Jon S. Matsumura

Outcomes Following Endovascular vs Open Repair of Abdominal Aortic Aneurysm: A Randomized Trial

CONTEXT Limited data are available to assess whether endovascular repair of abdominal aortic aneurysm (AAA) improves short-term outcomes compared with traditional open repair. OBJECTIVE To compare postoperative outcomes up to 2 years after endovascular or open repair of AAA in a planned interim report of a 9-year trial. DESIGN, SETTING, AND PATIENTS A randomized, multicenter clinical trial of 881 veterans (aged > or = 49 years) from 42 Veterans Affairs Medical Centers with eligible AAA who were candidates for both elective endovascular repair and open repair of AAA. The trial is ongoing and this report describes the period between October 15, 2002, and October 15, 2008. INTERVENTION Elective endovascular (n = 444) or open (n = 437) repair of AAA. MAIN OUTCOME MEASURES Procedure failure, secondary therapeutic procedures, length of stay, quality of life, erectile dysfunction, major morbidity, and mortality. RESULTS Mean follow-up was 1.8 years. Perioperative mortality (30 days or inpatient) was lower for endovascular repair (0.5% vs 3.0%; P = .004), but there was no significant difference in mortality at 2 years (7.0% vs 9.8%, P = .13). Patients in the endovascular repair group had reduced median procedure time (2.9 vs 3.7 hours), blood loss (200 vs 1000 mL), transfusion requirement (0 vs 1.0 units), duration of mechanical ventilation (3.6 vs 5.0 hours), hospital stay (3 vs 7 days), and intensive care unit stay (1 vs 4 days), but required substantial exposure to fluoroscopy and contrast. There were no differences between the 2 groups in major morbidity, procedure failure, secondary therapeutic procedures, aneurysm-related hospitalizations, health-related quality of life, or erectile function. CONCLUSIONS In this report of short-term outcomes after elective AAA repair, perioperative mortality was low for both procedures and lower for endovascular than open repair. The early advantage of endovascular repair was not offset by increased morbidity or mortality in the first 2 years after repair. Longer-term outcome data are needed to fully assess the relative merits of the 2 procedures. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00094575.

Long-Term Comparison of Endovascular and Open Repair of Abdominal Aortic Aneurysm

BACKGROUND Whether elective endovascular repair of abdominal aortic aneurysm reduces long-term morbidity and mortality, as compared with traditional open repair, remains uncertain. METHODS We randomly assigned 881 patients with asymptomatic abdominal aortic aneurysms who were candidates for both procedures to either endovascular repair (444) or open repair (437) and followed them for up to 9 years (mean, 5.2). Patients were selected from 42 Veterans Affairs medical centers and were 49 years of age or older at the time of registration. RESULTS More than 95% of the patients underwent the assigned repair. For the primary outcome of all-cause mortality, 146 deaths occurred in each group (hazard ratio with endovascular repair versus open repair, 0.97; 95% confidence interval [CI], 0.77 to 1.22; P=0.81). The previously reported reduction in perioperative mortality with endovascular repair was sustained at 2 years (hazard ratio, 0.63; 95% CI, 0.40 to 0.98; P=0.04) and at 3 years (hazard ratio, 0.72; 95% CI, 0.51 to 1.00; P=0.05) but not thereafter. There were 10 aneurysm-related deaths in the endovascular-repair group (2.3%) versus 16 in the open-repair group (3.7%) (P=0.22). Six aneurysm ruptures were confirmed in the endovascular-repair group versus none in the open-repair group (P=0.03). A significant interaction was observed between age and type of treatment (P=0.006); survival was increased among patients under 70 years of age in the endovascular-repair group but tended to be better among those 70 years of age or older in the open-repair group. CONCLUSIONS Endovascular repair and open repair resulted in similar long-term survival. The perioperative survival advantage with endovascular repair was sustained for several years, but rupture after repair remained a concern. Endovascular repair led to increased long-term survival among younger patients but not among older patients, for whom a greater benefit from the endovascular approach had been expected. (Funded by the Department of Veterans Affairs Office of Research and Development; OVER ClinicalTrials.gov number, NCT00094575.).

