Infrapopliteal Bypass In Patients On Dialysis: Patency And Survival.

INTRODUCTION: Portugal has one of the highest prevalence of patients on a regular dialysis program. This population has a higher incidence of peripheral arterial disease with higher rates of postoperative morbidity and mortality. Our goal was to compare outcomes between dialysis and non-dialysis patients with chronic limb threatening ischemia (CLTI) submitted to infrapopliteal bypass. MATERIALS AND METHODS: A retrospective single-center study of infrapopliteal bypass for CLTI was performed between 2012 and 2019. Patients were divided in two groups based on dialysis status (group 1 incorporated patients on dialysis). Primary end point was 1-year freedom from CLTI. Secondary end points were limb-salvage, survival and primary (PP) and tertiary patency (TP) rates at 3 years of follow-up. RESULTS: A total of 352 infrapopliteal bypasses were performed in 310 patients with CLTI. Fourteen percent of the revascularizations were performed on dialysis patients (48/352). Median age was 73 years (interquartile range - IQR 15) and 74% (259/352) were male. Median follow-up was 26 months (IQR 42). Overall, 92% (325/352) had tissue loss and 44% (154/352) had some degree of infection. The majority of revascularization procedures were performed with vein grafts (61%, 214/352). The 30-day mortality was 4% (11/310), with no difference between groups (p = 0.627). Kaplan-Meier analysis showed no difference between groups regarding freedom from CLTI (76% vs. 79%; HR 0.96, CI 0.65-1.44, p=0.857), limb-salvage (70% vs. 82%; HR 1.40, CI 0.71-2.78, p=0.327) and survival (62% vs. 64%; HR 1.08, CI 0.60-1.94, p=0.799). PP rates were 39% in group 1 and 64% in group 2 (HR 1.71, CI 1.05-2.79, p=0.030). TP rates were not different between groups (57% and 78%; HR 1.79, CI 0.92-3.47, p=0.082). CONCLUSION: Infrapopliteal bypass for CLTI, on dialysis patients, resulted in lower PP rates. No differences were observed in freedom from CLTI, TP, limb salvage and survival.

Acute limb ischemia in nonagenarians: Characteristics and factors related to outcomes in a single-center consecutive series.

BACKGROUND: The increasing aging and frailty of the population make the management of acute limb ischemia (ALI) more difficult, with decision-making far from being guided by evidence. The aim of the study was to evaluate the characteristics and results of ALI treatment in nonagenarians. MATERIALS AND METHODS: Retrospective analysis of a consecutive series of nonagenarian patients with ALI attended at our institution between 2008 and 2021. The primary outcomes of the study were 1-year limb salvage and survival rates. RESULTS: A total of 102 patients were included (mean age 92.38, 78.4% women). In 83 cases (81.4%) ALI was attributed to embolism, and 19 (18.6%) to acute arterial thrombosis. One-month overall survival was 70.6%. Fifteen patients (14.7%) were treated palliatively, including 8 (53.3%) irreversible ALI with associated malignancy/advanced dementia, 5 (33.3%) with associated cerebral/intestinal ischemia and 2 (13.3%) with aortic occlusion and poor medical condition. None of these patients survived after 10 days. The remaining 87 patients (85.3%) were treated with isolated anticoagulation (n = 8, 9.1%), primary major amputation (n = 1, 1.1%) or revascularization (n = 78, 89.6%), including 69 (67.6%) embolectomies, 6 (5.9%) bypass and 3 (2.9%) endovascular techniques. One-year limb salvage and survival rates were 96% and 48%, respectively. Predictive factors of lower survival included anemia (HR = 1.81, p = 0.014) and ALI severity (HR = 1.73, p = 0.032), but not cognitive or functional status. Patients surviving the ALI episode had a 1-year survival rate significantly below that of a similar matched population. CONCLUSION: Although nonagenarians with an ALI are often functionally and cognitively impaired and have a limited life expectancy, most patients need revascularization for limb salvage and this can be done successfully with a low invasive surgery.

The Use and Impact of Cilostazol on Patients Undergoing Endovascular Peripheral Interventions.

