Preclinical assessment of a mathematical model for ablation zone prediction in thyroid laser ablation.

To develop and validate a 3D simulation model to calculate laser ablation (LA) zone size and estimate the volume of treated tissue for thyroid applications, a model was developed, taking into account dynamic optical and thermal properties of tissue change. For validation, ten Yorkshire swines were equally divided into two cohorts and underwent thyroid LA at 3 W/1,400 J and 3 W/1,800 J respectively with a 1064-nm multi-source laser (Echolaser X4 with Orblaze™ technology; ElEn SpA, Calenzano, Italy). The dataset was analyzed employing key statistical measures such as mean and standard deviation (SD). Model simulation data were compared with animal gross histology. Experimental data for longitudinal length, width (transverse length), ablation volume and sphericity were 11.0 mm, 10.0 mm, 0.6 mL and 0.91, respectively at 1,400 J and 14.6 mm, 12.4 mm, 1.12 mL and 0.83, respectively at 1,800 J. Gross histology data showed excellent reproducibility of the ablation zone among same laser settings; for both 1,400 J and 1,800 J, the SD of the in vivo parameters was ≤ 0.7 mm, except for width at 1,800 J, for which the SD was 1.1 mm. Simulated data for longitudinal length, width, ablation volume and sphericity were 11.6 mm, 10.0 mm, 0.62 mL and 0.88, respectively at 1,400 J and 14.2 mm, 12.0 mm, 1.06 mL and 0.84, respectively at 1,800 J. Experimental data for ablation volume, sphericity coefficient, and longitudinal and transverse lengths of thermal damaged area showed good agreement with the simulation data. Simulation datasets were successfully incorporated into proprietary planning software (Echolaser Smart Interface, Elesta SpA, Calenzano, Italy) to provide guidance for LA of papillary thyroid microcarcinomas. Our mathematical model showed good predictability of coagulative necrosis when compared with data from in vivo animal experiments.

Enhancing continence post holmium laser enucleation of the prostate: assessment of novel technique through randomized clinical trial.

BACKGROUND: Transient urinary incontinence (UI) is distressing event following holmium laser enucleation of the prostate (HoLEP). Novel technique namely, veil sparing HoLEP (VS-HoLEP), was proposed to improve early continence outcome. In this trial (NCT03494049), VS-HoLEP was compared to standard HoLEP (St-HoLEP). METHODS: VS-HoLEP entails early apical separation with sparing of ventral apical mucosal veil proximal to the verumontanum. Eligible symptomatic BPH patients were randomly allocated to St-HoLEP (91) and VS-HoLEP (89). The primary outcome was UI as depicted by one-hour pad test at one month postoperatively. Other outcome measures include all perioperative parameters, complications, and urinary outcome measures at different follow-up points. RESULTS: Median preoperative prostate size was 138 (50:282) and 128 (50:228) mL in St-HoLEP and VS-HoLEP groups respectively. At one month the number of patients with positive one-hour pad test was 21 (23.1%) and 10 (11.4%) in St-HoLEP and VS-HoLEP groups respectively (P 0.047). The difference was significantly in favor of VS-HoLEP considering the number of patients reporting UI, the number of patients with positive one-hour pad test as well as the grade of UI reported at one and 4 months. The difference was not statistically significant at 12 months. The median time to patients' reported continence was 8 (1-52) and 1.5 (1-52) weeks in St-HoLEP and VS-HoLEP groups respectively (P≤0.005). The technique independently predicted positive one-hour pad test at one and four months respectively. At twelve months presence of DM (diabetes mellitus) and more percent PSA reduction independently predicted positive one-hour pad test. CONCLUSIONS: Veil sparing HoLEP enhances significantly early postoperative urine continence both subjectively and objectively. Optimization of the surgical technique could cut short the number of leaking patients and reduce the degree as well as the duration of transient postoperative urine leak.

Accounting for repeat intervention costs in the economic comparison of laser interstitial thermal therapy and anterior temporal lobectomy for treatment of refractory temporal lobe epilepsy.

