Fluoroscopy-free ultrasonography-guided percutaneous nephrolithotomy in pediatric patients: a single-center experience

Radiation exposure of patients during endourological procedures

PURPOSE

Considering the existing gaps in the literature regarding patient radiation dose (RD) and its associated risks, a systematic review of the literature on RD was conducted, focusing on percutaneous nephrolithotomy (PCNL), extracorporeal shock wave lithotripsy (SWL), and ureteroscopy (URS).

METHODS

Two authors conducted a literature search on PubMed, Web of Science, and Google Scholar to identify studies on RD during endourological procedures. Two thousand two hundred sixty-six articles were screened. Sixty-five publications met the inclusion criteria using the PRISMA standards.

RESULTS

RD was generally highest for PCNL, reaching levels up to 33 mSv, 28,700 mGycm2, and 430.8 mGy. This was followed by SWL, with RD reaching up to 7.32 mSv, 13,082 mGycm2, and 142 mGy. URS demonstrated lower RD, reaching up to 6.07 mSv, 8920 mGycm2, and 46.99 mGy. Surgeon experience and case load were inversely associated with RD. Strategies such as optimizing fluoroscopy settings, implementing ultrasound (US), and following the ALARA (As Low As Reasonably Achievable) principle minimized RD.

CONCLUSIONS

This is the first systematic review analyzing RD, which was generally highest during PCNL, followed by SWL and URS. There is no specific RD limit for these procedures. Implementation of strategies such as optimizing fluoroscopy settings, utilizing US, and adhering to the ALARA principle proved effective in reducing RD. However, further research is needed to explore the factors influencing RD, assess their impact on patient outcomes, and establish procedure-specific reference levels for RD.

Evaluation of the safety and efficiency of color Doppler ultrasound-guided percutaneous nephrolithotomy in clinical practice: results from a retrospective study

This study evaluated the clinical value of color Doppler ultrasound-guided percutaneous nephrolithotomy (PCNL) in avoiding bleeding caused by punctured blood vessels. Herein, we retrospectively included patients who underwent color Doppler ultrasound-guided PCNL or PCNL using the conventional channel technique from August 2018 to August 2022. The clinical characteristics of patients during surgery, complications, and hospital stay were recorded and compared. Overall, 228 patients were enrolled, with 126 patients (age, 47.6 ± 13.2 years; men: 57.14%) in the color Doppler ultrasound-guided PCNL group and 102 patients (age, 46.6 ± 12.3 years) in the B-mode ultrasound-guided puncture group. The total operation time (63.5 ± 15.5 vs. 61.3 ± 16.3 min, p = .5236) and stone clearance rate (86.50% vs. 83.33%, p = .7139) were similar between the two groups. However, the puncture time for the color Doppler ultrasound-guided PCNL group was longer than that for the B-mode ultrasound-guided puncture group (5.1 ± 2.3 vs. 2.6 ± 1.6 min, p = .0019). Moreover, the length of postoperative hospital stay in the color Doppler ultrasound-guided PCNL group reduced significantly by ∼1 day compared with that in the B-mode ultrasound-guided puncture group (4.5 ± 1.6 vs. 5.6 ± 2.1 days, p = .0087). The blood transfusion rate (1.58% vs. 4.9%, p = .0399), sedation-related adverse event rate (0.79% vs. 2.9%, p = .0332), perineal hematoma incidence (0% vs. 2.94%, p < .0001), and serum decreased hemoglobin levels (12.2 ± 9.7 vs. 23.5 ± 10.1 g/L, p < .001) after color Doppler ultrasound-guided PCNL were significantly lower than those after B-mode ultrasound-guided puncture. The stone clearance rate was similar between the two groups, with a similar operation time. Moreover, color Doppler ultrasound-guided PCNL shortened the postoperative hospital stay and decreased Hb levels, blood transfusion rate, and perineal hematoma incidence.

Endoscopic dilation using two guidewires: a novel approach for establishing access tract during percutaneous nephrolithotomy under ultrasonographic guidance

OBJECTIVE

To evaluate the efficacy and safety of a novel endoscopic dilation (END) method during percutaneous nephrolithotomy under ultrasonographic guidance.

