Category: Clinical Stones: PCNL
Introduction & Objective :
In recent years, new methods of percutaneous nephrolithotomy have been introduced, particularly those that involve using a smaller access tract. Stone surgeons have increasingly taken up these “mini” and “ultra-mini” techniques, so there is a need to evaluate their outcomes. This study evaluates the initial experience of a single surgeon’s use of mini- and ultra mini-PCNL at a UK teaching hospital, and reports outcomes and complications associated with the technique.
Methods : The data from the first 23 patients that underwent mini- and ultra-mini PCNL were collected retrospectively and analysed. All procedures were performed in the prone position by the same consultant urologist over a period of fifteen months. Intra-operative radiology assessed immediate stone free rates, and CT KUB was performed after three months of each procedure for more detailed assessment. Data was also collected for tubeless procedures, post-operative Hb drop, length of stay and complications.
A total of 15 mini and 8 ultra-mini PCNLs were performed depending on stone burden characteristics. Mean stone size was 16.1mm (8 – 32mm), with 15 procedures on patients with a single stone, and 8 on multiple stones. All procedures gained renal access via a single tract, with 21 subcostal and the remaining 2 with supracostal access. Stone free rates assessed with CT KUB at 3 months were 13/22 (59.1%) completely stone free (one patient lost to follow up); 21/22 (95.5%) of patients with stone fragments at <2mm. Only one patient was left with residual stones (3mm) at three months and has opted for surveillance. Mean haemoglobin drop was 1.23g/dL (1.33g/dL in mini and 1.06g/dL in ultra-mini). 10 patients underwent a totally tubeless procedure, 18 patients were tubeless, hence 8 with JJ stent only, and 5 patients had nephrostomy. Median length of stay was 2 days (1-11). There was one Clavien-Dindo Grade I complication (1 post-operative fever >38.0 requiring antibiotics). No patients required blood transfusion.
Mini and ultra-mini PCNL is safe and effective in treating stones which may have previously been treated with standard PCNL, multiple ureterorenoscopies, or when retrograde access has failed. These procedures come with low bleeding risk and few complications. Larger prospective studies will help corroborate their efficacy.
Barts and The London School of Medicine and Dentistry
London, England, United Kingdom