Assessment of distribution of Interstitial cell of Cajal like cell across upper urinary tract region in children with pelvic ureteric junction obstruction

Aims and objectives: To study the distribution of Interstitial cell of Cajal like cell (ICC-LC) across upper urinary tract region in children presenting with pelvic ureteric junction obstruction (PUJO) and its association with renal functional and sonological parameters of patients. Material and method: A prospective study was done on twenty children (excluding neonates) with primary PUJO undergoing dismembered pyeloplasty. All subject underwent renal sonography [anteroposterior diameter of pelvis (APPD), pelvi-calyceal ratio (P/C ratio), mid-polar renal parenchymal thickness (MPPD)] and functional imaging scan.Three specimens were taken intra-operatively from above, at and below PUJ and were examined immunohistochemically using CD-117 to count ICC-LC using standard criteria. ICC-LC distribution was correlated with above stated parameters. Result: The number of ICC-LC showed a continuous decreasing trend craniocaudally across PUJ. P/C ratio and APPD showed parallel trend with ICC-LC distribution across PUJ, while split renal function (SRF) showed inverse relationship with expression of ICC-LC. Group with lesser severity of obstruction (APPD<30 mm, SRF>40%) showed uniform decreasing trend in number of ICC-LC craniocaudally across PUJ. More severely obstructed patients (APPD>30 mm, SRF<40%) had decreasing trend up to the level of PUJO followed by a sudden relatively increased expression of ICC-LC below PUJ. Conclusion: The expression of ICC-LC shows a uniformly decreasing trend across PUJ when the severity of obstruction is less. Resurgence in the number of ICC-LC below PUJ in subjects with severe obstruction hints at emergence of new pacemaker area below severely blocked PUJ akin to that seen in complete heart-block patients and deserve early attention