Citations

Objective To analyze cases of medial migration of vestibular schwannomas to propose an underlying mechanism. Study Design Retrospective chart review. Patients Ten patients from one institution with sporadic vestibular schwannomas that demonstrated medial migration toward the cerebellopontine angle on serial imaging were reviewed. Interventions Among the 10 patients studied, 8 patients underwent stereotactic radiosurgery and 2 were managed with wait-and-scan. All serial imaging was analyzed throughout follow-up. Main Outcome Measures Volumetric and linear measurements were used to assess vestibular schwannoma growth. The fundal fluid cap length was measured from the most lateral end of the neoplasm within the internal auditory canal to the medial end of the cochlea. Pure tone averages of 0.5, 1, 2, and 3 kHz, word recognition scores, and AAO-HNS hearing class were used to assess levels of hearing loss per patient. Results Tumor growth exhibited a positive correlation with medial migration. Of the 10 patients studied, 9 exhibited tumor volume growth from initial to most recent imaging. Median changes in tumor volumes and fundal fluid cap lengths from initial diagnosis to the most recent imaging regardless of intervention were 130 mm3 (range 1,400–2,970) and 2.8 mm (range 1.8–6.0), respectively. Migration was noted in 4 patients prior to any intervention, in 4 patients postradiosurgery, and in 2 patients before and after radiosurgery. Therefore, half of the tumors studied migrated before an intervention and half migrated postradiosurgery. No correlation of migration and hearing decline was observed. Conclusion Medial migration of vestibular schwannoma is associated with an increase in tumor volume, supporting a “tumor squeeze” mechanism within a conical internal auditory canal toward the wider porus acusticus and cerebellopontine angle.

Blood flow restriction (BFR) is a popular resistance exercise technique purported to increase metabolic stress and augment training adaptations over time. However, short-term use may lead to acute neuromuscular fatigue and higher exertion ratings. Objective: The purpose of the current study was to examine acute physiological responses to low-load resistance exercise utilizing BFR compared to higher-load, non-BFR resistance exercise. Methods: Recreationally trained males (n = 6) and females (n = 7) (mean ± standard deviation, age: 20 ± 1 yrs.; height: 172 ± 8 cm; weight: 73 ± 11 kg; BMI: 24.4 ± 2.2 kg·m−2; training experience: 4 ± 2 yrs.) had limb occlusion pressure determined (50%; right leg: 118 ± 11 mmHg; left leg: 121 ± 13 mmHg) using an automated, self-inflating cuff system during baseline testing. In subsequent sessions, using a randomized, cross-over design, participants completed one of two experimental conditions: (1) Low-load + BFR and (2) High load + non-BFR. In both conditions, participants completed one set of back squats at either 30% (BFR) or 60% (non-BFR) of an estimated 1RM for a max of 30 repetitions, followed by three additional sets with the same loads and a target of 15 repetitions per set. Blood lactate and countermovement jump (CMJ) height were measured pre- and post-back squat. Ratings of perceived exertion (RPE) were assessed following each set. Results: When collapsed across all sets, participants completed significantly more total repetitions in the BFR condition compared to non-BFR (75.0 ± 0.0 vs. 68.23 ± 9.27 reps; p = 0.015; ES: 1.03), but a lower training load volume (2380 ± 728 vs. 4756 ± 1538 kg; p < 0.001; ES: 1.97). There was a significant time-by-condition interaction (p < 0.001), with a greater increase in blood lactate occurring from baseline to post-back squat in the non-BFR condition (11.61 mmol/L, 95%CI: 9.93, 13.28 mmol/L) compared to BFR (5.98 mmol/L, 95%CI: 4.30, 7.65 mmol/L). There was another significant time-by-condition interaction (p = 0.043), with a greater reduction in CMJ occurring in the non-BFR condition (−6.01, 95%CI: −9.14, −2.88 cm; p < 0.001) compared to BFR (−1.50, 95%CI: −1.50, 4.51 cm; p = 0.312). Conclusions: Utilizing a low-load BFR protocol may allow for a higher training volume, yet lower metabolic stress and reduce neuromuscular fatigue compared to lifting at a higher load without the use of BFR.

