Ultrasound-guided versus fluoroscopy-guided percutaneous nephrolithotomy: a systematic review and meta-analysis

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.

Cystine Stones: Developments in Minimally Invasive Surgery and Their Impact on Morbidity and Stone Clearance

Cystinuria is a rare genetic condition that is responsible for cystine stones. Besides stone recurrence, patients with cystine stones have reduced health-related quality of life, increased rates of chronic kidney disease and hypertension. Although lifestyle measures, medical therapy and close follow up are essential to reduce and monitor cystine stone recurrences, surgical intervention is frequently needed for most cystinuria patients. Shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy and active surveillance all have a role, and technological advances in endourology are vital in achieving a stone-free status and to prevent recurrences. The complexity of managing cystine stones necessitates a multidisciplinary team discussion, patient involvement and an individualised approach in a specialist centre for optimum management. Thulium fibre laser and virtual reality may have an increasing role in the future of cystine stone management.

Contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with a non-dilated collecting system: results of a pooled analysis of randomized controlled trials

BACKGROUND

Contrast-enhanced ultrasound in percutaneous nephrolithotomy (CEUS-PCNL) is an economical and practical technique for the treatment of patients with renal stones without significant collecting system dilatation. The aim of this systematic review is to compare the safety and efficacy of CEUS-PCNL and conventional ultrasound (US)-guided (US-PCNL) treatment of patients with renal calculi without significant hydronephrosis.

METHODS

This review was conducted with strict adherence to the PRISMA guidelines. Comparative studies on CEUS-PCNL and US-PCNL published in PubMed, SinoMed, Google Scholar, Embase, and Web of science until March 1, 2023, were systematically searched. RevMan 5.1 software was used for meta-analysis. Pooled odds ratios (ORs), weight mean differences (WMDs) and standard mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using the fixed-effects or random-effects model. Publication bias was evaluated using funnel plots.

RESULTS

Four randomized controlled trials involving 334 patients (168 with CEUS-guided PCNL and 166 with US-guided PCNL) were identified. There was no statistically significant difference between CEUS-guided PCNL and US-guided PCNL in terms of the operation time (SMD: - 0.14; 95% CI - 0.35 to 0.08; p = 0.21), minor complications (p = 0.48), major complications (p = 0.28) and overall complications (p = 0.25). However, CEUS-guided PCNL had a higher stone-free rate (OR: 2.22; 95% CI 1.2 to 4.12; p = 0.01), higher success rate of single-needle punctures (OR:3.29; 95% CI 1.82 to 5.95; p < 0.0001), shorter puncture time (SMD: - 1.35; 95% CI - 1.9 to - 0.79; p < 0.00001), shorter hospital stay (SMD: - 0.34; 95% CI - 0.55 to - 0.12; p = 0.002) and lesser hemoglobin loss (SMD: - 0.83; 95% CI - 1.06 to - 0.61; p < 0.00001) as compared with conventional US-guided PCNL.

CONCLUSIONS

According to almost all pooled data, CEUS-guided PCNL is superior to US-guided PCNL in terms of the perioperative outcomes. However, many rigorous clinical randomized controlled studies are required to obtain more accurate results. Registration The study protocol was registered with PROSPERO (CRD42022367060).

A mathematical method to estimate angle and distance for percutaneous renal puncture based on computed tomography data: Description and validation

Introduction

Gaining access to the kidney is crucial step in percutaneous nephrolithotomy (PCNL); it has a steep learning curve.

Objective

Describe the mathematical method to predict renal puncture angle and distance based on preoperative computed tomography (CT) measurements. Then evaluating how it correlates with measured values.

Patients and Methods

The study was prospectively designed. After ethical committee approval, the study uses data from preoperative CT to construct a triangle so we can estimate puncture depth and angle. A triangle of three points, the first is point of entry to the pelvicalyceal system (PCS), the second is point on the skin perpendicular to it, and the third where the needle punctures the skin. The needle travel is estimated using the Pythagorean theorem and puncture angle using the inverse sine function. We evaluated 40 punctures in 36 PCNL procedures. After PCS puncture using fluoroscopy-guided triangulation, we measured the needle travel distance and angle to the horizontal plane. Then compared the results with mathematically estimated values.

