treatment studied

Major amputation is often selected over infrainguinal bypass in patients with severe systemic comorbidities because of a presumed decrease in risk of perioperative morbidity and mortality. To investigate this presumption, researchers from the Division of Vascular and Endovascular Surgery at the Brigham and Women's Hospital in Boston undertook a risk-adjusted comparison of early postoperative morbidity and mortality of high-risk patients undergoing infrainguinal bypass and major amputation.

Results of this study were presented at the Society of Vascular Surgery's 64th Vascular Annual Meeting at the end of May.

            Examining a large database of patients, co-author Neal R. Barshes, MD, MPH said there were 780 in the infrainguinal bypass group and 792 patients in the major amputation group, with no significant differences among the demographic, preoperative or anesthetic variables.

"However, in this risk-adjusted propensity-matched comparison," Dr. Barshes said, "infrainguinal bypass had a lower 30-day postoperative mortality than major amputation (6.5 vs. 10.0 percent for bypass vs. amputation, respectively). While infrainguinal bypass was associated with significantly higher rates of return to the operating room (27.6 vs. 14.1 percent) and a trend toward higher bleeding requiring transfusion (2.1 vs. 0.9 percent), major amputation had higher rates of pulmonary embolism (0 vs. 0.9 percent) and urinary tract infection (2.7 vs. 5.2 percent)."

            The study further showed that there was no difference in the overall number of major adverse events or post-operative length of stay between the major amputation and infrainguinal bypass groups. Graft patency was 91 percent at 30 days.

            A review of procedural codes from the 2005-2008 National Surgical Quality Improvement Program database was used to identify all patients undergoing either IB or AMP. Propensity score matching was used to obtain the bypass and amputation groups from the high-risk patient subset matched in preoperative characteristics. Patients with systemic or local infections were excluded.

            Dr. Barshes said that high risk patients were defined as the American Society of Anesthesiologists (ASA) Class 4 or 5; or ASA 3 with either congestive heart failure within 30 days, myocardial infarction within 6 months, renal failure (serum creatinine was more than 3mg/dL or dialysis-dependence), dyspnea at rest or ventilator dependence.

            "Our study shows that the decision to perform infrainguinal bypass or major amputation should depend on well-established predictors of graft patency and functional success rather than presumptions about the perioperative risks associated with the two treatments," said Dr. Barshes. VTN

Researchers at Cedars-Sinai Medical Center in Los Angeles have found that in contrast to other studies about regional discrepancies in the utilization of some surgical procedures, the utilization of endovascular aortic abdominal aneurysm repair (EVAR) was not associated with physician capacity and distribution, socioeconomics or other non-medical factors.

            Bruce L. Gewertz, MD, surgeon-in-chief, and chair of the center's department of surgery, said highly variable utilization rates for a diverse group of surgical procedures are commonly attributed to physician practice patterns rather than clinical considerations.

"A previous investigation by our research team showed that variations in the rates of carotid endarterectomy actually reflected regional risk factors for atherosclerosis not physician density or other socioeconomic drivers," Dr. Gewertz said.

"In this study we examined the use of EVAR from 2001 to 2006 to test our hypothesis that the utilization of innovative vascular procedures by vascular surgeons more closely reflects disease prevalence and consistent clinical judgment than non-medical considerations."

            Data for the study was taken for the Nationwide Inpatient Samples and State Inpatient Databases. The total number of aneurysms repaired has not changed significantly (from 45,828 in 2001 to 45,111 in 2006). During this same time period the number of open aortic aneurysm (AAA) repairs nationwide decreased by 48 percent, while the number of AAA repaired endovascularly increased by 105 percent.

 "We examined multiple metrics pertaining to clinical risk factors, socioeconomic status, access to care, provider distribution and local healthcare capacity and quantified them for each state," said Dr. Gewertz. He added that regional malpractice pressure, specifically the number of paid claims and mean malpractice premium, both exhibited positive correlations with the EVAR rate.

            Researchers noted that in 2005 the utilization rate of EVAR among 29 states throughout the United States ranged widely from 39.3 percent to 69.9 percent. Use of EVAR was highest in states with higher incidences of aneurysms and greater number of deaths from heart disease, as well as in states with the greater number discharges for diabetes, carotid stenosis and chronic obstructive pulmonary disorder; EVAR is well correlated with higher risk populations (the number of diabetic patients and deaths secondary to heart disease).

            "Little has been known about what medical and non-medical factors influence the penetration of minimally invasive vascular surgical repair, specifically EVAR, into the healthcare market," Dr. Gewertz explained.

"Despite the progressive utilization of this progressive and innovative technique there is still considerable variation between states. Our key observation was that increased EVAR use correlated most closely with higher risk patient populations and increased experience in treating aneurysms, and that use was not strongly influenced by many of the socioeconomic measures thought to be predictive of the new technology.

“The appropriate matching of EVAR use with clinical indications may be explained by the fact that during the study vascular surgery specialists were responsible for carrying out virtually all treatments for aortic aneurysm disease."