OBJECTIVE: Laser interstitial thermal therapy (LITT) is an alternative to anterior temporal lobectomy (ATL) for the treatment of temporal lobe epilepsy that has been found by some to have a lower procedure cost but is generally regarded as less effective and sometimes results in a subsequent procedure. The goal of this study is to incorporate subsequent procedures into the cost and outcome comparison between ATL and LITT. METHODS: This single-center, retrospective cohort study includes 85 patients undergoing ATL or LITT for temporal lobe epilepsy during the period September 2015 to December 2022. Of the 40 patients undergoing LITT, 35 % (N = 14) underwent a subsequent ATL. An economic cost model is derived, and difference in means tests are used to compare the costs, outcomes, and other hospitalization measures. RESULTS: Our model predicts that whenever the percentage of LITT patients undergoing subsequent ATL (35% in our sample) exceeds the percentage by which the LITT procedure alone is less costly than ATL (7.2% using total patient charges), LITT will have higher average patient cost than ATL, and this is indeed the case in our sample. After accounting for subsequent surgeries, the average patient charge in the LITT sample ($103,700) was significantly higher than for the ATL sample ($88,548). A second statistical comparison derived from our model adjusts for the difference in effectiveness by calculating the cost per seizure-free patient outcome, which is $108,226 for ATL, $304,052 for LITT only, and $196,484 for LITT after accounting for the subsequent ATL surgeries. SIGNIFICANCE: After accounting for the costs of subsequent procedures, we found in our cohort that LITT is not only less effective but also results in higher average costs per patient than ATL as a first course of treatment. While cost and effectiveness rates will vary across centers, we also provide a model for calculating cost effectiveness based on individual center data.

Preclinical assessment of a noncooled MR thermometry-based neurosurgical laser therapy system.

OBJECTIVE: MRI-guided laser interstitial thermal therapy (MRgLITT) has recently gained interest as an ablative stereotactic procedure for intractable epilepsy, movement disorders, and brain tumors. Conventionally, a LITT system consists of a laser generator and cooled laser applicator, which is a fiber optic core surrounded by a sheath through which cooled fluid is pumped. However, this footprint can make the system bulky and nonmobile, limit the maximum depth of targeting, and increase the chances of breakdown. Herein, the authors conduct a preclinical assessment of a noncooled MRgLITT system in a porcine model. METHODS: Three-tesla MRI was used to guide the in vivo placement of noncooled laser applicators in the porcine brain. The study consisted of a survival arm and terminal arm. The laser was activated at a power of 4-7 W for ≤ 180 seconds. Temperature changes were monitored using the MR thermometry software ThermoGuide in the survival arm (n = 5) or both ThermoGuide software and adjacently inserted thermal probes in the terminal arm (n = 3). Thermal damage was determined by the software using the temperature-time relationship of cumulative equivalent minutes at 43°C (CEM43). Temperatures calculated by the software were compared with those recorded by the temperature probes. The dimensions of thermal damage thresholds (TDTs; 2-9, 10-59, 60-239, ≥ 240 CEM43 isolines) given by MR thermometry were compared with the dimensions of irreversible damage on histopathological analysis. RESULTS: There was a strong correlation between temperature recordings by ThermoGuide and those by thermal probes at both 4 mm (r = 0.96) and 8 mm (r = 0.80), with a mean absolute error of 0.76°C ± 2.13°C and 0.17°C ± 1.65°C at 4 and 8 mm, respectively. The area of 2-9 CEM43 was larger than the area of irreversible damage seen on histopathological analysis. The dimensions of the 10 and 60 CEM43 correlated well with dimensions of the lesion on histopathological analysis. A well-defined border (≤ 1 mm) was observed between the area of irreversible damage and healthy brain tissue. CONCLUSIONS: This preclinical assessment showed that the noncooled LITT system was able to precisely reach the target and create well-defined lesions within a margin of safety, without any adverse effects. MR thermometry software provided an accurate near-real-time temperature of the brain tissue, and dimensions of the lesion as visualized by the software correlated well with histopathological findings. Further studies to test the system's efficacy and safety in human subjects are in progress.

Venous ablation procedures by provider type, including advanced practice providers.

