Nutcracker Syndrome Research Articles

Hemodynamic Consequences of Pre-and Retroaortic Left Renal Vein Compression (“Nutcracker Syndrome”) Causing a Surprising Variety of Symptoms and Complaints, Especially in Patients Affected by Hypermobility Spectrum Disorders

Hemodynamic Consequences of Pre-and Retroaortic Left Renal Vein Compression (“Nutcracker Syndrome”) Causing a Surprising Variety of Symptoms and Complaints, Especially in Patients Affected by Hypermobility Spectrum Disorders

Vascular compression syndromes in the abdomen and pelvis: a concise pictorial review.

Vascular compression syndromes are a diverse group of pathologies that can manifest asymptomatically and incidentally in otherwise healthy individuals or symptomatically with a spectrum of presentations. Due to their relative rarity, these syndromes are often poorly understood and overlooked. Early identification of these syndromes can have a significant impact on subsequent clinical management. This pictorial review provides a concise summary of seven vascular compression syndromes within the abdomen and pelvis including median arcuate ligament (MAL) syndrome, superior mesenteric artery (SMA) syndrome, nutcracker syndrome (NCS), May-Thurner syndrome (MTS), ureteropelvic junction obstruction (UPJO), vascular compression of the ureter, and portal biliopathy. The demographics, pathophysiology, predisposing factors, and expected treatment for each compression syndrome are reviewed. Salient imaging features of each entity are illustrated through imaging examples using multiple modalities including ultrasound, fluoroscopy, CT, and MRI.

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 8mm 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.

Hemodynamics in nutcracker syndrome: implications for diagnosis.

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. 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. 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. The study indicated the presence of anevident 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. 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 thenutcracker syndrome supporting clinicians in diagnosis.

Nutcracker syndrome in childhood

Nutcracker phenomenon (NP) is defined as the compression of the left renal vein, often occurring between the aorta and the superior mesenteric artery (SMA). Patients with symptoms associated with the Nutcracker anatomy are called “Nutcracker syndrome” (NCS). Renal vein compression results in venous congestion, outlet obstruction, and increased pressure in the left renal vein. The clinical manifestations of NCS in children vary widely depending on the severity of compression. It can range from being asymptomatic to presenting with intermittent or persistent micro or macrohematuria, orthostatic proteinuria, renovascular hypertension, abdominal pain, left-sided flank pain, dysmenorrhea, pain in the testicles or scrotum, and left varicocele. Hematuria, proteinuria, and flank pain are prevalent symptoms. The anatomical and physiological degree of compression of the left renal vein can be diagnosed through Doppler ultrasound (DUS), computer tomography (CT) scan, or magnetic resonance imaging (MRI). In cases with mild symptoms, conservative treatment is an appropriate option, and ACE inhibitors can be used for patients with proteinuria. In more severe cases where conservative approaches and medical treatment fail to yield satisfactory results, endovascular, laparoscopic, or open surgical interventions are employed.

Outcomes of conservative management in patients with nutcracker syndrome.

This study aims to evaluate outcomes in nutcracker syndrome patients with tolerable symptoms and treated conservatively without invasive interventions. This prospective study included patients treated conservatively. Promoting weight gain, the endpoint of the study was spontaneous resolution of symptoms. Sixteen patients (75% female and mean age 24.4 ± 3.5years) underwent conservative management. Over a mean follow-up of 27.3months [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. This study shows that a conservative approach contributes to the spontaneous improvement or complete resolution in young adult patients with mild symptoms.

Bilateral Renal Hilar Nutcracker Phenomenon in a Male Cadaver

Nutcracker phenomenon (NCP) typically refers to the entrapment of the left renal vein (LRV) between the aorta and the superior mesenteric artery. Similar to the classic NCP, the renal vein can also get entrapped between the segmental branches of the renal artery at the renal hilum, which has been referred to as ‘renal hilar nutcracker phenomenon (RHNP).’ During routine dissection of a male cadaver of 67 years, the renal veins of both sides at the renal hilum were seen between the segmental branches of renal arteries, which we identified as the ‘renal hilar nutcracker phenomenon.’ The disposition of the rest of the perihilar structures was normal. ‘Renal hilar nutcracker phenomenon’ can have similar clinical presentation like that of the nutcracker phenomenon. Hence, knowledge of such anatomical variation at the renal hilum is desirable.

