Introduction - PDF document

. . . 22312.1.1 Introduction . . . 22312.1.2 Classication . . . 22312.1.3 Embryogenesis . . . 22412.1.4 Clinical Features . . . 22412.1.5 Investigations . . . 22412.1.6 22612.2.5 Investigations . . . 22712.2.6 Treatment . . . 22812.2.6.1 Medical Management . . . 22812.2.6.2 Surgical Treatment . . . 22812.2.7 Summary . . . References . . . Fig. . Revised classication of rectal atresia. Type I: rectal stenosis (rare); type II: rectal atresia with a septal defect; type : rectal atresia with a brous cord between the two atretic ends (common); type IV: rectal atresia with a gap; type V: multiple rectal atresia with stenosis (), and multiple atresia (only four cases reported) Devendra K. Gupta and Shilpa Sharma 226 that occurs in association with ARM may be an example of developmental overgrowth of the upper or lower primitive ampullae or both [18]. e tail gut is an extension of the undivided cloaca into the temporary tail of the human embryo. It is initially quite vol

uminous, but becomes atrophic and disappears before partition of the cloaca is complete. Incorporation and persistence of part of the tail gut into the rectum may result in anorectal ectasia [18]. It may be a variant of segmental dilatation of the intestine, which is a well-known cause of obstruction [18]. Primary hypomotility of the distal rectum has also been proposed [21]. Weakness of the posterior rectal wall or a defect in the external anal sphincter has been suggested. e authors have found a primary deciency of the musculature of the posterior rectal wall and the external anal sphincter, resulting in rectal inertia followed by rectal ectasia. is is well appreciated on surgical dissection during the PSARP procedure. Approximation of the defect improves the clinical symptoms.In 1984, Upadhyaya suggested a similar cause of mid-anal sphincteric defect as the possible cause of constipation in anterior perineal anus [22]. It may also be possible that not much attention has been given to this entity so far and many more cases may be diagnosed in fu

ture. is possible cause also explains the clinically and radiologically evident posterior rectal shelf in a few cases of primary rectal ectasia. PathophysiologyIt has been shown that the primary pathology in the causation of primary rectal ectasia is due to a deciency in the smooth muscle causing weakening and dilatation of the rectal wall [17]. Secondary rectal ectasia develops due to the response to the obstructed rectum. e elasticity of the rectal wall permits the normal rectum to expand to approximately double the caliber, but it returns to its normal size. In the newborn, ectasia beyond this diameter is predictive of a primary developmental ectasia, which is made even more apparent when overdistended by gas and meconium content.In the case of obstructive anorectal conditions, the rectal caliber soon reverts to normal dimensions aer the relief of obstruction by surgery. If the rectal ampulla is developmentally ectatic, the dilatation may persist and lead postoperatively to fecal accumulation, further enlargement, troublesome constipation, and so

iling.With high rectal anomalies, the terminal bowel is frequently focally ectatic, and in many patients the ectasia is primary or developmental. In others, hypertrophy and dilatation may occur as reactions to propulsive activity against an obstruction or upon a retained meconium bolus in the terminus of the bowel aer a defunctioning colostomy [23]. Primary and secondary rectal ectasia can be dierentiated histologically by examining rectal specimens: hypertrophy and hyperplasia of smooth muscle cells is evident in acquired cases, and are normal or smaller in newborns with a primary or developmental anomaly. Dysplastic nitrergic neurons in the rectum of a patient with rectal ectasia have also been demonstrated [24]. Bowel activity aer anorectal reconstruction for high lesions is compatible with near-normal continence in many children. Even when the sphincter muscles are adequate for high-grade continence, the ectatic terminal reservoir may overload and overow, requiring long-term treatment. Clinical Featurese most common symptom is refractory co

nstipation, either primarily or persistent aer successful reconstructive surgery for a known ARM. Rectal ectasia predisposes to ampullary overloading and constipation. Patients usually present aer 6 months of age, the most common period being around 1–3 years.Paradoxical diarrhea occurs when peristalsis relentlessly pushes the column of feces against the puborectalis sling and levator diaphragm. ese muscles fatigue, relax, and temporarily lose the important sphincter functions that control the entrance to the rectoanal canal. So feces are then massaged by peristalsis over the fecal masses to escape constantly from the anus (known as a “hold-back dyschesia cycle” or “pseudoincontinence”), in spite of good surgery y e clinical signicance of the anomaly is two fold. First, following PSARP, the ectatic rectum may become a passive reservoir for feces, which accumulates and impacts; second, the large bulk of the walls of the intact wide rectum may impair the reconstruction of the sphincter muscles at the time of the PS

