Excimer Laser-Assisted Recanalization of Long, Chronic Superficial Femoral Artery Occlusions

Purpose:

To examine the safety and efficacy of excimer laser-assisted angioplasty (ELA) for recanalization of superficial femoral artery (SFA) occlusions.

Methods:

Data were analyzed from 318 consecutive patients (207 men; mean age 64.2 ± 10.7 years, range 33–91) who underwent ELA of 411 SFAs with chronic occlusions averaging 19.4 ± 6.0 cm in length. More than 75% of patients had severe claudication (category 3). Critical lower limb ischemia with rest pain or minor tissue loss was present in 6 and 15 patients, respectively. The mean ankle brachial index (ABI) before and after exercise was 0.62 ± 0.15 and 0.40 ± 0.18, respectively.

Results:

The initial attempt (crossover approach 89.7%, antegrade 6.6%, transpopliteal 3.6%) to cross the occlusion with an excimer laser catheter was successful in 342 (83.2%) of 411 limbs. A secondary attempt performed in 44 of 69 failed cases was successful in 30 limbs, increasing the technical success rate to 90.5% (372/411). Complications included acute reocclusion (4, 1.0%), perforation (9, 2.2%), and distal thrombosis/embolization (16, 3.9%). Postprocedurally, 219 (68.8%) patients were asymptomatic; mild (category 1) or moderate (category 2) claudication remained in 53 (16.6%) and 26 (8.2%) patients, respectively. The primary patency at 1 year was 33.6%. In the majority of patients, reocclusion was treatable on an outpatient basis. The 1-year assisted primary and secondary patency rates were 65.1% and 75.9%, respectively.

Conclusions:

Long SFA occlusions can be recanalized safely and successfully by ELA. However, to maintain patency and quality of life, intensive surveillance using objective testing followed by prompt repeat intervention are mandatory.

Contemporary management of critical lower limb ischemia in TASC D lesions with subintimal angioplasty in femoro-popliteal lesions, tibial angioplasty and sequential compression biomechanical device for infra-inguinal arterial occlusion. Experience and quality of life outcome learned over 25 years

AIM

Patients with end-stage critical limb ischemia (CLI) survive on borrowed time and amputation is inevitable if an aggressive management stratagem is not instigated. Our primary aim was to equate effectiveness of subintimal angioplasty (SIA) and tibial balloon angioplasty (TBA) in sustaining clinical improvement and amputation free survival (AFS) in patients with CLI TASD II D. Moreover, patients with severe CLI, who were not suitable for revascularization and who were offered therapy with a sequential compression biomechanical device (SCBD) were scrutinised as part of a comprehensive lower limb salvage program.

METHODS

From 2002-2012, 5876 patients were referred with peripheral vascular disease (PVD); 987 presented with CLI and 798 had intervention; 189 patients presenting with CLI were not candidates for revascularisation, out of which 171 were offered SCBD. We formed a prospective observational group study of 441 patient who had TASC D disease. All of these patients presented as emergencies and were allocated to the next available treatment list. Duplex ultrasound arterial mapping (DUAM) was the sole preoperative investigation tool in 92% of all cases. Of the 441 patients studied, 190 patients (206 procedures) has SIA for TASC D femero-popliteal occlusions, 80 patients (89 procedures) had TBA and cool eximer laser angioplasty (CELA) for tibial artery occlusions and 171 patients with severe CLI were not suitable for revascularization and joined the SCBD program. Mean age (SIA 73±13 years vs. TBA/CELA 74±8 years vs. SCBD 75±13 years), and comorbidity severity scores (P>0.05) were similar between groups.

RESULTS

Perioperative mortality within the SIA group was 1.6% vs. 0% within the TBA group and 0.6% in SCBD. Length of hospital stay within the TBA group was 3.8±2 days vs. SIA 14±16 days, P<0.0001. The 5-year freedom from major adverse events (MAE) for the SIA group was 68% that was comparable to the results obtained for both the TBA group; 59%, and SCBD group: 62.5% (P=0.1935). Five-year freedom from target lesion revascularization was 85.9% within the SIA group and 79% within the TBA group. A sustained clinical improvement was seen in 82.8% of primary SIA and 68% of TBA, which mimics the outcome of SCBD at 68% at one year. A total of 83% SCBD patients had no rest pain within one week of starting the program and gangrene remained dry and non-progressive. Ulceration healed in all but 12 patients. There were no device-related complications. Limb salvage was 94% at 5 years. All-cause survival was 69%. Quality time spent without symptoms of disease or toxicity of treatment (Q-TWiST) was 24.7 months for SIA and 8.5 months for TBA and was 38.13 for SCBD for a total of 708 months of usage. Cost per quality adjusted-life years (QALY) for SIA was € 5662.79, € 12,935.18 for TBA and € 2943.56 for SCBD.

CONCLUSION

All treatment pathways augmented patient-specific Q-TWiST with substantial cost reduction. SIA, TBA and SCBD expand AFS and symptom-free survival. All treatment modalities are minimally invasive and allow for a high patient turnover without compromising limb salvage, once they are performed by experienced vascular surgeons in high deliberate practice volume centers.

Role of laser atherectomy for the management of in-stent restenosis in the peripheral arteries

The prevalence of PAD is expected to increase as the population ages and the treatment for chronic disease becomes more sophisticated. The safety, efficacy, and lower cost of endovascular treatment for peripheral vascular disease of the lower extremities when compared with surgical revascularization are well known. Despite the clinical improvements and advances in endovascular techniques over the past decade, in-stent restenosis of peripheral arteries remains a challenge for the endovascular specialist. The use of excimer laser atherectomy has been shown to be safe and effective for the revascularization of complex, critical de novo peripheral lesions and offers promise in the treatment and prevention of in-stent restenosis.

Laser debulking and DEB for in-stent restenosis: technique and review of the literature

This paper will describe the technique of the treatment of in-stent restenosis of the infrainguinal arteries, using a combined technique of laser debulking followed by drug-eluting balloon angioplasty. The results of this technique from the literature will be discussed, and a comparison with other techniques that are currently used will be made.

