A. M. Roe

Rectopexy is an ineffective treatment for obstructed defecation

The symptoms of obstructed defecation have been attributed to rectal intussusception, and thus rectopexy has been advocated in the surgical management. In this study, patients with obstructed defecation underwent manometry and proctography before and after rectopexy. Seventeen patients (16 females and one male, mean age 51.6 years) were studied. Eleven underwent anterior and posterior fixation of the rectum and six had posterior fixation only. Preoperatively five patients demonstrated rectoanal intussusceptions. Fifteen had significant pelvic descent. No significant change in maximum resting pressure, maximum voluntary contraction, pelvic descent, or anorectal angle was seen postoperatively. In the initial follow-up, many patients had significant amelioration of symptoms. However, on longer follow-up (mean 30.8 months) only two had long-term improvement. The remainder had a poor clinical result in spite of complete resolution of rectal intussusception. Many reported a worsening of symptoms as reflected by an increase in tenesmus and stool frequency. In the two cases with a satisfactory result, both could empty the rectum completely and demonstrated rectoanal intussusception on preoperative evacuation proctography. In those with poor results, four had complete emptying and three had rectoanal intussusception. In conclusion rectopexy is an ineffective treatment for obstructive defecation in most patients.

Improvement of anal sensation with preservation of the anal transition zone after ileoanal anastomosis for ulcerative colitis

One of the most important considerations in restorative proctocolectomy for ulcerative colitis is postoperative continence. Preservation of the anal transition zone has been associated with improved results after this procedure in the pediatric age group. This study was carried out to determine the effect of preservation of the amal transition zone in adult patients undergoing restorative proctocolectomy, comparing a group of patients with the anal transition zone preserved with a group of patients with the anal transition zone removed. Physiologic testing demonstrated improved sensation in those patients with a preserved anal transition zone. Functional results were not significantly improved, although there was a trend toward improved continence and discrimination in those with the anal transition zone preserved. Although the results are early and are not conclusive from the clinical standpoint, they are certainly encouraging and may justify continued use of this technique.

An analysis of rectal morphology in obstructed defaecation

Obstructed defaecation in the descending perineum syndrome has been attributed to anterior mucosal prolapse. Manometric and radiological measurements together with evacuation proctograms in 49 patients with obstructed defaecation and normal whole gut transit times were carried out and compared in a total of 25 controls. Proctography delineated four groups: (I) puborectalis accentuation,n=11; (II) rectal intussusception,n=25; (III) anterior rectal wall prolapse,n=11; (IV) rectocele,n=2. The anorectal angle at rest, maximum basal sphincter pressures and the rectoanal inhibitory reflex did not differ between the groups and controls. Group III achieved a greater increase in anorectal angle on straining than controls. Groups II and III exhibited significant perineal descent below the pubococcygeal line whereas group I did not. In perineal descent intussusception was the commonest morphological abnormality associated with obstructed defaecation. Isolated anterior mucosal prolapse was not observed, making local treatment aimed at reducing its bulk questionable.

Preoperative staging of local invasion in rectal cancer using endoluminal ultrasound.

Digital examination is the most commonly used method of assessing local invasion in rectal cancer, but it is highly subjective and accuracy is related to surgical experience. The use of transrectal ultrasound in the preoperative staging of rectal cancer has been assessed in 51 patients with histologically proven rectal cancers. Results showed a high degree of correlation when compared with postoperative histopathology (r = 0.91, P < 0.001). Invasion beyond the muscularis propria was predicted with a sensitivity of 97%. specificity of 92% and predictive value of 97%.

Anal sensation and the continence mechanism

Thermal sensation is thought to be important in sensory discrimination between different substances. The aim of this study was to determine the thermal sensitivity in the anal canal in continent patients with hemorrhoids (N=20), a group that has been reported to have a sensory deficit, and to compare the results with control subjects (N=40) and patients with idiopathic fecal incontinence (IFI) (N=22). Anal manometry was performed and sensation to mucosal electrostimulation and temperature change in the lower, middle, and upper zones of the anal canal assessed. Thermal sensation was impaired in the hemorrhoid group as compared with controls, but not to the same degree as in IFI (e.g., median thermal sensitivity in mid anal canal, control 0.9°C, hemorrhoid 1.2°C, IFI 2.0°C,P<.05 and <.001, respectively). The correlation between the two tests of sensation was 0.54 (P<.001) and the reproducibility of thermal sensory thresholds was 0.82 (P<.001). In conclusion, patients with hemorrhoids have a mild anal sensory deficit, but continence in this group is likely to be augmented by other factors.

