Dai- Do

Fixed low-dose ultrasound-assisted catheter-directed thrombolysis for intermediate- and high-risk pulmonary embolism

AIMS No standardized local thrombolysis regimen exists for the treatment of pulmonary embolism (PE). We retrospectively investigated efficacy and safety of fixed low-dose ultrasound-assisted catheter-directed thrombolysis (USAT) for intermediate- and high-risk PE. METHODS AND RESULTS Fifty-two patients (65 ± 14 years) of whom 14 had high-risk PE (troponin positive in all) and 38 intermediate-risk PE (troponin positive in 91%) were treated with intravenous unfractionated heparin and USAT using 10 mg of recombinant tissue plasminogen activator per device over the course of 15 h. Bilateral USAT was performed in 83% of patients. During 3-month follow-up, two [3.8%; 95% confidence interval (CI) 0.5-13%] patients died (one from cardiogenic shock and one from recurrent PE). Major non-fatal bleeding occurred in two (3.8%; 95% CI, 0.5-13%) patients: one intrathoracic bleeding after cardiopulmonary resuscitation requiring transfusion, one intrapulmonary bleeding requiring lobectomy. Mean pulmonary artery pressure decreased from 37 ± 9 mmHg at baseline to 25 ± 8 mmHg at 15 h (P < 0.001) and cardiac index increased from 2.0 ± 0.7 to 2.7 ± 0.9 L/min/m(2) (P < 0.001). Echocardiographic right-to-left ventricular end-diastolic dimension ratio decreased from 1.42 ± 0.21 at baseline to 1.06 ± 0.23 at 24 h (n = 21; P < 0.001). The greatest haemodynamic benefit from USAT was found in patients with high-risk PE and in those with symptom duration < 14 days. CONCLUSION A standardized catheter intervention approach using fixed low-dose USAT for the treatment of intermediate- and high-risk PE was associated with rapid improvement in haemodynamic parameters and low rates of bleeding complications and mortality.

Below-the-knee angioplasty in patients with end-stage renal disease.

Purpose: To determine clinical efficacy of below-the-knee (BTK) angioplasty in patients with end-stage renal disease (ESRD). Methods: Interrogation of a prospectively maintained database containing 2659 patients treated at a tertiary referral hospital between February 1995 and June 2004 identified 29 ESRD patients (21 men; median age 69 years, IQR 10.12) who had 73 infrapopliteal atherosclerotic lesions treated in 38 ischemic limbs. The indication for treatment was intermittent claudication in 13 (34%) and critical limb ischemia in 25 (66%) limbs. BTK angioplasty was attempted either alone (n=18) or combined with an endovascular inflow procedure (n=20). Primary clinical success was defined as hemodynamic improvement (ABI increase ≥0.1) and/or symptomatic improvement (at least one clinical category). Cumulative rates were calculated according to the Kaplan-Meier estimate. Results: Primary technical success reached 97%, whereas hemodynamic improvement was obtained in only 50% (19/38) of the limbs treated. The pedal arteries were severely diseased in all, and complete occlusion of the pedal arch was found in 58% (18/31) of limbs on completion angiography. Median follow-up was 5.9 months (IQR 11.5). Primary clinical success was 17%, 11%, 11%, and 11% in patients with BTK angioplasty alone and 53%, 45%, 45%, and 45% in patients with inflow procedures after 3, 6, 9, and 12 months, respectively (p=0.017). Limb salvage was 73% at 12 months. Subgroup analyses showed significantly better clinical results in men (p=0.003) and in patients on hemodialysis compared to peritoneal dialysis (p=0.037). Conclusions: Clinical efficacy of BTK angioplasty is limited in patients with ESRD because of the severely diseased pedal arteries. Further studies are warranted to define subgroups of patients likely to experience a more favorable outcome.