OBJECTIVE: The necessary training and certification of providers performing venous ablation has become a topic of debate in recent years. As venous interventions have shifted away from the hospital, the diversity of provider backgrounds has increased. We aimed to characterize superficial venous ablation practice patterns associated with different provider types. METHODS: We analyzed Medicare Fee-For-Service data from 2010 through 2018. Procedures were identified by their Current Procedural Terminology code and included radiofrequency ablation, endovenous laser ablation, chemical adhesive ablation (ie, VenaSeal; Medtronic, Inc), and mechanochemical ablation. These procedures were correlated with the practitioner type to identify provider-specific trends. RESULTS: Between 2010 and 2018, the number of ablation procedures increased by 107% from 114,197 to 236,558 per year (P < .001). Most procedures were performed by surgeons without vascular board certification (28.7%; 95% confidence interval [CI], 28.7%-28.8%), followed by vascular surgeons (27.1%; 95% CI, 27.0%-27.2%). Traditionally noninterventional specialties, which exclude surgeons, cardiologists, and interventional radiologists, accounted for 14.1% (95% CI, 14.1%-14.2%), and APPs accounted for 3.5% (95% CI, 3.4%-3.5%) of all ablation procedures during the study period. The total number of ablations increased by 9.7% annually (95% CI, 9.7%-9.8%), whereas procedures performed by APPs increased by 62.0% annually (95% CI, 61.6%-62.4%). There were significant differences between specialties in the use of nonthermal ablation modalities: APPs had the highest affinity for nonthermal ablation (odds ratio [OR], 2.60; 95% CI, 2.51-2.69). Cardiologists were also more likely to use nonthermal ablation (OR, 1.62; 95% CI, 1.59-1.66). Similarly, the uptake of new nonthermal technology (ie, chemical adhesives) was greatest among APPs (OR, 3.57; 95% CI, 3.43-3.70) and cardiologists (OR, 1.86; 95% CI, 1.81-1.91). Vascular surgeons were less likely to use nonthermal modalities (OR, 0.95; 95% CI, 0.92-0.97), including new nonthermal technology in the first year of availability (OR, 0.93; 95% CI, 0.90-0.95). CONCLUSIONS: The use of venous procedures has increased rapidly during the past decade, particularly as endovenous ablations have been performed by a wider practitioner base, including APPs and noninterventionalists. Practice patterns differ by provider type, with APPs and cardiologists skewing more toward nonthermal modalities, including more rapid uptake of new nonthermal technology. Provider-specific biases for specific ablation modalities might reflect differences in training, skill set, the need for capital equipment, clinical privileges, or reimbursement. These data could help to inform training paradigms, the allocation of resources, and evaluation of appropriateness in a real-world setting.

Advancing Holmium Laser Enucleation of the Prostate Outcomes Reporting: An Assessment of Patient-Reported Outcomes in the Literature.

Holmium laser enucleation of the prostate (HoLEP) is a size-independent option for benign prostatic hyperplasia surgical management. Since lower urinary tract symptoms (LUTS) are a quality-of-life issue, studies should prioritize patient-reported outcomes (PROs). This HoLEP review assesses PROs inclusion in the top 20 cited HoLEP studies and defines their limitations. PROs were categorized by domain: LUTS, incontinence, sexual function, pain, hematuria, and patient satisfaction. On review, no top-cited study included all PRO domains. The nuanced patient experience after HoLEP could be better defined via standardized utilization of validated PROs, while also improving comparability between HoLEP studies.

High-Value Epilepsy Care in the United States: Predictors of Increased Costs and Complications from the National Inpatient Sample Database 2016-2019.

BACKGROUND: For patients with medically refractory epilepsy, newer minimally invasive techniques such as laser interstitial thermal therapy (LITT) have been developed in recent years. This study aims to characterize trends in the utilization of surgical resection versus LITT to treat medically refractory epilepsy, characterize complications, and understand the cost of this innovative technique to the public. METHODS: The National Inpatient Sample database was queried from 2016 to 2019 for all patients admitted with a diagnosis of medically refractory epilepsy. Patient demographics, hospital length of stay, complications, and costs were tabulated for all patients who underwent LITT or surgical resection within these cohorts. RESULTS: A total of 6019 patients were included, 223 underwent LITT procedures, while 5796 underwent resection. Significant predictors of increased patient charges for both cohorts included diabetes (odds ratio: 1.7, confidence interval [CI]: 1.44-2.19), infection (odds ratio: 5.12, CI 2.73-9.58), and hemorrhage (odds ratio: 2.95, CI 2.04-4.12). Procedures performed at nonteaching hospitals had 1.54 greater odds (CI 1.02-2.33) of resulting in a complication compared to teaching hospitals. Insurance status did significantly differ (P = 0.001) between those receiving LITT (23.3% Medicare; 25.6% Medicaid; 44.4% private insurance; 6.7 Other) and those undergoing resection (35.3% Medicare; 22.5% Medicaid; 34.7% private Insurance; 7.5% other). When adjusting for patient demographics, LITT patients had shorter length of stay (2.3 vs. 8.9 days, P < 0.001), lower complication rate (1.9% vs. 3.1%, P = 0.385), and lower mean hospital ($139,412.79 vs. $233,120.99, P < 0.001) and patient ($55,394.34 vs. $37,756.66, P < 0.001) costs. CONCLUSIONS: The present study highlights LITT's advantages through its association with lower costs and shorter length of stay. The present study also highlights the associated predictors of LITT versus resection, such as that most LITT cases happen at academic centers for patients with private insurance. As the adoption of LITT continues, more data will become available to further understand these issues.

