Nutcracker syndrome: intravascular stenting approach

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.

A Rare Cause of Abdominal and Flank Pain in Children: Nutcracker Syndrome

The nutcracker phenomenon is characterized by compression of the left renal vein typically between the abdominal aorta and superior mesenteric artery. It is an uncommon and often undiagnosed condition that has the potential to cause a range of symptoms including hematuria and abdominal or flank pain. The term nutcracker syndrome refers to the clinical manifestations of the nutcracker phenomenon. Diagnosis can be made with Doppler ultrasound, computed tomography angiography, magnetic resonance angiography, or venography. Management can range from conservative treatment in the pediatric population due to high spontaneous remission rate to surgical and endovascular interventions. We discuss the case of a previously healthy young female who presented with abdominal pain. Diagnosis of nutcracker syndrome was made based on imaging. The patient was managed conservatively. This case highlights the importance of considering nutcracker syndrome in the differential diagnosis when evaluating patients with abdominal and flank pain.

Gonadal vein transposition is a safe and effective treatment of nutcracker syndrome

BACKGROUND

Nutcracker syndrome (NCS) is a pelvic venous disorder that results from outflow obstruction of the left renal vein, most often due to a decreased aortomesenteric angle, leading to gonadal vein reflux, pain, and varices. Although a number of open and minimally invasive procedures to treat NCS have been described, the optimal management of this condition remains uncertain. To the best of our knowledge, we have presented the largest case series to date using gonadal vein transposition (GVT) to treat NCS.

METHODS

Patients considered for intervention to treat NCS underwent a rigorous and standardized workup, including axial imaging studies, catheter-based diagnostic procedures, and urinalysis. GVT has been the institutional first-line treatment of NCS for appropriate patients. With institutional review board approval, a retrospective review of patients who had undergone GVT for NCS was conducted.

RESULTS

From 2014 to 2019, 18 GVTs had been performed. Of the 18 patients, none had died or required reintervention, although 2 had required readmission. During a median follow-up of 178 days, complete symptom relief was achieved in 11 patients (61.1%), with 4 patients (22.2%) reporting partial symptom relief and 2 (11.1%) reporting transient symptom relief.

CONCLUSIONS

GVT is a safe and effective procedure to treat NCS in appropriately selected patients with outcomes that compare favorably with those of other described procedures. Appropriate patient selection for this procedure is critical and requires a rigorous and standardized approach to diagnosis and management.

Endovascular treatment of anterior nutcracker syndrome and pelvic varices in a patient with an anterior and a posterior renal vein

There are few data on endovascular treatment of anterior nutcracker syndrome and pelvic varices in patients with anterior and posterior renal veins. Our objective is to report a case, identify occurrences and compare diagnosis and treatments. A 42-year-old woman presented with flank and pelvic pain and hematuria. She had anterior nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein. A successful complete endovascular approach was done with stent implantation in the anterior renal vein and left gonadal vein embolisation. After 12-month follow-up, the patient remained asymptomatic with good results on CT. Only two case reports of patients with nutcracker syndrome with anterior and posterior renal veins were identified. In both, a self-expanding stent was implanted in the anterior renal vein. In conclusion, endovascular treatment represents a safe and successful option in patients with nutcracker syndrome and pelvic varices with an anterior and a posterior renal vein.

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

Patient: Male, 18-year-old

Final Diagnosis: Superior mesenteric artery syndrome

Symptoms: Abdominal pain

Medication:—

Clinical Procedure: —

Specialty: Surgery

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.

Endovascular Treatment of Nutcracker Syndrome

BACKGROUND

Nutcracker syndrome, or mesoaortic compression of the left renal vein (LRV), with associated symptoms related to venous hypertension in the left kidney, is a rare entity that may result in severe symptoms requiring operative intervention. We report on 3 patients who presented with nutcracker syndrome, including one patient with a circumaortic LRV resulting in posterior nutcracker syndrome, who underwent successful endovascular treatment with renal vein stenting. A review of existing literature on endovascular management of nutcracker syndrome follows.

METHODS

Three women (age range 28-43 years) presented with symptoms and imaging studies consistent with nutcracker syndrome. Symptoms included pelvic and flank pain in all 3 patients, and episodes of hematuria in 2 patients. Imaging studies demonstrated compression of the LRV between the superior mesenteric artery and aorta in 2 of the patients. The third patient was noted to have a circumaortic LRV.

