Intraoperative parasympathetic nerve stimulation with tumescence monitoring during total mesorectal excision for rectal cancer.
BACKGROUND
Unilateral or bilateral division of the parasympathetic nerves during resection of rectal cancer may result in sexual erectile dysfunction. The purposes of this project were twofold: to determine the ability to demonstrate penile tumescence in response to parasympathetic nerve stimulation after rectal cancer resection and to correlate the nerve stimulation response with clinical sexual function 6 months after operation.


METHODS
In 21 consecutive male patients with normal erectile function undergoing total mesorectal excision, cavernous nerve identification and integrity before and after pelvic dissection were assessed intraoperatively, both visually by an experienced surgeon and by using the CaverMap nerve stimulator. The minimal effective current necessary to produce a 2% increase in penile tumescence was recorded for both the left- and right-sided nerves, primarily the largest nerve trunk, S3. Postclearance stimulation data were then correlated with sexual function outcomes, specifically erection and orgasm at 6 months after surgery.


RESULTS
The operating surgeon's visual assessment of the pelvic autonomic nerve's integrity after pelvic dissection was deemed intact in 20 of the 21 patients (95.2%). Of the 20 patients who were evaluated with CaverMap after completion of total mesorectal excision, 17 (85%) had tumescence response after nerve stimulation on either side, and 3 patients (15%) had unilateral response only. Of the 19 patients evaluated for sexual function 6 months after surgery, 18 (94.7%) had normal function, including the 3 patients with only unilateral nerve stimulation tumescence response.


CONCLUSIONS
Intraoperative mapping of the parasympathetic nerve trunks with the CaverMap nerve stimulator may be a valuable aid to less experienced pelvic surgeons and may help in autonomic nerve preservation during total mesorectal excision clearance.
Hanna
Nader N
NN
Department of Surgery, Markey Cancer Center, University of Kentucky, Lexington 40536, USA.
Guillem
Jose
J
Dosoretz
Amy
A
Steckelman
Eric
E
Minsky
Bruce D
BD
Cohen
Alfred M
AM
D000328:Adult; D000368:Aged; D004558:Electric Stimulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010275:Parasympathetic Nervous System / Q000033:anatomy & histology / Q000502:physiology*; D010410:Penile Erection; D010413:Penis / Q000294:innervation*; D012004:Rectal Neoplasms / Q000601:surgery*; D012007:Rectum / Q000601:surgery*