Predicting Outcomes Following Lower Extremity Endovascular Revascularization Using Machine Learning.

BACKGROUND: Lower extremity endovascular revascularization for peripheral artery disease carries nonnegligible perioperative risks; however, outcome prediction tools remain limited. Using machine learning, we developed automated algorithms that predict 30-day outcomes following lower extremity endovascular revascularization. METHODS AND RESULTS: The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity endovascular revascularization (angioplasty, stent, or atherectomy) for peripheral artery disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day postprocedural major adverse limb event (composite of major reintervention, untreated loss of patency, or major amputation) or death. Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 machine learning models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Overall, 21 886 patients were included, and 30-day major adverse limb event/death occurred in 1964 (9.0%) individuals. The best performing model for predicting 30-day major adverse limb event/death was extreme gradient boosting, achieving an area under the receiver operating characteristic curve of 0.93 (95% CI, 0.92-0.94). In comparison, logistic regression had an area under the receiver operating characteristic curve of 0.72 (95% CI, 0.70-0.74). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.09. The top 3 predictive features in our algorithm were (1) chronic limb-threatening ischemia, (2) tibial intervention, and (3) congestive heart failure. CONCLUSIONS: Our machine learning models accurately predict 30-day outcomes following lower extremity endovascular revascularization using preoperative data with good discrimination and calibration. Prospective validation is warranted to assess for generalizability and external validity.

Outcomes of carotid endarterectomy: Insights from a single-center retrospective cohort study.

OBJECTIVES: To analyze the outcomes of carotid endarterectomy in individuals with carotid artery stenosis in the context of a tertiary care center. METHODS: We carried out a retrospective cohort investigation between 2015-2022. Patient data includes demographics, risk factors, preoperative medications, and operative details. The primary outcomes were 30-day postoperative stroke and mortality rates, while the secondary outcome of the study was to assess the morbidity of the procedure. RESULTS: The mean age of the 54 patients was 66.9±9.88 years, and 57.4% were men. The 30-day stroke rate was 3.7%, and the mortality rate was 1.9%. Most patients did not develop postoperative complications; however, surgical site hematoma was the most common complication encountered (12.9%). Long-term follow-up showed disease regression in 68.5% of patients, with a minority of patients developing ipsilateral restenosis. Admission to an intensive care monitoring unit was the only independent predictor of postoperative complications. CONCLUSION: This study provided insights into the outcomes of carotid endarterectomy in patients with carotid artery stenosis, emphasizing the importance of careful patient selection and postoperative monitoring. Perioperative risks, including stroke and mortality, were within acceptable limits. Further research incorporating structured and non-structured data for predictive analyses, should explore refining patient profiling and optimizing treatment approaches for different carotid artery stenosis clinical and morphological presentations.

Predicting the need for subclavian artery revascularization in thoracic endovascular aortic repair: A systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis aims to investigate the effectiveness of left subclavian artery revascularization compared with non-revascularization in thoracic endovascular aortic repair, and to summarize the current evidence on its indications. METHODS: A computerized search was conducted across multiple databases, including MEDLINE, SCOPUS, Cochrane Library, and Web of Science, for studies published up to November 2023. Study selection, data abstraction, and quality assessment (using the Newcastle-Ottawa Scale) were independently conducted by two reviewers, with a third author resolving discrepancies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models and publication bias was assessed using funnel plots. RESULTS: In the 76 included studies, left subclavian artery revascularization was associated with reduced risks of stroke (OR, 0.67; 95% CI, 0.45-0.98; n = 15,331), spinal cord ischemia (OR, 0.75; 95% CI, 0.56-0.99; n = 11,995), and arm ischemia (OR, 0.09; 95% CI, 0.01-0.59; n = 8438). No significant reduction in paraplegia (OR, 0.56; 95% CI, 0.21-1.47; n = 1802) or mortality (OR, 0.77; 95% CI, 0.53-1.12; n = 11,831) was observed. Moreover, the risk of endoleak was comparable in both groups (OR, 1.25; 95% CI, 0.55-2.84; P = .60; n = 793), whereas the risk of reintervention was significantly higher in the revascularization group (OR, 1.98; 95% CI, 1.03-3.83; P = .04; n = 272). Both groups had similar risks of major (OR, 0.45; 95% CI, 0.19-1.09; P = .08; n = 1113), minor (OR, 0.21; 95% CI, 0.01-3.45; P = .27; n = 183), renal (OR, 0.61; 95% CI, 0.12-3.06; P = .55; n = 310), and pulmonary (OR, 0.59; 95% CI, 0.16-2.15; P = .42; n = 8083) complications. The most frequent indications for left subclavian artery revascularization were primary prevention of spinal cord ischemia, augmentation of the landing zone, and primary stroke prevention. CONCLUSIONS: Left subclavian artery revascularization in thoracic endovascular aortic repair was associated with reduced neurological complications but was not found to impact mortality. The study highlights important indications for revascularization as well as significant predictors of complications, providing a basis for clinical decision-making and future research.