BACKGROUND: Cilostazol is used for the treatment of intermittent claudication. The impact of cilostazol on the outcomes of peripheral vascular interventions (PVIs) remains controversial. This study assesses the use and impact of cilostazol on patients undergoing PVI for peripheral arterial disease (PAD). METHODS: The Vascular Quality Initiative (VQI) database files for PVI were reviewed. Patients with PAD who underwent PVI for chronic limb threatening-ischemia or claudication were included and divided based on the use of cilostazol preoperatively. After propensity matching for patient demographics and comorbidities, the short-term and long-term outcomes of the 2 groups (preoperative cilostazol use versus no preoperative cilostazol use) were compared. The Kaplan-Meier method was used to determine outcomes. RESULTS: A total of 245,309 patients underwent PVI procedures and 6.6% (N = 16,366) were on cilostazol prior to intervention. Patients that received cilostazol were more likely to be male (62% vs 60%; P < 0.001), White (77% vs. 75%; P < 0.001), and smokers (83% vs. 77%; P < 0.001). They were less likely to have diabetes mellitus (50% vs. 56%; P < 0.001) and congestive heart failure (14% vs. 23%; P < 0.001). Patient on cilostazol were more likely to be treated for claudication (63% vs. 40%, P < 0.001), undergo prior lower extremity revascularization (55% vs. 51%, P < 0.001) and less likely to have undergone prior minor and major amputation (10% vs. 19%; P < 0.001) compared with patients who did not receive cilostazol. After 3:1 propensity matching, there were 50,265 patients included in the analysis with no differences in baseline characteristics. Patients on cilostazol were less likely to develop renal complications and more likely to be discharged home. Patients on cilostazol had significantly lower rates of long-term mortality (11.5% vs. 13.4%, P < 0.001 and major amputation (4.0% vs. 4.7%, P = 0.022). However, there were no significant differences in rates of reintervention, major adverse limb events, or patency after PVI. Amputation-free survival rates were significantly higher for patients on cilostazol, after 4 years of follow up (89% vs. 87%, P = 0.03). CONCLUSIONS: Cilostazol is underutilized in the VQI database and seems to be associated with improved amputation-free survival. Cilostazol therapy should be considered in all patients with PAD who can tolerate it prior to PVI.

Transcatheter Arterialization of Deep Veins in Chronic Limb-Threatening Ischemia.

BACKGROUND: Approximately 20% of patients with chronic limb-threatening ischemia have no revascularization options, leading to above-ankle amputation. Transcatheter arterialization of the deep veins is a percutaneous approach that creates an artery-to-vein connection for delivery of oxygenated blood by means of the venous system to the ischemic foot to prevent amputation. METHODS: We conducted a prospective, single-group, multicenter study to evaluate the effect of transcatheter arterialization of the deep veins in patients with nonhealing ulcers and no surgical or endovascular revascularization treatment options. The composite primary end point was amputation-free survival (defined as freedom from above-ankle amputation or death from any cause) at 6 months, as compared with a performance goal of 54%. Secondary end points included limb salvage, wound healing, and technical success of the procedure. RESULTS: We enrolled 105 patients who had chronic limb-threatening ischemia and were of a median age of 70 years (interquartile range, 38 to 89). Of the patients enrolled, 33 (31.4%) were women and 45 (42.8%) were Black, Hispanic, or Latino. Transcatheter arterialization of the deep veins was performed successfully in 104 patients (99.0%). At 6 months, 66.1% of the patients had amputation-free survival. According to Bayesian analysis, the posterior probability that amputation-free survival at 6 months exceeded a performance goal of 54% was 0.993, which exceeded the prespecified threshold of 0.977. Limb salvage (avoidance of above-ankle amputation) was attained in 67 patients (76.0% by Kaplan-Meier analysis). Wounds were completely healed in 16 of 63 patients (25%) and were in the process of healing in 32 of 63 patients (51%). No unanticipated device-related adverse events were reported. CONCLUSIONS: We found that transcatheter arterialization of the deep veins was safe and could be performed successfully in patients with chronic limb-threatening ischemia and no conventional surgical or endovascular revascularization treatment options. (Funded by LimFlow; PROMISE II study ClinicalTrials.gov number, NCT03970538.).

Association of neutrophil-to-lymphocyte ratio with thirty-day mortality in acute peripheral arterial ischemia.

BACKGROUND: Acute peripheral arterial ischemia (APAI) is an acute ischemic condition that develops as a result of embolism or thrombosis, and its morbidity and mortality are still high today. The objective of this study is to determine the effect of preoperative Neutrophil-to-Lymphocyte ratio (NLR) on mortality in patients admitted with the diagnosis of APAI. METHODS: 178 patients who were diagnosed with acute peripheral arterial occlusion and underwent emergency embolectomy were evaluated retrospectively over a 7-year period. Patient demographics, clinical history, risk factors, comorbidity, and hemogram sub-parameters were documented. The endpoint of the patients was determined as death. RESULTS: A total of 178 patients were identified with a mean age 74.29±14.71 (range 28-111) years; among them, 105 (59%) were female. 18% patients (32/178) died within 30 days. Lower extremity involvement was present in 124 (69.7%) of the patients. A statistically significant difference was found between the mortality rates and blood parameters of the patients included in the study in terms of white blood count C-reactive protein (CRP), and age among those with normal distribution. Neutrophil, NLR, procalcitonin, lactate, aspartate aminotransferase, and urea; It was statistically significant in terms of mortality in our patients with APAI. NLR values of the deceased were determined as 7.98 ± 6.85. CONCLUSIONS: APAI patients with high NLRs had significantly higher risks of 30-day mortality. The NLR can be used as a prognostic marker in these patients and warrants further investigation.

