Percutaneous catheter thrombus aspiration for acute or subacute arterial occlusion of the legs: how much thrombolysis is needed?

Successful Treatment of Subacute Limb Ischemia by Thromboaspiration with an 8-Fr Long Sheath in a 10-Fr Short Sheath

A 79-year-old man with a history of atrial fibrillation presented for evaluation of sudden onset of intermittent claudication of the left lower limb. An angiogram revealed thrombotic total occlusion of the left superficial femoral artery (SFA). A 10-Fr sheath was antegradely inserted into the left common femoral artery (CFA), and the guidewire penetrated the lesion. Thromboaspiration using an 8-Fr long sheath inserted into a 10-Fr short sheath was performed repeatedly. Intravenous anticoagulant was administrated immediately after endovascular treatment. Follow-up angiography performed 12 days after the procedure confirmed the absence of residual thrombus in the SFA. Thromboaspiration using a large-diameter catheter is a feasible, cost-effective strategy for treatment of acute and subacute limb ischemia.

Endovascular revascularization strategies using catheter-based thrombectomy versus conventional catheter-directed thrombolysis for acute limb ischemia

Background

Acute limb ischemia (ALI) is an important clinical event threatening both life and the affected limbs, but the optimal treatment for ALI remains undefined. The aim of this study was to compare the safety and effectiveness of thrombectomy approaches via either catheter-based thrombectomy (CBT) or catheter-directed thrombolysis (CDT).

Methods

A total of 98 patients (mean age 69.7 years, 60 male) who underwent endovascular intervention for ALI from January 2015 to July 2019 were included. Of these, 57 were treated with primary CBT via a large-bore catheter, an AngioJet catheter or Rotarex catheter, and/or underwent low-dose CDT, and 41 were treated with primary CDT. The safety and effectiveness of CBT compared to conventional CDT and other various endovascular techniques were evaluated.

Results

More Rutherford IIb patients were treated with primary CBT (68.4%) than CDT (26.8%; P < .001). Patients who underwent primary CDT achieved a higher technical success rate than those who underwent primary CBT in a shorter procedure time (P < .001), whereas 42.1% of patients who underwent CBT did not need adjunctive CDT. The duration and dosage of adjunctive CDT in the CBT group were significantly decreased compared with those in the primary CDT group (both P < .001), and the CBT group achieved a shorter in-hospital length of stay (P < .001). Subgroup analysis revealed that patients treated with AngioJet and Rotarex catheters achieved slightly lower dosages, shorter CDT durations and shorter in-hospital stay lengths than those treated with large-bore catheters (P > .05). Clinical success was estimated to be achieved in 98.2% of patients who underwent CBT, which is similar to the 97.6% estimated in those who underwent primary CDT (P = 1.000), and this finding was similar among the CBT subgroups. Patients who underwent CBT had a higher procedure-related distal embolization rate and economic cost than those who underwent primary CDT (P < .05), but it had slightly fewer complications than those who underwent primary CDT (P = .059), especially minor complications (P = .036). The freedom from amputation at 6 and 12 months for CBT and CDT was assessed (93.0% vs 90.2% respectively, P = .625; 89.5% vs 82.9%, respectively, P = .34,). Comparable limb salvage was found for different techniques of large bore catheters, AngioJet catheters and Rotarex catheters. The Kaplan-Meier table analysis also showed similar limb salvage rates between groups.

Conclusions

Endovascular treatment of ALI with the use of catheter-based therapies is an effective modality that can reduce the requirement for thrombolysis, with expected reductions in hemorrhagic complications, but at the risk of remediable distal emboli and increased economic cost. It has a similar clinical outcome to conventional CDT alone. Different CBT techniques have comparable efficacy but different adverse event profiles.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00349-9.

Recent advancement on PD-L1 expression quantification: the radiologist perspective on CT-guided FNAC

PURPOSE

We aimed to evaluate the feasibility, accuracy, and safety of Programmed Death-1/ Programmed Death-Ligand 1 (PD-1/ PD-L1) expression quantification in cytology cell-block samples obtained through transthoracic CT-guided fine-needle aspiration cytology (FNAC) from the interventional radiologist's perspective.

METHODS

We performed a consecutive unselected series of 361 CT-guided biopsies of pulmonary nodules and masses which came to our observation from June 2017 to October 2018. For each case, exhaustive clinical, morphologic, molecular and tomographic data were available. All the material obtained was fixed in formalin to obtain a cell-block for the pathologist, who performed immunohistochemical analysis to detect PD-L1 expression levels on each sample.

