Nutcracker syndrome: diagnosis and therapy

Robotic Renal Vein Bypass: A Novel Technique for Treating a Challenging Case of Nutcracker Syndrome

This case report highlights the successful application of a robotic-assisted surgical approach in managing Nutcracker syndrome. The patient, a 36-year-old female presented with severe symptoms and underwent robotic left renal vein transposition after failing conservative management. The procedure was performed through a minimally invasive approach utilizing the Da Vinci robotic system™ which offers enhanced visualization and precision. However, challenges arose during the renal vein anastomosis due to tension and poor flow through the transposition, requiring two revisions with a bovine pericardial patch. Ultimately, an 8 mm ringed PTFE bypass was anastomosed from the distal left renal vein to the Inferior Vena Cava. Despite these challenges, the patient experienced a successful outcome with complete symptom resolution of this complicated pathology.

Outcomes of conservative management in patients with nutcracker syndrome

OBJECTIVE

This study aims to evaluate outcomes in nutcracker syndrome patients with tolerable symptoms and treated conservatively without invasive interventions.

METHODS

This prospective study included patients treated conservatively. Promoting weight gain, the endpoint of the study was spontaneous resolution of symptoms.

RESULTS

Sixteen patients (75% female and mean age 24.4 ± 3.5 years) underwent conservative management. Over a mean follow-up of 27.3 months [13-42, interquartile range (IQR)], the diameter ratio (5.5 [5-6.5, IQR] vs 4.3 [4.1-6], p = NS), the peak velocity ratio (6 [5-7, IQR] vs 4.8 [4.8-5.8], p = NS), beak angle (27° [24-30, IQR] vs 29° [24-32]; p = NS), and aortomesenteric angle (26° [23-29, IQR] vs 28° [24-30]; p = NS) exhibited no statistically significant changes. Complete resolution and improvement of symptoms were 28.5% and 31.4%, respectively, while 68.5% remained unchanged.

CONCLUSIONS

This study shows that a conservative approach contributes to the spontaneous improvement or complete resolution in young adult patients with mild symptoms.

Understanding Superior Mesenteric Artery Syndrome: Etiology, Symptoms, Diagnosis, and Management

Superior mesenteric artery (SMA) syndrome, also known as Wilkie's syndrome, poses a diagnostic challenge due to its rarity and varied clinical manifestations. This review explores the syndrome's etiology, symptoms, diagnostic challenges, and management strategies. Symptoms range from early satiety to severe abdominal pain, often leading to malnutrition. Diagnosis involves a thorough gastrointestinal evaluation and various imaging modalities. Management includes medical interventions like nasogastric decompression and nutritional support, along with surgical interventions such as duodenojejunostomy. A thorough understanding of SMA syndrome's complexities is crucial for its timely diagnosis and effective management, especially considering its potential overlap with other gastrointestinal disorders or eating disorders. Further research is needed to enhance understanding and improve patient outcomes.

Nutcracker syndrome: a case-based review

The nutcracker phenomenon, also known as left renal vein entrapment, occurs when there is extrinsic compression of the left renal vein, most often between the abdominal aorta and the superior mesenteric artery. Nutcracker syndrome refers to the constellation of clinical symptoms that may arise from the nutcracker phenomenon, typically inclusive of haematuria, flank/pelvic pain, orthostatic proteinuria and (in male patients) varicocele. We provide a short review of the nutcracker syndrome including various diagnostic and therapeutic modalities. We utilise our own experience with a patient as a case study and highlight the modern management option of endovascular stenting.

Hemodynamics in nutcracker syndrome: implications for diagnosis

BACKGROUND

Nutcracker syndrome is a disease characterized by complex symptoms, making its diagnosis challenging and often delayed, often resulting in a painful experience for the patients.

OBJECTIVE

This study aimed to investigate the pathogenesis of nutcracker syndrome through the perspective of hemodynamics by simulating blood flow with varying compression degrees of the left renal vein.

