Feasibility of Artificial Intelligence Powered Adverse Event Analysis: Using a Large Language Model to Analyze Microwave Ablation Malfunction Data.

Objectives: Determine if a large language model (LLM, GPT-4) can label and consolidate and analyze interventional radiology (IR) microwave ablation device safety event data into meaningful summaries similar to humans. Methods: Microwave ablation safety data from January 1, 2011 to October 31, 2023 were collected and type of failure was categorized by human readers. Using GPT-4 and iterative prompt development, the data were classified. Iterative summarization of the reports was performed using GPT-4 to generate a final summary of the large text corpus. Results: Training (n = 25), validation (n = 639), and test (n = 79) data were split to reflect real-world deployment of an LLM for this task. GPT-4 demonstrated high accuracy in the multiclass classification problem of microwave ablation device data (accuracy [95% CI]: training data 96.0% [79.7, 99.9], validation 86.4% [83.5, 89.0], test 87.3% [78.0, 93.8]). The text content was distilled through GPT-4 and iterative summarization prompts. A final summary was created which reflected the clinically relevant insights from the microwave ablation data relative to human interpretation but had inaccurate event class counts. Conclusion: The LLM emulated the human analysis, suggesting feasibility of using LLMs to process large volumes of IR safety data as a tool for clinicians. It accurately labelled microwave ablation device event data by type of malfunction through few-shot learning. Content distillation was used to analyze a large text corpus (>650 reports) and generate an insightful summary which was like the human interpretation.

Real-World Experience With the Angio-Seal Closure Device: Insights From Manufacturer and User Facility Device Experience Database.

PURPOSE: Angio-Seal (Terumo Medical Corporations, Somerset, New Jersey) device is indicated for femoral arteriotomy closure. Real-world published data on complications are limited. We present 1 year of safety events involving Angio-Seal from the US Food and Drug Administration's post-market surveillance database of Manufacturer and User Facility Device Experience (MAUDE). Steps for managing frequent device-related problems are discussed. MATERIALS AND METHODS: Angio-Seal MAUDE data from November 2019 to December 2020 was classified according to (1) mode of device failure, (2) complication, (3) treatment, and (4) Cardiovascular and Interventional Radiological Society of Europe (CIRSE) adverse event classification system. RESULTS: There were 715 safety events, involving Angio-Seal VIP (93.1%), Evolution (5.7%), STS Plus (1.1%), and sizes 6F (62.5%) and 8F (37.5%). Failure mode involved unrecognized use of a damaged device (43.4%), failed deployment (20.1%), failed arterial advancement (6.3%), detachment of device component (4.9%), failed retraction (3.6%), operator error (1.1%), and indeterminate (20.6%). Of total, 44.8% of events were associated with patient harm. Complications involved minor blood loss (34.1%), hematoma (5.6%), significant blood loss (1.4%), and pseudoaneurysm (1.4%). Of total, 43.3% of cases required manual compression (MC), whereas 8.8% required more advanced intervention. Interventions included surgical repair (49.2%), thrombin injection (9.5%), balloon tamponade (6.3%), covered stent (4.8%), and unspecified (30.2%). Majority of safety events were CIRSE grade 1 (92.0%), followed by grades 2 (3.1%), 3 (4.6%), and 6 (deaths, 0.3%). Minority of devices were returned for manufacturer analysis (27.8%). CONCLUSIONS: The majority of safety events were associated with minor blood loss or local hematoma and could be addressed with MC alone. Most events were attributed to damaged device; however, very few devices were returned to manufacturer for analysis. This should be encouraged to allow for root cause analysis in order to improve safety profile of devices. System-level strategies for addressing barriers to under-reporting of safety events may also be considered. CLINICAL IMPACT: Our study highlights important safety events encountered in real-world practice with Angio-Seal closure device. The MAUDE database captures real-world device malfunctions not typically appreciated in conventional clinical trials. Our study provides valuable insight for clinician-users on anticipating and managing the most common device malfunctions. Additionally, our data provide feedback for manufactures to optimize product design and direct manufacturer user training to improve safety. Finally, we hope that the study promotes system-level strategies that foster reporting of safety events and undertaking of root cause analysis.

Insights From the FDA's MAUDE Database Regarding the Real-World Safety of Jetstream Atherectomy for Peripheral Arterial Disease.

