Occurrence of Retrorenal Colon in the Indian Population – A Significant Finding from Urological Perspective

Abstract

Introduction: Ascending and descending coli normally are located anterolateral to kidneys. Retrorenal position of the colon has a reported prevalence of 10%–20% in the general population. Its occurrence is of significant while performing percutaneous nephrolithotomy (PNL) which is a routine management procedure for patients showing clinical disease associated with renal calculus. PNL in patients with retrorenal colon can lead to colonic perforation which is associated with significant morbidity and mortality related to septicemia, peritonitis, formation of abscess, and nephro-colic and/or colo-cutaneous fistulae. Hence, the preoperative information about the presence of retrorenal colon is essential for the prevention of surgical complications. Materials and Methods: Our retrospective study included patients who underwent computed tomography (CT)/magnetic resonance (MR) abdomen in our department of radiodiagnosis. All the scans were evaluated for the presence of retrorenal colon. The persistence of retrorenal colon was also observed with change in posture among those with prone scans. Results: The retrorenal colon was present in 130 out of 669 patients included in the study, with an occurrence rate of nearly 20%. Alteration in the position of retrorenal colon was noted with prone position in approximately 79%. Conclusion: The occurrence of retrorenal colon is high in the Indian population being approximately 20% without change with prone position in one-fifth. Thus, to reduce the risk of complication related to colonic perforation during PNL, all patients must be subjected to CT/MR abdomen to detect retrorenal colon followed by scan in the prone position, if retrorenal colon is present, to evaluate the alterations in colonic position with prone posture.