A primer on cohort studies in vascular surgery research.

Vascular research questions can be answered using various study designs. Observational studies are used frequently to address a wide range of clinical questions when randomized clinical trials are not feasible or practical. One of the powerful vascular research tools is the cohort study. The cohort study is a reliable observational study design in which individuals who share a common characteristic (a cohort) are followed over time and their outcomes are assessed at various intervals. This review focuses on the essential characteristics, design, implementation, bias, validity, and clinical significance of cohort studies and provides illustrative examples. A cohort study can be either a prospective or a retrospective study, depending on whether the outcome occurred before or after the enrollment of the cohort. Each type has its advantages and disadvantages. Confounding, selection, and information biases can all occur in cohort studies. Applications of the cohort study design include studying the natural history of a disease, describing a condition's frequency, and investigating multiple outcomes simultaneously.

Society for Vascular Surgery appropriate use criteria for management of intermittent claudication.

The Society for Vascular Surgery appropriate use criteria (AUC) for the management of intermittent claudication were created using the RAND appropriateness method, a validated and standardized method that combines the best available evidence from medical literature with expert opinion, using a modified Delphi process. These criteria serve as a framework on which individualized patient and clinician shared decision-making can grow. These criteria are not absolute. AUC should not be interpreted as a requirement to administer treatments rated as appropriate (benefit outweighs risk). Nor should AUC be interpreted as a prohibition of treatments rated as inappropriate (risk outweighs benefit). Clinical situations will occur in which moderating factors, not included in these AUC, will shift the appropriateness level of a treatment for an individual patient. Proper implementation of AUC requires a description of those moderating patient factors. For scenarios with an indeterminate rating, clinician judgement combined with the best available evidence should determine the treatment strategy. These scenarios require mechanisms to track the treatment decisions and outcomes. AUC should be revisited periodically to ensure that they remain relevant. The panelists rated 2280 unique scenarios for the treatment of intermittent claudication (IC) in the aortoiliac, common femoral, and femoropopliteal segments in the round 2 rating. Of these, only nine (0.4%) showed a disagreement using the interpercentile range adjusted for symmetry formula, indicating an exceptionally high degree of consensus among the panelists. Post hoc, the term "inappropriate" was replaced with the phrase "risk outweighs benefit." The term "appropriate" was also replaced with "benefit outweighs risk." The key principles for the management of IC reflected within these AUC are as follows. First, exercise therapy is the preferred initial management strategy for all patients with IC. Second, for patients who have not completed exercise therapy, invasive therapy might provide net a benefit for selected patients with IC who are nonsmokers, are taking optimal medical therapy, are considered to have a low physiologic and technical risk, and who are experiencing severe lifestyle limitations and/or a short walking distance. Third, considering the long-term durability of the currently available technology, invasive interventions for femoropopliteal disease should be reserved for patients with severe lifestyle limitations and a short walking distance. Fourth, in the common femoral segment, open common femoral endarterectomy will provide greater net benefit than endovascular intervention for the treatment of IC. Finally, in the infrapopliteal segment, invasive intervention for the treatment of IC is of unclear benefit and could be harmful.

Frail patients having vascular surgery during the early COVID-19 pandemic experienced high rates of adverse perioperative events and amputation.

BACKGROUND: Frailty predicts adverse perioperative outcomes and increased mortality in patients having vascular surgery. Frailty assessment is a potential tool to inform resource allocation, and shared decision-making about vascular surgery in the resource constrained COVID-19 pandemic environment. This cohort study describes the prevalence of frailty in patients having vascular surgery and the association between frailty, mortality and perioperative outcomes. METHODS: The COVID-19 Vascular Service in Australia (COVER-AU) prospective cohort study evaluates 30-day and six-month outcomes for consecutive patients having vascular surgery in 11 Australian vascular units, March-July 2020. The primary outcome was mortality, with secondary outcomes procedure-related outcomes and hospital utilization. Frailty was assessed using the nine-point visual Clinical Frailty Score, scores of 5 or more considered frail. RESULTS: Of the 917 patients enrolled, 203 were frail (22.1%). The 30 day and 6 month mortality was 2.0% (n = 20) and 5.9% (n = 35) respectively with no significant difference between frail and non-frail patients (OR 1.68, 95%CI 0.79-3.54). However, frail patients stayed longer in hospital, had more perioperative complications, and were more likely to be readmitted or have a reoperation when compared to non-frail patients. At 6 months, frail patients had twice the odds of major amputation compared to non-frail patients, after adjustment (OR 2.01; 95% CI 1.17-3.78), driven by a high rate of amputation during the period of reduced surgical activity. CONCLUSION: Our findings highlight that older, frail patients, experience potentially preventable adverse outcomes and there is a need for targeted interventions to optimize care, especially in times of healthcare stress.

