To compare endovascular and standard open repair of abdominal aortic aneurysms in terms of initial in-hospital costs and the costs of secondary interventions and surveillance.
A retrospective study.
A university-affiliated tertiary care medical centre.
Seven patients who underwent elective endovascular (EV) repair of an abdominal aortic aneurysm in 1998 and 31 patients anatomically suitable for endovascular repair who underwent standard (STAN) elective repair. Follow-up ranged from 2 to 14 months.
Elective repair of an abdominal aortic aneurysm with use of the standard technique or endovascular technology.
Costs common to both groups were not determined. Costs were determined for total hospital stay, preoperative or postoperative embolization, grafts, additional endovascular equipment, and follow-up computed tomography.
Groups were similar with respect to demographic data and aneurysm size (EV = 6.23 cm v. STAN = 6.05 cm). All patients were in American Society of Anesthesiologists class III or IV. Vanguar bifurcated grafts and extensions were used in the EV group. The total cost for both groups in Canadian dollars included: cost of stay (EV, 5.6 d, $2092.63 v. STAN, 10.7 d, $4449.19; p = 0.009); cost of embolization (EV, n = 3; $900/procedure); cost of follow-up CT (EV, 5.4 per patient; $450/CT); cost of grafts (EV = $8571.43, STAN = $374); additional radiologic equipment costs (EV = $1475). The mean total cost differed significantly between the 2 groups (EV = $14,967.63 v. STAN = $4823.19; p = 0.004). The additional cost associated with a reduction in hospital stay was calculated by determining the incremental cost-effectiveness ratio (ICER, difference in mean costs/difference in mean length of stay = $1604.51).
Endovascular repair continues to be more expensive than standard open repair determined according to procedural and follow-up costs. The technology is still in the developmental stage, but as it evolves and follow-up protocols are streamlined, it is hoped that there will be an eventual reduction in the costs associated with the endovascular procedure.
Worldwide, increasing proportions of aortic aneurysms are repaired electively via the endovascular route. The purpose of this study was to report the recent utilization of endovascular repair in Canada by reviewing a national administrative database.
The Canadian Institute for Health Information database (a collection of all acute care hospitalizations) was reviewed to identify patients who received nonemergent repair of an abdominal aortic aneurysm (AAA) between April 1, 2003 and March 31, 2004. During this 1-year period, differentiation between endovascular (EVAR) and open repair was possible using ICD-10-CA procedural codes in eight of ten provinces. Case volumes, patient age, length of hospitalization, and mortality were stratified by method of repair, province, and size and teaching status of hospitals.
In this 1-year period, 1996 patients in eight provinces (representing 72% of Canada's population) underwent open repair (n = 1818, 91.1%) or EVAR (n = 178, 8.9%) of a nonruptured AAA. National utilization rates were 8.4 and 0.8 per 100,000 population for open repair and EVAR. These rates were more constant for EVAR (0 to 1.3) then for open repair (4 to 18.3) when analyzed on a provincial basis. Mean patient age did not differ between EVAR and open repair (73.7 vs 71.9 years, P = 0.4) while mean length of stay (5.8 vs 11.9 days, P = 0.03) and in-hospital mortality (0.6% vs 4.6%, P = .025) were significantly lower for EVAR than for open repair. Most EVAR (96%) and more than half of open repairs (56%) were performed in academic teaching centers.
Although EVAR results in significant reductions in length of hospitalization and early mortality, it continues to be underutilized in Canada compared with other national reports involving administrative databases.
Endovascular repair of blunt traumatic thoracic aortic injuries (BTAI) has become routine at many trauma centers despite concerns regarding durability and aortic dilatation in these predominantly young patients. These concerns prompted this examination of thoracic aortic expansion after endovascular repair of a BTAI.
