Mark F. Conrad

Outcomes following endovascular abdominal aortic aneurysm repair (EVAR): an anatomic and device-specific analysis.

OBJECTIVE We performed a device-specific comparison of long-term outcomes following endovascular abdominal aortic aneurysm repair (EVAR) to determine the effect(s) of device type on early and late clinical outcomes. In addition, the impact of performing EVAR both within and outside of specific instructions for use (IFU) for each device was examined. METHODS Between January 8, 1999 and December 31, 2005, 565 patients underwent EVAR utilizing one of three commercially available stent graft devices. Study outcomes included perioperative (< or =30 days) mortality, intraoperative technical complications and need for adjunctive procedures, aneurysm rupture, aneurysm-related mortality, conversion to open repair, reintervention, development and/or resolution of endoleak, device related adverse events (migration, thrombosis, or kinking), and a combined endpoint of any graft-related adverse event (GRAE). Study outcomes were correlated by aneurysm morphology that was within or outside of the recommended device IFU. chi2 and Kaplan Meier methods were used for analysis. RESULTS Grafts implanted included 177 Cook Zenith (CZ, 31%), 111 Gore Excluder (GE, 20%), and 277 Medtronic AneuRx (MA, 49%); 39.3% of grafts were placed outside of at least one IFU parameter. Mean follow-up was 30 +/- 21 months and was shorter for CZ (20 months CZ vs 35 and 31 months for GE and MA, respectively; P < .001). Overall actuarial 5-year freedom from aneurysm-related death, reintervention, and GRAE was similar among devices. CZ had a lower number of graft migration events (0 CZ vs 1 GE and 9 MA); however, there was no difference between devices on actuarial analysis. Combined GRAE was lowest for CZ (29% CZ, 35% GE, and 43% MA; P = .01). Graft placement outside of IFU was associated with similar 5-year freedom from aneurysm-related death, migration, and reintervention (P > .05), but a lower freedom from GRAE (74% outside IFU vs 86% within IFU; P = .021), likely related to a higher incidence of graft thrombosis (2.3% outside IFU vs 0.3% within IFU; P = .026). The differences in outcome for grafts placed within vs outside IFU were not device-specific. CONCLUSION EVAR performed with three commercially available devices provided similar clinically relevant outcomes at 5 years, although no graft migration occurred with a suprarenal fixation device. As anticipated, application outside of anatomically specific IFU variables had an incremental negative effect on late results, indicating that adherence to such IFU guidelines is appropriate clinical practice.

Common femoral artery occlusive disease: Contemporary results following surgical endarterectomy

OBJECTIVE Proliferation of endovascular techniques with perceived reduction in treatment morbidity repetitively question the precept that surgical endarterectomy is the preferred treatment for occlusive disease of the common femoral artery (CFA). This study details a contemporary experience with common femoral endarterectomy (CFE) with and without concomitantly performed endovascular therapies. METHODS Technical, hemodynamic, and clinical success of CFE performed between 2002 and 2005 were determined according to the Society of Vascular Surgery reporting standards. Primary and assisted patencies of the CFA segment, freedom from reintervention in the ipsilateral limb, and survival were assessed using Kaplan-Meier life-table analysis. Multivariate analysis was performed to evaluate factors associated with patency and survival. RESULTS CFE was performed on 65 limbs in 58 patients (mean age 71 +/- 10; male 77%; diabetes 28%; creatinine >/= 1.5 mg/dL 19%). Forty-four cases (68%) were performed for claudication, and 21 cases (32%) for critical limb ischemia. Thirty-seven cases (57%) were performed as a hybrid procedure wherein concomitant endovascular interventions were performed. Twenty iliac (TASC II A-30%; B-35%; C-20%; D-15%) and 25 femoropopliteal (TASC II A-24%; B-60%; C-12%; D-4%) lesions were treated. Technical success was achieved in 100% of the cases. Hemodynamic success was achieved in 95% of the cases with mean postoperative increase in ankle-brachial index (ABI) of 0.24 +/- 0.24. All but one patient (98.5%) had improvement in symptoms and/or ABI. Average hospital stay was 3.2 days (range 1-12 days). There were 3 (5%) major complications requiring reintervention (early failure secondary to untreated inflow lesion, hematoma, and wound infection), six (9%) minor complications which were treated conservatively (five wound infections, one lymph leak), and no perioperative mortality. With a mean follow-up period of 27 months (range 1-58 months), 1- and 5-year primary patencies were 93% and 91%, respectively. Assisted patency was 100% at both time points. There was no difference in patencies between CFE performed alone or as a hybrid procedure. Multivariate analysis showed congestive heart failure (CHF) as the only predictor of primary failure (odds ratio [OR] 18.5 [2.6-142.9]; P = .004). Freedom from reintervention in the ipsilateral limb was 82% at 1 year and 78% at 5 years, with CHF again as the only predictor of reintervention (OR 5.3 [1.4-19.6]; P =.012). Survival was 89% at 1 year and 70% at 5 years. There were no amputations. CONCLUSIONS These data suggest CFE should remain the standard of care for occlusive disease of the CFA. Its safety and efficacy establish a standard for comparison with emerging endovascular therapies.

