Arterial emboli of the lower limbs: analysis of risk factors for mortality and amputation. Association Universitaire de Recherche en Chirurgie

Incidence and Predictors of Acute Limb Ischemia in Patients With Acute Myocardial Infarction-Insight from National Readmission Database

Acute limb ischemia (ALI) has been a rare complication of acute myocardial infarction (AMI), however, with the increasing use of mechanical circulatory devices it is seen more frequently. The incidence and predictors of ALI in patients with AMI in contemporary clinical practice are unknown. A retrospective review of patients with index hospitalization for AMI in the Nationwide Readmission Database from 2016 to 2019 was done. We evaluated the annual incidence of ALI and its impact on outcomes. We used multivariate logistic regression analysis to determine predictors of ALI. In 1,283,586 patients with AMI, 3,971 patients (0.31%) had ALI and 365 (0.03%) had limb amputation. The 3 major predictors of ALI were peripheral artery disease (odds ratio [OR] 11.91, 95% confidence interval [CI]: 10.78 to 13.51), intravascular microaxial left ventricular assist device (OR 4.39, 95% CI 3.86 to 5.00), and veno-arterial extracorporeal membrane oxygenation (OR 4.37, 95% CI 3.19 to 6.01). Intra-aortic balloon pump had a substantially lower predictive ability (OR 1.81, 95% CI 1.63 to 2.0, p <0.0001) than other forms of mechanical circulatory support. The mortality rate in patients with ALI was significantly higher than those without ALI (19.49% vs 4.85%, p <0.0001). Patients who developed ALI had higher rates of amputation (1.59% vs 0.02%, p <0.0001). This observational nationwide study showed that ALI is an important complication in patients with AMI and is more frequently seen in patients who have peripheral artery disease, and require a left ventricular assist device or venoarterial extracorporeal membrane oxygenation. This complication was also associated with significantly higher in-hospital mortality.

Blue toe syndrome caused by emboli from anomalous left atrial septal pouch thrombus: a case report

Background

Left atrial septal pouches (LASPs) are a relatively newly described but common anatomical cardiac variant thought to be associated with atrial fibrillation (AF) and cardio-embolic stroke. Blue toe syndrome (BTS) describes ischemic changes in the toes due to microembolisation of the digital arteries. Establishing the etiology of BTS is vital so that the underlying cause can be treated. Here we describe the first case of BTS arising due to emboli from LASP thrombus arising on a background of new-onset AF.

Case presentation

A 65-year-old man presented with a two-day history of progressive painful swelling and bluish-purple discoloration of the second and fourth toes of his left foot and new-onset AF. Tests for hypercoagulability disorders were negative. Duplex ultrasound and CT angiography excluded deep venous thrombosis and an absence of embolus, thrombus, or occlusion in the arterial tree in the lower extremities bilaterally, so BTS was diagnosed. While transthoracic echocardiography and chest CT initially showed no cardiac abnormalities or mural thrombus, subsequent transesophageal echocardiography revealed a LASP with an associated pedunculated thrombus. The affected toes were amputated due to wet gangrene, but the patient recovered well with thrombus resolution after anticoagulation.

Conclusion

The presence of a LASP in the absence of any other identifiable cause of BTS should trigger careful investigation of the interatrial septum, preferably using a multimodality imaging approach. The possibility that LASPs may not merely be an innocent bystander but a causative mechanism for peripheral ischemia must be considered.

Earliest effects of sudden occlusions on pressure profiles in selected locations of the human systemic arterial system

We have developed a numerical simulation method for predicting the time dependence (wave form) of pressure at any location in the systemic arterial system in humans. The method uses the matlab-Simulink environment. The input data include explicitly the geometry of the arterial tree, treated up to an arbitrary bifurcation level, and the elastic properties of arteries as well as rheological parameters of blood. Thus, the impact of anatomic details of an individual subject can be studied. The method is applied here to reveal the earliest stages of mechanical reaction of the pressure profiles to sudden local blockages (thromboses or embolisms) of selected arteries. The results obtained with a purely passive model provide reference data indispensable for studies of longer-term effects due to neural and humoral mechanisms. The reliability of the results has been checked by comparison of two available sets of anatomic, elastic, and rheological data involving (i) 55 and (ii) 138 arterial segments. The remaining arteries have been replaced with the appropriate resistive elements. Both models are efficient in predicting an overall shift of pressure, whereas the accuracy of the 55-segment model in reproducing the detailed wave forms and stabilization times turns out dependent on the location of the blockage and the observation point.

A unique case of acute embolus in a renal transplant with salvage by catheter-directed thrombolysis

INTRODUCTION

Acute renal transplant emboli can be disastrous and result in loss of the renal transplant. This case was successfully treated with thrombolysis.

