Effectiveness of Percutaneous Nephrolithotomy, Retrograde Intrarenal Surgery, and Extracorporeal Shock Wave Lithotripsy for Treatment of Renal Stones: A Systematic Review and Meta-Analysis

Optimizing targeting strategies for lithotripsy through in-vitro and in vivo studies with consideration of respiratory regularity

BACKGROUND

This work aimed to identify a method to achieve improved stone targeting and safety in shockwave lithotripsy by accounting for respiration.

METHODS

We set up an electromotive device simulating renal movement during respiration to place artificial stones within the phantom gel, measuring stone weight changes before and after shockwave exposure and the cavitation damage. We conducted clinical trials using respiratory masks and sensors to monitor and analyze patient respiration during shockwave lithotripsy.

RESULTS

The in vitro efficiency of lithotripsy was higher when adjusted for respiration than when respiration was not adjusted for. Slow respiration showed the best efficiency with higher hit rates when not adjusted for respiration. Cavitation damage was also lowest during slow respiration. The clinical study included 52 patients. Respiratory regularity was maintained above 90% in regular respiration. When respiration was regular, the lithotripsy rate was about 65.6%, which stayed at about 40% when respiration was irregular. During the lithotripsy, the participants experienced various events, such as sleep, taking off their masks, talking, movement, coughing, pain, nervousness, and hyperventilation. The generation of shockwaves based on respiratory regularity could reduce pain in patients.

CONCLUSION

These results suggest a more accurate lithotripsy should be performed according to respiratory regularity.

Use of artificial stones in training and laboratory studies, have we found the right material? Outcomes of a systematic review from the European School of Urology

Objective

In this review, we investigated the current literature to find out which artificial stones (AS) are available in endourology, and in which experimental and training schemes they are used.

Materials and Methods

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Twenty-one out of 346 studies met our inclusion criteria and are presented in the current review. The inclusion criteria were the existence of AS and their use for laboratory and training studies.

Results

There is a wide variety of materials used for the creation of AS. BegoStone powder (BEGO USA, Lincoln, Rhode Island) and plaster of Paris™ were used in most of the studies. In addition, Ultracal-30 (U. S. Gypsum, Chicago, IL) was also used. Other materials that were used as phantoms were AS created from plaster (Limbs and Things, UK), standardized artificial polygonal stone material (Chaton 1028, PP13, Jet 280; Swarovski), model stones consisting of spheres of activated aluminum (BASF SE, Ludwigshafen am Rhein, Deutschland), Orthoprint (Zhermack, Badia Polesine, Italy), and a combination of plaster of Paris, Portland cement, and Velmix (calcium sulfate powder). Many experimental settings have been conducted with the use of AS. Our research demonstrated nine studies regarding testing and comparison of holmium: yttrium-aluminum-garnet laser devices, techniques, and settings. Six studies were about extracorporeal shock wave lithotripsy testing and settings. Three experiments looked into treatment with percutaneous nephrolithotomy. Additionally, one study each investigated imaging perioperatively for endourological interventions, stone bacterial burden, and obstructive uropathy.

Conclusion

AS have been used in a plethora of laboratory experimental studies. Independent of their similarity to real urinary tract stones, they present a tremendous potential for testing and training for endourological interventions.

Does displacement of lower pole stones during retrograde intrarenal surgery improves stone-free status? A systematic review and meta-analysis

PURPOSE

Kidney stones are one of the most common urological diseases worldwide. The size and location of the stone are the most important factors in determining the most suitable treatment options. The aim of this review was to evaluate the displacement of lower pole stones.

METHODS

Three studies assessing the efficacy of translocating kidney stones from the lower pole of the kidney to other locations during retrograde intrarenal surgery published in the last 20 years were included. A systematic search was conducted in the PubMed, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), and Web of Science databases using the following search terms: "Lower pole," "Lithotripsy." Meta-analysis was performed using Review Manager version 5.4.

