Ultrasound Use in Urinary Stones: Adapting Old Technology for a Modern-Day Disease

Renal and Genitourinary Ultrasound Evaluation in Emergency and Critical Care: An Overview

Renal and genitourinary ultrasound are fundamental resources employed by emergency and critical care healthcare providers to make prompt diagnoses and perform ultrasound-guided procedures. At the bedside, ultrasound can aid in the diagnosis of relevant pathologies, such as post-renal obstruction or kidney stones, and life-threatening conditions such as aortic dissection or hemoperitoneum. A narrative overview was performed, providing an updated review of renal and genitourinary ultrasound for emergency and critical care healthcare providers, emphasizing its advantages and the latest advances in the field. A thorough summary that can be utilized as a guide for emergency and critical care healthcare providers is presented. The daily hemodynamic management of critically ill patients involves the implementation of new protocols, such as VexUS or the evaluation of the renal resistance index. The role of ultrasound in managing acute nephropathy and genitourinary issues is increasingly crucial given its bedside availability, thus this imaging modality not only facilitates the initiation of therapeutic interventions but also provides swift prognostic insights that are vital to provide tailored patient care. As further advances in ultrasound will arise, it is important for healthcare providers to foster the use of these technologies capable of improving patient outcomes.

Urolithiasis diagnosed with endovaginal ultrasound after vaginal prolapse repair surgery using mesh: A case report

Pain after vaginal prolapse repair surgery with mesh is generally attributed to the mesh fixation, particularly to mesh erosion, dislocation or the development of hematoma. However, once all the causes have been excluded, the urinary system, bladder and ureters should be accurately examined by means of endovaginal ultrasound. This report concerns the case of a 72-year-old woman who had undergone mesh-supported prolapse surgery 3 months prior, with no other relevant diseases, who visited the emergency department complaining of dull, right-sided colic pain. The endovaginal ultrasound examination revealed a prevesical ureteral calculus on the right side with consequent dilatation of the proximal ureter. Computed tomography of the abdomen and pelvis confirmed the calculus in the distal right ureter and revealed a right renal lower pole calculus. The patient underwent treatment via an operative ureterorenoscopy with removal of stones and placement of a double-J-stent. Two months later, a second ureterorenoscopy was performed with double-J-stent removal and concomitant stone extraction. It appears that no similar cases have been reported in the literature. This is why, during the urogynecological postoperative follow-up, it is of paramount importance to examine the entire urogenital system with endovaginal ultrasound. This case report highlights how, through a simple, non-invasive, radiation-free examination, like ultrasound, most of the post-operative complications of vaginal prolapse repair surgery using mesh, including urolithiasis, can be excluded.

Needle Aligned Ultrasound Image-Guided Access Through Dual-Segment Array

Ultrasound (US) guided access for percutaneous nephrolithotomy (PCNL) is gaining popularity in the urology community as it reduces radiation risk. The most popular technique involves manual image-needle alignment. A misaligned needle however needs to be retracted and reinserted, resulting in a lengthened operation time and complications such as bleeding. These limitations can be mitigated through the co-registration between the US array and needle. The through-hole array concept provides the primary solution, including a hole at the center of the array. Because of the central opening, the image-needle alignment is achieved inherently. Previous literature has described applications that are limited to superficial and intravascular procedures, suggesting that developing a through-hole array for deeper target applications would be a new breakthrough.

OBJECTIVE

Here, we present a dual-segment array with a central opening. As the prototype development, two segments of 32-element arrays are combined with an open space of 10 mm in length in between them.

METHOD

We conducted phantom and ex-vivo studies considering the target depth of the 80-100 mm range. The image quality and needle visibility are evaluated by comparing the signal-to-noise ratio (SNR), full width at half maximum (FWHM), and contrast-to-noise ratio (CNR) results measured with a no-hole linear array under equivalent conditions. An ex-vivo study is performed using porcine kidneys with ceramic balls embedded to evaluate the needle access accuracy.