Machine Learning to Predict Outcomes of Endovascular Intervention for Patients With PAD.

Importance: Endovascular intervention for peripheral artery disease (PAD) carries nonnegligible perioperative risks; however, outcome prediction tools are limited. Objective: To develop machine learning (ML) algorithms that can predict outcomes following endovascular intervention for PAD. Design, Setting, and Participants: This prognostic study included patients who underwent endovascular intervention for PAD between January 1, 2004, and July 5, 2023, with 1 year of follow-up. Data were obtained from the Vascular Quality Initiative (VQI), a multicenter registry containing data from vascular surgeons and interventionalists at more than 1000 academic and community hospitals. From an initial cohort of 262 242 patients, 26 565 were excluded due to treatment for acute limb ischemia (n = 14 642) or aneurysmal disease (n = 3456), unreported symptom status (n = 4401) or procedure type (n = 2319), or concurrent bypass (n = 1747). Data were split into training (70%) and test (30%) sets. Exposures: A total of 112 predictive features (75 preoperative [demographic and clinical], 24 intraoperative [procedural], and 13 postoperative [in-hospital course and complications]) from the index hospitalization were identified. Main Outcomes and Measures: Using 10-fold cross-validation, 6 ML models were trained using preoperative features to predict 1-year major adverse limb event (MALE; composite of thrombectomy or thrombolysis, surgical reintervention, or major amputation) or death. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). After selecting the best performing algorithm, additional models were built using intraoperative and postoperative data. Results: Overall, 235 677 patients who underwent endovascular intervention for PAD were included (mean [SD] age, 68.4 [11.1] years; 94 979 [40.3%] female) and 71 683 (30.4%) developed 1-year MALE or death. The best preoperative prediction model was extreme gradient boosting (XGBoost), achieving the following performance metrics: AUROC, 0.94 (95% CI, 0.93-0.95); accuracy, 0.86 (95% CI, 0.85-0.87); sensitivity, 0.87; specificity, 0.85; positive predictive value, 0.85; and negative predictive value, 0.87. In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). The XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs of 0.94 (95% CI, 0.93-0.95) and 0.98 (95% CI, 0.97-0.99), respectively. Conclusions and Relevance: In this prognostic study, ML models were developed that accurately predicted outcomes following endovascular intervention for PAD, which performed better than logistic regression. These algorithms have potential for important utility in guiding perioperative risk-mitigation strategies to prevent adverse outcomes following endovascular intervention for PAD.

Using machine learning to predict outcomes following suprainguinal bypass.

OBJECTIVE: Suprainguinal bypass for peripheral artery disease (PAD) carries important surgical risks; however, outcome prediction tools remain limited. We developed machine learning (ML) algorithms that predict outcomes following suprainguinal bypass. METHODS: The Vascular Quality Initiative database was used to identify patients who underwent suprainguinal bypass for PAD between 2003 and 2023. We identified 100 potential predictor variables from the index hospitalization (68 preoperative [demographic/clinical], 13 intraoperative [procedural], and 19 postoperative [in-hospital course/complications]). The primary outcomes were major adverse limb events (MALE; composite of untreated loss of patency, thrombectomy/thrombolysis, surgical revision, or major amputation) or death at 1 year following suprainguinal bypass. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features (Extreme Gradient Boosting [XGBoost], random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). The best performing algorithm was further trained using intra- and postoperative data. Model robustness was evaluated using calibration plots and Brier scores. Performance was assessed on subgroups based on age, sex, race, ethnicity, rurality, median Area Deprivation Index, symptom status, procedure type, prior intervention for PAD, concurrent interventions, and urgency. RESULTS: Overall, 16,832 patients underwent suprainguinal bypass, and 3136 (18.6%) developed 1-year MALE or death. Patients with 1-year MALE or death were older (mean age, 64.9 vs 63.5 years; P < .001) with more comorbidities, had poorer functional status (65.7% vs 80.9% independent at baseline; P < .001), and were more likely to have chronic limb-threatening ischemia (67.4% vs 47.6%; P < .001) than those without an outcome. Despite being at higher cardiovascular risk, they were less likely to receive acetylsalicylic acid or statins preoperatively and at discharge. Our best performing prediction model at the preoperative stage was XGBoost, achieving an AUROC of 0.92 (95% confidence interval [CI], 0.91-0.93). In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). Our XGBoost model maintained excellent performance at the intra- and postoperative stages, with AUROCs of 0.93 (95% CI, 0.92-0.94) and 0.98 (95% CI, 0.97-0.99), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.12 (preoperative), 0.11 (intraoperative), and 0.10 (postoperative). Of the top 10 predictors, nine were preoperative features including chronic limb-threatening ischemia, previous procedures, comorbidities, and functional status. Model performance remained robust on all subgroup analyses. CONCLUSIONS: We developed ML models that accurately predict outcomes following suprainguinal bypass, performing better than logistic regression. Our algorithms have potential for important utility in guiding perioperative risk mitigation strategies to prevent adverse outcomes following suprainguinal bypass.

