Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse.

BACKGROUND: The benefits of removing small (≤6 mm), asymptomatic kidney stones endoscopically is unknown. Current guidelines leave such decisions to the urologist and the patient. A prospective study involving older, nonendoscopic technology and some retrospective studies favor observation. However, published data indicate that about half of small renal stones left in place at the time that larger stones were removed caused other symptomatic events within 5 years after surgery. METHODS: We conducted a multicenter, randomized, controlled trial in which, during the endoscopic removal of ureteral or contralateral kidney stones, remaining small, asymptomatic stones were removed in 38 patients (treatment group) and were not removed in 35 patients (control group). The primary outcome was relapse as measured by future emergency department visits, surgeries, or growth of secondary stones. RESULTS: After a mean follow-up of 4.2 years, the treatment group had a longer time to relapse than the control group (P<0.001 by log-rank test). The restricted mean (±SE) time to relapse was 75% longer in the treatment group than in the control group (1631.6±72.8 days vs. 934.2±121.8 days). The risk of relapse was 82% lower in the treatment group than the control group (hazard ratio, 0.18; 95% confidence interval, 0.07 to 0.44), with 16% of patients in the treatment group having a relapse as compared with 63% of those in the control group. Treatment added a median of 25.6 minutes (interquartile range, 18.5 to 35.2) to the surgery time. Five patients in the treatment group and four in the control group had emergency department visits within 2 weeks after surgery. Eight patients in the treatment group and 10 in the control group reported passing kidney stones. CONCLUSIONS: The removal of small, asymptomatic kidney stones during surgery to remove ureteral or contralateral kidney stones resulted in a lower incidence of relapse than nonremoval and in a similar number of emergency department visits related to the surgery. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and the Veterans Affairs Puget Sound Health Care System; ClinicalTrials.gov number, NCT02210650.).

Randomized Controlled Trial of Ultrasonic Propulsion-Facilitated Clearance of Residual Kidney Stone Fragments vs Observation.

PURPOSE: Ultrasonic propulsion is an investigational procedure for awake patients. Our purpose was to evaluate whether ultrasonic propulsion to facilitate residual kidney stone fragment clearance reduced relapse. MATERIALS AND METHODS: This multicenter, prospective, open-label, randomized, controlled trial used single block randomization (1:1) without masking. Adults with residual fragments (individually ≤5 mm) were enrolled. Primary outcome was relapse as measured by stone growth, a stone-related urgent medical visit, or surgery by 5 years or study end. Secondary outcomes were fragment passage within 3 weeks and adverse events within 90 days. Cumulative incidence of relapse was estimated using the Kaplan-Meier method. Log-rank test was used to compare the treatment (ultrasonic propulsion) and control (observation) groups. RESULTS: The trial was conducted from May 9, 2015, through April 6, 2024. Median follow-up (interquartile range) was 3.0 (1.8-3.2) years. The treatment group (n = 40) had longer time to relapse than the control group (n = 42; P < .003). The restricted mean time-to-relapse was 52% longer in the treatment group than in the control group (1530 ± 92 days vs 1009 ± 118 days), and the risk of relapse was lower (hazard ratio 0.30, 95% CI 0.13-0.68) with 8 of 40 and 21 of 42 participants, respectively, experiencing relapse. Omitting 3 participants not asked about passage, 24 treatment (63%) and 2 control (5%) participants passed fragments within 3 weeks of treatment. adverse events were mild, transient, and self-resolving, and were reported in 25 treated participants (63%) and 17 controls (40%). CONCLUSIONS: Ultrasonic propulsion reduced relapse and added minimal risk. CLINICAL TRIAL REGISTRATION NO.: NCT02028559.

g Theorem from Strong Subadditivity.

We show that strong subadditivity provides a simple derivation of the g theorem for the boundary renormalization group flow in two-dimensional conformal field theories. We work out its holographic interpretation and also give a derivation of the g theorem for the case of an interface in two-dimensional conformal field theories. We also geometrically confirm strong subadditivity for holographic duals of conformal field theories on manifolds with boundaries.

Using structured problem solving to promote fluid consumption in the prevention of urinary stones with hydration (PUSH) trial.