RESULTS

Stone-free rates were improved through displacement (odds ratio - OR = -0.15; 95% confidence interval-95%CI -0.24--0.05; p = 0.002; I2 = 21%), but at the cost of increased surgical duration (mean difference = -12.50; 95%CI -24.06--0.95; p = 0.03; I2 = 94%). Although this represents a potentially negative outcome, the improvement in clearance rates justifies the additional investment of time and effort.

CONCLUSIONS

Displacement of lower pole kidney stones for subsequent lithotripsy brings significant benefits in terms of stone-free rate, with no difference in laser energy usage. However, it results in increased surgical time. Despite these factors, the benefits to patients undergoing the procedure are substantial.

Extracorporeal shock wave lithotripsy for treatment of large pediatric renal pelvic stone burden more than 2 cm

BACKGROUND

The high recurrence rates in pediatric urolithiasis indicate the need for none invasive or a minimally invasive treatment such as SWL. Therefore, EAU, ESPU and AUA recommend SWL as a first line treatment for renal calculi ≤ 2, and RIRS or PCNL for renal calculi > 2 cm. SWL is superior to RIRS and PCNL as it is inexpensive, outpatient procedure, and it has a high SFR in well selected cases specially pediatrics. On the other hand, SWL therapy has a limited efficacy with a lower SFR, and high retreatment rate and/or additional interventions for treatment of larger and harder renal calculi.

OBJECTIVE

We carried out this study to evaluate the efficacy and safety of SWL for treatment of renal stones > 2 cm to extend its indications for pediatric renal calculi.

METHODS

Between January 2016 and April 2022, we reviewed the records of patients with renal calculi treated by SWL, mini-PCNL, RIRS and open surgery in our institution. Forty-nine eligible children aged 1-5 years old, presented with renal pelvic and/or calyceal calculi measuring 2-3.9 cm and underwent SWL therapy were picked up and participated in the study. The data of an additional eligible 79 children with the same age and had renal pelvic and/or calyceal calculi > 2 cm up to stag horn calculi and underwent mini-PCNL, RIRS and open renal surgery were also picked up and participated in the study. We retrieved the following preoperative data from the records of the eligible patients; age, gender, weight, length, radiological findings (stone size, side, site, number and radio-density), renal function tests, routine laboratory findings, and urine analysis. The outcomes data in the form of; operative time, fluoroscopy time, hospital stay, SFRs, retreatment rates and complication rates were also retrieved from the records of patients treated with SWL and other techniques. Also, we collected the SWL characteristics in terms of; position, number and frequency of shocks, voltage, time of the session and U/S monitoring to assess stone fragmentation. All SWL procedures were performed according to the institution's standards.

RESULTS

The mean age of patients treated with SWL was 3.23 ± 1.19 years old, the mean size of the treated calculi was 2.31 ± 0.49 and the mean length of the SSD was 8.2 ± 1.4 cm. All patients had NCCT scan and the mean radio-density of the treated calculi was 572 ± 169.08 HUs based on NCCT scans Table (1). Single- and two-session SFRs of SWL therapy were 75.5% (37/49 patients) and 93.9% (46/49 patients), respectively. The overall success rate was 95.9% (47/49 patients) after three-session of SWL. Complications experienced by 7 patients (14.3%) in the form of fever (4.1%), vomiting (4.1%), abdominal pain (4/1%), and hematuria (2%). All complications were managed in outpatient settings. Our results were obtained on the basis of preoperative NCCT scans for all patients and postoperative plain KUB films and real-time abdominal U/S. Furthermore, single-session SFRs for SWL, mini-PCNL, RIRS and open surgery were 75.5%, 82.1%, 73.7% and 90.6%, respectively. Two-session SFRs by the same technique were 93.9%, 92.8%, and 89.5% for SWL, mini-PCNL and RIRS, respectively. A lower overall complication rate and higher overall SFR were found with SWL therapy compared to other techniques, Fig. (1).

