Predicting outcomes following lower extremity open revascularization using machine learning.

Lower extremity open revascularization is a treatment option for peripheral artery disease that carries significant peri-operative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following lower extremity open revascularization. The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent lower extremity open revascularization for chronic atherosclerotic disease between 2011 and 2021. Input features included 37 pre-operative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using tenfold cross-validation, we trained 6 ML models. Overall, 24,309 patients were included. The primary outcome of 30-day MALE or death occurred in 2349 (9.3%) patients. Our best performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve (95% CI) of 0.93 (0.92-0.94). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.08. Our ML algorithm has potential for important utility in guiding risk mitigation strategies for patients being considered for lower extremity open revascularization to improve outcomes.

Predicting Outcomes Following Endovascular Abdominal Aortic Aneurysm Repair Using Machine Learning.

OBJECTIVE: To develop machine learning (ML) models that predict outcomes following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). BACKGROUND: EVAR carries non-negligible perioperative risks; however, there are no widely used outcome prediction tools. METHODS: The National Surgical Quality Improvement Program targeted database was used to identify patients who underwent EVAR for infrarenal AAA between 2011 and 2021. Input features included 36 preoperative variables. The primary outcome was 30-day major adverse cardiovascular event (composite of myocardial infarction, stroke, or death). Data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, 6 ML models were trained using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve. Model robustness was evaluated with calibration plot and Brier score. Subgroup analysis was performed to assess model performance based on age, sex, race, ethnicity, and prior AAA repair. RESULTS: Overall, 16,282 patients were included. The primary outcome of 30-day major adverse cardiovascular event occurred in 390 (2.4%) patients. Our best-performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve (95% CI) of 0.95 (0.94-0.96) compared with logistic regression [0.72 [0.70-0.74)]. The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.06. Model performance remained robust on all subgroup analyses. CONCLUSIONS: Our newer ML models accurately predict 30-day outcomes following EVAR using preoperative data and perform better than logistic regression. Our automated algorithms can guide risk mitigation strategies for patients being considered for EVAR.

Predicting Major Adverse Cardiovascular Events Following Carotid Endarterectomy Using Machine Learning.

Background Carotid endarterectomy (CEA) is a major vascular operation for stroke prevention that carries significant perioperative risks; however, outcome prediction tools remain limited. The authors developed machine learning algorithms to predict outcomes following CEA. Methods and Results The National Surgical Quality Improvement Program targeted vascular database was used to identify patients who underwent CEA between 2011 and 2021. Input features included 36 preoperative demographic/clinical variables. The primary outcome was 30-day major adverse cardiovascular events (composite of stroke, myocardial infarction, or death). The 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 metric for evaluating model performance was area under the receiver operating characteristic curve. Model robustness was evaluated with calibration plot and Brier score. Overall, 38 853 patients underwent CEA during the study period. Thirty-day major adverse cardiovascular events occurred in 1683 (4.3%) patients. The best performing prediction model was XGBoost, achieving an area under the receiver operating characteristic curve of 0.91 (95% CI, 0.90-0.92). In comparison, logistic regression had an area under the receiver operating characteristic curve of 0.62 (95% CI, 0.60-0.64), and existing tools in the literature demonstrate area under the receiver operating characteristic curve values ranging from 0.58 to 0.74. The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.02. The strongest predictive feature in our algorithm was carotid symptom status. Conclusions The machine learning models accurately predicted 30-day outcomes following CEA using preoperative data and performed better than existing tools. They have potential for important utility in guiding risk-mitigation strategies to improve outcomes for patients being considered for CEA.

Biospecimen Repositories in Low- and Middle-Income Countries: Insights From an American University of Beirut and Memorial Sloan Kettering Collaboration.

PURPOSE: Biobanking helps source tissue and blood for studying cancer genomics. Access to biorepository resources in low- and middle-income countries is lacking. Memorial Sloan Kettering Cancer Center (MSK) and the American University of Beirut (AUB) established a joint tissue biorepository at AUB in Beirut, Lebanon. The undertaking encountered key challenges that were unanticipated. MATERIALS AND METHODS: Patients age 18 years or older were eligible for enrollment at AUB. After consent, biospecimens were obtained at the time of routine diagnostic and/or therapeutic interventions. Both normal and abnormal tissue and solid and/or liquid specimens were collected from varied body sites. Early on, declining consent was frequently observed, and this was highlighted for investigation to understand potential participants reasoning. RESULTS: Of 850 patients approached, 704 (70.8%) elected to consent and 293 (29.5%) declined participation. The number of declined consents led to an amendment permitting the documentation of reasons for same. Of 100 potential participants who declined to consent and to whom outreach was undertaken, 63% indicated lack of research awareness and 27% deferral to their primary physician or family member. A financial gain for AUB was cited as concern by 5%, cultural boundaries in 4%, and 1% expressed concern about confidentiality. Of the patients who elected to consent, 682 biospecimens were procured. CONCLUSION: The AUB-MSK biospecimen repository has provided a unique resource for interrogation. Patient participation rate was high, and analyses of those who elected not to consent (29%) provide important insights into educational need and the local and cultural awareness and norms.

