Factors affecting bleeding during percutaneous nephrolithotomy: single surgeon experience

Analysis of factors affecting intraoperative hemorrhage during percutaneous nephrolithotomy and establishment of nomogram model

Intraoperative hemorrhage is an important factor affecting intraoperative safety and postoperative patient recovery in percutaneous nephrolithotomy (PCNL). This study aimed to identify the factors that influence intraoperative hemorrhage during PCNL and develop a predictive nomogram model based on these factors.A total of 118 patients who underwent PCNL at the Department of Urology, The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University from January 2021 to September 2023 was included in this study. The patients were divided into a hemorrhage group (58 cases) and a control group (60 cases) based on the decrease in hemoglobin levels after surgery. The clinical data of all patients were collected, and both univariate analysis and multivariate logistic regression analysis were conducted to identify the independent risk factors for intraoperative hemorrhage during PCNL. The independent risk factors were used to construct a nomogram model using R software. Additionally, receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA) were utilized to evaluate the model.Multivariate logistic regression analysis revealed that diabetes, long operation time and low psoas muscle mass index (PMI) were independent risk factors for intraoperative hemorrhage during PCNL (P < 0.05). A nomogram model was developed incorporating these factors, and the areas under the ROC curve (AUCs) in the training set and validation set were 0.740 (95% CI: 0.637-0.843) and 0.742 (95% CI: 0.554-0.931), respectively. The calibration curve and Hosmer-Lemeshow test (P = 0.719) of the model proved that the model was well fitted and calibrated. The results of the DCA showed that the model had high value for clinical application.Diabetes, long operation time and low PMI were found to be independent risk factors for intraoperative hemorrhage during PCNL. The nomogram model based on these factors can be used to predict the risk of intraoperative hemorrhage, which is beneficial for perioperative intervention in high-risk groups to improve the safety of surgery and reduce the incidence of postoperative complications.

Assessment of Pre-operative Factors Associated With Blood Loss in Patients Undergoing Percutaneous Nephrolithotomy: A Prospective Study

Background One of the main risks associated with percutaneous nephrolithotomy (PCNL) is bleeding. In the present study, efforts are made to evaluate the pre-operative predictive factors contributing to bleeding due to the procedure of PCNL. Materials and methods From December 2019 to November 2021, data were collected prospectively from 193 patients undergoing PCNL procedures at Indira Gandhi Institute of Medical Sciences, Patna, India. Following PCNL, to check for hematuria and the extent of blood loss, the urethral catheter's and nephrostomy tube's outputs were evaluated. Multivariate regression analysis was used to evaluate the relationship between blood loss and a variety of patient-related demographic and clinical characteristics. Results Included in the study were 193 patients who underwent PCNL. Male patients made up the majority. The average age of study participants was 33.5 years. No statistically significant difference was reported in the mean hemoglobin level drop in the age groups of up to 25 years (2.211 ± 1.540 g/dL), 26-50 years (2.023 ± 1.882 g/dL), and > 50 years (1.855 ± 0.986 g/dL) with P = 0.64. The mean hemoglobin level drop in patients with stone burden > 30 mm2 was reported to be higher, 2.359 ± 1.822 g/dL, compared to 1.859 ± 1.540 g/dL in patients with lower stone burden, reaching a statistically significant difference (P =0.0408). By univariate regression analysis, the presence of a horseshoe-shaped kidney (odds ratio = -0.158, 95% confidence interval (CI): -0.911, -0.059; P = 0.026) was associated with a higher risk for a drop in mean hemoglobin level. By multivariate regression analysis, the presence of a horseshoe-shaped kidney (odds ratio = 0.071, 95% CI: 0.006, 0.839; P = 0.036) remained significantly and independently associated with a higher risk of a drop in mean hemoglobin level. Conclusion In conclusion, the patients' burden of stones and the presence of a horseshoe-shaped kidney may be associated with a higher risk of bleeding following PCNL.

Comparison of Percutaneous Renal Access Between Robot-Assisted Fluoroscopy Guidance Using the Bi-Plane Method and Ultrasound Guidance: A Multicenter Randomized Control Benchtop Study

Purpose: To evaluate the efficacy of supine percutaneous renal access by robot-assisted (RA) fluoroscopy and ultrasound (US) guidance in terms of procedural outcomes and surgeon workload. Methods: We conducted a multicenter, randomized, controlled benchtop study involving 32 urologists using a renal phantom model. RA puncture was performed using the developed version of automated needle targeting with X-ray (ANT-X), which determines the direction of the needle. US puncture was performed under US guidance. The primary endpoint was the single-puncture success rate, and the secondary outcomes were the procedural time for each step, time of fluoroscopic exposure, and workload assessment. Results: The single-puncture success rates were 90.6% and 56.3% for RA and US punctures, respectively (p < 0.01). In RA puncture, the median device setup time was 120 seconds longer, the median total procedural time was 100 seconds longer, the median time of fluoroscopic exposure was 40 seconds longer, the median needle puncture time was 17 seconds shorter, and the distance from the target sphere was 1 cm shorter than those in US puncture (all p < 0.01). The mental and physical task workload, effort required by the surgeons, frustration felt by the surgeons, and overall National Aeronautics and Space Administration Task Load Index scores were lower in the RA puncture group than in the US puncture group (p = 0.01, p = 0.046, p < 0.01, p = 0.021, and p ≤ 0.01, respectively). Conclusions: RA puncture using ANT-X, which can also be used for puncture in the supine position, offers advantages over renal puncture in terms of accuracy and surgical workload.

Predictive factors for percutaneous nephrolithotomy bleeding risks

Objective

This study aimed to identify predictive factors for percutaneous nephrolithotomy (PCNL) bleeding risks. With better risk stratification, bleeding in high-risk patient can be anticipated and facilitates early identification.

Methods

A prospective observational study of PCNL performed at our institution was done. All adults with radio-opaque renal stones planned for PCNL were included except those with coagulopathy, planned for additional procedures. Factors including gender, co-morbidities, body mass index, stone burden, puncture site, tract dilatation size, operative position, surgeon's seniority, and operative duration were studied using stepwise multivariate regression analysis to identify the predictive factors associated with higher estimated hemoglobin (Hb) deficiency.

Results

Overall, 4.86% patients (n=7) received packed cells transfusion. The mean estimated Hb deficiency was 1.3 (range 0-6.5) g/dL and the median was 1.0 g/dL. Stepwise multivariate regression analysis revealed that absence of hypertension (p=0.024), puncture site (p=0.027), and operative duration (p=0.023) were significantly associated with higher estimated Hb deficiency. However, the effect sizes are rather small with partial eta-squared of 0.037, 0.066, and 0.038, respectively. Observed power obtained was 0.621, 0.722, and 0.625, respectively. Other factors studied did not correlate with Hb difference.

Conclusion

Hypertension, puncture site, and operative duration have significant impact on estimated Hb deficiency during PCNL. However, the effect size is rather small despite adequate study power obtained. Nonetheless, operative position (supine or prone), puncture number, or tract dilatation size did not correlate with Hb difference. The mainstay of reducing bleeding in PCNL is still meticulous operative technique. Our study findings also suggest that PCNL can be safely done by urology trainees under supervision in suitably selected patient, without increasing risk of bleeding.

Predictive factors of delayed bleeding after percutaneous nephrolithotomy requiring angioembolization

Objectives

To investigate the predictive factors of delayed post-percutaneous nephrolithotomy (PCNL) haemorrhage because of arteriovenous fistula (AVF) or pseudoaneurysm (PA) and compare the factors between AVF and PA.

Patients and methods

This is a case-control study with a case-to-control ratio of 1:3. Out of 5077 patients who underwent PCNL from April 2015 to April 2018 in three different teaching hospitals, 113 had post-PCNL haemorrhages because of AVF and/or PA. Seventy-two patients met the inclusion criteria and entered the study as cases, while 216 patients without any postoperative complications were selected as controls.

Results

Of all 72 studied patients with complications after PCNL, 35 (48.6%) had AVF, and the rest had PA. The regression model revealed that a history of diabetes (odds ratio [OR]: 2.799, 95% confidence interval [CI]: 1.392-5.630, p-value = 0.004) and renal anomalies (OR: 2.929, 95% CI: 1.108-7.744, p-value = 0.03) were associated with developing delayed post-PCNL haemorrhage. However, no differences were seen between AVF and PA regarding selected variables (p-value > 0.05).

Conclusion

History of diabetes and renal anomalies were predictive factors for delayed post-PCNL haemorrhage, but no predictive factors were found to differentiate PA and AVF from one another.

Comparison of Treatment Outcomes for Fluoroscopic and Fluoroscopy-free Endourological Procedures: A Systematic Review on Behalf of the European Association of Urology Urolithiasis Guidelines Panel

CONTEXT

Endourological procedures frequently require fluoroscopic guidance, which results in harmful radiation exposure to patients and staff. One clinician-controlled method for decreasing exposure to ionising radiation in patients with urolithiasis is to avoid the use of intraoperative fluoroscopy during stone intervention procedures.