Excimer laser assisted angioplasty for complex infrainguinal peripheral artery disease: a 2008 update

Conventional percutaneous transluminal angioplasty (PTA) for complex or long segment infrainguinal occlusive arterial disease is limited by elastic recoil, dissection and restenosis, with high rates of intermediate and long term restenosis . Debulking with excimer laser has been advocated as a useful adjunctive strategy to improve procedural success and long term patency. This paper reviews the technological development of excimer laser, the studies supporting its use in infrainguinal arterial disease, effective and safe lasing techniques, its advantages, limitations and disadvantages. Case examples will be presented to illustrate its use in infrainguinal arterial disease. Although randomized controlled trials are lacking, existing registry and case series studies suggest efficacy of the excimer laser-assisted PTA for complex infrainguinal arterial disease, including patients with critical limb ischemia.

[Excimer laser coronary angioplasty in combination interventional treatment of patients with acute coronary syndrome]

The authors present first experience of application of the system for rheolytic therapy AngioJet in a group of patients with acute myocardial infarction. They describe principle of the work of rheolytic systems, possible procedure related complications. They also discuss results of clinical studies analyzing efficacy of antithrombotic therapy, efficacy and safety of rheolytic therapy in patients with acute coronary syndrome and complicated atherosclerotic plaques in coronary arteries.

Initial Experience with Directed Laser Atherectomy Using the Clirpath Photoablation Atherectomy System and Bias Sheath in Superficial Femoral Artery Lesions

PURPOSE

To report a safety and efficacy study of directed excimer laser atherectomy with the Bias Sheath guiding catheter to create larger lumens in the superficial femoral artery (SFA).

METHODS

Fourteen patients (9 men; mean age 66+/-9 years, range 46-76) with chronic lower limb ischemia (Rutherford class 2 to 5) referable to SFA stenoses were treated with the 8-F-compatible Bias Sheath and a 1.7- or 2.0-mm laser catheter. Eight (57%) lesions were de novo and 6 (43%) were in-stent restenoses (ISR). Mean diameter stenosis was 96%+/-8% (range 80%-100%; 10 total occlusions), and mean lesion length was 126+/-78 mm (range 30-290). The primary study endpoint was laser success, defined as <50% angiographic residual stenosis post-laser, without major perforations.

RESULTS

The primary endpoint was achieved in 8 (57%) lesions; all patients underwent additional balloon angioplasty, which achieved an angiographic residual stenosis <30% in all. Three lesions could not be completely traversed with the study device. Two dissections were detected after Bias Sheath application; 1 required stenting. There were 2 embolic events (specific to the antegrade device design); both were treated with aspiration therapy. Intravascular ultrasound (IVUS)-based minimal lumen diameters were 0.23+/-0.2 mm (range 0-1.0) at baseline and 3.2+/-0.8 mm after Bias Sheath application. Rutherford category improved at 1 month in 10 (71%) patients. One patient remained unchanged, another worsened (category 2 to 3), 1 died, and the fourth was not examined. The ankle-brachial index improved from 0.41+/-0.18 at baseline to 0.79+/-0.19 at discharge and to 0.80+/-0.19 at 1 month. Primary 1-month patency (<50% restenosis by duplex) was 85% (11/13 lesions).

CONCLUSION

SFA lesions, including ISR, can be treated in the majority of cases with directed laser atherectomy, significantly reducing plaque burden as measured by IVUS. Embolization was attributed to device-specific features of the prototype antegrade sheath design, which was discontinued. Larger studies are mandatory to document the long-term technical and clinical impact of this new device.

Devices for chronic occlusion

Interventional cardiology has advanced into domains once believed to be beyond the reach of percutaneous procedures. As technologic advances continue to push the limits of the interventionalist's capabilities, several areas still exert considerable resistance to this forward momentum. These technically difficult frontiers include bifurcated lesions, small-vessel disease, multivessel disease, diffuse disease, and chronic total occlusions.

Excimer Laser Assisted Angioplasty for Critical Limb Ischemia: Results of the LACI Belgium Study

BACKGROUND

The purpose of this study was to assess the safety and efficacy of translating into national practice methodology for infrainguinal excimer laser-assisted angioplasty, for the treatment of critical limb ischemia in poor surgical bypass candidates.

METHODS

A prospective five centre Belgian registry enrolled 48 patients, who presented with 51 chronic critically ischemic limbs (Rutherford category 4, 5 or 6) and were poor candidates for bypass surgery. Treatment included crossing the occlusion or stenosis by conventional guidewire followed by excimer laser angioplasty with, or without, adjunctive balloon angioplasty or stenting. A step-by-step technique was used in cases where the guidewire could not pass the occluded site. The primary endpoint was limb salvage, at 6 months, of the treated limb.

RESULTS

Initial treatment was successful in all 51 limbs. By 6 months there had been six deaths, six minor and four major amputations and further intervention was required in four patients. Among survivors, limb salvage rate at 6 month was 38/42 (90.5%), with freedom from critical limb ischemia in 86%.

CONCLUSIONS

This Belgian study of excimer laser assisted angioplasty, in high-risk patients who were poor candidates for surgical re-vascularisation, had a low incidence of surgical re-interventions and limb salvage rate in excess of 90%.

[Non-contact donor cornea trephination with a flying spot excimer laser system]

BACKGROUND

One of the most common complications after mechanical penetrating keratoplasty is the occurrence of irregular astigmatism. We developed a method to prepare donor grafts for transplantation applying excimer laser techniques. The quality of the cut edges and exposure time were evaluated.

MATERIALS AND METHODS

The beam of an experimental excimer laser (OPTex, Lambda Physik) was homogenized and guided by an optical system including lenses and scanner mirrors. A special software was used to conduct the laser beam in a circular mode over the surface of the cornea. Corneas from porcine eyes were stabilized in an artificial anterior chamber. Twenty in vitro explants were trephinated applying our method and subsequently investigated by electron microscopy and histology.

RESULTS

All experiments provided regular and smooth cut edges. The average exposure time until perforation was 10.5 min (SD 2.7 min), the diameter of the grafts was 8.0 mm.

CONCLUSION

The experiments showed the possibility of non-contact trephination and generation of smooth cut edges with a rotating focussed excimer laser beam in a porcine cornea model. A major advantage of the system is the possibility of customized "tailored" grafts.

