Characterization of resident surgeon participation during carotid endarterectomy and impact on perioperative outcomes.

INTRODUCTION: The impact of resident surgeon participation during vascular procedures on postoperative outcomes is incompletely understood. We characterized resident physician participation during carotid endarterectomy (CEA) procedures within the 2005-2009 American College of Surgeons National Surgical Quality Improvement Participant Use Datafile and evaluated associations with procedural characteristics and perioperative adverse events. METHODS: CEAs were identified using primary current procedural terminology codes; those performed simultaneously with other major procedures or unknown resident participation status were excluded. Group-wise comparisons based on resident participation status were performed using χ(2) or Fisher's exact test for categorical variables and t tests or nonparametric methods for continuous variables. Associations with perioperative adverse events (major = stroke, death, myocardial infarction, or cardiac arrest; minor = peripheral nerve injury, bleeding requiring transfusion, surgical site infection, or wound disruption) were assessed using multivariable logistic regression models adjusting for other known risk factors. RESULTS: A total of 25,280 CEA procedures were analyzed, of which residents participated in 13,705 (54.2%), while residents were absent in 11,575 (45.8%). Among CEAs with resident physician participation, resident level was categorized as junior (postgraduate year [PGY] 1-2) in 21.9%, senior (PGY 3-5) in 52.7%, and fellow (PGY ≥6) in 25.3%. Major adverse event rates with and without resident participation were 1.9% versus 2.1%, and minor adverse event rates with and without resident participation were 0.9% versus 1.0%, respectively. In multivariable models, resident physician participation was not associated with perioperative risk for major adverse events (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.75-1.08) or minor adverse events (OR, 0.93; 95% CI, 0.72-1.21). CONCLUSIONS: Resident surgeon participation during CEA is not associated with risk of adverse perioperative events.

The incidence of microemboli to the brain is less with endarterectomy than with percutaneous revascularization with distal filters or flow reversal.

BACKGROUND: Current data suggest microembolization to the brain may result in long-term cognitive dysfunction despite the absence of immediate clinically obvious cerebrovascular events. We reviewed a series of patients treated electively with carotid endarterectomy (CEA), carotid artery stenting (CAS) with distal filters, and carotid stenting with flow reversal (FRS) monitored continuously with transcranial Doppler scan (TCD) during the procedure to detect microembolization rates. METHODS: TCD insonation of the M1 segment of the middle cerebral artery was conducted during 42 procedures (15 CEA, 20 CAS, and 7 FRS) in 41 patients seen at an academic center. One patient had staged bilateral CEA. Ipsilateral microembolic signals (MESs) were divided into three phases: preprotection phase (until internal carotid artery [ICA] cross-shunted or clamped if no shunt was used, filter deployed, or flow reversal established), protection phase (until clamp/shunt was removed, filter removed, or antegrade flow re-established), and postprotection phase (after clamp/shunt was removed, filter removed, or antegrade flow re-established). Descriptive statistics are reported as mean ± SE for continuous variables and N (%) for categorical variables. Differences in ipsilateral emboli counts based on cerebral protection strategy were assessed using nonparametric methods. RESULTS: TCD insonation and procedural success were obtained in 33 procedures (79%; 14 CEA, 14 CAS, and 5 FRS). Highest ipsilateral MESs were observed for CAS (319.3 ± 110.3), followed by FRS (184.2 ± 110.5), and CEA (15.3 ± 22.0). Pairwise comparisons revealed significantly higher ipsilateral MESs with both FRS and CAS when compared to CEA (P = .007 for FRS and P < .001 for CAS vs CEA, respectively), whereas the difference in MESs between FRS and CAS was not significant (P = .053). Periods of maximum embolization were postprotection phase for CEA, protection phase for CAS, and preprotection phase for FRS. Preprotection MESs were frequently observed during both CAS and FRS (20.4% and 63.3% of total MESs across all phases, respectively), and the primary difference between these two methods seemed to be related to lower MESs during the protection phase with FRS. CONCLUSION: CEA is associated with lower rates of microembolization compared with carotid stenting. Flow reversal may represent a procedural modification with potential to reduce microembolization during carotid stenting; further investigation is warranted to determine the relationship between cerebral protection strategies and outcomes associated with carotid stenting.

Left subclavian artery coverage during thoracic endovascular aortic repair and risk of perioperative stroke or death.

