












































Final Nepas Journal 30-1.indd


-37-Journal of Nepal Paediatric Society January-June, 2010/Vol 30/Issue 1

Original Article January-June, 2010/Vol 30/Issue 1

Single stage Anterior Sagittal Anorectoplasty (ASARP) for 

Anorectal Malformations with Vestibular Fistula and Perineal 

Ectopic Anus in Females: A New Approach

Chaudhary RP1, Thapa B2, Thana S3, Singh PB4

1Dr. Ramananda Prasad Chaudhary, MBBS.MS. Consultant Pediatric Surgeon, 2Dr. Bijay Thapa, 3Dr. Santosh Thana, 
4Dr. Pradeep B. Singh. Medical Officers, Kanti Children’s Hospital, Kathmandu, Nepal.

Address for Correspondence: Dr. RP Chaudhary, E-mail: drchaudharyrp@hotmail.com

Abstract
Introduction: Despite a better understanding of the embryology, anatomy of anorectal malformations 
and of the physiology of continence, the management of children born with imperforate anus continues 
to be a surgical challenge and is still fraught with numerous complications and often leads to less than 
perfect qualitative results. Pediatric patients with recto-vestibular fistula have good prognoses in terms of 
bowel function when properly treated. Aim & Objective: The study was designed to assess the surgical 
morbidity of single stage Anterior Sagittal Anorectoplasty (ASARP). Methodology: This prospective 
study was carried for a period of 26 months. It included a total of 48 female patients (aged 0 – 14 
years) with diagnosis of Anorectal Malformations (ARM) with vestibular fistula or perineal ectopic anus. In 
ASARP, Patient in lithotomy position, the anterior portion of sphincter muscles were cut through a midline 
perineal skin incision, rectum was separated from the vagina & then rectum was pulled through the center 
of these muscles. The perineal body was reconstructed and the normal appearance of perineum was 
achieved. Results: Short-term surgical outcome was satisfactory in all cases. No one needed colostomy. 
Conclusion: Single-stage ASARP is a good approach in experience hands for ARM with vestibular fistula 
and perineal ectopic anus in females and thereby complications and time involved in staged procedures 
including colostomy can be avoided.

Key words: Anterior sagittal anorectoplasty, anorectal malformations, perineal ectopic anus, vestibular 
fistula.

Introduction

Vestibular fi stula and perineal ectopic anus are the most common anorectal malformations in female 
children1. Imperforate anus without a fi stula is a rather 
unusual defect2. Despite a better understanding of the 
embryology, anatomy of anorectal malformations and 
of the physiology of continence, the management of 
children born with imperforate anus continues to be a 
surgical challenge and is still fraught with numerous 
complications and often leads to less than perfect 
qualitative results3. Pediatric patients with recto-
vestibular fi stula have good prognoses in terms of 
bowel function when properly treated. The bowel opens 
immediately behind the hymen in the vestibule of the 

female genitalia. Immediately above the fi stula, rectum 
and vagina are separated by a thin common wall. These 
patients usually have well-developed muscles and a 
normal sacrum and nerves. A meticulous inspection of 
the newborn genitalia is needed for the diagnosis2. 

The conventional surgical treatment has not 
always been satisfactory. The previously used surgical 
techniques include cutback, perineal anal transplant, Y-
V plasty, sacroperineal repair, and colostomy followed 
by minimal posterior sagittal anorectoplasty. These 
procedures have been limited by incomplete anatomic 
exposure, blind tunneling of the rectum, lack of 



-38-January-June, 2010/Vol 30/Issue 1 Journal of Nepal Paediatric Society

reconstruction of the perineal body, need for a colostomy 
and a displeasing appearance of the perineum, with 
anterior migration of the anus in the long term. These 
limitations have been offset by ASARP1, 3.