DISCUSSION

Being a non-invasive outpatient procedure with a low complication rate and good spontaneous passage of stone fragments is the main advantage of SWL. In this study, the overall SFR is 93.9% where 46 out of 49 patients were completely rendered stone free after three session of SWL with overall success rate 95.9%. Badawy et al. reported overall success rates of 83.4% for renal stones with a mean stone size of 12.5 ± 7.2 mm. In children with renal stones measuring 18.2 mm, Ramakrishnan et al. reported a 97% SFR in accordance with our results. The high overall success rate (95.9%) and SFR (93.9%) in our research were attributed to the regular use of ramping procedure, low shock wave rate, percussion diuretics inversion (PDI) approach and alpha blocker therapy in all participants and short SSD. The limitations of our study are small sample of patients and its retrospective nature.

CONCLUSION

The non-invasive nature and replicability of the SWL procedure, along with the high success and low complication rates, give us a new insight to consider its application for treating pediatric renal calculi > 2 cm over the other more invasive techniques. Short SSD, the use of ramping procedure, low shock wave rate, 2 min break, PDI approach and alpha blockers therapy help better success of SWL.

LEVEL OF EVIDENCE

IV.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones

BACKGROUND

Nephrolithiasis is a common urological disease worldwide. Extracorporeal shock wave lithotripsy (ESWL) has been used for the treatment of renal stones since the 1980s, while retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are newer, more invasive treatment modalities that may have higher stone-free rates. The complications of RIRS and PCNL have decreased owing to improvement in surgical techniques and instruments. We re-evaluated the best evidence on this topic in an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effects of extracorporeal shock wave lithotripsy compared with percutaneous nephrolithotomy or retrograde intrarenal surgery for treating kidney stones.

SEARCH METHODS

We performed a comprehensive search in CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov with no restrictions on language or publication status. The latest search date was 6 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared ESWL with PCNL or RIRS for kidney stone treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies, extracted data, and assessed risk of bias. Our primary outcomes were treatment success rate at three months (defined as residual fragments smaller than 4 mm, or as defined by the study authors), quality of life (QoL), and complications. Our secondary outcomes were retreatment rate, auxiliary procedures rate, and duration of hospital stay. We performed statistical analyses using a random-effects model and independently rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 31 trials involving 3361 participants (3060 participants completed follow-up). Four trials were only available as an abstract. Overall mean age was 46.6 years and overall mean stone size was 13.4 mm. Most participants (93.8%) had kidney stones measuring 20 mm or less, and 68.9% had lower pole stones. ESWL versus PCNL ESWL may have a lower three-month treatment success rate than PCNL (risk ratio [RR] 0.67, 95% confidence interval [CI] 0.57 to 0.79; I2 = 87%; 12 studies, 1303 participants; low-certainty evidence). This corresponds to 304 fewer participants per 1000 (397 fewer to 194 fewer) reporting treatment success with ESWL. ESWL may have little or no effect on QoL after treatment compared with PCNL (1 study, 78 participants; low-certainty evidence). ESWL probably leads to fewer complications than PCNL (RR 0.62, 95% CI 0.47 to 0.82; I2 = 18%; 13 studies, 1385 participants; moderate-certainty evidence). This corresponds to 82 fewer participants per 1000 (115 fewer to 39 fewer) having complications after ESWL. ESWL versus RIRS ESWL may have a lower three-month treatment success rate than RIRS (RR 0.85, 95% CI 0.78 to 0.93; I2 = 63%; 13 studies, 1349 participants; low-certainty evidence). This corresponds to 127 fewer participants per 1000 (186 fewer to 59 fewer) reporting treatment success with ESWL. We are very uncertain about QoL after treatment; the evidence is based on three studies (214 participants) that we were unable to pool. We are very uncertain about the difference in complication rates between ESWL and RIRS (RR 0.93, 95% CI 0.63 to 1.36; I2 = 32%; 13 studies, 1305 participants; very low-certainty evidence). This corresponds to nine fewer participants per 1000 (49 fewer to 48 more) having complications after ESWL.

