V5-10: Retroperitoneal approach for arterial micro-dissection in partial nephrectomy without ischemia

Video

Introductions and Objectives
Nephron sparing surgery is the treatment of choice in T1 kidney tumors. There are different tricks for improving warm ischemia time (WIT), microdissection of the branches of the renal artery is one of them. Retroperitoneal access allows an easy dissection of the posterior segmental artery. We present a video of the technique and evaluate it’s outcome.

Methods
A 68 year-old patient with a history of dissecting thoracoabdominal aortic aneurysm involving the lumen of the left renal artery, was diagnosed of a posterior hilar mass (2.5 x 1, 8cm) of the right kidney. We proposed a RPN. The retroperitoneal approach provided direct access to the renal artery and its posterior segmental branch. Superselective micro-dissection of tertiary branches with subsequent ligation with 5-mm Hem-o-lok® clips allowed a partial nephrectomy without ischemia. Rummel tourniquet was placed at the main and posterior segmental renal arteries to be used if necessary. Renoraphy was challenging by the lack of space and triangulation because of the retroperitoneal approach. Between January 2011 and May 2103, patients with T1-T2 posterior renal masses or in the renal convexity were selected for RPN. Patient characteristics, operative details, complications, and long-term outcomes are analyzed.

Results
Operative time was 140 minutes with 100 cc of blood loss. There were no postoperative complications. Hospital stay was 5 days. There were 35 patients included (mean age 62, range 37-81 years; body mass index 27.5 kg/m, range 22-34 kg/m). Mean tumor size was 37.8 mm (20-62 mm), and preoperative aspects and dimensions used for an anatomical (PADUA/RENAL) classification score was 8.9/5.91. Surgical time was 170 min (90-360 min), and the global series warm ischemia time was 4.55 min (0-28 min). The off-clamp procedure was performed in 29 (80%) patients. Mean estimated blood losses (EBL) were 419 mL (100-1600 mL). Transfusion was necessary in three cases, while one reoperation (IIa Clavien) and one conversion to open surgery (IIIb Clavien) were needed. Mean hospital stay was 4.4 days (range 2-11). Three (8.3%) cases of positive margins were reported. Serum creatinine levels varied from 87 to 96 μmol/L (preoperative and 6-month follow-up).

Conclusions
The vascularisation of the dorsal kidney from a single segmental arterial branch makes it particularly attractive for retroperitoneal approach. The technical complexity lies more in the suture than in vascular dissection. Retroperitoneoscopy allowed us to perform nephron-sparing surgery ,for posterior tumours up to 6 cm, without any kind of ischemia in 80%.

Funding: None