The role of balloon angioplasty in the management of lower limb ischaemia

Prospective Evaluation of the TIGRIS Vascular Stent Within a Modern Treatment Algorithm

Purpose: To prospectively evaluate the safety and efficacy of the TIGRIS Vascular Stent in the superficial femoral artery (SFA) and proximal popliteal artery within a treatment algorithm that reserved stent usage for more challenging patients. Materials and Methods: This prospective, single-center study enrolled 97 patients (mean age 68.7 years; 66 men) who were treated for 100 de novo or nonstented restenotic femoropopliteal lesions (≥70% stenosis) and had recoil or dissection after plain balloon predilation. The average lesion length was 5.6±2.3 cm (maximum 8 cm per protocol). The composite primary efficacy outcome was 12-month primary patency, defined as a peak systolic velocity ratio ≤2.5 at the stented target lesion on duplex ultrasound, and no clinically-driven reintervention within the stented segment. The primary safety outcome was freedom from device- and procedure-related target vessel revascularization, target limb major amputation (above the metatarsals), or death through 30 days. Secondary outcomes included secondary patency, clinically-driven target lesion revascularization (TLR), Rutherford category change relative to baseline, and binary restenosis of the target lesion. Results: All devices were successfully implanted with no device-related complications at the time of implant or within the 30-day postimplant window. The average stented length was 7.0±2.5 cm; no stent elongation was observed during deployment. One patient was lost to follow-up before 12 months and another died of an unrelated cause, leaving 95 patients (98 lesions) available for 12-month follow-up and 77 patients/lesions for the 24-month preliminary analysis. The binary primary and secondary patency rates at 12 months were 92.9% and 100%. The binary freedom from TLR was 94.9%. At 24 months, the Kaplan-Meier estimate of primary patency was 90.0%. Conclusion: This prospective study demonstrated that the TIGRIS Vascular Stent is a safe and effective device in a modern treatment algorithm that reserved bare stent use for postangioplasty dissection or recoil in distal femoropopliteal arteries.

Exercise therapy or angioplasty? A summation analysis

OBJECTIVES

To compare the outcome of exercise therapy or angioplasty for the treatment of patients with intermittent claudication.

DESIGN

A summation analysis.

METHODS

A search using MEDLINE and PUBMED between 1966 and April 1999 followed by a review of the manuscripts yielded 54 studies involving angioplasty and 27 studies involving exercise therapy for intermittent claudication. Studies were only included (12 angioplasty and nine exercise series) when results were available for patients with intermittent claudication alone, and when outcome was assessed in terms of symptoms at a minimum of 6 months.

RESULTS

The total number of claudicants undergoing exercise therapy was 294 patients, with a mean symptomatic success rate of 38. 4% and a mean improvement in maximum walking distance of 189.7% at 6 months. The total number of claudicants undergoing angioplasty was 2071, with a mean overall symptomatic success rate of 76.6%. The mean overall complication rate was 9% and mean major complication rate was 2.7% for the angioplasty studies.

CONCLUSION

Although the result demonstrates an advantage of angioplasty over exercise therapy at 6 months, there is a small risk of major complications. However, comparison of studies was impaired due to disparity in patient numbers, limited follow-up time and lack of uniformity in outcome assessment. In order to achieve a valid comparison of these therapies in a future randomised study, a validated disease-specific instrument for the assessment of symptomatic outcome for claudicants is required.

Percutaneous transluminal angioplasty and enclosed thrombolysis versus percutaneous transluminal angioplasty in the treatment of femoropopliteal occlusions: results of a prospective randomized trial

PURPOSE

To determine whether percutaneous transluminal angioplasty (PTA) and enclosed thrombolysis (ET) is superior to PTA alone in the treatment of femoropopliteal occlusions.

METHODS

Twenty-five patients with 5-15-cm-long occlusions in the femoropopliteal segments, with otherwise normal run-in arteries and at least one normal tibioperoneal artery to the foot, were randomized to ET/PTA or PTA alone. Ankle brachial systolic index (ABI) was measured before the procedure and at 24 hr and 12 months after the procedure, when a duplex scan was also carried out. End points in the study were patency at, or repeat intervention before, 12 months.

RESULTS

Procedures were successful in 23 of 25 patients. There was one immediate occlusion of tibioperoneal arteries, and one early reocclusion of a reopened segment in the ET/PTA group. There was one early reocclusion in the PTA group. At 12 months patency was 70% and 69.2% in the ET/PTA and PTA groups respectively. Covariant analysis showed no significant difference in ABI between the two groups at any of the three measurement times.

CONCLUSION

This trial demonstrated no difference between ET/PTA and PTA alone in femoropopliteal occlusions associated with normal proximal arteries and at least one normal tibioperoneal artery.