RESULTS AND CONCLUSION

The mean needle access error of 20 trials is found to be 2.94 ±1.09 mm, suggesting its potential impact on realizing a simple and intuitive deep US image-guided access.

Diagnostic value ultrasound signs of stones less than or equal to 10 mm and clinico-radiological variants of ureteric colic

Objective

To determine the diagnostic value of ultrasound signs of urinary stones less than or equal to 10 mm and to determine clinico-radiological variants of ureteric colic.

Methods

A total of 455 ultrasound investigations were performed in patients referring to emergency department with urolithiasis and symptoms suspected of ureteric colic between January 2021 and May 2021. In addition to microscopic evaluation of urine sediment to detect different crystals and non-contrast spiral computed tomography to detect stones, B-mode and color Doppler sonography was performed to assess the presence of acoustic shadow (AS) and twinkle artifacts (TA) as possible signs of stone(s) in ureter.

Results

While the sensitivity and specificity of AS and TA were higher than 90% in patients with stones greater than 5 mm; positive prognostic values of these parameters were found to be extremely low for stones with sizes of 1-3 mm with specificity and sensitivity values not exceeding 53%. The sensitivity and specificity of AS and TA in the upper and lower ureters were higher for stones greater than or equal to 5 than for compared to those less than 5 mm. At the same time, the diagnostic values of TA and AS for middle ureter stones were very limited. The most prevalent clinico-radiological variants of ureteric colic were types I, III, and V being observed in 39%, 28% and 21% cases, respectively.

Conclusion

Our results demonstrate that TA and AS parameters seem to have a very low sensitivity and specificity in the diagnosis of urinary stones less than 5 mm. The diagnostic value of TA and AS increase significantly in stones greater than or equal to 5 mm. Therefore, clinicians need to be very careful for overestimating the diagnostic values of TA and AS for stones less than 5 mm and non-contrast spiral computed tomography must be the method of choice for patients presenting to emergency department with ureteric colic.

The Role of Radiological Imaging in the Diagnosis and Treatment of Urolithiasis: A Narrative Review

The incidence and prevalence of urolithiasis have been increasing worldwide for the last several decades. This increase could be attributed to many factors, including missed cases of small stones, a sedentary lifestyle, a high BMI, a lack of physical activity, and poor dietary intake. In addition, the increased incidence of co-morbidities such as diabetes, dyslipidemia, infections, and multiple urinary tract surgeries could contribute significantly to the formation of urolithiasis. Radiology has a major role in diagnosing a variety of these stone types and can be used in planning management approaches, either as guidance or as a direct therapeutic method for stones. Because of the availability, safety, cost, and effectiveness of radiological imaging nowadays, urolithiasis is rarely missed; furthermore, the availability of radiological treatment options decreases the need for surgical intervention for urolithiasis, which minimizes hospital stay and surgical-related complications. This review aims to scope and analyze the role of radiological imaging modalities in reaching a diagnosis and planning treatment options for urolithiasis in different circumstances. Information was gathered from relevant peer-reviewed publications in PubMed and thereafter refined and summarized to provide a comprehensive review. The selected indexing terms included "radiological imaging modality," "treatment of urolithiasis," and "diagnosis of urolithiasis," among others.

Percutaneous nephrolithotomy in horseshoe kidney: comparing ultrasound-guided access in flank position with conventional fluoroscopic-guided in prone position

