Claudio Schönholz

Transfemoral endoluminal stented graft repair of a popliteal artery aneurysm

This report describes the use of an endoluminally placed stented graft to repair a large (2.6 by 2.6 by 15 cm) popliteal aneurysm in a 63-year-old man with advanced heart disease. Two balloon-expandable stents were attached to a 6 mm polytetrafluoroethylene graft, which was inserted with the patient receiving local anesthetic through a proximal superficial femoral artery arteriotomy. Repeat arteriography and duplex ultrasonography performed up to 3 months after the procedure documented graft and distal artery patency and complete aneurysmal exclusion without distal emboli. This experience demonstrates technical feasibility and early graft patency. However, additional experience and follow-up will be needed to assess the value of this minimally invasive procedure in the management of popliteal aneurysmal disease.

Carotid Artery Stenting Protected With an Emboli Containment System

Background and Purpose— Fear of distal embolization and stroke has aroused concern regarding carotid stenting. Devices to protect the cerebral circulation may make carotid stenting safer. Methods— A multidisciplinary study group tested a balloon occlusion-aspiration emboli entrapment device in conjunction with carotid stenting. The device consists of an elastomeric balloon on a steerable wire with a detachable adapter that inflates and deflates the distal temporary occlusion balloon. An aspiration catheter is used to remove trapped emboli after stenting and before occlusion balloon deflation. Results— Seventy-five patients with severe internal carotid artery stenosis were treated with stents deployed with this cerebrovasculature protection system. All 75 patients (100%) had grossly visible particulate material aspirated, and all were treated successfully without major or minor stroke or death at 30 days. Preintervention stenosis was 81±10%, and residual stenosis was 5±7%. Nine patients (12%) had angiographic evidence of thrombus before intervention, but no patient had thrombus or vessel cutoff after the procedure. Four patients (5%) developed transient neurological symptoms during protection balloon occlusion, but symptoms resolved with balloon deflation. The 22 to 667 particles aspirated per patient ranged from 3.6 to 5262 &mgr;m in maximum diameter (mean, 203±256 &mgr;m). These particles included fibrous plaque debris, lipid or cholesterol vacuoles, and calcific plaque fragments. Conclusions— Protected carotid stenting was performed successfully and safely in this study early in the experience with cerebrovascular protection devices. Particulate emboli are frequent with stenting, and cerebral protection will likely be necessary to minimize stroke. Randomized trials comparing protected carotid stenting with endarterectomy are warranted.

Percutaneous transfemoral insertion of a stented graft to repair a traumatic femoral arteriovenous fistula

This case report describes a new approach to repair a femoral arteriovenous fistula with a transluminally placed intraarterial graft-covered stent. A balloon-expandable stented polytetrafluoroethylene graft was inserted percutaneously to obliterate an arteriovenous fistula after a bullet injured the left superficial femoral artery and vein of an 18-year-old man. Follow-up duplex ultrasonography at 5 months demonstrated patency and luminal integrity of the involved artery and vein, with resolution of the associated pseudoaneurysm. Additional follow-up will be needed to further substantiate the utility of this minimally invasive procedure in the treatment of traumatic arterial injuries.

Endoluminal Aortic Aneurysm Repair Using a Balloon-Expandable Stent-Graft Device: A Progress Report

We describe our experience with endoluminal repair of abdominal aortic aneurysms using the stent-graft device. Twenty-four patients underwent 25 procedures in the 27-month period ending December 31, 1992. Twenty-one of the patients were considered high-risk candidates for conventional surgical repair. The endoluminal stented grafts were aortoaortic in 16 procedures and unilateral aortoiliac in eight. One patient underwent a second procedure consisting of an ilioiliac graft to repair a separate common iliac artery aneurysm. Technical problems were primarily related to retrograde transluminal access across the iliac arteries, tortuous aneurysms, and misjudgments as to measurement of length. One patient died and another required secondary deployment of a distal stent at 4 months; subsequent aneurysm expansion mandated surgical replacement at 18 months. It is clear that this device and methodology will have to undergo further refinement before the technique is acceptable for wider clinical application. Current experience, however, is encouraging. Aneurysm exclusion with an endoluminal prosthesis is likely to become an important therapeutic alternative over the next several years.

