The Mysterious Risk of Arterial Thrombosis With COVID-19: A Case Series of Acute Limb Ischaemia in Vaccinated Patients

Introduction Coronavirus-19 (COVID-19) plays a vital role in viral-induced hypercoagulability through the initiation of a cytokine storm. This mechanism has been found to predispose unvaccinated patients to systemic complications including arterial thrombosis (AT) with poor 30-day amputation-free survival rates. There remains, however, little understanding regarding the incidence in patients who have received a COVID-19 vaccination. This study aims to assess the incidence, management and outcomes of vaccinated patients with COVID-19 who develop thrombotic complications to reduce amputation and direct mortality. Methods The case notes of all emergency patients with COVID-19 referred to the vascular services in a tertiary referral centre between November 2021 and April 2022 were reviewed. Patients who were unvaccinated or admitted with stroke or coronary thrombosis were excluded. The study was undertaken to measure 30-day outcomes. Results Between November 2021 and April 2022, 167,290 people tested positive for COVID-19 in Norfolk. Thirty-one patients under the vascular service had COVID-19, of which, one patient was unvaccinated. Only one vaccinated patient was referred with AT and had a positive COVID-19 result two days after admission. Above-knee amputation was performed within 30 days and he survived. Seventeen percent of patients contracted COVID-19 during their hospital admission. Conclusion The incidence of acute limb ischaemia in vaccinated patients is low; however, the 30-day outcomes remain poor. Compared to unvaccinated patients, there was a significant reduction in the presentation of AT in vaccinated patients during that timeframe, despite a higher background number of COVID-19 cases. Therefore, vaccination may minimise the risk of AT.

Acute limb ischaemia due to thrombosed persistent sciatic artery aneurysm presents a surgical challenge in a frail octogenarian

OBJECTIVES

Persistent sciatic artery (PSA) is a rare congenital anomaly, whereby the embryonic sciatic artery remains patent with associated degrees of femoral axis hypoplasia. Aneurysmal degeneration and distal ischaemia from thromboembolic complications are common. Revascularisation strategies include embolectomy, bypass or interposition grafting and catheter-directed thrombolysis.

METHODS

We describe a sedentary 88-year-old woman with right acute limb ischaemia secondary to a thrombosed PSA aneurysm and concurrent occlusive thrombus at the femoral bifurcation.

RESULTS

The patient presented with a 3-day history of a cold, painful right foot. Examination revealed Rutherford IIb ischaemia. CT-angiography demonstrated no continuity between the hypoplastic superficial femoral and popliteal arteries, complete occlusion of the right PSA distal to the thrombosed aneurysm and occlusive thrombus in the right profunda. As she was too frail for femoral-distal bypass, we restored femoral axis inflow via profunda embolectomy. Her prognosis remained guarded as we deliberately did not reconstruct the PSA. However, she was discharged pain-free and mobilising with aids 2 weeks later.

CONCLUSION

Limb ischaemia in frail, high-risk patients is an ever-increasing challenge for vascular surgeons and requires complex decision-making, balancing comorbidities against desired outcomes. This case illustrates that a selective approach can be sufficient to maintain function despite complex anatomy.

Anticoagulation With Platelet Transfusions for Acute Limb Ischemia With Severe Thrombocytopenia

Acute limb ischemia (ALI) is a medical and surgical emergency, and the mainstays of treatment are therapeutic anticoagulation and surgery. These interventions require adequate platelet count and functionality. Anticoagulation and surgery can be complicated in thrombocytopenic patients and require interdisciplinary management for optimal outcomes, as literature is limited in this population. We present a case of a patient with severe thrombocytopenia who developed limb ischemia from cancer-associated thrombosis (CAT). We propose a management strategy for anticoagulation and perioperative platelet transfusion, with successful revascularization without adverse bleeding events. While successful, more data is required to investigate long-term outcomes.