The optimal surgical repair should allow easy 
access to the fi stula, minimize the dissection to spare 
pelvic nerves, guide the rectal pouch through all the 
muscles of continence, restore a physiological anorectal 
angle, create good anal opening and take advantage of 
all existing structures. Most contemporary techniques 
attempt to preserve the major elements of continence, 
often at the cost of “Lesser” factors, increased dissection 
or poorer exposure4.

de Vries and Pena in 1982 reported posterior 
sagittal anorectoplasty as an operative procedure for 
high or intermediate imperforate anus. By the reference 
to the idea of this operative procedure, Okada et al 
devised a new approach, anterior sagittal anorectoplasty 
(ASARP) for repair of a vestibular fi stula, in which, in the 
lithotomy position, sphincter muscles are cut from the 
anterior aspect longitudinally through a median perineal 
skin incision and then the rectum is passed through the 
central portion of the sphincter muscle5. A number of 
pediatric surgeons repair this defect, primarily without a 
protective colostomy 6.

Methodology

In this prospective study, primary ASARP was 
performed from September 2004 to March 2009 (55 
months) on 48 patients of anoretal malformations 
with vestibular fi stula or perineal ectopic anus in Kanti 
Children’s Hospital and Ishan Children’s Nursing and 
Maternity Home (Table 1) their age range was from 
neonates (3 days) to fi ve years old children (Table 2).

Table 1: Showing the diagnosis of Patients.

Diagnosis No. of Patients
Vestibular Fistula 44
Perineal Ectopic Anus 4

All patients who underwent ASARP were included 
in this study. Patients with anorectal malformations with 
colostomy, with prematurity, with septicemia, with birth 
asphyxia and patients with major defects making them 
unfi t for GA were excluded from the study.

Table 2: Showing the Age Distribution of Patients.

Age No. of Patients
Neonates 15
1 -12 months 25
>1 year 8

Surgical anatomy: In normal individual, the 
voluntary striated muscle structures responsible for 
fecal control are represented by funnel-like muscle 
structure. Anatomically, the levator ani (also called 
the pelvic diaphragm) is arbitrary divided into three 
striated muscle groups: ileococcygeus, pubococcygeus 
and puborectalis. Functionally & anatomically, the 
puborectalis is therefore more likely linked to the external 
anal sphincter as a part of the striated muscle complex7.
Often acting as a single unit,they are sometimes referred 
to as the striated muscle complex8. Apart from this, the 
superfi cial and deep transverse perinei muscle muscle 
fuse in the midline to form perineal body along with the 
anterior most fi bers of the external sphincter.

In patients with a vestibular fi stula, the development 
of the sphincteric muscle is normal and the ‘anus’ or 
‘fi stula’ opens into the vestibule between the hymen and 
the fourchette, surrounded by moist mucous membrane 
rather dry skin9. In cases of perineal ectopic anus, only 
the postetior aspect of the anorectum is enclosed by the 
vertical muscle complex. They attributed the constipation 
seen with this defect to a ‘shelf’ effectof the ‘levator ani, 
or pelvic fl oor behind the abnormal anterior opening10.

Operative Technique: Patients were investigated 
to fi nd out any associated anomalies. Pre-operative 
preparations; They were treated for constipation with 
laxatives (Lactulose and fi stula irrigation with normal 
saline). They were kept nothing per oral for 48 hours in 
infants and older children and 24 hours in neonates. Oral 
antibiotics (Erythromycin 50 mg /kg and Metronidazole 
20 mg /kg in divided doses) were started 48 hours before 
surgery. The operation was performed under general 
anaesthesia along with caudal block. Proposed anal 
site was determined by the anal mark and confi rmed by 
the use of an electrostimulator. With patient in lithotomy 
position, a Foley catheter was passed through urethra 
into the bladder before surgery. Pre-operative calculated 
doses of i.v. antibiotics (Cephalosposin, Gentamicin 
& Metronidazole) were given with the induction of 
anaesthesia.

