Percutaneous arterial recanalization

Prognosis for Limb Loss in Patients with Chronic Critical Ischemia Considered Technically Inoperable

Of 427 patients with chronic critical ischemia of the lower extremity, admitted for infrapopliteal bypass surgery, 34 (8%) were considered technically inoperable : in 26 cases due to total occlusion of the runoff vessels and in 8 due to a poor runoff and no suitable vein. The symptoms were rest pain in 24 cases and gangrenous ulceration in 10. During a follow-up from eight to twenty-eight months 5 (15%) patients improved significantly and complained only of claudication. Three patients, suffering rest pain, were unchanged up to nine months, and 25 (74%) patients had a major amputation performed. The remaining patient died the day after admission. The mortality rate of these patients was significantly increased compared with that of the 393 patients who underwent infrapopliteal bypass surgery, who in turn had a higher mortality rate than that of an age- and sex-matched Danish population. Clinical judgment, together with ankle and toe pressure measurements, could not identify the group of patients who preserved their limb.

Percutaneous Angioplasty, Endothelial Markers, and Fibrin Turnover

Purpose:

A number of thrombotic mediators have been related to peripheral arterial disease in both epidemiological and pathological studies.

Methods:

We measured preoperative levels of fibrinogen, cross-linked fibrin degradation products (FDP), and the endothelial markers, von Willebrand factor (vWF), tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAD, in the venous blood of 43 claudicants undergoing percutaneous transluminal angioplasty (PTA). Samples were repeated 4 months later, and changes in the levels of thrombotic mediators were compared with ten controls undergoing angiography alone. Additional perilesional arterial samples were obtained from 11 of the patients.

Results:

Arterial sampling indicated that successful PTA led to an immediate fall in tPA levels and a rise in arterial vWF (p < 0.05), together with a trend toward a significant rise in cross-linked FDP levels. Only the increase in FDP following successful PTA (36 cases) (p < 0.05) was observed in 4-month postangioplasty venous samples, whereas all variables remained unchanged in cases of restenosis (4 patients) and in controls (all comparisons made by Wilcoxon matched pairs test).

Conclusions:

These findings suggest that successful PTA in patients with intermittent claudication results in acute endothelial disturbance and increased fibrin turnover at the site of angioplasty and in sustained increases in fibrin turnover (as reflected by FDP levels). The observation that this increase in fibrin turnover is absent in cases of restenosis within 4 months of PTA merits further study to determine whether increases in fibrin turnover are necessary to maintain patency following PTA.

Cumulative risk of bypass, amputation or death following percutaneous transluminal angioplasty

OBJECTIVE

To define cumulative risk of reconstruction, amputation or death following percutaneous transluminal angioplasty (PTA).

DESIGN

Non-randomised observational study.

PATIENTS AND METHODS

Two hundred and thirty-four PTAs in 212 patients. Minimum follow-up 6 months. Examination of data collected prospectively on manual card index. Examination of radiology and theatre ledgers over 2.5-year period. District Information System (Dis Data). Life-table analysis.

RESULTS

The cumulative risks of reconstruction at 12 months were 14.9% and 6.7%, respectively, following angioplasties below and above the inguinal ligament. Major and minor amputations were more common if the original lesions were below the inguinal ligament (relative risk (RR) 3.32, confidence interval (CI) CI 0.42-26.26 and RR 4.24, CI 0.055-32.9, respectively). They were also more likely in diabetic compared with non-diabetic patients (RR 9.95, CI 2.85-34.47 and RR 3.66, CI 1.28-10.44, respectively). No patient who presented with claudication underwent amputation. Death was more common in patients originally presenting with rest pain or gangrene than claudication (RR 3.94, CI 1.51-10.31).

CONCLUSION

This study confirms the poor outlook of diabetic patients with peripheral vascular disease or those presenting with rest pain, ulceration or gangrene. Percutaneous transluminal angioplasty was associated with approximately 80% limb salvage rate in those patients during the duration of the study.

A cost-utility analysis of laser-assisted angioplasty for peripheral arterial occlusions

Despite the perception of many people that lasers represent the cutting edge of high-technology medicine, this form of medical technology has been subject to relatively little rigorous evaluation. This dearth of research relates particularly to economic evaluation, where there have been few attempts to justify the high cost of laser equipment. This paper details an economic evaluation of the use of laser technology as a secondary adjunct to angioplasty to treat peripheral arterial occlusions. Using data from a range of sources, including a published randomized trial, a cost-utility model is developed to estimate the costs and benefits of the laser, relative to standard angioplasty. The best available data indicate a cost-effective role for the laser, but important areas of uncertainty exist, including the laser's secondary recanalization rate, which has been estimated on the basis of limited numbers of patients. This uncertainty suggests that further research is required before widespread diffusion of the laser for use in this clinical context.