Management of Vasopressor-Induced Acute Limb Ischemia (VIALI) in Septic Shock

Vasopressors used in critically ill patients with refractory shock poses a serious risk of non-occlusive peripheral limb ischemia leading to tissue necrosis and amputation. Acute limb ischemia is associated with high morbidity and mortality. Evidence-based medical literature is scarce on the prevention and management of vasopressor-induced acute limb ischemia (VIALI). Despite being a well-known and frequent complication of vasopressors, there is no standardized guideline for the prevention and management of vasopressor-induced limb ischemia. Vasopressors are required for the management of refractory shock which is defined as hypotension not responsive to intravenous fluid resuscitation alone. Distributive shock, which includes septic shock, causes inadequate tissue perfusion in adjunct with vasopressor use and is the most common cause of non-occlusive peripheral limb ischemia. This case study will focus on how early recognition and prompt treatment of VIALI are crucial in minimizing tissue necrosis and preventing amputations. We present a case of a middle-aged woman who developed distributive shock from sepsis of a urinary source secondary to obstructive uropathy (ureteral calculi). She presented with refractory shock and continued to remain in shock while undergoing emergent rigid cystoscopy with the placement of a ureteral stent. Despite adequate volume resuscitation, she required high doses of vasopressors resulting in peripheral extremity ischemia and necrosis of all her fingers and toes. By promptly initiating mitigation and preventive management strategies, we succeeded in minimizing tissue ischemia and reducing morbidity resulting from iatrogenic vasopressor-induced peripheral non-occlusive ischemia. These strategies include but are not limited to external warming of bilateral lower extremities, nitroglycerin paste application over the entire extremity, arterial assist pump, and low-dose therapeutic anticoagulation. The novel use of the arterial pump in acutely ischemic lower extremities likely helped salvage the toes which appeared to be at high risk of amputation.

COVID-19-induced adult multisystem inflammatory syndrome and fatal acute limb ischaemia

A case of coronavirus disease 2019 (COVID-19)-induced adult multisystem inflammatory syndrome (MIS) and fatal acute limb ischaemia is presented. Arterial thrombosis and MIS are reported as complications of COVID-19. This case further highlights that arterial thrombosis and MIS can occur in COVID-19.

An 18 year data-linkage study on the association between air pollution and acute limb ischaemia

Background: There is limited information regarding the effects of air pollutants, such as nitrogen oxides (NO_x), nitric oxide (NO₂), nitrous oxide (NO) and particulate matter with a diameter smaller than 10 μm (PM10), on acute limb ischaemia (ALI), a peripheral arterial disease (PAD) often with a poor clinical outcome. Patients and methods: We conducted an 18-year retrospective cohort study using routinely collected healthcare records from Ninewells Hospital, Dundee, and Perth Royal Infirmary, in Tayside, Scotland, UK from 2000 to 2017. ALI hospitalisation events and deaths were linked to daily NO_x, NO₂, NO and PM10 levels extracted from publicly available data over this same time period. Distributed lag models were used to estimate risk ratios for ALI hospitalisation and for ALI mortality, adjusting for temperature, humidity, day of the week, month and public holiday. Results: 5,608 hospital admissions in 2,697 patients were identified over the study period (mean age 71.2 years, ±11.1). NO_x and NO were associated with an increase of ALI hospital admissions on days of exposure to pollutant (p=.018), while PM10 was associated with a cumulative (lag 0-9 days) increase (p=.027) of ALI hospital admissions in our study. There was no increase of ALI mortality associated with pollution levels. Conclusions: ALI hospital admissions were positively associated with ambient NO_x and NO on day of high measured pollution levels and a cumulative effect was seen with PM10.

Value of peripheral perfusion index to predict acute limb ischaemia in newborns after peripheral artery cannulation

AIMS AND OBJECTIVES

To investigate the feasibility of using peripheral perfusion index (PPI) to monitor acute limb ischaemia (ALI) in newborns after catheterisations.

BACKGROUND

ALI is common complication of neonatal peripheral artery cannulation. It is important to address as soon as the early signs of ALI. PPI could aid in noninvasive evaluation of distal extremity perfusion in an effort to notify risk of potential ischaemic injury from catheterisations.

DESIGN

A nested case-control study.

METHODS

Clinical information of newborns who had been admitted to the Neonatal Intensive Care Unit of Jiangxi Provincial Children's Hospital and had received peripheral artery cannulation from January 2018 to January 2020 was prospectively collected. Transcutaneous blood oxygen saturation (TcSO₂ ), PPI and delta-PPI (ΔPPI1; the difference in PPI values of the two arms. ΔPPI2; difference in the PPI values before and after cannulation) were recorded. We used STROBE checklist as an EQUATOR in this study.

RESULTS

A total of 25 newborns with ALI were included in the study. These were then paired with 100 newborns without ALI. The PPI and TcSO₂ of the cannulated limb were significantly lower in the ALI group than in the non-ALI (NALI) group (p < .05). The area under the receiver-operating characteristic curve was significant for ΔPPI1. The ΔPPI1 had a sensitivity and specificity of 92% and 87%, respectively, for diagnosing ALI. ΔPPI1 greater than 0.315 suggested that the infant was at risk of ALI.

