Acute limb ischemia: contemporary approach

Practical Review on the Contemporary Diagnosis and Management of Compartment Syndrome

Acute compartment syndrome (ACS) is a limb-threatening pathology that necessitates early detection and management. The diagnosis of ACS is often made by physical examination alone; however, supplemental methods such as compartment pressure measurement, infrared spectroscopy, and ultrasound can provide additional information that support decision-making. This practical review aims to incorporate and summarize recent studies to provide evidence-based approaches to compartment syndrome for both resource-rich and -poor settings among several patient populations.

Neuromuscular complications of the lower extremity after thrombectomy in a patient with superficial femoral artery occlusion: Case series

BACKGROUND

Ischemia reperfusion (IR) injury may result in rhabdomyolysis and compartment syndrome when blood supply returns after thrombectomy for patients with acute limb ischemia.

OBJECTIVE

We highlight the value of early diagnosis and treatment in post-thrombectomy patients with IR injuries in their lower legs.

CASE DESCRIPTION

Two patients received thrombectomy due to left superficial femoral artery occlusion. Both patients complained of left calf pain during ambulation at the 1- and 3-day follow up post-thrombectomy, as well as a heating sensation, swelling, weakness, and sensory changes in the affected leg. For early diagnosis musculoskeletal ultrasounds were performed and in both cases revealed swelling and change of echogenicity in the left calf. To further diagnosis, magnetic resonance imaging of the left leg revealed limb IR-induced muscular injury and rhabdomyolysis, respectively. In both cases, an electrodiagnostic study revealed peripheral nerve injury in the left leg. Medications were provided for neuropathic pain control and early rehabilitation was performed to improve function. In both cases, patients reported during their follow-up that their pain and muscle weakness had improved.

CONCLUSION

When post-thrombectomy calf pain occurs early evaluation and treatment should be performed to identify any potential IR injury.

Acute Limb Ischemia after Cardiovascular Surgery: A Deadly Duo Combination with High Mortality

Acute limb ischemia (ALI) is a predictor of high morbidity and mortality. Previous studies showed that ALI developed after cardiac surgery may increase mortality. This study aimed to elucidate the clinical course and identify risk factors contributing to mortality in patients with ALI after cardiovascular surgery. This is a single-center retrospective cohort study. We analyzed data from 52 patients with ALI after cardiovascular surgery between 2016 and 2020. We evaluated the risk factors for 1-year mortality using Cox proportional hazards regression analysis. Most of the patients with ALI were male and the median age was 56 years (23-72 years). Most of the patients with ALI had coronary artery diseases. The 1-year mortality rate was 55.8% ( n  = 29 patients). Multivariable analysis revealed that cardiopulmonary bypass (CPB) time ≥ 100 minutes (hazard ratio [HR]: 3.067, 95% confidence interval [CI]: 1.158-8.120) and postoperative acute kidney injury (HR: 2.927, 95% CI: 1.358-6.305) were significantly increasing the risk of mortality in patients with ALI after an operation. ALI after cardiovascular surgery was associated with high 1-year mortality in our study and long CPB time and postoperative acute kidney injury contributed to the mortality.

Dynamic thiol-disulphide homeostasis as a biomarker for predicting the development of contrast medium-associated acute kidney injury in the endovascular treatment of peripheral arterial disease: should intravenous N-acetylcysteine be given before the procedure?

AIM

To determine the predictive ability of serum thiol-disulphide levels for contrast medium-associated acute kidney injury (CA-AKI) after endovascular treatment (EVT) of peripheral arterial disease (PAD) and evaluate the efficacy of intravenous N-acetylcysteine (NAC) in preventing CA-AKI.

MATERIAL AND METHODS

This double-blind, randomised controlled study included 85 consecutive adult patients who underwent EVT for PAD. Patients were divided into NAC negative (NAC-) and positive (NAC+) groups. While the NAC- group received only 500 ml saline, the NAC + group received 500 ml saline plus intravenous 600 mg NAC before the procedure. Intra- and intergroup patient characteristics, procedural details, preoperative thiol-disulphide levels, and ischaemia-modified albumin (IMA) levels were recorded.

RESULTS

There was a significant difference between NAC- and NAC + groups regarding native thiol, total thiol, disulphide/native thiol ratio (D/NT), and disulphide/total thiol ratio (D/TT). There was also a significant difference between the NAC- (33.3%) and NAC+ (13%) groups in CA-AKI development. Logistic regression analysis showed that the D/TT (OR 2.463) and D/NT (OR 2.121) were the most influential parameters for CA-AKI development. In the receiver operating characteristic (ROC) curve analysis, the sensitivity of native thiol to detect the development of CA-AKI was 89.1%. The negative predictive values of native thiol and total thiol were 95.6% and 94.1%, respectively.