Endovascular repair of traumatic thoracic aortic injury: Clinical practice guidelines of the Society for Vascular Surgery

The Society for Vascular Surgery® pursued development of clinical practice guidelines for the management of traumatic thoracic aortic injuries with thoracic endovascular aortic repair. In formulating clinical practice guidelines, the Society selected a panel of experts and conducted a systematic review and meta-analysis of the literature. They used the Grading of Recommendations Assessment, Development and Evaluation methods (GRADE) to develop and present their recommendations. The systematic review included 7768 patients from 139 studies. The mortality rate was significantly lower in patients who underwent endovascular repair, followed by open repair, and nonoperative management (9%, 19%, and 46%, respectively, P < .01). Based on the overall very low quality of evidence, the committee suggests that endovascular repair of thoracic aortic transection is associated with better survival and decreased risk of spinal cord ischemia, renal injury, graft, and systemic infections compared with open repair or nonoperative management (Grade 2, Level C). The committee was also surveyed on a variety of issues that were not specifically addressed by the meta-analysis. On these select matters, the majority opinions of the committee suggest urgent repair following stabilization of other injuries, observation of minimal aortic defects, selective (vs routine) revascularization in cases of left subclavian artery coverage, and that spinal drainage is not routinely required in these cases.

The Society for Vascular Surgery Practice Guidelines: Management of the left subclavian artery with thoracic endovascular aortic repair

The Society for Vascular Surgery pursued development of clinical practice guidelines for the management of the left subclavian artery with thoracic endovascular aortic repair (TEVAR). In formulating clinical practice guidelines, the society selected a panel of experts and conducted a systematic review and meta-analysis of the literature. They used the grading of recommendations assessment, development, and evaluation (GRADE) method to develop and present their recommendations. The overall quality of evidence was very low. The committee issued three recommendations. Recommendation 1: In patients who need elective TEVAR where achievement of a proximal seal necessitates coverage of the left subclavian artery, we suggest routine preoperative revascularization, despite the very low-quality evidence (GRADE 2, level C). Recommendation 2: In selected patients who have an anatomy that compromises perfusion to critical organs, routine preoperative LSA revascularization is strongly recommended, despite the very low-quality evidence (GRADE 1, level C). Recommendation 3: In patients who need urgent TEVAR for life-threatening acute aortic syndromes where achievement of a proximal seal necessitates coverage of the left subclavian artery, we suggest that revascularization should be individualized and addressed expectantly on the basis of anatomy, urgency, and availability of surgical expertise (GRADE 2, level C).

Clinical consequences of periprosthetic leak after endovascular repair of abdominal aortic aneurysm

