Exploring the potential utility of AI large language models for medical ethics: an expert panel evaluation of GPT-4.

Integrating large language models (LLMs) like GPT-4 into medical ethics is a novel concept, and understanding the effectiveness of these models in aiding ethicists with decision-making can have significant implications for the healthcare sector. Thus, the objective of this study was to evaluate the performance of GPT-4 in responding to complex medical ethical vignettes and to gauge its utility and limitations for aiding medical ethicists. Using a mixed-methods, cross-sectional survey approach, a panel of six ethicists assessed LLM-generated responses to eight ethical vignettes.The main outcomes measured were relevance, reasoning, depth, technical and non-technical clarity, as well as acceptability of GPT-4's responses. The readability of the responses was also assessed. Of the six metrics evaluating the effectiveness of GPT-4's responses, the overall mean score was 4.1/5. GPT-4 was rated highest in providing technical (4.7/5) and non-technical clarity (4.4/5), whereas the lowest rated metrics were depth (3.8/5) and acceptability (3.8/5). There was poor-to-moderate inter-rater reliability characterised by an intraclass coefficient of 0.54 (95% CI: 0.30 to 0.71). Based on panellist feedback, GPT-4 was able to identify and articulate key ethical issues but struggled to appreciate the nuanced aspects of ethical dilemmas and misapplied certain moral principles.This study reveals limitations in the ability of GPT-4 to appreciate the depth and nuanced acceptability of real-world ethical dilemmas, particularly those that require a thorough understanding of relational complexities and context-specific values. Ongoing evaluation of LLM capabilities within medical ethics remains paramount, and further refinement is needed before it can be used effectively in clinical settings.

Evaluating ChatGPT on Orbital and Oculofacial Disorders: Accuracy and Readability Insights.

PURPOSE: To assess the accuracy and readability of responses generated by the artificial intelligence model, ChatGPT (version 4.0), to questions related to 10 essential domains of orbital and oculofacial disease. METHODS: A set of 100 questions related to the diagnosis, treatment, and interpretation of orbital and oculofacial diseases was posed to ChatGPT 4.0. Responses were evaluated by a panel of 7 experts based on appropriateness and accuracy, with performance scores measured on a 7-item Likert scale. Inter-rater reliability was determined via the intraclass correlation coefficient. RESULTS: The artificial intelligence model demonstrated accurate and consistent performance across all 10 domains of orbital and oculofacial disease, with an average appropriateness score of 5.3/6.0 ("mostly appropriate" to "completely appropriate"). Domains of cavernous sinus fistula, retrobulbar hemorrhage, and blepharospasm had the highest domain scores (average scores of 5.5 to 5.6), while the proptosis domain had the lowest (average score of 5.0/6.0). The intraclass correlation coefficient was 0.64 (95% CI: 0.52 to 0.74), reflecting moderate inter-rater reliability. The responses exhibited a high reading-level complexity, representing the comprehension levels of a college or graduate education. CONCLUSIONS: This study demonstrates the potential of ChatGPT 4.0 to provide accurate information in the field of ophthalmology, specifically orbital and oculofacial disease. However, challenges remain in ensuring accurate and comprehensive responses across all disease domains. Future improvements should focus on refining the model's correctness and eventually expanding the scope to visual data interpretation. Our results highlight the vast potential for artificial intelligence in educational and clinical ophthalmology contexts.

Impact of fenestrated stent graft misalignment on patient outcomes.