Inhibition of Neuronal Necroptosis Mediated by RIPK1 Provides Neuroprotective Effects on Hypoxia and Ischemia In Vitro and In Vivo.

Ischemic brain injury is a widespread pathological condition, the main components of which are a deficiency of oxygen and energy substrates. In recent years, a number of new forms of cell death, including necroptosis, have been described. In necroptosis, a cascade of interactions between the kinases RIPK1 and RIPK3 and the MLKL protein leads to the formation of a specialized death complex called the necrosome, which triggers MLKL-mediated destruction of the cell membrane and necroptotic cell death. Necroptosis probably plays an important role in the development of ischemia/reperfusion injury and can be considered as a potential target for finding methods to correct the disruption of neural networks in ischemic damage. In the present study, we demonstrated that blockade of RIPK1 kinase by Necrostatin-1 preserved the viability of cells in primary hippocampal cultures in an in vitro model of glucose deprivation. The effect of RIPK1 blockade on the bioelectrical and metabolic calcium activity of neuron-glial networks in vitro using calcium imaging and multi-electrode arrays was assessed for the first time. RIPK1 blockade was shown to partially preserve both calcium and bioelectric activity of neuron-glial networks under ischemic factors. However, it should be noted that RIPK1 blockade does not preserve the network parameters of the collective calcium dynamics of neuron-glial networks, despite the maintenance of network bioelectrical activity (the number of bursts and the number of spikes in the bursts). To confirm the data obtained in vitro, we studied the effect of RIPK1 blockade on the resistance of small laboratory animals to in vivo modeling of hypoxia and cerebral ischemia. The use of Necrostatin-1 increases the survival rate of C57BL mice in modeling both acute hypobaric hypoxia and ischemic brain damage.

Reinterventions in Patients with Claudication and Chronic Limb Threatening Ischemia.

BACKGROUND: Patients with peripheral artery disease (PAD) present with claudication or chronic limb threatening ischemia (CLTI). CLTI patients have a more advanced stage of atherosclerosis and increased comorbidities compared to claudicants, and are at an elevated risk of major amputation and mortality after lower extremity revascularization (LER). However, the frequency of reinterventions for claudication and CLTI have not been compared. Our hypothesis is that patients with CLTI undergo more frequent reinterventions to prevent major amputation. METHODS: A single-center retrospective chart review of consecutive patients undergoing lower extremity revascularization (LER) for PAD in 2013-2015 was performed. Patients were stratified based on indication for revascularization into claudication or CLTI. Patient characteristics, outcomes, and reinterventions were compared between the 2 groups. RESULTS: There were 826 patients undergoing LER and 44% (N = 361) had CLTI. Patients treated for CLTI were more likely to be smokers (P < 0.001), to have diabetes (P< 0.001), chronic renal insufficiency (P< 0.001), end stage renal disease (P< 0.001), and cardiac disease (P< 0.001). CLTI patients were less likely to be on optimal medical management as reflected by decreased rate of aspirin (P< 0.001), ADP receptor/P2Y12 inhibitors (P< 0.001), and statins (P< 0.001) compared to patients with claudication. Patients with CLTI had significantly higher major amputation (3.7% vs. 0.2%, P< 0.001) and mortality (1.4% vs. 0.2%, P = 0.092) at 30 days. At long-term follow up, patients with CLTI had higher rates of major amputation (15.5% vs. 1.3%, P < 0.001) and mortality (37.1% vs. 18.1%, P < 0.001) compared to patients with claudication. There was a significant difference in mean follow-up time between the 2 cohorts (claudication: 3.7 ± 1.5 years versus CLTI: 2.6 ± 1.8 years, P < 0.001). There was no significant difference in the ipsilateral reintervention rate between the 2 groups (claudication: 39.6% vs. CLTI: 42.7%, P = 0.37) or the mean number of ipsilateral reinterventions (claudication: 2.0 ± 1.6 vs. CLTI: 2.0 ± 1.7). However, after adjusting for follow-up time, the mean number of reinterventions per year was significantly higher for CLTI patients compared to patients with claudication (1.4 ± 2.2 vs. .6 ± 0.7 intervention per year, P < 0.001). CONCLUSIONS: Patients undergoing LER for CLTI undergo more frequent reinterventions over time compared to patients treated for claudication. Research on reinterventions after LER should include reporting of the frequency of reintervention adjusted for the follow up period in addition to the reintervention rate defined as the percentage of patients undergoing reintervention.

Impact of Perioperative Blood Transfusion in Anemic Patients Undergoing Infra Inguinal Bypass.