Results

We targeted posterior lower calyx in 21 (70%) case. The correlation between measured and estimated needle travel distance with Rho coefficient of 0.76 with P < 0.001. The mean difference between the estimated and the measured needle travel was - 0.37 ± 1.2 cm (-2.6-1.6). Measured and estimated angle correlate with Rho coefficient of 0.77 and P < 0.001. The mean difference between the estimated and the measured angle was 2° ± 8° (-21°-16°).

Conclusion

Mathematical estimation of needle depth and angle for gaining access to the kidney correlates well with measured values.

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.

International Alliance of Urolithiasis (IAU) Guideline on percutaneous nephrolithotomy

The International Alliance of Urolithiasis (IAU) would like to release the latest guideline on percutaneous nephrolithotomy (PCNL) and to provide a clinical framework for surgeons performing PCNLs. These recommendations were collected and appraised from a systematic review and assessment of the literature covering all aspects of PCNLs from the PubMed database between January 1, 1976, and July 31, 2021. Each generated recommendation was graded using a modified GRADE methodology. The quality of the evidence was graded using a classification system modified from the Oxford Center for Evidence-Based Medicine Levels of Evidence. Forty-seven recommendations were summarized and graded, which covered the following issues, indications and contraindications, stone complexity evaluation, preoperative imaging, antibiotic strategy, management of antithrombotic therapy, anesthesia, position, puncture, tracts, dilation, lithotripsy, intraoperative evaluation of residual stones, exit strategy, postoperative imaging and stone-free status evaluation, complications. The present guideline on PCNL was the first in the IAU series of urolithiasis management guidelines. The recommendations, tips and tricks across the PCNL procedures would provide adequate guidance for urologists performing PCNLs to ensure safety and efficiency in PCNLs.

Ultrasound-Guided Mini Percutaneous Nephrolithotomy with Suction Sheath

The mini percutaneous nephrolithotomy (PCNL) is a mainstay in the treatment of kidney calculi, particularly in case of >2 cm kidney stones, large lower pole stones, large impacted proximal ureteral stones, and residual stones after failed extracorporeal shockwave lithotripsy or retrograde intrarenal surgery. An accurate renal access represents a fundamental part of the procedure, modalities to guide the percutaneous tract preparation include ultrasound, fluoroscopy, or their combination. Both ultrasound and fluoroscopy offer several advantages and some limitations. The combined utilization of ultrasound and fluoroscopy is less adopted nowadays; however, this strategy has its merits particularly in cases where the puncture can be problematic with one imaging modality alone. Ultrasound can easily identify the posterior renal calix and surrounding visceral structures, although some situations such as obese patients, undilated collecting system or complex stones may represent a challenge. Intracaliceal blood clots and air may reflect ultrasound, reducing significantly the image quality. Therefore, the assessment of the intrarenal anatomy, the stone identification, and the ability of guiding the needle during access may decrease significantly, particularly in cases with complex stones, when multiple tracts are required. In these cases, fluoroscopy could determine the relationship between the angle and depth of the puncture needle and the target calices by rotating the C-arm to help the needle puncture and tract dilation. Therefore, the benefits of dual guidance would be beneficial during PCNL. In addition to an improved accuracy of puncture and dilation, the combined approach improves the detection of residual stones, facilitating the achievement of a stone-free state. Herein we describe our experience with this technique, describing surgical steps and troubleshooting tips of mini-PCNL in the accompanying video. Further high-quality studies are needed to demonstrate the advantages of combined utilization of ultrasound and fluoroscopy during PCNL and its optimal indications.

On Surgical Planning of Percutaneous Nephrolithotomy with Patient-Specific CTRs

Percutaneous nephrolithotomy (PCNL) is considered a first-choice minimally invasive procedure for treating kidney stones larger than 2 cm. It yields higher stone-free rates than other minimally invasive techniques and is employed when extracorporeal shock wave lithotripsy or uteroscopy are, for instance, infeasible. Using this technique, surgeons create a tract through which a scope is inserted for gaining access to the stones. Traditional PCNL tools, however, present limited maneuverability, may require multiple punctures and often lead to excessive torquing of the instruments which can damage the kidney parenchyma and thus increase the risk of hemorrhage. We approach this problem by proposing a nested optimization-driven scheme for determining a single tract surgical plan along which a patient-specific concentric-tube robot (CTR) is deployed so as to enhance manipulability along the most dominant directions of the stone presentations. The approach is illustrated with seven sets of clinical data from patients who underwent PCNL. The simulated results may set the stage for achieving higher stone-free rates through single tract PCNL interventions while decreasing blood loss.