Predicting outcomes following open revascularization for aortoiliac occlusive disease using machine learning.

OBJECTIVE: Open surgical treatment options for aortoiliac occlusive disease carry significant perioperative risks; however, outcome prediction tools remain limited. Using machine learning (ML), we developed automated algorithms that predict 30-day outcomes following open aortoiliac revascularization. METHODS: The National Surgical Quality Improvement Program (NSQIP) targeted vascular database was used to identify patients who underwent open aortoiliac revascularization for atherosclerotic disease between 2011 and 2021. Input features included 38 preoperative demographic/clinical variables. The primary outcome was 30-day major adverse limb event (MALE; composite of untreated loss of patency, major reintervention, or major amputation) or death. The 30-day secondary outcomes were individual components of the primary outcome, major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death), individual components of MACE, wound complication, bleeding, other morbidity, non-home discharge, and unplanned readmission. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained six ML models using preoperative features. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. Variable importance scores were calculated to determine the top 10 predictive features. Performance was assessed on subgroups based on age, sex, race, ethnicity, symptom status, procedure type, and urgency. RESULTS: Overall, 9649 patients were included. The primary outcome of 30-day MALE or death occurred in 1021 patients (10.6%). Our best performing prediction model for 30-day MALE or death was XGBoost, achieving an AUROC of 0.95 (95% confidence interval [CI], 0.94-0.96). In comparison, logistic regression had an AUROC of 0.79 (95% CI, 0.77-0.81). For 30-day secondary outcomes, XGBoost achieved AUROCs between 0.87 and 0.97 (untreated loss of patency [0.95], major reintervention [0.88], major amputation [0.96], death [0.97], MACE [0.95], myocardial infarction [0.88], stroke [0.93], wound complication [0.94], bleeding [0.87], other morbidity [0.96], non-home discharge [0.90], and unplanned readmission [0.91]). The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. The strongest predictive feature in our algorithm was chronic limb-threatening ischemia. Model performance remained robust on all subgroup analyses of specific demographic/clinical populations. CONCLUSIONS: Our ML models accurately predict 30-day outcomes following open aortoiliac revascularization using preoperative data, performing better than logistic regression. They have potential for important utility in guiding risk-mitigation strategies for patients being considered for open aortoiliac revascularization to improve outcomes.

General Versus Locoregional Anesthesia in TEVAR: An NSQIP Analysis.

BACKGROUND: Thoracic Endovascular Aortic Repair (TEVAR) is a minimally invasive surgery for repairing thoracic aneurysms and dissections. This study aims to compare postoperative outcomes of TEVAR performed under general versus locoregional anesthesia. METHODS: Utilizing the 2008-2019 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, patients older than the age of 18 years who received TEVAR, were identified using the following current procedural terminology codes: 33,880, 33,881, 33,883, 33,884, or 33,886. Patients who underwent concomitant procedures, those with both thoracoabdominal and abdominal aortic pathologies, and trauma cases were excluded. Standard descriptive statistics, in addition to χ2, Fisher's exact test, and Mann-Whitney U-tests were used to compare patient baseline characteristics and postoperative outcomes between general and locoregional anesthesia groups as appropriate. Univariable and multivariable logistic regression analyses were performed to assess independent predictors of hospital length of stay (LOS) greater than 7 days. RESULTS: Of the 1,028 patients included in the study, 86.5% received general anesthesia, and 13.5% received locoregional anesthesia, such as local anesthesia with monitored anesthesia care or regional anesthesia. No significant differences were found between patients receiving locoregional versus general anesthesia in mortality (3.6% vs. 7.9%, respectively, P = 0.071) and morbidity (18.7% and 24.8%, respectively, P = 0.121) within 30 days post-TEVAR, including any wound, pulmonary, thromboembolic, renal, septic, and cardiac arrest complications. Patients who received general anesthesia had significantly higher median LOS compared to those who received locoregional anesthesia [5 days (interquartile range (IQR): 3-10) versus 4 days (IQR: 2-7), P = 0.002], with 34.3% of the general anesthesia group having an LOS greater than 7 days compared to 21.6% of locoregional anesthesia group, P = 0.003. On multivariable logistic regression analysis, general anesthesia was found to be an independent predictor of prolonged LOS greater than 7 days (odds ratio (OR): 1.72, 95% confidence interval (CI): 1.05-2.81, P = 0.031). CONCLUSIONS: Locoregional anesthesia results in significantly lower postoperative hospital LOS with similar postoperative mortality and morbidity compared to general anesthesia in patients undergoing TEVAR.