CONCLUSIONS

Monitoring the change in the PPI in newborns after catheterisations helped in the early assessment of ALI.

RELEVANCE TO CLINICAL PRACTICE

Drops in the PPI and TcSO₂ of the cannulated limbs might, to some extent, reflect the possibility of ALI in newborns. ΔPPI1 (the difference in PPI values of the two arms) proved to be a simple, objective parameter to predict the presence of ALI.

Anaemia: A risk factor for death and adverse outcomes following surgery for acute lower limb ischaemia

INTRODUCTION

Acute limb ischaemia (ALI) forms a significant part of the vascular surgery workload and carries with it high rates of morbidity and mortality. Anaemia is also common amongst vascular surgical patients and has been linked with poor outcomes in some subgroups. We aimed to assess the frequency of anaemia in patients with ALI and its impact on survival and complications following revascularisation to help direct future efforts to optimise outcomes in this patient group.

METHODS

A retrospective analysis of prospectively collected departmental data on patients undergoing surgical intervention for ALI between 2014 and 2018 was performed. Anaemia was defined as a pre-operative haemoglobin (Hb) of <120 g/L for women and <130 g/L for men. The primary outcome was overall survival, assessed with the Kaplan-Meier estimator, with application of Cox proportional hazard modelling to adjust for confounding covariates.

RESULTS

There were 158 patients who underwent treatment for ALI: 89 (56.3%) of these were non-anaemic with a mean Hb of 146 (SD = 18.4), and 69 (43.7%) were anaemic with a mean Hb of 106 (SD = 13.4). Anaemic patients had a significantly higher risk of death than their non-anaemic counterparts on univariate analysis (HR = 2.11, 95% CIs, 1.28-3.5, p = 0.0036). There was ongoing divergence in survival up to around 6 months between anaemic and non-anaemic groups. Under the Cox model, anaemia was similarly significant as a predictor of death (HR = 2.15, 95% CIs, 1.17-3.95, p = 0.013), accounting for recorded comorbidities, medication use and blood transfusion.

CONCLUSIONS

Anaemia is a significant and independent risk factor for death following revascularisation for ALI and can be potentially be modified. Vascular surgical centres should ensure they have robust pathways in place to identify and consider treating anaemia. There is scope for further work to assess how to best optimise a patient's levels of circulating haemoglobin.

Risk Factors for Fasciotomy After Revascularization for Acute Lower Limb Ischaemia

Background: Acute lower limb ischaemia (ALI) is a life and limb threatening vascular emergency. Acute compartment syndrome (ACS) may develop upon revascularization. The risk of fasciotomy was hypothesized to be decreased in women due to their lower calf muscle mass. The main aim was to evaluate risk factors for fasciotomy after revascularization for ALI.

Methods: This is a retrospective observational study of patients undergoing revascularization for ALI between 2001 and 2018. Factors associated with outcome at 1 year in univariable analysis (p < 0.1) were chosen for multi-variable analysis and expressed in Odds Ratios (OR) with 95% confidence intervals (CI).

Results: The median age for women (n = 394) was 75 years and men (n = 449) was 70 years (p < 0.001). The frequency of fasciotomy was 10.0% (84/843). The median in-hospital stay was 28 vs. 6 days for patients undergoing fasciotomy and not, respectively (p < 0.001). In adjusted analysis, renal insufficiency (OR 1.77, 95% CI 1.04–3.01), motor deficit (OR 4.40, 95% CI 2.45–7.92), popliteal artery aneurysm thromboembolism (OR 2.26, 95% CI 1.06–4.80), and open vascular surgery (OR 3.43, 95% CI 1.97–5.98) were associated with an increased risk of fasciotomy. Female patients (OR 0.49, 95% CI 0.28–0.84) and anemia (OR 0.52, 95% CI 0.28–0.84) had a lower risk. The major amputation/mortality rate at 1-year was 27.7%; fasciotomy (OR 1.94, 95% CI 1.11–3.40), anemia (OR 1.84, 95% CI 1.24–2.73) and female gender (OR 1.44, 95% CI 1.00–2.08) were independently associated with an increased risk.