ABSTRACT Background Surgical resection for pancreas ductal adenocarcinoma (PDAC) remains the mainstay of treatment. Regardless of enhanced survival rates, disparities in patient outcomes and experiences driven by the social determinants of health (SDH) persist. The area deprivation index (ADI) comprises 17 indicators related to education, employment, housing‐quality, and poverty. We sought to examine the impact of ADI on surgical outcomes of PDAC patients. Methods Patients who underwent pancreatoduodenectomy or distal pancreatectomy for PDAC between January 2011 and December 2022 were identified. ADI was calculated using patient zip codes and categorized into quartiles, with the highest indicating the most marginalized. The primary outcome was loss to follow‐up after surgical resection. To account for confounders, a competing risk multivariable regression analysis was used. Results A total of 1001 patients had a mean age of 66.6 (±9.64), with 46.3% ( n = 463) of patients being female. A majority, 94.6% ( n = 947), identified as white, and 64.1% ( n = 641) had at least a college degree. The median length of follow‐up after surgery was 1.8 years (interquartile range: 0.9–3.5). Multivariable analysis adjusting for competing risk of death, showed that patients who are least marginalized are 1.57 times more likely to have their follow‐up than those most marginalized (hazard ratio: 1.57, 95% confidence interval: 1.08–2.29, p = 0.017). Conclusion SDH impact many aspects of patient's care including a higher risk of loss to follow‐up for marginalized patients after surgery for PDAC. Future efforts should seek to identify and lower barriers faced by marginalized patients with system‐level changes to ensure equitable access.

Progression of liver disease is dependent on intercellular signaling, including those mediated by extracellular vesicles (EVs). Within these EVs, microRNAs (miRNAs) are packaged to selectively silence gene expression in recipient cells for upregulating or downregulating a specific pathway. Injured hepatocytes secrete EV-associated miRNAs which can be taken up by liver sinusoidal endothelial cells, immune cells, hepatic stellate cells, and other cell types. In addition, these recipient cells will secrete their own EV-associated miRNAs to propagate a response throughout the tissue and the circulation. In this review, we comment on the implications of EV-miRNAs in the progression of alcohol-associated liver disease, metabolic dysfunction-associated steatohepatitis, viral and parasitic infections, liver fibrosis, and liver malignancies. We summarize how circulating miRNAs can be used as biomarkers and the potential of utilizing EVs and miRNAs as therapeutic methods to treat liver disease.

BACKGROUND AND OBJECTIVES: Stereotactic procedures are used to manage a diverse set of patients across a variety of clinical contexts. The stereotactic devices and software used in these procedures vary between surgeons, but the fundamental principles that constitute safe and accurate execution do not. The aim of this work is to describe these principles to equip readers with a generalizable knowledge base to execute and understand stereotactic procedures. METHODS: A combination of a review of the literature and empirical experience from several experienced surgeons led to the creation of this work. Thus, this work is descriptive and qualitative by nature, and the literature is used to support instead of generate the ideas of this framework. RESULTS: The principles detailed in this work are categorized based on 5 clinical domains: imaging, registration, mechanical accuracy, target planning and adjustment, and trajectory planning and adjustment. Illustrations and tables are used throughout to convey the concepts in an efficient manner. CONCLUSION: Stereotactic procedures are complex, requiring a thorough understanding of each step of the workflow. The concepts described in this work enable functional neurosurgeons with the fundamental knowledge necessary to provide optimal patient care.

BACKGROUND AND OBJECTIVES: Identifying and characterizing sources of targeting error in stereotactic procedures is essential to maximizing accuracy, potentially improving surgical outcomes. We aim to describe a generic framework which characterizes sources of stereotactic inaccuracy. METHODS: We assembled a list of stereotactic systems: ROSA, Neuromate, Mazor Renaissance, ExcelsiusGPS, Cirq, STarFix (FHC), Nexframe, ClearPoint, CRW, and Leksell. We searched the literature for qualitative and quantitative work identifying and quantifying potential sources of inaccuracy and describing each system's implementation using Standards for Reporting Qualitative Research guidelines. Our literature search spanned 1969 to 2024, and various studies were included, with formats ranging from phantom studies to systematic reviews. Keyword searches were conducted, and the details about each system were used to create a framework for identifying and describing the unique targeting error profile of each system. RESULTS: We describe and illustrate the details of various sources of stereotactic inaccuracies and generate a framework to unify these sources into a single framework. This framework entails 5 domains: imaging, registration, mechanical accuracy, target planning and adjustment, and trajectory planning and adjustment. This framework was applied to 10 stereotactic systems. CONCLUSION: This framework provides a rubric to analyze the sources of error for any stereotactic system. Illustrations allow the reader to understand sources of error conceptually so that they may apply them to their practice.

