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.

Causa rara de dolor abdominal recurrente; coexistencia del síndrome de Wilkie y el síndrome del cascanueces / A rare cause of recurrent abdominal pain; the coexistence of Wilkie's syndrome and nutcracker syndrome

El síndrome del cascanueces es un síndrome que presenta síntomas clínicos como hematuria, proteinuria ortostática, congestión pélvica, varicocele del lado izquierdo, hipertensión y dolor en fosa renal. Estos síntomas se producen por la compresión de la vena renal izquierda entre la aorta y la arteria mesentérica superior. En el síndrome de Wilkie, la tercera porción del duodeno está comprimida entre la arteria mesentérica superior y la aorta abdominal, lo que provoca diversos síntomas gastrointestinales. La coexistencia de estos dos síndromes constituye una afección rara y se incluye como casos clínicos en la bibliografía. En este artículo, se presentan los resultados clínicos y radiológicos de un paciente de 17 años que presentaba dolor abdominal recurrente debido al síndrome de Wilkie, acompañado del síndrome del cascanueces que le provocaba proteinuria, por lo que el paciente fue derivado a los consultorios externos de reumatología pediátrica con un diagnóstico preliminar de fiebre mediterránea familiar.

Nutcracker syndrome is a syndrome that has clinical symptoms such as hematuria, orthostatic proteinuria, pelvic congestion, left-sided varicocele, hypertension, and flank pain. These symptoms occur because of the compression of the left renal vein between the aorta and the superior mesenteric artery. In Wilkie's syndrome, the third part of the duodenum is compressed between the superior mesenteric artery and the abdominal aorta, causing various gastrointestinal symptoms. The coexistence of these two syndromes is a rare condition and is included as case reports in the literature. This article presents the clinical and radiological results of a 17-year-old male patient who had recurrent abdominal pain due to Wilkie's syndrome, which was accompanied by nutcracker syndrome that caused proteinuria, and for this reason, the patient was referred to the Pediatric Rheumatology outpatient clinic with a preliminary diagnosis of familial Mediterranean fever.

A rare cause of recurrent abdominal pain; the coexistence of Wilkie's syndrome and nutcracker syndrome. / Causa rara de dolor abdominal recurrente; coexistencia del síndrome de Wilkie y el síndrome del cascanueces.

Nutcracker syndrome is a syndrome that has clinical symptoms such as hematuria, orthostatic proteinuria, pelvic congestion, left-sided varicocele, hypertension, and flank pain. These symptoms occur because of the compression of the left renal vein between the aorta and the superior mesenteric artery. In Wilkie's syndrome, the third part of the duodenum is compressed between the superior mesenteric artery and the abdominal aorta, causing various gastrointestinal symptoms. The coexistence of these two syndromes is a rare condition and is included as case reports in the literature. This article presents the clinical and radiological results of a 17-year-old male patient who had recurrent abdominal pain due to Wilkie's syndrome, which was accompanied by nutcracker syndrome that caused proteinuria, and for this reason, the patient was referred to the Pediatric Rheumatology outpatient clinic with a preliminary diagnosis of familial Mediterranean fever.

El síndrome del cascanueces es un síndrome que presenta síntomas clínicos como hematuria, proteinuria ortostática, congestión pélvica, varicocele del lado izquierdo, hipertensión y dolor en fosa renal. Estos síntomas se producen por la compresión de la vena renal izquierda entre la aorta y la arteria mesentérica superior. En el síndrome de Wilkie, la tercera porción del duodeno está comprimida entre la arteria mesentérica superior y la aorta abdominal, lo que provoca diversos síntomas gastrointestinales. La coexistencia de estos dos síndromes constituye una afección rara y se incluye como casos clínicos en la bibliografía. En este artículo, se presentan los resultados clínicos y radiológicos de un paciente de 17 años que presentaba dolor abdominal recurrente debido al síndrome de Wilkie, acompañado del síndrome del cascanueces que le provocaba proteinuria, por lo que el paciente fue derivado a los consultorios externos de reumatología pediátrica con un diagnóstico preliminar de fiebre mediterránea familiar.

