Spontaneous remission of persistent severe hematuria in an adolescent with nutcracker syndrome: seven years' observation

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.

Nutcracker syndrome: challenges in diagnosis and surgical treatment

BACKGROUND

Nutcracker syndrome (NCS) is an uncommon syndrome that presents with signs and symptoms caused by compression of the left renal vein (LRV), whereas 'nutcracker phenomenon' is solely used to refer to the anatomical configuration without clinical symptoms. Treatment for NCS may include non-operative management, open surgical intervention and in some instances endovascular stenting. We present a single-center retrospective case series of patients who presented with NCS managed with open surgical interventions.

METHODS

Single-center, retrospective review of patients managed from 2010-2021. We diagnosed NCS via a thorough clinical examination and additional cross-sectional imaging studies including magnetic resonance venography (MRV) and/or computed tomography venography (CTV). For further confirmation of the diagnosis, duplex ultrasound was frequently combined with contrast venography.

RESULTS

Thirty-eight patients were included in our study from 2010-2021 . Twenty-one (55.3%) patients presented with symptoms including flank pain, abdominal pain, hematuria and fatigue. The remaining 17 (44.7%) patients had nutcracker phenomenon. Within the group of patients diagnosed with NCS, 11 patients underwent LRV transposition. Symptoms related to NCS improved in 10 patients. Hematuria in one patient did not improve.

CONCLUSION

Transposition of the LRV is an effective treatment for NCS. Non-operative management is an option for those patients experiencing less severe or nonspecific clinical symptoms.

Diagnostic Clues in Pediatric Nutcracker Syndrome: From Two Clinical Cases to Current Literature Analysis

Nutcracker syndrome (NCS) is a rare pediatric disease caused by left kidney vein compression. Besides the "Triade's symptoms", including hematuria, proteinuria, and flank pain, a wide spectrum of clinical manifestations has been reported. As the significant hemodynamic changes secondary to the dilatation of the left renal vein, serious consequences such as renal vein thrombosis and severe anemia might occur in these children. NCS diagnosis includes a variety of invasive and non-invasive imaging tools, but cutoff values need to be further validated. A conservative treatment represents the most common therapeutic approach for these patients, but operative options are available in selected cases. To complicate matters, a standard diagnostic and treatment algorithm is currently lacking and scientific pediatric evidence in this field is still poor and limited. In this perspective, early recognition of NCS is crucial but challenging for pediatricians. Therefore, a better knowledge of the disease is recommended. Starting from two different clinical presentations of NCS, we aimed to provide a comprehensive overview of the disease in children.

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.

Bleeding from jejunal varices formed at the Roux-en-Y jejunum site caused by the compression of the left renal vein after living donor liver transplantation with renoportal anastomosis

Background

Renoportal anastomosis is an option for the portal vein reconstruction of a liver transplantation with grade 4 portal vein thrombosis and a splenorenal shunt. Here, we report the case of gastrointestinal bleeding who underwent living donor liver transplantation (LDLT) with renoportal anastomosis.

Case presentation

Six-year-old female patient who underwent LDLT with renoportal anastomosis at 1 year of age had severe anemia with normal liver function during the follow-up period. The varices at the Roux-en-Y jejunum were considered the source of bleeding, and the compression of the left renal vein, which is known as a cause of Nutcracker syndrome, seemed to induce venous hypertension through the splenorenal shunt, which might induce the formation of the varices. She underwent percutaneous transhepatic sclerotherapy of the varices, and the anemia improved at her last follow-up, 6 months after sclerotherapy. This is the first reported case of Roux-en-Y jejunal varices bleeding related to the compression of the left renal vein after LDLT was performed with renoportal anastomosis.

Conclusions

Although renoportal anastomosis should be cautiously performed when there are no options for severe portal vein thrombosis, the status of the left renal vein and new collateral formation should be observed carefully during the follow-up period in pediatric cases of renoportal anastomosis.

Serial ganglion impar blocks in a patient with nutcracker syndrome refractory to left renal vein transposition: a case report

Background

Nutcracker syndrome is a rare disorder caused by compression of the left renal vein, usually between the aorta and the superior mesenteric artery. It typically presents with left-sided abdominal pain and hematuria. Left renal vein transposition is the most commonly employed surgical technique to alleviate the compression.