METHODS

We retrospectively reviewed the clinical records of 138 patients who underwent percutaneous nephrolithotomy from June 2020 to December 2021. The patients were divided into three groups based on the method of nephrostomy tract creation: those who underwent fascial Amplatz serial fascial dilation (AMD) (n = 45), one-shot dilation (OSD) (n = 45), and END (n = 48). For END, a 20-Fr dilator with sheath was accessed over the first guidewire. A second guidewire was inserted into the collecting system via the endoscope. The nephroscope was then accessed to enlarge the renal puncture point using both guidewires. Demographic variables and important intraoperative and postoperative findings were compared among the three groups.

RESULTS

The preoperative characteristics were similar among the three groups. The END group had a significantly shorter access time than both the AMD and OSD groups and significantly less severe hemoglobin loss than the OSD group. There were no significant differences in the other important perioperative findings.

CONCLUSION

Use of this novel END method with two guidewires may be associated with less blood loss and a reduced access time.

Contemporary minimal invasıve surgical management of stones in children

Objective

Pediatric urolithiasis has been more common over the past 20 years, and urologists have unique challenges in managing it surgically because this particular demographic is recognized as one of the high-risk categories for stone recurrence. Given this reality, care focuses on maintaining renal function, achieving total stone-free status, and most importantly avoiding stone recurrences. In this presented article, we aimed to make a comprehensive review of the current minimally invasive treatment of pediatric kidney stone disease.

Methods

We evaluated the results of 74 studies following a comprehensive PubMed search till February 2023. This article was written by making use of current urology guidelines.

Results

Considering the reported occurrence of metabolic issues in up to 50% of cases in addition to the anatomic anomalies (about 30% of cases), the treatment of pediatric urolithiasis necessitates a full metabolic and urological examination on an individual basis. Timely management of metabolic imbalances and obstructive diseases is necessary. In addition to encouraging proper fluid consumption, it is advisable to improve urine volume and consider using medical therapeutics to raise urinary citrate levels. The location, content, and size of the stone(s), the morphology of the collecting system, the presence of urinary tract infection, as well as the presence of any obstruction, should all be taken into consideration while deciding on the best surgical procedure.

Conclusion

All modern endourological methods are now used in the safe and efficient care of pediatric urolithiasis as a consequence of the obvious advancements in instrument technology and expanding expertise derived from adult patients. Other minimally invasive procedures, such as ureterorenoscopy and percutaneous nephrolithotomy, require more expertise and can be successfully applied with careful management for an excellent stone-free rate with minimal morbidity. Of these procedures, shock wave lithotripsy is still the first choice in the majority of cases with upper tract calculi. Open surgery will still be the therapy of choice for pediatric patients with complicated and big stones as well as anatomical anomalies.

Antegrade Percutaneous Retrieval of Upward Migrated Double-J Stent in Very Small Size Pediatric Patients Under Ultrasonic Guide

Purpose: To evaluate the safety of antegrade percutaneous retrieval migrated ureteral stent in very small size pediatric patients with ultramini instruments under ultrasonography guide. Materials and Methods: A total number of 10 out of 115 patients who were referred to our center with upward migrated Double-J (DJ) were candidates for antegrade approach from 2017 to 2020. The pyelocalyceal system was punctured in a prone position by using an 18-gauge disposable needle with Chiba tip and visualization of the upper tract by 3.5 MHz ultrasonic guidance. Then 0.038-inch J tipped guide wire was passed through the needle and the tract was dilated up to 6F under ultrasonographic guide. The 8F access sheath was positioned over the 6F dilator. The semirigid 6F ureteroscope was introduced through the sheath and DJ was removed with a grasper. Results: The mean age was 11.4 ± 5.48 months. The mean time from the previous surgery to DJ removal procedure was 6.4 ± 0.84 weeks. The mean operation time was 11.7 ± 1.76 minutes. All the patients were discharged from the hospital within the 1st day. There were no serious complications (grade 3, 4, or 5) according to Clavien-Dindo classification. Conclusion: The antegrade retrieval of upward migrated DJ with ultramini instrument under ultrasonographic guidance in failed cases of retrograde approach is a safe and effective approach in very small size pediatric patients.