Clinical and Economic Impact of COVID-19 in Vascular Surgery at a Tertiary University "Hub" Hospital of Italy.

BACKGROUND: Since the first cases of a novel respiratory disease were reported in December 2019, coronavirus disease (COVID-19) Emergency State (Cov-ES) caused a worldwide outbreak requiring a complete reorganization of the healthcare system and new management of its personnel; aim of this study was to analyze the clinical and financial impact of Cov-ES in the Department of Vascular Surgery at a Tertiary University "Hub" Hospital in northeast Italy. METHODS: Differences in clinical practice according to Diagnostic Related Group (DRG) and International Statistical Classification of Diseases (ICD) and Related Health Problems and the financial impact of Cov-ES were considered. Vascular procedures performed between March 2019 and December 2019 (Prepandemic) were compared to those performed in the period March-December 2020 (Pandemic). Prepandemic and pandemic reimbursements of all vascular activities and the top 3 vascular diagnoses were evaluated. RESULTS: Prepandemic versus pandemic era documented a decrease of vascular consultations performed (2,882 vs. 2,270, -21.2%). The number of total vascular procedures decreased from 997 to 797 (-20.1%) with a higher reduction observed in outpatient surgical activities (247 to 136, -45.0%, P = 0.0005) rather than inpatient surgical activities (750 vs. 661, 11.9%, P = 0.02). Length of hospital stay (LOS) increased from 3.3 ± 2.7 days in prepandemic to 5.3 ± 3.9 in the pandemic era (P = 0.004). Among patients with limb-threatening ischemia, the rate of major limb amputation was higher in the pandemic (3.3% vs. 5.4%, respectively, P = 0.02), and a higher rate of elective hospitalization procedures was performed as urgent/emerging setting after clinical deterioration (2.8 % vs. 6.4%, P = 0.0002). According to DRG classification, an increase of "complicated" limb-threatening ischemia (DRG 554) and aortic aneurysm (DRG 110) was observed prepandemic to pandemic (+84.2% and +25.0%, respectively). Total reimbursement for vascular activities between pandemic versus prepandemic was 4,646,108€ vs. 5,054,398€, respectively (-8.0%). Management of "complicated" limb-threatening ischemia (DRG 554) and aortic aneurysm (DRG 110) required a higher clinical and financial support that was translated into higher economic reimbursement during the pandemic (273,035€ vs. 150,005€, +82.0% and 749,250€ vs. 603,680€, +24.1%, respectively). CONCLUSIONS: During the pandemic, the main resources were employed for the treatment of limb-threatening ischemia, aortic aneurysm, and carotid stenosis. Inpatient activities documented an increase in major limb amputation and LOS. An increased reimbursement for each vascular procedure and for all "complicated" diagnoses revealed that the more serious and resource-demanding pathology occurred in this period.

Impact of COVID-19 on vascular patients worldwide: analysis of the COVIDSurg data.

BACKGROUND: The COVIDSurg collaborative was an international multicenter prospective analysis of perioperative data from 235 hospitals in 24 countries. It found that perioperative COVID-19 infection was associated with a mortality rate of 24%. At the same time, the COVER study demonstrated similarly high perioperative mortality rates in vascular surgical patients undergoing vascular interventions even without COVID-19, likely associated with the high burden of comorbidity associated with vascular patients. This is a vascular subgroup analysis of the COVIDSurg cohort. METHODS: All patients with a suspected or confirmed diagnosis of COVID-19 in the 7 days prior to, or in the 30 days following a vascular procedure were included. The primary outcome was 30-day mortality. Secondary outcomes were pulmonary complications (adult respiratory distress syndrome, pulmonary embolism, pneumonia and respiratory failure). Logistic regression was undertaken for dichotomous outcomes. RESULTS: Overall, 602 patients were included in this subgroup analysis, of which 88.4% were emergencies. The most common operations performed were for vascular-related dialysis access procedures (20.1%, N.=121). The combined 30-day mortality rate was 27.2%. Composite secondary pulmonary outcomes occurred in half of the vascular patients (N.=275, 45.7%). CONCLUSIONS: Mortality following vascular surgery in COVID positive patients was significantly higher than levels reported pre-pandemic, and similar to that seen in other specialties in the COVIDSurg cohort. Initiatives and surgical pathways that ensure vascular patients are protected from exposure to COVID-19 in the peri-operative period are vital to protect against excess mortality.