Using Machine Learning (XGBoost) to Predict Outcomes After Infrainguinal Bypass for Peripheral Artery Disease.

OBJECTIVE: To develop machine learning (ML) algorithms that predict outcomes after infrainguinal bypass. BACKGROUND: Infrainguinal bypass for peripheral artery disease carries significant surgical risks; however, outcome prediction tools remain limited. METHODS: The Vascular Quality Initiative database was used to identify patients who underwent infrainguinal bypass for peripheral artery disease between 2003 and 2023. We identified 97 potential predictor variables from the index hospitalization [68 preoperative (demographic/clinical), 13 intraoperative (procedural), and 16 postoperative (in-hospital course/complications)]. The primary outcome was 1-year major adverse limb event (composite of surgical revision, thrombectomy/thrombolysis, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained 6 ML models using preoperative features. The primary model evaluation metric was the area under the receiver operating characteristic curve (AUROC). The top-performing algorithm was further trained using intraoperative and postoperative features. Model robustness was evaluated using calibration plots and Brier scores. RESULTS: Overall, 59,784 patients underwent infrainguinal bypass, and 15,942 (26.7%) developed 1-year major adverse limb event/death. The best preoperative prediction model was XGBoost, achieving an AUROC (95% CI) of 0.94 (0.93-0.95). In comparison, logistic regression had an AUROC (95% CI) of 0.61 (0.59-0.63). Our XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs (95% CI's) of 0.94 (0.93-0.95) and 0.96 (0.95-0.97), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.08 (preoperative), 0.07 (intraoperative), and 0.05 (postoperative). CONCLUSIONS: ML models can accurately predict outcomes after infrainguinal bypass, outperforming logistic regression.

Percutaneous versus Cutdown Access for Endovascular Aortic Repair.

BACKGROUND: This study aimed to compare the outcomes of the percutaneous femoral access and open surgical cutdown access approaches in patients undergoing thoracic/abdominal endovascular aortic repair. METHODS: We retrospectively reviewed the medical records of 59 patients who underwent a thoracic/abdominal endovascular aortic repair at a single tertiary care hospital between 2015 and 2022. Based on their femoral access type, the patients were categorized into the "percutaneous" or "cutdown" groups. Using a computerized sheet, relevant patient data (including demographic information and patient risk factors) were collected. The operative duration, complication rates, mortality rates, intensive care unit admission and stay durations, and total hospital stay were compared between the two groups. The primary outcomes were differences in the postoperative morbidity and mortality associated with the two approaches. RESULTS: The cutdown and percutaneous groups comprised 24 (41%) and 35 (59%) patients, respectively. The two groups displayed comparable demographic and clinical characteristics (p > 0.05). However, the vascular anatomy differed with the common femoral artery diameter being larger in the percutaneous group compared to the cutdown group (9.63 ± 1.81 mm vs. 8.49 ± 1.54 mm, p = 0.028). The ratio of the sheath diameter to the common femoral artery diameter was significantly lower in the percutaneous group than in the cutdown group (0.73 ± 0.16 vs. 0.85 ± 0.20, p = 0.027). A ratio of ≥0.74 was associated with a higher risk of complications (odds ratio, 12.0; 95% confidence interval, 1.4-102.2; p = 0.023) and mortality (odds ratio, 5.79; 95% confidence interval, 1.13-29.6; p = 0.035). Additionally, the operative duration was significantly shorter in the percutaneous group than in the cutdown group (141.43 ± 97.05 min vs. 218.46 ± 126.31 min, p = 0.001). Compared to the cutdown group, the percutaneous group experienced a shorter total hospital stay (21.54 ± 21.49 days vs. 11.60 ± 12.09 days, p = 0.022) and lower intensive care unit-admission rates (66.7% vs. 40%, p = 0.044). CONCLUSION: The percutaneous approach is a viable and more time-efficient alternative to the traditional cutdown method for delivering vascular endografts. It is associated with a significantly shorter operative duration and briefer hospital stays. Additionally, the ratio of the sheath diameter to the common femoral artery diameter can help surgeons preoperatively predict and anticipate the risks of complications and mortality. Future in-depth research is necessary to better understand the association between this ratio and postoperative outcomes and complications.