RESULTS

All 3 patients underwent venography and LRV stenting. Stents included a 12 × 40 mm self-expanding nitinol stent, 14 × 60 mm WALLSTENT, and 16 × 40 mm WALLSTENT. All patients were placed on clopidogrel postoperatively. The duration of follow-up ranged from 6 to 27 months. At follow-up, all 3 patients reported significant symptomatic improvement, and duplex ultrasonography demonstrated stent patency in all.

CONCLUSIONS

Nutcracker syndrome is a rare condition that can be successfully treated with renal vein stenting via an endovascular approach. Results are encouraging at follow-up periods beyond 2 years.

Renal venous hypertension

Renal venous hypertension usually seen in young, otherwise healthy individuals and can lead to significant overall morbidity. Aside from clinical findings and physical examination, diagnosis can be made with ultrasound, computed tomography, or magnetic resonance conventional venography. Symptoms and haemodynamic significance of the compression determine the ideal treatment method. This review of the literature discusses normal and pathological developmental aspects of renocaval venous segment and related circulatory disorders, summarizes congenital and acquired changes in left renal vein and their impact on development of renal venous hypertension. Also will be discussed surgical tactics of portosystemic shunting and their potential effects on renal hemodynamics.

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.

Postsurgical Follow-up for a Repaired Nutcracker Syndrome

Nutcracker syndrome is a venous entrapment phenomenon characterized by the impingement of the left renal vein between the superior mesenteric artery and abdominal aorta. Treatment, if necessary, consists of surgical intervention. In the case presented, a young female presented at an outpatient vascular surgical center for surveillance of a surgically repaired nutcracker syndrome. A renal sonogram was performed to evaluate patency and hemodynamics of the left renal vein. Color and spectral Doppler were used to evaluate the left renal vein as well as the left kidney to document appropriate renal perfusion.

Incapacitating pelvic congestion syndrome in a patient with a history of May-Thurner syndrome and left ovarian vein embolization

BACKGROUND

The aim of this article is to report a rare case of unresolved incapacitating pelvic congestion syndrome (PCS) in a patient with a history of May-Thurner syndrome previously treated with stenting and left ovarian vein embolization. Additionally, this article highlights the role of pelvic venography in patients with PCS and reviews the coexistence.

METHODS

A 32-year-old woman was referred to us for the evaluation of recurrent pelvic pain and dyspareunia requiring analgesics. Initially, she developed left lower-extremity deep vein thrombosis a few months after her first pregnancy. On further workup, she was diagnosed with May-Thurner syndrome and underwent left common iliac and left external iliac vein stenting. Furthermore, left ovarian vein coil embolization was performed for symptoms suggesting PCS at the same outside facility. The patient was referred to us for persistent pelvic pain approximately 1 year after she underwent left ovarian vein coil embolization. A diagnosis of incompletely resolved PCS was considered.

RESULTS

Iliocaval venogram demonstrated patent left common iliac and external iliac venous stents in situ. Subsequent right ovarian venogram revealed a patent, but grossly dilated, right ovarian vein with retrograde flow and cross-pelvic collaterals confirming grade III PCS. Right ovarian vein coil embolization was performed, with excellent patient outcome.

CONCLUSION

In the setting of a combined diagnosis of PCS and May-Thurner syndrome, persistent incapacitating PCS after initial iliac stenting should be followed with a complete pelvic venous evaluation including ovarian and left renal venography to rule out residual pelvic congestion secondary to any coexisting ovarian vein incompetencies or nutcracker syndrome.

Results of endovascular treatment for patients with nutcracker syndrome

OBJECTIVE

To retrospectively assess the therapeutic value of endovascular stenting for treatment of the nutcracker syndrome (NCS) in long-term follow-up and to explore the selection of the size of stents in Chinese patients with NCS.

METHODS

From January 2004 to August 2010, 30 patients (two women and 28 men) between 13 and 32 years old (mean, 18.2) who were diagnosed with NCS were admitted for endovascular treatment. Each patient received one self-expanding metallic stent (14-mm diameter, 60-mm long) in the compressed portion of the left renal vein during the operation, and three patients with severe left-sided varicoceles received left gonadal vein embolization. The postoperative follow-up was 12 to 80 months (median, 36.0 months).

