Percutaneous nephrolithotomy with ultrasound-assisted puncture: does the technique reduce dependence on fluoroscopic ionizing radiation?

Tubeless Percutaneous Nephrolithotomy in the Barts 'Flank-Free' Modified Supine Position with 24-Hour Discharge: A Single-Center Experience

Background and Objectives: To evaluate the effectiveness and outcomes of supine percutaneous nephrolithotomy (PCNL) using the Barts 'flank-free' position and ultrasound-guided puncture, assessing the feasibility of the tubeless technique for discharge within 24 h. Materials and Methods: We conducted a retrospective analysis of 208 patients across 220 renal units who underwent supine PCNL at a tertiary university hospital between May 2019 and December 2024. All procedures were performed by a single surgeon. Patient demographics, stone characteristics, and surgical outcomes were analyzed. The tubeless technique was applied in most cases, and outcomes were assessed in terms of operative time, complication rates, stone-free rates (SFRs), and length of hospital stay. Results: The mean operating time was 50.34 ± 30.80 min. Single-tract PCNL was performed in 94.55% of cases, with the tubeless technique used in 90% of patients. The overall complication rate was 9.55%, with no Clavien-Dindo grade IV-V complications observed. On the first postoperative day, 68.18% of patients were discharged, demonstrating 24 h discharge feasibility. SFR and complication rates aligned with existing literature. Conclusions: The Barts 'flank-free' position and ultrasound-guided puncture considerably improved surgical access and safety in supine PCNL. The tubeless technique facilitates faster recovery, making early discharge feasible, even with standard sheath sizes. Further research is warranted to validate these findings and optimize renal stone management outcomes.

Conventional ultrasonography enabled with augmented reality needle guidance for percutaneous kidney access: an innovative methodologies randomized controlled trial

IMPORTANCE

Successful needle puncture of the renal collecting system is a critical but difficult procedure in percutaneous nephrolithotomy (PCNL). Although fluoroscopy and ultrasound are the standard imaging techniques to guide puncture during PCNL, both have known limitations.

OBJECTIVE

To assess the feasibility and safety of a new navigation system for needle puncture in ultrasound-guided PCNL.

DESIGN

This study employed a single-center randomized controlled trial (RCT) design to assess the feasibility and safety of a new navigation system for needle puncture in ultrasound-guided PCNL. Conducted between May 2021 and November 2021, the trial utilized computer-generated random numbers for participant allocation to control for selection bias.

SETTING

The trial was executed at Department of Urology, Peking University First Hospital in Beijing, China, which serves as an academic medical center.

PARTICIPANTS

All patients who met the inclusion criteria were randomly divided into two groups, with 29 patients in each group. One group underwent PCNL procedures using the new navigation system, while the control group underwent standard ultrasound-guided PCNL procedures. Included patients had renal pelvis or caliceal calculi larger than 2.0 cm in diameter or had multiple or staghorn stones. The puncture procedure was performed with the support of real-time ultrasound imaging and visual guidance displayed on the screen.

MAIN OUTCOMES AND MEASURES

The primary outcome was system feasibility and puncture success rate. Secondary outcomes included puncture time, total surgical time, number of attempts, postprocedure complications, and 1-year and 3-year stone recurrence rates. Stone clearance was defined by postoperative CT. Descriptive statistics summarized patient demographics, stone size, and location. Independent samples t -tests analyzed puncture time and total surgical time. χ2 or Fisher's exact tests compared stone clearance, complications, socioeconomic status, renal hydronephrosis, stone location, race, and medical history. Linear regression examined the correlation between BMI and puncture time. Significance was set at P <0.05.

RESULTS

For all 58 patients undergoing PCNL, needle punctures of the renal collecting system were completed with a success rate of 100%. The average time from planning the puncture protocol to successful puncture was significantly shorter in the AcuSee guidance system group (3.12 min, range 0.2-6.88 min) compared to the standard ultrasound-guided group (7.58 min, range 5.41-10.68 min), representing a reduction of ~59%. The total surgical time was also shorter in the AcuSee group for patients with no and mild hydronephrosis ( P <0.05). Complication rates were lower in the AcuSee group, with no major complications observed. However, three patients in the standard ultrasound-guided group have adverse effects after the PCNL procedure. The 1-year stone recurrence rate was significantly lower in the AcuSee group (3.4%) compared to the standard group (24.1%), and the 3-year recurrence rate was also lower (6.9% vs. 41.4%). Patient-specific factors such as BMI, renal morphology, and prior surgical history did not significantly affect the performance of the AcuSee system.