Outcomes and Cost-Analysis of Open Versus Endovascular Abdominal Aortic Aneurysm Repair in a Developing Country: A 15-year Experience at a Tertiary Medical Center.

BACKGROUND: Endovascular aortic aneurysm repair (EVAR) has become the most common procedure for treating abdominal aortic aneurysms based on multiple studies conducted in the western world. The implication of such findings in developing countries is not well demonstrated. The objective of this study was to compare medical outcomes and costs of EVAR and open surgical repair (OSR) in a developing country. METHODS: This is a retrospective study of all patients undergoing elective abdominal aortic aneurysm repair between 2005 and 2020 at a tertiary medical center in a developing country. Medical records were used to retrieve demographics, comorbidities, and perioperative complications. Medical records were also used to provide data on the need of reintervention, date of last follow-up, and mortality. RESULTS: The study included a total of 164 patients. Median follow-up time was 41 months. The mean age was 69.9 +/- 7.84 years and 90.24% (n = 148) of patients were males. Regarding long-term mortality outcomes, no significant difference was detected between both groups; OSR patients had a survival rate of 91.38% and 74.86% at 5 and 10 years, compared to 77.29% and 56.52% in the EVAR group (P value = 0.10). Both groups had comparable long-term reintervention rates (P value = 0.334). The OSR group was charged significantly less than the EVAR group ($27,666.35 vs. $44,528.04, P value = 0.008). CONCLUSIONS: OSR and EVAR have comparable survival and reintervention outcomes. Unlike what was reported in developed countries, patients undergoing OSR in countries with low hospital stay costs incur lower treatment costs.

Lower limb amputation following venous cannulation for VA-ECMO: a case report.

Lower limb amputation following arterial cannulation for VA-ECMO has been described in the literature. Limb ischemia however following venous cannulation is very rare and not quite understood. We present a case of limb ischemia following venous cannulation. A combination of venous congestion, compartment syndrome and subsequent arterial insufficiency is the proposed pathophysiology. Shock and use of vasopressors are compounding factors. Limb ischemia can be transient and reversible if diagnosed immediately and treated by early removal of the cannula. Our patient was unstable and ECMO dependent, and removal of the cannula was not an option. This resulted in limb loss and eventual above knee amputation. Use of the smallest appropriate venous cannula and early fasciotomy, in addition to hemodynamic optimization are measures that could help in preventing major amputation.

Thromboembolectomy for acute lower limb ischemia: Contemporary outcomes of two surgical methods from a single tertiary center.

OBJECTIVES: The current treatment of acute lower limb ischemia (ALLI) includes open surgical and percutaneous pharmaco-mechanical thromboembolectomy (TE). We hereby report our results with open surgical TE over a 10-year period and compare our outcomes using routine fluoroscopic assisted TE (FATE) with blind and selective on demand fluoroscopic-assisted TE (BSTE). METHODS: This is a retrospective analysis of all patients who underwent open surgical TE for acute lower limb ischemia at a single tertiary center between 2008 and 2018. Patients were divided into a group who underwent BSTE and another who underwent routine FATE. Data on presentation, medical history, surgery performed, and short-term outcomes were retrieved from medical record. Comparison between baseline characteristics and outcomes of both groups were made using t-test and chi-square analysis. RESULTS: Over 10 years, 108 patients underwent surgical TE. Thirty-day mortality rate and 30-day major lower extremity amputation rate in the cohort were 12.0% and 6.5%, respectively. On subgroup analysis, 53 patients were treated by BSTE and 55 patients by FATE. There was no significant difference in 30-day mortality rate (11.3% vs 12.7%, p-value = .82) and 30-day major amputation rate (9.4% vs 3.6%, p-value = .454) between the two groups. Local anesthesia was more frequently performed in patients undergoing FATE (58.2% vs 24.5%, p-value < .001). More than one arteriotomy was more frequently required in patients undergoing BSTE (2.6% vs 45.5%, p-value < .001). Patients with infrapopliteal involvement undergoing FATE required less further interventions such as patch angioplasty (2.6% vs 36.4%, p-value < .001) and bypass (2.6% vs 22.7%, p-value = .01). CONCLUSION: ALLI remains a disease of high morbidity and mortality. Open surgical TE offers an effective approach to treat ALLI. The addition of fluoroscopy to the conduction of TE could be associated with valuable benefits, especially in patients with infra-popliteal involvement. Randomized controlled trials are needed to objectively assess the therapeutic potential of FATE.