Case presentation

A 22-year-old Caucasian man with a known diagnosis of nutcracker syndrome had undergone left renal vein transposition 1 year before presentation without any subsequent pain relief. In addition, his surgery was complicated by massive blood loss and a 1-week-long stay in an intensive care unit (ICU); as such, he was not amenable to further surgical intervention or stenting to treat his underlying pathology. His symptoms included constant sharp left-sided flank, perineal, and testicular pain. A series of ganglion impar blocks were performed every 3–4 months over the course of 5 years with substantial pain relief achieved.

Conclusions

Our case report highlights a treatment option that has not yet been described for patients with pain secondary to nutcracker syndrome refractory to surgical intervention.

A case report of a young girl with recurrent hematuria: a missed diagnosis - renal nutcracker syndrome

BACKGROUND

Nutcracker syndrome is an easily missed cause of hematuria in children. It is characterized by left renal vein entrapment between the abdominal aorta and the superior mesenteric artery causing renal venous hypertension. Intermittent hematuria and orthostatic proteinuria with or without abdominal or flank pain are the common clinical manifestations. Presence of variable non-specific symptoms and non-significant physical findings results in a delayed diagnosis.

CASE PRESENTATION

We present a ten -year -old girl with four episodes of painless gross hematuria and recurrent microscopic hematuria since the age of two years. Doppler ultrasound showed left renal vein compression while 3 D computerized tomography angiography confirmed the diagnosis of an anterior nutcracker. The patient was conservatively treated with nutritional support (pediasure complete formula and high calorie food), iron supplements and followed up, monitored for anemia, hypertension and renal insufficiency.

CONCLUSION

Nutcracker syndrome is a rare cause of recurrent gross hematuria in children. A high index of suspicion and proper imaging is needed to reach a proper diagnosis and avoid the psychological and financial stress on the family.

Nutcracker Syndrome-An Unusual Case of Chronic Left Upper Abdominal Pain: A Case Report

A 38-year-old woman presented with a chief complaint of sharp, achy left upper abdominal pain with radiation to the left flank. This pain started approximately one-and-a-half years before she consulted with a pain specialist. Although an extensive workup was completed, no organic cause was established as the cause of her pain. After undergoing successful fluoroscopically guided celiac plexus blocks, an abdominal magnetic resonance imaging scan was obtained that revealed nutcracker phenomenon. The patient was evaluated by an urologist and underwent renal autotransplantation. The patient subsequently had complete relief of her pain.

What Each Clinical Anatomist Has to Know about Left Renal Vein Entrapment Syndrome (Nutcracker Syndrome): A Review of the Most Important Findings

Nutcracker syndrome (NCS) is the most common term for compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. The development of NCS is associated with the formation of the left renal vein (LRV) from the aortic collar during the sixth to eighth week of gestation and abnormal angulation of the superior mesenteric artery from the aorta. Collateralization of venous circulation is the most significant effect of NCS. It includes mainly the left gonadal vein and the communicating lumbar vein. Undiagnosed NCS may affect retroperitoneal surgery and other radiological and vascular procedures. The clinical symptoms of NCS may generally be described as renal presentation when symptoms like haematuria, left flank pain, and proteinuria occur, but urologic presentation is also possible. Radiological methods of confirming NCS include Doppler ultrasonography as a primary test, retrograde venography, which can measure the renocaval pressure gradient, computed tomography angiography, which is faster and less traumatic, intravascular ultrasound, and magnetic resonance angiography. Treatment can be conservative or surgical, depending on the severity of symptoms and degree of LRV occlusion. Nutcracker syndrome is worth considering especially in differential diagnosis of haematuria of unknown origin.

Venous Compression Syndromes: a Review

OPINION STATEMENT

Venous compression syndromes present a diagnostic and therapeutic challenge as the clinical presentation can be vague, diagnostic criteria are often not present, and high quality standardization of when and how to treat is not available in part due to the limited number of cases reported and also due to the limited literature available. Significant venous compression should be considered when clinical symptoms correlate to location of compression and there is evidence of hemodynamic changes including venous hypertension, collateral/variceal formation, and/or thrombus formation. In general, treatment of venous compression should address the etiology of the compression as opposed to just treating symptoms associated with it such as significant varices or anticoagulation for thrombus to avoid recurrence of symptoms.

