring soft tissue proliferation. By reducing external acceleration and centrifugal force, a three-dimensional printed PEEK extravascular stent reduces adverse side effects. Such a stent has a distinctive personalized design, good stiffness, and durability that allows blood vessel growth, preventing stent migration and thrombosis. Therefore, it is suitable for both adult and pediatric patients. According to the abdominal ultrasound and multi-slice computed tomography scan, the postoperative follow-up results were satisfactory one year after surgery. The patient felt well, the blood flow in the LRV was not obstructed, and the blood flow velocity was average. The external stent was in place.

Nutcracker syndrome in children: Appearance, diagnostics, and treatment - A systematic review.

BACKGROUND: The nutcracker syndrome (NCS) is defined by compression of the left renal vein (LVR) and may present with a wide variety of symptoms. Due to its rarity in pediatric patients, incidence, diagnostics and performed therapy regimen are widely undefined. To this date, there are only case reports and small collectives of pediatric patients described but comprehensive research is lacking. METHODS: A systematic literature research on pediatric NCS was carried out on Medline and Scopus databases according to PRISMA principles using predefined search terms and inclusion criteria. The PROSPERO registered review (CRD42021237415) identified patients' characteristics regarding age, sex, clinical symptoms, applied diagnostic methods and treatment options. RESULTS: In total 47 articles were included. Overall, 423 children (218 boys and 205 girls) with diagnosed NCS were included in the analysis. Mean age was 12.0 (boys 12.9, girls 12.0) years. Hematuria was most common presentation (55.5%), followed by proteinuria (49.9%). Classical flank pain was only detected in 19.1% of patients. Sonographic evaluation was the most commonly used diagnostic tool (99%). Invasive diagnostic studies were performed in 97 children. 86.8% patients were treated conservatively and 94.9% showed complete resolution (42.8%) or at least improvement (52.2%) of symptoms. Type of operative treatment comprised of open surgery with transposition of LRV, endovascular stenting and laparoscopy. CONCLUSIONS: Overall, data quality regarding NCS in children is poor. However, conservative approach in pediatric patients is recommended and should be regarded first treatment option. Diagnostic and treatment should follow a defined algorithm when NCS is suspected. Sufficient observation and follow-up must be assured in all patients to get significant results in this heterogenous syndrome. LEVEL OF EVIDENCE: V-IV.

A Novel Approach for the Treatment of Nutcracker Syndrome: A Case Report.

We describe a case of nutcracker syndrome in a 35 year-old male that was treated with a left renal vein transposition via an open retroperitoneal approach. Our case highlights some of the advantages of the retroperitoneal approach, which may decrease the risk of postoperative complications when compared to the traditional midline abdominal transperitoneal approach. The patient agreed to publish the case details and images included below.

An Uncommon Variant of Nutcracker Syndrome Secondary to Left Renal Vein Compression Between the Right Renal Artery and The Proper Hepatic Artery.

Nutcracker syndrome refers to the compression of the left renal vein between the abdominal aorta and the superior mesenteric artery. The subsequent venous congestion of the left kidney, when symptomatic, could be associated with left flank pain, hematuria, varicocele, dyspareunia, dysmenorrhea, and proteinuria. Here we describe a 42-year-old female patient with simultaneous Dunbar syndrome and a rare variant of nutcracker syndrome in which the left renal vein (LRV) compression is secondary to the unusual path of the vein between the right renal artery and the proper hepatic artery. For both the nutcracker syndrome and the Dunbar syndrome, open approach by median mini-laparotomic access for transposition of LRV, and resection of the diaphragmatic pillars and arcuate ligament was attempted. During the intervention, due to anatomical issues, the LRV transposition was converted to endovascular stenting of the LRV, moreover the implanted stent was transfixed with an external non-absorbable suture to avoid migration. At the 12 months follow-up the patient was asymptomatic, and the duplex scan confirmed the patency of the celiac trunk without re-stenosis and a correct position of the LRV stent with no proximal or distal migration.

Nutcracker syndrome.

