Experience with early TEVAR treatment of uncomplicated type B aortic dissection.

The current paradigm for the treatment of chronic type B aortic dissection involves primarily medical treatment. The patients are then followed for sequelae like progressive dissection or aneurysmal degeneration, selecting this subgroup for further intervention. The European Collaborator Registry, the Talent Thoracic Retrospective Registry, and several meta-analysis showed that the uncomplicated type B dissection patients who underwent thoracic endovascular aortic repair (TEVAR) outperformed their counterpart in the complicated group. The INSTEAD trial, the first randomized trial to examine whether TEVAR is better than medical management in the chronic stable dissection patients, showed no benefit early on although mid-term data might show some benefit. Clearly more randomized controlled trials are necessary to create a paradigm shift. In the United States, the FDA approved TEVAR devices are for the descending thoracic aortic aneurysm and transection only. The use of these devices for dissection is off-label or for investigation only. As future study might broaden the use of TEVAR for the chronic dissection patients, the use of TEVAR in hybrid surgery and in the ascending aorta is also broadening the indication for this technology. With two decades of innovation behind, TEVAR will continue to evolve and innovate in the years ahead.

EVAR using the Nellix Sac-anchoring endoprosthesis: treatment of favourable and adverse anatomy.

OBJECTIVE: The study aimed to review the results of endovascular aneurysm repair (EVAR) using a novel sac-anchoring endoprosthesis in patients with favourable and adverse anatomy. DESIGN: This is a prospective, multicentre, clinical trial. MATERIALS: The Nellix endoprosthesis consists of dual, balloon-expandable endoframes, surrounded by polymer-filled endobags, which obliterate the aneurysm sac and maintain endograft position. METHODS: The study reviewed worldwide clinical experience and Core Lab evaluation of computed tomography (CT) scans. RESULTS: From 2008 to 2010, 34 patients (age 71 ± 8 years, abdominal aortic aneurysm (AAA) diameter 5.8 ± 0.8 cm) were treated at four clinical sites. Seventeen patients (50%) met the inclusion criteria for Food and Drug Administration (FDA)-approved endografts (favourable anatomy); 17 (50%) had one or more adverse anatomic feature: neck length <10 mm (24%), neck angle >60° (9%) and iliac diameter >23 mm (38%). Device deployment was successful in all patients; iliac aneurysm treatment preserved hypogastric patency. Perioperative mortality was 1/34 (2.9%); one patient died at 10 months of congestive heart failure (CHF); one patient had a secondary procedure at 15 months. During 15 ± 6 months follow-up, there were no differences in outcome between favourable and adverse anatomy patients. Follow-up CT extending up to 2 years revealed no change in aneurysm size or endograft position and no new endoleaks. CONCLUSIONS: Favourable and adverse anatomy patients can be successfully treated using the Nellix sac-anchoring endoprosthesis. Early results are promising but longer-term studies are needed.

Trends in cardiac morbidity and mortality after endoluminal abdominal aortic aneurysm repair; discussion 999-1000.

HYPOTHESIS: The adverse cardiac event rate following endoluminal abdominal aortic aneurysm (EAAA) repair has decreased as experience in performing the procedure has increased. Aneurysm complexity affects the rate of adverse cardiac events. DESIGN AND PATIENTS: Data from 173 consecutive patients undergoing EAAA repair from 2 successive periods were compared. There were 82 patients in the early group (group 1) and 91 patients in the later group (group 2). MAIN OUTCOME MEASURES: Myocardial infarction, congestive heart failure, unstable angina, major dysrhythmias, death. RESULTS: The cardiac event rate was 8.5% for group 1 vs 16.5% for group 2 (P =.16). Predictors of adverse cardiac events on multivariate analysis were the use of 4 or more graft extensions (P =.04), female sex (P =.01), and number of Eagle risk factors (P<.001). There were 2 postoperative deaths (2.4%) in group 1 and 4 (4.4%) in group 2 (P =.7). CONCLUSIONS: Following EAAA repair: (1) adverse cardiac events were found to correlate with use of 4 or more graft extensions, female sex, and the number of Eagle risk factors; (2) cardiac morbidity and mortality remain significant despite greater experience and improved technology; and (3) operative mortality remains acceptably low.