ARP, thus lessening the ultimate degree of continence. Paradoxical diarrhea and incontinence resulting from anatomically defective sphincters may be dierentiated by rectal examination. Digital palpation of the 230 10. Dias RG, Santiago Ade P, Ferreira MC (1982) Rectal atresia: treatment through a single sacral approach. J Pediatr Surg 17:424–425 Vinograd I, Lernau OZ, Nissan S (1983) High anorectal atresia – surgical treatment through a sacro-coccygeal-perineal approach. Z Kinderchir 38:359–360 Vaneerdeweg W, Hubens G, Deprettere A (1995) Mucosal proctectomy and coloanal anastomosis as treatment of rectal atresia. J Pediatr Surg 30:1722–1723 Gauderer MWL, Izant RJ (1984) String placement and progressive dilatations in the management of high membranous rectal atresia. J Pediatr Surg 19:600–602 Upadhyaya P (1990) Rectal atresia: transanal, end-to-end, rectorectal anastomosis: a simplied, rational approach to management: J Pediatr Surg 25:535–537 Upadhyaya Purushottam (1996) Rectal Atresia. In: Prem Puri (ed) Newborn Surg

eryButterworth-Heinemann, Oxford, UK, pp 395–398 Chiba T, Albanese CT, Jennings RW, Filly RA, Farrell JA, Harrison MR (2000) In utero repair of rectal atresia aer complete resection of a sacrococcygeal teratoma. Fetal Diagn er 15:187–190 Brent L, Stephens FD (1976) Primary rectal ectasia: a quantitative study of smooth muscle cells in normal and hypertrophied human bowel. In: Rickham PP, Hecker W, Prevot J (eds) Progress in Pediatric Surgery. Urban and Schwarzenberg Berlin, pp 41–62 Stephens FD (1988) Rectal ectasia: primary and secondary associated with anorectal anomalies. Birth Defects Orig Artic Ser 24:99–104 Cloutier R, Archambault H, D’Amours C, Levasseur L, Ouellet D (1987) Focal ectasia of the terminal bowel accompanying low anal deformities. J Pediatr Surg Powell RW, Sherman JO, Raensperger JG (1982) Megarectum: a rare complication of imperforate anus repair and its surgical correction by endorectal pullthrough. J Pediatr Surg 17:786–795 Peña A, El Behery M (1993) Megasigmoid: a source of pseudoincontine

nce in children with repaired anorectal malformations. J Pediatr Surg 28:199–203 Upadhyaya P (1984) Mid-anal sphincteric malformation, cause of constipation in anterior perineal anus. J Pediatr Surg 19:183–186 Stephens FD (1980) Anorectal continence and idiopathic constipation. In: Holter TM, Ashcra KW (eds) Pediatric Surgery. WB Saunders, Philadelphia, pp 418–428 Cuari C, Bass J, Rubin S, Krantis A (1997) Dysplastic nitrergic neurons in the rectum of a patient with rectal ectasia. J Pediatr Surg, 32:1237–1240 Gattuso JM, Kamm MA (1997) Clinical features of idiopathic megarectum and idiopathic megacolon. Gut Hallows MR, Lander AD, Corkery JJ (2002) Anterior resection for megarectosigmoid in congenital anorectal malformations. J Pediatr Surg 37:1464–1466 Zia-ul-Miraj A, Brereton RJ (1997) Rectal ectasia associated with anorectal anomalies. Pediatr Surg 32:621–623 De Vries PA, Peña A (1982) Posterior sagittal anorectoplasty. J Pediatr Surg 17:638–643Devendra K. Gupta and Shilpa Sharma: Rectal Atresia and Rectal E