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Michel S Makaroun

Publications and source records attributed to Michel S Makaroun.

At least 19 recordsLinked to original sources
PubMed2006

Sac behavior after aneurysm treatment with the Gore Excluder low-permeability aortic endoprosthesis: 12-month comparison to the original Excluder device.

BACKGROUND: The original Gore Excluder endoprosthesis (OGE) used both during and briefly after clinical trials was associated with less sac regression and more sac growth than some other devices, even without apparent endoleaks, presumably because of transmural movement of serous fluid across the expanded polytetrafluoroethylene material. In July 2004, the device was modified to decrease graft permeability. This study evaluated the efficacy of the new Excluder Low-Permeability Device (ELPD) at 1 year and compared it with the OGE and the Cook Zenith device (ZEN). METHODS: From Food and Drug Administration approval of the Excluder in November 2002 until June 2005, 283 patients underwent endovascular repair of abdominal aortic aneurysms with the Gore Excluder or the ZEN. Postoperative surveillance included computed tomographic scans at 1 and 12 months; 181 (64%) patients completed both scans. The 1-month computed tomographic scan served as a baseline, and the minor axis diameter, measured at the largest axial cut of the abdominal aortic aneurysm, was compared with the same measurement at 1 year. A sac size change of 5 mm or more was considered significant. Sixty patients treated with the OGE were compared with 72 patients treated with the ELPD. Forty-nine patients treated during the same time period with the ZEN, known for early sac shrinkage, were used as a reference. All measurements were performed by one observer from a digital workstation. Wilcoxon signed rank tests (pairwise) or Kruskal-Wallis tests (three groups) were used for intergroup comparison of continuous variables, whereas chi2 statistics or Fisher exact tests were used to compare categorical variables. RESULTS: Patient age and sex and mean maximum aneurysm diameter at baseline were similar among groups (P = .59, .27, and .46, respectively). Graft migration, stent fractures, acute surgical conversion, late abdominal aortic aneurysm rupture, or aneurysm-related deaths were not observed. Type II endoleak rates were similar between ELPD and ZEN (23.6% and 20.4%; P = .68). Although a higher rate of endoleaks was seen with OGE (36.7%), this was not significant when compared with the other two devices (P = .11). At 1 year, patients treated with ELPD had a sac regression rate that was significantly higher than that for patients treated with OGE (63.9% vs 25%; P < 0.001) and was similar to that for patients treated with ZEN (65.3%). Significant sac expansion was not observed with ELPD. CONCLUSIONS: At 1 year, similar to ZEN, significant aneurysm sac regression and minimal sac expansion were noted after endovascular repair of abdominal aortic aneurysms with ELPD. Low-porosity fabric used in the construction of endoprostheses seems to be an important factor in early aneurysm sac shrinkage. Long-term efficacy regarding the prevention of sac enlargement remains unclear, and further follow-up is suggested.

Aged↗
PubMed2006

Towards a noninvasive method for determination of patient-specific wall strength distribution in abdominal aortic aneurysms.

The spatial distributions of both wall stress and wall strength are required to accurately evaluate the rupture potential for an individual abdominal aortic aneurysm (AAA). The purpose of this study was to develop a statistical model to non-invasively estimate the distribution of AAA wall strength. Seven parameters--namely age, gender, family history of AAA, smoking status, AAA size, local diameter, and local intraluminal thrombus (ILT) thickness--were either directly measured or recorded from the patients hospital chart. Wall strength values corresponding to these predictor variables were calculated from the tensile testing of surgically procured AAA wall specimens. Backwards-stepwise regression techniques were used to identify and eliminate insignificant predictors for wall strength. Linear mixed-effects modeling was used to derive a final statistical model for AAA wall strength, from which 95% confidence intervals on the model parameters were formed. The final statistical model for AAA wall strength consisted of the following variables: sex, family history, ILT thickness, and normalized transverse diameter. Demonstrative application of the model revealed a unique, complex wall strength distribution, with strength values ranging from 56 N/cm2 to 133 N/cm2. A four-parameter statistical model for the noninvasive estimation of patient-specific AAA wall strength distribution has been successfully developed. The currently developed model represents a first attempt towards the noninvasive assessment of AAA wall strength. Coupling this model with our stress analysis technique may provide a more accurate means to estimate patient-specific rupture potential of AAA.