A circular incision was made in the mucocutaneous 
junction at the opening of the fi stula and extended 
posteriorly along the median line to reach the anal 
dimple. Several fi ne silk traction sutures were inserted 
around the fi stula orifi ce. Through the incision, the 
fi stula (anorectum) was fi rst dissected free bluntly little 
by little from surrounding tissues with meticulous care 
being taken not to cause damage to the musculature 
enclosing the rectum. The rectum was separated from 
the posterior wall of the vagina by sharp dissection; side 
by side retrorectal dissection is also done. The length of 



-39-Journal of Nepal Paediatric Society January-June, 2010/Vol 30/Issue 1

the rectal tube to be dissected was 4 to 5cm. Bleeding 
vessels were controlled by electro- coagulation. The 
fi rst muscle to come in sight was the superfi cial external 
sphincter muscle; next to come was the deep external 
sphincter muscle. The latter muscle soon joined the 
longitudinal muscles that spread out in a fan-shaped 
pattern. Behind these thin muscles lied puborectalis 
muscle, enclosing the rectum and was defi nitely 
palpable. Posterior part of those fan-shaped longitudinal 
muscle fi bers and puborectalis muscle was carefully 
preserved. 

Next, the dissected rectal tube was mobilized 
backward to be placed at the center of the fan-shaped 
muscles. Anterior ends of the fan shaped muscle fi bers 
were apposed and sutured by interrupted suture with 
several stitches of 4-0 vicryl suture beginning from the 
lower depths upward and outward. The rectum was 
fi xed to the deep external sphincter muscles over its 
entire circumference by 4-0 interrupted stitches. Sutures 
were placed between the rectal stump and surrounding 
skin by about 12 -16 stitches of 4-0 vicryl (Anoplasty). 
The neoanus should allow for the initial passage of 
at least number 10, Hegar dilator in neonates. Then, 
subcutaneous adipose and connective tissues extending 

up to the vaginal wall were approximated and sutured 
with interrupted 4-0 vicryl. The operation ended with 
closure of the surgical wound by suturing the perineal 
skin intradermally, with resultant creation of the perineal 
body. 

Post-operatively, patients were managed by – 
Analgesic for infants was Paracetamol drop (15 mg / kg 
/ dose) and that for others was intramuscular pethidine 
(1- 1.5 kg/dose) 6 hourly. Foley catheter was kept 
in situ up to 5th postoperative days for better perineal 
care. Aqeuous povidone iodine solution was applied 
over operated wound and neoanus several times a 
day. Patient was kept nothing per oral for 4 days. Oral 
feeding was started on 5th POD. Catheter was removed 
on 5th post operative day. Intravenous antibiotics were 
continued up to 5th postoperative days, followed by oral 
cephalosporin for 2 more days. Majority of the patients 
were discharged within 6 to 8 days of surgery unless 
indicated for some reasons. Parents were informed about 
the planned schedule of follow up and anal dilatation 
was started on 14th post operative day continued up to 
approximately 8 months as per Pena’s schedule12. The 
parents were demonstrated how to perform dilatation at 
home.

Fig 1: Showing ARM with Vestibular Fistula. Fig 2: Showing ARM with Perineal Ectopic Anus

Fig. 3: Detailed normal anorectal anatomy, coronal 
view (Pena 1990).

Fig. 4: Detailed normal anorectal anatomy, sagittal 
view (Pena 1990).



-40-January-June, 2010/Vol 30/Issue 1 Journal of Nepal Paediatric Society

Fig. 8: Clinical presentations of the patients

Results

Anterior sagittal anorectoplasty was performed 
on 32 female patients for anorectal malformations 
with vestibular fi stula or perineal ectopic anus from 
November, 2002 through June, 2004.

During perineal examinations following fi ndings 
were noted: type of fi stula, look of perineum, anal dimple 
and mark, anal pigmentation, midline groove, sacrum 
and perineal muscle contraction. 16 (33.33 %) patients 
had associated anomalies.