Blood flow in the lower limb after balloon angioplasty of the superficial femoral artery

Using duplex ultrasonography lower-limb blood flow measurements were obtained in 20 patients with intermittent claudication. Assessments of flow were made in the common femoral artery, profunda femoris artery (PFA) and superficial femoral artery (SFA) before and after angioplasty for stenoses of short segments of the SFA. Blood flow was measured at rest and after exercise on a cycle ergometer. Collateral flow was calculated using an established mathematical model. Results were compared with the ankle:brachial systolic pressure index (ABPI) after exercise. Although there was no overall increase in resting limb blood flow, an increase in mean(s.d.) SFA flow from 148(79) to 312(94) ml min-1, with a concomitant decrease in PFA flow from 224(84) to 98(43) ml min-1 was noted 1 week after angioplasty (P < 0.05). At rest there was an increase in mean(s.d.) ABPI from 0.62(0.12) to 0.89(0.23) (P < 0.05). Collateral flow was estimated to have decreased from 186(34) to 18(8) ml min-1; the pattern of change in flow was similar after exercise. Angioplasty of the SFA remains controversial because of the risk of restenosis. The above methodology allows assessment of whether patients can re-establish collateral flow or whether limb blood flow will be significantly compromised if restenosis occurs.

Angioplasty gives good results in critical lower limb ischaemia. A 5-year follow-up in patients with known ankle pressure and diabetic status having femoropopliteal dilations

137 consecutive patients with known ankle pressures and diabetic status had attempted femoro-popliteal dilatation for lower limb ischaemia in an English provincial teaching hospital. All except one were followed until failure or death to assess survival and amputation rates. Non-diabetic patients with critical limb ischaemia had a 5 year survival rate of 62.2% (SE 17.1) compared to 50.5% (SE 7.0) for claudicants, with no significant difference on logrank testing. Diabetics had a relative risk of amputation of 11.2 compared to nondiabetics. Patients with pre-treatment ankle pressures of 50 mm or less had a relative risk of amputation of 2.6 compared to those with higher resting pressures. It is concluded that angioplasty should be the treatment of first choice in critical lower limb ischaemia whenever it is technically possible. Including patients with rest pain in the critical ischaemia group does not significantly affect cumulative patency rates.

Femoropopliteal angioplasty for severe limb ischaemia

Fifty patients undergoing 51 percutaneous transluminal angioplasties of the femoropopliteal segment for severe limb ischaemia were reviewed regularly. They comprised 30 men and 20 women of median age 70 (range 56-85) years. There were two deaths within 30 days. At 2 years the cumulative patient survival rate was 60 per cent. Eleven angioplasties were technical failures, 25 failed in the first 6 months and 14 were successful at 6 months' follow-up; in addition one patient died from myocardial infarction within 30 days of technically successful angioplasty. Subsequent vascular procedures were successful in 11 limbs following failed angioplasty. The primary limb survival rate was 42 per cent at 2 years. There were eight major complications after angioplasty, requiring amputation in five instances. Of the 23 long occlusions (greater than 5 cm) that were recanalized and dilated, 22 procedures failed within 6 months. The run-off score and diabetic status did not predict outcome. In this group of patients angioplasty had a low durability. Dilatation of long occlusions is associated with high rates of reocclusion and, on the basis of these results, should not be performed.

Factors that influence the outcome of aortoiliac and femoropopliteal percutaneous transluminal angioplasty

In the past, patients with peripheral arterial occlusive disease were managed by conservative treatment or by vascular reconstructive surgery. Now, percutaneous transluminal angioplasty and other endovascular methods provide an important alternative for managing selected patients with peripheral arterial occlusive disease. Overall, the 5-year success rate after iliac angioplasty is 53.4%, but the success rate is higher if percutaneous transluminal angioplasty is performed on the common iliac artery or on a stenosed artery. In contrast, percutaneous transluminal angioplasty of the femoral and popliteal arteries has a relatively poor long-term success rate except for the treatment of patients with stenoses with good run-off. When the run-off is poor or an arterial occlusion is present, the role of femoropopliteal angioplasty is limited, and the procedure should be considered only for high-risk patients who do not have autogenous tissue for reconstructive surgery.

The effect of diabetes mellitus on the outcome of angioplasty for lower limb ischaemia

Angioplasty is an important tool in the armamentarium of the clinician dealing with atherosclerotic disease. Diabetic patients with occlusive disease pose special problems. Four hundred and twenty-five lesions were dilated in 370 patients. No difference in site was found when comparing the diabetic and non-diabetic groups (p less than 0.001), but a significant difference in indication for treatment was observed. Cumulative patency at 5 years for iliac lesions in non-diabetic patients was 61.2% and in diabetic patients was 35.6% (p less than 0.05), for superficial femoral and popliteal artery lesions in non-diabetic patients it was 49.7% and in diabetic patients it was 38.8% (NS). The need for subsequent surgical intervention (p less than 0.01) and risk of death (p less than 0.001) are both significantly greater in the diabetic group. This study shows that angioplasty is a technique that can be used with success in diabetic patients and if the indications for interventions are compared, diabetic patients do not worse.