We conducted this study to compare radiation-free US-guided percutaneous nephrolithotomy (PNL) in the flank position with conventional PNL in the prone position for the treatment of renal stones in patients with horseshoe kidneys. In a retrospective study, 14 HSK patients that were treated with conventional fluoroscopy-guided PNL in the prone position (group A) were compared with twenty-four HSK patients that were treated US-guided PNL in the flank position (group B). Data on baseline characteristics, percentage of successful entries, stone-free rate, duration of admission and complication rate were obtained from data registry. The average duration of the operation was 57.6 min in group B, which was statistically less than group A with 65.9 min (P = 0.001). Access time varied from 10 to 32.4 min (mean = 17.1 min) in group A and 5-29.5 min (mean = 10.9 min) in group B (P < 0.001). Access length had a significant relation to the surgery method so PNL with US-guided had less access length (P = 0.002). There was no significant relationship between the surgery guide and the residual stone rate (P = 0.6). Hemoglobin decrease (P = 0.5), hospitalization duration (P = 0.5) and need for blood transfusion (P value = 0.6) were not statistically different between the two groups. PNL with US guidance in flank position is a safe and effective technique in HSK patients and is associated with fewer complications than the traditional approach as well as reduced operating time, radiation exposure, and its complications.

Ultrasound versus fluoroscopy-guided ureteroscopy for distal ureteric stones in adults

Objective

To evaluate the safety and efficacy of ultrasound (US) as alternative to fluoroscopy for guidance of ureteroscopy (URS) during treatment of distal ureteric stones in adults.

Materials and methods

This study enrolled 80 patients older than 18 years presented with a single distal ureteric radio-opaque stone of ≤15 mm in longest diameter. Patients were randomized and allocated into two groups: the fluoroscopy group and the ultrasound group (n = 40 patients in each group). Patients with bilateral ureteric stones, solitary kidney, ureteric congenital anomalies, history of failed ureteroscopy, history of ureteric surgery, patients with uremia and pregnant women were excluded. Patients’ demographics, stone characteristics, operative data, stone-free status, hospital stay and complications were evaluated in both groups.

Results

No statistically significant difference between both groups was found regarding patients’ demographics and stone characteristics. Also there was no statistically significant difference in comparing fluoroscopy group versus ultrasound group regarding operative time (29.48 ± 15.3 versus 31.28 ± 18.24 min; P = 0.83), stone-free rate (97.5% versus 95%; P = 1.0), overall complications (15% versus 12.5%; P = 0.75), or hospital stay (1.17 ± 0.6 versus 1.02 ± 0.16 days; P = 0.12). Four patients (10%) in the ultrasound group required the addition of fluoroscopy beside ultrasound.

Conclusion

Ultrasound is effective in guidance during ureteroscopy for distal ureteric stones. It was comparable to fluoroscopy in terms of stone free rate, operative time, overall complications, and hospital stay. However, fluoroscopy must be available to be used when needed.

Mapping theme trends and recognizing research hot spots in the use of ultrasound in orthopaedics: a bibliometric analysis of global research

BACKGROUND

In the past decade, ultrasound has been increasingly used in the field of orthopaedics. The purpose of this study is to inspire future research in this field by analyzing the publications relating to ultrasound research in orthopaedics.

METHODS

All relevant articles published between 2009 and 2020 were retrieved from Web of Science. Statistical Package for Social Science and GraphPad Prism 8 software were used to generate and analyse diagrams. VOSviewer software and CiteSpace were employed to visualize the research trends based on co-occurring keywords. Finally, we obtained information about relevant clinical randomized controlled trials (http://clinicaltrials.gov.com/).

RESULTS

The United States had the most publications in this field and the most citations and the highest H-index. Furthermore, Skeletal Radiology published the most papers related to the use of ultrasound in orthopaedics, Ozcakar L published the most papers, and a study by Kwon, YM had the highest citation frequency. The keywords "MRI", "complication", "female" and "male" were identified as being indicative of emerging topics.

CONCLUSIONS

While the contribution of United States to publications in this field has been substantial, the future contributions of China cannot be ignored. Moreover, it is hypothesized that diagnostic and epidemiological aspects may become hotspots.

Current Trends in Percutaneous Nephrolithotomy in China: A Spot Survey

OBJECTIVE

To describe trends in the procedure of percutaneous nephrolithotomy (PCNL) in China to identify training needs.