Failed AAA endograft exclusion due to type II endoleak: explant analysis.

PURPOSE: To report the patient history and analysis of an explanted modular bifurcated endograft that was implanted to exclude an abdominal aortic aneurysm (AAA). CASE REPORT: An 80-year-old man with a 6-cm AAA underwent uneventful endovascular implantation of a bifurcated AneuRx stent-graft. His postprocedural clinical course was uneventful, although persistent contrast enhancement of the aneurysm remained via the inferior mesenteric artery (IMA). By 6 months, an endoleak connecting to the lumbar and mesenteric arteries became apparent. Over the ensuing 12 months, the endoleak and aneurysm enlarged; branch artery embolization was attempted in 4 percutaneous procedures. Despite successful IMA occlusion, the aneurysm continued to increase in diameter and volume, necessitating conversion to a conventional bypass at 20 months. Analysis of the explanted specimen revealed an intact endograft with fibrous incorporation of the stent framework at the proximal and distal fixation sites only; no incorporation of the endograft was noted within the aneurysm. The feeding channel for the endoleak was not identified. CONCLUSIONS: Serial imaging is a vital component of endograft surveillance, and persistent type II endoleaks that cannot be completely embolized endanger the longevity of the aneurysm exclusion. Explant analysis can play an important role in understanding the mechanisms of endograft failure.

Healing response of normal canine aorta and iliac artery to a nitinol stent encapsulated in carbon-lined ePTFE.

PURPOSE: To evaluate the healing response of normal canine arteries to a self-expanding nitinol stent encapsulated in carbon-lined expanded polytetrafluoroethylene (ePTFE). METHODS: Twenty-eight dogs were divided into aortic (n = 18) or iliac (n = 10) groups. In the latter, 2 animals were assigned to implantation intervals of 7, 30, and 90 days, respectively; 4 were designated for 180-day implantation. Half of the animals in each subgroup received a second overlapping stent-graft in one iliac artery. In the aortic cohort, 6 animals were assigned to the 180-day implantation group (2 with dual devices) and 3 to each of the others (1 dual implantation in each group). The devices were evaluated with angiography and intravascular ultrasound at implantation and explantation. After harvesting and gross examination, the specimens were examined microscopically and with scanning electron microscopy. RESULTS: The 49 implanted devices (24 aortic and 25 common iliac) were all widely patent at explantation, save for 2 iliac stents that had moderate (<40%) stenosis. No neointima was present at the 7-day interval. All stents were covered by thin neointima (<150 microm) at 30 days. At 180 days, an endothelial lining was present in the proximal and distal segments of all stents; in 4 of the 6 aortic stents, this endothelial lining was complete, whereas none of the iliac devices had endothelium in the midsegment at 180 days. At 1 year, 2 of the aortic specimens had an incomplete endothelial lining, whereas the lining was complete in the third. There was no evidence of stent-graft migration or inflammation associated with any device. CONCLUSIONS: The carbon-lined ePTFE-encapsulated stent is a novel approach to arterial stenting. The progressive endothelialization and lack of inflammatory reaction may provide improved long-term patency. Further study of this stent-graft design is warranted.

Abdominal pain and hemoperitoneum: sole presenting symptoms for "leaking AAA" after endovascular repair.

PURPOSE: To describe an unusual presentation of impending aortic endograft rupture and successful endovascular rescue. CASE REPORT: A 77-year-old man with an enlarging aortic aneurysm was treated with a Talent bifurcated endoprosthesis; a moderate endoleak that appeared to be related to either proximal or distal fixation sites was noted in the body of the aneurysm. The patient was observed for 1 month, and repeat imaging demonstrated persistent endoleak without major increase in the aneurysm diameter. Another examination was scheduled for 3 months hence, but, 2 months later, the patient presented with abdominal pain and a hemoperitoneum. A proximal extension cuff resolved the leak and led to resolution of the hemoperitoneum. CONCLUSIONS: A leaking aneurysm can be repaired using endovascular techniques in patients with an existing endograft. The need for frequent imaging surveillance of patients with endoleak is underscored.

Endovascular exclusion of descending thoracic aortic aneurysms and chronic dissections: Initial clinical results with the AneuRx device.