In all cases, operation was performed following the 
forementioned procedures after confi rming the site of 

Fig. 5: Vestibular Fistula (Pena 1995). Fig. 6: Female Perineal Anus (Pena 1995).

Fig. 7: Operative technique: Anterior Sagittal 
Anorectoplasty (Okada et al 1992).

anus by nerve stimulator. One patient who developed 
post operative complication of perianal excoriation, 
recovered well after 2 weeks of surgery. On assessment 
of results (Table 4), the site, size and appearance of 
the neoanus was normal in all cases. The frequency of 
bowel movement was 1-2 times in 40 patients and 2-3 
times in 8 patients. The consistency of fecal matter was 
normal (formed or semisolid) in all 48 cases. None of 
the patients in this study, suffered from constipation and 
soiling. All the parents of children were satisfi ed with the 
outcome. 

Follow up period was minimum of 6 months to 55 
months. Accordingly, the patient visited the hospital as 
follows: 1st follow up at 14 days of surgery, 2nd follow up 
at 1 month of surgery and 3rd follow up at 3 months of 
surgery. During each visit, following points were noted: i) 
Neoanual size, site and appearance. ii) Perineal wound. 
iii) Voluntary Bowel movements. iv) Fecal incontinence. 
v) Constipation. vi) Any complications.

0

10

20

30

40

50

Abscess of an anal 
opening at normal site

48

Constipation

8

Passage of meconium/
stool through an ectopic 

opening

48



-41-Journal of Nepal Paediatric Society January-June, 2010/Vol 30/Issue 1

Table 3: Associated anomalies

Associated Anomalies Number of Patients

Urogenital defects
Hydronephrosis (3 cases), ), Indirect Inguinal hernia (2 cases) Dys-
plastic kidney(1 case) and renal agenesis (1 case) VUR (1 case)

8 (16.66%)

Cardiac defects  VSD (3 cases), TOF with complex anomaly (1 case) 4 (8.33%)
Skeletal defects  Polydactyly (2 cases), Rudimentary index fi nger (1 case) 3 (6.25%)
Others Talipes Equino-Varus (1 case) 1(3.13%)

Table 4: Showing the results of ASARP

Neoanus 

  Appearance
 Round 48 (100%)

 Oval  -

  Site
 Correct 48 (100%)

 Incorrect  -

  Size
 Adequate 48 (100%)
 Stenosis  -

  Frequency Of Defaecation (Per Day)
 1-2 Times 40 (83.33%)
 2-3 Times  8 (16.66%)

  Consistency
 Normal 48 (100%)
 Loose  -

 Constipation
 Absent 348(100%)

 Present  -

 Soiling
 Absent 48 (100%)

 Present  -

 Neoanal Retraction
 Absent 48 (100%) 

 Present  -

 Parental Reaction
 Satisfi ed 48 (100%)

 Unsatisfi ed  -

Discussion

The technique described herein has several 
advantages over the posterior sagittal approach and 
other anterior perineal techniques. Conceptually, 
continence is dependent on the integrated function of the 
puborectalis, the internal and external sphincters, normal 
sensation of rectal fullness, and normal discrimination 
by the anoderm13. This technique has the advantages 
of the anterior perineal approach popularizes by 
Mollard14,15. Previous operative procedures like cut back 
operation or its modifi cation ‘ V-Y plasty’ for the repair 

of anovestibular fi stula, however have the disadvantage 
of the contamination of the vagina and urethra with 
consequent vaginitis and urethritis often results and 
soiling or staining due to mucosal involvement may 
occur at times16,17. 

