3D Views Give Surgeons the Illusion of Tactile Sensation

Researchers at Weill Cornell Medical College (New York, NY, USA) and New York-Presbyterian Hospital/Weill Cornell Medical Center (NYP; NY, USA) videotaped 1,340 robotic-assisted laparoscopic prostatectomies (RALPs). After every 200 procedures, they examined the pathology results of the prostate that was removed to determine the incidence of positive surgical margins, an indication that a surgeon might not have removed all of the cancer. For the study, the researchers focused on the postero-lateral surgical margin (PLSM), the area where the prostate is attached to the nerves.

The researchers found that robotic surgery did not compromise outcomes; the incidence of positive PLSM was 2.1%, which gradually declined to 1% in the last 100 patients. In comparison, positive PLSMs are found in 2.8-9% of the patients undergoing traditional laparoscopic prostatectomy. The researchers said that the robotic approach brings about, "a reverse Braille phenomenon,” seemingly an ability to "feel” the tissue when vision is enhanced. They also identified a number of visual cues that clinicians can use to improve outcomes, including the color of tissue, the location of veins as a landmark for the location of nerves, signs of inflammation, and appreciation of so-called compartments outside the prostate. The study was published in the March 2010 issue of British Journal of Urology International.

"Anatomical details and visual cues available through robotic surgery not only allow experienced surgeons to compensate for a lack of tactile feedback, but actually give the illusion of that sensation,” said lead author Prof. Ashutosh Tewari, M.D., M.Ch. "For patients, this means the safety of knowing the benefits of a robotic approach --including a quicker recovery -- don't compromise the surgery's primary mission of removing the cancer.”

"As someone with 30 years of experience as a pathologist, I too have developed the ability described in this paper. I can look at a tissue sample and know if it is firm or soft and what to expect in its pathology -- something that helps me to home in on the area with the abnormality,” said senior author Maria Shevchuk, M.D., an associate professor of pathology at Weill Cornell Medical College, and a pathologist at NYP. "It is only natural that this ability would also be present in experienced robotic surgeons.”

Cancer cells produce changes in tissue firmness that surgeons can feel; but because this tactile evaluation is not possible for surgeons using RALP, clinicians have wondered whether the robotic approach could lead surgeons to miss some of the cancerous tumor, and thus subject their patients to a greater risk of cancer recurrence.

Related Links:
Weill Cornell Medical College
New York-Presbyterian Hospital/Weill Cornell Medical Center