Aging↗
PubMed2006

Aortic neck morphology after endovascular repair of descending thoracic aortic aneurysms.

BACKGROUND: Endovascular repair has emerged as a less-invasive treatment for descending thoracic aortic (DTA) aneurysms. However, the durability of this procedure relies on the stability of proximal and distal fixation sites. This study analyzes 3 years of computed tomography (CT) data on aortic neck morphology after endovascular DTA aneurysm repair. METHODS: Between 1999 and 2001, 139 patients underwent successful endovascular DTA repair as part of a prospective, multicenter clinical trial investigating the Gore TAG thoracic endoprosthesis. Contrast-enhanced, high-resolution CT scans were obtained at 1 (baseline), 12, 24, and 36 months and submitted to an independent core laboratory for image analysis. The aorta was carefully measured by using computerized planimetry and a standardized protocol. Neck diameter was measured at 10-mm intervals for 2 cm above and below the aneurysm and correlated with graft migration and endoleak. RESULTS: The mean proximal neck diameter increased from a baseline of 30.2 +/- 4.6 mm to 32.0 +/- 4.3 mm at 36 months (P <.05), and the annual diameter increase was 0.8, 0.4, and 0.6 mm at 12, 24, and 36 months. The mean distal neck diameter increased from 29.4 +/- 3.8 mm to 32.1 +/- 5.0 mm at 36 months (P <.05), and the annual diameter increase was 1.1, 0.4, and 1.2 mm at 12, 24, and 36 months. At 36 months, freedom from neck dilation of > or =5 mm was 87%, and freedom from migration of > or =10 mm was 83%. An endoleak was present in 11 (9%) of 122 patients at baseline, 7 (7%) of 96 at 12 months, 6 (9%) of 68 at 24 months, and 1 (3%) of 33 at 36 months. Neck dilation was not associated with graft migration or endoleak. CONCLUSIONS: Three years after endovascular repair of DTA aneurysms, there is progressive enlargement of the proximal and distal aortic necks. Although uncommon for patients to develop significant neck dilation, when it does occur, it is not associated with graft migration or endoleak. Continued surveillance of aortic neck morphology after descending thoracic aneurysm endografting is recommended.

Aorta, Thoracic↗
PubMed2006

A decade of change in abdominal aortic aneurysm repair in the United States: Have we improved outcomes equally between men and women?

OBJECTIVES: Abdominal aortic aneurysm (AAA) repair has undergone vast changes in the last decade. We reviewed a national database to evaluate the effect on utilization of services and rupture rates. METHODS: From the Centers for Medicare Services (CMS), a 5% inpatient sample was obtained for 1994 to 2003 as beneficiary encrypted files (5% BEF) and as a limited data set file after 2001. Files were translated into Microsoft Access by using a custom program. Queries were performed using International Classification of Diseases (9th Revision) (ICD-9) diagnosis codes 441.3 (ruptured AAA) or 441.4 (non-ruptured AAA) and ICD-9 procedure codes 38.34, 38.36, 38.44, 38.64, 39.25, 39.52 for open, and 39.71 (available after October 2000) for endovascular repair. The 5% BEF totals were multiplied by 20 to calculate yearly volumes. Total cases were divided into the yearly CMS population of elderly Medicare recipients for repair rates per capita and are reported as cases per 100,000 elderly Medicare recipients. Statistics were performed using chi2, Student's t test, nonparametric tests, and multiple regression analysis; P < or = .05 was considered significant. RESULTS: Elective AAA repairs declined from 94.4/100,000 in 1994 to 87.7/100,000 in 2003. AAA rupture surgery declined from 18.7/100,000 (1994) to 13.6/100,000 (2003). Rupture repairs from 1994 to 2003 decreased by 29% for men and by 12% for women (P < .001). Rupture mortality has not changed, but the average is significantly higher for women at 52.8%, with men averaging 44.2% (P < .001). Mortality for elective AAA repair has decreased from 5.57% (1994) to 3.20% (2003) in men (P < .001) and from 7.48% (1994) to 5.45% (2003) in women (P < .001). Multivariate analysis demonstrated increasing age, female sex, and open surgery (vs endovascular) were significant predictors of elective and ruptured AAA repair mortality. For 2003 elective AAA repairs, the average length of stay was 6.9 days in men and 8.9 days in women (P < .01) For 2003, men were more likely to be discharged to home after rupture (32.9% of men vs 23.3% of women; P < .001) and elective repair (84.5% of men vs 70.1% of women; P < .001). CONCLUSIONS: Improvements in AAA management in the last decade have decreased aneurysm-related deaths and reduced the incidence of aneurysm ruptures, with a lower utilization of services. Women, however, continue to have a consistently higher mortality for open and ruptured AAA repair and are less likely to return to home after either.

