Endoluminal Grafting for Aneurysmal and Occlusive Disease in the Superficial Femoral Artery: Early Experience

Purpose:

To examine whether endoluminal grafts (ELGs) of radially expandable polytetrafluoroethylene (PTFE) can successfully form durable internal conduits to revascularize lengthy occlusive disease and exclude aneurysms in the femoropopliteal (FP) arteries.

Methods:

Under protocol, implantation of an unpredilated PTFE tube ELG anchored with Palmaz stents using a low-profile percutaneous delivery system was attempted in 50 symptomatic patients for a variety of pathologies: (1) restenosis; (2) complex lesions unlikely to be treated successfully with other endoluminal therapies; (3) acute angioplasty failure; and (4) aneurysms. There were 37 occlusions, 14 stenoses, and 2 long, combined stenoticaneurysmal lesions in 47 native arteries, 5 FP grafts, and 1 femorotibial (FT) vein graft. Thirty-two percent of the patients had ≤ 1 vessel runoff. The average lesion length was 20.4 ± 11.4 cm (range 1.5 to 40), and the mean preoperative ankle-brachial index (ABI) at rest was 0.53 ± 0.14.

Results:

In a 20-month period through April 1995, 50 patients (34 males, 16 females; mean age 69.5 years, range 45 to 87) underwent 54 procedures in 53 limbs; 55 ELGs were successfully deployed in 51 limbs; 2 patients were converted to FP bypass owing to technical problems (96% procedural success). There were 18 inhospital complications: 1 distal wire dissection repaired with an additional ELG; 2 hematomas requiring surgical repair; 1 graft collapse; 1 pseudoaneurysm at the site of a mid-ELG leak; 7 minor access sequelae; and 6 acute ELG thromboses, 4 treated with lytic therapy and balloon dilation, 1 with open thrombectomy, and 1 with bypass grafting. The mean postoperative ABI was 1.01 ± 0.10. During the 30-day postprocedure period, 2 ELGs rethrombosed and 2 other limbs (3 ELGs) occluded; 1 thrombosis and 1 rethrombosis were lysed successfully, but the other 2 patients had an FP bypass. Over the mean 8.3 ± 5.5 month follow-up, 6 additional ELGs occluded and 1 reoccluded; 4 were successfully treated by endovascular techniques for a primary patency of 72% and secondary patency of 84% by life-table analysis.

Conclusions:

Endovascular grafting is a conceptually attractive technique that has the potential to expand the current boundaries of interventional treatment. This preliminary experience attests to the feasibility and safety of ELG deployment in the superficial femoral arteries. Whether such a device can match the durability of classical revascularization techniques remains to be determined in clinical trials when device configurations and deployment techniques have been standardized.

Superficial Femoral Endarterectomy with Intraarterial PTFE Grafting

Purpose:

To report early experience with a new endovascular approach to treating occluded Wallstents™ in the superficial femoral artery (SFA).

Methods and Results:

A symptomatic female patient with a 20-cm SFA occlusion involving a 10-cm Wallstent placed 2 years previously was offered an endovascular intervention. However, when percutaneous recanalization techniques failed, a semiclosed endarterectomy was undertaken using a conventional ring stripper. Although the atherosclerotic core and stent were removed smoothly, a small perforation was seen in the distal SFA. To avoid surgical repair, the endarterectomized segment was lined endoluminally using a 3-mm diameter, thin-walled polytetrafluoroethylene graft. A 15-mm Palmaz stent was used for distal fixation, with a plasty procedure performed at the proximal arteriotomy. There were no postoperative complications, and the patient, who was discharged on the second day, remains asymptomatic with normal flow through the graft at 3 months.

Conclusion:

Newer endovascular techniques may be applied in concert with conventional semiclosed endarterectomy to successfully treat lengthy SFA occlusions, particularly those involving stents.

Long-term Results with the Palmaz Stent in the Superficial Femoral Artery

Purpose:

Femoral stenting has demonstrated inconsistent and often disappointing long-term results. To compare our experience, we retrospectively analyzed a series of patients who had Palmaz balloon-expandable stents placed exclusively for superficial femoral artery (SFA) lesions.

Methods:

From January 1990 to November 1993, 39 patients were evaluated for claudication (79%) or critical ischemia in 42 limbs. The culprit lesions were confined to the SFA: 24 (57%) occlusions and 18 (43%) stenoses, including 3 restenotic lesions. Stenting was elective in 12 (29%) cases: the 3 restenoses and 9 chronic, calcified occlusions. The remaining stents were applied for postangioplasty residual stenosis or angioscopic findings of thrombogenic luminal irregularities. A total of 55 prostheses were successfully implanted. All patients were maintained on ticlopidine and followed by routine duplex scanning. Follow-up angiography was performed in 28 (72%) patients between 4 and 45 months.