Managing Emergent Surgery for Ruptured Abdominal Aortic Aneurysm during the COVID-19 Pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has become a global pandemic which may compromise the management of vascular emergencies. An uncompromised treatment for ruptured abdominal aortic aneurysm (rAAA) during such a health crisis represents a challenge. This study aimed to demonstrate the treatment outcomes of rAAA and the perioperative prevention of cross-infection under the COVID-19 pandemic. METHODS: In cases of rAAA during the pandemic, a perioperative workflow was applied to expedite coronavirus testing and avoid pre-operative delay, combined with a strategy for preventing cross-infection. Data of rAAA treated in 11 vascular centers between January-March 2020 collected retrospectively were compared to the corresponding period in 2018 and 2019. RESULTS: Eight, 12, and 14 rAAA patients were treated in 11 centers in January-March 2018, 2019, and 2020, respectively. An increased portion were treated at local hospitals with a comparable outcome compared with large centers in Guangzhou. With EVAR-first strategy, 85.7% patients with rAAA in 2020 underwent endovascular repair, similar to that in 2018 and 2019. The surgical outcomes during the pandemic were not inferior to that in 2018 and 2019. The average length of ICU stay was 1.8 ± 3.4 days in 2020, tending to be shorter than that in 2018 and 2019, whereas the length of hospital stay was similar among 3 years. The in-hospital mortality of 2018, 2019, and 2020 was 37.5%, 25.0%, and 14.3%, respectively. Three patients undergoing emergent surgeries were suspected of COVID-19, though turned out to be negative after surgery. CONCLUSIONS: Our experience for emergency management of rAAA and infection prevention for healthcare providers is effective in optimizing emergent surgical outcomes during the COVID-19 pandemic.

COVID-19 and aortic disease: a practical systematic review of the literature on management and outcomes.

INTRODUCTION: Since the outbreak of the 2019 coronavirus (COVID-19), vascular specialists have faced dramatic changes in clinical and surgical practice. Although COVID-19 pulmonary signs and symptoms were the most pertinent problems initially, in the long term, cardiovascular complications became the most fearsome, with poor outcomes in terms of morbidity and mortality. Algorithms and decision-making procedures have been modified, not only to treat new clinical findings in COVID-19 positive patients, but also to avoid complications related to pulmonary and systemic infections. Additionally, COVID-19-negative patients experienced challenging management, due to hospital crowding, the risk of nosocomial COVID-19 transmission, and pandemic emergencies. In this context, aortic interventions were subject to several difficulties. First, in COVID-19-positive patients, there was the onset of new pathological scenarios including thrombotic manifestations and the subsequent complications. Second, in both COVID-19-negative and positive patients, there was a need to deliver optimal treatment with acceptable perioperative risks, forcing a rethinking of decision-making especially in terms of indications for treatments. The aim of this systematic review is to present evidence published on COVID-19 and aortic-related issues, highlighting some challenging aspects regarding management, treatment and outcomes. EVIDENCE ACQUISITION: Data search was performed on PubMed, Scopus and Web of Science, using as time range "January 1st, 2000 - May 1st, 2021." Only articles in English language were included. Key words used for the query were "Aorta" AND "COVID-19" OR "SARS-CoV-2." Furthermore, the NCBI database of "SARS-CoV-2 Resources" was interrogated to find further relevant studies. EVIDENCE SYNTHESIS: The search retrieved 416 papers; among these, 46 studies were eligible and reviewed in depth. The published literature suggests the existence of a hypercoagulable state in patients with COVID-19 disease occurring via direct and indirect mechanisms. COVID-19 infection seems to promote a prothrombotic status that aggravates vascular disease. Regardless of clinical laboratory or status, active COVID-19 infection is considered a risk factor for poor vascular surgery outcomes. Specifically, it is associated with a fourfold increased risk of death and a threefold increased risk of major adverse events. Prognosis of patients hospitalized with COVID-19 disease is often determined by the extent of pulmonary disease, although vascular complications also greatly affect outcomes. Nevertheless, although COVID­19 is highly morbid, in high­risk operations good outcomes can still be achieved even in elderly patients with COVID­19. CONCLUSIONS: In the case of aortic disease during active COVID-19 infection, poor outcomes are associated with COVID-19 vascular and non-vascular complications, while for COVID-19-negative patients not much changed in terms of outcomes, despite the difficulties in management. Endovascular repair, when possible, minimized the impact of treatment, reducing the risk of COVID-related postoperative complications or acquired infection in negative patients.