OBJECTIVE: During fenestrated endovascular aneurysm repair (FEVAR), accurate alignment of the fenestration and the target artery is necessary to prevent complications. This study's objective is to determine the incidence of clinical outcomes following fenestration misalignment during FEVAR. METHODS: A single-center, retrospective chart review was performed for all elective FEVARs between January 2008 and April 2015. Data were gathered from patient records and intraoperative imaging. Native vessel angles were calculated using the vessel centerlines. Intraoperative stent graft orientation was determined by changing the angle of the image intensifier as the fenestration was profiled for cannulation. Vertical fenestration misalignment was defined as 4 mm or greater and is the distance from the center of the fenestration markers to the center of the target vessel ostium at the time of cannulation. Horizontal stent graft misalignment was defined as a difference between the native vessel angle and the intraoperative fenestration angle of 15° or more. Early and late clinical outcomes were analyzed with respect to the presence of either vertical or horizontal misalignment of the renal artery fenestrations. RESULTS: The study cohort includes 65 patients who underwent FEVAR during this study period. A horizontal misalignment of 15° or more occurred in 40% of patients (n = 26) and 30° or more in 9.2% of patients (n = 6). A vertical misalignment of 4 mm or greater occurred in 32.3% of patients (n = 21). The incidence of severe postoperative complications, defined as any in-hospital end-organ ischemia and/or death, was significantly greater for patients with stent graft misalignment-31% (n = 11) vs 3% (n = 1) in the aligned group. There was a trend toward higher rates of target vessel cannulation failure in patients with stent graft misalignment 3% (n = 99 fenestrations) vs 0% (n = 76 fenestrations). The combined incidence of any intraoperative target vessel complication was significantly higher in patients with misalignment, 8.1% (4, 15) vs 1.3% (0, 8). Long-term survival was significantly lower in patients with stent graft misalignment, which was primarily driven by high intraoperative and in-hospital mortality rates (P < .05). CONCLUSIONS: Intraoperative stent graft misalignment is associated with higher rates of procedural target vessel complications and severe postoperative adverse events. Patients with stent graft misalignment should be considered at high risk for early postoperative complications. These results highlight an important need for improved FEVAR planning.

Impact of Insertion Technique and Iliac Artery Anatomy on Fenestrated Endovascular Aneurysm Repair.

Purpose: To develop a mechanically realistic aortoiliac model to evaluate anatomic variables associated with stent-graft rotation and to assess common deployment techniques that may contribute to rotation. Materials and Methods: Idealized aortoiliac geometries were constructed either through direct 3-dimensional (3D) printing (rigid) or through casting with polyvinyl alcohol using 3D-printed molds (flexible). Flexible model bending rigidity was controlled by altering wall thickness. Three flexible patient-specific models were also created based on the preoperative computed tomography angiograms. Zenith infrarenal and fenestrated devices were used in this study. The models were pressurized to 100 mm Hg with normal saline. Deployments were performed under fluoroscopy at 37°C. Rotation was calculated by tracking the change in position of gold markers affixed to the devices. Results: In the rigid idealized models, stent-graft rotation increased with increasing torsion; torsion levels of 1.6, 2.6, and 3.6 mm-1 had mean rotations of 5.2°±0.03°, 11.2°±4.8°, and 27.6°±13.0°, respectively (p<0.001). In the flexible models, the highest rotation (58°±3.0°) was observed in models with high torsion and high rigidity (7.5 mm-1 net torsion and 254 N·m2 flexural rigidity). No rotation was observed in the absence of torsion. Applying torque to the device during insertion significantly increased stent-graft rotation by an average of 28° across all levels of torsion (p<0.01). Multiple device insertions prior to deployment did not change the observed device rotation. The patient-specific models accurately predicted the degree of rotation seen intraoperatively to within 5°. Conclusion: Insertion technique plays an important role in the degree of stent-graft rotation during deployment. Our model suggests that in vivo correction of device orientation can increase the observed rotation and supports the concept of fully removing the device, adjusting the orientation, and subsequently reinserting. Additionally, increasing iliac artery torsion in the presence of increased vessel rigidity results in stent-graft rotation.

Prediction of advanced endovascular stent graft rotation and its associated morbidity and mortality.