Mural aortic thrombi: An important cause of peripheral embolization

PURPOSE Arterial thromboembolism in patients with an unknown source of embolization is still associated with significant morbidity and mortality. The advent of transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) and the more frequent use of computed tomography (CT) have led to the identification of mural aortic thrombi (MAT) as a source of distal embolization in a much higher proportion of patients than previously appreciated. The incidence, diagnosis, and treatment of patients with MAT is reported. METHODS In a prospective study, from January 1996 to December 1998, 89 patients with acute embolic events underwent an extensive diagnostic workup, consisting of TEE, CT, or MRI, to detect the source of embolization. Patients in whom the heart (n = 51), occlusive aortoiliac disease (n = 16), or aortic aneurysms (n = 12) was identified as the source of embolization were excluded. RESULTS Five female and three male patients, with a median age of 63 years (range, 35 to 76 years), with bilateral or repetitive embolic events resulting from MAT were identified, representing 9% of all patients with arterial thrombembolism. All patients had several risk factors for atherosclerosis, but only one young patient had a single risk factor that promoted thrombosis. Successful percutaneous catheter aspiration embolectomy was performed in six patients. The remaining two patients underwent surgical thromboembolectomy. A below-knee amputation had to be performed in two patients, thus representing a morbidity of the primary treatment of 25%. MAT of equal value were detected in the ascending (n = 1) and thoracic aorta (n = 3) by means of TEE, CT, or MRI. MAT in the abdominal aorta (n = 4) were identified by means of CT and MRI. Surgical removal of MAT was performed in seven patients by means of graft replacement of the ascending aorta (n = 1), open thrombectomy of the descending aorta (n = 2), and thrombendarterectomy of the abdominal aorta (n = 4), without intraoperative or postoperative complications. No recurrence of MAT occurred during a median follow-up period of 13 months (range, 4 to 24 months). CONCLUSION MAT represent an important source of arterial thrombembolism. A diagnostic workup of the aorta, preferably by means of CT or MRI, should be performed in all patients in whom other sources of embolization have been ruled out. The ideal therapeutic approach to these patients still awaits prospective evaluation. However, based on our experience, MAT can be successfully treated with a definitive surgical procedure in selected patients, with low mortality and morbidity.

Periprocedural Embolic Events Related to Carotid Artery Stenting Detected by Diffusion-Weighted MRI: Comparison between Proximal and Distal Embolus Protection Devices

Purpose: To evaluate and compare the efficacy of proximal versus distal embolus protection devices (EPD) during carotid artery angioplasty/stenting (CAS) based on diffusion-weighted magnetic resonance imaging (DW-MRI). Methods: Forty-four patients (31 men; mean age 68 years, range 48–85) underwent protected CAS and had DW-MRI before and after the intervention. The cohort was analyzed according to the type of EPD used: a proximal EPD was deployed in 25 (56.8%) patients (17 men; mean age 66 years, range 48–85) and a distal filter in 19 (14 men; mean age 70 years, range 58–79). Fifteen (60.0%) patients with proximal protection were symptomatic of the target lesion; in the distal protection group, 10 (52.6%) were symptomatic. Results: New lesions were seen on the postinterventional DW-MRI in 28.0% (7/25) of the proximal EPD group versus 32.6% (6/19) of those with a distal filter (p=NS). The majority were clinically silent. The new lesions in the vascular territory of the stented carotid artery in the group as a whole and per patient were fewer in the proximal EPD group (p=NS). No significant differences were noted in the T2 appearance of the new lesions or the number of new lesions observed away from the vascular territory of the stented artery. Conclusion: Proximal embolus protection devices show a nonsignificant trend toward fewer embolic events, which warrants large-scale studies. Furthermore, proximal protection devices can be useful to control and treat acute in-stent thrombosis.

Balloon angioplasty in chronic critical limb ischemia: factors affecting clinical and angiographic outcome.