INTRODUCTION: Left subclavian artery (LSA) coverage during thoracic endovascular aortic repair (TEVAR) is often necessary due to anatomic factors and is performed in to up to 40% of procedures. Despite the frequency of LSA coverage during TEVAR, reported associations with risk of periprocedural stroke or death are inconsistent in reported literature. We examined the 2005-2008 American College of Surgeons National Surgical Quality Improvement Program Participant Use Data file to determine associations between LSA coverage during TEVAR and risk of perioperative stroke or death. METHODS: Current procedural terminology (CPT) codes were used to identify patients undergoing TEVAR, LSA coverage, and subclavian revascularization. Patients undergoing coronary bypass, ascending aortic repair, abdominal aortic aneurysm repair, or nonvascular intra-abdominal procedures during the same operation were excluded. Perioperative stroke and mortality associations with LSA coverage were examined using logistic regression models for each outcome. Significance was assessed at α = 0.05, with univariable P < .05 required for multivariable model entry. RESULTS: Eight hundred forty-five TEVAR procedures were identified, of which 52 patients were excluded due to additional major procedures performed with TEVAR. Seven hundred thirty-three of the remaining 793 procedures included CPT codes indicating primary placement of an initial thoracic endograft and form the basis of this analysis. LSA coverage occurred in 279 procedures (38%). Thirty-day stroke and mortality rates were 5.7% and 7.0%, respectively. LSA coverage was associated with increased 30-day risk of stroke in multivariable modeling (odds ratio [OR], 2.17 95% confidence interval [CI], 1.13-4.14; P = .019). Other significant multivariable risk factors for stroke included proximal aortic cuff placement during TEVAR (OR, 2.58; 95% CI, 1.30-5.16; P = .007) and emergency procedure status (OR, 3.60; 95% CI, 1.87-6.94; P < .001). No significant association between LSA coverage and perioperative mortality was identified (univariable OR, 1.70; 95% CI, 0.98-2.93; P = .0578). CONCLUSION: LSA coverage during thoracic endovascular repair is associated with increased risk of perioperative stroke following TEVAR. Further evidence is needed to determine whether procedural modifications, including LSA revascularization, reduce the incidence of stroke associated with TEVAR.

Risk factors for late mortality after endovascular repair of the thoracic aorta.

OBJECTIVE: This study was conducted to identify risk factors for late mortality after thoracic endovascular aortic repair (TEVAR). METHODS: A retrospective analysis of consecutive TEVAR was conducted. Medical record review, telephone contact, or query of the Social Security Death Index was used to determine 30-day and late survival. Late mortality was assessed with respect to patient characteristics at the time of the initial treatment, preoperative laboratory values, pathology, clinical presentation, and treatment adjuncts. Significant univariate predictors of death were entered into a multivariate Cox proportional hazards model. RESULTS: From 1998 to 2009, 252 patients (149 men; mean age, 68 years) underwent TEVAR for degenerative thoracic aortic aneurysm (TAA, n = 143), type B dissection (n = 62), mycotic aneurysm (n = 13), traumatic disruption (n = 12), penetrating ulcer or intramural hematoma (n = 10), anastomotic pseudoaneurysm (n = 4), or other pathology (n = 8). The 30-day mortality was 9.5%, with stroke or spinal cord injury in 5.6%. Mean follow-up was 22 +/- 22 months. Kaplan-Meier mean survival was 53 months. Predictors of late mortality by univariate analysis included age (P < .01), cardiac arrhythmia (P = .03), chronic obstructive pulmonary disease (P = .05), aneurysm diameter (P < .01), rupture (P < .01), debranching (P = .02), leukocytosis (white blood cell count > 10.0 x 10(3)/microL; P < .01), albumin, (P < .01), and creatinine > 1.7 mg/dL (P = .01). Multivariate predictors of mortality included rupture (hazard ratio [HR], 3.10; 95% confidence interval [CI], 1.02-9.44; P = .03), debranching (HR, 2.20; 95% CI, 1.09-4.24; P = .03), preoperative leukocytosis (HR, 1.23; 95% CI, 1.09-1.39; P = .001), and aneurysm diameter (HR, 1.02; 95% CI, 1.01-1.03; P = .04). Subgroup analysis of patients undergoing TEVAR for asymptomatic, nonruptured TAA demonstrated that debranching (HR, 2.47; 95% CI, 1.13-5.39; P = .02), White blood cell count (HR, 1.19; 95% CI, 1.01-1.40; P < .04), and aneurysm diameter (HR, 1.03; 95% CI, 1.01-1.05, P < .01) remain independently predictive of late mortality. CONCLUSIONS: Preoperative leukocytosis, aneurysm diameter, and concurrent debranching independently predict late mortality irrespective of clinical presentation and may assist in risk stratification.

Endovascular aortic aneurysm operations.

