Comparison of ultrasound-assisted and pure fluoroscopy-guided extracorporeal shockwave lithotripsy for renal stones

International Alliance of Urolithiasis (IAU) guidelines on the management of pediatric urolithiasis

The aim of this study was to construct the sixth in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis (IAU) that by providing a clinical framework for the management of pediatric patients with urolithiasis based on the best available published literature. All recommendations were summarized following a systematic review and assessment of literature in the PubMed database from January 1952 to December 2023. Each generated recommendation was graded using a modified GRADE methodology. Recommendations are agreed upon by Panel Members following review and discussion of the evidence. Guideline recommendations were developed that addressed the following topics: etiology, risk factors, clinical presentation and symptoms, diagnosis, conservative management, surgical interventions, prevention, and follow-up. Similarities in the treatment of primary stone episodes between children and adults, incorporating conservative management and advancements in technology for less invasive stone removal, are evident. Additionally, preventive strategies aiming to reduce recurrence rates, such as ensuring sufficient fluid intake, establishing well-planned dietary adjustments, and selective use pharmacologic therapies will also result in highly successful outcomes in pediatric stone patients. Depending on the severity of metabolic disorders and also anatomical abnormalities, a careful and close follow-up program should inevitably be planned in each pediatric patient to limit the risk of future recurrence rates.

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.

Shock wave lithotripsy in the era of COVID-19

Objective

The objective of the study y was to evaluate factors which can improve shock wave lithotripsy (SWL) results to keep up with COVID-19 pandemic.

Methods

Between June 2020 and June 2021, patients with radio-opaque or faint radio-opaque upper urinary tract stones, stone attenuation value ≤1200 HU, and stones size <2.5 cm were treated by electrohydraulic SWL. Patients with respiratory tract symptoms elevated temperature, contact with COVID-19 patients, or positive COVID-19 swab 2 weeks preoperatively, skin-to-stone distance >11 cm, and body mass index >30 kg/m2 were excluded from the study. Patients were prospectively enrolled in SWL done at a rate of 40-50 SWs/min under combined ultrasound and fluoroscopy-guided, ramped into high power in the 1st 300 shocks. Success rate and complications were recorded.

Results

Five hundred and ninety patients completed the study. The success rate after 1st session was 408/590 patients (69.15%) which was augmented by 2nd session to reach 527/590 patients 89.3%. The success rate was 96.2% at 3 months postoperatively. Most complications were mild (Grade 1 or 2).

Conclusions

SWL results improved using slow rate high power from the start of the session under combined fluoroscopy and ultrasound guidance. SWL may be a preferred option during a pandemic.

Factors influencing the efficacy of ultrasound-guided extracorporeal shockwave lithotripsy in the treatment of ureteral stones: a retrospective study

The aim of the study was to analyze the factors influencing the efficacy of ultrasound-guided extracorporeal shockwave lithotripsy (ESWL) in the treatment of ureteral stones. The clinical data of 8102 patients (6083 men and 2019 women) who presented with ureteral stones were retrospectively analyzed. All the patients were treated with ultrasound-guided ESWL. The stone-free rate (SFR) was calculated to evaluate the effect of ESWL. The characteristics of the patients and their stones, and the ESWL parameters applied were compared to identify the factors affecting the treatment outcomes. The SFR and that following one ESWL session were 94.6% (7663/8102) and 75.4% (6107/8102), respectively. Multivariate analysis showed that stone location (OR 0.656, p < 0.001), stone size (OR 1.103, p < 0.001), and degree of hydronephrosis (OR 1.952, p < 0.001) independently affected SFR; and age (OR 1.005, p = 0.022), stone location (OR 0.729, p < 0.001), stone size (OR 1.103, p < 0.001), degree of hydronephrosis (OR 1.387, p = 0.001), maximum energy level(OR 0.691, p < 0.001) independently affected SFR following one session. Ultrasound-guided ESWL is effective in all levels of ureteral stones. Large stone size and moderate hydronephrosis are correlated with treatment failure. Ultrasound-guided ESWL may be the first choice for distal ureteral stones.