Isolated Superior Mesenteric Artery Dissection: A Novel Etiology and a Review.

Isolated superior mesenteric artery dissection (ISMAD) is a rare pathology with multifactorial etiology. The aim of this article is to provide a narrative review of the latest literature about ISMAD. Case reports, series, and recent meta-analyses were included. This review is introduced with a brief case report of a rare etiology of ISMAD, followed by a discussion of its etiology, clinical presentation, diagnosis, classification, and treatment, and we report a new cause of ISMAD, that is, blunt abdominal trauma. The etiology of ISMAD is multifactorial, consisting of anatomic, genetic, and systemic components. ISMAD is more common among middle-aged males and in East Asia. Its clinical presentation ranges from asymptomatic to mesenteric ischemia, albeit mortality remains <1%. It is diagnosed and classified mostly by computed tomography angiography, and there are five classification systems for ISMAD, though traumatic etiology may be added. The treatment of ISMAD is mostly conservative, with a success rate exceeding 90%. Endovascular stenting is second line, reserved so far for failed medical management, though its role is expanding to include earlier management of symptomatic patients, while open surgical repair is left for acute mesenteric ischemia with bowel compromise.

Face-to-face versus distance learning of basic suturing skills in novice learners: a quantitative prospective randomized trial.

BACKGROUND AND AIM: Traditionally, practical skills are taught on face-to-face (F-F) basis. COVID-19 pandemic brought distance learning (DL) to the spotlight because of the social distancing mandates. We sought to determine the acceptability and effectiveness of DL of basic suturing in novice learners. METHODS: A prospective randomized controlled trial involving 118 students was conducted. Participants were randomized into two groups for learning simple interrupted suturing: F-F and DL-groups. Evaluation was conducted by two assessors using a performance checklist and a global rating tool. Agreement between the assessors was calculated, and performance scores of the participants were compared. Participants' satisfaction was assessed via a questionnaire. RESULTS: Fifty-nine students were randomized to the F-F group and 59 to the DL-group. Satisfactory agreement between the assessors was demonstrated. All participants were successful in placing three interrupted sutures, with no significant difference in the performance between the groups. 25(44.6%) of the respondents in the DL-group provided negative comments related to the difficulties of remotely learning visuospatial concepts, 16(28.5%) preferred the F-F approach. CONCLUSION: DL of basic suturing is as effective as the F-F approach in novice learners. It is acceptable by the students despite the challenges related to the remote learning of practical skills.

Incidence and Predictors of Surgical Site Infection Complications in Diabetic Patients Undergoing Lower Limb Amputation.

BACKGROUND: Surgical site infections (SSIs) following lower extremity amputations (LEAs) are a major cause of patient morbidity and mortality. The objectives of this study are to investigate the annual incidence of SSI and risk factors associated with SSI after LEA in diabetic patients. METHODS: LEAs performed on diabetic patients between 2005 and 2017 were retrospectively analyzed from the American College of Surgeons National Surgical Quality Improvement Program database. Incidence rates were calculated and analyzed for temporal change. Multivariable logistic regression was conducted to identify the independent predictors of SSIs in LEA. RESULTS: In 21,449 diabetic patients, the incidence of SSIs was 6.8% after LEA, with an overall decreasing annual trend (P = 0.013). Amputation location (below-knee in reference to above-knee) [OR (95% CI): 1.35 (1.20 - 1.53), P <0.001], smoking [OR (95% CI): 1.25 (1.11 - 1.41), P <0.001)], female sex [OR (95% CI): 1.16 (1.03 - 1.30)], preoperative sepsis [OR (95% CI): 1.24 (1.10 - 1.40), P <0.001], P = 0.013], emergency status [OR (95% CI): 1.38 (1.17 - 1.63), P <0.001], and obesity [OR (95% CI): 1.59 (1.12 - 2.27), P = 0.009] emerged as independent predictors of SSIs, while moderate/severe anemia emerged as a risk-adjusted protective factor [OR (95% CI): 0.75 (0.62 - 0.91), P = 0.003]. Sensitivity analysis found that moderate/severe anemia, not body mass index (BMI) class, remained a significant risk factor in the development of SSIs in below-the-knee amputations; in contrast, higher BMI, not preoperative hematocrit, was significantly associated with an increased risk for SSI in above-the-knee amputations. CONCLUSIONS: The incidence of SSIs after LEA in diabetic patients is decreasing. Overall, below-knee amputation, smoking, emergency status, and preoperative sepsis appeared to be associated with SSIs. Obesity increased SSIs in above-the-knee amputations, while moderate/severe preoperative anemia appears to protect against below-the-knee SSIs. Surgeons should take predictors of SSI into consideration while optimizing care for their patients, and future studies should investigate the role of preoperative hematocrit correction and how it may influence outcomes positively or negatively.