OBJECTIVE

To comparatively assess the benefits and risks of "fluoroscopy-free" and fluoroscopic endourological interventions in patients with urolithiasis.

EVIDENCE ACQUISITION

A systematic review of the literature from 1970 to 2022 was performed using the MEDLINE/PubMed, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov. Primary outcomes assessed were complications and the stone-free rate (SFR). Studies reporting data on ureteroscopy and percutaneous nephrolithotomy (PCNL) were eligible for inclusion. Secondary outcomes were operative duration, hospital length of stay, conversion from a fluoroscopy-free to a fluoroscopic procedure, and requirement for an auxiliary procedure to achieve stone clearance.

EVIDENCE SYNTHESIS

In total, 24 studies (12 randomised and 12 observational) out of 834 abstracts screened were eligible for analysis. There were 4564 patients with urolithiasis in total, of whom 2309 underwent a fluoroscopy-free procedure and 2255 underwent a comparative fluoroscopic procedure for treatment of urolithiasis. Pooled analysis of all procedures revealed no significant difference between the groups in SFR (p = 0.84), operative duration (p = 0.11), or length of stay (p = 0.13). Complication rates were significantly higher in the fluoroscopy group (p = 0.009). The incidence of conversion from a fluoroscopy-free to a fluoroscopic procedure was 2.84%. Similar results were noted in subanalyses for ureteroscopy (n = 2647) and PCNL (n = 1917). When only randomised studies were analysed (n = 12), the overall complication rate was significantly in the fluoroscopy group (p < 0.001).

CONCLUSIONS

For carefully selected patients with urolithiasis, fluoroscopy-free and fluoroscopic endourological procedures have comparable stone-free and complication rates when performed by experienced urologists. In addition, the conversion rate from a fluoroscopy-free to a fluoroscopic endourological procedure is low at 2.84%. These findings are important for clinicians and patients, as the detrimental health effects of ionising radiation are negated with fluoroscopy-free procedures.

PATIENT SUMMARY

We compared treatments for kidney stones with and without the use of radiation. We found that kidney stone procedures without the use of radiation can be safely performed by experienced urologists in patients with normal kidney anatomy. These findings are important, as they indicate that the harmful effects of radiation can be avoided during kidney stone surgery.

Tranexamic acid for percutaneous nephrolithotomy

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of large kidney stones but comes with an increased risk of bleeding compared to other treatments, such as ureteroscopy and shock wave lithotripsy. Tranexamic acid (TXA) is an antifibrinolytic agent that has been used to reduce bleeding complications in other settings.

OBJECTIVES

To assess the effects of TXA in individuals with kidney stones undergoing PCNL.

SEARCH METHODS

We performed a comprehensive literature search of the Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, other sources of the grey literature, and conference proceedings. We applied no restrictions on the language of publication nor publication status. The latest search date was 11 May 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients ≥ 18 years old.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data. Primary outcomes were: blood transfusion, stone-free rate (SFR), and thromboembolic events (TEEs). Secondary outcomes were: adverse events (AEs), secondary interventions, major surgical complications, minor surgical complications, unplanned hospitalizations or readmissions, and hospital length of stay (LOS). We performed statistical analyzes using a random-effects model. We rated the certainty of evidence (CoE) according to the GRADE approach using a minimally contextualized approach with predefined thresholds for minimally clinically important differences (MCIDs).

MAIN RESULTS

We analyzed 10 RCTs assessing the effect of systemic TXA in PCNL versus placebo (or no TXA) with 1883 randomized participants. Eight studies were published as full text. One was published in abstract proceedings, but it was separated into two separate studies for the purpose of our analyzes. Average stone surface area ranged 3.45 to 6.62 cm2. We also found a single RCT published in full text assessing the effects of topical TXA in PCNL versus placebo (or no TXA) with 400 randomized participants, the results of which are further described in the review. Here we focus only on the results of TXA used systemically. Blood transfusion - Based on a representative baseline risk of 5.7% for blood transfusions taken from a large presentative observational studies, systemic TXA may reduce blood transfusions (risk ratio (RR) 0.45, 95% confidence interval (CI) 0.27 to 0.76; I2 = 28%; 9 studies, 1353 participants; low CoE). We assumed an MCID of ≥ 2%. Based on 57 participants per 1000 with placebo (or no TXA) being transfused, this corresponds to 31 fewer (from 42 fewer to 14 fewer) participants being transfused per 1000. Stone-free rate - Based on a representative baseline risk of 75.7% for SFR, systemic TXA may increase SFRs (RR 1.11, 95% CI 0.98 to 1.27; I2 = 62%; 4 studies, 603 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 757 participants per 1000 being stone free with placebo (or no TXA), this corresponds to 83 more (from 15 fewer to 204 more) stone-free participants per 1000. Thromboembolic events - There is probably no difference in TEEs (risk difference (RD) 0.00, 95% CI -0.01 to 0.01; I2 = 0%; 6 studies, 841 participants; moderate CoE). We assumed an MCID of ≥ 2%. Since there were no thromboembolic events in intervention and/or control groups in 5 out of6 studies, we opted to assess a risk difference with systemic TXA for this outcome. Adverse events - Systemic TXA may increase AEs (RR 5.22, 95% CI 0.52 to 52.72; I2 = 75%; 4 studies, 602 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 23 participants per 1000 with placebo (or no TXA) having an adverse event, this corresponds to 98 more (from 11 fewer to 1000 more) participants with adverse events per 1000. Secondary interventions - Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84 to 1.57; I2 = 0%; 2 studies, 319 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 278 participants per 1000 with placebo (or no TXA) having a secondary intervention, this corresponds to 42 more (from 44 fewer to 158 more) participants with secondary interventions per 1000. Major surgical complications - Based on a representative baseline risk for major surgical complications of 4.1%, systemic TXA may reduce major surgical complications (RR 0.36, 95% CI 0.21 to 0.62; I2 = 0%; 5 studies, 733 participants; moderate CoE). We assumed an MCID of ≥ 2%. Based on 41 participants per 1000 with placebo (or no TXA) having a major surgical complication, this corresponds to 26 fewer (from 32 fewer to 16 fewer) participants with major surgical complications per 1000. Minor surgical complications - Systemic TXA may reduce minor surgical complications (RR 0.71, 95% CI 0.45 to 1.10; I2 = 76%; 5 studies, 733 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 396 participants per 1000 with placebo (or no TXA) having a minor surgical complication, this corresponds to 115 fewer (from 218 fewer to 40 more) participants with minor surgical complications per 1000. Unplanned hospitalizations or readmissions - We are very uncertain how unplanned hospitalizations or readmissions are affected (RR 1.55, 95% CI 0.45 to 5.31; I2 = not applicable; 1 study, 189 participants; very low CoE). We assumed an MCID of ≥ 2%. Hospital length of stay - Systemic TXA may reduce hospital LOS (mean difference 0.52 days lower, 95% CI 0.93 lower to 0.11 lower; I2 = 98%; 7 studies, 1151 participants; low CoE). We assumed an MCID of ≥ 0.5 days.

AUTHORS' CONCLUSIONS

Based on 10 RCTs with substantial methodological limitations that lowered all CoE of effect, we found that systemic TXA in PCNL may reduce blood transfusions, major and minor surgical complications, and hospital LOS, as well as improve SFRs; however, it may increase AEs. We are uncertain about the effects of systemic TXA on other outcomes. Findings of this review should assist urologists and their patients in making informed decisions about the use of TXA in the setting of PCNL.

Predictive factors of selective transarterial embolization failure in acute renal bleeding: a single-center experience

PURPOSE

Transarterial embolization of renal artery branches (RTE) is a minimally invasive procedure commonly performed in life-threatening renal bleeding of different etiologies. Despite the widespread use of RTE, no consensus guidelines are currently available. Our aim was to investigate clinical and technical efficacy and to identify potential predictors for clinical failure of this procedure.

METHODS

All the RTE procedures performed in our Interventional Radiology unit in last 10 years were retrospectively collected and analyzed. All selected patients underwent both pre-procedural computed tomography angiography (CTA) and post-procedural CTA within 30 days. Clinical success was considered as primary endpoint. Demographic, laboratory, and diagnostic findings predictive of clinical failure of RTE were identified.

RESULTS

Over a total of 51 patients enrolled, 27 (53%) were females and 33 (64.7%) had a renal bleeding of iatrogenic origin. Technical and clinical success was 100% and 80.4%, respectively. Hematoma volumes > 258.5 cm3 measured at CTA, higher pre- and post-procedural serum creatinine (Scr) levels, an increase in Scr value > 0.135 mg/dl after the procedure, a worse post-procedural estimated glomerular filtration rate (eGFR), a post-procedural reduction of eGFR < 3.350 ml/min, and a post-procedural reduction of platelet count (PLT) > 46.50 × 103/mmc showed a significantly higher rate of clinical failure.

