Risks Associated with Drug Treatments for Kidney Stones

Introduction: Renal stones are one of the most painful medical conditions patients experience. For many they are also a recurrent problem. Fortunately, there are a number of drug therapies available to treat symptoms as well as prevent future stone formation. Areas covered: Herein, we review the most common drugs used in the treatment of renal stones, explaining the mechanism of action and potential side effects. Search of the Medline databases and relevant textbooks was conducted to obtain the relevant information. Further details were sourced from drug prescribing manuals. Recent studies of drug effectiveness are included as appropriate. Expert opinion: Recent controversies include medical expulsive therapy trials and complex role of urinary citrate in stone disease. Future directions in research will involve new medical therapies for stone prevention, for example new drugs for hyperoxaluria

The Circle Nephrostomy Tube: An Attractive Nephrostomy Drainage System Following Complex Percutaneous Nephrolithotomy

Objective To describe our experience with the circle nephrostomy tube (NT) (Cook Medical), a drainage system uniquely designed for use after multiple-access percutaneous nephrolithotomy (PNL). Methods A retrospective review of 1317 consecutive patients undergoing 1599 PNLs at IU Health Methodist Hospital was performed. All multiple access cases utilizing circle NTs were reviewed and analyzed. The method of insertion of circle NT was demonstrated. Results A total of 1843 accesses were obtained in 1599 renal units (RUs): 380 upper pole, 129 interpolar, and 1334 lower pole. Multiple accesses in this series were required in 282 RUs (17.6%). Following multiple-access PNL, circle NTs, Cope loop, and reentry Malecot NTs were inserted in 91 RUs (32.3%), 208 RUs (73.8%), and 31 RUs (11%), respectively. None of the patients who had circle NT experienced clogging, dislodgement, or obstruction of the tube. The cost of circle, Cope loop, and Malecot NTs are 121.73 USD, 95.20 USD, and 81 USD, respectively. Conclusion Circle NTs are easy to insert, secure, cost-effective compared with inserting two NTs. Circle NTs provide excellent drainage and facilitate secondary procedures

Percutaneous Nephrolithotomy in the Superobese: A Comparison of Outcomes Based on Body Mass Index

Introduction: Percutaneous nephrolithotomy (PCNL) is considered the gold standard for treatment of large renal calculi. Although several investigators have examined the feasibility and outcomes associated with PCNL in obese patients, these studies have been limited by small sample size, lack of a comparator group, or few patients at body mass index (BMI) extremes. We thus compared outcomes of superobese (BMI >50) patients undergoing PCNL vs both an “overweight” and “ideal” cohort. Methods: We used a prospectively maintained database to identify ideal (BMI 18.5–25), overweight (BMI 25.1–49.9), and superobese (BMI ≥50) patients who underwent PCNL. Our primary objective was to compare surgical outcomes between groups measured by the percent of patients who required secondary PCNL. We then compared complication rates, need for transfusion, and length of stay (LOS) using chi-square testing and ANOVA where appropriate. Results: A total of 1152 patients were identified of which 254 were classified as ideal, 840 as overweight, and 58 as superobese. The overweight cohort had a higher mean age and greater proportion of males, whereas staghorn stones were more common in the superobese group. Comorbid conditions were more commonly observed in the superobese cohort. Otherwise, the groups were similar. Surgical outcomes were comparable with 47.2%, 42.0%, and 38.0% of ideal, overweight, and superobese patients requiring secondary PCNL (p = 0.25) with no difference in complication rates, need for transfusion, or LOS. Conclusion: PCNL can be effectively and safely performed in superobese patients with no difference in surgical outcomes or complications when compared to ideal or overweight patient cohorts

A Usability Comparison of Laser Suction Handpieces for Percutaneous Nephrolithotomy