The Beirut Port Explosion Injuries and Lessons Learned: Results of the Beirut Blast Assessment for Surgical Services (BASS) Multicenter Study.

OBJECTIVE: This multicenter study aims to describe the injury patterns, emergency management and outcomes of the blast victims, recognize the gaps in hospital disaster preparedness, and identify lessons to be learned. SUMMARY BACKGROUND DATA: On August 4th, 2020, the city of Beirut, Lebanon suffered the largest urban explosion since Hiroshima and Nagasaki, resulting in hundreds of deaths and thousands of injuries. METHODS: All injured patients admitted to four of the largest Beirut hospitals within 72 hours of the blast, including those who died on arrival or in the emergency department (ED), were included. Medical records were systematically reviewed for: patient demographics and comorbidities; injury severity and characteristics; prehospital, ED, operative, and inpatient interventions; and outcomes at hospital discharge. Lessons learned are also shared. RESULTS: An estimated total of 1818 patients were included, of which 30 died on arrival or in the ED and 315 were admitted to the hospital. Among admitted patients, the mean age was 44.7 years (range: 1 week-93 years), 44.4% were female, and the median injury severity score (ISS) was 10 (5, 17). ISS was inversely related to the distance from the blast epicenter (r = --0.18, P = 0.035). Most injuries involved the upper extremities (53.7%), face (42.2%), and head (40.3%). Mildly injured (ISS <9) patients overwhelmed the ED in the first 2 hours; from hour 2 to hour 8 post-injury, the number of moderately, severely, and profoundly injured patients increased by 127%, 25% and 17%, respectively. A total of 475 operative procedures were performed in 239 patients, most commonly soft tissue debridement or repair (119 patients, 49.8%), limb fracture fixation (107, 44.8%), and tendon repair (56, 23.4%). A total of 11 patients (3.5%) died during the hospitalization, 56 (17.8%) developed at least 1 complication, and 51 (16.2%) were discharged with documented long-term disability. Main lessons learned included: the importance of having key hospital functions (eg, laboratory, operating room) underground; the nonadaptability of electronic medical records to disasters; the ED overwhelming with mild injuries, delay in arrival of the severely injured; and the need for realistic disaster drills. CONCLUSIONS: We, therefore, describe the injury patterns, emergency flow and trauma outcome of patients injured in the Beirut port explosion. The clinical and system-level lessons learned can help prepare for the next disaster.

Hypoalbuminemia is Associated with Mortality in Patients Undergoing Lower Extremity Amputation.

BACKGROUND: Poor nutritional status is common among patients undergoing lower extremity amputation (LEA). In this study, the association between preoperative hypoalbuminemia, a marker for malnutrition, and postoperative mortality in patients undergoing LEA was explored. METHODS: Data on patients undergoing LEA between 2005 and 2017 were retrospectively analyzed from the prospectively collected American College of Surgeons National Surgical Quality Improvement Program database. Patients were divided into clinically relevant categories based on their serum albumin level (<2.5, 2.5-3.39, ≥3.4 g/dl) and were further stratified according to amputation level. Operative death was compared across groups and multivariable logistic regression was performed to estimate risk-adjusted odds ratio (AOR). RESULTS: In 35,383 patients, the rate of 30-day postoperative mortality was 7.6% (n = 2693). Mortality rate was highest in patients with very low albumin levels (11%) as compared to low (6.8%) and normal levels (3.9%). On multivariable analysis, lower albumin levels emerged as a risk-adjusted independent predictor of mortality. After risk-adjustment, patients with very low albumin levels (AOR [95% CI]: 2.25 [1.969-2.56], P < 0.001) and low albumin levels (AOR [95% CI]: 1.42 [1.239-1.616], P < 0.001) had higher odds of mortality when compared to patients with normal albumin levels. On sensitivity analysis, a similar trend was seen in patients undergoing above knee amputation but not in patients undergoing minor amputations. CONCLUSIONS: In patients undergoing major LEA, hypoalbuminemia is associated with an increased risk of postoperative mortality in a dose response manner, specifically in above knee amputations. Monitoring and optimizing patients' nutritional status before surgery, when possible, may be warranted and should be further explored.

