Trends in Endovascular Surgery

Percutaneous Laser-Facilitated Thrombectomy: An Innovative, Easily Applied, and Effective Therapeutic Option for Recanalization of Acute and Subacute Thrombotic Hemodialysis Shunt Occlusions

PURPOSE

To report our experience with excimer laser-facilitated recanalization of acute and subacute thrombotic occlusions of hemodialysis shunts.

METHODS

Twenty-one patients (16 women; mean age 54+/-19 years, range 31-76) presented with acute and subacute thrombotic occlusions of their hemodialysis shunts (4 Cimino, 17 prosthetic; 18 forearm, 3 upper arm); mean occlusion time was 4.1+/-3 days (range 1-14), and the thrombotic occlusion measured a mean 17.4+/-9 cm (range 5-27). Fresh thrombus was observed in addition to the total shunt occlusion in all cases. All patients were treated initially with a pulsed ultraviolet (308-nm) excimer laser. Eighteen (85.7%) patients received adjunctive local thrombolysis for treatment of residual thrombus. Nineteen (90.5%) patients underwent angioplasty of the underlying anastomotic stenosis.

RESULTS

The angiographic occlusion was reduced from 100% to 63%+/-28% after laser treatment and to 36%+/-18% after 1 hour of thrombolytic therapy (20 mg tissue plasminogen activator). TIMI flow increased significantly from grade 0 to 2.7+/-0.5 following laser ablation (p<0.001) and to 3.0+/-0.2 upon completion of the angioplasty procedure (p>0.001 versus baseline). The immediate procedural success was 95.2% (20/21). Detectable thrombotic embolization and laser-related complications were not observed in any case. Primary patency was 85%; 3 patients had abnormal Doppler flow within 6 weeks and underwent reintervention (secondary patency 100%). All successfully treated shunts were usable for further dialysis at the 6-week follow-up.

CONCLUSION

Percutaneous excimer laser-facilitated thrombus vaporization is safe and effective for recanalization of acute and subacute thrombotic occlusions of hemodialysis shunts.

Prevention of distal embolization and no-reflow in patients with acute myocardial infarction and total occlusion in the infarct-related vessel: A subgroup analysis of the cohort of acute revascularization in myocardial infarction with excimer laser?CARMEL multicenter study

To overcome the adverse complications of percutaneous coronary interventions in thrombus laden lesions (i.e., distal embolization, platelet activation, no-reflow phenomenon), mechanical removal of the thrombus or distal embolization protection devices are frequently required. Pulsed-wave ultraviolet excimer laser light at 308 nm can vaporize thrombus, suppress platelet aggregation, and, unlike other thrombectomy devices, ablate the underlying plaque. The following multicenter registry was instituted to evaluate the safety and efficacy of laser ablation in patients presenting with acute myocardial infarction (AMI) complicated by persistent thrombotic occlusions. Patients with AMI and complete thrombotic occlusion of the infarct-related vessel were included in eight participating centers. Patients with further compromising conditions (i.e., cardiogenic shock, thrombolysis failures) were also included. Primary endpoint was procedural respective laser success; secondary combined endpoints were TIMI flow and % stenosis by quantitative coronary analysis and visual assessment at 1-month follow-up. Eighty-four percent of all patients enrolled (n = 56) had a very large thrombus burden (TIMI thrombus scale > or = 3), and 49% were compromised by complex clinical presentation, i.e., cardiogenic shock (21%), degenerated saphenous vein grafts (26%), or thrombolysis failures (5%). Laser success was achieved in 89%, angiographic success in 93%, and the overall procedural success rate was 86%. The angiographic prelaser total occlusion was reduced angiographically to 58% +/- 25% after laser treatment and to 4% +/- 13% final residual stenosis after adjunctive balloon angioplasty and/or stent placement. TIMI flow increased significantly from grade 0 to 2.7 +/- 0.5 following laser ablation (P < 0.001) and 3.0 +/- 0.2 upon completion of the angioplasty procedure (P > 0.001 vs. baseline). Distal embolizations occurred in 4%, no-reflow was observed in 2%, and perforations in 0.6% of cases. Laser-associated major dissections occurred in 4% of cases, and total MACE was 13%. The safety and efficacy of excimer laser for thrombus dissolution in a cohort of high-risk patients presenting with AMI and total thrombotic occlusion in the infarct-related vessel are encouraging and should lead to further investigation.

Laser-facilitated thrombectomy: a new therapeutic option for treatment of thrombus-laden coronary lesions

To overcome the adverse complications of balloon angioplasty in thrombus burden lesions (i.e., distal embolization, platelet activation, no-reflow phenomenon with persistent myocardial hypoxemia), mechanical removal of the thrombus or distal embolization protection devices is required. Pulsed ultraviolet excimer laser light at 308 nm can vaporize thrombus and suppress platelet aggregation. Clinical experience has already shown its efficacy in acute ischemic-thrombotic acute coronary syndromes. Unlike other thrombectomy devices, a 308 nm excimer laser can ablate thrombi as well as the underlying plaque, speed up thrombus clearing, and enhance thrombolytic and GP IIb/IIIa activity. It can also be employed in patients with contraindications for systemic thrombolytic agents or GP IIb/IIIa antagonists. Our report covers clinical data and technical aspects concerning three patients with acute myocardial infarction who presented with a large thrombus burden. After successful laser-transmitted vaporization of the thrombus mass in these patients, the remaining thrombus burden was evacuated, and normal antegrade coronary flow was successfully restored. This approach can be useful for selective patients with acute coronary syndromes.