RESULTS

Of all the analyzed samples, 93.6% (338/361) were defined to be diagnostic, including neoplastic (72%, 260/361) and non-neoplastic lesions (21.6%, 78/361); only 6.4% (23/361) of them resulted in nondiagnostic specimens. Non-small cell lung cancer (NSCLC) accounted for 73.8% of neoplastic lesions (192/260): most of them were adenocarcinoma (83%, 160/192), followed by squamous carcinoma (14%, 27/192) and poorly differentiated carcinoma (3%, 5/192). In 96% of NSCLC (184/192), the diagnosis was reached either in the absence of complications or with early minor complications. PD-L1 expression was evaluated in all 192 NSCLC cytology specimens: 180 immunostainings were found to be adequate for PD-L1 testing. In 76% of cases, PD-L1 expression level was lower than 50%.

CONCLUSION

The findings of our study indicate that PD-L1 quantification using a cell-block approach on CT-guided FNAC is a feasible and safe technique and should be taken into account alongside with core biopsy approach, especially in case of advanced disease and/or fragile and older patients.

Percutaneous mechanical thrombectomy in acute and subacute lower-extremity ischemia: impact of adjunctive, solely nonthrombolytic endovascular procedures

PURPOSE

We aimed to evaluate the role of adjunctive, solely nonthrombolytic endovascular therapy in treatment of acute lower-extremity ischemia by rotational percutaneous mechanical thrombectomy.

METHODS

A retrospective, single-center evaluation of 165 patients (167 limbs) that underwent rotational percutaneous mechanical thrombectomy between 2009 and 2016 was performed.

RESULTS

Rotational percutaneous mechanical thrombectomy was used as a single therapy in 9.0% (15 limbs), followed by percutaneous aspiration thrombectomy in 6.0% (10 limbs), percutaneous transluminal angioplasty in 19.8% (33 limbs) and stenting in 25.7% (43 limbs). Rotational percutaneous mechanical thrombectomy was followed by any combination of these three interventions in 39.5%. Clinical and technical success was documented in 92.2%, complications in 10.3% (n=17). No significant difference in clinical and technical success was observed using rotational percutaneous mechanical thrombectomy alone or with additional endovascular therapy. On a long-term basis, the re-ischemia-free survival was nearly twice as high as in previous studies that reported more cases treated by rotational percutaneous mechanical thrombectomy alone.

CONCLUSION

To assure a long-lasting primary patency after percutaneous mechanical thrombectomy, concomitant treatment of underlying lesions with adjunctive, nonthrombolytic endovascular methods should be considered.

Endovascular approach for acute limb ischemia without thrombolytic therapy

Background:

Endovascular therapy for acute lower limb ischemia (ALLI) has developed and demonstrated safety and efficacy. The purpose of this study was to assess clinical outcomes in patients treated for ALLI with conventional endovascular or surgical revascularization.

Method:

This study was a retrospective single-center review. Consecutive patients with ALLI treated with conventional endovascular revascularization (ER) without thrombolytic agent or surgical revascularization (SR) between 2008 and 2014 were investigated. The 1 year and 3 year amputation rate and mortality rate were assessed by time-to-event methods, including Kaplan–Meier estimation.

Result:

A total of 64 limbs in 62 patients with ALLI due to thromboembolism or thrombosis of a native artery, bypass graft, or previous stented vessel were included. The majority of limbs (90.9%) presented with Rutherford clinical categories 1 to 2 ischemia. Technical success rate was 95.5% in ER and 92.9% in SR group (p = 0.547). Overall amputation rates were 9.1% in ER versus 9.5% in SR after 1 year (p = 0.971) and 9.1% in ER versus 11.9% in SR after 3 year (p = 0.742). Overall mortality rates were 15% in ER versus 7.1% in SR after 1 year (p = 0.491) and 15% in ER versus 11.2% in SR after 3 year (p = 0.878).

Conclusion:

Endovascular or surgical revascularization of ALLI resulted in comparable outcomes in limb salvage and mortality rate at 1 year and 3 year. Conventional endovascular therapy without thrombolytic agent such as stenting, balloon angioplasty, or catheter-directed thrombosuction may be considered as a treatment option for ALLI.

Endovascular treatment for chronic lower extremity ischaemia with sub-acute deterioration

OBJECTIVES

The purpose of this study is to report the efficacy of endovascular treatment for patients with sub-acute (14-day to 2-month) deterioration of chronic lower extremity ischaemia.

MATERIALS AND METHODS

Between June 2013 and May 2015, 26 consecutive patients (22 men, 4 women; mean age, 68.6 years; range, 50-86 years) were treated for sub-acute deterioration of chronic lower extremity ischaemia in our hospital. All patients were treated with catheter-directed thrombolysis initially and then adjunctive percutaneous transluminal angioplasty and/or stenting was performed to correct underlying lesions.

