Advanced Solid-State Lasers: feature issue introduction.

This joint issue of Optics Express and Optical Materials Express features 23 peer-reviewed articles primarily by authors who participated in the Advanced Solid State Lasers conference, which was part of the Optica Laser Congress held in Tacoma, Washington, USA on October 8-12, 2023. This review provides a brief summary of these articles covering the latest developments in laser gain materials and nonlinear crystals, mode-locked lasers, fiber lasers and amplifiers, nonlinear optical sources, and novel concepts in laser design.

Advanced Solid-State Lasers: feature issue introduction.

This Joint Issue of Optics Express and Optical Materials Express features 40 peer-reviewed articles written by authors who participated in the Advanced Solid State Lasers Conference, part of the Optica Laser Congress and Exhibition held in Barcelona, Spain from December 11-15, 2022. This review provides a brief summary of these articles covering the latest developments in laser host and nonlinear crystals, structured materials, fiber lasers and amplifiers, ultrafast mode-locked lasers and optical parametric amplifiers, frequency-doubled Raman lasers, vortex beams, and novel concepts in laser design.

A head and neck treatment planning strategy for a CBCT-guided ring-gantry online adaptive radiotherapy system.

PURPOSE: A planning strategy was developed and the utility of online-adaptation with the Ethos CBCT-guided ring-gantry adaptive radiotherapy (ART) system was evaluated using retrospective data from Head-and-neck (H&N) patients that required clinical offline adaptation during treatment. METHODS: Clinical data were used to re-plan 20 H&N patients (10 sequential boost (SEQ) with separate base and boost plans plus 10 simultaneous integrated boost (SIB)). An optimal approach, robust to online adaptation, for Ethos-initial plans using clinical goal prioritization was developed. Anatomically-derived isodose-shaping helper structures, air-density override, goals for controlling hotspot location(s), and plan normalization were investigated. Online adaptation was simulated using clinical offline adaptive simulation-CTs to represent an on-treatment CBCT. Dosimetric comparisons were based on institutional guidelines for Clinical-initial versus Ethos-initial plans and Ethos-scheduled versus Ethos-adapted plans. Timing for five components of the online adaptive workflow was analyzed. RESULTS: The Ethos H&N planning approach generated Ethos-initial SEQ plans with clinically comparable PTV coverage (average PTVHigh V100%  = 98.3%, Dmin,0.03cc  = 97.9% and D0.03cc  = 105.5%) and OAR sparing. However, Ethos-initial SIB plans were clinically inferior (average PTVHigh V100%  = 96.4%, Dmin,0.03cc  = 93.7%, D0.03cc  = 110.6%). Fixed-field IMRT was superior to VMAT for 93.3% of plans. Online adaptation succeeded in achieving conformal coverage to the new anatomy in both SEQ and SIB plans that was even superior to that achieved in the initial plans (which was due to the changes in anatomy that simplified the optimization). The average adaptive workflow duration for SIB, SEQ base and SEQ boost was 30:14, 22.56, and 14:03 (min: sec), respectively. CONCLUSIONS: With an optimal planning approach, Ethos efficiently auto-generated dosimetrically comparable and clinically acceptable initial SEQ plans for H&N patients. Initial SIB plans were inferior and clinically unacceptable, but adapted SIB plans became clinically acceptable. Online adapted plans optimized dose to new anatomy and maintained target coverage/homogeneity with improved OAR sparing in a time-efficient manner.

Outcomes of adjunct posterior wall isolation in atrial fibrillation patients with cardiac implantable electronic devices.

