Visual cues as a surrogate for tactile feedback during robotic-assisted laparoscopic prostatectomy: posterolateral margin rates in 1340 consecutive patients.

OBJECTIVE: To analyse consecutive cases of robotic-assisted laparoscopic prostatectomy (RALP), present the incidence of nerve-sparing-related positive surgical margins (SM+), include visual cues that might assist in smoothly changing to the robotic platform, and discuss the scientific rationale for 'intersensory integration' which might explain the 'reverse Braille' phenomenon, i.e. the ability to feel when vision is greatly enhanced, as the lack of tactile feedback during RALP is often cited as a disadvantage of robotic surgery, interfering with a surgeon's ability to make intraoperative oncological decisions.

PATIENTS AND METHODS: Data from 1340 consecutive patients undergoing RALP from one institution were analysed and trends for positive posterolateral SM+ (PLSM+) were correlated with oncological variables before and after RALP. A sample of patient slides were reviewed by a extramural pathologist. Multivariate regression modelling was used to compare the projected rates of PLSM+ vs the actual rate, given the effect of a conscious effort to use visual cues. Finally, video recordings of the procedure were systematically reviewed and correlated with anatomical and histopathological images in an integrated session involving the surgeon and the pathology team.

RESULTS: The incidence of PLSM+ was 2.1%, which gradually declined to 1.0% in the last 100 patients. The reduction in PLSM+ occurred despite an increased rate of high-risk tumours operated on during this period. Forecasting analysis showed that the actual PLSM+ rate declined by half in the most recent 1000 patients, due to an integrated effort involving the use of visual cues during surgery. The following visual cues were considered important; appreciation of periprostatic (lateral prostatic) fascial compartments; colour and texture of the tissue; periprostatic veins as a landmark for athermal dissection; signs of inflammation; and a freely separating bloodless plane showing loose shiny areolar tissue.

CONCLUSION: Adapting to the robotic platform is easy and there is no compromise of the oncological safety of this procedure. Experienced surgeons can use visual cues to assist during nerve-sparing RALP and achieve low PLSM+ rates.