Laser angioplasty of peripheral arteries: an epilogue?

This review gives a short overview of the results of 15 years of experimental and clinical work on laser angioplasty. Experimentally, photothermal and photomechanical ablation of plaque could be demonstrated. However, laser angioplasty did not cause reduction of platelet adhesion and intimal hyperplasia. Clinically, the technique of laser angioplasty was continuously improved until the initial recanalization rates and long-term patency rates in femoropopliteal artery occlusions were the same as the success rates of percutaneous transluminal angioplasty (PTA). This was proven by various randomized studies. Currently, laser angioplasty cannot be proposed as a routine procedure because it is an expensive technology. However, laser recanalization and debulking of total occlusions should be further developed, especially in combination with endoluminal graft placement.

Percutaneous angioplasty, endothelial markers, and fibrin turnover

PURPOSE

A number of thrombotic mediators have been related to peripheral arterial disease in both epidemiological and pathological studies.

METHODS

We measured preoperative levels of fibrinogen, cross-linked fibrin degradation products (FDP), and the endothelial markers, von Willebrand factor (vWF), tissue plasminogen activator (tPA), and plasminogen activator inhibitor (PAI), in the venous blood of 43 claudicants undergoing percutaneous transluminal angioplasty (PTA). Samples were repeated 4 months later, and changes in the levels of thrombotic mediators were compared with ten controls undergoing angiography alone. Additional perilesional arterial samples were obtained from 11 of the patients.

RESULTS

Arterial sampling indicated that successful PTA led to an immediate fall in tPA levels and a rise in arterial vWF (p < 0.05), together with a trend toward a significant rise in cross-linked FDP levels. Only the increase in FDP following successful PTA (36 cases) (p < 0.05) was observed in 4-month postangioplasty venous samples, whereas all variables remained unchanged in cases of restenosis (4 patients) and in controls (all comparisons made by Wilcoxon matched pairs test).

CONCLUSIONS

These findings suggest that successful PTA in patients with intermittent claudication results in acute endothelial disturbance and increased fibrin turnover at the site of angioplasty and in sustained increases in fibrin turnover (as reflected by FDP levels). The observation that this increase in fibrin turnover is absent in cases of restenosis within 4 months of PTA merits further study to determine whether increases in fibrin turnover are necessary to maintain patency following PTA.

Provision of vascular surgical services in the Oxford Region

Vascular surgical practice across an entire health region was studied. There was a mean of 115.9 inpatient episodes and 46.9 vascular reconstructions per 100,000 population, with considerable variation between districts. Vein utilization for infrainguinal grafts was greater in the teaching hospital and few femorodistal grafts or carotid endarterectomies were carried out elsewhere; there were few tertiary referrals of elective vascular cases. Only two districts have formal arrangements for emergency vascular 'on-call'. There is marked inequality of provision of vascular surgical services across the region.

Evaluation of a prototype steerable angioscopic laser catheter in a canine model: a feasibility study

To overcome some of the persisting technical problems related to laser angioplasty, a new catheter was designed and investigated in a canine model. This 5F catheter contained a deflectable tip for steerability, an angioscope, and a laser fiber. Catheter steerability, angioscopic function, and the effects of a 480 nm flash lamp pumped pulsed dye laser on normal canine vessel walls were evaluated. Steering, angioscopic guidance, and application of laser energy were easy and fast to perform in a bloodless vessel segment. Maintaining a condition of bloodlessness at the target site, critical to angioscopic guidance, proved to be the most difficult part in this prototype evaluation. It was noted that the 480 nm pulsed dye laser did not cause macroscopic alterations or perforations to the normal vessel wall. We conclude that a relatively simple deflection mechanism of a small-caliber angioscope provides the kind of aiming ability requisite for precise endovascular therapy. Complete bloodlessness of the area is necessary for both viewing and laser ablation at 480 nm.

Current and future trends in laser medicine

In this overview, a number of the major current, and possible future developments in laser medicine are explored. In therapeutic applications, particular emphasis is given to obtaining selectivity in tissue targets and interaction mechanisms in order to achieve specific biological effects. This includes spatial confinement of thermal damage by pulsed laser irradiation and targetting by exogenous photothermal or photochemical chromophores. The potential for diagnostic applications of lasers in medicine is illustrated primarily by various in vivo spectroscopic techniques. Both therapeutic and diagnostic applications will rely increasingly on the development of total systems in which lasers will form only one, albeit an essential, part. Numerous scientific and technical problems need to be solved in order to realize the full clinical potential of the many new concepts in laser medicine. The impetus for such progress will come from integrated, multidisciplinary collaborations between medical, scientific and industrial groups.