Disparities in access to endovenous treatment options in chronic lower extremity superficial venous insufficiency: A national 7-year analysis.

OBJECTIVE: The goal of this study was to analyze trends in treatment access for chronic superficial venous disease and to identify disparities in care. METHODS: This retrospective study was exempt from institutional review board approval. The American College of Surgeon National Surgical Quality Improvement Program database was used to identify patients who underwent vein stripping (VS) and endovenous procedures for treatment of chronic superficial venous disease. Endovenous options included radiofrequency ablation (RFA) and laser ablation. Data was available from 2011 to 2018 and demographic information was extracted for each patient identified by Current Procedural Terminology codes. For all racial and ethnic groups, trend lines were plotted, and the relative rate of change was determined within each specified demographic. RESULTS: There were 21,025 patients included in the analysis. The overall mean age was 54.2 years, and the majority of patients were female (64.8%). In total, 27.9%, 55.2%, and 16.9% patients underwent VS, RFA, and laser ablation, respectively. Patients who received laser ablation were older (P < .001). Hispanic ethnicity was associated with significantly lower odds of receiving endovascular thermal ablation (EVTA) over VS (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.64-0.78; P < .001). American Indian/Alaska Native patients were more likely to receive EVTA over VS (OR, 4.02; 95% CI, 2.48-6.86); similarly, Native Hawaiian/Pacific Islander patients were more likely to receive EVTA over VS, although this difference was not statistically significant (OR, 1.44; 95% CI, 0.93-2.27). On multinomial regression, Hispanic patients were less likely to receive RFA over VS, whereas American Indian/Alaskan Native patients were more likely to receive RFA over VS. In all racial and ethnic groups, the percentage of endovenous procedures increased, whereas vein stripping decreased. CONCLUSIONS: Based on a hospital-based dataset, demographic indicators, including age, sex, race, and ethnicity, are associated with differences in endovenous treatments for chronic superficial venous insufficiency suggesting disparities in obtaining minimally invasive treatment options among certain patient groups.

Practice Patterns and Sociodemographic Disparities in the Clinical Care of Anatomical Narrow Angles in the United States.

PURPOSE: To assess treatment and visit patterns among patients with newly diagnosed anatomical narrow angle (ANA) and identify sociodemographic factors associated with disparities in care. DESIGN: Retrospective practice pattern evaluation study. METHODS: A total of 263,422 patients diagnosed with ANA between 2007 and 2019 were identified in the Optum Clinformatics Data Mart. Inclusion was limited to newly diagnosed ANA, defined as (1) continuous enrollment during a 2-year lookback period and 1-year study period from first diagnosis; (2) diagnosis by an ophthalmologist or optometrist; and (3) no history of pseudophakia, ANA treatments, or prior primary angle closure glaucoma diagnosis. Outcome measures were treatment with laser peripheral iridotomy (LPI), cataract surgery, or intraocular pressure-lowering medications and number of eye care visits. Logistic and Poisson regression were performed to assess factors associated with treatment and eye care visits, respectively. RESULTS: Among 52,405 eligible cases, 27.7% received LPI, 13.9% received drops, and 15.1% received cataract surgery. Odds of LPI were higher in Asians and Hispanics (odds ratio [OR] ≥ 1.16, P < .001). Non-Whites had higher odds of drops (OR ≥ 1.19, P < .001), but Hispanics had lower odds of cataract surgery (OR = 0.79, P < .001). The mean number of eye care visits was 2.6±2.1 including the day of diagnosis. Older age and treatment were associated with higher rates of eye care visits (rate ratio > 1.15, P < .001). CONCLUSION: More than a quarter of patients with newly diagnosed ANA receive treatment with LPI. Racial minorities are more likely to receive ANA-specific treatments but less likely to receive cataract surgery. These differences may reflect racial differences in disease severity and the need for clearer practice guidelines in ANA care.

Automated segmentation of ablated lesions using deep convolutional neural networks: A basis for response assessment following laser interstitial thermal therapy.