Conclusions: Female patients had lower rates of fasciotomies, but subsequent higher risk of major amputation/mortality, which may be attributed to inferior results of revascularization. Lower muscle mass and underdiagnosis of ACS could also explain the lower frequency of fasciotomy for female patients. Further studies are needed to better understand gender differences in presentation of ALI, revascularization results and diagnosis of ACS.

Regional Survey in Lombardy, Northern Italy, on Vascular Surgery Intervention Outcomes During The COVID-19 Pandemic

OBJECTIVE

The characteristics and outcomes of patients undergoing vascular surgery hospitalised and managed in Lombardy are described with a comparison of patients tested positive for COVID-19 (CV19-pos) vs. those tested negative (CV19-neg).

METHODS

This was a multicentre, retrospective, observational cohort study which involved all vascular surgery services in Lombardy, Northern Italy. Data were retrospectively merged into a combined dataset covering the nine weeks of the Italian COVID-19 pandemic phase 1 (8 March 2020 to 3 May 2020). The primary outcome was freedom from in hospital death, secondary outcomes were re-thrombosis rate after peripheral revascularisation, and freedom from post-operative complication.

RESULTS

Among 674 patients managed during the outbreak, 659 (97.8%) were included in the final analysis: 121 (18.4%) were CV19-pos. CV19-pos status was associated with a higher rate of complications (OR 4.5; p < .001, 95% CI 2.64 - 7.84), and a higher rate of re-thrombosis after peripheral arterial revascularisation (OR 2.2; p = .004, 95% CI 1.29 - 3.88). In hospital mortality was higher in CV19-pos patients (24.8% vs. 5.6%; OR 5.4, p < .001;95% CI 2.86 - 8.92). Binary logistic regression analysis identified CV19-pos status (OR 7.6; p < .001, 95% CI 3.75 - 15.28) and age > 80 years (OR 3.2; p = .001, 95% CI 1.61 - 6.57) to be predictors of in hospital death.

CONCLUSION

In this experience of the vascular surgery group of Lombardy, COVID-19 infection was a marker of poor outcomes in terms of mortality and post-operative complications for patients undergoing vascular surgery treatments.

[Multiple embolism of arterial vessels of the systemic circulation: classification, clinical manifestations, and outcomes]

Embologenic arterial obstruction remains an extremely important problem of modern medicine. Emboli may affect virtually all arterial vessels of the greater circulation and in some cases arterial emboli may be multiple. The purpose of the present study was to work out a classification of multiple arterial emboli. Analysing the clinical material including over 30 years a total of 1804 patients with embolism of the aorta and major arteries of the limbs made it possible to define the range of the terms used and to submit for discussion a classification describing a situation where emboli affect simultaneously several arteries or occur repeatedly. Both cases involve several emboli migrating from the primary source into the arterial bed, therefore we suggest that all these emboli be called multiple. Simultaneous multiple emboli were classified as combined, multifocal, and layered, with repeated emboli classified as preceding, recurrent, early and remote. Simultaneous emboli were observed in 91 (5%) patients, of these, in 22 - combined, in 49 - multifocal, in 19 - layered, and in 1 case - combined and multifocal. Repeated emboli were revealed at various terms and encountered virtually in each third patient. Overall mortality amongst the patients with embolism of the aorta and arteries of the limbs over 30 years amounted to 13%, having over the last decade decreased to 7.6%. Multiple arterial emboli significantly influenced the outcomes of treatment, with the mortality rate in combined emboli increasing virtually to 50% and that in multifocal and layered emboli exceeding 20% (p<0.05). Early recurrent emboli in the postoperative period were observed in 6.8% of patients, significantly deteriorating the prognosis (mortality - 49.2%). In the remote period, 22.4% of the patients were operated on for recurrent embolism of arteries of the extremities, with more than 25% of the patients having experienced emboli of cerebral or visceral arteries. Recurrent thromboembolic complications played a significant role in the thanatogenesis in each 4th patient.

Role of rural general surgeons in managing vascular surgical emergencies

BACKGROUND

A rural general surgeon has historically been required to perform a wide variety of subspecialist procedures. Increasingly sub-specialized training programs have restricted younger surgeons' experience in the general surgery-associated subspecialties. Time critical vascular surgical emergencies are frequently encountered by rural general surgeons. This study aims to audit the prevalence of vascular surgical emergencies at a geographically remote regional centre and define the role of the general surgeon in managing these patients.