The limitations like incomplete anatomic exposure, 
blind tunneling of the rectum, lack of reconstruction 
of the perineal body, need for a colostomy and a 
displeasing appearance of the perineum, with anterior 
migration of the anus in the long term have been offset 
by ASARP; colostomy is obviated, can be performed 
even in neonates, mobilizqtion of the rectum is 
visualized, only the anterior aspect of the sphincteric 
muscle complex is divided, continence mechanism is 
preserved (puborectalis muscle is preserved), there is 
minimal dissection, allows better anatomic exposure for 
separation of rectum from vagina, sphincter muscles 
and the perineal body are accurately reconstituted, 
easy- to- perform approach of salient repairing effi cacy. 
The extensive preoperative and postoperative measures 
advocated by Okada et al 18 weren’t needed in this study. 
Chatterjee advocated use of a colostomy if the patient 
is over 5 years of age or in cases of mega rectum or a 
small fi stula that prevents bowel preparation19. But no 
colostomy was performed in these cases too and there 
weren’t any serious complications. None of the 2 (6.25%) 

Fig. 9: Showing the perinium after ASARP



-42-January-June, 2010/Vol 30/Issue 1 Journal of Nepal Paediatric Society

patients who suffered peroperative complications of 
vaginal wall tear developed further complications. One 
patient who suffered post-operative complication (of 
perianal skin excoriation improved with local application 
of zinc oxide paste. 

In this series complications were less than Wakhlu 
et al (1996) series (11.53%) but higher than Okada et al 
(1992) & Okada et al (1993) series where, in all cases, 
the postoperative course was uneventful without any 
wound infection or laceration and their bowel habits & 
anorectal discharge control were nearly satisfactory in all 
the infants. Short-term surgical outcome was acceptable 
in all 48 cases and all patients had normal size, round 
shaped neoanus at normal site. 

There is evidence that the cortical intergration of 
somatosensory input from the anal skin may be lost 
after the third or fourth month of life20 if unused. This 
strongly supports early repair of high imperforate anus, 
enabling the development of normal stooling patterns at 
the appropriate time. When an anterior sagittal incision 
is used in a neonate, the preoperative differentiation 
between low, intermediate and high types becomes less 
necessary21. Colostomy or not, the important thing is 
to establish normal stooling as soon as possible. The 
modern trend is to operate on newborns with anorectal 
malformations, primarily without a protective colostomy. 
Even more ambitious and bold is the tendency to repair 
these babies primarily without a protective colostomy 
and laparoscopically11. 

I believe that this technique makes maximal use 
of native tissues, with minimal dissection and optimal 
reconstruction of this deformity. This study demonstrates 
that single stage ASARP can be performed with 
acceptable surgical outcome in cases of ARM with 
vestibular fi stula or perineal ectopic anus in female. I 
would like to follow up these patients to see the long-
term outcome of the approach.

Conclusion

Outcome of single-stage Anterior sagittal 
anorectoplasty is good and is an acceptable approach 
for ARM with vestibular fi stula or perineal ectopic anus 
in female and thereby complications and time involved in 
staged procedure including colostomy can be avoided. 

Acknowledgement: None

Funding: Nil

Confl ict of interest: None

References

1. Wakhlu A, Pandey A, Prasad A, Kureel SN, Tandon 
RK, Wakhlu AK. Anterior Sagittal Anorectoplasty 
for Aorectal Malformatios and Perineal Trauma in 
the Female Child. J Pediatr Surg.1996; 31:1236-
1240.

2. Pena A. Imperforate Anus and Cloacal Malformations 
in Pediatric Surgery, 3rd. edn, ed. K.W.Ashcraft, 
W.B.Saunders company, Philadelphia, 2000: 473-
492.

3. Smith ED. The bath Water Needs Changing, But 
Don’t Throw out the Baby: An overview of Anorectal 
Anomalies. J. Pediatr Surg. 1987; 22: 335-348.

4. Yazbeck S, Luks FI, St-vil D. Anterior Perineal 
Approach and Three-Flap Anorectoplasty for 
Imperforate Anus: Optimal Reconstruction With 
Minimal Destruction. J. Pediatr Surg. 1992; 27: 
190-195.

