Nutcracker syndrome: a rare cause of hematuria

Nutcracker syndrome in children: Appearance, diagnostics, and treatment - A systematic review

BACKGROUND

The nutcracker syndrome (NCS) is defined by compression of the left renal vein (LVR) and may present with a wide variety of symptoms. Due to its rarity in pediatric patients, incidence, diagnostics and performed therapy regimen are widely undefined. To this date, there are only case reports and small collectives of pediatric patients described but comprehensive research is lacking.

METHODS

A systematic literature research on pediatric NCS was carried out on Medline and Scopus databases according to PRISMA principles using predefined search terms and inclusion criteria. The PROSPERO registered review (CRD42021237415) identified patients' characteristics regarding age, sex, clinical symptoms, applied diagnostic methods and treatment options.

RESULTS

In total 47 articles were included. Overall, 423 children (218 boys and 205 girls) with diagnosed NCS were included in the analysis. Mean age was 12.0 (boys 12.9, girls 12.0) years. Hematuria was most common presentation (55.5%), followed by proteinuria (49.9%). Classical flank pain was only detected in 19.1% of patients. Sonographic evaluation was the most commonly used diagnostic tool (99%). Invasive diagnostic studies were performed in 97 children. 86.8% patients were treated conservatively and 94.9% showed complete resolution (42.8%) or at least improvement (52.2%) of symptoms. Type of operative treatment comprised of open surgery with transposition of LRV, endovascular stenting and laparoscopy.

CONCLUSIONS

Overall, data quality regarding NCS in children is poor. However, conservative approach in pediatric patients is recommended and should be regarded first treatment option. Diagnostic and treatment should follow a defined algorithm when NCS is suspected. Sufficient observation and follow-up must be assured in all patients to get significant results in this heterogenous syndrome.

LEVEL OF EVIDENCE

V-IV.

Micro- and macroscopic hematuria caused by renal vein entrapment: systematic review of the literature

BACKGROUND

Hematuria secondary to renal vein entrapment is mentioned only passing in textbooks and reviews.

METHODS

We performed a search of the National Library of Medicine database for peer-reviewed publications using the terms "renal vein" or "nutcracker" and "hematuria".

RESULTS

We identified 187 published reports/studies that covered 736 patients, of whom 288 had microscopic hematuria and 448 had macroscopic hematuria. The patient cohort comprised 159 patients aged ≤17 years. Abdominal pain was absent in  approximately 65% of all patients, and a clinically relevant left-sided varicocele was observed in 29% of the male patients. A normal pre-aortic left renal vein and an anomalous anatomy were noted in 680 and 56 patients, respectively. The body mass index (BMI) was lower in patients with renal vein entrapment than in the controls, with a regression of hematuria correlating with an increase in BMI. A surgical procedure was attempted in 34% of the patients, of which the most common were endovascular stenting and transposition of the renal vein distally into the vena cava.

CONCLUSIONS

In cases of unexplained hematuria with or without abdominal pain, clinicians should consider the diagnosis of renal vein congestion, especially in males with varicocele. Ultrasonic Doppler flow scanning is the recommended initial diagnostic modality in these patients. Expectation management is advised in the great majority of cases.

Macroscopic hematuria caused by congenital portosystemic shunt and concomitant nutcracker syndrome

Nutcracker syndrome (NCS) is an uncommon vascular abnormality that causes a variety of symptoms that range from asymptomatic microscopic hematuria to severe pelvic congestion. Congenital portosystemic shunt (CPSS) is an extremely rare anomaly that causes serious complications. Many cases of NCS and CPSS that have presented separately have been reported, but no cases of concomitant NCS and CPSS have been reported. We present a case of intermittent macroscopic hematuria in a patient with both NCS and CPSS. We diagnosed NCS on pressure gradient between the left renal vein (LRV) and the inferior vena cava. The presence of CPSS, which emerged from the LRV and connected to the extrahepatic portal vein, was confirmed on computed tomography. The interaction between NCS and CPSS resulted in mild intermittent macroscopic hematuria only, rather than the more common symptoms that occur when NCS or CPSS present separately.

Nutcracker syndrome--how well do we know it?

Nutcracker syndrome (NCS), which is caused by compression of the left renal vein between the abdominal aorta and the superior mesenteric artery, leads to a series of clinical symptoms including hematuria, proteinuria, flank pain, and varicocele. The diagnosis of NCS is difficult due to variations in normal anatomy. Treatment, which ranges from observation to nephrectomy, remains controversial. We conducted a review based on the related literature and our experience with hundreds of cases. We summarize the characteristics of NCS, the different measurements used in diagnosis, and the current treatment options. We present our diagnostic criteria and recommend endovascular stenting as the primary option for NCS.