Electromagnetic-guided puncture: a tool or a tale?

PURPOSE OF REVIEW

The puncture technique and site of the puncture can impact the clinical outcome and the development of postoperative adverse events following percutaneous nephrolithotomy (PCNL). The aim of the current review was to discuss the available puncture guidance approaches and outline the potential role of the recently introduced electromagnetic-guided method.

RECENT FINDINGS

The puncture and PCNL tract establishment is usually performed using fluoroscopic or ultrasound guidance or a combination of two approaches. Electromagnetic-guided puncture is one of the most recent advancements of technology. The puncture navigation to the renal collecting system is available after placing a special wire with an electromagnetic tracking sensor into the desired calyx through the flexible ureterorenoscope. The available experimental and clinical studies have shown a high first puncture rate, decreased median time for obtaining a puncture, and shorter learning curves for beginners.

SUMMARY

Fluoroscopic and ultrasound guidance are the main approaches used by urologists. However, these modalities require a steep learning curve, approximately 60 cases for reaching competency. The initial data on electromagnetic navigation have shown the feasibility and potential promising outcomes of this novel approach. New studies are required to investigate its potential implementation opportunities in the daily practice of urologists.

Worldwide practice patterns of percutaneous nephrolithotomy

PURPOSE

To evaluate the current practice of percutaneous nephrolithotomy (PCNL), conducting a worldwide survey among urologists with a special interest in endo-urology.

METHODS

A 22-question survey was specifically developed by the European Association of Urology (EAU) young academic urologists (YAU) and uro-technology (ESUT) groups and globally distributed via SurveyMonkey to almost 2000 members of Endourology Society. The questionnaire included questions dedicated to the demographics and general practice of the participating urologists.

RESULTS

In total, 441 responses (male/female ratio - 418/23) were received. A comparatively higher percentage of specialists (56.2%) practiced in academic institutions and had specific endo-urological fellowship training (56.7%). The classical prone PCNL remained the most practiced approach among the surveyed specialists, 47.7% stated to always do prone PCNLs, while 51.8% of respondents used multiple positioning options as required. The PCNL tract was mostly performed by urologists (84.3%) and fluoroscopic guidance was still predominantly used by 74.5% of respondents. The most practiced tract dilation method was balloon dilator used by 42% of respondents. Most of the surveyed urologists had ultrasonic, pneumatic or laser lithotripsy devices in their armamentarium. The use of some form of post-procedural drainage was reported in 85.1% of respondents, whereas tubeless PCNL remained a fairly uncommon practice.

CONCLUSION

The majority of urologists still use prone positioning, get their own access under fluoroscopy guidance and use a balloon for tract dilation. However, we also identified that when necessary, urologists will deviate from routine practice and change strategy, adopting other approaches for PCNL.

Approach to nephrostomy tubes in the emergency department

BACKGROUND

Nephrostomy tubes are commonly placed for urinary obstruction, urinary diversion, or future endourologic procedures. While the technical success of nephrostomy tube placement is high, nephrostomy tube complications may occur.

OBJECTIVE OF REVIEW

Limited literature exists regarding the complication of nephrostomy tubes and their approach in the emergency department. This review summarizes the existing literature and provides a framework for emergency providers regarding the evaluation and management of nephrostomy tube complications.

DISCUSSION

Nephrostomy tube failure, caused by kinking, dislodgment, or migration can manifest with obstructive signs and symptoms. In well appearing patients, asymptomatic bacteriuria is common and should not be treated. However, in the presence of infectious symptoms, patients should be treated similarly to complicated cystitis or pyelonephritis. While gross hematuria is common following catheter placement, prolonged hematuria, or the return of hematuria after previous resolution should trigger investigation for hematoma formation or a delayed presentation of an intraoperative vascular injury. Finally, clinicians should obtain laboratory testing, advanced imaging, and specialty consultation if serious complications are suspected.