The Journey and Barriers to Treatment of Patients With Renal Nutcracker Syndrome.

OBJECTIVE: To better understand renal nutcracker syndrome (NCS) from a patients' perspective starting at presentation and followed through to diagnosis and management METHODS: This descriptive study was conducted on a national level via a self-selected online survey distributed via river sampling by a post on the Facebook Page 'Renal Nutcracker Syndrome Support Group.' RESULTS: Of the 22 responses collected, 95.5% were female and 91% self-identified as White. 43% experienced symptoms as teenagers and 62% were diagnosed as young adults. Prior to receiving a definitive diagnosis, over half of the respondents were worked up for kidney stones (57%) and ovarian cysts (48%) and saw at least 10-15 providers. Nearly 80% experienced constant pain throughout the day. Pain management included prescription oral pain relievers (38%), prescription patches (29%), and physical therapy (19%). Surgical procedures included nephrectomy with auto transplant (38%), left renal vein transposition (10%), and laparoscopic extravascular stent placement (10%). Respondents had high healthcare utilization for management of NCS. Nearly 30% were unable to work and had filed for disability. CONCLUSION: Awareness of NCS should increase among healthcare providers of all specialties to improve quality of care to those living with NCS. It is crucial to keep NCS within the differential diagnosis in patients presenting with gross hematuria and unusual abdominal and/or flank pain.

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 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.

Haematuria without diagnosis? Think about the rare causes .

We describe a case of a 17-year-old man admitted in the emergency room with a 2-month history of intermittent macroscopic haematuria and left lumbar pain. Physical examination and vital signs were normal. Investigation indicated a recurrent non-glomerular haematuria. The Doppler ultrasound revealed a compression of the left renal vein with upstream dilatation which was subsequently confirmed by CT angiography. These findings are in keeping with a case of nutcracker syndrome (NutS). Although asymptomatic in most cases, it can be a rare cause of haematuria. The teenager was referred to paediatric nephrology and was treated conservatively with spontaneous resolution of macroscopic haematuria. With this case, we would like to highlight that in children or adolescents with haematuria without an apparent cause, a high level of suspicion and appropriate imaging are necessary for the diagnosis of NutS.

Two Peculiarities of the Nutcracker Syndrome: Rare Association with Multiples Thrombosis and Successful Medical Treatment (Pentoxifylline).

The nutcracker syndrome (NCS) is a rare condition characterized by the entrapment of the left renal vein between the superior mesenteric artery and the aorta. Clinically, it presents with hematuria, flank pain, and symptoms of pelvic venous congestion. It is more frequent in females. Conservative treatment is usually proposed children but in adults, NCS has to be treated by surgical or endovascular methods. Drug therapy is not proposed for the treatment of NCS. We report a case of a young patient who presented with recurrent gross hematuria. Our patient was treated with pentoxifylline three times daily and anti-coagulation, with a favorable outcome.

Combined Superior Mesenteric Artery Syndrome and Nutcracker Syndrome in a Young Patient: A Case Report and Review of the Literature.

BACKGROUND Superior mesenteric artery syndrome is the compression of the third portion of the duodenum between the superior mesenteric artery and the aorta causing abdominal pain and vomiting. Nutcracker syndrome is the compression of the left renal vein between the superior mesenteric artery and the aorta causing symptoms related to renal congestion. Both entities, although well described in the literature, are individually rare, and even though they might share a common etiology, their co-existence has been reported in only a few case reports. CASE REPORT An 18-year-old male, previously healthy, presented with postprandial abdominal pain relieved by bilious vomiting that started shortly after he lost weight fasting. Our investigation revealed superior mesenteric artery syndrome as well as a compressed left renal vein. He was started on an enriched fluid diet which was progressed gradually as he regained weight. His left renal vein compression at the time was asymptomatic; it will be followed up for possible resolution after the patient's weight returns to normal. CONCLUSIONS Superior mesenteric artery syndrome is to be suspected in patients with abdominal pain following weight loss. Conservative treatment with a focus on weight regain will cure most cases. Asymptomatic or mildly symptomatic nutcracker syndrome is treated conservatively. For patients requiring intervention, laparoscopic extravascular titanium stent placement seems to be the least invasive promising option today, awaiting further definitive studies.

