The surgical management of acute limb ischaemia due to native vessel occlusion

PATIENTS WITH ACUTE LOWER LIMB ISCHEMIA CONTINUE TO HAVE SIGNIFICANT MORBIDITY AND MORTALITY

BACKGROUND

The treatment of acute lower limb ischemia (ALLI) has evolved over the last several decades with the availability of several new treatment modalities. This study was undertaken to evaluate the contemporary presentation and outcomes of ALLI patients.

METHODS

We retrospectively analyzed data from a prospectively collected database of all patients who presented to our tertiary referral hospital with acute ischemia of the lower extremity between May 2016 and October 2020. The cause of death was obtained from the Michigan State Death Registry.

RESULTS

During the study period, 233 patients (251 lower limbs) were evaluated for ALLI. Seventy-three percent had thrombotic occlusion 24% had embolic occlusion, and 3% due to a low-flow state. Rutherford classification of ischemia severity was 7%, 49%, 40%, and 4% for Rutherford grade I, IIA, IIB, and III, respectively. Five percent underwent primary amputations, and 6% received medical therapy only. The mean length of stay was 11 ± 9 days. Nineteen percent of patients were readmitted within 30 days of discharge. At 30 days postoperatively, mortality was 9% and limb loss was 19%. On multivariate analysis, one or no vessel runoff to the foot post-operatively was associated with higher 30-day limb loss. Patients with no run-off vessels post-operatively had significantly higher 30-day mortality. Cardiovascular complications accounted for most deaths (48%). At 1-year postoperatively, mortality and limb loss reached 17% and 34%, respectively.

CONCLUSION

Despite advances in treatment modalities and cardiovascular care, patients presenting with ALLI continue to have high mortality, limb loss, and readmission rates at 30 days.

Anaesthesia for vascular emergencies - a state of the art review

In this state-of-the-art review, we discuss the presenting symptoms and management strategies for vascular emergencies. Although vascular emergencies are best treated at a vascular surgical centre, patients may present to any emergency department and may require both immediate management and safe transport to a vascular centre. We describe the surgical and anaesthetic considerations for management of aortic dissection, aortic rupture, carotid endarterectomy, acute limb ischaemia and mesenteric ischaemia. Important issues to consider in aortic dissection are extent of the dissection and surgical need for bypasses in addition to endovascular repair. From an anaesthetist's perspective, aortic dissection requires infrastructure for massive transfusion, smooth management should an endovascular procedure require conversion to an open procedure, haemodynamic manipulation during stent deployment and prevention of spinal cord ischaemia. Principles in management of aortic rupture, whether open or endovascular treatment is chosen, include immediate transfer to a vascular care centre; minimising haemodynamic changes to reduce aortic shear stress; permissive hypotension in the pre-operative period; and initiation of massive transfusion protocol. Carotid endarterectomy for carotid stenosis is managed with general or regional techniques, and anaesthetists must be prepared to manage haemodynamic, neurological and airway issues peri-operatively. Acute limb ischaemia is a result of embolism, thrombosis, dissection or trauma, and may be treated with open repair or embolectomy, under either general or local anaesthesia. Due to hypercoagulability, there may be higher numbers of acutely ischaemic limbs among patients with COVID-19, which is important to consider in the current pandemic. Mesenteric ischaemia is a rare vascular emergency, but it is challenging to diagnose and associated with high morbidity and mortality. Several peri-operative issues are common to all vascular emergencies: acute renal injury; management of transfusion; need for heparinisation and reversal; and challenging postoperative care. Finally, the important development of endovascular techniques for repair in many vascular emergencies has improved care, and the availability of transoesophageal echocardiography has improved monitoring as well as aids in surgical placement of endovascular grafts and for post-procedural evaluation.

Comparison of digital subtraction angiography combined arterial thrombectomy versus simple arterial thrombectomy in the treatment of acute lower limb ischemia

BACKGROUND

This study aimed to compare the clinical efficacy of digital subtraction angiography (DSA) combined arterial thrombectomy versus simple arterial thrombectomy in the treatment of acute lower limb ischemia (ALI).

METHODS

This retrospective cohort study collected the clinical data from 124 patients (128 affected lower limbs) with ALI who underwent emergency surgery from March 2010 to November 2019. Patients were consecutively divided into Group A and Group B. Patients in Group A underwent simple arterial thrombectomy via the Fogarty catheterization. Patients in Group B underwent arterial thrombectomy, and the DSA was performed during the surgery. The differences in the success rate of primary surgery, the second intervention rate, and the amputation/mortality rate within 30-days after surgery were compared.