CONCLUSION

RTE is a safe and effective procedure in the management of acute renal bleeding of various origins. Hematoma volume, Scr, PLT, and eGFR values were found to be predictive factors of poor clinical outcome and should be closely monitored.

Surgical Delay Increases the Perioperative Blood Transfusion Rate In Percutaneous Nephrolithotomy

Objectives

We aimed to investigate the effect of prolonged time from diagnosis to treatment (TDT) on surgical outcomes in patients undergoing percutaneous nephrolithotomy (PNL).

Methods

This study included a total of 544 patients who underwent PNL in our clinic between November 2017 and November 2021. Clinicodemographical, radiological, and perioperative data of the patients were recorded. The stone-free rate as assessed by abdominal computed tomography at 3 months was estimated. The possible relation of the stone-free rate and perioperative complications with TDT was examined.

Results

The median age was 48 (range, 38-58) years, the median stone size was 405 (range, 250-700) mm2, and the median stone density was 1,000 (range, 730-1,221) Hounsfield units. The median TDT was 75 (range, 42-133) days. Twenty-seven patients (5.0%) required perioperative blood transfusion (PBT). There was a statistically significant correlation between TDT and the need for PBT (p=0.022). However, there was no significant correlation between TDT and stone-free rate (p>0.05). Using a cutoff value of 90.5 days, TDT could predict the need for PBT with 59.3% sensitivity and 60% specificity.

Conclusion

Our study results suggest that the need for PBT increases in patients undergoing PNL longer than 90.5 days after the diagnosis. However, further large-scale, prospective studies are warranted to elucidate the effect of prolonged TDT on surgical outcomes in this patient population.

The Mayo adhesive probability score predicts postoperative fever and intraoperative hemorrhage in mini-percutaneous nephrolithotomy

PURPOSE

Contemporary predictive tools for miniaturized percutaneous nephrolithotomy (mPCNL) mainly focus on stone clearance but not perioperative complications, especially infection and hemorrhage. This study aimed to evaluate whether the Mayo adhesive probability (MAP) score, an index of the perinephric fat characteristics, can predict postoperative fever and intraoperative hemorrhage in mPCNL.

METHODS

This is a retrospective study recruiting 159 mPCNL patients from July 2018 to January 2022. MAP scores were recorded using preoperative computed tomography. Postoperative complications included postoperative fever and intraoperative bleeding, defined as hemoglobin drop.

RESULTS

Over half patients had the MAP score ≧ 3. Men, elderly, chronic kidney disease, and diabetes were associated with a higher MAP score. The patients with a higher MAP score were more likely to have postoperative fever after mPCNL. On multivariate analysis, preoperative positive urine culture (OR 2.68) and a higher MAP score (OR 2.28) were both significantly associated with postoperative fever. ROC curves analysis of the combination of these two factors on predicting postoperative fever showed AUC values were 0.731 (0.652-0.810). Moreover, a higher MAP score (OR 2.30) and longer operative time (OR 2.16) were significantly associated with higher hemoglobin drop on multivariate analysis.

CONCLUSION

A high MAP score was associated with postoperative fever and intraoperative hemorrhage in patients undergoing mPCNL. The MAP score can be a novel and easy predictive tool to help endourologists improve the awareness of mPCNL safety.

Application of Bipolar Cauterization During Standard Percutaneous Nephrolithotomy

Introduction: We aimed to evaluate the efficacy of bipolar cauterization for tract site bleeding during standard percutaneous nephrolithotomy (PCNL). Methods and Materials: We defined tract site bleeding as when the visual field across the parenchymal tract starts to bleed while the sheath of a balloon dilator is being withdrawn just before the operation is completed. Among 181 patients, 90 patients showed no significant bleeding, and 91 patients required further procedures to resolve tract site bleeding. In cases of unresolved tract site bleeding, either nephrostomy placement (n = 60) or cauterization (n = 31) was performed. The outcomes of three groups (no procedure group, nephrostomy group and cauterization group) were compared. Results: The median decrease in hemoglobin at 2-hour intervals postoperatively was -1.75, -1.0, and -0.2 in the nephrostomy, cauterization, and no procedure groups, respectively (P < .001). There were 25 patients (41.7%) who received transfusions in the nephrostomy group, whereas only 1 patient (3.2%) received a transfusion in the cauterization group (P < .001). Conclusion: The bipolar cauterization of bleeding points at the end of PCNL could efficiently decrease tract site bleeding and reduce the need for transfusion. Clinical Research Information Service (https://cris.nih.go.kr/cris; No. KCT0008303).

Comparative analysis of re-entry malecot and nelaton catheters after standard percutaneous nephrolithotomy in adult patients: a cross-sectional study

Drainage catheters are used almost routinely to provide urinary drainage, prevent extravasation of urine, and create tamponade against bleeding after percutaneous nephrolithotomy (PNL). In the literature, there is no standardized approach to determining which type of catheter is superior. In this context, we aimed to comparatively analyze two different types of catheters (re-entry malecot catheter and nelaton catheter) in terms of success and complications, which we use for drainage after a PNL operation and which have very different costs. Patients who underwent PNL for kidney stones between January 2018 and October 2022 were included in the study. The data of a total of 148 patients who had a 16-F reentry malecot nephrostomy catheter or a 16-F nelaton catheter were analyzed. In addition to the demographic characteristics of the patients, stone characteristics, operative data, hospitalization time, analgesia requirement, hemoglobin exchange, amount of blood transfusion, and postoperative data (success and complications) were comparatively evaluated. The current unit price for a reentry malecot and a nelaton catheter is 4.7 United States dollars (USD) and 0.11 USD, respectively. There were a total of 148 patients in the study, 63 of whom were nelaton catheters and 85 were reentry malecots, and the mean age was 39.95 ± 13.28 years. There was no statistically significant difference between preoperative stone sizes and residual stone rates according to the groups. In addition, there was no statistically significant difference between the groups in terms of access site and stone localization. There was no significant difference between the groups in terms of complication rates according to the Clavien-Dindo classification, Hb levels, blood transfusion rates, operation times, or hospitalization times. In conclusion, if a second procedure is planned, a reentry malecot catheter may be preferred. Apart from this situation, nelaton catheters should be preferred because they are similar to reentry catheters in terms of effectiveness, and side effects and are more economical than reentry catheters in terms of cost.

Successful Management of an Inadvertent Placement of a Nephrostomy Tube Into the Inferior Vena Cava Following Percutaneous Nephrolithotomy: A Case Discussion and Literature Review of a Rare Complication

In a percutaneous nephrolithotomy (PCNL) procedure, the placement of the nephrostomy tube is usually inserted last to monitor and maintain urine drainage, avoid potential urine extravasation, and ensure hemostasis. In this report, we provide a clinical case involving the misplacement of a nephrostomy tube, resulting in direct perforation of the inferior vena cava (IVC) after undergoing one-sided PCNL that was successfully treated conservatively, and investigate the current management censuses from the literature for intravenous misplacement of a nephrostomy tube. In our patient, the tip of the nephrostomy catheter was located in the IVC. It was successfully managed using a one-step catheter withdrawal with the surgical vascular team on standby for any potential encounters with massive uncontrollable bleeding. An enhanced CT angiogram on day 14 post-PCNL revealed a lower polar renal arteriovenous pseudoaneurysm which required our patient to undergo selective angioembolization, resulting in maximal parenchymal preservation. The patient was successfully managed and discharged uneventfully. Thirteen cases that have reported inadvertent misplacements in the PubMed database have been discussed in this review. Our case would be the first documented report where a percutaneous nephrostomy drainage tube pierced through the IVC directly. Our case provides an argument for patients to be managed by tube withdrawal under one-step fluoroscopic guidance. Intensive care measures and ultrasound monitoring for two hours followed by another CT angiogram proved effective successful conservative management in a high-volume urologic practice.

Development and internal validation of a prediction model to evaluate the risk of severe hemorrhage following mini-percutaneous nephrolithotomy

PURPOSE

To develop a new prediction model for assessing the severe hemorrhage events in post mini-percutaneous nephrolithotomy (mini-PCNL) patients and internally validate it, thus to guide decision making in clinical practice.

METHODS

The patients who underwent mini-PCNL were retrospectively reviewed. Potential risk factors were included as prediction variables for multivariate logistic regression analysis to identify independent risk factors, and prediction model was constructed. The predictive ability of the model was evaluated using the Concordance index (C-index) and Brier score. Bootstrapping resampling technique was used to perform internal validation. The related packages in R were used to generate the web application based on the prediction model.