Area ablation: a new lasing concept provides significantly enhanced acute and long-term results for treatment of in-stent restenosis

BACKGROUND AND OBJECTIVES

Debulking is still a technique of choice for in-stent restenosis (ISR). Excimer laser debulking has enabled high procedural success with very low complication rates, but has demonstrated markedly heterogeneous results owing to differences in lasing and laser technology, and selected patient populations. Since new area-ablation technique enables ablation of larger areas than its own device size, we have evaluated their effectiveness and safety in an uncontrolled study.

STUDY DESIGN/MATERIALS AND METHODS

Fifty-three patients with diffuse ISR were treated by laser area ablation, followed by adjunctive balloon angioplasty. Primary endpoint was percent of binary stenosis at 6-month follow-up; secondary endpoints were procedural success; target lesion revascularization (TLR); major adverse cardiac events (MACE); diameter stenosis (DS); and minimal lumen diameter (MLD) before and after laser debulking, and at 6-month follow-up.

RESULTS

Laser debulking was feasible (as defined as < or =30% residual stenosis) in 98.1% of patients. At 6-month follow-up, binary stenosis was 26.4%; angiographic TLR, 20.7%; and MACE, 3.7%. DS decreased from 87+/-17% to 20 +/- 9% after laser debulking, and to 9+/-7% after PTCA; it was 29+/-14% at follow-up (P-values in comparison to baseline: 0.0047; 0.0036; 0.0064). MLD increased from 0.6+/-0.3 to 2.4+/-0.5 mm after laser debulking, to 2.8+/- 0.6 mm after adjunctive PTCA, and to 1.9 +/- 0.4 mm at follow-up (P-values in comparison to baseline: 0.0059; 0.0031; 0.0088).

CONCLUSIONS

Owing to a significantly greater MLD, area ablation facilitates significantly enhanced immediate and follow-up results for diffuse ISR, including a simpler and more effective laser-debulking procedure than former lasing techniques.

[Role of atherectomy devices in interventional cardiology]

BACKGROUND

Unsatisfactory results and restenosis rates of up to 70% in complex coronary lesions created the necessity for alternative methods of percutaneous revascularization. Debulking of excess tissue seemed a promising approach in comparison to conventional PTCA. Most frequently used techniques included directional coronary atherectomy (DCA), laser angioplasty (ELCA), and rotational atherectomy (rotablation, RA). Neither of these techniques managed to establish a clear advantage over conventional PTCA so that they are indicated only under special circumstances. Even in a randomized controlled comparison of PTCA and rotablation in the treatment of in-stent restenosis, rotablation failed to show a clear advantage.

AIM

This review aims to give an overview over currently used atherectomy techniques and their role in interventional cardiology.

Laser angioplasty and laser-induced thrombolysis in revascularization of anomalous coronary arteries

Acute coronary syndromes such as unstable angina and myocardial infarction are attributed to a pathophysiologic process that involves rupture of atherosclerotic plaque and subsequent thrombosis. Percutaneous intervention of anomalous coronary arteries in patients who present with acute coronary syndromes impose unique technical challenges related to the specific anatomic course and morphology of these vessels. Selection of appropriate guiding catheter configuration, choice of supportive guidewire, and proper delivery and activation of debulking devices and stents are important steps toward achieving adequate results. Excimer laser angioplasty is a debulking technology for removal of atherosclerotic plaque and associated thrombi. To date, application of laser angioplasty in anomalous coronary arteries is unreported. We herein present clinical data and discuss technical aspects related to performance of excimer laser angioplasty in three symptomatic patients with acute coronary syndrome, two having an anomalous right coronary artery and one with an anomalous circumflex artery. The delivery of laser energy in these cases resulted in rapid thrombolysis of an occlusive thrombus, successful debulking of the underlying atherosclerotic plaque, facilitation of adjunct balloon angioplasty and stenting, and ultimately, improved clinical condition.

"Optimally spaced" excimer laser coronary catheters: performance analysis

BACKGROUND

Excimer laser angioplasty is a percutaneous treatment modality for management of selected patients with severe obstructive coronary artery disease. This technology entails application of multifiber catheters that vaporize intra-arterial plaque and thrombus with the 308-nm wavelength light. A coronary laser catheter ("OS") with increased space between its optic fibers (90 microns) at the tip was recently developed. The previous design used a closely packed fiber bundle ("CP") with a smaller space between the fibers (77 microns). We sought to determine the ablation characteristics of the new, OS design.

METHODS

Experiments testing the new catheter and comparing it to the existing catheter included: (1) measurement of the laser output beam sizes and divergences; (2) evaluation of particulate matter generation during ablation of atherosclerotic tissue; (3) measurement of ablation hole sizes and tissue penetration rates; (4) histopathologic examination of laser-induced in vivo vessel wall injury.

RESULTS

The new OS catheters produce a wider beam with higher divergence than the traditional CP catheters (6.7 degrees vs. 4.7 degrees, respectively). Testing two different levels of energy revealed the generation of a reduced number of particulate matter and shallower penetration depth with the OS catheter compared with traditional CP catheters. The OS catheters created a larger diameter of ablated hole than the CP catheters (for 2.0-mm catheters: 2.7 mm2 vs. 1.5 mm2, respectively, p = 0.01). Lasing with the OS catheters with slow advancement rates (0.2-0.5 mm/sec) resulted in creation of significantly larger-diameter holes than those produced at higher speeds (1-3 mm/sec). The in vivo vessel wall injury scores were similar among the two types of catheters tested.

CONCLUSIONS

A new design of spaced optical fibers for coronary laser catheters provides increased tissue ablation in comparison to the traditional closely packed fibers catheter. Slow advancement rates during lasing with the new OS catheter are crucial for achievement of adequate plaque debulking.

[PTLA (percutaneous transluminal laser angioplasty) recanalization of femoral artery stenoses/occlusions after Angio-Seal administration]

PURPOSE

To demonstrate desobliration of Angio-Seal-induced femoral artery stenosis and occlusion by Excimer-laser assisted angioplasty and PTA.