BACKGROUND: Structured Problem Solving (SPS) is a patient-centered approach to promoting behavior change that relies on productive collaboration between coaches and participants and reinforces participant autonomy. We aimed to describe the design, implementation, and assessment of SPS in the multicenter Prevention of Urinary Stones with Hydration (PUSH) randomized trial. METHODS: In the PUSH trial, individuals with a history of urinary stone disease and low urine output were randomized to control versus a multicomponent intervention including SPS that was designed to promote fluid consumption and thereby prevent recurrent stones. We provide details specifically about training and fidelity assessment of the SPS coaches. We report on implementation experiences related to SPS during the initial conduct of the trial. RESULTS: With training and fidelity assessment, coaches in the PUSH trial applied SPS to help participants overcome barriers to fluid consumption. In some cases, coaches faced implementation barriers such as variable participant engagement that required tailoring their work with specific participants. The coaches also faced challenges including balancing rapport with problem solving, and role clarity for the coaches. CONCLUSIONS: We adapted SPS to the setting of kidney stone prevention and overcame challenges in implementation, such as variable patient engagement. Tools from the PUSH trial may be useful to apply to other health behavior change settings in nephrology and other areas of clinical care. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03244189.

Investigating the citing communities around three leading health-system frameworks.

Of numerous proposed frameworks for analyzing and impacting health systems, three stand out for the large number of publications that cite them and for their links to influential international institutions: Murray and Frenk (Bull World Health Organ 78:717-31, 2000) connected initially to the World Health Organization (WHO) and then to the Global Burden of Disease Project; Roberts et al. (Getting health reform right: a guide to improving performance and equity, Oxford University Press, Oxford, 2004) sponsored by the World Bank/Harvard Flagship Program; and de Savigny and Adam (Systems thinking for health systems strengthening, WHO, 2009) linked to the WHO and the Alliance for Health Policy and Systems Research. In this paper, we examine the citation communities that form around these works to better understand the underlying logic of these citation grouping as well as the dynamics of Global Health research on health systems. We conclude that these groupings are largely independent of one another, reflecting a range of factors including the goals of each framework and the problems that it was meant to explore, the prestige and authority of institutions and individuals associated with these frameworks, and the intellectual and geographic proximity of the citing researchers to each other and to the framework authors.

Indications and versatility of the posterior tibial artery flap in head and neck reconstruction.

Importance Free tissue transfer for reconstruction of the head and neck requires complicated repair of complex anatomy. The posterior tibial flap is a free tissue flap that has viability and versatility to be used for complex reconstructions that is not offered by other free flaps. OBJECTIVE: The posterior tibial artery flap is a perforator flap which is found between the flexor digitorum longus and the soleus. It has been described as both a pedicled flap for lower extremity reconstruction as well as a free flap, including for head and neck reconstruction. Limited data exists on the subject in the English literature. The objective of this study is to present our experience with the flap in the head and neck. DESIGN: Retrospective review of cases from a single institution between October 2019 and May 2023. Primary indications included patients whose defects were felt to be larger than a conventional radial forearm free flap that were not well served by the anterolateral thigh flap, either because of body habitus or room for the associated muscle. SETTING: Tertiary academic hospital system performing free tissue transfer reconstruction of within the head and neck. RESULTS: Fifteen patients underwent posterior tibial artery free flap during the study period. Indications for flap reconstruction included oral cavity, tongue, oropharynx and skin of the scalp and forehead. Flap size ranged from 24cm2 to 143cm2. Only one flap failure was observed. Flap harvest time was universally under forty-six minutes, and as little as thirty-two. CONCLUSION: The posterior tibial artery flap is a useful option in head and neck reconstruction. It provides an intermediary in size and bulk between the radial forearm and the anterolateral thigh flap. Additionally, it provides a straightforward harvest with minimal donor site morbidity.

Second sensor to improve near-infrared spectroscopy flap monitor utility: A prospective study.