OBJECTIVE: The objective of this study was to analyze a single-center experience in which descending thoracic aortic aneurysms (TAAs) were treated with a new self-expanding endovascular prosthesis (Medtronic AVE). METHODS: Twenty-six patients (13 men, 13 women) with American Society of Anesthesiology grades II to IV and ages ranging from 53 to 92 years (average, 74 years) consented as part of a Phase I Food and Drug Administration-approved trial. Treated lesions included TAAs that were 5 to 10 cm in diameter, 12 diffuse dilations or fusiform aneurysms, and four saccular aneurysms. There were also nine chronic dissections (2 aneurysmal dilations and 7 symptomatic acute recurrent dissections). Three patients (2 with diffuse/fusiform and 1 with dissection) presented with hemothorax, contrast extravasation, or both. RESULTS: Twenty-five of the 26 patients who consented (96% technical success) were treated successfully with no surgical conversions. Eighteen patients have been followed up from 1 to 22 months (average, 9 months). One patient is lost to follow-up, and six patients have died (24%). One procedure-related death (4%) occurred within the 30-day postoperative period and was caused by diffuse embolization. There were no device-related deaths. Five additional patients (20%) have died during the study of comorbid conditions. Complications included one massive myocardial infarction 24 hours after the procedure requiring balloon counterpulsation and long-term dialysis, one cardiac tamponade resulting from central line placement before the procedure, one progression of aneurysm dilation proximal to the device at 1 year, and one bilateral lower extremity paralysis occurring 12 hours after successful deployment. Seven patients (5 women) had femoral artery reconstructions or iliac artery grafts to repair injuries during deployment catheter passage. Other significant parameters included average procedure time (2 hours 40 minutes; range, 1 hour 30 minutes to 5 hours 30 minutes), 450 cc average blood loss (n = 25; 100-3000 cc) being replaced by means of autotransfusion with only two patients receiving banked blood products, and an average 2 days to resumption of normal diet, 1 day in the intensive care unit, and 5 days' hospitalization postprocedure in uncomplicated cases (n = 22). One patient had an endoleak immediately after the procedure that sealed without treatment. Follow-up of all patients ranging from 1 to 22 months (average, 9 months; n = 18) demonstrates continued exclusion of the aneurysm with no endoleaks and either stable or decreasing aneurysm volume, except in one patient with volume increase and no obvious etiology who continues to be investigated. CONCLUSIONS: The study suggests that endovascular prosthesis exclusion of TAAs with an AneuRx self-expanding tubular device may be effective in many patients who are at significant risk for open surgical repair and substantiates further clinical investigation to confirm these findings.

An abnormal dipyridamole thallium/sestamibi fails to predict long-term cardiac events in vascular surgery patients.

Recent data demonstrate that dipyridamole-thallium (DTHAL) and sestamibi (DMIBI) are not predictive of adverse perioperative cardiac events in moderate-risk patients (one or more Eagle risk factors) undergoing major elective vascular surgery. Less data are available regarding the ability of DTHAL/DMIBI to predict adverse cardiac events on long term follow-up. We sought to determine whether an abnormal DTHAL/DMIBI is predictive of adverse cardiac events on long-term follow-up in moderate-risk patients undergoing major elective vascular surgery. Patients were enrolled prospectively between June 1997 and June 1999 at West Los Angeles VA and Harbor-UCLA Medical Centers. Adverse cardiac events were defined as congestive heart failure (CHF), myocardial infarction (MI), unstable angina (USA), and ventricular arrhythmias. Follow-up was obtained via clinic visits, telephone calls, and chart review. We studied 75 patients (76% male, 24% female) with a mean age of 65 years. Operative procedures were primarily femorodistal (83%) and aortic (16%). DTHAL/DMIBI results were normal in 35 patients (47%), demonstrated reversible ischemia in 26 (35%), and showed a fixed defect alone in 14 (18%). From the follow-up results of this study we conclude that there is no association between a reversible ischemia or an abnormal (fixed or reversible) DTHAL/DMIBI and adverse cardiac events or mortality on long-term follow-up in moderate-risk patients who have undergone major vascular surgery.

Computed tomography assessment of abdominal aortic aneurysm morphology after endograft exclusion.