RESULTS

The 26 intra-arterial thrombolysis procedures were all performed in native lower arteries including 8 iliac, 13 femoropopliteal and 5 diffuse occlusions involving the iliac and femoropopliteal segments. Lesion length decreased from 194 mm (70-350 mm) to 92 mm (20-270 mm) after the thrombolytic procedures, and the residual lesions were corrected with percutaneous transluminal angioplasty alone in 4 (15.4%) limbs and stenting in 22 (84.6%) patients. No cross-joint stenting was seen in the 22 affected limbs that used stents. Throughout the treatment process, nine patients with intermittent claudication achieved an unrestricted walking distance, and 17 patients with rest pain or foot ulcers showed significant symptom improvement. The mean ankle-brachial index increased from 0.42 ± 0.16 preoperatively to 0.81 ± 0.25 postoperatively ( p < 0.01).

CONCLUSION

Endovascular therapy with catheter-directed thrombolysis and percutaneous transluminal angioplasty/stenting is feasible for sub-acute deterioration of chronic lower extremity ischaemia patients with favourable midterm results.

Urokinase Thrombolysis in Acute-on-Chronic Vascular Occlusion of Lower Limb

Between January 2000 and June 2003, 70 patients (63 men and 7 women) with acute-on-chronic lower limb vascular occlusion underwent thrombolysis with 1 million units of urokinase. Forty-eight patients had unilateral and 22 had bilateral involvement; 9 had gangrenous changes. The mean age was 47 ± 9 years, 73% were smokers, and 13% had diabetes. The definition of a good response was either return of distal pulses or a warm limb and relief of pain at rest. Fifty-three (76%) patients (including 5 with gangrenous changes) had symptomatic improvement with thrombolysis (group 1), and 17 (24%) did not respond (group 2). All 70 patients (including 7 who later required amputation) underwent surgical intervention with a polytetrafluoroethylene interposition graft or arterioplasty. A good response to surgical treatment was found in significantly more patients (49/53, 92%) in group 1 compared to group 2 (7/17, 41%). Claudication distance after 6 months of follow-up improved in a significantly higher percentage of patients in group 1 (85%) than group 2 (38%). Preoperative thrombolysis improved the outcome and predicted the result of arterial surgery.

Foot Embolization During Limb Salvage Procedures in Critical Limb Ischemia Patients Successfully Managed With Mechanical Thromboaspiration: A Technical Note

PURPOSE

To illustrate the use of a mechanical thromboaspiration device originally designed for clot retrieval in acute stroke in the treatment of acute distal embolism occurring during percutaneous revascularization of the femoropopliteal and below-the-knee arterial segments.

TECHNIQUE

The Penumbra system was adapted for aspiration of thrombus in the distal foot arteries as a standalone device. The 2 over-the-wire, tapered lumen catheters have long working lengths (139 cm for the 4MAX to 153 cm for the 3MAX) that allow advancement below the ankle even with a retrograde contralateral approach. Once the occluded arterial segment is reached, the catheters are connected to the dedicated pump for continuous vacuum aspiration. The use of the device is illustrated in 3 diabetic patients (1 woman and 2 men; ages 88, 70, and 73 years, respectively) undergoing limb salvage procedures who experienced distal embolization that would have seriously jeopardized the foot circulation. The lumens of the occluded arteries were restored without complication.

CONCLUSION

While further evaluation in a larger cohort of patients is needed, this initial experience using the Penumbra system in the peripheral vasculature suggests that this is a rapid, effective approach to address intraprocedural foot embolization and avoid possible grave clinical sequelae.

Acute Limb Ischemia

Acute limb ischemia is a vascular event presenting with sudden decrease in limb perfusion (of <14 days' duration) that threatens limb viability. Acute thrombosis of the native artery or graft makes up the bulk of etiopathogenesis. Prompt revascularization is the cornerstone of management of acute limb ischemia in limbs that have not undergone irreversible tissue and nerve damage. Amputation is performed in patients with irreversible tissue and nerve damage.

Effect of systemic urokinase infusion after lower limb percutaneous transluminal angioplasty on limb salvage rate in patients with late-stage critical limb ischemia

OBJECTIVE

To evaluate the effect of systemically administered urokinase (UK) after percutaneous transluminal angioplasty with or without stent (PTA ± stent) on the reduction in the rate and level of amputation in patients with critical limb ischemia (CLI) with tissue loss.