PATIENTS AND METHODS

The Angio-Seal hemostatic closure device was applied to the puncture site in 1500 patients after diagnostic or therapeutic coronary artery catheterisation. In 5 of 1500 cases symptoms of claudication occurred. Following the determination of the walking distance and ankle-brachial systolic pressure index (ABI) and diagnostic angiography, therapeutic percutaneous transluminal laser angioplasty (PTLA) and PTA was performed.

RESULTS

5 patients with acute symptoms of peripheral artery disease presented with superficial femoral artery occlusions (three cases) and high grade stenoses of the common femoral arteries (two cases). Angiographic and clinical improvement was achieved after PTLA/PTA in all five patients. The mean walking distance increased from 61 meters to 600 meters. The average ankle-brachial systolic pressure index increased from 0.40 to 0.82.

CONCLUSIONS

PTLA/PTA is a satisfactory therapeutic method for femoral artery occlusion or high-grade stenosis following Angio-Seal application.

[Acute results of ablation of coronary in-stent restenoses with eccentric excimer laser catheters]

Laser catheters which run eccentrically on a guide wire were developed for maximization of luminal gain by excimer laser angioplasty (ELCA). We investigated the safety and efficacy of ELCA with these new catheters plus PTCA in patients with restenoses or occlusions in coronary stents. ELCA was performed in 57 patients (60 +/- 9 years) with stenoses in 75 stents (35 AVE Micro stents, 26 Palmaz-Schatz stents, 7 NIR stents, 7 other stents). In 44 patients eccentric 1.7 mm catheters and in 13 patients 2.0 mm catheters were used. The success of the intervention was analyzed by intravascular ultrasound (IVUS) in a subgroup of 7 patients treated with five 1.7 mm and two 2.0 mm catheters. The laser catheters could be advanced through the in-stent restenoses in 56 patients. A passage inhibition occurred in one patient with an inadequately expanded stent < 2.0 mm in diameter. ELCA reduced the diameter stenoses from 77 +/- 10% before intervention to 44 +/- 8% after treatment with the 1.7 mm catheter (n = 43) or to 34 +/- 9% after passages with the 2.0 mm catheter (P < 0.001). PTCA further reduced the diameter stenosis to 11 +/- 12% (P < 0.001). The IVUS analysis revealed a smooth ablation profile in all patients. In 4 patients creatine kinase elevations > or = 2 times normal value occurred. There was no evidence of a Q-wave infarction. No dissections were observed within the stents. Outside of the stents there were dissections in 5 vessels, which required the implantation of additional stents.

CONCLUSIONS

ELCA with eccentric laser catheters for treatment of in-stent restenosis is safe and effective. The incidence of complications is acceptable.

Application of solid-state pulsed-wave, mid-infrared laser for percutaneous revascularization in heart transplant recipients

BACKGROUND

Severe allograft coronary artery disease is a significant cause of death in heart transplant recipients. Percutaneous revascularization has thus far been attempted with balloon angioplasty and, to a lesser extent, with directional atherectomy. The new, investigational, solid-state pulsed-wave mid-infrared laser (holmium:YAG) can vaporize and remove atheromatous and thrombotic plaques. This mechanism of plaque ablation may be useful for allograft coronary artery disease associated with focal stenoses deemed unsuitable for standard balloon angioplasty, especially thrombus-containing lesions.

METHODS

Five adult heart transplant recipients with severe focal stenoses related to allograft coronary artery disease underwent six laser angioplasty procedures. Laser catheters (2.1 microm, 250 to 600 mJ, 5 Hz) varying from 1.2 mm to 2.0 mm delivered 45 +/- 7.4 pulses (mean +/- SD). Five laser procedures were completed with adjunct balloon angioplasty and one with directional atherectomy.

RESULTS

Laser success (defined as stenosis reduction > 20%, no cardiac catheterization laboratory or in-hospital major complication) was achieved in six of seven lesions (85%), and the overall (laser and adjunct balloon) procedural success rate was 100%. No major complications occurred. Laser-assisted angioplasty reduced mean stenosis from 90% +/- 3% to 9% +/- 11%. All five patients recovered and were discharged. Angiographic follow-up demonstrated a 50% restenosis rate.

CONCLUSIONS

In selected heart transplant recipients laser-assisted angioplasty can provide safe and successful acute revascularization. Focal lesions considered "nonideal" for balloon angioplasty and, in particular, thrombotic lesions can benefit from application of this device; however, long-term reduction of restenosis rates is not expected from this modality.

New devices in interventional cardiology: present and future

Interventional cardiology emerged with the development of balloon angioplasty some 20 years ago, and has undergone tremendous changes since then. The coronary balloon was brought to a mature development stage, being the major "workhorse" of interventional cardiology. Various atherectomy techniques, aimed at removing plaque material, have been developed and showed immediate beneficial effects on the angioplasty results. Laser angioplasty is still looking for an appropriate place in interventional cardiology, with most of the results to date being disappointing. Stents are emerging as a breakthrough technology which has been proven to prevent restenosis and provide an important adjunctive device for suboptimal results following balloon angioplasty. Medically coated stents may have an important impact on the future of interventional cardiology. Novel imaging and flow measurement technologies are being further developed and optimized to assist clinical decisions and treatment strategies in interventional cardiology. In summary, interventional cardiologists today are provided with a set of tools from which they can select the appropriate ones for each lesion subset. Together with the appropriate adjunctive pharmaceutical therapy, prevention of restenosis is on the horizon.

Recanalization of chronic coronary occlusions using a laser wire

Between August, 1993-December, 1994, recanalization of a chronically occluded coronary artery was attempted in 412 patients, with an overall success rate of 77%. The main reason for failure was subintimal tracking of the guide wire. However, in 13 patients, advancing the guide wire was not possible either subintimally or in the former true lumen. In 8 of these 13 patients with failed conventional recanalization, a second attempt was made using a 0.018" laser wire. The suspected occlusion duration was 6 wk-6 yr, and the occlusion length 6-21 mm. Successful crossing of the occlusion was achieved in 7 of 8 patients. One patient experienced pericardial hematoma without severe clinical consequences. Adjunctive conventional laser angioplasty and/or balloon dilatation led to a residual stenosis of < 50% in 7 patients. The laser wire technique may become an important new method for recanalizing chronic total coronary occlusions in selected patients.

