Nutcracker syndrome also known as left renal vein entrapment is an uncommon cause of hematuria [1] [2] [3]. Most usually, the left renal vein (LRV) is entrapped between aorta and superior mesenteric artery and it is called anterior Nutcracker syndrome. Posterior nutcracker syndrome is due to a retroaortic position of the LRV compressed between the aorta and the vertebral column [4]. This entity affects women more than men and in most cases present in the third or fourth decades of life [5].

Herein, we present a case report of a posterior nutcracker syndrome with LVR duplication observed in our institution in an eight-year-old boy.

An eight-year-old boy, with a history of left varicocele treated by Palomo technique one year ago, was admitted to the pediatric department with a gross hematuria. On physical examination, the patient was pale, his vital signs were within normal limits, and systemic examination revealed only high degree of left varicocele. His hemoglobin on presentation was 9.2 g/dL, the urine analysis confirmed gross hematuria and the other biological analyses were normal.

X-ray and ultrasonography of the abdomen were normal. When we asked him again, he complained of abdominal pain spatially in the left flank. He denied any other urological signs or symptoms, namely, dysuria, fever, asthenia, or fatigue.

The abdominopelvic computed tomography angiography (CTA) revealed LRV duplication with a retroaortic branch entrapped between aorta and vertebral column, promoting a posterior nutcracker syndrome (Figure 1) and (Figure 2). Based on the clinical and radiological presentation, early recurrent left varicocele, left flank pain and gross hematuria and imageries finding; a posterior nutcracker syndrome with duplication of the LRV was confirmed. Blood transfusion was not needed.

For the management of nutcracker syndrome, transposition of the posterior branch of LRV or autotransplantation of the left kidney were decided, but refused by parents of the patient.

A surgical cure for the recurrent left varicocele was performed by inguinal approach. Thereafter, he was counseled to restrict intense physical exercise and take oral iron supplements. This therapy showed decrease in episodes of hematuria and substantial improvement of anemia (actual hemoglobin: 11 g/dL). The patient is currently asymptomatic and proposed to clinical and analytical assessment. At the last follow-up, he was asymptomatic without recurrence of hematuria or varicocele.

The first case of nutcracker syndrome was described in 1950 but this term must be distinguished from the nutcracker phenomenon which is a relatively common anatomical variance, in which the patient stays asymptomatic [4] [6]. The degree and the stage of syndrome depend on the renal venous pressure. Well developed collateral veins or the presence of the preaortic branch of duplicated renal vein as in our case could dissipate the high pressure gradient and diminish the blood flow volume of the LRV, resulting in the absence of distended LRV and LRV hypertension [7].

The clinical manifestation of nutcracker syndrome ranges a wide variety from asymptomatic microscopic hematuria to severe pelvic congestion syndrome characterized by an array of signs and symptoms such as dyspareunia, dysmenorrhea, lower abdominal pain and pelvic, perineal and lower limb varices [8]. The classic presentation include symptoms which are often aggravated by physical activity such as hematuria, varicocele as seen in our case, pain or gonadal vein syndrome, orthostatic proteinuria and orthostatic intolerance [9] [10] [11] [12]. Hematuria is the most commonly reported symptom and is attributed to the communication between dilated venous sinuses and adjacent renal calices [13]. Varicoceles almost always occur on the left side and affect up to 9.5% of cases and it is admitted that LRV hypertension is the usual cause of varicoceles [14] [15]. The ultrasonography is a good first radiographic study as it is safe, cost effective and screens possible renal and bladder abnormalities and identifies the turbulent vessel renal flow [16] [17] [18]. On the other hand, computed tomography (CT) scan is the most appropriate and single imaging modality in a patient with multiple abnormalities like ours [19].

In this case, the computed tomographic angiography (CTA) led to this diagnosis by showing a dilated posterior LRV branch being compressed between aorta and vertebral column.

The management of nutcracker syndrome evolved in the last four decades depends upon the clinical presentation, and the severity of the left renal vein hypertension, including close expectant surveillance, endoscopic proceedings such as external or internal stenting and more complex open surgical procedures LRV transposition, renal autotransplantation of the left kidney [20] [21] [22] [23]. Patients in prepubertal age like our case should be offered less aggressive forms of treatment since the likelihood of spontaneous remission due to normal physical development and despite the initial presentation with hospitalization, our patient was managed conservatively with good evolution [4].

Posterior nutcracker syndrome with duplication of the left renal vein is a rare vascular anomaly, which may be a possible cause of hematuria and recurrent varicocele. Computed tomography angiography is the optimum choice of imaging modality to diagnose posterior nutcracker syndrome as well as to find out associated other abnormalities. Conservative treatment with strict follow-up is recommended for patients with microscopic hematuria or intermittent short periods of painless gross hematuria, insignificant pain. Surgical reconstruction can be indicated in case of severe symptoms or complications.

