LIMITATIONS OF CROSS TABLE PRONE LATERAL X-RAY/INVERTOGRAM IN DIAGNOSING OF TYPES OF ANORECTAL MALFORMATIONS

INTRODUCTION Anorectal malformation is the very common congenital malformation with the incidence of 1 in 5000 (1,2). The diagnosis is made on perineal examination which is further corroborated by cross table prone lateral x-ray or invertogram to find out the level of anorectal atresia. The cross table prone lateral x-ray is considered better investigation tool as compared to invertogram for demonstration of the level of rectal atresia in neonates. In prone cross table lateral x-ray, effect of gravity is negated, positioning of the baby is more comfortable and the rectal gas shadow is better delineated. AIM To evaluate the sensitivity and specificity of cross table prone lateral x-ray in labelling a patient of anorectal malformation as high or low. MATERIAL AND METHODS The study was conducted in retrospective manner. Radiological materials, clinical and operative records of the neonates with anorectal malformation operated in Department of Surgery, Pediatric Surgery unit, BRD Medical College over a period of 2 years (June 2017 to July 2019) were retrieved. Total 100 neonates with anorectal malformation were admitted in our hospital during this time frame. Out of these patients, colostomy was done in 79 patients, anoplasty was performed in 18 cases. Two patients underwent primary posterior sagittal anorectoplasty while 1 patient had ileostomy done. During this study, we came across four unusual cases of low anorectal malformation where the x-ray picture did not coincide with the clinical diagnosis. CONCLUSION Diagnosis of anorectal malformation is clinical but to diagnose the type of anorectal malformation it requires both clinical as well as radiological workup. In case of diagnostic dilemma, our clinical interpretation should lead the diagnosis as none of the x-ray modality has 100% sensitivity.