Faculty Bibliography

BACKGROUND: Carotid artery stenting (CAS) is considered by many as an alternative to carotid endarterectomy (CEA) for the management of carotid artery stenosis. However, recent trials demonstrated inferior results for CAS in symptomatic patients compared with CEA. We reviewed the literature to evaluate the appropriateness of CAS for symptomatic carotid artery stenosis and to determine the pathogenetic mechanism(s) associated with stroke following the treatment of such lesions. Based on this, we propose steps to improve the results of CAS for the treatment of symptomatic carotid stenosis. METHODS: PubMed/Medline was searched up to March 25, 2010 for studies investigating the efficacy of CAS for the management of symptomatic carotid stenosis. Search terms used were 'carotid artery stenting,' 'symptomatic carotid artery stenosis,' 'carotid endarterectomy,' 'stroke,' 'recurrent carotid stenosis,' and 'long-term results' in various combinations. RESULTS: Current data suggest that CAS is not equivalent to CEA for the treatment of symptomatic carotid stenosis. Differences in carotid plaque morphology and a higher incidence of microemboli and cerebrovascular events during and after CAS compared with CEA may account for these inferior results. CONCLUSIONS: Currently, most symptomatic patients are inappropriate candidates for CAS. Improved CAS technology referable to stent design and embolic protection strategies may alter this conclusion in the future

BACKGROUND: Open abdomen treatment (OAT) is considered a lifesaving procedure in patients with abdominal compartment syndrome (ACS) after endovascular or open intervention for ruptured abdominal aortic aneurysms (RAAA). Standardized treatment methods and algorithms for its use are still lacking. The high, published mortality rates may reflect difficulties in detecting and treating ACS, especially in patients treated by emergency endovascular aneurysm repair (eEVAR). Presented are standardized algorithms for OAT, including a new technique using the vacuum-assisted closure (VAC) system developed during 10 years of experience with eEVAR for RAAA. METHODS: We retrospectively analyzed 102 patients with RAAA treated by eEVAR from January 1998 to April 2008. Abdominal decompression was done when intravesical pressure >20 mm Hg or when abdominal perfusion pressure was <50 to 60 mm Hg and concomitant organ deterioration occurred. OAT was initially done with a subcutaneously sutured plastic bag or with a nonsutured zipper drape combined with a VAC device (VAC/ETHIZIP; KCI International Inc, Amstelveen, The Netherlands; Ethicon, Somerville, NJ). All patients were switched to VAC/ETHIZIP as soon as possible. Dressings were generally changed every 3 to 5 days. Intra-abdominal pressure was monitored until stability was observed after delayed direct abdominal closure. RESULTS: Overall 30-day mortality for eEVAR was 13% (13 of 102); 8% (7 of 82) for patients without ACS and 30% (6 of 20) for those with ACS. Decompression for ACS was needed in 20 patients (20%) primarily during the intervention (n = 14) or secondarily in the intensive care unit (n = 6). Six of 20 (30%) patients requiring OAT died <or=30 days (4 primary, 2 secondary). A mean of 3.6 (range, 1-12) planned second-look interventions were done per patient at an interval of 3 to 5 days. No bowel lesions were observed. Four patients required antibiotic therapy for abdominal infection, and all infections resolved. Delayed abdominal wall closure (direct closure, 11; closure with polypropylene mesh, 3; bilateral anterior rectus abdominis sheath turnover flap, 1) was achieved after a median of 6 days (range, 1-47 days). CONCLUSION: The use of standardized novel techniques and a treatment protocol and algorithm for OAT after eEVAR for RAAA were feasible and safe. It decreased the workload of the medical and nursing staff, enhanced patient comfort because the need for dressing changes was minimized, and likely contributed to lower overall mortality in RAAA patients. Delayed direct fascial closure was possible in most patients

Improvements in the design of endovascular grafts are based on lessons learned from difficulties encountered with prior-generation devices. The most common difficulties in device design relate to how the device is delivered and how it can safely and durably fix the aneurysm. This concept is especially true in patients with difficult anatomy. Difficult anatomy, such as small, calcified, tortuous access vessels and short angulated sealing zones, continue to challenge engineers. Currently, the US Food and Drug Administration has approved eight endovascular devices for the treatment of aortic aneurysms: five for abdominal aortic aneurysms and three for thoracic aortic aneurysms. Compared to the first-generation devices approved in 1999, current devices have smaller and more flexible delivery systems. The devices themselves are more flexible and have better fixation than prior-generation devices. This article will focus on the next generation of devices that are not yet approved, but currently under investigation in the United States