This study represents a concise review of Nutcracker syndrome with its history, incidence, clinical presentation and currently available diagnostic criteria and treatment options. This should help any clinician identify and better serve patients with rare venous disorders such as this. Although the literature is scarce, clinicians should be keen to diagnose and treat patients with this potentially debilitating syndrome.

Current results of left gonadal vein transposition to treat nutcracker syndrome.

OBJECTIVE: Nutcracker syndrome can cause disabling chronic pain requiring surgical intervention. At present, data describing a straightforward management approach are lacking. Transposition of the left gonadal vein is one of the surgical therapeutic alternatives. The aim of the present study was to describe our clinical results with gonadal vein transposition. METHODS: All 11 patients from three centers who had undergone left gonadal vein transposition for nutcracker syndrome from 2016 to 2019 were retrospectively included. The surgical cases were mainly selected according to the morphologic criteria of the left gonadal vein. The diameter and length dictated the type of approach (laparotomy or retroperitoneal) and the transposition level. A minimally invasive retroperitoneal approach was preferred. Pain was assessed using a numeric rating scale. RESULTS: We included 11 patients (10 women) with a median age of 35 years (range, 25-69). Preoperative computed tomography angiography showed anterior nutcracker syndrome in 10 patients (91%). All 11 patients had experienced lower back and/or pelvic pain, which was associated with pelvic congestion syndrome in 6 patients (55%) and hematuria in 5 patients (45%). The median preoperative numeric rating scale score for pain was 7.0 (range, 3.5-10.0) and 6.0 (range, 3.5-8.0) for lower back pain and pelvic pain, respectively. At the level of the iliac vein crossing (external or common), the median diameter of the left gonadal vein was 7.87 mm (range, 6.45-11.28). The left gonadal vein was transposed to the inferior vena cava in one case (9%), the left external iliac vein in five (45%), and the left common iliac vein in five cases (45%). The median in-hospital stay was 4 days (range, 2-20 days). Two early complications (18%) requiring surgical revision occurred: one of active bleeding and one hematoma. The median follow-up was 15 months (range, 6-44 months). The median postoperative pain score was 1.0 (range, 0.0-4.0) and 0.0 (range, 0.0-6.0) for lower back and pelvic pain, respectively. Incisional and/or neuropathic pain was noted, with a median score of 3.5 (range, 1.0-6.0) in seven patients (64%). Two late complications (18%) were observed: one case of thrombosis and one case of anastomotic stenosis. The hematuria had disappeared in all patients who had presented with it initially. CONCLUSIONS: Left gonadal vein transposition can be proposed as a first approach if the diameter of the left gonadal vein is sufficient to perform the anastomosis. It is an easily achievable, minimally invasive alternative that achieves satisfactory results without the use of foreign material.

Endovascular management of nutcracker syndrome in an adolescent patient population.

BACKGROUND: Nutcracker syndrome is defined as left renal vein compression with concomitant clinical symptoms that include flank pain and hematuria. Historically, pediatric and adolescent patients with mild symptoms of nutcracker syndrome were simply observed while those with more severe symptoms underwent left renal vein transposition. Endovascular stenting of the left renal vein is a potentially efficacious and less invasive alternative for managing nutcracker syndrome in adolescents. OBJECTIVE: The purpose of this study was to investigate the technical feasibility, efficacy and safety of left renal vein stenting in adolescents with nutcracker syndrome. MATERIALS AND METHODS: We conducted a retrospective review of electronic medical records and imaging archives to identify adolescents undergoing endovascular stenting for nutcracker syndrome. We reviewed patient demographics including age, gender, presenting symptoms and diagnostic imaging findings. We compared pre- and post-stent deployment intravascular ultrasound (IVUS) and venography and evaluated patient symptoms in clinic up to 6 months following stent placement. RESULTS: Ten patients (average age 16 years, range 12-20 years) underwent 13 procedures. Initial symptoms included pain (n=10) and gross hematuria (n=5). Diagnostic imaging studies included CT abdomen pelvis (n=8), retroperitoneal US (n=6), MRI abdomen/pelvis (n=4), scrotal US (n=2), pelvic US (n=1) and renal Doppler US (n=2). Venography and IVUS demonstrated venous collaterals, proximal blanching at the left-renal-vein-IVC junction, pre-stenotic dilation and intraluminal compression. Most patients (n=9) experienced symptomatic resolution; however, three patients required reintervention to achieve asymptomatic status. No periprocedural complications occurred. CONCLUSION: In this carefully selected adolescent cohort, left renal vein stenting for nutcracker syndrome was often technically feasible, safe and effective in symptom management.

