Anorectal Agenesis with Rectovaginal Fistula: A Rare/Regional Variant.

AIMS AND
OBJECTIVES: The anatomical types of female anorectal malformation (ARM) are complex and include several rare and regional variants. The aim of this report is to highlight the diagnosis and management of cases of anorectal agenesis with rectovaginal fistula (RVF).
MATERIALS AND METHODS: This is a retrospective chart review of cases of RVF who underwent definitive surgery between November 2000 and September 2016 in a single institution.
RESULTS: Of the 244 female patients with anorectal anomalies treated in our institution over a 16-year period, there were 15 cases of RVF with anorectal agenesis giving it an incidence of 6%. All cases of RVF with anorectal agenesis presented with absence of anal opening, varying degree of abdominal distension, and history of passage of fecal matter per vaginum. The mean age of presentation was 3 months (newborn to 1 year). Sigmoid colostomy was done in 13 cases. Distal colostogram demonstrated high RVF which was further confirmed by examination under anesthesia (EUA) and endoscopy before definitive surgery. With the posterior sagittal approach, division of the RVF and anorectoplasty was possible in 14 cases; however, one patient required an abdominal mobilization of the colon for pull through due to a very short distal bowel segment. During a mean postoperative follow-up of 5 years, cosmetic and functional results were satisfactory.
CONCLUSION: RVF with anorectal agenesis is a rare/regional variant of female ARMs. Clinical examination along with distal colostogram, EUA, and endoscopy clinches the diagnosis. Anorectal reconstruction by posterior sagittal anorectoplasty results in a satisfactory outcome.

Introduction

The classification of anorectal malformation (ARM) in female patients is still evolving due to its complexity and presence of various rare and regional variants. According to the Krickenbeck classification, rectovaginal fistula (RVF) with anorectal agenesis is one of the rare/regional variants, although no regional specification has been mentioned.[1] There is no clear demarcation between high and low anorectal anomalies in girls. Similarly, the surgical management of these anomalies is confusing and not standardized. We reviewed the cases of female ARM treated in our institution with special emphasis on anorectal agenesis with RVF cases regarding their diagnosis and management.

Materials and Methods

Case records of all female patients with anorectal anomaly treated between November 2000 and September 2016 in our institution were reviewed. Cases of RVF with anorectal agenesis were further analyzed in respect of their age of presentation, presenting symptoms, physical examination findings, investigations, and surgical procedures. A preset management protocol for female ARM was followed [Figure 1]. Follow-up period ranged from 1 to 14 years (mean 5 years) after completion of treatment. Functional results in terms of cosmetic appearance, voluntary bowel movement, soiling, constipation, and bladder function were evaluated.

Figure 1

Management protocol for anorectal malformations in girls. (EUA - Examination under anesthesia, PSARP - Posterior sagittal anorectoplasty)

Results

The types of anomalies are shown in Table 1.

Table 1

Distribution of types of anomalies

The age of presentation of anorectal agenesis with RVF cases varied from newborn to 1 year with the mean age of 3 months. All cases of RVF presented with absence of anal opening on perineal examination, varying degree of abdominal distension, and history of passage of fecal matter per vaginum. Five newborn cases presented with abdominal distension. Sigmoid colostomy was done in 13 cases, two of which were done in different hospitals before referral. Pressure augmented distal colostogram performed later; demonstrated high RVF at the level of the upper third of the vagina in all thirteen cases [Figure 2]. Bony sacral anomaly was noted in three cases and unilateral vesicoureteric reflux (VUR) on voiding cystourethrogram in three cases. The age at corrective surgery varied from 1 to 3 years with the mean of 1.5 years. Examination under anesthesia (EUA) and urethrovaginoscopy preceding the definitive surgery defined the anatomy. Posterior sagittal anorectoplasty (PSARP) with division of the fistula and repair of vaginal wall was performed in 14 cases [Figure 3]; however, one patient required abdominal mobilization of the colon for pull through due to a very short distal bowel segment. Two patients, who presented at 1 year of age without abdominal distension, underwent bowel preparation, EUA, urethrovaginoscopy followed by primary PSARP without a colostomy.