Effect of visceral fat tissue on superior mesenteric artery configuration: Is it superior to BMI?

BACKGROUND/AIMS: To determine the effect of visceral fat volume measured via computed tomography (CT) images of umbilical slices on superior mesenteric artery (SMA) configuration, as compared with body mass index (BMI). In addition, this study aims to determine the effect of lumbar lordosis angle (LLA) on SMA configuration. MATERIALS AND METHODS: The study included 310 patients who underwent abdominal CT. On CT images, the aortomesenteric angle (AMA), the distance between SMA and aorta at three levels, and LLA were measured. Visceral fat volume was measured using three consecutive images obtained at the level of the umbilicus. The relationship among AMA, and distances measured between SMA and aorta, and visceral fat tissue volume were determined. The effect of LLA on AMA and distances measured between SMA and aorta was analyzed. RESULTS: There was a significant positive correlation between visceral fat volume, and patient age, AMA, distances between SMA and aorta, LLA, and BMI (p<0.001). There were not any significant differences in AMA, distances between SMA and aorta, BMI, or visceral fat volume between the patients with an LLA of 20°-45° and those with an LLA >45° (p>0.05). There was a significant positive correlation between BMI, and AMA, distances between SMA and aorta (p<0.001). There was a significant positive correlation between visceral fat volume, and AMA, distances between SMA and aorta (p<0.001). CONCLUSION: Visceral fat tissue volume is more valuable than BMI for evaluating the SMA configuration.

Hematúria levando ao diagnóstico de duas condições singulares na prática clínica - síndrome de quebra-nozes e traço falcêmico: um relato de caso / Hematuria leading to the diagnosis of two singular conditions in clinical practice - renal nutcracker syndrome and sickle cell trait: a case report

RESUMO: A hematúria é definida como o achado de mais que duas hemácias por campo de aumento na análise microscópica de urina coletada por jato médio. Na sua forma macroscópica, caracteriza-se por sua coloração típica (avermelhada ou marrom), acompanhada pela presença de mais de 106 hemácias/ml na sedimentoscopia. É uma condição que necessita de investigação da causa e apresenta-se com prevalência incerta e definição às vezes imprecisa, mas com vasto diagnóstico diferencial. Dentre as possíveis causas, encontramos a presença do traço falciforme, aparentemente subdiagnosticado, e a síndrome de quebra-nozes, possibilidade mais rara. No caso relatado a seguir, foram diagnosticadas simultaneamente as duas causas acima citadas, descobertas após a investigação do primeiro episódio de hematúria macroscópica em uma mulher jovem previamente hígida. Com o objetivo de chamar a atenção para a concomitância de duas possíveis e incomuns causas de hematúria numa mesma paciente, relatamos o caso a seguir. (AU)

ABSTRACT: Hematuria is defined as the finding more than two red blood cells per field of analysis in the microscopic analysis of the urine collected by the medium jet. In its macroscopic form, it is characterized by its typical coloration (reddish or brown), accompanied by the presence of more than 106 red cells/ml in urinary sediment. It is a condition that needs investigation and it presents itself sometimes with imprecise definition, but with vast differential diagnosis. Among the possible etiologies, there is the presence of the sickle cell trait, apparently underdiagnosed, and the renal nutcracker syndrome, a rarer possibility. In the case reported below, these two findings were diagnosed simultaneously, following an investigation of the first episode of macroscopic hematuria in a young and previously healthy woman. In order to draw attention to the simultaneous presence of two unusual causes of hematuria in the same patient, we report the following case. (AU)

Nutcracker syndrome mimicking new daily persistent headache: A case report.

