Laparoscopic Partial Nephrectomy for T1 Renal Cell Carcinoma: Comparison of Two Resection Techniques in a Multi-institutional Propensity Score-Matching Analysis.

Background: Enucleoresection is defined as presence of a minimal paratumor parenchyma that allows for clear visualization of the tumor's contours during partial nephrectomy (PN). Because there is variability in published reports regarding resection techniques during PN before the surface-intermediate-base (SIB) margin score reporting system, the association between postoperative outcomes and resection techniques are rarely reported. This study was designed to compare the perioperative, oncologic, and functional outcomes between laparoscopic enucleoresection (LER) (SIB score 1 + 1 + 1 = 3) and traditional laparoscopic partial nephrectomy (TLPN) (SIB score 1 + 2 + 2 = 5).

Methods: Data from 270 consecutive patients who underwent laparoscopic partial nephrectomy for single T1 RCC at 3 medical centers were prospectively collected. Propensity score matching was performed on age, gender, body mass index, American Society of Anesthesiologists score, preoperative estimated glomerular filtration rate (eGFR), tumor size, RENAL nephrometry score, Charlson score, and solitary kidney status. Normal parenchyma width of each patient was evaluated right after the surgery, and SIB score was assigned retrospectively. Ninety-eight matched patients undergoing LER or TLPN were compared for perioperative, oncologic, and functional outcomes.

Results: After matching, warm ischemia time (WIT) and operative time were significantly shorter in LER than TLPN group (20.8 vs. 23.8 min, P = 0.003 and 130.8 vs. 152.1 min, P = 0.005, respectively). Estimated blood loss (EBL) also was lower in LER than TLPN group (50 vs. 90 mL, P = 0.045). Complication rates, positive surgical margin rates, and local recurrence rates were comparable between groups (P = 0.3, P = 0.62, and P = 1.0, respectively). At last follow-up, the eGFRs also were comparable in both groups (P = 0.6).

Conclusions: LER has similar oncologic, functional outcomes and complication rates with the advantage of a shorter WIT, operative time, and lower EBL compared with TLPN.