OBJECTIVE: This study assesses whether use of continuous noninvasive near-infrared spectroscopy (NIRS) sensor on head and neck free flap (FF) with a second sensor on nonoperated tissue improves distinction between systemic hypoperfusion and FF compromise. METHODS: Single-institution, prospective study of patients undergoing head and neck FF reconstruction from December 2018 to April 2020. FFs were continuously monitored using NIRS on a monitor paddle with a second (control) sensor on the shoulder. Crude StO2 and percent change in StO2 were compared between the FF and control sensors on each patient, and percent change and percent difference between the control and the monitor paddle were documented to assess for congruity. Sentinel events (e.g., hypotension and hematoma) were documented to assess the association with change in StO2. These events and timing of StO2 changes were noted to assess associations with change in StO2. RESULTS: A total of 48 patients had complete data. Donor sites included 35 soft-tissue FFs and 13 fibula FFs. Average StO2 was 73.7 ± 5.5 for FFs and 71.4 ± 5.0 for control sensors. There were seven sentinel events during the study. At the time of the events, StO2 dropped significantly more for the FF than the control sensor (FF = 52.2% drop; control = 6.2% drop; p = .016). NIRS signal denoted change prior to changes in implantable arterial Doppler in all cases. CONCLUSIONS: The addition of a second sensor when using NIRS as a primary modality for FF monitoring may improve distinction between FF compromise events and systemic hypoperfusion. By increasing accuracy of the monitor, there is a potential for decreased resident burden and decreased use of higher level of care nursing, which could reduce overall costs.

Initial outcomes and insights from a novel high-risk prostate cancer screening clinic.

INTRODUCTION: Guidelines for germline testing in patients with prostate cancer (PCa) are identifying family members who require additional surveillance given pathogenic variants (PVs) that confer increased PCa risk. We established an interdisciplinary clinic for cancer surveillance in high-risk individuals aimed to implement screening recommendations. This study aimed to characterize the clinical features of this cohort. PATIENTS AND METHODS: The Prostate Cancer Risk Clinic (PCRC) was established for unaffected individuals with germline PVs or a strong PCa family history. PCa screening, urine labs, and questionnaires were included in the visit. Individuals with BRCA1/2 PVs underwent clinical breast exam as well. Data from the initial visit were abstracted from the medical record and questionnaires for analysis. RESULTS: Thirty-five individuals with increased PCa risk were followed by the PCRC with a median age of 47 years of age. Twenty individuals (57%) had a family history of PCa, and 34 (97%) had a germline PV associated with an increased risk for developing PCa. Four individuals underwent biopsy due to care in the PCRC, with one PCa identified in an individual with TP53 PV. Median patient response scores indicated mild symptoms of an enlarged prostate (AUASS), normal erectile function (SHIM), and relatively low anxiety about developing PCa (MAX-PC). However, there were notable "outlier" scores on each questionnaire. CONCLUSIONS: Individuals with prostates and BRCA1/2 PVs, among other germline PVs, can benefit from a comprehensive interdisciplinary approach to high-risk management. PCa was identified in an individual with a non-BRCA PV, emphasizing the importance and need for high-risk screening guidelines across all genes with increased risk for PCa. "Outlier" patient response scores demonstrate that some participants experienced worse symptoms or anxiety than was indicated by median scores alone.

Risk Factors for Increased Stent-associated Symptoms Following Ureteroscopy for Urinary Stones: Results From STENTS.

PURPOSE: The STudy to Enhance uNderstanding of sTent-associated Symptoms sought to identify risk factors for pain and urinary symptoms, as well as how these symptoms interfere with daily activities after ureteroscopy for stone treatment. MATERIALS AND METHODS: This prospective observational cohort study enrolled patients aged ≥12 years undergoing ureteroscopy with ureteral stent for stone treatment at 4 clinical centers. Participants reported symptoms at baseline; on postoperative days 1, 3, 5; at stent removal; and day 30 post-stent removal. Outcomes of pain intensity, pain interference, urinary symptoms, and bother were captured with multiple instruments. Multivariable analyses using mixed-effects linear regression models were identified characteristics associated with increased stent-associated symptoms. RESULTS: A total of 424 participants were enrolled. Mean age was 49 years (SD 17); 47% were female. Participants experienced a marked increase in stent-associated symptoms on postoperative day 1. While pain intensity decreased ∼50% from postoperative day 1 to postoperative day 5, interference due to pain remained persistently elevated. In multivariable analysis, older age was associated with lower pain intensity (P = .004). Having chronic pain conditions (P < .001), prior severe stent pain (P = .021), and depressive symptoms at baseline (P < .001) were each associated with higher pain intensity. Neither sex, stone location, ureteral access sheath use, nor stent characteristics were drivers of stent-associated symptoms. CONCLUSIONS: In this multicenter cohort, interference persisted even as pain intensity decreased. Patient factors (eg, age, depression) rather than surgical factors were associated with symptom intensity. These findings provide a foundation for patient-centered care and highlight potential targets for efforts to mitigate the burden of stent-associated symptoms.