AUTHORS' CONCLUSIONS

ESWL compared with PCNL may have lower three-month success rates, may have a similar effect on QoL, and probably leads to fewer complications. ESWL compared with RIRS may have lower three-month success rates, but the evidence on QoL outcomes and complication rates is very uncertain. These findings should provide valuable information to aid shared decision-making between clinicians and people with kidney stones who are undecided about these three options.

Analysis of Nephrolithiasis Treatment in Highest Reference Hospital-Occurrence of Acromegaly in the Study Group

BACKGROUND

Urolithiasis is one of the most common diseases of the urinary system, the incidence of which is assumed to be up to 100,000 cases per million (10% of the population). The cause of it is dysregulation of renal urine excretion. Acromegaly is a very rare endocrine disorder that causes a somatotropic pituitary adenoma producing higher amounts of growth hormone. It occurs approximately in 80 cases per million (about 0.008% of the population). One of the acromegaly complications may be urolithiasis.

METHODS

Clinical and laboratory results of 2289 patients hospitalized for nephrolithiasis in the highest reference hospital were retrospectively analyzed, distinguishing a subgroup of patients with acromegaly. Statistical analysis was performed to compare the prevalence of the disease in the analyzed subgroup with the epidemiological results available in up-to-date literature.

RESULTS

The distribution of nephrolithiasis treatment was definitely in favor of non-invasive and minimally invasive treatment. The methods used were as follows: ESWL (61.82%), USRL (30.62%), RIRS (4.15%), PCNL (3.1%), and pyelolithotomy (0.31%). Such a distribution limited the potential complications of the procedures while maintaining the high effectiveness of the treatment. Among two thousand two hundred and eighty-nine patients with urolithiasis, two were diagnosed with acromegaly before the nephrological and urological treatment, and seven were diagnosed de novo. Patients with acromegaly required a higher percentage of open surgeries (including nephrectomy) and also had a higher rate of kidney stones recurrence. The concentration of IGF-1 in patients with newly diagnosed acromegaly was similar to those treated with somatostatin analogs (SSA) due to incomplete transsphenoidal pituitary surgery.

CONCLUSIONS

In the population of patients with urolithiasis requiring hospitalization and interventional treatment compared to the general population, the prevalence of acromegaly was almost 50-fold higher (p = 0.025). Acromegaly itself increases the risk of urolithiasis.

Performing percutaneous nephrolithotomy under modified local anesthesia

Objective

This pilot study aimed to assess the practicability and effectiveness of percutaneous nephrolithotomy (PCNL) with vacuum-assisted nephrostomy sheaths for patients under modified local anesthesia (m-LA).

Methods

PCNL with a vacuum-assisted nephrostomy sheath under m-LA was performed in 83 patients between November 2020 and May 2021. An 18F or 20F ClearPetra Nephrostomy Sheath connected vacuum aspiration was used in surgery to keep low pressure in the renal pelvis. For LA, lidocaine and ropivacaine hydrochloride were 1:1 mixed and instilled under ultrasound guidance through the percutaneous nephrolithotomy channel directed toward the design calix. Demographic characteristics, stone characteristics, visual analogue scale (VAS) score, vital signs, operation time, complications, and stone clear rate were recorded and analyzed.

Results

All operations were completed. The mean VAS score was 3.9 ± 1.0. The mean operation time was 55.1 ± 23.6 min. The changes for systolic blood pressure, diastolic blood pressure, and heart rate were 3 ± 21 mmHg, 1 ± 14 mmHg, and −6 ± 14 beats/min, respectively. The change for hemoglobin was −10.7 ± 10.9 g/L. The change for C-reactive protein was 5.39 ± 43.1 mg/L. The total stone-free rate was 69.9% (93.8% for simple stones and 54.9% for complex stones).

Conclusion

Performing PCNL with vacuum-assisted nephrostomy sheaths under modified local anesthesia under ultrasound guidance was found to be strongly practical and effective.

Massive Ureterolithiasis

The authors present the case of a 40-year-old male who visited the emergency department with left-sided flank pain. He was found to have a 12 mm ureteropelvic stone and was provided parenteral analgesia before being admitted to the hospital for urology consultation. The presentation and diagnosis of his case along with treatment options against a backdrop of related studies are discussed.

