Middle calyx access in complete supine percutaneous nephrolithotomy

Abstract

Background: Middle calyx access has been underused in percutaneousnephrolithotomy (PCNL), especially in the supine position.We compared the safety and efficacy outcomes between middlecalyx and lower calyx accesses in the complete supine PCNL in anon-randomized single-surgeon clinical study.Methods: Between February 2008 and October 2011, 170 patientsunderwent posterior subcostal single tract complete supine PCNLwith one-shot dilation and middle calyx (n = 48) and lower calyx(n = 122) accesses. Stone location and surgeon decision determinedtarget calyx for access. Inclusion criteria were pelvis stones,staghorn stones and multiple location stones. Exclusion criteriawere renal anomalies, only upper calyx stones, only middle calyxstones and only lower calyx stones. Important parameters werecompared between the two groups. A p value of <0.05 was consideredsignificant.Results: Two groups were similar in important patient- and stonerelatedparameters. Mean operative time (60.7 minutes), meanpostoperative hospital stay (1.84 days) and mean hemoglobin drop(0.67 g/dL) in the middle calyx group were significantly lesser thanin the lower calyx group (80.1 minutes, 2.19 days, 1.36 g/dL). Themiddle 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%), complicationand transfusion rates were lesser (p > 0.05) than lowercalyx group (14.8%; 7.4%). No significant difference (p = 0.40)was seen between two groups using the modified Clavien classificationof complications.Interpretation: Middle calyx can be an optimal access in PCNLwith the complete supine position for many of upper urinary tractstones due to its superior outcomes.