Machine learning to predict outcomes following endovascular abdominal aortic aneurysm repair.

BACKGROUND: Endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) carries important perioperative risks; however, there are no widely used outcome prediction tools. The aim of this study was to apply machine learning (ML) to develop automated algorithms that predict 1-year mortality following EVAR. METHODS: The Vascular Quality Initiative database was used to identify patients who underwent elective EVAR for infrarenal AAA between 2003 and 2023. Input features included 47 preoperative demographic/clinical variables. The primary outcome was 1-year all-cause mortality. Data were split into training (70 per cent) and test (30 per cent) sets. Using 10-fold cross-validation, 6 ML models were trained using preoperative features with logistic regression as the baseline comparator. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. RESULTS: Some 63 655 patients were included. One-year mortality occurred in 3122 (4.9 per cent) patients. The best performing prediction model for 1-year mortality was XGBoost, achieving an AUROC (95 per cent c.i.) of 0.96 (0.95-0.97). Comparatively, logistic regression had an AUROC (95 per cent c.i.) of 0.69 (0.68-0.71). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.04. The top 3 predictive features in the algorithm were 1) unfit for open AAA repair, 2) functional status, and 3) preoperative dialysis. CONCLUSIONS: In this data set, machine learning was able to predict 1-year mortality following EVAR using preoperative data and outperformed standard logistic regression models.

Using machine learning to predict outcomes following open abdominal aortic aneurysm repair.

OBJECTIVE: Prediction of outcomes following open abdominal aortic aneurysm (AAA) repair remains challenging with a lack of widely used tools to guide perioperative management. We developed machine learning (ML) algorithms that predict outcomes following open AAA repair. METHODS: The Vascular Quality Initiative (VQI) database was used to identify patients who underwent elective open AAA repair between 2003 and 2023. Input features included 52 preoperative demographic/clinical variables. All available preoperative variables from VQI were used to maximize predictive performance. The primary outcome was in-hospital major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death). Secondary outcomes were individual components of the primary outcome, other in-hospital complications, and 1-year mortality and any reintervention. We split our data into training (70%) and test (30%) sets. Using 10-fold cross-validation, six ML models were trained using preoperative features (Extreme Gradient Boosting [XGBoost], random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. The top 10 predictive features in our final model were determined based on variable importance scores. Performance was assessed on subgroups based on age, sex, race, ethnicity, rurality, median area deprivation index, proximal clamp site, prior aortic surgery, and concomitant procedures. RESULTS: Overall, 12,027 patients were included. The primary outcome of in-hospital MACE occurred in 630 patients (5.2%). Compared with patients without a primary outcome, those who developed in-hospital MACE were older with more comorbidities, demonstrated poorer functional status, had more complex aneurysms, and were more likely to require concomitant procedures. Our best performing prediction model for in-hospital MACE was XGBoost, achieving an AUROC of 0.93 (95% confidence interval, 0.92-0.94). Comparatively, logistic regression had an AUROC of 0.71 (95% confidence interval, 0.70-0.73). For secondary outcomes, XGBoost achieved AUROCs between 0.84 and 0.94. The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. These findings highlight the excellent predictive performance of the XGBoost model. The top three predictive features in our algorithm for in-hospital MACE following open AAA repair were: (1) coronary artery disease; (2) American Society of Anesthesiologists classification; and (3) proximal clamp site. Model performance remained robust on all subgroup analyses. CONCLUSIONS: Open AAA repair outcomes can be accurately predicted using preoperative data with our ML models, which perform better than logistic regression. Our automated algorithms can help guide risk-mitigation strategies for patients being considered for open AAA repair to improve outcomes.

Venous Ulcers: An Unusual Presentation of Iatrogenic Arteriovenous Fistula Caused by Lumbar Disc Surgery.

Iatrogenic arteriovenous (AV) fistula is a rare complication of lumbar disc surgery. We report a 38-year-old man who presented with bilateral lower limb venous ulcerations and was diagnosed with an AV fistula from previous L4-L5 laminectomy between the right common iliac artery and left common iliac vein, which was successfully treated using an endovascular stent graft.

