How I Do It: ERAS protocol featuring erector spinae plane block for percutaneous nephrolithotomy.

Percutaneous nephrolithotomy (PCNL) is the gold-standard treatment for large and complex renal stones. Though associated with higher stone-free rates compared to other minimally invasive stone procedures, this comes at the expense of increased morbidity including postoperative pain and discomfort. We describe our enhanced recovery after surgery (ERAS) protocol for PCNL with emphasis on the use of erector spinae plane blocks to improve patient satisfaction and reduce postoperative opioid use and bother.

Frailty as predictor of complications in patients undergoing percutaneous nephrolithotomy (PCNL).

INTRODUCTION & OBJECTIVE: Surgical complications are difficult to predict, despite existing tools. Frailty phenotype has shown promise estimating postoperative risk among the elderly. We evaluate the use of frailty as a predictive tool on patients undergoing percutaneous renal surgery. METHODS: Frailty was prospectively analyzed using the Hopkins Frailty Index, consisting of 5 components yielding an additive score: patients categorized not frail, intermediate, or severely frail. Primary outcomes were complications during admission and 30-day complication rate. Secondary outcomes included overall hospital length of stay (LOS) and discharge location. RESULTS: A total of 100 patients recruited, of whom five excluded as they did not need the procedure. A total of 95 patients analyzed; 69, 10, and 16 patients were not frail, intermediate, and severely frail, respectively. There were no differences in blood loss, number of dilations, presence of a staghorn calculus, laterality, or location of dilation. Severely frail patients were likely to be older and have a higher American Society of Anesthesiologists score and Charlson comorbidity index. Patients of intermediate or severe frailty were more likely to exhibit postoperative fevers, bacteremia, sepsis, and require ICU admissions (P < 0.05). Frail patients had a longer LOS (P < 0.001) and tended to require skilled assistance when discharge (p < 0.0001). CONCLUSIONS: Frailty assessment appears useful stratifying those at risk of extended hospitalization, septic complications, and need for assistance following percutaneous renal surgery. Risks of sepsis, bacteremia, and post-operative hemorrhage may be higher in frail individuals. Preoperative assessment of frailty phenotype may give insight into treatment decisions and represent a modifiable marker allowing future trials exploring the concept of "prehabilitation".

Management and treatment options when facing malignant ureteral obstruction.

Malignant ureteral obstruction is an unfortunate finding that can be caused by a wide-ranging number of malignancies with a prognosis of limited survival. Given its presentation and progression, it can be refractory to treatment by traditional single polymeric ureteral stents. With a higher failure rate than causes of benign ureteral obstruction, a number of other options are available for initial management, as well as in cases of first-line therapy failure, including tandem stents, metallic stents, percutaneous nephrostomies and extra-anatomic stents. We reviewed the literature and carried out a PubMed search including the following keywords and phrases: "malignant ureteral obstruction," "tandem ureteral stents," "metallic ureteral stents," "resonance stent," "metal mesh ureteral stents" and "extra-anatomic stents." The vast majority of studies were small and retrospective, with a large number of studies related to metallic stents. Given the heterogenous patient population and diversity of practice, it is difficult to truly assess the efficacy of each method. As there are no guidelines or major head-to-head prospective trials involving these techniques, it makes practicing up to the specific provider. However, this article attempts to provide a framework with which the urologist who is presented with malignant ureteral obstruction can plan in order to provide the individualized care on a case-by-case basis. What is clear is that prospective, randomized clinical trials are necessary to help bring evidence-based medicine and guidelines for patients with malignant ureteral obstruction.

Incorporation of the fluoroless C-Arm Trainer at the American Urological Association hands on training percutaneous renal access.

OBJECTIVES: To assess for usefulness and validity evidence for incorporating the C-Arm Trainer (CAT) simulator into the annual AUA hands on course for training percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: The course started with a didactic session followed by four stations for training the "bull's eye" technique using the CAT simulator. Each station included a pre-test, 30-min practice on the simulator, and post-test. All participants were assessed using a 4-item checklist. All participants were asked to fill in a qualitative self-assessment questionnaire after the pre- and the post-test, and respond to a course evaluation questionnaire and post-course survey. RESULTS: A total of 38 physicians, who attended the hands on course, voluntarily participated in the study. Only 21.1% had previous practice on PCNL simulators. Compared with the results of the checklist total score and the qualitative self-assessment questionnaire scores after the pre-test, there was significant improvement in the checklist total score (p < 0.001), temporal demands (p = 0.003), situational stress (p = 0.003, and performance (0.003) after the post-test. A total of 14 (36%) participants responded to the course evaluation questionnaire, 50% evaluated the course as excellent, 28.6% as very good, and 21.4% as good. Unfortunately, only five (13%) participants responded to the post-course survey, 4/5 implemented the new competencies and knowledge into their practice, and 3/5 have attempted to obtain fluoroscopic guided PCA without assistance. CONCLUSION: The CAT simulator was considered useful for training the percutaneous renal access procedure. There was significant improvement in the qualitative and quantitative assessment parameters after the post-test compared with the pre-test.