Aortic remodeling after endovascular repair of acute complicated type B aortic dissection

OBJECTIVE The role of thoracic endovascular aortic repair (TEVAR) in the management of acute type B aortic dissection remains undefined. Entry tear coverage during the acute phase is an appealing method to treat acute complications, and by inducing false lumen thrombosis, might also prevent late aneurysm formation. This study evaluated structural changes by serial computed tomography (CT) in the thoracic aorta after TEVAR performed for acute complicated aortic dissection. METHODS Between August 2005 and October 2007, 33 patients with complicated acute type B aortic dissection were treated with TEVAR (19 from a prospective industry sponsored trial, 14 from our institution). CT images obtained preprocedurally (PP), at 1 month (1M), and 1 year (1Y) were evaluated for each patient. Four patients with no postprocedural imaging were excluded. The largest diameters of the thoracic aorta, dissection true lumen, and false lumen were recorded at each time point. Changes in total aortic and true and false lumen diameters were evaluated using a mixed effect analysis of variance model of repeated measures. RESULTS The average age was 58 years (range, 38-87 years); 26 (81%) were male. Indications for TEVAR included malperfusion syndrome in 17 (53%), refractory hypertension in 14 (44%), impending rupture in 12 (28%), and refractory pain in 14 (44%); 19 (59%) had more than one indication. The average length of aorta covered was 19.5 cm (range, 10-29.3 cm). The maximum aortic diameter decreased over time (P = .04) and averaged 39.9 (PP), 41.3 (1M), and 34.8 mm (1Y). The true lumen diameter increased over time (P = .02) and averaged 23.7 (PP), 29.0 (1M), and 31.1 mm (1Y). The false lumen diameter decreased (P = .046) and averaged 19.5 (PP), 12.1 (1M), and 9.6 mm (1Y). Partial or complete thrombosis of the false lumen along the stented segment of aorta was recorded in 87% (PP), 93% (1M), and 88% (1Y). CONCLUSIONS TEVAR of acute complicated aortic dissection appears to promote early aortic remodeling. Nearly 90% of patients maintained at least partial false lumen thrombosis at 1 year. Because continued false lumen patency correlates strongly with late aneurysm formation, such favorable remodeling is considered a surrogate for prevention of late aneurysm, but longer follow-up is required.