Options for the treatment of abdominal and thoracic aortic aneurysms are in a state of evolutionary change. The development and continued refinement of the endoluminal approaches has decreased the need for open aortic aneurysm surgery. Endovascular stent graft technology is an area of active research in which both the delivery systems and the endografts are undergoing continued improvement so that patients with what was previously thought to be unfavorable anatomy may be treated by these means. The design and deployment techniques of the currently available endografts, as well as those in clinical trials, are presented.

Conservatism and new technology: the impact on abdominal aortic aneurysm repair.

The last decade has represented a time of fundamental change in the treatment of abdominal aortic aneurysms (AAAs). Potentially, vascular surgeons will either acquire catheter-based skills or relinquish the care for many patients with infrarenal AAA. We investigated AAA referral patterns and method of AAA repair after the establishment of an endovascular AAA program at our institution. We conducted a retrospective review of elective AAA repairs after the initiation of an endovascular AAA program in April 1994. Six vascular surgeons performed all procedures with a clear distinction between the surgeons (n=3) who performed traditional AAA repair only and those (n=3) who managed AAAs by means of either endovascular or traditional treatment. From April 1994 through December 2000, 740 elective AAA repairs were performed. During this time the mean number of AAA repairs has been 106/year ranging from 75 to 155/year. More notable however is the steady increase in the percentage of endovascular AAA repairs from 6 per cent of all AAA repairs in 1994 to 61 per cent in 2000. During this time traditional surgeons have experienced a plateau in total AAA repairs performed per year with their number of open repairs decreasing by 36 per cent. At the same time endovascular surgeons have seen a progressive rise in total AAA cases including an increase of 200 per cent in open repairs and of 1367 per cent in endovascular repairs. Our vascular surgeons who repair AAA utilizing both endovascular and open techniques have experienced an increase in aneurysm referrals since the advent of an endovascular AAA program. Those who have not adopted endovascular skills have seen a decline in their aneurysm practice. The larger question about whether or not to embrace new technology before the availability of long-term follow-up remains unanswered.

Endovascular repair for diverse pathologies of the thoracic aorta: an initial decade of experience.

BACKGROUND: Endovascular grafts have rapidly evolved as a minimally invasive treatment for a variety of acute and chronic disorders of the thoracic aorta. Application of this technology at a single center is reported. STUDY DESIGN: Between 1998 and 2007, 197 patients underwent thoracic endovascular aortic repair. Primary indications included degenerative aneurysms (n = 121), type B aortic dissection (n = 44), mycotic aneurysms (n = 9), traumatic disruptions (n = 9), intramural hematoma (n = 5), pseudoaneurysm (n = 4), and miscellaneous pathology (n = 5). An analysis of patient demographics, periprocedural records, complications, reinterventions, and survival was conducted. RESULTS: Thirty-day mortality was 6%, which was lowest among patients undergoing treatment for a degenerative thoracic aortic aneurysm (2.4%, 3 of 121). Major adverse events included stroke in 3%, spinal cord ischemia in 2%, peripheral vascular repair in 4.5%, renal failure in 4.5%, and open conversion in one patient (0.5%). Both preoperative serum creatinine (odds ratio 1.44, 95% CI 1.02 to 2.04, p = 0.039) and number of endograft components (odds ratio 1.43, 95% CI 1.01 to 2.01, p = 0.043) were predictors of major adverse events. Kaplan-Meier analysis revealed a reduction in late survival among patients with preoperative creatinine >or=1.8 mg/dL (p < 0.001). One- and 5-year intervention-free survivals were 77%+/-3% and 41%+/-6%, respectively. CONCLUSIONS: Thoracic endovascular aortic repair represents an effective treatment for a variety of pathologic states. But the risk-benefit analysis for thoracic endovascular aortic repair should carefully consider the extent of disease, pathologic condition, and renal function.

A single-institution experience with the AneuRx Stent Graft for endovascular repair of abdominal aortic aneurysm.

We report our experience of endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) using the modular AneuRx Stent Graft System. We retrospectively reviewed the outcomes of 113 patients who underwent EVAR with the AneuRx system performed at our institution between October 1999 and August 2003. The mean age of this group was 72.5 years, with 71% (n = 80) over the age of 70 years and 95% (n = 107) males. Aneurysm diameter ranged 4.0-9.0 cm, with 33% (n = 37) >6.0 cm. The average duration of late follow-up was 32.6 +/- 24.8 months (median = 37). Successful deployment of the modular AneuRx system was noted in all patients. There were no immediate operative conversions, deaths within 24 hr of operation, or type I or III endoleaks observed at the completion of the procedure. Thirty-day mortality was 3.5% (n = 4). Acute deployment-related complications occurred in 10% (n = 13) of patients and included misdeployment, operative bleeding, arterial perforation/dissection, and access site complications. Acute systemic complications were present in nine patients, predominantly renal and cardiac complications. An endoleak noted at any time occurred in 25% of patients, with 40% of those requiring a secondary intervention. Two patients suffered late aneurysm rupture due to a type I endoleak and graft infection. Kaplan-Meier analysis revealed 5-year freedom from secondary intervention of 72.4%; freedom from aneurysm-related death of 93.9%; and probability of survival based on all-cause mortality of 60.1%. Endovascular treatment with the modular AneuRx Stent Graft System is safe and effective, producing acceptable rates of disease-free survival and mid-term clinical outcome.

