Teresa V. Novick

A Cost-Effectiveness Model Comparing Endovascular Repair to Open Surgical Repair of Abdominal Aortic Aneurysms in Canada

OBJECTIVES The primary risk of abdominal aortic aneurysms (AAAs) is rupture, which is associated with a high mortality rate. Elective surgical options for AAA include open repair (OR) and endovascular aneurysm repair (EVAR). EVAR is less invasive than OR, and therefore may have less surgical risk than OR. However, the graft used for EVAR is much more expensive then the graft used for OR. METHODS A decision model with a 10-year time horizon was used to assess the cost-effectiveness of EVAR versus OR. The primary outcome measure was quality-adjusted life-years (QALYs). The model incorporated the costs and benefits of both perioperative outcomes and postoperative outcomes. A systematic review was conducted to derive clinical outcome rates. Cost and utility model variables were based on various literature sources and data from a recent Canadian observational study. Parameter uncertainty was assessed using probabilistic sensitivity analysis. RESULTS In the base-case model, the incremental cost per QALY of EVAR was estimated to be

Trends in management of abdominal aortic aneurysms

268,337, whereas the incremental cost per life-year was found to be

The Role of Platelet-Rich Plasma in Inguinal Wound Healing in Vascular Surgery Patients

444,129. The incremental cost per QALY of EVAR remained above

Effects of study design and trends for EVAR versus OSR

295,715 under different assumptions of cohort age and model time horizon. CONCLUSIONS Based on commonly quoted willingness-to-pay thresholds, EVAR was not found to be cost-effective compared to OR.

Should Endovascular Repair Be Reimbursed for Low Risk Abdominal Aortic Aneurysm Patients? Evidence from Ontario, Canada

OBJECTIVE The purpose of this study was to evaluate patients undergoing elective repair of infrarenal abdominal aortic aneurysms (AAAs) and the longitudinal trends in surgical management (open repair vs endovascular aneurysm repair [EVAR]), factors associated with the choice of surgical technique, and differences in the rate of in-hospital mortality at a single large-volume Canadian center. METHODS This retrospective cohort study used data from a prospectively collected vascular surgery database and reviewed all patients undergoing elective repair of an infrarenal AAA over a recent 10-year period (June 2000-May 2010). Information was reviewed regarding surgical techniques, patient demographics, and short-term outcomes. Subsequent analysis included univariate statistics and multivariable logistic regression with data presented as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS A total of 1942 patients underwent elective AAA repair over this 10-year study period, 1067 (54.9%) via open repair and 875 (45.1%) via EVAR. The proportion of patients undergoing EVAR was significantly higher in the latter half of the study period compared to the first half (55.8% vs 33.9%; P < .01). Older patients (75 vs 71; P < .01) and those with higher American Society of Anesthesiologists classifications (P < .01) were more likely to receive endovascular repair than open repair. The overall in-hospital mortality rate in the entire cohort was low (2.3% for EVAR and 3.9% for open repair), and after multivariable logistic regression and adjustment for preoperative factors, in-hospital mortality was significantly higher in patients with open AAA repair (OR, 1.8; 95% CI, 1.04-3.13; P = .04). CONCLUSIONS This 10-year analysis shows a significant shift toward an endovascular approach in the repair of infrarenal AAAs at our Canadian center. Similar to other jurisdictions, higher risk and older patients are more likely to be treated with an endovascular repair resulting in a survival advantage in these patients compared to standard open repair.

International trends in patient selection for elective endovascular aneurysm repair: sicker patients with safer anatomy leading to improved 1-year survival.

The objective was to determine whether incision application of platelet-rich plasma (PRP) will decrease postoperative wound complications in vascular surgery patients. A prospective, randomized trial randomized 81 incisions in 51 patients who underwent femoral artery exposure for elective revascularization procedures or endovascular abdominal aneurysm repairs. Incidence of diabetes, chronic renal failure, prosthetic grafts, body mass index (BMI), and steroid use did not differ. Using the ASEPSIS wound classification system, we found no difference in incidence of wound infection. Wound complications occurred in 9 (23%) of 40 of PRP group and 9 (22%) of 41 of non-PRP. Severe wound complications developed in 5 (13%) PRP and 6 (5%) of non-PRP (P = NS). In multivariate analysis, there were no predictors for wound infection. Groin wound complications rates are common in this patient group. Platelet-rich plasma did not decrease the incidence of groin wound complications in our patients

Determination of Patient Preference for Location of Elective Abdominal Aortic Aneurysm Surgery

