A Comparative Study of Antegrade Air Pyelogram and Retrograde Air Pyelogram for Initial Puncture Access during Percutaneous Nephrolithotomy.

Introduction: Access into the collecting system is considered to be the most critical step for Percutaneous Nephrolithotomy (PCNL). Aim: The present study provides a comparative view into antegrade air pyelography and retrograde air pyelography procedures for percutaneous renal access. Materials and Methods: A cross-sectional study was conducted on 100 patients with radiopaque renal calculi indicated for PCNL procedure. These patients were randomly assigned to two groups namely antegrade air pyelogram group (Group I) and retrograde air pyelogram group (Group II). In antegrade air pyelogram group, the collecting system was delineated by targeting the renal stone using a 22 gauge spinal needle where the patients were in the prone position. In another group, the collecting system was delineated by retrograde air pyelogram under fluoroscopy guidance. The method of tract dilatation and stone extraction were the same in both groups for comparison of outcome and complication. Results: The mean age of patients was 41.7±13 and 41.4±13.6 years in Group-I and Group-II respectively. The male to female ratio in Groups I and II was 35/15 (70.00%) and 38/12 (76.00%) respectively. In Group-I the average duration of access was 2.66±1.0 minutes after prone positioning whereas it was recorded to be 19.48±5.0 minutes in Group-II, after lithotomy followed by prone positioning of the patient. Duration of radiation exposure was almost similar in both groups. Additional procedural cost was significantly higher in Group II. Conclusion: Our study indicated that access for PCNL using antegrade air pyelogram can be a cost-effective and acceptable alternative to retrograde air pyelogram with decreased access time. [ABSTRACT FROM AUTHOR]