Solid-state mid-infrared laser facilitated coronary angioplasty: clinical and quantitative coronary angiographic results in 112 patients

BACKGROUND AND OBJECTIVE

Holmium:YAG is a solid-state, investigational coronary laser device. Preliminary reports indicate the clinical potential for this laser; however, its safety and efficacy in a single center experience have not yet been reported and analyzed in detail.

STUDY DESIGN, PATIENTS, AND METHODS

One hundred and twelve consecutive symptomatic patients underwent percutaneous holmium:YAG laser (2.1 micron wavelength, 250-600 mJ/pulse, 5 Hz) facilitated coronary angioplasty. Sixty-six patients (Gr 1) had 74 thrombotic lesions, and 46 patients (Gr 2) had 55 thrombus-free stenoses.

RESULTS

Overall laser success was achieved in 120 out of 129 lesions (93%), with 95% subsequent balloon angioplasty success. Laser and clinical successes among the two groups were similar. By quantitative coronary angiography, reduction in the percent diameter stenosis (mean +/- SD) was similar (79 +/- 16% to 37 +/- 14% vs. 73 +/- 16% to 37 +/- 11.5%; P = NS) in both groups. However, minimal luminal diameter improved significantly more in Gr 1 patients, (0.7 +/- 0.5 mm to 2.0 +/- 0.5 mm, vs. 0.9 +/- 0.4 mm to 1.8 +/- 0.4 mm, P = 0.03). Angiographic and clinical complications were similar in patients with thrombus and without thrombus. No death, perforation, or Q-wave infarction occurred in the catheterization laboratory in either group. In-hospital mortality occurred in two patients from cardiac causes unrelated to the laser application. Of the 98 patients who reached the 6 month anniversary, 76 (77%) remained asymptomatic. The restenosis rate among the patients who underwent repeat angiography was 50%.

CONCLUSIONS

Solid-state, mid-infrared laser can be safely and successfully applied to symptomatic patients with thrombotic and nonthrombotic lesions. Similar to other debulking devices, the effectiveness of this laser in yielding long-term patency has not been proved.

The changing profile of patient selection, procedural techniques, and outcomes in excimer laser coronary angioplasty. Participating Investigators of the Percutaneous Excimer Laser Coronary Angioplasty Registry

During the course of development of excimer laser angioplasty, several changes in patient selection and technique have occurred. It is uncertain, however, whether these changes have been associated with improved procedural outcome. In this study, multivariable regression methods were used to identify the factors responsible for clinical success, major complications, and vessel perforation in 2,041 consecutive patients treated with excimer laser coronary angioplasty. The overall rates of clinical success were 89%, major complications 7.5%, and vessel perforation 2.1%. Clinical success was 86% in patients treated with prototype catheters, 89% with flexible catheters, 92% with extremely flexible catheters, and 95% in patients treated with directional eccentric catheters (P < 0.001). By multivariable analysis, clinical success increased with each subsequent catheter design (odds ratio [OR] = 1.4 per iteration [95% confidence interval 1.2, 1.6]), and with improved lesion selection. Major complications were reduced when operators had performed more than 25 cases (rate = 6.5%, OR = 0.7 [0.5, 0.9]), and the incidence of vessel perforation was decreased when the size of the target vessel was > 1.0 mm larger than the diameter of the laser catheter (rate = 1.1%, OR = 0.3 [0.2, 0.5]). In conclusion, during the course of clinical investigation with excimer laser angioplasty, procedural outcome has improved. These results emphasize the importance of careful patient selection and procedural technique to enhance the success of excimer laser angioplasty.

Efficacy of preconditioning with intracoronary diltiazem in preventing laser-induced spasm

Laser energy produces a multitude of effects, resulting both in therapeutic tissue ablation and complications such as laser-induced spasm (LIS). LIS can occur during lasing itself or during subsequent adjunctive angioplasty. Intracoronary diltiazem (ICD) can partially reverse LIS after it occurs. To determine whether pre-treatment with ICD might prevent LIS during laser interventions, 3 groups of 50 lesions each were studied. Group 1 served as controls receiving no ICD during the procedure. Group 2 received 2.5 mg ICD before lasing. Group 3 received ICD before lasing and then a second infusion of 2.5 mg ICD after lasing but before adjunctive therapy. There were no differences in clinical characteristics of the 3 groups. Over 75% of lesions in each group were complex (B2 or C) lesions, and average lesion length was 15 mm in all 3 groups. Procedural success was > or = 94% in all groups. There was no significant difference among groups in pre-procedure artery stenosis, post-procedure stenosis, laser power used or number of laser pulses delivered. Pretreatment with ICD produced vasodilation of the minimum lumen diameter from 0.86 +/- 0.1 to 1.0 +/- 0.1 mm (p < 0.01) and was well tolerated. Control patients exhibited a 12% incidence of LIS. Group 2 had an 80% reduction of LIS during lasing (p < 0.01) but had increased LIS during adjunctive therapy with the same 12% incidence of LIS overall. Group 3 had only a 2% incidence of LIS (p < 0.01). We concluded that pretreatment with ICD significantly reduces LIS. Multiple infusions of ICD are necessary to sustain this protective effect.

Laser for optical thrombolysis and facilitation of balloon angioplasty in acute myocardial infarction following failed pharmacologic thrombolysis

This report discusses a new indication for the use of holmium:YAG laser. It includes facilitation of thrombolysis and plaque ablation in acute myocardial infarction after failure of thrombolytic agents. Further study is required to define optimal utilization and integration of this novel device for patients who fail to respond to thrombolytic agents.

[PTCA or alternative techniques? Balloon angioplasty remains dominant]

The use of second generation devices like excimer laser, rotablator, directional atherectomy, and stents is increasing. It is noteworthy that they are used in most cases in combination with "balloon" dilatation. The application of these more expensive techniques requires more experience and skills than mere balloon dilatation. Today, however, only three randomized trials were able to document some advantage of alternative devices in comparison to the traditional lumen enlargement with balloons (BENESTENT, STRESS, ERBAC). The following paper reflects our experience with balloon angioplasty in more than 15,000 patients, as well a critical review of new devices that were used in 19% of our patients in 1993.