RESULTS

Multiple-tract was the strongest predictor of severe hemorrhage following mini-PCNL. Other risk factors were none or mild hydronephrosis, congenital anomalies of urinary system, urinary tract infection, operation time and stone peak Hounsfield unit. A prediction model was constructed to assess the probability of severe hemorrhage after mini-PCNL. The C-index and Brier score were 0.731 and 0.093, respectively after correcting for optimism, which signified the excellent discrimination and calibration.

CONCLUSION

A new prediction model was developed to estimate risk of severe hemorrhage after mini-PCNL. It had been internally validated with good discrimination and calibration. The prediction model might be beneficial for endourologists in surgical decision-making and risk aversion.

Knowledge-map analysis of percutaneous nephrolithotomy (PNL) for urolithiasis

Percutaneous nephrolithotomy (PNL) has been used in the treatment of urolithiasis for more than 20 years. However, bibliometric analysis of the global use of PNL for urolithiasis is rare. We retrieved the literatures on PNL and urolithiasis from Web of science core collection database. VOSviewer was used to analyze keywords, citations, publications, co-authorship, themes, and trend topics. A total of 3103 articles were analyzed, most of which were original ones. The most common keywords were "percutaneous nephrology" and "urolithiasis", both of which were closely related to "ureteroscopy". Journal of Urology and Zeng Guohua from the First Affiliated Hospital of Guangzhou Medical University were the most published journal and author in this field. The most productive country was the United States, and its closest partners were Canada, China, and Italy. The five hot topics were the specific application methods and means, risk factors of urolithiasis, the development of treatment technology of urolithiasis, the characteristics, composition, and properties of stones, and the evaluation of curative effect. This study aimed to provide a new perspective for PNL treatment of urolithiasis and provided valuable information for urologic researchers to understand their research hotspots, cooperative institutions, and research frontiers.

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.

Comparison Between Percutaneous Nephrolithotomy and Retrograde Flexible Nephrolithotripsy in Obese Patients with 2 - 4 cm Renal Stones

Background: Nowadays, because of remarkable advancements in retrograde intrarenal surgery (RIRS), modest attention toward this procedure as the second or alternative choice for renal stones treatment has been drawn. Objectives: In the present study, we compared RIRS and percutaneous nephrolithotomy (PCNL) outcomes in treating obese patients with 2 - 4 cm renal stones. Methods: Eighty-two patients who underwent PCNL (n = 40) and RIRS (n = 42) between June 2015 and December 2018 at the Department of Urology of Sina Hospital were enrolled in our retrospective cohort study. Results: After the first surgery session, stone-free rates for the RIRS group were 92.9% and for the PCNL group was 95% (P value = 0.52). The mean operation time for the RIRS and PCNL groups were 71.6 ± 11 and 93.3 ± 12.2, respectively (P < 0.001). The hospitalization stay for all of the PCNL group was more than 1 day (mean = 2.5 days); however, that for the majority of the RIRS group was less than 1 day (P < 0.001). The analgesic use in the RIRS group was significantly lower than in the PCNL group (9.0 ± 5.5, 61.8 ± 13.6, respectively; P < 0.001). The overall complication rates were higher in the RIRS group. However, none of them were statically significant (P > 0.05). Conclusions: According to satisfactory outcomes obtained in the RIRS groups, it can be concluded that RIRS can be applied as an alternative or even the first choice in obese patients with 2 - 4 cm renal stones.

Independent risk factors affecting hemorrhage in percutaneous nephrolithotomy: Retrospective study

INTRODUCTION

The perioperative and postoperative concern in percutaneous nephrolithotomy (PNL) is bleeding. Disease-related conditions (such as stone size, stone HU, tract number, and diameter) affecting this situation were determined. To determine independent risk factors that may affect the amount of hemorrhage in PNL.

MATERIAL AND METHOD

A total of 308 adult patients (211 men, 97 women) undergoing the PNL procedure were included in the study. Renal anatomy and stone size were evaluated using non-contrast thin-section computed tomography (NCCT). NCCT was used to assess Hounsfield unit (HU) values of kidney stones, presence of atheroma plaque and obesity. The difference between preoperative hemoglobin (Hgb) values and postoperative 1st day Hgb values was recorded. This variation was evaluated for the effect of gender, age, atherosclerotic vein disease, urine pH and density, leukocyte count, lymphocyte count, neutrophil count (NEU), platelet count, mean platelet volume (MPV), neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR), stone volume, HU, and obesity.

RESULTS

The mean Hgb variation was identified as 2.1 (standard deviation: 1.6). There were positive, significant, and weak correlations between the Hgb variation with NEU (P=0.019), MPV (P=0.000), NLR (P=0.005), stone volume (P=0.041) and HU (P=0.024) values. There was a negative significant and weak correlation between Hgb variation and PLT (P=0.022). No effects at significant levels were identified for gender (P=0.078), presence of atheroma plaque (P=0.949), obesity (P=0.869), age (P=0.686), urine pH (P=0.746), urine density (P=0.421), and PLR (P=0.855) on Hgb variations.

CONCLUSION

In addition to HU and stone volume, NEU count, MPV, NLR and PLT count may be used as independent risk factors to predict blood loss during PNL.

Risk Factors for Intra-operative Bleeding in Percutaneous Nephrolithotomy in an Academic Center: A Retrospective Study

Background

Percutaneous nephrolithotomy (PNL) is the treatment of choice for renal stones as a safe, effective, and minimally invasive method. However, bleeding remains a major concern in the procedure.

Objectives

This study aimed to investigate the risk factors of bleeding in PNL.

Methods

This retrospective descriptive cross-sectional study was conducted in the Urology department of Razi hospital. The data of patients with urinary calculi staghorn type who underwent PNL in a prone position under general anesthesia were recorded. A checklist including patients' demographics, surgical characteristics, and outcomes was filled out for each patient.

Results

The data from 151 complete files were gathered. The mean age of the cases was 47.89 ± 12.41 years. The mean hemoglobin (Hb) drop was 1.92 ± 1.56 mg/dL. At least 1 mg/dL Hb drop was observed in all cases. The highest Hb drop was 3 mg/dL.). There was no significant relationship between stone bulk, age, BMI, GFR, surgery duration, and the number of tracts, and Hb drop during PNL (P > 0.05). But there was a positive correlation between Urinary Tract Infection (UTI) history (P = 0.01) and transfusion (P = 0.0001) and Hb drop during PNL. Also, the history of open kidney surgery (P = 0.031), nephrostomy insertion (P = 0.003), and extracorporeal shock wave lithotripsy therapy (ESWL) (P = 0.041) were correlated with the increased risk of Hb drop.

Conclusions

Urinary tract infection, history of open surgery, nephrostomy implantation, and ESWL were significantly associated with more bleeding in PNL.

Presence of a Novel Anatomical Structure May Cause Bleeding When Using the Calyx Access in Mini-Percutaneous Nephrolithotomy

Background

Fused renal pyramid (FRP) is a kidney anatomical structure which was first identified by us. The vascular anatomy of FRP exhibits different from that of the normal renal pyramid (NRP), manifested by the distribution of the ectopic interlobar arteries in FRP. In this study, we analyzed the effect of FRPs on bleeding when using calyx access in mini-percutaneous nephrolithotomy (PCNL).

Patients and Methods

Overall, 633 patients who underwent ultrasound-guided single-tract mini-PCNL were divided into two groups according to the puncture method used: in group A, puncture was performed through the axial direction of the renal calyx, the line from the apex of the fornix to the center of the neck plane under B-mode ultrasound guidance; and in group B, Doppler ultrasound-guided axillary puncture through calyces corresponding to NRPs when the plane of renal column blood vessels on both sides was selected or calyx puncture through the hypovascular area of the FRPs. Relevant demographic and clinical data were retrospectively analyzed.

Results

The two groups exhibited similar baseline characteristics. No significant differences were found in hemoglobin reduction, puncture site, tract size, postoperative creatinine level, or stone-free rate between the two groups (P > 0.05). Blood transfusion and embolization rates in group B were significantly lower than those in group A (P = 0.03 and 0.045, respectively). No differences were found between the two groups in terms of persistent pain, hydrothorax, fever, subcapsular hematoma, and urosepsis (P > 0.05). The overall complication rate was not significantly different between the two groups (P = 0.505).

Conclusions

FRP is a non-negligible anatomical structure that may cause hemorrhage when using calyx access. Doppler ultrasound can identify ectopic blood vessels in FRPs to reduce bleeding during calyx access in mini-PCNL procedures.

