Size matters: first-in-human study of a novel 4 French REBOA device.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technique used for non-compressible torso hemorrhage. However, its current use continues to be limited and there is a need for a simple, fast, and low profile REBOA device. Our objective was to evaluate the feasibility of a novel 4 French REBOA device called the COBRA-OS (Control of Bleeding, Resuscitation, Arterial Occlusion System). METHODS: This study is the first-in-human feasibility trial of the COBRA-OS. Due to the difficulty of trialing the device in the trauma setting, we performed a feasibility study using organ donors (due to the potential usefulness of the COBRA-OS for normothermic regional perfusion) after neurological determination of death (NDD) prior to organ retrieval. Bilateral 4 French introducer sheaths were placed in both femoral arteries and the COBRA-OS was advanced up the right side and deployed in the thoracic aorta (Zone 1). Once aortic occlusion was confirmed via the left-sided arterial line, the device was deflated, moved to the infrarenal aorta (Zone 3), and redeployed. RESULTS: A total of 7 NDD organ donors were entered into the study, 71% men, with a mean age 46.6 years (range 26 to 64). The COBRA-OS was able to occlude the aorta in Zones 1 and 3 in all patients. The mean time of placing a 4 French sheath was 47.7 seconds (n=13, range 28 to 66 seconds). The mean time from skin to Zone 1 aortic occlusion was 70.1 seconds (range 58 to 105 seconds); mean balloon volumes were 15 mL for Zone 1 (range 13 to 20 mL) and 9 mL for Zone 3 (range 6 to 15 mL); there were no complications and visual inspection of the aorta in all patients revealed no injury. DISCUSSION: The COBRA-OS is a novel 4 French REBOA device that has demonstrated fast and safe aortic occlusion in this first-in-human feasibility study. LEVEL OF EVIDENCE: Level V, therapeutic.

Long-term outcomes comparing endovascular and open abdominal aortic aneurysm repair in octogenarians.

OBJECTIVE: Patients older than 80 years have significantly lower early mortality with endovascular aneurysm repair (EVAR) compared with open repair for abdominal aortic aneurysms (AAAs), but long-term results remain poorly studied. We analyzed the results of both emergent and elective AAA repair in patients aged 80 years or older who had at least 5 years of follow-up. METHODS: Retrospective review of a prospectively collected vascular surgery database was performed to identify all patients who underwent elective repair of an AAA between 2007 and 2012 and were 80 years of age or older at the time of surgery. Open and EVAR groups were compared using univariate statistics. RESULTS: The study cohort was composed of 314 patients 80 years of age or older (median, 83 years; interquartile range, 5 years) who underwent repair (96 open, 218 EVAR). The groups had similar comorbidities, except that EVAR patients were more likely to be male and open repair patients were more likely to have larger aneurysms. Compared with open repair, elective early postoperative mortality was significantly lower for EVAR patients (1% vs 14%; P < .001). Overall mean life expectancy was 5.9 years (EVAR, 5.8 years; open repair, 5.8 years; P = .98). The 1-year survival was significantly higher for EVAR (92.9%) than for open repair (84.1%; P = .02). The 2-year survival (EVAR, 83.4%; open repair, 74.6%; P = .07) and 5-year survival (EVAR, 57.8%; open repair, 60.3%; P = .98) did not differ between EVAR and open repair. Reintervention rates (EVAR, 18%; open repair, 2%; P = .05) were higher in the endovascular treatment group. CONCLUSIONS: EVAR results in an improved 1-year mortality in octogenarians compared with open repair, although 5-year survival is similar between the groups. With average life expectancies of >5 years and an 18% reintervention rate, diligent follow-up is required after EVAR even in elderly patients.

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

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: Relatively few outcomes have been examined in randomized comparisons of endovascular and open aortic aneurysm repair, and no patient input was obtained in the selection of these outcomes. The aim of this study was to identify patient-derived, potentially novel outcomes that may be used to guide future clinical trials in aneurysm surgery. METHODS: Focus group interviews were conducted with patients who had undergone endovascular or open aortic aneurysm repair. The discussions were transcribed and the transcript was analyzed by two indexers using constant-comparison analysis and grounded theory to identify potentially novel, patient-derived outcomes. Other potential themes relating to the patients' experience and their decision-making were also sought. RESULTS: Six focus groups were conducted (three with endovascular aneurysm repair patients and three with open aortic aneurysm repair patients), with a median of six participants, 2 to 12 months from surgery. Functional outcomes were most commonly mentioned and emphasized by patients. Recovery time and energy level were most frequently verbalized as important in the decision-making process between endovascular and open aneurysm repair. Other potential outcomes identified as important to patients included postoperative pain, time to walking normally, loss of appetite, extent and location of incisions, impact on cognition, being able to go home after surgery, and impact on caregivers. In addition to these outcomes, we identified three themes relating to the patient's experience: undervaluing or underappreciating the risk of death during surgery, differing informational needs and level of involvement in decision-making, and unrealistic patient expectations about the risks of and recovery after the procedure. CONCLUSIONS: Functional outcomes emerged as most important during qualitative analysis of patients' experiences with aneurysm repair. Perceived differences in recovery time were identified as an important consideration for aneurysm patients in deciding between open and endovascular repair. More work needs to be done clarifying the concept of recovery and other related functional outcomes for the development of methods to assess and to evaluate these in prospective clinical trials.

