Excimer laser angioplasty during aortocoronary bypass grafting.

Laser coronary angioplasty using the 308-nm Excimer laser was successfully performed intraoperatively during coronary artery bypass grafting. It achieved a reduction of the left anterior descending artery stenosis from 99% to 25% as seen on angioscopy, without evidence of vascular perforation or intimal disruption. The Excimer laser offers the opportunity for intraoperative endovascular remodeling and recanalization and has a potential role as an adjunct to existing standard coronary artery bypass grafting protocol.

Angioscopy for intraoperative management of thromboembolectomy.

Our experience with angioscopy suggests that direct visualization of the arterial lumen during thromboembolectomy procedures would provide a more reliable method of assessing luminal morphologic characteristics than angiography alone. We inspected 32 grafts (seven aortobifemoral, 18 infrainguinal bypass, and seven dialysis access fistula grafts) in 32 patients. Thirty-one patients had thrombotic events and one patient had an acute embolus. Angioscopy following standard catheter thrombectomy revealed significant amounts of retained thrombus or neointima in all thrombectomies. Angioscopic information from 18 patients with an infrainguinal bypass graft led to graft revision in six cases and placement of a new graft in 10 cases. One graft limb was replaced in seven aortobifemoral grafts, and multiple repeated thrombectomies were employed to extract debris in the remaining six cases. Repeated graft thrombectomy was also beneficial in dialysis access fistulas. Angioscopy allowed us to omit the completion angiogram and led to an improved technical result. We conclude that angioscopy is useful during thromboembolectomy procedures.

Falloposcopy: a microendoscopic technique for visual exploration of the human fallopian tube from the uterotubal ostium to the fimbria using a transvaginal approach.

A transvaginal microendoscopic technique has been developed for safely exploring the human fallopian tube from the utero tubal ostium to the fimbria and adjacent peritoneal cavity. Falloposcopy was performed without complication or evidence of endotubal damage in 44 women, 38 of whom also underwent a concurrent laparoscopy. Eight women with normal tubes served as controls and 36 women with tubal damage underwent falloposcopy in an attempt to document endotubal defects. Previous salpingectomy in 13 women and ostial obstruction in 4 cases left 71 tubes available for falloposcopy. Technical failures, defined as an inability to negotiate the tubal lumen in the absence of obstructive disease occurred in 8 of 71 (11%) procedures. In 63 successful procedures, the tubal lumen was considered to be falloposcopically normal in 28 cases (44%) and contained defects ranging from partial to total obstruction secondary to intraluminal fibrosis within the intramural, isthmic, and ampullary segments in the remaining 35 tubes (56%). Falloposcopy provides a nonincisional modality for defining the normal and abnormal surface anatomy of the tubal epithelium.

Interventional cardiovascular therapy by laser and thermal angioplasty.

The advent of balloon angioplasty as a clinical device crystallized the concept of nonsurgical revascularization. The problems of restenosis, diffuse disease, and total occlusions persist despite the demonstrated efficacy of balloon angioplasty. During the past 5 years, a variety of laser devices and catheter designs have demonstrated usefulness in the treatment of peripheral vascular disease. Initial success rates of 70-90% have been reported in occluded femoropopliteal arteries. Further clinical trials are warranted to compare the relative efficacy of these devices with each other and conventional therapies. Thermal ablative devices have not yet shown great promise for treatment of coronary disease. Modified versions of these devices as well as nonthermally acting excimer lasers are promising as clinical tools for enhancing our ability to nonsurgically revascularize patients, and trials with these devices are now underway.

Percutaneous excimer-laser and excimer-laser-assisted angioplasty of the lower extremities: results of initial clinical trial.

Percutaneous peripheral excimer-laser angioplasty at 308 nm was used for treatment of 30 patients with peripheral vascular disease. Twenty-eight patients underwent laser-assisted balloon angioplasty, and two patients underwent laser angioplasty alone. Acute angiographic and clinical success was achieved in 24 of 31 (77%) femoropopliteal stenoses and occlusions. Seven of nine (78%) stenoses, six of seven (86%) short (0-5 cm) occlusions, seven of eight (88%) medium-length (6-10 cm) occlusions, three of four (75%) long (11-15 cm) occlusions, and one of three (33%) extreme (greater than 15 cm) occlusions were successfully treated. Inability to treat total occlusions was in each case related to a failure to maintain coaxial position and subintimal passage of the fiber. These cases demonstrate the feasibility of safely performing percutaneous peripheral excimer-laser or excimer-laser-assisted angioplasty. The overall frequency of restenosis after a mean follow-up period of 9.1 months was 29%. The data suggest that these procedures may be useful for the treatment of peripheral vascular disease in selected patients.

Intraoperative decisions based on angioscopy in peripheral vascular surgery.

We describe the technique of intraoperative angioscopy for delineation of peripheral vascular anatomy. Angioscopes with outer diameters of 0.85-2.9 mm have been used during 86 peripheral vascular procedures. Angioscopic inspections were performed during 68 femoral popliteal bypasses, four aortofemoral bypass grafts, one abdominal aortic aneurysm, two extra anatomic axillary femoral bypass grafts, and 11 other vascular procedures. We obtained useful images in 73 of 86 procedures (85%), thereby yielding 118 angioscopic inspections (53 arteries, 37 anastomoses, and 28 vein grafts). Changes in intraoperative management based on angioscopic findings included revision of five of 37 (14%) anastomoses, deletion of four of 31 (13%) completion angiograms, revision of eight of 17 (47%) in situ venous valves, and repetition of thrombectomy in six of seven (86%) cases. In 22 of 73 (30%) peripheral angioscopies, potential causes of graft occlusion were recognized. Complications from intraoperative angioscopy have included one anastomotic flap from intimal disruption that required anastomotic revision. Three small flaps, possibly resulting from angioscopic trauma, were recognized but appeared to have no clinical significance. In conclusion, intraoperative angioscopy provides visual assessment of luminal patency and anastomotic anatomy. This assessment alters intraoperative procedures in some cases and cannot be obtained by angiography.

Pulsed laser angioplasty: wavelength power and energy dependencies relevant to clinical application.

Despite the theoretical advantages of submicrosecond pulsing for clinical laser angioplasty systems, the optimal laser parameters for clinical application are undefined. Further, the enormous peak powers achieved by submicrosecond pulses destroy available fiberoptics. We irradiated 797 segments of cadaver atherosclerotic aorta with nanosecond pulses at 266, 308, 355, 532, and 1064 nanometers. Effective cutting occurred at lower energy fluences in the ultraviolet than in the visible or infrared. For 308 nanometers, at any energy density, number of pulses to perforation was relatively independent of power density. Therefore, long-pulse ultraviolet wavelengths which could be transmitted through fiberoptics were identified as well suited for a clinical, submicrosecond pulsed laser angioplasty system.