Factors Affecting Transfusion during Percutaneous Nephrolithotomy: A Retrospective Study of 665 Cases

Objective

This study was designed to evaluate the aspects that affect transfusion following percutaneous nephrolithotomy (PCNL). Patients and Methods. From 2016 to 2019, 665 patients underwent PCNL for the removal of renal calculi at our center (Department of Urology, Shanghai Xu-hui Central Hospital). Complications, including hemorrhages, have been reported. Twenty-three patients (3.5%) have received a blood transfusion, and 12 (1.9%) patients were treated with hyper-selective embolization. We focused on the influencing factors related to postoperative blood transfusion. The factors analyzed were age, sex, hypertension, diabetes, serum creatinine level, preoperative hemoglobin, and the use of anticoagulants or antiplatelet medications; renal and stone factors (i.e., previous surgery, abnormal anatomy, stone side, stone burden, and stone type); and surgical features (i.e., access number, the calyx of puncture, and stone-free rate). These data were analyzed for the presence of bleeding.

Results

Among individual factors, preoperative hemoglobin level (p < 0.001) and urinary infections (p < 0.001) were significantly correlated with blood transfusion. Among renal and stone factors, only a history of open surgery was significantly correlated with blood transfusion (p < 0.05). Stone type or stone burden did not correlate with transfusion. Furthermore, no statistically significant correlation was found between surgical features and bleeding, and a lower stone-free rate was reported for the transfusion group.

Conclusion

The obtained results demonstrated that PCNL is a safer surgical procedure in a high-volume center; however, anemic conditions, infections, and history of open surgery will significantly increase the transfusion rate following PCNL.

Comparison of percutaneous nephrolithotomy and retrograde intrarenal surgery outcomes for kidney stones larger than 2 cm from Guy's stone scoring system perspective

OBJECTIVE

To compare surgical outcomes of percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgeries (RIRS) as a result of kidney stones larger than 2 cm, together with Guy's stone scores (GSS).

MATERIALS AND METHODS

The data of 811 patients with stone sizes 2-6 cm were operated using PNL (n = 361) and RIRS (n = 450) reviewed retrospectively. GSS were graded 1, 2, 3 or 4 according to the computed tomography findings. Stone-free rate (SFR), operation times, length of hospital stay (LOHS) and Clavien complications (CC) were recorded.

RESULTS

Although mean operative times were significantly longer in the RIRS group than the PNL group in GSS grades 1, 2 and 3 (P < .001), it was similar between the two groups in GSS grade 4 (P = .186). SFRs in the PNL and RIRS group were 90.3% and 58.4% on post-operative 10th day (P < .001), and it raised up to 95.3% and 81.6% after secondary interventions (P < .001). Significantly higher SFRs observed in the PNL group in GSS grades 1, 2 and 3 categories. On postoperative 10th day, the SFRs were similar in both GSS grade 4 categories (P = .06). LOHS was longer in the PNL group (P < .001). Although LOHS was significantly longer only in GSS grade 3 (P = .043) and GSS grade 4 (P < .001) in the PNL group, it was similar in GSS grade 1 and 2 between groups. Clavien complications increased in line with GSS in the PNL group (P < .001), but the difference did not differ between GSS grade 3 and 4.

CONCLUSION

SF of PNL in a single session and short operation time seems to be significant especially in GSS grades 1, 2 and 3 category stones. Although the number of patients in the GSS 4 group is very small to claim this, RIRS might be considered as an alternative to PNL in a special group of patients such as GSS grade 4 because of its lower complication rates and shorter LOHS.

Combination laparoscopy and nephrolithotomy technique in the same session in patients with complete staghorn stones and poor performance status: case series in a single center with long-term follow-up

BACKGROUND

The management of complete staghorn stones remains a challenge for urologists, owing to the high stone burden, low stone free rate, and high rate of complications. Hence, we aimed to evaluate the outcomes of a technique involving combination laparoscopy and nephrolithotomy in the same session in patient with complete staghorn stones and poor performance status.

METHODS

We retrospectively evaluated seven patients with complete staghorn stones who underwent a combination of laparoscopy and nephrolithotomy in the same session in our center between December 2016 and October 2019. The surgical technique was as follows. Through a four-port transperitoneal laparoscopic approach, the kidney was mobilized after complete dissection of the renal pedicle. The renal pelvis was then incised with a cold scalpel. A nephroscope was inserted into the renal collecting system through both a laparoscopic port and the renal pelvis incision. This method enabled visualization of and access to almost all calyces for clearing the stones from the affected kidneys in a hand-assisted manner which a hand was inserted in the peritoneal cavity. The outcome data included the stone-free rate, short-term and long-term complication rates, and stone recurrence rate.

RESULTS

The stone free rate was 85.70% (6/7). No patients had sepsis or required blood transfusion perioperatively, and no major short-term complications occurred. After 24.00 (15.00, 48.00) months' follow-up, no patients had long-term complications, and only one patient had stone recurrence.

CONCLUSION

The technique of combining laparoscopy and nephrolithotomy in the same session was an effective and safe treatment for patients with complete staghorn stones and poor performance status. The method was scarcely affected by the stone burden and morphology, had a satisfactory stone free rate, and resulted in no major complications, particularly life-threatening sepsis. It might be an option for such patients.

Case selection and implementation of tubeless percutaneous nephrolithotomy

Background

The tubeless percutaneous nephrolithotomy (PCNL) was proposed to eliminate the side effects of the nephrostomy tube in recent years, such as pain, channel infection, postoperative bleeding, and longer hospital stay. But there is neither clinical guidelines nor consensus about tubeless PCNL in clinical practice. The study is aimed to how to implement the tubeless PCNL step by step, including case selection preoperatively, improving the technique of the surgeon, making the correct decisions at the end of the procedure, which had not been previously examined.

Methods

From January 2017 to March 2018, 364 consecutive patients requiring PCNL were comprehensively analyzed preoperatively and patients were selected for scheduled tubeless PCNL based on four aspects. The selected patients were divided into two groups according to whether the nephrostomy tube was finally placed. The mean operative time, intraoperative blood loss, stone clearance rate, visual pain score, postoperative hospitalization days and perioperative complications were all evaluated.

Results

Based on the preoperative evaluation, 42 patients were selected for tubeless PCNL, among which there were finally 37 cases of completed tubeless PCNL. Compared with patients undergoing conventional PCNL, there were not statistical differences in the mean operative time (P=0.207) or intraoperative blood loss (P=0.450) in the tubeless group. Stone clearance rate was 100% in both groups. The visual pain scores in the tubeless PCNL group were lower on operation day (P=0.029), first postoperative day (P<0.001) and the day of discharge (P=0.025). The postoperative hospitalization for the tubeless PCNL group was shorter than that of the control group (P<0.001). No significant difference in grade 1 complications was seen (P=0.424), and no grade 2 or higher complications were observed in either group.

Conclusions

Postoperative pain was significantly relieved and postoperative hospitalization was significantly shortened in the tubeless PCNL group. Tubeless PCNL is safe if patients are carefully selected using four criteria before operation, attention is paid to four key points and five confirmations are made during operation.

No staghorn calculi and none/mild hydronephrosis may be risk factors for severe bleeding complications after percutaneous nephrolithotomy

Background

To explore the risk factors for severe bleeding complications after percutaneous nephrolithotomy (PCNL) according to the modified Clavien scoring system.

Methods

We retrospectively analysed 2981 patients who received percutaneous nephrolithotomies from January 2014 to December 2020. Study inclusion criteria were PCNL and postoperative mild or severe renal haemorrhage in accordance with the modified Clavien scoring system. Mild bleeding complications included Clavien 2, while severe bleeding complications were greater than Clavien 3a. It has a good prognosis and is more likely to be underestimated and ignored in retrospective studies in bleeding complications classified by Clavien 1, so no analysis about these was conducted in this study. Clinical features, medical comorbidities and perioperative characteristics were analysed. Chi-square, independent t tests, Pearson’s correlation, Fisher exact tests, Mann–Whitney and multivariate logistic regression were used as appropriate.

Results

Of the 2981 patients 70 (2.3%), met study inclusion criteria, consisting of 51 men and 19 women, 48 patients had severe bleeding complications. The remaining 22 patients had mild bleeding. Patients with postoperative severe bleeding complications were more likely to have no or slight degree of hydronephrosis and have no staghorn calculi on univariate analysis (p < 0.05). Staghorn calculi (OR, 95% CI, p value 0.218, 0.068–0.700, 0.010) and hydronephrosis (OR, 95% CI, p value 0.271, 0.083–0.887, 0.031) were independent predictors for severe bleeding via multivariate logistic regression analysis. Other factors, such as history of PCNL, multiple kidney stones, site of puncture calyx and mean corrected intraoperative haemoglobin drop were not related to postoperative severe bleedings.

Conclusions

The absence of staghorn calculi and a no or mild hydronephrosis were related to an increased risk of post-percutaneous nephrolithotomy severe bleeding complications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00866-9.

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.

The Outcomes of Minimally Invasive Percutaneous Nephrolithotomy with Different Access Sizes for the Single Renal Stone ≤25 mm: A Randomized Prospective Study

OBJECTIVES

The aim of this study was to provide a randomized controlled trial comparing the outcomes of different access sizes used in the solo ultrasonic-guided minimally invasive percutaneous nephrolithotomy (mini-PCNL).