BACKGROUND: To evaluate the effectiveness of the Viabahn Open Revascularization Technique (VORTEC) in the treatment of thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PAAAs) by hybrid procedures. METHODS: Between December 2004 and March 2009, 58 patients (45 male, mean age, 74 years) were diagnosed with TAAA (n = 30) and PAAA (n = 28) and treated electively by combined hybrid techniques. Hybrid procedure includes bypass surgery of the visceral and renal arteries (debranching or rerouting), followed by endovascular exclusion of the aortic aneurysm. One hundred thirteen renovisceral vessels were revascularized in a retrograde fashion (ie, 98 renal and 15 visceral arteries), using VORTEC. The novel technique consists of the placement of self-expanding stent-grafts (Viabahn graft, Gore and Associates, Flagstaff, Ariz) in Seldinger technique into the renal and visceral arteries after surgical identification of the origin of the arteries. The end of the stent outside of the renal artery was sutured end to side directly with the main feeding graft, bypassing the aneurysm, or was fixed into an interposition branch graft on the main bypass. All cases were treated by two-staged approach (endovascular aneurysm repair [EVAR] performed after recovery from the debranching procedure). Computed tomography angiography and clinical follow-up were obtained before discharge, at six weeks, and three, six, and 12 months after the procedure and then annually. RESULTS: Primary technical success of VORTEC was achieved in all patients. Overall primary patency rate of the novel technique was 97% during a mean follow-up of 22.1 +/- 12.9 months (range, 1-52 months); the primary patency of the subgroups PAAAs and TAAAs was 97.7% and 96.4%, respectively; the assisted primary patency rate was 98%, as two occluded Viabahn grafts were reopened by thrombolysis and thrombus aspiration. No patient required long-term hemodialysis. Thirty-day mortality rate was 8.6% (5/58) and 25.8% (15/58) for the entire follow up. Permanent neurologic deficit occurred in two cases (3.4%; paraplegia, n = 1; paraparesis, n = 1). The overall endoleak rate was 17.1% as three patients presented early (30-day) type I endoleak, treated by cuff-implantation, and six patients presented type II endoleak, three of them treated by coil embolization of the patent vessel and the others treated conservatively with radiological surveillance. CONCLUSION: VORTEC allows performance of easy, safe, and minimally invasive revascularization of renal and visceral arteries and may represent a significant technical advance in the hybrid repair of TAAAs and PAAAs. However, the questions of reproducibility by other centers and long-term results are mandatory to establish this alternative revascularization option

A floating thrombus within the aortic arch is a rare condition that is generally detected after cerebral, visceral, or peripheral embolization. Endovascular exclusion of such mobile thrombus has been described but exclusively involved the descending aorta, or debranching of the supra-aortic trunk was done by open surgical bypass procedure. We present a case with a floating thrombus that extended throughout the whole aortic arch and involved all of the supra-aortic trunks. The pathology was treated by debranching the supra-aortic trunks using a new nonsutured Viabahn-based (W. L. Gore & Associates, Flagstaff, Ariz) technique (Viabahn Open Revascularization TEChnique [VORTEC]) for revascularization of the left common carotid artery and performing an antegrade endograft implantation from the ascending aorta, distal to the origin of the feeding graft for debranching, to the descending aorta in one procedure

BACKGROUND: Intracranial hemorrhage (ICH) following carotid endarterectomy (CEA) or carotid artery stenting (CAS) is a rare but potentially devastating complication. The effect of more intense dual antiplatelet therapy required for CAS on the frequency of ICH has not been established. This study was undertaken to evaluate the nationwide occurrence of ICH associated with CAS vs CEA. METHODS: The Nationwide Inpatient Sample was used to identify patients discharged after CAS and CEA during 2005. The type of revascularization and major adverse events, ie, in-hospital ICH, postprocedural stroke, and death rates, were determined by cross-tabulating specific procedural codes for CAS and CEA and diagnostic codes for carotid stenosis. Risk stratification was performed using the Charlson Comorbidity Index. Univariate and multivariate logistic regression analyses were used to assess the association between type of revascularization, comorbidities, ICH, and risk-adjusted mortality. RESULTS: In 2005, the estimated number of carotid revascularizations was 135,903. The vast majority of patients underwent CEA (90.4%), whereas CAS was performed in 13,093 (9.6%) patients. Most patients (92.2%) underwent treatment for asymptomatic carotid stenosis. CAS patients had higher postoperative stroke rates (2.1% vs 1.1%; P < .001) and in-hospital mortality (1.1% vs 0.6%; P < .001) than CEA patients. ICH occurred in 19 patients (0.15%) after CAS and in 20 patients (0.016%) after CEA (P < .001). CAS was identified as an independent predictor for postoperative stroke (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.5-2.0; P < .001), in-hospital mortality (OR, 1.49; 95% CI, 1.2-1.8; P < .001) and ICH (OR, 5.9; 95% CI, 3.1-11.1; P < .001) after adjusting for age, gender, symptomatic status, comorbidities, admission, and hospital type using logistic regression. In-hospital mortality was 12.5% among patients developing ICH (OR, 23.2; 95% CI, 9.1-54.4; P < .001). CONCLUSION: In the United States, patients undergoing CAS have not only significantly increased postoperative stroke and death rates compared with those undergoing CEA, but also a sixfold increased risk of ICH. Although ICH after CAS is extremely rare, its devastating nature and high mortality warrant further investigation to define specific risk factors, prevention, and treatment strategies