RESULTS

In Group A, 4 of 70 limbs (5.7%) were amputated, 54 of 70 limbs (77.1%) had improved blood flow, 14 of 70 limbs (20.0%) received a second intervention, and 3 of 68 patients (4.4%) died within 30 days. In Group B, 1 of 58 limbs (1.7%) was amputated, 56 of 58 limbs (96.6%) had improved blood flow, 3 of 58 limbs (5.2%) received a second intervention, and 2 of 56 patients (3.5%) died within 30-days. The success rate of primary surgery, the second intervention rate, and the amputation rate of Group B were significantly lower than Group A (P < 0.05).

CONCLUSION

Arterial thrombectomy combined with DSA may effectively improve the clinical efficacy of patients with ALI.

Successful thrombolysis of acute upper limb ischemia using ekosonic endovascular system ultrasound catheter in a patient with atrial fibrillation

Acute upper limb ischemia is considered a vascular emergency. These events are mostly thromboembolic and are often detected in patients with atrial fibrillation (AF). Surgical thrombectomy and percutaneous mechanical thrombectomy are the usual methods to treat this medical emergency. In this case, we report the case of a 75-years old woman with a history of AF who initially presented to our center because of syncope resulting from Torsades de pointes due to a known long-QT syndrome. Those episodes were treated adequately from the implanted ICD. In addition to the symptoms of syncope, the patient also noted symptoms of right upper-limb ischemia. Using duplex sonography, we noticed a thrombotic occlusion at the level of the axillary artery. Using femoral access, we performed an antegrade angiography of the axillary artery, which confirmed a fresh thrombotic occlusion. The initially performed thrombus aspiration wasn't successful, and the decision was made to use an ekosonic endovascular system (Ekosonic ™ Endovascular System, Boston Scientific, EKOS) catheter to perform catheter-directed thrombolysis. Locally, 10 mg Actilyse were administrated. Then an EKOS Catheter was delivered to the occlusion area and was placed for 6 h. Symptoms of ischemia were resolved, and the angiographic control showed normal flow in the axillary artery. The patient was discharged without any local deficits of the right hand.

Percutaneous Rotational Mechanical Atherectomy Plus Thrombectomy Using Rotarex S Device in Patients With Acute and Subacute Lower Limb Ischemia: A Review of Safety, Efficacy, and Outcomes

Acute and subacute ischemia of lower limbs is associated with high risk of amputation and potential severe life-threatening complications. Despite a lack of clear therapeutic recommendations, surgical treatments such as thrombectomy or bypass and/or catheter-directed thrombolysis (CDT) have been first-line procedures in both acute and subacute limb ischemia, but each therapy may lead to significant morbidity and mortality. Such situations demand fast restoration of appropriate flow to preclude limb loss and other complications. Percutaneous mechanical atherectomy plus thrombectomy (MATH) represents a minimally invasive approach for quickly recanalizing thrombus-containing lesions whatever the age of thrombus. Indeed, many chronic patients can present with critical limb ischemia, with thrombus-containing occlusive lesions triggered by underlying atherosclerotic disease. MATH offers various advantages over surgery and CDT, with lower invasiveness, faster recanalization, and the possibility to immediately treat the underlying lesions, with a lower rate of bleeding complications and no need for intensive care unit stay. Currently, several mechanical thrombectomy devices are offered as an alternative therapy and can be divided into pure rotational MATH systems and rheolytic thrombectomy devices. The only pure rotational MATH device currently available on the market is the Rotarex S device. We aimed to review contemporary clinical data regarding the safety, efficacy, and outcomes of MATH therapy using Rotarex S catheter in acute and subacute thrombus-containing arterial lesions of lower limbs. Future perspectives of Rotarex S MATH treatment and cost-effectiveness of its routine use will be also discussed.

Catheter-directed intra-arterial thrombolysis for lower extremity arterial occlusions

Catheter-directed intra-arterial thrombolysis (CDT) is a rational treatment method in patients with acute/subacute and even some chronic occlusions of lower extremity arteries and bypass grafts having salvageable limb ischemia. Immediate vessel patency can be achieved with an acceptable complication rate in many patients, especially those with fresh thrombus or emboli. It can be also an adjuvant treatment modality for endovascular interventions for chronic occlusions. There is no standard method of CDT including thrombolytic agent dose and technique. Selection of treatment strategy should be based on individual judgment based on viability of limb, lesion characteristics, and risks of hemorrhage.

The Indigo System in Acute Lower-Limb Malperfusion (INDIAN) Registry: Protocol

Background

Acute lower limb ischemia (ALLI) poses a major threat to limb survival. For many years, surgical thromboembolectomy was the mainstay of treatment. Recent years have brought an endovascular revolution to the management of ALLI. It seems that the newly designed endovascular thrombectomy devices may shift treatment recommendations toward endovascular options. This protocol study aims to collect evidence supporting the latest hypothesis.

