A comparative study of air pyelogram and contrast pyelogram for initial puncture access and to see its efficacy...

The current investigation was aimed to compare the safety, efficacy, adverse effects, and outcome of air pyelogram versus contrast pyelogram for percutaneous nephrolithotomy.

This was a cross-sectional study conducted from August 2018 to November 2020, which included 400 patients with a clinical diagnosis of renal calculus and randomly (1:1) assigned into Group I (air pyelogram) and Group II (contrast pyelogram). Air was injected in Group I and diatrizoate meglumine 76% was used in Group II for PCS identification. In the case of difficulty in visualization in either group, a mixture of contrast and air was used. The following parameters were assessed: duration of access, total duration of radiation exposure during access, total attempts needed to puncture the desired calyx, failure rate, complications, and outcomes.

Both the groups were comparable including renal calculus characteristics. The mean (standard deviation) duration of access was 3.08 (1.21) and 5.23 (1.02) min (P < 0.0001) in Groups I and II, respectively; in 85% and 57.5% of patients (P < 0.0001), respectively, the caliceal puncture was done in a single attempt. The duration of radiation exposure was more in Group II (P < 0.0001). The failure rate (22%) was higher and statistically significant in Group II. The stone clearance rate was not statistically significant between the groups (P = 0.380). No patient had hypoxia, cardiopulmonary complications, and air embolism in perioperative period.

Air contrast is effective and safe, and it reduces the duration of caliceal puncture and radiation exposure with lower failure rate. If both air and contrast fail, a combination of both may be effective.