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".

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.

Stenting for malignant ureteral obstruction: Tandem, metal or metal-mesh stents.

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal-mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms "malignant ureteral obstruction," "tandem ureteral stents," "ipsilateral ureteral stents," "metal ureteral stent," "resonance stent," "silhouette stent" and "metal mesh stent." A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal-mesh stents. Metal and metal-mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost-effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal-mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal-mesh stents for their use in malignant ureteral obstruction.

Effects of visceral fat area and other metabolic parameters on stone composition in patients undergoing percutaneous nephrolithotomy.

PURPOSE: Obesity is a risk factor for metabolic syndrome and urolithiasis, particularly uric acid stones. As estimated by visceral fat area, visceral obesity is a more specific measure of the risk of metabolic syndrome than body mass index. We investigated the effects of visceral fat area and other metabolic factors on uric acid stone formation in patients treated with percutaneous nephrolithotomy. MATERIALS AND METHODS: We retrospectively reviewed the records of 269 patients who underwent percutaneous nephrolithotomy. Visceral fat area was measured in each patient on a CT axial slice at the umbilical level using the Aquarius iNtuition fat analysis tool. Analysis was performed to determine the effect of visceral fat area and other comorbidities on uric acid stone formation. RESULTS: Of the 269 patients analyzed there was no difference in baseline comorbidities between uric acid and nonuric acid stone formers. Patients with uric acid stones had a significantly higher mean visceral fat area (209.3 vs 161.9 cm², p = 0.001), and rates of hypertension (67.4% vs 47.3%) and coronary artery disease (14.3% vs 4.6%, each p = 0.011). On logistic regression analysis hypertension (OR 2.16, 95% CI 1.05-4.45, p = 0.04) and a high visceral fat area (OR 3.64, 95% CI 1.22-10.85, p = 0.02) were independent risk factors for uric acid stones. CONCLUSIONS: As a marker of visceral obesity, visceral fat area contributes to the risk of metabolic syndrome and urolithiasis. Uric acid stone formers showed a significantly higher hypertension rate and mean visceral fat area, which were independent risk factors for uric acid urolithiasis. Evaluating these characteristics in stone formers may facilitate a tailored metabolic assessment and treatment plan.

LeGrand N. Denslow: Pioneer in dermatology or charlatan?

LeGrand N. Denslow (1852-1918) was a pioneer of American dermatology and one of its most controversial figures. His professional career revolved around the cities of New York; St. Paul; Minnesota; and London, England. In 1885, he became professor of skin diseases and genitourinary surgery, and secretary of the St. Paul Medical College, thus making him one of the earliest dermatologists to practice in the state of Minnesota. In 1908, Denslow created a sensation in the news media when he announced, in a paper read before the New York Academy of Medicine, that he had cured patients suffering from tabes dorsalis by treating various abnormalities that he had found in their urethras. Although some American physicians hailed Denslow's "cure" as a major advance in the treatment of tabetic patients, other physicians denounced his treatments as being worthless or, at best, providing minimal and transient symptomatic benefits. This contribution presents the highlights of Denslow's personal life and professional career. It also describes his urologic treatment of tabes dorsalis and the controversy that surrounded it.

Adjuncts to improve outcomes of shock wave lithotripsy.

Shock wave lithotripsy (SWL) has been a major tool in the treatment of urinary stones for nearly three decades. In recent years, SWL technology has been less effective at fragmenting stones than earlier devices; thus, adjunctive maneuvers to improve stone-free rates after SWL have been required. This article summarizes several of these adjuncts, such as slower shock wave rate, the use of percussion therapy to clear fragments, medications to hasten expulsion of fragments, and appropriate selection and positioning of patients for SWL.

Predicting differential renal function using computerized tomography measurements of renal parenchymal area.