Introduction: The holmium laser has revolutionized the practice of minimally invasive endoscopy for kidney stones. Recently, a novel, rigid handpiece for use in percutaneous nephrolithotomy (PCNL) that couples the holmium laser with suction has been developed. To date, limited data exist regarding the usability and ergonomics of such treatment systems. We thus sought to compare surgeon-rated usability with three different suction laser handpieces in a porcine model. Materials and Methods: We performed bilateral reverse PCNL on four female domestic farm pigs. After induction of general anesthesia, percutaneous access was obtained into each kidney by using biplanar fluoroscopy and 8?mm stones (plaster of Paris) were inserted into the calix or renal pelvis for treatment. Four surgeons tested the LASER Suction Tube (Karl Storz?, Germany), LithAssist? (Cook? Medical), and Suction Handpiece (HP) (Lumenis?, Israel) by using a combination of fragmentation (5 Joules/20 Hertz) and dusting (0.8 Joules/80 Hertz) settings on the Lumenis pulse 120 H laser. The primary outcome assessed was the ease of use of the three devices as measured by a surgeon questionnaire. Results: A total of 15 stones were treated in 8 renal units. The mean time required for stone fragmentation was 8?min. The mean handling and suction efficiency scores were similar between devices. The Suction HP offered the best laser fiber visibility during lithotripsy. Conclusion: Suction laser handpieces offer an option to treat renal stones via PCNL, with limited differences noted in most surgeon ratings between devices.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140086/1/end.2016.0203.pd

Getting Out of a PCCL: Percutaneous Cholecystolithotomy as a Salvage Treatment Option for Gallstone Removal in Patients Deemed Unfit for Standard Surgical Approaches

Definitive management of acute cholecystitis or symptomatic cholelithiasis in exceedingly high-risk patients remains a clinical dilemma. In certain cases, treatment through a percutaneous approach following standard techniques and principles similar to those of percutaneous nephrolithotomy may be considered. However, one potential challenge, particularly among a high-risk population, is the possible necessity to stay on obligate anticoagulation for pre-existing medical reasons. To date, there have been no prior reports documenting the role of this procedure in patients on systemic anticoagulation, particularly clopidogrel. Here we report a case of a percutaneous cholecystolithotomy performed on an elderly patient unable to stop dual antiplatelet therapy (aspirin and clopidogrel) secondary to recent drug eluting stent placement for myocardial infarction

Comprehensive Costs Associated with Fiberoptic and Digital Flexible Ureteroscopes at a High Volume Teaching Hospital

Introduction Modern flexible ureteroscope ownership costs are considerable. Most prior estimates focus exclusively on repair costs, likely underestimating overall costs, including those of acquisition and reprocessing. Furthermore, to our knowledge no prior cost analyses focus on the latest generation digital flexible ureteroscope, which may differ due to unique purchase and repair prices. We sought to gain greater insight into the comprehensive costs associated with modern flexible ureteroscope use, particularly the difference between digital and fiberoptic models. Methods Data on use and repair of fiberoptic Storz Flex-X2 and digital Flex-Xc flexible ureteroscopes from 2011 to 2015 were reviewed. List prices and repair costs were obtained from Storz. Per case reprocessing costs were estimated, accounting for disposables, reagents and labor. Maintenance costs were estimated by combining cost of repairs and reprocessing. Analyses were performed at list pricing and standard discount rates. Global flexible ureteroscope costs were calculated to account for the cost of acquisition, repair and maintenance of a new scope during its first 100 uses. Results Global costs associated with digital flexible ureteroscope ownership were 1.3 to 1.4 times greater than fiberoptic on a per case basis ($1,008/$1,086 vs $715/$835). The majority of expenses went toward scope repairs (73% vs 71%), with instrument purchase (23% vs 24%) and reprocessing (4% vs 5%) being less costly. Repair rates were not significantly different between fiberoptic and digital devices (12.5 vs 11.5, p=0.757). Conclusions Expenditures associated with ownership of modern flexible ureteroscopes are considerable and driven primarily by the high cost of repairs. Digital instruments are more costly despite comparable rates of flexible ureteroscope damage