Cracking haematuria in adolescent with negative work up

A 16-year-old girl was referred to our nephrology clinic with persistent visible haematuria (2 months), no urinary tract infection, proteinuria ranging from negligible to 1.5 g/l, normal kidney function and otherwise negative work up including immunology screen. After negative ultrasound scans of the kidneys and bladder, normal renal biopsy and normal cystoscopy, a CT angiogram was obtained. It showed no evidence of arteriovenous malformation but revealed compression of left renal vein (nutcracker syndrome).

[Successful endovascular treatment of nutcracker's syndrome with self-expanding stent]

Nutcracker's syndrome is caused by compression of the left renal vein between aorta and superior mesenteric artery, causing extrinsic compression generated functional stenosis. This causes congestion and hypertension of the left renal vein resulting in insufficiency and left gonadal vein varicose, unilateral hematuria and left flank pain, diagnosis is rarely identified by their low frequency and difficulty of suspecting, treatment of nutcracker's syndrome include renal autotransplantation, transposition of superior mesenteric artery revascularization and recently stenting in renal vein, we present the case of a patient, who showed this pathology by diagnostic support by image studies, was performed successfully implant a self-expanding stent with immediate success criteria by angiography, collateral reduction and by disappearance of cava/renal gradient.

The nutcracker syndrome: an underrecognized cause of hematuria

Nutcracker syndrome (NCS) is an uncommon cause of hematuria. It refers to the compression of the left renal vein between the aorta and superior mesenteric artery. It can cause both microscopic and gross hematuria. Hematuria may be associated with left flank pain. The diagnosis of NCS is often delayed. Most patients may have symptoms for many years and non-diagnostic evaluations before accurate diagnosis can be established. It should be included in the differential diagnosis of unexplained hematuria. The diagnosis and treatment of nutcracker syndrome are discussed.

CONCLUSION

NCS is a rare but treatable clinical condition. An inclusion of this entity in the differential diagnosis of patients with unknown cause of hematuria and flank pain can achieve efficient management of this condition.

From the nutcracker-phenomenon of the left renal vein to the midline congestion syndrome as a cause of migraine, headache, back and abdominal pain and functional disorders of pelvic organs

This paper presents the hypothesis, that pain and functional disturbances of organs which lie on the midline of the body might be caused by a venous congestion of these organs. Cause of their congestion is the participation of these organs (vertebral column, skull, brain, spinal medullary, uterus, prostate, left ovary/testis, urinary bladder rectum, vagina, urethra) in the collateral circulation of the left renal vein. In many patients with complaints of the above mentioned organs the left renal vein is compressed inside the fork formed by the superior mesenteric artery and the aorta. This so called nutcracker phenomenon is incompletely understood today. It can lead to a marked reduction of left renal perfusion and forces the left renal blood to bypass the venous compression site via abundant collaterals. These collaterals are often not sufficient. Their walls become stretched and distorted - varices with inflamed walls are formed. These dilated veins are painful, interfere with the normal organ's function and demand more space than usual. This way pain in the midline organs and functional derangement of the midline organs can occur. The term "midline congestion syndrome" seems appropriate to reflect the comprehensive nature of this frequent disorder. The rationale for this hypothesis is based on the novel PixelFlux-technique (www.chameleon-software.de) of renal tissue perfusion measurement. With this method a relevant decline of left renal cortical perfusion was measured in 16 affected patients before therapy (left/right ratio: 0.79). After a treatment with acetylsalicylic acid in doses from 15 to 200mg/d within 14-200 days a complete relief of so far long lasting therapy-resistant midline organ symptoms was achieved. Simultaneously the left/right renal perfusion ratio increased significantly to 1.24 (p=0.021). This improvement of left renal perfusion can be explained by a better drainage of collateral veins, diminution of their wall distension, thereby decline of their intramural inflammation, reduction of their mass effects (especially by the replaced spinal fluid inside the spinal canal and the skull), and altogether a reduction of pain and functional derangement in the affected midline organs. The proposed theory might influence the current understanding of such frequent and difficult to treat diseases as chronic back pain, headaches, frequent cystitis, enuresis, abdominal pain, flank pain and might spur new theories of arterial hypertension, placental insufficiency, prostate diseases and myelopathies.