Failure of peripheral arterial balloon angioplasty: does platelet deposition play a role?

The pathophysiological response to peripheral percutaneous transluminal balloon angioplasty in 20 patients was investigated using 111-Indium labelled platelets. Platelet deposition was quantified by measuring the degree of radioactivity uptake at angioplasty and control sites using a computer linked system and expressing the uptake as a ratio of angioplasty/control. Following platelet labelling, scans were performed before angioplasty and at 1, 24 and 48 h after angioplasty. To assess patency of the angioplasty, ankle brachial Doppler pressure indices were performed and supported by repeat angiograms if doubt of patency existed. All patients were followed-up at 1 week, 1 month and 6 months to correlate the degree of early platelet uptake with failure. The mean +/- sem platelet radioactivity ratio at the angioplasty site increased from 1.1 +/- 0.1 prior to the procedure to a peak of 2.1 +/- 0.3 at 1 h (p less than 0.01), 1.6 +/- 0.2 at 24 h (p less than 0.05), and 1.7 +/- 0.3 at 48 h (p less than 0.05). Angioplasties that failed within 6 months tended to have a higher maximum early platelet uptake (3.1 +/- 0.6) compared to successful angioplasties (1.9 +/- 0.3) but the difference was not significant in the numbers studied. This study provides a suitable model to assess the role of platelet accumulation in angioplasty failure and the influence of various antiplatelet regimes.

Femoro-popliteal artery occlusions treated by percutaneous transluminal angioplasty and enclosed thrombolysis: results in 55 patients

Removal of fibrin from the site of a newly dilated femoro-popliteal occlusion may be an attractive way of preventing rethrombosis. A double balloon catheter with a dilating tip balloon and an occlusive balloon 10, 15 or 20 cm approximately were introduced percutaneously. Following successful dilatation of femoro-popliteal occlusions, the balloons were inflated on both sides of the lesion. The dilated segment was then isolated from the circulation. Through a sideport between the balloons 5 mg of tissue type plasminogen activator and 1000 IU of heparin were installed within the segment for 30 min. The authors report the results of 53 technically successful dilatations of femoro-popliteal occlusions followed by enclosed thrombolysis. A 100% patency at 3 months was noted in 33 patients having one to three run-off arteries, and the one year patency was 90%. In 20 patients, with no infrapopliteal run-off artery, four rethrombosis occurred within 24 h, and the one year patency was 62%. This difference is significant. (Log rank test, Chi-square = 4.73, p less than 0.05). We conclude that enclosed thrombolysis prevents early reocclusion following PTA of femoro-popliteal occlusions provided that at least one infra-popliteal artery is patent.

Complications in percutaneous transluminal angioplasty: relationships with patient age

Five hundred consecutive attempted lower limb angioplasties for ischaemic disease (370 patients, mean age 65.6 years, range 33-91 years) were reviewed. Significant complications occurred in 44 cases (8.8%). Nine patients (1.8%) underwent emergency surgery related to a complication. A further 12 patients (2.4%) underwent elective surgery related to a complication. In addition, four patients died within 30 days of the procedure; one following surgery performed because of a complication of angioplasty, one following a myocardial infarction, one following severe bleeding associated with subsequent thrombolytic therapy and one during emergency surgery related to a complication of angioplasty. A correlation was found between complication rate and age. This relationship was independent of the approach to, the position of, and the severity of the treated lesion. Elderly patients are at increased risk of complication in lower limb angioplasty.

Angioplasty of the iliac and femoral arteries. Initial and long-term results in short stenotic lesions

This retrospective study presents the initial and long-term results of 212 iliac and femoral angioplasties in a selected group of 175 patients with one to three short stenotic lesions (less than 3 cm each). Patients who had iliac (n = 157) and femoral (n = 55) angioplasties were followed for 6-101 months. Claudication was the principal indication for intervention. Success or failure was defined by using a combination of clinical and objective vascular laboratory criteria. Long-term success was estimated by the Kaplan-Meier method. Differences between survival curves for factors such as site of angioplasty and status of run-off were analysed with the log-rank test. For all 212 angioplasties, the initial technical success rate was 93%. The immediate failure rate was 7% (15/212). The cumulative patency rate after 5 years of all technical successful angioplasties was 82% (SE 4%). Five-year patency rates were 84% (SE 4%) for iliac and 73% (SE 11%) for femoral angioplasty. Only one variable in this selected group of patients was associated with success: the site of the lesion.