METHODS

A spot survey with 36 questions, which revealed demographic data, patterns of PCNL practice, and opinions regarding specific clinical cases, was administered to Chinese urologists during the 17th National Urological Urolithiasis Symposium held in Dandong in 2018.

RESULTS

Out of 400 participants, 221 responses to the survey were received. PCNL was performed by 80.5% of the participants, and 70.2% of them were senior clinicians. It was found that 91% used the prone decubitus in training programs and 27.6% the modified supine, and 46.6% were apprenticeship trained for PCNL, while 5.6% trained during their residency. The prone position was the preferred decubitus, even for obese patients. All of the urologists established their own access, 93.7% used ultrasonography guidance alone, 70.7% used ultrasonic and/or pneumatic lithotripters, and 29.2% used laser. When exiting the kidney, 73.8% placed a nephrostomy tube whereas 26.2% used the tubeless technique. For postoperative follow-up, 51.3% used computed tomography (CT) or ultrasonography plus kidney-ureter-bladder (KUB) to monitor the results of procedures, while 45% used KUB alone. Colonic injury was reported by 8.9%. Average hospital stays of >3 days were reported for 81.2% of procedures.

CONCLUSION

Chinese urologists obtain their own access during PCNL, with ultrasonic guidance in most cases, and almost a half of them are apprenticeship trained. They prefer the prone position, use fascial dilators, and place a nephrostomy tube when exiting the kidney. Most urologists follow the official management guidelines in special cases. Skilled use of urological ultrasound examination, flexible nephroscopy, postoperative CT, tubeless procedures in selected patients, and urology residency training are recommended for PCNL practice.

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.

Live Renal Ultrasonography Facilitates Double-J Ureteral Stent Insertion at the Bedside: A Pilot Study for the COVID-19 Era

Objectives: To investigate the feasibility and efficacy of live renal ultrasonography to guide Double-J ureteral stent placement at the bedside. Patients and Methods: Between April 12 and June 5, 2020, patients presenting with acute ureteral obstruction requiring decompression were prospectively selected for ultrasound-guided bedside ureteral stent placement. During stent placement, upper tract access confirmed using ultrasound with or without retrograde injection of ultrasound contrast before Double-J stent insertion. A postprocedural abdominal X-ray was obtained for stent position confirmation. Results: Eight patients (four men and four women) were offered bedside ultrasound-guided ureteral stent placement, and all eight consented to proceed. Stents were placed in seven of eight patients. One patient had an impacted ureterovesical junction stone and stricture requiring ureteroscopy and laser lithotripsy in the operating room. All patients tolerated procedures without immediate complications. Conclusion: Live renal ultrasonography can facilitate a high success rate for bedside ureteral stent placement outside the operating room. This approach is an attractive alternative to fluoroscopy-guided stent placement in the operating room and is of particular value in the COVID-19 era when judicious use of these resources is salient.

Point-of-care ultrasound in nephrology

PURPOSE OF REVIEW

The use of POCUS has grown tremendously with the introduction of innovative, easy-to-carry and maneuver hand-held devices. This review focuses on nephrology-centric applications of POCUS that can be incorporated on a daily basis to make impactful and prompt clinical decisions.

RECENT FINDINGS

We review articles covering use of POCUS in the dialysis unit, the Emergency Department, office, and ICU for assessment of volume status, access issues, stones, obstruction, and to help manage patients with AKI, shock, and heart failure.

SUMMARY

POCUS is a welcome addition to our bedside diagnostic armamentarium and has great utility in nephrology. Trials are ongoing in evaluating outcomes with POCUS and physicians' clinical experience using it has been extremely positive.