METHODS

A single-centre, retrospective study was performed to analyse the outcomes of the patients who presented to Dubbo Base Hospital with an emergency vascular pathology or developed such a condition during admission, between October 2010 and June 2019. Patients were identified by relevant International classification of diseases (ICD) (10th revision) diagnostic codes for vascular emergencies. Acute complications following surgery for haemodialysis access were excluded.

RESULTS

A total of 134 patients were identified during the study period and the majority were transferred to a tertiary centre for surgical intervention. Sixteen patients underwent emergency vascular surgery locally due to concerns about potential loss of life or limb if intervention was delayed by transfer; 69% of patients who underwent surgery locally survived with limb salvation.

CONCLUSION

While most patients can safely be transferred to a tertiary centre, some require surgery locally in order to maximize chance of life or limb preservation. There is a strong argument for exposure of general surgical trainees with an interest in rural surgery to vascular surgery and other subspecialties.

Mechanical rotational thrombectomy with Rotarex system augmented with drug-eluting balloon angioplasty versus stenting for the treatment of acute thrombotic and critical limb ischaemia in the femoropopliteal segment

Introduction

Mechanical thrombectomy is an alternative to local thrombolysis for the treatment of severe ischaemia in the femoropopliteal segment, but stent implantation is usually required after this procedure. The use of drug-eluting balloons (DEBs) may overcome long-term problems associated with stents, but it remains unclear how often such a treatment is technically feasible and efficient.

Aim

This post hoc single-centre study was aimed at assessment of the feasibility, safety and efficacy of mechanical thrombectomy followed by application of DEBs.

Material and methods

Fifty-one patients, aged 69.1 ±11.6 years, were managed for acute thrombotic or chronic critical ischaemia in the femoropopliteal segment using the Rotarex device. Following mechanical thrombectomy, on condition that there was no significant residual stenosis or dissection, lesions were managed with paclitaxel-coated DEBs, which was a desired strategy (24 patients). The remaining 25 patients underwent stent implantations, which was regarded as bailout treatment. Final follow-up was scheduled 12 months after the procedure.

Results

The primary-assisted patency rate after mechanical rotational thrombectomy with additional balloon angioplasty and/or stenting was 97.1% (49 patients). The early mortality rate was 2.0% (1 patient) and the amputation rate was 4.1% (2 patients). There were no late mortalities or limb amputations at 12-month follow-up, but significant restenoses occurred in 13 (27.1%) patients. These restenoses were more frequent in patients who underwent stent implantation (45.5%) than those managed with DEBs (12.5%), and in patients managed for secondary lesions.

Conclusions

In selected patients mechanical rotational thrombectomy in the femoropopliteal segment followed by application of DEB is a safe, effective and long-lasting method of revascularisation.

Long-term follow-up after endovascular revascularisation for acute limb ischaemia--a retrospective single-centre cohort

BACKGROUND

We evaluated the long-term outcome after endovascular revascularisation for acute limb ischaemia (ALI).

PATIENTS AND METHODS

From a prospectively maintained database, 318 endovascular interventions for ALI were identified between 2004 and 2010. Event history and survival were analysed using the Kaplan-Meier method and Cox regression. Endpoints were target vessel revascularisation (TVR), non-target extremity revascularisation (NTER), amputation, major vascular events, coronary artery revascularisation and amputation-free survival.

RESULTS

Follow-up data of 303 patients (mean age 68.5 ± 12.7 years, 40% female) were available. The mean follow-up time was 38.7 ± 26.2 months. TVR was performed in 40.1 ± 2.9% at 1 year and 66.5 ± 3.8% at 5 years. NTER at 1 and 5 years were 7.1 ± 1.5% and 29.2 ± 4%, respectively. The proportion of patients who needed major or minor amputation was 4.3 ± 1.2% after 1 year and 9 ± 2.1% after 5 years. Amputation-free survival at 1 year was 90.3 ± 1.8% and 74.8 ± 3.2% at 5 years. Coronary artery disease (HR 2.22, 95% CI 1.33 to 3.7, p = 0.002) and atrial fibrillation (HR 2.56, % CI 1.3 to 5.04, p = 0.007) were independently associated with a worse amputation-free survival. The cumulative proportion surviving one year following acute limb ischemia was 95.4 ± 1.2% and 79.7 ± 3.1% after 5 years.

CONCLUSIONS

Long-term amputation-free survival after successful revascularisation for ALI is high; negative predictors are coronary artery disease and atrial fibrillation.