Unexpected arterial thrombosis and acute limb ischemia in a young male patient with COVID-19: A case report.

Introduction: The spread of severe acute respiratory syndrome coronavirus 2 has resulted in coronavirus disease 2019 (COVID-19) pandemic, raising significant concerns. COVID-19 can lead to thrombotic complications such as acute limb ischemia (ALI). In patients with COVID-19, thrombotic complications may increase the risk of morbidity and mortality. Presentation of case: We report the case of a 37-year-old man who presented with a 2 weeks history of right foot pain, toes blackish discoloration, and numbness. He tested positive for COVID-19 10 days prior to his presentation. Computed tomography angiography (CTA) of the lower limbs revealed near-complete occlusion of the right popliteal artery with single-vessel posterior tibial artery runoff. The patient was brought to a hybrid operating room, and diagnostic angiography confirmed the diagnosis. He underwent popliteal artery thromboembolectomy and intraoperative thrombolysis through a posterior approach. A completion angiography demonstrated a patent popliteal artery with a 2-vessels patency to the foot. His postoperative recovery was uneventful. After surgery, the popliteal, anterior tibial, and posterior tibial arteries were all palpable. The patient was discharged home on antiplatelet therapy with frequent postoperative follow-ups during the last 1 year in our outpatient clinic. Discussion: The frequency of ALI has reduced worldwide, and the hypercoagulable condition remains an infrequent cause of limb ischemia. Patients with COVID-19 have a 35%-45% thromboembolic complication rate. In many studies, the virus launches a second attack between 7 and 14 days after symptom onset, possibly causing hypercoagulability. If conservative treatment fails, various surgical methods, including thromboembolectomy, thrombolysis, and thrombosuction, can be performed to treat ALI. Conclusion: In mild ALI symptoms, unfractionated heparin can be used with vigilant follow-up. Open and endovascular procedures are currently used to treat patients with acute limb ischemia, and technological advancements continue to make interventions easier and safer.

Carotid body tumor encounters over a two-decade period in an academic hospital.

Carotid body tumors (CBTs) are rare and mostly benign. Research outcomes usually arise from single-center data. We conducted this study to present the characteristics and outcomes of patients who underwent surgical resection of CBT at our hospital over the past 20 years. In this retrospective review, the records of CBTs in our hospital were reviewed between 1998 and 2021. All patients who underwent CBT resection were included. The follow-up period was 12 months. A total of 44 CBTs were treated in our hospital. The male-to-female ratio was 1:2.4. Only 4.5% of patients had Shamblin I tumors. Patients with Shamblin II and III tumors were 56.8% and 38.6%, respectively. Duplex scan was used to diagnose CBT in all of the patients. The majority of our patients (97.7%) did not receive any preoperative embolization despite an average tumor size of 4.9 cm. Cranial nerve injuries were observed in 29.5% of cases. Meanwhile, stroke was reported in only two cases (4.5%). No deaths were encountered. Surgery is the definitive treatment for CBT. Size and local extension appear to be the main reasons for adverse events rather than surgical techniques. Our results are consistent with those of previously published studies. Good outcomes are expected in high-volume centers with appropriate preoperative imaging.

Vascular thoracic outlet syndrome: Registry of 30-years of patient's outcomes at King Saud University Medical City, Riyadh, Saudi Arabia.

OBJECTIVES: To outline our experience with both arterial vascular thoracic outlet syndrome (ATOS) and venous TOS (VTOS). METHODS: This was a retrospective review carried out at King Saud University Medical City, Riyadh, Saudi Arabia, from 1992-2022. All patients were diagnosed based on clinical presentation, imaging, and underwent surgical decompression solely via the supraclavicular approach. The median follow-up period was 18 months (range: 4-36 months). RESULTS: A total of 90 limbs were diagnosed with vascular TOS in 69 patients. Females accounted for 69.6% of the patients and approximately 86.7% had ATOS. All patients were symptomatic and underwent plain thoracic inlet and cervical spine radiography, along with duplex scans in both rest and provocative positions. Total cervical rib resection was carried out in 60% of cases, while 2% had partial resection. First rib resection was carried out in 13.3% of cases and combined cervical and first rib resections were carried out in 23.3%. Vascular procedures were needed for arterial repair in 20% of cases, while venous repair were carried out in 2.2%. No recurrence or post-operative mortality had been reported. Post-operative complications were observed in 18.9% of cases. CONCLUSION: Careful patient selection and diagnosis using advanced, but less invasive radiological imaging coupled with adequate surgical treatment can improve the patient's outcome.