Age Factors↗
PubMed2006

Carotid artery stenting in octogenarians is associated with increased adverse outcomes.

BACKGROUND: Carotid artery stenting is an increasingly common endovascular treatment of carotid artery stenosis advocated in high-risk patients despite reports of increased adverse periprocedural outcomes in patients aged >80 years. We sought to evaluate our single institution experience with octogenarians and whether they have an increased incidence of major complications with carotid artery stenting. METHODS: Three hundred eighty-six patients, including 260 patients from 10 regulatory trials, who underwent carotid artery stenting between June 1996 and March 2004 for symptomatic or asymptomatic carotid stenosis were reviewed from a prospectively maintained database. Periprocedural (< or =30 days after carotid artery stenting) cerebrovascular accident, transient ischemic attack, myocardial infarction, and death outcomes were compared between 87 octogenarians and 295 nonoctogenarians. Univariate and multivariate analysis was performed for confounding factors. Kaplan-Meier analysis of stroke and death outcomes was performed for a 1-year follow-up. RESULTS: All adverse outcomes were significantly higher in octogenarians compared with younger patients: 30-day stroke rate, 8.0% vs 2.7% (P = .02); 30-day stroke, myocardial infarction, or death, 9.2% vs 3.4% (P = .02). Cohorts were similar in terms of gender, comorbidities, antiplatelet medications, symptomatic status, and use of cerebral protection. Octogenarians had a greater incidence of contralateral internal carotid artery occlusion (26% vs 12%, P = .001), atrial fibrillation (21% vs 8%, P = .001), and congestive heart failure (28% vs 15%, P = .007), but a lower incidence of hypercholesterolemia (53% vs 72%, P = .001) and active smoking (8% vs 24%, P = .001). Multivariate analysis of 30-day major adverse outcomes demonstrated an association between age > or =80 and adverse outcome (odds ratio, 2.85; P = .043) as well as a protective effect of the preprocedural use of aspirin (odds ratio, 0.30, P = .027). At 1-year follow-up, only 75% of octogenarians and 87% of nonoctogenarians were free from stroke, myocardial infarction, or death (P = 005, Kaplan-Meier analysis). CONCLUSIONS: Octogenarians undergoing carotid artery stenting are at higher risk than nonoctogenarians for periprocedural complications, including neurologic events and death. Major event-free survival at 1 year is also significantly better in nonoctogenarians. These risks should be weighed when considering carotid stenting in elderly patients.

Age Factors↗
PubMed2006

Biomechanical properties of ruptured versus electively repaired abdominal aortic aneurysm wall tissue.