METHODS

3D patient-specific vascular models of the abdominal aorta, superior mesenteric artery and left renal vein were constructed based on CT images of patients suspected of having nutcracker syndrome. A hemodynamic simulation was then conducted using computational fluid dynamics to identify the correlation between alterations in hemodynamic parameters and varying degrees of compression.

RESULTS

The study indicated the presence of an evident gradient in velocity distribution over the left renal vein with relatively high degrees of stenosis (α ≤ 50°), with maximum velocity in the central region of the stenosis. Additionally, when the compression degree of the left renal vein increases, the pressure distribution of the left renal vein presents an increasing number of gradient layers. Furthermore, the wall shear stress shows a correlation with the variation of blood flow velocity, i.e., the increase of wall shear stress correlates with the acceleration of the blood flow velocity.

CONCLUSIONS

Using computational fluid dynamics as a non-invasive instrument to obtain the hemodynamic characteristics of nutcracker syndrome is feasible and could provide insights into the pathological mechanisms of the nutcracker syndrome supporting clinicians in diagnosis.

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.

Venous compression syndromes in females: A descriptive review

Venous compression syndromes have been described, yet the role of sex is poorly understood. Although iliac vein compression has been discussed more often with the advent of newer technologies, research has fallen short on defining epidemiology, best practices for evaluation and treatment, and differences in responses to treatment between men and females. The authors report on iliac vein compression, nonthrombotic renal vein compression, and other venous compression syndromes in females. Literature searches of PubMed were performed using the following keywords: females/females and May Thurner, venous stenting, venous outcomes, deep venous disease, deep venous compression, venous stenting, renal vein compression, renal vein surgery/stent, popliteal vein entrapment, venous thoracic vein entrapment, and popliteal vein entrapment. The articles prompted the authors to research further as the referenced articles were reviewed. Sex representation has not been addressed adequately in the research of venous compression syndromes, making the discussion of best treatment options and long-term outcomes difficult. More specific understanding of epidemiology and response to interventions will only come from research that addresses these issues directly, understanding that some of these syndromes occur rarely.

Therapeutic Donor Kidney Transplant Outcomes: Comparing Early US Experiences Using Optimal Matching

Background

Therapeutic donors (TDs) are individuals who undergo organ removal for medical treatment with no replacement organ, and the organ is then transplanted into another person. Transplant centers in the United States have started using TDs for kidney transplantation (KT). TD-KT recipient outcomes may be inferior to those of non-TD-living-donor (non-TD-LD)-KT or deceased-donor (DD)-KT because of the conditions that led to nephrectomy; however, these outcomes have not been sufficiently evaluated.

Methods

This was a retrospective cohort study using Organ Procurement and Transplantation Network data. Via optimal matching methods, we created 1:4 fivesomes with highly similar characteristics for TD-KT and non-TD-LD-KT recipients and then separately for TD-KT and DD-KT recipients. We compared a 6-mo estimated glomerular filtration rate (eGFR) between groups (primary endpoint) and a composite of death, graft loss, or eGFR <30 mL/min/1.73 m2 at 6 mo (secondary).

Results

We identified 36 TD-KT recipients with 6-mo eGFR. There was also 1 death and 2 graft losses within 6 mo. Mean ± SD 6-mo eGFR was not significantly different between TD-KT, non-TD-LD-KT, and DD-KT recipients (59.9 ± 20.7, 63.3 ± 17.9, and 59.9 ± 23.0 mL/min/1.73 m2, respectively; P > 0.05). However, the 6-mo composite outcome occurred more frequently with TD-KT than with non-TD-LD-KT and DD-KT (18%, 2% [P < 0.001], and 8% [P = 0.053], respectively).

Conclusions

Early graft function was no different between well-matched groups, but TD-KT demonstrated a higher risk of otherwise poor 6-mo outcomes compared with non-TD-LD-KT and DD-KT. Our results support selective utilization of TD kidneys; however, additional studies are needed with more detailed TD kidney information to understand how to best utilize these kidneys.

