Robot-assisted laparoscopic placement of extravascular stent for nutcracker syndrome

Abstract

A 20-year-old man complained of debilitating left flank pain for 6 months with an episode of gross hematuria. Computed tomography showed compression of the left renal vein between the aorta and superior mesenteric artery with an aortomesenteric angle of 25 degrees. Venography showed a gradient of 3 mm Hg across the compression and 94.4% luminal compression of the left renal vein. After discussion of all surgical and endovascular options, robot-assisted laparoscopic placement of an extravascular cuff around the left renal vein was performed using the da Vinci X Surgical System (Intuitive Surgical, Sunnyvale, Calif). The patient did well with full resolution of the left flank pain.

This is a case of robot-assisted laparoscopic placement of an extravascular stent for management of nutcracker syndrome using the da Vinci X Surgical System (Intuitive Surgical, Sunnyvale, Calif). Renal nutcracker syndrome is the venous entrapment caused by compression of the left renal vein between the aorta and superior mesenteric artery (SMA). Surgical options for the treatment of nutcracker syndrome include left renal vein transposition, gonadal vein transposition, renocaval bypass, and renal autotransplantation. Endovascular left renal vein stenting may lead to stent migration, occlusion, and fracture. Thus, we present an alternative, unique, minimally invasive treatment option. The patient consented for publication of the video and case report.

Case report

A 20-year-old man presented with intermittent, debilitating left flank pain for 6 months. He had an episode of gross hematuria without hypertension, oliguria, dysuria, or fever. His body mass index was 19.6 kg/m². Physical examination showed grade 3 left varicocele. The results of workup were negative for other causes. Computed tomography venography showed compression of the left renal vein between the aorta and SMA with an aortomesenteric angle of 25 degrees. The patient was referred to us from an outside institution with a diagnosis of nutcracker syndrome. Preoperatively, we proceeded with venography, intravascular ultrasound, and pressure measurement as an additional modality to confirm the diagnosis. Measurement with pressure gradient showed a gradient of 3 mm Hg across the compression. Intravascular ultrasound showed 94.4% luminal compression of the left renal vein. After discussion of all surgical and endovascular options, the patient decided to proceed with the robot-assisted laparoscopic resection of the fibrous band around the left renal vein with placement of an extravascular polytetrafluoroethylene (PTFE) cuff using the da Vinci X Surgical System (Video).

The patient was placed in the right lateral decubitus position and the bed was flexed in the Trendelenburg position. Six ports were used by transperitoneal technique. After the left colon was reflected, the left renal vein was mobilized. Careful dissection was performed to prevent injury to the tortuous splenic artery. We identified the pancreas, left adrenal vein, and left adrenal gland. Tissue surrounding the left gonadal vein was excised. Vessel sealer was used to dissect the tissue around the aorta. The fibrous bundle was excised around the left renal vein between the aorta and SMA to release the renal vein compression. Hook electrocautery was used to skeletonize around the left renal vein and adrenal vein. A red vessel loop was used to retract the outflow of the left renal vein. We measured the left renal vein to assess for the appropriately sized graft. An externally reinforced, expanded PTFE graft measuring 16 mm in diameter was cut into a 20-mm length. The PTFE cuff was then introduced and placed around the left renal vein along the long axis to prevent blood vessel compression. The PTFE cuff was sutured with three interrupted Gore-Tex sutures (Gore Medical, Newark, Del) and tied down. The PTFE cuff was tacked down to the retroperitoneal and aortic tissues. Avicel (DuPont, Wilmington, Del) was placed for hemostasis around the space. The SMA was mobilized so it could be pulled over the cuff and fixed in place by clipping the surrounding bowel mesentery to the kidney to help ensure that the SMA did not migrate off the graft. The authors believe that preservation of the left gonadal vein will protect a future pathway for possible coil embolization of the left gonadal vein. In addition, by not ligating the gonadal vein, the PTFE cuff would be further prevented from migration laterally because the adrenal vein and gonadal vein hold the PTFE cuff in place near the renocaval junction.

Results showed the operative time of 3 hours and estimated blood loss of 10 mL. Length of stay was 1 day with no complications. The patient has an improvement in varicocele grading from grade 3 preoperatively with visible varicoceles to grade 2 postoperatively with nonvisible but palpable varicocele without a Valsalva maneuver. He was doing well with full resolution of left flank pain at the 4-week postoperative visit. Follow-up abdominal duplex ultrasound showed patent left renal vein with no elevated flow velocities. The renal vein cuff was visualized at the SMA with a peak systolic velocity of 67 cm/s. The left gonadal vein was patent with retrograde flow noted.

Conclusions

Robot-assisted laparoscopic resection of the fibrous band with placement of an extravascular cuff around the left renal vein is an effective, minimally invasive approach for the treatment of nutcracker syndrome with no warm ischemia injury and no venous anastomosis. Open transposition of the left renal vein and open bypass with PTFE from the left renal vein to the inferior vena cava have been the traditional “gold standard” for surgical management of nutcracker syndrome. Magnification and stability of the dual-lens, robotic camera offer excellent visibility and substantially lower blood loss compared with open surgery.

From the Vascular and Endovascular Surgery Society

Supplementary data

Video 1

Nutcracker syndrome video.