OBJECTIVE: The purpose of this study was to evaluate and compare the biomechanical properties of abdominal aortic aneurysm (AAA) wall tissue from patients who experienced AAA rupture with that of those who received elective repair. METHODS: Rectangular, circumferentially oriented AAA wall specimens (approximately 2.5 cm x 7 mm) were obtained fresh from the operating room from patients undergoing surgical repair. The width and thickness were measured for each specimen by using a laser micrometer before testing to failure with a uniaxial tensile testing system. The force and deformation applied to each specimen were measured continuously during testing, and the data were converted to stress and stretch ratio. The tensile strength was taken as the peak stress obtained before specimen failure, and the distensibility was taken as the stretch ratio at failure. The maximum tangential modulus and average modulus were also computed according to the peak and average slope of the stress-stretch ratio curve. RESULTS: Twenty-six specimens were obtained from 16 patients (aged 73 +/- 3 years [mean +/- SEM]) undergoing elective repair of their AAA (diameter, 7.0 +/- 0.5 cm). Thirteen specimens were resected from nine patients (aged 73 +/- 3 years; P = not significant in comparison to the electively repaired AAAs) during repair of their ruptured AAA (diameter, 7.8 +/- 0.6 cm; P = not significant). A significant difference was noted in wall thickness between ruptured and elective AAAs: 3.6 +/- 0.3 mm vs 2.5 +/- 0.1 mm, respectively (P < .001). The tensile strength of the ruptured tissue was found to be lower than that for the electively repaired tissue (54 +/- 6 N/cm2 vs 82 +/- 9.0 N/cm2; P = .04). Considering all specimens, no significant correlation was noted between tensile strength and diameter (R = -0.10; P = .55). Tensile strength, however, had a significant negative correlation with wall thickness (R = -0.42; P < .05) and a significant positive correlation with the tissue maximum tangential modulus (R = 0.76; P < .05). CONCLUSIONS: Our data suggest that AAA rupture is associated with aortic wall weakening, but not with wall stiffening. A widely accepted indicator for risk of aneurysm rupture is the maximum transverse diameter. Our results suggest that AAA wall strength, in large aneurysms, is not related to the maximum transverse diameter. Rather, wall thickness or stiffness may be a better predictor of rupture for large AAAs.

Aged↗
PubMed2006

Improving aneurysm-related outcomes: nationwide benefits of endovascular repair.

OBJECTIVES: Endovascular aneurysm repair (EVAR) has changed the practice of abdominal aortic aneurysm (AAA) surgery. We examined a national Medicare database to establish the effect of EVAR introduction into the United States. METHODS: A 5% random sample of inpatient Medicare claims from 2000 to 2003 was queried using International Classification of Diseases, 9th Revision (ICD-9) diagnosis and procedure codes. An EVAR procedure code was available after October 2000. Occurrences were multiplied by 20 to estimate yearly national volumes and then divided into the yearly Centers for Medicare and Medicaid Services (CMS) population of elderly Medicare recipients for rates per capita, reported as cases per 100,000 elderly Medicare recipients. Statistical analysis was performed by using chi2, Student's t test, nonparametric tests, and multiple regression analysis, with significance defined as P < or = .05. RESULTS: Elective AAA repairs averaged 87.7 per 100,000 Medicare patients between 2000 and 2003, with EVAR has steadily increasing to 41% of elective repairs in 2003. From 2000 to 2003, overall elective AAA mortality declined from 5.0% to 3.7% (P < .001), while open repair mortality remained unchanged. EVAR patients are significantly older than patients treated with open repair. From 2000 to 2003 patients >84 years receiving EVAR increased to 62.7% (P < .001). Overall hospital length of stay (LOS) decreased from 8.6 days in 2000 to 7.3 days in 2003, P < .001, but increased for open AAA patients. EVAR patients were more likely to be discharged home rather than to skilled facilities. Average elective repair hospital charges were not different between groups, but Medicare reimbursement was lower for EVAR, with a higher proportion cases classified as DRG 111 (major cardiovascular procedure without complications). EVAR was used in 10.6% of ruptured AAA repairs in 2003, with a significant reduction in mortality compared with open repairs for rupture (31.8% vs 50.8%; P < .001). CONCLUSIONS: EVAR is replacing open surgery without an increase in overall case volume. EVAR is responsible for overall decrease in operative mortality even in ruptured aneurysms while decreasing utilization variables. Reimbursement to hospitals is shrinking, however.

Aged↗
PubMed2006

Are type II endoleaks after endovascular aneurysm repair endograft dependent?