Secondary conversion of the Gore Excluder to operative abdominal aortic aneurysm repair.

OBJECTIVE: Reports continue to document the occurrence of major adverse events after endovascular aortic aneurysm repair. Although many of these problems can be successfully managed through endovascular salvage, operative conversion with explantation of the endoprosthesis remains necessary in some patients. We report herein a review of all patients initially enrolled in multicenter US clinical trials of the Excluder endograft who underwent secondary conversion to open surgical repair. METHODS: Clinical data and relevant medical records of patients enrolled in phase I and II multicenter US clinical trials of the Excluder endograft were retrospectively reviewed for adverse events and further narrowed to those patients who underwent secondary operative conversion. Hospital records, operative and anesthesia reports, and all imaging studies were analyzed at initial implantation and at the time of subsequent open surgical repair. RESULTS: Late open conversion was performed in 16 (2.7%) of the 594 patients enrolled in the Excluder clinical trials. Presumed endotension accounted for 8 of 16 of secondary conversions. In two of these patients, however, an endoleak was identified at the time of open surgical repair. Of the remaining eight patients, two underwent conversion for device infection, five for persistent endoleak, and one for aneurysm rupture. The overall 30-day mortality was 6.25% (1/16), with one death occurring in a patient with a ruptured aneurysm. Of patients who underwent conversion because of endotension, the maximal abdominal aortic aneurysm diameter (mean +/- SD) at the time of initial implantation and subsequent graft removal was 61 +/- 11 mm and 70 +/- 10 mm, respectively. The mean time to open conversion for treatment of endotension was 37 +/- 12 months (range, 20-50 months; median, 42 months). Freedom from conversion was 98.6% and 96.7% at 24 and 48 months, respectively. CONCLUSIONS: Endotension in the absence of a demonstrable endoleak has been a major indication for late surgical conversion in patients treated with the Excluder endograft. Given the potential presence of an undetected endoleak and the possible effects of progressive sac enlargement on long-term device stability, continued close surveillance of patients with assumed endotension is required. Should changes in device design eliminate endotension, a further reduction in the already low incidence of late open conversion of the Excluder endograft can be anticipated.

Endovascular abdominal aortic aneurysm repair in the octogenarian.

The aim of this study was to analyze patient outcomes following endovascular repair of infrarenal abdominal aortic aneurysms (EAR) among patients 80 years of age or older. In this study, reporting standards of the Ad Hoc Committee for Standardized Reporting Practices for Endovascular Aortic Aneurysm Repair of the Society of Vascular Surgery/American Association for Vascular Surgery (SVS/AAVS) were followed. Between August 8, 1996 and February 12, 2001 EAR was performed in 31 patients (29 male and 2 female) with an average age of 83 +/- 3 years and an average maximum aneurysm diameter of 59 +/- 7 mm. Overall technical success was 90% (28/31) with a single acute conversion and a 6% (2/32) incidence of major morbidity. There were no in-hospital deaths, but two patients (6%) died within 30 days of intervention. Four endoleaks, two type I and two type II, were observed within the first 30 days after endograft implantation and three new type II endoleaks were noted after implant periods that exceeded 1 month. Average follow-up was 16 months, with a single aneurysm-related death that occurred after late conversion to open repair, 2 years following initial endovascular treatment. Kaplan-Meier analysis revealed 3-, 12-, and 24-month estimated survivals of 93% (+/-5), 75% (+/-8), and 68% (+/-10), respectively. Clinical success rates were 90% (+/-5), 90% (+/-5), and 72% (+/-17) at 12, 24, and 36 months, respectively. We conclude that, in the octogenarian with mild to moderate medical comorbidities, endovascular aneurysm repair provides an alternative to open AAA repair with low operative morbidity and good clinical success rates. Elevated SVS/AAVS medical comorbidity scores were not associated with increased operative mortality rates, but they did show a trend toward decreased mid-term survival. Careful consideration of life expectancy and the probability of rupture, as with traditional AAA repair, should dictate necessity for intervention.

