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.

Nutcracker syndrome in pediatrics: initial findings and long-term follow-up results

BACKGROUND

Nutcracker syndrome (NCS) describes a set of symptoms and signs resulting from compression of the left renal vein (LRV). There is a lack of knowledge about its natural course, diagnosis, and management, especially in children. Herein, we present our single-center experience with a large number of patients who have long-term follow-up results.

METHODS

All patients with NCS diagnosed between January 2011 and March 2021 were included and their data were obtained retrospectively.

RESULTS

A total of 123 NCS patients (85 females) were included. The median age at the time of diagnosis was 12 (IQR 10-14) years, and BMI percentiles were below 5% in 38% of the cases. At the time of diagnosis, two-thirds of the patients were asymptomatic. The most common laboratory finding was nephritic proteinuria (98%), followed by microscopic hematuria (16%). Signs of LRV compression were significantly more evident in upright position Doppler ultrasonography (DUS) examination. All patients have been followed conservatively; hematuria and/or proteinuria resolved in 43 of the 108 patients (40%) within 35.8 ± 25.8 months of follow-up. Control DUS was performed in 52 patients after a mean period of 39.1 ± 21.3 months. The median peak velocity and diameter ratios of the LRV in the upright position were found to be decreased significantly when compared to the initial assessment (p < 0.05). Normal DUS findings were noted in 13 patients at the final evaluation.

CONCLUSIONS

In unexplained proteinuria and/or hematuria, NCS should be considered, especially in asthenic adolescents. Our results support conservative management in children as the first-line treatment approach.

Left renal vein entrapment in postural proteinuria: the diagnostic utility of the aortomesenteric angle

Nutcracker syndrome related to the left kidney vein compression is a cause of orthostatic proteinuria during childhood. Some studies have shown that the ratios between maximum velocities and anterior-posterior diameters of hilar and aortomesenteric segments of the left kidney vein between upright and supine positions must be more than 4 in order to make a Nutcracker syndrome diagnosis. Our aim was to investigate whether the use of a decrease in aortomesenteric angle between upright and supine positions in the presence of isolated orthostatic proteinuria can be a criterion for the diagnosis of Nutcracker syndrome. Relevant patient information, which included demographic data, clinical examination findings, laboratory data, urinary system ultrasound, and kidney color flow Doppler ultrasound results, were prospectively collected. Thirty-nine pediatric patients with orthostatic proteinuria were included in the study. Left kidney vein compression findings were demonstrated in 31 patients. The ratio of maximum velocities of hilar and aortomesenteric segments of the left kidney vein between upright and supine positions was above 4 in only 7 of our patients. Ratio of aortomesenteric angle between upright and supine positions was significantly decreased for patients with left kidney vein compression findings.  Conclusion: The use of a decrease in the ratio of aortomesenteric angle between upright and supine positions in the presence of orthostatic proteinuria, instead of the ratios for maximum velocities and anterior-posterior diameters of hilar and aortomesenteric segments, can be more helpful for the diagnosis of Nutcracker syndrome in the differential diagnosis of orthostatic proteinuria. What is Known: • Proteinuria may be a sign of an impending kidney disease • Nutcracker syndrome is a cause of orthostatic proteinuria. What is New: • Ratio of aortomesenteric angle between upright and supine positions > 0.6 can be used for Nutcracker syndrome diagnosis.

Nutcracker Syndrome with the Superimposition of Thin Basement Membrane Syndrome

A 21-year-old woman was referred to our hospital because of proteinuria and hematuria. She had occasional flank pain. A renal biopsy was performed and revealed a thin basement membrane. Therefore, she was diagnosed with thin basement membrane disease. However, the frequency of her flank pain increased. Since her left kidney was slightly larger than the right, nutcracker syndrome (NCS) was suspected. Renal vein ultrasonography and venography were performed, and NCS was confirmed. Her hematuria was multifactorial, and NCS can go unnoticed if there is a comorbidity that also causes hematuria.

[Nutcracker syndrome]

Nutcracker syndrome is a vascular anomaly consisting in the compression of the left renal vein between the superior mesenteric artery and the aorta. Clinical features in nutcracker syndrome include pelvic pain, flank pain, haematuria, gonadal varices or simply asymptomatic. We are presenting two cases, one of them with macroscopic haematuria and flank pain and the other was studied for hypertension but with previous antecedents of left renal vein embolization in the setting of varicocele. We discuss the clinical presentation as well as diagnostic and therapeutic aspects related to this syndrome.

