Intravascular Ultrasound Imaging: Use in Peripheral Laser-Assisted Angioplasty

Classical and endovascular surgery: indications and outcomes

For more than 40 years, endarterectomy and bypass grafting have been the primary means of surgically revascularizing peripheral vessels threatened by atherosclerotic disease. However, with today's endovascular technology, stenoses and occlusions in nearly every circulatory system can be approached intraluminally with a wide variety of techniques: thrombolysis, laser angioplasty, atherectomy, balloon dilation, and intravascular stents. Just as exciting is the newer technique of endoluminal grafting, which has extended percutaneous therapy to aneurysmal disease in the thoracic and abdominal aorta and distal arteries, as well as to long-segment occlusive disease. Today's vascular surgeon is in a unique position to combine his or her classical surgical training with these catheter-based interventions. Certainly, the potential advantages of percutaneous therapy as compared to surgical reconstruction are significant: no general anesthesia or lengthy incisions, shorter hospitalization, lower morbidity and mortality, earlier intervention in the course of the disease, and less complicated reapplication in the event of disease recurrence. Undoubtedly, endovascular techniques will become a major component of the vascular surgeon's armamentarium, and as we approach the year 2000, they will be the treatment of choice in nearly every vascular pathology and circulatory system.

Endovascular treatment of abdominal aortic occlusive disease: the impact of stents and intravascular ultrasound imaging

Distal abdominal aortic occlusive disease has been conventionally treated with endarterectomy or bypass grafting. However, today's expanding spectrum of intraluminal devices and techniques may well replace classical surgery in this arterial region in all but a few instances. Since January 1990, we have investigated the potential for such endovascular therapies as thrombolysis, balloon dilation and intravascular stenting in 29 symptomatic patients with a variety of distal abdominal aortic pathologies. The prudent application of these intraluminal therapies hinges on accurate intra-arterial assessment. Arteriographic data are notably inadequate for most endovascular procedures; however, intravascular ultrasound imaging (IVUS) is a newer diagnostic tool that works particularly well in the aortoiliac region where angioscopy is more difficult to utilize for assessment. Using IVUS as a complement to arteriography, we were able to assess the need for 43 Palmaz stents in these cases of distal abdominal aortic pathologies; 23 additional iliac stents were deemed necessary. Moreover, IVUS was the only tool available to confirm adequate stent deployment. Given the apparent long-term success of stents in large-bore arteries, abdominal aortic stenting may ensure proximal inflow to distal vessels, saving many patients from an intra-abdominal operation. The specific intraluminal and transmural data offered by IVUS facilitates stent application and documents adequate deployment, two vitally important elements in the percutaneous treatment of abdominal aortic occlusive disease.

Preliminary observations on the use of the Palmaz stent in the distal portion of the abdominal aorta

The opportunities to avoid surgical treatment of distal abdominal aortic occlusive disease are expanding because of the proliferation in catheter-based techniques. Since January 1990, 24 symptomatic patients with distal abdominal disorders have been treated percutaneously with balloon angioplasty and intraluminal stenting. A total of 38 Palmaz stents were deployed at distal abdominal aortic sites; 21 additional iliac stents were implanted. After the procedure all patients improved clinically, and 83% (21/24) improved by objective measurement (average ABI 0.93 +/- 0.21). Three access-related complications occurred (two hematomas, one thrombus), but no complications were related to the stents. At up to 29 months of follow-up (average 10.3 +/- 6.7 months), clinical improvement persists in all patients (average ABI 0.93 +/- 0.22). In 11 patients eligible for follow-up aortography, all aortic stents are patent without evidence of restenosis. With the low likelihood for restenosis in the abdominal aorta, the long-term outcome of aortic stenting looks promising and may equal or surpass that found in the iliac region.

Ultrasound guided therapeutic catheters: recent developments and clinical results

The increasing use of intravascular ultrasound technology by clinicians is providing detailed and immediate information about the results of interventions, and this is stimulating the development of new catheters that use ultrasound imaging to control therapy in real time. Cold and thermal balloon angioplasty, atherectomy, embolectomy, laser ablation and rotational recanalization are a few of the interesting capabilities now being added to ultrasound catheters. We report on the development and characteristics of some of these devices and attempt to assess their potential to precisely direct therapy.