Complications and conversions of upper tract urological laparoendoscopic single-site surgery (LESS): multicentre experience: results from the NOTES Working Group


Brian H. Irwin, Division of Urology, Flether Allen Health Care/ACC EP5, Burlington, VT 05401, USA.


Study Type – Therapy (case series)
Level of Evidence 4

What’s known on the subject? and What does the study add?

Several studies have shown the feasibility of performing both complex and reconstructive laparoendoscopic single site (LESS) surgical procedures in urology. To date, no studies have evaluated the rates of conversion to conventional laparoscopy and complications at the time of LESS procedures in urology.

This study, a compilation of results from members of the NOTES working group, is the first study to address the rates of complications and conversions to conventional laparoscopy at the time of LESS surgery in urology.


• To present complications and rates of conversion from LESS to conventional laparoscopy (CL) at the time of upper tract LESS urologic procedures.


• Patients undergoing LESS upper tract procedures between September, 2007 and November, 2008 (n = 125) were identified at six high-volume academic centers pioneering urologic LESS procedures. All LESS procedures were performed transperitoneally via a single umbilical incision using either adjacent conventional trocars or a dedicated single-site access device. Reconstructive procedures incorporating a single planned 2 mm accessory needle port were included as LESS procedures and were not considered conversions.

• Patients, undergoing LESS procedures requiring conversion to CL with the placement of additional ports were identified. Conversion was defined as the placement of additional 5 or 10/12 mm ports beyond the primary incision. In each case the operative reports were reviewed, the reason for conversion was determined, and the number and types of additional ports and complications were noted.


• Upper tract LESS procedures were performed in 125 patients comprising 13.3% of the total 937 laparoscopic procedures performed at the participating institutions during this time period. Conversion to CL was necessary in 7 patients (5.6%) undergoing LESS requiring the addition of 2–5 ports.

• Reasons for conversion included: facilitate dissection in 3 (43%), facilitate reconstruction in 3 (43%), and control of bleeding in 1 (14%). All attempted LESS cases were completed laparoscopically without need for open conversion.

• Complications occurred in 15.2% of patients undergoing LESS surgery. Three of the 7 patients that required conversion to CL developed postoperative complications (Clavien grade II in two and IIIa in one).

• Limitations of this study included the inability to standardize LESS patient selection criteria, instrumentation and surgical technique as well as the lack of available complete data from a CL control group for comparison.


• LESS surgery is technically feasible for a variety of upper urinary tract reconstructive and ablative procedures, although it appears to be associated with higher rates of complications than in mature CL series. Conversion to CL occurs infrequently and may be a reflection of stringent patient selection.