Michael E. R. Williamson

Recovery of physiologic and clinical function after low anterior resection of the rectum for carcinoma: myth or reality?

PURPOSE: The aim of this study was to examine the serial changes that take place in the first year after low anterior resection for rectal carcinoma, in terms both of anorectal physiology and clinical bowel function. Our hypothesis was that some patients never regain satisfactory anorectal function, because the operative procedure leads to permanent impairment of anorectal reflex and motor function. METHOD: Nineteen patients underwent serial tests of anorectal function, before and for one year after low anterior resection. The median level of the anastomosis above the anal high-pressure zone was 3 (range, 1–6) cm. RESULTS: Anal resting pressure (median (interquartile range)) was significantly decreased three months after operation (62 (46–72) cm H2O) and one year after operation was still significantly less (58 (48–73) cm H2O) than before operation (77 (58–93) cm H2O)(P<0.01). Maximum tolerated volume in the neorectum decreased from 130 (88–193) ml before operation to 80 (51–89) ml three months after operation (P<0.005) but returned to preoperative values by six months (125 (60–140) ml) (P=not significant) and remained at these values one year after operation. The volume in the “neorectal” balloon required to elicit a maximum rectoanal inhibitory reflex was significantly less three months after operation than before operation (50 (43–60) ml compared with 100 (73–100) ml;P<0.005); one year after operation, the volume required was still significantly less than before operation (50 mlvs.100 ml) (P<0.015). Bowel frequency increased from 1 (1–2) in 24 hours before operation to 4 (2–5) times in 24 hours after operation and remained at 4 times in 24 hours throughout the first year after operation. Three months after operation, 53 percent of patients experienced some degree of fecal leakage and 24 percent experienced urgency of defecation. These aspects of bowel function improved with time, but even one year after operation, 29 percent of patients continued to experience fecal leakage and 18 percent wore a protective pad. CONCLUSIONS: Anal resting pressure decreased significantly after low anterior resection and did not recover in the course of the first year after operation. Moreover, the volume of an air-filled balloon in the neorectum that was required to elicit maximum inhibition of the anal sphincter was significantly less after anterior resection than before operation. These long-term and presumably permanent changes in physiologic behavior of the anoneorectum after low anterior resection provide an explanation for the failure of some patients to regain satisfactory bowel function following that procedure.

One-stage restorative proctocolectomy without temporary ileostomy for ulcerative colitis

PURPOSE: This study was designed to determine the safety of omitting a temporary defunctioning ileostomy in restorative proctocolectomy for ulcerative colitis. METHOD: One hundred consecutive patients with ulcerative colitis were treated electively by restorative proctocolectomy and pouch-anal anastomosis, without mucosal stripping; 50 had a defunctioning ileostomy added, and 50 underwent a one-stage procedure without ileostomy. RESULTS: There was no operative mortality. The incidence of postoperative complications was similar in the two groups of patients. Lifethreatening complications, however, were more common among patients who did not have a defunctioning ileostomy, of whom 11 developed pelvic sepsis and 7 required reoperation. Among patients with an ileostomy, seven developed pelvic sepsis but none required reoperation (P<0.02). Emergency reoperations were required in 11 patients without an ileostomy but in only 1 patient with an ileostomy (P<0.01). CONCLUSION: One-stage restorative proctocolectomy without a defunctioning ileostomy is associated with increased risk to life. Its routine use cannot be recommended.

Decrease in the anorectal pressure gradient after low anterior resection of the rectum. A study using continuous ambulatory manometry.

PURPOSE: Changes in anorectal function after low anterior resection of the rectum (LAR) often lead to symptoms of urgency and frequency of defecation, the anterior resection syndrome. It has been reported that preservation of part of the rectum improves clinical results, but why this should be remains unclear. METHODS: We have carried out continuous ambulatory manometric studies in two groups of patients: 11 patients, a median of 11 (range, 5–96) months after LAR, in whom the median anastomotic level above the anal high-pressure zone was 0 (range, 0–2) cm; 9 patients, a median of 6 (range, 3–12) months after sigmoid colectomy, in whom the rectum remainedin situ and who acted as controls. RESULTS: Comparing the LAR group with controls, resting anal pressures were lower, median 68 (range 27-102) cm H2Ovs. 95 (45–116) cm H2O (P<0.05), and neorectal pressures were higher, 25 (0–48) cm H2Ovs. 10 (0–10) cm H2O (P<0.01). Thus the anorectal pressure gradients were less, 34 (0–74) cm H2Ovs. 81 (35–113) cm H2O (P<0.01). Slow-wave activity in the anal sphincter was present in six patients (55 percent) after coloanal anastomosis and eight patients (89 percent) after sigmoid colectomy. Sampling episodes were seen in only two patients (18 percent) after coloanal anastomosis and five patients (56 percent) after sigmoid colectomy. When clinical endpoints were compared (LARvs. controls), bowel frequency in 24 hours was higher, 5 (3–8)vs. 2 (1–3) (P<0.01); fecal leakage was more common, affecting seven patients (64 percent)vs. one patient (11 percent) (P<0.05), and urgency of defecation was also more common. CONCLUSIONS: The inferior clinical results observed after LAR compared with the results after sigmoid colectomy are thus in part because of higher neorectal pressure acting on a weakened sphincter mechanism. These observations lend support to the idea that neorectal capacity should be increased in patients who undergo low anterior resection.