Results:

In the postprocedural period, two acute thromboses (4.8%) occurred within 48 hours in patients who had long occlusions and poor runoff; no other major complications were encountered, for a clinical success rate of 95%. Follow-up evaluation ranged from 4 months to 4 years with a mean of 25 months. The restenosis rate was 19% (34% in occlusions; 10% in stenotic lesions, p = NS). At 24 months, cumulative primary patency was 77% and secondary patency 89%.

Conclusions:

Palmaz stents performed well in the SFA, demonstrating a low acute thrombosis rate and good long-term patency. The incidence of restenosis is likely to be greater in occlusions than in stenoses.

Stenting in the Carotid Artery: Initial Experience in 110 Patients

Purpose:

To evaluate the feasibility, safety, and efficacy of intravascular stents in the treatment of extracranial carotid artery occlusive disease.

Methods:

According to protocol, stent therapy was offered to symptomatic patients with ≥ 70% arteriographically defined carotid stenoses or ulcerative lesions and, after September 1994, to asymptomatic patients with ≥ 75% stenoses. From April 1993 to September 1995, 110 nonconsecutive patients (79 males; mean age 72 years, range 45 to 85) consented to participate in the study. The majority (79 [72%]) were asymptomatic. Lesions meeting the treatment criteria were in the proximal common (n = 3); mid common (n = 12); distal common (n = 8); internal (ICA) (n = 92); and external (n = 2) carotid arteries. Seven patients had bilateral ICA stenoses, and 17 patients were treated for postsurgical recurrent disease. The mean lesion length and diameter stenosis for all lesions were 12.4 ± 9.2 mm and 86.5% ± 10.6%, respectively. The procedures were performed either via direct percutaneous access to the cervical common carotid artery or through a retrograde femoral artery approach. Standard balloon dilation preceded deployment of balloon-expandable stents in most cases. No postprocedural anticoagulation was used (aspirin only).

Results:

In 110 patients (117 arteries) intended for treatment, 109 (99.0%) (116 arteries [99.1%]) were successfully treated with 129 stents (128 Palmaz, 1 Wallstent). One percutaneous procedure failed (0.9%) for technical reasons (stent could not be deployed) and was converted to carotid endarterectomy. Minor complications included 4 cases of spasm (successfully treated with papaverine); 1 flow-limiting dissection (stented); and 6 access-site problems. There were 7 strokes (2 major, 5 reversible) (6.4%) and 5 minor transient events (4.5%) that resolved within 24 hours. Three patients were converted to endarterectomy (2.7%) prior to discharge; 1 stroke patient expired (0.9%), and another patient died of an unrelated cardiac event in hospital. In the 30-day postprocedural period, 2 ICA stents occluded (patients asymptomatic). Clinical success at 30 days (no technical failure, death, endarterectomy, stroke, or occlusion) was 89.1% (98/110). Over a mean 7.6-month follow-up (range 2 to 31), no new neurological symptoms developed. Another stent occlusion at 2 months and one case of flow-limiting intimal hyperplasia at 7 months were detected on routine duplex scanning in asymptomatic patients. Life-table analysis shows an 89% cumulative primary patency rate.

Conclusions:

Based on this early experience, carotid stenting appears feasible from a technical standpoint, with good midterm patency. However, the incidence of neurological sequelae is a serious problem. Technical enhancements and a more aggressive antiplatelet regimen may have a positive impact on these events.

Percutaneous treatment of long superficial femoral artery occlusive disease: efficacy of the Hemobahn stent-graft

PURPOSE

To assess the efficacy of the Hemobahn stent-graft in the percutaneous treatment of long occlusive lesions of the superficial femoral artery (SFA).

METHODS

Fifty-nine limbs in 54 patients (42 men; mean age 73.3+/-8.2 years, range 55.2-91.3) with 59 symptomatic SFA occlusions >10 cm in length were selected for percutaneous treatment with the Hemobahn stent-graft. The treated SFA was assessed for patency and degree of stenosis by color-flow duplex ultrasound prior to discharge and at 1, 3, and 6 months and yearly thereafter. The actuarial life-table method was used to derive primary and secondary patency rates.

RESULTS

Primary technical success was achieved in 56 (95%) of 59 limbs on an intention-to-treat basis (2 access and 1 device failures). In the first 30 days, 4 (6.8%) stent-graft thromboses and 5 (8.5%) minor technical difficulties occurred. Up to 1 year, there were 15 (25.4%) primary occlusions, 7 (11.9%) of which were associated with restenosis. Cumulative primary patencies were 88%, 67%, and 58% at 1, 6, and 12 months, respectively; secondary patencies were 92%, 82%, and 73% at the same intervals. There was no statistically significant difference (p<0.05) in patency (primary or secondary) with respect to presenting symptoms, lesion length, stent-graft length, or distal runoff.

CONCLUSIONS

Symptomatic long occlusive lesions of the SFA treated percutaneously with the Hemobahn stent-graft achieved good outcomes initially with a low complication rate. Primary and secondary patencies were similar to those reported for open synthetic femoropopliteal bypass procedures.