The Modified Procedure of Totally Tubeless PNL

Mini percutaneous nephrolithotomy (mPNL) is a standard treatment for kidney stones larger than 1.5 cm, with the placement of a nephrostomy drainage at the end of it, which is considered the standard procedure, but tubeless/ totally tubeless mPNL techniques reduce postoperative discomfort in patients and shorten hospital stays. The aim of article was to compare the efficacy and safety of our proposed modified method of totally tubeless mPNL with control of the parenchymal canal, with existing methods of tubeless/totally tubeless mPNL. Novelty of the study presented by modified method of totally tubeless mPNL. During the period from 2018 to 2020 we performed 486 mPNL were performed in our clinic in total, among which 63 (12.9%) patients underwent tubeless PNL. Patients whose surgeries ended with using tubeless techniques were divided into three groups: Group I – 22 patients who had tubeless mPNL (with ureteral stent), Group II (20 patients) – totally tubeless mPNL with a safety thread (the proposed procedure), Group III (21 patients) – totally tubeless mPNL. In all three groups, the access point was most often made through the lower group of renal calyces: Group I – 12 (54.5%), Group II – 14 (70.0%), Group III – 13 (61.9%); then through the middle calyx: Group I – 8 (36.4%), Group II – 6 (30.0%), Group III – 7 (33.3%); and the upper calyx: Group І – 2 (9.1%), Group ІІ – 0%, Group ІІІ – 1 (4.8%), no differences in the distribution of access points between groups were found (p=0.67). There were no differences in the distribution of tract sizes between the groups (p=0.95) with tract dilatation to 16.5/17.5 Fr was performed most often: Group I – 12 (54.5%), in Group II – 11 (55.0%) and Group III – 11 (52.4%). The mean duration of surgery in Group I was 83.0±22.9 min, in Group II – 74.9±13.6 min, in Group III – 72.6±12.0 min (p=0.47). This study confirms the high effectiveness of totally tubeless mPNL. The proposed modification to perform totally tubeless mPNL allows you to have permanent postoperative control over the parenchymal channel and in case of postoperative bleeding it enables you to immediately insert nephrostomy drainage through the safety thread. Study contributes to practical methods as an intermediate step for surgeons who are considering transition to a totally tubeless PCNL technique.