Nutcracker syndrome: a case-based review

The nutcracker phenomenon, also known as left renal vein entrapment, occurs when there is extrinsic compression of the left renal vein, most often between the abdominal aorta and the superior mesenteric artery. Nutcracker syndrome refers to the constellation of clinical symptoms that may arise from the nutcracker phenomenon, typically inclusive of haematuria, flank/pelvic pain, orthostatic proteinuria and (in male patients) varicocele. We provide a short review of the nutcracker syndrome including various diagnostic and therapeutic modalities. We utilise our own experience with a patient as a case study and highlight the modern management option of endovascular stenting.

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.

Using the Resected Kidney for Transplantation After Nephrectomy for Nutcracker Syndrome

Nutcracker syndrome (NCS) is the clinical manifestation of unilateral renal venous hypertension. It develops secondary to the nutcracker phenomenon caused by compression of the left renal vein between the superior mesenteric artery and the aorta. We present the case of a 43-year-old female with a history of left flank pain, pelvic congestion, and hematuria secondary to NCS. The patient frequently required high-dose non-steroidal anti-inflammatory medications with minimal relief. She initiated a kidney donor evaluation after electing to undergo a nephrectomy for the possible long-term resolution of NCS symptoms. If diagnosed early, NCS does not generate pathology within the kidney. This finding allows an individual with medically refractory NCS to avoid the morbidity of a complex surgical procedure by instead donating their kidney. Attention to this treatment modality could provide individuals with NCS resolution of symptoms while providing someone with end-stage renal disease with a life-saving organ.

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.

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.

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.

A minimally invasive alternative for the treatment of nutcracker syndrome using individualized three-dimensional printed extravascular titanium stents

BACKGROUND

This study was designed to evaluate the clinical and radiographic outcomes of patients with nutcracker syndrome (NCS) who were treated with three-dimensional printing (3DP) extravascular titanium stents (EVTSs). The 3DP EVTS was expected to release the hypertension of the left renal vein (LRV) produced by its compression between the superior mesenteric artery (SMA) and the aorta without causing any complications.

METHOD

The pre-operative kidney model of each patient was printed out to enable surgical planning. After that, the EVTS was designed based on the LRV's primitive physiologic structure using computer-aided design software, and each stent was printed out with a precision setting of 20 μm. Seventeen patients who had been suffering from NCS underwent laparoscopic 3DP EVTS placement. The surgical procedure was designed for the placement of EVTS, taking great care in positioning and fixing the stent. Surgical data, which included patient demographic characteristics as well as pre- and post-operative test results, were collected and analyzed.

RESULTS

The mean duration of surgery was 75 ± 9 min, and the mean blood loss was 20 ± 5 mL. Computed tomography examinations revealed that the pre- and post-operative angle between the SMA and the aorta ranged from 18.7° ± 4.3° to 48.0° ± 8.8° (P < 0.05); in patients with left varicocele, the mean diameter of the left spermatic vein ranged from 3.7 ± 0.5 to 1.3 ± 0.2 mm (P < 0.05). Moreover, Doppler ultrasound examinations showed that the peak velocity of blood flow at the hilar area ranged from 12.4 ± 3.3 to 18.5 ± 3.4 cm/s (P < 0.05). No side effects were observed in the 24 to 42 months following surgery.

CONCLUSION

The findings after 2 years of follow-up suggest that the 3DP EVTS is a safe and effective minimally invasive alternative for the treatment of NCS.

Co-occurring superior mesenteric artery syndrome and nutcracker syndrome requiring Roux-en-Y duodenojejunostomy and left renal vein transposition: a case report and review of the literature

BACKGROUND

The duodenum and the left renal vein occupy the vascular angle made by the superior mesenteric artery and the aorta. When the angle becomes too acute, compression of either structure can occur. Each type of compression is associated with specific clinical symptoms that constitute a rare disorder. If clinical symptoms are mild, conservative treatment is implemented. However, surgery is often the only solution that can improve quality of life and/or avoid life-threatening complications. This report describes a case of a patient with both types of aortomesenteric compression that required two separate surgeries to alleviate all symptoms.

CASE PRESENTATION

A 20-year-old white woman presented to the Emergency Room complaining of sudden onset severe left flank and lower left quadrant abdominal pain, nausea, and vomiting. A clinical work-up revealed elevated white blood cells and hematuria. She was discharged with a diagnosis of urinary tract infection. Symptoms continued to worsen over the subsequent 2 months. Repeated and extensive clinical work-ups failed to suggest evidence of serious pathology. Ultimately, an endoscopy revealed obstruction of her duodenum, and barium swallow identified compression by the superior mesenteric artery, leading to the diagnosis of superior mesenteric artery syndrome. She underwent a Roux-en-Y duodenojejunostomy. Six weeks later she continued to have severe left-sided pain and intermittent hematuria. Venography revealed compression of the left renal vein, extensive pelvic varices, and significant engorgement of her left ovarian vein. A diagnosis of nutcracker syndrome was made and a left renal vein transposition was performed. Significant improvement was seen after 8 weeks.

CONCLUSIONS

The disorders associated with aortomesenteric compression can lead to serious symptoms and sometimes death. Diagnosis is challenging not only because of the lack of awareness of these rare disorders, but also because they are associated with symptoms that are similar to those seen in less serious diseases. Guidance for health care professionals with respect to relevant radiological and clinical markers needs to be reconsidered in order to clarify the etiology of the diseases and create better diagnostic protocols.

