Standardized Protocol for Assessing Left Renal Vein Compression Using Diagnostic Ultrasound

Nutcracker Syndrome—How Well Do We Know It?

Left Renal Vein compression, entitled as Nutcracker Syndrome, usually is described as cause of Pelvic Congestion once the difficult of drainage of the left kidney deviate vein flow to Gonadal vein developing Pelvic varices in women, and Varicocele in men. Recurrence of Varicocele is described to be between 1 to 35%, dependent on the surgical technique used to repair it. Among the cause of recurrent varicocele, include surgical technique failure, low Body Mass Index, venous plexus variation (persistence of branched spermatic veins), and venous compression. In this study, the authors present 2 cases of recurrent varicocele in young men caused by pelvic congestion due to the Left Renal Vein (LRV) and Left Common Iliac Vein (LCIV) compression, treated by endovascular techniques with good results. In the Literature there are few papers relating the association of both syndromes. Authors discuss of the association of recurrent varicocele and pelvic congestion, and also suggest a routine investigation of it in this recurrence.

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

Endovascular stenting in the treatment of pelvic vein congestion caused by nutcracker syndrome: Lessons learned from the first five cases

Unusual Presentation of Nutcracker Syndrome in Patient With Prior Gonadal Vein Embolization for Pelvic Congestion Syndrome

A 46-year-old man was found to have an increased carcinoembryonic antigen level (25.7 μg/L) during physical examination, and an (18)F-FDG PET/CT scan was subsequently performed. The PET image indicated abnormal radioactivity levels in the left kidney, and the coregistered CT revealed compression of the left renal vein between the aorta and superior mesenteric artery. An ultrasonography was then performed, which revealed that the ratio between the renal hilum and the aortomesenteric left renal vein was 3.2. Therefore, the nutcracker phenomenon was diagnosed. When abnormal radioactivity is found in the left kidney on PET/CT scanning, the nutcracker syndrome should be considered.

BackgroundThe issues of diagnosis and treatment strategy for the left renal vein compression (LRVC) have not been fully resolved, and treatment methods vary widely from medical therapy to renal autotransplantation. The aim of this study was to determine the feasibility of isolated interventions on the left ovarian vein in patients with LRVC of varying severity.MethodsThis prospective cohort study included 63 female patients with LRVC (30 symptomatic and 33 asymptomatic), selected out of 266 consecutively examined patients with pelvic venous disorders (PeVD). All participants underwent blood and urine tests, duplex ultrasound studies (DUS) of the renal and pelvic veins, and dynamic renal scintigraphy (DRS). Patients with LRVC and symptoms of pelvic venous insufficiency (PVI) and/or reflux in the left ovarian vein (LOV) further underwent ovarian vein resection or embolization. Follow-up clinical and laboratory evaluations, DUS, and DRS were performed 1 to 12 months after the intervention.ResultsLRVC was diagnosed in 23.6% of patients with PeVD, and was symptomatic in 11.3% and hemodynamically significant, according to DUS, in 4.9% of them. None of patients with LRVC had renal symptoms (pain in the left flank of the abdomen, hematuria) or impaired filtration and secretory dysfunction of the left kidney (LK), according to DRS. Symptomatic LRVC was accompanied by clinical manifestations of PeVD. Ovarian vein interventions were performed in 24 symptomatic patients and resulted in elimination of chronic pelvic pain (CPP) and pelvic venous reflux (PVR) in all cases. Follow-up examinations did not reveal any deterioration in the blood outflow through LRV or disturbances in the LK function after intervention in any patient.ConclusionsLRVC without hematuria does not deteriorate the LK filtration and secretory functions. Patients with symptomatic LRVC without hematuria can undergo isolated interventions on LOV. These interventions are effective in eliminating CPP and do not impair the LK function.

Endovascular Treatment of Nutcracker Syndrome

Objective: Nutcracker syndrome (NCS), caused by the compression of the left renal vein (LRV) between the superior mesenteric artery (SMA) and the abdominal aorta, is a rare clinical condition. While renal Doppler ultrasonography has been used to diagnose NCS, there have been few studies linking LRV compression measurements to symptoms in pediatric patients. This long-term retrospective study aimed to evaluate the clinical characteristics of NCS and its Doppler ultrasonographic measurements in children. Material and Methods: Demographic, clinic, and laboratory data were collected from the medical records of patients with NCS. All renal Doppler ultrasonography (DUS) findings of the study population were also reviewed. Results: A total of 50 patients with NCS were identified with a mean follow-up of 6.3 years. The proportion of proteinuria was 70%, and 36% of the patients exhibited symptoms of hematuria. Varicocele was also observed in 55.5% of male patients. While patients with hematuria were diagnosed earlier, patients with varicocele and proteinuria were diagnosed later in life. The mean SMA angle of patients in the supine position was significantly lower patients with varicocele (23.80±3.04° vs 27.87±4.49°, p=0.049). The estimated glomerular filtration rate (eGFR) did not differ in patients with hematuria and in patients with variocele. On the other hand, patients with proteinuria had a lower eGFR than those without (129.85±18.48 ml/min/1.73 m² vs 141.82±20.72 ml/min/1.73 m², p=0.030). The Doppler ultrasonographic parameters of the LRV did not change according to the gender, but the SMA angle decreases significantly with aging. Conclusion: Although hematuria seems to be common, proteinuria is also common in NCS and SMA angle should thought to be important in children with varicocele.