PURPOSE: Most clinical end points after endovascular aneurysm repair (EVAR) are endograft-specific, but type II endoleaks have been assumed to be an unavoidable consequence of the repair method and independent of the type of endograft used. Some recent data have suggested that the rate of type II endoleaks may also be graft-dependent. We reviewed a large clinical experience with six endografts to determine the behavior of type II endoleaks and whether they are graft-specific. METHODS: All elective EVAR cases from five university institutions from 1996 to 2003 were retrospectively analyzed. Endografts used in <50 patients were excluded. Endoleaks were diagnosed and classified from contrast-enhanced computed tomography (CT) scans by the treating surgeons. Results of angiography and interventions for endoleaks were tracked. The rate of type II endoleaks was compared among endografts at 1, 6, and 12 months, and yearly thereafter. Statistical significance was defined as P < .05. RESULTS: During the study period, 1909 patients underwent elective EVAR and had an adequate imaging follow-up at one of the specified time points. At 1 month, the overall rate of type II endoleak was 14.0% (range, 9.8% to 25.2%.) The Excluder had a significantly higher incidence of type II endoleaks at 1 month but was similar to most other grafts during longer follow-up. At 6 months, the overall rate of type II endoleak was 16.3% (range, 8.3% to 16.8%). The Talent and Lifepath had an apparent lower initial rate of type II leaks, but this was only significant for the Talent at 6 months compared with Excluder, Zenith, and Ancure, and at 1 year compared with Excluder and Zenith. No graft had a long-term statistically significant difference in the rate of type II endoleak formation. Intervention rates varied by institution and graft type but in general were quite low. Of 25 successful interventions (Ancure, 12; AneuRx, 8; Excluder, 2; Lifepath, 2; Zenith, 1; Talent, 0), 21 were performed during the first year. Interim spontaneous resolution, defined as a negative CT scan after a CT positive for endoleak, was high, especially in the first year. Resolution of type II endoleaks occurred in 54 (33%) of 164 between 1 and 6 months, in 37 (33%) of 112 between 6 and 12 months, in 20 (35%) of 57 from 12 to 24 months, and in 5 (20%) of 25 between 24 and 36 months. The various grafts had a nearly identical pattern, but the rates were highest for the Talent. Late appearing endoleaks, defined as a positive CT after a negative CT, were frequent. At 6 months, 44 (30%) of 147 type II endoleaks were newly diagnosed. The rates were 37 (35%) of 107 at 12 months, 15 (27%) of 56 at 2 years and 5 (25%) of 20 at 3 years. No conversions to open repair for type II endoleaks were noted in the first 4 years. The thrombus burden could not be determined in this analysis. CONCLUSIONS: Type II endoleaks occur in nearly 15% of patients treated by EVAR. The early incidence varies only slightly with graft type. The long-term prevalence and clinical significance are masked by different treatment patterns, spontaneous resolution, newly evident endoleaks, and aneurysm size at initial treatment.

Adult↗
PubMed2006

Endovascular management of isolated iliac artery aneurysms.

OBJECTIVE: We reviewed our experience with endovascular treatment of isolated iliac artery aneurysms (IAAs). METHODS: Medical records for consecutive patients undergoing endovascular IAA repair from 1995 to 2004 were reviewed. Computed tomography (CT) angiograms were used to assess IAA location, size, and presence of endoleaks after endovascular repair. Rates of primary patency and freedom from secondary interventions were estimated using the Kaplan-Meier life-table method. RESULTS: From July 1995 to November 2004, 45 patients (42 men), with a mean age of 75 years, underwent endovascular repair of 61 isolated IAAs: 41 common iliac, 19 internal iliac, and one external iliac. Five patients (11%) were symptomatic, although none presented with acute rupture. The mean preoperative IAA diameter was 4.2 +/- 1.7 cm. Fifteen patients (33%) had prior open abdominal aortic aneurysm repair. Local or regional anesthesia was used in 28 cases (62%). Thirty-four patients (75%) were treated with unilateral iliac stent-grafts, eight (18%) with bifurcated aortic stent-grafts, and three (7%) with coil embolization alone. Perioperative major complications included one early graft thrombosis that eventually required conversion to open repair and one groin hematoma that required operative evacuation. On follow-up, late complications included one additional graft thrombosis and one late death after amputation. No late ruptures occurred after endovascular repair, with a mean follow-up of 22 months (range, 0 to 60 months). The mean postoperative length of stay was 1.3 +/- 1.0 days. On postoperative CT scans obtained at 1, 6, 12, 24, and 36 months, aneurysm shrinkage was noted in 18%, 29%, 57%, 67%, and 83% of IAAs, respectively, compared with the baseline diameter. One hypogastric aneurysm enlarged in the presence of a later identified type II endoleak. Five endoleaks were noted (4 type II, 1 indeterminate) at 1 month, with four other endoleaks (1 type II, 1 type III, 2 indeterminate) identified on later CT scans. At 2 years, primary patency was 95%, and freedom from secondary interventions was 88%. CONCLUSIONS: Endovascular repair of isolated IAAs appears safe and effective, with initial results similar to those after endovascular abdominal aortic aneurysm repair.