Treatment of Nutcracker Syndrome with Left Renal Vein Transposition and Endovascular Stenting

Nutcracker syndrome is a rare condition that occurs as a result of the entrapment of the left renal vein (LRV) between the aorta and the superior mesenteric artery. It is typically associated with symptoms such as left flank pain, hematuria, proteinuria, and pelvic congestion. The current treatment approach may be conservative in the presence of tolerable symptoms, and surgical or hybrid and stenting procedures in the order of priority in the presence of intolerable symptoms. The aim of this study is to review our experiences to evaluate the results of both methods in this series in which we have a greater tendency toward surgery instead of stenting. The clinical data of consecutive patients with nutcracker syndrome who underwent LRV transposition and LRV stenting between July 2019 and October 2023 were retrospectively reviewed. The patients were divided into 2 groups based on the methods of treatment: surgical and stenting. For procedure selection, LRV transposition was primarily recommended, with stenting offered to those who declined. Primary end points were morbidity and mortality. Secondary end points included late complications, patency, freedom from reintervention, and resolution of symptoms. Standard basic statistics and survival analysis methods were employed. Nineteen patients with nutcracker syndrome (female: 100%) were treated with LRV stentings (n=5) and LRV transposition (n=14). The mean age was 24 (20-27, interquartile range [IQR]) years. The mean follow-up was 23 (9-32, IQR) months. There were no major complications and mortality after both procedures. The most frequent sign and symptom associated with LRV entrapment were left flank pain 100% (n=19), proteinuria 88% (n=15), and hematuria 47% (n=9). The mean peak velocity ratio on Doppler ultrasound was 6.13 (6-6.44, IQR). Aortomesenteric angle, beak angle (beak sign), and mean diameter ratio on computed tomography were 26° (22.6-28.5, IQR), 25° (23.9-28, IQR), and 5.3 (5-6, IQR), respectively. Venous pressure measurements were only used to confirm the diagnosis in 5 patients in the stenting group. The measured renocaval gradient was 4 (3.9-4.4, IQR) mm Hg. After both procedures, the classical symptoms, including left flank pain, proteinuria, and hematuria, resolved in 89.5% (n=17), 57.8% (n=11), and 82.3% (n=15) of the cases, respectively. A total of 4 patients required reintervention, 3 patients after LRV transposition (occlusion, n=2; stenosis, n=1), and 1 patient after stenting (occlusion, n=1). The 1-year and 3-year primary patency for the 19 patients was 87% and 80%, respectively. Three-year primary-assisted patency was 100%. Similarly, the 1-year and 3-year freedom from reintervention rate was 83% and 72%, respectively. Additionally, the 1-year and 3-year primary patency for the surgical group was 91% and 81%, respectively, and the 1-year and 3-year primary patency for the stenting group was 75%. Nutcracker syndrome should be kept in mind in cases where flank pain and hematuria cannot be associated with kidney diseases. Radiographic evidence must be accompanied by serious symptoms to initiate the treatment of nutcracker syndrome with LRV transposition and endovascular stenting procedures. Both procedures, along with their respective advantages and disadvantages, can be preferred as primary treatments for nutcracker syndrome. Our study demonstrates that both procedures can be safely and effectively performed, yielding good outcomes.

Patient-Reported Outcomes for Robot-Assisted Laparoscopic Extravascular Renal Vein Stent Placements for Nutcracker Syndrome.

Introduction: Nutcracker phenomenon is the compression of the left renal vein between the superior mesenteric artery (SMA) and the abdominal aorta. Nutcracker syndrome refers to the presence of nutcracker phenomenon with symptoms. Between 2016 and 2022, we performed 18 robot-assisted laparoscopic extravascular renal vein stent (RALERVS) placements. We sought to assess patient-reported outcomes of RALERVS placement by a single institution. Methods: We performed a single-center retrospective review of 18 patients with a minimum of 3 months follow-up. Symptoms were assessed utilizing a questionnaire conducted with a 5-point Likert scale at a minimum of 3 months postoperatively. Five on the Likert scale was severe while 1 was none. Primary study outcomes compared pre- and postoperative patient-reported symptom scores. Results: Twelve out of 18 patients responded to the survey. The average length of time from date of operation to completion of survey was 2.6 years. Average age of the cohort was 36 years with a mean BMI of 19.4 kg/m2. There was only one man. Mean operative time was 137 minutes and mean estimated blood loss was 12 mL. Mean preoperative SMA angle was 19° and mean postoperative SMA angle was 36°. Patients reported that flank pain, abdominal pain, nausea, headaches, back pain, pelvic pain, and early satiety improved (p < 0.05). Ten of 12 respondents would recommend RALERVS for nutcracker syndrome. Conclusion: RALERVS demonstrates an effective treatment for nutcracker syndrome. Patients reported improved symptoms at 3 months postoperatively across multiple domains. Further studies need to be conducted to assess long-term durability of the extravascular renal vein graft.

