Biplanar oblique access technique: A new approach to improve the success rate of percutaneous nephrolithotomy

Achieving suitable percutaneous access to the kidney is the most important step in percutaneous nephrolithotomy. The triangulation biplanar access technique under fluoroscopy is the standard method to achieve percutaneous renal access, but it is not successful in all cases. We used the new biplanar oblique access technique as a rescue method for the failed standard biplanar technique. The aim of this study was to evaluate the effects of this oblique access technique on access outcome.

In total, 782 percutaneous nephrolithotomy procedures were performed under the standard triangulation biplanar technique. The biplanar access failed in 35 cases. Access failure was defined as no urine dropping from the needle or inability to insert the guide wire into the renal pelvis or selected calyx. In 28 failed access cases, the lower calyx was the targeted calyx. We used the oblique access technique for these cases. Initially, the arm of fluoroscopy was in the vertical position. Then the fluoroscopy device was rotated to 30° near the surgeon and 30° caudal to the patient and the needle was inserted into the appropriate calyx.

Percutaneous nephrolithotomy procedures were performed by the oblique access technique in 28 patients. Successful access was achieved in eight patients by the oblique technique (success access rate = 28.6%). No major or minor complication occurred in these patients.

The oblique technique is an auxiliary method for accessing the lower calyx in cases which the standard triangular biplanar method has failed. As the failure rate of the biplanar technique is low, the oblique technique can be considered as a useful method for percutaneous access.