New methods of making blocked coronary arteries patent again

The use of percutaneous transluminal coronary angioplasty is limited by procedural complications and the serious drawback of restenosis, but some new techniques have been developed in an attempt to lower the complication rate for difficult lesions and reduce the rate of restenosis. These include devices to physically remove atheromatous plaque, such as the Simpson Coronary AtheroCath and the transluminal extraction catheter, as well as devices to ablate the plaque in situ, including the Rotablator and the excimer laser catheter. Although each device may have advantages in certain types of lesion, few data on their use have been reported in properly controlled randomised trials. The data available so far do not suggest that these devices will be safer than balloon angioplasty or that they will reduce restenosis. However, using metallic stents to support coronary arteries after balloon angioplasty seems to reduce acute complications and to lower the rate of restenosis, and the use of stents is likely to increase.

[Laser-assisted angioplasty in chronic obliterative arteriopathies of the lower limbs. The authors' personal experience]

The laser represents one of the most interesting new methods of vascular surgery. As for laser-assisted angioplasty, the major clinical experience has come with Nd: Yag and Argon lasers. The authors comment on the 1989-1992 series of cases consisting of 51 arteries recanalized with a Nd:Yag laser--the patients were 42 men and 9 women, their mean age being 56.6 years. Four iliac obliterations, 36 femoropopliteal and 11 popliteotibial obliterations were treated surgically, according to the single anatomical radiologic circumstances. The immediate results showed 41 recanalizations (80.4%) 3 perforations (5.9%), 6 dissections (11.8%) and 2 distal emboli (3.9%). The long-term results, with a follow-up period ranging 6 months to 4 years (average: 1.8 years), were investigated with seriated c.w. Doppler, Doppler US and digital venous angiography and showed, in 34 examined patients, 22 patencies (64.7%), 8 stenoses > 50% (23.5%) and 3 occlusions (11.8%). These findings prove the value of laser-assisted--both percutaneous and surgical--angioplasty in the treatment of arterial occlusions both alone and combined with surgery. The results, whose positivity comes also from an eclectic interaction with surgery, and mostly from a systematic enhancement of the laser channel with balloon angioplasty, could be markedly improved upon by means of more selective and effective equipment.

Percutaneous laser recanalisation of femoropopliteal occlusions using continuous wave Nd-YAG laser and sapphire contact probe delivery system

A conventional continuous wave Nd-YAG medical laser system delivered by transparent sapphire tipped optical fibres was used for percutaneous recanalisation of 32 chronic femoropopliteal occlusions in 27 patients (19 men, eight women; median age 68 years, range 46-83 years). Twenty-four patients had severe intermittent claudication and three had critical ischaemia. The median occlusion length was 8 cm (range 3-35 cm) and lesions were not negotiable by guidewire. Laser energy was delivered at powers of 10-15 Watts using intermittent 1 second emissions (mean total energy 315 Joules, range 30-1015]). The sapphire tips used were 1.8 to 3.0 mm diameter. After laser recanalisation adjunctive balloon dilatation was necessary to widen the resulting lumen. All patients received anti-platelet therapy. Initial clinical success was achieved in 22 limbs (69%) with symptomatic relief and increase in mean (+/- S.D.) ankle-brachial pressure ratio from 0.52 (+/- 0.25) to 0.80 (+/- 0.21) [Mann-Whitney U, p < 0.001]. Recanalisation was unsuccessful in all calcified lesions (four cases). There was a high incidence of vessel perforation (28%) and wall dissection (25%). Emergency surgery was not required after failed procedures. The median follow-up was 12 months (range 6-20 months). By 6 months, 15 of 22 successfully recanalised lesions (68%) had reoccluded. The cumulative primary patency at 1 year was only 12%. These disappointing results do not support routine use of this system. Clearly, modifications of the laser/delivery system or the technique, or both, are required. The aim should be to achieve sole laser recanalisation without concomitant balloon dilatation.

Angioscopy after laser and balloon coronary angioplasty

OBJECTIVES

Percutaneous intracoronary angioscopy was used to study the morphologic changes occurring in coronary arteries after balloon or laser angioplasty.

BACKGROUND

Angioscopy is thought to provide details of the coronary vessel lumen and the inner wall.

METHODS

Coronary lesions were studied in 44 patients with a 4.5F Imagecath angioscope before and after each interventional procedure. Balloon and laser angioplasty were performed in 21 (group I) and 23 patients (group II), respectively. There was no difference in age, gender or angiographic lesion appearance before the procedure between the two groups.

RESULTS

Circumferential visualization of the target lesion was successfully completed in 17 group I and 19 group II patients. A larger lumen than that observed at baseline was seen in all 17 group I and in 13 of the 19 group II patients. Tissue remnants were observed in all group I and II patients. Laser irradiation resulted in characteristic sharp-edged craters. Dissection was identified in 2 of 19 patients before versus 9 of 19 patients after balloon angioplasty (p < 0.05) and in 0 of 23 patients before versus 4 of 23 patients after laser angioplasty (p = NS). Subintimal hemorrhage was observed in 3 of 19 patients before versus 11 of 19 patients after balloon angioplasty (p < 0.05) and in 2 of 23 patients before versus 4 of 23 patients after laser angioplasty (p = NS). The frequency of hemorrhage was higher in group I than in group II (11 of 19 vs. 4 of 23, respectively, p < 0.02).

CONCLUSIONS

Angioscopy provides valuable information on lesion morphology after coronary interventions. Balloon dilation results in a high rate of dissection and subintimal hemorrhage. Laser angioplasty is able to ablate obstructing tissue and results in a lower rate of subintimal hemorrhage than balloon dilation.

The crumpled coronary: an enigma of arteriographic pseudopathology and its potential for misinterpretation

A series of angioplasty cases is presented in which dynamic alterations in coronary artery configuration developed. These changes were suggestive of extensive, complex dissections. Several common features emerged in these cases of which interventional cardiologists should be aware. These features included complex vessel morphology (tortuous segments, anomalous takeoffs, and complex stenoses) and the use of certain types of PTCA hardware (Amplatz guiding catheters and 0.018-inch wires). This phenomenon, termed pseudo narrowing, remains largely unrecognized. Identification of these characteristics and employment of proper management strategies will ensure a good outcome in these situations when they arise.