METHODS

This was an observational, nonrandomized, retrospective study of 183 Taiwanese patients with Rutherford stage 5 or 6, and Fontaine stage 4 lower extremity CLI. Patients received either PTA ± stent or PTA ± stent + UK infusion (250,000 IU, daily for 5 days). PTA of the iliac, femoral, anterior tibial artery, posterior tibial artery, and peroneal arteries was included. Amputation was classified as minor, with direct wound healing, and minor amputation or surgical debridement of toes and major, with below- (BKA) and above-knee amputation (AKA).

RESULTS

In groups of patients with comparable baseline characteristics, 85 and 90 patients received PTA ± stent and PTA ± stent + UK, respectively. There were 24 major limb amputations performed. A significant majority (20/24 (83.3%) were performed in patients who did not receive adjuvant urokinase, compared with 4/24 (16.7%) of patients who did receive urokinase (p = 0.000287). There was a significant increase in the limb salvage rate for infrapopliteal lesions in patients treated with PTA + UK (12/72 with UK; 60/72 without UK; p ≤ .0001). Intracranial hemorrhage (n = 1) and bleeding at the inguinal puncture site (n = 2) were reported in the PTA ± stent + UK group. Eight deaths (one in the PTA ± stent + UK group; seven in the PTA ± stent) occurred during the study.

CONCLUSION

Systemic administration of UK with the PTA ± stent procedure may reduce the requirement for major amputation in patients with CLI with tissue loss (Rutherford 5 or 6). The difference is more pronounced in patients undergoing infrapopliteal interventions. However, these findings need to be confirmed in a randomized prospective study.

One of the most urgent vascular circumstances: Acute limb ischemia

Acute limb ischemia is a sudden decrease in limb perfusion that threatens limb viability and requires urgent evaluation and management. Most of the causes of acute limb ischemia are thrombosis of a limb artery or bypass graft, embolism from the heart or a disease artery, dissection, and trauma. Assessment determines whether the limb is viable or irreversibly damaged. Prompt diagnosis and revascularization by means of catheter-based thrombolysis or thrombectomy and by surgery reduce the risk of limb loss and mortality. Amputation is performed in patients with irreversible damage. Despite urgent revascularization, amputation rate is 10%–15% in patients during hospitalization, mostly above the knee, and mortality within 1 year is 10%–15% due to the coexisting conditions.

Antiplatelet and anticoagulant drugs for prevention of restenosis/reocclusion following peripheral endovascular treatment

BACKGROUND

Peripheral arterial disease (PAD) is frequently treated by balloon angioplasty. Restenosis/reocclusion of the dilated segments occurs often, depending on length of occlusion, lower leg outflow, stage of disease and presence of cardiovascular risk factors. To prevent reocclusion, patients are treated with antithrombotic agents. This is an update of a review first published in 2005.

OBJECTIVES

To determine whether any antithrombotic drug is more effective in preventing restenosis or reocclusion after peripheral endovascular treatment, compared to another antithrombotic drug, no treatment, placebo or other vasoactive drugs.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched 14 February 2012) and CENTRAL (2012, Issue 1).

SELECTION CRITERIA

We selected randomised controlled trials (RCTs). Participants were patients with symptomatic PAD treated by endovascular revascularisation of the pelvic or femoropopliteal arteries. Interventions were anticoagulant, antiplatelet or other vasoactive drug therapy compared with no treatment, placebo or any other vasoactive drug. Clinical endpoints were reocclusion, restenosis, amputation, death, myocardial infarction, stroke, major bleeding and other side effects, such as minor bleeding, puncture site bleeding, gastrointestinal side effects and haematoma.

DATA COLLECTION AND ANALYSIS

We independently extracted and assessed details of the number of randomised patients, treatment, study design, patient characteristics and risk of bias. Analysis was based on intention-to-treat data. To examine the effects of outcomes such as reocclusion, restenosis, amputation and major bleeding, we computed odds ratios (OR) with 95% confidence intervals (CI) using a fixed-effect model.