Acute Traumatic Aortic Injury: Imaging Evaluation and Management

Despite recent advances in prehospital care, multidetector computed tomographic (CT) technology, and rapid definitive therapy, trauma to the aorta continues to be a substantial source of morbidity and mortality in patients with blunt trauma. The imaging evaluation of acute aortic injuries has undergone radical change over the past decade, mostly due to the advent of multidetector CT. Regardless of recent technologic advances, imaging of the aorta in the trauma setting remains a multimodality imaging practice, and thus broad knowledge by the radiologist is essential. Likewise, the therapy for acute aortic injuries has changed substantially. Though open surgical repair continues to be the mainstay of therapy, percutaneous endovascular repair is becoming commonplace in many trauma centers. Here, the historical and current status of imaging and therapy of acute traumatic aortic injuries will be reviewed.

Neuroprotection During Carotid Artery Stenting Using the GORE Flow Reversal System: 30-Day Outcomes in the EMPiRE Clinical Study

Background: Each of the embolic protection devices used in carotid artery stenting (CAS) has advantages and disadvantages. The prospective, multicenter, single‐arm EMPiRE Clinical Study investigated a proximally placed device (GORE Flow Reversal System) that provides distal neuroprotection during CAS by reversing blood flow in the internal carotid artery, thereby directing emboli away from the brain. Methods: The study evaluated 30‐day outcomes in 245 pivotal high‐surgical‐risk patients (mean age, 70 years; 32% symptomatic; 16% ≥80‐years old) with carotid stenosis who underwent CAS using the flow reversal system. The primary endpoint was a major adverse event (MAE; stroke, death, myocardial infarction, or transient ischemic attack) within 30 days of CAS. The MAE rate was compared with an objective performance criterion (OPC) derived from CAS studies that included embolic protection. Results: The MAE rate was 4.5% (11 patients; P = 0.002 compared with the OPC). The stroke and death rate was 2.9%. No patient had a major ischemic stroke. Six patients (2.4%) had intolerance to flow reversal. The death and stroke rates in the symptomatic, asymptomatic, and octogenarian subgroups were 2.6, 3, and 2.6%, respectively, meeting American Heart Association guidelines for carotid endarterectomy. Conclusion: The stroke and death rate in this study was among the lowest in CAS trials. The results indicate that the flow reversal system is safe and effective when used for neuroprotection during CAS and that it provides benefits in a broad patient population.

“Seat Belt and Air Bag” Technique for Cerebral Protection during Carotid Stenting

Purpose: To present a 2-device technique for cerebral protection during carotid stenting of the internal carotid artery (ICA) in patients with high-grade lesions, contralateral occlusion, and/or an aberrant or nonfunctioning circle of Willis. Technique: A reverse flow system (Parodi Anti-Embolism System [PAES]) is first placed with a 260-cm exchange wire in the common carotid artery 3 cm below the carotid bifurcation. Flow reversal is obtained by inflating the balloons in the external and common carotid arteries. Via an external connector, a guidewire and E-Trap filter are delivered to the distal ICA with active suction from a syringe on the PAES catheter. Once the filter is above the stenosis, the reversed flow is discontinued, and the procedure proceeds under cerebral protection with the filter. Conclusions: The combination of 2 existing cerebral protection devices could, at least in theory, achieve what neither of them could independently. The “seat belt and air bag” approach may represent the ideal means of treating ICA stenoses in patients with a nonfunctioning circle of Willis.

Carotid artery stenting versus surgery: adequate comparisons?