INTRODUCTION: Compression of the duodenum and left renal vein between the aorta and superior mesenteric artery usually leads to symptoms of proximal bowel obstruction or hematuria and, more rarely, nonspecific mild headaches. CASE: A young woman presented with new daily persistent headache refractory to numerous pharmacological treatments, onabotulinumtoxinA, nerve blocks, and occipital nerve stimulation. Following several years of daily severe headache, worsening abdominal pain and intolerance for food intake led to the discovery of aortomesenteric compression. Surgical treatment gave prompt improvement in gastric symptoms but also essentially resolved the headache. CONCLUSION: This is the first description of new daily persistent headache in association with aortomesenteric compression as well as marked improvement of headache following aortomesenteric decompression. In patients with new daily persistent headache and orthostatic symptoms one may consider a differential diagnosis of Nutcracker syndrome, especially in patients with comorbid hypermobility syndromes, hematuria or gastric symptoms.

Localized solitary left renal vein thrombus complicating nutcracker syndrome: a case report and review of the literature.

Nutcracker syndrome (NCS) refers to compression of the left renal vein (LRV) between the abdominal aorta and the superior mesenteric artery (SMA). The clinical presentation of NCS includes hematuria, abdominal and left flank pain, gonadal varices, and varicocele formation. Theoretically, thrombosis can occur in the LRV in patients with NCS. However, an isolated solitary left renal vein thrombus (LRVT) complicating NCS is rare. In addition, the clinical features of an LRVT complicating NCS remain unclear. We describe a 43-year-old woman presenting with an asymptomatic LRVT complicating NCS. She was referred to our hospital for investigation of dysfunctional uterine bleeding, and detailed examination revealed endometrial cancer. Computed tomography angiography (CTA) and Doppler ultrasonography revealed compression of the LRV between the aorta and the SMA, as well as an LRVT. CTA performed 4 months after the administration of an anticoagulant showed complete disappearance of the LRVT. We have also included a review of published reports describing LRVT complicating NCS and discussed the clinical features of such a presentation.

Hematuria recidivante como síntoma guía del síndrome del desfiladero aortomesentérico / Recurrent hematuria as a guiding symptom of aortomesenteric gorge síndrome

INTRODUCCIÓN: Este síndrome define la compresión de la vena renal izquierda entre la aorta y la arteria mesentérica superior, provocando una presión elevada de dicha vena renal con posible desarrollo de venas colaterales. Clínicamente, aparece hematuria intermitente, proteinuria con o sin dolor abdominal o en hemiabdomen izquierdo. CASOS CLÍNICOS: Presentamos 15 niños de entre 7 y 13 años, la mayoría con examen físico normal y clínica de dolor abdominal o del flanco izquierdo con presión arterial normal (46,6%); hallazgos urinarios: hematuria no glomerular (20%) y proteinuria de rango no nefrótico (20%), con microalbúmina inferior a 300 mg en orina de 24 horas. Un paciente (6,7%) presentó proteinuria asociada a glucosuria e hipertensión. Las mediciones de ultrasonografía Doppler del diámetro anteroposterior (AP) y las velocidades máximas de la vena renal izquierda son diagnósticas: dilatación y enlentecimiento del flujo proximal a la pinza aortomesentérica, disminución del calibre con flujo acelerado a nivel distal y ángulo de la pinza menor de 30º. En dos casos precisó angio-TAC, mostrando la vena renal izquierda comprimida entre la aorta y la arteria mesentérica superior. La angiografía por RM ofrece una excelente definición anatómica. El tratamiento es conservador. Puede ser necesario tratamiento con inhibidores de la enzima convertidora de la angiotensina, intervenciones quirúrgicas o procedimientos extravasculares. CONCLUSIÓN: Sospechar SHVR ante la presencia de hematuria, proteinuria, dolor abdominal recurrente, diagnóstico que requiere alto índice de sospecha. Precisa ecografía. En casos seleccionados, angio-TAC, RM o flebografía, siendo esta última el gold standard para el diagnóstico, que no suele precisarse