Objective

The devices under investigation are the Penumbra/Indigo Systems (Penumbra Inc). The objective of this clinical investigation is to evaluate, in a controlled setting, the early safety and effectiveness of the devices and to define the optimal technique for the use of these systems in patients with confirmed peripheral acute occlusions.

Methods

This study will be an interventional prospective trial of patients with a diagnosis of ALLI treated with Penumbra/Indigo devices. This project is intended to be a national platform where every physician invited to participate could register his or her own data procedure. The primary outcome is the technical success of thromboaspiration with the Indigo System. Assessment of vessel patency will be recorded using the Thrombolysis in Myocardial Infarction (TIMI) score classifications before and after use of the device. Clinical success at follow-up is defined as an improvement of Rutherford classification at 1-month follow-up of one class or more as compared to the preprocedure Rutherford classification. Secondary endpoints include the following: (1) safety rate at discharge, defined as the absence of any serious adverse events; (2) primary patency at 1 month, defined as a target lesion without a hemodynamically significant stenosis or reocclusion on duplex ultrasound (>50%) and without target lesion reintervention within 1 month; and (3) limb salvage at 1 month.

Results

The study is currently in the recruitment phase and the final patient is expected to be treated by the end of March 2019. A total of 150 patients will be recruited. Analyses will focus on primary and secondary endpoints.

Conclusions

These new endovascular thrombectomy devices that are specifically designed for peripheral intervention in this difficult set of patients, as those under investigation in the proposed registry, may offer improved clinical outcomes with lower rates of major systemic and local complications. Following completion of this study, it is expected that the value of the Indigo Thrombectomy System in the treatment of ALLI will be better defined. As a result, a shift of treatment recommendations toward endovascular options may be observed in the near future.

International Registered Report Identifier (IRRID)

DERR1-10.2196/9972

Acute on chronic limb ischemia: From surgical embolectomy and thrombolysis to endovascular options

After the invention of the balloon catheter by Fogarty in 1963, surgical thromboembolectomy was considered the gold standard treatment for many years in patients with acute lower limb ischemia (ALLI). ALLI is a dramatic event, carrying a high risk of amputation and perioperative morbidity and mortality. The evolution of endovascular technologies has resulted in a variety of therapeutic options to establish arterial patency. In the 1970s, Dotter first introduced the idea of clot lysis in the treatment of ALLI, which was modified to catheter-directed thrombolysis, and now clot aspiration techniques. Currently, the majority of ALLI (about 70%) is arterial thrombosis, which generally occurs in the setting of preexisting vascular lesion. This condition is very common in patients with diabetes. Clinical presentation in case of thrombosis on atherosclerotic stenosis (so called "acute on chronic ischemia") may be less severe, but treatment is generally more challenging than ALLI due to embolism, considering the complexity in device trackability through the diseased vessels, potential vessel injury, incomplete revascularization, and need of correction of underlying vascular lesions. Although surgery is still a treatment option, especially for ALLI, endovascular interventions have assumed a prominent role in restoring limb perfusion. In this review, the treatment options for ALLI are detailed from surgical thromboembolectomy to thrombolysis and current endovascular techniques, including mechanical fragmentation, rheolytic thrombectomy, and aspiration thrombectomy. The evolution to endovascular therapies has resulted in improved clinical outcomes and lower rates of morbidity.

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.

Peripheral Arterial Embolism: Prevalence, Outcome, and the Role of Echocardiography in Management

The aims of this study were to review the prevalence and outcome of all surgically treated upper and lower limb emboli presenting to one vascular unit in the last 3 years and to compare transthoracic with transesophageal echocardiography for defining the source of the embolus. All patients who underwent surgical embolectomy for acute limb ischemia from January 2001 to June 2004 were reviewed. Transthoracic and transesophageal echocardiography were carried out on a subset of consecutive unselected patients. Forty-two patients, with a mean age of 80 years, underwent surgical embolectomy from January 2001 to June 2004 (M/F 1:1.8): 27 for lower limb ischemia and 15 for upper limb ischemia. Two thirds of these patients were found to be in atrial fibrillation at presentation (n=28), of whom less than a third were receiving anticoagulants or antiplatelet agents (n=8). The mean hospital stay was 15 days with 36 patients (86%) being fully anticoagulated before discharge from hospital. The 30-day mortality rate was 11% (n=3/27) with 5 patients requiring fasciotomies (12%) and 3 patients requiring an amputation of the lower limb (11%). Postoperatively, 34 patients (81%) had transthoracic echocardiography (TTE), which demonstrated a source or potential source for thrombus in 19 (56%). Fifteen patients (36%) had transesophageal echocardiography (TEE), which changed the subsequent management in 3 patients. All patients in whom TEE altered clinical management would have required this investigation if standard clinical guidelines were followed. TEE did not identify any additional patients with cardiac embolic sources that were not detected by TTE. Arterial limb emboli are still prevalent, but limb salvage and mortality rates appear to be improving. Despite clear guidelines on anticoagulation for patients in atrial fibrillation, many are not receiving appropriate treatment. Transthoracic echocardiography is a good screening tool for detecting a potential cardiac source for peripheral embolism, with transesophageal echocardiography being reserved for specific indications.