BACKGROUND: Laser interstitial thermal therapy (LITT) of intracranial tumors or radiation necrosis enables tissue diagnosis, cytoreduction, and rapid return to systemic therapies. Ablated tissue remains in situ, resulting in characteristic post-LITT edema associated with transient clinical worsening and complicating post-LITT response assessment. METHODS: All patients receiving LITT at a single center for tumors or radiation necrosis from 2015 to 2023 with ≥9 months of MRI follow-up were included. An nnU-Net segmentation model was trained to automatically segment contrast-enhancing lesion volume (CeLV) of LITT-treated lesions on T1-weighted images. Response assessment was performed using volumetric measurements. RESULTS: Three hundred and eighty four unique MRI exams of 61 LITT-treated lesions and 6 control cases of medically managed radiation necrosis were analyzed. Automated segmentation was accurate in 367/384 (95.6%) images. CeLV increased to a median of 68.3% (IQR 35.1-109.2%) from baseline at 1-3 months from LITT (P = 0.0012) and returned to baseline thereafter. Overall survival (OS) for LITT-treated patients was 39.1 (9.2-93.4) months. Lesion expansion above 40% from volumetric nadir or baseline was considered volumetric progression. Twenty-one of 56 (37.5%) patients experienced progression for a volumetric progression-free survival of 21.4 (6.0-93.4) months. Patients with volumetric progression had worse OS (17.3 vs 62.1 months, P = 0.0015). CONCLUSIONS: Post-LITT CeLV expansion is quantifiable and resolves within 6 months of LITT. Development of response assessment criteria for LITT-treated lesions is feasible and should be considered for clinical trials. Automated lesion segmentation could speed the adoption of volumetric response criteria in clinical practice.

Histopathological assessment of depth of coagulation necrosis with Holmium, Moses, and Thulium fiber lasers in human prostate tissue.

PURPOSE: To evaluate coagulation necrosis depth (CND) of Holmium (HL), Moses (ML), and Thulium fiber laser (TFL) in ex vivo human prostate tissue at various energy settings. METHODS: After endoscopic HL enucleation, small prostate tissue fragments were removed from the bladder with graspers and used for study. Immediately after surgery, a single incision was made on the surface of the tissue kept under normal saline at room temperature using a hand-held 550-µm laser fiber. Variable energy settings were tested for all three lasers. Two pathologists measured the CND with light microscopy using ocular micrometer. Impact of various laser settings on CND was analyzed. The differences in CND of all three lasers at similar laser power were compared. RESULTS: Mean CND was 0.56 ± 0.53 mm for long-pulse HL, 0.54 ± 0.53 mm for ML, 0.67 ± 0.67 mm for low-pulse TFL, and 0.81 ± 0.78 mm for high-pulse TFL. There was no significant difference between mean CND of HL and ML at various laser settings ranging from 10 to 120 W and CND with long- and short-pulse settings of TFL at settings from 10 to 60 W. There was a trend of increasing CND in HL and ML with increasing laser power; however, it was not statistically significant. TFL had similar tissue effects as HL and ML. CONCLUSION: There is no significant difference in CND of HL, ML, and TFL in ex vivo human prostate tissue. Other factors besides laser type and settings need to be studied to explain clinical differences among various lasers used for prostate enucleation.

Laser enucleation of the prostate (LEP) vs. simple prostatectomy: an analysis of hospital charges and comparison of practice trends.

PURPOSE: Laser enucleation of the prostate (LEP) and simple prostatectomy (SP) are surgical treatment options for large gland Benign Prostatic Hyperplasia. While multiple studies compare clinical outcomes of these procedures, there are limited data available comparing hospital charges in the United States. Here, we present current practice trends and a hospital charge analysis on a national level using an annual insurance claims data repository. METHODS: The Healthcare Cost and Utilization Project National Inpatient Sample and Nationwide Ambulatory Surgery Sample databases for 2018 were queried. CPT and ICD-10PCS codes identified patients undergoing LEP or SP, who were then compared for practice setting, total hospital charges, and payor. Laser type for LEP and surgical approach for SP could not be differentiated. RESULTS: The median hospital charge of 5782 LEPs and 973 SPs is $26,689 and $51,250 (p < 0.001), respectively. LEP independently predicts a decreased hospital charge of $16,464 (p < 0.001) per case. Medicare is the primary payor for both procedures. More LEP procedures are completed in the outpatient setting (87.8%) vs. SPs (5.7%, p < 0.001). Median length of stay is longer for SP (LEP: 0, IQR: 0; SP: 3, IQR: 2-4; p < 0.001). In the Western region, LEP is least commonly performed (184, p < 0.001), most expensive ($43,960; p < 0.001), and has longer length of stay (2, p < 0.001). CONCLUSIONS: LEP should be considered a cost-effective alternative to SP. Regions of the U.S. that perform more LEPs have shorter length of stay and lower hospital charges associated with the procedure.