CONCLUSIONS AND RELEVANCE

The authors report the first clinical application of a new navigation system for needle puncture in ultrasound-guided PCNL. It has been demonstrated that it is feasible and safe compared to the standard ultrasound-guided group in percutaneous renal puncture. This technology provides intuitive and easy-to-use visual guidance, which may facilitate safe, accurate, and fast needle puncture of the kidney.

Adopting ultrasound guided PCNL in nephrolithiasis management

INTRODUCTION

This study aimed to evaluate the learning curve associated with the adoption of US guided PCNL and demonstrate that it can be carried out safely with results comparable to those obtained using standard PCNL.

METHODS

Prospective study with 65 patients who underwent PCNL between 2019 and 2020. all procedures were performed in supine position and an initial attempt to gain access to the kidney using US was made.

RESULTS

Mean procedure duration was 69.5 ± 27.8 min. Fluoroscopy was used with a mean dose of 276.68 ± 560.71 (cGycm3) and mean fluoroscopy time 40.25 ± 77.69 (s). Throughout the study there was a steady decrease in the use of fluoroscopy and amount of radiation to gain access to the kidney to only 25% at the study end. 76.5% of the patients were stone free at follow-up. Complication rate was 9.2%.

CONCLUSIONS

Fluoroless US guided PCNL is safe, feasible and reproducible procedure.

Ureteral stent after PCNL: is leaving the threads through the percutaneous tract safe and better tolerated?

OBJECTIVE

To assess safety, urinary symptoms, and feasibility of JJ stent removal with exteriorized threads through the percutaneous tract after percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

Prospective, transversal, comparative, experimental, randomized 1-to-1 cohort study in 52 patients who underwent "tubeless" PCNL from October 2020 to November 2022. Group A with threads through the urethra and Group B through the percutaneous tract. The validated USSQ (Ureteral Stent Symptom Questionnaire) was applied in the Urology office a week after the procedure, and the JJ stent was withdrawn by pulling the threads. Hemoglobin and urine culture, and pre- and post-surgery were evaluated.

RESULTS

There is a statistically significant difference in favor of group B when comparing urinary symptoms (p = 0.008), body pain (p = 0.009), and general condition (p = 0.042), mainly for non-urgency incontinence, frequency of analgesic use, and dysuria. There were significant differences between groups (p = 0.028, p = 0.026, p = 0.027, respectively). There is no association with urinary infections (p = 0.603) nor an increased risk of bleeding (p = 0.321).

CONCLUSION

The removal of the JJ stent with exteriorized threads through the percutaneous tract after PCNL in the office is a feasible and safe procedure if it is removed before 8 days and has better tolerance regarding the urinary symptoms.

Percutaneous nephrolithotomy guided by 5G-powered robot-assisted teleultrasound diagnosis system: first clinical experience with a novel tele-assistance approach (IDEAL stage 1)

BACKGROUND

To demonstrate the technical feasibility of percutaneous nephrolithotomy (PCNL) guided by 5G-powered robot-assisted teleultrasound diagnosis system (RTDS) in a complex kidney-stone (CKS) cohort and present our preliminary outcomes. PCNL is highly skill-required, which hinders it popularization in primary medical units of remote regions. We designed an innovative tele-assistance approach to make PCNL easy to be operated by inexperienced surgeons.

METHODS

This was a prospective proof-of-concept study (IDEAL phase 1) on intraoperative tele-assistance provided by online urological experts via a 5G-powered RTDS. Total 15 CKS patients accepted this technology. Online experts manipulated a simulated probe to assist unskilled local operators by driving a patient-side robot-probe to guide and monitor the steps of access establishment and finding residual stones.

RESULTS

Median total delay was 177ms despite one-way network-connecting distance > 5,800 km. No perceptible delay of audio-visual communication, driving robot-arm or dynamic ultrasound images was fed back. Successful tele-assistance was obtained in all cases. The first-puncture access-success rate was 78.6% with a one-session SF rate of 71.3% and without complications of grade III-V.