Nutcracker syndrome: A rare cause of left flank pain that can also manifest as unexplained pelvic pain

Nutcracker syndrome (NCS) is symptomatic unilateral renal venous hypertension due to compression of the left renal vein between the superior mesenteric artery and aorta (anterior NCS) or between the aorta and spine (posterior NCS). The left ovarian or spermatic vein empties into the left renal vein and is an additional site of venostasis in about half the cases of NCS. The presenting symptom of NCS in about half the cases is atypical left flank pain suggesting a disorder of the lower ribs or thoracolumbar spinal junction, particularly as the pain worsens with standing and increased lumbar lordosis. NCS may be suggested by any combination of the following manifestations: hematuria, which is often only microscopic; orthostatic proteinuria; varicocele and infertility; dyspareunia and other gynecological symptoms; varicose veins in the pelvis, buttocks, or upper thighs; orthostatic hypotension and fatigue; and abdominal pain. Narrowing of the left renal vein on imaging studies is required but far from sufficient to establish the diagnosis. Several converging clinical findings and a marked pressure gradient between the left renal vein and inferior vena cava must be present also. Urological procedures and vascular surgery are being superseded by endovascular stenting with or without simultaneous treatment of the acquired gonadal vein insufficiency by embolization.

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.

[Nutcracker syndrome: Cause of non-glomerular hematuria and massive proteinuria]

BACKGROUND

Nutcracker syndrome caused by compression of the left renal vein between the aorta and superior mesenteric artery is a non-glomerular cause of left renal bleeding and left varicocele. It has also been recognized to be an important cause of orthostatic proteinuria.

CASE REPORT

A 17-year-old male was evaluated due to recurrent macroscopic hematuria. Physical examination showed left varicocele. Body mass index 16.3 kg/m2. Urinalysis demonstrated hematuria and massive proteinuria. Renal biopsy showed mild mesangial glomerular proliferation. Cystoscopy showed hematuria originating from the left ureter. Doppler ultrasonography and contrast-enhanced computed angiotomography revealed a peak velocity of the left renal vein of 20cm/s, ratio of peak velocity of aortomesenteric and hilar portions of left renal vein of 7.7 and enlargement of the left renal vein in the hilar portion. With a diagnosis of nutcracker syndrome, the patient received conservative treatment. During follow-up, progressive remission of the recurrent episodes of hematuria and proteinuria was observed. The patient had no clinical symptoms or abnormal urinalysis. At 13 months of follow-up the body mass index was 19 kg/m2.

CONCLUSIONS

This case shows the relationship between the increase in body mass index and remission of nutcracker syndrome, manifested as left varicocele, hematuria and massive proteinuria. All symptoms disappeared with the increase of body mass index, probably due to increase in retroperitoneal fat with improvement of the aortomesenteric angle of the left renal vein.

Nonatherosclerotic obstructive vascular diseases of the mesenteric and renal arteries

Nonatherosclerotic vascular diseases of the mesenteric and renal arteries are considered to occur less frequently than those caused by occlusive atherosclerotic disease. However, when present, they pose a significant diagnostic and therapeutic challenge. Such disorders include fibromuscular dysplasia, median arcuate ligament syndrome, the renal nutcracker syndrome, and some forms of acute and chronic mesenteric ischemia (embolic and thrombotic). This is a heterogeneous group of disorders with substantial differences in the pathogenesis and diagnostic approaches to these diseases. We provide an overview of the pathogenesis, clinical presentation, diagnosis, and current management of fibromuscular dysplasia, median arcuate ligament syndrome, and the renal nutcracker syndrome.

Clinical course of children with nutcracker syndrome

OBJECTIVE

To evaluate the clinical properties of patients with nutcracker syndrome (NCS).

MATERIALS AND METHODS

The medical records of the patients with NCS were retrospectively investigated, and the patients' sex, age, presenting symptoms, urinalysis findings, associated diseases, and body mass indexes were recorded.