Purpose: To investigate if study design factors such as randomization, multi-center versus single center evidence, institutional surgical volume, and patient selection affect the outcomes for endovascular repair (EVAR) versus open surgical repair (OSR). Finally, we investigate trends over time in EVAR versus OSR outcomes. Methods: Search strategies for comparative studies were performed individually for: OVID’s MEDLINE, EMBASE, CINAHL, HAPI, and Evidence Based Medicine (EBM) Reviews (including Cochrane DSR, ACP Journal Club, DARE and CCTR), limited to 1990 and November 2006. Results: Identified literature: 84 comparative studies pertaining to 57,645 patients. These include 4 randomized controlled trials (RCTs), plus 2 RCTs with long-term follow-up. The other 78 comparative studies were nonrandomized with 75 reporting perioperative outcomes, of which 16 were multi-center, and 59 single-center studies. Of the single-center studies 31 were low-volume and 28 were high-volume centers. In addition, 5 studies had all patients anatomically eligible for EVAR, and 8 studies included high-risk patients only. Finally, 25 long term observational studies reported outcomes up to 3 years. Outcomes: Lower perioperative mortality and rates of complications for EVAR versus OSR varied across study designs and patient populations. EVAR adverse outcomes have decreased in recent times. Conclusion: EVAR highlights the problem of performing meta-analysis when the experience evolves over time.

Outcomes after endovascular abdominal aortic aneurysm repair are equivalent between genders despite anatomic differences in women.

Background. This paper presents unpublished clinical and economic data associated with open surgical repair (OSR) in low risk (LR) patients and how it compares with EVAR and OSR in high risk (HR) patients with an AAA > 5.5 cm. Design. Data from a 1-year prospective observational study was used to compare EVAR in HR patients versus OSR in HR and LR patients. Results. Between 2003 and 2005, 140 patients were treated with EVAR and 195 with OSR (HR: 52; LR: 143). The 1-year mortality rate with EVAR was statistically lower than HR OSR patients and comparable to LR OSR patients. One-year health-related quality of life was lower in the EVAR patients compared to OSR patients. EVAR was cost-effective compared to OSR HR but not when compared to OSR LR patients. Conclusions. Despite a similar clinical effectiveness, these results suggest that, at the current price, EVAR is more expensive than open repair for low risk patients.

Midterm Results of Endovascular Infrarenal Abdominal Aortic Aneurysm Repair in High-Risk Patients:

BACKGROUND To review the trends in patient selection and early death rate for patients undergoing elective endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) in 3 countries. For this study, audit data from 4,163 patients who had undergone elective infrarenal EVAR were amalgamated. The data originated from Australia, Canada (Ontario), and England (London, Cambridge, and Leicester). METHODS Statistical analyses were undertaken to determine whether patient characteristics and early death rate varied between and within study groups and over time. The study design was retrospective analysis of data collected prospectively between 1999 and 2012. RESULTS One-year survival improved over time (P = 0.0013). Canadian patients were sicker than those in Australia or England (P < 0.001). American Society of Anesthesiologists classification (ASA) increased over time across all countries although more significantly in Canada. Age at operation remained constant, although older patients were treated more recently in London (P < 0.001). English centers treated larger aneurysms compared with Australia and Canada (P < 0.001). Australian centers treated a much larger proportion of aneurysms that were <55 mm than other countries. Preoperative creatinine levels decreased over time for all countries and centers (P < 0.001). Infrarenal neck angles have significantly decreased over time (P < 0.001). Recent data from London (UK) showed that operations were performed on longer (P < 0.001) and wider (P < 0.001) infrarenal necks than elsewhere. CONCLUSIONS In this international comparison, several trends were noted including improved 1-year survival despite declining patient health (as measured by increasing ASA status). This may reflect greater knowledge regarding EVAR that centers from different countries have gained over the last decade and improved medical management of patients with aneurysmal disease.

Identification of patient-derived outcomes after aortic aneurysm repair

Objective: Aneurysm repair is centralized in higher volume centers resulting in reduced mortality, with longer travel distances. The purpose of this study is to explore patients’ preference between local care versus longer distances and lower mortality rates. Methods: Patients with abdominal aortic aneurysm (AAA) measuring 4 to 5 cm and living at least a 1-hour drive from our hospital were asked to assume it had grown to 5.5 cm, and repair was recommended with a mortality risk of 2%. The level of additional risk they would accept to undergo surgery locally was determined. Results: A total of 67 patients were surveyed. If mortality risk was equivalent at the local and regional hospitals, 44% preferred care at our tertiary center, while 56% preferred surgery locally. If perioperative mortality was increased at the local hospital, 9% preferred local surgery. Conclusions: The vast majority of patients with AAA will accept longer travel distances for care as long as it results in a reduction in perioperative mortality.