BACKGROUND: Although pulmonary vein isolation (PVI) remains the cornerstone of catheter ablation of atrial fibrillation (AF), several studies have illustrated clinical benefits associated with PVI with posterior wall isolation (PWI). METHODS: This retrospective study investigated the outcomes of PVI alone versus PVI+PWI performed using the cryoballoon in patients with cardiac implantable electronic devices (CIEDs) and paroxysmal AF (PAF) or persistent AF (PersAF). RESULTS: Acute PVI was achieved in all patients using cryoballoon ablation. Compared to PVI alone, PVI+PWI was associated with longer cryoablation, fluoroscopy, and total procedure times. Adjunct radiofrequency was required to complete PWI in 29/77 patients (37.7%). Adverse events were similar with PVI alone versus PVI+PWI. But at 24 ± 7 months of follow-up, not only cryoballoon PVI+PWI was associated with improved freedom from recurrent AF (74.3% vs. 46.0%, P = .007) and all atrial tachyarrhythmias (71.4% vs. 38.1%, P = .001) in patients with PersAF, cryoballoon PVI+PWI also yielded greater freedom from AF (88.1% vs. 63.7%, P = .003) and all atrial tachyarrhythmias (83.3% vs. 60.8%, P = .008) in those with PAF. Additionally, PVI+PWI was associated with higher reductions in atrial tachyarrhythmia burden (97.9% vs. 91.6%, P < .001), need for cardioversion (5.2% vs. 23.6%, P < .001) and repeat catheter ablation (10.4% vs. 26.1%, P = .005), and a longer time-to-arrhythmia recurrence (16 ± 6 months vs. 8 ± 5 months, P < .001) in both PersAF and PAF patients. CONCLUSION: In CIED patients with PersAF or PAF, cryoballoon PVI+PWI is associated with a greater freedom from recurrent AF and atrial tachyarrhythmias, as compared to PVI alone during long-term follow-up.

Pulmonary Vein Isolation With and Without Posterior Wall Isolation in Paroxysmal Atrial Fibrillation: IMPPROVE-PAF Trial.

BACKGROUND: Prior studies have demonstrated clinical benefits associated with cryoballoon pulmonary vein isolation (PVI) and concomitant posterior wall isolation (PWI) in patients with persistent atrial fibrillation (AF). However, the role for this approach in patients with paroxysmal atrial fibrillation (PAF) remains unclear. OBJECTIVES: This study investigated the acute and long-term outcomes of PVI vs PVI+PWI using cryoballoon in patients with symptomatic PAF. METHODS: This retrospective study (NCT05296824) examined the outcomes of cryoballoon PVI (n = 1,342) vs cryoballoon PVI+PWI (n = 442) in patients with symptomatic PAF during long-term follow-up. Using the nearest-neighbor method, a 1:1 matched sample of patients receiving PVI alone and PVI+PWI was created. RESULTS: The matched cohort consisted of 320 patients (PVI: n = 160; PVI+PWI: n = 160). PVI+PWI was associated with longer cryoablation (23 ± 10 minutes vs 42 ± 11 minutes; P < 0.001) and procedure times (103 ± 24 minutes vs 127 ± 14 minutes; P < 0.001). In 39 (24.4%) of 160 patients, adjunct radiofrequency ablation was required for PVI+PWI. Adverse event rates were similar (PVI 3.8% vs PVI+PWI 1.9%; P = 0.31). Though there were no differences at 12 months, freedom from all atrial arrhythmias (67.5% vs 45.0%; P < 0.001) and AF (75.6% vs 55.0%; P < 0.001) were significantly greater with PVI+PWI vs PVI alone at 39 ± 9 months of follow-up. PVI+PWI was also associated with reduced long-term need for cardioversion (16.9% vs 27.5%; P = 0.02) and repeat catheter ablation (11.9% vs 26.3%; P = 0.001), and emerged as the only significant predictor of freedom from recurrent AF (HR: 2.79; 95% CI: 1.64-4.74; P < 0.001). CONCLUSIONS: Compared with cryoballoon PVI, cryoballoon PVI+PWI appears to be associated with greater freedom from recurrent atrial arrhythmias and AF in patients with PAF during long-term follow-up >3 years.