CONCLUSION

The serum thiol-disulphide level can be used as a biomarker to detect CA-AKI development and reveal patients with a low risk for CA-AKI development before EVT of PAD. Furthermore, thiol-disulphide levels allow for the indirect quantitative monitoring of NAC. Preprocedural intravenous NAC administration significantly inhibits CA-AKI development.

Percutaneous thrombectomy or ultrasound-accelerated thrombolysis for initial management of acute limb ischaemia

BACKGROUND

Acute limb ischaemia (ALI), the sudden and significant reduction of blood flow to the limb, is considered a vascular emergency. In the general population, the incidence is estimated as 14 per 100,000. Prognosis depends on the time it takes to diagnose the condition and begin appropriate treatment. Standard initial interventional treatments include conventional open surgery and endovascular interventions such as catheter-directed thrombolysis (CDT). Percutaneous interventions, such as percutaneous thrombectomy (PT, including mechanical thrombectomy or pharmomechanical thrombectomy) and ultrasound-accelerated thrombolysis (USAT), are also performed as alternative endovascular techniques. The proposed advantages of PT and USAT include reduced time to revascularisation and when combined with catheter-directed thrombolysis, a reduction in dose of thrombolytic agents and infusion time. The benefits of PT or USAT versus open surgery or thrombolysis alone are still uncertain. In this review, we compared PT or USAT against standard treatment for ALI, in an attempt to determine if any technique is comparatively safer and more effective.

OBJECTIVES

To assess the safety and effectiveness of percutaneous thrombectomy or ultrasound-accelerated thrombolysis for the initial management of acute limb ischaemia in adults.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, the World Health Organization (WHO) International Clinical Trials Registry Platform, and ClinicalTrials.gov to 3 March 2021. We searched reference lists of relevant studies and papers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared PT (any modality, including mechanical thrombectomy (aspiration, rheolysis, rotation) or pharmomechanical thrombectomy) or USAT with open surgery, thrombolysis alone, no treatment, or another PT modality for the treatment of ALI.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, assessed risk of bias, extracted data, performed data analysis, and assessed the certainty of evidence according to GRADE. Outcomes of interest were primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

MAIN RESULTS

We included one RCT in this review. This study had a total of 60 participants and compared USAT with standard treatment (CDT). The study included 32 participants in the CDT group and 28 participants in the USAT group. We found no evidence of a difference between USAT and CDT alone for the following evaluated outcomes: amputation rate (risk ratio (RR) 1.14, 95% confidence interval (CI) 0.17 to 7.59); major bleeding (RR 1.71, 95% CI 0.31 to 9.53); clinical success (RR 1.00, 95% CI 0.94 to 1.07); and adverse effects (RR 5.69, 95% CI 0.28 to 113.72). We rated the certainty of the evidence as very low for these outcomes. We downgraded the certainty of the evidence for amputation rate, major bleeding, clinical success, and adverse effects by two levels due to serious limitations in the design (there was a high risk of bias in critical domains) and by two further levels due to imprecision (a small number of participants and only one study included). The study authors reported 30-day patency, but did not report primary and secondary patency separately. The patency rate in the successfully lysed participants was 71% (15/21) in the USAT group and 82% (22/27) in the CDT group. The study authors did not directly report secondary patency, which is patency after secondary procedures, but they did report on secondary procedures. Secondary procedures were subdivided into embolectomy and bypass grafting. Embolectomy was performed on 14% (4/28) of participants in the USAT group versus 3% (1/32) of participants in the CDT group. Bypass grafting was performed on 4% (1/28) of participants in the USAT group versus 0% in the CDT group. As we did not have access to the specific participant data, it was not possible to assess these outcomes further. We did not identify studies comparing the other planned interventions.

AUTHORS' CONCLUSIONS

There is insufficient evidence to assess the safety and effectiveness of USAT versus CDT alone for ALI for our evaluated outcomes: amputation rate, major bleeding, clinical success, and adverse effects. Primary and secondary patency were not reported separately. There was no RCT evidence for PT. Limitations of this systematic review derive from the single included study, small sample size, short clinical follow-up period, and high risk of bias in critical domains. For this reason, the applicability of the results is limited. There is a need for high-quality studies to compare PT or USAT against open surgery, thrombolysis alone, no treatment, or other PT modalities for ALI. Future trials should assess outcomes, such as primary patency, amputation rate, major bleeding, clinical success, secondary patency, and adverse effects.