RESULTS

A total of 23 nonconsanguineous patients (11 male and 12 female patients, mean age 141 ± 36 months). Two patients had posterior NCS. Seventeen patients presented with 1 or >1 symptom. Fatigue and lassitude (n = 1), flank pain (n = 8), abdominal pain (n = 7), varicocele (n = 2), and macroscopic hematuria (n = 9) were the presenting symptoms. Only 6 patients had received a diagnosis of NCS from the urinalysis findings, which revealed microscopic hematuria or non-nephrotic proteinuria. The urinalysis findings disclosed isolated proteinuria in 6, hematuria plus proteinuria in 8, and macroscopic hematuria in 9 patients. Orthostatic proteinuria was detected in 7 patients. In patients with regressed hematuria and proteinuria, the body mass index was markedly increased at the end of the follow-up period relative to at diagnosis (at diagnosis 16.9 ± 4.0 kg/m(2); at the end of the follow-up period 18.6 ± 4.6 kg/m(2); P = .028).

CONCLUSION

The diagnosis of NCS should be considered in the presence of symptoms such as proteinuria and hematuria and should be absolutely ruled out before attempting renal biopsy. An apparent correlation between an increased body mass index and regression of symptoms was seen.

Evaluation of left renal vein entrapment using multidetector computed tomography

BACKGROUND

Nutcracker syndrome, also called left renal vein entrapment syndrome, is a cause of non-glomerular hematuria with difficulties in diagnosis. Multidetector computed tomography (MDCT) is a powerful tool to prevent unnecessary diagnostic procedures.

PURPOSE

To retrospectively determine the prevalence of nutcracker phenomenon and nutcracker syndrome seen in MDCT in consecutive patients.

MATERIAL AND METHODS

The institutional review board approved the study and waived the requirement for informed consent. Abdominal contrast-enhanced MDCT scans were reviewed from 1000 consecutive patients. MDCT scan assessment included renal vein diameter measurements and evaluation for the presence of anterior or posterior left renal vein entrapment. Electronic medical records and urine analysis reports of patients with left renal vein entrapment were reviewed. Student's t test was used to assess differences in renal vein diameter in patients with left renal vein entrapment.

RESULTS

Left renal vein entrapment was observed in 10.9% (109), retro-aortic left renal vein in 6.5% (65), entrapment of left renal vein between superior mesenteric artery and aorta in 4.1% (41), and circumaortic left renal vein in 0.3% (3) of patients. Mean diameters of right (8.8 ± 1.9 mm) and unentrapped left (8.9 ± 1.8 mm) renal veins were not significantly different (P = 0.1). The mean diameter of anterior entrapped left renal veins (10.3 ± 2 mm) was significantly greater (P = 0.04) than contralateral renal veins (8.6 ± 2.1 mm) in their widest portion. In 8.8% of patients with the left renal vein entrapment, urine analysis showed isomorphic hematuria or proteinuria with no other known cause. Varicocele and pelvic congestion were seen in 5.5% of patients with the left renal vein entrapment.

CONCLUSION

Left renal vein entrapment is not a rare entity and renal nutcracker phenomenon might be underdiagnosed.

Newly-identified symptoms of left renal vein entrapment syndrome mimicking orthostatic disturbance

BACKGROUND

In addition to the urinary abnormalities, symptoms of left renal vein entrapment between the aorta and superior mesenteric artery (left renal vein entrapment syndrome, LRVES) may include abdominal and flank pain as well as chronic fatigue. We investigated various LRVES symptoms in this study.

METHODS

In 53 pediatric LRVES patients treated at our department, 22 had a score of 5 points or higher on orthostasis. Initial evaluation of LRVES by abdominal ultrasonography showed a stenotic-to-prestenotic vein diameter ratio of 0.2 or less. Definitive diagnosis was made by computed tomography and magnetic resonance angiography. Cortisol, catecholamine (CA), and brain natriuretic peptide (BNP) were also measured.

RESULTS

The frequency of LRVES was 2.5 times higher in girls than in boys. Low or very low body mass indexes were seen in both sexes. The most common initial finding was urine abnormalities, followed by dizziness and malaise. In 6 patients, orthostasis precluded school attendance. Ten patients had orthostasis scores above 12. Patients unable to attend school had either low levels of plasma or urinary cortisol. Midodrine significantly decreased orthostasis scores. Some patients required treatment with fludrocortisone. Plasma CA, renin, and BNP levels were all normal.

CONCLUSIONS

Locally excessive venous pressure may cause reversible adrenal dysfunction with transitory Addisonian symptoms. Children with cryptogenic malaise or severe orthostasis should be evaluated for LRVES.