Accuracy of Daily Fluid Intake Measurements Using a "Smart" Water Bottle

High fluid intake is an effective preventative strategy against recurrent kidney stones but is known to be challenging to achieve. Recently, a smart water bottle (Hidrate Spark™, Minneapolis, MN) was developed as a non-invasive fluid intake monitoring system. This device could help patients who form stones from low urine volume achieve sustainable improvements in hydration, but has yet to be validated in a clinical setting. Hidrate Spark™ uses capacitive touch sensing via an internal sensor. It calculates volume measurements by detecting changes in water level and sends data wirelessly to users’ smartphones through an application. A pilot study was conducted to assess accuracy of measured fluid intake over 24 h periods when used in a real life setting. Subjects were provided smart bottles and given short tutorials on their use. Accuracy was determined by comparing 24-h fluid intake measurements calculated through the smart bottle via sensor to standard volume measurements calculated by the patient from hand over the same 24 h period. Eight subjects performed sixty-two 24-h measurements (range 4–14). Mean hand measurement was 57.2 oz/1692 mL (21–96 oz/621–2839 mL). Corresponding mean smart bottle measurement underestimated true fluid intake by 0.5 ozs. (95% CI −1.9, 0.9). Percent difference between hand and smart bottle measurements was 0.0% (95% CI − 3%, 3%). Intraclass correlation coefficient (ICC), calculated to assess consistency between hand measures and bottle measures, was 0.97 (0.95, 0.98) indicating an extremely high consistency between measures. 24-h fluid intake measurements from a novel fluid monitoring system (Hidrate Spark™) are accurate to within 3%. Such technology may be useful as a behavioral aide and/or research tool particularly among recurrent stone formers with low urinary volume

Salvage Percutaneous Nephrolithotomy: Analysis of Outcomes Following Initial Treatment Failure

Purpose Percutaneous nephrolithotomy has high potential for morbidity or failure. There are limited data regarding risk factors for failure and to our knowledge no published reports of surgical outcomes in patients with prior failed attempts at percutaneous stone removal. Materials and Methods We identified patients referred to 3 medical centers after prior failed attempts at percutaneous nephrolithotomy. A retrospective chart review was performed to analyze reasons for initial failure and outcomes of salvage percutaneous nephrolithotomy. Outcomes were compared to those in a prospectively maintained database of more than 1,200 patients treated with a primary procedure. Results Salvage percutaneous nephrolithotomy was performed in 31 patients. Unsuitable access to the stone was the reason for failure in 80% of cases. Other reasons included infection, bleeding and inadequate instrument availability in 6.5% of cases each. Compared to patients who underwent primary percutaneous nephrolithotomy those treated with salvage were more likely to have staghorn calculi (61.3% vs 31.4%, p <0.01) and a larger maximum stone diameter (3.7 vs 2.5 cm, p <0.01), and require a secondary procedure (65.5% vs 42.1%, p <0.01). There was no significant difference between the cohorts in the remaining demographics or perioperative outcomes. All patients were deemed completely stone free except one who elected observation for a 3 mm nonobstructing fragment. Conclusions Despite the more challenging nature and prior unsuccessful attempts at treatment, the outcomes of salvage percutaneous nephrolithotomy were no different from those of primary percutaneous nephrolithotomy when performed by experienced surgeons

Transgluteal CT-Guided Percutaneous Renal Access for Percutaneous Nephrolithotomy in a Pelvic Horseshoe Kidney

CT-guided percutaneous renal access has been described as a safe and effective access technique in patients with complex anatomy, including ectopic kidney, retrorenal colon, spinal dysraphism, hepatomegaly, and splenomegaly. In comparison to conventional intraoperative fluoroscopic-guided access, CT imaging allows for delineation of surrounding structures that are at risk for injury during percutaneous access. However, previous reports indicate that pelvic kidneys might be inaccessible percutaneously without laparoscopic assistance. Herein, we present a novel transgluteal route to renal access for percutaneous nephrolithotomy (PCNL) in a patient with a pelvic horseshoe kidney and severe spinal deformity

Integration and utilization of modern technologies in nephrolithiasis research

Nephrolithiasis, or stones, is one of the oldest urological diseases, with descriptions and treatment strategies dating back to ancient times. Despite the enormous number of patients affected by stones, a surprising lack of conceptual understanding of many aspects of this disease still exists. This lack of understanding includes mechanisms of stone formation and retention, the clinical relevance of different stone compositions and that of formation patterns and associated pathological features to the overall course of the condition. Fortunately, a number of new tools are available to assist in answering such questions. New renal endoscopes enable kidney visualization in much higher definition than was previously possible, while micro-CT imaging is the optimal technique for assessment of stone microstructure and mineral composition in a nondestructive fashion. Together, these tools have the potential to provide novel insights into the aetiology of stone formation that might unlock new prevention and treatment strategies, and enable more effective management of patients with nephrolithiasis