204 Journal of the College of Physicians and Surgeons Pakistan 2016, Vol. 26 (3): 204-207
INTRODUCTION
Anorectal malformations (ARMs) are common
anomalies in neonates.
1
The catastrophe happens as a
result of antenatal dysmorphogenesis of cloaca and
urorectum.
2
Currently survival rate of ARMs is much
improved because of advancement in surgical
techniques and availability of improved neonatal
perioperative intensive care facilities. Mostly, children
are diagnosed postnatally, and have associated other
anomalies; mostly, urological, cardiac, and musculo-
skeletal systems.
3
Majority of these babies have
associated recto urinary fistula. Recto urethral and recto
vestibular fistulae are the most common presentations
respectively in males and females.
3
Ammussat, the father of proctoplasty, in 1835 attempted
the first classification of ARMs. His work was followed by
Ladd and Gross in 1934, producing the first standard
classification of this anomaly. Further development led
to an international classification on the basis of
puborectalis muscle, followed by International classifi-
cation in 1970 and Wingspread classification in 1984.
Pena's classified ARMs on the bases of presence and
position of fistula. He also shared his experience with a
new surgical technique, i.e. Posterior Sagittal Anorecto-
plasty (PSARP).
All these classifications categorized the ARMs but there
were variations in terms of follow-up of these children as
it was difficult to compare the functional outcome of
these children. Krickenbeck group in 2005 published
their findings and incorporated criteria from Wingspread
and Pena's works. They gave the concept of
categorization of ARMs in to three categories, i.e.
diagnostic category, surgical procedure category, and
functional outcome category. Since then it is this
Krickenbeck classification that has been used to
measure functional outcome of patients of anorectal
malformation.
To the best of authors' knowledge, there is no national
study available regarding the classification of this
anomaly according to this classification. This study was
conducted with the objective of describing the
management and functional outcome of anorectal
malformations and associated anomalies, according to
Krickenbeck classification.
METHODOLOGY
It was retrospective case series. Prior approval was
taken from the Medical Record Audit Committee at The
ORIGINAL ARTICLE
Functional Outcome of Anorectal Malformations and Associated
Anomalies in Era of Krickenbeck Classification
Saqib Hamid Qazi
1
, Ahmad Vaqas Faruque
1
, Muhammad Arif Mateen Khan
1
and Umama Saleem
2
ABSTRACT
Objective: To describe the management and functional outcome of anorectal malformations and associated anomalies
according to Krickenbeck classification.
Study Design: Case series.
Place and Duration of Study: The Aga Khan University Hospital, Karachi, from January 2002 to December 2012.
Methodology: Anorectal anomalies were classified according to Krickenbeck classification. Data was collected and
proforma used regarding the primary disease associated anomalies, its management and functional outcome, according
to Krickenbeck classification. Cases included were: all those children with imperforate anus managed during the study
period. Qualitative variables like gender and functional outcome were reported as frequencies and percentages.
Quantitative variables like age were reported as medians with interquartile ranges.
Results: There were 84 children in study group. Most common associated anomaly was cardiac (38%), followed by
urological anomaly (33%). All children were treated by Posterior Sagittal Anorectoplasty (PSARP). Fistula was present in
64 out of 84 (76%) cases. The most common fistula was rectourethral (33%), followed by recto vestibular (31%). According
to Krickenbeck classification, continence was achieved in 62% children; however 27% children were constipated, followed
by 12% children having fecal soiling.
Conclusion: Functional outcome of anorectal malformation depends upon severity of disease. A thorough evaluation of
all infants with ARM should be done with particular focus on cardiovascular (38%) and genitourinary abnormalities (33%).
Key Words: Anorectal malformation. Functional outcome. Krickenbeck classification.
Department of Surgery
1
/ Medical Student
2
, The Aga Khan
University Hospital, Karachi.
Correspondence: Dr. Muhammad Arif Mateen Khan, Head,
Section of Pediatric Surgery, The Aga Khan University Hospital,
Karachi.
E-mail: arif.mateen@aku.edu
Received: October 27, 2014; Accepted: December 14, 2015.
Aga Khan University Hospital, Karachi. Medical records
of all the patients were reviewed who had needed
surgical intervention and presented over a period of 10
years from January 1, 2002 to December 31, 2012 at the
Aga Khan University Hospital, Karachi, Pakistan. The
inclusion criterion was all children with anorectal
malformations who were born and presented to
Emergency / Pediatric Surgery clinics at the study centre
and needed surgical intervention during the study
period. Children who were shifted out of the Hospital and
those with inadequate follow-up information were
excluded from the study.