Acute Iliac and Femoral Arterial Thrombosis Secondary to Total Hip Arthroplasty

In the presented case report, we evaluated the mechanism of the external iliac, the common femoral and the superficial femoral arterial thrombosis secondary to total hip arthroplasty. A 75-year-old female sufferd from 5.5 cm shorter left lower limb and same sade coxarthritis. Next day after arthroplasty and eqalisation of the lower limbs, an acute ishemia of the treated leg was presented. Multyscan CT angiography revealed the presence of the external iliac, the common femoral and the superficial femoral arterial thrombosis. From the best of our knowledge, it seems to be the only case of this arterial segment thrombosis after total hip arthroplasty and equalistaion of the lower limbs reported.

Therapeutic outcomes and thromboembolic events after treatment of acute arterial thromboembolism of the upper extremity

BACKGROUND

To investigate short- and long-term outcomes of patients with acute arterial thromboembolism of upper extremity, focusing on postoperative thromboembolic events by etiology.

METHODS

Hospital records of 53 patients (average age 70 years; males 49%) with acute arterial thromboembolism of upper extremity treated between June 1993 and December 2013 were retrospectively reviewed, evaluating patient characteristics and clinical outcomes, both short and long term. Subjects were stratified as those with (group I, 34) and without (group II, 19) atrial fibrillation as underlying cause.

RESULTS

Two patients received anticoagulation alone as conservative treatment. The remainder (n = 51) underwent surgical revascularization. Symptoms resolved in 51 patients (96%) except 2 patients with postoperative reocclusion, and there was no need of amputation in all patients. Overall inpatient mortality was 5.6% (3/53). Patients of group I suffered most of the recurrent thromboembolic events (group I: 17 events, 14 patients; group II: 2 events, 2 patients) recorded during follow-up (mean duration 56.8 ± 62.2 months). Respective event-free survival rates at 1, 3, and 5 years differed significantly by group: 77%, 44%, and 44% for group I; 100%, 100%, and 83% for group II (P = 0.004). Among 14 patients with recurrent embolic events in group I, half of the patients were not receiving anticoagulants; however, anticoagulant cessation was generally arbitrary. Overall survival rates at 1, 3, and 5 years were 82%, 69%, and 52% for group I and 84%, 78%, and 70% for group II (P = 0.21).

CONCLUSIONS

In this study, surgical treatment of acute arterial thromboembolism of upper extremity was largely successful. Especially in patients with atrial fibrillation, adequate long-term anticoagulation is indicated as prophylaxis, given the high rates of recurrent thromboembolic events.

Acute limb ischemia in cancer patients: aggressive treatment is justified

BACKGROUND

The outcome of cancer patients with acute limb ischemia (ALI) is not well defined. The purpose of this study is to report our experience treating patients with active malignancy who developed ALI and compare their outcome with non-cancer patients.

METHODS

A retrospective review of patients treated for ALI between 2009 and 2012 with ALI. We identified those patients who suffered from ALI and compared the outcome of those with active malignancy to those without malignancy.

RESULTS

Of 147 patients treated for ALI (122 lower extremity, 25 upper extremity), 24 (16%) were cancer patients. Mean follow-up was 9.8 months for the malignancy group and 13.4 months for the control. Perioperative mortality rates were similar among cancer and non-cancer patients (20% vs. 16%, respectively, NS). Freedom from major amputation at 30 months was similar (95% vs. 89%, NS). Long-term survival rates of cancer patients were significantly lower compared to non-cancer patients (45% vs. 77% respectively, P<0.05).

CONCLUSIONS

Treatment of ALI among cancer patients can be achieved with perioperative mortality and limb salvage rates comparable to non-cancer patients. Aggressive treatment is justified when treating cancer patients with ALI.

