Imperforate anus: long- and short-term outcome

Seminars in Pediatric Surgery (2008) 17, 79-89

Imperforate anus: long- and short-term outcome Risto J. Rintala, MD, PhD, Mikko P. Pakarinen, MD, PhD From the Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland. KEYWORDS Anorectal malformations; Functional results; Imperforate anus; Short-term outcomes; Long-term outcomes

Anorectal malformations are common anomalies observed in neonates. Survival of these babies is currently achieved in most cases and improvements in operative technique, patient care, and better follow-up have led to improved functional results. A new, simplified classification system (Krickenbeck classification) and method of functional assessment has led to an improved understanding of these anomalies and has allowed for a better comparison of outcomes. Following successful anatomical repair and appropriate programs of bowel care, socially acceptable continence can be achieved in a majority of patients, especially those with an intact sacrum. © 2008 Elsevier Inc. All rights reserved.

The outcomes of patients with anorectal malformations have greatly improved by modern surgical techniques and neonatal care facilities during the last decades. Early survival is currently the rule, except in some rare cases with associated cardiac and urogenital anomalies or chromosomal defects that are not compatible with life. The overall long-term functional outcome expectancy in terms of fecal and urinary continence is relatively optimistic today. The majority of patients reaching adolescence and adulthood are able to maintain socially acceptable continence. There is no generally accepted method to classify anorectal malformations. The most commonly used method has been the Wingspread International Classification for Anorectal Malformations.1 Recently, a new simplified classification, the Krickenbeck classification (Table 1), that is based on consensus recommendations of world authorities has emerged.2 The classification used in the present communication is the Krickenbeck classfication; patients who have no perineal fistula are grouped under the title “high malformations,” and those with a perineal bowel opening are included under the title “low malformations.”

Address reprint requests and correspondence: Risto J. Rintala, MD, PhD, Hospital for Children and Adolescents, PO Box 281, FIN-00029 HUS, Finland. E-mail: [email protected].

1055-8586/$ -see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1053/j.sempedsurg.2008.02.003

The present review is based mainly on pertinent literature. In addition, the author’s personal experience with 270 patients treated with posterior sagittal anorectoplasty (PSARP) procedures for high malformations and management of 140 low anomalies between 1984 and 2006 is used as a basis to address specific previously unpublished issues in the management of anorectal malformations.

Short-term outcome Mortality Anorectal malformations are very often a part of a malformation complex. Some associated anomalies, especially cardiovascular malformations, may be uncorrectable. Therefore, there is always going to be some mortality among these patients. The mortality of patients with anorectal malformations during the last few decades has been between 10% and 20% of all cases.3,4 The mortality of patients with high anomalies has been about three times higher than that of patients with low anomalies, which corresponds to the higher incidence of severe associated anomalies. Only a minority of deaths are directly related to the anorectal anomaly and its treatment.3-5 At Children’s Hospital, University of Helsinki, the mortality of anorectal

80

Seminars in Pediatric Surgery, Vol 17, No 2, May 2008

Table 1 International classification of anorectal malformations (Krickenbeck)2 Major clinical groups Perineal (cutaneous) fistula Rectourethral fistula Bulbar Prostatic Rectovesical fistula Vestibular fistula Cloaca No fistula Anal stenosis Rare/regional variants Pouch colon Rectal atresia/stenosis Rectovaginal fistula H-type fistula Others

malformations has decreased from 23% in the late 1940s and early 1950s to 3% in the 1980s and 1990s (Figure 1). The decrease is clearly due to improved care of severe associated anomalies, especially cardiac defects.

Operative complications A colostomy performed in the neonatal period carries a high morbidity. The most common complications are colostomy prolapse and stricture.6,7 Stoma complications may be less common with a completely divided sigmoid colostomy.8 The reported total incidence of complications of infant colostomies ranges between 17% and 68% of the cases; the complications also include a few colostomy-related deaths. Early complications occur following all commonly used reconstructions for severe anorectal anomalies. The incidence of major complications, such as peritonitis, retraction or dehiscence of the pull-through segment, and recurrent fistula, has ranged from 10% to 30% following abdominoperineal or sacroabdominoperineal pull-through operations.3,4,6 Severe complications are less common following posterior sagittal anorectoplasty. In the large series by Peña and coworkers, serious complications requiring major reoperative surgery occurred in 2% of the cases, mainly following repair of a cloaca.9 In the authors’ series of 270 patients with high anomalies who underwent posterior sagittal anorectoplasty, the incidence of major early complications requiring reoperation has been also 2%. Postoperative anal complications have been common following traditional pull-through operations. Anal stenosis and mucosal prolapse have been found in up to 15% to 78% of reported patients.3,4,6,10,11 Stenosis has usually been attributed to inadequate anal dilatations during the follow-up period. On the other hand, local anal problems have been rare following posterior sagittal anorectoplasty. Peña reported very few local complications in his series of 792 patients.9 In the author’s series of 279 posterior sagittal

anorectoplasties, anal stenosis requiring surgery occurred in 5 patients. In addition, 3 patients, early in the series, required local operation for a minor mucosal ectopy. Early complications including wound problems after neonatal treatment of low anomalies are very uncommon. Urological complications following surgery for low anorectal malformations are unacceptable, and we have been fortunate enough to avoid them. However, local complications may occur later and are usually caused by insufficient longterm follow-up and care. Postoperative anal stenosis can be prevented by appropriate dilatations and careful follow-up. Untreated anal stenosis may cause secondary megacolon, which may even require operative treatment.3,12 Especially in cases with delayed diagnosis, the blind rectal pouch may be primarily ectatic enough to cause constipation without any associated anal stricture or stenosis.12 Before the definitive repair, it is essential to minimize the risk of urinary tract infections and permanent damage to kidneys caused by the rectourogenital connection if such is present and/or urinary tract anomalies that are common in patients with anorectal malformations.13,14 This is best accomplished by establishing a completely diverting colostomy and by careful washout of the rectal pouch.9

Outcome during early childhood Many patients with repaired high malformations have abnormal bowel function following closure of the protecting colostomy. The most common problem is frequent bowel movements causing perineal skin problems. In patients with traditional pull-through operations, this stage of bowel function, which is best characterized as uncontrollable soiling, continued for a long period of time, often for years. This is particularly the case with operations where the terminal rectal reservoir is resected, such as sacroabdominoperineal and endorectal abdominoperineal pull-through.3,15 Constipation is a major problem with patients who have had posterior sagittal anorectoplasty. Females with rectovestibular fistula are especially affected.3,9,12,16 Constipation may develop as a result of untreated anal stenosis but more commonly is a consequence of disordered colonic

25 20 Percent of Total

15 10 5 0

46-53 54-63 64-73 74-83 84-98

Figure 1 Mortality rate in patients with anorectal malformations in Helsinki (1946 –1998). (Color version of figure is available online.)

