Ultrasound guidance can be used safely for renal tract dilatation during percutaneous nephrolithotomy

Abstract

ObjectivesTo compare clinical outcomes in patients who underwent percutaneous nephrolithotomy (PCNL) with renal tract dilatation performed under fluoroscopic guidance vs renal tract dilatation with ultrasound guidance. Patients and MethodsWe conducted a prospective observational cohort study, enrolling successive patients undergoing PCNL between July 2015 and March 2018. Included in this retrospective analysis were cases where the renal puncture was successfully obtained with ultrasound guidance. Cases were then grouped according to whether fluoroscopy was used to guide renal tract dilatation or not. All statistical analyses were performed using STATA version 15.1 including univariate (Fisher's exact test, Welch's t-test) and multivariate analyses (binomial logistic regression, ordinal logistic regression, and linear regression). ResultsA total of 176 patients underwent PCNL with successful ultrasonography-guided renal puncture, of whom 38 and 138 underwent renal tract dilatation with fluoroscopic vs ultrasound guidance, respectively. There were no statistically significant differences in patient age, gender, body mass index (BMI), preoperative hydronephrosis, stone burden, procedure laterality, number of dilated tracts, and calyceal puncture location between the two groups. Among ultrasound tract dilatations, a higher proportion of patients were placed in the modified dorsal lithotomy position as opposed to prone, and a significantly shorter operating time was observed. Only modified dorsal lithotomy position remained statistically significant after multivariate regression. There were no statistically significant differences in postoperative stone clearance, complication rate, or intra-operative estimated blood loss. A 5-unit increase in a patient's BMI was associated with 30% greater odds of increasingly severe Clavien-Dindo complications. A 5-mm decrease in the preoperative stone burden was associated with 20% greater odds of stone-free status. No variables predicted estimated blood loss with statistical significance. ConclusionsRenal tract dilatation can be safely performed in the absence of fluoroscopic guidance. Compared to using fluoroscopy, the present study demonstrated that ultrasonography-guided dilatations can be safely performed without higher complication or bleeding rates. This can be done using a variety of surgical positions, and future studies centred on improving dilatation techniques could be of impactful clinical value.

A Safe and Effective Two-Step Tract Dilation Technique in Totally Ultrasound-Guided Percutaneous Nephrolithotomy

“…In one study with 138 subjects, totally ultrasound-guided balloon dilation was achieved in 131 (94.9%), and the remaining 7 (5.1%) cases required a switch to fluoroscopy (17). In another study with 207 cases undergoing ultrasoundguided balloon dilation, the success rate of tract dilation on the first attempt was 88.4% (11).…”

“…A few authors reported their technique of ultrasound monitoring the dilation process, including balloon dilator (11,17), serial Amplatz dilators(9), one-shot Amplatz dilators (18), or telescopic metal (Alken) dilators (19). Among these dilators, balloon has been widely used in ultrasound-guided PCNL and has been considered relatively easier to apply under ultrasound guidance (12).…”

Zero‐radiation stone treatment

“…As urologists, we should all be aware of these risks and follow the ALARA (As Low As Reasonably Achievable) principals of keeping doses to a minimum. Thus, this paper is particularly welcome and shows zero‐radiation procedures can be safely performed. The authors now attempt this technique for all PCNL procedures and achieve US‐only puncture and dilatation in over half of their patients.…”

“…In this month’s BJUI , Armas‐Phan et al report on a prospective observational trial of fluoroscopic vs ultrasound (US)‐guided tract dilatation during percutaneous nephrolithotomy (PCNL). A total of 176 patients underwent successful initial US‐only guided puncture; of these patients, 138 had US‐only dilatation, while in 38 fluoroscopy was required.…”

Comparison of antegrade and retrograde ureterolithotripsy for proximal ureteral stones: a systematic review and meta-analysis

“…Although thought to be less invasive than open or laparoscopic stone removal, surgeons are sometimes reluctant to proceed with PCNL due to complications related to renal access (7). A variety of renal access methods, such as ultrasound guidance (8) and miniaturized tract, possibly with the utilization of a flexible nephro-or ureteroscope (9), could mitigate the major unique complications of PCNL without reducing its efficacy for stone removal. While the European Association of Urology (EAU) (10) and the Urological Association of Asia (UAA) (11) guidelines suggest that antegrade ureterolithotripsy (URSL) may be a good alternative for the treatment of proximal ureteral stones larger than 10 mm, there is still a lack of evidence on the optimal case for the application of antegrade URSL over retrograde URSL in real practice.…”