Tract dilation monitored by ultrasound in percutaneous nephrolithotomy: feasible and safe

Evaluating the learning curve of total ultrasound guided percutaneous nephrolithotomy in complex renal stones using"30-degree triangulation"technique

PURPOSE

To investigate the learning curve of in the training of total ultrasound(US) guided percutaneous nephrolithotomy(PCNL) in complex renal stones using "30-degree principle" technique.

PATIENTS AND METHODS

A total of 80 patients were included in this study to evaluate the learning curve of US guided PCNL in an inexperienced novice. They were divided into 8 groups based on timing of the surgery to evaluate the outcomes within the groups. The operator has mastered the"30-degree triangulation" technique for US-guided percutaneous renal puncture by education and theoretical study. Two important parameters were reviewed, namely US screening time and puncture time. Other peri-operative data were also recorded.

RESULTS

The mean US screening time was 509.3 s for the first 10 cases. It decreased significantly to an average of 226.3 s through 30 to 40. Although the US screening time gradually shortened with accumulated experience and stabilized at an average of 152.5 s through 70-80 cases, there was no significant difference between the following groups. Puncture time declined from 558.8 s in the first group to a mean of 202.3 s in the patients 30 to 40. Consistent with the trend in US screening time, although puncture time continued to decrease, there was no significant difference between them in subsequent patient groups. There were no significant differences in the hemoglobin drop, stone-free rate(SFR), post-hospitalization, or severe complication rate between each groups.

CONCLUSIONS

The acceptable outcome of PCNL guided by total ultrasound in complex stones could be achieved after 40 cases under the premise of mastering the "30-degree triangulation"technique. The US screening time and puncture time dropped to a relative steady level after 40 times of practice.

Ultrasound-guided renal puncture followed by endoscopically guided tract dilatation vs standard fluoroscopy-guided percutaneous nephrolithotomy for non-opaque renal stones; a randomized clinical trial

This study was designed to evaluate the non-inferiority of ultrasound puncture followed by endoscopically guided tract dilatation compared to the standard fluoroscopy-guided PCNL. Forty patients with non-opaque kidney stones eligible for PCNL were randomly divided into two groups. The standard fluoroscopy-guided PCNL using the Amplatz dilator was performed in the XRAY group. In the SONO group, the Kidney was punctured under an ultrasound guide followed by tract dilatation using a combination of the Amplatz dilator based on the tract length and an endoscopically guided tract dilatation using a bi-prong forceps in cases of short-advancement. The primary outcome was successful access. In 90% of cases in the XRAY and 95% in the SONO group access dilatation process was performed uneventfully at the first attempt (p = 0.5). In 45% of cases in the SONO group, bi-prong forceps were used as salvage for short-advancement. In one case in the X-ray group over-advancement occurred. One month after surgery, the stone-free rate on the CT-scan was 75% for the X-ray group and 85% for the SONO group (p = 0.4). There were no significant differences in operation time, hospitalization duration, transfusion, or complication rates between the two groups. We conclude that ultrasound-guided renal puncture, followed by endoscopically guided tract dilatation can achieve a high success rate similar to X-ray-guided PCNL while avoiding the harmful effects of radiation exposure and the risk of over-advancement.