Rintala and Pakarinen

Imperforate Anus

motility.9,17 Constipation may begin early after the operation, and its severity is related to the degree of the initial dilation of the rectal blind pouch.9,16 Constipation is the most common early functional problem in patients with low anomalies, occurring in about 40% of the children.18-20 Constipation responds to regular laxatives most of the time. Enemas are seldom needed but are promptly prescribed if fecal impaction occurs. Severe soiling, not associated with constipation, is extremely rare and may be caused by operative sphincter damage or severe sacral defects. The mean age at toilet training for feces and urine as well as frequency of day- and night-time wetting is similar when compared with age-matched controls.18-20

Long-term outcome Evaluation of long-term functional outcome Clinical evaluation There is a great variation in the literature regarding functional results after repair of anorectal malformations. This is due to the fact that there is no generally agreed method to assess the bowel function of patients with anorectal malformations. The main problem in comparing different series is the highly variable criteria used in the evaluation of fecal continence. Evaluation of bowel function during childhood may be biased because the information concerning the functional outcome is mainly derived from the parents. They may not want to report unfavorable results to a surgeon who has been responsible for the treatment of their child. The parents may also ignore minor and moderate defects in continence for a child whose bowel function has been deficient from birth or, in the case of smaller children, may consider the situation to be part of normal maturation of defecation. The final outcome may not be fully assessed until the patients have reached adulthood when as independent individuals, patients can evaluate the social consequences of possibly defective bowel control. Scoring methods based on subjective parameters with or without clinical examination have been designed to get quantitative information about the bowel function. The most commonly used classifications are the Kelly-score,6 the Templeton score,15 Holschneider score,21,22 and Rintala score.23 All these classifications ultimately categorize the outcomes as good, fair, or poor. Descriptive, nonscoring methods to assess and describe functional outcome were advocated by the Wingspread group of pediatric surgeons.1 This method and the descriptive, nonscoring outcome classification of Peña, based on his extensive series,9 are the basis of the new Krickenbeck outcome classification method (Table 2). Objective methods Manometric assessment has been the principal method to obtain objective data of postoperative sphincter function.

81 Table 2

Assessment of outcome (Krickenbeck)2

1. Voluntary bowel movements Feeling of urge Capacity to verbalize Hold the bowel movement 2. Soiling Grade 1: occasionally (1 to 2/week) Grade 2: every day Grade 3: constant, social problem 3. Constipation Grade 1: manageable with diet Grade 2: requires laxatives Grade 3: resistant to diet and laxatives

yes/no

yes/no

yes/no

However, there is no standard for manometric evaluation. Single fluid-filled balloons in the anal canal have been used by several authors.24,25 Balloon devices allow only static measurements, therefore the open tip perfused catheter method is favored by others.26,27 The quantitative pressure recordings in static and dynamic studies are not directly comparable; the values of manometric tracings tend to be higher with the balloon method. Manometric and clinical results have often been found contradictory. Some investigators have found positive correlation between clinical continence and the anal resting pressure profile,23,25,28 whereas others have found no such correlation but a relationship between continence and voluntary squeeze force,29 and still others suggest no correlation at all between clinical continence and pressure profile or squeeze force.26,30 However, a clear correlation between the presence of inhibitory rectoanal reflex and clinical continence has been reported by several authors.23,25,26,28 Decreased rectal sensitivity with rectal distension has been reported to correlate with poor functional outcome.25,26,29 Of the available and relevant imaging modalities, MRI is superior because of excellent soft tissue characterization, multiplanar imaging, and lack of exposure to ionizing radiation. Hypoplastic sphincter complex, the misplacement of bowel in relation to sphincters, and obtuse anorectal angle have been factors related to poor outcome.31 However, correlation between clinical results and the findings with MRI have not been convincing. The primary value of MRI in patients with anorectal malformations is not in detecting abnormalities in the sphincter complex, but in revealing associated spinal dysraphism, which is common in these patients.32 Long-term bowel function A major difficulty lies in comparing functional results between reported follow-up series. The criteria used to evaluate long-term outcome are quite variable and mostly designed for high anomalies.1,6,15,21,33 In patients with high anomalies, a good result usually means socially acceptable continence which is not equivalent to normal anal function. A patient with a high anomaly and a good functional result rarely has normal bowel function, and although socially

82 continent, they often have a minor degree of smearing or soiling associated with physical straining or loose stools. Although many patients with low malformations have normal bowel function at long-term evaluation, a method designed to assess long-term outcome in high anomalies may underestimate minor defects in bowel function, and these may become significant when the patient leads a life of an independent adult individual.

Results in high anomalies Prognostic factors The level of the anomaly is an important prognostic factor in terms of bowel function. Males with a bladder neck fistula and females with a high confluence cloaca9 have significantly poorer prognosis than patients with a lower urogenital connection.23,28 The obvious cause of poorer prognosis in very high anomalies is the more marked hypoplasia of the voluntary sphincter muscles, especially the infralevator component of the muscles.9 The presence of severe sacral abnormalities is associated with hypoplastic sphincters. If more than two sacral vertebrae are missing or if the patient has other major sacral deformities, such as hemivertebrae and vertebral fusions, the functional outcome is worse than in patients with normal sacrum or lesser degree of sacral maldevelopment.9,23 The role of the internal sphincter in anorectal malformations is a topic which has been debated for decades. Recently, embryological, animal, and clinical studies have documented the presence of the internal sphincter in the region of the fistulous bowel termination.34-36 The functioning internal sphincter can be demonstrated by the presence of rectoanal relaxation reflex in anorectal manometry. Most patients with a low anomaly have positive rectoanal reflex.3,28,37 In patients with high malformations, rectoanal relaxation reflex has traditionally been present in only a minority of patients.28,30,37 However, when the rectourogenital fistulous connection has been preserved at the time of anorectal reconstruction, the percentage of patients with preserved functional internal sphincter has been between 40% and 80%.23,38,39 The presence of internal sphincter has been clearly shown to correlate with favorable functional outcome.23,25,28,38 Colonic motility disorders usually presenting as constipation have been earlier reported to be a problem in patients with low anorectal malformations and in females with a vestibular fistula.3,9 Chronic constipation is also the main functional complication following repair of high anomalies by posterior sagittal anorectoplasty.9,16,40 The incidence of constipation following PSARP procedure has varied between less than 10%41 and 73%.23 Constipation seems to be more common when internal sphincter-preserving techniques have been used.23,38 The cause of constipation is unclear; the extensive mobilization of the anorectum may cause partial sensory denervation of the rectum and impair the awareness of rectal fullness. Also, rectosigmoid hypo-

