Incidence and risk factors of renal hematoma: a prospective study of 1,300 SWL treatments

Risk factors of hematoma after SWL for renal calculi: analysis from RCTs and a literature review

OBJECTIVE

To identify risk factors of perinephric hematoma following extracorporeal shockwave lithotripsy (SWL) for renal calculi through combined analysis of two randomized controlled trials.

PATIENTS AND METHODS

This post-hoc analysis included adult patients with solitary renal calculi ranging from 5 to 15 mm, treated with SWL between 2016 and 2022. All patients received cross-sectional imaging (either non-contrast computer tomography scan or magnetic resonance imaging) two days post-SWL to assess the presence and severity of perinephric hematoma.

RESULTS

Among 573 patients analyzed, 173 (30.9%) developed perinephric hematoma by Day 2 post-SWL. Multivariate logistic regression identified higher total energy delivered (odds ratio [OR] = 1.533, p = 0.003), higher mean stone density (OR = 2.603, p = 0.01), higher maximal stone density (OR = 3.578, p = 0.03), and lower pole stone location (OR = 1.545, p = 0.029) were risk factors for the development of hematoma. Conversely, the stepwise ramping protocol was a protective factor for hematoma formation. (OR = 0.572, p = 0.042).

CONCLUSIONS

This study elucidates key factors influencing the risk of perinephric hematoma post-SWL, highlighting the importance of procedural adjustments such as the stepwise ramping protocol to reduce complications. These insights call for targeted patient and treatment strategy optimization to enhance SWL safety and efficacy.

Extracorporeal shock wave lithotripsy for lower calyx stones: predicting treatment success

INTRODUCTION

The use of extracorporeal shock wave lithotripsy (ESWL) for lower calyx stones is associated with a high rate of residual fragments. Our aim is to analyse the effectiveness and complications of ESWL for lower calyx stones.

METHODS

Retrospective review of patients with lower renal calyx stones treated with ESWL between January-2014 and December-2020. Measurement of infundibular length, infundibular width and infundibulopelvic angle in lower renal pole to determine favourable anatomy. ESWL failure: fragments >3 mm detected in plain abdominal film, CT scan and/or renal ultrasound 3 months after treatment. Complications after ESWL, auxiliary procedures along with risk factors associated with perirenal haematoma were analysed. SPSS statistical software was used.

RESULTS

512 patients with lower calyx stones were treated with ESWL. 80.3% of patients had a favourable anatomy. Overall stone-free rate was 70.5%. Regarding main complications after ESWL, stainstrasse was described in 5 patients and urinary tract infection in 3 patients. 10 perirenal haematomas (2%) were reported. Statistical association was found between antiplatelet treatment and the risk of perirenal haematoma (p = 0.004). Logistic binary regression proved the association between unfavourable anatomy of the lower renal pole (p = 0.000), size of the stone (p = 0.001), number of shock waves (p = 0.003), energy applied (p = 0.038) and the need for additional treatment after ESWL.

CONCLUSIONS

ESWL can still be considered as the initial treatment option for lower renal pole stones. The size of the stone, an unfavourable anatomy of the lower renal calyx, number of shock waves and energy applied can help predict the need for additional treatment.

The Ideal Interval Between Repeated Shockwaves Lithotripsy Sessions for Renal Stones: A Randomized Controlled Trial

Objectives: To assess the ideal interval between repeated extracorporeal shockwave lithotripsy (SWL) for renal stones. Patient and Methods: Eligible patients with a single renal stone ≤20 mm who required SWL were randomly assigned to one of three groups based on intervals between first and second sessions. Patients underwent the second session after 3, 7, and 14 days in Groups 1, 2, and 3, respectively. Tubular functions were assessed through comparisons of urinary execration of kidney injury molecule-1 (KIM-1), neutrophil gelatinase associated lipocalin (NGAL), and interleukin-18 (IL-18) with pre-SWL values, whereas glomerular function was assessed by comparisons of protein/creatinine ratio with pre-SWL and changes in ipsilateral renal function on isotope scans. Treatment success was assessed by noncontrast CT after 3 months. Results: All demographics of the 166 patients included in the study were comparable between the three groups. There were significant elevations of tubular biomarkers and protein/creatinine ratio after first and second SWL sessions compared with pre-SWL values (p < 0.0001). All tubular biomarkers returned to pre-SWL values at 7 and 14 days after second session, whereas they remained significantly elevated 3 days after second session (p = 0.027, < 0.001 and <0.001 for KIM-1, NGAL, and IL-18, respectively). SWL success was 73.6% in Group 1, 83.7% in Group 2, and 81% in Group 3. A significant decrease in ipsilateral renal split function was observed in Group 1 at the 3-month follow-up. Conclusions: An interval of 7 days is required between SWL sessions when treating renal stones to allow for complete recovery of kidney functions. Clinical Trial Registration: ID: NCT04575480.