New guiding catheter configuration for aortocoronary vein graft angioplasty

A new family of four guiding catheters (8 French and 9 French) has been developed for angioplasty of aortocoronary vein grafts and native coronary arteries beyond vein graft insertions. In 67 consecutive grafts and native vessels dilated through the grafts in 54 patients, the procedural success rate was 97%. The G-1 standard catheter was employed for the majority of the procedures (66%), but the G-3 catheter was better for high anterior grafts and the G-4 catheter was better for high left grafts. The G-2 catheter was better for lower right grafts, especially in dilated aortas. Balloon angioplasty alone using 8 French catheters was performed in 60 procedures, and excimer laser with adjunctive balloon angioplasty using 9 French catheters was performed in 7 procedures. These unique guiding catheters provide an attractive alternative to existing vein graft guides by their improved seating and backup support. They may be the primary choice for vein graft angioplasty and may have future application in stent deployment and transluminal extraction catheter (TEC) atherectomy.

[Transvenous sonography of the peripheral arterial vessels. The initial clinical results]

Intravascular ultrasound with 20 MHz/6.2-French transducer systems was used for arterial imaging via a transvenous approach. In 20 patients suffering from chronic arterial occlusive disease, 15 iliac arteries were evaluated during diagnostic angiography and 5 femoropopliteal arteries during balloon angioplasty (n = 3) and laser-assisted angioplasty (n = 2), respectively. Transvenous sonography did not allow differentiation of arterial wall layers and determination of vessel diameters as is usually possible during intraarterial sonography. Visualisation of iliac arteries was incomplete. In femoropopliteal vessels, guide wires could be detected within the arterial lumen but not in complete occlusions. Delivery of pulsed laser energy induced bright echoes near the catheter tip within a distance of 1-2 cm. Transvenous sonography is insufficient for monitoring of peripheral angioplasty; however, improved imaging quality might be possible at lower frequencies.

Laser angioplasty and intracoronary stents: going beyond the balloon

Laser angioplasty and balloon-expandable intracoronary stenting are two valuable clinical devices that are now used in interventional cardiology. The description, rationale, and clinical application of each device are examined to enhance the nurse's understanding of intervention choices. Primary nursing diagnoses are described, and special nursing considerations are discussed to aid the critical-care nurse in assessing patient needs, monitoring therapies, optimizing care, and being a mediator of stress between the patient and new technology.

Percutaneous excimer laser coronary angioplasty: results in the first consecutive 3,000 patients. The ELCA Investigators

OBJECTIVES

We report the comprehensive results of the first consecutive 3,000 patients treated in an excimer laser coronary angioplasty registry.

BACKGROUND

Excimer laser coronary angioplasty involves the use of a pulsed, 308-nm ultraviolet laser transmitted by optical fibers to reduce coronary stenoses. Preliminary reports have described safety and efficacy profiles in small numbers of patients.

METHODS

Patients were enrolled in a prospective, nonrandomized manner. The catheters used were 1.3, 1.6, 2.0, 2.2 and 2.4 mm in diameter, at energy densities up to 70 mJ/mm2. Procedures were performed by standard angioplasty technique with conventional guide catheters.

RESULTS

Seventy-five percent of patients were male, 68% were in Canadian Cardiovascular Society functional class III or IV and the cohort included 3,592 lesions. Procedural success (final stenosis < or = 50% without in-hospital Q wave myocardial infarction, coronary artery bypass surgery or death) was 90% and did not differ between the first 2,000 and the last 1,000 patients treated. There was no significant difference in success or complication rates with respect to lesion length, nor were there differences between selected complex and simple lesions. Complications included in-hospital bypass surgery (3.8%), Q wave myocardial infarction (2.1%) and death (0.5%). Coronary artery perforation occurred in 1.2% of patients (1% of lesions) but significantly decreased to 0.4% in the last 1,000 patients (0.3% of lesions). Angiographic dissection occurred in 13% of lesions, transient occlusion in 3.4% and sustained occlusion in 3.1%. Comprehensive lesion morphologic data collected in the latter portion of the study showed the procedure predominantly limited to American College of Cardiology-American Heart Association type B2 and C lesions, with no significant difference in short-term outcome between groups.

CONCLUSIONS

Excimer laser angioplasty can be safely and effectively applied, even in a variety of complex lesions not well suited for percutaneous transluminal coronary angioplasty. These types may include aorto-ostial, long lesions, total occlusions crossable with a wire, diffuse disease and vein grafts. Most recent data show a trend for the selection of predominantly complex lesions and a reduction in the incidence of perforation. This procedure may broaden the therapeutic window for the interventional treatment of selected complex coronary artery disease.

Coronary laser angioplasty

With the widespread growth of percutaneous transluminal coronary angioplasty (PTCA), the realization of limitations of balloon angioplasty stimulated the development of alternative revascularization approaches such as laser angioplasty. PTCA is best suited for the treatment of discrete atherosclerotic stenoses, with lower success rates and more difficult application in patients with diffuse atherosclerotic disease or total occlusions [1-3]. Moreover, despite an initially high primary success rate, coronary angioplasty is still plagued by a restenosis rate as high as 57% [4]. The potential advantages of laser angioplasty address the limitations of PTCA. In contrast to balloon angioplasty where the plaque material is compressed or displaced, laser angioplasty ablates the plaque material [5]. This bulk removal of plaque material could improve acute procedural success rates, decrease complication rates, treat "untreatable" lesions, and decrease restenosis rates. Because laser energy can vaporize atherosclerotic plaque, there may be no requirement for a preexisting channel, and therefore laser angioplasty may have a high success rate for the treatment of coronary occlusions. In its best embodiment, laser angioplasty offers the potential for passing a fiberoptic catheter through the entire length of the coronary circulation to vaporize all atherosclerotic plaque along the arterial wall. This applicability for the treatment of diffuse atherosclerotic disease would offer treatment opportunities currently unavailable with conventional bypass surgery or angioplasty.