Aged↗
PubMed2006

Endovascular therapy of thoracic aneurysms: Gore TAG trial results.

Although many thoracic endografts are commercially available in Europe, only three such devices have been introduced to the United States. Gore TAG endoprosthesis was the first to enter clinical trials in the United States for treatment of descending thoracic aortic aneurysm, and gained the approval of the US Food and Drug Administration for general use in March 2005. Through clinical trials, the safety and efficacy of the Gore TAG endoprosthesis were proven and shown to be superior to those of open surgical repair. This article details the device and results of these trials.

Aged↗
PubMed2006

A biomechanics-based rupture potential index for abdominal aortic aneurysm risk assessment: demonstrative application.

Abdominal aortic aneurysms (AAAs) can typically remain stable until the strength of the aortic wall is unable to withstand the forces acting on it as a result of the luminal blood pressure, resulting in AAA rupture. The clinical treatment of AAA patients presents a dilemma for the surgeon: surgery should only be recommended when the risk of rupture of the AAA outweighs the risks associated with the interventional procedure. Since AAA rupture occurs when the stress acting on the wall exceeds its strength, the assessment of AAA rupture should include estimates of both wall stress and wall strength distributions. The present work details a method for noninvasively assessing the rupture potential of AAAs using patient-specific estimations the rupture potential index (RPI) of the AAA, calculated as the ratio of locally acting wall stress to strength. The RPI was calculated for thirteen AAAs, which were broken up into ruptured (n = 8 and nonruptured (n = 5) groups. Differences in peak wall stress, minimum strength and maximum RPI were compared across groups. There were no statistical differences in the maximum transverse diameters (6.8 +/- 0.3 cm vs. 6.1 +/- 0.5 cm, p = 0.26) or peak wall stress (46.0 +/- 4.3 vs. 49.9 +/- 4.0 N/cm(2), p = 0.62) between groups. There was a significant decrease in minimum wall strength for ruptured AAA (81.2 +/- 3.9 and 108.3 +/- 10.2 N/cm(2), p = 0.045). While the differences in RPI values (ruptured = 0.48 +/- 0.05 vs. nonruptured = 0.36 +/- 0.03, respectively; p = 0.10) did not reach statistical significance, the p-value for the peak RPI comparison was lower than that for both the maximum diameter (p = 0.26) and peak wall stress (p = 0.62) comparisons. This result suggests that the peak RPI may be better able to identify those AAAs at high risk of rupture than maximum diameter or peak wall stress alone. The clinical relevance of this method for rupture assessment has yet to be validated, however, its success could aid clinicians in decision making and AAA patient management.

Aortic Aneurysm, Abdominal↗
PubMed2006

Gender-related differences in the tensile strength of abdominal aortic aneurysm.

A recent study investigated the association of gender with the growth rate of AAAs and found a significant increase in the growth rate of AAAs in women than in men. On the basis of these observations, we hypothesize that there are gender-associated differences in AAA wall integrity and mechanical strength. The purpose of this study was to explore this hypothesis by comparing the tensile strength of freshly resected AAA tissue specimens between women and men. Seventy-six rectangular specimens (20 mm long x 5 mm wide) from 34 patients (24 male, 10 female) were excised from the anterior wall of patients undergoing open repair of their abdominal aortic aneurysm and tested in a uniaxial tensile tester. Ultimate tensile strength (UTS) was taken as the peak stress obtained before specimen failure. While there were no statistical differences in strength between specimens taken from male and female patients, there was a trend toward a decrease in strength in females as compared to males (87.6 +/- 6.7 N/cm(2) vs. 67.6 +/- 8.1 N/cm(2), p = 0.09). To the authors knowledge this work represents the first report of differences in biomechanical properties as a function of gender. The nearly significant decrease in UTS in women versus men reported here may be important in assessing the risk of rupture in AAA. Further testing is warranted to confirm the current trends.