Details of this study were reported in the April issue of the Journal of Vascular Surgery, published by the Society for Vascular Surgery. VTN

Select patients with blunt aortic injury (BAI) can be safely managed non-operatively with beta-blockade to lower the heart rate and blood pressure, according to a new study released during the 64th Vascular Annual Meeting presented by the Society for Vascular Surgery.

Researchers reported that during the 10-year study period from Jan. 1, 1999, to Dec. 31, 2008, a total of 141 patients with BAI were treated at the University of Washington Medical Center in Seattle. Fifty-five had open repair and 49 had endovascular repair.

Survival in those who received an open repair was 69 percent (31 percent mortality) when compared to those who had an endovascular procedure at 84 percent (16 percent). The remaining 36 patients were treated non-operatively with a mortality of 28 percent; however, of significance is that none died from their blunt aortic injury.

            Patients were analyzed based on type and location of aortic injury (determined by imaging), method of repair, injury severity score, morbidity and mortality," Rachel Lundgren, MD, and vascular fellow from the Center's Division of Vascular Surgery, said.

"The injuries were categorized radiographically into Intimal Ter: with the absence of external aortic contour abnormality (EACA) and a small intimal injury o of less than 10 mm (23 patients); Large Intimal Flap (LIF) with absence of EACA, and an intimal injury of more than 10 mm (8 patients); Pseudoaneurysm (PSA) with positive EACA and no extravasation (99 patients); and Rupture (RUPT) with positive EACA and extravasation (9 patients)."

Patients who were treated non-operatively principally had intimal tears (56 percent) and PSA (39 percent) with a small proportion of  patients having large intimal flaps (5 percent). Follow-up imaging was available in 88 percent of survivors treated non-operatively with 35 percent of the injuries remaining stable and a majority (65 percent) completely healing.

Most intimal tears healed (14 healed, 2 stable); whereas the LIF and PSA rema

"At this point in time, CT angiography(CTA) has become the new 'gold standard' for diagnosing BAI's and increased utilization of CTA in the work-up of trauma patients has led to increasing diagnosis of MAI," Dr. Lundgren said.

"At our Center a CTA of the chest is obtained in most high-mechanism or unstable trauma patients and in those with a widened mediastinum on initial chest x-ray; however some patients are transferred from other hospitals with the CT already done.

not recomended

Patients with abdominal aortic aneurysms (AAAs) of less than 5.5 cm have no significant differences in clinical outcomes after endovascular repair (EVAR) than those with larger AAAs, according to data from a five-year prospective clinical trial setting. The researchers maintain their recommendation that small aneurysms should not be treated surgically. Details of this study were presented at the 64th Vascular Annual Meeting presented by the Society for Vascular Surgery.

Researchers from the Washington University School of Medicine in St. Louis reported data from a subgroup analysis of the prospective Metronic Talent Enhanced Low Profile System trial. There were no statistically significant differences in the rate of freedom from major adverse events (84.6 percent versus 75.8 percent) or freedom from aneurysm-related mortality (98.7 percent  versus 96.8 percent) at one year. Long term outcomes at 5 years also showed no difference.

            Jeffrey Jim, MD, a fellow from the Section of Vascular Surgery, said that 156 patients enrolled in the prospective Metronic Talent Enhanced Low Profile System trial were evaluated. Analyses were performed for patients with AAAs that measured less than 5.5 cm and for those with AAAs larger than 5.5cm. Demographics, aneurysm morphology, and perioperative endpoints were assessed. Safety and effectiveness endpoints were evaluated at 30 days, one year, and five years after the procedures.

"All patients in the study (85 small AAAs and 71 large) had similar age, gender and medical risk profile," said Dr. Jim. "However, there were anatomic differences between the two group with the aortic neck in small AAA patients being longer (24.7 mm vs 20.7 mm), less angulated (27.20 vs 34.20) and smaller (24.6 mm vs 26.1 mm). In terms of perioperative outcomes, the two groups were very similar with the only difference being the small AAA patients spent less time in the intensive care unit (8.1 hours vs 26.3 hours). The small AAA patients also had higher rate of successful aneurysm treatment at 12 months (96.8 percent  vs 84.9 percent ) as defined by the study as the combination of technical success, absence of aneurysm expansion, and absence of reintervention for type I or type III endoleaks."

            He added that there were no other statistically significant differences during the perioperative period or any other effectiveness endpoints at 12 months. There were also no differences in rates of migration, endoleaks, change in aneurysm diameter or freedom from aneurysm-related mortality at five years.

"We even did further subgroup analyses by separating groups by AAA centimeter size: 55 patients with very small (less than 5 cm), 30 with small (5.1-5.4 cm); and 71 with larger (more than 5.5 cm). The findings were similar to our original comparison," said Dr. Jim.

"The data from this study is unique in that it comes from a prospective 5-year clinical trial. The results confirm the intuitive notion that smaller AAAs have aortic neck characteristics that are more favorable for EVAR. However, the important take home message is that there were no differences in long-term 5-year outcomes between the two groups. So our position remains that EVAR should not be routinely recommended for those with small AAAs." VTN