PURPOSE The study was conducted to evaluate risk factors, natural history, and clinical consequences of a periprosthetic leak after endovascular repair of an abdominal aortic aneurysm. METHODS We reviewed the initial and follow-up data, including angiograms, contrast-enhanced computed tomography (CT) scans, abdominal duplex scans, and plain abdominal films for all patients undergoing tube graft repair using the endovascular graft system (early prototype) between February 10, 1993, and January 24, 1995. RESULTS Sixty-eight patients underwent placement or attempted placement of a tube graft implant in 13 centers in the United States. Nine patients required conversion to open repair, leaving 59 patients with functioning grafts for evaluation. The mean follow-up time was 27 +/- 8 months (range, 2 to 48 months). Twenty-eight (47%) of 59 patients had initial periprosthetic leaks (6 proximal, 14 distal, 3 proximal and distal, 5 indeterminate) on their first postoperative CT scans. Fourteen (50%) of the initial 28 leaks sealed spontaneously. Two other patients had their leaks sealed by endovascular means, leaving 12 patients with persistent leaks for follow-up evaluation. Four patients developed late leaks between 18 and 24 months of follow-up: one who had a spontaneously sealed initial leak, one with a second leak, and two who developed late leaks. Of the 16 patients with sealed leaks, 10 had aneurysm size reduction during follow-up. Three aneurysm sacs enlarged before spontaneous sealing but have not had sufficient follow-up time to document the size change since the seal. One patient died of respiratory failure 5 months after graft implantation. One patient whose leak was sealed by intervention has not yet had a CT scan for evaluation. In one patient with a sealed leak and whose aneurysm had initially shrunk, the area reopened and progressed to a nonfatal rupture that was surgically corrected. There were two late deaths from unrelated causes. Twelve patients in the sealed group are alive and well. Of the 12 patients with persistent leaks, five underwent open surgical repair without complication, and one underwent successful endovascular repair with a second graft. Six patients continue to live with their initial grafts and have an average aneurysm sac enlargement of 0.1 cm per year. CONCLUSIONS Although initial periprosthetic leaks were common with the use of this early prototype, 50% spontaneously sealed. The subsequent clinical course of patients with persistently sealed leaks was no different from that of patients who had no leaks. However, continued CT surveillance is warranted, because in one patient with an initially sealed leak, the area reopened and progressed to nonfatal rupture. Another two patients without initial leaks developed late leaks. In a small group of selected patients with continued leaks, their aneurysms appeared to enlarge at a rate considerably slower than would have been expected in patients with untreated aneurysm, suggesting that even a person after endovascular repair with a persistent leak may have had some beneficial hemodynamic modification.

Reduction in aortic aneurysm size: Early results after endovascular graft placement

PURPOSE Previous reports demonstrate initial technical success with transluminally placed endovascular grafts (TPEG) for the treatment of abdominal aortic aneurysms. However, long-term changes in the size of the aorta and aneurysmal segments are unknown. The purpose of this study was to determine aortic dimensions at several levels by computed tomographic (CT) scans 1 year after TPEG. METHODS Thirty-four patients underwent TPEG with 1-year CT scans. Patients were divided into three groups: group I, no perigraft leak; group II, early perigraft leak that sealed during the first year; and group III, persistent perigraft leak. Aortic minor and major diameters, perimeter, and area were measured at four locations: the celiac aorta, proximal neck, maximal aneurysm size, and distal neck. RESULTS There were 32 men and two women, with a mean age of 73 +/- 8 years. In group I there were 20 patients (58%), and groups II and III had seven patients (21%) each. The overall mean aneurysm minor diameter decreased from 4.79 +/- 0.68 cm at implantation to 4.39 +/- 0.86 cm at 1 year (p < 0.0001). The aneurysm sac decreased by 0.63 +/- 0.58 cm in group I, and by 0.34 +/- 0.24 cm in group II. In group III, however, the aneurysm sac increased by 0.19 +/- 0.21 cm. Aneurysm size change did not correlate with inferior mesenteric or lumbar artery patency. The dimensions of the celiac aorta and proximal neck did not change significantly. However, diameter of the distal neck enlarged by 0.12 +/- 0.27 cm (p < 0.01). CONCLUSIONS TPEG exclusion is associated with reduction of aneurysm size 1 year after implantation. Expansion of the aneurysms occurred with persistent perigraft leak. The aortic size at the celiac artery and proximal neck did not change. Dilation of the distal neck was minor but requires further long-term follow-up to determine clinical significance.