METHODS

From January 2018 to December 2019, a total of 160 cases with single renal stones of <25 mm were randomized to undergo mini-PCNLs with Fr16, Fr18, Fr20, or Fr22 accesses. All accesses were established with the axis of the target calyx as the marker for puncture location and then expanded to the desired size. Hemoglobin reduction, operative time, stone-free rate, complications, etc., were all recorded and assessed.

RESULTS

The demographic data were similar, and there were no significantly intergroup differences in stone-free rate, complications, and hospital stay time. The hemoglobin reduction was comparable and was 0.9 ± 0.6, 0.9 ± 0.7, 1.0 ± 0.5, and 1.1 ± 0.7 g/dL for the groups Fr16, Fr18, Fr20, and Fr22, respectively. The operative time was 53.4 ± 14.5, 48.5 ± 15.2, 42.8 ± 13.3, and 43.3 ± 13.1 min for the 4 groups, which decreased significantly from group Fr16 to Fr20, but there was no significant difference between Fr20 and Fr22 groups.

CONCLUSIONS

The axis of target calyx is a reliable marker for establishment of percutaneous renal access under ultrasonic guidance. The surgical outcomes of different access sizes were comparable, but the operation time was significantly shortened with the increase of size. However, Fr22 was not more efficient than Fr20.

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.

The impact of nephrostomy balloon inflation volume on post percutaneous nephrolithotomy hemorrhage

Introduction

the study aims to match different volumes of nephrostomy balloon inflation to point out the foremost effective volume size of post percutaneous nephrolithotomy (PCNL) bleeding control.

Methods

we have retrospectively reviewed “560” medical records of patients who underwent percutaneous nephrolithotomy between (the years 2017 and 2018) at Prince Hussein Urology Center. The Patients were divided into two teams, group-1 (a number of 280 patients) with nephrostomy balloon inflated concerning three ml and group-2 (a number of 280 patients) the balloon inflated concerning one ml. The preoperative and postoperative hematocrit, the operation duration, the stone size, the postoperative pain severity, the transfusion rate and the duration of hematuria between the two groups were compared during hospitalization.

Results

regarding patients with ages (between 18 and 68 years); the preoperative hematocrit (mean values ± SDs) was (40.35% ± 3.57) vs (39.95% ± 3.43) for groups-1 and 2, respectively; the p value=0.066. The postoperative hematocrit was (37.91% ± 3.96) vs (34.38 ± 2.78), respectively; the p value was (0.008); the blood transfusion rate was 11.2% vs 13.4% (the p value was 0.039), respectively. The Postoperative pain score was (4.93 ± 1.44) vs (3.89 ± 1.45) (the p value was 0.012), respectively.

Conclusion

increasing the nephrostomy balloon volume to a “3cc” competes for a task to decrease bleeding which was found to be as a secure and considerable effective procedure-related factor. However, the disadvantage of this technique resulted in increasing the postoperative pain in patients undergoing such a procedure.

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.

Frequency of Blood Transfusion in Percutaneous Nephrolithotomy

Introduction

Percutaneous nephrolithotomy (PNL) has replaced open surgery for the treatment of kidney stones due to its less invasive nature. Bleeding still occurs due to renal vascular injuries, dependent upon the access route of the procedure. Several other factors are also related to the increased risk of bleeding. This study aims to find the association between blood transfusion and other factors such as age, gender, body mass index (BMI), size of the stone, operative time, preoperative hemoglobin (Hb) level, stone surface area, hypertension, and diabetes mellitus.

Materials and methods

This was a descriptive cross-sectional study conducted over a period of six months between November 2019 and April 2020 at a tertiary care hospital in Karachi, Pakistan. The sample size of 131 patients was calculated using open-source epidemiological software (Open-Epi). Inclusion criteria included patients from both genders and ages between 26 and 70 years. Patients ≤25 years, having a liver disease or bleeding disorders, or refusing to participate in the study, were excluded. Laboratory data included preoperative routine complete blood count, serum creatinine (normal 0.5-1.5 mg/dL), platelet count, bleeding and coagulation profile, and urine culture. All patients also underwent renal ultrasound scans. Treatment was postponed until a negative urine culture was obtained from patients with a positive urine culture. 

Results

The mean age of the patients was 42.4 ± 15.65 years. One third (29.8%) of the patients were females. The stone size was 850 ± 121.43 mm², the mean operative time of the procedure was 125.76 ± 53.4 minutes, and the mean number of cell packs transfused was 1.10 ± 0.31 units. Blood transfusion was done in 24 (18.3%) of the patients. Gender, diabetes mellitus, stone size, preoperative Hb level, and operative time were significantly related to blood transfusion. 

Conclusions

Increased bleeding risk while performing PNL has been associated with many factors such as operating time, the gender of the patients, and stone size. Therefore, these factors should be controlled for the procedure to decrease the risk of bleeding and the need for blood transfusion. Furthermore, the kidney vasculature should not be compromised while performing the procedure.

Renal Artery Embolization for Acute Renal Hemorrhage: A Single-Center Experience

Background

Emergency renal artery embolization (RAE) is a useful method in treating renal trauma and bleeding renal tumors. The aim of this study was to evaluate the clinical efficacy and safety of emergency RAE, and factors associated with RAE failure.

Methods

This retrospective study included patients treated with emergency RAE for acute renal hemorrhage between 1 January 2009 and 31 October 2019 in Srinagarind Hospital. The embolization was performed using coils, glues, and/or gel foams. Factors associated with unsuccessful outcomes were analyzed using univariate and multivariate regression analyses.

Results

A total of 94 patients were treated at the center during the study period with the clinical success rate of 91.5%. The most common cause of acute renal hemorrhage was iatrogenic injury (76.5%). Factors associated with unsuccessful RAE according to multivariate analyses were hypertension (adjusted odds ratio [AOR] 24.2) and ruptured tumor/aneurysm (AOR 26.8).

Conclusion

RAE is an effective procedure for acute renal hemorrhage. Hypertension and ruptured tumor/aneurysm were negative predictors for success.

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.

Peri-Operative Factors Affecting Blood Transfusion Requirements During PCNL: A Retrospective Non-Randomized Study

Background

Percutaneous nephrolithotomy (PCNL) is accepted as the gold standard of care for the treatment of large renal calculi. Kidney hemorrhage, which requires blood transfusion, is one of the most common complications after percutaneous kidney stone surgery.

Objective

To evaluate perioperative factors associated with transfusion requirements during PCNL.

Materials and Methods

A total of 226 patients with kidney calculi undergoing PCNL between January 2011 and December 2019 were reviewed retrospectively. We analyzed the impact of perioperative clinical factors on the necessity of blood transfusion during PCNL.

Results

The overall blood transfusion rate was 9.29%. Multiple perioperative determinants were significantly correlated with the application of packed red blood cells (PRCs), including larger stone size (p = 0.006), multiple tract punctures (p = 0.029), presence of staghorn calculi (p = 0.026), and long operative time (OT; p = 0.017). Multivariate analysis demonstrated that only multiple tract punctures independently affected blood transfusion requirements during PCNL (p = 0.038).

Conclusion

In accordance with the present study, only the multiple tract punctures were associated with blood transfusion requirements in PCNL.

Can antibiotic preference affect bleeding in percutaneous nephrolithotomy? Retrospective comparative study of two commonly used antibiotics

Objective

Bleeding is one of the most common and alarming complication of percutaneous nephrolithotomy (PCNL). In this study, we aimed to compare the effects of ciprofloxacin and cefuroxime on the bleeding in PCNL procedures.

Methods

The study was a retrospective analysis of 97 patients who underwent PCNL between February 2011 and June 2017. We just included the patients who had single tract lower pole PCNL for more objective evaluation of bleeding in the study. The patients were divided into two groups as ciprofloxacin group (Group-I, n:40) and cefuroxime group (Group-II, n:56) according to the type of antibiotic used in the operation. Patient age, gender, body mass index, stone size, preoperative INR, preoperative and postoperative platelet counts and difference, operative time, need for blood transfusion, postoperative fever, hospital stay, postoperative hemoglobin and hematocrit drop were analyzed.

Results

There was no statistically significant difference in patients' gender distribution, body mass index, preoperative INR, preoperative and postoperative platelet counts, preoperative and postoperative platelet difference, duration of operation, hospital stay, postoperative fever and need for postoperative blood transfusion between two antibiotic groups (p > 0.05). Mean patient age was 42,75±16,97 in Group-I and 35,54±14,71 in Group-II (p < 0.05). The mean stone size of Group-I and Group-II were 27,23±7,05 mm and 30,59±8,20, respectively (p < 0.05). The mean postoperative hemoglobin and hematocrit drop were significantly higher in Group-I than in Group-II. The mean hemoglobin drop was 1,73±0,95 for Group-I and 1,28±0,67 for Group-II (p < 0.05). The mean hematocrit drop was 5,17±2,76 for Group-I and 3,80±1,99 for Group-II (p < 0.05).