Pseudoentropy in dS/CFT and Timelike Entanglement Entropy.

We study holographic entanglement entropy in dS/CFT and introduce timelike entanglement entropy in CFTs. Both of them take complex values in general and are related with each other via an analytical continuation. We argue that they are correctly understood as pseudoentropy. We find that the imaginary part of pseudoentropy implies an emergence of time in dS/CFT.

Ureteral Strictures Following Ureteroscopy for Kidney Stone Disease: A Population-based Assessment.

PURPOSE: As the prevalence of urolithiasis increases and ureteroscopy is used more frequently, the risks of uncommon complications such as ureteral stricture may become more notable. Our objective is to assess the rate and associated risk factors of ureteral stricture formation in patients undergoing ureteroscopy. MATERIALS AND METHODS: Utilizing the IBM MarketScan research database, we evaluated data from 2008 to 2019 and compared ureteral stricture rates and their management following ureteroscopy to subjects who had shock wave lithotripsy. Shock wave lithotripsy was used as a comparison group to represent the rate of stricture from stone disease alone. A third group of those having both shock wave lithotripsy and ureteroscopy was included. Patients and secondary procedures were identified using Current Procedural Terminology, and International Classification of Diseases-9 and -10 codes. RESULTS: A total of 329,776 patients received ureteroscopy, shock wave lithotripsy, or shock wave lithotripsy+ureteroscopy between 2008 and 2019. Stricture developed in 2.9% of patients after ureteroscopy, 1.5% after shock wave lithotripsy, and 2.6% after shock wave lithotripsy+ureteroscopy. In the multivariable model, rates of stricture were 1.7-fold higher after ureteroscopy vs shock wave lithotripsy (OR:1.71, 95% CI 1.62-1.81). Preoperative hydronephrosis, age, prior stones/intervention, and concurrent kidney and ureteral stones were associated with increased risk of stricture. Of those with strictures incurred after ureteroscopy, 35% required drainage, 21% had endoscopic intervention, 4.8% required reconstructive surgery, and 1.7% underwent nephrectomy. CONCLUSIONS: Ureteral stricture rate after ureteroscopy of nearly 3% was higher than expected and approximately twice the rate attributable to stone disease alone. Factors associated with the stone as well as instrumentation were found to be risk factors. The morbidity of stricture disease following ureteroscopy was significant.

Fragmentation of Stones by Burst Wave Lithotripsy in the First 19 Humans.

PURPOSE: We report stone comminution in the first 19 human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses. MATERIALS AND METHODS: This was a prospective multi-institutional feasibility study recruiting subjects undergoing clinical ureteroscopy (URS) for at least 1 stone ≤12 mm as measured on computerized tomography. During the planned URS, either before or after ureteroscope insertion, BWL was administered with a handheld transducer, and any stone fragmentation and tissue injury were observed. Up to 3 stones per subject were targeted, each for a maximum of 10 minutes. The primary effectiveness outcome was the volume percent comminution of the stone into fragments ≤2 mm. The primary safety outcome was the independent, blinded visual scoring of tissue injury from the URS video. RESULTS: Overall, median stone comminution was 90% (IQR 20, 100) of stone volume with 21 of 23 (91%) stones fragmented. Complete fragmentation (all fragments ≤2 mm) within 10 minutes of BWL occurred in 9 of 23 stones (39%). Of the 6 least comminuted stones, likely causative factors for decreased effectiveness included stones that were larger than the BWL beamwidth, smaller than the BWL wavelength or the introduction of air bubbles from the ureteroscope. Mild reddening of the papilla and hematuria emanating from the papilla were observed ureteroscopically. CONCLUSIONS: The first study of BWL in human subjects resulted in a median of 90% comminution of the total stone volume into fragments ≤2 mm within 10 minutes of BWL exposure with only mild tissue injury.