Muscle fiber viability, a novel method for the fast detection of ischemic muscle injury in rats

Acute lower extremity ischemia is a limb- and life-threatening clinical problem. Rapid detection of the degree of injury is crucial, however at present there are no exact diagnostic tests available to achieve this purpose. Our goal was to examine a novel technique - which has the potential to accurately assess the degree of ischemic muscle injury within a short period of time - in a clinically relevant rodent model. Male Wistar rats were exposed to 4, 6, 8 and 9 hours of bilateral lower limb ischemia induced by the occlusion of the infrarenal aorta. Additional animals underwent 8 and 9 hours of ischemia followed by 2 hours of reperfusion to examine the effects of revascularization. Muscle samples were collected from the left anterior tibial muscle for viability assessment. The degree of muscle damage (muscle fiber viability) was assessed by morphometric evaluation of NADH-tetrazolium reductase reaction on frozen sections. Right hind limbs were perfusion-fixed with paraformaldehyde and glutaraldehyde for light and electron microscopic examinations. Muscle fiber viability decreased progressively over the time of ischemia, with significant differences found between the consecutive times. High correlation was detected between the length of ischemia and the values of muscle fiber viability. After reperfusion, viability showed significant reduction in the 8-hour-ischemia and 2-hour-reperfusion group compared to the 8-hour-ischemia-only group, and decreased further after 9 hours of ischemia and 2 hours of reperfusion. Light- and electron microscopic findings correlated strongly with the values of muscle fiber viability: lesser viability values represented higher degree of ultrastructural injury while similar viability results corresponded to similar morphological injury. Muscle fiber viability was capable of accurately determining the degree of muscle injury in our rat model. Our method might therefore be useful in clinical settings in the diagnostics of acute ischemic muscle injury.

Controlled Reperfusion Versus Conventional Treatment of the Acutely Ischemic Limb

Background—

Amputation rates and mortality in patients with severe acute limb ischemia remain high. The protective effect of controlled reperfusion (CR) on tissue damage because of local and systemic reperfusion injury is unclear.

Methods and Results—

A total of 174 patients from 14 centers were randomized between conventional treatment (CT) by thrombembolectomy and normal blood reperfusion and thrombembolectomy followed by CR. The primary end point was amputation-free survival (AFS) after 4 weeks (CT, 82.4%; CR, 82.6%). Secondary end points were AFS (CT, 62.4%; CR, 63.1%) and overall survival (CT, 71.6%; CR, 76.3%) after 1 year. Analysis of the prognostic effects of preoperative factors revealed a strong adverse effect of bilateral involvement on AFS. In the subgroup with unilateral ischemia (n=160), age >80 years and central localization of the occlusion had independent negative prognostic effects on AFS. In the per-protocol population of 104 patients with unilateral ischemia, treatment per protocol, and successful revascularization, amputation or death within 4 weeks occurred in only 8% as compared with 33% in patients not fulfilling these criteria. No differences between treatment groups CT and CR were found, neither overall nor in the per-protocol population nor in patient subgroups defined by other pre- and intraoperative factors.

Conclusions—

Similar AFS in patients with CT or with CR was observed in this large randomized multicenter trial.

Clinical Trial Registration—

URL: http://www.drks.de . Unique identifier: DRKS00000579.

Therapeutic effect of liposomal prostaglandin E1 in acute lower limb ischemia as an adjuvant to hybrid procedures

Prostaglandin E₁ (PGE₁) is widely used in the treatment of limb ischemia for its potent vasodilatory and antiplatelet effects. In order to assess the curative effect of liposomal PGE₁ (lipo-PGE₁) as an adjuvant to surgery in patients with acute lower limb ischemia (ALLI), 204 patients who underwent hybrid procedures (operative thromboembolectomy or bypass and necessary endovascular interventions) for ALLI were randomly divided into a blank control group and a lipo-PGE₁ group (intravenous infusion of 20 μg/day for 12–14 consecutive days following surgery). Patients were followed-up for 6 months after surgical revascularization for clinical events. The primary study endpoint, which was the combined incidence of perioperative (30 days) mortality (POM) and major adverse limb events (MALE; amputation or major intervention), was significantly reduced in patients treated with lipo-PGE₁ (5.1% compared with 13.2% in the control group). The overall incidence of clinical events, including POM, MALE and major adverse cardiovascular events, was significantly reduced in patients receiving lipo-PGE₁ (8.2%) compared with the controls (20.8%). Hybrid procedures are an improved method for treating ALLI and may remedy underlying lesions of vessels following thromboembolectomy.

[Long ischemic period of the lower limb--study of skeletal muscle viability in experimental animal models]

INTRODUCTION

Surgical treatment for acute limb ischemia is revascularization or - when the limb is in a critical stage - amputation. Correct staging of the disease is relatively difficult, therefore complication and mortality rates are extremely high. Our aim was to invesitigate acute critical ischemia in rats and to test postconditioning on this model.

METHODS

Experiment I: male Wistar rats underwent 4, 6, 8 hours of bilateral lower limb ischemia without reperfusion. Experiment II: suspected critical ischemia was followed by 2 hours of reperfusion with or without postconditioning. Histological samples were collected for routine staining and nitroblue-tetrazolium (NBT) enzyme-histochemistry. In Experiment II the microcirculatory changes were measured by laser Doppler flowmetry and blood samples were collected for laboratory testing (kreatin-kinase, CK).

