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.

Early recoil after balloon angioplasty of tibial artery obstructions in patients with critical limb ischemia.

PURPOSE: To assess the extent of early recoil in patients with critical limb ischemia (CLI) undergoing conventional tibial balloon angioplasty. METHODS: Our hypothesis was that early recoil, defined as lumen compromise >10%, is frequent and accounts for considerable luminal narrowing after tibial angioplasty, promoting restenosis. To test this theory, 30 consecutive CLI patients (18 men; mean age 76.2±12.1 years) were angiographically evaluated immediately after tibial balloon angioplasty and 15 minutes later. Half the patients were diabetics. Target lesions included anterior and posterior tibial arteries and the peroneal artery with / without the tibioperoneal trunk. Mean tibial lesion length was 83.8 mm. Early elastic recoil was determined on the basis of minimal lumen diameter (MLD) measurements at baseline (MLDbaseline), immediately after tibial balloon angioplasty (MLDpostdilation), and 15 minutes thereafter (MLD15min). RESULTS: Elastic recoil was observed in 29 (97%) patients with a mean luminal compromise of 29% according to MLD measurements (MLDbaseline 0.23 mm, MLD postdilation 2.0 mm, and MLD15min 1.47 mm). CONCLUSION: Early recoil is frequently observed in CLI patients undergoing tibial angioplasty and may significantly contribute to restenosis. These findings support the role of dedicated mechanical scaffolding approaches for the prevention of restenosis in tibial arteries.

Femoral pseudoaneurysms requiring surgical treatment.

BACKGROUND: Despite use of arterial closure devices (APCDs) and thrombin injection , surgery is needed at times to repair femoral pseudoaneurysms (FPA) in patients undergoing endovascular interventions. We analysed the indications and results of surgical repair in a tertiary referral center performing more than 6.000 angiographies and/or interventions annually. OBJECTIVES: The aim of this retrospective observational study was to identify local and clinical factors related to the need of surgical repair. PATIENTS AND METHODS: In this retrospective study, 122 (0.06%) FPAs treated among 21060 patients over a period of five years were assessed. Patient characteristics and therapeutic procedures were analyzed through hospital records. RESULTS: There were 15.163 (72%) coronary and 5.897 (27%) peripheral interventions, respectively. In 89 (73%) patients, FPA was successfully treated by ultrasound guided compression (USGC) alone.Thirty-three (28%) patients underwent open surgical repair. Indication for operative treatment was hemodynamic instability in 9 (7%) patients, rapidly expanding haematoma unsuitable for USGC or after unsuccessful USGC in 23 (19%). One (0.8%) patient had an arterio-venous fistula. Intraoperative findings suggest that atypical endovascular access (e.g. deep femoral artery, lateral or medial puncture) and multiple puncture sites and/or laceration of the vessel wall were related to the need for surgery in 22 (67%) cases. Most patients had active antithrombotic therapy. Gender or the nature of procedure (diagnostic vs. intervention) did not increase risk for open repair. One (0.8%) patient died. No amputations were performed. Mean hospital stay of patients undergoing open surgical repair was 11 (range 4-36) days. CONCLUSIONS: Technical puncture problems were identified in 2/3 of patients requiring open surgery.

Use of a latest-generation vascular plug for peripheral vascular embolization with use of a diagnostic catheter: preliminary clinical experience.

PURPOSE: The latest-generation Amplatzer vascular plug (AVP), the AVP 4, is designed for embolization of smaller vessels without a sheath or guiding catheter. This study evaluated the AVP 4 in peripheral vascular embolization. MATERIALS AND METHODS: Embolization with the AVP 4 was attempted in 13 patients (11 men) for trauma (n = 7) and other indications (n = 6). Technical success rate, vascular bed, size of catheter, and number and size of AVP 4 devices were recorded. RESULTS: Embolization with the AVP 4 was successful in 10 of 13 patients (77%). In trauma patients (n = 7), embolization of the splenic artery (n = 4), lumbar artery (n = 2), and superior gluteal artery (n = 1) was performed. In other patients, preoperative embolization of the right portal vein (n = 1), a gastric varix after transjugular intrahepatic portosystemic shunt creation (n = 1), an aneurysm of the internal iliac artery (n = 1), and inferior mesenteric artery (IMA) embolization before aneurysm repair (n = 2) was performed. Sizes of the AVP 4 were 4 mm (n = 6), 6 mm (n = 5), and 8 mm (n = 1). In all patients, 4- and 5-F catheters with a 0.038-inch minimum inner lumen were used. In one patient, IMA embolization was attempted via a femoral approach but was unsuccessful as a result of repeated catheter tip dislocation because of acute angle; coils were used instead. CONCLUSIONS: Peripheral embolization with the AVP 4 was successful in the majority of patients. Future comparative study is necessary to evaluate this device's benefits over other embolization materials such as earlier-generation AVPs or microcoils.