PURPOSE: We evaluated any correlation between measured renal parenchymal area on computerized tomography and differential function on (99m)technetium-mercaptoacetyltriglycine renal scan to ascertain whether computerized tomography measurements could predict differential renal function. MATERIALS AND METHODS: Between 2005 and 2007 we identified 111 patients who underwent computerized tomography and renal scan. Average renal parenchymal thickness was calculated by measurements made at the upper and lower poles of each kidney. The product of average renal parenchymal thickness and renal length was calculated bilaterally and the ratio of parenchymal area was compared to the differential shown on renal scan. RESULTS: The average difference between predicted and observed renal function was 4.73% (Pearson's correlation coefficient 0.959). Patients with positive urine cultures at renal scan were compared to the other 89. The average functional difference was 6.54% vs 4.28% (Pearson's correlation 0.955 vs 0.965, p = 0.0045). The 89 uninfected patients were then compared based on contrast vs noncontrast computerized tomography and obstructed vs unobstructed renal units. No statistical difference was found with contrast administration. When compared based on evidence of obstruction, unobstructed kidneys resulted in a lower Pearson correlation (0.743 vs 0.975) but they had a statistically significant average functional difference in favor of unobstructed units (3.28% vs 5.10%, p = 0.0036). No difference was found in the obstructed group with prior drain placement. CONCLUSIONS: Differential renal parenchymal area measured by computerized tomography strongly correlates with differential function on renal scintigraphy and it may obviate the need for nuclear renal scan in some circumstances.

Comparison of open and laparoscopic nephrectomy in obese and nonobese patients: outcomes stratified by body mass index.

PURPOSE: Laparoscopic radical nephrectomy has been accepted as the preferred management for low stage renal masses not amenable to partial nephrectomy. Early in the mid 1990s several studies suggested that obesity should be a relative contraindication to laparoscopy. We present our surgical outcomes and complications in patients undergoing open and laparoscopic nephrectomy, stratified by body mass index. MATERIALS AND METHODS: We retrospectively identified 88 patients, of whom 43 underwent open nephrectomy and 45 were treated laparoscopically. All patients were stratified by body mass index to compare multiple perioperative end points and pathological outcomes of laparoscopy. RESULTS: Overall our data showed that compared to open nephrectomy laparoscopic nephrectomy resulted in statistically significant lower estimated blood loss (147.95 vs 640.48 cc, p <0.0002), operative time (156.11 vs 198.95 minutes, p <0.003) and hospital stay (3.7 vs 5.9 days, p <0.004). When stratified by body mass index less than 25, 25 to 29.9 and 30 kg/m(2) or greater, there was a statistically significant difference in estimated blood loss and hospital stay that was in favor of the laparoscopic approach in each body mass index category. Operative time did not show a statistical difference in the subgroups but all laparoscopic procedure times were shorter than open procedure times in each body mass index category. When patients with a body mass index of greater than 30 kg/m(2) were further subgrouped into 35 kg/m(2) or greater and 40 kg/m(2) or greater, there was a statistically significant difference in estimated blood loss and hospital stay that was again in favor of the laparoscopic method. CONCLUSIONS: Laparoscopic radical nephrectomy is technically more challenging as body mass index increases due to many factors but our data show that it is feasible and safe in experienced hands. Laparoscopy appears to result in perioperative outcomes that are superior to those of open nephrectomy in this high risk population with a complication profile that is equivalent to that of the open method for each stratified body mass index category.

Retrograde endoscopic-assisted percutaneous renal access: a novel "lasso" technique to achieve rapid secure access to the collecting system.

Image-guided percutaneous renal access for placement of an access sheath for percutaneous nephrolithotomy can be a challenging procedure, especially in patients with nondilated collecting systems, obstructed infundibula (stones or stricture), or extreme body habitus. We describe our experience using ureteroscopy along with a zero-tip stone basket to facilitate a through-and-through (percutaneous-urethra) access to the collecting system.

Safety and efficacy of synchronous percutaneous nephrostolithotomy and contralateral ureterorenoscopy for bilateral calculi.