Outcomes of left renal vein stenting in patients with nutcracker syndrome

BackgroundTo investigate the relationship between the level of left renal vein (LRV) compression and changes in the perfusion of the left kidney in patients with nutcracker syndrome (NCS) by one-stop whole-organ perfusion imaging of bilateral kidneys using 640-slice volume CT.MethodsTwelve patients, clinically diagnosed with NCS, were subjected to one-stop examination of kidneys. Angiography and whole-organ perfusion imaging of bilateral kidneys were conducted, and the compression segment of LRV was demonstrated and measured. Information including the results of whole-organ perfusion images of both kidneys in 12 patients was collected. Results of epigastrium dynamic volume scanning by 640-slice volume CT were collected for 12 patients as control group. Left and right renal cortexes were chosen as regions of interest (ROI), and their perfusion values were measured.ResultsThe perfusion values of the left and right renal cortexes in the control group were 323.8 ml·min−1·100 ml−1 and 322.9 ml·min−1·100 ml−1, respectively. The difference was not statistically significant (t = 1.388, P = 0.193). For NCS patients, the perfusion values of the left and right renal cortexes were 350.8 ml·min−1·100 ml−1 and 391.1 ml·min−1·100 ml−1, respectively. Significantly decreased value was observed in left renal cortex compared to that of the right renal cortex, with the mean decrease of 40.3 ml·min−1·100 ml−1, and the difference was statistically significant (t = −4.204, P = 0.001).ConclusionAs a non-invasive functional imaging technique, whole-organ perfusion imaging of kidneys can be used to evaluate the organ and tissue perfusion status and to accurately reflect the hemodynamic changes of the left renal cortex in the patients with NCS. Whole organ perfusion imaging may also provide the basis for quantitative diagnosis and clinical interventions of NCS.

Compression of the left renal vein (LRV) between the superior mesenteric artery and the aorta is thought to be a cause of hematuria, periureteral and gonadal varices, and varicocele ("Nutcracker phenomenon"). Previous investigators have suggested that this diagnosis can be made on computed tomography when the LRV ratio greater than or equal to 1.5 (the diameter of the LRV proximal to the aorto-mesenteric angle divided by the diameter of the LRV distal to the aorto-mesenteric angle). This study was designed to establish the normal range for the LRV ratio on CT in children. The LRV ratio was measured in thirty-nine consecutive children undergoing intravenously enhanced CT of the abdomen. None of the children had hematuria on urinalysis immediately before or after the CT. Children with any known abnormality involving the kidneys, adrenal glands, IVC, or renal or gonadal veins were excluded. The patients ranged in age from 3.4 to 18.5 years (mean = 10.6 years). LRV ratio ranged from 0.78 to 2.00 (mean = 1.46; S.D. = 0.312). Twenty of the 39 children (51.3%) had a LRV ratio greater than or equal to 1.50. The conclusion is that the normal range for the LRV ration is too wide for it to be useful in diagnosing LRV entrapment and that a LRV ratio greater than or equal to 1.5 on CT is normal in children.

Nutcracker syndrome is defined as a compression of left renal vein leading to symptomatic hematuria and flank pain. There are very few reports about its association with May-Thurner syndrome that is related to compression of left iliac vein causing severe leg edema. We are reporting a rare case of a patient having both conditions successfully treated with sequential percutaneous interventions. This case and treatment options are discussed in detail.

The nutcracker syndrome is defined by the compression of the left renal vein between the aorta and superior mesenteric arteries, accompanied by a classic, but less specific, symptomatology. We reported a case of a 37-year-old woman who had been investigated because of intermittent gross hematuria of unknown origin. Computed tomographic angiography revealed compression of the left renal vein as it ran between the superior mesenteric artery and the abdominal aorta, associated with significant dilation of the left ovarian vein. The nutcracker syndrome, caused by compression of the left renal vein by the aorta and superior mesenteric arteries, is probably more prevalent in women, and it is caused by specific situations, such as renal ptosis and paucity of retroperitoneal fat. Hematuria, a typical symptom, is due to rupture of the thin-walled septum separating the veins of the urinary collecting system. Imaging tests may help with the diagnosis. The best treatment is still elusive, but there are several surgical approaches, such as intravascular stenting, and also a conservative management. Diagnosis is usually delayed, and the syndrome should be included in the differential of hematuria of unknown origin.

Young woman with nutcracker syndrome without main clinic manifestation: Hematuria—Case report