RESULTS

Experiment I: After an eight-hour-obstruction, severe ischemic lesions were detectable, with rutine and NBT stainings, therefore 8 hours of ischemia was chosen for further testing. Experiment II: The CK levels showed significant (p < 0.05) drop, quantitative evaluation of enzyme-histochemisty resulted in significantly (p < 0.001) less viability depletion and microcirculation showed significant (p < 0.05) amelioration of the reperfusion parameters in the postconditioned group compared to the control.

CONCLUSIONS

Eight hours of lower limb ischemia is a suitable model to investigate acute critical ischemia in rats. Postconditioning could be a feasible technique to reduce IR injury associated with acute lower limb ischemia.

[Acute and critical ischemia of the lower limb]

Acute limb arterial occlusion has great clinical significance due to its high mortality and complication rates. Its diagnosis is easy; however staging after long-term occlusions can be very difficult with lack of exact criteria. It is crucial, since reversible stage should undergo revascularization, while with irreversible stage only amputation is curative. Due to occlusion, long-term ischemia occurs, resulting in injury of the muscle fibers and endothelial cells. In case of revascularization the reperfusion causes more damage, than ischemia alone locally and initiates a remote organ injury. The aim of the review is to summarize the knowledge and fact and focus on some exact methods or parameters which can determine the degree of injury. One of these methods is a new approach which is the use of enzyme-histochemical reactions, and could give rapid, precise results even preoperatively regarding tissue viability. Routine clinical application of it is predictable after proper standardization.

Recanalisation of thrombotic arterial occlusions with rotational thrombectomy

PURPOSE

This study sought to assess the effectiveness of rotational thrombectomy (RT) with the Rotarex device in the treatment of thrombotic occlusions in native arteries, by-pass grafts, stents and stent-grafts.

MATERIALS AND METHODS

Over the last 4 years, 22 patients (14 men and 8 women; mean age 62.6 years) affected by 5 acute (<14 days) thrombotic occlusions of the native arteries (4 plaque thromboses in the common iliac artery and one on a dissection intimal flap of the external iliac artery), 17 subacute and chronic thromboses affecting 4 femoro-popliteal by-pass grafts, 10 stents (7 in the common iliac artery and 3 in the superficial femoral artery) and 3 stents-grafts were studied. Acute thromboses of native arteries were follow-up with colour-Doppler ultrasound (US) examination at 1 and 3 months. Subacute and chronic thrombotic occlusions were follow-up with colour-Doppler US examination at 1, 3, 6 and 12 months and yearly thereafter.

RESULTS

Immediate technical success was achieved without any need for additional procedures in all acute occlusions of native arteries (4/22 cases). In the subacute and chronic occlusions, the procedure was completed with percutaneous transluminal angioplasty (PTA) (8/22), cutting balloon (6/22) and stenting (5/22). The complication rate was 4.8% (1 rupture of the external iliac artery repaired with a stent-graft).

CONCLUSIONS

Arterial recanalisation with RT is the treatment of choice for acute thrombosis of healthy native arteries (4-7 mm); the treatment of thrombosis complicating calcified plaques or dissection intimal flaps may cause rupture of the arterial wall. In subacute and chronic occlusions of by-pass grafts, stents and stent grafts, additional procedures are necessary to achieve complete recanalisation.

Recurrent upper extremity embolism due to a crutch-induced arterial injury: a different cause of upper extremity embolism

Acute embolism of the upper extremity is a relatively infrequent event compared to the lower extremity, but it will affect the function of the limb involved and may occasionally lead to amputation. Most upper extremity emboli are of cardiac origin, with the remainder arising from subclavian aneurysm, occlusive disease, or iatrogenic causes. Rarely, crutch-induced repetitive trauma of an upper extremity can produce recurrent embolic events. Frequently, this process is initially diagnosed and treated as a brachial artery embolism; such a misdiagnosis is associated with recurrent embolism. We report herein two uncommon cases of axillobrachial arterial injuries secondary to crutch trauma as a source of recurrent emboli to an upper extremity.

Update experience of surgery for acute limb ischaemia in a district general hospital - are we getting any better?

INTRODUCTION

The aims of this study were to audit results of a 10-year experience of surgery for acute limb ischaemia (ALI) in terms of limb salvage and mortality rates, and to compare results with a historical published series from our unit.

PATIENTS AND METHODS

All emergency operations performed during the period 1993-2003 were identified from theatre registers and patient notes reviewed to determine indications for, and outcome of, surgery. Data were compared to a similar cohort who underwent surgery from 1980 to 1990.