Feasibility, safety, and effectiveness of adult-sized instruments in pediatric percutaneous nephrolithotomy: A systematic review and meta-analysis

INTRODUCTION

Little evidence exists regarding the benefits and disadvantages of adult-sized instruments for Percutaneous Nephrolithotomy (PCNL) in pediatric patients. This systematic review aims to clarify the safety and efficacy of this approach.

MATERIALS AND METHODS

We conducted a systematic literature review using databases of PubMed, Scopus, Embase, Web of Science, and Cochrane and included studies that evaluated PCNL in children. All identified records underwent two-phase title/abstract and full-text screening. Pediatric patients were defined as 17 years or younger, and adult-sized instruments as 24Fr and above. The primary outcomes were success (stone-free) rate and surgical complications obtained from studies comparing adult-sized and pediatric-sized instruments.

RESULTS

A total of 84 abstracts and 16 full text article were assessed till July 2021 and 6 studies were included. All studies were retrospective. Number of accesses (Odds ratio (OR), adult-sized to pediatric-sized: 0.96, 95% CI: 0.52-1.78, p = 0.89), initial stone-free rate (OR: 0.73, 95% CI: 0.42-1.27, p = 0.26), final stone-free rate (OR: 1.14, 95% CI: 0.38-3.44, p = 0.82), and residual stones (OR: 0.79, 95% CI: 0.42-1.49, p = 0.46) could be analyzed, none with significant differences. Overall complication rates did not differ significantly between the groups. However, one study reported more grade III/IV complications in the adult-sized instrument group. The adult-sized instrument group had a higher hemoglobin/hematocrit decrease in 3 studies. Duration of surgery, fluoroscopy time, length of hospital stay, times to nephrostomy tube removal, and transfusion rate could not be assessed in meta-analysis; however, they were comparable between the adult-sized and pediatric-sized groups. Studies also showed that adult-sized instruments are applicable in children younger than 3 years and those with staghorn calculi as well as in fluoroscopy-free ultrasound-guided PCNL.

CONCLUSION

Adult-sized instruments had comparable outcomes to the pediatric-sized ones and can be applied in pediatric PCNL when factors such as accessibility justify their use. The number and design of the studies restrict the reliability of the comparisons. Therefore, future studies with improved methodology may better reveal the impact of instruments on the outcome of PCNL in children.

Minimizing radiation dose in management of stone disease: how to achieve 'ALARA'

PURPOSE OF REVIEW

Exposure to radiation is known to have adverse effects such as secondary malignancies. Patients with nephrolithiasis are exposed to radiation in the workup and treatment of their condition. Furthermore, exposure to radiation is often repeated due to the high recurrence rate of nephrolithiasis.

RECENT FINDINGS

We discuss practices inside and outside of the operating room to strive to keep radiation exposure as low as reasonably achievable (ALARA) for patients being treated for nephrolithiasis. These efforts include reduced dose computed tomography scans, fluoroless surgical techniques and new alternative technologies.

SUMMARY

Maintaining radiation exposure ALARA for our patients is increasingly practical. The urologist must make every effort to adhere to ALARA principles to protect patients from the stochastic effects of radiation.

Techniques - Ultrasound-guided percutaneous nephrolithotomy: How we do it

Ultrasonography has emerged as an alternative to fluoroscopy for image-guided percutaneous nephrolithotomy (PCNL) in many countries. Compared to fluoroscopy-guided PCNL (F-PCNL), ultrasound-guided PCNL (US-PCNL) is easier to learn and reduces radiation exposure to patients and providers. Despite these advantages, uptake of ultrasound-guided PCNL (US-PCNL) in Canada has been almost nonexistent, largely because it is not incorporated into urologists' training. In this article, we seek to familiarize Canadian urologists with this approach by describing our step-by-step technique for US-PCNL. Additionally, we provide keys to successful implementation of this technique.

Amplatz versus Balloon for Tract Dilation in Ultrasonographically Guided Percutaneous Nephrolithotomy: A Randomized Clinical Trial

Purpose

To compare balloon with Amplatz for tract dilation in totally ultrasonographically guided PCNL (UPCN).