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.

The nutcracker syndrome. Morphology and clinical aspects of the important vascular variations: a systematic study of 112 cases

Nutcracker syndrome (NCS) is the name given to entrapment of the left renal vein (LRV) between the aorta and superior mesenteric artery (SMA). The aim of the study was to review current research and clarify the most common clinical image of the syndrome. A systematic review of PubMed and EBSCO databases was performed. Articles included in the study had to meet the following criteria: publication between 1980 and 2014, a detailed report on patient symptoms and laboratory test results, medical imaging confirmation of LRV entrapment diagnosis. Fifty-five publications which met the inclusion criteria provided the final database containing 112 cases. The male-female distribution was equal, the mean age on diagnosis for the whole group was 26.47±13.77years. Diagnosis was made earlier in males (23.59±13.09) than females (29.34±13.93). The following frequency of symptoms was noted: 78.57% for haematuria, 38.39% for left flank pain, 35.71% for varicocele in males, 30.36% for proteinuria and 13.39% for anaemia. NCS diagnosis was made earlier if proteinuria occurred as one of the symptoms (P<0.001). Anemia occurred more often in older patients (P=0.0128). NCS was diagnosed in younger age in patients with varicocele (P=0.037). Although NCS is not a common diagnosis, it should be taken into consideration, particularly in hematuria of unknown origin and varicocele.

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.

Gross hematuria caused by nutcracker syndrome and segmental pseudoaneursym

Nutcracker syndrome is a rare disorder characterized by extrinsic compression of left renal vein by the superior mesenteric artery and aorta. Prevalence of the disease is unknown, but presents most commonly with gross hematuria and flank pain. Diagnosis requires a high index of suspicion and treatment consists of a wide range of vascular surgical options with a more recent focus using an endovascular approach. We present a case of a 29-year-old female with continuous gross hematuria and flank pain from a segmental artery pseudoaneursym secondary to nutcracker and pelvic congestion syndrome.

Endovascular stenting for nutcracker syndrome

Nutcracker syndrome (NCS) is a rare pathology manifested by pain or hematuria in males and females alike. It can be easily overlooked, and should be considered in young men or women with symptoms of extended duration. We present a case of a 54-year-old female with chronic lower abdominal pain radiating to the left thigh of 4 years in duration. Computed tomography (CT) eventually revealed engorged left renal, gonadal, and uterine veins due to compression between the superior mesenteric artery (SMA) and the abdominal aorta, consistent with NCS. After a successful endovascular stenting and a 6-month period of antiplatelet and anticoagulant therapy, the patient returned to stable health. NCS, while rare, should be suspected in patients of both sexes with persistent pain or hematuria.

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.

Nutcracker syndrome as an incidental finding on computed tomography scan after blunt abdominal trauma

BACKGROUND

The nutcracker syndrome refers to compression of the left renal vein between the aorta and the superior mesenteric artery. It may be asymptomatic for long period and constitute casual findings.

AIM

To report a new case diagnosed by radiological exploration after an abdominal trauma. The diagnosis and treatment of nutcracker syndrome are discussed.

CASE

A 32-year-old man was a victim of traffic accident causing leg and abdominal trauma. Three days after orthopedic surgery, he presented an isolated gross hematuria. Abdominal computed tomography showed that the left renal vein was compressed between the aorta and the superior mesenteric artery. The diagnosis of nutcracker syndrome was established. Surveillance was indicated with excellent evolution.

CONCLUSION

The nutcracker syndrome is a rare entity. It may be asymptomatic. Its diagnosis is the privilege of medical imaging. Its treatment is controversial and should be discussed case by case.

Nutcracker syndrome in a patient with a history of inferior vena cava ligation

We report the case of a child with clinical and radiological signs of nutcracker syndrome who had a history of inferior vena cava ligation during a previous surgery. He was referred for evaluation of abdominal pain and hematuria. Entrapment of the left renal vein between the superior mesenteric artery and the aorta with aneurysmal dilatation was detected on Doppler ultrasonography. Magnetic resonance angiography revealed paravertebral and epidural collateral vessels.