The cost-effectiveness of endovascular repair versus open surgical repair of abdominal aortic aneurysms: A decision analysis model

PURPOSE: Endovascular repair (EVR) is a less-invasive method for the treatment of abdominal aortic aneurysms (AAAs) as compared with open surgical repair (OSR). The potential benefits of EVR include increased patient acceptance, less resource utilization, and cost savings. This study was designed to determine whether the EVR of AAAs is a cost-effective alternative to OSR. METHODS: A cost-effectiveness analysis was performed using a Markov decision analysis model to compute long-term survival rates in quality-adjusted life years and lifetime costs for a hypothetical cohort of patients who underwent either OSR or EVR. Probability estimates of the different outcomes of the two alternative strategies were made on the basis of a review of the literature. The average costs of (1) the immediate hospitalization ($16,016 for OSR, $20,083 for EVR), (2) the complications that resulted from each procedure, (3) the subsequent interventions, and (4) the surveillance protocol were determined on the basis of average resource utilization as reported in the literature and from our hospital's cost accounting system. Our measure of outcome was the cost-effectiveness ratio. RESULTS: For our base-case analysis (70-year-old men with 5-cm AAAs), EVR was cost-effective with a cost-effectiveness ratio of $22,826-society usually is willing to pay for interventions with cost-effectiveness ratios of less than $60,000 (eg, cost-effectiveness ratios for coronary artery bypass grafting and dialysis are $9500 and $54,400, respectively). This conclusion did not vary significantly with increases in procedural costs for EVR (ie, if the cost of the endograft increased from $8000 to $12,000, EVR remained cost-effective with a cost-effectiveness ratio of $32,881). The cost-effectiveness of EVR was critically dependent on EVR producing a large reduction in the combined mortality and long-term morbidity rate (stroke, dialysis-dependent renal failure, major amputation, myocardial infarction) as compared with OSR (ie, a reduction in the combined mortality and long-term morbidity rate of OSR from 9.1% to 4.7% made EVR no longer cost-effective). CONCLUSION: Despite the high cost of new technology and the need for close postoperative surveillance, EVR is a cost-effective alternative for the repair of AAAs. However, the cost-effectiveness of this new technology is critically dependent on its potential to reduce morbidity and mortality rates as compared with OSR. EVR may not be cost-effective in medical centers where OSR can be performed with low risk.     

A cost-effectiveness analysis of standard versus endovascular abdominal aortic aneurysm repair.

OBJECTIVE: 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. DESIGN: A retrospective study. SETTING: A university-affiliated tertiary care medical centre. PATIENTS: 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. INTERVENTIONS: Elective repair of an abdominal aortic aneurysm with use of the standard technique or endovascular technology. OUTCOME MEASURES: 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. RESULTS: 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). CONCLUSIONS: 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.     

Endovascular abdominal aortic aneurysm repair: a 7 year experience at the Launceston General Hospital

BACKGROUND: To review our 7 year experience of endovascular abdominal aortic aneurysm repair (EVR) and to compare this to open repair (OR) during the same time period. METHODS: One hundred and one EVR and 65 OR patients were studied. Parameters analysed included patient and procedure details, intensive care unit (ICU) and hospital admission time, and morbidity and mortality with particular emphasis on procedure-related problems. RESULTS: Endovascular grafts were deployed with successful abdominal aortic aneurysm (AAA) exclusion in 100 patients. Primary technical success was achieved in 84%, clinical success in 86% and secondary success in 90% of cases. Complications occurred in 63% and 88% of EVR and OR patients, respectively. Early device-related complications occurred in 40 EVR patients (40%); 24 (60%) were corrected immediately by further stenting. Late device-related complications occurred in 15 EVR patients (15%); four (27%) required additional stenting. Most of the complications in the OR group were systemic (89%) resulting in longer ICU and hospital stays (median 48 vs 17 h and 13 vs 4 days for OR and EVR, respectively). Death within 30 days of the procedure occurred in three EVR patients. There was no perioperative mortality in the OR group. CONCLUSION: Endovascular AAA repair can be undertaken successfully in a district general hospital. The majority of local and device-related complications can be corrected immediately, while those persisting beyond the initial procedure usually resolve spontaneously. EVR offers a minimally invasive approach to a problem that in the past has involved major surgery.     