OBJECTIVE: Patients who present with lower extremity ischemia are frequently anemic and the optimal transfusion threshold for this cohort remains controversial. We sought to evaluate the impact of blood transfusion on postoperative major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients. METHODS: All consecutive patients who underwent infra-inguinal bypass at our institution from 2011 to 2020 were included. Perioperative red blood cell transfusion was the primary exposure, and the primary outcome was MACE. Univariate and multivariable analyses were performed to assess the impact of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hgb) nadir: <7, 7-8, and >8 g/dL. RESULTS: Of the 287 patients reviewed for analysis, 146 (50.9%) had a perioperative transfusion (mean: 1.6 ± 3 units). Patients who received a transfusion had a mean nadir Hgb of 8.3 ± 1.0 g/dL, compared to 10.1 ± 1.7 g/dL without a transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P = 0.009), lower Hgb nadir (P = 0.02), and higher blood loss (P = 0.003). On multivariate analysis, transfusion was independently associated with MACE for patients with a Hgb nadir >8 g/dL (OR: 3.09; P = 0.006), but not for patients with Hgb nadir 7-8 g/dL (OR: 0.818; P = 0.77). Additionally, patients with MACE had significantly longer length of hospital stay than for patients without (13 vs. 7.7 days, P = 0.001). CONCLUSIONS: For patients undergoing infra-inguinal bypass, receiving a red blood cell transfusion with a Hgb nadir >8 g/dL was associated with a 3-fold increase in MACE, with nearly twice the length of stay. For patients with a Hgb 7-8 g/dL, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusion for patients with Hgb nadir >7 g/dL and harm for Hgb >8 g/dL, however causation cannot be proven due to the retrospective nature of the study and randomized studies are needed to confirm or refute these findings.

Acute Compartment Syndrome Following Thrombolysis For Acute Lower Limb Ischemia.

BACKGROUND: Acute Compartment syndrome (ACS) with subsequent need for fasciotomy is a serious and insidious complication after revascularization for acute lower limb ischemia (ALI). The development of ACS during endovascular catheter directed thrombolysis is particularly difficult to identify. The aim was to identify the incidence, predisposing factors, wound treatment, and outcome in terms of amputation and survival for patients presenting with ALI that develop ACS during catheter directed thrombolysis. Patients who did not develop ACS after thrombolysis were analyzed as controls. METHODS: Descriptive retrospective analysis of prospective databases from two large tertiary-referral vascular centers. Patients with ACS after thrombolysis for ALI between 2001-2017 were analyzed. RESULTS: Seventy-eight cases and 621 controls were identified. Mean age was 72 years and 30 (38.5%) were women in the ACS group. Patients that developed ACS presented with significantly more severe preoperative ischemia. With 38.5% having Rutherford 2b classification as compared to 22.7 % in the control group (P = 0.002). Occluded popliteal artery aneurysms were also associated with a higher incidence of ACS (P = 0.041). Treatment of the fasciotomy wound was most commonly treated with regular wound dressing in 45 (58%) of cases, while wound dressing and foot pump and vacuum assisted closure were used in 14 (18%) and 19 (24%) respectively. These differing approaches did not affect the number of wound infections and amputations, which was similar regardless of treatment type. Vacuum assisted closure was associated with a higher degree of skin graft closure (P = 0.001). The median time to complete wound closure was 10 days. One year after thrombolysis, the major amputation rate in the ACS group was 31% as opposed to 17% in control group, P = 0.003. Mortality measured at 16.7% and 15.3%, respectively, P = 0.872. Amputation-free survival in the ACS group was 62% vs. 73% in the control group, P = 0.035. These differences level out, however, when applying long-term analysis of amputation-free survival in Kaplan-Meier analysis (log-rank 0.103). CONCLUSIONS: Patients that developed ACS during endovascular CDT presented with a more severe pre-operative ischemia, more occluded popliteal artery aneurysms and had a higher amputation rate during the first year, compared to controls. The development of ACS during endovascular treatment of ALI with thrombolysis is not uncommon and warrants both clinical awareness and rapid treatment.

The Impact of Anemia on One-Year Amputation-Free Survival in Patients Undergoing Revascularization for Chronic Limb-Threatening Ischemia: A Retrospective Cohort Study.