COVID-19 and acute limb ischemia: a systematic review.

INTRODUCTION: The main goal of this systematic review was to analyze the outcomes of acute limb ischemia (ALI) in patients suffering from the novel Coronavirus: COVID-19 (SARS-CoV-2). EVIDENCE ACQUISITION: A systematic review on Medline and Embase was conducted up to May 15, 2021. All papers were sorted by abstract and full text by two independent authors. Systematic reviews, commentaries, and studies that did not distinguish status of COVID-19 infection were excluded from review. Patient demographics were recorded along with modality of treatment (endovascular and/or surgical). We analyzed 30-day outcomes, including mortality. Primary outcome was to evaluate clinical characteristic of ALI in patients affected by SARS-CoV-2 in term of location of ischemia, treatment options and 30-day outcomes. EVINDENCE SYNTHESIS: We selected 36 articles with a total of 194 patients. Most patients were male (80%) with a median age of 60 years old. The treatment most used was thromboembolectomy (31% of all surgical interventions). A total of 32 patients (19%) were not submitted to revascularization due to critical status. The rate of technical success was low (68%), and mortality rate was high (35%). CONCLUSIONS: This review confirms that SARS-CoV-2 is associated with a high risk of ALI. Further studies are needed to investigate the association and elucidate potential mechanisms, which may include a hypercoagulable state and hyperactivation of the immune response. Furthermore, management of ALI is not standardized and depends on patient condition and extension of the thrombosed segment. ALI in COVID-19 patients is associated with high risk of failure of revascularization and perioperative mortality.

Outcomes After Vascular Surgery Procedures in Patients with COVID-19 Infection: A National Multicenter Cohort Study (COVID-VAS).

OBJECTIVES: To analyze the outcome of vascular procedures performed in patients with COVID-19 infection during the 2020 pandemic. METHODS: This is a multicenter, prospective observational cohort study. We analyzed data from 75 patients with COVID-19 infection undergoing vascular surgery procedures in 17 hospitals across Spain and Andorra between March and May 2020. The primary end point was 30-day mortality. Clinical Trials registry number NCT04333693. RESULTS: The mean age was 70.9 (45-94) and 58 (77.0%) patients were male. Around 70.7% had postoperative complications, 36.0% of patients experienced respiratory failure, 22.7% acute renal failure, and 22.7% acute respiratory distress syndrome (ARDS). All-cause 30-days mortality rate was 37.3%. Multivariate analysis identified age >65 years (P = 0.009), American Society of Anesthesiologists (ASA) classification IV (P = 0.004), preoperative lymphocyte count <0.6 (×109/L) (P = 0.001) and lactate dehydrogenase (LDH) >500 (UI/L) (P = 0.004), need for invasive ventilation (P = 0.043), postoperative acute renal failure (P = 0.001), ARDS (P = 0.003) and major amputation (P = 0.009) as independent variables associated with mortality. Preoperative coma (P = 0.001), quick Sepsis Related Organ Failure Assessment (qSOFA) score ≥2 (P = 0.043), lymphocytes <0.6 (×109/L) (P = 0.019) leucocytes >11.5 (×109/L) (P = 0.007) and serum ferritin >1800 mg/dL (P = 0.004), bilateral lung infiltrates on thorax computed tomography (P = 0.025), and postoperative acute renal failure (P = 0.009) increased the risk of postoperative ARDS. qSOFA score ≥2 was the only risk factor associated with postoperative sepsis (P = 0.041). CONCLUSIONS: Patients with COVID-19 infection undergoing vascular surgery procedures showed poor 30-days survival. Age >65 years, preoperative lymphocytes <0.6 (x109/L) and LDH >500 (UI/L), and postoperative acute renal failure, ARDS and need for major amputation were identified as prognostic factors of 30-days mortality.

Dissecting the Management and Outcomes of Thoracic Aortovascular Disease During the COVID-19 Pandemic.