A Teenager with Nutcracker Syndrome and Primary Nephrotic Syndrome

A Teenager with Nutcracker Syndrome and Primary Nephrotic Syndrome

Nutcracker syndrome in children: review of symptom, diagnosis, and treatment

Renal nutcracker syndrome (NCS) is the entrapment of the left renal vein between the abdominal aorta and superior mesenteric artery. Although uncommon in pediatric patients, early diagnosis is crucial to avoid potential severe complications, such as anemia or renal vein thrombosis. NCS presents a variety of symptoms, most commonly including “Triade’s symptoms”–hematuria, proteinuria, and flank pain. Diagnosis and treatment include invasive and noninvasive management, although due to a lack of pediatric clinical studies, management is widely variable. Conservative diagnosis and treatment are recommended as a firstline option for pediatric patients; however, invasive surgical treatment may be recommended based on symptom severity. This review aims to provide a comprehensive overview of NCS in children to better understand the widely variable incidence, occurrence, and management from early on to allow for early-onset management.

An unusual cause of severe tricuspid regurgitation: migration of left renal vein stent in nutcracker syndrome

An unusual cause of severe tricuspid regurgitation: migration of left renal vein stent in nutcracker syndrome

Nutcracker syndrome combined with immunoglobulin A nephropathy: two case reports

Nutcracker syndrome (NCS) is a disease caused by compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. Immunoglobulin A (IgA) nephropathy (IgAN) is characterized by the predominance of IgA deposits in the glomerular mesangial area. Hematuria and proteinuria can be present in both diseases, and some patients can be concurrently diagnosed with NCS and IgAN; however, a causal relationship between the two diseases has not yet been clarified. Here, we report two pediatric cases of NCS combined with IgAN. The first patient presenting with microscopic hematuria and proteinuria was diagnosed with NCS at the initial visit, and the second patient was later diagnosed with NCS when proteinuria worsened. Both patients were diagnosed with IgAN based on kidney biopsy findings and treated with angiotensin-converting enzyme inhibitors and immunosuppressants. A high index of suspicion and timely imaging or biopsy are essential for the proper management of NCS combined with glomerulopathy.

Response to: Is there any clinical reason to administer anticoagulant therapy to patients with the Jugular Vein Nutcracker Syndrome?

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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.

Patient reported outcome measures (PROMS) and patient reported experience measures (PREMS): Measuring outcomes in pelvic venous disorders

Pelvic venous disorders (PeVD) present with a range of heterogenous symptoms that arise from altered venous hemodynamics in the pelvis. Many of these symptoms lead to mental health and quality of life issues and are not limited to the pelvic region. The nutcracker phenomenon causing left renal vein compression and left ovarian venous hypertension as well as the compression of the left common iliac vein by the overlying right common iliac artery are often stated as the common underlying pathologies. As a result, there has been a sudden increase in the number of ovarian vein coil embolizations and iliac vein stents placed. In truth however, the altered venous hemodynamics in PeVD is more complex. There appears to be little correlation between the symptoms patients experience and the obvious image detected anatomical lesions being treated. In addition, these anatomical lesions are very commonly seen in asymptomatic and especially muti-parous women as well. To compare outcomes of these and other more extensive procedures being performed for these commonly seen anatomical changes in the pelvic veins, objective assessments of the outcomes as seen from the symptom relief they bring to patients treated is essential. Validated Patient-reported outcome measures (PROMS) can be an important tool to compare outcomes across interventions for PeVD. However, as the impact of similar symptoms on different patients’ quality of life (QoL) can vary, developing a validated PROM that can be used to compare procedural outcomes in PeVD is a challenge. On the other hand, complications and procedural success as reported by physician do not assess the effect on a patient’s QoL. This paper provides a narrative review of PROMs, patient reported experience measures (PREMs) and individualized-PROMs. It also suggests a process for how a validated PROM for comparing procedural outcomes in PeVD may be developed. This could provide a framework that incorporates the recently adopted Symptoms-Varices-Pathophysiology (SVP) classification of pelvic venous disorders into the PROM development process to ensure that a like-for-like comparison is made between procedures being performed on a very heterogenous, but long-suffering group of patients.