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.

Best Practice in Interventional Management of Urolithiasis: An Update from the European Association of Urology Guidelines Panel for Urolithiasis 2022

PURPOSE

The European Association of Urology (EAU) has updated its guidelines on clinical best practice in urolithiasis for 2021. We therefore aimed to present a summary of best clinical practice in surgical intervention for patients with upper tract urolithiasis.

MATERIALS AND METHODS

The panel performed a comprehensive literature review of novel data up to May 2021. The guidelines were updated and a strength rating was given for each recommendation, graded using the modified Grading of Recommendations, Assessment, Development, and Evaluations methodology.

RESULTS

The choice of surgical intervention depends on stone characteristics, patient anatomy, comorbidities, and choice. For shockwave lithotripsy (SWL), the optimal shock frequency is 1.0-1.5 Hz. For ureteroscopy (URS), a postoperative stent is not needed in uncomplicated cases. Flexible URS is an alternative if percutaneous nephrolithotomy (PCNL) or SWL is contraindicated, even for stones >2 cm. For PCNL, prone and supine approaches are equally safe. For uncomplicated PCNL cases, a nephrostomy tube after PCNL is not necessary. Radiation exposure for endourological procedures should follow the as low as reasonably achievable principles.

CONCLUSIONS

This is a summary of the EAU urolithiasis guidelines on best clinical practice in interventional management of urolithiasis. The full guideline is available at https://uroweb.org/guidelines/urolithiasis.

PATIENT SUMMARY

The European Association of Urology has produced guidelines on the best management of kidney stones, which are summarised in this paper. Kidney stone disease is a common condition; computed tomography (CT) is increasingly used to diagnose it. The guidelines aim to decrease radiation exposure to patients by minimising the use of x-rays and CT scans. We detail specific advice around the common operations for kidney stones.

Retrograde intrarenal surgery for the treatment of renal stones in patients with a solitary kidney: Does access sheath matter?

Background

Treating renal stones in patients with a solitary functioning kidney is challenging. The present study was aimed to assess the competence and safety of retrograde intrarenal surgery (RIRS) for the treatment of renal stones in a solitary kidney.

Methods

Between August of 2017 and August of 2019, 25 ensuing patients with a solitary kidney and renal calculi and who were treated with RIRS were prospectively enlisted in the study. All patients were assessed by non-contrast computed tomography before surgery. Stone-free status was determined if there were no residual fragments. The final stone-free rates (SFRs) were assessed 3 months after the last treatment session by plain X-ray KUB and ultrasonography. Patient demographics, perioperative and postoperative outcomes were prospectively evaluated. Serum creatinine levels and glomerular filtration rate (GFR) pre-procedure and during follow-up were correlated.

Results

Twenty-five patients underwent 26 procedures. The mean patient age was 42.81 ± 12.3 (range 22–67) years. The mean stone size was 18.23 ± 6.27 mm (range 9–25 mm) and the mean operative time was 46.15 ± 15.34 min (range 25–100 min). A ureteral access sheath (UAS) was used in five (19.2%) pre-stented patients. One patient (3.8%) required the second stage RIRS for residual stones. The SFR after the initial and final procedures, the SFR was 84% and 92%, respectively.

The mean serum creatinine levels were significantly reduced post-surgery compared to preoperative levels (1.76 ± 1.21 mg/dL; 1.37 ± 0.60 mg/dL; p value 0.001) while GFR not encounter any significant variation post-surgery (63.04 ± 33.16 ml/min) compared to preoperative rates (61.12 ± 34.76 ml/min, p value 0.502). Minor complications classified as Clavien I or II developed in 5 patients (20%). Clavien IIIb, a major complication, developed in one (4%) patient, which was caused by steinstrasse and necessitated emergency surgical intervention.

Conclusion

Renal stones in a solitary kidney can be managed using RIRS safely and effectively with and without the use of UAS, without compromising renal function.