INTRODUCTION: Rotational atherectomy has shown promise as an adjunctive therapy to percutaneous transluminal angioplasty (PTA) and stenting for the treatment of peripheral arterial disease (PAD). However, published data regarding the safety of these devices are limited. The Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database collects reports of adverse event for medical devices. We present 3 years of MAUDE adverse events data for the Jetstream Atherectomy System (Boston Scientific) for the treatment of PAD. MATERIALS AND METHODS: We searched MAUDE from January 1, 2019 to December 31, 2021. Duplicate reports and those with insufficient information were excluded, leaving a total of 500 reports for analysis. Adverse events were categorized as either patient complication, device malfunction, or both. Adverse events were classified using the Cardiovascular and Interventional Radiological Society of Europe's (CIRSE) classification system for adverse events. RESULTS: The most common patient complications were embolism (22; 4.4%), dissection (17; 3.4%), vessel perforation (12; 2.4%), and device fracture in the patient (6; 1.2%). The most common modes of device failure were entrapment of the device on the guidewire (134; 27%), loss of blade rotation (116; 23%), loss of aspiration (99; 20%), and mechanical damage (57; 11%). As per the CIRSE adverse events classification, most events had no post-procedural sequelae (475; 95%), followed by those requiring prolonged observation (14; 2.8%), and post-procedural therapy without long-term sequelae (10; 2.0%). One hundred six devices (21%) were returned for manufacturer analysis. CONCLUSION: We highlight important adverse events encountered in real-world practice with the Jetstream Atherectomy System. This analysis provides further understanding of the safety profile and modes of failure of Jetstream, and could help guide improvements in product design and manufacturer-user training. There is greater need for root-cause analysis that can aided by returning devices to the manufacturer. CLINICAL IMPACT: We highlight important adverse events encountered in real-world practice with the Jetstream Atherectomy System. The MAUDE database is useful for capturing and characterizing modes of device failure/malfunction not typically described in conventional clinical studies. This may provide valuable information to help guide improvements in product design and manufacturer-user training. This information could also potentially be useful in helping establish manufacturer and product liability in the setting of medicolegal claims. We hope that by contributing to the growing understanding of the safety profile of the Jetstream Atherectomy System, our study may help physicians and patients come to more informed decisions regarding treatment options for PAD.

Emphysematous cystitis, iliopsoas abscess, and pneumorrhachis in an elderly woman: a case report.

BACKGROUND: Emphysematous cystitis is a well-described life threatening complication of urinary tract infection, most commonly seen in patients with diabetes and typically caused by gas forming bacterial or fungal pathogens. Pneumorrhachis is the rare finding of gas within the spinal canal, most commonly reported in the context of cerebrospinal fluid leakage secondary to trauma or spinal instrumentation. To our knowledge there is only one other reported case of pneumorrhachis in the setting of emphysematous cystitis. CASE PRESENTATION: This is a single case report of pneumorrhachis in the setting of emphysematous cystitis. An 82-year-old Asian female patient originally from East Asia, with no prior medical history besides hypertension, presented to hospital with a chief complaint of acute on chronic neck pain and functional decline. Examination revealed nonspecific neurosensory deficits and suprapubic tenderness. Laboratory investigations demonstrated leukocytosis and extended-spectrum beta-lactamase containing Escherichia coli bacteremia and bacteriuria. Computed tomography showed emphysematous cystitis with widespread gas within the cervical and lumbar spinal canal, as well as multiple gas-containing soft tissue collections in the bilateral psoas muscles and paraspinal soft tissues. Despite prompt antimicrobial therapy the patient passed away within 48 hours from septic shock. CONCLUSIONS: Our case adds to a growing body of literature showing that the spread of air to distant sites, including the spine, may be a poor prognostic indicator in patients with gangrenous intraabdominal infections. This report highlights the importance of recognizing the causes and presentation of pneumorrhachis to facilitate early diagnosis and treatment of potentially life threatening and treatable causes.

A Single-Center Experience With Percutaneous Interventional Management of Refractory Chylous Ascites.

PURPOSE: Management of chylous ascites is poorly understood with no management guidelines. We retrospectively reviewed patients treated for chylous ascites at our institution to evaluate efficacy and safety of lipiodol lymphangiography and embolization. MATERIALS AND METHODS: Seven patients underwent percutaneous interventional management of chylous ascites (average age 52.5 years, 3 female, 6 post-surgical, 1 pancreatitis) from 2012. All patients underwent lipiodol inguinal lymph node injection. Adjunctive glue embolization was performed if a leak was identified. Data were collected on the cause of chylous ascites, conservative management strategies, procedural details, and success. RESULTS: All patients had chylous ascites refractory to conservative management. Preprocedure lymphoscintigraphy identified a retroperitoneal leak in 6 patients. Seven patients underwent 12 lymphangiogram procedures; 8 were performed at our institution. Lymphangiography identified a leak in 5 patients (71%). Success was achieved in 2 patients (28%) treated at our institution after glue embolization following cannulation of the leaking lymphatic channels and 1 patient (14%) after lymphangiography alone for an overall success rate of 43% (3/7). Two patients (29%) were successfully treated after one procedure. Two patients (29%) unsuccessfully treated at our institution were referred to a specialized center in the United States. No 30 day post procedural complications. CONCLUSIONS: In our experience, lymphangiography and embolization was a safe, relatively effective and minimally invasive method for treating medically refractory chylous ascites. Complex cases required referral to a specialized institution with resources unavailable at our tertiary care center.