First Series Using Ultrasonic Propulsion and Burst Wave Lithotripsy to Treat Ureteral Stones.

PURPOSE: Our goal was to test transcutaneous focused ultrasound in the form of ultrasonic propulsion and burst wave lithotripsy to reposition ureteral stones and facilitate passage in awake subjects. MATERIALS AND METHODS: Adult subjects with a diagnosed proximal or distal ureteral stone were prospectively recruited. Ultrasonic propulsion alone or with burst wave lithotripsy was administered by a handheld transducer to awake, unanesthetized subjects. Efficacy outcomes included stone motion, stone passage, and pain relief. Safety outcome was the reporting of associated anticipated or adverse events. RESULTS: Twenty-nine subjects received either ultrasonic propulsion alone (n = 16) or with burst wave lithotripsy bursts (n = 13), and stone motion was observed in 19 (66%). The stone passed in 18 (86%) of the 21 distal ureteral stone cases with at least 2 weeks follow-up in an average of 3.9±4.9 days post-procedure. Fragmentation was observed in 7 of the burst wave lithotripsy cases. All subjects tolerated the procedure with average pain scores (0-10) dropping from 2.1±2.3 to 1.6±2.0 (P = .03). Anticipated events were limited to hematuria on initial urination post-procedure and mild pain. In total, 7 subjects had associated discomfort with only 2.2% (18 of 820) propulsion bursts. CONCLUSIONS: This study supports the efficacy and safety of using ultrasonic propulsion and burst wave lithotripsy in awake subjects to reposition and break ureteral stones to relieve pain and facilitate passage.

Quality of life impact and recovery after ureteroscopy and stent insertion: insights from daily surveys in STENTS.

BACKGROUND: Our objective was to describe day-to-day evolution and variations in patient-reported stent-associated symptoms (SAS) in the STudy to Enhance uNderstanding of sTent-associated Symptoms (STENTS), a prospective multicenter observational cohort study, using multiple instruments with conceptual overlap in various domains. METHODS: In a nested cohort of the STENTS study, the initial 40 participants having unilateral ureteroscopy (URS) and stent placement underwent daily assessment of self-reported measures using the Brief Pain Inventory short form, Patient-Reported Outcome Measurement Information System measures for pain severity and pain interference, the Urinary Score of the Ureteral Stent Symptom Questionnaire, and Symptoms of Lower Urinary Tract Dysfunction Research Network Symptom Index. Pain intensity, pain interference, urinary symptoms, and bother were obtained preoperatively, daily until stent removal, and at postoperative day (POD) 30. RESULTS: The median age was 44 years (IQR 29,58), and 53% were female. The size of the dominant stone was 7.5 mm (IQR 5,11), and 50% were located in the kidney. There was consistency among instruments assessing similar concepts. Pain intensity and urinary symptoms increased from baseline to POD 1 with apparent peaks in the first 2 days, remained elevated with stent in situ, and varied widely among individuals. Interference due to pain, and bother due to urinary symptoms, likewise demonstrated high individual variability. CONCLUSIONS: This first study investigating daily SAS allows for a more in-depth look at the lived experience after URS and the impact on quality of life. Different instruments measuring pain intensity, pain interference, and urinary symptoms produced consistent assessments of patients' experiences. The overall daily stability of pain and urinary symptoms after URS was also marked by high patient-level variation, suggesting an opportunity to identify characteristics associated with severe SAS after URS.

A survey and analysis of pediatric stroke protocols.

