Contemporary Practice Patterns Associated with Percutaneous Nephrolithotomy Among Certifying Urologists

Laser Endoscopic X-Ray-Guided Intrarenal Tract: Comparison Among Renal Access Modalities in the Porcine Kidney

Introduction and Objectives: Laser endoscopic X-ray-guided intrarenal tract (LEXIT) is a recently described holmium laser retrograde access technique for creating percutaneous access during a percutaneous nephrolithotomy. We compared bleeding, ease of access, and the time to achieve access for each of the following three modalities: LEXIT, retrograde Lawson puncture wire, and antegrade 18-gauge nephrostomy needle access in the porcine kidney. Methods: Eight pigs underwent an average of five nephrostomy accesses per kidney under simultaneous laparoscopic vision at 5 mm Hg insufflation pressure. Data collected included: access time (seconds), bleeding intensity (scale: 1 [no bleeding] - 10 [severe bleeding]), bleeding duration (seconds), accuracy of caliceal entry, and surgeon comfort with the technique (scale: 1 [very easy] - 10 [very difficult]). Results: A total of 64 nephrostomy accesses were obtained. The speed of nephrostomy access with LEXIT was significantly faster than the nephrostomy needle and Lawson wire (p < 0.001). Bleeding intensity (p = 0.002) and severity (p = 0.001) were lower with the Lawson puncture wire, followed by LEXIT and then by the nephrostomy needle. LEXIT was rated as easier in acquiring access within the upper pole (p = 0.003) and interpolar calices (p < 0.001). Histopathology demonstrated no difference in parenchymal damage between LEXIT and nephrostomy needle (p = 0.18); however, LEXIT was associated with significantly increased peri-tract thermal injury, although within a narrow focus of 1.6 mm (p < 0.01). Conclusion: Among the three renal access techniques, LEXIT provided the fastest access times and greatest ease of access specifically for upper pole and interpolar calices. Also, bleeding with LEXIT was significantly less compared with the standard antegrade nephrostomy needle access. Histopathological analysis demonstrated that the holmium laser resulted in focal thermal tissue effects similar in range to the blunt tissue trauma caused by the 18-gauge nephrostomy needle.

Differences in the percutaneous nephrolithotomy practice patterns among Latin American urologists with and without endourology training

PURPOSE

Although the worldwide percutaneous nephrolithotomy (PCNL) practice patterns determined via a survey sent to members of the Endourological Society have been published, differences in PCNL practice patterns among Latin American urologists based on endourological or lithiasis training have not been published. To determine the PCNL practice patterns among Latin American urologists with and without training in endourology.

MATERIALS AND METHODS

The SurveyMonkey® web platform was used to develop a 27- item survey on PCNL for the treatment of renal stones, and the survey was sent via e-mail and other electronic media to 2000 urologists from 15 Latin American countries. Endourology-trained (group 1) and nontrained urologists (group 2) were analyzed. The group results were compared using the chi-squared and Fisher's exact tests. SPSS version 20 for Windows was used for all analyses.

RESULTS

A total of 331 urologists responded to the survey (rate of 16.55%): 221 (66.7%) in group 1 and 110 (33.2%) in group 2). In groups 1 and 2, 91.9% and 63.2% performed PCNL, respectively; 85.1% and 58.5% used preoperative tomography, respectively; 12.7% and 4.7% used preoperative nephrolitometry nomograms, respectively; 45.2% and 32.1% used endoscopic combined intrarenal surgery, respectively; 68.3% and 38.7% used multiple percutaneous tract realization, respectively; and 19.9% and 5.7% used minimally invasive PCNL, respectively (all p=0.0005).

CONCLUSIONS

Statistically significant differences were observed in PCNL practice patterns of Latin American urologists with and without training in endourology. Specific training in endourology significantly influence the practice patterns of Latin American urologists.