Seminars in Pediatric Surgery, Vol 17, No 2, May 2008 motility and generalized colonic motility disturbance have been suggested.17 It is likely that the surgical method of anorectal reconstruction in high malformations is a significant prognostic factor. However, this is very difficult to prove since randomized controlled studies are unavailable. Holschneider40 reported significantly better continence outcome in 21 patients who had posterior sagittal anorectoplasty compared with 16 patients having abdominoperineal pull-through with or without submucosal rectal resection advocated by Rehbein. Mulder and coworkers42 found no difference among patients undergoing sacroabdominoperineal operation and those who had posterior sagittal anorectoplasty. deVries in a literature review43 could not find conclusive evidence to support superiority for any procedure used for anorectal reconstruction in instances of high anomalies. Long-term bowel function during childhood Reports concerning long-term results for high anomalies are highly variable. Most series grade the results as good, fair, or poor. It must be remembered that a good outcome does not mean that the patient has normal bowel function. The patients with a good result have usually been considered socially continent, which implies that the defects in bowel function do not cause significant social disability. In the era before the posterior sagittal anorectoplasty, the reported percentages of patients, evaluated by clinical criteria, with a “good” result varied between 6% and 56%. The percentage of poor results (which has meant more or less total incontinence) varied between 10% and 70% of affected patients (Table 3). It is unlikely that such a wide variation would reflect true differences in long-term results. The operative methods used in all these series were routine procedures for anorectal reconstruction, and the number of patients in each series were relatively large which implies that the reporting authors/centers had experience in the repair of anorectal malformations. The plausible explanation for the variation is differences in the strictness of assessment criteria. The two relatively recent large series reported by Templeton15 and Rintala3 both used a quantitative multifactorial evaluation for continence. Both these series identified a lower percentage of poor results than the other series using mainly qualitative criteria. These multifactorial quantitative assessments seemed to grade continence higher than a qual-

Table 3 Functional outcome during childhood: high malformations Before the era of posterior sagittal anorectoplasty

50

Partridge, et al. Stephens and Smith6 Taylor, et al.30

No.

Good

Fair

Poor

63 25 45

33% 56% 24%

43% 32% 20%

24% 12% 56%

Rintala and Pakarinen

Imperforate Anus

83

Table 4 Functional outcome during childhood: high malformations Posterior sagittal anorectoplasty Total Significant continence soiling Constipation Peña9 36% Rintala, et al.23 35% Langemeijer, et al.41 7%

41% 30% 56%

43% 60% 5%

itative clinical assessment, probably because they are more sensitive to the patient’s social adaptation to abnormal anorectal function.22 Only Taylor and coworkers30 and Rintala3 have reported the incidence of patients with a completely normal bowel function without soiling or staining in any circumstances. In both series, only 7.5% of the patients had full bowel control comparable to that of healthy children. It is probable that this figure reflects the true incidence of unequivocally good long-term outcome in the patients treated with abdominoperineal and sacral approaches. There are still only a few reports concerning long-term functional outcome following posterior sagittal anorectoplasty, and the results have been contradictory (Table 4). Some surgeons report a dismal outcome with most patients requiring adjunctive measures to maintain social continence.41 On the other hand, Peña9 reports that approximately one-third of the patients with high or intermediate anomalies in his personal series could be considered as totally continent. In the series reported by Rintala and coworkers,23 in which the bowel function of the patients were compared with that of healthy children with similar age and sex distribution, 35% of the patients had an age-appropriate normal bowel function. A fair outcome with intermittent soiling requiring frequent change of underwear or protective aids, or poor outcome with intractable constipation or total incontinence was found in 30% of the patients. Many authors report an improvement in fecal continence with increasing age in patients operated by abdominoperineal procedure with or without a sacral approach.3,15,33 In Rintala’s series, the incidence of good outcome increased from 35% in the age group between 5 and 10 years to 58% in patients between 11 and 15 years. The improvement in fecal continence is more clearly shown in the series including adolescent or adult patients.33,44 It is not clear whether this improvement is true improvement of sphincter function or simply adaptation to the residual dysfunction. On the other hand, recent reports by Peña and Rintala9,23 on patients operated on by posterior sagittal anorectoplasty have shown that patients with favorable anatomy gain normal or near normal bowel function as early as age 3 years, provided that the inherent functional complications related to the procedure, especially constipation, are treated early and vigorously. In many cases, soiling during the early years after posterior sagittal anorectoplasty has been a conse-

quence of severe constipation with overflow incontinence, rather than sphincter insufficiency. The treatment of soiling associated with constipation is much more rewarding than treatment of soiling related to sphincter insufficiency. Long-term bowel function at adult age The pediatric surgical literature has only a few reports concerning functional outcome for high anorectal anomalies assessed at adult age (Table 5). The functional results in adults, however, illustrate the endpoint in the development of bowel function. Nixon and coworkers44 found normal bowel control in 7 (15%) of 47 adolescent and young adult patients. Twentynine patients (62%) had occasional soiling and 11 (23%) frequent soiling or a colostomy. More recently, Rintala and coworkers45 studied 33 adult patients with a mean age of 35 years using a questionnaire-based scoring system. Healthy adults with an age and sex distribution similar to the patients were used as controls. None of the patients reached a score indicating normal bowel function, and only 6 (18%) had a good continence score. All controls had good scores and 80% a score indicating normal bowel function. Thirty-one (94%) of the 33 patients reported some degree of fecal soiling. Hassink and coworkers46 evaluated 58 patients with a median age of 26 years by using similar scoring methods as Rintala and coworkers. Also in this study none of their patients met the criteria for normal bowel habits. About 80% of the patients had soiling. In these series, most patients had an abdominoperineal repair as a primary reconstruction. In Nixon’s44 series, 68% of the patients had major secondary surgery in an attempt to improve continence. In Rintala’s45 series 30% and in Hassink’s46 series half of the patients had secondary sphincter repairs. According to above data, it is obvious that almost all adult patients who have undergone repair of a high anorectal malformation with traditional methods, such as direct perineal, abdominoperineal, or sacro-abdominoperineal operations, have some form of fecal incontinence despite many secondary sphincter reconstructions. Although many patients report being satisfied with their current level of fecal continence,46 objective evaluation of the data concerning bowel function provides a different picture. It is likely that the adult patients have accepted their handicap. The patients have developed measures to cope with unsatisfactory bowel control, such as staying near toilets, wearing liners or dia-

Table 5 Functional outcome at adult age: high malformations No. Normal Good 46

Hassink, et al. 58 0 Rintala, et al.45 33 0 Nixon, et al.44 47 15 Rintala 2007* *Unpublished data.