Conclusion

On the basis of the results of the initial study, the antibiotic preference in patients undergoing surgery may be one of the bleeding factors during and after PCNL.

Multiple-tract percutaneous nephrolithotomy as a day surgery for the treatment of complex renal stones: an initial experience

PURPOSE

The purpose of this study was to evaluate the safety and efficiency of multiple-tract percutaneous nephrolithotomy (PCNL) as a day surgery for the treatment of complex renal stones. PATIENTS AND METHODS: A mature protocol for day surgery was implemented. Forty-six patients who underwent planned day-surgery PCNL via multiple tracts for the treatment of complex renal stones were retrospectively reviewed. All procedures were performed by an experienced surgeon. The outcomes were recorded.

RESULTS

The mean stone size and burden were 4.8 cm and 990.2 mm², respectively. There were 26 (56.5%) and 20 (43.5%) patients with staghorn stones and multiple stones, respectively. Totals of two, three, and more than three tracts (with up to 7 tracts) were established in 22, 11, and 13 patients, respectively. The tract sizes ranged from 14 to 24 Fr. One to four nephrostomy tubes were placed in most patients, and a tubeless process was accomplished in only 3 (6.5%) patients. The mean surgery time was 116 min with a hemoglobin drop of 22.1 ± 16.8 g/L. Eight (17.4%) patients developed postoperative complications, with severe complications (Clavien grades III-IV) in two cases (4.4%). 39 (84.8%) patients were discharged within 24 h after surgery, and 7 (15.2%) patients were fully admitted. Only 1 (2.2%) patient required readmission. The stone clearance rate was 84.8%.

CONCLUSIONS

Day-surgery PCNL can be safely performed via multiple percutaneous tracts by experienced surgeons and is an efficient strategy for the treatment of complex renal stones.

Multitract percutaneous nephrolithotomy in staghorn calculus

Staghorn calculi are branched stones which occupy a majority portion of the pelvicaliceal system. An untreated staghorn calculus over time can damage the kidney and deteriorate its function and/or cause life threatening sepsis. Total stone clearance is an important goal in order to eradicate any infective focus, relieve obstruction, prevent recurrence and preserve the kidney function. Percutaneous nephrolithotomy (PCNL) is currently the accepted first-line treatment option for staghorn calculi. The options available are single-tract PCNL with an auxiliary procedure like shockwave lithotripsy, single-tract PCNL with flexible nephroscopy, or multitract PCNL. Each has its own pros and cons. But the ultimate goal of treatment for any patient with staghorn calculi should be safety, cost-effectiveness, and to achieve total stone clearance. With this article, we review the management of staghorn calculi with multiple percutaneous (“multitract”) access, its advantages and disadvantages and its current position by studying the various published materials across the globe.

Percutaneous nephrolithotomy for staghorn calculi: Troubleshooting and managing complications

Staghorn calculi comprise a unique subset of complex kidney stone disease. Percutaneous nephrolithotomy (PCNL) is the gold standard treatment for staghorn stones. Despite continuous refinements to the technique and instrumentation of PCNL, these stones remain a troublesome challenge for endourologists and are associated with a higher rate of perioperative complications than that for non-staghorn stones. Common and notable intraoperative complications include bleeding, renal collecting system injury, injury of visceral organs, pulmonary complications, thromboembolic complications, extrarenal stone migration, and misplacement of the nephrostomy tube. Postoperative complications include infection and urosepsis, bleeding, persistent nephrocutaneous urine leakage, infundibular stenosis, and death. In this review, we report recommendations regarding troubleshooting measures that can be used to identify and characterize these complications. Additionally, we include information regarding management strategies for complications associated with PCNL for staghorn calculi.

Risk factors for hemorrhage requiring embolization after percutaneous nephrolithotomy: a meta-analysis

Background

The aim of this meta-analysis was to systematically review and identify the risk factors for severe hemorrhage after percutaneous nephrolithotomy (PCNL).

Methods

We searched the PubMed and EMBASE database for literature related to the risk factors of severe hemorrhage after PCNL requiring angiography and embolization through to September 2019. The necessary data for each eligible study were extracted by 2 independent reviewers. The Newcastle-Ottawa Scale (NOS) was used for assessing the methodological quality of the included studies. Statistical analyses were conducted using Comprehensive Meta-Analysis version 2 to identify whether there was a statistical association between risk factors and severe hemorrhage post-PCNL.

Results

The results of this meta-analysis showed that urinary tract infection (UTI) (OR =1.98, 95% CI, 1.21–3.26, P=0.007), diabetes mellitus (OR =4.07, 95% CI, 1.83–9.06, P=0.001), staghorn stone (OR =3.49, 95% CI, 1.25–9.76, P=0.017), and multiple tracts (OR =2.09, 95% CI, 1.33–3.28, P=0.001) were independent risk factors for severe hemorrhage post-PCNL, while hypertension (OR =1.18, 95% CI, 0.58–2.42, P=0.65) showed no significant statistical difference.

Conclusions

Urologists should focus on the above identified risk factors for severe hemorrhage post-PCNL, including UTI, diabetes mellitus, staghorn stone, and multiple tracts. More high-quality studies with larger sample sizes are needed to validate these conclusions.

Critical causes in severe bleeding requiring angioembolization after percutaneous nephrolithotomy

Background

To identify the risk factors for severe bleeding requiring angioembolization among patients who received transfusions after PCNL, particularly those who underwent anatomically incorrect renal puncture.

Methods

A total of 53 patients, who received transfusions after PCNL and simultaneously had a postoperative CT scan performed between November 2009 and May 2019 at two teaching hospitals, were retrospectively reviewed. The patients were divided into two groups: those who underwent angioembolization and those who did not. Patient, stone and procedural factors were compared between the two groups. Puncture correctness was evaluated using postoperative CT scans. Puncture was defined as being a correct puncture if the fornix or papilla of the posterior calyx was punctured and the trajectory of the tract was within 20 degrees posterior to the frontal plane of the kidney (i.e., within Brödel’s line).

Results

21 patients underwent angioembolization after PCNL. Incorrect puncture was seen in 14/21 (66.7%) patients who underwent angioembolization after PCNL, whereas it was seen in 11/32 (34.4%) patients who did not undergo angioembolization (p = 0.021). On multivariable regression analysis, puncture correctness was found to be the only significant factor, with an OR of 3.818, 95% CI of 1.192–12.231 and p value of 0.024.

Conclusions

Incorrect renal puncture was related to severe bleeding requiring angioembolization after PCNL. Our results emphasize the importance of the basic principle of renal puncture for PCNL.

Robotic management of large stone disease: a case series

The gold standard for urologic management of large stone disease traditionally has been percutaneous nephrolithotomy (PCNL). An alternative to PCNL is robotic pyelolithotomy (RP), which continues to gain traction. This study is a retrospective review of ten cases performed over a 2 year period presenting operative outcomes for large stone disease treated with RP. The mean and standard deviation were calculated for age, body mass index, stone volume, stone diameter, pre-operative creatinine, operative time, robot-docked time, length of stay, post-operative creatinine, and estimated blood loss. In addition, results were collected for post-operative complications and secondary procedure requirements. Complete stone clearance was successful in 9 of 10 cases. The average renal function remained stable from a pre-operative creatinine of 0.917 mg/dL to a post-operative creatinine level of 0.943 mg/dL. This case series demonstrates that robotic assisted surgery has practical application when managing large stone disease.

The impact of post PCNL tube type on blood loss and postoperative pain

Objective:

To evaluate the impact of nephrostomy tube type on postoperative pain and blood loss following percutaneous nephrolithotomy (PCNL).

Methods:

This is a prospective non-randomized study performed at Aga Khan University Hospital from July 2017 to June 2018. In this study we prospectively studied adult patients (16 to 65 years) who underwent unilateral PCNL. Patients who had nephrostomy with balloon (12Fr Foley’s catheter) were compared with patients who had nephrostomy without balloon (12Fr Nelaton™ catheter). STONE Nephrolithometry score was used to assess the stone complexity. Mean pain score at six and 24 hours and mean hemoglobin drop at 24 hours was compared between two groups using independent sample t-test, p-value of <0.05 was considered significant.

Results:

Over one year, 198 PCNL were performed out of which 119 were included for analysis. Sixty-six had nephrostomy tube with balloon and 53 had nephrostomy tube without balloon. Mean STONE score (9.66±1.4 vs. 9.64±1.24) and operative time (72.84±28.34 vs. 86.05±32.1 minutes) was comparable. Mean postoperative pain score at 6 hours and 24 hours postoperative was significantly lower in balloon group as compared to without balloon group. Mean Hemoglobin drop was similar in both groups (p=0.60).