[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 (［2.53 ± 0.27］ vs ［1.84 ± 0.22］ and ［3.53 ± 0.19］ vs ［2.16 ± 0.25］ mm, P<0.05) and B (［2.62 ± 0.33］ vs ［2.15 ± 0.43］ and ［3.36 ± 0.25］ vs ［2.44 ± 0.27］ mm, P<0.05) but increased in group C (［2.56 ± 0.28］ vs ［2.94 ± 0.24］ and ［3.33 ± 0.21］ vs ［3.77 ± 0.26］ mm, P<0.05). No statistically significant differences were found in the left testis volume at 6 months after treatment in group A (［9.85 ± 1.86］ vs ［10.27 ± 1.18］ ml, P>0.05), B (［9.77 ± 2.03］ vs ［9.96 ± 1.72］ ml, P>0.05), or C (［9.83 ± 1.59］ vs ［10.48 ± 2.05］ 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.

Diagnosis and successful surgical management of posterior nutcracker syndrome in a patient with loin pain hematuria

The syndrome of loin pain hematuria in the absence of stones is poorly understood but must be considered in the differential diagnosis for patients with clinical manifestations resembling nephrolithiasis. A 22-year-old white female with a 4-year history of left flank pain and hematuria underwent an extensive workup with normal renal ultrasound and cystourethroscopies. CT scan and MRI revealed a retro-aortic left renal vein. Posterior nutcracker syndrome was considered the most likely diagnosis. The patient underwent a left laparoscopic nephrectomy with auto-transplantation in the right iliac fossa. She developed azotemia shortly after, which resolved and since then has become asymptomatic.

Laparoscopic inferior mesenteric-gonadal vein bypass for the treatment of nutcracker syndrome

Nutcracker syndrome is a rare entity caused by extrinsic compression on the left renal vein (LRV) crossing between the superior mesenteric artery and the aorta. This article reports the treatment of two cases of nutcracker syndrome using laparoscopic inferior mesenteric-gonadal vein bypass, knowing that this treatment option would avoid renal reperfusion injury and LRV hypertension. In addition, it is easier to operate compared with laparoscopic splenorenal venous bypass and laparoscopic transposition of LRV into the inferior vena cava.

Endovascular stent placement for nutcracker phenomenon

The nutcracker syndrome is a rare clinic condition associated with severe hematuria and left flank pain due to the entrapment of the left renal vein between the superior mesenteric artery and the aorta. Its diagnostic criteria are not well defined, often causing delayed or misdiagnosis. Although surgical repair has been the standard of care, more recently endovascular stenting of the renal vein has been proposed. We presented six patients (aged 7 to 31 years old; median age, 16.5 years old) with nutcracker syndrome who were endovascularly managed from June 2002 to July 2011. All patients underwent laboratory test and computed tomography (CT) or ultrasound examination before and after endovascular procedures. Self-expandable stents were successfully placed in all cases. The diameter of the left renal vein at aorto-superior mesenteric artery portion significantly increased from 1.88 ± 0.95 mm pre-procedure to 5.24 ± 0.61 mm post-procedure (p< 0.01). Left renal vein pressure significantly decreased from 11.00 ± 4.34 mmHg pre-procedure to 6.00 ± 2.55 mmHg post-procedure (p< 0.01). Severe gross hematuria completely subsided within 2 months to 6 months and left flank pain completely subsided within 7 days to 1 month after treatment. Endovascular therapy provides an alternative therapy with satisfactory long-term clinical and imaging results for symptomatic patients with nutcracker syndrome.

Laparoscopic transperitoneal gonadal vein ligation for treatment of pelvic congestion secondary to Nutcracker syndrome: a case report

Nutcracker syndrome is the term used to describe the patient with clinical symptoms of entrapment of the left renal vein between the aorta and the superior mesenteric artery. Pelvic congestion syndrome, which is a cause of chronic pelvic pain in women, may be due to Nutcracker syndrome. There are many modalities of treatment for Nutcracker syndrome. This is a case report of a 32-year old woman with pelvic congestion syndrome due to Nutcracker syndrome, who subsequently underwent laparoscopic transperitoneal left gonadal vein ligation. She has had complete remission of pain in 4 months after the operation and after 12 months of follow-up. Laparoscopic transperitoneal gonadal vein ligation is an approach that is safe, simple and provides good results for patient with pelvic congestion syndrome secondary to Nutcracker syndrome.

Unusual presentation of midgut malrotation with incidental nutcracker syndrome in adulthood: case report and literature review

Malrotation of the midgut is generally regarded as paediatric pathology with the majority of patients presenting in childhood. The diagnosis is rare in adults, which sometimes results in delayed diagnosis and treatment. We present the case of a 28-year-old woman who presented with vomiting and mild acute pain in the abdomen. CT scan showed abnormal location of the midgut and abnormal relation of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) and duodenal jejunal flexure, confirming midgut malrotation. Peroperative findings showed the duodenum, small bowel loops located on the right side of the abdomen. The caecum and appendix were located at the midline in the epigastrium with the presence of Ladd's bands. SMA right and anterior to SMV whirled around SMA. Incidentally, the intraoperatively dilated left renal vein was compressed between the SMA and the aorta, which was confirmed retrospectively on CT scan with no symptoms related to the condition.