RESULTS

There was a 33% increase in workload from 87 to 116 patients between the two time periods. The number of patients with idiopathic ALI reduced (24% versus 4%; P < 0.05), and there were fewer smokers (71% versus 39%; P < 0.05) and a greater number of claudicants (17% versus 35%; P < 0.05) in those treated from 1993-2003. Latterly, more patients underwent pre-operative heparinisation (33% versus 80%; P < 0.05), received prophylactic antibiotics (14% versus 63%; P < 0.05), and had anaesthetic presence in theatre (46% versus 88%; P < 0.05). There was also a reduction in local anaesthetic procedures (80% versus 41%; P < 0.05). Despite increased pre-operative (15% versus 47%; P < 0.05) and on-table imaging (0% versus 16%; P < 0.05) technical success did not improve. Whilst complication rates were identical at 62%, there were fewer cardiovascular complications in the recent cohort. The 30-day mortality rate for embolectomy fell from 45% to 33%. Multivariate analysis revealed age > 70 years, prolonged symptom duration, ASA score > or = III, lack of prophylactic antibiotics, absence of an anaesthetist, and operations performed under local anaesthetic to be associated with increased risk of mortality. Factors adversely affecting limb salvage included prolonged duration from symptom onset to operation, and a history of claudication or smoking.

CONCLUSIONS

Despite improvements in pre- and peri-operative management, arterial embolectomy/thrombectomy remains a procedure with a high morbidity and mortality. Further attempts to improve outcome must be directed at early diagnosis and referral as delay from symptom onset to surgery is a major determinant of outcome.

[Clinical and therapeutic characteristics of limb emboli]

INTRODUCTION

To treat an extremity embolus seems to be a simple and safe procedure. However, it is not exempt from potentially serious complications. We review our experience of treating acute peripheral arterial occlusion due to emboli.

PATIENTS AND METHOD

We retrospectively analyzed the data of 127 embolectomies performed during the last five years, in 120 extremities in 116 patients. The mean age of the patients was 80 years and 66% were female. All cases were presented as acute threatened limb ischemia grades IIA or IIB, and the mean evolution time was 27 hours. The patency, limb salvage and morbidity-mortality rates in the postoperative period and the salvage and survival rates in the follow-up were analyzed.

RESULTS

Of the embolectomies, 55% were femoral and 30% brachial. Although 90% of the cases improved, only 75% of them recovered distal pulses. In the postoperative period the patency, limb salvage, morbidity and mortality rates were 90%, 96%, 13% and 6.4%, respectively. The mean follow-up was 24 months. Up until this time, the patency and survival rates are 91% and 61%, respectively. The only factor related with an increase in the amputation rate was a clinical presentation, such as a threatened immediate ischemia. The factors related with an increase in survival rate were appropriate cardiological treatment and control, and long-term anticoagulation treatment.

CONCLUSIONS

Suffering an embolus of the extremities and its treatment causes considerable morbidity-mortality and limb amputation rates. The extremity salvage is associated with the clinical presentation at the time of the treatment. Long-term anticoagulation treatment and appropriate cardiological control increase the survival of these patients.

The ILAILL study: iloprost as adjuvant to surgery for acute ischemia of lower limbs: a randomized, placebo-controlled, double-blind study by the italian society for vascular and endovascular surgery

SUMMARY BACKGROUND DATA

High rate of complications has been reported following revascularization for acute limb ischemia (ALI). No adjuvant pharmacologic treatment, apart from anticoagulation and standard perioperative care, has been shown clinically effective.

OBJECTIVE

Aim of this study was to evaluate the effects of the prostacyclin analog iloprost as adjuvant to surgery for ALI.

METHODS

A total of 300 patients were randomly assigned to receive perioperative iloprost (intra-arterial, intraoperative bolus of 3000 ng, plus intravenous infusion of 0.5-2.0 ng/kg/min for 6 hours/day for 4-7 days following surgery), or placebo. The primary endpoint was the combined incidence of death and amputation at 3-month follow-up. Secondary endpoints were the incidence of each single major complication, total event rate, symptomatology, and tolerability.

RESULTS

The combined incidence of death and amputation was 19.9% in the placebo and 14.1% in the iloprost group (relative risk, 1.56; 95% confidence interval, 0.89-2.75, P = 0.12, Cox regression analysis). A statistically significant lower mortality (4.7%) was reported in patients receiving iloprost, compared with controls (10.6%; relative risk, 2.61; 95% confidence interval, 1.07-6.37, P = 0.03). The overall incidence of fatal plus major cardiovascular events was 33.1% and 22.8% in placebo and iloprost groups, respectively (relative risk, 1.61; 95% confidence interval, 1.04-2.49, P = 0.03). No serious adverse reactions occurred after iloprost administration, nor differences in the incidence of bleeding or hypotension between treatment groups.