Optimisation of shock wave lithotripsy: a systematic review of technical aspects to improve outcomes

Shock wave lithotripsy (SWL) remains an important treatment option for the management of upper urinary tract stones. The optimisation of certain technical principles can help to improve the results of SWL. We performed a systematic review based on preferred reporting items for systematic review and meta-analysis (PRISMA) standards for studies reporting on technical aspects of SWL. A literature search was conducted on the PubMed database between January 1984 and November 2018 using 'shockwave lithotripsy' and 'stone' as keywords. Summaries and manuscripts of relevant articles were reviewed in order to select studies with the best level of evidence in each theme covered during the review. From 4,135 titles, 165 abstracts and full-text articles were reviewed. Overall, SWL has good outcomes in the treatment of upper urinary tract stones. It remains the only truly non-invasive stone treatment. While stone-free rate (SFR) might not be equivalent to ureteroscopy or percutaneous nephrolithotomy outcomes, SWL can be optimised by changing several technical factors, including type of machine, patient position, number, rate and energy of shocks, stone targeting, and patient analgesia. For each of these included SWL themes, relevant and selected studies with the highest level of evidence were described and discussed. Paired with these improved technical factors and appropriate patient selection, SWL, with its low complication rates, remains an excellent treatment option in 2019.

Endometriosis treatment with shock waves: A novel approach

Endometriosis affects 10-15% of women. When medication is unsatisfactory, not well tolerated or unwanted, surgery remains the sole option. There is a need for a less invasive treatment. We suggest the application of shock wave therapy (SWT) to endometriotic nodules (including deep infiltrating endometriosis), endometriomas and adenomyosis. We hypothesize pain relief via an antiinflammatory effect, an antioxidant effect and neural pathways modulation, as well as a direct effect on the lesions by the energy thus delivered. Questions to be answered before a clinical application is tested include route of administration (external versus internal transducers), dose regimen, optimal duration of treatment and type of shock waves used (focalised versus radial).

Diffuse Renal Cortical Hemorrhage in the Setting of Subcapsular Hematoma: Diagnosis and Treatment with Embolization

PURPOSE

To describe radiologic findings, embolization technique, and clinical outcomes in patients with renal subcapsular hematoma and diffuse cortical hemorrhage.

MATERIALS AND METHODS

Ten patients with renal subcapsular hematoma and diffuse cortical hemorrhage were reviewed. Nine of the 10 had undergone procedures (nephrostomy, n = 4; biopsy, n = 4; embolization of a cerebral aneurysm, n = 1) and 1 patient was receiving oral anticoagulation. Computed tomography (CT), angiography, and embolization of bleeding sites were performed in all patients.

RESULTS

CT and angiography revealed subcapsular hematoma with diffuse cortical hemorrhage at the level of the interlobar and/or arcuate branches. Total embolization of intrarenal arterial branches was required in 3 patients. Partial embolization, which also resulted in permanent functional loss, was required in 4. The functional loss was likely caused by the embolization procedure and the underlying renal disease. In these 4 patients, renal failure was demonstrated by scintigraphy in 3 cases and based on the need to start chronic hemodialysis in 1 case. In the remaining three patients, embolization did not compromise renal function.

CONCLUSIONS

Diffuse cortical hemorrhage unrelated to the site of puncture may be seen in some cases of subcapsular hematoma. The cause is likely the laceration of transcortical capsular arteries secondary to enlargement of the subcapsular hematoma. In the present case series, embolization achieved hemorrhage control, but loss of renal function was observed in patients with underlying renal disease.

Influence of acetylsalicylic acid and low-molecular weight heparins on the formation of renal hematoma after shock wave lithotripsy

PURPOSE

To investigate the risk of renal hematoma (RHT) after shock wave lithotripsy (SWL) among patients on acetylsalicylic acid (ASA) or low-molecular-weight heparin (LMWH).

PATIENTS AND METHODS

Retrospective analysis of 434 patients treated with SWL for nephrolithiasis and ureterolithiasis of the proximal ureter. Primary endpoint was detection of RHT by ultrasound the day after SWL. Secondary outcome variables included transfusion of erythrocyte concentrate(s), interventions, hospital readmission or death due to RHT within 30 days of SWL. Binary logistic regression analysis was used including a post hoc one-way analysis.

RESULTS

Of 434 patients, 33 (7.6%) and 67 (15.4%) patients were medicated with ASA and LMWH, respectively. RHT was detected in 20 of 434 (4.6%) patients. Of those, 3 (20%) were on ASA, 6 (35%) were on LMWH, 1 (5%) was on ASA and LMWH, and 10 (50%) had no anticoagulation. Univariate analysis showed a statistically significant higher risk for RHT among patients on ASA (p = 0.04) and LWMH (p = 0.02) with an untreated urinary tract infection (UTI) (p = 0.008) and history of cardiovascular disease (p = 0.028). On multivariate analysis, ASA medication, untreated UTI (OR 4.4, 95% CI 1.31-14.75, p = 0.016 and OR 5.79, 95% CI 1.65-20.32, p = 0.03) and a therapeutic dose of LMWH (OR 10.4, 95% CI 1.74-62.27, p = 0.01) were independent predictors for RHT.