Position Paper on Young Vascular Surgeons Training of the Mediterranean Federation for the Advancing of Vascular Surgery (MeFAVS): State of the Art and Perspectives.

The Mediterranean Federation for the Advancing of Vascular Surgery (MeFAVS) was founded in 2018, with the aim to promote cooperation among vascular professionals within Mediterranean countries. Due to its prominent social and economic impact on national health systems, diabetic peripheral artery was selected as the very first topic to be investigated by the federation. In this second paper, different experiences from delegates of participating countries were shared to define common strategies to harmonize, standardize, and optimize education and training in the Vascular Surgery specialty.

Citrobacter koseri Surgical Site Infection after Femoropopliteal Vein Bypass for Popliteal Artery Aneurysm Treated with a Graft Preserving Strategy.

Background: A 69-year-old man underwent ligation and evacuation of a popliteal artery aneurysm with a femoral-to-popliteal vein bypass. He had a history of Citrobacter koseri prostatitis two months prior to the surgery. One month postoperatively, he presented with extremity swelling, redness, and fluid collections around the graft. Methods: A graft preserving strategy was adopted. The patient underwent operative drainage, washing, and received long-term antibiotic therapy. Fluid culture grew Citrobacter koseri, previously not reported as cause of surgical site infection with infrainguinal graft involvement. Results: The infection was treated successfully, and the patient is remains symptom free 18 months post-operatively. Conclusions: This case highlights the importance of considering culturing the aneurysm content in the presence of infectious history.

Mass casualty management during a pandemic surge: The American University of Beirut Medical Center experience.

Mass casualty incidents can be devastating events associated with a large number of fatalities, morbidities, and long-lasting sequelae. The negative outcomes can be further amplified if the incident occurred during a pandemic surge, such as what occurred in Beirut, Lebanon with the August 4, 2020 Beirut Port explosion. To decrease the mortality and morbidity and avoid inefficiency, management depends on having an established coordinated multidisciplinary approach from transport and triage to emergency department care and in-hospital management. In this article, the mass casualty management and the impact of the coronavirus disease 2019 pandemic will be discussed based on the American University of Beirut Medical Center experience.

Performance of the AUB-HAS2 Cardiovascular Risk Index in vascular surgery patients.

The American University of Beirut (AUB)-HAS2 risk index is a recently published tool for preoperative cardiovascular evaluation. It is based on six data elements: history of Heart disease, symptoms of Heart disease (angina or dyspnea), Age ⩾ 75 years, Anemia (hemoglobin < 12 mg/dL), emergency Surgery, and vascular Surgery. This study analyzes the performance of a modified AUB-HAS2 index (excluding the vascular surgery element) in a broad spectrum of vascular surgery procedures. The study population consisted of 90,476 vascular surgeries registered in the American College of Surgeons National Surgical Quality Improvement Program database. The performance of the AUB-HAS2 index was studied in seven groups: carotid endarterectomy (CEA), open abdominal aortic aneurysm surgical repair (OAAA), endovascular aortic aneurysm repair, supra-inguinal bypass, infra-inguinal bypass, lower extremity thrombo-endarterectomy, and lower extremity angioplasty. The outcome measure was death, myocardial infarction, or stroke at 30 days after surgery. Each patient was given an AUB-HAS2 score of 0, 1, 2, or > 2 depending on the number of data elements s/he has. The AUB-HAS2 index was able to stratify risk in the majority of patients into low (< 3%, score 0), intermediate (3-10%, score 1-2), and high (> 10%, score > 2) (p < 0.0001). The receiver operating curve had an area of 0.71 in the overall group and it ranged from 0.60 in CEA patients to 0.75 in OAAA patients. In conclusion, the AUB-HAS2 index is a simple tool that can quickly and effectively stratify the risk of patients undergoing a broad spectrum of vascular surgeries into low, intermediate, and high.