CONCLUSION

This narrative review highlights general nephrostomy tube care, minor complications, and troubleshooting in the emergency department. The majority of these minor complications can be managed at the bedside without specialty consultation. However, in patients with more serious complications including dislodgement, obstruction, infection, bleeding, and pleural injury, laboratory assessment and advanced imaging to include ultrasound and computed tomography with specialty consultation are essential in the patient's evaluation and management, particularly in cases of immune compromise and worsening renal function.

Intracardiac Migration of the Ureteral Double-J Stent during Percutaneous Nephrolithotomy

The complications of percutaneous nephrolithotomy (PNL) include hemorrhage, damage to adjuvant organs, and other medical issues, although intracardiac migration of ureteral double-J stent has never been found during PNL and delaying the diagnosis might cause mortality. We report the case of a 60-year-old male who was admitted to receive one-stage PNL for right renal stones. During operation, an unexpected atrial fibrillation with a drop in blood pressure was suddenly encountered and the chest X-ray subsequently showed that the ureteral double-J had penetrated deep into the heart. Emergent endovascular intervention was performed to remove the stent and the patient was uneventfully discharged 2 days later.

How does puncture modality affect the risk of intraoperative bleeding during percutaneous nephrolithotomy? A prospective randomized trial

INTRODUCTION AND OBJECTIVES

To evaluate the possible effects of two different renal puncture techniques (ultrasound-assisted [US-assisted], fluoroscopic-guided [FG]) on the intraoperative hemorrhage risk during percutaneous nephrolithotomy (PCNL).

MATERIAL AND METHODS

A total of 130 patients with Guy stone scores of 1-2 were prospectively allocated to US-assisted and FG puncture groups by simple randomization. Patients with intraoperative pelvicalyceal rupture and the ones requiring multiple accesses were excluded from the study. Apart from the puncture steps, all other steps of the PCNL procedure were performed with similar techniques by a single surgeon. Patient characteristics, operative data, and postoperative outcomes were compared.

RESULTS

A total of 10 patients were excluded from the study due to intraoperative complications after puncture. Patient demographics and stone characteristics were similar between the two groups (p > 0.05). Mean hemoglobin drop was meaningfully greater in the FG group (1.7 g/dL) when compared with US-assisted group (1.3 g/dL) (p < 0.01). The mean duration of radiation exposure was significantly higher for the FG (p < 0.001). Total operative time, number of attempts for a successful puncture, length of hospital stay, and stone free rates were similar between the groups (p > 0.05). In addition, the remaining complications classified according to the modified Clavien-Dindo grading system were similar between groups (p > 0.05).

CONCLUSION

US-assisted puncture provides significantly decreased level of hemoglobin drop and radiation exposure time when compared with FG.

A study on comparative outcomes of totally ultrasonography-guided percutaneous nephrolithotomy in prone versus flank position: a randomized clinical trial

PURPOSE

The percutaneous nephrolithotomy (PCNL) has become the gold-standard for treating patients with the larger renal stones and staghorn calculi. This study was designed to evaluate the outcomes of flank versus prone position in patients underwent ultrasonic-guided PCNL for treatment of large kidney stones.

METHODS

This prospective randomized clinical trial was conducted from September 2017 to September 2019 in the department of Urology, Labbafinejad University hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Two hundred patients with kidney stones larger than 2 cm underwent PCNLs in prone (n = 100) or flank position (n = 100). Success rate, operative time, access time, hemoglobin and creatinine changes, hospital stay, auxiliary procedure and surgical complications were compared between the two groups.

RESULTS

The two groups were similar in their baseline characteristics. The success rates in prone (87%) versus flank position (85%) were not significantly different at the first post-operative follow-up (p = 0.91). At the three-month follow-up, the overall stone free rates for the prone position PCNLs and flank position PCNLs were 94/100 (94%) and 90/100 (90%) (p = 0.96). There were no significant difference between the groups in operative time (p = 0.42), access time (p = 0.66), hemoglobin (p = 0.46) and creatinine (p = 0.22) changes, hospital stay (p = 0.05), auxiliary procedures (p = 0.75) and surgical complications.