Purpose: To assess factors that affect clinical and angiographic outcome in chronic critical limb ischemia (CLI) 12 months after primary, technically successful balloon angioplasty (BA) in infrainguinal arteries. Methods: Sixty consecutive patients (37 women; mean age 75 ± 10 years, range 53–99) with technically successful BA in 66 limbs were followed for 12 months or until death, for major amputation, or repeat target lesion revascularization (TLR). Assessment at baseline and 1 day and 12 months after BA or at an endpoint event, if feasible, was performed with angiography or duplex ultrasound (above-knee revascularization only). Mortality, limb prognosis, and restenosis rate were correlated with cardiovascular risk factors, hemodynamic measures, and angiographic features. Results: Mortality was 25% at 1 year; compared to survivors, nonsurvivors more often had coronary artery disease (93% versus 44% for survivors, p<0.001), bilateral CLI (60% versus 29%, p=0.033), and higher fibrinogen levels (5.1 g/L versus 4.3 g/L, p=0.049). CLI resolved in more than half (35, 53%) of the limbs without repeat TLR. The major amputation rate was 6%. Limb prognosis correlated with ankle pressures after BA. Restenosis rates were 65% at the femoropopliteal and 56% at the infrapopliteal level (NS); these correlated with the length of the treated arterial segment (8.7 cm with restenosis versus 4.0 cm without, p<0.001). Conclusions: High mortality in CLI was associated with an extensive, clinically manifest arteriosclerotic process and high fibrinogen levels. Limb prognosis and restenosis after BA were primarily influenced by local hemodynamic and technical factors. Despite considerable restenosis, more than 90% of survivors avoided major amputations.

PTA of the subclavian and innominate arteries : Long-term results

BACKGROUND To investigate the long-term clinical and duplex sonographic results of percutaneous transluminal angioplasty (PTA) of the subclavian and innominate arteries, and the potential of a new double balloon technique to avoid cerebrovascular thromboembolism. PATIENTS AND METHODS Forty-three PTAs were performed on 38 subclavian, four innominate arteries and one subclavian-subclavian bypass in 37 patients. In three instances a protective double balloon technique was used. Indication for the intervention was: subclavian steal syndrome (n = 14 [38%]), upper extremity arterial insufficiency (n = 26 [70%]), peripheral thromboembolism (n = 8 [22%]) and PRIND/stroke (n = 3 [8%]). Analysis of long-term follow-up (median 15, range 2 to 100 months) was possible of 28 patients including duplex sonographic assessment in 23 patients. The cumulative patency rate was calculated by means of life-table analysis. RESULTS Technical success was achieved in 36 endovascular procedures (84%). Minor peripheral catheter complications occurred in three interventions (7%), cerebrovascular thromboembolism in four (9%). No cerebrovascular complications were seen using the double balloon technique. On final check-up 4 patients (14%) suffered from subclavian steal syndrome, 3 (11%) from mild upper extremity arterial insufficiency and one (4%) from rest pain. Duplex sonography showed no stenosis in 12 of 23 patients (52%) and a stenosis of less than 50% in 8 (35%). The life-table analysis showed a secondary cumulative patency rate of 72% after 100 months with all restenoses occurring within 24 months. CONCLUSIONS PTA of the subclavian and innominate arteries appears to be a useful alternative to surgery with a low complication rate. The long-term patency rate of 72% is comparable to results of other series. In high risk situations cerebrovascular complications may be reduced using the new double balloon technique.Background: To investigate the long-term clinical and duplex sonographic results of percutaneous transluminal angioplasty (PTA) of the subclavian and innominate arteries, and the potential of a new double balloon technique to avoid cerebrovascular thromboembolism. Patients and methods: Forty-three PTAs were performed on 38 subclavian, four innominate arteries and one subclavian-subclavian bypass in 37 patients. In three instances a protective double balloon technique was used. Indication for the intervention was: subclavian steal syndrome (n = 14 [38%]), upper extremity arterial insufficiency (n = 26 [70%]), peripheral thromboembolism (n=8 [22%]) and PRIND / stroke (n = 3 [8%]). Analysis of long-term follow-up (median 15, range 2 to 100 months) was possible of 28 patients including duplex sonographic assessment in 23 patients. The cumulative patency rate was calculated by means of life-table analysis. Results: Technical success was achieved in 36 endovascular procedures (84%). Minor peripheral catheter co...

Endovascular Treatment of Malignant Superior Vena Cava Syndrome: Is Bilateral Wallstent Placement Superior to Unilateral Placement?

