THE IMPACT OF ANATOMICAL VARIATION OF LOWER POLE COLLECTING SYSTEM OF KIDNEY ON STONE FORMATION

Abstract

Objective: To determine the effect of lower pole renal anatomy in terms of infundibuloureteropelvic angle (IUPA), infundibulocalyceal length (ICL), infundibular width (IW) on the formation of solitary stone of the lower pole of kidney in our set up. Methodology: We conducted retrospective analysis of renal collecting system of 40 adult patients with non-obstructed kidney having solitary stone of lower pole. This study was carried out from January 2008 to January 2011 at Anatomy department Khyber Medical College Peshawar in collaboration with Anatomy and Surgical department of Khyber Medical University Institute of Medical Sciences (KIMS) Kohat. The morphometeric parameters of the lower pole of kidney like IUPA, ICL and 1W were measured from standard intravenous urograms. The data of stone forming and nonstone forming contra lateral side were compared. Statistical analysis was performed by paired t test. Results: In 30 (72%) patients the IUPA of stone forming side was more acute than on the non-stone forming side. The difference between the stone forming and contralateral normal side was statistically significant (P<0.05). The mean ICL of stone forming side was 32.15±9.02 mm compared to 27.38±4.58 mm on non-stone forming contralateral side (P<0.05). The mean width of lower pole infundibulum was 3.16±0.8 mm on stone forming side versus 6.8±1.6 mm on non-stone forming side (p<0.05). Conclusion: Abnormal renal anatomy of lower Pole collecting system was found to be more common in patients with lower calycael stones so it is considered to be a risk factor for forming lower pole kidney stone. Key Words: Pyelocalyceal Factors, Kidney Lower Pole, Stone Formation, Infundibuloureteropelvic Angle, Infundibulocalyceal Length, Infundibular Width.