February 2000, Volume 50, Issue 2

Case Reports

Diagnosis and Management of the Neonatal Cloaca

Abdul Samad  ( Department of Surgery, The Aga Khan University Hospital, Karachi. )
Shabbir Hussain  ( Department of Surgery, The Aga Khan University Hospital, Karachi. )
Muhammad Arshad  ( Department of Surgery, The Aga Khan University Hospital, Karachi. )
Farhat Moazam  ( Department of Surgery, The Aga Khan University Hospital, Karachi. )

Introduction

The cloaca is one of the most complex and challenging developmental malformations managed by paediatric surgeons. The word Cloaca is latin in origin and means Sewer. It is classically defined as a common chamber into which the urinary, genital and intestinal tracts terminate before draining to the exterior through a common opening1. Normally, this is a transient embryological event at about 7-8 mm stage of the human embryo but may persist as a rare congenital anomaly2,3. Its incidence is reported to be one in 50,000 births annually4. Although the incidence of true persistent cloaca is much more rare, the cloaca includes a wide range of anomalies from the almost insignificant to the very complex. This paper describes two neonates with cloacal anomalies recently managed at the Aga Khan University Hospital (AKUH), Karachi.

Case Report

Case One
A female neonate was born at 36 weeks of gestation to a 22 years old nulliparous woman. Although the earlier antenatal ultrasounds were reported to be normal, one done at 29th gestational week revealed an irregular mass in the fetal abdomen measuring about 3.1 x 2.2 cm together with bilateral hydronephros is and ol igohydram n i os. Subsequent ultrasounds showed rapid increase in the size of the mass. The neonate required incubation and ventilatory support due to the respiratory distress at birth. Clinical examination revealed 3 palpable abdominal masses and a single orifice (Figure 1)
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in the depth of the labia niajora. Catheterization of the orifice drained urine with some mucoid debris. The child did not pass meconium. Congenital dislocation of the left hip was also noted. A provisional diagnosis of cloaca was made. An ultrasound as well as sinograms (Figure 2)
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were not helpful in defining the internal anatomy clearly.
The neonate’s serum creatinine increased from 0.8 to 1 .5 mg/dl over the first 3 days of life. Endoscopy revealed a common channel leading to two chambers, anteriorly’ the urinary bladder and posteriorly to a vagina with haernorrhagic mucosa. A subsequent exploratory laparotomy revealed a bicornuate uterus and a short colon with a dilated pouch, both communicating with the urinary bladder, confirming a case of classical cloaca. Two appendices at the base of the caecum were also found. A divided ileosuomy and a tube vesicostomy were performed to decompress the gastrointestinal and genitourinary systems. The patient improved and the ventilatory support was gradually discontinued. The serum creatinine had gradually dropped to 0.5 at the time of’ discharge from the hospital. During follow—up, the patient was passing urine and mucus from the cloacal opening with very little residual urine in the urinaiy bladder. The Foley’s catheter in the vesicostomy was removed and the vesicosuomy closed spontaneously. The mother was instructed in clean internuittent catheterization to ensure complete decompression of the urinary bladder. Future plans for this infant include the contrast studies through stoma to determine the status of her anatomical structures followed by definitive reconstruction.
Case Two
A female neonate was horn at about 35 weeks of gestation with no abnormality detected on two antenatal ultrasounds in early pregnancy. However, the ultrasound clone a few days prior to birth, showed oligohydraninios. a markedly distended fetal urinary bladder, moderate bilateral hydronephrosis and a breech presentation. The neonate required ventilatory support due to respiratory distress at birth. Clinical examination revealed a complex pelvic mass and a bitid clitoris with a single urogenital opening. Meconium was adequately passed via an anteriorly placed ectopic anus. Polydactyly of left hand was also found. A sinograrn done on the third day of life showed a massively’ distended vagina with the urinary bladder pushed anteriorly. An echocardiogram showed ventricular septal defect. On endoscopy, a long common urogenital sinus with an anteriorly placed urinary bladder was also noted. An exploratory laparotomy performed on the same day revealed a uterus pushed up by an enormously distended vagina. A tube vaginostomy was clone to decompress the system. Ventilatory support was gradually’ weaned off and the patient was discharged on the 6th post-operative day. Future plans for this infant include contrast studies through stoma for further demarcation of’ various anatomical structures followed by elective, definitive reconstruction.

Discussion

The basic embryological defect that results in a cloacal anomaly is failure of the complete descent of uro—rectal septum5. The uro-rectal septum, which appears in a 4 weeks embryo and fuses with the cloacal membrane in the 7th week, divides the cloaca into dorsal hindgut and ventral urogenital sinus6. The urogenital sinus gets further subdivided into cranial urethro—vesicle canal and caudal definitive urogenital sinus at the point of entry of mesonephric duct7. If there is testicular differentiation, there is associated mullerian duct regression and the primitive urogenital sinus, caudal to the Wolfan duct forming prostatic, nwmbranous urethra and the penis. In case of differentiation into the female sex, the mullerian duct along with definitive urogenital sinus form fallopian tubes, uterus and vagina.
The cloacal anomalies have a wide spectrum ranging from almost insignificant like ectopic antis to the very bizarre. Attempts to classify the cloacal anomalies have been unsuccessful and currently there is no universally accepted classification system8,9, due to enormous variations. External examination does not accurately predict internal anatomy. A battery of investigations is required to evaluate internal anatomy. Despite this significant number of anomalies can only be accurately evaluated through surgical exploration1.
Approximately 60% of cloacal anomalies are associated with upper urinary tract malformations and hydrocolpas caused by partial or complete obstruction of the vaginal outlet. Frequently hydrocolpas contributes to bladder outlet and/or ureteral obstruction, urinary stasis and sepsis. Both our cases presented antenatally with hydrocolpas, due to vaginal obstruction and associated upper urinary tract dilatation with deteriorating renal function. Case one presented with classical cloacal anomaly while case two had urogenital sinus associated with ectopie an us.
The basic aim of neonatal exploration is decompression of stagnant system and the proper evaluation of cloacal anatomy. Gastro-intestinal system is decompressed by enterostomy12. Right transverse colostomy with preservation of mid-colic, left colic and sigmoid arteries is preferred, as distal colon may be required for later vaginal reconstruction13. In case one, we did divided ileostomy because of extremely short colon. Hydronephrosis and urinary bladder distension are the main indications for urinary bladder decompression. In both our patients, the urogenital tract required decompression by stoma. Allen and Husmann reported upto 60% of patients with cloacal anomalies required vesicostomy1. Many may have varying degrees of neurogenic dysiunct ion of bladder while vesico-ureteric reflux is reported in over 60%.
Definitive cloacal reconstruction involves surgical separation of the three systems and bringing them to the perineum with construction of three continent openings. The decision for the timing of re-constructive surgery depends on the condition of infant, complexity of malformation and experience of the surgeon. Although the neonatal reconstruction is possible14, it is best deferred beyond the first month of the life12.

References

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11.Hendren Wit. Urologieal aspects of eloaeal unalformauions. J. tirol 1988:140:1207-13.
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13.Hendren WH. Cloaeal anomalies: Abdominal Surgery of Infancy and Childhood. I 996;26: 1-12.
14.Raffensperger JG. Rausuenofsky ML. The unanageuneni of a eloaca. 3. Pediatr. Surg., 1973:8:647-57.

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