Purpose: To report our experience with unilateral versus bilateral stent placement in the treatment of malignant superior vena cava syndrome (SVCS). Methods: The records and films of 84 consecutive patients (69 men; mean age 64±10 years, range 39–79) referred for stent placement in malignant SVCS were reviewed for venous compromise, technical and clinical success, complications, and reocclusions. Wallstents were placed covering the SVC and both (bilateral technique) brachiocephalic veins (BCV) preferentially; unilateral stenting of only one BCV in addition to the SVC was performed based on operator preference or inability to access both sides. Technical success was defined as the ability to stent the SVC and at least one BCV; clinical success was the elimination of SVCS symptoms. Results: Technical success was achieved in 83 (99%) patients, using the unilateral technique in 22 and bilateral stenting in 61 patients. The groups did not differ with regard to age, sex, underlying diseases, or location and extent of venous compromise. Immediate clinical success was achieved in 20 (91%) of 22 patients in the unilateral group and 55 (90%) of 61 patients in the bilateral group. Two patients suffered late occlusion in the unilateral group, while in the bilateral group, 8 patients had early occlusion and 9 had late occlusion. Thus, the total occlusion rate was significantly (p<0.05) lower in the unilateral group. There was 1 other complication (pericardial tamponade) in the bilateral group, for a 28% total complication rate, which was significantly higher (p = 0.039) than the 9% in the unilateral group. The 1, 3, 6, and 12-month primary stent patency rates were 90%, 81%, 76%, and 69%, respectively. Patency tended to last longer in the unilateral group, but the difference was not significant (p = 0.11). Conclusions: Although bilateral Wallstent placement achieved equal technical and clinical success, it tended to confer shorter-lived patency and caused more complications.

Ultrasound-Assisted Versus Conventional Catheter-Directed Thrombolysis for Acute Iliofemoral Deep Vein Thrombosis

Background—For patients with acute iliofemoral deep vein thrombosis, it remains unclear whether the addition of intravascular high-frequency, low-power ultrasound energy facilitates the resolution of thrombosis during catheter-directed thrombolysis. Methods and Results—In a controlled clinical trial, 48 patients (mean age 50±21 years, 52% women) with acute iliofemoral deep vein thrombosis were randomized to receive ultrasound-assisted catheter-directed thrombolysis (N=24) or conventional catheter-directed thrombolysis (N=24). Thrombolysis regimen (20 mg r-tPA over 15 hours) was identical in all patients. The primary efficacy end point was the percentage of thrombus load reduction from baseline to 15 hours according to the length-adjusted thrombus score, obtained from standardized venograms and evaluated by a core laboratory blinded to group assignment. The percentage of thrombus load reduction was 55%±27% in the ultrasound-assisted catheter-directed thrombolysis group and 54%±27% in the conventional catheter-directed thrombolysis group (P=0.91). Adjunctive angioplasty and stenting was performed in 19 (80%) patients and in 20 (83%) patients, respectively (P>0.99). Treatment-related complications occurred in 3 (12%) and 2 (8%) patients, respectively (P>0.99). At 3-month follow-up, primary venous patency was 100% in the ultrasound-assisted catheter-directed thrombolysis group and 96% in the conventional catheter-directed thrombolysis group (P=0.33), and there was no difference in the severity of the post-thrombotic syndrome (mean Villalta score: 3.0±3.9 [range 0–15] versus 1.9±1.9 [range 0–7]; P=0.21), respectively. Conclusions—In this randomized controlled clinical trial of patients with acute iliofemoral deep vein thrombosis treated with a fixed-dose catheter thrombolysis regimen, the addition of intravascular ultrasound did not facilitate thrombus resolution. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01482273.