Aortic Aneurysm, Abdominal↗
PubMed2005

Endovascular treatment of thoracic aortic aneurysms: results of the phase II multicenter trial of the GORE TAG thoracic endoprosthesis.

OBJECTIVE: A decade after the first report of descending thoracic aortic aneurysm (DTA) repair with endografts, a commercial device is yet to be approved in the United States. The GORE TAG endoprosthesis, an investigational nitinol-supported expanded polytetrafluoroethylene tube graft with diameters of 26 to 40 mm, is the first DTA device to enter phase II trials in the United States and has been used worldwide for a host of thoracic pathologies. METHODS: A multicenter prospective nonrandomized phase II study of the GORE TAG endoprosthesis was conducted at 17 sites. Enrollment was from September 1999 to May 2001. Preoperative workup included arteriography and spiral computed tomography scans of the chest, abdomen, and pelvis. Follow-up radiographs and computed tomography scans were obtained at 1, 6, and 12 months and yearly thereafter. RESULTS: A total of 139 (98%) of 142 patients had a successful implantation of the device. Inadequate arterial access was responsible for the 3 failures. The mean DTA size was 64.1 +/- 15.4 mm. Men slightly outnumbered women (57.7%), with an average age of 71 years, and 88% of the patients were white. Ninety percent were American Society of Anesthesiologists category III or IV. One device was used in 44% of patients, and 56% required two or more devices to bridge the thoracic aorta. The left subclavian artery was covered in 28 patients, with planned carotid-subclavian transposition. The procedure time averaged 150 minutes, estimated blood loss averaged 506 mL, intensive care unit stay averaged 2.6 days, and hospital stay averaged 7.6 days. Within 30 days, 45 (32%) patients had at least 1 major adverse event: 5 (4%) experienced a stroke, 4 (3%) demonstrated temporary or permanent paraplegia, 20 (14%) experienced vascular trauma or thrombosis, and 2 (1.5%) died. Mean follow-up was 24.0 months. Four patients had aneurysm-related deaths. Three patients underwent endovascular revisions for endoleak. No ruptures have been reported. Twenty wire fractures have been identified in 19 patients; 18 (90%) of these occurred in the longitudinal spine, and only 1 patient required treatment. At 2 years, aneurysm-related and overall survival rates are 97% and 75%, respectively. CONCLUSIONS: The GORE TAG thoracic endoprosthesis provides a safe alternative for the treatment of DTAs, with low mortality, relatively low morbidity, and excellent 2-year freedom from aneurysm-related death. Longitudinal spine fractures have so far been associated with rare clinical events.

Adult↗
PubMed2005

Is abdominal aortic aneurysm repair appropriate in oxygen-dependent chronic obstructive pulmonary disease patients?

BACKGROUND: The life expectancy of patients with oxygen-dependent chronic obstructive pulmonary disease (COPD) is significantly reduced, but the risk of any intervention is considered prohibitive. However, severe COPD may increase the risk of abdominal aortic aneurysm (AAA) rupture. We reviewed our experience with AAA repair in oxygen-dependent patients to determine whether operative risk and expected long-term survival justify surgical intervention. METHODS: A retrospective review of 44 consecutive patients with oxygen-dependent COPD undergoing AAA repair over an 8-year period was performed. Information was recorded for survival, length of follow-up, patient age, medical comorbidities, pulmonary function tests, and operative approach. Survival data were analyzed by Kaplan-Meier curves and compared with published cohorts of oxygen-dependent patients and the natural history of untreated aneurysms. RESULTS: Twenty-four patients underwent endovascular aneurysm repair (EVAR), and 20 underwent open procedures (14 retroperitoneal and 6 transabdominal). The mean AAA diameter was 6.1 cm (range, 5-9.5 cm). The mean age was 71.4 years, and 82% of patients were male. Operative mortality was 0%. The mean length of stay was 11.2 days for open procedures and 4.3 days for EVAR (significantly longer than that for standard-risk patients). The mean survival time was 37.9 months (range, 2-91 months). Preoperative medical comorbidities, type of repair, and pulmonary function tests were not predictive of survival. Postoperative morbidity was significantly higher with open repair. Long term survival was comparable to historical series of the natural history of O2 dependent patients without AAA but better than untreated 6 cm AAA cohorts. At 42 months, almost 50% of patients in our study group were still alive, compared to 20% survival at 34 months for those with untreated 6 cm AAAs. CONCLUSIONS: It is reasonable to continue to offer AAA repair to home oxygen-dependent COPD patients who are ambulatory and medically optimized and who are without untreated coronary artery disease. Although EVAR may be the most suitable treatment for oxygen-dependent COPD patients, our results show that even open repair may be safely performed in this population, with acceptable results.