Three-dimensional mapping, recording and ablation in simulated and induced ventricular tachyarrhythmias during mechanical circulatory support using the percutaneous heart pump.

PURPOSE: Due to their internal rotating magnets, conventional impeller-driven percutaneous ventricular assist devices (PVADs) yield high-frequency electrogram artifact and electromagnetic interference (EMI) when used with magnetic-based 3D electroanatomic mapping systems. The new percutaneous heart pump (PHP; Abbott, Chicago, IL) is a 14-French, 5-L/min, impeller axial-flow PVAD with a novel design that utilizes an external motor. METHODS: We evaluated the feasibility of 3D mapping and radiofrequency ablation (RFA) in vivo during PHP mechanical circulatory support (MCS) in simulated ventricular tachycardia (pacing at 300 ms) and ventricular flutter (VFL, pacing at 200 ms) and also during ventricular fibrillation (VF) in a porcine model. Anterograde (right ventricular), transseptal, retrograde, and epicardial right and left ventricular 3D mapping (EnSite/CARTO) and RFA were performed in 6 swine using high-density mapping and force-sensing RFA catheters (TactiCath/ThermoCool). Surface and intracardiac electrograms and 3D maps were analyzed for noise/interference with and without MCS using PHP in sinus rhythm and simulated VT/VFL and VF. RESULTS: Mapping and RFA proved feasible in the presence of MCS using PHP. The mean arterial pressure in sinus rhythm was 55 ± 2 mmHg (baseline) and 84 ± 4 mmHg during MCS with PHP and well-maintained during simulated VT (73 ± 8 mmHg) and VFL (65 ± 2 mmHg) and even in VF (65 ± 5 mmHg). No electrogram noise/artifact, EMI, or 3D map distortions were observed during mapping/RFA with either of two mapping systems. CONCLUSIONS: Endocardial and epicardial 3D mapping and RFA in the presence of PHP are feasible and offer significant MCS during simulated VT/VFL and VF. Furthermore, PHP yielded no electrogram noise/artifact, EMI, or 3D mapping distortions in conjunction with magnetic-based 3D mapping systems.

Feature issue introduction: advanced solid-state lasers.

This joint issue of Optics Express and Optical Materials Express features 36 state-of-the art articles written by authors who participated in the international conference advanced solid state lasers held online from October 3-7, 2021. This review provides a summary of these articles covering a wide spectrum of topics around solid-state lasers from materials research to sources and from design innovation to applications.

Maintaining dosimetric quality when switching to a Monte Carlo dose engine for head and neck volumetric-modulated arc therapy planning.

Head and neck cancers present challenges in radiation treatment planning due to the large number of critical structures near the target(s) and highly heterogeneous tissue composition. While Monte Carlo (MC) dose calculations currently offer the most accurate approximation of dose deposition in tissue, the switch to MC presents challenges in preserving the parameters of care. The differences in dose-to-tissue were widely discussed in the literature, but mostly in the context of recalculating the existing plans rather than reoptimizing with the MC dose engine. Also, the target dose homogeneity received less attention. We adhere to strict dose homogeneity objectives in clinical practice. In this study, we started with 21 clinical volumetric-modulated arc therapy (VMAT) plans previously developed in Pinnacle treatment planning system. Those plans were recalculated "as is" with RayStation (RS) MC algorithm and then reoptimized in RS with both collapsed cone (CC) and MC algorithms. MC statistical uncertainty (0.3%) was selected carefully to balance the dose computation time (1-2 min) with the planning target volume (PTV) dose-volume histogram (DVH) shape approaching that of a "noise-free" calculation. When the hot spot in head and neck MC-based treatment planning is defined as dose to 0.03 cc, it is exceedingly difficult to limit it to 105% of the prescription dose, as we were used to with the CC algorithm. The average hot spot after optimization and calculation with RS MC was statistically significantly higher compared to Pinnacle and RS CC algorithms by 1.2 and 1.0 %, respectively. The 95% confidence interval (CI) observed in this study suggests that in most cases a hot spot of ≤107% is achievable. Compared to the 95% CI for the previous clinical plans recalculated with RS MC "as is" (upper limit 108%), in real terms this result is at least as good or better than the historic plans.

