Background: This article describes a chimney technique (ChEVAR) to preserve the patency of the inferior mesenteric artery (IMA) in a patient with abdominal aortic aneurysm (AAA) and bilateral internal iliac artery obstruction. In addition, a review of the literature is performed. Case report: This article describes a male in his 70s with multiple comorbidities and a 5.6 cm infrarenal aortic aneurysm. CT scan showed bilateral iliac internal artery obstruction with compensatory hypertrophy of lumbar arteries along with a 6 mm inferior mesenteric artery. We planned a staged treatment: embolization of lumbar arteries to prevent type 2 endoleak as a first step, followed two months later by standard EVAR with chimney graft to maintain patency of IMA. The postoperative course was uneventful. The endograft was widely patent on CT scan at his 6-month follow-up visit. Conclusions: ChEVAR to preserve the patency of IMA is a feasible and valid technique that could be considered in the case of bilateral hypogastric obstruction.

Early prediction of COVID-19 in-hospital mortality relies usually on patients’ preexisting comorbidities and is rarely reproducible in independent cohorts. We wanted to compare the role of routinely measured biomarkers of immunity, inflammation, and cellular damage with preexisting comorbidities in eight different machine-learning models to predict mortality, and evaluate their performance in an independent population. We recruited and followed-up consecutive adult patients with SARS-Cov-2 infection in two different Italian hospitals. We predicted 60-day mortality in one cohort (development dataset, n = 299 patients, of which 80% was allocated to the development dataset and 20% to the training set) and retested the models in the second cohort (external validation dataset, n = 402).Demographic, clinical, and laboratory features at admission, treatments and disease outcomes were significantly different between the two cohorts. Notably, significant differences were observed for %lymphocytes (p < 0.05), international-normalized-ratio (p < 0.01), platelets, alanine-aminotransferase, creatinine (all p < 0.001). The primary outcome (60-day mortality) was 29.10% (n = 87) in the development dataset, and 39.55% (n = 159) in the external validation dataset. The performance of the 8 tested models on the external validation dataset were similar to that of the holdout test dataset, indicating that the models capture the key predictors of mortality. The shap analysis in both datasets showed that age, immune features (%lymphocytes, platelets) and LDH substantially impacted on all models' predictions, while creatinine and CRP varied among the different models. The model with the better performance was model 8 (60-day mortality AUROC 0.83 ± 0.06 in holdout test set, 0.79 ± 0.02 in external validation dataset). The features that had the greatest impact on this model's prediction were age, LDH, platelets, and %lymphocytes, more than comorbidities or inflammation markers, and these findings were highly consistent in both datasets, likely reflecting the virus effect at the very beginning of the disease.

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.