Comparing rectal biopsy using artery forceps and full-thickness rectal biopsy in diagnosing hirschsprung’s disease at University teaching hospital, Lusaka

Abstract

Hirschprung’s disease is a congenital disorder that is characterised by functional constipation whose onset is dependent on the length of affected bowel and always involves the rectum. Despite having a diagnostic challenge, rectal biopsy for histological analysis is the most definitive form of diagnosis. The average number of patients seen at University Teaching Hospital in Zambia, generally come as referrals. Superficial thickness biopsy using the rectal suction method has been adopted as the gold standard for obtaining rectal biopsy in the western world leaving the invasive full thickness biopsy for inconclusive cases. However, superficial thickness biopsy using special types of forceps have been quoted to be as good or even superior to the rectal suction biopsy. Superficial thickness biopsy using curved artery forceps is proposed in this study to provide a simple cost-effective method of obtaining adequate rectal biopsy sample for diagnosis. The aim of this study was to compare superficial rectal biopsy using an artery forceps and full thickness rectal biopsy in the diagnosis of Hirschsprung’s disease in a resource limited environment at University Teaching Hospital, Lusaka This was a prospective single-blind study conducted at University Teaching Hospital in the department of Surgery, paediatric unit from June 2018 to March 2019. Thirty-one patients, who presented with chronic constipation and delayed passage of meconium, were enrolled in the study. A structured questionnaire was used to gather information from the patient and record files. Two rectal biopsies using two different procedures under study were obtained from each patient and submitted for histopathological evaluation to the histopathology department. The results of the two methods were then compared. All patients had chronic constipation and some had a history of delayed passage of meconium. 19 out of 31 full thickness biopsies had adequate biopsy whereas only four out of 31 had adequate biopsy with superficial thickness method using curved artery forceps. The biopsy obtained using the curved artery forceps had a high sensitivity and poor specificity and predictive value. This meant that too many patients would require a re-biopsy. Although not all patients required suturing hence saving on consumables, none of the patients developed any complications during or after the procedures. Based on these results, this study recommends that the traditional full-thickness biopsy procedure should continue to be used until such a time when rectal suction biopsy sets for superficial-thickness biopsy can be made available. Keywords : Hirschsprung’s disease, full-thickness rectal biopsy, superficial-thickness rectal biopsy, curved artery forceps