Fifth Metatarsal Jones Fractures: Diagnosis and Treatment.

A Jones fracture, located at the metaphyseal-diaphyseal junction of the fifth metatarsal, is at an increased risk for nonunion and continued pain. Even with excellent surgical technique and postoperative management, a delayed union and refracture can occur. These complications in athletes can have deleterious effects on performance and delay return to sport. This article reviews the classification, diagnosis, and treatment considerations for Jones fractures. Treatment options including nonsurgical management, intramedullary screw, and plate fixation will be covered. The authors preferred technique using intramedullary screw fixation will be discussed in depth. Emerging considerations including biologic augmentation, primary bone grafting, and refracture will be examined as well. Ideal rehabilitation protocols, orthoses, and shoe wear suggestions will be given to optimize patient outcomes.

Spatio-temporal focal spot characterization and modeling of the NIF ARC kilojoule picosecond laser.

The advanced radiographic capability (ARC) laser system, part of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, is a short-pulse laser capability integrated into the NIF. The ARC is designed to provide adjustable pulse lengths of ∼1-38ps in four independent beamlets, each with energies up to 1 kJ (depending on pulse duration). A detailed model of the ARC lasers has been developed that predicts the time- and space-resolved focal spots on target for each shot. Measurements made to characterize static and dynamic wavefront characteristics of the ARC are important inputs to the code. Modeling has been validated with measurements of the time-integrated focal spot at the target chamber center (TCC) at low power, and the space-integrated pulse duration at high power, using currently available diagnostics. These simulations indicate that each of the four ARC beamlets achieves a peak intensity on target of up to a few 1018W/cm2.

Concomitant Pulmonary Vein and Posterior Wall Isolation Using Cryoballoon With Adjunct Radiofrequency in Persistent Atrial Fibrillation.

OBJECTIVES: The aim of this multicenter, randomized, single-blind study was to prospectively evaluate the short-and long-term outcomes of pulmonary vein isolation (PVI) versus PVI with concomitant left atrial posterior wall isolation (PWI) using the cryoballoon in patients with symptomatic persistent/long-standing persistent atrial fibrillation (P/LSP-AF). BACKGROUND: Some studies have suggested a clinical benefit associated with PVI+PWI in patients with P/LSP-AF. However, there are limited safety and efficacy data on this approach using cryoballoon ablation. METHODS: The immediate and long-term outcomes in patients with P/LSP-AF randomized to PVI (n = 55) versus PVI+PWI (n = 55) using the cryoballoon were prospectively examined. RESULTS: Baseline characteristics were similar. PVI was achieved in all patients (21 ± 11 min). PWI was attained using 23 ± 8 min of cryoablation. Adjunct radiofrequency ablation was required in 4 of 110 patients (7.3%) to complete PVI (3 ± 2 min) and in 25 of 55 patients (45.5%) to complete PWI (4 ± 6 min). Although left atrial dwell time (113 ± 31 min vs. 75 ± 32 min; p < 0.001) and total procedure time (168 ± 34 min vs. 127 ± 40 min; p < 0.001) were longer with PVI+PWI, this cohort required fewer intraprocedural cardioversions (89.1% vs. 96.4%; p = 0.04). Adverse events occurred in 5.5% in each group (p = 1.00). However, the incidence of recurrent atrial fibrillation at 12 months was significantly lower with PVI+PWI (25.5% vs. 45.5%; p = 0.028). Additionally, in a multivariate analysis, PVI+PWI emerged as a significant predictor of freedom from recurrent atrial fibrillation (odds ratio: 3.67; 95% confidence interval: 1.44 to 9.34; p = 0.006). CONCLUSIONS: In patients with P/LSP-AF, PVI+PWI using the cryoballoon is associated with a significant reduction in atrial fibrillation recurrence, but similar safety, as compared with PVI alone.

