Maria Schoder

Heparin-bonded covered stents versus bare-metal stents for complex femoropopliteal artery lesions: the randomized VIASTAR trial (Viabahn endoprosthesis with PROPATEN bioactive surface [VIA] versus bare nitinol stent in the treatment of long lesions in superficial femoral artery occlusive disease).

OBJECTIVES The hypothesis that endovascular treatment with covered stents has equal risks but higher efficacy than bare-metal stents (BMS) in long femoropopliteal artery disease was tested. BACKGROUND Although endovascular treatment of short superficial femoral artery lesions revealed excellent results, efficacy in long lesions remains unsatisfactory. METHODS In a prospective, randomized, single-blind, multicenter study, 141 patients with symptomatic peripheral arterial disease were assigned to treatment with heparin-bonded, covered stents (Viabahn 72 patients) or BMS (69 patients). Clinical outcomes and patency rates were assessed at 1, 6, and 12 months. RESULTS Mean ± SD lesion length was 19.0 ± 6.3 cm in the Viabahn group and 17.3 ± 6.6 cm in the BMS group. Major complications within 30 days were observed in 1.4%. The 12-month primary patency rates in the Viabahn and BMS groups were: intention-to-treat (ITT) 70.9% (95% confidence interval [CI]: 0.58 to 0.80) and 55.1% (95% CI: 0.41 to 0.67) (log-rank test p = 0.11); treatment per-protocol (TPP) 78.1% (95% CI: 0.65 to 0.86) and 53.5% (95% CI: 0.39 to 0.65) (hazard ratio: 2.23 [95% CI: 1.14 to 4.34) (log-rank test p = 0.009). In lesions ≥20 cm, (TransAtlantic Inter-Society Consensus class D), the 12-month patency rate was significantly longer in VIA patients in the ITT analysis (VIA 71.3% vs. BMS 36.8%; p = 0.01) and the TPP analysis (VIA 73.3% vs. BMS 33.3%; p = 0.004). Freedom from target lesion revascularization was 84.6% for Viabahn (95% CI: 0.72 to 0.91) versus 77.0% for BMS (95% CI: 0.63 to 0.85; p = 0.37). The ankle-brachial index in the Viabahn group significantly increased to 0.94 ± 0.23 compared with the BMS group (0.85 ± 0.23; p < 0.05) at 12 months. CONCLUSIONS This randomized trial in symptomatic patients with peripheral arterial disease who underwent endovascular treatment for long femoropopliteal lesions demonstrated significant clinical and patency benefits for heparin-bonded covered stents compared with BMS in lesions ≥20 cm and for all lesions in the TPP analysis. In the ITT analysis for all lesions, which was flawed by major protocol deviations in 8.5% of the patients, the difference was not significant. (GORE VIABAHN® endoprosthesis with bioactive propaten surface versus bare nitinol stent in the treatment of TASC B, C and D lesions in superficial femoral artery occlusive disease; ISRCTN48164244).

PTA Versus Carbofilm-Coated Stents in Infrapopliteal Arteries: Pilot Study

Purpose:To determine the primary success and short-term patency of stent application as a primary treatment modality for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia in a randomized prospective study.Methods:Endovascular therapy was performed on 95 lesions in 51 patients (mean age 72.0 years, range 47–80 years) who presented clinically with Fontaine stages III and IV. One patient underwent treatment in both limbs. After angiographic lesion identification, patients were randomized for treatment by PTA (53 lesions in 27 patients) or stent application (42 lesions in 24 patients). Follow-up by clinical investigation and conventional angiography or spiral CT angiography was performed in 37 patients (57 lesions) 6 to 12 months after the procedure, or when clinically indicated. Evaluation was performed by two observers, double-blinded, with thresholds for lesion restenosis of 50% and 70%. Statistical evaluation was performed on a lesion basis by Kaplan–Meier estimated probability rates, and log-rank and Wilcoxon tests. The primary endpoint was the angiographic patency rate of treated lesions.Results:The inter-reader agreement was high (κ = 0.82). For the stent group the cumulative primary patency at 6 months was 83.7% at the 70% restenosis threshold, and 79.7% at the 50% restenosis threshold. For PTA, the primary patency at 6 months was 61.1% at the 70% restenosis threshold and 45.6% at the 50% restenosis threshold. Both results were statistically significant (p < 0.05).Conclusion:Infrapopliteal stent application is an effective treatment modality for high-grade lesions in chronic critical limb ischemia. Compared with PTA, higher patency rates can be expected after 6 months.