CASE PRESENTATION

A 66-year-old female underwent a right-sided deceased heart-beating donor renal transplant. She had excellent transplant function but presented acutely three years later with pain in the transplanted kidney, an acute rise in serum creatinine and new onset atrial fibrillation. Bedside ultrasound scan demonstrated absent transplant perfusion. Emergency angiogram confirmed acute emboli in the transplant renal artery with some kidney perfusion. Thrombolysis with alteplase and anticoagulation with heparin was commenced. Serial imaging at 24 and 36 h demonstrated significant improvement in transplant perfusion. Following a period of supportive therapy, her transplant function recovered, although not to pre-morbid baseline levels.

CONCLUSION

Consider acute embolus in a renal transplant patient with acute kidney injury, transplant tenderness and cardiac arrhythmia. Early thrombolysis may salvage renal transplants and good transplant function may be regained.

Arterial embolism

Surgical and intensive care patients are at a heightened risk for arterial embolization due to pre-existing conditions such as age, hypercoagulability, cardiac abnormalities and atherosclerotic disease. Most arterial emboli are clots that originate in the heart and travel to distant vascular beds where they cause arterial occlusion, ischemia, and potentially infarction. Other emboli form on the surface of eroded arterial plaque or within its lipid core. Thromboemboli are large clots that dislodge from the surface of athesclerotic lesions and occlude distal arteries causing immediate ischemia. Atheroemboli, which originate from fracturing the lipid core tend to cause a process of organ dysfunction and systemic inflammation, termed cholesterol embolization syndrome. The presentation of arterial emboli depends on the arterial bed that is affected. The most common manifestations are strokes and acute lower limb ischemia. Less frequently, emboli target the upper extremities, mesenteric or renal arteries. Treatment involves rapid diagnosis, which may be aided by precise imaging studies and restoration of blood flow. The type of emboli, duration of presentation, and organ system affected determines the treatment course. Long-term therapy includes supportive medical care, identification of the source of embolism and prevention of additional emboli. Patients who experienced arterial embolism as a result of clots formed in the heart should be anticoagulated. Arterial emboli from atherosclerotic disease of the aorta or other large arteries should prompt treatment to reduce the risk for atherosclerotic progression, such as anti-platelet therapy and the use of statin drugs. The use of anticoagulation and surgical intervention to reduce the risk of arterial embolization from atherosclerotic lesions is still being studied.

Anesthésie–réanimation d’un patient en ischémie aiguë des membres inférieurs

OBJECTIVES

To appreciate the severity of a patient with acute limb ischaemia, to know how to manage these patients during the perioperative period.

DATA SOURCES

References were obtained from PubMed data bank (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) using the following keywords: acute limb, ischaemia, prognosis, complications, rhabdomyolysis, hyperkalaemia, compartment syndrome, fasciotomy.

DATA SYNTHESIS

Ischaemia of the lower limbs is a medico-surgical emergency. The ischaemia implies a decrease of cellular energetic stocks and an increase in intracellular calcium. During reperfusion, the calcium paradox is exacerbated and ROS formation produces membrane damage. Tissue oedema and a local and general inflammatory syndrome occur. Clinical symptoms of acute ischaemia include pallor, pulselessness, decrease of temperature and pain. Occurrence of neurological symptoms is a sign of severity. Prognosis of patients relates directly to preexisting collateral circulation, aetiology of the occlusion (thrombosis vs embolus), duration of ischaemia, topography of the occlusion (severity of proximal occlusions as the acute aortic occlusion), and co-morbidity (renal failure, heart failure). The temperature of the ischaemic limb, quality of the downstream circulation, extension of the thrombus, arterial pressure and association to a venous thrombosis are other prognostic factors of lower limb ischaemia. The first treatment to be initiated is high doses of heparin. Once the diagnosis is made, the number of preoperative tests will be as small as possible because of the urgency of revascularization. Arteriography will be performed only when really needed and when its realization will not delay revascularization and will not alter the patient's prognosis. Where general anesthesia is required, the choice of anaesthetic agents will be based on their haemodynamic stability. During severe acute limb ischaemia, monitoring of invasive pressure is recommended, as well as regular dosages of potassium, arterial gases and CPK. Preoperatively in case of severe ischaemia, (proximal occlusion lasting more than 6 hours), preventive treatment, including controlled reperfusion with heparinized serum is indicated. Surveillance and prevention of a rhabdomyolysis and renal failure are imperative. Immediately after reperfusion, a dosage of potassium must be performed; moreover that hyperkalaemia is favoured by acidosis or renal failure. Postoperative haemodialysis is performed in case of hyperkalaemia or renal failure. Occurrence of compartment syndrome has to be checked and fasciotomy must be performed in case of a doubt on the microcirculation integrity.

