Rectal ectasia associated with anorectal anomalies

Treatment of megarectum in anorectal malformation with emphasis on preventive aspects: 17 years experience

PURPOSE

Megarectum in anorectal malformation (ARM) causes severe morbidity. To compare conservative management (CM) of megarectum with excision (EX), to propose a new classification and to analyse management strategies.

METHODS

Between 2000-2016, we reviewed all ARM to identify megarectum, defined by radiological recto-pelvic ratio > 0.61. A new classification was proposed: primary megarectum (PM) pre-anorectoplasty, and secondary megarectum (SM) post-anorectoplasty, with sub-types. Complications and Krickenbeck bowel function were compared between CM and EX.

RESULTS

Of 124 ARM, 22 (18%) developed megarectum; of these, 7 underwent EX. There was no difference in functional outcomes when comparing CM vs EX-voluntary bowel movement (both 86%), soiling (40% vs. 57%) and constipation (both 86%). However, EX was associated with major complications (43%) and the requirement for invasive bowel management, compared to CM (85% vs. 27%, P = 0.02). 6/7 EX needed antegrade continence enema (ACE), one of these has a permanent ileostomy. With strategic changes, incidence of megarectum reduced from 20/77 (26%) to 2/47 (4%) after 2013 (P = 0.002).

CONCLUSION

EX did not confer benefit in the functional outcome but carried a high risk of complications, often needing ACE or stoma. By adhering to strategies discussed, we reduced the incidence of megarectum and have avoided EX since 2013.

The dilated bowel: a liability and an asset

The gastrointestinal tract responds to significant mechanical or functional obstruction by dilatation and hypertrophy of the segment proximal to the obstruction. Excessive dilatation compromises motility, and absorption and is associated with considerable morbidity (intraluminal stasis, sepsis) such that bowel dilatation represents a major liability that predisposes the patient to intestinal failure. The dilated bowel proximal to an obstruction provides valuable autologous material for reconstruction with "tissue appropriate to the part." Bowel elongation and dilatation are integral to the natural intestinal adaptation response to loss of small bowel and can also be induced through a structured "Bowel Expansion" program. The additional absorptive tissue that is progressively generated is essential for reconstruction of the bowel (tailoring and lengthening), to restore gastrointestinal dynamics (effective propulsion and absorption), and to reduce morbidity (intraluminal stasis, sepsis). In enhancing the prospects for enteral autonomy, dilatation and elongation of the residual autologous bowel are crucial to long-term survival and good quality life, and represent a most welcome asset. This paper reviews the impact and management of bowel dilatation along the gastrointestinal tract.

Importance of extrasphincteric mechanisms in the pathophysiology of faecal incontinence in adults with a history of anorectal anomaly

BACKGROUND

Although surgery for congenital anorectal anomalies (ARAs) aims to preserve anorectal function, faecal incontinence and constipation often result. Apart from the anal sphincters, continence is dependent on multiple anatomical and physiological factors. The aim of this study was to evaluate adults with a history of ARA to determine the role of such factors in functional outcome.

METHODS

The study included 20 consecutive adult patients with faecal incontinence who had undergone anorectal surgery as infants. Comprehensive testing included anal manometry, endoanal ultrasonography, tests of pudendal nerve function and rectal sensory function, evacuation proctography and colonic transit studies.

RESULTS

Anal resting tone and squeeze increments were both attenuated in 15 of 19 patients. Integrity of the internal and external anal sphincters was compromised in 16 and 15 of 18 patients respectively. Eleven of 13 had evidence of pudendal neuropathy. Rectal sensation was abnormal in 14 of 18 patients, of whom ten were hypersensitive and four hyposensitive. Rectal evacuation was abnormal in nine of 14. Colonic transit was delayed in five of eight patients with constipation.

CONCLUSION

Faecal incontinence in adult patients with ARA is related to various pathophysiologies. Structural integrity of the anal sphincters is a major factor, but extrasphincteric mechanisms, notably rectal sensory function, may be as important.

Posterior urethral valves in a newborn with imperforate anus: clinical presentation and management

Anorectal malformations are frequently associated with urinary tract abnormalities, which generally consist of vesicoureteral reflux, renal agenesis, and bladder dysfunction. Posterior urethral valves associated with anorectal malformations are exceedingly rare. We report the third case described in literature and the unique management.

Congenital pouch colon associated with anorectal agenesis

This article presents a review of the history and development of the various types of congenital pouch colon. Also described are the criteria for diagnosis, the treatment modalities and the results of follow-up studies to emphasize the post-operative problems. The problem of pre-operative and post-operative fecal incontinence is dealt with in more detail.

Anterior resection for megarectosigmoid in congenital anorectal malformations

PURPOSE

The aim of this study was to review the effectiveness of resecting dilated distal bowel in children suffering unmanageable constipation or soiling who have been operated on previously for anorectal malformations.

METHODS

A retrospective review was performed of 9 children. Each child underwent excision of dilated bowel to leave normal caliber bowel anastomosed by hand to a rectal reservoir at the peritoneal reflection. The documented follow-up was reviewed.

RESULTS

The 9 children had primary surgery for the following anomalies: high (n = 1), intermediate (n = 1), low (n = 3), rectal stenosis (n = 3), and anal stenosis (n = 3), Seven children had persistent fecalomas, and 7 had major problems with soiling. All were on large doses of laxatives, with 5 having regular rectal washouts and 4 having regular enemas. In all radiologic studies there was a prompt change from normal caliber bowel to dilated bowel at the upper limit of the dilatation. The mean age at operation for excision was 4 years, 11 months (range, 11 months to 9 years, 11 months). The mean period of follow-up was 4 years, 7 months (range, 2 years, 3 months to 10 years). Follow-up showed that all children improved. None had major complications. All were having between one and 3 bowel actions per day. Three continued to soil but improved. Of the remaining 6, only 2 required occasional laxatives and had regular spontaneous bowel actions without soiling. No child was having enemas or washouts.

CONCLUSION

Anterior resection for the treatment of megarectosigmoid is a safe and effective procedure.