Stones in special situations.

There are several special situations in which urinary lithiasis presents management challenges to the urologist. An in-depth knowledge of the pathophysiology, unique anatomy, and treatment options is crucial in order to maintain good health in these patients. In this review, we summarize the current literature on the management of the following scenarios: bladder stones, stones in bowel disease, during pregnancy, in association with renal anomalies, with skeletal deformities, in urinary diversions, and in children.

Can Activities of Daily Living Predict Complications following Percutaneous Nephrolithotomy?

PURPOSE: Activities of daily living provide information about the functional status of an individual and can predict postoperative complications after general and oncological surgery. However, they have rarely been applied to urology. We evaluated whether deficits in activities of daily living could predict complications after percutaneous nephrolithotomy and how this compares with the Charlson comorbidity index and the ASA(®) (American Society of Anesthesiologists(®)) classification. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients who underwent percutaneous nephrolithotomy between March 2013 and March 2014. Those with complete assessment of activities of daily living were included in analysis. Perioperative outcomes, complications and hospital length of stay were examined according to the degree of deficits in daily living activities. RESULTS: Overall 176 patients underwent a total of 192 percutaneous nephrolithotomies. Deficits in activities of daily living were seen in 16% of patients, including minor in 9% and major in 7%. Complications developed more frequently in those with vs without deficits in daily living activities (53% vs 31%, p = 0.029) and length of stay was longer (2.0 vs 4.5 days, p = 0.005). On multivariate logistic regression activities of daily living were an independent predictor of complications (OR 1.11, p = 0.01) but ASA classification and Charlson comorbidity index were not. CONCLUSIONS: Activities of daily living are easily evaluated prior to surgery. They independently predict complications following percutaneous nephrolithotomy better than the Charlson comorbidity index or the ASA classification. Preoperative assessment of daily living activities can help risk stratify patients and may inform treatment decisions.

Percutaneous nephrolithotomy in super obese patients (body mass index ≥ 50 kg/m²): overcoming the challenges.

OBJECTIVE: To analyse our experience with and the outcomes and lessons learned from percutaneous nephrolithotomy (PCNL) in the super obese (body mass index [BMI] ≥50 kg/m(2) ). PATIENTS AND METHODS: In this institutional review board approved study we retrospectively reviewed our PCNL database between July 2011 and September 2014 and identified all patients with a BMI ≥ 50 kg/m(2) . Patient demographics, peri-operative outcomes and complications were determined. Additionally, we identified a number of special PCNL considerations in the super obese that can maximize safe outcomes. RESULTS: A total of 21 PCNL procedures performed on 17 super obese patients were identified. The mean patient age was 54.8 years, the mean BMI was 57.2 kg/m(2) and the mean stone area was 1 037 mm(2) . Full staghorn stones were observed in six patients and partial staghorns in four patients. The mean operating time was 106 min and the mean haemoglobin decrease was 1.2 g/dL. The overall stone-free rate was 87%. There were four total complications: two Clavien grade II, one Clavien IIIb and one Clavien IVb. We identified several special considerations for safely preforming PCNL in the suber obese, including using extra-long nephroscopes and graspers, using custom-cut extra long access sheaths with suture 'tails' secured to easily retrieve the sheath, choosing the shortest possible access tract, readily employing flexible nephroscopes, placing nephroureteral tubes rather than nephrostomy tubes postoperatively, and meticulous patient positioning and padding. CONCLUSION: With appropriate peri-operative considerations and planning, PCNL is feasible and safe in the super obese. Stone clearance was similar to that reported in previous PCNL series in the morbidly obese, and is achievable with few complications.

Does Peak Inspiratory Pressure Increase in the Prone Position? An Analysis Related to Body Mass Index.