Nutcracker syndrome manifesting with severe proteinuria: a challenging scenario in a single-kidney patient

Nutcracker syndrome (NS) refers to compression of the left renal vein between the aorta and the superior mesenteric artery which results in left renal venous hypertension. The typical clinical presenting feature is hematuria. In this report we describe the case of patient with a single kidney who developed severe proteinuria due to NS. She was successfully treated with left renal vein transposition. This case clearly shows the relation between NS and severe proteinuria based on normal biopsy findings and the complete disappearance of proteinuria following surgery.

A rare cause of recurrent hematuria in children: Nutcracker syndrome

Nutcracker syndrome (NCS), the left renal vein hypertension due to compression between aorta and superior mesenteric artery, may present with hematuria, flank pain and proteinuria. We report a 6-year-old girl with episodic macroscopic hematuria who was diagnosed as NCS with Doppler ultrasound and 3D computerized tomography angiography. She was managed conservatively with spontaneous resolution of macroscopic hematuria. With this case we would like to emphasize that in children with hematuria and orthostatic proteinuria without an apparent cause, a great index of suspicion and appropriate imaging is necessary for the diagnosis of NCS.

Varicocele and nutcracker syndrome: sonographic findings

OBJECTIVE

Varicocele is a vascular lesion commonly associated with infertility. Its etiology is only partly understood; hence, the purpose of the study was to establish its correlation with intrinsic anatomic differences and nutcracker syndrome.

METHODS

A total of 93 patients with varicocele and 76 patients without varicocele were enrolled. The diagnosis of varicocele was based on physical examination, followed by sonographic evaluation of the hilar portion and aortomesenteric portion (AMP) of the left renal vein (LRV). The anteroposterior diameter in millimeters and peak flow in centimeters per second in each region were measured.

RESULTS

A total of 28 patients with the nutcracker syndrome were identified in the study group (30.10%), and 2 were identified in the control group (2.63%). The mean diameters of the hilar portion and AMP of the LRV were significantly different in varicocele-affected patients compared with the control group (P < .0001 for both). The mean peak velocities in the hilar portion and AMP were significantly different in patients with varicocele (P < .0001). Patients with varicocele and nutcracker syndrome did not have a significant difference in either the hilar or AMP diameter compared with patients with varicocele without nutcracker syndrome. They had a significant difference in both the hilar and AMP peak flow velocity (P = .0001 for both).

CONCLUSIONS

Our findings indicate that nutcracker syndrome is a frequent finding in varicocele-affected patients and should be routinely excluded as a possible cause of varicocele. In addition, intrinsic anatomic differences in the AMP and hilar portion of the LRV could be directly responsible for the onset of varicocele.

Nutcracker phenomenon and nutcracker syndrome

Nutcracker phenomenon refers to compression of the left renal vein, most commonly between the aorta and the superior mesenteric artery, with impaired blood outflow often accompanied by distention of the distal portion of the vein. The nutcracker syndrome (NCS) is the clinical equivalent of nutcracker phenomenon characterized by a complex of symptoms with substantial variations. Depending on specific manifestations, NCS may be encountered by different medical specialists. Although it may be associated with substantial morbidity, the diagnosis of NCS is often difficult and is commonly delayed. Diagnostic and treatment criteria are not well established, and the natural history of NCS is not well understood. We performed an initial review of the literature through MEDLINE, searching from 1950 to date and using the keywords nutcracker syndrome, nutcracker phenomenon, and renal vein entrapment. We performed additional reviews based on the literature citations of the identified articles. We attempted to elucidate clinical relevance of these conditions and their prominent features and to summarize professional experience.

Entrapment syndromes

Entrapment syndromes represent a pathological process that vascular specialists encounter infrequently. However symptomatic patients are often young with impaired quality of life and successful treatment can produce great benefit, making knowledge of these conditions essential. The purpose of this review was to bring together the entrapment syndromes to understand and gain consensus on the aetiology, pathogenesis, diagnosis and modern management of these rare and interesting vascular disorders. This includes entrapment syndromes of the popliteal artery, superior mesenteric artery, coeliac artery, renal vein and iliac vein.

Nutcracker syndrome in children: the role of upright position examination and superior mesenteric artery angle measurement in the diagnosis

OBJECTIVE

The purpose of this study was to evaluate the pathophysiologic characteristics of nutcracker syndrome (NS) and to assess the role of upright position imaging and superior mesenteric artery (SMA) angle measurement in the diagnosis.