OBJECTIVE: The COVID-19 pandemic has forced the cancellation of planned surgery and led to significant surgical service reductions. Early intervention in aortovascular disease is often critical and cannot be deferred despite these reductions. There is urgent need to evaluate the provision and outcomes of thoracic aortovascular intervention during the peak of the pandemic. METHODS: Prospective data was collected for patients receiving open and endovascular thoracic aortovascular intervention over two-time points; January-May 2020 and January-May 2019 at three tertiary cardiovascular centres. Baseline demographics, cardiovascular risk and COVID-19 screening results were noted. Primary outcomes were median length of intensive care unit and hospital stay, intra-operative mortality, 30-day mortality, post-operative stroke, and spinal cord injury. RESULTS: Patients operated in 2020 (41) had significantly higher median EuroSCORE II than 2019 (53) (7.44 vs. 5.86, P = 0.032) and rates of previous cardiac (19.5% vs. 3.8%, P = 0.019), aortic (14.6% vs. 1.9%, P = 0.041), and endovascular (22.0% vs. 3.8%, P = 0.009) intervention. There was an increase in proportion of urgent cases in 2020 (31.7% vs. 18.9%). There were no intra-operative deaths in 2020 and 1 in 2019 (P = 1.00). There were no significant differences (P ≥ 0.05) in 30-day mortality (4.9% vs. 13.2%), median intensive care unit length of stay (72 vs. 70 hr), median hospital length of stay (8 vs. 9 days), post-operative stroke (3 vs. 6), or spinal cord injury (2 vs. 1) between 2020 and 2019 respectively. CONCLUSIONS: Despite the increased mortality risk of patients and urgency of cases during COVID-19, complicated by the introduction of cohorting and screening regimens, thoracic aortovascular intervention remained safe with comparable in outcomes to pre-COVID-19.

Progression of Changes in Vascular Surgery Practices during the Novel Corona Virus SARS-CoV-2 Pandemic.

INTRODUCTION: The novel coronavirus SARS-CoV-2 (COVID-19) has spread rapidly since it was identified. We sought to understand its effects on vascular surgery practices stratified by VASCON surgical readiness level and determine how these effects have changed during the course of the pandemic. METHODS: All members of the Vascular and Endovascular Surgery Society were sent electronic surveys questioning the effects of COVID-19 on their practices in the early pandemic in April (EP) and four months later in the pandemic in August (LP) 2020. RESULTS: Response rates were 206/731 (28%) in the EP group and 108/731 (15%) in the LP group (P < 0.0001). Most EP respondents reported VASCON levels less than 3 (168/206,82%), indicating increased hospital limitations while 6/108 (6%) in the LP group reported this level (P < 0.0001). The EP group was more likely to report a lower VASCON level (increased resource limitations), and decreased clinic, hospital and emergency room consults. Despite an increase of average cases/week to pre-COVID-19 levels, 46/108 (43%) of LP report continued decreased compensation, with 57% reporting more than 10% decrease. Respondents in the decreased compensation group were more likely to have reported a VASCON level 3 or lower earlier in the pandemic (P = 0.018). 91/108(84%) of LP group have treated COVID-19 patients for thromboembolic events, most commonly acute limb ischemia (76/108) and acute DVT (76/108). While the majority of respondents are no longer delaying the vascular surgery cases, 76/108 (70%) feel that vascular patient care has suffered due to earlier delays, and 36/108 (33%) report a backlog of cases caused by the pandemic. CONCLUSIONS: COVID-19 had a profound effect on vascular surgery practices earlier in the pandemic, resulting in continued detrimental effects on the provision of vascular care as well as compensation received by vascular surgeons.

Impact of COVID-19 on the Society for Vascular Surgery Vascular Quality Initiative Venous Procedure Registries (varicose vein and inferior vena cava filter).

In response to the pandemic, an abrupt pivot of Vascular Quality Initiative physician members away from standard clinical practice to a restrictive phase of emergent and urgent vascular procedures occurred. The Society for Vascular Surgery Patient Safety Organization queried both data managers and physicians in May 2020. Approximately three-fourths (74%) of physicians adopted restrictive operating policies for urgent and emergent cases only, whereas one-half proceeded with "time sensitive" elective cases as urgent. Data manager case entry was negatively affected by both low case volumes and staffing due to reassignment or furlough. Venous registry volumes were reduced fivefold in the first quarter of 2020 compared with a similar period in 2019. The consequences of delaying vascular procedures for ambulatory venous practice remain unknown with increased morbidity likely. Challenges to determine venous thromboembolism mortality impact exist given difficulty in verifying "in home and extended care facility" deaths. Further ramifications of a pandemic shutdown will likely be amplified if postponement of elective vascular care extends beyond a short window of time. It will be important to monitor disease progression and case severity as a result of policy shifts adopted locally in response to pandemic surges.