A Patient-Tailored Approach to Management of Acute Limb Ischemia in Patients with COVID-19: A Case Series.

BACKGROUND Coronavirus disease 2019 (COVID-19) has a tremendous impact on the respiratory tract. In severe COVID-19 infections, patients may experience shock and multiple organ failure. We described 4 cases of severe arterial thrombosis induced by COVID-19 with and without other stressors and their responses to treatment measures. CASE REPORT In Case 1, a 61-year-old man was hospitalized for COVID-19 pneumonia 2 weeks prior to the presentation of acute upper-limb ischemia after intravenous forearm line insertion. He was classified as IIB and thus underwent emergency thrombectomy followed by 3 months of enoxaparin. Case 2 was a 41-year-old female patient with granulomatosis who was admitted to the Intensive Care Unit due to COVID-19 pneumonia and developed acute upper-limb ischemia. A medical approach using therapeutic heparin was used. Case 3 was a 65-year-old man who was admitted due to COVID-19-related pneumonia and was otherwise medically and surgically free. We assessed and managed a new onset of the lower-limb IIB acute limb ischemia (ALI). Case 4 was a patient with the first COVID-19 presentation of ALI, which was managed accordingly. CONCLUSIONS The development of a thrombotic event in patients with COVID-19 was previously reported. Moreover, different management options and outcomes have been reported in the literature. Therefore, careful planning is needed for procedures such as cannulation or central line insertion to prevent such events. In addition, short-term anticoagulation therapy might be of clinical benefit when planning a procedure or if the patient exhibits minor arterial complications.

Outcomes of abdominal aortic aneurysm repair among patients with rheumatoid arthritis.

OBJECTIVE: In the present study, we compared the outcomes of elective abdominal aortic aneurysm (AAA) repair in patients with and without rheumatoid arthritis (RA) stratified by the type of surgery. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. Linked administrative health data from Ontario, Canada were used to identify all patients aged ≥65 years who had undergone elective open or endovascular AAA repair during the study period. Patients were identified using validated procedure and billing codes and matching using propensity scores. The primary outcome was survival. The secondary outcomes were major adverse cardiovascular events (MACE)-free survival (defined as freedom from death, myocardial infarction, and stroke), reintervention, and secondary rupture. RESULTS: Of 14,816 patients undergoing elective AAA repair, a diagnosis of RA was present for 309 (2.0%). The propensity-matched cohort included 234 pairs of RA and control patients. The matched cohort was followed up for a mean ± standard deviation of 4.93 ± 3.35 years, and the median survival was 6.76 and 7.31 years for the RA and control groups, respectively. Cox regression analysis demonstrated no statistically significant differences in the hazards for death, MACE, reintervention, or secondary rupture. Analysis of the differences in outcomes stratified by repair approach also showed no statistically significant differences in the hazards for death, MACE, reintervention, or secondary rupture. CONCLUSIONS: We found no statistically significant differences in survival, MACE, reintervention, or secondary rupture among patients with RA undergoing elective AAA repair compared with controls. Further studies are required to evaluate the impact of comorbidities and antirheumatic medications on the outcomes of elective AAA repair.

The economic burden of inpatient diabetic foot ulcers in Toronto, Canada.

OBJECTIVE: Diabetic foot ulcer, which often leads to lower limb amputation, is a devastating complication of diabetes that is a major burden on patients and the healthcare system. The main objective of this study is to determine the economic burden of diabetic foot ulcer-related care. METHODS: We conducted a multicenter study of all diabetic foot ulcer patients admitted to general internal medicine wards at seven hospitals in the Greater Toronto Area, Canada from 2010 to 2015, using the GEMINI database. We compared the mean costs of care per patient for diabetic foot ulcer-related admissions, admissions for other diabetes-related complications, and admissions for the top five most costly general internal medicine conditions, using the Ontario Case Costing Initiative. Regression models were used to determine adjusted estimates of cost per patient. Propensity-score matched analyses were performed as sensitivity analyses. RESULTS: Our study cohort comprised of 557 diabetic foot ulcer patients; 2939 non-diabetic foot ulcer diabetes patients; and 23,656 patients with the top 5 most costly general internal medicine conditions. Diabetic foot ulcer admissions incurred the highest mean cost per patient ($22,754) when compared to admissions with non-diabetic foot ulcer diabetes ($8,350) and the top five most costly conditions ($10,169). Using adjusted linear regression, diabetic foot ulcer admissions demonstrated a 49.6% greater mean cost of care than non-diabetic foot ulcer-related diabetes admissions (95% CI 1.14-1.58), and a 25.6% greater mean cost than the top five most costly conditions (95% CI 1.17-1.34). Propensity-scored matched analyses confirmed these results. CONCLUSION: Diabetic foot ulcer patients incur significantly higher costs of care when compared to admissions with non-diabetic foot ulcer-related diabetes patients, and the top five most costly general internal medicine conditions.