Objectives Despite their comparative rarity, about 10,000 ischemic strokes occur in children every year, and no standardized method of treatment exists. Protocols have been effective at increasing diagnosis accuracy and treatment efficacy in adults, but little has been done to evaluate such tools in children. A survey was developed to identify the proportion of pediatric hospitals that have stroke protocols and analyze the components used for diagnosis and treatment to identify consensus. Materials and methods Physicians at 50 pediatric hospitals that contributed to the Pediatric Hospital Inpatient Sample in specialties involved in the treatment of stroke (i.e, neurology, neurosurgery, radiology, pediatric intensive care, and emergency medicine) were invited in a purposive and referral manner to complete and 18-question survey. Consensus agreement was predefined as >75%. Results Of 264 surveys distributed, 93 (35%) were returned, accounting for 46 (92%) hospitals. Among the respondents, 76 (82%) reported the presence of a pediatric stroke protocol at their hospital. Consensus agreement was reached in 9 components, including the use of intravenous tissue plasminogen activator (90%) and mechanical thrombectomy (77%) as treatments for acute stroke. Consensus agreement was not reached in 10 components, including the use of prehospital (16%) and emergency department (59%) screening tools and a centralized contact method (57%). Conclusions Pediatric ischemic stroke is a potentially devastating disease that is potentially reversible if treated early. Most pediatric hospitals have developed stroke protocols to aid in diagnosis and treatment, but there is a lack of consensus on what the protocols should contain.

Prevention of Urinary Stones With Hydration (PUSH): Design and Rationale of a Clinical Trial.

RATIONALE & OBJECTIVE: Although maintaining high fluid intake is an effective low-risk intervention for the secondary prevention of urinary stone disease, many patients with stones do not increase their fluid intake. STUDY DESIGN: We describe the rationale and design of the Prevention of Urinary Stones With Hydration (PUSH) Study, a randomized trial of a multicomponent behavioral intervention program to increase and maintain high fluid intake. Participants are randomly assigned (1:1 ratio) to the intervention or control arm. The target sample size is 1,642 participants. SETTING & PARTICIPANTS: Adults and adolescents 12 years and older with a symptomatic stone history and low urine volume are eligible. Exclusion criteria include infectious or monogenic causes of urinary stone disease and comorbid conditions precluding increased fluid intake. INTERVENTIONS: All participants receive usual care and a smart water bottle with smartphone application. Participants in the intervention arm receive a fluid intake prescription and an adaptive program of behavioral interventions, including financial incentives, structured problem solving, and other automated adherence interventions. Control arm participants receive guideline-based fluid instructions. OUTCOMES: The primary end point is recurrence of a symptomatic stone during 24 months of follow-up. Secondary end points include changes in radiographic stone burden, 24-hour urine output, and urinary symptoms. LIMITATIONS: Periodic 24-hour urine volumes may not fully reflect daily behavior. CONCLUSIONS: With its highly novel features, the PUSH Study will address an important health care problem. FUNDING: National Institute of Diabetes and Digestive and Kidney Diseases. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT03244189.

Estimating the health-related quality of life of kidney stone patients: initial results from the Wisconsin Stone Quality of Life Machine-Learning Algorithm (WISQOL-MLA).

OBJECTIVE: To build the Wisconsin Stone Quality of Life Machine-Learning Algorithm (WISQOL-MLA) to predict urolithiasis patients' health-related quality of life (HRQoL) based on demographic, symptomatic and clinical data collected for the validation of the Wisconsin Stone Quality-of-Life (WISQOL) questionnaire, an HRQoL measurement tool designed specifically for patients with kidney stones. MATERIAL AND METHODS: We used data from 3206 stone patients from 16 centres. We used gradient-boosting and deep-learning models to predict HRQoL scores. We also stratified HRQoL scores by quintile. The dataset was split using a standard 70%/10%/20% training/validation/testing ratio. Regression performance was evaluated using Pearson's correlation. Classification was evaluated with an area under the receiver-operating characteristic curve (AUROC). RESULTS: Gradient boosting obtained a test correlation of 0.62. Deep learning obtained a correlation of 0.59. Multivariate regression achieved a correlation of 0.44. Quintile stratification of all patients in the WISQOL dataset obtained an average test AUROC of 0.70 for the five classes. The model performed best in identifying the lowest (0.79) and highest quintiles (0.83) of HRQoL. Feature importance analysis showed that the model weighs in clinically relevant factors to estimate HRQoL, such as symptomatic status, body mass index and age. CONCLUSIONS: Harnessing the power of the WISQOL questionnaire, our initial results indicate that the WISQOL-MLA can adequately predict a stone patient's HRQoL from readily available clinical information. The algorithm adequately relies on relevant clinical factors to make its HRQoL predictions. Future improvements to the model are needed for direct clinical applications.