OBJECTIVE: Advanced endovascular aneurysm repair (EVAR) with fenestrated and branched stent grafts is increasingly being used to repair complex aortic aneurysms; however, these devices can rotate unpredictably during deployment, leading to device misalignment. The objectives of this study were to quantify the short-term clinical outcomes in patients with intraoperative stent graft rotation and to identify quantitative anatomic markers of the arterial geometry that can predict stent graft rotation preoperatively. METHODS: A prospective study evaluating all patients undergoing advanced EVAR was conducted at two university-affiliated hospitals between November 2015 and December 2016. Stent graft rotation (defined as ≥10 degrees) was measured on intraoperative fluoroscopic video of the deployment sequence. Standard preoperative computed tomography angiography imaging was used to calculate the geometric properties of the arterial anatomy. Any in-hospital and 30-day complications were prospectively documented, and a composite outcome of any end-organ ischemia or death was used as the primary end point. RESULTS: Thirty-nine patients undergoing advanced EVAR were enrolled in the study with a mean age of 75 years (interquartile range [IQR], 71-80 years) and a mean aneurysm diameter of 64 mm (IQR, 59-65 mm). The incidence of stent graft rotation was 37% (n = 14), with a mean rotation of 25 degrees (IQR, 21-28 degrees). A nominal logistic regression model identified iliac artery torsion, volume of iliac artery calcification, and stent graft length as the primary predictive factors. The total net torsion and the total volume of calcific plaque were higher in patients with stent graft rotation, 8.9 ± 0.8 mm-1 vs 4.1 ± 0.5 mm-1 (P < .0001) and 1054 ± 144 mm3 vs 525 ± 83 mm3 (P < .01), respectively. The length of the implanted stent grafts was also higher in patients with intraoperative rotation, 172 ± 9 mm vs 156 ± 8 mm (P < .01). The composite outcome of any end-organ ischemia or death was also substantially higher in patients with stent graft rotation (36% vs 0%; P = .004). In addition, patients with stent graft rotation had significantly higher combined rates of type Ib and type III endoleaks (43% vs 8%; P = .03). CONCLUSIONS: Patients with intraoperative stent graft rotation have a significantly higher rate of severe postoperative complications, and this is strongly associated with higher levels of iliac artery torsion, calcification, and stent graft length. These findings suggest that preoperative quantitative analysis of iliac artery torsion and calcification may improve risk stratification of patients before advanced EVAR.

Predicting Rotation in Fenestrated Endovascular Aneurysm Repair Using Finite Element Analysis.

Fenestrated endovascular aneurysm repair (FEVAR) is a minimally invasive method of abdominal aortic aneurysm (AAA) repair utilized in patients with complex vessel anatomies. Stent grafts (SG) used in this process contain fenestrations within the device that need to be aligned with the visceral arteries upon successful SG deployment. Proper alignment is crucial to maintain blood flow to these arteries and avoid surgical complications. During fenestrated SG deployment, rotation of the SG can occur during the unsheathing process. This leads to misalignment of the vessels, and the fenestrations and is associated with poor clinical outcomes. The aim of this study was to develop a computational model of the FEVAR process to predict SG rotation. Six patient-specific cases are presented and compared with surgical case data. Realistic material properties, frictional effects, deployment methods, and boundary conditions are included in the model. A mean simulation error of 2 deg (range 1-4 deg) was observed. This model was then used to conduct a parameter study of frictional properties to see if rotation could be minimized. This study showed that increasing or decreasing the coefficients of friction (COF) between the sheath and the vessel walls would decrease the amount of rotation observed. Our model accurately predicts the amount of SG rotation observed during FEVAR and can be used as a preoperative planning tool within the surgical workflow.

Publication outcomes for research presented at a Canadian surgical conference.

BACKGROUND: The failure of investigators to publish research in peer-reviewed journals following acceptance at a national or international meeting can lead to significant publication biases in the literature. Our objective was to evaluate the abstract to manuscript conversion rate for abstracts presented at the Canadian Society for Vascular Surgery (CSVS) annual meeting and to evaluate the conversion rate for CSVS-awarded research grants. METHODS: We searched for authors of abstracts accepted at the CSVS Annual Meeting (2007-2013) and recipients of CSVS research awards (2005-2013) on Scopus and PubMed databases to identify related publications. RESULTS: We identified 84 publications from 188 research abstracts (45%) and 17 publications from 39 research grants (44%). The mean time to publication was 1.8 years and the mean impact factor was 2.7. Studies related to endovascular therapies demonstrated a trend toward a higher rate of publication relative to open surgical therapies (64 [56%] v. 37 [27%]). Additionally, we observed a similar trend in research grant topics related to endovascular therapies relative to open surgical therapies (9 [67%] v. 8 [38%]). Finally, CSVS research grant recipients who subsequently published had a significantly higher h-index at the time of receipt than those who had not published. CONCLUSION: The CSVS annual meeting's abstract to publication conversion rate is comparable to that of its Canadian peers as well as to other medical specialties; however, a substantial publication gap remains. We identified several potential areas that may help to improve the effectiveness of CSVS research grants.

