A Novel Technique of Ultra-Mini-Percutaneous Nephrolithotomy: Introduction and an Initial Experience for Treatment of Upper Urinary Calculi Less Than 2 cm

Abstract

Objectives. To describe our novel modified technique of ultra-mini-percutaneous nephrolithotomy (UMP) using of a novel 6 Fr mininephroscope through an 11–13 Fr metal sheath to perform holmium: YAG laser lithotripsy. Methods. The medical records of 36 patients with moderate-sized (<20 mm) kidney stones treated with UMP from April to July 2012 were retrospectively reviewed. Patients were assessed at the 1st day and 1st month postoperatively by KUB and US to assess stone-free status. Results. The mean stone size was 14.9 ± 4.1 mm (rang: 6–20). The average operative time was 59.8 ± 15.9 (30–90) min. The stone-free rate at postoperative 1st day and 1st month was 88.9% and 97.2%. The mean hospital stay was 3.0 ± 0.9 (2–5) days. Complications were noted in 6 (16.7%) cases according to the Clavien classification, including sepsis in 2 (5.6%) cases (grade II), urinary extravasations in 1 (2.8%) case (grade IIIa), and fever in 3 (8.3%) cases (grade II). No patients needed blood transfusion. Conclusions. UMP is technically feasible, safe, and efficacious for moderate-sized renal stones with an advantage of high stone-free rates and low complication rates. However, due to the limits of its current unexplored indications, UMP is therefore a supplement to, not a substitute for, the standard mini-PCNL technology.

How can the operation time be shortened by reducing the tract size?

“…On the other hand, stone fragments to be extracted associated with the tract size will be smaller and the operation will be time consuming. This is supported by the literature so far [2]. It is observed that authors did not consider this fact in their study.…”

Minimally invasive percutaneous nephrolithotomy compared with retrograde intrarenal surgery: a meta-analysis

“…This was followed by the description of micro-PCNL by Bader et al [28] and ultra mini-PCNL by Desai et al [29]. The most important change in these instruments is the size of the sheath, but it must be noted that the scale of the procedure may have some limitations on the surgeon's performance.…”

The role of ultra-mini percutaneous nephrolithotomy in the treatment of kidney stones

“…Later Bader et al [9] described the micropercutaneous (microperc) technique allowing stone fragmentation using a single-step access under direct vision. Finally, in 2013, Desai et al [10] introduced the ultramini-PNL (UMP), in which a 6 Fr mini nephroscope is used through a 13 Fr metal sheath and stones are fragmented with a laser. This new treatment modality seems to be promising for the management of middle-sized stones; however, up to now only a few studies have been published from certain centers reporting the limited number of experiences of the same few surgeons.…”

“…This new treatment modality seems to be promising for the management of middle-sized stones; however, up to now only a few studies have been published from certain centers reporting the limited number of experiences of the same few surgeons. [10][11][12][13][14][15][16] We report herein the outcomes of the prospective clinical study of UMP compared with the findings cited in the literature. With the surgeons' increased experience using UMP and presentation of series, the role of UMP in the management of renal stones will be more clearly understood.…”