Endovascular stent graft placement in patients with acute thoracic aortic syndromes.

OBJECTIVE In the present study, the effectiveness of endovascular stent grafts (ESG) in the treatment of acute aortic complications, such as acute dissection type B, penetrating ulcer and traumatic aortic rupture is evaluated. PATIENTS AND METHODS From June 1997 to February 2002, 66 patients were treated with ESG. Out of this cohort, 19 patients (28.8%) were subjected to stent grafting due to acute aortic syndromes. Acute dissection type B was present in 11 patients (16.6%), a penetrating ulcer was diagnosed in six patients (9%) and in 2 patients (3%) a traumatic aneurysm was the indication for operation. There were 16 male and three female patients with a mean age of 60 years (20-85 years). Excluder stent grafts (Gore) were used in 15 patients, the Talent device (Medtronic) was implanted in four patients. RESULTS Stent graft placement was technically successful in all patients. Hospital mortality was 0%. Paraparesis occurred in one patient (5.2%), which could be managed successfully without remaining neurological deficit after installation of cerebrospinal fluid drainage for 72h. In another patient, overstenting of the left subclavian artery caused ischemia of the left arm and left subclavian to carotid artery bypass had to be performed. ICU-stay ranged from 1 to 6 days (mean 2.4 days) and the patients could be discharged after an average hospital stay of 8 days. In the follow-up period, one patient died due to myocardial infarction and one patient had to be re-operated due to contained rupture of the thoracic aorta caused by an endoleak. CONCLUSIONS The study suggests that endovascular stent grafting is an excellent and effective treatment modality for the acute aortic accident, which can be recommended for high-risk patients too. However, close follow-up examination is indicated and long-term results have to be awaited to evaluate the real effectiveness of this method.

Stent-graft placement in atherosclerotic descending thoracic aortic aneurysms: midterm results.

PURPOSE To determine midterm durability and need for reinterventions after stent-graft placement in atherosclerotic descending thoracic aortic aneurysms. METHODS Fifty-four patients (38 men; mean age 68 years, range 33-87) underwent stent-graft repair of chronic atherosclerotic aneurysms of the descending thoracic aorta between November 1996 and December 2002. Acute aortic syndromes (type B aortic dissections, perforating ulcers, and traumatic dissections) were excluded from analysis. Two types of commercially available stent-grafts were used (Talent and Excluder). RESULTS The primary technical success rate was 94.4%. In-hospital mortality was 3.7% (2/54). No adverse neurological events were encountered. Of 3 (5.6%) early type I endoleaks, 2 (3.7%) required reintervention; the other type I endoleak closed spontaneously. Mean follow-up was 38 months (range 1-72) in the 52 surviving patients. Four (7.7%) type I, 7 (13.5%) type II, and 4 (7.7%) type III endoleaks were seen. Three 3 patients had additional treatment for endoleaks (proximal stenting [type Ia], open thoracoabdominal repair [type Ib], and embolization [type II]). Two of the 3 reinterventions were performed in the first year of follow-up. One additional patient with a type Ia endoleak not suitable for reintervention is under close observation. There were no differences in the number of endoleaks between the 2 types of stent-grafts. Three-year event-free survival was 63%. CONCLUSIONS Midterm durability of endovascular stent-graft placement in atherosclerotic descending aortic aneurysms seems promising, as the rate of endoleaks requiring reintervention is acceptably low. In our series, endoleak formation occurred during the first year after stent-graft placement, so close follow-up of patients after aortic aneurysm repair is crucial. Further studies are warranted to evaluate long-term durability of this new treatment modality.

Elective and Emergent Endovascular Treatment of Subclavian Artery Aneurysms and Injuries

Purpose: To demonstrate our short and long-term results after transbrachial treatment of subclavian artery aneurysms and injuries with stent-grafts in elective and emergency settings. Methods: Ten of 12 consecutive patients (6 men; mean age 63.8 years, range 38–80) were treated electively with commercially prepared endografts delivered via a transbrachial access to repair a subclavian artery aneurysm (n = 3) or an injury from a misplaced central venous catheter (n = 7). Two patients required emergency treatment for a ruptured atherosclerotic aneurysm in one and an unintentional arterial puncture during placement of a central venous access in the other. Stent-graft patency during follow-up was assessed by physical examination with comparison of brachial blood pressures in all patients; computed tomography angiography (CTA) was performed in available patients. Results: Successful deployment of stent-grafts with sealing of the lesion was achieved in all cases. There were 2 (17%) procedural complications. One patient developed an access-site hematoma that required surgical revision. The second patient, who had a right subclavian injury, suffered an embolic cerebral infarction. The primary stent-graft patency during follow-up (mean 11.6 months) was 100%. CTA examinations in 7 patients at a mean 18 months showed strut dislocation at the thoracic outlet without luminal narrowing in 1 patient. A 50% intraluminal narrowing due to compression between the clavicle and the first rib occurred in another patient. Six patients with a mean follow-up of 23 months (range 0.3–4.5 years) are still alive with patent stent-grafts. Conclusions: Endovascular stent-graft treatment of subclavian artery aneurysms and injuries is a less invasive alternative to surgical repair. Long-term results must still be confirmed in further studies.