CONTEXTE: Le fait que des chercheurs ne publient pas leurs recherches dans des revues évaluées par les pairs après acceptation de leur résumé à un congrès national ou international peut entraîner des biais de publication importants dans la littérature scientifique. Notre but était d'évaluer le taux de conversion de résumé à manuscrit pour les résumés présentés au congrès annuel de la Société canadienne de chirurgie vasculaire (SCCV) ainsi que le taux de conversion dans le cas des subventions de recherche accordées par la SCCV. MÉTHODES: Nous avons interrogé les bases de données de Scopus et PubMed afin d'identifier les auteurs de résumés acceptés au congrès annuel de la SCCV (2007-2013) ainsi que les récipiendaires de subventions de recherche de la SCCV (2005-2013) et les publications connexes. RÉSULTATS: Nous avons relevé 84 publications à partir de 188 résumés de recherche (45 %) ainsi que 17 publications liées à 39 subventions de recherche (44 %). Le délai moyen de publication était de 1,8 année et le facteur d'impact moyen, de 2,7. Les études sur les thérapies endovasculaires avaient un taux de publication plus élevé comparativement à celles sur les traitements chirurgicaux ouverts (64 [56 %] c. 37 [27 %]). De plus, nous avons observé une tendance similaire lorsque le sujet des recherche subventionnées était lié aux thérapies endovasculaires comparativement aux traitements chirurgicaux ouverts (9 [67 %] c. 8 [38 %]). Enfin, les récipiendaires de subventions de recherche de la SCCV qui publiaient par la suite avaient un indice h beaucoup plus élevé au moment de recevoir la subvention que les chercheurs qui n'avaient pas publié. CONCLUSION: Le taux de conversion de résumé à publication du congrès annuel de la SCCV est comparable à celui de ses pairs au Canada et à celui d'autres spécialités médicales. Il reste néanmoins une lacune importante au niveau de la publication. Nous avons cerné plusieurs aspects susceptibles d'améliorer l'efficacité des subventions de recherche de la SCCV.

Clinical outcomes and material properties of in situ fenestration of endovascular stent grafts.

OBJECTIVE: In situ fenestration of endovascular stent grafts has been used as a method for branch vessel revascularization in urgent and emergent settings. The objective of this manuscript was to review the clinical and experimental evidence related to this technique. METHODS: PubMed, MEDLINE, and Embase databases were searched for papers published until December 2015 describing in situ fenestration of aortic stent grafts. Benchtop, animal, and human studies were included. RESULTS: The literature review identified 118 articles, of which 28 studies were selected for inclusion. These included 16 clinical papers (2 case series and 14 case reports) reporting in situ fenestration of 46 aortic branch vessels in 44 patients. There were 42 retrograde and 4 antegrade instances of in situ fenestration. The most frequent target vessel for in situ fenestration was the left subclavian artery (72%), and the most frequent indication for stent graft implantation was a degenerative aortic aneurysm (43%). Technical success was reported in 44 of 46 attempted fenestrations (96%). The combined rate of perioperative mortality, stroke, and paralysis was 7%. In situ fenestration was predominantly performed with the Talent (Medtronic, Santa Rosa, Calif) stent graft (54%), followed by the Zenith (Cook Medical, Bloomington, Ind) stent graft (37%) and the TAG (W. L. Gore & Associates, Newark, Del) stent graft (9%). In vitro benchtop evaluations of in situ fenestration showed minimal change in fenestration size after 1 year of pulsatile fatigue testing. The use of energy-based fenestration techniques (radiofrequency or laser) has been associated with less fabric fraying than in needle-based techniques. The larger caliber initial fenestration created by these devices also avoids the need for cutting balloons, which have also been linked with increased fabric tears and fraying of the fibers surrounding the fenestration. In addition, the Zenith stent graft was shown in benchtop testing to be the strongest in postfenestration mechanical testing, but it was also the most resistant to balloon dilation. CONCLUSIONS: In the short to moderate term, in situ fenestration appears to be a reasonable and effective method to extend the proximal landing zone for revascularization of the left subclavian artery. However, longer follow-up is needed to fully assess the long-term durability of this procedure. Based on studies of material properties, an energy-based fenestration technique (radiofrequency or laser) is recommended, along with the avoidance of cutting balloons for dilation of the fenestration.