2022 Recommendations of the AFU Lithiasis Committee: Extracorporeal shock wave lithotripsy (ESWL)

Extracorporeal shock wave lithotripsy (ESWL) is a minimally invasive technique for the fragmentation of urinary tract stones using shock waves under fluoroscopic and/or ultrasound guidance. ESWL results depend on the indication (stone size/composition, clinical context) and also on how it is performed. The stone structure, nature and density (Hounsfield units; evaluated by CT without contrast agent) influence the fragmentation achieved by ESWL. The upper size limit of kidney stones has been lowered to 15mm (1.68cm3) due to the increased risk of steinstrasse with larger sizes and the potential need of anesthesia and ureteral stenting. Conversely, the development of endourological technologies allows a finer stone fragmentation and/or better elimination, thus reducing the risk of steinstrasse and decreasing the potential number of sessions or additional interventions. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations method (CPR) and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

Ultrasound-guided extracorporeal shock wave lithotripsy with minimal x-ray exposure prevented genitourinary tract injury patients with urolithiasis in Taiwan

BACKGROUND

This study investigated the use of ultrasound-guided extracorporeal shock wave lithotripsy (ESWL) to break stones in the genitourinary tract and prevent genitourinary injury. Our goals were to achieve accurate focusing and minimal X-ray exposure for the benefit of the patients.

METHODS

The LiteMed LM-9200 lithotripter with ultrasonography and fluoroscopy was used for two different procedures: autoaimed and autoperiodical. These procedures enabled dual focusing on stone localization and tracking.

RESULTS

Out of 108 patients who underwent autoperiodical procedures, 29 had no gross hematuria. Among the 335 patients who received autoaimed procedures, 194 had no gross hematuria. The average duration of X-ray exposure during autoperiodical and autoaimed procedures was 120 and 50 s, respectively.

CONCLUSION

The ultrasound-guided ESWL with minimal X-ray exposure was found to be useful in treating genitourinary upper-tract urolithiasis in the autoaimed procedure. Patients who underwent the autoaimed procedure experienced less gross hematuria compared to those who underwent the autoperiodical procedure.

International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL.

Which is better, fluoroscopic-guided or ultrasonic-guided shock wave lithotripsy for pediatric renal stones? Prospective randomized comparative study

OBJECTIVES

To compare the efficacy and clinical outcomes of two different stone localization modalities (fluoroscopic or ultrasonic) in SWL treatment of pediatric renal stones.

PATIENTS AND METHODS

This study was conducted in the period between January 2021 and June 2022 and included 100 children aged 2-16 years who presented with radio-opaque renal pelvic stones < 20 mm. The children were divided in two groups: group I, US-guided (50 patients), and group II, FS-guided SWL (50 patients). SWL was applied under general anesthesia. The follow-up of the patients included a visit every two weeks up to three months.

RESULTS

Even though group II's stone-free rate after one month of follow-up was higher than group I's (90% vs. 84%), no statistically significant difference was found between the groups (p = 0.749). While the success rate was higher in group II than in group I (92% vs. 86%), no statistically significant difference was observed between the two groups (p = 0.338). The complication rate was 28% (14 patients) and 12% (6 patients) in Groups I and II, respectively. However, no significant difference was found between the two groups (p = 0.132).

CONCLUSIONS

SWL is a non-invasive and safe method for treating pediatric renal stones. We recommend the use of the ultrasonic focusing modality in SWL of the pediatric age group, which has similar success rates, avoiding radiation and low complication rate instead of the fluoroscopic focusing modality, which uses ionizing radiation during SWL.