Perioperative outcomes after open and endovascular repair of intact abdominal aortic aneurysms in the United States during 2001

OBJECTIVE: Small patient numbers, mixed data from clinical trials, and longitudinal series representing institutional learning curves have characterized previous studies of early outcomes after endovascular abdominal aortic aneurysm (AAA) repair. We compared the perioperative outcomes of endovascular and open surgical AAA repair in an unselected sample of patients in a single calendar year using a national administrative database. METHODS: The 2001 National Inpatient Sample database was retrospectively reviewed. This database represents 20% of all-payer stratified sample of non-federal US hospitals. Patients older than 49 years were identified by primary diagnostic codes (International Classification of Disease, ninth revision [ICD-9], 441.4, intact, nonruptured AAA) and procedure codes (ICD-9 38.44 for open, 39.71 for endovascular repair). Patient demographic data (age, sex), comorbid conditions (ICD-9 coded), inpatient complications (ICD-9 coded), length of stay, final discharge disposition (home vs institution vs death), and hospital charges were examined with univariate and multivariate analyses. RESULTS: In calendar year 2001, 7172 patients underwent either open (64%) or endovascular (36%) repair of intact, nonruptured AAAs. Despite comparable rates of preoperative comorbid conditions and a greater proportion of octogenarians (23% vs 16%%; P =.0001), morbidity (18% vs 29%; P =.0001) and mortality (1.3% vs 3.8%; P =.0001) were significantly lower for endovascular repair than for open repair. The median length of stay (2 vs 7 days; P =.0001) and the rate of discharge to an institutional facility versus home (6% vs 14%; P =.0001) were also much lower in the endovascular group than in the open repair group. At multivariate analysis, open AAA repair and age older than 80 years were strong independent predictors (P =.0001 for all) for death (open repair: odds ratio [OR], 3.3; 95% confidence interval [CI], 2.3-4.9; age: OR, 14.2; 95% CI, 3.5-58.1), complications (open repair: OR, 1.9; 95% CI, 1.7-2.1; age: OR, 1.9; 95% CI, 1.5-2.5), and not being discharged to home (open repair: OR, 3.4; 95% CI, 2.9-4.1; age: OR, 12.0; 95% CI, 7.0-20.4). Mean hospital charges were significantly greater (difference, $3337; P =.0009) for endovascular repair than for open repair. Extrapolated to the total number of endovascular AAA repairs performed during the single 2001 calendar year, this resulted in a staggering $50.3 million in additional hospital charges. CONCLUSIONS: Endovascular repair of intact AAAs results in a significantly lower number of complications and deaths, shorter hospital stay, and improved likelihood of discharge to home, even in older patients, when compared with open surgical repair. These impressive gains in clinical outcome, however, are achieved at similarly impressive increases in health care costs.     

Cost-effectiveness of conventional and endovascular repair of abdominal aortic aneurysms: results of a randomized trial

