Mini PCNL for renal calculi: does size matter?

Abstract

ObjectiveTo evaluate the minimally invasive percutaneous nephrolithotomy (MIP) system for renal calculi. Patients and MethodsConsecutive patients undergoing mini-percutaneous nephrolithotomy (mPCNL) procedures with the MIP system were enrolled. Patient position, American Society of Anesthesiologists classification, puncture location, stone clearance, postoperative drainage and complications were recorded, and features unique to MIP were noted. ResultsIn all, 30 patients underwent 32 mPCNL procedures. The mean stone size was 17 (10.75-21.25) mm and the mean number of stones was 1 (1-2). The median stone clearance rate was 96.5 (95-100)%. The complication rate was 9.3%. No patient required a transfusion. In addition to these outcomes, we noted that the MIP system has many advantages over conventional PCNL (cPCNL). It is easy to learn and can be performed in both supine and prone positions. It is safe for supracostal puncture, provides excellent access to nearly all calyces and upper ureter, has multiple stone treatment options, can be used as an adjunct to cPCNL, and can be performed as a tubeless procedure. ConclusionOur experience with the MIP system has shown several advantages over cPCNL. mPCNL with the MIP system has several features that suggest it should be considered as an alternative or adjunct to cPCNL, ureteroscopy and extracorporeal shockwave lithotripsy.

Experiences of Renal Stone Fragmentation with the Use of the Ultrasound-guided Mini-percutaneous Nephrolithotipsy in 650 Patients

“…In 2012, Abdelhafez et al reported on 83 patients treated with the mini-PCNL, in which the upper calyx of kidney puncture accounted for 4.8%, the middle calyx of kidney puncture 10.8%, and the rest was the lower calyx of kidney [3]. Hennessey et al studied 32 cases treated using the mini-PCNL, of which 24 cases (75%) were punctured at the lower calyx of kidney, 12.5% at the middle calyx of kidney, and 12.5% the upper calyx of kidney [5]. For simple stones, using the calyx of kidney, renal pelvis puncture to directly approach the stones is the best way to the stone fragmentation and to limit damage and complications.…”

“…Among 642 patients who were successfully punctured, with a tunnel created and the kidney approached, the mean operative time was 49.3 (37-90) min, and the longest was 90 min, recorded in the case with staghorn stones (Table 2). According to Hennessey et al (2017), for 32 patients, the mean operative time was 50 (40-82) min, with the mean size of stones equivalent to our study 17 [5]. The operative time was linked with the location and size of the stones, according to Abdelhafez et al (2012), who studied the treatment by mini-PCNL with the mean size of stones of 36.7 ± 23.37 mm: In this case, the mean operative time was 99.2 ± 48.3 minutes [3].…”

“…In 2013, Zeng et al examined and summarized 10,000 cases treated with the mini-PCNL; the results showed that the stone-free rate (SFR) in respect of simple calyx of kidney stones was 77.6%, and for complex stones, it was 66.4% [4]. In 2017, Hennessey et al reported 30 cases treated using the mini-PCNL, in which the SFR was 96.5% [5].…”

Miniaturised percutaneous nephrolithotomy: Its role in the treatment of urolithiasis and our experience

“…In another study, Hennessey et al. [20] identified other advantages of MIP over both standard PCNL and RIRS. Firstly, patients' position was more flexible than RIRS and at least as equally flexible as standard PCNL.…”

Present indications and techniques of percutaneous nephrolithotomy: What the future holds?

“…Combined, standard and mini tracts could be advised for staghorn, large burden or multiply located in the collecting system stones. In these cases, additional small tracts can improve anatomic approachability while decreasing renal trauma and bleeding and improving stone free rates [47] , [48] .…”