Conclusion:

The use of nephrostomy tube with balloon after PCNL as this is associated with less pain and comparable hemoglobin drop as compare to nephrostomy tube without balloon.

Effects of Tranexamic Acid on Bleeding and Hemoglobin Levels in Patients with Staghorn Calculi Undergoing Percutaneous Nephrolithotomy: Randomized Controlled Trial

Background:

The incidence of renal hemorrhage during percutaneous nephrolithotomy (PCNL) is high. We sought to evaluate the effects of tranexamic acid (TXA) on bleeding and hemoglobin levels of patients with staghorn calculi treated with PCNL.

Methods:

In a double-blind clinical trial, 120 patients with staghorn calculi candidated for PCNL in Alzahra Hospital between January 2014 and November 2017, Isfahan, Iran, were classified into two groups in terms of the stone size (>4 cm and <4 cm). The patients in both groups were then randomly assigned to receive either 1 g of TXA intravenously or normal saline. (The generation of random numbers was done by computer.) Thus, there were four groups of 30 patients each. The transfusion rate, the mean volume of blood loss, the operative duration, and the hemoglobin level were compared between the intervention and control groups for each stone-size category. Statistical analysis was performed using SPSS, version 19. The paired and independent t test and the Pearson coefficient correlation were used, and a P value less than 0.05 was considered statistically significant.

Results:

The mean volume of blood loss was significantly higher in the control group patients than in those receiving TXA, in both stone-size categories (P<0.001). There was no significant difference in the postoperative hemoglobin level between the intervention and control groups, in both stone-size categories (P=0.26 and P=0.10, respectively). In addition, the mean volume of blood loss increased significantly with an increase in the operative duration (P<0.001).

Conclusion:

TXA reduced the risk of bleeding during and after PCNL and attenuated the drop in the hemoglobin level in the postoperative period. Longer operative procedures were associated with an increase in the bleeding volume.

Trial Registration Number: IRCT20180209038673N1

Safety and efficacy of a single middle calyx access (MCA) in mini-PCNL

To compare outcomes of a single middle calyx access (MCA) with a single upper or lower calyceal access in mini-PCNL. From May 2015 through August 2018, patients' files who underwent a single renal access mini-PCNL were retrospectively reviewed. All patients underwent fluoroscopic-guided access (16-20 F) in the prone position. They were categorized into group 1 (MCA) and group 2 (either upper or lower calyceal access). Compared preoperative items included stone location, size, number and complexity (according to Guy's score). The compared outcome parameters were complication and stone-free rates. The study comprised 512 consecutive patients, 374 patients in group 1 and 138 in group 2. A single MCA was utilized to access 95% of proximal ureteral calculi, 89% for ureteropelvic junction stones, and 84% for stones present in the pelvicalyceal system and ureter. MCA was used in 89% of complete staghorn stones and 73% of multiple stones. the Stone-free rates (93% vs 90.6%, P = 0.350) and the complications rates (8% vs 7.2%, P = 0.772) were comparable between group 1 and 2 despite that MCA was used for most cases with complex stones. Complications severity were also comparable (P = 0.579). Mini-PCNL performed through a single MCA is effective and safe. This access can be used for the treatment of renal and upper ureteral calculi of different complexities and locations.

Percutaneous Nephrolithotomy with Different Temperature Irrigation and Effects on Surgical Complications and Anesthesiology Applications

OBJECTIVE

Percutaneous nephrolithotomy (PCNL) is a widely accepted and frequently performed operation for large kidney stones. However, there is not much information about the effects of irrigation fluid temperature as well as many other factors that affect success and complications during the operation. In this study, we aimed to investigate the surgical and anesthesiological effects of irrigation fluid used in body temperature and room temperature during and after PCNL.

MATERIAL AND METHODS

A total of 108 PCNL patients were performed between June 2016 and April 2018. The half of these patients (54) were performed with body temperature (37°C) irrigation fluid, hence known as body temperature group (BTG), and the other half with room temperature (22°C) irrigation fluid, called as room temperature group (RTG). For the study, we recorded the body temperature of the patients during and after the operation, the amount of irrigation fluid used, the size and location of the kidney stones, the duration of the operation, postoperative shivering time during the patient's wake-up period, pre- and postoperative hemoglobin value, additional blood requirements, postoperative analgesic requirements, and postoperative urinary tract infections.

RESULTS

The age of patients, gender distribution, height, weight, body mass index, stone size, and postoperative analgesic requirement showed no significant differences in two groups. The postoperative body heat was significantly higher in the BTG than the RTG. The duration of waking was significantly higher in the RTG than the BTG. The amount of hemorrhage was significantly less in the patients who were irrigated in the RTG.

CONCLUSION

The temperature of the irrigation fluid can affect many parameters in the PCNL. We recommend using irrigation in room temperature especially with patients having bleeding risks and irrigation fluid in body temperature especially with patients having anesthetic risks for easier waking process.

Failure of initial superselective renal arterial embolization in the treatment of renal hemorrhage after percutaneous nephrolithotomy: A respective analysis of risk factors

Superselective renal arterial embolization (SRAE) is a well-established method for the treatment of severe hemorrhage following percutaneous nephrolithotomy (PCNL). However, there remains a significant rate of failures requiring repeat SRAE or nephrectomy. To identify risk factors for initial treatment failure of SRAE, the data of patients who had undergone SRAE for severe bleeding due to PCNL between August 2005 and June 2016 were retrospectively analyzed. A total of 98 patients required SRAE for bleeding control following PCNL. Renal arteriography revealed pseudoaneurysm in 65 patients, arteriovenous fistula in 6 patients, and a combination of both in 11 patients. Free extravasation was observed in 11 patients; 8 of these patients exhibited coexisting pseudoaneurysm. Vascular aberration/tortuosity was identified in 10 patients. A total of 17 patients (17.3%) experienced initial treatment failure and underwent repeat SRAE. Multivariate analysis identified percutaneous tract size, number of bleeding sites and vascular aberration/tortuosity as significant predictors of initial treatment failure. The results from the present study suggested that repeated SRAE is preferred for patients who have experienced initial treatment failure with recurrent hemorrhage following PCNL. Large tract size, multiple bleeding sites and renal vascular aberration/tortuosity were significantly associated with increased risk of initial treatment failure of SRAE. These data may assist interventional radiologists in the planning and execution of SRAE in the treatment of PCNL.

Comparison between retrograde intrarenal surgery and percutaneous nephrolithotripsy in the management of renal stones: A meta-analysis

Percutaneous nephrolithotripsy (PCNL) is recommended as the first-line treatment for the management of kidney stones that are ≥2 cm in diameter. Retrograde intrarenal surgery (RIRS) has become increasingly preferred due to its high level of safety and repeatability, particularly in small stones. However, whether PCNL has superior efficacy and lower complication rates when compared with RIRS remains controversial. Therefore, the present meta-analysis was conducted to compare the clinical outcomes of patients treated with PCNL and RIRS as therapy for renal stones. Clinical trials published in PubMed, Web of Science, Excerpta Medica dataBASE (EMBASE), and the Chinese Biomedical Database (CBM) were systematically reviewed to evaluate the efficacy and safety profiles of patients with renal stones who were treated with PCNL or RIRS. Main outcomes measures included stone-free rate, operative time, hospital stay, and complication rate. Results were expressed as risk ratio (RR), or weighted mean difference (WMD) with 95% confidence intervals (CIs). Pooled estimates were calculated using a fixed-effects or random-effects model according to the heterogeneity among the studies. In total, 17 studies [4 randomized controlled trials (RCTs) and 13 cohort studies] involving 1,717 patients met the inclusion criteria, and were included in this meta-analysis. Pooled results showed that PCNL exhibited a significantly higher stone-free rate (RR=0.90, 95% CI: 0.86 to 0.95; P<0.001) but was associated with a longer hospital stay, when compared with RIRS (WMD=-2.72, 95% CI: -3.9 to -1.54; P<0.001). Operative time (WMD=7.86, 95% CI: -0.89 to 16.61; P=0.078) and complication rate (RR=0.71, 95% CI: 0.48 to 1.05; P=0.083) did not significantly differ between the groups. Subgroup analysis revealed that PCNL had a shorter operation time than RIRS in patients with stone sizes ≥2 cm (WMD=12.88, 95% CI: 4.77 to 20.99; P=0.002), and PCNL had a similar stone-free rate as RIRS when the estimates were pooled from RCTs (RR=0.88, 95% CI: 0.76 to 1.01; P=0.078). Compared with PCNL, RIRS had a significantly lower stone-free rate, shorter hospital stay, but a similar operation time and complication rate. Therefore, we propose that RIRS may be an alternative therapy to PCNL, with acceptable efficacy and complication rates for renal stones. Further large-scale, well-conducted RCTs are required to verify our findings.