69 43%

Fair Poor

36% 43% 21% 18% 54% 27% 62% 23% (good/fair) 36% 9% 12% (ACE)

84 pers, having regular enemas, or having dietary restrictions.45-47 At adult age, defective fecal continence has significant social consequences. The main problem is fecal soiling which restricts social activities. In Rintala’s series,45 85% of the adult patients reported social disability related to soiling. Other problems especially disturbing to occupational life were inability to hold back flatus and fecal urgency. Hassink and coworkers47 reported that adult patients had significantly lower educational level than expected. There are no reports concerning the functional outcome in adult patients who have undergone repair of their severe anorectal malformation by posterior sagittal anorectoplasty. In our institution, we reviewed the functional outcome in 69 patients that were older than 15 years at the time of assessment (Table 5). Normal continence without any fecal soiling or constipation requiring medication was found in 30 patients (43%). Twenty-five (36%) had minor problems, such as constipation requiring medication or occasional staining; these functional aberrations did not have any social impact, and none of these 25 used any protective aids. Six patients (9%) had significant continence problems causing frequent soiling and need to use protective pads or change of underwear. Five of these were mentally retarded. In 8 patients (12%), fecal continence was so poor that they required a permanent appendicostomy for bowel management with regular washouts. These preliminary data from 1 institute largely support the former reports of functional outcome during childhood,9,44 suggesting that PSARP is superior to the prior traditional methods of repair. In our institution, nearly half of patients who have undergone PSARP-procedure have normal fecal continence beyond childhood.

Seminars in Pediatric Surgery, Vol 17, No 2, May 2008 had scores within the 90th percentile of the controls of healthy children; constipation was found in 42% and soiling in 10% of the patients. Four (10%) patients reported restricted social life due to fecal soiling. The issue was assessed further by our institution in a recent prospective follow-up study including only boys (median age, 8.5 years; range 4.3-13.5 years) with perineal (anocutaneous) fistula who were compared with age- and sex-matched healthy controls.19 The children and their caregivers were interviewed by an independent third party. A total of 68% of the patients had bowel function scores within the 90th percentile of the controls; constipation occurred in 41% and soiling in 55% of the patients. The figures for constipation and soiling among controls were statistically and clinically significantly lower: 8% and 24%, respectively. Soiling occurred occasionally in every child with a reconstructed low malformation, but bowel dysfunction restricted social life in only 1 of the 22 patients. In perineal fistula, the anus is anteriorly displaced but is surrounded by the sphincter muscles. One may accept the anterior displacement of the anus and perform a simple anoplasty or perform more complex PSARP. It may be argued that the latter surgical approach is associated with better functional outcome. To address this issue, we performed a prospective multicenter comparison of functional outcome between these 2 surgical techniques.18 There were 24 boys treated with anoplasty and 17 boys treated with PSARP. The groups were comparable regarding age, associated malformations, and sacral dysplasia. The results suggest that functional outcome is very similar following both procedures without any differences in the overall bowel function score or in the rate of constipation and soiling.18 However, the need for redo surgery was significantly increased in the PSARP group.

Results in low anomalies Traditionally, the long-term results in low malformations are considered to be good in the great majority of patients.33,48-50 Poor outcomes have been related to neurological damage and mental retardation37 or insufficient longterm follow-up and care of the patients.4,44 More critical reviews on the long-term outcome have clearly demonstrated a significant number of children with functional defects, the most common of which is chronic constipation followed by soiling. In Yeung’s series,51 15 of the 32 children with a follow-up between 1 and 7 years had normal bowel function. Of the remaining 17 patients, all had constipation and 9 occasional or frequent soiling requiring treatment. In the series of Ong and coworkers52 concerning 70 patients with low anorectal anomalies, there were 35 children under the age of 15 years, 9 of whom were clean, 14 had occasional smearing, and 12 had soiling. Rintala and coworkers48 compared the bowel function of 40 children with low anomalies, including patients with perineal fistula, anal stenosis, and operatively treated stenotic anterior perineal anus, to that of healthy children using a scoring system. Only 52% of the reconstructed patients

Bowel function at adult age There are only a few functional outcome studies of low anorectal malformations with a follow-up extending to adulthood. Karkowski53 reported good continence in 12 (80%) of his 15 patients with low malformations. Nixon and coworkers4 found entirely normal bowel control in 23 (74%) of his 31 adult or adolescent patients. The remaining patients had occasional or frequent soiling. More recently, the large series of Ong and coworkers52 and Rintala and coworkers22 have demonstrated that a significant percentage of these patients have abnormal anorectal function at the adult age. Ong and coworkers reported 35 patients with a follow-up of more than 15 years. Although the majority were considered to have good continence according to commonly used clinical scoring methods, only 13 (37%) of the patients were clean at all times. Seventeen patients (49%) had fecal smearing and 5 (14%) intermittent soiling.52 Rintala and coworkers, using a quantitative scoring method, compared the bowel function of 83 patients to that of healthy individuals with similar age and sex distribution.22 All controls had good fecal continence, 76% with completely normal bowel function. In contrast, 60% of the

Rintala and Pakarinen

Imperforate Anus

patients with a low anorectal anomaly had good continence, but completely normal bowel function was observed only in 15%. It should be noted that these findings are not fully comparable with our more recent studies because the patients included 38 women with anovestibular fistula. Nevertheless, social problems related to deficient fecal control were reported by 39% of the patients. In addition, 13% of the patients had difficulties in sexual functions. Other health problems were reported by 52% of the patients, but only by 6% of the controls. Based on our experience, overall long-term bowel function is impaired at least in one-third of children with a low anorectal malformation. The main reasons for impaired anorectal function are constipation and occasional soiling affecting up to half of the patients. In most patients, the nature of constipation and soiling is modest enough not to produce social problems or restrict social activities. Patients with operated low anorectal malformations require continuing follow-up and care beyond childhood.

