Abstract
Background
The left renal vein (LRV) entrapment syndrome is a rare condition. Here, we present a 22-year-old female presenting with recurrent nausea, vomiting, weight loss and evidence of the LRV compression by the superior mesenteric artery and the abdominal aorta. Hemodynamic assessment confirmed a pressure gradient of > 3 mmHg between the LRV and the inferior vena cava. A self-expandable stent was then deployed in the LRV. Subsequent clinical follow-ups ensure full resolution of the patient’s symptoms.
Methods
Multilingual search was performed in PubMed, Google scholar, Scielo, Korea Med and EMBASE with the medical subheadings “nutcracker syndrome”, “nutcracker phenomenon” and “compression vein syndrome” from January 1983 to September 2013.
Results
Review of the literature exhibited a plethora of individual case reports (291 citations). Importantly, few retrospective case series [5] comprising a total of 157 patients included successful endovascular interventions.
Conclusion
Endovascular therapy for nutcracker syndrome represents a safe and suitable treatment option, but prospective studies are needed to confirm these data.
1
Introduction
The clinical scenario of the left renal vein (LRV) entrapment syndrome (also known as nutcracker syndrome, NCS) comprises two main variants depending on the location where the vein compression occurs. When the compression takes place between the abdominal aorta and the superior mesenteric artery (SMA), it is called anterior NCS. When the LRV is compressed between the aorta and the vertebral column, it is termed as posterior NCS . It has also been described a circumaortic LRV trajectory, with concomitant vein compression both in the anterior and posterior compartment . Another variant of the NCS includes the LRV compression by the SMA to the right renal artery, also called lateral NCS . An incidental finding of the LRV compression in asymptomatic patients merits no therapy, and it is known as a nutcracker phenomenon. Noninvasive and invasive modalities have been used to evaluate the severity of the LRV compression. The different diagnostic criteria for NCS includes: the ratio of the duplex ultrasound peak systolic velocity of the aortomesenteric segment to the hiliar portion of the LRV > 4.2–5.0 , the relation between the diameter of the aortomesenteric segment to the hiliar portion of the LRV by multidetector computed tomography (< 50%) , the angle between the SMA and the aorta (normal > 41°), the presence of collaterals veins in the retroperitoneum and around the renal hilium, and the evidence of a pressure gradient between the LRV and the inferior vena cava (> 3 mmHg) . Here, we describe a symptomatic patient with LRV compression syndrome treated with an endovascular procedure and a systematic review of the literature with emphasis in the intervention studies.
2
Case presentation
A 21 year-old African American female with no significant medical history presented with intractable nausea, bilious vomiting, left upper quadrant abdominal pain, decreased oral intake and 10-pound weight loss. Review of symptoms was positive for dyspareunia. Her past medical history included the prior presentations to multiple community hospitals where she was diagnosed with gastroenteritis and subsequently prescribed antiemetic medications. Additionally, she had a cesarean section 3 years prior, smoking history (1 pack of cigarettes per day for the last 5 years) with occasional marijuana use, but otherwise denied ethanol or other illicit drugs consumption. Her family history was noncontributory. Laboratory data revealed hyponatremia, hypokalemia, metabolic alkalosis and negative pregnancy test. Prior imaging test included a non-diagnostic abdominal and pelvic ultrasound. The rest of the laboratory data was otherwise unremarkable. A CT scan of the abdomen with contrast revealed compression of the LRV between the superior mesenteric artery and the abdominal aorta ( Fig. 1 A ). To evaluate the severity of the stenosis, intravascular ultrasound and hemodynamic assessment of the pressure gradient between LRV and the inferior vena cava were performed. A minimal luminal area of 2.8 mm 2 and a > 3 mmHg gradient between the LRV and the inferior vena cava were found. These results prompted an intervention with a self-expandable SMART stent 14 × 40 mm deployment (Cordis, Hialeah, FL USA; Fig. 1 B–D). Repeated assessment of the pressure gradient documented a ≤ 1 mmHg difference. Additionally, intravascular ultrasound confirmed that the minimal luminal area increased to 10 mm 2 . Following the procedure, full anticoagulation with low molecular weight heparin was started. Subsequent clinical follow-ups ensure that the patient’s nausea and vomit were resolved. Also, her oral intake improved, and the patient was then discharged home. Due to the high risk of stent thrombosis reported in case series , the patient was discharged home with oral anticoagulation (warfarin) for 6 months.
2
Case presentation
A 21 year-old African American female with no significant medical history presented with intractable nausea, bilious vomiting, left upper quadrant abdominal pain, decreased oral intake and 10-pound weight loss. Review of symptoms was positive for dyspareunia. Her past medical history included the prior presentations to multiple community hospitals where she was diagnosed with gastroenteritis and subsequently prescribed antiemetic medications. Additionally, she had a cesarean section 3 years prior, smoking history (1 pack of cigarettes per day for the last 5 years) with occasional marijuana use, but otherwise denied ethanol or other illicit drugs consumption. Her family history was noncontributory. Laboratory data revealed hyponatremia, hypokalemia, metabolic alkalosis and negative pregnancy test. Prior imaging test included a non-diagnostic abdominal and pelvic ultrasound. The rest of the laboratory data was otherwise unremarkable. A CT scan of the abdomen with contrast revealed compression of the LRV between the superior mesenteric artery and the abdominal aorta ( Fig. 1 A ). To evaluate the severity of the stenosis, intravascular ultrasound and hemodynamic assessment of the pressure gradient between LRV and the inferior vena cava were performed. A minimal luminal area of 2.8 mm 2 and a > 3 mmHg gradient between the LRV and the inferior vena cava were found. These results prompted an intervention with a self-expandable SMART stent 14 × 40 mm deployment (Cordis, Hialeah, FL USA; Fig. 1 B–D). Repeated assessment of the pressure gradient documented a ≤ 1 mmHg difference. Additionally, intravascular ultrasound confirmed that the minimal luminal area increased to 10 mm 2 . Following the procedure, full anticoagulation with low molecular weight heparin was started. Subsequent clinical follow-ups ensure that the patient’s nausea and vomit were resolved. Also, her oral intake improved, and the patient was then discharged home. Due to the high risk of stent thrombosis reported in case series , the patient was discharged home with oral anticoagulation (warfarin) for 6 months.