Effects of Pulsatile Fatigue on In Situ Antegrade Fenestrated Polyester Stent Grafts Deployed in a Patient-Specific Phantom Model of Juxtarenal Aortic Aneurysm.

PURPOSE: To evaluate the effects of in situ fenestration on the fabric of stent grafts deployed in a patient-specific phantom of a juxtarenal abdominal aortic aneurysm. MATERIALS AND METHODS: Four patient-specific juxtarenal abdominal aortic aneurysm polyurethane models were created, and bifurcated Zenith (Cook, Inc, Bloomington, Indiana) and Endurant (Medtronic, Minneapolis, Minneapolis) endografts were deployed into the models, covering the renal arteries. Antegrade in situ fenestration was carried out with radiofrequency puncture followed by balloon dilation with either conventional or cutting balloons. Renal covered stents were deployed and flared. Specimens were mounted onto an accelerated fatigue tester for 40M cycles (1 patient life-year), and evaluated with microscopy, caliper measurements, and fabric counts. RESULTS: Cutting balloons resulted in more fabric fraying. None of the fenestrations grew beyond the targeted 6-mm diameter despite accelerated fatigue. Fluoroscopic images demonstrated a very prominent waist of the renal fenestration in the Cook device when a conventional balloon was used compared with a cutting balloon. The average fenestration diameter for the Cook device was only 3.1 mm with the conventional balloon compared with 4.8 mm with the cutting balloon. The average fenestration diameter for the Medtronic device was 3.8 mm with the conventional balloon compared with 5.1 mm with the cutting balloon. The fabric counts suggested crowding of yarns around the fenestrations with conventional balloons but less with cutting balloons. CONCLUSIONS: This experimental work suggests that the size of in situ renal fenestrations does not expand beyond the target diameter despite cyclic fatigue. Although the small number of devices tested and selected aortorenal anatomy in this study may limit conclusions, textile analysis suggests that cutting balloons should be used for the Cook Zenith device, whereas conventional balloons should be used for the Medtronic Endurant device when performing in situ fenestration.

Iatrogenic distal aortic rupture in a patient with vascular Ehlers-Danlos syndrome.

Vascular Ehlers-Danlos syndrome is a rare inherited connective tissue disorder that can result in significant morbidity and mortality. This report details an iatrogenic aortic rupture during an endovascular approach in the management of critical limb ischemia in a 27-year-old woman who presented with acute onset of severe sensory deficit of the left leg. Conversion to open repair with a midline laparotomy and an aortic-left popliteal bypass was performed. In the endovascular era, we highlight that even minimally invasive therapeutic interventions can have devastating adverse events in patients with vascular Ehlers-Danlos syndrome.

Comparison of Qualitative and Quantitative Assessments of Iliac Artery Tortuosity and Calcification.

INTRODUCTION: During endovascular aneurysm repair, the iliac artery typically serves as a conduit for device delivery. The degree of tortuosity and calcification in the iliac artery ultimately determines whether the device can successfully traverse the vessel. These 2 parameters can be assessed using qualitative approaches or calculated using quantitative methods based on the Society for Vascular Surgery (SVS) reporting standards. The objective of this study was to determine whether qualitative methods are sufficient to accurately assess iliac artery tortuosity and calcification by calculating interobserver variability and comparing them to the SVS Reporting Standards. METHODS: Three vascular surgeons reviewed preoperative computed tomography scans for 50 patients who underwent fenestrated endovascular aneurysm repair and qualitatively assessed left and right iliac artery tortuosity and calcification. Iliac artery geometries were segmented from these image sets. Tortuosity index and calcification length ratio were calculated and categorized based on the SVS Reporting Standards. RESULTS: Interobserver variability was calculated for the qualitative assessments using interclass correlation coefficients. For tortuosity index, among the 3 observers, good agreement was found for the left iliac artery and fair agreement was found for the right. For calcification length ratio, excellent agreement was found for both iliac arteries. When compared to the quantitative assessment, the qualitative assessments underpredicted tortuosity in 2.3% of cases, matched the quantitative values in 16.7% of cases, and overpredicted tortuosity in 81.0% of cases. The qualitative assessments underpredicted calcification in 46.3% of cases, matched the quantitative values in 49.3% of cases, and overpredicted calcification in 4.3% of cases. CONCLUSION: Qualitative assessment of iliac artery tortuosity showed fair-to-good interobserver agreement and poor agreement to SVS Reporting Standards. Qualitative assessment of iliac artery calcification showed excellent interobserver agreement and fair agreement to SVS Reporting Standards. These trends should be considered when qualitative reporting methodologies are used.