MAIN RESULTS

Twenty-two trials with a total of 3529 patients are included (14 in the original review and a further eight in this update). For the majority of comparisons, only one trial was available so results were rarely combined in meta-analyses. Individual trials were generally small and risk of bias was often unclear due to limitations in reporting. Three trials reported on drug versus placebo/control; results were consistently available for a maximum follow-up of only six months. At six months post intervention, a statistically significant reduction in reocclusion was found for high-dose acetylsalicylic acid (ASA) combined with dipyridamole (DIP) (OR 0.40, 95% CI 0.19 to 0.84), but not for low-dose ASA combined with DIP (OR 0.69, 95% CI 0.44 to 1.10; P = 0.12) nor in major amputations for lipo-ecraprost (OR 0.89, 95% CI 0.44 to 1.80). The remaining trials compared different drugs; results were more consistently available for a longer period of 12 months. At 12 months post intervention, no statistically significant difference in reocclusion/restenosis was detected for any of the following comparisons: high-dose ASA versus low-dose ASA (OR 0.98, 95% CI 0.64 to 1.48; P = 0.91), ASA/DIP versus vitamin K antagonists (VKA) (OR 0.65, 95% CI 0.40 to 1.06; P = 0.08), clopidogrel and aspirin versus low molecular weight heparin (LMWH) plus warfarin (OR 0.31, 95% CI 0.06 to 1.68; P = 0.18), suloctidil versus VKA: reocclusion (OR 0.59, 95% CI 0.20 to 1.76; P = 0.34), restenosis (OR 1.87, 95% CI 0.66 to 5.31; P = 0.24) and ticlopidine versus VKA (OR 0.71, 95% CI 0.37 to 1.36; P = 0.30). Treatment with cilostazol resulted in statistically significantly fewer reocclusions than ticlopidine (OR 0.32, 95% CI 0.13 to 0.76; P = 0.01). Compared with aspirin alone, LMWH plus aspirin significantly decreased occlusion/restenosis (by up to 85%) in patients with critical limb ischaemia (OR 0.15, 95% CI 0.06 to 0.42; P = 0.0003) but not in patients with intermittent claudication (OR 1.73, 95% CI 0.97 to 3.08; P = 0.06) and batroxobin plus aspirin reduced restenosis in diabetic patients (OR 0.28, 95% CI 0.13 to 0.60). Data on bleeding and other potential gastrointestinal side effects were not consistently reported, although there was some evidence that high-dose ASA increased gastrointestinal side effects compared with low-dose ASA, that clopidogrel and aspirin resulted in fewer major bleeding episodes compared with LMWH plus warfarin, and that abciximab resulted in more severe bleeding episodes.

AUTHORS' CONCLUSIONS

There is limited evidence suggesting that restenosis/reocclusion at six months following peripheral endovascular treatment is reduced by use of antiplatelet drugs compared with placebo/control, but associated information on bleeding and gastrointestinal side effects is lacking. There is also some evidence of variation in effect according to different drugs with cilostazol reducing reocclusion/restenosis at 12 months compared with ticlopidine and both LMWH and batroxobin combined with aspirin appearing beneficial compared with aspirin alone. However, available trials are generally small and of variable quality and side effects of drugs are not consistently addressed. Further good quality, large-scale RCTs, stratified by severity of disease, are required.

Quality improvement guidelines for percutaneous catheter-directed intra-arterial thrombolysis and mechanical thrombectomy for acute lower-limb ischemia

Percutaneous catheter-directed intra-arterial thrombolysis is a safe and effective method of treating acute and subacute lower limb ischemia, as long as accurate patient selection and procedural monitoring are ensured. Although larger, controlled trials are needed to establish the role of PTDs in ALI, mechanical thrombectomy could currently be applied combined with lytic infusion in selected cases where rapid recanalization is required or as a stand-alone therapy when the administration of thrombolytic agents is contraindicated.

Stent-assisted recanalisation of acute occlusive arteries in patients with acute limb ischaemia

OBJECTIVE

To assess the efficacy of stent-assisted recanalisation for acute limb ischaemia in patients considered unfit for thrombolysis or in patients with failed surgical recanalisation.

MATERIALS AND METHODS

Fifteen patients with acute limb ischaemia, treated with stent implantation, were analysed retrospectively. The reasons for acute limb ischaemia were a cardiogenic embolism (n=3), a traumatic injury (n=3), acute in situ thrombosis with atherosclerosis (n=6), immediate graft thrombosis (n=2), or a delayed thrombotic occlusion after a thrombin injection in the pseudoaneurysm (n=1). This study examined the technical and clinical outcomes of the procedures, including complications during the procedural and follow-up periods.

RESULTS

Stent-assisted recanalisation was technically successful and provided immediate recanalisation in all patients (15/15 patients, 100%) and reduced or eliminated the clinical symptoms in 12 patients (12/15 patients, 80%). Two patients died of multi-organ failure related to reperfusion injury, and one patient with a crash injury underwent a below-the-knee amputation as a result of wound necrosis despite recanalisation of the occluded bypass graft.

CONCLUSIONS

Stent-assisted recanalisation has a high technical success rate with good clinical results as a bailout procedure for the management of acute limb ischaemia in patients, considered unfit for thrombolysis or in patients with failed surgical recanalisation.