Evaluating Access to Laser Eye Surgery by Driving Times Using Medicare Data and Geographical Mapping.

Importance: Recently, several states have granted optometrists privileges to perform select laser procedures (laser peripheral iridotomy, selective laser trabeculoplasty, and YAG laser capsulotomy) with the aim of increasing access. However, whether these changes are associated with increased access to these procedures among each state's Medicare population has not been evaluated. Objective: To compare patient access to laser surgery eye care by estimated travel time and 30-minute proximity to an optometrist or ophthalmologist. Design, Setting, and Participants: This retrospective cohort database study used Medicare Part B claims data from 2016 through 2020 for patients accessing new patient or laser eye care (laser peripheral iridotomy, selective laser trabeculoplasty, YAG) from optometrists or ophthalmologists in Oklahoma, Kentucky, Louisiana, Arkansas, and Missouri. Analysis took place between December 2021 and March 2023. Main Outcome and Measures: Percentage of each state's Medicare population within a 30-minute travel time (isochrone) of an optometrist or ophthalmologist based on US census block group population and estimated travel time from patient to health care professional. Results: The analytic cohort consisted of 1 564 307 individual claims. Isochrones show that optometrists performing laser eye surgery cover a geographic area similar to that covered by ophthalmologists. Less than 5% of the population had only optometrists (no ophthalmologists) within a 30-minute drive in every state except for Oklahoma for YAG (301 470 [7.6%]) and selective laser trabeculoplasty (371 097 [9.4%]). Patients had a longer travel time to receive all laser procedures from optometrists than ophthalmologists in Kentucky: the shortest median (IQR) drive time for an optometrist-performed procedure was 49.0 (18.4-71.7) minutes for YAG, and the the longest median (IQR) drive time for an ophthalmologist-performed procedure was 22.8 (12.1-41.4) minutes, also for YAG. The median (IQR) driving time for YAG in Oklahoma was 26.6 (12.2-56.9) for optometrists vs 22.0 (11.2-40.8) minutes for ophthalmologists, and in Arkansas it was 90.0 (16.2-93.2) for optometrists vs 26.5 (11.8-51.6) minutes for ophthalmologists. In Louisiana, the longest median (IQR) travel time to receive laser procedures from optometrists was for YAG at 18.5 (7.6-32.6) minutes and the shortest drive to receive procedures from ophthalmologists was for YAG at 20.5 (11.7-39.7) minutes. Conclusions and Relevance: Although this study did not assess impact on quality of care, expansion of laser eye surgery privileges to optometrists was not found to lead to shorter travel times to receive care or to a meaningful increase in the percentage of the population with nearby health care professionals.

Transient simulation of laser ablation based on Monte Carlo light transport with dynamic optical properties model.

Laser ablation is a minimally invasive therapeutic technique to denature tumors through coagulation and/or vaporization. Computational simulations of laser ablation can evaluate treatment outcomes quantitatively and provide numerical indices to determine treatment conditions, thus accelerating the technique's clinical application. These simulations involve calculations of light transport, thermal diffusion, and the extent of thermal damage. The optical properties of tissue, which govern light transport through the tissue, vary during heating, and this affects the treatment outcomes. Nevertheless, the optical properties in conventional simulations of coagulation and vaporization remain constant. Here, we propose a laser ablation simulation based on Monte Carlo light transport with a dynamic optical properties (DOP) model. The proposed simulation is validated by performing optical properties measurements and laser irradiation experiments on porcine liver tissue. The DOP model showed the replicability of the changes in tissue optical properties during heating. Furthermore, the proposed simulation estimated coagulation areas that were comparable to experimental results at low-power irradiation settings and provided more than 2.5 times higher accuracy when calculating coagulation and vaporization areas than simulations using static optical properties at high-power irradiation settings. Our results demonstrate the proposed simulation's applicability to coagulation and vaporization region calculations in tissue for retrospectively evaluating the treatment effects of laser ablation.

Practice patterns and costs of glaucoma treatment in Japan.