Outcomes of Retrograde Intrarenal Surgery Performed Under Neuraxial vs. General Anesthesia: An Updated Systematic Review and Meta-Analysis

Background

The current review aimed to assess if the outcomes of retrograde intrarenal surgery (RIRS) differ with neuraxial anesthesia (NA) or general anesthesia (GA).

Methods

The databases of PubMed, Embase, CENTRAL, ScienceDirect, and Google Scholar were searched up to 3rd December 2021 for randomized controlled trials (RCTs) and observational studies comparing outcomes of RIRS with NA or GA.

Results

Thirteen studies involving 2912 patients were included. Eight were RCTs while remaining were observational studies. Meta-analysis revealed that stone free status after RIRS did not differ with NA or GA (OR: 0.99 95% CI: 0.77, 1.26 I2 = 10% p = 0.91). Similarly, there was no difference in operation time (MD: -0.35 95% CI: -4.04, 3.34 I2 = 89% p = 0.85), 24 h pain scores (MD: -0.36 95% CI: -0.96, 0.23 I2 = 95% p = 0.23), length of hospital stay (MD: 0.01 95% CI: -0.06, 0.08 I2 = 35% p = 0.78), Clavien-Dindo grade I (OR: 0.74 95% CI: 0.52, 1.06 I2 = 13% p = 0.10), grade II (OR: 0.70 95% CI: 0.45, 1.07 I2 = 0% p = 0.10) and grade III/IV complication rates (OR: 0.78 95% CI: 0.45, 1.35 I2 = 0% p = 0.37) between NA and GA. Except for grade I complications, the results did not change on subgroup analysis based on study type and NA type.

Conclusion

Our results suggest that NA can be an alternative to GA for RIRS. There seem to be no difference in the stone-free rates, operation time, 24-h pain scores, complication rates, and length of hospital stay between NA and GA for RIRS. Considering the economic benefits, the use of NA may be preferred over GA while taking into account patient willingness, baseline patient characteristics, and stone burden.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021295407.

Volume should be used instead of diameter for kidney stones between 10 and 20 mm to determine the type of surgery and increase success

Aim of this study is to categorize stones between 10 and 20 mm according to stone diameter or volume and compare mini percutaneous nephrolithotomy (mPNL) and retrograde intrarenal surgery (RIRS) outcomes. Files of 515 patients who underwent surgery for kidney stones with sizes 10-20 mm were reviewed. Patients were divided into RIRS or mPNL groups. An attempt was made to find the diameter and volume threshold values above which the success of the operation, complication rates and the number of auxiliary treatments deteriorated. Subgroup analysis was performed below and above the threshold value to reveal the optimal treatment methods. RIRS complications increased with volumes above 1064 mm³, number of auxiliary interventions increased with volumes above 1256 mm³, and success of the operation decreased with volumes above 1416 mm³. A subgroup analysis under and over 1064 mm³ was performed in RIRS group. Complication and auxiliary treatment rates were higher, operative success was lower in patients with a stone volume greater than 1064 mm³. In patients who underwent RIRS, for every 1000 mm³ increase in stone volume success of the operation decreased by 2.1 times, while the probability of auxiliary treatment increased by 2.8 times. In patients with kidney stones between 10 and 20 mm, it is more meaningful to use volume instead of diameter to determine the success rate. When mPNL is used instead of RIRS for volumes greater than 1064 mm³, the success rate will be higher, complication rate will be similar, and the need for auxiliary treatment will be lower.