OBJECTIVES: Assessment of the long-term function of endografts to exclude abdominal aortic aneurysm (AAA) includes determination of aneurysm dimensions and morphologic changes that occur after implantation. This study reports the dimensional analysis of patients treated with AneuRx bifurcated endoprostheses with postintervention, 1-year (n = 51), 2-year (n = 28), and 3-year (n = 10) postimplantation contrast computed tomography data. METHODS: Maximal diameter (D) and cross-sectional area (CSA) of the AAA were measured from axial computed tomography images. Total volume, AAA thrombus volume (AAA volume minus the volume of the device and luminal blood flow), diameter of the aorta at the level of the renal arteries and within the device, distance from the renal arteries to the device, length of the device limbs, and the angle of the proximal neck were also determined at the same follow-up intervals after deployment with computed tomography angiograms reconstructed in an interactive environment. RESULTS: Fifty-one of 98 consecutively treated patients with the AneuRx bifurcated prosthesis (29 "stiff" and 22 "flexible" body devices) had complete data from the postprocedure and follow-up computed tomography studies available for analysis. Max D, CSA, total volume of the AAA, and AAA thrombus volume decreased sequentially from year to year compared with the postimplantation values. D and CSA decreased or were unchanged in all except four patients, two who had unrestricted enlargement of the aneurysm with eventual rupture and one who had surgical conversion for continued expansion despite four diagnostic angiograms and attempted embolizations. Total volume of the AAA increased in 11 of 51 patients at 1 year, eight of whom had endoleaks at some interval during the follow-up. Thrombus volume increased more than 5% in four of these patients, including the two with eventual rupture and the one conversion. Patients with endoleaks who had spontaneous thrombosis or were successfully treated either remained at the same volume or had decreased volume on subsequent examinations. D at the renal arteries increased an average of 0.9 mm during the first year, with a concomitant increase of 2.8 mm within the proximal end of the device related to the self-expanding nature of the Nitinol suprastructure. Subsequent enlargement of the proximal neck continued at a slow rate in some cases but never exceeded the diameter of the endoluminal device. The distance from the renal arteries to the device increased by an average of 3 mm over the first year, with the greatest increases occurring in patients with a "stiff" body device and those with rapid regression (>10% total volume) in 1 year. As regression of the AAA occurred, the angle of the proximal neck varied from -5 degrees to +25 degrees from the original alignment. Limb length varied from -8 mm to +10 mm, with no consistent pattern for the change, that is, ipsilateral or contralateral limb. CONCLUSION: Significant variation in the quantitation of aneurysm size occurs depending on the technique of computed tomography assessment used. In most patients diameter assessment is adequate, although volumetric analysis appears to be very helpful in certain patients who do not show aneurysm regression, or in whom the diameter increases or where endoleaks persist. Three-dimensional reconstruction and volumetric analysis are also useful to assess the mechanism by which the endovascular device accommodates to morphology changes and to determine criteria for reintervention.

Abdominal aortic aneurysm rupture following endoluminal graft deployment: report of a predictable event.

PURPOSE: To describe the predictability of an abdominal aortic aneurysm (AAA) rupture secondary to a type II endoleak following stent-graft exclusion. METHODS AND RESULTS: An 81-year-old man with an enlarging AAA underwent endovascular repair using an AneuRx aortic stent-graft, but a type II endoleak fed by an accessory renal artery was detected at postprocedural computed tomography (CT). Surveillance CT scans at 6 and 16 months showed an increase in the aneurysm diameter and endoleak volume, but the patient refused advised treatment to close the leak. He suffered a fatal aneurysm rupture 24 months after endografting. Retrospective analysis of CT data documented progressive aneurysm enlargement that correctly predicted the rupture. CONCLUSIONS: Type II endoleaks can lead to aneurysm rupture. Three-dimensional (3D) spiral CT angiography offers an opportunity to track endoleak volume and the effect of exposure to systemic pressure on the aneurysm sac.

Dipyridamole-thallium/sestamibi before vascular surgery: a prospective blinded study in moderate-risk patients.

