Neonatal posterior sagittal anorectoplasty for a subset of males with high anorectal malformations

Abstract

Aim:

To assess the results of primary posterior sagittal anorectoplasty (PSARP) in male neonates with high anorectal malformations (ARM) who on invertogram showed well descended rectum.

Materials and Methods:

Twelve full-term male neonates with high ARM over a period of one and half years were selected for primary PSARP based on the findings of invertogram. Primary PSARP was performed in all neonates with lower limit of rectal gas bubble at or below the ossified fifth sacral vertebra. The patients were followed-up for a period between three to four and half years. The clinical evaluation of fecal continence was performed using Pena's criteria for assessment of continence.

Results:

All neonates underwent PSARP on second to fourth postnatal day. The fistula with urinary tract was found in 11 patients (seven had fistula to bulbar urethra and four to prostatic urethra). Rectal tapering was not required in any neonate. No patient had urinary problems after removal of catheter. Most of the neonates were discharged by ninth day. Postoperatively, two patients had superficial wound infection of anoplasty without any disruption or bowel retraction. Two patients had severe perianal excoriation. No patient had anorectal stenosis. Nine of twelve patients on follow-up had good voluntary bowel movements. Of the three patients who had grade I soiling two had recto-prostatic urethral fistula. No patient had constipation. All patients had good urinary stream.

Conclusions:

Repair of high ARM in male neonates with a well descended rectum is feasible without significant morbidity and good continence.

INTRODUCTION

The traditional approach for the surgical correction of high anorectal malformation (ARM) in a newborn male entails a high sigmoid colostomy, posterior sagittal anorectoplasty (PSARP) as described by Pena,[1,2] and colostomy closure. However, colostomy itself is a source of morbidity in these patients. There are reports in the literature, which aim at single stage repair of anorectal malformation in both sexes to avoid the morbidity associated with colostomy.[3–6] Also, such repair at birth has been related to early “training” of the perineal musculature and subsequent improved long-term fecal continence.[7]

With this background, we designed this prospective study to assess the results of primary PSARP in a subset of male neonates with high ARM who on invertogram showed well descended rectum.

MATERIALS AND METHODS

From May 2006 to October 2007, a total 41 male patients with ARM were admitted to the pediatric surgery unit at Government Medical College Nagpur. Of these, 12 full-term male neonates with high ARM having lower limit of rectal gas shadow at or below the ossified fifth sacral vertebra on invertogram were selected for primary PSARP (intermediate ARM as per Wingspread classification). Neonates with low ARM, sacral defects and pouch colon were excluded. PSARP was performed in all neonates as described by De vries and Pena.[1] Care was taken to suck out the meconium as soon as the rectal pouch was opened. After closing the perineum and anoplasty the rectum was irrigated to remove meconium. Postoperatively regular wound cleaning was done with regular squirting of diluted povidone-iodine solution and application of antibiotic ointment. The urethral catheter was removed on 6^th postoperative day. Dilatation of “neo-anus” was started two weeks postoperatively using a standard protocol. Follow-up was available in all patients for a period between three to four and half years. The clinical evaluation of fecal continence, by means of a personal interview of the parents, was performed postoperatively after three years of age using Pena's criteria for assessment of continence.

RESULTS

All neonates underwent PSARP on second to fourth postnatal day. Abdominal exploration was not required in any patient. The fistula with urinary tract was found in 11 patients. Seven patients had fistula to bulbar urethra and four had to prostatic urethra. Meconium soiling of wound was not troublesome in any patient. Rectal tapering was not required in any neonate. Dissection in all patients was easy and there were no intraoperative complications. All neonates except one were allowed feeds after 48 hours. They started passing meconium just after surgery and required strict regular local cleansing. No patient had urinary problems after removal of catheter. Most of the neonates were discharged by ninth day. One neonate operated on second day developed septicemia in postoperative period and he was discharged on twentieth day. This patient, on follow-up, was found to have bilateral vesico-ureteric reflux.

Postoperatively, two patients (16.7%) had superficial wound infection of anoplasty site. It was managed conservatively. No patient had disruption of anoplasty or bowel retraction. Two patients (16.7%) had severe perianal excoriation. All parents strictly followed anal dilatation program as informed and no patients had anorectal stenosis. Nine of twelve patients (75%) on follow-up had good voluntary bowel movements. Of the three patients who had grade I soiling, two had recto-prostatic urethral fistula. No patients have constipation. All patients have good urinary stream.