Medical Therapy Following Urgent/Emergent Revascularization in Peripheral Artery Disease Patients (Canadian Acute Limb Ischemia Registry [CANALISE I])

Background

Following severe limb ischemia requiring urgent/emergent revascularization, peripheral arterial disease patients suffer a high risk of recurrent atherothrombosis.

Methods

Patients discharged from Hamilton General Hospital (Hamilton, Ontario) between April 2016 and September 2017 following severe limb ischemia requiring urgent/emergent revascularization were identified via the Local Health Integration Network CorHealth database, with supplemental information from chart review.

Results

A total of 158 patients admitted for urgent/emergent revascularization were identified (148 alive at discharge). Among patients without a pre-existing indication for anticoagulation, 38.8% (n = 47) were discharged on single-antiplatelet therapy, 27.3% (n = 33) on dual-antiplatelet therapy, 19.8% (n = 24) on anticoagulants plus antiplatelet therapy, 6.6% (n = 8) on anticoagulants alone, and 2.6% (n = 3) on unknown therapy. Patients who received angioplasty with stenting were more likely be discharged on dual-antiplatelet therapy (hazard ratio [HR]: 7.14; 95% confidence interval [CI]: 2.87-17.76; P < 0.01); patients who received an embolectomy/thrombectomy were more likely be discharged on an anticoagulant alone (HR: 2.61; 95% CI: 1.00-6.81; P = 0.049); and patients who received peripheral bypass grafting were more likely be discharged on single-antiplatelet therapy (HR: 2.28; 95% CI: 1.11-4.69; P = 0.024). Neither statins (60.8% vs 56.3%; P = 0.23) nor renin–angiotensin–aldosterone system inhibitors (48.7% vs 50.6%; P = 0.58) were prescribed at higher rates at discharge, compared with the rate at admission.

Conclusions

Substantial heterogeneity exists in antithrombotic prescription following urgent/emergent revascularization. No intensification of non-antithrombotic vascular protective medications occurred during hospitalization. Clinical trials and health system interventions to optimize medical therapy in peripheral arterial disease patients are urgently needed.

Case Report: Diabetic nephropathy aggravates the progression and prognosis of COVID-19-associated acute limb ischemia

Hypercoagulation is a hallmark of both the novel coronavirus disease (COVID-19) and type 2 diabetes mellitus (T2DM). It increases the risk for vascular thrombosis, including peripheral artery diseases. Among others, acute limb ischemia (ALI) is one of most common complications that requires immediate and prompt treatments to reduce morbidity and mortality. However, the complex interplay between COVID-19, T2DM and its complications (e.g., diabetic nephropathy), and ALI creates a great challenge in the management of the disease. Here, we present a case of a 59-year-old diabetic female with progressive pain in her left leg in the last five years, which was significantly intensified following COVID-19 diagnosis. Bluish coloration, numbness and functional impairments were observed during examinations with no palpable pulsation on left posterior tibial and dorsalis pedis arteries. The patient also had diabetic nephropathy (stage III), hypoalbuminemia, anemia and a urinary tract infection that complicated the management of the disease. Due to the excruciating pain and the worsening of the limb conditions, right leg revascularization and left leg amputation were performed at day 14 after admission. Following the surgeries, no more pain was observed and patient was discharged for further follow-up at the outpatient clinic.

Surgical embolectomy in a cat with cardiogenic aortic thromboembolism

A seven-year-old, spayed female, domestic longhair cat was referred for management of a sudden aortic thromboembolism (ATE). Echocardiography showed hypertrophic cardiomyopathy with severe left atrial enlargement. Ultrasonography of the abdominal aorta confirmed a large thrombus at the level of the aortic trifurcation, involving both iliac arteries. Considering the recent onset and bilateral involvement of the iliac arteries, the cat underwent emergent surgical embolectomy (SE) of the aortoiliac embolus. A standard caudal celiotomy was performed and the abdominal aorta was identified. Vessel loops with tourniquets were placed around the abdominal aorta proximal to the thrombus and on both iliac arteries distal to the thrombus. A full-thickness incision was made in the ventral surface of the aorta. The aortic thromboembolus was removed. The trifurcation was subsequently flushed with sterile saline. The SE resulted in a good outcome, with both clinical and ultrasound signs of complete reperfusion of the rear limbs within a few hours. Long-term treatment included antiplatelet drugs, furosemide and benazepril. Eighteen months after surgery, the cat was free of clinical signs, without recurrence of ATE or congestive heart failure. Based on the present case, SE could be considered as a feasible alternative to traditional conservative treatment in cats with a very recent onset of bilateral ATE.