Slow transit constipation

We have studied 31 patients with slow transit constipation. Fourteen developed severe symptoms following a hysterectomy, while the remainder had symptoms arising de novoand unrelated to pelvic surgery. To establish whether there were specific abnormalities which might be linked to hysterectomy, we compared the two groups. Rectosigmoid motility was impaired in the de novogroup. Functional sphincter length, maximum resting anal canal pressure, and the rectoanal inhibitory reflex were not significantly different from controls. The majority of patients were able to significantly increase the anorectal angle on straining to defecate. Patients in the de novogroup had a higher sensory threshold for rectal filling compared with controls, whereas the posthysterectomy group was not significantly different. Electromyography of the external sphincter showed failure of appropriate inhibition of resting activity in 57% of the de novoand 38% of posthysterectomy patients. The de novogroup had hypoactivity of the rectosigmoid and an insensitive rectum. The abnormality in the hysterectomy group is less clear and any precise link between slow transit constipation and hysterectomy remains obscure.We have studied 31 patients with slow transit constipation. Fourteen developed severe symptoms following a hysterectomy, while the remainder had symptoms arising de novoand unrelated to pelvic surgery. To establish whether there were specific abnormalities which might be linked to hysterectomy, we compared the two groups. Rectosigmoid motility was impaired in the de novogroup. Functional sphincter length, maximum resting anal canal pressure, and the rectoanal inhibitory reflex were not significantly different from controls. The majority of patients were able to significantly increase the anorectal angle on straining to defecate. Patients in the de novogroup had a higher sensory threshold for rectal filling compared with controls, whereas the posthysterectomy group was not significantly different. Electromyography of the external sphincter showed failure of appropriate inhibition of resting activity in 57% of the de novoand 38% of posthysterectomy patients. The de novogroup had hypoactivity of the rectosigmoid and an insensitive rectum. The abnormality in the hysterectomy group is less clear and any precise link between slow transit constipation and hysterectomy remains obscure.

The relationship between perineal descent and denervation of the puborectalis in continent patients

It has been suggested that perineal descent causes puborectalis neuropathy. To elucidate this, perineal descent was measured on standard proctograms and prolongation of mean motor unit potential duration was used as the index of denervation of the external sphincter and puborectalis in 9 male and 18 female patients with perineal descent and obstructed defaecation. The findings were compared with 21 normal controls. There was no significant perineal descent below the pubococcygeal line at rest but both males and females had abnormal descent of the anorectal angle on straining and a similar degree of external sphincter neuropathy. Females, however, exhibited a significant degree of puborectalis denervation compared with controls (p<0.001) and with male patients (p<0.001). Thus external sphincter denervation was associated with perineal descent in both sexes whereas other causes, of which obstetric trauma is a possibility, must be implicated in the puborectalis neuropathy of the females studied.

Perineal reconstruction with rectus abdominis flap after resection of anal carcinoma in Crohn's disease.

Acknowledgments: Our thanks are due to: Dr J Wade, Consultant Neurologist; Dr J Pearce, Consultant Paediatrician; Professor J Newsom-Davis, National Hospital for Nervous Diseases; Dr M Webley, Stoke Mande~iIIe Hospital for referral; Tissue Typing Laboratory, Northwick Park Hospital; Royal Free Hospital for acetyl choline receptor antibodies. Journal of the Royal Society of Medicine Volume 82 June 1989 369

Ano-rectal sensation

Whilst the bulk of published work on disordered defaecation has concentrated on the motor function of the anal sphincter [1,2], ano-rectal sensation may also play a crucial role in the preservation of continence, but there are surprisingly few published data on the subject.