Aged↗
PubMed2005

Use of endoluminal aortic stent-grafts for the repair of abdominal aortic aneurysms.

Abdominal aortic aneurysms affect approximately 1.5% of the United States population. Randomized trials recommend repair when the maximal aneurysm diameter is 5.5 cm or greater. Since the first report of this technique in 1991, endovascular repair has become the preferred method for elective therapy of AAA disease. This has been a direct result of reported decreased hospital length of stay, reduced patient recovery time and improved survival. The application of endovascular aneurysm repair (EVAR) requires a thorough understanding of aneurysm anatomy, which is critical for appropriate patient selection. In particular the surgeon must be familiar with device-related criteria for proximal fixation and distal fixation as well as access vessels size, tortuosity, and calcification which can often be the limiting factor in the application of EVAR. Although the reported results of EVAR indicate significant advantages when compared with conventional open repair, it is critical to have an understanding of the particular complications associated with EVAR. The development of endoleaks, reports of stent migration and stent fracture as well as the development of limb stenosis and/or occlusion have been reported in up to 20% of patients treated with EVAR and thus necessitate appropriate long-term surveillance protocols.

Angioplasty↗
PubMed2005

Determining in-stent stenosis of carotid arteries by duplex ultrasound criteria.

PURPOSE: To develop customized duplex ultrasound criteria for assessment of in-stent restenosis in the carotid arteries. METHODS: A retrospective review was conducted of 605 patients who underwent carotid artery stenting (CAS) from July 1996 to August 2004 at a single institution. Data on the stented carotid artery were accumulated from patients who had carotid angiography and duplex ultrasound (US) within 30 days of each other. Preliminary review found 118 pairs of ultrasound scans and angiograms in stented carotid arteries. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and internal carotid artery to common carotid artery ratio (ICA/CCA) were examined. Angiographic stenosis was graded by NASCET criteria and compared to velocity parameters at clinically relevant levels of stenosis. The Student t test was used to compare similarly obtained data from 41 nonstented carotid arteries. RESULTS: PSV, ICA/CCA ratio, and EDV increased to a greater degree in stented arteries with stenosis. In 50% to 69% stenotic arteries, mean ICA/CCA ratio was 4.74+/-0.61 in stented versus 3.68+/-0.24 in nonstented carotid arteries (p = 0.043). In arteries with > or = 70% stenosis, there were increases in PSV (475+/-22 versus 337+/-26 cm/s, p = 0.001), EDV (172+/-23 versus 122+/-8 cm/s, p = 0.043), and the ICA/CCA ratio (8.18+/-2.19 versus 5.11+/-0.66, p = 0.063) in stented versus nonstented arteries, respectively. To detect > or = 70% angiographic stenosis, PSV > or = 350 cm/s had 100% sensitivity, 96% specificity, 55% positive predictive value (PPV), and 100% negative predictive value (NPV); an ICA/CCA ratio > or = 4.75 had 100% sensitivity, 95% specificity, 50% PPV, and 100% NPV. To predict > 50% stenosis, combining PSV > or = 225 cm/s and ICA/PCA ratio > or = 2.5 increased sensitivity (95%), specificity (99%), PPV (95%), NPV (99%), and accuracy (98%). CONCLUSIONS: PSV and ICA/CCA increase with stenosis to a greater extent in stented carotid arteries, necessitating revision of existing US criteria to follow CAS patients. To determine > or = 70% in-stent stenosis, PSV > or = 350 cm/s and ICA/CCA ratio > or = 4.75 are sensitive criteria. To determine > or = 50% stenosis, combining PSV > or = 225 cm/s and ICA/PCA ratio > or = 2.5 is optimal.

Angiography↗