Supra-aortic Transposition for Combined Vascular and Endovascular Repair of Aortic Arch Pathology

BACKGROUND Supra-aortic transpositions in various extents followed by endovascular stent graft placement are now an established tool in the treatment of various pathologies affecting the aortic arch. Results remain to be determined. METHODS From 1996 through 2007, 73 patients (median age, 71 years) presented with aortic arch pathology (atherosclerotic aneurysms, n = 42; type B dissections, n = 9; penetrating ulcers, n = 17; traumatic lesions, n = 2; aneurysms based on prior surgery for aortic coarctation, n = 3). Strategy for distal arch disease was subclavian-to-carotid transposition (n = 24) or autologous double-vessel transposition through upper hemisternotomy (n = 36). For entire arch disease, total supra-aortic rerouting with a reversed bifurcated prosthesis was applied (n = 13). Endovascular stent graft placement was performed metachronously. RESULTS In-hospital mortality was 6.8% (n = 5). Persistent early type I and III endoleak rate was 9.6%. Persistent late type I and III endoleak rate was 5.5%. Overall actuarial survival was 90%, 86%, and 72% at 1, 3, and 5 years. Mean follow-up is 37 months (range, 1 to 120). Early and late endoleak formation was independently predicted by the number of prostheses (early odds ratio [OR] 0.210, p = 0.0003; late OR 0.216, p = 0.012), whereas logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) reached borderline significance regarding late endoleaks (OR 2.1, p = 0.095). An earlier year of implantation reached borderline significance predicting survival (OR 1.9, p = 0.062). Furthermore, survival was independently predicted by higher logistic EuroSCORE levels (OR 1.8, p = 0.020). Interestingly, type of arch rerouting did not influence endoleak formation and survival (OR 0.9, p = 0.812). CONCLUSIONS Results after supra-aortic transpositions in various extents followed by endovascular stent graft placement for the treatment of various pathology affecting the aortic arch are promising. Endoleak formation is directly related to the number of prostheses and may be reduced by longer devices. Each type of arch rerouting, irrespective of extent, has turned out to be effective. Therefore, extended applications of these combined treatment strategies substantially augment the therapeutic options.

MR angiography vs CT angiography in the follow-up of nitinol stent grafts in endoluminally treated aortic aneurysms

Abstract. Our objective was to evaluate the accuracy of contrast-enhanced 3D MR angiography (MRA) in the follow-up of patients with endoluminally treated aortic aneurysms and correlate these findings with uni- or biphasic CT angiography (CTA). Forty MR angiograms in 32 patients with implanted aortic nitinol stent grafts were compared to CTA. Twenty-two MR examinations were correlated with arterial-phase CTA (uniphasic), and 18 MR examinations were correlated with biphasic CTA. Uniphasic CTA demonstrated three type-1/type-3 endoleaks and four reperfusion (type-2) endoleaks. In addition, MRA depicted two type-2 reperfusion endoleaks that were missed by CTA. Using biphasic CTA, two type-1/type-3 endoleaks and three reperfusion (type-2) endoleaks were detected; of those, delayed scanning detected three reperfusion (type-2) endoleaks missed during arterial-phase CTA. In addition to the findings by CTA, MRA depicted another type-2 reperfusion endoleak. Magnetic resonance angiography is at least as sensitive as uni- or biphasic CTA for detecting endoleaks and may consequently offer advantages in patients with contraindications to iodinated contrast agents.

Endoluminal stent-graft placement in patients with acute aortic dissection type B.