Recanalization of acute and subacute femoropopliteal artery occlusions with the rotarex catheter: one year follow-up, single center experience

PURPOSE

To assess the efficacy and safety of a new rotational catheter for percutaneous removal of fresh and organized thrombi in the femoropopliteal artery.

METHODS

Forty-one limbs in 38 patients (age 56--90 years, mean 75.6 years) with acute, subacute or chronic femoropopliteal occlusions of 1--180 days' duration (mean 31.6 days) were treated with the Rotarex device. The Fontaine stage was mainly IIB (Rutherford 2--3, 22 patients) or III (Rutherford 4, 14 patients). The length of occlusion varied from 2 to 35 cm (mean 13.1 cm). After recanalization percutaneous transluminal angioplasty (PTA) was performed if there was a residual stenosis of >25%. Patients were followed up with color Doppler ultrasound at 48 hr and clinically with Doppler pressures and oscillometry at 3, 6, and 12 months.

RESULTS

After an average of two passages with the Rotarex catheter all but two limbs required PTA for residual stenosis >25%. Five patients needed additional stenting. Major complications were one groin hematoma requiring blood transfusion and one arteriovenous fistula spontaneously thrombosing after unsuccessful primary prolonged balloon dilation. Distal embolizations occurred in 10 patients; 6 clinically relevant emboli were aspirated. All occlusions were technically successfully recanalised there were 2 early reocclusions after 1 day and two at 2 weeks. Brachial-ankle indices improved from an average of 0.41 before to 0.93 after recanalization. Primary and secondary patency rates were 62% / 84% after 6 months and 39% / 68% after 1 year. The amputation-free survival at 12 months was 100%.

CONCLUSION

The Rotarex mechanical thrombectomy device is an efficient, quick, easy to handle, and safe tool for the treatment of acute, subacute or even chronic peripheral arterial thromboembolic occlusions. It can be used for short or long occlusions with equal success, provided the obstruction is not heavily calcified and has been safely passed with a guidewire first.

Management of Peripheral Vascular Disease

The management of patients with peripheral arterial occlusive disease (PAD) has to be planned in the context of natural history, epidemiology, and apparent risk factors that predict deterioration. The ankle-brachial index to date has proved to be the most effective, accurate, and practical method of PAD detection. Given that PAD is a powerful indicator of systemic atherosclerosis and (independent of symptoms) is associated with an increased risk of myocardial infarction and stroke, as well as a six times greater likelihood of death, the prevalence and demographic distribution of measurable PAD becomes particularly relevant. Reliable information on interventions to confer symptom relief is much weaker and reflects discrepancies between published reports from centers of excellence and the experience of patients routinely treated in communities around the world. The impact of newer treatment modalities, such as complex endovascular procedures and therapeutic angiogenesis, has been a subject of recent controversy.

Antiplatelet and anticoagulant drugs for prevention of restenosis/reocclusion following peripheral endovascular treatment

BACKGROUND

Peripheral arterial disease (PAD) is frequently treated by balloon angioplasty. Restenosis/reocclusion of the dilated segments occurs often depending on length of occlusion, lower leg outflow, stage of disease and presence of cardiovascular risk factors. To prevent reocclusion, patients are treated with antithrombotic agents.

OBJECTIVES

To determine whether any antithrombotic drug is more effective in preventing reocclusion after peripheral endovascular treatment, compared to another antithrombotic drug, no treatment, placebo, or other vasoactive drugs.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group's trials register (last searched April 2004), the Cochrane Central Register of Controlled trials (CENTRAL Issue 2, 2004), MEDLINE and EMBASE (last searched June 2004).

SELECTION CRITERIA

Randomised trials were categorised as A (double or single blinded) or B (not blinded). Participants included patients with symptomatic PAD treated by endovascular revascularisation of the pelvic or femoropopliteal arteries. Interventions were anticoagulant, antiplatelet or other vasoactive drug therapy compared with no treatment, placebo, or any other vasoactive drug. Clinical endpoints were re-obstruction, amputation, death, myocardial infarction, stroke and major bleeding.

DATA COLLECTION AND ANALYSIS

Details of the number of randomised patients, treatment, study design, study category, allocation concealment and patient characteristics were extracted. Analysis was based on intention-to-treat data. To examine the effects of binary outcomes such as amputation and major bleeding, odds ratios were computed using a fixed effect model. The 95% confidence intervals of the effect sizes were calculated.