1. Cope C, Isard HJ. Left renal vein entrapment: A new diagnostic finding in retroperitoneal disease. Radiology 1969;92(4):867–2.   [Pubmed]    
2. Barnes RW, Fleisher HL 3rd, Redman JF, Smith JW, Harshfield DL, Ferris EJ. Mesoaortic compression of the left renal vein (the so-called nutcracker syndrome): Repair by a new stenting procedure. J vasc surg 1988;8(4):415–21.   [CrossRef]   [Pubmed]    
3. Rudloff U, Holmes RJ, Prem JT, Faust GR, Moldwin R, Siegel D. Mesoaortic compression of the left renal vein (nutcracker syndrome): Case reports and review of the literature. Ann vasc surg 2006;20(1):120–9.   [CrossRef]   [Pubmed]    
4. Shin JI, Park JM, Lee SM, et al. Factors affecting spontaneous resolution of hematuria in childhood nutcracker syndrome. Pediatr Nephrol 2005;20(5):609–13.   [CrossRef]   [Pubmed]    
5. Shin JI, Lee JS, Kim MJ. The prevalence, physical characteristics and diagnosis of nutcracker syndrome. Eur J Vasc Endovasc Surg 2006;32(3):335–6.   [CrossRef]   [Pubmed]    
6. EL-Sadr AR, Mina E. Anatomical and surgical aspects in the operative management of varicocele. The Urologic and Cutaneous Review 1950;54(5):257–62.   [Pubmed]    
7. Takebayashi S, Ueki T, Ikeda N, Fujikawa A. Diagnosis of the nutcracker syndromewith color Doppler sonography: Correlation with flow patterns in retrograde leftrenal venography. AJR Am J Roentgenol 1999;172(1):39–43.   [CrossRef]   [Pubmed]    
8. Rogers A, Beech A, Braithwaite B. Transperitoneal laparoscopic left gonadal vein ligation can be the right treatment option for pelvic congestion symptoms secondary to nutcracker syndrome. vascular 2007;15(4):238–40.   [CrossRef]   [Pubmed]    
9. Wendel RG, Crawford ED, Hehman KN. The "nutcracker" phenomenon: An unusual cause for renal varicosities with hematuria. J urol 1980;123(5):761–3.   [Pubmed]    
10. Coolsaet BL. Ureteric pathology in relation to right and left gonadal veins. Urology 1978;12(1):40–9.   [CrossRef]   [Pubmed]    
11. Shintaku N, Takahashi Y, Akaishi K, Sano A, Kuroda Y. Entrapment of left renal vein in children with orthostatic proteinuria. Pediatr Nephrol 1990;4(4):324–7.   [CrossRef]   [Pubmed]    
12. Dever DP, Ginsburg ME, Millet DJ, Feinstein MJ, Cockett AT. Nutcracker phenomenon. Urology 1986;27(6):540–2.   [CrossRef]   [Pubmed]    
13. Buschi AJ, Harrison RB, Norman A, et al. Distented left renal vein: CT/sonographic normal variant. AJR Am J Roentgenol 1980;135(2):339–42.   [CrossRef]   [Pubmed]    
14. Kurklinsky AK, Rooke TW. Nutcracker Phenomenon and Nutcracker Syndrome. Mayo Clin Proc 2010;85(6):552–9.   [CrossRef]   [Pubmed]    
15. Zerhouni EA, Siegelman SS, Walsh PC, White RI. Elevated pressure in the left renal vein in patients with varicocele: preliminary observations. J Urol 1980;123(4):512–3.   [Pubmed]    
16. Campbell-Walsh Urology, vol. 4 of Section XVII, 10th edition 2012.    
17. Takemura T, Iwasa H, Yamamoto S, et al. Clinical and radiological features in four adolescents with nutcracker syndrome. Pediatr Nephrol 2000;14(10-11):1002–5.   [CrossRef]   [Pubmed]    
18. Shin JI, Park JM, Lee JS, Kim MJ. Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria. Eur J Pediatr 2007;166(5):399–404.   [CrossRef]   [Pubmed]    
19. Martínez-Salamanca García JI, Herranz Amo F, Gordillo Gutiérrez I, et al. Nutcracker's syndrome: Demostration with helicoidal TC with volumetric reconstruction "3D". Actas Urol Esp 2004;28(7):549–52. [Article in Spanish].   [Pubmed]    
20. Ahmed K, Sampath R, Khan MS. Current trends in the diagnosis and management of renal nutcracker syndrome: A review. Eur J Vasc Endovasc Surg 2006;31(4):410–6.   [CrossRef]   [Pubmed]    
21. Zhang HK, Shen LG, Li M, et al. Diagnosis and treatment of left renal vein entrapment Syndrome. Chinese Journal of General Surgery 2001;16:511.    
22. Neste MG, Narasimham DL, Belcher KK. Endovascular stent placement as a treatment for renal venous hypertension. J Vasc Interv Radiol 1996;7(6):859–61.   [CrossRef]   [Pubmed]    
23. Marone EM, Psacharopulo D, Kahlberg A, Coppi G, Chiesa R. Surgical treatment of posterior nutcracker syndrome. J Vasc Surg 2011;54(3):844–7.   [CrossRef]   [Pubmed]