DISCUSSION

PSARP is the most common corrective procedure performed for high ARM in males. However, the complete surgical correction requires a classical three stage approach as advocated by Pena and devries.[1] Nevertheless, this approach is not free from problems. Problems encountered include co-morbidity associated with a colostomy,[8] increased cost of 3-stage operations and number of drop outs after colostomy especially in developing world.[9] Another important issue especially in developing world is that most patients may not return at 6-8 weeks for definitive surgery. Thus, the chance of benefit from early restoration of defecation reflex is lost.

Primary corrective procedure without colostomy is a valid option, which has been tried by various surgeons with variable success. Such correction has been efficiently done in female subjects with vestibular fistula with good results.[9,10] However, correction at birth in male neonates is not much popularized and there are only few published studies. Moore first described sagittal anorectoplasty performed through an anterior approach without colostomy in newborns with rectourinary tract fistulas with excellent surgical results.[4] Albanese et al., described five male newborns who underwent successful primary PSARP.[7] Liu and Hill series of seven male newborns with rectourinary tract fistula who underwent primary PSARP also showed good results.[11] Mishra et al., in their comparative study of primary PSARP and staged procedure described 14 neonates who underwent primary corrective procedure at birth.[12] Mirshemirani described 17 male newborns with recto-urethral fistula who underwent primary PSARP safely and effectively.[13]

One of the concerns for primary correction is unawareness about local anatomy with subsequent risk of damaging the local structures. Experienced surgeons agree to the fact that most accidents occur in patients with high ARMs, i.e., in patients with recto-bladder neck fistulas. Such mishaps may result in permanent urethral damage, division of the vas, pull-through of dilated ectopic ureters, or a neurogenic bladder. To prevent such problems, but still to repair these malformations at an earlier age, Pena suggested to start one stage repair of such malformations in neonates with low-lying rectum.[7] Selection of such patients is very important. Albanese et al., have used preoperative cystoscopy for detection of fistulous communication in their five patients. However, cystoscopy identified the fistula in three patients only.[7] Most other surgeons have directly proceeded with primary PSARP without paying much attention to the urinary communications, which were dealt only intraoperatively. We have used a lateral invertogram to know the rectal descent in relation to normally developed sacral vertebral column. By applying this selection criterion, our intention was to include neonates with lower lesions like recto-bulbourethral fistula. However, even with this selection criteria, we have encountered four neonates with recto-prostatic urethral fistulas. But, low lying rectal pouch, the ease of dissection in virgin neonatal tissue planes (no fibrosis due to pouchitis as seen in the older patients with staged procedure) and no need for tapering of the rectal pouch made the primary PSARP a valid and safe approach.

Another important concern during primary PSARP is the wound contamination with meconium resulting in wound infection and wound dehiscence. However, we observed that once the rectum was emptied of meconium early, meconium soiling of wound was never a problem. Similarly, wound infection does not appear to be alarming in reported experience on primary PSARP.[6,11,13] One of the important reasons is probably neonatal bowel is sterile and it takes approximately 1 week to colonize the bowel with gram-negative and anaerobic bacteria.[14]

Continence after correction of ARM depends upon multiple factors. These include well developed spine, properly developed perineal musculature, properly placed rectum in sphincter, uneventful postoperative period and proper conditioning of defecation reflex in critical period of development. Neonatal PSARP done meticulously in well selected male ARM patients appears to provide the “best utilization of all existing resources” resulting in better continence. This fact can be emphasized from the fact that three-fourth of patients in our study have voluntary bowel movements after three year follow-up. Although the total number of patients in the literature who underwent primary repair is not many, most authors have reported good results.[6,7,11,13,15] However, Mishra et al., on comparison of the results of primary PSARP with the staged procedure found superior continence in the staged procedure as assessed by Kiesewetter's method.[12]

Such neonatal repair of high ARM not only has obvious advantages of single stage correction without increasing the risk to patients but also has financial and psychological benefits to parents. Also, there is an institutional advantage, of decreasing waiting time and reduced cost as in our case. About one-third of cases of male ARM (12 out of 41) were managed with one surgery alone, thus contributing in reducing the overall workload. However, a word of caution to be noted that the procedure should not be taken lightly and only be done by an experienced surgeon.

To conclude, primary repair of high ARM in a subset of male neonates who have a well descended rectum is safe and feasible without significant morbidity and good continence. However, it should be noted that the number of patients in present study are few and all of our patients at follow-up are still in preschool age. Whether this approach is preferable over classical 3-stage repair depends on multi-institutional experience in large number of patients and on the long-term anorectal function. Therefore, the long-term outcome of these patients should be the subject of future studies.