There was a standard protocol of managing all children
presented with anorectal malformation with fistula as
multistage surgery; first divided sigmoid colostomy
followed by standard Posterior Sagittal Anorectoplasty
(PSARP), and colostomy closure usually 6 to 8 months
after the PSARP. Regular fortnightly follow-up initially
and then monthly clinic visits were required depending
on the outcome of all these children in the surgical
outpatient clinic for monitoring of regular anal dilatation
and postoperative wound care. Throughout the
postoperative course, there was a close communication
with parents all the time regarding the need of regular
anal dilatation and toilet training.
Cases were identified via Hospital Information
Management System (HIMS) by using International
classification of Disease (ICD-9-CM) codes. ARMs were
classified and functional outcomes were assessed
according to Krickenbeck classification using detailed
questionnaire completed at each child visit whenever
possible or by contacting the parents via telephone.
Collected data were double entered in Epi-Data (version
3.2) by two different data entry persons. SPSS
(Statistical Software for Social Sciences) version 17 was
used for statistical analysis. Qualitative variables like
gender and functional outcome were reported as
frequencies and percentages. Quantitative variables like
age were reported as medians with interquartile ranges.
All the possible efforts were made to maintain the
confidentiality of patients. No identifiable information
was collected. Data was stored under lock and key in the
custody of the principal investigator.
RESULTS
There were 84 children including 57 (68%) males and 27
(32%) females. The median age at presentation was the
day of birth, as 56% of children presented immediately
after birth. Associated anomalies were present in 45
(53%) children. Cardiac anomalies (17/45, 38%) were
the most common co-existed anomalies with anorectal
malformations, followed by urological anomalies in
15/45 (33%) children. Fistula was present in 64/84
(76%) children. Out of those who had associated fistula,
recto-urethral fistula was present in 21/64 (33%),
followed by recto-vestibular fistula in 20/64 (31%,
Table I).
Three-stage procedures were performed in 64/84 (76%).
All children with fistula were managed initially by making
divided descending colostomy followed by PSARP, while
5 children (06%) were offered single-stage limited
PSARP. All of them were newborn and were offered
single-stage procedure (Table II). There was one child
who had a perineal repair and 8 children were managed
by cutback anoplasty (Table III). All children with PSARP
had colostomy closure later on. There were 18 children
who developed complications later (Table IV). The most
common complication was anal stenosis (8/84, 10%).
Four children later presented with recurrent fistulae,
which were managed by Redo PSARP.
The functional outcome of the patients, who were more
than 3 years, was assessed according to the
Krickenbeck classification and found that 32/52 (62%)
were continent. Most of them had low anorectal
anomalies (17/32, 53%). However, there were 14/52
(27%) children who had constipation followed by
different grading of soiling (6/52, 12%), reported by the
parents (Figure 1).
Functional outcome of anorectal malformations and associated anomalies
Table I: Frequency of different types of fistulae associated with anorectal
anomalies.
Presence of fistula - 64
Rectourethral 21/64 (33%)
Rectovesicular 11/64 (17%)
Rectovestibular 20/64 (31%)
Rectoperineal 06/64 (9%)
Rectovaginal 06/64 (9%)
Table II: Types of surgical interventions.
Surgical intervention - 84
Divided descending colostomy 64 (76%)
Total PSARP 69 (82%)
Limited PSARP (single stage) 05 (6%)
Anoplasty 08 (10%)
Perineal repair 01 (1%)
Table III: Frequency of other associated anomalies with anorectal
malformations.
Other anomalies - 13
Ectopic anus 05/84 (6%)
Anal atresia 03/84 (4%)
Pouch colon 02/84 (2%)
Cloacal malformation 03/84 (4%)
Table IV: Surgical complications.
Surgical complication - 18
Anal stenosis 08 (10%)
Stoma prolapsed 05 (6%)
Recurrence of fistula 04 (5%)
Stoma stenosis 01 (1%)
Journal of the College of Physicians and Surgeons Pakistan 2016, Vol. 26 (3): 204-207
205
DISCUSSION
Anorectal malformations comprise a wide spectrum of
defects ranging from slight malpositioning of the anus
with excellent functional outcomes to complex
anomalies of the hindgut and urogenital organs that are
difficult to manage.
4
Commonly known as imperforate
anus, it affects 1 in 4000 to 5000 live births worldwide
with a slight male predominance.