BACKGROUND: Two randomized trials have shown similar mid-term outcomes for survival and quality of life after endovascular and conventional open repair of abdominal aortic aneurysms (AAA). With reduced hospital and intensive care stay, endovascular repair has been hypothesized to be more efficient than open repair. The Dutch Randomized Endovascular Aneurysm Management (DREAM) trial was undertaken to assess the balance of costs and effects of endovascular vs open aneurysm repair. METHODS: We conducted a multicenter, randomized trial comparing endovascular repair with open repair in 351 patients with an AAA and studied costs, cost-effectiveness, and clinical outcome 1 year after surgery. In addition to clinical outcome, costs and quality of life were recorded up to 1 year in 170 patients in the endovascular repair group and in 170 in the open repair group. Incremental cost-effectiveness ratios were estimated for cost per life-year, event-free life-year, and quality adjusted life-year (QALY) gained. Uncertainty regarding these outcomes was assessed using bootstrapping. RESULTS: Patients in the endovascular repair group experienced 0.72 QALY vs 0.73 in the open repair group (absolute difference, 0.01; 95% confidence interval [CI], -0.038 to 0.058). Endovascular repair was associated with additional euro 4293 direct costs (euro 18,179 vs euro 13.886; 95% CI, euro 2,770 to euro 5,830). Most of the bootstrap estimates indicated that endovascular repair resulted in slightly longer overall and event-free survival associated with respective incremental cost-effectiveness ratios of euro76,100 and euro 171,500 per year gained. Open repair appeared the dominant strategy in costs per QALY. CONCLUSION: Presently, routine use of endovascular repair in patients also eligible for open repair does not result in a QALY gain at 1 year postoperatively, provides only a marginal overall survival benefit, and is associated with a substantial, if not prohibitive, increase in costs.     

腹主动脉瘤血管腔内治疗与开放手术治疗的疗效比较

目的 比较腹主动脉瘤血管腔内治疗与开放手术治疗的近期疗效。方法 对34例肾下型腹主动脉瘤患者的临床资料进行分析，比较腔内治疗组（15例）与传统开放手术治疗组（19例）的术前状况、手术相关情况、术后并发症、死亡率及手术前后的实验室检查数据。结果 腔内组术中出血量和输血量明显少于手术组（P=0．005、P=0．015），腔内组术后平均禁食时间和平均住院时间较手术组明显缩短（P〈0．0l、P：0．001）。手术组术后并发症发生率明显高于腔内组（P〈0．01）。术后第3天白细胞计数腔内组明显低于手术组（P=0．020）；术后第5天红细胞计数及血肌酐水平在腔内组均明显高于手术组（P=0．011、P=0．034）。结论 腹主动脉瘤血管腔内治疗具有安全、微创、对人体内环境干扰小的优点，近期疗效较传统开放手术好。     

Quality of life before and after endovascular and retroperitoneal abdominal aortic aneurysm repair

PURPOSE: This study was undertaken to evaluate changes in quality of life and to compare conventional outcomes in patients undergoing endovascular and open retroperitoneal abdominal aortic aneurysm (AAA) repair. METHODS: Between October 2000 and May 2003, 129 patients underwent elective AAA repair, endovascular repair in 22 patients and open retroperitoneal repair in 107 patients. The Short-Form Health Survey, 12 items (SF-12) was administered preoperatively and at 3 weeks, 4 months, and 1 year after discharge. Quality of life, hospital and intensive care unit stay, perioperative complications, discharge disposition, readmission, and hospital cost were statistically evaluated. RESULTS: For the total group, significant differences were observed for both Physical Component Summary scores (P<.001) and Mental Component Summary scores (P=.001) between time points. There were no significant differences for either Component Summary score between open and endovascular procedures for any time period. Number of weeks required to return to baseline functional status was similar after either open or endovascular repair (7.22 vs 5.47 weeks, respectively; P=.09). Mean hospital and intensive care unit stay was 4.4 and 1 days, respectively, for open repair versus 1.9 and 0 days, respectively, for endovascular repair (P<.0001). No significant difference between groups was observed in terms of perioperative complications, discharge disposition, or hospital readmission (P> or =.54). Mean total hospital cost for endovascular repair was 1.60 times that for open repair (mean difference, $11,662; P<.0001; 95% confidence interval, $17,799-$5525). CONCLUSIONS: Hospital stay is significantly shorter after endovascular AAA repair. However, hospital cost is almost twice that for open retroperitoneal repair. Perioperative complications, discharge disposition, and hospital readmission are not statistically different between the two groups. Effect on health-related quality of life is similar after either open retroperitoneal or endovascular AAA repair.     