Methods

We randomized 66 patients candidate for sonographically guided PCNL in the flank position in two study groups. In the first group, we used single step Amplatz dilation (AG) technique in which the 28- or 30-French Amplatz dilator is used for tract dilation. In the other group, we dilated the tract using balloon dilator (BG). We compared procedure time, success rate of dilation, and postoperative clinical outcomes and cost between two groups.

Results

The rate of short dilation was higher in the Amplatz group (57.6%) compared with Balloon group (36.4%) (P=0.08). When using Amplatz for lower pole access, short dilation occurred in 81% of cases compared with 44% in the BG (P=0.02). Overall operation was longer in the AG (80±21 versus 65±20 minutes P=0.02). Stone free rate was 87.9% in the AG compared with 72.7% in the BG (p=0.12). Mean cost of the surgery was 603±85 USD and 718±78 USD in the AG and BG, respectively (P=0.0001). Hemoglobin drop, transfusion rate, renal function alteration, duration of hospitalization, and complication rate based on Clavien classification were similar in both groups.

Conclusions

AG showed a higher rate of short dilation compared with BG; consequently, overall operating time was significantly longer in the AG whereas BG was significantly more expensive than AG. Bleeding and other complications were similar in two groups. We observed an advantage for balloon dilation over Amplatz when approaching the lower pole calyxes.

Mini-percutaneous nephrolithotomy for pediatric complex renal calculus disease: one-stage or two-stage?

OBJECTIVES

To compare two different treatment strategies, one-stage and two-stage multi-tract mini-percutaneous nephrolithotomy (mt-mPCNL), for pediatric complex renal calculus disease.

METHODS

Between the period of July 2016 and July 2018, a total of 36 children aged 15 years and younger, with complex renal calculi disease, who underwent total ultrasound-guided mt-mPCNL by a single experienced urologist were enrolled in our study. All patients were assigned either to Group 1 (n = 18) who received one-stage mt-mPCNL or Group 2 (n = 18) who received planned two-stage mt-mPCNL.

RESULTS

The demographic data were comparable between the two groups. There were no serious complications (Modified Clavien Grade ≥ III) observed in either group. The stone -free rate (SFR), operation time, postoperative creatinine increase, and perioperative complication rates were similar in both groups (P = 0.603, 0.818, 0.161, and 0.402, respectively). The postoperative hospital stay (5.8 days vs. 7.4 days) and cost (17373.3 CNY vs. 23717.1 CNY) were statistically less in Group 1. Group 2 had significantly less total estimated blood loss (70.6 ml vs. 130.0 ml, P < 0.001). The operation time of two cases in Group 1 with perioperative sepsis or systemic inflammatory response syndrome (SIRS) was more than two hours.

CONCLUSIONS

Our preliminary results indicated that both one-stage and two-stage mt-mPCNL were safe and effective for pediatric complex renal calculi. Two-stage mt-mPCNL could significantly reduce blood loss; while one-stage mt-mPCNL could significantly decrease the length and costs of hospitalization. We also suggest that the planned two-stage mt-mPCNL should be applied in children with estimated operation time more than two hours.

Approaches to Eliminate Radiation Exposure in the Management of Pediatric Urolithiasis

PURPOSE OF REVIEW

Traditional management of pediatric urolithiasis has been associated with a significant amount of radiation exposure. The steady increase in pediatric urolithiasis in recent years has raised concerns of long-term consequences in this special population. This review seeks to highlight the newer insights towards eliminating radiation exposure in pediatric urolithiasis from contemporary literature.

RECENT FINDINGS

Establishing a clinical care pathway restricting usage of computed tomography in emergency rooms in suspected pediatric urolithiasis can eliminate unnecessary radiation exposure. Ultrasound can successfully replace fluoroscopy at ureteroscopy and percutaneous nephrolithotomy. Accredited technicians who use optimized settings combined with dose monitoring can significantly reduce fluoroscopic radiation. Radiation exposure in pediatric urolithiasis can be significantly reduced and potentially eliminated by employing standard protocols during workup, intervention, and follow-ups. Larger studies can support the feasibility of routinely performing ultrasound-guided surgeries instead of fluoroscopy. There is a need for development of consensus towards standardization of the management of pediatric urolithiasis.