Infrapopliteal balloon angioplasty for the treatment of chronic occlusive disease

OBJECTIVE There is little documentation of the effectiveness of percutaneous balloon angioplasty (PTA) of infrapopliteal vessels for the treatment of chronic lower extremity ischemia. This study reviewed our recent experience with infrapopliteal PTA in a large series of patients to determine its effectiveness as a treatment modality. METHODS All patients undergoing primary infrapopliteal PTA from March 2002 to June 2006 were included. Primary study end points were primary patency, assisted patency, limb salvage, and patient survival assessed by Kaplan-Meier life-table analysis. Factors predictive of PTA failure and patient longevity were evaluated by multivariate methods. RESULTS There were 155 PTAs undertaken in 144 patients (70% men; mean age, 74 years), with critical limb ischemia (86%), diabetes (66%), and renal insufficiency (45%). Infrapopliteal lesions were classified as TransAtlantic Inter-Society Consensus A (7%), B (18%), C (39%), and D (35%). PTA was confined to the infrapopliteal segment in 40 (26%), and 115 (74%) underwent multilevel treatment. Five patients (3%) received stents. Technical success was 95%. The 30-day mortality was 2%, and major morbidity was 3%. The mean follow-up was 22 months (range, 0-54 months). The 40-month actuarial primary patency was 62% (standard error, 5%), with assisted patency (infrapopliteal re-PTA, 25 [16%]) of 90%. Interval conversion to bypass surgery occurred in seven (5%). Nonhealing ulcers occurred in 118 patients (76%), of which 76 (64%) healed during follow-up. Of the 42 unhealed ulcers, 15 (13%) required major amputations for a 40-month limb salvage of 86.2%. Multivariate predictors that were negative for primary patency included 0/1 vessel runoff (P = .01), critical limb ischemia (P = .002), and dialysis (P = .03). Negative predictors of limb salvage included dialysis (P = .007) and failure to improve runoff to the foot (P = .006). At 40-months, patient survival was 54%, with negative predictors including severe pulmonary disease (P = .01), coronary artery disease (P = .04), and renal insufficiency (P < .001). CONCLUSIONS Infrapopliteal angioplasty can be performed safely with favorable results in patients with limited longevity. Primary patency is related to disease extent. Secondary interventions may be necessary to maintain clinical success. These data indicate that PTA should be considered as initial therapy for infrapopliteal occlusive disease in patients with lower extremity ischemia.

Management of diseases of the descending thoracic aorta in the endovascular era: a Medicare population study.

Objective:Prospective trials have shown improved perioperative outcomes with endovascular repair of thoracic aortic (TEVAR) pathologies compared with conventional surgery (OPEN). There are no long-term population data detailing the impact of TEVAR on practice patterns and results of treatment of descending thoracic aortic pathology (DTA), which are the goal of this study. Methods:All procedures performed on the DTA captured in the Medicare database from 2004 to 2007 were identified by ICD-9 codes and stratified into OPEN and TEVAR cohorts. Outcomes included perioperative mortality (&khgr;2) and 5-year actuarial survival. Results:There were 11,166 patients identified (4838 [43%] TEVAR vs. 6328 [57%] OPEN) with 7247 (65%) nonruptured, degenerative thoracic aortic aneurysms (TAA), 2701 (24%) descending aortic dissections, 1033 (9%) thoracic aortic ruptures, and 185 (2%) traumatic aortic tears. The distribution of cases changed significantly during the study period (P < 0.0001) with an increase in TEVAR, decrease in OPEN, and increase in total cases over time (Table 1). The perioperative mortality was lower in the TEVAR group for the entire population (360 [7.4%] TEVAR vs. 1175 [18.5%] OPEN, P < 0.0001), and for the individual pathologies: TAA (182/3529 [5%] TEVAR vs. 451/3718 [12%] OPEN, P < 0.001), dissections (76/833 [9%] TEVAR vs. 399/1868 [21%] OPEN, P < 0.001) and ruptures (87/368 [24%] TEVAR vs. 298/665 [45%] OPEN, P < 0.0001). The Kaplan–Meier curve significantly favored TEVAR for the entire cohort because of the early mortality of the OPEN cohort but the curves converged by 5 years. The 5-year survival by indication was: entire population (53.4% TEVAR vs. 53.3% OPEN, P < 0.0001), TAA (55.8% TEVAR vs. 59.7% OPEN, P = 0.84), dissection (58.2% TEVAR vs. 50.6% OPEN, P < 0.0001), ruptures (23.3% TEVAR vs. 25.3% OPEN, P = 0.001), and trauma (62.9% TEVAR vs. 50.9% OPEN, P = 0.12). Conclusion:There has been a significant increase in the use of TEVAR for management of diseases of the DTA. TEVAR offers a significant perioperative survival advantage when compared with OPEN regardless of the indication for repair. However, in the Medicare population, the 5-year survival is similar between the 2 cohorts.