BACKGROUND: Anemia is potentially associated with increased morbidity and mortality following vascular surgery procedures. This study investigated whether peri-procedural anemia is associated with reduced 1-year amputation-free survival (AFS) in patients undergoing revascularization for chronic limb-threatening ischemia (CLTI). METHODOLOGY: A retrospective analysis of patients diagnosed with CLTI between February 2018-February 2019, who subsequently underwent revascularization, was conducted. Hemoglobin concentration measured at index assessment was recorded and stratified by WHO criteria. Subsequent peri-procedural red blood cell transfusions (RBC) were also recorded. The primary outcome was 1-year AFS. Kaplan Meier survival analysis and Cox's proportional hazard modelling were conducted to assess the effect of anemia and peri-procedure transfusion on outcomes. RESULTS: 283 patients were analyzed, of which 148 (52.3%) were anemic. 53 patients (18.7%) underwent RBC transfusion. Patients with anemia had a significantly lower 1-year AFS (64.2% vs. 78.5%, P = 0.009). A significant difference in 1-year AFS was also observed based upon anemia severity (P = 0.008) and for patients who received RBC transfusion (45.3% vs 77.0%, P < 0.001). On multivariable analysis, moderately severe anemia was independently associated with increased risk of major amputation/death (aHR 1.90, 95% CI 1.06-3.38, P = 0.030). After adjusting for severity of baseline anemia, peri-procedural RBC transfusion was associated with a significant increase in the combined risk of major amputation/death (aHR 3.15, 95% CI 1.91-5.20, P < 0.001). CONCLUSION: Moderately severe peri-procedural anemia and subsequent RBC transfusion are independently associated with reduced 1-year AFS in patients undergoing revascularization for CLTI. Future work should focus on investigating alternative measures to managing anemia in this cohort.

Cohort Study Examining the Association of Immunosuppressant Drug Prescription With Major Adverse Cardiovascular and Limb Events in Patients With Peripheral Artery Disease.

AIM: Immune activation is strongly implicated in atherosclerotic plaque instability, however, the effect of immunosuppressant drugs on cardiovascular events in patients with peripheral artery disease (PAD) is not known. The aim of this study was to assess whether prescription of one or more immune suppressant drugs was associated with a lower risk of major adverse cardiovascular (MACE; i.e. myocardial infarction, stroke or cardiovascular events) or limb events (MALE; i.e. major amputation or requirement for peripheral revascularization) in patients with PAD. METHODS: A total of 1506 participants with intermittent claudication (n = 872) or chronic limb threatening ischemia (CLTI; n = 634) of whom 53 (3.5%) were prescribed one or more immunosuppressant drugs (prednisolone 41; methotrexate 17; leflunomide 5; hydroxychloroquine 3; azathioprine 2; tocilizumab 2; mycophenolate 1; sulfasalazine 1; adalimumab 1) were recruited from 3 Australian hospitals. Participants were followed for a median of 3.9 (inter-quartile range 1.2, 7.3) years. The association of immunosuppressant drug prescription with MACE or MALE was examined using Cox proportional hazard analyses. RESULTS: After adjusting for other risk factors, prescription of an immunosuppressant drug was associated with a significantly greater risk of MACE (Hazard ratio, HR, 1.83, 95% confidence intervals, CI, 1.11, 3.01; P = 0.017) but not MALE (HR 1.32, 95% CI 0.90, 1.92; P = 0.153). In a sub-analysis restricted to participants with CLTI findings were similar: MACE (HR 2.44, 95% CI 1.32, 4.51; P = 0.005); MALE (HR 1.38, 95% CI 0.87, 2.19; P = 0.175); major amputation (HR 1.37, 95% CI 0.49, 3.86; P = 0.547). CONCLUSIONS: This cohort study suggested that immunosuppressant drug therapy is associated with a greater risk of MACE amongst patients with PAD.

The Relationship Between Obesity and Amputation-free Survival in Patients Undergoing Lower-limb Revascularisation for Chronic Limb-threatening Ischaemia: A Retrospective Cohort Study.

BACKGROUND: The obesity paradox is a well-documented phenomenon in cardiovascular disease, however it remains poorly understood. We aimed to investigate the relationship between body mass (as measured by body mass index [BMI]) and 1-year amputation-free survival (AFS) for patients undergoing lower limb revascularisation for chronic limb-threatening ischaemia (CLTI). METHODS: A retrospective analysis was undertaken of all consecutive patients undergoing lower limb revascularisation for CLTI at the Leicester Vascular Institute between February 2018-19. Baseline demographics and outcomes were collected using electronic records. BMI was stratified using the World Health Organization criteria. One-year AFS (composite of major amputation/death) was the primary outcome. Kaplan-Meier survival analysis and adjusted Cox's proportional hazard models were used to compare groups to patients of normal mass. RESULTS: One-hundred and ninety patients were included. Overall, no difference was identified in 1-year AFS across all groups (pooled P = 0.335). Compared to patients with normal BMI (n = 66), obese patients (n = 43) had a significantly lower adjusted combined risk of amputation/death (aHR 0.39, 95% CI 0.16-0.92, P = 0.032), however no significant differences were observed for overweight (aHR 0.89, 95% CI 0.47-1.70, P = 0.741), morbidly obese (aHR 1.15, 95% CI 0.41-3.20, P = 0.797) and underweight individuals (aHR 1.86, 95% CI 0.56-6.20, P = 0.314). CONCLUSIONS: In the context of CLTI, obesity is potentially associated with favourable amputation-free survival at 1 year, compared to normal body mass. The results of this study support the notion of an obesity paradox existing within CLTI and question whether current guidance on weight management requires a more patient-specific approach.