Short-term outcomes of combined neuraxial and general anaesthesia versus general anaesthesia alone for elective open abdominal aortic aneurysm repair: retrospective population-based cohort study†.

BACKGROUND: Use of neuraxial anaesthesia for open abdominal aortic aneurysm repair is postulated to reduce mortality and morbidity. This study aimed to determine the 90-day outcomes after elective open abdominal aortic aneurysm repair in patients receiving combined general and neuraxial anaesthesia vs general anaesthesia alone. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. All patients ≥40 yr old undergoing open abdominal aortic aneurysm repair were included. The propensity score was used to construct inverse probability of treatment weighted regression models to assess differences in 90-day outcomes. RESULTS: A total of 10 447 elective open abdominal aortic aneurysm repairs were identified; 9003 (86%) patients received combined general and neuraxial anaesthesia and 1444 (14%) received general anaesthesia alone. Combined anaesthesia was associated with significantly lower hazards for all-cause mortality (hazard ratio [HR]=0.47; 95% confidence interval [CI], 0.37-0.61) and major adverse cardiovascular events (HR=0.72; 95% CI, 0.60-0.86). Combined patients were at lower odds for acute kidney injury (odds ratio [OR]=0.66; 95% CI, 0.49-0.89), respiratory failure (OR=0.41; 95% CI, 0.36-0.47), and limb complications (OR=0.30; 95% CI, 0.25-0.37), with higher odds of being discharged home (OR=1.32; 95% CI, 1.15-1.51). Combined anaesthesia was also associated with significant mechanical ventilation and ICU and hospital length of stay benefits. CONCLUSIONS: Combined general and neuraxial anaesthesia in elective open abdominal aortic aneurysm repair is associated with reduced 90-day mortality and morbidity. Neuraxial anaesthesia should be considered as a routine adjunct to general anaesthesia for elective open abdominal aortic aneurysm repair.

Ultrasound-guided thrombin injections for arterial pseudoaneurysms: a 14-year study conducted at King Khalid University Hospital Vascular Lab.

BACKGROUND: Arterial pseudoaneurysms are a well-known complication resulting from procedures requiring arterial wall puncture. Previously, surgical repair was the definitive treatment option for arterial pseudoaneurysms despite being relatively invasive and time-consuming. Ultrasound-guided thrombin injection (UGTI) has become the standard of care since its initial description back in 1997. We aimed to evaluate the safety and efficacy of UGTI for the treatment of arterial pseudoaneurysms at the King Khalid University Hospital Vascular Lab. METHODS: A retrospective analysis of prospectively maintained data was conducted on all patients diagnosed with arterial pseudoaneurysms by Doppler ultrasound between 2006 and 2019. Patients with large arterial pseudoaneurysms (>1.5 cm) qualified for thrombin injections. Individuals with a known hypersensitive to thrombin were excluded. All included patients were treated with UGTI until resolution and were followed at postoperative days 7 and 30. RESULTS: In all, 35 patients qualified for thrombin injections. The mean age of the included patient population was 56.5 (range, 24-81) years. The majority of them were hypertensive (N.=26, 74.3%), and a quarter of them were on anticoagulant treatment (N.=9, 25%). The mean thrombin injection dose was 1000 U (range, 500-1500 U). In 34 of 35 (97.1%) patients, a thrombin injection resulted in complete thrombosis of the pseudoaneurysm lumen within a few seconds. There were no complications or recurrence of pseudoaneurysm after UGTI during the follow-up period. CONCLUSIONS: Throughout the study period of 14 years, we did not encounter any procedural complications or arterial pseudoaneurysm recurrence. This is attributed to a safe procedural technique and proper patient selection. UGTI for arterial pseudoaneurysms is a safe, successful, and convenient treatment for both patients and surgeons.

Population-based long-term outcomes of open versus endovascular aortic repair of ruptured abdominal aortic aneurysms.