Carotid plaque morphology correlates with presenting symptomatology

PURPOSE In carotid artery disease, correlation of carotid plaque morphology with the patients presenting symptoms has drawn conflicting conclusions. The purpose of this series was to correlate carotid plaque characteristics with the presenting symptoms from a large cohort of patients who underwent operation for carotid artery disease. METHODS From a series of 1252 consecutive patients who underwent carotid endarterectomy, presenting symptoms were divided into three groups: transiently symptomatic (transient ischemic attack [TIA] or amaurosis fugax), prior stroke, and asymptomatic. Plaque characteristics, including ulceration, intraplaque hemorrhage, and degree of stenosis, were recorded prospectively for 1008 procedures. All endarterectomy specimens were inspected during the procedure, and plaque characteristics were recorded immediately after operation. RESULTS There was a higher incidence of plaque ulceration in the transiently symptomatic and prior stroke groups (391 of 508 [77%] and 91 of 115 [79%]) than in the asymptomatic cohort (231 of 385 [60%]; p < 0.0001, chi2 test). There was no significant difference in the incidence of plaque hemorrhage between the transiently symptomatic and prior stroke patients compared with the asymptomatic patients. There was no statistical difference for ulcerated plaque or plaque hemorrhage between the transiently symptomatic and prior stroke group. Intraplaque hemorrhage occurred more frequently in patients with high-grade stenosis (90% to 99%) than in those with less than 90% stenosis (202 of 299 [68%] versus 97 of 299 [32%]; p = 0.01, chi2 test). CONCLUSIONS On gross examination of the carotid specimen in the operating room, plaque ulceration correlates with an initial presentation of amaurosis fugax, TIA, or prior stroke compared with patients operated on for asymptomatic disease. The presence of intraplaque hemorrhage is associated with more advanced stenosis of the internal carotid artery. These findings suggest that plaque morphology does play an important role in the presentation of carotid artery disease.

Continued expansion of aortic necks after endovascular repair of abdominal aortic aneurysms

BACKGROUND Longitudinal studies have revealed that the aortic segment proximal to an infrarenal abdominal aortic aneurysm (AAA) is at risk for continued enlargement after a standard aneurysm repair. Similarly, preliminary reports have shown expansion of one or both aortic necks after endovascular repair. Although some investigators have suggested that this may be a transient effect, continued dilatation at the endograft attachment site could effect the overall device stability. METHODS As part of a multi-institutional trial of endovascular grafting for the treatment of AAA, 59 patients were successfully implanted with straight endografts between February 1993 and January 1995. A morphometric analysis of aortic neck size was undertaken with serial review of computed tomography scans available through April 1997. The neck sizes at both graft attachment sites were measured, with investigators blinded to patient identity and date of scan. Changes in minor diameter were defined, annual interval expansion rates were calculated, and the data were correlated with endoleak, device migration, aneurysm size change, endograft diameter, attachment system fractures, and initial preimplant neck size. RESULTS Significant aortic neck enlargement, particularly at the level of the distal neck, was observed for at least 24 months after AAA repair. The annual interval dilation rates of the proximal aortic neck were 0.7 +/- 2.1 mm/year (P = .023) and 0.9 +/- 1.9 (P = .008) mm/year during the first and second years, respectively. Enlargement of the distal neck during the observation period was more marked, with corresponding annual expansion rates of 1.7 +/- 2.9 mm/year (P < .001) and 1.9 +/- 2.5 (P < .001) mm/year. In 5 patients (14%), the minor diameter of the distal neck was at least 6 mm larger than the preimplant diameter of the graft. Migration of the distal attachment system was observed in 3 of these 5 patients. Expansion rates did not have a statistically significant correlation with initial neck size, endograft dimensions, aneurysm size change, presence of endoleak, or attachment system fracture. CONCLUSIONS Aortic neck enlargement was observed for at least 2 years after endovascular grafting. Close patient follow-up remains mandatory in lieu of the potential risk of late failure as a result of continued aortic expansion. The relative contribution of device design to this phenomenon will need to be defined.

The United States StuDy for EvalUating EndovasculaR TreAtments of Lesions in the Superficial Femoral Artery and Proximal Popliteal By usIng the Protégé EverfLex NitInol STent SYstem II (DURABILITY II)

