Background: Middle calyx access has been underused in percutaneous nephrolithotomy (PCNL), especially in the supine position. We compared the safety and efficacy outcomes between middle calyx and lower calyx accesses in the complete supine PCNL in a non-randomized single-surgeon clinical study.
Methods: Between February 2008 and October 2011, 170 patients underwent posterior subcostal single tract complete supine PCNL with one-shot dilation and middle calyx (n = 48) and lower calyx (n = 122) accesses. Stone location and surgeon decision determined target calyx for access. Inclusion criteria were pelvis stones, staghorn stones and multiple location stones. Exclusion criteria were renal anomalies, only upper calyx stones, only middle calyx stones and only lower calyx stones. Important parameters were compared between the two groups. A p value of <0.05 was considered significant.
Results: Two groups were similar in important patient- and stone-related parameters. Mean operative time (60.7 minutes), mean postoperative hospital stay (1.84 days) and mean hemoglobin drop (0.67 g/dL) in the middle calyx group were significantly lesser than in the lower calyx group (80.1 minutes, 2.19 days, 1.36 g/dL). The middle calyx group (89.6%; 79.6%) had a higher stone-free rate (p = 0.054) and efficiency quotient than the lower calyx group (76.2%; 61.6%). In the middle calyx group (10.4%; 2.1%), complication and transfusion rates were lesser (p > 0.05) than lower calyx group (14.8%; 7.4%). No significant difference (p = 0.40) was seen between two groups using the modified Clavien classification of complications.
Interpretation: Middle calyx can be an optimal access in PCNL with the complete supine position for many of upper urinary tract stones due to its superior outcomes.