Influence of perioperative risk factors on the development of transmural colonic ischemia after open repair of ruptured abdominal aortic aneurysm.

BACKGROUND: Development of colonic ischemia (CI) after ruptured abdominal aortic aneurysm (RAAA) treatment is a lethal complication with perioperative mortality reported to be high as 50%. Therefore, the main goal of this study was to identify pre-, intra- and postoperative risk factors associated with CI in patients undergoing open repair (OR) due to RAAA, that might help to select patients who are more prone to develop CI. METHODS: This was a single-center prospective cohort study on patients with RAAA undergoing OR between January 1st 2018 and July 1st 2019, at the Clinic for Vascular and Endovascular Surgery, Clinical Center of Serbia. During this period 89 patients were treated due to RAAA and all were included in the study. The primary endpoint was grade III CI, or transmural necrosis, diagnosed by laparotomy. RESULTS: Out of 89 patients operated due to RAAA, CI was diagnosed in 14 (15.73%). During the operation, patients with CI had a longer duration of hypotension (42.86±35.82 vs. 24.13±23.48, P=0.021) and more common significant hypotension (54.54% vs. 14.66%, P=0.024). In the postoperative course, patients with CI had more common signs of abdominal compartment syndrome (71.42% vs. 25.33%, P=0.001) and higher mortality rate (78.57% vs 29.33%, P=0.001). The univariate regression model showed that one of the most significant factors that were associated with CI were age higher than 75 years, significant hypotension lasting more than one hour, organ lesion, development of abdominal compartment syndrome and higher potassium values on third and fourth quartile. CONCLUSIONS: Grade III colon ischemia (transmural) remains the important cause of mortality after ruptured abdominal aortic aneurysm repair. We identified pre- and intraoperative and postoperative risk factors that could improve the selection of patients for primary open abdomen treatment or early exploratory laparotomy in order to prevent or timely diagnose colon ischemia.

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.

Risk stratification and mortality prediction in octo- and nonagenarians with peripheral artery disease: a retrospective analysis.

OBJECTIVES: Among changes in demographics, aging is the most relevant cardiovascular risk factor. The prevalence of peripheral artery disease (PAD) is high in elderly patients and is associated with a worse prognosis. Despite optimal treatments, mortality in the high-risk population of octo- and nonagenarians with PAD remains excessive, and predictive factors need to be identified. The objective of this study was to investigate predictors of mortality in octo- and nonagenarians with PAD. METHODS: Cases of treated octo- and nonagenarians, including the clinical characteristics and markers of myocardial injury and heart failure, were studied retrospectively with respect to all-cause mortality. Hazard ratios [HR] were calculated and survival was analyzed by Kaplan-Meyer curves and receiver operating characteristic curved were assessed for troponin-ultra and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and chronic limb-threatening ischemia (CLTI). RESULTS: A total of 123 octo- and nonagenarians admitted for PAD were eligible. The troponin level was the major predictor of all-cause mortality (HR: 4.6, 95% confidence interval [CI]: 1.4-15.3), followed by the NT-proBNP level (HR: 3.9, 95% CI 1.8-8.8) and CLTI (HR: 3.1, 95% CI 1.6-5.9). Multivariate regression revealed that each increment of 1 standard deviation in log troponin and log NT-proBNP was associated with a 2.7-fold (95% CI 1.8-4.1) and a 1.9-fold (95% CI 1.2-2.9) increased risk of all-cause death. Receiver operating characteristic curve analysis using a combination of all predictors yielded an improved area under the curve of 0.888. In a control group of an equal number of younger individuals, only NT-proBNP (HR: 4.2, 95% CI 1.2-14.1) and CLTI (HR: 6.1, 95% CI 1.6-23.4) were predictive of mortality. CONCLUSION: Our study demonstrates that cardiovascular biomarkers and CLTI are the primary predictors of increased mortality in elderly PAD patients. Further risk stratification through biomarkers in this high-risk population of octo- and nonagenarians with PAD is necessary.

Analysis of a Novel Inpatient Acute Limb Ischemia Alert System.