PURPOSE: Percutaneous nephrolithotomy is commonly performed with the patient prone. There is concern that the prone position, especially in obese patients, negatively affects ventilation due to the restriction of chest compliance and respiratory mechanics. We analyzed the change in airway resistance between supine and prone positioning of patients undergoing percutaneous nephrolithotomy. MATERIALS AND METHODS: We retrospectively reviewed the intraoperative respiratory parameters of 101 patients who underwent prone percutaneous nephrolithotomy. Peak inspiratory pressure was assessed with the patient supine, at several time points after being turned prone and at the end of the case. The change in peak inspiratory pressure with time was calculated. Results were stratified based on body mass index and data were compared using the paired t-test and Spearman ρ. RESULTS: Of 101 patients 50 (50%) were obese (body mass index 30 kg/m(2) or greater). Median body mass index was 25.6 kg/m(2) in the nonobese cohort and 38.3 kg/m(2) in the obese cohort. Average peak inspiratory pressure while supine and prone was 18.0 and 18.5 cm H2O in the nonobese cohort, and 25.5 and 26.6 cm H2O, respectively, in the obese cohort. Obese patients had significantly higher peak inspiratory pressure in the supine and the prone positions relative to nonobese patients (p <0.0001). However, there was no change in peak inspiratory pressure from the supine to the prone position in either cohort. CONCLUSIONS: Obese patients have higher baseline peak inspiratory pressure regardless of position. However, prone positioning does not impact peak inspiratory pressure in either cohort. It remains a safe and viable option.

Evaluation and comparison of urolithiasis scoring systems used in percutaneous kidney stone surgery.

PURPOSE: Contemporary predictive tools for percutaneous nephrolithotomy outcomes include the Guy stone score, S.T.O.N.E. nephrolithometry and the CROES nephrolithometric nomogram. We compared each scoring system in the same cohort to determine which was most predictive of surgical outcomes. METHODS: We retrospectively reviewed the records of patients who underwent percutaneous nephrolithotomy between 2009 and 2012 at a total of 3 academic institutions. We calculated the Guy stone score, the S.T.O.N.E. nephrolithometry score and the CROES nephrolithometric nomogram score based on preoperative computerized tomography images. A single observer at each institution reviewed all images and assigned scores. Univariate and multivariate analysis was done to determine the most predictive scoring system. RESULTS: We enrolled 246 patients in study. In stone-free patients vs those with residual stones the mean Guy score was 2.2 vs 2.7, the mean S.T.O.N.E. score was 8.3 vs 9.5 and the mean CROES nomogram score was 222 vs 187 (each p <0.001). Logistic regression revealed that the Guy, S.T.O.N.E. nephrolithometry and CROES nomogram scores were significantly associated with stone-free status (p = 0.02, 0.004 and <0.001, respectively). The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss (p <0.0001 and 0.03) and length of stay (p = 0.03 and 0.009, respectively). The CROES nomogram did not predict estimated blood loss or length of stay. CONCLUSIONS: All scoring systems and the stone burden equally predicted stone-free status. The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss and length of stay. A single scoring system should be adopted to unify reporting.

Differences in 24-h urine composition between nephrolithiasis patients with and without diabetes mellitus.

OBJECTIVES: To examine the differences in 24-h urine composition between nephrolithiasis patients with and without diabetes mellitus (DM) in a large cohort of stone-formers and to examine differences in stone composition between patients with and without DM. PATIENTS AND METHODS: A retrospective review of 1117 patients with nephrolithiasis and a 24-h urine analysis was completed. Univariable analysis of 24-h urine profiles and multivariable linear regression models were performed, comparing patients with and without DM. A subanalysis of patients with stone analysis data available was performed, comparing the stone composition of patients with and without DM. RESULTS: Of the 1117 patients who comprised the study population, 181 (16%) had DM and 936 (84%) did not have DM at the time of urine analysis. Univariable analysis showed significantly higher total urine volume, citrate, uric acid (UA), sodium, potassium, sulphate, oxalate, chloride, and supersaturation (SS) of UA in individuals with DM (all P < 0.05). However, patients with DM had significantly lower SS of calcium phosphate and pH (all P < 0.05). Multivariable analysis showed that patients with DM had significantly lower urinary pH and SS of calcium phosphate, but significantly greater citrate, UA, sulphate, oxalate, chloride, SSUA, SS of calcium oxalate, and volume than patients without DM (all P < 0.05). Patients with DM had a significantly greater proportion of UA in their stones than patients without DM (50.2% vs 13.5%, P < 0.001). CONCLUSIONS: DM was associated with multiple differences on 24-h urine analysis compared with those without DM, including significantly higher UA and oxalate, and lower pH. Control of urinary UA and pH, as well as limiting intake of dietary oxalate may reduce stone formation in patients with DM.