OBJECTIVE: Existing data regarding endovascular aortic repair (EVAR) of ruptured abdominal aortic aneurysm (rAAA) are conflicting in their findings. The purpose of this paper was to determine the long-term outcomes of EVAR vs open surgical repair (OSR) for treatment of rAAA. METHODS: A population-based retrospective cohort study of all patients 40 years or more that underwent OSR or EVAR of rAAA in Ontario, Canada, from 2003 to 2016 was conducted. Administrative data from the province of Ontario was used as the data source. The propensity for repair approach was calculated using a logistic regression model including all covariates and used for inverse probability of treatment weighting. Cox proportional hazards regression was conducted using the weighted cohort to determine the survival and major adverse cardiovascular event (MACE)-free survival of EVAR relative to OSR for rAAA up to 10 years after repair. RESULTS: A total of 2692 rAAA (261 EVAR [10%] and 2431 OSR [90%]) repairs were recorded from April 1, 2003, to March 31, 2016. Mean follow-up for the entire cohort was 3.4 years (standard deviation [SD], 3.9 years), with a maximum follow-up of 14.0 years. OSR patients were followed for a mean of 3.5 years (SD, 4.0 years) and maximum of 14.0 years, and EVAR patients were followed for a mean of 2.7 years (SD, 2.7 years) and a maximum of 11.4 years. Median survival was 2.7 years overall, and 2.5 and 3.7 years for OSR and EVAR patients, respectively. There were no significant baseline differences between EVAR and OSR patients after inverse probability of treatment weighting. EVAR patients were at lower hazard for all-cause mortality (hazard ratio, 0.49; 95% confidence interval, 0.37-0.65; P < .01), and MACE (hazard ratio, 0.51, 95% confidence interval, 0.40-0.66; P < .01) within 30 days of repair. There were no statistically significant differences between EVAR and OSR in the hazard for all-cause mortality or MACE from 30 days to 5 years, and 5 to 10 years. Despite this, the upfront mortality and MACE benefits of EVAR persisted for more than 4.5 years after repair. CONCLUSIONS: This population-based cohort study using administrative data from Ontario, Canada, demonstrated lower hazards for all-cause mortality and MACE within 30 days of operation in favor of EVAR, but no differences in the mid- or longer-term results. More work is needed to understand and improve the long-term outcomes of ruptured endovascular aortic aneurysm repair and ruptured open surgical repair.

A systematic review and meta-analysis of plain versus drug-eluting balloon angioplasty in the treatment of juxta-anastomotic hemodialysis arteriovenous fistula stenosis.

OBJECTIVE: Owing to the lack of comparative evidence between the endovascular technologies for arteriovenous fistula (AVF) stenosis treatments, we sought to summarize the reported data comparing the effectiveness of different endovascular approaches for the treatment of AVF stenoses at the juxta-anastomotic site. METHODS: We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched from inception to June 12, 2018 for observational and randomized studies that had examined the effectiveness of AVF stenosis treatment using plain percutaneous balloon angioplasty (PTA), cutting balloon angioplasty, drug-eluting balloon (DEB) angioplasty, high-pressure balloon angioplasty, and stenting. Bias was assessed using the Newcastle-Ottawa scale for observational studies and the Cochrane Collaboration tool for randomized studies. Article screening, full-text review, assessment of bias, and data collection were conducted in duplicate, with a third reviewer to reconcile any discrepancies. We conducted a qualitative synthesis of the available evidence and a quantitative meta-analysis for the primary assisted patency outcome. The meta-analysis was conducted using Review Manager, version 5.3, using random effects models, with the I2 statistic used to assess heterogeneity. Statistical significance was set at P < .05. RESULTS: Our search yielded 3683 reports. Of these, three randomized trials and three observational studies were included. Three studies with 342 patients had described the effectiveness of high-pressure balloon angioplasty, conventional PTA, and stenting and had analyzed the data qualitatively. Three studies with 141 patients had investigated native AVF patency after DEB angioplasty and conventional PTA and were included in the meta-analysis. DEB angioplasty showed significantly greater primary assisted patency rates at 12 months after treatment compared with PTA (odds ratio, 3.66; 95% confidence interval, 1.32-10.14; I2 = 49%). No statistically significant differences were found in 6-month primary assisted patency among the treatment groups (odds ratio, 2.03; 95% confidence interval, 0.64-6.45; I2 = 50%). A total of 58 of 72 AVFs remained patent 6 months after DEB angioplasty compared with 45 of 69 at 6 months after PTA. At 12 months after treatment, 48 of 72 AVFs remained patent after DEB angioplasty compared with 23 of 69 AVFs after PTA. CONCLUSIONS: Our findings suggest DEB angioplasty is a more effective treatment option for AVF stenosis at the juxta-anastomotic site compared with PTA. Although DEB angioplasty might provide longer term patency than other endovascular treatments, further high-quality data are needed to confirm this finding.