5
The anomaly may
occur in isolation but is commonly associated with other
anomalies with incidence ranging from 40 - 60% in
different series. The commonest of these are in the
urinary tract (35%), the vertebral system (18%), and in
the developing heart (10%). A known association of
anomalies is known as the VACTERL group (vertebral,
anorectal, cardiac, tracheoesophageal, renal and limb).
6
Many classification systems for ARM have been devised
over the years; the first of which was in 1970s which
described low, high, intermediate and miscellaneous
lesions for both genders based on the position of the
terminal rectum to the levator ani. The same anatomic
relationship formed the basis of the widely used 1984
Wingspread classification where the categories
aforementioned were subdivided for males and females
separately.
7,8
A more surgically oriented classification
was then proposed in 1995 by Pena as a result of his
experience with posterior sagittal anorectoplasty
(PSARP).
4
This was based on the presence and position
of fistula and on the relationship of the terminal colon to
the levator sling muscles of the pelvic floor. The
advantage of the classification of Pena was that the type
of the fistula provided information not only about
localization of the blind pouch but also on the anticipated
extent of mobilization of the atretic rectal segment
necessary to perform sacro perineal or abdomino-
sacroperineal pull-through.
9,10
This classification system
was also the first one which attempted to determine
prognosis for each group in terms of functional bowel
outcomes.
With recognition of rarer anomalies not previously
included in any classification and development of
advanced surgical procedures other than PSARP, the
Krickenbeck International Classification emerged in
2005, which is based on consensus recommendations
of world authorities.
11
This classification system is
composed of 3 distinct elements: a diagnostic category,
a surgical procedure category, and a category
documenting functional outcome criteria. With the
inclusion of all defects including rarer ones and surgical
options, Krickenbeck classification aims to rationalize
functional outcome among different clinical and surgical
groups to allow more meaningful comparisons.
12
Since the development of this system is fairly recent,
there is paucity of literature on large long-term outcome
studies using this classifications especially in our region.
Long term functional outcome in children with ARM,
primarily entails bowel function which is of vital
importance as fecal incontinence and/or constipation
remain major postoperative complications that impede
social and psychological development of these
patients.
13,14
Continences, defined as the ability to
initiate voluntary bowel movement with no soiling,
regular bowel habits with no constipation, in turn defined
as the passage of infrequent or hard stools, and overall
quality of life, are the parameters looked at when
assessing functional prognosis in such patients.
15
In this
study, there were 32/52 (62%) children who were
continent. Mother's education is part and parcel of the
better functional outcome as most of these children were
toilet trained mainly because of mother's compliance to
toilet training drills.
The Krickenbeck classification allows for international
criteria for their treatment and development of a uniform
international scoring system for comparable follow-ups.
One of the first such studies was conducted in 2008 by
Hassett et al. which evaluated the 10-year outcome of
children born with ARM and treated by posterior sagittal
anorectoplasty.
3
This group of authors advocated with
attempts to rationalize and demonstrate application of
the Krickenbeck classification for both diagnosis and
functional outcome in terms of constipation, urinary
control and soiling.
Here, the researchers evaluated the follow-up of these
children according to Krickenbeck classification and we
found that continence, followed by constipation and fecal
soiling, was the most common functional outcome in this
study. Commonly, constipation occurs as a consequence
of chronic dilatation of the rectal pouch due to failure to
evacuate stool adequately. Mostly, it is seen in low
fistulae.
16-18
Soiling occurs because of defects in the
sphincter mechanism or as a consequence of overflow
from chronic constipation.
19
Similar results were seen in
this study as 9/18 (50%) children, who were constipated,
had low anorectal anomalies.
Cardiovascular anomalies (38%) followed by urological
anomalies (33%) were the most commonly associated
anomalies in this study. Similar results were found in a
Saqib Hamid Qazi, Ahmad Vaqas Faruque, Muhammad Arif Mateen Khan and Umama Saleem
206 Journal of the College of Physicians and Surgeons Pakistan 2016, Vol. 26 (3): 204-207
Figure 1: Follow-up according to Krickenbeck classification (age > 3 years,
n = 52).
Functional outcome of anorectal malformations and associated anomalies
Journal of the College of Physicians and Surgeons Pakistan 2016, Vol. 26 (3): 204-207
207
study from Singapore, in which they found similar
associated anomalies (28% and 19%, respectively).
20
To the best of authors' understanding, there is no
national study published which stratifies the functional
outcome of this anomaly. This study is one of its own
kind from Pakistan, addressing the need of uniform
application of this classification for measuring functional
outcome. The authors strongly suggest to make an
anorectal malformation registry at national level so that
we will come across the multicenter functional outcome
of this anomaly for better understanding and
management. Like all retrospective studies, there are
the same limitations, as some time it was very difficult to
recall although all possible measures were taken to
double-confirm the findings by other observers. In
addition to the parents’ understanding about the
functional outcome, there were variations of responses
by mothers in terms of different grading of constipation.