Socioeconomic and geographic disparities in access to endovascular abdominal aortic aneurysm repair.

BACKGROUND: Within Southwestern Ontario, abdominal aortic aneurysm (AAA) surgery has been centralized to a single university-affiliated medical center. The referral area serves 1.9 million people and includes community hospitals with limited vascular surgery capabilities. We reviewed the role of patients' travel distance, geographic location, and socioeconomic status (SES) to determine if centralization of endovascular programs results in disparity in access to endovascular surgery. We hypothesized that patients would travel a longer distance to specifically seek elective endovascular surgery while having open and emergent surgery closer to home. METHODS: All patients who underwent AAA repair (July 2005-June 2010) at London Health Science Centre were identified from the vascular surgery database. Method of repair, clinical presentation, and in-hospital mortality were recorded. Travel distance from each patient's home to our hospital and rural versus urban status was determined for each patient. SES was determined by using a previously validated, locally developed deprivation index. RESULTS: During this 5-year period, 1,243 patients were included in our analysis; 46.8% (n=581) underwent endovascular repair (EVAR) and 53.2% (n=662) underwent open repair. For elective cases, the in-hospital mortality rate was 2.0% (n=11) for EVAR and 3.6% (n=20) for open repair (P=0.1). There was no difference in clinical presentation between SES groups, but open repair was more frequently used in patients of lower SES compared to higher SES (odds ratio=1.32; 95% confidence interval: 1.02-1.72). Travel distance and rural/urban status were not associated with increased odds of EVAR. When ruptured aneurysms were excluded, elective patients of lower SES continued to have a higher rate of open surgery. CONCLUSION: Despite the centralization of endovascular programs in Canada, patients do not appear to be traveling a longer distance for EVAR while having open repairs closer to home as we expected. We did note that higher SES was associated with increased odds of EVAR, which may suggest a health care access bias for EVAR for patients of higher SES. Larger, population-based studies at the provincial or national level could confirm these initial findings.

Determination of patient preference for location of elective abdominal aortic aneurysm surgery.

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.

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

OBJECTIVE: Prior work confirms gender-specific anatomic differences in patients undergoing endovascular aneurysm repair, but the clinical implications remain ill defined. The purpose of this study was to compare gender-specific early outcomes after endovascular aneurysm repair using a large international registry. METHODS: Over the 2-year period ending in 2011, 1,262 patients (131 women, 10.4%; 1,131 men, 89.6%) with infrarenal aneurysms treated with the Endurant stent graft were prospectively enrolled in the ENGAGE registry and followed clinically and radiographically. RESULTS: Women were older (75.5 ± 7.0 vs 72.8 ± 8.1; P = .0003) and had smaller aneurysms (57.8 ± 9.5 vs 60.6 ± 11.9 mm; P = .01). Women's infrarenal aortic necks were of narrower diameter (21.8 ± 3.4 vs 24.0 ± 3.5 mm; P < .0001), shorter length (24.3 ± 11.8 vs 27.3 ± 12.4 mm; P = .009), and greater angulation (37.7 ± 26.2° vs 29.4 ± 23.3°; P = .0002). More women had an infrarenal neck angle >60° (19.2% vs 9.1%; P = .001). Technical success was achieved in equal numbers of women and men (97.7% vs 99.2%; P = .10). On completion angiography, the incidence of any endoleak (21.5% vs 15.4%; P = .08) and type I endoleak (1.5% vs 1.1%; P = .60) did not differ between genders. At the 1-month follow-up, there were no differences between women and men with respect to endograft occlusion (2.5% vs 1.9%; P = .70), and differences observed in any endoleak (17.2% vs 11.4%; P = .08) and type I endoleaks (3.3% vs 1.2%; P = .08) did not reach statistical significance. Freedom from major adverse events was similar for women and men at 30 days (98.5% vs 95.8%; P = .23) and 1 year (85% vs 89.8%; P = .40). Survival at 30 days (100% vs 98.6%) and 1 year (92.5% vs 91.6%; P = .99) was similar for women and men. CONCLUSIONS: This large multinational registry confirms the previously observed prevalence of suboptimal neck anatomy in women. Even though women have shorter and more angulated infrarenal necks, their technical outcomes at 30 days and clinical outcomes at 1 year were similar to those of men. Much longer follow-up is necessary to determine whether these outcomes proved durable.

