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.

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.

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.

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.

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.

CT Angiography of Posterior Nutcracker Syndrome.

Online supplemental material is available for this article.

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.

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.

Robot-Assisted Laparoscopic Left Renal Vein Transposition for the Treatment of Nutcracker Syndrome: A Preliminary Experience.

BACKGROUND: The aim of this study was to describe our robot-assisted laparoscopic left renal vein (LRV) transposition experiences for nutcracker syndrome treatment. METHODS: From August 2016 through May 2017, three patients with nutcracker syndrome underwent robot-assisted laparoscopic LRV transpositions. The patient demographics, surgical outcomes, and postoperative morbidities were reviewed. RESULTS: Successful surgical procedures were performed in all three patients. The operative times for the three cases were 150, 175, and 162 minutes, respectively, while the LRV anastomosis times were 19, 22, and 13 minutes, respectively. No major perioperative complications were encountered, and the hematuria and flank pain were resolved in all three cases. At the 6-month follow-up, the computed tomography scan showed that the LRV narrowing had disappeared in two of the patients. Although one patient still exhibited LRV flattening, his symptoms were also relieved, and the varicose tributaries spontaneously ceased. CONCLUSIONS: Robot-assisted laparoscopic LRV transposition can be a viable minimally invasive treatment option for patients with nutcracker syndrome.

Gonadal Vein Transposition in Nutcracker Syndrome.

BACKGROUND: Nutcracker syndrome, caused by mesoaortic compression of the left renal vein leading to symptoms related to venous hypertension, is an uncommon entity that may require operative intervention. Traditional open transposition of the left renal vein to the vena cava has been shown to have a reintervention rate of up to 30%, while also having additional morbidity associated with laparotomy. More recently, endovascular stenting has been described in several small series but have reported stent fracture, thrombosis, and migration. METHODS: We report the case of a 26-year-old woman with 4 months of intermittent flank pain and hematuria, diagnosed with nutcracker syndrome by both duplex ultrasound and axial based imaging. RESULTS: The patient underwent catheter venography confirming left renal vein compression, which also demonstrated a dilated gonadal vein measuring 11 mm leading to significant pelvic varices. Through a left lower quadrant retroperitoneal exposure, the gonadal vein was transposed to the left common iliac vein with completion venography demonstrating relief of renal venous congestion. The patient was discharged uneventfully with immediate resolution of symptoms and remains symptom-free at 6-month follow-up. CONCLUSIONS: Gonadal vein transposition is an effective alternative surgical treatment for nutcracker syndrome.

Nutcracker Syndrome: An Update on Current Diagnostic Criteria and Management Guidelines.

BACKGROUND: Nutcracker syndrome (NCS) describes left renal vein compression between the superior mesenteric artery and the aorta. Although uncommon, it is an important diagnosis due to the important morbidity associated with it, including the risk of chronic kidney disease from long-term left renal vein (LRV) hypertension and the risk of LRV thrombosis. METHODS: This article reviews the literature on NCS, particularly with respect to the diagnostic accuracy of different imaging modalities and the success rates, complications, and long-term follow-up data associated with various surgical interventions. RESULTS AND DISCUSSION: The diagnosis of this condition is based on a stepwise work-up with history and clinical examination, followed by Doppler ultrasonography, computed tomography, magnetic resonance imaging, intravascular ultrasound (IVUS) and phlebography with measurement of the renocaval pressure gradient. Management is determined by symptom severity; often symptom resolution occurs following a conservative approach. However, in some cases, surgical management is required, particularly when conservative management is unsuccessful. When it comes to the surgical management of NCS three main pathways exist: open surgery, laparoscopic surgery and endovascular approaches, with the latter 2 becoming increasingly popular due to their minimal invasiveness. Additionally, cases involving the use of robotic surgery in the management of NCS have been reported. CONCLUSION: Despite the rarity of NCS, its recognition and management are important. This article has explored the evidence basis for conservative, medical and surgical options.

Surgically Treated Pelvic Pain Caused by Nutcracker Syndrome and Worsened by Cockett Syndrome in a Child.

Nutcracker syndrome is rarely seen in the young. Most of the symptoms regress during follow-up. Rarely surgical intervention is necessary. This case presentation is unique for being the first case of nutcracker syndrome and coexistent Cockett syndrome that is treated with surgical intervention.

Nutcracker Syndrome: laparoscopic external stenting of the renal vein (″the shield technique″).

Nutcracker syndrome refers to the complex of clinical symptoms caused by the compression of the left renal vein (LRV) between the abdominal aorta and the superior mesenteric artery, leading to stenosis of the aortomesenteric portion of the LRV and dilatation of the distal portion. Hematuria, proteinuria, flank pain, varicocele and pelvic congestion may occur, occurring more frequently in young adults. Conservative management, might be the option whenever it is possible. When surgical treatment is required, classically open surgery have been performed, with major surgeries as LRV transposition or bypass techniques. The main caveats regards the fact that these are large and risky surgeries. Endovascular surgery with venous stent placement has gained some space as it is minimally invasive alternative. However, venous stents are associated with a high number of trombotic complications and in many cases requirement of life-long anticoagulants. External stenting of the LRV with this "shield technique" is a minimally invasive alternative, with good medium term results. We herein demonstrate our second experience with the technique of this surgery in a patient with 12 months of follow up and excellent results.