CONCLUSIONS

The current technology based on 5G-powered RTDS can provide high-quality intraoperative tele-assistance, which has preliminarily shown satisfactory outcomes and reliable safety. It will break down a personal competence-based barrier to endow PCNL with more popular utilization.

TRIAL REGISTRATION

The study was approved by ethics committee of the Xinjiang Kezhou People's Hospital and ethics committee of the First Affiliated Hospital of Nanjing Medical University and was registered on http://www.chictr.org.cn (ChiCTR2200065849, 16/11/2022).

Ultrasound-Guided PCNL - Why Are We Still Performing Exclusively Fluoroscopic Access?

PURPOSE OF REVIEW

While urologists are traditionally taught to perform percutaneous nephrolithotomy (PCNL) utilizing exclusively fluoroscopy, ultrasound has emerged as a safe alternative. This article showcases the major reasons why ultrasound-guided access should be considered the first-line approach for performing access for PCNL.

RECENT FINDINGS

There continues to be a need to further reduce radiation exposure in the management of kidney stone patients. This review showcases how performing ultrasound-guided PCNL has been associated with a shorter learning curve, increased patient safety, and the ability to perform x-ray free PCNL. Ultrasound-guided PCNL is not only an achievable skill for urologists to learn but provides multiple advantages over traditional fluoroscopic access. As every effort should be given to help reduce radiation exposure for kidney stone patients as well as performing surgeons and operating theater personnel, endourologists should strive to add this technique to their armamentarium.

Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application

Background

To assess the outcome of the mini-track, mini-nephroscopy, mini ultrasonic probe percutaneous nephrolithotomy for upper ureteral and kidney stones.

Methods

We collected data of 53 patients (55 kidney units) who underwent mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy between September 2020 and March 2021. The study included single and upper ureteral stones from 12 kidneys, multiple stones from 28 kidneys, and staghorn stones from 15 kidneys.

Results

The mean operative duration was 50.6 min, ranging from 15 to 200 min, whereas the mean lithotripsy and stone removal time was 17.2 min (3–45 min). Moreover, the mean postoperative length of stay was 4.0 days (1–7 days). Besides, the stone-free rate (SFR) of discharge was 89.1% (49/55). The mean hemoglobin drop was 15.3 mg/dL, ranging 1–32 mg/dL. Out of the total cases, only 4 of them displayed minor complications. The outcomes of < 40 mm versus ≥ 40 mm calculi were compared by performing subgroup analysis. The results demonstrated a longer operation duration (65.2 vs. 40.2 min), higher complication rate (13.0% vs. 3.3%), and lower SFR in the ≥ 40 mm calculi subgroup.

Conclusions

In summary, mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy is an effective and safe method to treat patients with upper ureteral and kidney calculi. This is especially significant for the stone size of 20–40 mm, demonstrating excellent SFR and a lower complication rate.

Percutaneous nephrolithotomy - the puncture

OBJECTIVE

To determine what importance is given to the puncture and assistive technologies in percutaneous nephrolithotomy (PNL) in the current urological literature.

METHODS

PubMed was searched for English publications and reviews for the keywords: 'percutaneous nephrolithotomy', 'percutaneous nephrostomy', 'puncture'. The search was limited to the last 5 years, January 2016 until February 2021. Based on 183 abstracts, 121 publications were selected, read, and reviewed. References, older or seminal papers were read and cited if they contributed to a better understanding. A total of 198 references form the basis of this narrative review.

RESULTS

The puncture is frequently referred to as the most crucial part of PNL. In contrast, the influence of the puncture on the failure rate of PNL and the specific puncture-related complications seems to be low in the single-digit percentage range. However, there are no universally accepted definitions and standards measuring the quality of puncture. Consequently, the impact of the puncture on general PNL complications, on stone scores predicting success rates and on learning curves evaluating surgeons' performance have not been systematically studied. Assistive technologies rely on fluoroscopy and ultrasonography, the latter of which is becoming the preferred imaging modality for monitoring the entire procedure. Needle bending, a problem relevant to all puncture techniques, is not addressed in the urological literature.

CONCLUSIONS

The importance attached to puncture in PNL in the current urological literature is subjectively high but objectively low. Some basics of puncture are not well understood in urology. Disciplines other than urology are more actively involved in the development of puncture techniques.