PURPOSE: This study assessed in a prospective, blinded fashion whether a reversible defect on dipyridamole-thallium (DTHAL)/sestamibi (DMIBI) can predict adverse cardiac events after elective vascular surgery in patients with one or more clinical risk factors. METHODS: Consecutive patients with one or more clinical risk factors underwent a preoperative blinded DTHAL/DMIBI. Patients with recent congestive heart failure (CHF) or myocardial infarction (MI) or severe or unstable angina were excluded. RESULTS: Eighty patients (78% men; mean age, 65 years) completed the study. Diabetes mellitus was the most frequent clinical risk factor (73%), followed by age older than 70 years (41%), angina (29%), Q wave on electrocardiogram (26%), history of CHF (7%), and ventricular ectopy (3%). The results of DTHAL/DMIBI were normal in 36 patients (45%); a reversible plus or minus fixed defect was demonstrated in 28 patients (36%), and a fixed defect alone was demonstrated in 15 patients (19%). Nine adverse cardiac events (11%) occurred, including three cases of CHF, and one case each of unstable angina, Q wave MI, non-Q wave MI, and cardiac arrest (successfully resuscitated). Two cardiac deaths occurred (2% overall mortality), one after a Q wave MI and one after CHF and a non-Q wave MI. The cardiac event rate was 14% for reversible defect and 9.8% without reversible defect (P =.71). The cardiac event rate was 12.5% (one of eight cases) for two or more reversible defects, versus 11.1% (eight of 72 cases) for fewer than two reversible defects (P = 1.0). The sensitivity rate of two or more areas of redistribution was 11% (95% CI, 0.3%-48%), the specificity rate was 90%, and the positive and negative predictive values were 12.5% and 89%, respectively. CONCLUSION: Our study demonstrated no association between reversible defects on DTHAL/DMIBI and adverse cardiac events in moderate-risk patients undergoing elective vascular surgery.

Central venous injuries of the subclavian-jugular and innominate-caval confluences.

Injuries to the central venous system can result from penetrating trauma or iatrogenic causes. Injuries to major venous confluences can be particularly problematic, because the clavicle and sternum seriously limit exposure of the injury site. We report our institution's experience with central venous injuries of the subclavian-jugular and innominate-caval venous confluences. Significant injuries of the subclavian-jugular venous confluence frequently result from penetrating trauma, while injuries to the innominate-caval confluence are usually catheter-related. Median sternotomy provides adequate exposure of the innominate-caval confluence, while exposure of the subclavian-jugular venous confluence requires extension of the median sternotomy incision into the neck and resection of the clavicle. The literature is reviewed.

Endovascular vs open abdominal aortic aneurysm repair: a comparison of cardiac morbidity and mortality.

HYPOTHESIS: Adverse cardiac event rates following endovascular abdominal aortic aneurysm (EAAA) and open abdominal aortic aneurysm (OAAA) repair are similar. We also hypothesized that the Eagle criteria (Q wave on electrocardiogram, diabetes, angina, congestive heart failure, age >70 years, and ventricular ectopy) are useful predictors of cardiac events in patients undergoing EAAA repair. DESIGN: Prospective (patients undergoing EAAA repair) and retrospective (patients undergoing OAAA repair). SETTING: Public teaching and Veterans Affairs medical centers. PATIENTS: Eighty-three EAAA and 63 OAAA repairs. MAIN OUTCOME MEASURES: Myocardial infarction, congestive heart failure, and cardiac death. RESULTS: Patients with EAAA were older (73 vs 68 years, P=.003). There were no differences in the mean number of Eagle criteria (1.2 vs 1.3), cardiac event rates (6% vs 4.8%), or mortalities (3.6% vs 4.8%). Within the EAAA group, congestive heart failure (P=.005) and Q wave on electrocardiogram (P=.006) were the only predictors of cardiac events. CONCLUSIONS: Patients undergoing OAAA and EAAA repair had similar cardiac event rates and mortality. In patients undergoing EAAA repair, history of congestive heart failure and Q wave on electrocardiogram were predictors of cardiac events.

Cardiac morbidity and operative mortality following lower-extremity amputation: the significance of multiple Eagle criteria.

