Ultrasound versus fluoroscopy as imaging guidance for percutaneous nephrolithotomy: A systematic review and meta-analysis

OBJECTIVES

To determine whether the outcomes of ultrasound-guided percutaneous nephrolithotomy (UG-PCNL), an alternative to traditional fluoroscopy-guided percutaneous nephrolithotomy (FG-PCNL), are comparable.

METHODS

A systematic search of PubMed, Embase, and the Cochrane Library was carried out to discover investigations comparing UG-PCNL to FG-PCNL, and accordingly, a meta-analysis of those studies was performed. The primary outcomes included the stone-free rate (SFR), overall complications based on Clavien-Dindo classification, duration of surgery, duration of patients' hospitalization, and hemoglobin (Hb) drop during the surgery. All statistical analyses and visualizations were implemented utilizing R software.

RESULTS

Nineteen studies, including eight randomized clinical trials (RCTs) and eleven observational cohorts, comprising 3016 patients (1521 UG-PCNL patients) and comparing UG-PCNL with FG-PCNL met the inclusion criteria of the current study. Considering SFR, overall complications, duration of surgery, duration of hospitalization, and Hb drop, our meta-analysis revealed no statistically significant difference between UG-PCNL and FG-PCNL patients, with p-values of 0.29, 0.47, 0.98, 0.28, and 0.42, respectively. Significant differences were discovered between UG-PCNL and FG-PCNL patients in terms of the length of time they were exposed to radiation (p-value< 0.0001). Moreover, FG-PCNL had shorter access time than UG-PCNL (p-value = 0.04).

CONCLUSION

UG-PCNL provides the advantage of requiring less radiation exposure while being just as efficient as FG-PCNL; thus, this study suggests prioritizing the use of UG-PCNL.

Advances in percutaneous renal puncture: a comprehensive review of the literature

PURPOSE OF REVIEW

Percutaneous nephrolithotomy (PCNL) constitutes the gold standard procedure for patients suffering from more than 2 cm renal stones. The puncture is a very critical step of PCNL, affecting manoeuvrability of the nephroscope, possibility to remove stone fragments, risk of bleeding and radiation exposure. The aim of the current review was to discuss the advances in percutaneous renal puncture.

RECENT FINDINGS

Following technological evolution in medicine, there was a consistent development in the puncture techniques, aiming at the improvement of its efficacy and safety. The use of specific agents can improve ultrasonic guidance, making the challenging step of gaining access to the kidney easier for the experienced surgeon and more accessible for the resident urologist. Future developments in the electromagnetic and three-dimensional (3D) technology may establish a high level of accuracy with decreased rates of related complications, even in the hands of beginners.

SUMMARY

The advances in percutaneous puncture can lead to improved safety and accuracy of this procedure decreasing the radiation exposure and the complication rate.

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.

An insight into predominance of pulmonary complications on right side in supracostal percutaneous nephrolithotomy

PURPOSE

To analyse pulmonary complications following supracostal percutaneous nephrolithotomy especially after right sided supracostal punctures, both in initial and relook PCNL.

MATERIAL AND METHODS

From February 2016 till date, 90 patients underwent PCNL in Government Medical College, Jammu through supracostal puncture - 53 on right side and 37 on left side. All supracostal punctures were made about 7-8.5 cm from midline. Tract dilatation was done using metal dilators and calculi were fragmented using pneumatic lithotripsy. Patients with supracostal superior calyceal punctures were evaluated for chest complications intraoperatively by fluoroscopy, X-ray chest on evening of postoperative day 0 and repeated thereafter on third and seventh postoperative days.

RESULTS

Stone configuration included complete staghorn in 16, partial staghorn in 23, multiple stones in 16 and pelvic stone in 35 cases. Age range of patients was 07-76 years. There was 14.4% (13 out of 90) incidence of early or delayed chest complications - 20.8% (11 out of 53) on right side and 5.4% (2 out of 37) on left side.

CONCLUSION

Pulmonary complications in supracostal punctures; especially on right side should not be underestimated. There are always chances of delayed hydrothorax after supracostal puncture. A chest X-ray should be repeated after 1 week in patients with supracostal PCNL punctures.

Comparison of vacuum-assisted sheaths and normal sheaths in minimally invasive percutaneous nephrolithotomy: a systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis was conducted to compare the safety and efficacy of vacuum-assisted sheaths and conventional sheaths in minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of nephrolithiasis.