CONCLUSIONS

Before SWL, a patient risk profile should be evaluated. If feasible, LMWH in therapeutic dosing should be avoided, and ASA should be discontinued. UTI should be treated before SWL in any case.

TRIAL REGISTRATION

http://www.clinicaltrials.gov ; Identifier NCT02875717.

Hospital admission for treatment of complications after extracorporeal shock wave lithotripsy for renal stones: a study of risk factors

The objective of this study was to determine risk factors of hospital admission for treatment of complications after extracorporeal shock wave lithotripsy (SWL). The electronic files and images of all patients who underwent SWL for treatment of renal stones between January 2011 and December 2015 were retrospectively reviewed. All patients underwent SWL with the same electromagnetic lithotripter (Dornier Lithotripot S). The data of those who needed hospital admission for treatment of complications within 30 days after SWL were compared with patients who did not require hospital admission. Compared data included patients' demographics (age, gender, BMI, ASA score, and pre-SWL stenting), renal characters (side, hydronephrosis, and solitary kidney), and stone characters (site, length, density, and previous treatment). Univariate and multivariate statistical analyses were used to identify risk factors. The study included 1179 patients. Complications that required hospital admission were observed in 108 patients (9.2%). They included obstructing steinstrasse in 91 (7.7%), peri-renal hematoma in 3 (0.25%), and fever (>38.0 °C) in 14 (1.2%). Independent risk factors on multivariate analysis were solitary kidney (OR 2.855, P = 0.017), pre-SWL stenting (RR 2.03, P = 0.044), ASA II (OR 1.965, P = 0.007), hydronephrosis (RR 1.639, P = 0.024), and stone length (RR 1.083, P < 0.001). Patients with medical co-morbidities, pre-SWL ureteral stents, large stones and those with obstructed and/or solitary renal unit are more liable to post-SWL complications that need hospital admission. The probability of hospital admission has to be explained to patients with these risk factors.

[S2k guidelines on diagnostics, therapy and metaphylaxis of urolithiasis (AWMF 043/025) : Compendium]

Every tenth German citizen will suffer from at least one urinary calculus during the lifetime. The diagnostics, treatment and follow-up treatment of urolithiasis are, therefore, part of the daily routine practice for all urologists in hospitals and private practices as well as in many other disciplines, such as general practitioners, internists, nephrologists and pediatricians. Although the diagnostics and therapy have experienced substantial alterations over the last 10 years, the possibilities of metabolic diagnostics and secondary prevention for patients at risk are, unfortunately and unjustly, in many places very poorly represented. The present S2k guidelines, which for the first time were established in an interdisciplinary consensus process, represent the current practical recommendations and, whenever possible, use tables and algorithms in order to facilitate easy reference in the routine daily work. Last but not least, this greatly simplifies the measures for metaphylaxis.

Successful evacuation of large perirenal hematoma after extracorporeal shock wave lithotripsy (ESWL) - step 1 of the IDEAL recommendations of surgical innovation

Larger perirenal hematomas after extracorporeal shock wave lithotripsy (ESWL) are sometimes related to the loss of renal function due to compression of the normal renal tissue. After computed tomography-guided drainage and locally applied urokinase, the hematoma was fractionally evacuated. This procedure is a save and fast way to recover normal renal function.

Hypovolemic Shock Caused by Massive Renal Hematoma After a Third Consecutive Extracorporeal Shockwave Lithotripsy Session: A Case Report

Extracorporeal shockwave lithotripsy (SWL) is a commonly used technique for treating urinary calculi. Although noninvasive, highly effective, and widely accepted, SWL is not without complications. Next to fragmenting the calculi, the surrounding tissue is damaged, which can result in renal hematoma, a well-described complication. In most cases, the collateral tissue damage is mild and resolves with conservative treatment. However, rarely, severe complications may arise. Here we present a case of a 46-year-old male who developed a massive hematoma, both subcapsular and retroperitoneal, after a third consecutive SWL session, resulting in hypovolemic shock. Different probable causes are proposed, of which one cause, the length of the interval between SWL sessions, is not yet studied properly. Probably, short intervals keep the damaged tissue from healing sufficiently, as proposed in our case. Possibly, life-threatening situations can be avoided if more evidence-based guidelines are available.

Does Stepwise Voltage Ramping Protect the Kidney from Injury During Extracorporeal Shockwave Lithotripsy? Results of a Prospective Randomized Trial

BACKGROUND

Renal damage is more frequent with new-generation lithotripters. However, animal studies suggest that voltage ramping minimizes the risk of complications following extracorporeal shock wave lithotripsy (SWL). In the clinical setting, the optimal voltage strategy remains unclear.