Comparison of Contrast-Enhanced Ultrasound vs Conventional Ultrasound-Guided Percutaneous Nephrolithotomy in Nondilated Collecting System: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: It has been demonstrated that ultrasound (US)-guided renal collecting system access during percutaneous nephrolithotomy (PCNL) is efficient and secure. The puncture success rate fell to 82%, and the total complication rate rose to 15% in kidneys with nondilated collecting systems. Contrast-enhanced ultrasonography (CEUS) has been used in PCNL techniques to address this issue. Methods: We did this meta-analysis following the preferred reporting criteria for systematic reviews and meta-analysis to combine the data of published studies to compare the CEUS-guided PCNL and the standard US-guided PCNL (PRISMA). For relevant literature, we searched PubMed, Embase, Web of Science, CKNI, and the Cochrane Library. The final inclusion date for this meta-analysis was May 1, 2022, and three randomized controlled trials (RCTs) were finally included. RevMan V5.4.1 was used in this work. Standard mean difference (SMD) with a 95% confidence interval (CI) was utilized as the major estimate in the synthesis of continuous data, while odds ratio (OR) with a 95% CI was synthesized as the main estimate in the synthesis of discontinuous data. Results: We found that compared with traditional US-guided PCNL, CEUS-guided PCNL could offer more benefits in terms of single-needle success rate (OR: 3.02, 95% CI: 1.62 to 5.61, p = 0.0005), shorter puncture time (SMD: -1.33, 95% CI: -2.06 to -0.60, p = 0.0004), shorter hospital stays (SMD: -0.37, 95% CI: -0.60 to -0.13, p = 0.002), and a better stone clearance rate (OR: 2.32, 95% CI: 1.15 to 4.68. p = 0.02). Although the PCNL complication rate after surgery was not significantly reduced by the CEUS technique (overall complication: OR = 0.70, 95% CI: 0.37 to 1.30, p = 0.25. Grade 1/2 complication: OR = 0.79, 95% CI: 0.41 to 1.53, p = 0.48; Grade 3/4 complication: OR = 0.44, 95% CI: 0.10 to 1.98, p = 0.28), it could reduce hemoglobin dropping compared with conventional US-guided PCNL (SMD: -0.82, 95% CI: -1.06 to -0.58, p < 0.001). Conclusion: The CEUS-guided PCNL technique is superior to the US-guided PCNL, according to almost all synthesized data. Additional randomized studies are still required.

Radiation protection measures during endourological therapies

Objective

The objective of this narrative review was to search the existing literature for studies reporting measures to minimize radiation use during endoscopic management of stone disease and present ways of reducing the exposure of both patients and operating room staff.

Methods

A literature review in PubMed was performed to identify studies describing protocols or measures to reduce radiation received during endourological procedures from January 1970 to August 2022. Eligible studies were those that reported outcomes for ureteroscopy or percutaneous nephrolithotripsy regarding measures to minimize radiation doses used intraoperatively, performed either in real-life theatres or using phantoms. Both comparative and non-comparative studies were deemed eligible.

Results

Protection can be achieved initially at the level of diagnosis and follow-up of patients, which should be done following an algorithm and choice of more conservative imaging methods. Certain protocols, which follow principles for minimized fluoroscopy use should be implemented and urologists as well as operating room staff should be continuously trained regarding radiation damage and protection measures. Wearing protective lead equipment remains a cornerstone for personnel protection, while configuration of the operating room and adjusting X-ray machine settings can also significantly reduce radiation energy.

Conclusion

There are specific measures, which can be implemented to reduce radiation exposure. These include avoiding excessive use of computed tomography scans and X-rays during diagnosis and follow-up of urolithiasis patients. Intraoperative protocols with minimal fluoroscopy use can be employed. Staff training regarding dangers of radiation plays also a major role. Use and maintenance of protective equipment and setting up the operating room properly also serve towards this goal. Machine settings can be customized appropriately and finally continuously monitoring of exposure with dosimeters can be adopted.

Totally X-ray-Free Ultrasound-Guided Mini-Percutaneous Nephrolithotomy in Galdakao-Modified Supine Valdivia Position: A Novel Combined Surgery

We introduced a novel surgery that combines ultrasound guidance, miniaturization and Galdakao-modified supine Valdivia (GMSV) position in percutaneous nephrolithotomy (PCNL) and evaluated the safety and efficacy. This retrospective, single-center study retrospectively reviewed 150 patients who underwent ultrasound-guided mini-PCNL in the GMSV position from November 2019 to March 2022. All perioperative parameters were collected. Stone-free status was defined as no residual stones or clinically insignificant residual fragments (CIRF) <0.4 cm on postoperative day one. Among the 150 patients, the mean age was 56.96 years. The mean stone size was 3.19 cm (427 mm2). The mean S.T.O.N.E. score was 7.61, including 36 patients (24%) with scores ≥9. The mean operative time was 66.22 min, and the success rate of renal access creation in the first attempt was 88.7%. One hundred and forty (93.3%) patients were stone free. The mean decrease in Hemoglobin was 1.04 g/dL, and no patient needed a blood transfusion. Complications included transient hematuria (n = 13, 8.7%), bladder blood clot retention (n = 2, 1.3%), fever (n = 15, 10%) and sepsis (n = 2, 1.3%). Totally X-ray-free ultrasound-guided mini-PCNL in the GMSV position is feasible, safe and effective for patients with upper urinary tract stones, indicating the synergistic and complementary effects of the three novel techniques.