[Laser-assisted angioplasty in the treatment of obliterations of the iliac-femoral axis]

In the last years, intraluminal techniques and instrumentations grown from the primitive concept of balloon angioplasty, have made an incredible leap among these techniques, Laser assisted balloon angioplasty plays, in selected cases, an important role in the treatment of vascular occlusive disease. The focus of this report will be to present the preliminary experience of the authors about the use of this technique, in the treatment of 18 patients with atherosclerotic occlusive iliac-femoro-popliteal disease. In spite of short number of cases; they try to focalize indications, limits and principal complications of the technique.

The state of the art of CO laser angioplasty system

A unique percutaneous transluminal coronary angioplasty system using new infrared therapy laser with infrared glass fiber delivery under novel angioscope guidance was described. Carbon monoxide (CO) laser emission of 5 mm in wavelength was employed as therapy laser to achieve precise ablation of atheromatous plaque with a flexible As-S infrared glass fiber for laser delivery. We developed the first medical CO laser as well as As-S infrared glass fiber cable. We also developed 5.5 Fr. thin angioscope catheter with complete directional manipulability at its tip. The system control unit could manage to prevent failure irradiations and fiber damages. This novel angioplasty system was evaluated by a stenosis model of mongrel dogs. We demonstrated the usefulness of our system to overcome current issues on laser angioplasty using multi-fiber-catheter with over-the-guidewire system.

[The laser-assisted balloon angioplasty of insufficient hemodialysis-access fistulae]

Patients with end-stage renal failure frequently develop venous stenoses or occlusions in their haemodialysis access fistulas caused by intimal fibrosis. A complete dilation with high pressure balloons up to 20 atm may be unsuccessful in such cases. We investigated two pulsed dye laser devices for the ablation of obstructions, which were not adequately treatable with a previous balloon angioplasty. From 11/90 to 4/92 a total amount of 154 PTAs of haemodialysis access fistulas were performed. In 23 of them additive laser angioplasty was necessary. 20 patients with Cimino fistulas presented 28 stenoses and two occlusions, whereas all the three patients with Goretex loops presented with occlusions. Two pulsed dye laser devices emitted at the wavelengths 504 nm (green) and 595 nm (red). Technical success was achieved in 22/23 cases, but clinical success was obtained in only 20/23 patients, due to two early reocclusions caused by thrombosis. 5 restenoses occurred two, three, 10, and twice 14 months after angioplasty with a mean follow-up period of 13.5 (5-18) months. Pulsed dye laser ablation in haemodialysis access fistula lesions due to intimal fibrosis greatly enriches radiological recanalisation techniques and is a valuable alternative to surgery if stand-alone balloon PTA fails.

Treatment of refractory coronary occlusions with a new excimer laser catheter: preliminary clinical observations

BACKGROUND

Total coronary occlusion is a frequent cause of procedural failure after coronary angioplasty, often because of the inability to recanalize the occluded segment with a conventional coronary guidewire. The novel excimer laser catheter described in this report contains a highly efficient, pulsed excimer laser guidewire designed to create a small channel within the occluded coronary segment. A preliminary report of the safety and efficacy of this excimer laser catheter is provided.

METHODS

Ten patients with refractory coronary occlusions that could not be crossed by experienced operators using conventional guidewire techniques were treated using a novel laser catheter system. The laser catheter consisted of a densely packed, multiple fiber, helical guidewire measuring 0.020 inches (0.51 mm) in diameter, interfacing a 308 nm excimer laser system and delivering 70-80 mJ/mm2 of energy to the output surface. After the laser guidewire had been advanced to the occlusion site, laser energy was applied to ablate a channel as the wire was advanced through the occlusion. Once the occlusion had been recanalized, standard concentric laser or balloon angioplasty was performed.

RESULTS

Complete recanalization was achieved in three total occlusions, and partial recanalization was established in a further three; thus, normal coronary perfusion was attained in six out of 10 patients after adjunct excimer laser or balloon angioplasty. The final minimum lumen diameter averaged 1.51 mm and the final residual stenosis diameter was 27%. In two patients the procedure was unsuccessful but without significant complications; two other patients developed limited coronary perforations without clinical sequelae.

CONCLUSION

Refractory coronary occlusions were successfully recanalized in six out of 10 patients using a novel excimer laser catheter. Treatment failures in four patients were not associated with major complications, although limited coronary perforation occurred in two patients.

New devices for coronary revascularization

A variety of instruments, including atherectomy catheters, intra-arterial stents, and lasers, have been developed in order to outdo balloon angioplasty with regard to procedural success, complications, and restenosis. Controlled trials are needed to assess the newcomers, but it is likely that each type of device will find its own clinical niche rather than supersede the others.

Vascular complications after balloon and new device angioplasty

BACKGROUND

Despite their potential advantages, new coronary angioplasty devices may be associated with more frequent vascular complications than noted after standard balloon angioplasty, theoretically due to the larger sheaths and prolonged periods of anticoagulation required by some of these devices. This study sought to identify the incidence, predictors, and clinical outcome of vascular complications after new device angioplasty.

METHODS AND RESULTS

The clinical course of 1413 patients was reviewed after balloon or new device angioplasty. Vascular complications were defined as formation of a pseudoaneurysm, arteriovenous fistula, retroperitoneal hematoma, or groin hematoma associated with a > 15-point hematocrit drop or the need for surgical repair. Stepwise logistic regression was used to identify independent predictors for vascular complications. Vascular complications developed after 84 (5.9%) procedures; they occurred more frequently after intracoronary stenting (14.0%) and extraction atherectomy (12.5%) than after balloon angioplasty (3.2%) (odds ratios, 4.86; P < .001, and 4.26, P < .05, respectively). Independent predictors of vascular complications included the use of intraprocedural thrombolytic agents (P < .01), intracoronary stenting (P < .005), or extraction atherectomy (P < .05); high maximum creatinine level (P < .005); low nadir platelet count (P < .001); longer periods of excess anticoagulation (P < .05); and the need for repeat coronary angioplasty (P < .005). Vascular complications were not related to the size of the arterial sheath used.

CONCLUSIONS

Vascular complications developed more frequently after new device angioplasty than after balloon angioplasty, with the risk for vascular complications directly related to the degree of periprocedural anticoagulation.