Abstract OBJECTIVES The effect of allograft ischaemic time (AIT) on postoperative events after lung transplantation remains unclear. This study aims to assess the feasibility of extending the duration of AIT. METHODS The United Network for Organ Sharing database was queried for adult lung transplantation from 4 May 2005 to 30 June 2020. Patients were divided as per AIT into standard ischaemic time (&lt;6 h) and prolonged ischaemic time (≥6 h) groups using propensity score matching and evaluated on a continuous scale using restricted cubic splines. The primary outcome was overall 1-year and 5-year survival. RESULTS Among 11 438 propensity-matched recipients, standard ischaemic time and prolonged ischaemic time showed no differences in overall 1-year (P = 0.29) or 5-year (P = 0.29) survival. Prolonged ischaemic time independently predicted early postoperative ventilator support for &gt;48 h (OR = 1.33, 95% CI 1.22–1.44), dialysis (OR = 1.55, 95% CI 1.30–1.84), primary graft dysfunction (PGD; OR = 1.28, 95% CI 1.09–1.50), acute rejection (OR = 1.42, 95% CI 1.24–1.62), and interestingly, decreased 5-year bronchiolitis obliterans syndrome (HR = 0.91, 95% CI 0.85–0.97). In relative risk curves, 1-year mortality, prolonged ventilation, dialysis and PGD steadily increased per hour as AIT extended. The risk of acute rejection and 5-year bronchiolitis obliterans syndrome also showed significant changes between 5 and 8 h of AIT. In contrast, 5-year mortality remained constant despite rising AIT. CONCLUSIONS Prolonged AIT worsened early outcomes such as PGD, but improved bronchiolitis obliterans syndrome freedom at later time points. Despite this, both short- and long-term survival were similar between prolonged ischaemic time and standard ischaemic time patients. Dynamic risk changes in post-transplant events should be noted for prolonged ischaemia lung use.

Abstract Immune thrombotic thrombocytopenic purpura (iTTP) is a chronically relapsing disorder caused by autoantibody-mediated deficiency of ADAMTS13. Rituximab is frequently administered to prevent relapses, but whether the durability of rituximab effect is maintained with subsequent treatment courses has not been studied. Using the United States Thrombotic Microangiopathy Consortium (USTMA) retrospective iTTP registry, we evaluated clinical relapse-free survival (RFS) with subsequent courses of rituximab treatment in multiply relapsing patients. Separately, we evaluated overall RFS (composite of time to clinical relapse, ADAMTS13 relapse, or preemptive rituximab) in a prospective iTTP cohort from the Johns Hopkins University and the University of Minnesota. In the USTMA registry, median clinical RFS was shorter after the second or subsequent rituximab-treated episode than the first (2.1 vs 6.0 years; P = .04). White patients’ clinical relapse risk after the second and subsequent rituximab courses was not significantly different compared with the first (hazard ratio [HR], 1.86; 95% confidence interval [CI], 0.22-15.80; P = .57), whereas for Black patients, clinical relapse risk was significantly higher after the second or subsequent courses (HR, 2.82; 95% CI, 1.52-5.24; P = .001). In the prospective cohort, overall RFS progressively shortened after each episode of rituximab treatment with the first episode having the longest RFS (2.8 years; interquartile range, 2.0-6.0) and this loss of response durability was most pronounced in Black patients. The durability of rituximab’s effect declines with subsequent treatments, which is more pronounced in Black patients, who may benefit from closer monitoring and alternative immunomodulatory approaches such as maintenance rituximab and consideration of other agents.

Abstract Background and Aims Artificial intelligence (AI) algorithms in 12-lead electrocardiogram (ECG) provides promising age prediction methods. This study investigated whether the discrepancy between ECG-derived AI-predicted age (AI-ECG age) and chronological age, termed electrocardiographic aging (ECG aging), is associated with atrial fibrillation (AF) risk. Methods An AI-ECG age prediction model was developed using a large-scale dataset (1 533 042 ECGs from 689 639 participants) and validated with six independent and multi-national datasets (737 133 ECGs from 330 794 participants). The AI-ECG age gap was calculated across two South Korean cohorts [mean (standard deviation) follow-up: 4.1 (4.3) years for 111 483 participants and 6.1 (3.8) years for 37 517 participants], one UK cohort [3.0 (1.6) years; 40 973 participants], and one US cohort [12.9 (8.6) years; 90 639 participants]. Participants were classified into two groups: normal group (age gap &lt; 7 years) and ECG-aged group (age gap ≥ 7 years). The predictive capability of ECG aging for new- and early-onset AF risk was assessed. Results The mean AI-ECG ages were 51.9 (16.2), 47.4 (12.5), 68.4 (7.8), and 56.7 (14.6) years with age gaps of .0 (6.8), −.1 (6.0), 4.7 (8.7), and −1.4 (8.9) years in the two South Korean, UK, and US cohorts, respectively. In the ECG-aged group, increased risks of new-onset AF were observed with hazard ratios (95% confidence intervals) of 2.50 (2.24–2.78), 1.89 (1.46–2.43), 1.90 (1.55–2.33), and 1.76 (1.67–1.86) in the two South Korean, UK, and US cohorts, respectively. For early-onset AF, odds ratios were 2.89 (2.47–3.37), 1.94 (1.39–2.70), 1.58 (1.06–2.35), and 1.79 (1.62–1.97) in these cohorts compared with the normal group. Conclusions The AI-derived ECG aging was associated with the risk of new- and early-onset AF, suggesting its potential utility to identify individuals for AF prevention across diverse populations.