INTRODUCTION: Endovascular replacement of failed Vanguard endoprosthesis with a newly inserted bifurcated Excluder endograft in 6 selected patients over a 10-year period is reported. REPORT: Six male patients were treated by secondary EVAR procedures for endograft failure (type I and/or III endoleaks caused by endograft disintegration and/or migration). All failed endografts (1 tube, 5 bifurcated) were Vanguard prostheses. Technically, a new bifurcated Excluder endograft was placed within the old failing Vanguard endograft. All reinterventions were performed under local anesthesia supplemented by systemic analgesia/sedation. In 3 patients, insertion of the new Excluder endograft was possible without any additional technical measure as the failing Vanguard endograft trunk had migrated distally. In another 3 patients, the failed Vanguard endograft trunk was still in place. In these patients, the Vanguard main body was pulled caudally with a transfemoral cross-over guide wire in order to gain sufficient length to allow the short limb of the Excluder endograft to open within the trunk of the failed Vanguard endoprosthesis. This guide wire was introduced through a second femoral 5F in the main access and exeteriorized with a snare through the contralateral 12 Fr sheath. The main body and short limb of the Excluder was then deployed whilst pulling on the cross-over wire. RESULTS: Six patients initially treated by a Vanguard endograft underwent complete relining with a newly inserted Excluder bifurcated stentgraft. The mean interval from the first EVAR procedure to the described replacement procedure was 75+/-20.2 months (range: 53-109). The new bifurcated Excluder endografts were successfully deployed in all patients (technical success: 100%). Primary sealing (defined as absence of endoleaks type I, III or IV in the postoperative contrast enhanced CT scan) was achieved in 6 of the 6 patients. There was no operative mortality. No further endovascular or open treatment was needed in the other 5 patients. During the mean follow-up period of 26+/-20.1 months (range 2.5-50 months), 2 patients died from unrelated causes. CONCLUSION: Secondary endovascular replacement of failed Vanguard endografts with a bifurcated Excluder endograft proved to be feasible and safe with no 30-day mortality. Technical detail requires traction on a cross-over wire to pull the old graft caudally and create enough space for the new bifurcated graft to be deployed

BACKGROUND: Case and single center reports have documented the feasibility and suggested the effectiveness of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs), but the role and value of such treatment remain controversial. OBJECTIVE: To clarify these we examined a collected experience with use of EVAR for RAAA treatment from 49 centers. METHODS: Data were obtained by questionnaires from these centers, updated from 13 centers committed to EVAR treatment whenever possible and included treatment details from a single center and information on 1037 patients treated by EVAR and 763 patients treated by open repair (OR). RESULTS: Overall 30-day mortality after EVAR in 1037 patients was 21.2%. Centers performing EVAR for RAAAs whenever possible did so in 28% to 79% (mean 49.1%) of their patients, had a 30-day mortality of 19.7% (range: 0%-32%) for 680 EVAR patients and 36.3% (range: 8%-53%) for 763 OR patients (P < 0.0001). Supraceliac aortic balloon control was obtained in 19.1% +/- 12.0% (+/-SD) of 680 EVAR patients. Abdominal compartment syndrome was treated by some form of decompression in 12.2% +/- 8.3% (+/-SD) of these EVAR patients. CONCLUSION: These results indicate that EVAR has a lower procedural mortality at 30 days than OR in at least some patients and that EVAR is better than OR for treating RAAA patients provided they have favorable anatomy; adequate skills, facilities, and protocols are available; and optimal strategies, techniques, and adjuncts are employed