The immediate postoperative and most recent computed tomography (CT) scans of patients who had undergone urgent endovascular repair of a BTAI and had at least 1 year of follow-up were reviewed. Diameter measurements were made at four predetermined sites: immediately proximal to the left subclavian artery (D1), immediately distal to the left subclavian artery (D2), distal extent of the endograft (D3), and 15 mm beyond the distal end of the endograft (D4). Split screens permitted direct comparison of measurements between CTs at the corresponding levels.
During a 6-year period (2001-2007), 21 patients (mean age, 42.9 years; range, 19-81 years) underwent endovascular repair of a BTAI, 17 with at least 1 year of follow-up (mean, 2.6 years; range, 1-5.5 years). No patients required reintervention during this period. The mean rate of dilatation for each level of the thoracic aorta in mm/year was: D1, 0.74 (95% confidence interval [CI], 0.42-1.06); D2, 0.83 (95% CI, 0.55-1.11); D3, 0.63 (95% CI, 0.37-0.89); D4, 0.47 (95% CI, 0.27-0.67). The rate of expansion of D2 differed significantly vs D4 (P = .025).
During the first several years of follow-up, the proximal thoracic aorta dilates minimally after endovascular repair of BTAIs, with the segment just distal to the left subclavian artery expanding at a slightly greater rate. Longer-term follow-up is necessary to determine whether this expansion continues and becomes clinically significant.
The purpose of the present study was to determine whether an institution's prior endovascular experience influenced the learning curve of subsequent surgeons. A prospective analysis of the initial 70 endovascular abdominal aortic aneurysm repair (EVAR) cases attempted by an individual surgeon was performed with the primary outcome variable being achievement and 30-day maintenance of initial clinical success. Along with standard statistical analyses, the cumulative sum failure method (CUSUM) was used to analyze the learning curve, with a predetermined acceptable failure rate of 10%. Seventy elective EVAR cases were performed by this surgeon during a 4-year period (2000-2004) (mean age, 73.7 -/+ 5.4 years; mean aneurysm diameter 63.3 -/+ 7.2 mm). Initial clinical success was achieved in 68 of 70 cases (97%), which differed significantly with that of our initial surgeon (88.5%, P = .01). Causes of failure in the present series included 1 early mortality (1.4%) and 1 case of conversion to open repair with no instances of type I endoleak or endograft limb thrombosis. Both surgeons' cases were plotted sequentially with CUSUM curves revealing a significantly shorter learning curve for the second surgeon. Optimal results were achieved following 10 to 20 EVAR cases, as opposed to 60 cases in the initial series. Such an analysis confirms that as an institution's experience with EVAR increases, an individual surgeon's learning curve shortens considerably.
Successful endovascular repair of abdominal aortic aneurysms (AAAs) requires specific infrarenal neck anatomy to allow for a durable seal and fixation. This is a single-center study reviewing outcomes in relation to neck length after placement of a Zenith endograft.
Retrospective single-center review of all AAAs electively repaired with a Zenith endograft during a recent 5-year period. Patients were divided into those with infrarenal necks 4-15 mm in length and those >15 mm using center line measurements. Clinical outcomes and follow-up computed tomography scans were reviewed.
Between 2003 and 2008, 318 patients underwent elective repair of an infrarenal AAA with the Zenith endograft. Of 318 patients, 68 (21.4%) had necks measuring 4-15 mm in length and 250 (79.5%) had necks measuring >15 mm. Overall early mortality was 0.9% (p = 0.11) and the rate of type II endoleaks was 19% (p = 0.11); neither differed between the groups. Four patients in each group had immediate proximal type I endoleaks, which resolved spontaneously in two patients in each group. The remaining two in each group required further intervention (two endovascular and two conversion to open repair). Type I endoleaks and reinterventions did not differ statistically between groups (p = 0.06). On further analysis, those patients requiring reintervention or conversion for type I endoleaks had other unattractive neck features (large diameter, angulation). There have been no instances of new type I endoleaks during 5-yearfollow-up period.
These midterm results indicate that patients with shorter infrarenal necks can be treated as effectively as those with longer necks with the Zenith endograft unless these necks are tortuous or wide.