Herein we describe the technique and review the medical records of 26 patients who underwent percutaneous nephrostolithotomy (PCNL) and simultaneous contralateral retrograde ureterorenoscopy (URS) for bilateral urolithiasis of discordant sizes at our institution. Preoperative factors, operative time, change in hemoglobin, change in serum creatinine, stone free, and efficacy rates after a single procedure were analyzed retrospectively. The total efficacy rate--defined as residual calculus of 4 mm or less--was 92.3%. A second look PCNL or URS was used to target any residual calculi; 5 of the 26 (19%) patients required further therapy following the initial intervention. All cases that required a second look were ultimately rendered stone-free. No preoperative factor was statistically significant with respect to treatment failures. In terms of complications, temporary, acute renal insufficiency occurred in 2 patients, (7.7%) and the duration was transient. Performing synchronous PCNL and contralateral retrograde URS is efficient, safe, and not more dramatically lengthy in terms of operative time or morbid in terms of complications when compared to a traditional unilateral percutaneous procedure. In this approach, management of bilateral urolithiasis in one operative procedure is practical and efficacious. The approach allows patients to return to normal activity within the same time period as those having a unilateral approach and to be free of stone without a need for a second, staged procedure.

Efficacy of Multi-Detector Computed Tomography for the Diagnosis of Medullary Sponge Kidney.

OBJECTIVE: To expand the diagnostic armamentarium for medullary sponge kidney (MSK), we evaluate the use of high-resolution multidetector computed tomography (MDCT) for MSK diagnosis and compare to the standard intravenous urography (IVU). Despite a significant prevalence amongst stone formers, diagnosis of this well described condition has declined. IVU, the gold standard in MSK diagnosis, has largely been replaced by CT, which has previously been shown unable to demonstrate signs of MSK. METHODS AND MATERIALS: Patients with known history of MSK based on IVU underwent limited MDCT urogram. Control group patients, without MSK, also had MDCT urograms performed for other clinically indicated conditions. Studies were scored by board-certified radiologists on a 0-2 scale based on the likelihood of MSK. IVU studies, when available, were similarly graded. RESULTS: MDCT was diagnostic of MSK in 9 out of the 10 patients with known history of MSK. No false positives were present in our series. The one case of MSK not detected on MDCT was graded as a "1" on its respective IVU. Sensitivity and specificity were 90 and 100%, respectively, when compared with IVU. CONCLUSION: Concordance with IVU findings, despite a small reduction in sensitivity, indicates MDCT to be a suitable, and more readily available replacement for IVU in the diagnosis of MSK.

Case report: intrarenal arteriovenous fistula after ureteroscopic stone extraction with holmium laser lithotripsy.

A 79-year-old woman presented with gross hematuria 10 days after flexible ureteroscopic stone extraction with holmium laser lithotripsy. Work-up revealed a bleeding intrarenal arteriovenous fistula that was embolized. To our knowledge, this is the first report of this complication causing delayed hematuria after ureterorenoscopy.

Outcome of percutaneous surgery stratified according to body mass index and kidney stone size.

OBJECTIVE: To stratify outcome and morbidity of percutaneous nephrostolithotomy (PCNL) with regard to body mass index (BMI) and kidney stone burden. METHODS: The charts of 148 patients who underwent PCNL procedures were reviewed retrospectively. Hospital stay, blood loss, maximal temperature during inpatient stay, and stone-free outcomes were evaluated. Patients were divided into 3 groups depending on their BMIs: <25 kg/m, 25 to 29.9 kg/m, and >30 kg/m. Kidney stone burden was measured in terms of square area in millimeters, as measured by retrospective review of computerized tomography scans. Preoperative computerized tomography scan for measurement of stone burden was available for only 85 patients who are included in the study. Analysis of variance for a single variable was performed with regard to the values of the hospital stay, postoperative maximal temperature, and hemoglobin change. RESULTS: Of the 85 patients, 37 (43.5%) were obese or morbidly obese (BMI, >30 kg/m), 33 (38.8%) were overweight (BMI, 25 to 29.9 kg/m), and 15 (17.7%) were within or below their ideal weight (BMI, <25 kg/m). No statistically significant difference among the 3 groups was seen for stone-free rate, postoperative fever, or change in hemoglobin when stratified by BMI alone or by BMI and kidney stone burden. However, significantly longer length of stay for the group with BMI <25 kg/m was observed when stratifying either by BMI alone (P=0.01) or by BMI and kidney stone burden (P=0.03). CONCLUSIONS: In this retrospective review of patients with kidney stones undergoing PCNL, the stone-free outcome and associated morbidity of PCNL (except for the length of hospital stay) is independent of both patients' BMI and stone burden when stratifying by commonly defined parameters.