Long-term problems related to associated malformations Urinary tract problems Urinary tract anomalies occur in more than 40% of all patients with anorectal malformations; however, the actual incidence of long-term urological morbidity is difficult to assess because only a few long-term follow-up reports have specifically addressed urological problems. A high incidence of neurovesical dysfunction in patients with anorectal malformations has been reported by several authors.13,54-56 Neurovesical dysfunction is usually congenital and often associated with lumbosacral or intraspinal abnormalities.56,57 Vesicoureteral reflux in patients with anorectal malformations is commonly associated with neurovesical dysfunction, and therefore, carries a high risk of recurrent urinary tract infection and subsequent renal damage. Urinary incontinence is related to dysplastic sacrum, urethral and bladder anomalies, and neurovesical dysfunction. Operative damage to bladder neck or urethra seem to account for a minority of causes of urinary incontinence.56,57 Urinary incontinence is uncommon in patients with low anomalies, which probably reflects the lower incidence of spinal anomalies or neurogenic bladder in these patients. Rintala and coworkers44 and Peña9 reported no such cases with urinary incontinence in their recent series. Recent reports have shown that the age of toilet training for urine is similar in patients with low anal anomalies and healthy children.18,19,48 Urinary incontinence was common in patients with high anomalies operated on by traditional methods in the past (Table 6). It appears, however, that patients who have had posterior sagittal anorectoplasty have a lower incidence of neurogenic bladder and urinary incontinence than patients operated on by earlier traditional methods, although poste-

85 Table 6

Urinary incontinence No.

Low anomalies Peña9 Rintala, et al.48 Trusler, et al.49 Rintala, et al.22 High anomalies (before posterior sagittal anorectoplasty) Trusler, et al.49 Wiener, et al.57 Smith, et al. Rintala, et al.45 Hassink, et al.46 High anomalies (posterior sagittal anorectoplasty) Peña9 Rintala, et al.58

Incontinence (%)

14 40 20 83

0 0 10 11

15 90 18 33 58

33 31 28 33 22

233 65

10 8

rior sagittal anorectoplasty requires often extensive dissection behind the urethra and bladder neck (Table 6). Peña9 described a 10% incidence of urinary incontinence in his 233 children who had posterior sagittal anorectoplasty for high or intermediate anomalies, including rectovestibular fistulas. In Rintala’s series,58 of 65 patients with high or intermediate anorectal malformations repaired by internal sphincter preserving posterior sagittal anorectoplasty, 8% had long-term postoperative urinary incontinence. Also in this series, urinary incontinence was correlated with severe sacral anomalies and high cloacal deformities. A recent institutional analysis of 69 patients older than 15 years of age showed that some kind of urinary incontinence was present in 11% of patients with high anomalies. In a majority of these patients, the symptoms were mild and caused no social disability. Two of these 69 patients required clean intermittent catheterization to remain dry. Genital anomalies, fertility, and sexual problems Females with anorectal malformations have a high incidence of genital anomalies; the most common are vaginal and uterine septation anomalies and vaginal agenesis.59 Genital tract and sexual function has been reported to be impaired in almost half of these patients because of vaginal scarring.59,60 Vaginal scarring may cause dyspareunia and may interfere with child birth.60 Late gynecological problems are especially common in patients with cloaca. Obstruction of Mullerian structures with subsequent cystic menstrual blood collections have been reported to develop in a high percentage of postpubertal girls with cloaca.62 There is little information about fertility in patients with anorectal malformations. In Rintala’s series of 83 adult patients21 with low malformations, 47 (57%) had offspring of their own. In the same study, 54% of the healthy controls with similar age and sex distribution had children of their own. On the other hand, in another study from the same

86 institution,45 concerning high malformations, only 39% of the patients had children, which was significantly less than healthy controls, 60% of whom had offspring. Obviously, the low frequency of offspring in patients with high anomalies reflects true infertility in a significant percentage of patients. Ejaculatory duct obstruction has been reported in males,61 some have erectile dysfunction, weak or missing erections, or retrograde ejaculations,45 and some females have Mullerian structure agenesis.59 On the other hand, some patients may avoid sexual contacts because of defective fecal continence. Rintala21,45 reported that 20% of the patients with high anomalies and 13% of the patients with low anomalies avoided sexual intercourse because of poor bowel control. Vertebral anomalies and myelodysplasias In the literature, there are essentially no reports concerning late problems related to vertebral anomalies in patients with anorectal malformations. In the senior author’s consecutive series of 270 high anorectal anomalies operated on between the years 1984 and 2006, 5 patients have required operative spinal stabilization because of progressive scoliosis. A report from the same institution noted that 16% of adults with anorectal malformations had spine-related symptoms, mainly chronic back pain.21,45 Recently, much attention has been placed on the occurrence of myelodysplasias in patients with anorectal anomalies.54,63,64 The effect of spinal abnormalities, especially tethered cord on long-term functional outcome in terms of bladder and bowel function or neurological symptoms in the lower extremities, is unclear, although some recent reports suggest that worsening of neurologic function due to spinal anomalies is possible.63 There appears to be no evidence to support prophylactic detethering of patients who do not have specific symptoms related to tethering.64,65 There is also no evidence to support the concept that tethered cord affects functional outcome in terms of fecal or urinary continence in patients with anorectal malformations.64,66 Screening for spinal abnormalities is clearly indicated in all patients with anorectal malformations, including patients with low anomalies.32,63 Normal vertebral anatomy on plain spinal radiographs does not preclude the presence of spinal cord abnormalities.63 Screening can be performed by ultrasound during early infancy or by MRI at any age.

Methods to improve defective fecal continence Secondary reconstructions Secondary reconstructions to improve fecal continence have been used extensively in patients with anorectal malformations. In most long-term follow-up series extending to adulthood, a significant proportion of patients have undergone various types of redo-surgery.44-46 In most reports, the longterm functional outcome is not better in patients who had secondary surgery45 and may be worse than in those with only primary repair.46 It is, however, possible that the pa-