The ability of the Eagle criteria (age >70 years, angina, diabetes, Q wave on EKG, history of congestive heart failure) to predict adverse cardiac events following major vascular surgery has previously been demonstrated. However, the utility of these criteria for lower-extremity amputation is not well established. To determine the value of the Eagle criteria for predicting cardiac morbidity and operative mortality following major lower-extremity amputation, we reviewed 214 consecutive procedures performed at two institutions over a 3-year period. Mean age was 62.7 years and 85% of the patients were male. Diabetes was the most frequent Eagle criterion (74%). The mean number of Eagle criteria was 1.6. Fifty-six percent of the amputations were below the knee, 24% were above the knee, and 20% were guillotine. On multivariate regression analysis, the presence of two or more Eagle criteria (16% vs. 4%, p = 0.04) and decompensated heart failure (39% vs. 7%, p = 0.003) were predictive of adverse cardiac events. The only predictor of postoperative mortality was the presence of two or more Eagle criteria (15% vs. 4%, p = 0.004). Our evaluation of the results of this study led us to conclude that patients requiring major lower-extremity amputation for major vascular disease who have multiple Eagle criteria or decompensated congestive heart failure are at high risk for adverse cardiac events and postoperative death. These findings should be used to guide perioperative cardiac evaluation and therapy.

Iliac to popliteal artery bypass through the iliac wing: An alternative extracavitary route for management of complex groin injuries.

Extracavitary bypass through the iliac wing allows placement of the grafts into the posterior thigh and is another alternative route when an obturator bypass is not possible, or an axillary-popliteal bypass is to be avoided. The transiliac wing bypass is relatively simple and easy to perform. The bypass route is short and direct, has excellent inflow, and is accompanied by minimal neurological or bleeding risks. An illustrative case is presented with a complete description of the operative technique. Review of the literature is also included.

The impact of intravascular ultrasound (IVUS) on endovascular interventions.

Intravascular ultrasound (IVUS) has undergone rapid evolution with the recent expansion of endovascular techniques and devices. This device can aid the surgeon, cardiologist, and interventional radiologist by increasing the accuracy of imaging and by adding important information to peripheral vascular and coronary interventions. Modern intravascular ultrasound provides a detailed view of the lumen, wall, and surrounding structures of blood vessels. Compared with other modalities, the diagnostic advantages of IVUS for examining arterial wall architecture and lesion morphology are evident. IVUS can determine lesion shape, length, and configuration, as well as identifying and examining the origins of branches and tributaries. Using this information, IVUS can guide the choice of appropriate angioplasty techniques, aid in the placement of endovascular devices, and assess and follow the efficacy of such interventions. IVUS helps reduce the use of radiation and contrast agents. Even though intravascular ultrasound requires additional equipment, personnel, and interpretative skills, it can be invaluable as a sensitive real-time imaging tool for complex endovascular interventions, therapeutic challenges, and diagnostic dilemmas.

Wallgraft endoprosthesis: initial canine evaluation.

This study evaluated the in vivo deployment and the healing characteristics of a self-expanding endoluminal graft [Wallgraft (WG) Endoprosthesis] in a canine (n = 22) aorta. The WG consisted of a 10 or 12 mm x 7.5 cm Wallstents (Schneider, Inc.) covered with polyethylene terephthalate (Dacron) graft material. Twenty-two WGs were deployed using fluoroscopic guidance. Devices were oversized approximately 10 per cent. Intravascular ultrasound (IVUS) was repeated, and balloon expansion along the length of the WG was performed to assure maximum expansion. WGs were evaluated with IVUS, angiography, and histology at 14 (n = 4), 30 (n = 4), 90 (n = 4), 180 (n = 5), and 365 (n = 5) days. Predeployment aortic diameters were 9.9 +/- 1 mm. Mid-WG diameters were 9.0 +/- 0.8 mm before balloon dilation and 9.2 +/- 0.5 mm after dilation with 8- (n = 1), 10- (n = 16), and 12- (n = 5) mm balloons. Twenty-two of 23 devices were deployed accurately with good apposition and aortic flow after deployment. On explant, all of the covered grafts were widely patent on IVUS and angiogram. Four explants demonstrated gaps (due to WG taper) between the proximal or distal ends of the graft on IVUS. The device length (9.1 + 0.5 cm) did not change significantly after deployment. Histologically at 6 months and 1 year the lumens were cell-lined. Scanning electron micrography demonstrated endothelial-like cells. This study demonstrates the ability of a WG to be accurately deployed and maintain excellent patency. Balloon expansion after deployment did not significantly increase the diameter. Clinical evaluation of this device is in progress.