Surgical management of popliteal artery embolism at the turn of the millennium

Popliteal artery embolism has been a focus of study at the Massachusetts General Hospital for over 60 years. It is a formidable vascular problem with significant limb loss and mortality. To assess the impact of advances in cardiac and vascular therapies, we reviewed our outcomes over 12 years. A retrospective review from our databases identified 66 patients with 72 popliteal artery emboli between January 1989 and October 2000. Patients undergoing nonsurgical therapy or with in situ atherosclerotic thrombosis were excluded. Demographics, comorbidities, presentation, duration, etiology, treatment, and outcomes were analyzed. Patients were classified into those with acute (AP; symptoms <7 days; 59 of 72, 82%) or delayed (DP; symptoms >7 days; 13 of 72, 18%) presentation. The presentation was typically acute ischemia (85%) in the AP group and claudication (69%), rest pain (15.5%), or gangrene (15.5%) in the DP group. The most common etiology was embolism secondary to atrial fibrillation (17 of 72, 24%). Femoral artery access (15 of 72, 21%) was more prevalent than in our prior experience. In the AP group, 9 of 59 (15%) were treated with a femoral artery approach, 44 of 59 (75%) with a popliteal artery approach, and 6 of 59 (10%) with bypass. In the DP group, 11 of 13 (85%) were treated with a popliteal approach and 2 of 13 (15%) with bypass. Completion angiography was done in 17 cases (24%). Limb salvage rate was 88% (88% AP, 85% DP); the rate was 94% with angiography and 85% without it (p > 0.1). There were seven deaths (10%). The mortality rate was 33% after amputation and 7% after limb salvage (p < 0.05). Except for a greater prevalence of femoral artery access as an etiology, the demographics of patients with popliteal embolism were similar to those of prior reports. Although a femoral approach may be appropriate in select AP cases, a popliteal approach is preferred in most patients and is necessary in DP cases. Completion angiography should be performed to ensure adequacy of the embolectomy. Outcomes are unchanged. Future therapies should aim to improve limb salvage and mortality rates.

Surgical thrombectomy: current role in thromboembolic occlusions

Thromboembolic disease occurs in a heterogeneous group of patients with significant co-morbidities and variable presentations, resulting in high morbidity and mortality rates. To decrease these complications, multiple different endovascular modalities have been developed and used to treat this challenging problem. Physicians are now left with a broad array of endovascular and surgical options. Unfortunately, there are little data that accurately compare these modalities. Therefore, an individual approach to each patient with acute ischemia from thromboembolic disease must be employed. In order to tailor the treatment to the needs of each patient, the physician must be familiar with the techniques, complications, technology, and relative strengths and weaknesses of each treatment modality. This article will first outline the main technical considerations for performing surgical thromboembolectomy. The complications of operative thromboembolectomy will then be discussed followed by the data comparing operative and nonoperative therapy. Finally, clinical scenarios that are best treated by surgical intervention will be described.

Acute occlusion of popliteal and/or tibial arteries: the value of percutaneous treatment

OBJECTIVES

to describe early and mid-term results with a percutaneous therapeutic protocol including thromboaspiration, thrombolysis, and correction of the underlying lesion by PTA.

METHODS

thirty-three consecutive selected patients with recent (<1 month) reversible acute ischaemia associated with popliteal and/or tibial occlusion were studied. The primary endpoints were technical success (defined as residual mural thrombus less than 20% of the lumen and the presence of at least one tibial artery on angiogram), patient survival and limb salvage at 1 and 12 months. Secondary endpoints included complications, primary, assisted primary and secondary patency determined by duplex scan at 1, 6 and 12 months.

RESULTS

technical success was achieved in 27 patients (82%). Twenty patients were treated by thrombo- aspiration+/-thrombolysis only, and seven required additional PTA (26%). In six patients (18%), percutaneous techniques failed, and embolectomy was performed in two, bypass in one and major amputations in three (9%). For the entire series, the survival rate was 100% at 1 month and 94% at 1 year. The limb salvage rate was 91% at 1 month and 1 year. The cumulative primary patency, assisted primary patency and secondary patency rates were 81%, 81% and 86% respectively at 1 month and 66%, 72% and 77%, respectively, at 12 months. Early complications occurred in 10 patients (30%): five groin haematomas (15%), four compartment syndromes (12%) and one haemoglobinuria (3%).

CONCLUSION

percutaneous techniques offer excellent early and mid-term results in selected patients presenting with acute ischaemia with popliteal and/or tibial arteries occlusion.