Endovascular treatment of common femoral artery obstructions

OBJECTIVE To evaluate the clinical efficacy of endovascular therapy of symptomatic obstructions of the common femoral artery (CFA). METHODS Consecutive series of patients undergoing endovascular therapy of chronic CFA obstructions between 1995 and 2009 and who were followed systematically within a prospectively maintained database. Clinical assessment was based on current guidelines including ankle-brachial index (ABI) and was performed at baseline and the day of discharge and then repeated at 3, 6, and 12 months and annually thereafter. Technical success of intervention was defined as a final residual diameter stenosis of <30%. Sustained clinical improvement was defined as a sustained upward shift of at least one category on the Rutherford classification compared with baseline without the need for repeated target lesion revascularization (TLR) or amputation in surviving patients. Limb salvage was defined as absence of a major (ie, above the ankle) amputation. Survival analysis was performed using the Kaplan-Meier method. RESULTS Ninety-eight patients (38 women, mean age 72 ± 11 years) presented with 104 ischemic limbs, 20 of which (19%) were classified as having critical limb ischemia (CLI). Technical success rate was 98%. Stents were placed in eight CLI patients (40%) and in 20 claudicants (24%). Mean ABI improved from 0.28 to 0.54 (P < .001) in CLI patients and from 0.61 to 0.85 (P < .001) in claudicants. Mean follow-up was 16 months. Primary sustained clinical improvement rates at 3, 6, 12, and 24 months were 55%, 55%, 40%, and 0% in CLI patients and 81%, 75%, 68%, and 52% in claudicants, respectively. Limb salvage rates at 24 months were 94% in CLI patients and 100% in claudicants. After adjustment for confounding factors, presence of ischemic ulcers (hazard ratio [HR], 4.7; 95% confidence interval [CI], 1.49-14.85; P = .009), obstruction of the femoropopliteal arterial tract (HR, 3.9; 95% CI, 1.66-9.16; P = .002) and diabetes mellitus (HR, 2.3; 95% CI, 1.02-5.28; P = .045) were independently associated with lower rates of sustained clinical improvement. CONCLUSIONS Endovascular therapy of CFA obstruction is associated with high rates of sustained clinical success in claudicants with patent femoropopliteal outflow. Presence of ischemic skin ulcers and diabetes mellitus, however, are associated with impaired efficacy of endovascular CFA treatment.

Endovascular brachytherapy after femoropopliteal balloon angioplasty fails to show robust clinical benefit over time.

Purpose: To determine if the short-term efficacy of adjunctive endovascular brachytherapy (EVBT) is maintained over time in patients undergoing balloon angioplasty (BA) of femoropopliteal atherosclerotic lesions. Methods: To evaluate the long-term clinical and angiographic outcome of EVBT, 147 consecutive patients (82 men; mean age 70.8±8.5 years) with 147 treated limbs were randomized to BA with (n=72, 49%) or without (n=75, 51%) adjunctive EVBT (12 or 14-Gy from an 192Ir source, no centering, a 5-mm reference depth). Sixty-eight (46%) limbs were treated for de novo and 79 (54%) for recurrent femoropopliteal lesions. Clinical follow-up at 1, 3, 6, and 12 months and annually thereafter included evaluation of symptoms, ankle-brachial index (ABI), and intra-arterial angiography for new/worsening symptoms or at follow-up between 2 and 5 years. Sustained clinical success was defined as improvement in ABI ≥0.1 and/or of symptoms without repeated target lesion revascularization. Angiographic restenosis was defined as ≥50% diameter reduction. Subgroup analysis was performed for de novo versus recurrent lesions. Results: Mean clinical follow-up was 32.3±21.5 months. Angiographic follow-up was available in 83 (56%) patients (41 BA and 42 BA+EVBT) at a mean 31.8±20.7 months. Cumulative sustained clinical success rates at 1, 2, and 3 years, respectively, were 84.3%, 82.1%, and 76.4% after BA versus 82.4%, 69.8%, and 67.5% after BA+EVBT (p=0.26 by log-rank). Although the proportion of patients undergoing follow-up angiography was moderate, the freedom from angiographic restenosis at 1, 2, and 3 years was 70.7%, 63.1%, and 47.1% after BA versus 82.7%, 64.3%, and 64.3% after BA+EVBT (p=0.16 by log-rank). No differences were found between BA and BA+EVBT outcomes in patients with de novo versus recurrent femoropopliteal lesions. Conclusion: The seemingly beneficial short-term effects of BA+EVBT are not sustained in the longer term, with no robust clinical improvement after angioplasty of atherosclerotic de novo or recurrent femoropopliteal lesions at up to 5 years.