Point-of-care ultrasound for evaluating intra-abdominal calcification in the pediatric emergency department: case series and review of literature

Background

The presence of intra-abdominal calcification in the pediatric population can be due to a wide range of conditions. Calcification in the abdomen can be seen in normal or abnormal anatomical structures. In some patients, abnormal calcification points towards the pathology; whereas in others, calcification itself is the pathology. After a thorough history and clinical examination, point-of-care ultrasound (POCUS) would complement the assessment of acute abdominal pain, based on the list of differentials generated as per the abdominal region. The main objective of this article is to review commonly encountered causes of intra-abdominal calcifications in the pediatric population and help in clinical decision-making in a Pediatric Emergency Department.

Case presentation

We describe a series of pediatric patients who presented to the Pediatric Emergency Department with acute abdominal pain, in whom point-of-care ultrasound helped expedite the diagnosis by identifying varying types of calcification and associated sonological findings. For children who present to the Pediatric Emergency Department with significant abdominal pain, a rapid distinction between emergencies and non-emergencies is vital to decrease morbidity and mortality.

Conclusions

In a child presenting to the Pediatric Emergency Department with abdominal pain, POCUS and the findings of calcifications can narrow or expand the differential diagnosis when integrated with history and physical exam, to a specific anatomic structure. Integrating these findings with additional sonological findings of an underlying pathology might raise sufficient concerns in the emergency physicians to warrant further investigations for the patient in the form of a formal radiological ultrasound and assist in the patient's early disposition. The use of POCUS might also help to categorize the type of calcification to one of the four main categories of intra-abdominal calcifications, namely concretions, conduit wall calcification, cyst wall calcification, and solid mass-type calcification. POCUS used thoughtfully can give a diagnosis and expand differential diagnosis, reduce cognitive bias, and reduce physician mental load. By integrating the use of POCUS with the history and clinical findings, it will be possible to expedite the management in children who present to the Pediatric Emergency Department with acute abdominal pain.

Ultrasound guidance can be used safely for renal tract dilatation during percutaneous nephrolithotomy

OBJECTIVES

To compare clinical outcomes in patients who underwent percutaneous nephrolithotomy (PCNL) with renal tract dilatation performed under fluoroscopic guidance vs renal tract dilatation with ultrasound guidance.

PATIENTS AND METHODS

We conducted a prospective observational cohort study, enrolling successive patients undergoing PCNL between July 2015 and March 2018. Included in this retrospective analysis were cases where the renal puncture was successfully obtained with ultrasound guidance. Cases were then grouped according to whether fluoroscopy was used to guide renal tract dilatation or not. All statistical analyses were performed using Stata version 15.1 including univariate (Fisher's exact test, Welch's t-test) and multivariate analyses (binomial logistic regression, ordinal logistic regression, and linear regression).

RESULTS

A total of 176 patients underwent PCNL with successful ultrasonography-guided renal puncture, of whom 38 and 138 underwent renal tract dilatation with fluoroscopic vs ultrasound guidance, respectively. There were no statistically significant differences in patient age, gender, body mass index (BMI), preoperative hydronephrosis, stone burden, procedure laterality, number of dilated tracts, and calyceal puncture location between the two groups. Among ultrasound tract dilatations, a higher proportion of patients were placed in the modified dorsal lithotomy position as opposed to prone, and a significantly shorter operating time was observed. Only modified dorsal lithotomy position remained statistically significant after multivariate regression. There were no statistically significant differences in postoperative stone clearance, complication rate, or intra-operative estimated blood loss. A 5-unit increase in a patient's BMI was associated with 30% greater odds of increasingly severe Clavien-Dindo complications. A 5-mm decrease in the preoperative stone burden was associated with 20% greater odds of stone-free status. No variables predicted estimated blood loss with statistical significance.

CONCLUSIONS

Renal tract dilatation can be safely performed in the absence of fluoroscopic guidance. Compared to using fluoroscopy, the present study demonstrated that ultrasonography-guided dilatations can be safely performed without higher complication or bleeding rates. This can be done using a variety of surgical positions, and future studies centred on improving dilatation techniques could be of impactful clinical value.