High-Energy Achilles Tendon Rupture With Associated Medial Malleolus Fracture and Traumatic Peroneal Dislocation: A Case Report.

Fracture, Achilles tendon rupture, or traumatic dislocation of the peroneal tendons are often seen in isolation after a trauma or sports-related injury. However, in rare circumstances, a combination of these injuries can occur simultaneously. Multiple previous case reports describe a combination of 2 of these injuries. Missed or delayed diagnosis is common in these combination injuries and can lead to significant patient morbidity and result in long-term consequences. We report a case of a 35-year-old man who sustained an Achilles tendon rupture with an associated medial malleolus fracture and traumatic peroneal dislocation after a snowboarding injury. These injuries were treated surgically, and at 9 months postoperatively, the patient had returned to all activities. Clinicians should have a high index of suspicion for concomitant injuries with higher-energy trauma to the ankle and should perform a thorough history, physical examination, and plain radiographs at a minimum.Levels of Evidence: LEVEL 5.

Same-day discharge after cryoballoon ablation of atrial fibrillation: A multicenter experience.

BACKGROUND: It is common practice to observe patients during an overnight stay (ONS) following a catheter ablation procedure for the treatment of atrial fibrillation (AF). OBJECTIVES: To investigate the safety and economic impact of a same-day discharge (SDD) protocol after cryoballoon ablation for treatment of AF in high-volume, geographically diverse US hospitals. METHODS: We retrospectively reviewed 2374 consecutive patients (1119 SDD and 1180 ONS) who underwent cryoballoon ablation for AF at three US centers. Baseline characteristics, acute procedure-related complications, and longer-term evaluations of safety were recorded during routine clinical follow-up. The mean cost of an ONS was used in a one-way sensitivity analysis to evaluate yearly cost savings as a function of the percentage of SDD cases per year. RESULTS: The SDD and ONS cohorts were predominately male (69% vs. 67%; p = .3), but SDD patients were younger (64 ± 11 vs. 66 ± 10; p < .0001) with lower body mass index (30 ± 6 vs. 31 ± 61; p < .0001) and CHA2 DS2 -VASc scores (1.4 ± 1.0 vs. 2.2 ± 1.4; p < .0002). There was no difference between SDD and ONS in the 30-day total complication rate (n = 15 [1.26%] versus n = 24 [2.03%]; p = .136, respectively). The most common complication was hematoma in both the SDD (n = 8; 0.67%) and ONS (n = 11; 0.93%) cohorts. Sensitivity analysis demonstrated that when 50% of every 100 patients treated were discharged the same day, hospital cost savings ranged from $45 825 to $83 813 per year across US hospitals. CONCLUSIONS: SDD following cryoballoon ablation for AF appears to be safe and is associated with cost savings across different US hospitals.

Long-term durability of posterior wall isolation using the cryoballoon in patients with persistent atrial fibrillation: a multicenter analysis of repeat catheter ablations.