RESULTS

The diameters at the ostium of left renal vein measured by the ultrasonic examination before treatment were 11.8 ± 1.8 mm. Technical success of operation was achieved in all patients. No perioperative complications occurred. Two cases of stent migration were found at 12 months: both stents prolapsed into the inferior vena cava, with uneventful follow-up (49 and 56 months, respectively). At 1-month follow-up, patients improved, including two patients who had persistent but less microscopic hematuria than before treatment. The clinical symptoms related to NCS almost disappeared at 3 months after the treatment. All stents were patent at the duplex scan examination, without restenosis, and no secondary recurrence of the symptoms occurred at the end of the follow-up.

CONCLUSIONS

Endovascular treatment is a safe, effective, and very minimally invasive technique that provides good long-term patency rates for patients with NCS, and under the premise morphologic measurements, 14-mm-diameter, 60-mm-long self-expanding stents should be first considered for Chinese patients with NCS.

Unintended coil migration into the right ventricle during the right ovarian vein coil embolization

PURPOSE

The aim of this article is to report a rare case of unintended coil migration into the right (Rt) ventricle.

MATERIALS AND METHODS

A 36-year-old Brazilian female was referred to us for the evaluation of pelvic pain. Venous duplex ultrasound findings were consistent with incompetent venous systems of right lower extremity (RLE). The diagnosis of grade III pelvic varices was confirmed with ovarian venography, and bilateral ovarian vein coil embolization was performed. The procedure was complicated with unintended migration of a small coil into the Rt ventricle.

DISCUSSION

In cases where coil or foreign body migration into the Rt heart or pulmonary circulation has occurred, endovascular retrieval or a thoracotomy has been performed. In our case, the migrated coil was left in situ without any hemodynamic disturbances in the follow-up.

CONCLUSIONS

Coil migration to the Rt ventricle can be conservatively managed depending upon the location and coil profile.

Endovascular stenting for treatment of Nutcracker syndrome: report of 61 cases with long-term followup

PURPOSE

We report the efficacy and safety of endovascular stenting for nutcracker syndrome at long-term followup.

MATERIALS AND METHODS

We retrospectively evaluated the endovascular stenting experience with 61 patients with a median age of 26 years. Symptoms were hematuria, proteinuria or flank pain. Median followup was 66 months.

RESULTS

Peak velocity in the aortomesenteric portion, and the anteroposterior diameter ratio of the renal hilum and the aortomesenteric portion of the left renal vein on Duplex ultrasound after stenting was significantly decreased compared to that on Duplex ultrasound before stenting (p<0.05). However, peak velocity in the hilar portion did not statistically differ (p>0.05). Symptoms resolved or improved in 15, 24 and 20 of the 61 patients within 1 week, and 1 and 6 months, respectively, after endovascular stenting. Symptoms remained unchanged in 2 patients and recurred in 1. A perioperative complication was noted in 1 patient, that is a stent that was mistakenly moved and poorly deployed in a left renal vein collateral required operative intervention. Postoperative complications included stent migration into the right atrium, stent protrusion into the inferior vena cava and stent migration into the hilar left renal vein in 1 case each.

CONCLUSIONS

Based on our long-term followup endovascular stenting is a safe, effective procedure in select adults. We recommend endovascular stenting as primary option for nutcracker syndrome.

The nutcracker syndrome

Left renal vein (LRV) compression, commonly referred to as the nutcracker syndrome or renal vein entrapment syndrome, is a rare and often overlooked condition. Anatomically, the LRV traverses the space between the superior mesenteric artery and the aorta in close proximity to the origin of the artery. In affected individuals, the LRV is subjected to compression between these two structures, resulting in renal venous hypertension. A review of published data on this condition reveals either case reports or small case series. The classic symptoms of nutcracker syndrome include left flank pain with gross or microscopic hematuria. Patients are often children or young adults, with a slight predisposition for women who may also present with pelvic congestion symptoms such as pelvic pain and dyspareunia. Most patients have disease symptoms for many years and nondiagnostic investigations before proper diagnosis can be made. Appropriate diagnostic work-up and treatment may help alleviate patient morbidity from this chronic condition. Although surgical repair has been the standard of care, more recently endovascular intervention has become the first line of therapy. This tabular review compiles published cases in the adult population during the period between 1980 and 2009.