A Novel Method for Repositioning Suboptimally Preoperatively Placed Nephrostomy Tubes for Percutaneous Nephrolithotomy Without Renal Repuncture

Objective: Nephrostomy tubes (NTs) inserted in emergency settings by interventional radiologists are frequently unsuitable for subsequent percutaneous nephrolithotomy (PCNL). We report a novel method of adjusting these NTs to be used as PCNL tracts and avoid renal repuncture. Patients and Methods: A retrospective search of 981 consecutive PCNLs performed in our institution between 2002 and 2017 identified all patients with preoperatively inserted NTs. The NTs unsuitable for PCNL were adjusted by a novel approach in which a 5-mm incision was made at the ideal puncture location (IPL) as indicated under fluoroscopic guidance. The preinserted NT was removed after passing a guidewire into the kidney. A dissector clamp was introduced through the entry wound of the removed NTs to bluntly dissect a retroperitoneal tunnel and pull out the distal tip of guidewire through the IPL, while its proximal segment was maintained in the kidney. The newly positioned guidewire was used for PCNL tract preparation without repuncturing the kidney. Results: The NTs were located in the mid calix, lower calix, and renal pelvis in 6 (26%), 13 (57%), and 4 (17%) cases, respectively. The NT was suitable for PCNL in 5 (22%) cases, a new renal access was performed in 3 (13%), and the novel adjustment approach was used in 15 (65%), all successfully. The place of entry was moved an average of 6 cm (range 47) and the angle between the tract axis and the calix axis was reduced by 65° in average. The procedure was done uneventfully in an average of 4 minutes. Conclusions: The novel method of adjusting preoperatively inserted NTs for PCNL by repositioning their original entry location to the IPL offers the possibility of avoiding kidney repuncture. It is feasible, safe, and easy to implement, and it spares potential morbidity related to additional puncturing of the kidney.

Persistence of Open Stone Surgery in the United States in the 21st Century

INTRODUCTION

In the era of minimally invasive surgery, endoscopic and percutaneous interventions for urinary tract stones have become a mainstay, and the need for open stone surgery (OSS) has decreased. We sought to determine the contemporary incidence of OSS among urologists in the United States.

METHODS

Case logs submitted for certification to the American Board of Urology from 2005 to 2015 were queried for Current Procedural Terminology codes relevant to OSS. Cases were analyzed for the associated practice type, practice area population, geographic region, provider subspecialty, and certifying status of the reporting urologist.

RESULTS

A total of 334 cases of OSS were identified, with 73.4% performed by urologists self-identified as generalists. The most common subspecialists performing OSS were endourologists (12.3%). Most cases were done in the private practice setting (80.4%), and in practice areas with populations exceeding 1,000,000 (43.2%). OSS was more commonly reported by urologists applying for recertification than initial certification. Thirty open stone cases were reported each year on average, and there was no decrease in stone cases over time based on linear regression analysis (R² = 0.06). OSS was most commonly performed in the Western Section of the American Urological Association (AUA) (25.1%) and least commonly performed in the Northeastern Section (1.5%). A chi-square analysis was performed, and the Western Section had a significantly higher number of OSSs than expected as its urologists represent only 17% of the total AUA membership (p < 0.01). The Northeastern Section comprises 7% of the AUA membership but only performed 1.5% of OSSs that were significantly lower than expected (p < 0.001).

CONCLUSIONS

Domestic performance of OSS remains stable. It is unclear as to whether the majority of these cases could be served by less-invasive technologies or whether the volume represents a true nadir. Future work may be warranted to assess attitudes, training, and feasibility of minimally invasive stone management in areas where OSS is most common.

Current trends in percutaneous nephrolithotomy: an internet-based survey

BACKGROUND

The aim of this study was to report current practices of percutaneous nephrolithotomy (PCNL) among endourologists.

METHODS

An internet survey was administered to Endourological Society members. Responders were distributed into three groups according to the number of PCNL cases per year (<50, 50-100, >100). PCNL technical details as well as opinions regarding specific clinical case scenarios were evaluated and compared between groups.

RESULTS

We received 300 responses from 47 different countries. Prone position was used in 77% of cases, while 16% used supine position and only 7% used modified lateral decubitus. Most endourologists performed their own access. There were no significant differences between the three groups regarding patient position (p = 0.1), puncture acquisition by urologist or radiologist (p = 0.2) and fluoroscopic puncture technique (p = 0.2). Endourologists with high annual PCNL practice (>100) had least probability to utilize nephrostomy tube (p = 0.0005) or use balloon dilator (p = 0.0001). They also had the highest probability of performing mini-PERC (p = 0.0001).