Comparison of ultrasonography and fluoroscopy as guides for extracorporeal shock wave lithotripsy in nephrolithiasis patients: a systematic review

BACKGROUND Extracorporeal shock wave lithotripsy (ESWL) is one of the first-line treatment options for patients with renal stones <2 cm. The large variability in ESWL results may be due to the stone visualization methods using ultrasonography (USG), fluoroscopy, or a combination of both. This study aimed to review the efficacy and safety of the stone visualization method on the stone-free rate (SFR) and postprocedural complications in nephrolithiasis patients. METHODS We conducted a systematic review of USG and fluoroscopy on ESWL until July 2022, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We assessed and collected summaries of the screened papers. The main outcomes assessed were the SFR of renal stones and postprocedural complications between imaging modalities. RESULTS A total of 7 studies were assessed, including 6 comparative assessments of USG versus fluoroscopy and 1 comparative assessment of USG and fluoroscopy versus fluoroscopy only. Although all studies showed that USG had a higher SFR than fluoroscopy, only 1 study showed a significant difference (p = 0.008). Additionally, superior results were obtained using a combination of USG and fluoroscopy compared with fluoroscopy only. Most studies agreed that USG was not inferior in post-ESWL complication results. CONCLUSIONS Overall, the use of USG is comparable to fluoroscopy because it does not provide a significant difference in the SFR and complications. In most cases, USG is preferred because of the absence of radiation. The combination of fluoroscopy and USG also provides more promising results than a single modality.

Importance of precise imaging for stone identification during shockwave lithotripsy: a critical evaluation of "OptiVision" as a post-processing radiography imaging modality

To evaluate the efficacy of a unique imaging software "OptiVision" on the confidence of stone identification using X-ray imaging during shockwave lithotripsy. A total of 57 patients with solitary radio-opaque kidney stones sized < 15 mm were included and evaluated with appropriate radiological imaging and laboratory studies before undergoing shockwave lithotripsy (SWL). The size of the stones was measured on KUB and CT images using maximal stone diameters. All patients were evaluated with radiography on the Dornier Delta III immediately before SWL and at the end of the SWL session with fluoroscopy, a snapshot image, and the OptiVision modality (applied over the acquired snapshot image without additional radiation exposure) for precise identification of the stone. All images obtained with these three different imaging modalities (fluoroscopy, snapshot, and OptiVision) were comparatively evaluated for confidence levels in stone identification using a five-point Likert scale (1 = poor diagnostic confidence, 5 = excellent diagnostic confidence). These confidence levels were also used to differentiate between stones and bony structures using these same imaging modalities. Results were evaluated for statistical significance regarding their impact on the precise identification of renal stones. A total of 57 patients with solitary stones were evaluated using flouroscopy, snapshot, and OptiVision images before and after SWL to ascertain the efficacy of these 3 imaging modalities on the precise identification of the calculi. Stone sizes ranged from 4 to 15 mm, with a mean of 8.30 mm in the longest dimension. Evaluation of the findings demonstrated that while the pre- and post-SWL confidence of fluoroscopic stone identification was from 29.51 to 31.15%, the values using snapshot ranged from 31.15 to 39.34%. Pre- and post-SWL confidence of stone identification with OptiVision post-processing imaging was approximately 89%. In the majority of cases (n = 43), the use of OptiVision image processing enabled urologists to identify the stone with a higher level of confidence rating than the use of both fluoroscopy (n = 0) and snapshot (n = 0) image processing tools. While a rating level of 4 or higher was given in 89% of images obtained by OptiVision during the pre- and post-SWL phase, this value was only 37% (4 or more points) using fluoroscopy and Snapshot image processing techniques. For all the radiography image processing tools, the distribution of the Likert score differed significantly among the OptiVision, fluoroscopy, and snapshot imaging modalities (p < 0.001). Precise and reliable identification of stone(s) located in the kidney is essential in delivering shock waves to the desired focal point and achieving higher stone-free rates. Our findings demonstrated that using the specially designed imaging modality OptiVision was significantly helpful in identifying and localizing stones with high-quality images before SWL for effective stone disintegration during this procedure.