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.

Laparoscopic splenorenal venous bypass for nutcracker syndrome

Nutcracker syndrome is a rare entity caused by extrinsic compression on the left renal vein as it crosses between the superior mesenteric artery and the aorta. It can clinically present with flank pain and hematuria. Accepted treatments include open vascular bypass procedures or endoluminal stenting. We present the first description, to our knowledge, of a laparoscopic splenic vein-left renal vein bypass to relieve the outflow obstruction. The patient, a 29-year-old woman with debilitating left flank pain, presented with nutcracker syndrome. Left renal vein outflow was obstructed at the level of the intersection between the aorta and the superior mesenteric artery. The option of laparoscopic splenic to left renal vein bypass was discussed and performed. A five-port transperitoneal approach was used. Meticulous vascular control was achieved with numerous laparoscopic vascular bulldog clamps. With completely intracorporeal suturing techniques, the splenic vein was anastomosed to the superior aspect of the anterior left renal vein. Total warm ischemia time was 37 minutes. The anastomosis was watertight immediately upon unclamping. Interestingly, upon unclamping, the luminal diameter of the splenic vein appeared to increase to twice its native diameter. The proximal left renal vein appeared less distended, indicating preferential venous outflow through the newly created venous bypass. Blood loss was minimal, no intraoperative or postoperative complications occurred, and the patient's symptoms improved. This report continues to augment the indications for laparoscopic surgery in even complex, urologic vascular situations.

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.

Percutaneous Nitinol Stent Implantation in the Treatment of Nutcracker Syndrome in Young Adults

The present report describes three young adults with nutcracker syndrome caused by left renal vein stenosis managed with nitinol stent implantation. The patients treated included a 20-year-old woman with persistent microhematuria and dyspareunia and two 18-year-old men with proteinuria, hematuria, and flank pain. All three patients were asymptomatic after a follow-up of 14-18 months.

The left renal entrapment syndrome: diagnosis and treatment

A retrospective analysis was performed to review 20 patients with left renal vein (LRV) entrapment syndrome. All cases were diagnosed based on ultrasonography, magnetic resonance angiography, and renal venography. Technical success was achieved in all patients. Transposition of superior mesenteric artery was performed in three cases, transposition of LRV in two, and stent implantation in the LRV in 15. Stent migration occurred in one case, and stent reimplantation was performed. One case suffered from hematoma after transposition of the superior mesenteric artery, and reoperation was performed. Follow-up was made from 6 months to 6 years after the operation. Abnormalities were not found in the urine test of 18 patients and their symptoms disappeared. Two cases still had microscopic hematuria after exercise. All surgical operations are effective for nutcracker syndrome except excessive invasiveness. Stent may be one of the mainstream therapies because of its minimal invasiveness.

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.

Unexplained hematuria during pregnancy: right-sided nutcracker phenomenon

We report a case of hematuria in a pregnant patient caused by right renal vein hypertension, as a result of compression of right renal, the inferior caval and the right gonadal veins because of posterior displacement of the pancreas caused by the presence of the gravid uterus. Hematuria resolved after a cesarean delivery. This condition has not been, to our knowledge, previously described.

Mesoaortic compression of the left renal vein (nutcracker syndrome): case reports and review of the literature

Compression of the left renal vein between the aorta and the superior mesenteric artery has been termed the nutcracker syndrome. Obstruction of left renal vein outflow results in venous hypertension with the formation of intra- and extrarenal collaterals and/or the development of gonadal vein reflux. To date, a variety of clinical symptoms due to mesoaortic compression of the left renal vein (nutcracker syndrome) have been described. It is not known what pathophysiological variables play a role in the different clinical manifestations of nutcracker syndrome. We report two patients representing the two different forms of the condition. In the first, hematuria and left flank pain resolved in a young man after successful renocaval reimplantation. In the second, symptoms of pelvic congestion due to pelvic varices improved in a middle-aged woman after successful embolization of the gonadal vein and pelvic collaterals. This report reviews the pathophysiology, presentation, diagnosis including radiographic findings, management options, as well as the current literature on nutcracker syndrome.