Can We Identify Patients in Danger of Complications in Retrograde Intrarenal Surgery?-A Retrospective Risk Factors Analysis

Retrograde intrarenal surgery (RIRS) is an innovative and effective method of kidney stones treatment, as it had great influence on the development of endoscopy in urology. The increasing prevalence of urolithiasis together with the rapid development of endourology leads to a rise in the number of procedures related to the disease. Flexible ureteroscopy is constantly being improved, especially regarding the effectiveness and safety of the procedure. The purpose of this study is to evaluate intraoperative and early post-operative complications of RIRS in the treatment of kidney stones. A retrospective analysis of medical records was performed. A series was comprised of 207 consecutive operations performed from 2017 to 2020. Complications occurred in 19.3% (n = 40) of patients. Occurrence according to the Clavien-Dindo scale was: 11.1% for grade I, 5.8% for grade II and 2.4% for grade IV. Infectious complications included SIRS (5.3%, n = 11) and sepsis (2.4%, n = 5). Statistical analysis revealed a correlation between acute post-operative infections and positive midstream urine culture, history of chronic or recurrent urinary tract infections, and increased body mass index (BMI). Furthermore, a significant correlation was observed between pain requiring the use of opioids with BMI over 25. Consequently, history of urinary tract infections, positive pre-operative urine culture, and increased BMI are considered risk factors and require appropriate management.

Should we support prophylactic intervention for asymptomatic kidney stones? A retrospective cohort study with long-term follow-up

The purpose of this study was to evaluate the long-term outcomes of patients undergoing prophylactic intervention or active surveillance for asymptomatic kidney stones and identify factors influencing the outcomes. In this retrospective cohort study, we reviewed the medical records of patients with asymptomatic kidney stones in two institutes between November 2014 and November 2019. Standardized questions were asked via phone calls to supplement the outcomes. Pain, hydronephrosis, stone growth, serious infection, gross hematuria, and spontaneous passage were defined as stone-related events. Future intervention was also recorded to evaluate management. A total of 101 patients with 120 kidney units were enrolled in this study. The median follow-up time was 63 months. The patients were classified into the control group (79 cases) or exposure group (41 cases) according to whether they underwent prophylactic intervention before any stone-related events. Generally, the rates of stone-related events and future intervention were significantly different between the two groups (57.0 vs. 12.2%, p < 0.001; and 31.6 vs. 4.9%, p = 0.002, respectively). After applying stabilized inverse probability of treatment weighted, Cox regression suggested that patients who underwent prophylactic intervention were less likely to experience stone-related events and future intervention (HR = 0.175, and HR = 0.028, respectively). In conclusion, patients who underwent prophylactic intervention had a lower risk of stone-related events and future intervention, although they had some slight complications.

Erector Spinae Plane Block for Perioperative Analgesia after Percutaneous Nephrolithotomy

Erector spinae plane block was recently introduced as an alternative to postoperative analgesia in surgical procedures including thoracoscopies and mastectomies. There are no clinical trials regarding erector spinae plane block in percutaneous nephrolithotomy. The aim of our study was to test the efficacy and safety of erector spinae plane block after percutaneous nephrolithotomy. We analyzed 68 patients, 34 of whom received erector spinae plane block. The average visual analogue scale score 24 h postoperatively was the primary endpoint. The secondary endpoints were nalbuphine consumption and the need for rescue analgesia. Safety measures included the mean arterial pressure, Ramsey scale score, and rate of nausea and vomiting. The visual analogue scale, blood pressure, and Ramsey scale were assessed simultaneously at 1, 2, 4, 6, 12, and 24 h postoperatively. The average visual analogue scale was 2.9 and 3 (p = 0.65) in groups 1 (experimental) and 2 (control), respectively. The visual analogue scale after 1 h postoperatively was significantly lower in the erector spinae plane block group (2.3 vs. 3.3; p = 0.01). The average nalbuphine consumption was the same in both groups (46 mL vs. 47.2 mL, p = 0.69). The need for rescue analgesia was insignificantly different in both groups (group 1, 29.4; group 2, 26.4%; p = 1). The mean arterial pressure was similar in both groups postoperatively (91.8 vs. 92.5 mmHg; p = 0.63). The rate of nausea and vomiting was insignificantly different between the groups (group 1, 17.6%; group 2, 14.7%; p = 1). The median Ramsey scale in all the measurements was two. Erector spinae plane block is an effective pain treatment after percutaneous nephrolithotomy but only for a very short postoperative period.