Failure of endovascular repair (EVAR) of an abdominal aortic aneurysm can result in significant risk of morbidity and mortality. We review our experience with late conversions to open repair.
We conducted a retrospective database review to identify all EVAR procedures performed between 1997 and 2010 and the number converted to open repair at our university-affiliated medical centre. Late conversion was defined as those occurring at least 30 days after initial EVAR.
In all, 892 EVARs took place during the study period. Six patients (0.7%) required late conversion to open repair. Their mean age was 71 (range 58-83) years, and half were women. Half of the initial EVARs were for ruptured aneurysms. The median time to conversion was 15.6 (range 1.7-61.3) months. Indications for secondary conversion (50% urgent, 50% elective) included persistent type I endoleak (n = 3), combined type II and III endoleak (n = 1), graft thrombosis (n = 1) and aneurysm rupture (n = 1). Supraceliac clamping was required in most patients (67%), and the mean transfusion requirement was 2.6 units. Total endograft explantation occurred in 2 patients (33%), whereas partial or total endograft preservation occurred in 4 (67%). Median length of stay in hospital after conversion was 7 (range 6-73) days. There were no instances of early or in-hospital mortality following conversion.
Our EVAR experience includes a low rate of late conversion to open repair, with most conversions being a result of persistent aneurysm perfusion. Although technically challenging, late conversion can be safe. Our experience supports ongoing surveillance after EVAR.
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Unlike in the United States, endovascular aneurysm repair (EVAR) has not been widely disseminated in Canada but has remained limited to large-volume vascular surgery units. Since the development of the endovascular program at our hospital, we have experienced a growth in our aneurysm practice and the area of referral. The purpose of this study was to compare the geographic referral area of our aneurysm practice between 1997 (prior to the introduction of EVAR) and 2003 (EVAR and open surgery). Our prospective database was reviewed to identify patients who underwent elective open aneurysm repair in 1997 and 2003 and those who underwent EVAR in 2003. Each patient's county of residence was identified, allowing for grouping of patients into one of four geographic regions (I-IV) increasingly more distant from our hospital. Proportions were compared with the chi(2) test. In 1997, 105 patients underwent open abdominal aortic aneurysm repair, with the majority of patients originating from the two regions in closest proximity to our hospital (I, 34%; II, 46%; III, 18%; IV, 2%). This contrasts with the 2003 EVAR group (n = 63), which had a higher proportion of patients referred from greater distances (I, 13%; II, 27%; III, 27%; IV, 33%) (p
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.
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.
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.
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.
To determine whether endovascular repair (EVAR) offers a survival advantage over open repair (OAR) with ruptured abdominal aortic aneurysms (RAAA).
Retrospective analysis of RAAA patients treated between 2003 and 2008. Univariate and multivariate analyses were performed.
167 patients presented with RAAA (OAR = 135, 80.8%, EVAR = 32, 19.2%). On univariate analysis, EVAR was associated with a decreased mortality relative to OAR, (15.6% vs 43.7%, P = .004). Patients who survived were younger (P
We aimed to explore the feasibility of a nurse-supervised aneurysm screening program to identify any independent risk factors for abdominal aortic aneurysm (AAA) formation in high-risk patients.
We conducted a prospective observational study of 90 male patients in a university- affiliated hospital in southern Ontario. The patients were prospectively evaluated and all underwent abdominal ultrasonography, with the main outcome measure being detection of an AAA.
AAAs were identified in 18 patients (20%) and had a mean diameter of 3.6 (range 2.8-6.0) cm. A separate analysis was performed to identify risk factors for the presence of an aneurysm. The presence of carotid artery disease proved to be the only statistically significant independent predictor of the presence of AAA (odds ratio 2.23, 95% confidence interval 1.76-2.56).
This study confirms the feasibility of a nurse-supervised AAA screening program, and on the basis of these results we recommend ultrasonographic screening for AAA in patients with a history of carotid artery disease.