Endovascular stenting in the treatment of pelvic vein congestion caused by nutcracker syndrome: Lessons learned from the first five cases

BACKGROUND

Compression of the left renal vein between the aorta and the superior mesenteric artery is a rare but possibly underestimated condition. Surgical correction (42 cases reported in the literature) can be performed by means of a variety of different techniques. Although endovascular stenting is well accepted for iliocaval occlusive disease, it has been poorly evaluated in this indication. We describe five patients who were treated for nutcracker syndrome by using stenting and analyze the nine cases previously reported.

METHODS

From November 2002 to September 2004, five women (mean age, 34.7 years) were admitted for endovascular treatment of a nutcracker syndrome. They all had incapacitating pelvic congestion syndrome, including two with a history of left ovarian vein embolization; moreover, two had left lumbar pain, and three had hematuria. The mean preoperative venous disability score was 2.4. The patients underwent a gynecologic examination and laparoscopy to eliminate other causes of pelvic pain. The laparoscopy revealed large pelvic varicose veins and no signs of endometriosis. Duplex scan, computed tomographic scan, and iliocavography revealed left renal vein compression, with proximal distention and collateral pathways, with dilatation and permanent reflux in the left ovarian vein in the three patients who had not had prior embolization. The mean renocaval pullback gradient was 4.3 mm Hg. A percutaneous endovascular procedure, during in which a self-expanding metallic stent was implanted, was performed under general anaesthesia.

RESULTS

Technical success was achieved in all cases. One case of stent migration occurred: the stent was pulled down in the inferior vena cava, with uneventful follow-up (mean, 14.3 months). One month later, patients were all improved and stents were patent at the duplex scan examination, without restenosis. The mean venous disability score was 1. No further left ovarian vein reflux was evident at duplex scan in patients who did not have prior embolization. Pelvic pain recurred in one patient who had initially improved, and endometriosis was diagnosed 15 months after the procedure. Two other patients, who received 40-mm-long stents, had a secondary recurrence of the symptoms caused by stent dislodgement. The two other patients were asymptomatic.

CONCLUSIONS

This study shows that stenting is feasible, but some guidelines should be followed, mainly the use of long stents protruding into the inferior vena cava. Stenting can eliminate the symptoms of the condition, and the technique is only very slightly invasive. Further experience and follow-up are needed before accepting such a procedure for treatment of the nutcracker syndrome.

Percutaneous stent placement as treatment of renal vein obstruction due to inferior vena caval thrombosis

A patient who had undergone his third orthotopic liver transplantation nearly 9 years prior to presentation developed worsening hepatic and renal function, as well as severe bilateral lower extremity edema. Magnetic resonance imaging demonstrated vena caval thrombosis from the suprahepatic venous anastomosis to the infrarenal inferior vena cava, obstructing the renal veins. This was treated by percutaneous placement of metallic stents from the renal veins to the right atrium. At 16 months clinical follow-up, the patient continues to do well.

Nutcracker or left renal vein compression phenomenon: multidetector computed tomography findings and clinical significance

The use of multidetector computed tomography (MDCT) in routine abdominal explorations has increased the detection of the nutcracker phenomenon, defined as left renal vein (LRV) compression by adjacent anatomic structures. The embryology and anatomy of the nutcracker phenomenon are relevant as a background for the nutcracker syndrome, a rare cause of hematuria as well as other symptoms. MDCT examples of collateral renal vein circulation (gonadal, ureteric, azygous, lumbar, capsular) and aortomesenteric (anterior) and retroaortic (posterior) nutcracker phenomena in patients with no urologic complaint are shown as well as studies performed on patients with gross hematuria of uncertain origin. Incidental observation of collateral veins draining the LRV in abdominal MDCT explorations of asymptomatic patients may be a sign of a compensating nutcracker phenomenon. Imbalance between LRV compression and development of collateral circulation may lead to symptomatic nutcracker syndrome.

Transposition of the left renal vein for treatment of the nutcracker phenomenon: long-term follow-up

OBJECTIVES

To assess the therapeutic value of left renal vein transposition for treatment of the nutcracker phenomenon in long-term follow-up.

METHODS

Eight patients (4 women and 4 men) between 23 and 58 years old (mean 39.1) underwent transposition of the left renal vein for treatment of the nutcracker phenomenon associated with recurrent gross hematuria and flank pain. The postoperative follow-up was 41 to 136 months (mean 66.4).