Acute pouchitis and deficiencies of fuel

PURPOSE: Acute pouchitis is a troublesome complication after restorative proctocolectomy. Deficiency of fuel, especially short chain fatty acids (SCFA), produced by anaerobic bacterial fermentation of saccharides, is implicated in ulcerative and diversion colitis. Our hypothesis was that SCFA deficiency occurs in acute pouchitis, and correction of the deficiency is associated with resolution of pouchitis. METHODS: Thirty-two patients were studied, 10 with histologically confirmed acute pouchitis and 22 with healthy pouches. Stool concentrations of SCFA (acetic, propionic, butyric, and valeric acids) were determined by gas-liquid chromatography. Quantitative bacteriologic studies of stool were carried out, and four-quadrant pouch biopsies were assessed by a pathologist who was unaware of the clinical state. Patients with pouchitis were treated for six weeks with metronidazole and given dietary advice to increase their intake of fermentable saccharides. RESULTS: Stool concentrations of SCFA were significantly less in pouchitis patients compared with patients with healthy pouches (340μmol/g (range, 124–492)vs.93 (range, 44–136)P<0.01). No differences in anaerobic or aerobic counts were seen. Resolution of pouchitis was associated with a significant increase in SCFA, but anaerobic counts fell. CONCLUSION: Deficiency of SCFA is implicated in acute pouchitis

Paradoxical high anal resting pressures in men with idiopathic fecal seepage

PURPOSE: Fecal incontinence has been a matter of concern for many years, but seepage is poorly understood, especially in men. METHODS: We compared the results of anorectal physiologic tests in a group of 16 male patients who complained of fecal soiling but had no previous history of anorectal surgery or disease and had normal clinical examinations with findings of 16 normal male controls. Physical examination and proctosigmoidoscopy were normal in each patient. RESULTS: Maximum anal resting pressure (median interquartile range) was 136 (120–145) cm H2O in the “seepage” group and 104 (83–112) cm H2O in controls (P<0.01). Inflation volumes at which patients and controls experienced rectal sensation were 45 (35–80) and 90 (75–100) ml of air, respectively (P<0.01). Maximum tolerated volumess in the rectum were 130 (85–180) ml of air in the seepage group and 190 (140–240) ml of air in controls (P<0.01). Median length of the anal sphincter was 3.75 (3.5–4) cm in patients and 3 (3–3.5) cm in controls (P<0.01). Maximum squeeze pressures, sensation in the anal canal, and sphincter relaxation in response to rectal distention were similar in the two groups. CONCLUSION: Male patients with “idiopathic” fecal seepage have a long anal sphincter with abnormally high resting tone.

Internal anal sphincter activity after restorative proctocolectomy for ulcerative colitis: A study using continuous ambulatory manometry

PURPOSE: The aim of this study was to further investigate continuous ambulatory anal manometry which has recently been introduced as a method for studying anorectal activity in ambulant patients, thereby avoiding many of the potential drawbacks of static techniques. METHOD: In this study continuous ambulatory manometry was used to assess the activity of the internal anal sphincter in patients who had undergone restorative proctocolectomy, and, in particular, to compare patients who had undergone conventional mucosal proctectomy with sutured endoanal, ileoanal anastomosis with patients who had undergone restorative proctocolectomy with preservation of the entire anal canal by means of stapled, end-to-end, ileoanal anastomosis without mucosectomy. RESULTS: Evidence of basal internal sphincter activity was found in only 38 percent of patients after mucosal proctectomy with sutured endoanal anastomosis, whereas all patients after restorative proctocolectomy with stapled end-to-end anastomosis and all control individuals showed such activity of the internal sphincter. Similarly, the number of sampling episodes seen in patients after mucosal proctectomy with endoanal anastomosis was significantly less (median, 0.0/hours (0–30/hours)) than the number of sampling episodes observed in patients after end-to-end anastomosis (median, 4.5/hours (1–48/hours)) or in control individuals (median, 5.6/hours (0–31/hours)) (P<0.001). CONCLUSIONS: These results suggest that the internal anal sphincter is damaged in the course of mucosal proctectomy and endoanal anastomosis. In contrast, after restorative proctocolectomy with stapled, end-to-end anastomosis normal function of the internal sphincter is preserved.