OBJECTIVES: Acute limb ischemia (ALI) is a surgical emergency that generally develops in the outpatient setting. Hospitalized patients are also at risk for acute limb ischemia, but their presentation may be atypical or altered by medical therapy. Our institution developed an alert system to facilitate the prompt recognition and treatment of ALI that occurs in the inpatient population. We aimed to evaluate the usage of the system after the first 2 years of operation. METHODS: All ALI alerts from October 2017 to December 2019 were collected from paging records and analyzed for location, timing, and the need for intervention. Alerts undergoing vascular intervention were classified as urgent (within 8 hours) or delayed (after 8 hr). Time and location data were evaluated to determine patterns of usage and true-positive rate of the system. RESULTS: From October 2017 to December 2019, there were 237 ALI alerts obtained from paging records containing time and location information for the alert. More alerts originated from ICUs relative to non-ICU floors (68% vs. 33%, P< 0.001), however a greater proportion of non-ICU floor alerts required intervention compared to ICU alerts (32.0% vs. 5.1%, P < .0001). The highest number of ALI alerts were from the Medical ICU (MRICU) (45.9%) and medical/surgical floors (33.3%), followed by Surgical ICU (20.2%). Alerts were more common within 3 hr of morning and evening nursing shift changes (47.3%, P < 0.001). From the 237 total alerts, the patient was able to be identified retrospectively in 186 cases, and of these 27 resulted in operative interventions (14.5%, positive predictive value), with 11 patients (40.7%) requiring urgent intervention with a median time to intervention of 3.5 hr (range 2.2-4.8), and 16 (59%) alerts undergoing a delayed intervention at a mean of 3 days (range 2-4). A total of 73 (39.2%) alert patients died during their admission, of which 65 (89.0%) were in an ICU, and no deaths were directly related to ALI. The median time to death was 2 days (range 0-95 days), and in 22 cases death occurred <24 hr from time of alert. CONCLUSION: Our novel hospital-wide ALI alert system demonstrates a 14.5% positive predictive value for ischemia that resulted in an intervention. Alerts were more likely to originate from the ICU setting and during nursing shift changes. Alerts originating from non-ICU floors were 5 times more likely to undergo surgical intervention for ALI. Further analysis is required to assess the effect of this system on patient safety, outcome, and allocation of institutional resources.

Acute limb ischemia in a cancer patient has high morbidity, high mortality, and atypical presentation: a tertiary cancer center's retrospective study.

BACKGROUND: Acute Limb Ischemia (ALI) carries a high morbidity and mortality rate that is compounded in the cancer patient. Though it is a relatively uncommon event, it is of extremely high adverse impact and carries poor awareness among clinicians. METHODS: Retrospective review of electronic medical records was performed of cancer patients presenting with acute limb ischemia (ALI) to the tertiary cancer center's urgent care center or as inpatient between January 1, 2014 and January 1, 2020. RESULTS: Out of the 29 cancer patients with ALI, 12 (41%) died within 3 month and 9 (31%) patients died within 1 months of ALI diagnosis. 65% had long term adverse outcome after ALI - 31% with death in 1 month, 2 (7%) with an amputation, 5 (17%) with lifestyle-limiting claudication, and 3 (10%) with subsequent wound ulceration or gangrene. Patients not eligible for standard of care (12 patients, 41%) (RR 2.33 95% CI [1.27-4.27], p <  0.01) and heparin administration ≥6 h from presentation (19 patients, 65%) (RR 2.81 [1.07-7.38], p = 0.04) were at increased risk of adverse outcome. Atypical/confounded presentation of ALI (13 patients, 45%) (RR 1.84 95% CI [1.03-3.29], p = 0.04), pulse exam not documented (12 patients, 41.4%) (RR 1.95 [95% CI [1.14-3.32], p = 0.01), and patients with services other than a vascular specialist initially consulted (8 patients, 27.6%) (RR 1.91 95% CI [1.27-2.87], p <  0.01) were significant risk factors for heparin administered ≥6 h from presentation. CONCLUSIONS: ALI is devastating in cancer patients, with a high number presenting with atypical/confounded signs and symptoms which delays treatment. Heparin administered ≥6 h from presentation is associated with adverse outcome.

Underutilization of Palliative Care for Patients with Advanced Peripheral Arterial Disease.

BACKGROUND: Advanced peripheral arterial disease is associated with an overall annual mortality between 20-40%. Amputees are at particularly high risk for perioperative and long-term mortality and may benefit from palliative care programs to improve quality of life and to align medical treatments with their goals of care. As studies of palliative care in vascular patients are scarce, we sought to examine palliative care utilization using below knee amputation (BKA) as a surrogate for advanced peripheral arterial disease. METHODS: All patients who underwent below knee amputation over a 5-year period at a single large academic medical center were identified through chart review. Demographics, preoperative conditions, intraoperative factors, and perioperative outcomes were recorded. The primary outcome was palliative care consultation at the time of the amputation. The secondary outcomes included one-year mortality and palliative care consultation prior to death. RESULTS: The cohort comprised 111 patients (76 men, 35 women) who received BKA for chronic limb threatening ischemia. Three patients (2.7%) received palliative care consultations at the time of their amputation. Of these, one had been obtained remotely for an oncologic condition and the others for surgical decision-making. Follow-up was available for 73 patients. One-year mortality was 21.9% (n = 16) at a mean of 102 ± 86 days after BKA. Among patients who died within 1 year of their amputation, 37.5% (n = 6) received palliative care consultations prior to their death. The median interval between amputation and palliative consultation was 26 (IQR 14-81) days. The median interval between palliative consultation and death was 9 (IQR 4-39) days. CONCLUSION: Palliative care services were rarely provided to patients with advanced peripheral arterial disease. When obtained, consultations occurred closer to death than to amputation suggesting a missed opportunity to receive the benefits of early evaluation. Future studies can be aimed at identifying a cohort of vascular patients who would most benefit from early palliative evaluation and determining if palliative consultations alter health care utilization patterns and outcomes for vascular patients.