OBJECTIVES This study was performed to evaluate the feasibility, safety and effectiveness of endovascular stent-grafting in treating Stanford type B acute aortic dissection. We describe our first clinical experiences and initial results with stent-grafting across the primary entry tear in patients with acute aortic dissection type B. METHODS Between March 2000 and August 2001, nine patients with acute type B dissection were treated endoluminally by stent-graft implantation. There were seven male and two female patients with a mean age of 63 years (between 48 and 85 years). In all nine patients aortic dissection was diagnosed by multislice computed tomography (CT) angiography. All nine patients had a maximal aortic diameter of 5.5 cm or more and recurrent pain, one patient showed hemoptysis. This patient with signs of a contained rupture was treated under emergency condition, the eight remaining patients were in hemodynamic stabile condition at the time of intervention. The GORE Excluder stent-graft system was used in eight patients (mean 1.8 stents/patient) and the TALENT stent-graft system in one patient, which were introduced transfemorally. RESULTS The primary entry tear could be sealed successfully in all nine patients. Complete thrombosis of the false thoracic aortic lumen was obtained in two patients, in the remaining seven patients the false lumen was obliterated in the area of the thoracic aorta but perfused via re-entries in the abdominal region. No severe intraoperative complications occurred. One patient developed bilateral incomplete paraplegia with motor and sensory deficits affecting completely the right leg and partially the left leg, 14 h after intervention. A cerebrospinal fluid drainage was initiated by inserting a lumbar catheter. All nine patients, including the patient with the transient paraplegia, could be discharged from the hospital in excellent condition and without remaining neurologic deficits. Control CT scans showed a reduction of the false lumen from 2.34+/-0.58 to 0.7+/-0.44 cm and an increase of the true lumen from 1.56+/-0.5 to 4.10+/-0.6 cm in the thoracic aortic region. Mean ICU stay was 1.8 days, mean postoperative hospital stay was 7.6 days. CONCLUSIONS Stent-grafting of acute type B dissections may represent a very effective and promising new method by closure of the primary entry tear, thereby minimizing the risk of rupture of the thoracic aorta and optimizing distal perfusion by decompression of the true lumen.

Endovascular Management of Lost or Misplaced Intravascular Objects: Experiences of 12 Years

This paper reports our experience with endovascular techniques for the retrieval of lost or misplaced intravascular objects. Over 12 years, 78 patients were referred for interventional retrieval of intravascular foreign objects. In this retrospective study, radiological procedure records and patients’ medical records were reviewed to determine the exact removal procedure in every case, to report success rates, and to identify significant procedure-related complications. Written, informed consent was obtained from all patients prior to the intervention; this retrospective analysis was performed according to the guidelines of the Institutional Review Board. Thirty-six of seventy-eight foreign objects (46%) were located in the venous system, 27 of 78 (35%) in the right heart, and 15 of 78 (19%) in the pulmonary arteries. For foreign object removal, in 71 of 78 (91%) cases a snare loop was used, in 6 of 78 (8%) cases a sidewinder catheter combined with a snare loop was used, and in 1 case (1%) a sidewinder catheter alone was used for foreign object removal. In 68 of 78 (87%) cases, primary success was achieved. In 3 of 78 cases (4%), foreign objects were successfully mobilized to the femoral vessels and surgically removed. In 7 of 78 cases (9%), complete removal of the foreign object was not possible. In 5 of 78 cases (6%), minor complications occurred during the removal procedure. In conclusion, endovascular retrieval of lost or misplaced intravascular objects is highly effective, with relatively few minor complications. On the basis of our findings, these techniques should be considered as the therapy of choice.

Novel Insights Into the Mechanisms and Treatment of Intramural Hematoma Affecting the Entire Thoracic Aorta

BACKGROUND The purpose of this study was to address a previously not described mechanism underlying intramural hematoma (IMH) of the entire thoracic aorta and to test the hypothesis whether endovascular stent graft placement in this particular mechanism could be beneficial. METHODS Within a 5-year period, we treated 8 patients with IMH affecting the entire thoracic aorta. The presumed site of initial plaque rupture was chosen as target for endovascular stent graft placement. RESULTS In all patients, a small atherosclerotic plaque at the free lateral wall or at the concavity of the distal aortic arch could be identified as initial site of IMH. Endovascular stent graft placement was performed successfully in all patients. By covering the suspected primary lesion, resorption of IMH especially within the ascending aorta could be achieved. Mean follow-up is 16 months (range, 1 to 25). CONCLUSIONS Plaque rupture may be identified as the cause of IMH in a previously unrecognized subgroup of patients. If at the convexity of the distal arch, supra-aortic branches prevent retrograde extension toward the ascending aorta. If at the free lateral wall or at the concavity, IMH may affect the entire thoracic aorta, owing to the lack of the natural barrier of the supra-aortic branches. Endovascular stent graft placement of this plaque-associated IMH may be more effective and less invasive than conventional surgery to treat the entire thoracic aortic disease.