An angiographic analysis of atherosclerosis progression in below-the-knee arteries after femoropopliteal angioplasty in claudicants.

PURPOSE: To report an angiographic investigation of midterm atherosclerotic disease progression in below-the-knee (BTK) arteries of claudicants. METHODS: Angiograms were performed in 58 consecutive claudicants (35 men; mean age 68.3+/-8.7 years) with endovascular treatment of femoropopliteal arteries in 58 limbs after a mean follow-up of 3.6+/-1.2 years. Angiograms were reviewed in consensus by 2 experienced readers blinded to clinical data. Progression of atherosclerosis in 4 BTK arterial segments (tibioperoneal trunk, anterior and posterior tibial arteries, and peroneal artery) was assessed according to the Bollinger score. The composite per calf Bollinger score represented the average of the 4 BTK arterial segment scores. The association of the Bollinger score with cardiovascular risk factors and gender was scrutinized. RESULTS: A statistically significant increase in atherosclerotic burden was observed for the mean composite per calf Bollinger score (5.7+/-8.3 increase, 95% CI 3.5 to 7.9, p<0.0001), as well as for each single arterial segment analyzed. In multivariate linear regression analysis, diabetes mellitus was associated with a more pronounced progression of atherosclerotic burden in crural arteries (beta: 5.6, p = 0.035, 95% CI 0.398 to 10.806). CONCLUSION: Progression of infrapopliteal atherosclerotic lesions is common in claudicants during midterm follow-up. Presence of diabetes mellitus was confirmed as a major risk factor for more pronounced atherosclerotic BTK disease progression.

Long-term outcome of symptomatic severe ostial vertebral artery stenosis (OVAS).

INTRODUCTION: The optimal management of patients with symptomatic severe ostial vertebral artery stenosis (OVAS) is currently unclear. We analyzed the long-term outcome of consecutive patients with OVAS who received either medical treatment (MT) or vertebral artery stenting (VAS). METHODS: Thirty-nine (>70%) patients with severe OVAS were followed for a mean period of 2.8 years. The decision for VAS (n = 10) or MT (n = 29) was left to the clinician. The Kaplan-Meier method was used to assess the risk of recurrent stroke, transient ischemic attack (TIA), or death over the study period. RESULTS: Patients in the VAS group were significantly younger and more likely to have bilateral VA disease (P = 0.04 and P = 0.02). VAS was successfully performed in all ten patients. The periprocedural risk within 30 days was 10% (one TIA). The overall restenosis rate was 10%. One restenosis occurred after 9 months in a patient treated with bare-metal stent. At 4 years of follow-up, VAS showed a nonsignificant trend toward a lower risk for the combined endpoint of TIA and stroke in posterior circulation compared to medical treatment (10% vs. 45%, P = 0.095; relative risk (RR) = 0.24, 95% confidence interval (CI) 0.031-1.85). Patients with bilateral VA disease had a significantly lower recurrence risk after VAS compared with medical treatment (0% vs. 91% at 4 years, P = 0.004; RR 0.10, 95% CI 0.022-0.49) CONCLUSION: VAS was performed without permanent complications in this small series of patients with symptomatic severe OVAS. The long-term benefit seems to be confined to patients with bilateral but not to those with unilateral VA disease.

Stent placement in acute cerebral artery occlusion: use of a self-expandable intracranial stent for acute stroke treatment.