Ultrasound-guided renal access and balloon dilation for PCNL in the prone position: results of a multicenter prospective observational study

PURPOSE

To investigate the safety and efficacy of ultrasound-guided renal access and tract dilation using balloon dilators, as well as to identify suitable patients for this technique.

METHODS

Consecutive patients undergoing ultrasound-guided PCNL using balloon dilators between December 2019 and June 2020 in seven large medical centers from China were prospectively enrolled. Demographic and perioperative parameters of the patients were collected. Logistic regression analysis was used to analyze factors that would affect the success rate of tract establishment using ultrasound-guided renal access and balloon dilation.

RESULTS

A total of 170 patients were included in this study, among whom, 91.18% of the (155/170) patients had a successful tract establishment under ultrasound guidance on the first attempt. The stone-free rate was 83.5% and postoperative complications occurred in 14 patients (8.23%). In univariate analysis, history of ipsilateral surgery (p = 0.026), and stone diameter (p = 0.01) were significantly associated with tract establishment failure, while a larger width of the target calyx (p = 0.016) and the presence of hydronephrosis (p = 0.001) were significantly associated with a successful tract establishment. In multivariate analysis, only hydronephrosis in target calyx (p = 0.027) was a favorable factor for successful tract establishment, and the history of ipsilateral renal surgery (p = 0.012) was the only independent risk factor for failure of tract establishment.

CONCLUSION

It was safe and effective to establish percutaneous renal access with balloon dilation under whole-process ultrasound monitoring during PCNL. Furthermore, patients with a hydronephrotic target calyx and without history of ipsilateral renal surgery were most suited to this technique. Trial registration CHiCTR1800014448.

Recent advances in percutaneous lithotripsy techniques

PURPOSE OF REVIEW

To describe and critically discuss the most recent evidence regarding the percutaneous nephrolithotomy (PCNL) techniques.

RECENT FINDINGS

Three-dimensional printing and virtual reality are promising tools to improve surgeon experience and operative performance. Totally ultrasound-guided PCNL is feasible and can reduce the radiological risk. Growing evidence highlights the safety and advantages of the use of miniaturized instrumentations, although some related limitations place the mini PCNL (mPCNL) in direct challenge with the retrograde intrarenal surgery. LithoClast Trilogy and ClearPetra system can improve the stone clearance. Thulium laser is a new source of energy with growing expectations and promising in-vitro results.

SUMMARY

Significant advances have recently been recorded in PCNL techniques. Thulium fiber laser, LithoClast Trilogy, new suction devices, and the development of novel technologies for teaching and planning procedures may overcome mPCNL drawbacks. Further studies are needed to confirm the promising preliminary results available on the topic.

Study on Clinical Application of Different Ultrasound-Guided Planar Techniques in Minimally Invasive Percutaneous Nephrolithotomy

Objective. The objective is to explore the clinical application value of ultrasound long- and short-axis planar technology in real-time guided puncture in minimally invasive percutaneous nephrology. Methods. The clinical data of 80 patients undergoing real-time ultrasound-guided minimally invasive percutaneous nephrolithotomy from September 2018 to October 2019 were analyzed. The patients were randomly divided into 2 groups with different ultrasound-guided puncture techniques, long-axis in-plane technique and short-axis out-of-plane technique. Results. Minimally invasive percutaneous nephrolithotomies under real-time ultrasound guidance were successfully completed in both groups of patients. The success rate of the first puncture in the short-axis out-of-plane group was significantly higher than that in the long-axis in-plane group, and the differences were statistically significant (P <.05); the total puncture time in the short-axis out-of-plane group was significantly less than the long-axis in-plane group, and the differences were statistical significance (P <.05); there was no significant difference in the single-stage stone removal rate, total percutaneous renal channels, total hospital stay, and rate of complications by the Clavien classification between the 2 groups (P > .05). Conclusion. Ultrasound long-axis and short-axis planar technologies can achieve good clinical application results in real-time guided puncture to establish percutaneous renal channels during minimally invasive percutaneous nephrolithotomy. Compared with the long-axis in-plane technique, the short-axis out-of-plane technique can shorten the puncture time and improve the success rate of the first puncture.