Thoracoabdominal aneurysm repair: Hybrid versus open repair

OBJECTIVE Hybrid repair of thoracoabdominal aortic aneurysms (TAAA) may reduce morbidity and mortality in high-risk candidates for open repair. This study reviews the outcomes of hybrid TAAA repair for Crawford extent I-III TAAA in high-risk patients in comparison to patients who underwent concurrent open TAAA repair. METHODS During the interval from June 2005 to December 2007, a total of 23 high-risk patients with TAAA (type I: 9 [39%], II: 5 [22%], and III: 9 [39%]) underwent renal and/or mesenteric debranching (11 [48%] with four vessel debranching) with subsequent placement of a thoracic stent graft; 77 patients underwent open TAAA repair (type I: 13 [17%], II: 11 [14%], III: 27 [35%], and IV: 26 [34%]) during the same interval. The primary high-risk criteria for hybrid TAAA included advanced age/poor functional status (n = 14), major pulmonary dysfunction (n = 8), and technical consideration (prior thoracic aortic aneurysm repair [n = 4] or prior thoracoabdominal aneurysm repair [n = 2] and obesity [n = 2]) with 6 patients having overlapping high-risk criteria. Composite (30-day) mortality and/or permanent paraplegia (PP) were the major study endpoints. RESULTS The hybrid and open TAAA groups had (respectively) no statistical difference in mean age (76.6 vs 72.7 years), aneurysm size (6.51 vs 6.52 cm), and non-elective operation (30.4% vs 26.0%). The hybrid group had a higher mean Society for Vascular Surgery (SVS) risk score (9.1 vs 6.0; P <or= .001), incidence of oxygen-dependent chronic obstructive pulmonary disease (COPD) (34.8% vs 2.6%; P <or= .001), and prior thoracic (n = 4) or thoracoabdominal (n = 2) repair (26.1% vs 1.3%; P <or= .001). Composite mortality and/or PP was doubled in the hybrid group (21.7% vs 11.7%; P = .33). The rate of any type of reoperation was higher in hybrid TAAA repair (39.1% vs 20.8%; P = .03). One year actuarial survival for both groups was comparable (hybrid, 68 +/- 12%; open, 73 +/- 6%). A total of 5/23 (22%) hybrid TAAA patients developed an endoleak (type I: 3/23 and type II: 2/23) with 3 requiring endovascular re-intervention. A total of 7/70 (10%) visceral/renal bypass grafts were noted to be occluded during follow-up (1 superior mesenteric artery, 1 celiac, and 5 renal). Examination of patients with an SVS risk score <or=8 (mean SVS risk score in hybrid 6.2 [n = 10] vs 5.5 [n = 68] in open; P = .27) revealed the hybrid group had a higher incidence of composite mortality and/or PP (40% vs 10.3%; P = .03). CONCLUSION Hybrid TAAA repair in high-risk patients has significant morbidity and mortality suggesting a non-interventional approach may be appropriate in many such patients. The morbidity and mortality of the hybrid TAAA repair was substantial even in lower risk patients (SVS risk score <or=8), albeit patient numbers were small. Prospective study in comparable patient risk cohorts is required to define the role of hybrid TAAA repair.