National Imaging Trends after Ureteroscopic or Shock Wave Lithotripsy for Nephrolithiasis.

PURPOSE: The study of diagnostic imaging after procedural intervention for nephrolithiasis is limited. We sought to characterize actual national imaging patterns and longitudinal trends after ureteroscopic or shock wave lithotripsy. MATERIALS AND METHODS: We analyzed the MarketScan® database and identified a nationally representative sample of insured, employed patients, 17 to 64 years old who underwent ureteroscopic or shock wave lithotripsy for nephrolithiasis between 2007 and 2014. Patients were excluded from study if they lacked at least 1 year of postoperative database enrollment or underwent a repeat nephrolithiasis procedure of any type within 90 days after the initial procedure. We identified and tracked postoperative imaging modalities by medical billing codes. RESULTS: We identified 101,554 patients treated with ureteroscopy, of whom 55% and 39% underwent no postoperative imaging within 3 and 12 months, respectively. Of the 101,590 patients treated with shock wave lithotripsy 23% and 16% underwent no postoperative imaging within 3 and 12 months, respectively. Abdominal x-ray was the most common imaging modality after either procedure type. Ultrasound use increased with time while computerized tomography decreased. In about 25% of ureteroscopy and shock wave lithotripsy cases at least 1 postoperative computerized tomography was done within a year. Female gender and older age were associated with higher imaging rates. Ultrasound was more commonly performed in the northeast region and in more densely populated areas. CONCLUSIONS: A notable portion of patients treated with ureteroscopy and a smaller percent treated with shock wave lithotripsy do not undergo any followup imaging within 1 year. In the majority who undergo imaging abdominal x-ray is done, precluding the ability to screen for hydronephrosis or silent obstruction in almost 75% of patients treated with ureteroscopy.

National Imaging Trends after Percutaneous Nephrolithotomy.

PURPOSE: Followup imaging after percutaneous nephrolithotomy serves to detect postoperative complications, residual fragments and silent hydronephrosis. However, the timing and optimal imaging modality remain poorly defined. We describe imaging use patterns after percutaneous nephrolithotomy. MATERIALS AND METHODS: In the MarketScan® database we identified patients 17 to 64 years old who underwent percutaneous nephrolithotomy between 2007 and 2014. Imaging modalities were identified by CPT, and ICD-9 and 10 codes, and tracked for 1 year after percutaneous nephrolithotomy. The modalities included computerized tomography, renal ultrasound, abdominal x-ray and intravenous pyelogram. Cumulative longitudinal use patterns were characterized and the association with demographic factors was assessed by the chi-square test. RESULTS: Of the 6,495 patients included in analysis 29% and 15% had undergone no postoperative imaging by 3 and 12 months, respectively. While abdominal x-ray was the most common modality at 3, 6 and 12 months, performed in 46%, 53% and 62% patients, respectively, nearly 50% underwent computerized tomography by 1 year. Of these patients 34% underwent computerized tomography within 3 months, which was done within the first 3 days in 69%. During the study period renal ultrasound use increased by 13% while computerized tomography and abdominal x-ray use remained relatively stable. Female gender, residence in the Northeast, no health maintenance organization status and treatment in a metropolitan statistical area were independently associated with higher rates of renal ultrasound on multivariate analyses (p <0.05). CONCLUSIONS: Among insured adults national imaging patterns vary following percutaneous nephrolithotomy. Many patients do not receive any followup imaging while approximately half undergo computerized tomography within a year. Imaging patterns may be evolving with the increased use of ultrasound.