An evaluation of the costs to health care institutions of endovascular aortic aneurysm repair

BACKGROUND: Endovascular graft techniques hold great potential as a less invasive means for the repair of aortic aneurysms, yet the impact of these new modalities remains poorly elucidated. METHODS: Over a 10-month period at a single institution, 139 patients underwent infrarenal aortic aneurysm repair through a traditional open surgical technique (OS group, 94 patients) or an endovascular approach (ES group, 45 patients). Coated polyester prostheses (Hemashield; Boston Scientific Corporation, Boston, Mass) were used in the OS patients, whereas a modular nitinol polyester device (AneuRx; Medtronic, Sunnyvale, Calif) was used in the ES group. The hospital costs exclusive of professional charges were tabulated for the two groups using the hospital cost accounting system. Outliers were included in the data analysis. RESULTS: The mean operating room time was longer in the OS group than in the ES group (285 minutes vs 166 minutes). The average length of stay was also longer in the OS group (9.7 days vs 3.2 days). Hospital costs related to the length of stay were higher in the OS group, including laboratory costs ($327 higher), pharmacy costs ($688 higher), and nursing costs ($780 higher). Anesthesia costs were also higher in the OS group ($493 higher). Despite these marked differences, the total hospital cost averaged $7205 more in the ES group, a finding that was driven by the cost of the implantable devices themselves ($8976 in the ES group vs $597 in the OS group). CONCLUSIONS: Despite reductions in the length of hospitalization, the cost of care was substantially greater in patients undergoing endovascular aneurysm repair than in patients in whom an open surgical technique was used. These differences are driven by the cost of the endograft device itself, a cost that must not exceed $6000 if the economic impact of endovascular repair is to be in parity with traditional methods. Unless these economic disparities can be ameliorated, the economic impact of endovascular aneurysm repair may limit the widespread application of this technology.     

Minimal incision aortic surgery.

PURPOSE: In this study we evaluated the clinical and economic impact of minimal incision aortic surgery (MIAS) for treatment of patients with abdominal aortic aneurysms (AAAs) and aortoiliac occlusive disease (AIOD). METHOD: Fifty patients with either AAA (34) or AIOD (16), prospectively treated with the MIAS technique, were compared with 50 patients (40 AAA and 10 AIOD) treated in the same time period with long midline incision and extracavitary small bowel retraction. MIAS was also compared with a cohort of 32 patients with AAA treated by means of endoaortic stent-grafts. Outcomes and cost (based on metric mean length of stay) were compared for the open and endoaortic techniques. RESULTS: Patients who experienced no perioperative complications after the MIAS or endovascular repair technique had shorter hospital stays than patients with uncomplicated aortic repairs performed with a traditional long midline abdominal incision (3 days vs 3 days vs. 7.2 days). Hospital stay was also significantly shorter for the less invasive procedures when perioperative complications were included (4.8 days vs. 4.3 days vs 9.3 days). The MIAS and endovascular aortic repair groups had a shorter intensive care unit stay (< or = 1.0 day) and a quicker return to general dietary feeding (2.5 days) than patients treated with standard open repair (1.8 days, 4.7 days). The overall morbidity for the MIAS technique (14%) and endovascular technique (21%) was not significantly different from standard open repair (24%). The mortality rate for the different treatment groups was equivalent (MIAS, 2%; endovascular repair, 3%; standard repair, 2%). The MIAS was more cost-efficient than standard open repair ($12,585 vs $18,445) because of shorter intensive care unit and hospital stay and was more cost-efficient than endoaortic repair ($12,585 vs $32,040) because of reduced, direct intraoperative costs. CONCLUSIONS: MIAS is as safe as standard open or endovascular repair in the treatment of AAA and AIOD. MIAS is more cost-efficient than standard open or endoaortic repair.     