Percutaneous kidney stone surgery and radiation exposure: A review

During the past 3 decades, radiation exposure (RE) has increased drastically among patients undergoing percutaneous nephrolithotomy (PCNL), thus potentially causing new cases of cancer each year. The effective dose received by patients comes from pre- and post-operative computed tomography (CT) and intraoperative fluoroscopy (FL). We reviewed literature to find novel techniques and approaches that help to decrease RE of patients and personnel. We performed PubMed search using keywords percutaneous nephrolithotomy, intraoperative fluoroscopy, radiation exposure, imaging, percutaneous access, ultrasound, computed tomography, endoscopy, reconstruction, innovations, and augmented reality. Forty-four relevant articles were included in this review. As much as 20% of patients with first diagnosed urolithiasis exceed background RE level almost 17-fold. For diagnosing purposes using low-dose and ultra-low-dose CT, as well as low-dose dual energy scan protocols can be efficient ways to decrease RE while maintaining decent accuracy. Patients with urinary stones can be effectively monitored with digital tomosynthesis, ultrasound alone or ultrasound combined with plain film of the abdomen. Percutaneous access (PCA) into the kidney can be performed with reduced or even no RE, using novel PCA methods. REs from conventional imaging techniques during diagnosis and treatment increase probability of non-stochastic radiation effects. Urologists should be aware of protocols that decrease RE from CT and FL in diagnosis and management of urinary stones. Consideration of recently developed imaging modalities and PCA techniques will also aid in adherence to the “as low as reasonably achievable” principle.

Innovations in Ultrasound Technology in the Management of Kidney Stones

This article reviews new advances in ultrasound technology for urinary stone disease. Recent research to facilitate the diagnosis of nephrolithiasis, including use of the twinkling signal and posterior acoustic shadow, have helped to improve the use of ultrasound examination for detecting and sizing renal stones. New therapeutic applications of ultrasound technology for stone disease have emerged, including ultrasonic propulsion to reposition stones and burst wave lithotripsy to fragment stones noninvasively. The safety, efficacy, and evolution of these technologies in phantom, animal, and human studies are reviewed herein. New developments in these rapidly growing areas of ultrasound research are also highlighted.

Leave no stone unturned: defining recurrence in kidney stone formers

PURPOSE OF REVIEW

Established guidelines provide recommendations on the management of kidney stones to prevent recurrence. However, clear and clinically useful terminology for recurrence of kidney stones is needed. This review describes the various manifestations of kidney stone recurrence and the reported rates of kidney stone recurrence in various clinical settings.

RECENT FINDINGS

Kidney stone recurrence has a wide range of symptomatic and radiographic presentations. Symptomatic recurrence may include characteristic symptoms of stone passage via the ureter (renal colic and gross hematuria). This may be self-managed or result in clinical care, with or without confirmation of an obstructing stone on imaging. Radiographic recurrence has been variably defined as new stone formation, stone growth, or stone disappearance (from passage with or without symptoms). Studies have used inconsistent definitions of recurrence, and recurrence rates vary substantially. Stone free rates and residual stone fragment size after surgical interventions are useful predictors of symptomatic recurrence.

SUMMARY

The recurrence rate of kidney stones has been assessed in stone formers from sub-specialty clinics, the general community, and clinical trials. The definition of recurrence is quite heterogenous between studies, but the rate of recurrence generally increases as more manifestations are included in the definition.

Urolithiasis: Comparison of diagnostic performance of digital tomosynthesis and ultrasound. Which one to choose and when?

OBJECTIVE

To assess the diagnostic performance of digital tomosynthesis (DT) in detecting urolithiasis and compare it with ultrasonography (USG), keeping standard volumetric multi-detector computed tomography (MDCT) as the reference.

MATERIALS AND METHODS

This prospective analytical study was approved by our institutional ethical committee. A total of 66 patients were enrolled who had either clinical suspicion of urolithiasis or history of recurrent urolithiasis. All patients underwent DT, USG and MDCT within 24 h. In all these three investigations, the calculi were categorised according to their location and size by two radiologists. Sensitivity, specificity, positive and negative predictive values of DT and USG were calculated with MDCT as a reference standard.

