RESUMO
OBJECTIVE: Lower pole percutaneous nephrostomy is performed frequently for percutaneous nephrolithotomy (PCNL), using a variety of imaging modalities such as fluoroscopic, computed tomography (CT) or ultrasound guidance. This study was performed to estimate the potential risk of colonic injury during lower pole percutaneous nephrostomy for PCNL. METHODS: We observed the position of the colon relative to the kidney in 134 patients who underwent CT kidney, ureter, bladder (KUB) examinations in the prone position. RESULTS: We found the prevalence of colon lying posterior to the kidney (i.e. retrorenal) in males to be 13.6% on the right, and 11.9% on the left, whilst in females it was 13.4% on the right and 26.2% on the left. CONCLUSIONS: Patients at higher risk for retrorenal colon should be considered for preoperative imaging to identify those patients in whom the colon may be situated posterior to the kidney, allowing for appropriate alterations in technique to be made, such as the use of ultrasound or CT guidance.
