Sacral nerve terminal motor latency in patients with or without soiling more than 2 years after low anterior resection for low rectal cancer.
BACKGROUND
To clarify the neurologic function with respect to puborectalis muscle (PM) in patients after low anterior resection (LAR) for low rectal cancer, author examined the sacral nerve terminal motor latency (SNTML) of the PM.


METHODS
The latency of the response in the PM following transcutaneous magnetic stimulation of the cauda equina at the levels from S3 to S4 by SNTML was measured in 33 patients after LAR. They were divided into groups. Group A, which experienced soiling, comprised 15 patients (11 men, 4 women) aged 58 to 77 years (mean 63.5 years). Group A was further divided into patients having soiling with mucous secretions and feces on underwear on awaking everyday (group A1, 9 cases) and those with soiling during the daytime only when diarrhea occurred (group A2, 6 cases). Group B, which did not experience soiling comprised 18 patients (12 men, 6 women), aged 47 to 76 years (mean 62.2 years). The results from the groups were compared with data obtained from 33 control subjects (group C), who comprised 23 men and 10 women, aged 47 to 74 years (mean 62.4 years).


RESULTS
The distance of the anastomosis from the dentate line (DL) in group A1 was significant shorter than in groups A2 and B (p = 0.0071, p < 0.0001, respectively). Patients in group A displayed significant prolongation of the SNTML values compared with patients in groups B and C at the right, left, and posterior sites (all p < 0.0001). Moreover, patients in group B showed more extended SNTML than those in group C at all sites. Patients in group A1 exhibited significant prolongation of the SNTML compared with patients in groups A2 and B at all sites (all p < 0.0001). Moreover, patients in group A2 showed more prolonged SNTML than those in group B at all sites. A significant correlation was found between the distance of the anastomosis from the DL and the SNTML values at all sites of the PM (right side: r = 0.786, p < 0.0001; left side: r = 0.739, p < 0.0001; posterior: r = 0.773, p < 0.0001).


CONCLUSIONS
Soiling after LAR may be caused by damage to the bilateral sacral motor nerves.
Tomita
Ryouichi
R
Department of Surgery, Nippon Dental University Hospital, School of Life Dentistry at Tokyo, Tokyo, Japan. rtomita-ndus@mvg.biglobe.ne.jp
D000368:Aged; D001003:Anal Canal / Q000294:innervation* / Q000503:physiopathology / Q000601:surgery; D000714:Anastomosis, Surgical / Q000009:adverse effects / Q000379:methods; D015331:Cohort Studies; D003082:Colectomy / Q000009:adverse effects* / Q000379:methods; D004576:Electromyography; D005242:Fecal Incontinence / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008160:Lumbosacral Plexus / Q000503:physiopathology*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009431:Neural Conduction; D011183:Postoperative Complications / Q000503:physiopathology; D011336:Probability; D011351:Proctoscopy / Q000379:methods; D011930:Reaction Time; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013997:Time Factors