Seminars in Pediatric Surgery, Vol 17, No 2, May 2008 tients with redo-operations had initially worse continence than those with only one operation. Gracilisplasty has been a common method for secondary sphincter reconstruction. Several reports have shown a clear improvement in fecal continence in the short term.67,68 The improvement in continence is caused by somewhat increased resting pressure67 and significantly increased squeeze pressure. In adults who have had gracilisplasty during childhood, the functional results are not encouraging.44-46 The fecal continence is no better and may be worse than in patients with only primary reconstruction. Recently, continuous electrical stimulation of the gracilis muscle has been shown to induce a transition in muscle composition, from fatigable type II fibers to fatigue-resistant type I fibers.69 In this report, patients underwent gracilisplasty followed by implantation of a muscle stimulator. After a training period, the stimulator was used continuously to maintain constant anal tone. Short-term clinical and manometric results were promising,69 but longer follow-up has, however, revealed that only one-third of patients develop satisfactory continence.70 Levatorplasty, originally described by Kottmeier and coworkers,71 was popularized as a secondary sphincter reconstruction by Puri and Nixon.72 Encouraging results have been published by several authors.44,73,74 The functional improvement following this procedure has been thought to be related to creation of an acute anorectal angle, because actual resting or squeeze pressures are not changed at the level of the anal canal. Long-term outcomes in adults are not encouraging. There are no significant differences in fecal continence between those who had secondary levatorplasty and those with primary repair only.45,46 Rerouting of the pulled-through bowel has been advocated for patients who have a misplaced anal canal following primary operation.6,75 The bowel may traverse the levator and not lay anterior to it. Essentially identical procedures for rerouting and repair of the muscular anal canal have been suggested by Stephens, Kiesewetter, and Peña.6,75,76 The repair is performed through a posterior sagittal sacroperineal incision and includes splitting of the voluntary sphincter muscles in the midline as in standard posterior sagittal anorectoplasty. The reported outcomes in terms of improved fecal continence have been variable. Following redo posterior sagittal anorectoplasty, Peña found very significant improvement in 52% of his 62 patients, mild improvement in 18%, and no improvement in 12%; the length of follow-up is not given. Mulder and coworkers reported that 25% of their 20 patients became continent following this procedure; the mean follow-up period was 3.5 years. Brain and coworkers77 had a success rate of 16% following a relatively short follow-up period. Rintala and coworkers78 followed-up 16 patients with redo-posterior sagittal anorectoplasty beyond childhood (mean follow-up period 6 years). Although the clinical continence and manometric findings initially improved in 13 of the 16 patients, at adult age only 4 (25%) of the patients could be considered continent. According to the results of these

Rintala and Pakarinen

Imperforate Anus

reports, the role of secondary PSARP in the treatment of fecal incontinence after primary reconstruction of anorectal malformations remains unestablished. Other secondary sphincter substituting methods for fecal incontinence following reconstruction of anorectal malformations include free transplantation of palmaris longus muscle, gluteus muscle plasty, free smooth muscle transplantation, and artificial sphincters. None of these methods has gained widespread popularity. Sacral nerve stimulation has yielded promising results in patients with neurogenic bladder and bowel dysfunction.79 It remains to be seen if this modality can be successfully used in patients with anorectal anomalies. Other modern modalities to treat fecal incontinence (bulk agents, Secca procedure, artificial sphincters) have been used in patients with anorectal anomalies only infrequently, and presently no follow-up data are available. In some patients, late fecal soiling is related to intractable constipation.9,12,23,80 Many of these patients have an adynamic megarectum, which cannot be emptied with medical management or regular enemas. Aganglionosis, although a rare occurrence in patients with anorectal anomalies, should be ruled out by rectal biopsies. In recalcitrant cases, resection of the dilated distal colon has given favorable results.80,81 The constipation may, however, not be resolved permanently; recurrent constipation has been reported following rectosigmoid resection of a megarectum.17 The Malone antegrade colonic enema (MACE) has proven to be a powerful modality to treat fecal incontinence of various etiologies.82 Two-thirds to 95% of the patients have gained full continence following this procedure. Most treated patients have had neurogenic fecal incontinence. Most series also include patients with anorectal malformations. In the authors’ institution, 27 patients with anorectal malformations have had MACE procedure for fecal incotinence, with excellent or good continence outcome in 80% of the patients. Biofeedback conditioning has been used to treat fecal incontinence in patients with anorectal malformations.83,84 Limited results have been encouraging, but in the author’s experience, most patients with severe incontinence never gain full bowel control in the long-term. Minor defects in continence are more likely to respond to biofeedback.

Conclusion Despite significant developments in the understanding of the pathological anatomy and physiology of anorectal malformations, the results of surgical therapy remain far from perfect. Completely normal bowel function, comparable to that of healthy individuals, is possible, however, in a significant proportion of patients. In low malformations, most patients develop fecal continence by adulthood. In high anomalies up to half of the patients who have had PSARP procedure have excellent fecal continence beyond child-

87 hood. Secondary surgery for failed or inadequate primary reconstruction is unlikely to provide results that are comparable to those following a successful primary repair. Patients with anorectal malformations need careful follow-up throughout their childhood. Functional complications, especially treatable ones such as constipation, should be detected and treated early to achieve optimal outcome. The treatment of defective continence should be started well before the child reaches school age to overcome the devastating social consequences of fecal soiling and to integrate the child into the social context of his peers. Because the management of anorectal malformations requires years of commitment and special knowledge concerning the anatomical and physiological characteristics of this complex group of congenital malformations, these children should be treated by experienced medical personnel in specialized referral centers.

References 1. Stephens FD, Smith ED. Classification, identification and assessment of surgical treatment of anorectal anomalies. Pediatr Surg Int 1986;1: 200-5. 2. Holschneider A, Hutson J, Peña A, et al. Preliminary report on the International Conference for the Development of Standards for the Treatment of Anorectal Malformations. J Pediatr Surg 2005;40:1521-6. 3. Rintala R, Lindahl H, Louhimo I. Anorectal malformations - results of treatment and long term follow-up of 208 patients. Pediatr Surg Int 1991;6:36-41. 4. Hecker WC, Holschneider AM, Kraeft H, et al. Complications, lethality and long-term results after surgery of anorectal atresia. Z Kinderchir 1980;29:238-44. 5. Kiesewetter WB, Hoon A. Imperforate anus: an analysis of mortalities during a 25-year period. Prog Pediatr Surg 1979;13:211-7. 6. Stephens FD, Smith ED. Ano-Rectal Malformations in Children. Chicago, IL: Year Book Medical Publishers, 1971. 7. Mollitt DL, Malangoni MA, Ballantine TVN, et al. Colostomy complications in children. Arch Surg 1980;115:455-60. 8. Wilkins S, Peña A. The role of colostomy in the management of anorectal malformations. Pediatr Surg Int 1988;3:105-9. 9. Peña A. Anorectal malformations. Semin Pediatr Surg 1995;4:35-47. 10. Guttman M, Laberge Y, Yazbeck S. Anterior perineal approach for high imperforate anus using the Mollard technique. In. Stephens FD, Smith ED, eds. Anorectal Malformations in Children: Update 1988, Birth defects: Original article series, vol 24, Number 4, pp 349-355. 11. Kiesewetter WB. Rectum and anus: malformations. In: Ravitch MM, Welch KJ, Benson CD, et al., eds. Pediatric Surgery (3rd edition). Chicago, IL: Year Book Medical Publishers, 1979:1059-72. 12. Powell RW, Sherman JO, Raffensperger JG. Megarectum: a rare omplication of imperforate anus repair and its surgical correction by endorectal pull-through. J Pediatr Surg 1982;17:786-95. 13. Sheldon CA, Gilbert A, Lewis AG, et al. Surgical implications of genitourinary anomalies in patients with imperforate anus. J Urol 1994;152:196-9. 14. McLorie GA, Sheldon CA, Fleischer M, et al. The genitourinary system in patients with imperforate anus. J Pediatr Surg 1987;22: 1100-4. 15. Templeton JM, Ditesheim JA. High imperforate anus - quantitative result of long-term fecal continence. J Pediatr Surg 1985;20:645-52. 16. Rintala R, Lindahl H, Marttinen E, et al. Constipation is a major functional complication after internal sphincter-saving posterior sagittal anorectoplasty for high and intermediate anorectal malformations. J Pediatr Surg 1993;28:1054-8.