CT Angiography of Posterior Nutcracker Syndrome.

Online supplemental material is available for this article.

Gonadal vein transposition is a safe and effective treatment of nutcracker syndrome.

BACKGROUND: Nutcracker syndrome (NCS) is a pelvic venous disorder that results from outflow obstruction of the left renal vein, most often due to a decreased aortomesenteric angle, leading to gonadal vein reflux, pain, and varices. Although a number of open and minimally invasive procedures to treat NCS have been described, the optimal management of this condition remains uncertain. To the best of our knowledge, we have presented the largest case series to date using gonadal vein transposition (GVT) to treat NCS. METHODS: Patients considered for intervention to treat NCS underwent a rigorous and standardized workup, including axial imaging studies, catheter-based diagnostic procedures, and urinalysis. GVT has been the institutional first-line treatment of NCS for appropriate patients. With institutional review board approval, a retrospective review of patients who had undergone GVT for NCS was conducted. RESULTS: From 2014 to 2019, 18 GVTs had been performed. Of the 18 patients, none had died or required reintervention, although 2 had required readmission. During a median follow-up of 178 days, complete symptom relief was achieved in 11 patients (61.1%), with 4 patients (22.2%) reporting partial symptom relief and 2 (11.1%) reporting transient symptom relief. CONCLUSIONS: GVT is a safe and effective procedure to treat NCS in appropriately selected patients with outcomes that compare favorably with those of other described procedures. Appropriate patient selection for this procedure is critical and requires a rigorous and standardized approach to diagnosis and management.

Endovascular treatment of anterior nutcracker syndrome and pelvic varices in a patient with an anterior and a posterior renal vein.

There are few data on endovascular treatment of anterior nutcracker syndrome and pelvic varices in patients with anterior and posterior renal veins. Our objective is to report a case, identify occurrences and compare diagnosis and treatments. A 42-year-old woman presented with flank and pelvic pain and hematuria. She had anterior nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein. A successful complete endovascular approach was done with stent implantation in the anterior renal vein and left gonadal vein embolisation. After 12-month follow-up, the patient remained asymptomatic with good results on CT. Only two case reports of patients with nutcracker syndrome with anterior and posterior renal veins were identified. In both, a self-expanding stent was implanted in the anterior renal vein. In conclusion, endovascular treatment represents a safe and successful option in patients with nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein.

A Case of Nutcracker Syndrome Combined with Wilkie Syndrome with Unusual Clinical Presentation.

BACKGROUND Nutcracker syndrome and Wilkie's syndrome are rare vascular diseases due to the abnormal course of the superior mesenteric artery originating from the abdominal aorta with reduced angle (<22°) and consequent compression of the left renal vein (nutcracker) and duodenum (Wilkie). Here, we report the case of a patient with a rare combination of these 2 syndromes and with unusual clinical manifestation of post-prandial pain. CASE REPORT We describe the case of a young male patient with rapid weight loss, coupled with post-prandial abdominal pain, with sub-acute onset, not associated with other symptoms. The ultrasound examination found an aorto-mesenteric angle of 18° and compression of the left renal vein and left varicocele. A CT study was performed to exclude oncological diseases and/or other pathologies responsible for the pain and weight loss, which confirmed the ultrasound findings and showed compression of the third part of the duodenum. The patient underwent endovascular treatment, with stent placement in the left renal vein, which resolved the vascular compression and of the duodenum, with regression of symptoms. CONCLUSIONS The ultrasound scan promptly highlighted the reduction of the aorto-mesenteric angle and the signs of venous congestion of the left renal vein. Based on this experience, in patients with weight loss and post-prandial pain, in our opinion, diagnostic investigations should also be extended to the study of the aorto-mesenteric angle to confirm or exclude any vascular and/or duodenal compression.