Immunohistochemistry in Ureteropelvic Junction Obstruction and Its Correlation to Postoperative Outcome

To investigate the correlation between the status of interstitial cells of Cajal (ICC) in ureteropelvic junction (UPJ) and the resected ureteric margin and the postoperative outcome of Anderson-Hynes pyeloplasty in UPJ obstruction (UPJO) and to compare the ICC in the UPJ and the resected margin of the normal ureter.

An observational study was conducted over a period of 2 years at the Department of Pediatric Surgery at Niloufer Institute of Women and Child Health. Children with intrinsic UPJO who underwent Anderson-Hynes dismembered pyeloplasty were included in the study. Six months postoperatively, the patients were divided into two groups based on diuretic isotopic renogram using technetium-99m-labeled diethylene triaminepentaacetic acid. Group 1 comprised patients with good surgical outcome. Group 2 comprised patients with a poor outcome. The histologic specimens were evaluated for ICC, and the immunohistochemical findings were correlated with the outcome.

Twenty-five patients were included in this study (19 male and 6 female). Seventy-six percent of patients were under the age of 1 year. Group 1 had 23 cases and Group 2 had 2 cases. Out of the two patients with a poor outcome, one had negative grading at the UPJ and one had positive grading. Both these patients had a negative grading at the lower resected margins. More number of patients (24%) had +++ grading at the lower resected margin when compared to the UPJ (8%).

This is the first study which correlates the status of ICC in UPJ with the outcome of pyeloplasty in pediatric patients. Both the cases with bad outcome had no ICC at the lower margin of the resected specimen and one case had no ICC at the UPJ. There is a statistically significant difference (P = 0.001) in the number of ICC at the UPJ and the resected margin.