MAIN RESULTS

A 60% reduction of recurrent obstruction was found with aspirin (ASA) 330 mg combined with dipyridamol (DIP) as compared to placebo at 12 months follow-up. At six months following endovascular treatment, a positive effect on patency was found with 50 to 100 mg ASA combined with DIP (n = 356). However, this was not significant. ASA/DIP tended towards showing a superior effect on patency after femoropopliteal angioplasty compared with VKA at three, six, and twelve months. Periinterventional treatment with LMWH in femoropopliteal obstructions resulted in significantly lower restenosis/reocclusion rates than with unfractionated heparin.

AUTHORS' CONCLUSIONS

Aspirin 50 to 300 mg started prior to femoropopliteal endovascular treatment appears to be the most effective and is safe. Clopidogrel might be an alternative, but data are lacking. Abciximab might be a useful adjunctive for high risk patients with long segmental femoropopliteal interventions. Low molecular weight heparin seems to be more effective in preventing reocclusion or restenosis than unfractionated heparin.

Thrombus aspiration as a bailout procedure during percutaneous renal angioplasty

PURPOSE

To present a case in which thrombus aspiration, urokinase, and abciximab were used to recanalize a sudden acute thrombotic occlusion of the right renal artery during percutaneous renal angioplasty.

CASE REPORT

A 72-year-old man with severe arterial hypertension, impaired renal function, and peripheral artery disease was referred for interventional renal revascularization of a proximal stenosis of the right renal artery. Predilation was unsuccessful, and stent placement was followed by immediate occlusion of the distal renal artery, probably due to dislocation of a mural thrombus. Since intra-arterial administration of urokinase (300,000 IU) was ineffective, thrombus aspiration was performed using the 7-F guiding catheter. After successful removal of the thrombus, abciximab was given intravenously. Control angiograms showed recanalization of the stented segment and patency of the distal renal arteries, an outcome confirmed 8 months later by duplex ultrasound.

CONCLUSIONS

As demonstrated in our case, thromboembolic complications can be rapidly and successfully treated on the table by combined measures, such as catheter thrombus extraction and pharmacological strategies.

Acute stenting and thromboaspiration in basilar artery occlusions due to embolism from the dominating vertebral artery

Intra-arterial thrombolysis (IAT) is the only treatment that has demonstrated benefit in patients with acute basilar artery occlusions (ABAO). IAT may be difficult to perform when access to the occluded basilar artery (BA) is prevented by pathology of the vertebral arteries (VA). We report on two patients with ABAO due to embolism from the dominating VA. Catheter navigation through the occluded VA and thromboaspiration enabled access to the BA. Thromboaspiration alone or in addition to IAT resulted in a complete recanalization of the BA and a favorable clinical outcome. A stent was deployed at the site of the stenosis in the VA either prior to or immediately after BA recanalization.

A national and single institutional experience in the contemporary treatment of acute lower extremity ischemia

OBJECTIVE

To determine the contemporary clinical relevance of acute lower extremity ischemia and the factors associated with amputation and in-hospital mortality.

SUMMARY BACKGROUND DATA

Acute lower extremity ischemia is considered limb- and life-threatening and usually requires therapy within 24 hours. The equivalency of thrombolytic therapy and surgery for the treatment of subacute limb ischemia up to 14 days duration is accepted fact. However, little information exists with regards to the long-term clinical course and therapeutic outcomes in these patients.

METHODS

Two databases formed the basis for this study. The first was the National Inpatient Sample (NIS) from 1992 to 2000 of all patients (N = 23,268) with a primary discharge diagnosis of acute embolism and thrombosis of the lower extremities. The second was a retrospective University of Michigan experience from 1995 to 2002 of matched ICD-9-CM coded patients (N = 105). Demographic factors, atherosclerotic risk factors, the need for amputation, and in-hospital mortality were assessed by univariate and multivariate logistic regression analysis.

RESULTS

In the NIS, the mean patient age was 71 years, and 54% were female. The average length of stay (LOS) was 9.4 days, and inflation-adjusted cost per admission was $25,916. The amputation rate was 12.7%, and mortality was 9%. Decreased amputation rates accompanied: female sex (0.90, 0.81-0.99), age less than 63 years (0.47, 0.41-0.54), angioplasty (0.46, 0.38-0.55), and embolectomy (0.39, 0.35-0.44). Decreased mortality accompanied: angioplasty (0.79, 0.64-0.96), heparin administration (0.50, 0.29-0.86), and age less than 63 years(0.27, 0.23-0.33). The University of Michigan patients' mean age was 62 years, and 57% were men. The LOS was 11 days, with a 14% amputation rate and a mortality of 12%. Prior vascular bypasses existed in 23% of patients, and heparin use was documented in 16%. Embolectomy was associated with decreased amputation rates (0.054, 0.01-0.27) and mortality (0.07, 0.01-0.57).