Vascular Surgery During COVID-19 Emergency in Hub Hospitals of Lombardy: Experience on 305 Patients.

OBJECTIVE: During the most aggressive phase of the COVID-19 outbreak in Italy, the Regional Authority of Lombardy identified a number of hospitals, named Hubs, chosen to serve the whole region for highly specialised cases, including vascular surgery. This study reports the experience of the four Hubs for Vascular Surgery in Lombardy and provides a comparison of in hospital mortality and major adverse events (MAEs) according to COVID-19 testing. METHODS: Data from all patients who were referred to the Vascular Surgery Department of Hubs from 9 March to 28 April 2020 were collected prospectively and analysed. A positive COVID-19 polymerase chain reaction swab test, or symptoms (fever > 37.5 °C, upper respiratory tract symptoms, chest pain, and contact/travel history) associated with interstitial pneumonia on chest computed tomography scan were considered diagnostic of COVID-19 disease. Patient characteristics, operative variables, and in hospital outcomes were compared according to COVID-19 testing. A multivariable model was used to identify independent predictors of in hospital death and MAEs. RESULTS: Among 305 included patients, 64 (21%) tested positive for COVID-19 (COVID group) and 241 (79%) did not (non-COVID group). COVID patients presented more frequently with acute limb ischaemia than non-COVID patients (64% vs. 23%; p < .001) and had a significantly higher in hospital mortality (25% vs. 6%; p < .001). Clinical success, MAEs, re-interventions, and pulmonary and renal complications were significantly worse in COVID patients. Independent risk factors for in hospital death were COVID (OR 4.1), medical treatment (OR 7.2), and emergency setting (OR 13.6). COVID (OR 3.4), obesity class V (OR 13.5), and emergency setting (OR 4.0) were independent risk factors for development of MAEs. CONCLUSION: During the COVID-19 pandemic in Lombardy, acute limb ischaemia was the most frequent vascular disease requiring surgical treatment. COVID-19 was associated with a fourfold increased risk of death and a threefold increased risk of major adverse events.

Acute limb ischemia in patients with COVID-19 pneumonia.

Objective: The aim of our study was to determine the incidence, characteristics, and clinical outcomes of patients with the novel coronavirus (COVID-19) infection who had presented with and been treated for acute limb ischemia (ALI) during the 2020 coronavirus pandemic. Methods: We performed a single-center, observational cohort study. The data from all patients who had tested positive for COVID-19 and had presented with ALI requiring urgent operative treatment were collected in a prospectively maintained database. For the present series, successful revascularization of the treated arterial segment was defined as the absence of early (<30 days) re-occlusion or major amputation or death within 24 hours. The primary outcomes were successful revascularization, early (≤30 days) and late (≥30 days) survival, postoperative (≤30 days) complications, and limb salvage. Results: We evaluated the data from 20 patients with ALI who were positive for COVID-19. For the period from January to March, the incidence rate of patients presenting with ALI in 2020 was significantly greater than that for the same months in 2019 (23 of 141 [16.3%] vs 3 of 163 [1.8%]; P < .001)]. Of the 20 included patients, 18 were men (90%) and two were women (10%). Their mean age was 75 ± 9 years (range, 62-95 years). All 20 patients already had a diagnosis of COVID-19 pneumonia. Operative treatment was performed in 17 patients (85%). Revascularization was successful in 12 of the 17 (70.6%). Although successful revascularization was not significantly associated with the postoperative use of intravenous heparin (64.7% vs 83.3%; P = .622), no patient who had received intravenous heparin required reintervention. Of the 20 patients, eight (40%) had died in the hospital. The patients who had died were significantly older (81 ± 10 years vs 71 ± 5 years; P = .008). The use of continuous postoperative systemic heparin infusion was significantly associated with survival (0% vs 57.1%; P = .042). Conclusions: In our preliminary experience, the incidence of ALI has significantly increased during the COVID-19 pandemic in the Italian Lombardy region. Successful revascularization was lower than expected, which we believed was due to a virus-related hypercoagulable state. The use of prolonged systemic heparin might improve surgical treatment efficacy, limb salvage, and overall survival.