88 17. Rintala R, Marttinen E, Virkola K, et al. Segmental colonic motility in patients with anorectal malformations. J Pediatr Surg 1997;32:453-6. 18. Pakarinen MP, Goyal A, Koivusalo A, et al. Functional outcome in correction of perineal fistula in boys with anoplasty versus posterior sagittal anorectoplasty. Pediatr Surg Int 2006;22:961-5. 19. Pakarinen MP, Koivusalo A, Lindahl H, et al. Prospective controlled long-term follow-up for functional outcome after anoplasty in boys with perineal fistula. J Pediatr Gastroenterol Nutr 2007;44:436-9. 20. Rintala RJ, Lindahl HG, Rasanen M. Do children with repaired low anorectal malformations have normal bowel function? J Pediatr Surg 1997;32:823-6. 21. Holschneider AM. Elektromanometrie des Enddarms. Munich: Urban & Schwarzenberg, 1983:213-8. 22. Rintala R, Mildh L, Lindahl H. Fecal continence and quality of life in adult patients with an operated low anorectal malformation. J Pediatr Surg 1992;27:902-5. 23. Rintala R, Lindahl H. Is normal bowel function possible after repair of intermediate and high anorectal malformations. J Pediatr Surg 1995; 30:491-4. 24. Arhan P, Faverdin C, Devroede G, et al. Manometric assessment of continence after surgery for imperforate anus. J Pediatr Surg 1976;11: 157-66. 25. Hedlund H, Peña A, Rodriquez G, et al. Long-term anorectal function in imperforate anus treated by a posterior sagittal anorectoplasty: manometric investigation. J Pediatr Surg 1992;27:906-9. 26. Doolin EJ, Black CT, Donaldson JS, et al. Rectal manometry, computed tomography and functional results of anal atresia surgery. J Pediatr Surg 1991;28:195-8. 27. Rintala R. Postoperative internal sphincter function in anorectal malformations: a manometric study. Pediatr Surg Int 1990;5:127-30. 28. Iwai N, Hashimoto K, Goto Y, et al. Long term results after surgical correction of anorectal malformations. Z Kinderchir 1984;39:35-9. 29. Molander ML, Frenckner B. Anal sphincter function after surgery for high imperforate anus: a long term follow-up investigation. Z Kinderchr 1985;40:91-6. 30. Taylor I, Duthie HL, Zachary RB. Anal continence following surgery for imperforate anus. J Pediatr Surg 1973;8:497-503. 31. Fukuya T, Honda H, Kubota M, et al. Postoperative MRI evaluation of anorectal malformations with clinical correlation. Pediatr Radiol 1993; 23:583-6. 32. Beek FJA, Boemers TML, Witkamp TD, et al. Spine evaluation in children with anorectal malformations. Pediatr Radiol 1995;25:S28-32. 33. Kiesewetter WB, Chang JHT. Imperforate anus: a five to thirty year follow-up perspective. Prog Pediatr Surg 1977;10:110-20. 34. Lamprecht W, Lierse W. The internal sphincter in anorectal malformations: morphologic investigations in neonatal pigs. J Pediatr Surg 1987;22:1160-8. 35. Kluth D, Hillen M, Lamprecht W. The principles of normal and abnormal hindgut development. J Pediatr Surg 1995;30:1143-7. 36. Rintala R, Lindahl H, Sariola H, et al. The rectourogenital connection in anorectal malformations is an ectopic anal canal. J Pediatr Surg 1990;25:665-8. 37. Scharli AF, Kiesewetter WB. Imperforate anus: anorectosigmoid pressure studies as a quantitative evaluation of postoperative continence. J Pediatr Surg 1969;4:694-704. 38. Husberg B, Lindahl H, Rintala R, et al. High and intermediate imperforate anus: Results after surgical correction with special respect to internal sphincter function. J Pediatr Surg 1992;27:185-9. 39. Mollard P, Meunier P, Mouriquand P, et al. High and intermediate imperforate anus: functional results and postoperative manometric assessment. Eur J Pediatr Surg 1991;1:282-6. 40. Holschneider AM, Pfrommer W, Gerresheim B. Results in the treatment of anorectal malformations with special regard to the histology of the rectal pouch. Eur J Pediatr Surg 1994;4:303-9. 41. Langemeijer RATM, Molenaar JC. Continence after posterior sagittal anorectoplasty. J Pediatr Surg 1991;26:587-90. 42. Mulder W, de Jong E, Wauters I, et al. Posterior sagittal anorectoplasty: functional results of primary and secondary operations in com-

Seminars in Pediatric Surgery, Vol 17, No 2, May 2008

43.

44. 45.

46.

47.

48.

49. 50. 51. 52. 53. 54.

55.

56.

57. 58.

59. 60. 61. 62. 63. 64. 65.

66.