CONCLUSION
Functional outcome of anorectal malformation is related
to severity of disease. Children with low anorectal
malformations usually have a good functional outcome;
however, soiling is likely to be a long-term complication.
There should be uniform approach to know the
functional outcome which should be part and parcel for
preoperative counselling to parents. A thorough
evaluation of all infants with ARM should be done with
particular focus on cardiovascular and genitourinary
abnormalities.
Acknowledgement: We would like to acknowledge the
parents of all those children who participated in this
study, without which this study was not possible. Also we
would like to acknowledge Dr. Noman Shahzad, resident
in general surgery at Aga Khan University Hospital,
Karachi for his help in statistical analysis and revision of
manuscript.
REFERENCES
1. Risto J. Rintala, Mikko P. Pakarinen. Imperforate anus: long-
and short-term outcome. Semin Pediatr Surg 2008; 17:79-89.
2. Qi BQ, Williams A, Beasley S. Clarification of the process of
separation of the cloaca into rectum and urogenital sinus in the
rat embryo. J Pediatric Surg 2000; 35:1810-6.
3. Hassett S, Snell S, Hughes-Thomas A, Holmes K. 10-Year
outcome of children born with anorectal malformation, treated
by posterior sagittal anorectoplasty, assessed according to the
Krickenbeck classification. J Pediatr Surg 2009; 44:399-403.
4. Pena A. Anorectal malformations.
Semin Pediatr Surg 1995;
4:35-47.
5. Blesa Sanchez E. Anorectal malformations: anatomy,
classification and diagnosis. Cir Pediatr 1988; 1:58-61.
6. Cho S, Moore SP, Fangman T. One hundred three consecutive
patients with anorectal malformations and their associated
anomalies.
Arch Pediatr Adolesc Med 2001; 155:587-91.
7. Kelly JH. Cine radiography in anorectal malformations.
J Pediatr Surg 1969; 4:538-46.
8. V.D. Upadhyaya AG, Srivastava P, Hasan Z, Sharma S.
Evolution of management of anorectal malformation through
the ages. Internet J Surg 2008; 17. Available from: http://
ispub.com/IJS/17/1/3593
9. Pena A. Advances in the management of fecal incontinence
secondary to anorectal malformations.
Surg Annu 1990; 22:
143-67.
10. Pena A, Hong A. Advances in the management of anorectal
malformations.
Am J Surg 2000; 180:370-6.
11. Holschneider A, Hutson J, Pena A, Beket E, Chatterjee S,
Coran 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.
12. Rintala RJ. Congenital anorectal malformations: anything
new? J Pediatr Gastroenterol Nutr 2009; 48:S79-82.
13. Davies MC, Creighton SM, Wilcox DT. Long-term outcomes of
anorectal malformations.
Pediatr Surg Int 2004; 20:567-72.
14. Kaselas C, Philippopoulos A, Petropoulos A. Evaluation of
long-term functional outcomes after surgical treatment of
anorectal malformations. Int J Colorectal Dis 2011; 26:351-6.
15. Aminoff D, La Sala E, Zaccara A. Follow-up of anorectal
anomalies: the Italian parents' and patients' perspective.
J Pediatr Surg 2006; 41:837-41.
16. Rintala RJ, Lindahl HG, Rasanen M. Do children with repaired
low anorectal malformations have normal bowel function?
J Pediatr Surg 1997; 32:823-6.
17. Pakarinen MP, Koivusalo A, Lindahl H. Prospective controlled
long-term follow-up for functional outcome after anoplasty in
boys with perineal fistula.
J Pediatr Gastroenterol Nutr 2007;
44:436-9.
18. Yeung CK, Kiely EM. Low anorectal anomalies: a critical
appraisal. Pediatr Surg Int 1991; 6:333-5.
19. Cheu HW, Grosfeld JL. The atonic baggy rectum: a cause of
intractable obstipation after imperforate anus repair.
J Pediatr
Surg 1992; 27:1071-3.
20. Shireen A. Nah, Caroline CP Ong, Narasimhan K. Lakshmi, Te-
Lu Yap, Anette S. Jacobsen, Yee Low. Anomalies associated
with anorectal malformations according to the Krickenbeck
anatomic classification. J Pediatr Surg 2012; 47: 2273-8.
