WCE 2018: Small Renal Masses – Latest in Partial Nephrectomy

Paris, France (UroToday.com) The treatment of kidney tumors <4 cm has evolved from the classic radical nephrectomy to open nephron-sparing surgery and currently, the majority of surgeries are performed using minimally invasive techniques. The goal of partial nephrectomy (PN) is to remove the cancerous tissue while preserving the healthy parenchyma of the involved kidney, as well as the overall renal function. Renal failure has been associated with increased cardiovascular-associated morbidity and mortality. The overall survival advantage of PN vs. radical nephrectomy (RN) is an unresolved issue due to the lack of multiple large-scale randomized trials. It is generally accepted, however, that PN should be offered for patients with small renal tumors when technically feasible.

PN for clinically localized tumors up to 7 cm has been equivalent with RN with regard to cancer-specific survival. In experienced hands, it is a safe procedure with a comparable rate of perioperative morbidity. Both renal function preservation (short and long-term), as well as patients quality of life, have been shown to be superior with PN for small renal masses. In addition, other parameters such as total costs and hospital length of stay are improved with PN.

The introduction of robotic PN has overcome the challenge of laparoscopic suturing, and this procedure is now performed by a larger number of surgeons with a shorter learning curve. The two main factors associated with preservation of renal function are ischemia time (better under 25 minutes) and the relative volume of the remaining kidney. Some have therefore advocated for early unclamping of the renal artery (following first layer renorrhaphy) and even totally off-clamp resection of the tumor. Various techniques of tumor excision during partial nephrectomy have been described (Figure 1) and depend on tumor size, shape, depth, and nearness to structures such as blood vessels or the collecting system. In an effort to preserve the remaining renal parenchyma, renorrhaphy is sometimes limited to a single layer of sutures, and knotless suturing techniques have been developed (e.g. sliding clip).  

UroToday WCE2018 . Renal tumor excision techniques during
Figure 1. Renal tumor excision techniques during PN

A recent retrospective matched-pair analysis compared the retroperitoneal (RP) approach of robotic PN to the conventional transperitoneal approach. It was found that both approaches were similar with regard to ischemia time, blood loss, postoperative complications, and positive surgical margins. The RP approach resulted in shorter operative time (18 minutes) and 1 day shorter length of stay. It was therefore concluded that the cost saving associated with the RP approach is $2300. RP approach offers direct access to hilum and posterior tumors, and it has the advantage of avoiding the bowel or intraperitoneal adhesions. However, many urologists are unfamiliar with the anatomical landmarks and the smaller working space is challenging. 

Presented by: Duke Herrell, MD, Professor,  Department of Urology, Vanderbilt University, Tennessee, USA

Written by: Shlomi Tapiero, MD, Department of Urology, University of California-Irvine, medical writer for UroToday.com at the 36th World Congress of Endourology (WCE) and SWL - September 20-23, 2018 Paris, France

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