RESULTS

No perioperative complications were encountered. The postoperative complications comprised deep vein thrombosis (n = 1), retroperitoneal hematoma necessitating surgical revision (n = 1), and paralytic ileus that resolved with conservative management (n = 1). One patient underwent laparotomy for treatment of mechanical ileus due to adhesions 4 years after the initial surgery. In 7 of 8 patients, transposition of the left renal vein efficiently relieved the symptoms related to the nutcracker phenomenon. In 1 patient, the hematuria persisted despite postoperative normalization of the pressure gradient between the left renal vein and the inferior vena cava.

CONCLUSIONS

Transposition of the left renal vein is an efficient surgical approach for the treatment of the nutcracker phenomenon and is associated with an acceptable risk of complications. However, rare cases may be encountered in which the shunted connections between the renal veins and the collecting system are so matured that, despite removal of the obstruction of the renal venous backflow, gross hematuria may persist.

Endovascular stenting for the nutcracker phenomenon

PURPOSE

To present a case highlighting the efficacy of stent implantation for left renal vein (LRV) entrapment, otherwise known as the nutcracker phenomenon.

CASE REPORT

A 17-year-old boy presented with a history of gross hematuria and left flank pain. Magnetic resonance angiography documented compression of the LRV between the superior mesenteric artery and aorta. A Memotherm stent was successfully placed across the LRV to restore adequate luminal flow after a Wallstent failed to adequately span the narrowed segment. Spiral CT angiography at 6 months confirmed LRV patency; the patient remains asymptomatic and free of hematuria at 12 months.

CONCLUSIONS

Endovascular stenting for the nutcracker phenomenon is safe and effective and may represent a valuable approach for lessening the morbidity of surgical procedures.

The nutcracker syndrome: its role in the pelvic venous disorders

BACKGROUND

Symptoms of pelvic venous congestion (chronic pelvic pain, dyspareunia, dysuria, and dysmenorrhea) have been attributed to massive gonadal reflux. However, obstruction of the gonadal outflow may produce similar symptoms. Mesoaortic compression of the left renal vein (nutcracker syndrome) produces both obstruction and reflux, resulting in symptoms of pelvic congestion. We describe the diagnosis and management of nine patients studied in our institutions.

MATERIALS AND METHODS

From a group of 51 female patients with pelvic congestion symptoms studied at our institutions, there were nine patients with symptoms of pelvic congestion, microscopic hematuria, and left-sided flank pain. The diagnosis of the nutcracker syndrome was suspected based on clinical examination, Doppler scan, duplex ultrasound scan, computed tomography scan, and magnetic resonance imaging. The diagnosis was confirmed by retrograde cine-video-angiography with renocaval gradient determination and catheterization of both internal iliac venous systems. All patients had a renocaval pressure gradient >4 mm Hg (normal, 0-1 mm Hg). Renal compression was relieved by external stent (ES) in two patients, internal stent (IS) in one patient, and gonadocaval bypass (GCB) in three. GCB was preceded by coil embolization of internal iliac vein tributaries connecting with lower-extremity varicose veins in three patients. Three patients deferred surgery and are under observation. Mean follow-up time was 36 months (range, 12-72 months).

RESULTS

Hematuria disappeared postoperatively in all patients. ES and IS normalized the renocaval gradient and resulted in significant alleviation of symptoms (90% improvement on a scale of 0-10 where 0 = no improvement and 10 = greatest improvement). Two patients with GCB had a residual gradient of 3 mm Hg. The third patient normalized the gradient. In this group, improvement of symptoms was 60%. Patients awaiting surgery are being treated conservatively (elastic stockings, hormones, and pelvic compression). They have shown only moderate improvement.

CONCLUSION

The nutcracker syndrome should be considered in women with symptoms of pelvic venous congestion and hematuria. The diagnosis is suspected by compression of the left renal vein on magnetic resonance imaging or computed tomography scan and confirmed by retrograde cine-video-angiography with determination of the renocaval gradient. Internal and external renal stenting as well as gonadocaval bypass are effective methods of treatment of the nutcracker syndrome. IS and ES were accompanied by better results than GCB. Surgical and radiologic interventional methods should be guided by the clinical, radiologic, and hemodynamic findings.