Recent changes in the treatment of aortoiliac occlusive disease by the Oxford Regional Vascular Service

Over the four years from 1 January 1985 to 31 December 1988, 192 patients were treated for aortoiliac occlusive disease by the Oxford Regional Vascular Service. The number of patients treated by percutaneous transluminal angioplasty increased from two in the first year of the study to 34 in the third year of the study. This increase was accompanied by a decrease in the proportion of patients treated by aortobifemoral bypass but the proportion of patients treated by extra-anatomic bypass remained constant at around 30 per cent. Twice as many patients were treated in the fourth year as in the first year of the study so that the number of surgical operations increased despite many patients being treated exclusively by percutaneous transluminal angioplasty. The number of patients requiring mandatory treatment for limb salvage increased by 109 per cent and optional treatment for intermittent claudication by 85 per cent. The introduction of percutaneous transluminal angioplasty in Oxford has coincided with an increase in the number of patients presenting with symptomatic aortoiliac occlusive disease and has allowed twice as many people to be treated while the number of aortobifemoral bypass operations has remained unchanged. It is concluded that the introduction of percutaneous transluminal angioplasty has not only generated its own workload but has also led to an increased demand for surgical reconstruction for aortoiliac occlusive disease.

Early rethrombosis in femoropopliteal occlusions treated with percutaneous transluminal angioplasty

One hundred and thirty-seven consecutive percutaneous transluminal angioplasties (PTA) were performed for femoropopliteal vascular disease including 58 stenoses and 79 total occlusions. Nine occlusions could not be crossed with the guidewire, but in the remaining 128 the haemodynamic and clinical success as well as vascular patency were evaluated. The results were grouped into the following subsets: the indication for PTA, the severity of the vascular lesion, the crural run-off and the length of lesion. The results were in every respect poor with total occlusions when compared with stenoses. This was explained by a high incidence (41%) of rethrombosis within hours of dilatation. Early rethrombosis was seen with all lengths of occlusion (1-27 cm) with no statistically significant difference from other subsets. This study concludes that conventional PTA in femoropopliteal occlusions should be reserved for cases of limb salvage, preferably in patients who are technically inoperable. We suggest a new technique of segmentally enclosed thrombolysis to prevent early rethrombosis after PTA in femoropopliteal occlusions.

Is percutaneous transluminal angioplasty better than exercise for claudication? Preliminary results from a prospective randomised trial

Percutaneous transluminal angioplasty (PTA) is a commonly performed procedure for the treatment of intermittent claudication despite the lack of controlled studies. The aim of this study was to compare PTA with supervised exercise therapy for patients with arterial occlusive disease judged suitable for PTA at angiography. Patients were assessed before treatment commenced and at three monthly intervals afterwards. Assessment included measurement of resting ankle brachial pressure indices (ABPI), and claudicating and maximum walking distances on a treadmill up a 10 degrees incline. Twenty patients were randomised to receive PTA and 16 exercise. The groups were similar in age, sex, smoking habits and arteriographic pattern of disease. In the PTA group two patients had angioplasties that were technically unsuccessful and two other patients subsequently required surgery. One patient in the exercise group subsequently had a PTA. After PTA, mean ABPI were significantly improved at 3, 6 and 9 months (P less than 0.01) without a corresponding significant increase in mean maximum walking distances. However in the exercise group despite no increase in mean ABPI, mean maximum walking distances increased progressively, with significant increases at 6, 9 and 12 months (P less than 0.01).

Randomized trial of laser-assisted passage through occluded femoro-popliteal arteries

A randomized trial was carried out in patients with occlusions of the femoro-popliteal artery to compare the passage of metal-tipped optical fibres with guide wires and catheters through the occlusions, prior to balloon angioplasty. The study was in a provincial English teaching hospital providing a vascular service for the area. Fifty patients were entered; 25 into the "laser" group and 25 into the "control" group. End points were (a) the success in passage through the occlusion and (b) the outcome 1 month after passage. Comparison of the groups showed no appreciable difference between the two methods with regard to age, sex, symptoms, incidence of diabetes, or previous myocardial infarctions. Successful passage through the occlusion followed by dilatation was achieved in 18 (72%) patients in the laser group and 20 (80%) in the control group. After 1 month, 13 (52%) arteries in the laser group were patent compared to 13 (57%) in the control group. Confidence limits for the difference in success of passage are -15% to +31%, and -24% to +33% for patency after 1 month. Since these limits include zero, it is unlikely that a longer trial would alter the difference between the two methods. The results suggest that the laser system currently in use is no better than conventional methods.