The retrospective study of perioperative application of dexamethasone and furosemide for postoperative anti-inflammation in patients undergoing percutaneous nephrolithotomy

Objectives

To investigate whether the perioperatively combined application of dexamethasone and furosemide could alleviate the inflammation in patients undergoing percutaneous nephrolithotomy (PCNL).

Patients and methods

147 patients undergoing PCNL between November 2018 and October 2019 were enrolled in the study. 77 patients accepted a single dose of dexamethasone and furosemide administration (EXP group, n = 77), and 70 patients did not (CON group, n = 70). Demographic and perioperative data, inflammatory markers including interleukin-6 (IL-6) and procalcitonin (PCT), and clinical outcomes were compared between the two groups.

Results

Compared with the CON group, the incidence rate of urosepsis of the EXP group were significantly lower (11.69% vs. 24.29%, p = 0.046). 3 patients developed severe urosepsis in the EXP group, while 5 patients developed severe urosepsis in the CON group. Compared with those in the CON group, the patients with postoperative urosepsis in the EXP group showed lower serum levels of IL-6 at postoperative hour two (p = 0.045) and at postoperative day one (p = 0.031) and lower serum levels of PCT at postoperative day one (p = 0.015). There was a better clinical outcome of a shorter postoperative hospital stay (p = 0.015) in patients with postoperative urosepsis in the EXP group than in those in the CON group.

Conclusion

The perioperatively combined application of dexamethasone and furosemide was beneficial for alleviating postoperative inflammatory reaction and caused a better clinical outcome of a shorter postoperative hospital stay.

Balloon versus Amplatz for tract dilation in fluoroscopically guided percutaneous nephrolithotomy: a systematic review and meta-analysis

OBJECTIVE

To compare the safety and efficacy of balloon and Amplatz for tract dilation in fluoroscopically guided percutaneous nephrolithotomy (PCNL).

METHOD

EMBASE, PUBMED, MEDLINE and the Cochrane Central Register of Controlled Trials were searched for pertinent studies up until 30 October 2019. Pooled effects were calculated as ORs with 95% CIs or mean differences (MD) with 95% CIs. Endpoints included postoperative decrease in haemoglobin, transfusion rate, complication rate, successful dilation rate, stone-free rate, fluoroscopy time, access time, total operation time and length of postoperative hospitalisation (LPH). Bonferroni's correction was intercalated to reduce the likelihood of making a meta-analytical false positive.

RESULTS

One randomised controlled trial and five controlled clinical trials were included, which involved 1317 patients in total. We found a lower drop in postoperative haemoglobin for patients receiving balloon dilation compared with those in the Amplatz group (MD=-0.21, 95% CI -0.33 to 0.09, p=0.0005; Bonferroni correction a=0.005). Access time in the balloon group was also, on average, 2.61 min shorter than the Amplatz group (MD=-2.61, 95% CI -4.20 to 1.01, p=0.001; Bonferroni correction a=0.005). No significant differences were identified between the two dilation methods in terms of transfusion rate, complication rate, successful dilation rate, stone-free rate, fluoroscopy time, total operation time and LPH.

CONCLUSION

Balloon dilation is a safe and effective tract dilation technique for access creation during fluoroscopically guided PCNL. Both of methods have similar success rates although balloon dilation is associated with significantly less postoperative haemoglobin decline and shorter access time. Therefore, balloon dilation appears to be the superior tract dilation technique, but further confirmatory research is required to confirm these findings.