CONCLUSION

Overall, there is no significant difference between prone and flank positions in success rate and complications. More prospective studies must be carried out to identify patient populations who are most apt to benefit from one position over the other.

TRIAL REGISTRATION NUMBER

IRCT20200902048597N1 DATE OF REGISTRATION: 2020-11-21, retrospectively registered.

How does puncture modality affect the risk of intraoperative bleeding during percutaneous nephrolithotomy? A prospective randomized trial

INTRODUCTION AND OBJECTIVES

To evaluate the possible effects of two different renal puncture techniques (ultrasound-assisted [US-assisted], fluoroscopic-guided [FG]) on the intraoperative hemorrhage risk during percutaneous nephrolithotomy (PCNL).

MATERIAL AND METHODS

A total of 130 patients with Guy stone scores of 1-2 were prospectively allocated to US-assisted and FG puncture groups by simple randomization. Patients with intraoperative pelvicalyceal rupture and the ones requiring multiple accesses were excluded from the study. Apart from the puncture steps, all other steps of the PCNL procedure were performed with similar techniques by a single surgeon. Patient characteristics, operative data, and postoperative outcomes were compared.

RESULTS

A total of 10 patients were excluded from the study due to intraoperative complications after puncture. Patient demographics and stone characteristics were similar between the two groups (P>.05). Mean hemoglobin drop was meaningfully greater in the FG group (1.7g/dL) when compared with US-assisted group (1.3g/dL) (P<.01). The mean duration of radiation exposure was significantly higher for the FG (P<.001). Total operative time, number of attempts for a successful puncture, length of hospital stay, and stone free rates were similar between the groups (P>.05). In addition, the remaining complications classified according to the modified Clavien-Dindo grading system were similar between groups (P>.05).

CONCLUSION

US-assisted puncture provides significantly decreased level of hemoglobin drop and radiation exposure time when compared with FG.

Intrarenal foreign body after PCNL procedure: A rare complication

The use of LASER for lithotripsy has not only improved PCNL results, but also reported complications related to laser's use. We report a case of severed guide wire after PCNL.

Management of Colon Perforation During Percutaneous Nephrolithotomy in Patients with Complex Anatomy: A Case Series

Percutaneous nephrolithotomy (PCNL), first described in 1976, is the gold standard for the management of large kidney stones, with stone-free rates as high as 95% in contemporary literature. Colonic injuries during PCNL are a rare complication with an estimated incidence of 0.3%-0.5%. However, given the high morbidity incurred and the necessity of prompt operative intervention, it is imperative that practitioners have a low suspicion threshold for such injuries, particularly in those patients with altered or complex anatomy. This case series addresses peri- and postoperative outcomes of colon perforation during PCNL in patients with complex anatomy and reviews the technical challenges of surgery with potential methods to avoid injury in the future. Herein we review three instances of colonic injuries and their subsequent management to highlight both the presentation and the optimal management of these rare occurrences.

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.

The Correlation Between STONE Nephrolithometry Score and Hemoglobin Drop in Patients Undergoing Percutaneous Nephrolithotomy

Objective

In this study, we aimed to determine the correlation between the STONE score [(S)ize of the stone, (T)opography or location, degree of (O)bstruction of the urinary system, (N)umber of stones, and (E)valuation of Hounsfield units] and postoperative hemoglobin drop in patients undergoing percutaneous nephrolithotomy (PCNL).

Methods

This was a prospective observational study and all adult patients aged 18-65 years undergoing unilateral, single-tract PCNL using 26 Ch. Amplatz sheath for renal calculi were included. The five variables of the STONE nephrolithometry score were calculated prior to the procedure. The stone-free rates were assessed on imaging at four weeks and complications were graded using the modified Clavien system.