5. Okada A, Shinkichi K, Imura K, Fukuzawa M, 
Kubota A, Yagi M, Azuma T, Tsuji H. Anterior 
Sagittal Anorectoplasty for Rectovestibular and 
Anovestibular Fistula. J.Pediatr Surg. 1992; 27: 
85-88. 

6. Moore TC. Advantages of Performing the Sagittal 
Anoplasty Operation for Imperforate Anus at Birth. 
J. Pediatr Surg. 1990; 25: 276-277. 

7. Stafford, P.E.W. Other disorders of the Anus and 
Rectum, Anorectal Function in Pediatric Surgery, 
5th. edn, vol-2, eds. J.A. O’Neill,Jr., M.I. Rowe, 
J.L.Grosfeld, E.W.Fonkalsrud, & A.G.Coran, 
Mosby-Year Book, St.Louis, 1998; pp. 1449-1460.

8. Weinberg G, Boley SC. Anorectal continence and 
Management of constipation in Pediatric Surgery, 
3rd. edn, ed. K.W. Ashcraft, W.B.Saunders 
Company, Philadelphia, 2000; pp.502-510.

9. Freeman NV. Anorectal Malformations’, in Surgery 
of the Newborn, eds. N.V.Freeman, D.M. Burge, 
M.Griffi ths and P.S.J.Maline, Churchill Livingstone, 
Edinburgh, 1994; pp. 171-199.

10. de Vries PA. Complications of surgery for congenital 
Anomalies of the Anorectum in Complications of 
Pediatric surgery, eds. P.A.deVries, S.R.Shapiro, 
John Wiley & sons, New York, 1982; pp. 233-262.

11. Pena A., ‘An atlas of Surgical Management of 
Anorectal Malformations’, Spring-Verlag, Newyork, 
1990 pp. 1- 95.



-43-Journal of Nepal Paediatric Society January-June, 2010/Vol 30/Issue 1

17. Nixon HH. Review of anorectal anomalies. J R Soc 
Med, 1984(suppl); 77:27-29.

18. Okada A, Tamada H, Tsuji H, Azuma T, Yagi 
M, Kubota A, Kamata S. Anterior Sagittal 
Anorectoplasty as a Redo Operation for Imperforate 
Anus. J.Pediatr Surg. 1993; 28: 933-938. 

19. Chaterjee SK. Lesions in the Wingspread list 
management in the neonatal period, in Chaterjee 
SK ed: Anorectal Malformations – A Surgeons 
Experience, Oxford University, New Delhi, India 
1991 pp 48-64.

20. Freeman NV, Burge DM, Soar JS et al. Anal Evoked 
potentials. Z Kinderchir, 1980; 31:22-30.

21. Sigalet DL, Laberge JM, Adolph VR, Guttman FR. 
The Anterior Sagittal Approach for High Imperforate 
Anus: A simplifi cation of the Mollard Approach. J. 
Pediatr Surg. 1996; 31:625-629.

12. Pena A. ‘Anorectal anomalies’, in Newborn Surgery, 
2nd. edn, ed. P. Puri, Arnold, London, 2003; pp. 
535-552.

13. Holschneider AM, Freeman NV. Anatomy and 
function of the normal rectum and anus, in 
Stephen FD, Smith ED, Paul NW eds. Anorectal 
Malformations in Children: Update 1988, NY Liss, 
Newyork,1988 pp. 125-154.

14. Mollard P, Marechal JM, de Beaujeu MJ. Surgical 
Treatment of High Imperforate Anus with Defi nition 
of the Puborectalis Sling by an Anterior Perineal 
Approach. J. Pediatr Surg. 1978; 13: 499-504.

15. Mollard P, Soucy P, Louis D et al. Preservation of 
Infralevator structures in imperforate anus repair. J 
Pediatr Surg, 1989; 27: 185-189.

16. Ishihara M, Morita K. Techniques and indication of 
the cut back procedure and Potts method for low 
deformities. Jpn J Pediatr Surg. 1981; 13: 1199-
1204.