Prediction of surgical complications in the elderly: Can we improve outcomes?

As the number of Americans aged 65 years and older continues to rise, there is projected to be a corresponding increase in demand for major surgeries within this population. Consequently, it is important to utilize accurate preoperative risk stratification techniques that are applicable to elderly individuals. Currently, commonly used preoperative risk assessments are subjective and often do not account for elderly-specific syndromes that may pose a hazard for geriatric patients if not addressed. Failure to accurately risk-stratify these patients may increase the risk of postoperative complications, morbidity, and mortality. Therefore, we aimed to identify and discuss the more objective and better-validated measurements indicative of poor surgical outcomes in the elderly with special focus on frailty, patient optimization, functional status, and cognitive ability.

Laparoscopic nephrectomy for a nonfunctioning pelvic kidney in preparation for renal transplantation.

Pelvic kidneys pose a problem for any planned surgical intervention given their anomalous blood supply. Although minimally invasive approaches have been described for the management of benign conditions, only a handful of reports have described the use of laparoscopy for removal of ectopic or fused kidneys. We describe the laparoscopic removal of a symptomatic pelvic kidney in a patient before renal transplantation.

A Randomized Controlled Comparison of Nephrostomy Drainage vs Ureteral Stent Following Percutaneous Nephrolithotomy Using the Wisconsin StoneQOL.

OBJECTIVE: We compared postoperative outcomes and quality of life (QoL) between patients who received a nephrostomy tube vs a ureteral stent following percutaneous nephrolithotomy (PCNL) in a prospective, double-blind, randomized manner. MATERIALS AND METHODS: Between September 2015 and March 2016, we randomized 30 patients undergoing PCNL to receive nephrostomy drainage (Group 1: 8F or 10F) or Double-J ureteral stent (Group 2) at conclusion of surgery. Nephrostomy tubes were removed within 48 hours (before discharge) and ureteral stents were removed at least 2 weeks after surgery. Patients' QoL was assessed with the Wisconsin StoneQOL questionnaire preoperatively and then 7 to 10 days and 30 days following surgery. Inclusion criteria included an uncomplicated procedure, normal preoperative renal function, and clinically insignificant residual stone fragments on postoperative imaging. We calculated the preoperative and postoperative QoL score difference between the two groups. We also evaluated perioperative characteristics, inpatient analgesic requirements, length of stay (LOS), and postsurgical complications. OUTCOME: Patient characteristics between Groups 1 and 2 were comparable with similar age (58.3 vs 54.7, p = 0.534), gender ratio, and stone burden (276.6 mm2 vs 259 mm2, p = 0.84) and composition. There was no significant difference between perioperative outcomes, including stone-free rate (93.3% vs 86.7%), operative times (125.7 minutes vs 115 minutes, p = 0.29), estimated blood loss (103.3 mL vs 100.7 mL, p = 0.9), LOS (3.2 days vs 1.9 days, p = 0.1), and complications (2 in each group). Inpatient analgesic requirements were also the same (both 21.1 mg, p = 1.0). Assessment of QoL using the Wisconsin StoneQOL questionnaire showed significant differences between preoperative and postoperative health-related QoL in 18 of the 28-question instrument at 7 to 10 days. Patients in Group 2 had significantly worse QoL change and a multitude of negative responses on the StoneQOL assessment, not only those commonly associated with stent irritation. Eighty percent of participants in Group 2 also attributed their complaints to having a stent placed. Both groups had similar QoL status at 30 days after surgery. CONCLUSION: Despite the literature advocating "tubeless" PCNL with ureteral stent placement at conclusion of surgery, our randomized prospective study shows that QoL is significantly worse with stent placement than with temporary nephrostomy drainage in the immediate aftermath following PCNL, using a validated QoL assessment instrument specific for nephrolithiasis.