METHODS

PubMed, Web of Science, Embase, EBSCO, and Cochrane Library databases (updated March 2021) were used to search for studies assessing the effect of vacuum-assisted sheaths in patients who underwent MPCNL. The search strategy and study selection processes were implemented in accordance with the PRISMA statement.

RESULT

Three randomized controlled trials and two case-controlled trials that satisfied the inclusion criteria were enrolled in this meta-analysis. Overall, the stone-free rate (SFR) in patients who underwent vacuum-assisted sheaths was significantly higher than that in patients who underwent conventional sheaths (RR 1.23, 95% CI 1.04, 1.46, P = 0.02), with significant heterogeneity among the studies (I² = 72%, P = 0.03). In terms of the outcome of complications, vacuum-assisted sheath could bring a benefit to the postoperative infection rate (RR 0.48, 95% CI 0.33, 0.70, P < 0.00001) with insignificant heterogeneity among the studies (I² = 0%, P = 0.68). There was no significant difference in the blood transfusion rate (RR 0.35, 95% CI 0.07, 1.73, P = 0.17), with significant heterogeneity (I² = 66%, P = 0.35). Three studies contained operative time data, and the results indicated that the vacuum-assisted sheath led to a shorter operative time (MD = - 15.74; 95% CI - 1944, - 12.04, P < 0.00001) with insignificant heterogeneity (I² = 0%, P = 0.91).

CONCLUSION

The application of a vacuum-assisted sheath in MPCNL improves the safety and efficiency compared to the conventional sheath. A vacuum-assisted sheath significantly increases the SFR while reducing operative time and postoperative infection.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Percutaneous Nephrolithotomy

CONTEXT

Although percutaneous nephrolithotomy (PCNL) has been performed for decades and has gone through many refinements, there are still concerns regarding its more widespread utilization because of the long learning curve and the potential risk of severe complications. Many technical details are not included in the guidelines because of their nature and research protocol.

OBJECTIVE

To achieve an expert consensus viewpoint on PCNL indications, preoperative patient preparation, surgical strategy, management and prevention of severe complications, postoperative management, and follow-up.

EVIDENCE ACQUISITION

An international panel of experts from the Urolithiasis Section of the European Association of Urology, International Alliance of Urolithiasis, and other urology associations was enrolled, and a prospectively conducted study, incorporating literature review, discussion on research gaps (RGs), and questionnaires and following data analysis, was performed to reach a consensus on PCNL.

EVIDENCE SYNTHESIS

The expert panel consisted of 36 specialists in PCNL from 20 countries all around the world. A consensus on PCNL was developed. The expert panel was not as large as expected, and the discussion on RGs did not bring in more supportive evidence in the present consensus.

CONCLUSIONS

Adequate preoperative preparation, especially elimination of urinary tract infection prior to PCNL, accurate puncture with guidance of fluoroscopy and/or ultrasonography or a combination, keeping a low intrarenal pressure, and shortening of operation time during PCNL are important technical requirements to ensure safety and efficiency in PCNL.

PATIENT SUMMARY

Percutaneous nephrolithotomy (PCNL) has been a well-established procedure for the management of upper urinary tract stones. However, according to an expert panel consensus, core technical aspects, as well as the urologist's experience, are critical to the safety and effectiveness of PCNL.

The impact of anterior calyceal stones on the outcomes of percutaneous nephrolithotomy for complex kidney stones: a comparative study

BACKGROUND

This study aimed to evaluate the possible effect of anterior calyceal stones on the surgical outcomes of percutaneous nephrolithotomy.

METHODS

Consecutive patients with complex kidney stones from 2012 to 2020 were evaluated retrospectively. In total, 219 patients were divided into 2 groups based on the presence of anterior calyceal stones (group 1; N.=89) or not (group 2; N.=130). The groups were compared in terms of surgical outcomes (i.e., stone-free rate [SFR], operation time, and hemoglobin drop) and complications.

RESULTS

The patient demographics and stone characteristics were similar between the groups. Multiple access was more frequently done in group 1 than it was in group 2 (47.2% vs. 30.8%; P=0.014), and the SFR was lower in group 1 (51.7%) than it was in group 2 (67.7%; P=0.017). Of the anterior calyceal stones in group 1, 42.6% could not be cleaned. However, when excluding patients who have only anterior residual stones from the statistical analysis, the groups had similar SFRs (68.5% vs. 67.7% for group 1 and group 2, respectively).

CONCLUSIONS

The presence of complex kidney stones with anterior calyceal extension are associated with higher residual stones rates in the anterior calyx. Also, it increases multiple access, the operation time, and level of hemoglobin drop.