OBJECTIVE

To evaluate whether stepwise voltage ramping can protect the kidney from damage during SWL.

DESIGN, SETTING, AND PARTICIPANTS

A total of 418 patients with solitary or multiple unilateral kidney stones were randomized to receive SWL using a Modulith SLX-F2 lithotripter with either stepwise voltage ramping (n=213) or a fixed maximal voltage (n=205).

INTERVENTION

SWL.

OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was sonographic evidence of renal hematomas. Secondary outcomes included levels of urinary markers of renal damage, stone disintegration, stone-free rate, and rates of secondary interventions within 3 mo of SWL. Descriptive statistics were used to compare clinical outcomes between the two groups. A logistic regression model was generated to assess predictors of hematomas.

RESULTS AND LIMITATIONS

Significantly fewer hematomas occurred in the ramping group(12/213, 5.6%) than in the fixed group (27/205, 13%; p=0.008). There was some evidence that the fixed group had higher urinary β2-microglobulin levels after SWL compared to the ramping group (p=0.06). Urinary microalbumin levels, stone disintegration, stone-free rate, and rates of secondary interventions did not significantly differ between the groups. The logistic regression model showed a significantly higher risk of renal hematomas in older patients (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05; p=0.04). Stepwise voltage ramping was associated with a lower risk of hematomas (OR 0.39, 95% CI 0.19-0.80; p=0.01). The study was limited by the use of ultrasound to detect hematomas.

CONCLUSIONS

In this prospective randomized study, stepwise voltage ramping during SWL was associated with a lower risk of renal damage compared to a fixed maximal voltage without compromising treatment effectiveness.

PATIENT SUMMARY

Lithotripsy is a noninvasive technique for urinary stone disintegration using ultrasonic energy. In this study, two voltage strategies are compared. The results show that a progressive increase in voltage during lithotripsy decreases the risk of renal hematomas while maintaining excellent outcomes.

TRIAL REGISTRATION

ISRCTN95762080.

Sudden onset of a huge subcapsular renal hematoma following minimally invasive ureteroscopic holmium laser lithotripsy: A case report

The postoperative complication rate of ureteroscopic lithotripsy (URSL) is low, and the most frequent complication is fever. Thus, urological surgeons often neglect or are unaware of subcapsular renal hematoma (SRH) as a rare complication following URSL. Although a SRH after undergoing URSL is uncommon, the occurrence may be fatal. The current study reports on a rare life-threatening case that occurred recently at Zhongnan Hospital (Wuhan, China). A 24-year-old male patient presented with a large SRH (11×14×11 cm) after undergoing a failed, but minimally invasive URSL with a holmium laser. The presence of the large SRH was confirmed by computerized tomography imaging. The patient underwent conservative management, which prevented hematoma enlargement, and no further treatment was conducted. In conclusion, SRH, although rare following URSL, should be noted by the urological surgeon.

Safety and efficacy of retrograde intrarenal surgery for renal stones in patients with a solitary kidney: a single-center experience

BACKGROUND AND PURPOSE

The management of urolithiasis in patients with a solitary kidney is challenging for endourologists. This study was aimed at evaluating the safety and efficacy of retrograde intrarenal surgery (RIRS) in the treatment of such patients with renal stones.

PATIENTS AND METHODS

Between January 2010 and January 2014, we enrolled 45 patients who had a solitary kidney and underwent RIRS and holmium:yttrium-aluminum-garnet lithotripsy for the management of renal stones. We collected data pertaining to the preoperative patient characteristics, stone dimensions, and postoperative outcomes.

RESULTS

Sixty-eight procedures were performed in all. The mean stone diameter was 1.84±0.19 cm (range 0.5-6.0 cm), and the mean operative time, 76.4±40.14 minutes (range 18-190 min). The percentages of patients free of renal stones at the initial and final procedures were 64.44% and 93.33%, respectively. The mean number of procedures needed for the patients with renal stones of diameters ≥20 mm and <20 mm were 1.93 per patient and 1.23 per patient, respectively (P=0.009). Postoperative complications (graded by the Clavien system) were noted in 26.6% of the patients (12/45): Grade I complications, in 20% (9/45); grade II complications, in 4.4% (2/45); and grade III complication, in 2.2% (1/45). The grade III complication was anuria because of Steinstrasse, which necessitated emergency surgery.

CONCLUSIONS

RIRS for the removal of renal stones in patients with a solitary kidney affords a high success rate and low morbidity rate. For patients with large stones, however, a multistaged approach may be needed.