Results

Of the 142 patients included, 75% were below 55 years of age. More than half of our patients were diabetic with more than 60% having a body mass index (BMI) above 25 kg/m². The mean STONE score was 7 with 33% having a high (>9) STONE score. The mean hemoglobin drop was 1.15 +0.92 g/dL with eight patients (5.63%) requiring transfusion and one (0.7%) requiring angioembolization; one patient required readmission for observation. Complete STONE clearance was achieved with PCNL alone in 78.2% of the patients. There was a significant correlation of hemoglobin drop with the STONE score, stone size, and preoperative creatinine clearance. Patients with a hemoglobin drop of >1 g/dL had a higher STONE score and mean stone size. The overall complication rate was significantly higher (10.5%) in patients with a hemoglobin drop of >1 g/dL as compared to those with a hemoglobin drop of <1 g/dL (2.8%).

Conclusion

Stone complexity as measured by the STONE score correlates with post-PCNL hemoglobin drop, stone clearance, and complication rates. The STONE score may be used for preoperative counseling and to evaluate the potential need for transfusion.

The use of Alken Metal Telescopic Dilator for ‘X-ray-free’ PCNL in neglected DJ stent patient: A case report

Neglected DJ stent is a challenging case, due to the procedures required, using fluoroscopy, as seen in ESWL, URS, and PCNL. This study presents the case of a 54 years old woman with pyelum and ureter stones, alongside neglected DJ stent for about a year. Treatment was started with cystoscopy, URS lithotripsy, which was continued with kidney puncture, and the subsequent dilatation with Alken Metal Telescopic Dilator. All steps were performed under the guidance of ultrasonography without fluoroscopy. The result showed a successful removal of DJ stent, which was achieved percutaneously, and no remaining stone was found.

Simultaneous transurethral bipolar enucleation of the prostate, supine ultrasound-guided percutaneous nephrolithotomy and open cystolithotomy: A feasible and safe approach

Management of the coexisting hard renal pelvic stone, large urinary bladder stone and benign prostatic hyperplasia is not common which can be difficult.

Here we reported a case of a 70-year-old Asian male who presented with 1.5cm renal pelvic stone, 5cm large bladder stone and 96 cc benign enlarged prostate, which were managed by simultaneous transurethral bipolar enucleation of the prostate (BipoLEP), supine ultrasound-guided percutaneous nephrolithotomy (PCNL) and open cystolithotomy.

Simultaneous transurethral BipoLEP, supine ultrasound-guided PCNL and open cystolithotomy are feasible and safe, with the advantage of minimizing the patient's operation and anesthesia time.

Ultrasound or Fluoroscopy for Percutaneous Nephrolithotomy Access, Is There Really a Difference? A Review of Literature

Objective: To compare whether the outcomes of ultrasound-guided access percutaneous nephrolithotomy (USGA-PCNL) are similar to standard fluoroscopy-guided access percutaneous nephrolithotomy (FGA-PCNL). Methods: A review was developed by using the MEDLINE and Scopus databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Studies comparing the USGA-PCNL and the FGA-PCNL were included. Case reports, editorials and letters, unpublished studies, posters, and comments abstracts were excluded. Results: We found 12 published articles that compared USGA-PCNL and FGA-PCNL. These included six randomized controlled trials, three case-control trials, and three meta-analyses. The overall results showed no difference in the success of percutaneous access, bleeding, blood transfusion, operative time, postoperative complications, or hospital stay. Conclusion: The reported data demonstrate that there are no significant differences between the fluoroscopic-guided access PCNL and the ultrasonographic access PCNL. The choice of puncture depends on the surgeon's expertise in a particular technique and the patient and stone characteristics. Both approaches are equally safe and effective in experienced hands. It is important to recall that the use of one technique does not exclude the use of the other, and they can sometimes be complementary to each other.

X-ray-free ultrasound-guided versus fluoroscopy-guided percutaneous nephrolithotomy: a comparative study with historical control

PURPOSE

To compare the outcomes and complications of supine X-ray-free ultrasound-guided percutaneous nephrolithotomy (XG-PCNL) with fluoroscopy-guided (FG)-PCNL in both prone and supine positions.

METHODS

This was a comparative study that included a prospective cohort and historical control groups. This study analysed 40 consecutive patients who undergone supine XG-PCNL between October 2019 and March 2020. The control groups were composed of historical control formed from the last 40 consecutive patients who underwent FG-PCNL in both supine and prone positions from our PCNL database from January 2018 and September 2019. Patients' demographics, stone characteristics and intraoperative and postoperative outcomes were compared.

