Risk factors for bowel dysfunction after sphincter-preserving rectal cancer surgery: a prospective study using the Memorial Sloan Kettering Cancer Center bowel function instrument.

BACKGROUND: Until recently, no studies have prospectively evaluated bowel function after sphincter-preserving surgery for rectal cancer with the use of a validated bowel function scoring system. OBJECTIVE: The aim of this study was to investigate possible risk factors for altered bowel function after sphincter-preserving surgery. DESIGN: This was a prospective study. SETTINGS: The study was conducted between January 2006 and May 2012 at the authors' institution. PATIENTS: Patients who underwent sphincter-preserving rectal cancer surgery were recruited. MAIN OUTCOME MEASURES: Bowel function was assessed 1 day before (baseline) and at 1 year after sphincter-preserving surgery or temporary ileostomy takedown with the use of the Memorial Sloan Kettering Cancer Center questionnaire. Multivariable analysis was performed to identify the factors associated with altered bowel function after surgery. RESULTS: Overall, 266 patients were eligible for the analysis. The tumor was located in the upper, middle, and lower rectum in 68 (25.5%), 113 (42.5%), and 85 (32.0%) patients. Intersphincteric resection and temporary ileostomy were performed in 18 (6.8%) and 129 (48.5%) patients. The mean Memorial Sloan Kettering Cancer Center score was 64.5 ± 7.6 at 1 year after sphincter-preserving surgery or temporary ileostomy takedown. The Memorial Sloan Kettering Cancer Center score decreased in 163/266 patients (61.3%) between baseline and 1 year after surgery. Tumor location (p = 0.01), operative method (p = 0.03), anastomotic type (p = 0.01), and temporary ileostomy (p = 0.01) were associated with altered bowel function after sphincter-preserving surgery in univariate analyses. In multivariable analysis, only tumor location was independently associated with impaired bowel function after sphincter-preserving rectal cancer surgery. LIMITATIONS: This study was limited by its nonrandomized design and the lack of measurement before preoperative chemoradiotherapy. CONCLUSION: We suggest that preoperative counseling should be implemented to inform patients of the risk of bowel dysfunction, especially in patients with lower rectal cancer, although this study cannot exclude the effect of chemoradiotherapy owing to the limitation of study.

Injection of porous polycaprolactone beads containing autologous myoblasts in a dog model of fecal incontinence.

PURPOSE: Few studies have examined whether bioengineering can improve fecal incontinence. This study designed to determine whether injection of porous polycaprolactone beads containing autologous myoblasts improves sphincter function in a dog model of fecal incontinence. METHODS: The anal sphincter of dogs was injured and the dogs were observed without and with (n = 5) the injection of porous polycaprolactone beads containing autologous myoblasts into the site of injury. Autologous myoblasts purified from the gastrocnemius muscles were transferred to the beads. Compound muscle action potentials (CMAP) of the pudendal nerve, anal sphincter pressure, and histopathology were determined 3 months after treatment. RESULTS: The amplitudes of the CMAP in the injured sphincter were significantly lower than those measured before injury (1.22 mV vs. 3.00 mV, P = 0.04). The amplitudes were not different between dogs with and without the injection of autologous myoblast beads (P = 0.49). Resting and squeezing pressures were higher in dogs treated with autologous myoblast beads (2.00 mmHg vs. 1.80 mmHg; 6.13 mmHg vs. 4.02 mmHg), although these differences were not significant in analyses of covariance adjusted for baseline values. The injection site was stained for smooth muscle actin, but showed evidence of foreign body inflammatory reactions. CONCLUSION: This was the first study to examine whether bioengineering could improve fecal incontinence. Although the results did not show definite evidence that injection of autologous myoblast beads improves sphincter function, we found that the dog model was suitable and reliable for studying the effects of a potential treatment modality for fecal incontinence.

The use of a staged drainage seton for the treatment of anal fistulae or fistulous abscesses.

PURPOSE: The aim of this retrospective study was to evaluate the rate of recurrence and incontinence after the treatment of fistulae or fistulous abscesses by using the staged drainage seton method. METHODS: According to the condition, a drainage seton alone or a drainage seton combined with internal opening (IO) closure and relocation of the seton was used. After a period of time, the seton was changed with 3-0 nylon; then, after another period of time, the authors terminated the treatment by removing the 3-0 nylon. Telephone interviews were used for follow-up. The following were evaluated: the relationship between the type of fistula and recurrence; the relationship between the type of fistula and the period of treatment; the relationship between the recurrence and presence of abscess; the relationship between IO closure and recurrence; the relationship between the period of seton change and recurrence; reported continence for flatus, liquid stool, and solid stool. RESULTS: The recurrence rate of fistulae or suppuration was 6.5%, but for cases of horseshoe extension, the recurrence rate was 57.1%. The rate of recurrence was related to the type of fistula (P = 0.001). Incontinence developed in 3.8% of the cases. No statistically significant relationship was found between the rate of recurrence and the presence of an abscess or between the closure of the IO and the period of seton change or removal. CONCLUSION: In the treatment of anal fistulae or fistulous abscesses, the use of a staged drainage seton can reduce the rate of recurrence and incontinence.