CONCLUSIONS

In patients with acute limb ischemia, the more widespread use of heparin anticoagulation and, in select patients, performance of embolectomy rather than pursuing thrombolysis may improve patient outcomes.

Approach to the patient with acute limb ischemia: diagnosis and therapeutic modalities

Good patient outcomes depend on the rapidity and completeness with which re-establishment of arterial blood flow to the limbs occurs. Patients with a greater magnitude of ischemic tissue--such as with an acute aortic occlusion--have worse outcomes than patients with a segmental artery occlusion such as a popliteal arterial thrombosis. Limb loss is high in any situation in which a delay in diagnosis occurs. It is unclear whether or not endovascular therapy will supercede traditional surgery because the etiologies of ALI are too broad to make sweeping conclusions at this time. The author and others [14,15], including those who have promulgated the use of thrombolytic therapy, have come to reasonable conclusions regarding how to deal with ALI: The diagnosis of ALI should be established rapidly. Determine its classification based on the patient's history and physical examination, and promptly institute anticoagulant therapy. Determine whether or not the patient should be taken emergently for surgical thromboembolectomy or a revascularization procedure versus arteriogram and possible thrombolysis. Adjunctive therapy such as antiplatelet agents (e.g., GIIb/IIIa antagonists) and other anticoagulant agents must be better investigated before recommendations can be made. Save life over limb. Emergent guillotine amputation is sometimes required to save a patient's life.

Acute leg ischaemia from thrombosed popliteal artery aneurysms: role of preoperative thrombolysis

OBJECTIVE

to evaluate early and long term results of thrombolysis and surgery in acutely thrombosed popliteal artery aneurysms.

SETTING

retrospective study; teaching hospital.

MATERIALS

between 1990 and 2000, 109 popliteal artery aneurysms were operated on. In 24 patients acute leg ischaemia due to thrombosis of aneurysm was present.

METHODS

ten patients underwent urgent surgical intervention (group 1); and 14 thrombolysis with urokinase, until patency of popliteal and tibial vessels was achieved or for a maximum of 3 days (group 2). Ultrasonographic follow-up was performed at 1, 3, 6 and 12 months and then annually. Early results and follow-up data were analysed by chi-square test and life-table analysis (Kaplan-Meier curve) and late results were compared by mean of log rank test.

RESULTS

in group 1 early limb salvage was 70%; in group 2 it was 86% (p=n.s.). When thrombolysis was successful, patency and limb salvage were 100%. There was no local or systemic complications during thrombolysis nor worsening of ischaemia. Follow-up was completed in 91 cases, with a mean duration of 26 months. Forty-eight months primary patency rate was better, even if not statistically significant, in group 2 than in group 1.

CONCLUSIONS

in patients with acute leg ischaemia due to thrombosis of popliteal artery aneurysms, preoperative thrombolysis can be considered a safe and effective alternative to urgent surgery.

Recombinant tissue plasminogen activator versus urokinase for local thrombolysis of femoropopliteal occlusions: a prospective, randomized multicenter trial

PURPOSE

To report the outcome of a prospective, randomized, open multicenter trial comparing (1) the effects of local thrombolysis with recombinant tissue plasminogen activator (rtPA) or urokinase (UK) and (2) 2 administration techniques.

METHODS

Two hundred thirty-four patients with thromboembolic occlusions in 223 native femoral or popliteal arteries (95%) and 11 bypass grafts (5%) were randomized to rtPA (n = 124) or UK (n = 110) administered either through an endhole catheter (Hess technique) in 81 patients or a microporous balloon catheter (Schneider technique) in 153 patients. When lysis was incomplete, additional catheter interventions were applied to achieve patency. Results were analyzed by fluoroscopy during intervention and by angiography evaluated by independent experts blinded to the methods applied.

RESULTS

The only significant difference between rtPA and UK was found at the end of lysis using the Hess technique. Complete reperfusion (TIMI grade 3) was produced in 60% of patients by rtPA versus 37% by UK (p = 0.045). By both techniques TIMI grade 3 was achieved in 62% with rtPA and in 50% with UK (p = 0.18). Independent of delivery technique, thrombolytic agent, or additional catheter interventions, TIMI grade 3 was achieved in 81% and angiographic patency in 88%. Primary patency at 6 months was 66%, which was increased by secondary interventions to 75%. Major amputations were performed in 6%, all in patients with initial Fontaine stage III/IV ischemia.

CONCLUSIONS

With local thrombolysis alone, rtPA appears to be more effective than UK; however, additional catheter interventions further improved patency, abolishing the difference between the lytic agents.