Rupture rate of large abdominal aortic aneurysms in patients refusing or unfit for elective repair.

CONTEXT: Among patients with abdominal aortic aneurysm (AAA) who have high operative risk, repair is usually deferred until the AAA reaches a diameter at which rupture risk is thought to outweigh operative risk, but few data exist on rupture risk of large AAA. OBJECTIVE: To determine the incidence of rupture in patients with large AAA. DESIGN AND SETTING: Prospective cohort study in 47 Veterans Affairs medical centers. PATIENTS: Veterans (n = 198) with AAA of at least 5.5 cm for whom elective AAA repair was not planned because of medical contraindication or patient refusal. Patients were enrolled between April 1995 and April 2000 and followed up through July 2000 (mean, 1.52 years). MAIN OUTCOME MEASURE: Incidence of AAA rupture by strata of initial and attained diameter. RESULTS: Outcome ascertainment was complete for all patients. There were 112 deaths (57%) and the autopsy rate was 46%. Forty-five patients had probable AAA rupture. The 1-year incidence of probable rupture by initial AAA diameter was 9.4% for AAA of 5.5 to 5.9 cm, 10.2% for AAA of 6.0 to 6.9 cm (19.1% for the subgroup of 6.5-6.9 cm), and 32.5% for AAA of 7.0 cm or more. Much of the increased risk of rupture associated with initial AAA diameters of 6.5-7.9 cm was related to the likelihood that the AAA diameter would reach 8.0 cm during follow-up, after which 25.7% ruptured within 6 months. CONCLUSION: The rupture rate is substantial in high-operative-risk patients with AAA of at least 5.5 cm in diameter and increases with larger diameter.

Endovascular repair of abdominal aortic aneurysms: risk stratified outcomes.

OBJECTIVE: The impact of co-morbid conditions on early and late clinical outcomes after endovascular treatment of abdominal aortic aneurysm (AAA) was assessed in concurrent cohorts of patients stratified with respect to risk for intervention. SUMMARY BACKGROUND DATA: As a minimally invasive strategy for the treatment of AAA, endovascular repair has been embraced with enthusiasm for all prospective patients who are suitable anatomical candidates because of the promise of achieving a durable result with a reduced risk of perioperative morbidity and mortality. METHODS: From April 1994 to March 2001, endovascular AAA repair was performed in 236 patients using commercially available systems. A subset of patients considered at increased risk for intervention (n = 123) were categorized, as such, based on a preexisting history of ischemic coronary artery disease, with documentation of myocardial infarction (60%) or congestive heart failure (35%), or due to the presence of chronic obstructive disease (21%), liver disease, or malignancy. RESULTS: Perioperative mortality (30-day) was 6.5% in the increased-risk patients as compared to 1.8% among those classified as low risk (P = NS). There was no difference between groups in age (74 +/- 9 years vs. 72 +/- 6 years; mean +/- SD), surgical time (235 +/- 95 minutes vs. 219 +/- 84 minutes), blood loss (457 +/- 432 mL vs. 351 +/- 273 mL), postoperative hospital stay (4.8 +/- 3.4 days vs. 4.0 +/- 3.9 days), or days in the ICU (1.3 +/- 1.8 days vs. 0.5 +/- 1.6 days). Patients at increased risk of intervention had larger aneurysms than low-risk patients (59 +/- 13 mm vs. 51 +/- 14 mm; P <.05). Stent grafts were successfully implanted in 116 (95%) increased-risk versus 107 (95%) low-risk patients (P = NS). Conversion rates to open operative repair were similar in increased-risk and low-risk groups at 3% and 5%, respectively. The initial endoleak rate was 22% versus 20%, based on the first CT performed (either at discharge or 1 month; P = NS). To date, increased-risk patients have been followed for 17.4 +/- 15 months and low-risk patients for 16.3 +/- 14 months. Kaplan-Meier analysis for cumulative patient survival demonstrated a reduced probability of survival among those patients initially classified as at increased risk for intervention (P <.05, Mantel-Cox test). Both cohorts had similar two-year primary and secondary clinical success rates of approximately 75% and 80%, respectively. CONCLUSIONS: Early and late clinical outcomes are comparable after endovascular repair of AAA, regardless of risk-stratification. Notably, 2 years after endovascular repair, at least one in five patients was classified as a clinical failure. Given the need for close life-long surveillance and the continued uncertainty associated with clinical outcome, caution is dictated in advocating endovascular treatment for the patient who is otherwise considered an ideal candidate for standard open surgical repair.