67.

parison to the pull-through method in anorectal malformations. Eur J Pediatr Surg 1995;5:170-3. deVries P. Results of treatment and their assesment. In: Stephens FD, Smith ED, eds. Anorectal Malformations in Children: update 1988. Birth defects: original article series, Vol 24, Number 4. New York, NY: Alan R. Liss, 1988:481-500. Nixon HH, Puri P. The results of treatment of anorectal anomalies: a thirteen to twenty year follow-up. J Pediatr Surg 1977;12:27-37. Rintala R, Mildh L, Lindahl H. Fecal continence and quality of life in adult patients with an operated high or intermediate anorectal malformation. J Pediatr Surg 1994;29:777-80. Hassink EA, Rieu PN, Severijnen RS, et al. Are adults content or continent after repair for high anal atresia? A long-term follow-up study in patients 18 years of age and older. Ann Surg 1993;218:196200. Hassink EA, Rieu PN, Brugman AT, et al. Quality of life after operatively corrected high anorectal malformation. A long-term follow-up study in patients 18 years of age and older. J Pediatr Surg 1994;29:773-6. Rintala RJ, Lindahl HG, Rasanen M. Do children with repaired low anorectal malformations have normal bowel function? J Pediatr Surg 1997;32:823-6. Trusler GA, Wilkinson RH. Imperforate anus: a review of 147 cases. Can J Surg 1962;5:269-77. Partridge JP, Gough MH. Congenital abnormalities of the anus and rectum. Br J Surg 1961;49:37-50. Yeung CK, Kiely EM. Low anorectal anomalies: a critical appraisal. Pediatr Surg Int 1991;6:333-5. Ong NT, Beasley SW. Long-term functional results after perineal surgery for low anorectal anomalies. Pediatr Surg Int 1990;5:238-40. Karkowski J, Pollock WF, Landon CW. Imperforate anus. Eighteen to thirty year follow-up study. Am J Surg 1973;126:141-7. Rivosecchi M, Lucchetti MC, De Gennaro M, et al. Spinal dysraphism detected by magnetic resonance imaging in patients with anorectal anomalies: incidence and clinical significance. J Pediatr Surg 1995; 30:488-90. De Gennaro M, Rivosecchi M, Lucchetti MC, et al. The incidence of occult spinal dysraphism and the onset of neurovesical dysfunction in children with anorectal anomalies. Eur J Pediatr Surg 1994;4:12-4. Ralph DJ, Woodhouse CRJ, Ransley PG. The management of the neuropathic bladder in adolescents with imperforate anus. J Urol 1992;148:366-8. Wiener ES, Kiesewetter WB. Urologic abnormalities associated with imperforate anus. J Pediatr Surg 1973;8:151-8. Rintala R, Lindahl H. Internal sphincter saving PSARP for high and intermediate anorectal malformations: technical considerations. Pediatr Surg Int 1995;10:345-9. Hall R, Fleming S, Gysler M, et al. The genital tract in female children with imperforate anus. Am J Obstet Gynecol 1985;151:169-71. Matley PJ, Cywes S, Berg A, et al. A 20-year follow-up of children born with vestibular anus. Pediatr Surg Int 1990;5:37-40. Pryor JP, Hendry WF. Ejaculatory duct obstruction in subfertile males: analysis of 87 patients. Fertil Steril 1991;56:725-30. Levitt MA, Stein DM, Peña A. Gynecologic concerns in the treatment of teenagers with cloaca. J Pediatr Surg 1998;33:188-93. Sato S, Shirane R, Yoshimoto T. Evaluation of tethered cord syndrome associated with anorectal malformations. Neurosurgery 1993;32:125-7. Levitt MA, Patel M, Rodriguez G, et al. The tethered spinal cord in patients with anorectal malformations. J Pediatr Surg 1997;32:462-8. Tuuha SE, Aziz D, Drake J, et al. Is surgery necessary for asymptomatic tethered cord in anorectal malformation patients? J Pediatr Surg 2004;39:773-7. Taskinen S, Valanne L, Rintala R. Effect of spinal cord abnormalities on the function of the lower urinary tract in patients with anorectal abnormalities. J Urol 2002;168:1147-9. Holschneider AM, Pöschl U, Hecker WC. Pickrell’s gracilis muscle transplantation and its effect on anorectal continence. A five year prospective study. Z Kinderchir 1979;27:135-43.

Rintala and Pakarinen

Imperforate Anus

68. Raffensperger J. The gracilis sling for faecal incontinence. J Pediatr Surg 1979;14:794-7. 69. Baeten CGMI, Konsten J, Heineman E, et al. Dynamic graciloplasty for anal atresia. J Pediatr Surg 1994;29:922-5. 70. Koch SM, Uludag O, Rongen MJ, et al. Dynamic graciloplasty in patients born with an anorectal malformation. Dis Colon Rectum 2004;47(10):1711-9. 71. Kottmeier PK, Dziadiw R. The complete release of the levator ani sling in fecal incontinence. J Pediatr Surg 1967;2:111-7. 72. Puri P, Nixon HH. Levatorplasty: a secondary operation for fecal incontinence following primary operation for anorectal agenesis. J Pediatr Surg 1976;11:77-82. 73. Ninan GK, Puri P. Levatorplasty using a posterior sagittal approach in secondary faecal incontinence. Pediatr Surg Int 1994;9:17-20. 74. Kottmeier PK, Velcek FT, Klotz DH, et al. Results of levatorplasty for anal incontinence. J Pediatr Surg 1986;21:647-50. 75. Peña A. Posterior sagittal anorectoplasty as a secondary operation for the treatment of fecal incontinence. J Pediatr Surg 1983;18:762-72. 76. Kiesewetter WB, Jeffries R. Secondary anorectal surgery for the missed puborectalis muscle. J Pediatr Surg 1981;16:921-5.

89 77. Brain AJL, Kiely EM. Posterior sagittal anorectoplasty for reoperation in children with anorectal malformations. Br J Surg 1989;76:57-9. 78. Rintala R, Lindahl. Secondary PSARP for anorectal malformations - a long term follow-up extending beyond childhood. Pediatr Surg Int 1995;10:414-7. 79. Tan JJ, Chan M, Tjandra JJ. Evolving therapy for fecal incontinence. Dis Colon Rectum 2007;50:1950-67. 80. Cheu HW, Grosfeld JL. The atonic baggy rectum: a cause of intractable obstipation after imperforate anus repair. J Pediatr Surg 1992;27:1071-4. 81. Peña A, El Behery M. Megasigmoid: a source of pseudoincontinence in children with repaired anorectal malformations. J Pediatr Surg 1993;28:199-203. 82. Malone PS, Ransley PG, Kiely EM. Preliminary report: the antegrade continence enema. Lancet 1990;336:1217-8. 83. Olness K, McParland FA, Piper J. Biofeedback: a new modality in the management of children with fecal soiling. J Pediatr 1980;96:505-9. 84. Rintala R, Lindahl H, Louhimo I. Biofeedback conditioning for fecal incontinence in anorectal malformations. Pediatr Surg Int 1988;3:418-21.