An analysis of standard open and endovascular surgical repair of abdominal aortic aneurysms in octogenarians

While elective open abdominal aortic aneurysm (AAA) repair has been shown to be safe in selected octogenarians, very little is known about the role of endovascular AAA exclusion in this high-risk cohort. A retrospective review of our vascular surgical registry from January 1996 to December 2001 revealed 51 octogenarians that underwent infrarenal AAA repair. Since 1999 all octogenarians who presented for AAA repair were evaluated for preferential endovascular stent graft placement. Over the 6-year period, 35 patients underwent standard open repair while 16 patients were found to be anatomic candidates for and were treated with an endovascular stent graft. Hospital and office charts were reviewed to compare the endovascular cohort to the standard open cohort. Factors considered included patient comorbidities, perioperative data, and operative outcomes. Statistical analysis was done using Wilcoxon rank sum test and Fisher exact test. The median age for the entire group was 83 years. There were 11 females in the open group and 1 female in the endovascular group. There were no statistically significant differences in preoperative patient comorbidities between groups. Total mortality for the entire series was 11.8 per cent but this included 5 ruptured AAAs, all of which patients died, and 11 additional AAAs that were symptomatic, of which 1 patient died. Total nonruptured mortality for the entire series was 2.2 per cent (0% for the endo-group and 3.3% for the open group). There were statistically significant differences between the endovascular versus the open groups when comparing aneurysm diameter (5.6 cm vs. 6.2 cm; P = 0.016), estimated blood loss (225 cc vs. 2100 cc; P < 0.001), ICU days (0 vs. 3; P < 0.001), length of hospital stay (2 days vs. 12 days; P < 0.001), and patients with blood transfusions (1 vs. 27; P < 0.001). When comparing postoperative morbidities, 4 of the endovascular patients (25%) and 25 of the open patients (68.6%) had a complication (P = 0.006). In conclusion, endovascular stent graft treatment of nonruptured infrarenal AAAs in octogenarians led to significantly better outcomes and should probably be considered the preferred treatment whenever anatomically appropriate. Endovascular exclusion of ruptured AAAs may potentially improve future outcomes in this high-risk group.     

The cost of elective and emergency repair of AAA in patients under and over the age of 80.

BACKGROUND: As Australia's population ages, the number of elderly patients presenting for surgery of abdominal aortic aneurysms (AAA), both elective and ruptured, will increase. The aim of the present study was to compare the costs of treatment of patients with AAA, under and over the age of 80, in the elective and emergency settings in a hospital with a divisional structure in which the true costs can be accurately obtained. METHODS: A total of 40 patients were selected at random from a series of 267 patients treated with open surgery for AAA between January 1987 and December 1994, 10 in each of four groups: group A, elective repair in patients aged < 80 (171/267); group B, elective AAA repair in patients aged > 80 (25/267); group C, emergency AAA repair in patients aged < 80 (50/267); and group D, emergency AAA repair in patients aged > 80 (11/267). A retrospective analysis of the hospital costs of treatment of these patients at St George Hospital was conducted. These true costs were then compared to Australian National Diagnostic Related Group (AN-DRG) costs. RESULTS: Group A and B had no mortality. In Group C and D the mortality was 20 and 60%, respectively. The emergency treatment groups also had longer lengths of stay. A statistically significant difference in cost of AAA repair between elective and emergency groups in both age groups was seen; that is, group A cost less than group C and group B cost less than group D. Costs per survivor, however, showed a dramatic difference between the cost of group C patients ($30000) and group D patients ($60000). In comparison with AN-DRG calculated costs, the true costs of groups A and B were equivalent to AN-DRG costs. In the emergency groups, however, there were marked discrepancies between the true cost ($61000) and that calculated by the DRG ($25000) in group D, with similar differences seen in group C to a lesser extent. CONCLUSION: Emergency repair of AAA is significantly more expensive and has a high mortality in the over-80 age group. Also, there is a substantial shortfall between the true costs of treating these patients and the funds allocated for treatment in this group.     