RESULTS

Our study comprised of 66 patients (36 males and 30 females with age range of 19-73 years). A total of 121 calculi were assessed with 52 calculi <5 mm in size, 32 calculi measuring 5-10 mm and 37 calculi >10 mm. Kappa test of agreement was used to assess the interobserver agreement for all observations. The measurement of agreement kappa value was 1. The overall sensitivity of DT and USG in detecting urolithaisis was 50% (p value <0.001) and 50.4% (p value 0.005) respectively. No statistically significant difference was noted between USG and DT in detecting urolithiasis. The sensitivity of DT and USG in detecting renal calculi was 47.1% and 50.9% respectively and the sensitivity of DT and USG in detecting ureteric calculi was 74.9% and 39.2% respectively. We observed statistically significant difference between USG and DT in detecting ureteric calculi.

CONCLUSION

In our study, there was no statistically significant difference noted between USG and DT in diagnosis of urolithiasis. DT performed significantly better than USG in detecting ureteric calculi with a higher sensitivity. Hence, we are tempted to opine that DT may be preferred over USG for initial evaluation of patients with suspected ureteric calculi. However considering the strength of ultrasound in demonstrating associated signs as hydroureteronephosis, we are still of the opinion, that both DT and USG should be used as complementary techniques in resolving these common clinical screnarios.

Ultrasound guided ureteroscopy in children: Safety and success

INTRODUCTION

Ureteroscopy has been shown to be a highly efficacious and safe modality for the treatment of pediatric urolithiasis. However, conventional ureteroscopy relies on fluoroscopy for intraoperative guidance, exposing both patient and operating room personnel to ionizing radiation. Pediatric urolithiasis patients are at a particularly increased risk from this radiation exposure. The use of ultrasound in place of fluoroscopy for intraoperative guidance has emerged as one modification that can reduce radiation exposure during ureteroscopy. Although ultrasound-guided ureteroscopy has been shown to be a safe, and effective approach to stone management in adults, there have been no studies to date utilizing this approach in children.

OBJECTIVE

The aim was to describe our initial experience with ultrasound-guided ureteroscopy in children as a safe and feasible modality to manage pediatric urolithiasis.

STUDY DESIGN

A retrospective review of consecutive patients that underwent ultrasound-guided ureteroscopy by one pediatric urologist (A.K.S.) from 2014 to 2016 for symptomatic urolithiasis was performed. Patient data were extracted from our center's IRB-approved prospectively maintained database of all children with urolithiasis.

MATERIALS AND METHODS

Real-time ultrasonic guidance was provided by a pediatric uroradiology attending, with fluoroscopy available on standby. With the probe positioned on the patient's flank, ultrasound was used to visualize advancement of guidewire, dual-lumen catheter, and ureteroscope through the ureteral orifice and up to the renal pelvis (Figure). Stones were identified and removed via basket retrieval. At the conclusion of each case, ultrasonography was then used to confirm stent placement of indwelling double pigtail ureteral catheters.

RESULTS

Eleven patients were identified that underwent 12 ultrasound-guided ureteroscopic procedures in an outpatient setting. Stones were accessed in various locations and were removed by basket retrieval. Laser calycostomy into calyceal diverticulum and balloon dilations of ureterovesical junction and calyceal infundibulum were also performed. There were Clavien grade I and II complications in four patients; all of which were related to pain control.

DISCUSSION

To our knowledge, this is the first study reporting the successful use of ultrasound-guided ureteroscopy in children. The main limitation of this feasibility study is its small sample size. A larger series is needed to corroborate these findings and make them generalizable to a wider population.

CONCLUSION

This feasibility study accomplished its aim of demonstrating for the first time that ultrasound-guided ureteroscopy can be safely used in children to manage urolithiasis.