METHODS

Doppler sonographic findings in 23 children with NS and in 26 healthy control subjects were compared. The mesenteric angle, peak velocity (PV), and anteroposterior diameter of the left renal vein (LRV) at the hilar and aortomesenteric portions were measured in both the supine and upright positions. The means +/- SD of the SMA angle, anteroposterior diameter, and PV ratio between the two portions were calculated, and cutoff levels for the diagnosis of NS were established.

RESULTS

The diameter and PV ratios were significantly different between the patient and control groups in both the supine and upright positions (P < .001). Differences between the supine and upright positions were also significant for the diameter of the LRV at the aortomesenteric portion, diameter ratio, and SMA angle in both groups. Upright position imaging revealed comparatively narrower SMA angles and more pronounced entrapment findings in patients with NS. The SMA angle measurement had sensitivity and specificity of 69.6% and 61.5%, respectively, in the supine position and 87.0% and 76.9% in the upright position when the cutoff values were set to less than 41 degrees and 21 degrees , respectively.

CONCLUSIONS

The upright position has significant effects on the LRV hemodynamics and angle of the SMA in both patients and healthy subjects. Superior mesenteric artery angle measurement may be a useful adjunct parameter in the diagnosis of NS.

Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria

To assess the detection rate of nutcracker syndrome in children with isolated hematuria, renal Doppler ultrasound examinations were routinely performed on 216 consecutive children (176 microscopic hematuria and 40 gross hematuria). Renal Doppler ultrasound was also performed on 32 healthy normal children. The peak velocity (PV) was measured at the hilar portion of the left renal vein (LRV) and at the LRV between the aorta and the superior mesenteric artery. The PV at the aortomesenteric portion (P=0.003) and the PV ratios of the LRV (P=0.003) were significantly higher in children with hematuria than in normal children, while the PV at the hilar portion was not different. If a PV ratio of the LRV of at least 4.1 (the cut-off level set at the mean +/-2 SD of the value for the normal children) was defined as abnormal, 72 cases (33.3%) in children with hematuria and no cases in normal children were diagnosed as having nutcracker syndrome. The prevalence of nutcracker syndrome is relatively high in children with isolated hematuria, and the inclusion of renal Doppler ultrasound as a screening examination has a substantial effect on the detection of nutcracker syndrome.

Interventional management of renal vascular origin hematuria

Several renal vascular pathological processes have been associated with hematuria. These include renal artery aneurysm (RAA), fibromuscular dysplasia (FMD), renal nutcracker syndrome (RNS), renal arteriovenous malformation, renal vasculitis, and renal artery or vein thrombosis. We present an unusual case of hematuria in a patient eventually diagnosed with RAA, FMD, and RNS. Percutaneous therapy, including endovascular coiling, percutaneous transluminal angioplasty, and stent placement were used to address the underlying pathology. The differential diagnosis, pathophysiology, and surgical and interventional management of these renal vascular disorders are reviewed.

Gross hematuria in children: a ten-year review

OBJECTIVES

Gross hematuria in children is uncommon. We reviewed our experience characterizing its clinical presentation and diagnosis.

METHODS

The charts of all patients who presented for the 10-year period of 1994 through 2003 were reviewed, and 342 patients were identified. Of these 342 patients, 272 were boys (80%) and 70 (20%) were girls. At presentation, 21 patients (6%) were younger than 3 years (17 were boys and 4 were girls); 199 (58%) were 3 to 12 years old (155 were boys and 44 were girls); and 122 (36%) were 13 to 20 years old (100 were boys and 22 were girls).

RESULTS

Of the 272 male patients, 52 (19%) had benign urethrorrhagia; 48 (14%) had trauma; and 48 had a urinary tract infection (14%), and 10 of those also had urologic anomalies. Of the 342 patients, 45 (13%) had one or more congenital urologic anomalies. Of these 45 patients, 20 boys and 2 girls had vesicoureteral reflux, 10 boys had posterior urethral valves, 7 boys and 1 girl had ureteropelvic junction obstruction, 7 boys had proximal hypospadias, 2 boys and 1 girl had ureterovesical junction obstruction, 2 boys and 1 girl had ureterocele, and 1 boy had caliceal diverticulum. Also, 18 patients (5%) had stones; 3 had low-grade bladder transitional cell carcinoma; and 1 had a Wilms tumor. For 118 patients (34%; 95 boys and 23 girls), no etiology was found.