CONCLUSIONS

The majority of endourologists performing PCNL obtain their own access. Prone positioning is predominant, while totally tubeless PCNL are uncommon. Mini-PERC is gaining more popularity among endourologists. Most endourologists follow the guidelines for their choice of treatment modality in different sizes and locations of upper tract calculi.

Is extended preoperative antibiotic prophylaxis for high-risk patients necessary before percutaneous nephrolithotomy?

PURPOSE

The goal of this study was to compare the rate of systemic inflammatory response syndrome (SIRS) in high-risk patients undergoing percutaneous nephrolithotomy (PCNL) between patients who received 7, 2, or 0 days of preoperative antibiotics.

MATERIALS AND METHODS

We retrospectively reviewed a series of consecutive PCNLs performed at our institution. Patients with infected preoperative urine cultures were excluded. High-risk patients were defined as those with a history of previous urinary tract infection (UTI), hydronephrosis, or stone size ≥2 cm. Patients were treated with 7, 2, or 0 days of preoperative antibiotic prophylaxis prior to PCNL. All patients received a single preoperative dose of antibiotics within 60 minutes of the start of surgery. Fisher exact test was used to compare the rate of SIRS by preoperative antibiotic length.

RESULTS

Of the 292 patients identified, 138 (47.3%) had sterile urine and met high-risk criteria, of which 27 (19.6%), 39 (28.3%), and 72 (52.2%) received 7, 2, and 0 days of preoperative antibiotics, respectively. The 3 groups were similar in age, sex, and duration of surgery (p>0.05). There was no difference in the rate of SIRS between the groups, with 1 of 27 (3.7%), 2 of 39 (5.1%) and 3 of 72 patients (4.2%) meeting criteria in the 7, 2, and 0 days antibiotic groups (p=~1).

CONCLUSIONS

Extended preoperative antibiotic prophylaxis was not found to reduce the risk of SIRS after PCNL in our institutional experience of high-risk patients. For these patients, a single preoperative dose of antibiotics is sufficient.

Multicenter External Validation and Comparison of Stone Scoring Systems in Predicting Outcomes After Percutaneous Nephrolithotomy

BACKGROUND AND PURPOSE

Several scoring systems have recently emerged to predict stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL). We aimed to compare the most commonly used scoring systems (Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram), assess their predictive accuracy for SFR and other postoperative variables, and develop a risk group stratification based on these scoring systems.

MATERIALS AND METHODS

We performed a retrospective review of patients who have had a PCNL at four academic institutions between 2006 and 2013. Primary outcome was SFR within 3 weeks of the surgery and secondary outcomes were operative time (OT), complications, and length of stay (LOS). We performed chi-squared, t-test, logistic, linear, and Poisson regressions, as well as receiver operating characteristics curve with area under the curve (AUC) calculation.

RESULTS

We identified 586 patients eligible for analysis. Of these, 67.4% were stone free. Guy's, S.T.O.N.E., and CROES score were predictive of SFR on multivariable logistic regression (odds ratio [OR]: 1.398, 95% confidence interval [CI]: 1.056, 1.852, p = 0.019; OR: 1.417, 85% CI: 1.231, 1.631, p < 0.001; OR: 0.993, 95% CI: 0.988, 0.998, p = 0.004) and have similar predictive accuracy with AUCs of 0.629, 0.671, and 0.646, respectively. On multivariable linear regression, only S.T.O.N.E. was an independent predictor of longer OT (β = 14.556, 95% CI: 12.453, 16.660, p < 0.001). None of the scores were independent predictors of postoperative complications or a longer LOS. Poisson regression allowed for risk group stratification and showed the S.T.O.N.E. score and CROES nomogram to have the most distinct risk groups.

CONCLUSIONS

The three evaluated scoring systems have similar predictive accuracy of SFR. S.T.O.N.E. has additional value in predicting OT. Risk group stratification can be used for patient counseling. Further research is needed to identify whether or not any is superior to the others with regard to clinical usefulness and predictive accuracy.