Use of tubularized bovine pericardium in left renal vein transposition for nutcracker syndrome

Nutcracker syndrome is an extrinsic compression of the left renal vein by the superior mesenteric artery anteriorly and aorta posteriorly, resulting in hallmark manifestations of hematuria, proteinuria, and flank and/or pelvic pain. This report illustrates the case of a patient with a history of left flank pain and intermittent gross hematuria every 2 weeks. The patient denies any pelvic pain or gastrointestinal or lower extremity symptoms. Urinalysis revealed red blood cells, but no infection was noted. The cystoscopy findings were normal. Computed tomography urography showed left renal vein and duodenal compression between the aorta and superior mesenteric artery with a narrow aortic-superior mesenteric artery angle. The patient underwent left renal vein transposition to the distal inferior vena cava via a transabdominal approach. The left renal vein was transected at the inferior vena cava; however, the length was too short to create a tension-free anastomosis. Thus, a bovine pericardium sheet was tubularized and used as an interposition graft. The patient recovered well and is symptom-free. Left renal vein transposition is a well-described surgical technique in the treatment of nutcracker syndrome. The use of a vein or prosthetic graft has been described. This case demonstrates the use of an alternate conduit for reconstruction.

Superior Mesenteric Artery Syndrome and Nutcracker Syndrome as the Presentation of Crohn's Disease in a Young Patient: A Case Report and Review of Literature

Superior mesenteric artery syndrome and nutcracker syndrome are rare vascular complications most often seen after marked weight loss caused by compression of the duodenum and left renal vein between the superior mesenteric artery and the aorta, respectively. The coexistence of superior mesenteric artery syndrome and nutcracker syndrome has been rarely reported. Herein, we present the case of a 16-year-old male with intermittent periumbilical abdominal pain, bilious vomiting, and weight loss who was found to have both of these vascular complications of significant weight loss as the initial presentation of Crohn's disease. This report provides insight into the diagnosis and treatment of these syndromes while highlighting the importance for practitioners to keep vascular complications on their differential diagnosis of vomiting and abdominal pain in patients with Crohn's disease.

A Rare Case of Nutcracker Phenomenon Associated With Midgut Malrotation and Congenital Solitary Kidney

Medical conditions such as the nutcracker phenomenon, midgut malrotation, and congenital solitary kidney are rare. Hereby, we present a 21-year-old South Asian male referred to the nephrology clinic for hypertension and increased serum creatinine and was diagnosed with all three conditions. We briefly reviewed the literature on this subject. We present this case report to highlight the complex interplay of multiple renal and gastrointestinal anomalies and to emphasize the importance of a multidisciplinary approach in patient care to optimize outcomes and quality of life.

Nutcracker Syndrome in a 77-Year-Old Female With Bilateral May-Thurner Syndrome: A Case Report

Nutcracker syndrome (NCS) is an uncommon condition that predominantly affects the left renal vein (LRV) because of its entrapment between the aorta and superior mesenteric vein. It can result in pain in the left flank or back, hematuria, and proteinuria. May-Thurner syndrome (MTS) is described as a condition in which the left common iliac vein is compressed by the right common iliac artery, causing swelling, fullness, venous ulcers, or varicose veins in the leg. We present a case of a 77-year-old female who had these symptoms for over a decade, until she was diagnosed in 2017. Initially, she experienced swelling and pain in her left leg, which began in 2005; however, treatment did not begin until she had her left ovarian vein embolized in 2017. Her symptoms returned the following year, leading to the diagnosis of bilateral MTS. Owing to recurring symptoms in 2022, a repeat venogram revealed bilateral external iliac vein constriction, requiring intervention. She presented to our clinic in 2023 after being referred by her cardiologist because of persistent back pain and venous congestion. This led to the findings and diagnosis of NCS with bilateral MTS.