Acute Limb Ischemia: An Update on Diagnosis and Management

This review presents an update on the diagnosis and management of acute limb ischemia (ALI), a severe condition associated with high mortality and amputation rates. A comprehensive spectrum of ALI etiology is presented, with highlights on embolism and in situ thrombosis. The steps for emergency diagnosis are described, emphasizing the role of clinical data and imaging, mainly duplex ultrasound, CT angiography and digital substraction angiography. The different therapeutic techniques are presented, ranging from pharmacological (thrombolysis) to interventional (thromboaspiration, mechanical thrombectomy, and stent implantation) techniques to established surgical revascularization (Fogarty thrombembolectomy, by-pass, endarterectomy, patch angioplasty or combinations) and minor or major amputation of necessity. Postprocedural management, reperfusion injury, compartment syndrome and long-term treatment are also updated.

ANTIOXIDANT ENZYMES ACTIVITY IN EXPERIMENTAL ISCHEMIA-REPERFUSION INJURY

Background. Blood loss during civil and military limb trauma is the most common cause of preventable death. Complications due to the use of a hemostatic tourniquet are widely investigated nowadays. Therefore, the standards of the past have to be improved. Objective. The aim of the research is to study the reaction of the enzyme chain of the liver antioxidant system in the presence of modifications of ischemia-reperfusion injury (IRI). Methods. 210 white male-rats, aged 5-5.5 months, were used in the research. The dynamics of antioxidant enzymes activity catalase (Cat) and superoxide dismutase (SOD) in liver tissue in cases of modifications of ischemia-reperfusion injury (IRI) were studied. The period of investigation was in 24 hours, 3, 7, 14 days after the injury. Results. In cases of simulated IRI the catalase level mainly decreased at each period of the experiment. The peak of SOD activity was evidenced on the 1st, 3rd or 7th days after the experimental IRI according to the degree of trauma severity. Thus, IRI combined with severe blood loss and mechanical trauma caused the severest affection of the antioxidant system. Even a single application of hemostatic tourniquet caused similar wavelike reactions at different times. Conclusions. The development of IRI is accompanied by a significant depression of the liver antioxidant system. The most significant changes were evidenced in cases of IRI combined with blood loss and mechanical trauma, but even a single application of a tourniquet caused active response of the antioxidant enzymes.

Acute Limb Ischemia

Acute limb ischemia (ALI) is a rapid decrease in lower limb blood flow due to acute occlusion of peripheral artery or bypass graft, and in ALI not only limbs but also life prognosis will be poor unless quick and appropriate treatment is given. The etiology is broadly divided into embolism and thrombosis with various comorbidities. The symptoms of ALI are abrupt with pain, numbness, and coldness of lower limb, and paresthesia, contracture, and irreversible purpura will appear with the exacerbation of ischemia. Severity and treatment strategy should be determined based on physical findings and image findings. Considering life prognosis, limb amputation should be done without hesitation when the limb was diagnosed as irreversible. ALI can be treated by means of open surgical revascularization, endovascular, or hybrid approach with rapid systemic administration of heparin. In any cases, evaluating the lesions by intraoperative angiography and appropriate additional treatment are important. ALI is a serious disease requiring urgent treatment, and it is essential to promptly perform the best initial treatment that can be performed at each facility. (This is a translation of Jpn J Vasc Surg 2018; 27: 109–114.)

Traumatic anterior dislocation of a prosthetic knee, from trauma to delayed onset of vascular injury

Anterior dislocation of a prosthetic knee is a rare event. Only few episodes have been described in the past and have never been linked with neurovascular injury. This could lead orthopaedic surgeons to focus on the implant instability factors and underrate other complications. The authors report a case of a patient who experienced popliteal artery dissection 80 hours after traumatic anterior knee dislocation of a previously well-functioning total knee arthroplasty. Given that there is a lack of clinical cases that have established guidelines for management of this problem, the authors have focused on the importance of performing computed tomography angiography in the management of an anterior traumatic knee dislocation of a prosthetic knee.