A moratorium on carotid artery stenting (CAS) has been recently proposed. Current randomised evidence supports the notion that carotid endarterectomy (CEA) is better than CAS. A meta-analysis of the randomised trials compared the two strategies and included data from the recent International Carotid Stenting Study (ICSS). This meta-analysis indicated that patients who received CAS had a signifi cant increased risk of 30-day death or stroke compared with patients who received CEA (odds ratio 1·60; 95% CI 1·26–2·02). As randomised clinical trials are the gold standard of clinical investigation, it seems unwise to challenge them. However, for the comparison of CAS versus CEA, most of the randomised trials should be considered not only scientifi cally but also ethically questionable because the endovascular experience required for interventionalists to be eligible for the studies was minimal (table). As a consequence, patients allocated to CAS might have been exposed to unnecessary risk and the assessment of safety and effi cacy of the endovascular approach confounded. In the French Endarterectomy Versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) study, a lifetime experience of at least 12 CAS interventions was required. Alternatively, a minimum of fi ve CAS procedures was deemed to be suffi cient if the interventionalist had a lifetime experience of at least 30 stenting procedures in supraaortic vessels. The rationale for this adjustment is diffi cult to understand given that subclavian and carotid interventions diff er substantially. For investigators who did not comply with these minimum requirements, the EVA-3S protocol allowed the procedure “under the supervision of an experienced tutor”, defi ned in the protocol as “a clinician who qualifi ed to perform stenting in this study”. In later correspondence, the investigators acknowledged that only 16% of the 265 patients treated with stenting were managed by operators who had done more than 50 CAS procedures in their lifetime and that 39% of patients were treated by physicians in training. Although such a track record can hardly be defi ned as good clinical practice or trial conduct, the information was not thought to be suffi ciently relevant to be reported in any of the EVA-3S publications. Concerns about CAS safety in the EVA-3S trial were raised after the enrolment of 80 patients in the endovascular arm. The safety committee recommended stopping the performance of CAS without the use of embolic protection devices, because the 30-day rate of stroke among patients undergoing un protected CAS was 26·7%, which was 3·9 times higher than that of patients treated with embolic protection (8·6%). However, in the clinical alert published by the EVA-3S investigators, the experience of the interventionalists was not questioned because “a learning eff ect is also unlikely to explain the diff erent complications rates, since protected CAS is a more complex technique than unprotected CAS”. This quote reveals a fundamental gap in understanding of the CAS procedure. In real-life practice, the use of embolic protection devices is widely embraced by experienced CAS interventionalists, whereas those with less expertise might be reluctant to use these devices. Additional evidence of the little endovascular experience among the investigators of EVA-3S is derived from the high rate of emergent conversion from CAS to CEA (5%). The fact that CAS was never reimbursed in France did not help the investigators to gain exposure to the procedure. According to the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study, a minimum of 25 successful consecutive CAS procedures was needed to participate as an investigator. However, a subsequent report revealed that, during the course of the trial, the protocol was amended to allow for tutoring of physicians who had only undertaken ten CAS procedures. Finally, in ICSS, a minimum of 50 total stenting procedures was required as long as at least ten of these involved the carotid artery. Tutor-assisted procedures were allowed for investigators with insuffi cient experience, again raising the concern of adequacy of training. The inexperience of the EVA-3S, SPACE, and ICSS investigators might have exposed the endovascular patients to an increased risk, not only because of insuffi cient operator skills, but also (and equally important) owing to inappropriate selection of patients. Interventions in patients with complex anatomy at the level of the aortic arch and supra-aortic vessels require more catheter manipulation than in patients with less tortuous or diseased vessels and place patients at increased risk of periprocedural stroke.

Endovascular Treatment of Abdominal Aortic Aneurysms: Lessons Learned

The authors offer an overview of their 20-year involvement in the development of an endovascular graft for abdominal aortic aneurysm exclusion. Clinical experience gained throughout 6 years of clinical evaluation are reviewed, along with observations and insights on preoperative assessment, implantation techniques, and complications.

Predictive factors for the development of type II endoleaks.

Purpose To define predictive factors for endoleak type II (EL-II) based on quantifiable factors in the imaging studies of patients undergoing endovascular aneurysm repair (EVAR). Methods The data on 208 consecutive patients (137 men; mean age 75.2 years, range 62–84) who underwent EVAR between the years 2003 and 2008 were retrospectively reviewed. The abdominal aortic aneurysm (AAA) diameter ranged from 4.8 to 12.8 cm. Data were collected on the type of AAA; the type of stent-graft (aortomonoiliac versus bifurcated); the performance of hypogastric artery embolization; the presence, number, diameter, and patency of aortoiliac branches identified on the pre and post-EVAR imaging studies; and the presence and type of EL-II (transient vs. persistent) with the goal of identifying any imaging-based predictive factors for the development of EL-II. Results Among the 208 cases, 11 patients had endoleaks other than type II and were excluded, leaving 195 patients for analysis. In all, 28 (13.4%) patients were diagnosed with EL-II. All had ≥4 patent lumbar arteries (mean diameter >2.3 mm). Ten patients with a transient EL-II had a mean of 4.3 patent lumbar arteries, which had diameters <2 mm (mean 1.5 mm). In the 18 patients with persistent EL-II, the mean diameter of the 4 lumbar arteries was 2.7 mm; at least 1 of the lumbar arteries was >2 mm. The presence of at least 4 patent lumbar arteries (p<0.001) and at least 1 patent hypogastric artery (p<0.001) were predictive factors for EL-II. At least 1 lumbar artery >2 mm in diameter was a positive predictive factor for the development of persistent EL-II (p<0.001). Conclusion Patent hypogastric and lumbar arteries are significantly associated with a higher risk of developing EL-II. Larger diameter lumbar arteries tend to be associated with persistent EL-IIs, while lumbar arteries <2 mm would more likely be seen with a transient EL-II. If substantiated in larger studies, these angiographic criteria may guide early treatment of EL-II to avoid aneurysm sac expansion and potential rupture.