Double nutcracker syndrome in a patient with circumaortic venous ring: a rare case report

Aim of the study

In this article, we describe a rare case of the nutcracker syndrome caused by combined compression of the left anteroaortic and retroaortic renal veins. Case description: A 42-year-old woman presented with microhematuria and left flank pain. The patient underwent computed tomography and Doppler ultrasound which showed the left renal veins with anteroaortic and retroaortic courses, with signs of compression. Compression of the anteroaortic renal vein was caused by a narrowing of the aortomesenteric space, whereas compression of the retroaortic renal vein was caused by a narrowing of the aortovertebral space.

Conclusions

NCS is a rare disease, poorly understood and difficult to diagnose mainly due to the non-specificity of symptoms. Imaging is essential for diagnosis, and the combination of ultrasound and computed tomography allows for better classification of the disease. Increased disclosure of these cases can significantly contribute to a reduction of false negatives.

Systematic review of endovascular versus laparoscopic extravascular stenting for treatment of nutcracker syndrome

OBJECTIVE

The aim of the present study was to assess the current strategies of endovascular and laparoscopic extravascular stenting for symptomatic compression of the left renal vein (LRV), most frequently between the aorta and superior mesenteric artery (nutcracker syndrome [NCS]).

METHODS

We performed a systematic review of all studies of endovascular and laparoscopic extravascular LRV stenting for NCS using the PubMed/MEDLINE, Scopus, Embase, Cochrane, Science Citation Index Expanded, Emerging Sources Citation Index, and Epistemonikos databases. Data were collected in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analysis) guidelines. The English, Spanish, and German language literature was searched from January 1, 1946 to February 9, 2022. The outcomes assessed included symptom resolution, hematuria resolution, and reintervention at follow-up.

RESULTS

The search yielded 3498 reports. After removing the duplicates and those without the full text available, 1724 studies were screened. Of these, 11 studies were included in the present review. Of the 11 studies, 7 were on endovascular stenting and 4 on laparoscopic extravascular stenting; all 11 studies were retrospective, single-center case series. Of the 233 patients, 170 (80 women) had undergone endovascular stenting and 63 (9 women) had undergone extravascular stenting. The follow-up period varied from 1 to 60 months after endovascular stenting and 3 to 55 months after extravascular stenting. The symptoms had resolved in 76% (range, 50%-100%) after endovascular stenting and 83% (range, 71%-100%) after extravascular stenting. Hematuria had resolved in 86% (range, 60%-100%) after endovascular stenting and 89% (range, 77%-100%) after extravascular stenting. Of 185 patients, 9 had required reintervention after endovascular stenting and none after extravascular stenting.

CONCLUSIONS

Endovascular and laparoscopic extravascular stenting are less invasive and, thus, more attractive treatment options that have been more recently developed for the management of NCS. The results from the present study have shown that symptom and hematuria resolution must be provided before they can be considered preferred management options for patients affected by NCS. Given the limited number of patients involved, no definitive conclusion could be drawn regarding the superiority of one technique compared with the other.

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.

Daily persistent headache with nutcracker physiology and spinal epidural venous congestion: Treatment with lumbar vein embolization

Nutcracker phenomenon (NCP) can cause various congestion syndromes secondary to the superior mesenteric artery (SMA) compressing the left renal vein (LRV) resulting in venous reflux. It has recently been suggested that reflux into the lumbar vein (LV) and epidural venous plexus (EVP) may cause headaches in some patients with NCP. This report illustrates an example of a patient with refractory headaches and imaging findings suggestive of NCP that underwent treatment with percutaneous LV embolization. The patient is a 60-year-old female with daily persistent headaches for 5 years that failed numerous headache preventative medications. Time-resolved magnetic resonance angiography demonstrated NCP with reflux and congestion of the LV and EVP. Catheter-based venography confirmed these findings and the patient was treated with percutaneous embolization of the LV. This case report demonstrates the use of LV embolization to prevent EVP reflux and treat daily headaches due to NCP. The patient's headache resolved the next day. She has been headache-free for 5 months post-treatment. These findings support prior data suggesting that NCP can cause retrograde LV flow, EVP congestion, and elevated cerebrospinal fluid pressures leading to daily persistent headaches. Percutaneous embolization of the LV may be a minimally invasive treatment option for refractory headaches in patients with NCP, retrograde LV flow, and EVP congestion.