Is there any clinical reason to administer anticoagulant therapy to patients with the Jugular Vein Nutcracker syndrome?

Is there any clinical reason to administer anticoagulant therapy to patients with the Jugular Vein Nutcracker syndrome?

Surgical treatment of nutcracker syndrome results in improved pain and quality of life

BackgroundLeft renal vein (LRV) compression, or nutcracker phenomenon, describes the compression of the LRV, most commonly between the aorta and the superior mesenteric artery. The outflow obstruction that occurs from the compression causes venous hypertension leading to the development of pelvic collaterals, lumbar vein engorgement and gonadal vein reflux. The symptoms associated with LRV compression include abdominal pain, left flank pain, back pain, headache, pelvic pain/pressure, and hematuria. Symptomatic LRV compression can cause chronic pain and disability that impedes activities of daily living. Left renal auto transplantation (LR-AT) is one mode of treatment, leading to decreased pain with no significant vascular or urological complications. Herein we present a five patient case series with symptomatic LRV compression who underwent LR-AT with improved pain and quality of life after surgery. MethodsFive patients underwent LR-AT between June 2020-December 2020 to resolve their symptomatic LRV compression. These patients were given three validated surveys pre- and post- intervention, then again at their three month follow up visit to assess their pain and health-related quality of life. ResultsThe five patients were all female with the average age of 36.8 years old (36–41) and underwent LR-AT to treat their symptomatic LRV compression. The average Numeric Rating Scale (NRS) pain score pre intervention was 8.3 (range 6.7 to 10) which improved to pain rating 5.22 (range 2.7 to 6) post intervention, p-value = 0.013. The average pain NRS score at 3 month follow up was 3.86 (range 1.3–6), p-value = 0.006 when compared to pre-intervention pain scores. The average pain intensity pre intervention was 4.5 (4 to 5) and 2.7 (1 to 4.3) post intervention, p-value = 0.024. The average pain intensity score at 3 month follow up was 2.24 (range 1.3–3.3), p-value = 0.002 when compared to pre-intervention. The VascuQoL-6 survey score pre intervention averaged score of 9.6 (range 7–12) which improved to an average score of 20.6 (range 18–24), p-value = 0.001. The average VascuQoL score at 3 month follow up was 22.6 (range 22–24), p-value = < 0.001 when compared to pre intervention QoL scores all showing a statistically significant improvement of health-related quality of life. ConclusionThe diagnosis of LRV compression can be challenging due to the non-descript symptoms and overall lack of awareness. Understanding venous tributary pathways and drainage can help clarify why patients present with unusual symptoms. Surgical treatment of LRV compression through LR-AT can improve patients’ pain and improve vascular quality of life.

How I treat nutcracker syndrome

Anatomic compression of the left renal vein in the angle between the aorta and superior mesenteric artery may be asymptomatic or may result in symptoms, including flank pain, hematuria, or pelvic pain and/or congestion. Patients can be referred to a vascular surgeon due to symptoms and/or radiologic findings. Because symptoms of nutcracker syndrome can be vague and/or nondiagnostic, careful evaluation, assessment, and counseling with patients are required before undertaking intervention, which is often an open surgical procedure. The definitive diagnosis is ideally confirmed with diagnostic venography, including pressure measurements from the left renal vein and inferior vena cava. The optimal treatment includes open decompression of the left renal vein with renal vein transposition or gonadal vein transposition, with or without concomitant management of pelvic varicosities if symptomatic. Because most patients with nutcracker syndrome are young, long-term follow-up with scheduled ultrasound examinations should be maintained.

Case Report: A rare story of dysmenorrhea and hematuria in a young female with a case of nutcracker syndrome

Nutcracker syndrome (NCS) is a sporadic syndrome due to the compression of the left renal vein (LRV) between the abdominal aorta and the superior mesenteric artery (SMA). This condition may present with unexplainable pain, hematuria, orthostatic hypotension, proteinuria, or dysfunction of the kidneys. These symptoms would be explained by the fact that if a chronically standing venous congestion is there then there could be the development of gonadal vein and pelvic vein collateral drainage pathways. Doppler USG (ultrasound), cross-sectional and invasive imaging modalities are frequently used for the purpose of diagnosis. Here, in this report, there's a female patient in her mid- 20's. She was asymptomatic since birth and presented with a history of abdominal pain and blood in the urine. USG is not the best modality for describing the findings hence a further contrast-enhanced computed tomography was done which reported an NCS. In all cases of unexplained hematuria, after excluding all differential diagnoses, NCS must be taken into account.