CONCLUSIONS

Gross hematuria most often had a benign cause in children and adolescents. It was more common in boys for almost all etiologic categories and ages. The extent of the urologic evaluation should depend on the clinical setting. Voiding cystourethrography is useful in those with suspicious ultrasound findings, urinary tract infection, or voiding symptoms. Cystoscopy should be reserved for the minority in whom hematuria persists or those with ambiguous imaging study findings.

Superimposition of nutcracker syndrome in a hematuric child with idiopathic hypercalciuria and urolithiasis

We report a 5-year-old girl with idiopathic hypercalciuria who developed gross hematuria and left flank pain despite normalization of calciuria, a renal stone, and microscopic hematuria. She was found to have nutcracker syndrome by renal Doppler ultrasound, which revealed the significant differences of the peak blood flow velocities in the two portions of the left renal vein.

Current trends in the diagnosis and management of renal nutcracker syndrome: a review

Nutcracker syndrome is caused by compression of the left renal vein between the aorta and the superior mesenteric artery where it passes in the fork formed at the bifurcation of these arteries. The phenomenon results in left renal venous hypertension. The syndrome is manifested by left flank and abdominal pain, with or without unilateral haematuria. Other common presentation is as "pelvic congestion syndrome" characterized by symptoms of dysmenorrhea, dyspareunia, post-coital ache, lower abdominal pain, dysuria, pelvic, vulvar, gluteal or thigh varices and emotional disturbances. Likewise compression of the left renal vein can cause left renal-to-gonadal vein reflux resulting in lower limb varices and varicoceles in males. Its diagnosis is based on history and physical examination, basic lab tests to exclude other causes of haematuria, cystoscopy and ureteroscopy to confirm unilateral haematuria and exclude other causes of this sinister symptom. Sequence of imaging has more or less been rationalised to USS with Doppler studies, CT or MR angiography and finally phlebography with renal vein and IVC manometery to confirm the diagnosis.

Superimposition of nutcracker syndrome in a haematuric child with Henoch-Schönlein purpura

We report a child with Henoch-Schönlein purpura (HSP) who had shown persistent microscopic haematuria for 26 months and was found to have nutcracker syndrome by renal Doppler ultrasound. Haematuria subsided in accordance with radiological improvement of nutcracker syndrome. These findings suggest that the origin of urinary abnormalities in patients with HSP may not always be due to the renal involvement of vasculitis.

Doppler ultrasonographic detection of nutcracker syndrome in a young child with intussusception: a case report

We report on a 2-y-old male with intussusception accompanying nutcracker syndrome detected by renal Doppler ultrasound. Renal Doppler ultrasound revealed a significant difference in the peak velocity between the hilar and aortomesenteric portions of the left renal vein.

CONCLUSION

Renal Doppler ultrasound has been very useful and effective in detecting nutcracker syndrome in a young child.

Factors affecting spontaneous resolution of hematuria in childhood nutcracker syndrome

To identify factors affecting spontaneous resolution of hematuria in children with nutcracker syndrome, 20 patients diagnosed as having nutcracker syndrome using renal Doppler ultrasound (US) were analyzed retrospectively. Sixteen patients had microscopic hematuria, and four had gross hematuria at presentation. The mean age was 10.6 years (range 2.5-14 years). All underwent a follow-up Doppler US examination after a mean period of 1.4 years (range 0.5-3.5 years) after the first US was performed, and height and weight were measured at the time of US. At the time of follow-up US, hematuria disappeared in 15 patients and improved in 3. The peak velocity (PV) ratios of the left renal vein (LRV) at the follow-up US decreased significantly when compared to the first US examination (7.74+/-2.64 vs 3.50+/-1.09, p<0.0001), and height (147.4+/-20.1 vs 152.3+/-18.8 cm) and weight (36.1+/-10.9 vs 42.3+/-12.7 kg) increased (p<0.0001). Changes in the PV ratios of the LRV correlated positively with changes in the PV at the aortomesenteric portion (r=0.569, p=0.009). Changes in the PV at the aortomesenteric portion correlated negatively with changes in body mass index (BMI) (r=-0.543, p=0.013). Although spontaneous resolution of hematuria in children with nutcracker syndrome is obscure, our findings suggest the increase in BMI may be a possible hemodynamic factor.