BACKGROUND AND PURPOSE: Stent placement has been applied in small case series as a rescue therapy in combination with different thrombolytic agents, percutaneous balloon angioplasty (PTA), and mechanical thromboembolectomy (MT) in acute stroke treatment. These studies report a considerable mortality and a high rate of intracranial hemorrhages when balloon-mounted stents were used. This study was performed to evaluate feasibility, efficacy, and safety of intracranial artery recanalization for acute ischemic stroke using a self-expandable stent. METHODS: All patients treated with an intracranial stent for acute cerebral artery occlusion were included. Treatment comprised intraarterial thrombolysis, thromboaspiration, MT, PTA, and stent placement. Recanalization result was assessed by follow-up angiography immediately after stent placement. Complications related to the procedure and outcome at 3 months were assessed. RESULTS: Twelve patients (median NIHSS 14, mean age 63 years) were treated with intracranial stents for acute ischemic stroke. Occlusions were located in the posterior vertebrobasilar circulation (n=6) and in the anterior circulation (n=6). Stent placement was feasible in all procedures and resulted in partial or complete recanalization (TIMI 2/3) in 92%. No vessel perforations, subarachnoid, or symptomatic intracerebral hemorrhages occurred. One dissection was found after thromboaspiration and PTA. Three patients (25%) had a good outcome (mRS 0 to 2), 3 (25%) a moderate outcome (mRS 3), and 6 (50%) a poor outcome (mRS 4 to 6). Mortality was 33.3%. CONCLUSIONS: Intracranial placement of a self-expandable stent for acute ischemic stroke is feasible and seems to be safe to achieve sufficient recanalization.

Magnetic resonance angiography in infrapopliteal arterial disease: prospective comparison of 1.5 and 3 Tesla magnetic resonance imaging.

PURPOSE: To prospectively determine the accuracy of 1.5 Tesla (T) and 3 T magnetic resonance angiography (MRA) versus digital subtraction angiography (DSA) in the depiction of infrageniculate arteries in patients with symptomatic peripheral arterial disease. PATIENTS AND METHODS: A prospective 1.5 T, 3 T MRA, and DSA comparison was used to evaluate 360 vessel segments in 10 patients (15 limbs) with chronic symptomatic peripheral arterial disease. Selective DSA was performed within 30 days before both MRAs. The accuracy of 1.5 T and 3 T MRA was compared with DSA as the standard of reference by consensus agreement of 2 experienced readers. Signal-to-noise ratios (SNR) and signal-difference-to-noise ratios (SDNRs) were quantified. RESULTS: No significant difference in overall image quality, sufficiency for diagnosis, depiction of arterial anatomy, motion artifacts, and venous overlap was found comparing 1.5 T with 3 T MRA (P > 0.05 by Wilcoxon signed rank and as by Cohen k test). Overall sensitivity of 1.5 and 3 T MRA for detection of significant arterial stenosis was 79% and 82%, and specificity was 87% and 87% for both modalities, respectively. Interobserver agreement was excellent k > 0.8, P < 0.05) for 1.5 T as well as for 3 T MRA. SNR and SDNR were significantly increased using the 3 T system (average increase: 36.5%, P < 0.032 by t test, and 38.5%, P < 0.037 respectively). CONCLUSIONS: Despite marked improvement of SDNR, 3 T MRA does not yet provide a significantly higher accuracy in diagnostic imaging of atherosclerotic lesions below the knee joint as compared with 1.5 T MRA.

Falsely high ankle-brachial index predicts major amputation in critical limb ischemia.

Falsely high ankle-brachial index (ABI) values are associated with an adverse clinical outcome in diabetes mellitus. The aim of the present study was to verify whether such an association also exists in patients with chronic critical limb ischemia (CLI) with and without diabetes. A total of 229 patients (74 +/- 11 years, 136 males, 244 limbs with CLI) were followed for 262 +/- 136 days. Incompressibility of lower limb arteries (ABI > 1.3) was found in 45 patients, and was associated with diabetes mellitus (p = 0.01) and renal insufficiency (p = 0.035). Limbs with incompressible ankle arteries had a higher rate of major amputation (p = 0.002 by log-rank). This association was confirmed by multivariate Cox regression analysis (relative risk [RR] 2.67; 95% CI 1.27-5.64, p = 0.01). The relationship between ABI > 1.3 and amputation rate persisted after subjects with diabetes and renal insufficiency had been removed from the analysis (RR 3.85; 95% CI 1.25-11.79, p = 0.018). Dividing limbs with measurable ankle pressure according to tertiles of ABI, the group in the second tertile (0.323 < or = ABI < or = 0.469) had the lowest amputation rate (4/64, 6.2%), and a U-shaped association between the occurrence of major amputation and ABI was evident. No association was found between ABI and mortality. In conclusion, this study demonstrates that falsely high ABI is an independent predictor of major amputation in patients with CLI.

Activated coagulation during open and endovascular abdominal aortic aneurysm repair.