OBJECTIVE Angioplasty and stenting are options for revascularization of symptomatic femoral popliteal disease. Although angioplasty alone is effective in short lesions, longer lesions are often treated with stents. Multiple overlapping stents are expensive and may be associated with stent fracture. This trial evaluated the safety and efficacy of a single self-expanding stent up to 20 cm in length in patients with atherosclerotic disease of the superficial femoral artery (SFA) and proximal popliteal artery. METHODS Patients with lesions >4 cm and <18 cm were enrolled in this nonrandomized, prospective, multicenter trial that evaluated the Protégé EverFlex Self-Expanding Peripheral Stent System (Covidien, Plymouth, Minn). The studys primary end points were the 30-day major adverse event rate and duplex ultrasound-assessed patency at 1 year. These were compared with published performance goals. A preplanned analysis was conducted for the primary effectiveness end points at 1 year. Follow-up, including history, ankle-brachial index, patient-reported outcomes, duplex ultrasound assessment, and radiographs, is planned through 3 years. There was core laboratory review of angiograms, ultrasound scans, and plain radiographs. A subgroup of patients was studied with graded treadmill testing. RESULTS The study enrolled 287 patients (66% male; mean age, 68 years) with stenotic, restenotic, or occluded lesions of the SFA at 44 investigational sites in the United States and Europe. Systemic comorbidities included hypertension (88%), hyperlipidemia (86%), diabetes (43%), and prior SFA intervention (41%). The mean lesion length measured by the core laboratory was 89 mm. The mean normal-to-normal lesion length measured by sites was 110 mm. A total of 303 stents were implanted, and 95% of patients received a single stent. No major adverse events occurred at 30 days. At 1 year, primary outcome of duplex ultrasound stent patency was 67.7% in evaluable patients, and among 1-year secondary outcomes, the mean ankle-brachial index increased by 0.25. Walking Improvement Questionnaire scores improved in pain by 33.7, distance by 37.1, speed by 18.6, and stair climbing by 24.7. The Kaplan-Meier estimate of primary patency was 77.2%, primary assisted patency was 86.9%, and secondary patency was 87.3%. Rutherford clinical category improved in 83.5% of patients. Stent fracture rate was 0.4%. Matched absolute claudication distance was 412 feet greater and was not statistically different in this subgroup of 29 individuals. CONCLUSIONS The results of DURABILITY II (StuDy for EvalUating EndovasculaR TreAtments of Lesions in the Superficial Femoral Artery and Proximal Popliteal By usIng the Protégé EverfLex NitInol Stent SYstem II) suggest that a new single stent strategy is safe and effective for the treatment of long lesions of the SFA and proximal popliteal arteries at 1 year.

Helical computed tomography of the normal thoracic outlet

PURPOSE This study was performed to determine the detailed anatomy of the thoracic outlet in normal subjects using helical computed tomography (CT), with particular attention to vascular compression with arm movement. METHODS Ten volunteers underwent detailed clinical evaluation and helical CT scanning of the upper thorax and neck with the arm in a neutral position and with the arm abducted 90 degrees or greater and externally rotated. Anterior scalene-clavicle distance (SC), costoclavicular distance (CC), and vessel diameters were measured with electronic calipers in each position. Comparisons were made with Students t test. RESULTS With abduction the SC decreased from 18.4 +/- 3.9 mm to 5.2 +/- 2.4 mm (p < 0.001), and the CC decreased from 12.6 +/- 2.7 mm to 6.3 +/- 3.3 mm (p = 0.005). At these same anatomic planes, the vein diameter decreased from 11.0 +/- 1.6 mm at the neutral position to 5.1 +/- 1.5 mm (p < 0.001) and from 16.1 +/- 3.0 mm to 7.4 +/- 2.6 mm with the arm abducted (p < 0.001). The artery diameter changed from 6.6 +/- 0.8 mm to 6.2 +/- 0.5 mm (p = 0.08) and from 7.2 +/- 0.8 mm to 6.0 +/- 0.5 mm (p = 0.001) with arm movement. CONCLUSIONS Both the distances between the anterior scalene muscle and the clavicle and between the clavicle and the first rib are significantly reduced with abduction of the upper extremity. Venous compression is universal at both the SC and CC spaces in normal subjects with this maneuver. Arterial narrowing occurs less frequently and appears to be minor. Minor changes in these thoracic outlet dimensions (SC/CC) may produce venous compression without movement.