INTRODUCTION: This syndrome defines the compression of the left renal vein between the aorta and the superior mesenteric artery, causing an elevated pressure of said renal vein with possible development of collateral veins. Clinically, intermittent hematuria, proteinuria appears with or without abdominal pain or in the left abdomen. CLINICAL CASES: We present 15 children between 7 and 13 years old. Most with normal physical and clinical examination of abdominal or left flank pain with normal blood pressure (46.6%); urinary findings: non-glomerular hematuria (20%) and non-nephrotic range proteinuria (20%), with microalbumin less than 300 mg in 24-hour urine. One patient (6.7%) presented proteinuria associated with glucosuria and hypertension. Doppler ultrasound measurements of the anteroposterior diameter (AP) and the maximum velocities of the left renal vein are diagnostic: dilatation and slowing of the flow proximal to the aortomesenteric clamp, decrease in caliber with accelerated flow at the distal level and angle of the clamp less than 30º. In two cases, angio-TAC was required, showing the compressed left renal vein between the aorta and the superior mesenteric artery. MR angiography offers excellent anatomical definition. The treatment is conservative. Treatment with angiotensin-converting enzyme inhibitors, surgery, or extravascular procedures may be necessary. CONCLUSION: Suspect RVS, in the presence of hematuria, proteinuria, recurrent abdominal pain, a diagnosis that requires a high index of suspicion. Requires ultrasound. In selected cases, CT angiography, MRI or phlebography, the latter being the gold standard for diagnosis, which is not usually required

Eighteen years of experience with pediatric nutcracker syndrome: the importance of the conservative approach.

INTRODUCTION: Nutcracker syndrome (NS) defines an entity generated by the compression of the left renal vein resulting in venous hypertension, which transmitted in a retrograde direction may cause hematuria, proteinuria, and varicocele. The literature concerning exclusively pediatric patients is very rare. OBJECTIVE: To report the authors' experience with pediatric NS in the last 18 years. STUDY DESIGN: This is a retrospective review of the patients followed up in the authors' center with diagnosis of NS based on clinical and imaging tests (ultrasound, computed tomography/magnetic resonance imaging, and phlebography). The primary outcome was the success of the conservative approach in the study patients. RESULTS AND DISCUSSION: A total of 21 patients were diagnosed with NS and followed up for a mean period of 52.3 months (37.1-67.5). The mean age at diagnosis was 11.7 years (9.9-13.4). The most frequent symptom of presentation was hematuria in 16 patients (76.2%), being macroscopic in 75% patients and related to physical exercise in 42.9% patients. Other symptoms were left varicocele in 7 patients (33%) and proteinuria in 6 patients (28.6%). Mild to moderate cases received conservative treatment (change of physical activity, postural hygiene), which achieved resolution of symptoms in 16 patients (76.2%). Five cases (23.8%) finally needed a more aggressive approach. Two (9.5%) of them required endovascular procedures (intravascular stent in the renal vein in 1 case and embolization of the spermatic vein in 1 case); in one (4.8%) of the patients, transposition of the left renal vein and kidney autotransplantation were performed, and 2 (9.5%) of the patients with mild cases required surgical correction of the varicocele. CONCLUSIONS: Hematuria, usually macroscopic and related to physical exercise, is the most frequent symptom in pediatric patients with NS. The authors advocate studying the aortomesenteric junction by abdominal ultrasound in patients with varicocele or with intermittent macroscopic hematuria. Diagnosis is based on non-invasive tests; phlebography should be reserved for severe cases that require an interventionist attitude. A long period of conservative treatment is the first approach for pediatric patients with NS.