Does eversion of the anorectum during restorative proctocolectomy influence functional outcome

PURPOSE: The aim of this study was to determine the effect of eversion of the anorectum during restorative proctocolectomy (RP) for ulcerative colitis on functional outcome. METHODS: One hundred seventeen patients underwent RP with stapled end-to-end ileal pouch-anal anastomosis (EEA), without resection of the anal mucosa. Sixty-four underwent EEA with eversion of the anorectum, and 53 underwent EEA without eversion. Each patient underwent paired studies of anorectal function before and a median of 12 months after RP. RESULTS: One year after RP, median (interquartile range) maximum resting pressure was 69 (range, 51–88) cmH2O in those patients who underwent eversionvs. 80 (range, 64–90) cmH2O in patients without eversion (P{bd>0.04). Threshold sensation in the upper, middle, and lower thirds of the anal canal were 9.1, 7.4, and 6.8 mA after eversionvs.6.9, 4.9, and 3.8 mA without eversion (P=0.003,P<0.001,P<0.001, respectively). Before operation, all patients had a rectoanal inhibitory reflex; however, after RP, 54 of 64 patients in the eversion group and 50 of 53 patients with a stapled EEA without eversion had an inhibitory reflex (P=not significant). Leakage of mucus was experienced by 11 patients who underwent eversion, compared with 9 patients without eversion. Fifty-six of 64 patients with eversion could defer defecation for more than 30 min compared with 43 of 53 patients without eversion. Twenty-two of 64 patients in the eversion group retained perfect discrimination between flatus and feces compared with 38 of 54 without eversion (P<0.001). Level of the anastomosis was 1 (range, 0.5–3) cm above dentate line after eversion compared with 1.5 (range, 0–6) cm without eversion. CONCLUSION: Clinical outcome after RP with eversion was not as good as outcome after stapled EEA without eversion. Such a conclusion requires confirmation in a prospective control trial.

The effect of pelvic ileal reservoir volume and antiperistaltic reflux on emptying efficiency

PURPOSE: The emptying efficiency of four different designs of pelvic ileal reservoir was compared using two different techniques of measurement. METHOD: Thirty-four patients were studied one year after restorative proctocolectomy. In each the ileal reservoir was filled with methyl cellulose paste labeled with51chromium-chromate and technetium Tc 99m-diethylenetriamine pentaacetic acid. Percentage evacuation was calculated from 1) the difference in51chromium activity between the recovered effluent and the total paste administered and 2) gamma camera measurements of technetium Tc 99m-diethylenetriamine pentaacetic acid activity within the ileal reservoir before and after evacuation. RESULTS: Median evacuation using the51chromium method was 84, 90, 70, and 75 percent for the W40, W30, J40, and J30 reservoirs respectively. The results were not significantly different from those obtained using the gamma camera: 83, 87, 67, and 71 percent (P=not significant). Patients with either type of W reservoir evacuate isotope-labeled paste more efficiently than patients with J40 reservoirs (P<0.05 andP<0.001, respectively) but not J30 reservoirs (P=not significant). However, if the actual volume of paste evacuated during a visit to the lavatory is measured, it is greatest for J40 reservoirs (median, 300 ml compared with 258 ml for W40, 289 ml for W30, and 268 ml for J30;P=not significant). CONCLUSIONS: Gamma camera measurement of ileal reservoir emptying is as accurate as our previous standard technique and provides a qualitative record of pouch evacuation, which may reveal reasons for inefficient emptying. The gamma camera images reveal that the difference in emptying percentage between W and J pouches is because of reflux of paste into the afferent ileum occurring more frequently in J pouches than in W pouches. The effect of this phenomenon on emptying is more than compensated for by the increase in reservoir capacity created by the reflux.