Timing and causes of death in severe COVID-19 patients.

BACKGROUND: Previous studies reporting the causes of death in patients with severe COVID-19 have provided conflicting results. The objective of this study was to describe the causes and timing of death in patients with severe COVID-19 admitted to the intensive care unit (ICU). METHODS: We performed a retrospective study in eight ICUs across seven French hospitals. All consecutive adult patients (aged ≥ 18 years) admitted to the ICU with PCR-confirmed SARS-CoV-2 infection and acute respiratory failure were included in the analysis. The causes and timing of ICU deaths were reported based on medical records. RESULTS: From March 1, 2020, to April 28, 287 patients were admitted to the ICU for SARS-CoV-2 related acute respiratory failure. Among them, 93 patients died in the ICU (32%). COVID-19-related multiple organ dysfunction syndrome (MODS) was the leading cause of death (37%). Secondary infection-related MODS accounted for 26% of ICU deaths, with a majority of ventilator-associated pneumonia. Refractory hypoxemia/pulmonary fibrosis was responsible for death in 19% of the cases. Fatal ischemic events (venous or arterial) occurred in 13% of the cases. The median time from ICU admission to death was 15 days (25th-75th IQR, 7-27 days). COVID-19-related MODS had a median time from ICU admission to death of 14 days (25th-75th IQR: 7-19 days), while only one death had occurred during the first 3 days since ICU admission. CONCLUSIONS: In our multicenter observational study, COVID-19-related MODS and secondary infections were the two leading causes of death, among severe COVID-19 patients admitted to the ICU.

Pre-operative Neutrophil to Lymphocyte Ratio is Associated With 30 Day Death or Amputation After Revascularisation for Acute Limb Ischaemia.

OBJECTIVE: Inflammation is an early feature of acute limb ischaemia (ALI), hence the potential prognostic significance of inflammatory biomarkers. This study aimed to assess the value of pre-operative inflammatory biomarkers, specifically the neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR), for predicting an adverse outcome after revascularisation for ALI. METHODS: All patients submitted to lower limb revascularisation for Rutherford IIa or IIb ALI at the authors' institution between 2009 and 2019 were screened retrospectively. Pre-operative NLR and PLR were analysed, along with other known prognostic factors. Primary outcome was the composite endpoint of 30 day death or amputation. RESULTS: A total of 345 patients were included, 84 of whom suffered the primary outcome (24.3%). The median follow up was 23.1 months (3.1 - 52.2). Higher age (OR 1.05 per year increase, 95% CI 1.01 - 1.09), diabetes (OR 2.63, 95% CI 1.14 - 6.06), Rutherford grade IIb vs. IIa (OR 5.51, 95% CI 2.11 - 14.42), higher NLR (OR 1.28 per unit increase, 95% CI 1.12 - 1.47), and fasciotomy need (OR 3.44, 95% CI 1.14 - 10.34) were independently associated with 30 day death or amputation, whereas pre-operative statin or anticoagulant medication were associated with a risk reduction (OR 0.23, 95% CI 0.53 - 0.96 and OR 0.20, 95% CI 0.05 - 0.84, respectively). PLR did not show an independent effect on this population. Pre-operative NLR presented a good discriminative ability (AUC 0.86, 95% CI 0.82 - 0.90). A cut off NLR level ≥ 5.4 demonstrated a 90.5% sensitivity and 73.6% specificity for 30 day death or amputation. Kaplan-Meier analysis showed that patients with pre-operative NLR ≥ 5.4 had significantly lower 30 day, six month and one year amputation free survival when compared with those with NLR < 5.4 (64.8 ± 4.0%, 44.1 ± 4.1%, and 37.5 ± 4.1% vs. 98.5 ± 0.9%, 91.9 ± 2.0%, and 85.9 ± 2.5%, log rank p < .001). CONCLUSION: In this study, higher pre-operative NLR was associated with 30 day death or amputation following intervention for Rutherford grade IIa or IIb ALI. NLR potentially stands as a simple, widely available and inexpensive biomarker that can refine decision making and possibly contribute to ALI morbidity and mortality reduction.