OBJECTIVE: The study was conducted to determine activation of coagulation in patients undergoing open and endovascular infrarenal abdominal aortic aneurysm repair (EVAR). METHODS: In a prospective, comparative study, 30 consecutive patients undergoing open repair (n = 15) or EVAR (n = 15) were investigated. Blood samples to determine fibrinopeptide A, fibrin monomer, thrombin-antithrombin complex, and D-dimer were taken up to 5 days postoperatively. Routine hematologic and hematochemical parameters as well as clinical data were collected. RESULTS: Both groups showed comparable demographic variables. Operating time was longer in open repair (249 +/- 77 minutes vs 186 +/- 69 minutes, P < .05). Perioperatively elevated markers of coagulation were measured in both groups. Fibrinopeptide A levels did not differ significantly between the groups (P = .55). The levels of fibrin monomer and thrombin-antithrombin complex were significantly higher in patients undergoing EVAR (P < .0001), reflecting increased thrombin activity and thrombin formation compared with open surgery. The D-dimer level did not differ significantly between the groups. These results were also valid after correction for hemodilution. CONCLUSION: These data suggest increased procoagulant activity in EVAR compared with open surgery. A procoagulant state may favor possible morbidity derived from micro- and macrovascular thrombosis, such as in myocardial infarction, multiple organ dysfunction, venous thrombosis and thromboembolism, or disseminated intravascular coagulation.

Does deep femoral artery revascularization as an isolated procedure play a role in chronic critical limb ischemia?

PURPOSE: To prospectively evaluate the midterm outcome after balloon angioplasty or surgical profundaplasty of the deep femoral artery (DFA) as an isolated procedure in chronic critical limb ischemia (CLI). METHODS: Between 1995 and 2001, 21 limbs in 20 patients (mean age 77+/-8 years) were treated by revascularization of the deep femoral artery (DFA) as an isolated procedure for limb salvage. All patients had long-segment femoropopliteal occlusions unsuitable for revascularization and critical obstruction of the DFA. Clinical outcome was assessed at 1, 3, 6, and 12 months. Clinical treatment efficacy was defined as resolved CLI in surviving patients without major amputation after isolated DFA revascularization. Repeat target limb revascularization, major amputation, and death were solitary study endpoints; survival analyses were performed using the Kaplan-Meyer method. RESULTS: Angioplasty with or without stenting was performed in 14 (67%) limbs and surgical profundaplasty in 7 (33%) limbs, with a technical success rate of 100%. Clinical treatment efficacy was 25% at 12 months; the cumulative rates of repeat target limb revascularization, major amputation, and death were 49%, 36%, and 55%, respectively. Major amputation and persistent CLI dominated in patients with stage IV disease (89%), whereas rest pain resolved in the majority of patients with stage III disease (67%; p<0.05). CONCLUSIONS: Isolated DFA revascularization seems insufficient to support wound healing in CLI, but might be a treatment option in CLI patients with rest pain.

Late acute thrombotic occlusion after endovascular brachytherapy and stenting of femoropopliteal arteries.

OBJECTIVES: The aim of this article is to underline the importance of this complication after endovascular brachytherapy (EVBT) and intravascular stenting of the femoropopliteal arteries occurring in a running randomized trial. BACKGROUND: Endovascular brachytherapy has been proposed as a promising treatment modality to reduce restenosis after angioplasty. However, the phenomenon of late acute thrombotic occlusion (LATO) in patients receiving EVBT after stenting is of major concern. METHODS: In an ongoing prospective multicenter trial, patients were randomized to undergo EVBT (iridium 192; 14 Gy at a depth of the radius of the vessel +2 mm) after percutaneous recanalization of femoropopliteal obstructions. Of the 204 patients who completed the six months follow-up, 94 were randomized to EVBT. RESULTS: Late acute thrombotic occlusion occurred exclusively in 6 of 22 patients (27%) receiving EVBT after intravascular stenting and always in concomitance with reduction of antithrombotic drug prevention (clopidogrel). Conversely, none of the 13 patients with stents and without EVBT (0%; p < 0.05) and none of the 72 patients (0%; p < 0.01) undergoing EVBT after simple balloon angioplasty presented LATO. CONCLUSIONS: Late thrombotic occlusion occurs not only in patients undergoing EVBT after percutaneous coronary recanalization but also after stenting of the femoropopliteal arteries and may compromise the benefits of endovascular radiation. The fact that all our cases with LATO occurred concomitantly with stopping clopidogrel may indicate a possible rebound mechanism. An intensive and prolonged antithrombotic prevention is probably indicated in these patients.