Unenhanced Dual-Energy Computed Tomography: Visualization of Brain Edema.

PURPOSE: The aim of this study was to determine whether dual-energy computed tomography (DECT) imaging is superior to conventional noncontrast computed tomography (CT) imaging for the detection of acute ischemic stroke. MATERIALS AND METHODS: This was a retrospective, single-center study of 40 patients who presented to the emergency department (ED) of a major, acute care, teaching center with signs and symptoms of acute stroke. Only those patients who presented to the ED within 4 hours of symptom onset were included in this study. All 40 patients received a noncontrast DECT of the head at the time of presentation. Each patient also received standard noncontrast CT of the head 24 hours after their initial presentation to the ED. "Brain edema" images were then reconstructed using 3-material decomposition with parameters adjusted to suppress gray/white matter contrast while preserving edema and increasing its conspicuity. The initial unenhanced, mixed images, brain edema, and 24-hour follow-up true noncontrast (TNC) images were reviewed and assigned Alberta Stroke Program Early CT scores. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. RESULTS: Of the 40 patients, 28 (70%) were diagnosed with an acute infarction. Brain edema reconstructions were better able to predict end infarction volume, with Alberta Stroke Program Early CT scores similar to the 24-hour follow-up TNC CT (7.75 vs 7.7; P > 0.05), whereas the mixed images routinely underestimated the extent of infarction (8.975 vs 7.7; P < 0.001). Initial TNC images had a sensitivity, specificity, PPV, and NPV of 80% (95% confidence interval [CI], 51.9%-95.7%), 72.7% (95% CI, 39%-94%), 80% (95% CI, 51.9%-95.7%), and 72.73% (95% CI, 51.91%-95.67%), respectively. The DECT brain edema images provided a sensitivity, specificity, PPV, and NPV of 93.33% (95% CI, 68.05%-99.83%), 100% (95% CI, 71.51%-100%), 100% (95% CI, 76.84%-100%), and 91.67% (95% CI, 61.52%-99.79%), respectively. There was very good interrater reliability across all 3 imaging techniques. CONCLUSION: Brain edema reconstructions are able to more accurately detect edema and end-infarct volume as compared with initial TNC images. This provides a better assessment of the degree and extent of infarction and may serve to better guide therapy in the future.

Clinical Decision Support Decreases Volume of Imaging for Low Back Pain in an Urban Emergency Department.

PURPOSE: To determine whether point-of-care clinical decision support can effectively reduce inappropriate medical imaging of patients who present to the emergency department (ED) with low-back pain (LBP). MATERIALS AND METHODS: This was a prospective, single-center study of lumbar imaging referrals made by 43 emergency physicians at a major acute care center. Each physician saw at least 10 LBP cases in both pre- and post-intervention periods. A point-of-care checklist of accepted red flags for LBP was designed by a working group of physicians and embedded in the computerized order entry form for lumbar imaging. We compared imaging rates of LBP and physician variation in imaging ordering before and after the implementation of the checklist. We then measured the potential harms of reduced imaging. RESULTS: After intervention, the proportion of LBP patients with an imaging order fell significantly (median: 22% to 17%; mean: 23% to 18%; P = .0002) compared with pre-intervention baseline. The percentage of patients without imaging who were later imaged at a hospital outpatient clinic within 30 days was 2.3% before intervention and 2.2% after (P = .974). In addition, the proportion of patients discharged from the ED without imaging who returned to the ED within 30 days was 8.2% before intervention and 6.9% after (P = .170). One minor thoracic spine compression fracture was missed, but management was not impacted. No serious diagnoses were missed. CONCLUSION: Clinical decision support integrated in electronic order entry forms can safely and effectively reduce imaging orders for LBP patients in the ED.

Gß4γ1 as a modulator of M3 muscarinic receptor signalling and novel roles of Gß1 subunits in the modulation of cellular signalling.

Much is known about the how Gßγ subunits regulate effectors in response to G protein-coupled receptor stimulation. However, there is still a lot we don't know about how specific combinations of Gß and Gγ are wired into different signalling pathways. Here, using an siRNA screen for different Gß and Gγ subunits, we examined an endogenous M3 muscarinic receptor signalling pathway in HEK 293 cells. We observed that Gß(4) subunits were critical for calcium signalling and a downstream surrogate measured as ERK1/2 MAP kinase activity. A number of Gγ subunits could partner with Gß(4) but the best coupling was seen via Gß(4)γ(1). Intriguingly, knocking down Gß(1) actually increased signalling through the M3-mAChR most likely via an increase in Gß(4) levels. We noted that Gß(1) occupies the promoter of Gß(4) and may participate in maturation of its mRNA. This highlights a new role for Gßγ signalling beyond their canonical roles in cellular signalling.