PURPOSE: Understanding the practice patterns and costs of glaucoma care in real-world clinical settings is important for optimizing medical expenses. However, glaucoma treatment trends and associated costs in Japan are unknown. We aimed to unveil glaucoma treatment trends and costs using a large administrative claims database in Japan. STUDY DESIGN: Retrospective cohort study. METHODS: We included patients diagnosed with glaucoma between April 2014 and March 2021 using the DeSC database. We calculated the frequencies and costs of antiglaucoma eyedrops, incisional or laser procedures, and ophthalmic examinations stratified by fiscal year and age. In the year-by-year analyses, the age distribution was standardized based on the 2020 distribution. RESULTS: A total of 841,747 patient-years (429,051 patients) were included. The number of prescribed eyedrops significantly increased and the fixed-combination eyedrops proportion decreased with age. Trabeculectomy frequency decreased, and that of laser trabeculoplasty increased during the observation period. The frequencies of both incisional and laser procedures peaked in the 75-79 age group. In 2020, 16.1 bottles of eyedrops per patient-year were prescribed, and 15.9 incisional surgeries and 11.3 laser therapies were performed per 1000 patient-years. Intraocular pressure measurement and visual field testing were performed 6.5 times and 2.0 times per patient-year, respectively. The total direct cost of glaucoma treatment was 55,139 yen (US $399.5) per patient-year, of which medications accounted for 44.2%, ophthalmic examinations for 47.4%, and incisional or laser procedures for 8.4%. CONCLUSION: These results may be useful for understanding glaucoma treatment trends and costs in Japan.

A cost analysis of MR-guided laser interstitial thermal therapy for adult refractory epilepsy.

OBJECTIVE: MR-guided laser interstitial thermal therapy (LITT) is used increasingly for refractory epilepsy. The goal of this investigation is to directly compare cost and short-term adverse outcomes for adult refractory epilepsy treated with temporal lobectomy and LITT, as well as to identify risk factors for increased costs and adverse outcomes. METHODS: The National Inpatient Sample (NIS) was queried for patients who received LITT between 2012 and 2019. Patients with adult refractory epilepsy were identified. Multivariable mixed-effects models were used to analyze predictors of cost, length of stay (LOS), and complications. RESULTS: LITT was associated with reduced LOS and overall cost relative to temporal lobectomy, with a statistical trend toward lower incidence of postoperative complications. High-volume surgical epilepsy centers had lower LOS overall. Longer LOS was a significant driver of increased cost for LITT, and higher comorbidity was associated with non-routine discharge. SIGNIFICANCE: LITT is an affordable alternative to temporal lobectomy for adult refractory epilepsy with an insignificant reduction in inpatient complications. Patients may benefit from expanded access to this treatment modality for both its reduced LOS and lower cost.

Cost Utility and Value of Information Analysis of Femtosecond Laser-Assisted Cataract Surgery.

Importance: The efficacy and safety of femtosecond laser-assisted cataract surgery is well documented. An important requirement for decision makers is the evaluation of the cost-effectiveness of femtosecond laser-assisted cataract surgery (FLACS) over a sufficiently long horizon. Evaluating the cost-effectiveness of this treatment was a preplanned secondary objective of the Economic Evaluation of Femtosecond Laser Assisted Cataract Surgery (FEMCAT) trial. Objective: To estimate the cost utility of FLACS compared with phacoemulsification cataract surgery (PCS) on a 12-month time horizon. Design, Setting, and Participants: This multicenter randomized clinical trial compared FLACS with PCS in parallel groups. All FLACS procedures were performed using the CATALYS precision system. Participants were recruited and treated in ambulatory surgery settings in 5 university-hospital centers in France. All consecutive patients eligible for a unilateral or bilateral cataract surgery 22 years or older with written informed consent were included. Data were collected from October 2013 to October 2018, and data were analyzed from January 2020 to June 2022. Interventions: FLACS or PCS. Main Outcomes and Measures: Utility was measured through the Health Utility Index questionnaire. Costs of cataract surgery were estimated by microcosting. All inpatient and outpatient costs were collected from the French National Health Data System. Results: Of 870 randomized patients, 543 (62.4%) were female, and the mean (SD) age at surgery was 72.3 (8.6) years. A total of 440 patients were randomized to receive FLACS and 430 to receive PCS; the rate of bilateral surgery was 63.3% (551 of 870). The mean (SD) costs of cataract surgery were €1124.0 (€162.2; US $1235) for FLACS and €565.5 (€61.4; US $621) for PCS. The total mean (SD) cost of care at 12 months was €7085 (€6700; US $7787) in participants treated with FLACS and €6502 (€7323; US $7146) in participants treated with PCS. FLACS yielded a mean (SD) of 0.788 (0.009) quality-adjusted life-years (QALYs), and PCS yielded 0.792 (0.009) QALYs. The difference in mean costs was €545.9 (95% CI, -434.1 to 1525.8; US $600), and the difference in QALYs was -0.004 (95% CI, -0.028 to 0.021). The incremental cost-effectiveness ratio (ICER) was -€136 476 (US $150 000) per QALY. The cost-effectiveness probability of FLACS compared with PCS was 15.7% for a cost-effectiveness threshold of €30 000 (US $32 973) per QALY. At this threshold, the expected value of perfect information was €246 139 079 (US $270 530 231). Conclusions and Relevance: The ICER of FLACS compared with PCS was not within the $50 000 to $100 000 per QALY range frequently cited as cost-effective. Additional research and development on FLACS is needed to improve its effectiveness and lower its price. Trial Registration: ClinicalTrials.gov Identifier: NCT01982006.