Combined ureterorenoscopy and shockwave lithotripsy for large renal stone burden: an alternative to percutaneous nephrolithotomy?

PURPOSE: To investigate the feasibility and initial outcomes of a combination of ureterorenoscopy (URS) using holmium laser lithotripsy and extracorporeal shockwave lithotripsy (SWL) in a single outpatient session for the treatment of large renal stone burdens in patients refusing or unsuitable for percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS: Fourteen patients with a mean age of 52.7 years (range 34-81 years) having a mean stone burden of 847 mm2 (range 58 mm2-1850 mm2) were treated with combined URS laser lithotripsy and SWL as an alternative to PCNL. The SWL (mean 2800 shockwaves) was performed using the Storz Modulith SL-X, and flexible URS with holmium laser lithotripsy was performed either during or following SWL. RESULTS: Ninety-three percent of the patients (13/14) were treated successfully on an outpatient basis. Two patients were rendered stone free after the initial procedure alone (14%). Overall, including secondary outpatient treatment with a second session of URS alone (N = 7) URS and SWL (N = 1), SWL (N = 1), or oral alkalinization therapy (N = 1), the stone-free rate was 76.9% (10/13). One patient was excluded secondary to death from unrelated causes after the initial procedure, and the success rate (residual fragments <4 mm) was 84.6% (11/13). The two treatment failures included one patient who required a third URS procedure and one patient who developed urosepsis necessitating nephrostomy-tube placement who underwent subsequent PCNL. CONCLUSIONS: In comparison with traditional approaches using PCNL and second-look nephroscopy, single-session combined URS and SWL with a second outpatient procedure may offer equivalent results with decreased morbidity in carefully selected patients.

Laparoscopic nephron-sparing surgery for the small exophytic renal mass.

OBJECTIVES: Nephron-sparing surgery has emerged as the treatment of choice for the incidentally detected small renal mass, especially those less than 4 cm in size. We describe our technique and experience with the laparoscopic excision of these lesions. METHODS: Between June 2001 and October 2003, 20 patients underwent nephron-sparing surgery at our institution. Twenty-one laparoscopic partial nephrectomy procedures were performed. All tumors were detected incidentally by cross-sectional imaging. All patients had a solid renal mass or a complex cystic renal mass of Bosniak category III or greater. All solid tumors were exophytic and less than 4cm in diameter. Both transperitoneal and retroperitoneal approaches were used. Hemostasis was achieved without hilar control in 20 of the 21 cases. RESULTS: Twenty renal units were approached transperitoneally, and 1 retroperitoneally. Mean tumor size was 2.6 cm (range, 1.2 to 4). Mean estimated blood loss was 211 mL (range, 50 to 500), and mean operative time was 165 minutes. Pathology revealed renal cell carcinoma in 14 (70%). No intraoperative complications occurred. Two patients required blood transfusions postoperatively. CONCLUSION: Carefully selected patients with small, exophytic renal masses can safely undergo laparoscopic excision. When achievable, this procedure can be a more logical alternative to ablative techniques for the minimally invasive management of such lesions.

The visceral fat compartment is independently associated with changes in urine constituent excretion in a stone forming population.

The objective of this study was to identify the independent effect of visceral fat on urine constituent excretion in a stone forming population. Using a database of 382 kidney stone patients with available visceral fat quantification, we created multiple linear regression models predicting changes in urinary solutes based on visceral fat area and body mass-index, divided by gender. Chi-square tests were used to compare stone composition by body mass-index and visceral fat area. Visceral fat predicts increases in urinary creatinine, sodium, and volume in men, but only urinary phosphate in women. In women, total body mass-index does not appear to modify this effect, but in men it is more pronounced in overweight patients for creatinine and volume only. Elevated visceral fat is associated with increased probability of uric acid stone composition. Different fat compartments likely effect urine composition in different ways. This effect appears to be different in men and women. Understanding and quantifying the effects of different fat compartments is probably important to understanding the metabolism of urolithiasis.