PURPOSE: There is a growing interest in performing pulmonary vein isolation (PVI) with concomitant posterior wall isolation (PWI) using the cryoballoon for the treatment of patients with persistent atrial fibrillation (AF). However, there is little known about the long-term durability of PWI using this approach. METHODS: In this multicenter study, we retrospectively examined the durability of PVI + PWI using the 28-mm cryoballoon by investigating the outcomes from consecutive patients referred for repeat catheter ablation. RESULTS: Altogether, 81/519 patients (15.6%) were referred for repeat catheter ablation. Repeat ablation was associated with a longer AF duration, hypertension, heart failure, multiple cardioversions, and antiarrhythmic therapy as well as larger left atrial (LA) diameters (49 ± 4 mm versus 43 ± 5 mm; P < 0.001) and greater need for "touch-up" (adjunct) radiofrequency ablation (44.4% versus 18.3%; P < 0.001). LA diameter also emerged as a significant predictor for adjunct radiofrequency ablation (P < 0.001). Durable PVI was observed in 66/81 patients (81.5%) and PWI in 67/81 patients (82.7%). Those with incomplete PWI exhibited larger LA diameters, particularly > 48 mm (negative predictive value = 89.7%). Lastly, an atypical LA posterior wall/roof flutter represented the third most common cause of arrhythmia recurrence and essentially every patient with incomplete PWI exhibited such an arrhythmia. CONCLUSION: PWI performed using a 28-mm cryoballoon in conjunction with PVI exhibits long-term durability in the vast majority of patients with persistent AF. While LA diameter (particularly > 48 mm) is a significant predictor for the need for adjunct radiofrequency ablation when performing this technique, those with incomplete PWI invariably present with an atypical flutter using this substrate.

Ultrasound-Guided Peripheral Intravenous Catheter Insertion: The Nurse's Manual.

Peripheral intravenous catheter placement is a skill that is used daily in the hospital. However, many nurses face the challenge of cannulating increasingly complex and difficult-to-access vasculature. Although emergency department clinicians have been using ultrasound to facilitate this procedure for the last 18 years, ultrasound-guided peripheral intravenous catheter placement has not been as rapidly adopted in the critical and acute care nursing realms. Given the benefits of this procedure, including increased patient satisfaction and reduced use of central catheters, its use should be encouraged among all acute care clinicians. The aim of this article is to provide the bedside nurse with a basic understanding of the techniques involved in placing ultrasound-guided peripheral intravenous catheters in patients with difficult venous access.

Injection laser system for Advanced Radiographic Capability using chirped pulse amplification on the National Ignition Facility.

We report on the design, performance, and qualification of the injection laser system designed to deliver joule-level chirped pulse beamlets arranged in dual rectangular beam formats into two main laser amplifier beamlines of the National Ignition Facility. The system is designed to meet the requirements of the Advanced Radiographic Capability upgrade with features that deliver performance, adjustability, and long-term reliability.

Outcomes Following Treatment of the Infected Achilles Tendon.

BACKGROUND: Infection following Achilles tendon surgery is a devastating complication and can be difficult to treat and often leads to poor outcomes. A number of treatments have been described, but there is little information concerning outcomes of these treatments. Our purpose was to evaluate the clinical and functional outcomes of patients who have undergone treatment for an infected Achilles tendon after acute and chronic midsubstance repair. METHODS: We retrospectively reviewed the medical records of 20 patients who had undergone surgical treatment for an infected Achilles tendon between 2000 and 2016. The mean follow-up time was 21 months (range, 2-68 months). All patients underwent extensive debridement of the tendon with removal of all infected tissue and foreign material. Soft tissue wound coverage was utilized for large wounds that were not amenable to primary or secondary closure. All patients received culture-specific intravenous (IV) antibiotics for 3 to 6 weeks. Postoperatively, the extremity was immobilized in a splint followed by a cast until the wound was healed. The cast was then replaced with a walking boot and the patients were provided a physical therapy program. Functional outcomes were measured using the Foot and Ankle Ability Measure (FAAM) Activity of Daily Living (ADL) scale. RESULTS: All wounds had healed at the time of last follow-up. Three patients (15%) required an unplanned return to the operating room for repeat debridement. All patients were able to walk without the use of a gait aid. Five patients (25%) required continued use of a boot or brace during ambulation. Fourteen patients participated in the FAAM ADL survey. There were 6 patients lost to follow-up. The average FAAM score was 87 (range, 71.4-100). At last follow-up, most patients reported their overall function as "normal" or "nearly normal." Eradication of infection and satisfactory functional results can be attained after radical debridement, wound closure, and administration of culture-specific IV antibiotics. LEVEL OF EVIDENCE: Level IV, retrospective case series.