Endovascular management of patients with critical limb ischemia

BACKGROUND Although percutaneous intervention (PTA) is considered first-line therapy for peripheral vascular disease in many scenarios, its role in critical limb ischemia (CLI), wherein anatomic disease is more extensive, remains unclear. In the present study, late (5-year) clinical and patency data for PTA in CLI are defined. METHODS From January 2002 to December 2007, 409 patients underwent infrainguinal PTA ± stent for CLI (Rutherford IV-VI) of 447 limbs. Primary patency, assisted patency, limb salvage, and survival were assessed using Kaplan-Meier. Predictors of patency, limb salvage, and death were determined using multivariate models. RESULTS Demographics included age (70 ± 12 years old), diabetes (65.8%), and dialysis dependence (13%). The superficial femoral artery was treated in 58% of the patients, 16% were limited to the crural vessels, 38% had multilevel treatment, and stents were placed in 26%. Eighty percent of patients received postprocedure clopidogrel. Mean follow-up was 28 months (0-83). Five-year primary and assisted patency were 31% ± 0.04 and 75% ± 0.04, respectively. Limb salvage at 5 years was 74% ± 0.038. Sixty-three patients had major amputations. Survival at 5 years was 39% ± 0.03. Multivariate analysis identified dialysis dependence (P = .0005; 2.7 [1.6-4.8]), ≤1 vessel runoff (P = .02; 1.5 [1.1-2.0]), and warfarin use (P = .001; 1.7 [1.25-2.3]) as negative predictors of primary patency, but none of these were negative predictors of assisted patency. Dialysis dependence (P = .006; 2.5 [1.3-4.8]), female gender (P = .02; 2.0 [1.1-3.7]), and ≤1 vessel run-off (P = .04; 1.8 [1.0-3.2]) predicted limb loss. Dialysis dependence (P = .0003; 2.3 [1.5-3.5]), diabetes (P = .04; 1.5 [0.5-2.1]), and poor run-off (P = .04; 1.6 [1.2-2.1]) were predictors of mortality. CONCLUSION Although primary patency is low, excellent limb salvage rates can be achieved in patients with CLI through close follow-up and secondary interventions. These data, and the 12% annual death rate, validate PTA as first-line therapy in patients with CLI.

Preoperative functional status predicts perioperative outcomes after infrainguinal bypass surgery

OBJECTIVE Infrainguinal surgical bypass (BPG) is a durable method for lower extremity revascularization, but is accompanied by significant 30-day morbidity and mortality (MM). The goal of this study is to relate preoperative functional status, a defined metric in the National Surgical Quality Improvement Program (NSQIP) database, to perioperative MM. METHODS Between January 1, 2005 and December 31, 2007, all patients who underwent BPG from the NSQIP private sector database were reviewed. The primary end-point was 30-day MM. Patients were stratified by preoperative functional status: independent (IND) vs dependent (DEP). Associated patient demographic/clinical data were analyzed using univariate and multivariate methods. Composite odds ratios were constructed with clusters of high-risk comorbidities. RESULTS There were 5639 BPG patients (4600 [81.6%] IND and 1039 [18.4%]) DEP. DEP patients were significantly older (71.6 +/- 11.8 vs 66.8 +/- 11.8 years; P < .0001), had more chronic obstructive pulmonary disease (COPD) (16.7% vs 11.4%; P < .0001), diabetes (54.2% vs 40.7%; P < .0001), dialysis dependence (16.4% vs 5.6%; P < .0001), and critical limb ischemia (64.6% vs 44.0%; P < .0001). DEP patients had a higher incidence of death (6.1% vs 1.5%; P < .0001) and major complications (30.3% vs 14.2%; P < .0001). DEP was an independent predictor of major complications (odds ratio [OR]: 2.0; 95% confidence interval [CI]: [1.7-2.4]; P < .0001) major systemic complications (2.5 [1.9-3.2]; P < .0001), major operative site complications (1.6 [1.4-1.9]; P < .0001) and death (2.3[1.6-3.4]; P < .0001). The combination of DEP with emergency surgery, Cr > 1.8, or rest pain increased the odds of major complications by five, seven, or 11-fold, respectively. The combination of DEP with hemodialysis, emergency surgery, or age > or = 80 years increased the odds of death by 13, 38, or 87-fold, respectively. CONCLUSION Preoperative DEP is significantly correlated with all adverse 30-day outcomes in BPG patients. Furthermore, when combined in high-risk composites with specific preoperative clinical variables, DEP is associated with prohibitive MM, thereby identifying patient cohorts that may be unsuitable for BPG.