Figure 2

(a and b) Distal colostogram showing rectovaginal fistula (arrow)

Figure 3

Peroperative photograph. (a) Showing rectovaginal fistula (arrow) through opened distal rectum. (b) Rectum mobilized, rectovaginal fistula closed (arrow)

All patients were followed-up with regular anal dilatation for a period of 6 months. Closure of colostomy was done between 3 and 6 months after PSARP. The cosmetic appearance was satisfactory in all but one who had abdominal mobilization with colonic pull through and developed mucosal prolapse requiring trimming. Ten patients were assessed for fecal continence after 3 years of age and minimum 6 months postsurgery using Kelly's score out of which six patients had a good and four had a fair continence score.[2] None of the patients had urinary disturbance.

Discussion

The anatomy of female ARMs is complex due to the approximation of genital organs. Although the incidence of true anorectal agenesis with RVF is very low (1%), the reported incidence of RVF varies widely (0%–84%) in English literature.[3] The false high incidences were attributed to indiscriminate labeling of rectovestibular fistula and cloaca as RVF. Careful anatomical categorization should eliminate the confusion in nomenclature.

Congenital pouch colon (CPC), H-type fistula, and RVF are more commonly reported from India and some Asian countries and are now included in the rare/regional types in the Krickenbeck classification for ARM.[4567] Chatterjee reported 22 cases of RVF, three of which were high anomalies opening in the posterior fornix of vagina, and rest were intermediate anomalies opening in the lower vagina.[8] Similar cases have also been reported by Upadhyaya et al.[9] In this series, the incidence of RVF was 6% (15 out of 244 female ARM), although this does not reflect the true incidence as ours being a referral center, more complex cases are being undertaken. Hashmi and Hashmi reported twenty cases of RVF out of 130 female patients with ARM treated in their center.[7] High incidences of vaginal and other urogenital anomalies were noted with these malformations.[10] Some sacral anomaly and VUR were noted in our cases.

The importance of careful clinical examination of the female perineum cannot be over emphasized as it provides vital clues to the underlying ARM and guides the management plan [Figure 1]. However, it is often difficult to delineate the anatomy of the female genitalia in the newborn period.

Patients with wide fistula may present late as they decompress well.[7] Our patients presented at an average age of 3 months and only six cases presented in the newborn period. Although finding of a vestibular fistula indicates low anomaly, it may still herald a high anomaly like CPC.[511] Presence of two openings can be due to vestibular anus with vaginal agenesis or RVF with anorectal agenesis.[4] EUA and endoscopy before definitive reconstructive surgery can confirm the diagnosis, and a preoperative magnetic resonance imaging scan may be useful.[4] Rare and regional variants of ARM add up to the difficulties in formulating a universal management protocol. Adherence to the above-mentioned management protocol had been crucial in our series as it not only guided treatment for the common varieties but also avoided any mismanagement for the rare/regional varieties of malformations.

The posterior sagittal approach provided excellent exposure of the anatomy in all cases, and reconstruction was possible in all except one due to short distal colon. Abdominal mobilization and pull through are associated with higher incidence of bladder and bowel dysfunction due to damage to presacral nerves. At present, there is more emphasis on one stage correction of ARM.[912] We have been able to successfully manage two RVF cases by a single stage PSARP who had a wide fistula and were decompressing well, rest were managed by a preliminary colostomy. Laparoscopic corrections of high RVF have also been reported.[1314] The follow-up results in terms of bowel continence and cosmetic appearances were similar to most of the reported series of intermediate and high ARM.[7]

Conclusion

Anorectal agenesis with RVF is a rare anomaly. Careful clinical examination supplemented with distal colostogram, preoperative EUA, and endoscopy helps in planning the management. Anorectal reconstruction by PSARP results in a favorable outcome.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.