Contemporary patterns of local ablative therapies for prostate cancer at United States cancer centers: results from a national registry.

PURPOSE: To describe the national-level patterns of care for local ablative therapy among men with PCa and identify patient- and hospital-level factors associated with the receipt of these techniques. METHODS: We retrospectively interrogated the National Cancer Database (NCDB) for men with clinically localized PCa between 2010 and 2017. The main outcome was receipt of local tumor ablation with either cryo- or laser-ablation, and "other method of local tumor destruction including high-intensity focused ultrasound (HIFU)". Patient level, hospital level, and demographic variables were collected. Mixed effect logistic regression models were fitted to identify separately patient- and hospital-level predictors of receipt of local ablative therapy. RESULTS: Overall, 11,278 patients received ablative therapy, of whom 78.8% had cryotherapy, 15.6% had laser, and 5.7% had another method including HIFU. At the patient level, men with intermediate-risk PCa were more likely to be treated with local ablative therapy (OR 1.05; 95% CI 1.00-1.11; p = 0.05), as were men with Charlson Comorbidity Index > 1 (OR 1.36; 95% CI 1.29-1.43; p < 0.01), men between 71 and 80 years (OR 3.70; 95% CI 3.43-3.99; p < 0.01), men with Medicare insurance (OR 1.38; 95% 1.31-1.46; p < 0.01), and an income < $47,999 (OR 1.16; 95% CI 1.06-1.21; p < 0.01). At the hospital-level, local ablative therapy was less likely to be performed in academic/research facilities (OR 0.45; 95% CI 0.32-0.64; p < 0.01). CONCLUSIONS: Local ablative therapy for PCa treatment is more commonly offered among older and comorbid patients. Future studies should investigate the uptake of these technologies in non-hospital-based settings and in light of recent changes in insurance coverage.

In vivo Temperature Assessment during Holmium Laser Enucleation of the Prostate.

INTRODUCTION: Holmium laser enucleation of the prostate (HoLEP) has become popular worldwide for the surgical treatment of benign prostate hyperplasia. Holmium laser is considered an ideal transurethral thermomechanical device for enucleating the prostate. Although there is evidence on Ho:YAG laser-related heat generation, the studies mainly investigated ex vivo temperature generation during holmium laser lithotripsy. In this in vivo study, we aimed to assess for the first time the real-time heat generated during HoLEP. METHODS: Fifteen HoLEP procedures were included. The study was conducted over a time period of 16 months. To investigate the temperature generation, a preoperatively inserted rectal temperature probe and a temperature sensor within a suprapubic bladder catheter were used to record the temperature change during enucleation and coagulation. RESULTS: The mean values of the temperature change during the laser enucleation and coagulation were -0.35 ± 0.203 K (IQR: 0.23) and +0.14 ± 0.259 K (IQR: 0.3), respectively, in rectal measurements. Temperature differences during laser use and coagulation were <+1 K and <+5 K, respectively, in bladder measurements. We measured no temperature >37.1°C during the procedures and no temperature values considered harmful to the human body. CONCLUSION: Sufficient irrigation flow rates and irrigation monitoring during HoLEP are obligatory. To prevent a high and uncontrolled temperature rise, the surgeon or operating room staff should pay attention to the irrigation's continuity.