RESULTS

A total of 120 patients were classified into the supine XG-PCNL, supine FG-PCNL, and prone FG-PCNL groups (each N = 40). They had similar baseline characteristics and initial stone burden. The supine XG-PCNL group had higher puncture attempts, nephrostomy tube placement, and longer surgery duration than both the supine and prone FG-PCNL groups. However, the stone-free rate was similar in all groups (85%, supine XG-PCNL; 72.5%, supine FG-PCNL; 77.5% prone FG-PCNL; p = 0.39). No significant difference was found in the complication rate and length of stay among the three groups.

CONCLUSION

Supine XG-PCNL is an alternative to both supine and prone FG-PCNL with similar efficacy and complication rates for kidney stone patients. This could be a good alternative to urological centres with no access to fluoroscopy.

X-ray-free Ultrasound-guided Percutaneous Nephrolithotomy in Supine Position Using Alken Metal Telescoping Dilators in a Large Kidney Stone: A Case Report

X-ray-free ultrasound-guided percutaneous nephrolithotomy (PCNL) has been proven to be safe, feasible, and affordable. Kidney dilatation during X-ray-free ultrasound-guided PCNL is mostly using balloon dilators. This report presents our experience of performing X-ray-free ultrasound-guided PCNL in supine position using Alken metal telescopic dilators in a patient with a large kidney stone. A 50-year-old male presented with right complete staghorn stone sized 46×30×24 mm (stone burden: 50,985 mm3 with sphere formula) and grade II hydronephrosis. The computed tomography (CT) scan showed no right ureteric stone, kinking, or stenosis. Ureteral catheter and guidewire were placed retrogradely under ultrasound guidance during cystoscopy. Normal saline was pumped via the ureteral catheter to make artificial hydronephrosis thus assisting the process. Kidney dilatation was performed with Alken metal telescoping dilators. Urine flow from the dilators confirmed that our dilator had reached the collecting system. The stone was identified and fragmented with combination of both pneumatic and shock pulse lithotripter. Double J stent and nephrostomy tubes were inserted at the end of the procedure. All of the steps were performed purely under ultrasound guidance. There was no residual stone after the procedure, confirmed by ultrasound, nephroscope, and postoperative X-ray. There was no significant complication during or after the procedure. The patient was discharged on postoperative day two. X-ray-free ultrasound-guided PCNL in supine position using Alken metal telescoping dilators seems to be a feasible, safe, and cost-effective approach in managing kidney stones, including staghorn and large stones.

Personalized Renal Collecting System Mockup for Procedural Training Under Ultrasound Guidance

Objective: In recent years, there has been increasing interest in the use of ultrasound guidance for endoscopic and percutaneous procedures. Kidney mockups could be used for training, however, available mockups are normally incompatible with ultrasound imaging. We developed a reproducible method to manufacture an ultrasound-compatible collecting system mockup that can be made at urology laboratories. Methods: Positive and negative molding methods were used. A three-dimensional (3D) digital model of a urinary collecting system and the overlying skin surface were segmented from computed tomography. A containment mold (negative) was made following the shape of the skin surface using 3D printing. A collecting system mold (positive) was also 3D printed, but made of a dissolvable material. The containment mold was filled with a gelatin formula with the collecting system mold submersed in situ within. After the gelatin solidified, a solution was used to dissolve the collecting system mold, but not the gelatin, leaving a cavity with the shape of the collecting system. The gelatin was extracted from the container mockup and the collecting system cavity was filled with water. The mockup was imaged with ultrasound to assess echogenicity and suitability for simulating ultrasound-guided procedures. Results: A clear shape corresponding to the collecting system was observed inside the gel structure. Structural integrity was maintained with no observable manufacturing marks or separation seams. Ultrasound images of the mockup demonstrated clear differentiation at the gelatin/water interface. A mock stone was placed in the collecting system and needle targeted to simulate percutaneous needle access. Conclusion: We developed a simple method to manufacture a personalized mockup of the renal collecting system of a patient that can be used for ultrasound-guided percutaneous needle access. Generic collecting system mockups can be used for training, and patient-specific models can be used to simulate and decide the best access path before a clinical case.

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.