CONCLUSIONS

Although at lower levels than previously reported, our results confirm the severity of ALI. Iloprost as adjuvant to surgery significantly reduced mortality and overall major event rate. Further data are needed to support this finding, and to face a still open medical issue.

Controlled reperfusion using a simplified perfusion system preserves function after acute and persistent limb ischemia: A preliminary study

OBJECTIVE

Reperfusion of the limb after acute and persistent ischemia is associated with high rates of morbidity and mortality despite complete revascularization. Although reperfusion is a prerequisite for maintaining limb function, it may in itself cause further injury. There is experimental evidence that modification of the initial reperfusion modalities can minimize this reperfusion injury. We hypothesized that controlled reperfusion using a simple blood bag perfusion system reduces reperfusion injury and facilitates the return of normal function.

METHODS

Fifteen consecutive patients (mean age, 80.5 +/- 5.0 years) with severe, acute lower-limb ischemia were allocated to two treatment arms in this prospective, controlled observational study. Group I (n = 8) underwent surgical embolectomy alone, and group II (n = 7) underwent surgical embolectomy plus controlled reperfusion using a simplified perfusion system. Indication for controlled reperfusion was made by the responsible surgeon. Controlled reperfusion consisted of a 30-minute infusion of a crystalloid reperfusion solution that was mixed with oxygenated blood (the blood:reperfusion solution ratio was 6:1) distal to the occlusion. Duration of ischemia, postoperative amputation rate, motor function of the ischemic limb, and pre- and postoperative serum creatine kinase levels were assessed.

RESULTS

The duration of ischemia was 10.7 +/- 1.1 hours in group I and 19 +/- 5.2 hours in group II (P < .05). The site of the arterial occlusion was the iliac artery in nine patients and the common femoral artery in six patients. Full recovery was achieved in six of seven patients in group II and in only two of eight patients in group I (P < .05). There were three in-hospital deaths in group I, and two patients underwent major amputations. No in-hospital deaths or major amputations occurred in group II.

CONCLUSION

The results from this preliminary study strongly suggest the hypothesis that the results of conventional embolectomy for acute, severe lower-limb ischemia can be improved by controlled reperfusion. To prove our preliminary findings, a large randomized, prospective, controlled, multicenter trial, the Controlled Reperfusion of the Acutely Ischemic Limb trial (CRAIL-Trial) is currently being conducted to prove our preliminary findings.

Early experience with a rotational thrombectomy device for treatment of acute and subacute infra-aortic arterial occlusions

PURPOSE

To evaluate a rotational thrombectomy device in the treatment of acute and subacute/chronic thrombotic infra-aortic occlusions of native vessels and bypass grafts.

METHODS

From July 2000 to February 2002, 98 patients (65 men; mean age 66+/-9 years, range 47-90) with 100 thrombotic occlusions (mean age of occlusion 31+/-33 days, range 0-140) measuring an average of 21+/-11 cm long (range 2-40) were treated with rotational thrombectomy (Rotarex). There were 33 acute (</=14 days) thrombotic/embolic native artery occlusions (group I), 58 subacute/chronic (>14 days) native artery occlusions (group II), and 9 acute bypass graft occlusions (group III).

RESULTS

The device activation time was 4.9+/-1.4 minutes, during which 4.0+/-1.4 passes of the device were performed. The amount of aspirated fluid was 240+/-119 mL. Slightly less than half the arteries (48%) were stented. Primary success (residual stenosis <30%) was achieved in 92% (94% for group I, 93% for group II, and 78% for group III; 100% for the ipsilateral approach, 56% for the crossover approach). Among the 18 complications, 3 were serious (2 amputations after unsuccessful intervention and 1 death); there were 8 vessel perforations and 7 cases of peripheral embolization. Thirty-day survival and limb salvage was 88% for group I, 100% for group II, and 66% for group III.

CONCLUSIONS

The device is an easy-to-handle, useful tool for ipsilateral treatment of acute and subacute thrombotic arterial and bypass graft occlusions. The use of this device is limited by the 8-F diameter of the catheter and the limited capacity for crossover interventions.

Current options in the diagnosis and management of acute limb ischemia

Acute limb ischemia occurs due to a sudden decrease in the blood flow to a limb, resulting in a potential threat to the viability of the extremity. Unfortunately, the threat is not only to the limb, but these patients are also at high risk for death. Limb hypoperfusion results in systemic acid-base and electrolyte abnormalities that impair cardiopulmonary and renal function. Successful reperfusion may result in the release of highly toxic free radicals, further compromising these critically ill patients. Therapeutic choices are often few and patient expectations are not always realistic. The management of acute limb ischemia requires a thorough understanding of the anatomy of the arterial occlusion and the open surgical and percutaneous options for restoring limb perfusion. Priorities for the diagnosis and effective management of these critically ill patients are provided.