Analysis of Iliac Artery Geometric Properties in Fenestrated Aortic Stent Graft Rotation.

INTRODUCTION: A complication of fenestrated endovascular aneurysm repair is the potential for stent graft rotation during deployment causing fenestration misalignment and branch artery occlusion. The objective of this study is to demonstrate that this rotation is caused by a buildup of rotational energy as the device is delivered through the iliac arteries and to quantify iliac artery geometric properties associated with device rotation. METHODS: A retrospective clinical study was undertaken in which iliac artery geometric properties were assessed from preoperative imaging for 42 cases divided into 2 groups: 27 in the nonrotation group and 15 in the rotation group. Preoperative computed tomography scans were segmented, and the iliac artery centerlines were determined. Iliac artery tortuosity, curvature, torsion, and diameter were calculated from the centerline and the segmented vessel geometry. RESULTS: The total iliac artery net torsion was found to be higher in the rotation group compared to the nonrotation group (23.5 ± 14.7 vs 14.6 ± 12.8 mm-1; P = .05). No statistically significant differences were found for the mean values of tortuosity, curvature, torsion, or diameter between the 2 groups. CONCLUSION: Stent graft rotation occurred in 36% of the cases considered in this study. Cases with high iliac artery total net torsion were found to be more likely to have stent graft rotation upon deployment. This retrospective study provides a framework for prospectively studying the influence of iliac artery geometric properties on fenestrated stent graft rotation.

'In-stock' fenestrated stent graft for the urgent repair of an abdominal aortic aneurysm.

Endovascular aneurysm repair (EVAR) is a minimally invasive method for the treatment of abdominal aortic aneurysms; however, the implementation of this technique is often limited by the aortic pathology, especially in the urgent or emergent setting. An 82-year-old male with a 7.3 cm symptomatic juxtarenal aneurysm presented at our centre for assessment. He was diagnosed as a high-risk candidate for open repair and therefore, not suitable for a conventional EVAR. Fortunately, a custom two-vessel fenestrated stent graft, which was originally constructed for another patient, was available. This device was implanted with no complications and all branches remain unobstructed; clear of aneurysms at 1 year. We present the use of 'in-stock' fenestrated grafts as a potential option to be considered in the urgent or emergent repair of abdominal aortic aneurysms.

Long-term high-fat feeding induces greater fat storage in mice lacking UCP3.

Uncoupling protein-3 (UCP3) is a mitochondrial inner-membrane protein highly expressed in skeletal muscle. While UCP3's function is still unknown, it has been hypothesized to act as a fatty acid (FA) anion exporter, protecting mitochondria against lipid peroxidation and/or facilitating FA oxidation. The aim of this study was to determine the effects of long-term feeding of a 45% fat diet on whole body indicators of muscle metabolism in congenic C57BL/6 mice that were either lacking UCP3 (Ucp3(-/-)) or had a transgenically induced approximately twofold increase in UCP3 levels (UCP3tg). Mice were fed the high-fat (HF) diet for a period of either 4 or 8 mo immediately following weaning. After long-term HF feeding, UCP3tg mice weighed an average of 15% less than wild-type mice (P < 0.05) and were 20% less metabolically efficient than both wild-type and Ucp3(-/-) mice (P < 0.01). Additionally, wild-type mice had 21% lower, whereas UCP3tg mice had 36% lower, levels of adiposity compared with Ucp3(-/-) mice (P < 0.05 and P < 0.001, respectively), indicating a protective effect of UCP3 against fat gain. No differences in whole body oxygen consumption were detected following long-term HF feeding. Glucose and insulin tolerance tests revealed that both the UCP3tg and Ucp3(-/-) mice were more glucose tolerant and insulin sensitive compared with wild-type mice after short-term HF feeding, but this protection was not maintained in the long term. Findings indicate that UCP3 is involved in protection from fat gain induced by long-term HF feeding, but not in protection from insulin resistance.