Trends in management of abdominal aortic aneurysms.

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.

Should endovascular repair be reimbursed for low risk abdominal aortic aneurysm patients? Evidence from ontario, Canada.

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.

The role of platelet-rich plasma in inguinal wound healing in vascular surgery patients.

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.

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 $268,337, whereas the incremental cost per life-year was found to be $444,129. The incremental cost per QALY of EVAR remained above $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.

Cost-effectiveness analysis of elective endovascular repair compared with open surgical repair of abdominal aortic aneurysms for patients at a high surgical risk: A 1-year patient-level analysis conducted in Ontario, Canada.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a prevalent health condition affecting up to 14% of men and 6% of women. The objective of this study was to estimate the cost-effectiveness and cost-utility of elective endovascular aneurysm repair (EVAR) compared with open surgical repair (OSR) in patients at a high risk of surgical complications. METHODS: Patient-level cost and outcome data from a 1-year prospective observational study conducted at London Health Sciences Centre, London, Ontario, Canada, was used to determine the incremental cost per life-year gained and the incremental cost per quality-adjusted life year (QALY) gained of EVAR compared with OSR in patients with an AAA >5.5 cm and a high risk of surgical complications. The analysis was taken from a societal perspective and the time horizon was 1 year. To measure sampling uncertainty on costs and effects, nonparametric bootstrap techniques were applied. Uncertainty results were expressed using cost-effectiveness acceptability curves. Extrapolations of the 1-year results to a 5-year time horizon were conducted in sensitivity analyses. RESULTS: Between August 11, 2003, and April 3, 2005, 192 patients at a high risk of surgical complications were enrolled: 140 received EVAR and 52 OSR. Point estimates during a 1-year period showed that EVAR dominated OSR for high-risk patients in terms of incremental cost per life-year gained and incremental cost per QALYs. However, bootstrap estimates for the two cost-effectiveness measures indicated there was a great deal of uncertainty regarding the costs and the QALYs and less uncertainty regarding life-years gained. If society was willing to pay $50,000 per life-year gained or per QALY gained, the probability of EVAR being cost-effective was found to be 0.76 and 0.55, respectively. Five-year extrapolations indicated that EVAR was cost-effective compared with OSR. CONCLUSIONS: According to this 1-year observational study, EVAR may be a cost-effective strategy compared with OSR for high-risk patients. Longer-term data are needed to decrease the uncertainty associated with the results.

Effects of study design and trends for EVAR versus OSR.

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.

Midterm results of endovascular infrarenal abdominal aortic aneurysm repair in high-risk patients.

Short-term and midterm clinical outcomes after endovascular repair of abdominal aortic aneurysms (AAAs) have been well documented. Evaluation of longer term outcomes is now possible. Here we describe our initial 100 high-risk patients treated with endovascular aneurysm repair (EVAR), all with a minimum of 5 years of follow-up. A retrospective review of prospectively recorded data in a departmental database was undertaken for the first 100 consecutive EVAR patients with a minimum of 5 years (range, 60-105 months) of follow-up performed between December 1997 and June 2001. Information was obtained from surgical follow-up visits and family doctors' offices. Endovascular repair of AAA in high-risk patients can be achieved with acceptably low postoperative mortality and morbidity. Longer term results in this high-risk cohort suggest that EVAR is effective in preventing aneurysm-related deaths at 5 years and beyond. All late mortalities were due to patients' comorbid diseases.

Sedative doses of remifentanil have minimal effect on ECoG spike activity during awake epilepsy surgery.

The use of remifentanil for sedation during awake epilepsy surgery has been described in a case report. However, little information is available regarding the effect of remifentanil on the quality of intraoperative electrocorticography (ECoG). This study was designed to investigate the effect of sedative doses of remifentanil on ECoG interictal spike activity among patients undergoing awake anterior temporal lobectomy for refractory epilepsy. Ten adult patients were studied prospectively. After baseline EcoG recordings were obtained, remifentanil was administered as a continuous infusion at 0.1 microg/kg/min and the ECoG recorded continuously for 15 minutes. Recordings obtained before and during the administration of remifentanil were compared with respect to spike frequency and location. A trend toward a small decrease in spike frequency was observed as patients became increasingly somnolescent and background ECoG activity slowed. The difference was not statistically significant. Blood pressure and heart rate were not adversely affected by the administration of remifentanil. Respiratory rates decreased in all patients (mean decrease, 8 breaths/min) and one patient transiently developed a respiratory rate of 4 breaths per minute that elicited a decrease in the rate of remifentanil administration. Remifentanil administered at sedation doses does not adversely affect intraoperatively recorded interictal spike activity. Further investigation of the use of this drug during awake epilepsy surgery is warranted.