Contemporary Management of Descending Thoracic and Thoracoabdominal Aortic Aneurysms: Endovascular Versus Open

Aneurysms that originate in the descending thoracic aorta occur at an estimated incidence of 5.9 to 10.4 per 100 000 person-years and rupture at a rate of 3.5 per 100 000 person-years.1–3 In a population-based study of patients with untreated thoracic aortic aneurysms (TA), Bickerstaff et al1 reported an actuarial 5-year survival rate of 19.2% for patients with degenerative aneurysms, and rupture was identified as the cause of death in 51% of patients. This disease presents across a spectrum of anatomic complexity that ranges from isolated descending TA to thoracoabdominal aneurysms (TAA) that can extend from the subclavian artery to the aortic bifurcation. Repair of aneurysms across this spectrum presents a multitude of technical and cognitive challenges that span the preoperative and postoperative periods. Indeed, conventional open surgical treatment of TA/TAA is accompanied by significant morbidity and mortality compared, for example, with repair of abdominal aortic aneurysm. Improvements in operative care, particularly an aggressive posture toward intercostal artery preservation and the adoption of protective adjuncts against spinal cord ischemia (SCI) complications, have halved the overall incidence of SCI associated with open operative repair since Crawford’s benchmark series describing a 16% incidence of SCI in 1500 patients.4–8 Despite considerable progress, contemporary series from centers of excellence continue to report a consistent overall risk of SCI in the 5% to 10% range.6,9–11 In addition, when ruptures are included, the perioperative mortality of open TA/TAA repair is 8% and has remained essentially unchanged over the last 40 years.6,12 The recent emergence of stent graft repair in the thoracic aorta has the potential to substantially diminish the morbidity and mortality of surgical repair and alter long-standing treatment paradigms. In this article, we review contemporary management of TA/TAA and adjunctive methods to decrease end-organ injury and SCI. We include clinical …

Secondary intervention after endovascular abdominal aortic aneurysm repair.

Objective:Endovascular Abdominal Aortic Aneurysm Repair (EVAR) has been criticized because of the need for frequent secondary interventions (2ndINT) to maintain effective abdominal aortic aneurysm (AAA) exclusion. The study goal is to detail such interventions and determine their effect on clinical outcomes. Methods:From January 1997 to December 2007, 832 patients underwent EVAR. Those requiring 2ndINT were stratified according to the indications and specific nature of 2ndINT and treatment. Study endpoints included freedom from 2ndINT, aneurysm-related and overall survival. Results:There were 91 (11%) patients who underwent 131 2ndINT (mean follow-up 35 months). No demographic features (age, gender, etc) predicted the need for 2ndINT. Actuarial 5-year freedom from 2ndINT was 80%. Indications for 2ndINT included: sac rupture 5 (4%), graft migration/ type I endoleak 37 (28%), persistent type II endoleak 40 (38%), endotension with sac growth 5 (4%), and limb occlusion/kinking 24 (18%). The majority of 2ndINT were accomplished with an endovascular approach (76%) with a >80% initial success rate for all indications except type II endoleak in which the initial intervention was successful only 34% of the time. Initial 2ndINT were successful in 62% and 35 (38%) patients underwent more than one 2ndINT. Multivariate predictors of 2ndINT were AAA sac size >5.5cm (OR = 2.1, P = 0.004), and preprocedure coil embolization (hypogastric or inferior mesenteric artery) (OR = 2.1, P = 0.008). The actuarial survival was 70% at 5 years and the aneurysm-related survival was 97.5% with no difference in either parameter in patients who underwent 2ndINT compared with those who did not. Conclusions:Although 2ndINT are common after EVAR, most were addressed through an endovascular approach; technical success thereof varies widely with the specific indication for 2ndINT. Secondary intervention did not adversely affect aneurysm-related or overall actuarial 5-year survival.