[Microscopic spermatic vein ligation for nutcracker phenomenon complicated with left varicocele].

OBJECTIVE: To investigate the clinical effect of microscopic spermatic vein ligation in the treatment of nutcracker phenomenon (NCP) complicated with left varicocele (VC). METHODS: This retrospective study included 31 cases of NCP complicated with left VC treated in our hospital by subinguinal microscopic ligation of the left spermatic vein (group A, n = 11), open retroperitoneal high ligation of the left spermatic vein (group B, n = 11), or conservative therapy (group C, n = 9). The patients were followed up for 6－24 (15.3 ± 5.4) months. We compared the semen parameters, spermatic vein diameter, left testis volume, and recurrence rate among the three groups of patients before and after treatment. RESULTS: Compared with the baseline, the semen quality parameters were significantly improved in both groups A and B at 6 months after treatment (P<0.05) but reduced in group C (P<0.05); the spermatic vein diameter at rest and that at Valsalva maneuver were markedly decreased in groups A (ï¼»2.53 ± 0.27ï¼½ vs ï¼»1.84 ± 0.22ï¼½ and ï¼»3.53 ± 0.19ï¼½ vs ï¼»2.16 ± 0.25ï¼½ mm, P<0.05) and B (ï¼»2.62 ± 0.33ï¼½ vs ï¼»2.15 ± 0.43ï¼½ and ï¼»3.36 ± 0.25ï¼½ vs ï¼»2.44 ± 0.27ï¼½ mm, P<0.05) but increased in group C (ï¼»2.56 ± 0.28ï¼½ vs ï¼»2.94 ± 0.24ï¼½ and ï¼»3.33 ± 0.21ï¼½ vs ï¼»3.77 ± 0.26ï¼½ mm, P<0.05). No statistically significant differences were found in the left testis volume at 6 months after treatment in group A (ï¼»9.85 ± 1.86ï¼½ vs ï¼»10.27 ± 1.18ï¼½ ml, P>0.05), B (ï¼»9.77 ± 2.03ï¼½ vs ï¼»9.96 ± 1.72ï¼½ ml, P>0.05), or C (ï¼»9.83 ± 1.59ï¼½ vs ï¼»10.48 ± 2.05ï¼½ ml, P>0.05), nor in the recurrence rate between groups A and B (P>0.05). CONCLUSIONS: Hematuria, proteinuria and other mild symptoms of nutcracker phenomenon complicated with left VC can be treated palliatively by microscopic ligation of the spermatic vein, which can relieve the clinical symptoms, improve the semen quality, and protect the testicular function of the patient.

Laparoscopic Left Renal Vein Transposition for Nutcracker Syndrome.

The left renal vein (LRV) reimplantation into the distal inferior vena cava is considered to be the gold standard of care for symptomatic nutcracker syndrome (NCS). The vast majority of these surgical procedures are performed by open surgery. Experiences with minimally invasive laparoscopic surgery in this field are very limited. We present a case of a 17-year-old boy with NCS in whom the transposition of the LRV was done laparoscopically. The patient suffered from left flank pain, painful left-sided varicocele, microscopic hematuria, proteinuria, and oligoasthenospermia. There were no intraoperative complications, and the postoperative course was uneventful. At 12-month follow-up, hematuria, left flank pain, and left testicular pain resolved. Duplex ultrasonography revealed patent LRV. Laparoscopic LRV transposition appears to be safe, feasible, and has favorable postoperative course.

Laparoscopic inferior mesenteric to gonadal vein end-to-side bypass: a new attempt for nutcracker syndrome treatment.

The nutcracker syndrome (NCS) is because of the compression of the left renal vein when it passes between the aorta and the superior mesenteric artery. The treatment of NCS is controversial, and conservative, endovascular stent implantation, open surgical, and laparoscopic treatments have been previously described. In this study, we present a new method of conducting end-to-side anastomosis between the inferior mesenteric and left gonadal vein. The proposed method was proven feasible for treating NCS.

Late stent migration into the right ventricle in a patient with nutcracker syndrome.

BACKGROUND: Stent migration into the right ventricle is rare in patients treated with endovenous stenting, but can have potentially serious complications including endocarditis, cardiac arrhythmias, and heart failure. METHODS: We present a case of stent migration into the right ventricle 5 months after stent placement in a patient with nutcracker syndrome. RESULTS: Echocardiography revealed a stent caught within the subvalvular chordal structures, with significant tricuspid regurgitation. Subsequent severe damage to the tricuspid apparatus necessitated prosthetic valve replacement, as tricuspid valvuloplasty failed after stent removal. CONCLUSIONS: Because stent migration is a potential complication in left renal vein stenting that can occur up to 5 months after intervention therapy, follow-up using ultrasonography is necessary. In addition, knowing the precise location of the stent, which is important for subsequent treatment, is essential when transabdominal ultrasonography reveals the absence of the stent in the left renal vein.