How to define and assess the clinically significant causes of hematuria in childhood

Given the wide diversity of causes of hematuria, ranging from simple urinary tract infections with rapid recovery to severe glomerulonephritis with fast decline in kidney function, it is essential to recognize the underlying disease. The first objective of the assessment is to determine whether the cause of the hematuria is medically significant. The combination of hematuria with proteinuria, the presence of hypertension, or worsening kidney function can represent signs of progressive kidney disease. Differentiating the various causes of hematuria is often simple and obvious based on the clinical signs and gross appearance of the urine. However, in some instances, additional non-invasive investigations, such as ultrasound imaging, urinary red cell morphology, measurement of calcium and other solutes in the urine, evaluation of kidney function, and protein excretion, are needed to elucidate the nature of the hematuria. Taking a detailed family history can help in establishing the underlying cause in cases of familial hematuria. On the other hand, the decision to perform a kidney biopsy in children with asymptomatic hematuria remains a challenging issue for clinicians. Ultimately, the frequency of diagnosis of glomerular involvement causing hematuria may depend on the threshold for performing a kidney biopsy. The following review will focus on the diagnostics of hematuria, starting with difficulties regarding its definition, followed by various means to differentiate between urinary, glomerular, and other causes, and finally reviewing the most common diseases that, due to their frequency or their effect on kidney function, present a diagnostic challenge in everyday practice.

Diagnosis and Management of Pelvic Venous Disorders in Females

Pelvic venous pathologies in females are responsible for chronic symptoms grouped under the term pelvic congestion syndrome, which includes chronic pelvic pain, perineal heaviness, urgency, and postcoital pain, along with vulvar, perineal, and lower limb varicose veins. These conditions are also associated with ovarian and pelvic venous reflux and venous obstruction. This review aimed to explore the clinical and imaging modalities for diagnosing pelvic congestion syndrome, pelvic venous pathologies, their therapeutic management, and their outcomes.

Interventional Management of a Rare Combination of Nutcracker and Wilkie Syndromes

Nutcracker and Wilkie syndromes are rare mesoaortic compression entities, and their association is even less common. Data on interventional treatment of these pathologies are still scarce, but results from limited case series are encouraging. We report the case of a previously healthy 45-year-old woman diagnosed with nutcracker and Wilkie syndromes who presented with macroscopic hematuria, intermittent pain in the left flank and hypogastric region, postprandial nausea, and unexplained significant weight loss. A successful endovascular approach with stent implantation in the left renal vein was performed, but the stent migrated toward the left kidney, and this acute complication was managed through an interventional strategy as well. At the three-month follow-up, the patient described a marked improvement in all symptoms, except for the macroscopic hematuria. As it was our strong belief that the approach was efficient, we further investigated the “hematuria”, which eventually led to the diagnosis of endometrial carcinoma. A hysterectomy and bilateral adnexectomy were planned, and chemoradiotherapy was initiated with the goal of preoperative tumor reduction. To our knowledge, this is the first reported case in which both Wilkie and nutcracker syndromes were effectively treated by stent implantation in the left renal vein, complicated with very early stent migration due to inadequate apposition to the less compliant venous lumen. The treatment of the duodenal compression was indirectly included in the stenting of the left renal vein, as reclaiming the venous lumen widened the aortomesenteric angle. The aim of this review is to discuss our center’s transcatheter experience with these rare disorders and explore the literature in order to establish the benefits and limitations of such an approach.

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.