Contemporary Management and Outcome After Lower Extremity Fasciotomy in Non-Trauma-Related Vascular Surgery

INTRODUCTION

Acute compartment syndrome (ACS) is a challenging and recognized complication to vascular surgery revascularization. The aim of this study was to investigate the current epidemiology, management, and early outcomes of fasciotomy in vascular surgery.

METHODS

Retrospective cohort study of all patients undergoing lower extremity fasciotomy at a single university center between January 2008 and December 2014. Patient demographics, operative techniques, and outcomes were analyzed.

RESULTS

The cohort (n = 113 limbs; 107 patients; 48% women; mean age was 74 (12) years [range, 50-97 years]) included 81 (72%) limbs undergoing revascularization for acute limb ischemia, 7 (6.2%) limbs related to acute aortic disease, and 23 (20%) limbs undergoing elective vascular surgery. Five patients underwent bilateral lower extremity fasciotomy. In all, 64 (57%) limbs had signs of ACS and underwent a therapeutic fasciotomy, while 49 (43%) fasciotomies were prophylactic. There were 20 (18%) fasciotomies performed after endovascular interventions. A 4-compartment fasciotomy was performed in 82% (n = 93) of limbs with a double incision technique. Split thickness skin graft was required in 11% (12/112) and vacuum-assisted closure treatment in 11% (12/111). The mean length of stay in hospital was 11 (9) days. Most common complication was lower extremity nerve deficit 32% (33/104) followed by wound infection 30% (32/108). At 30-day follow-up, amputation rate was 13% (14/107 limbs) and mortality 23% (25/107 patients). In the multivariate logistic regression analysis, prophylactic fasciotomy was associated with amputation (odds ratio: 28.9; 95% confidence interval: 1.96-425; P = .014).

CONCLUSION

Acute compartment syndrome is primarily related to acute ischemic conditions but occurs after both aortic or elective vascular procedures and endovascular treatments. There are significant complications related to lower extremity fasciotomy in vascular surgery.

Acute Limb Ischemia-Much More Than Just a Lack of Oxygen

Acute ischemia of an extremity occurs in several stages, a lack of oxygen being the primary contributor of the event. Although underlying patho-mechanisms are similar, it is important to determine whether it is an acute or chronic event. Healthy tissue does not contain enlarged collaterals, which are formed in chronically malperfused tissue and can maintain a minimum supply despite occlusion. The underlying processes for enhanced collateral blood flow are sprouting vessels from pre-existing vessels (via angiogenesis) and a lumen extension of arterioles (via arteriogenesis). While disturbed flow patterns with associated local low shear stress upregulate angiogenesis promoting genes, elevated shear stress may trigger arteriogenesis due to increased blood volume. In case of an acute ischemia, especially during the reperfusion phase, fluid transfer occurs into the tissue while the vascular bed is simultaneously reduced and no longer reacts to vaso-relaxing factors such as nitric oxide. This process results in an exacerbative cycle, in which increased peripheral resistance leads to an additional lack of oxygen. This whole process is accompanied by an inundation of inflammatory cells, which amplify the inflammatory response by cytokine release. However, an extremity is an individual-specific composition of different tissues, so these processes may vary dramatically between patients. The image is more uniform when broken down to the single cell stage. Because each cell is dependent on energy produced from aerobic respiration, an event of acute hypoxia can be a life-threatening situation. Aerobic processes responsible for yielding adenosine triphosphate (ATP), such as the electron transport chain and oxidative phosphorylation in the mitochondria, suffer first, thus disrupting the integrity of cellular respiration. One consequence of this is irreparable damage of the cell membrane due to an imbalance of electrolytes. The eventual increase in net fluid influx associated with a decrease in intracellular pH is considered an end-stage event. Due to the lack of ATP, individual cell organelles can no longer sustain their activity, thus initiating the cascade pathways of apoptosis via the release of cytokines such as the BCL2 associated X protein (BAX). As ischemia may lead to direct necrosis, inflammatory processes are further aggravated. In the case of reperfusion, the flow of nascent oxygen will cause additional damage to the cell, further initiating apoptosis in additional surrounding cells. In particular, free oxygen radicals are formed, causing severe damage to cell membranes and desoxyribonucleic acid (DNA). However, the increased tissue stress caused by this process may be transient, as radical scavengers may attenuate the damage. Taking the above into final consideration, it is clearly elucidated that acute ischemia and subsequent reperfusion is a process that leads to acute tissue damage combined with end-organ loss of function, a condition that is difficult to counteract.