Follow-up costs increase the cost disparity between endovascular and open abdominal aortic aneurysm repair

OBJECTIVE: This study compared the hospital and follow-up costs of patients who have undergone endovascular (EVAR) or open (OR) elective abdominal aortic aneurysm repair. METHODS: The records of 195 patients (EVAR, n = 55; OR, n = 140) who underwent elective aortic aneurysm repair between 1995 and 2004 were reviewed. Primary costing data were analyzed for 54 EVAR and 135 OR patients. Hospital costs were divided into preoperative, operative, and postoperative costs. Follow-up costs for EVAR patients were recorded, with a median follow-up time of 12 months. RESULTS: Mean preoperative costs were slightly higher in the EVAR group (AU $961/US $733 vs AU $869/US $663; not significant). Operative costs were significantly higher in the EVAR group (AU $16,124/US $12,297 vs AU $6077/US $4635; P < .001); this was entirely due to the increased cost of the endograft (AU $10,181/US $7,765 for EVAR vs AU $476/US $363 for OR). Postoperative costs were significantly reduced in the EVAR group (AU $4719/US $3599 vs AU $11,491/US $8,764; P < .001). Total hospital costs were significantly greater in the EVAR group (AU $21,804/US $16,631 vs AU $18,437/US $14,063; P < .001). The increase in total hospital costs was due to a significant difference in graft costs, which was not offset by reduced postoperative costs. The average follow-up cost per year after EVAR was AU $1316/US $999. At 1 year of follow-up, EVAR remained significantly more expensive than OR (AU $23,120/US $17,640 vs AU $18,510/US $14,122; P < .001); this cost discrepancy increased with a longer follow-up. CONCLUSIONS: EVAR results in significantly greater hospital costs compared with OR, despite reduced hospital and intensive care unit stays. The inclusion of follow-up costs further increases the cost disparity between EVAR and OR. Because EVAR requires lifelong surveillance and has a high rate of reintervention, follow-up costs must be included in any cost comparison of EVAR and OR. The economic cost, as well as the efficacy, of new technologies such as EVAR must be addressed before their widespread use is advocated.     

Durability of benefits of endovascular versus conventional abdominal aortic aneurysm repair

PURPOSE: Endovascular abdominal aortic aneurysm (AAA) repair is reported to result in less initial patient morbidity and a shorter hospital length of stay (LOS) when compared with conventional AAA repair. We sought to examine the durability of this result during the intermediate follow-up interval. METHODS: The records of all admissions for all patients who underwent AAA repair during a 26-month interval were reviewed. RESULTS: Three hundred thirty-seven (337) patients underwent procedures to repair AAAs (163 open and 174 endovascular). Endovascular procedures were performed with a variety of devices (Talent, 108; Ancure, 36; AneuRx, 26; Zenith, 2; and Cordis, 2) and configurations (141 bifurcated and 33 aortomonoiliac). The mean follow-up period was 10.6 months (endovascular repair) and 12.3 months (open repair). LOS did not significantly vary by device (P =.24 to P =.92) or configuration (P =.24). The initial median LOS for procedures was significantly shorter (P =.009) for endovascular repairs (5 days) than for open procedures (8 days). However, the patients who underwent endovascular repair were more likely to be readmitted during the follow-up interval when compared with patients who underwent open procedure. The readmission-free survival rate after AAA repair at 12 months was 95% for patients for open AAA repair versus 71% for patients for endovascular repair (P <.001). If the total hospital days were compared, including the initial and all subsequent AAA-related admissions, there was no significant difference for mean LOS for patients who underwent endovascular versus open AAA procedures (11 days versus 13.6 days; P =.21). The patients for endovascular AAA repair most commonly needed readmission for treatment of endoleak (n = 31), wound infection (n = 12), and graft limb thrombosis (n = 9). Although women had similar LOS to men for endovascular repair (P =.44), they had longer initial LOS for open AAA repair (15 versus 10 days; P =.03). After endovascular repair, women were more likely than men to be readmitted by 12 months (51% versus 71% readmission-free survival rate; P =.03) and they had longer LOS on readmission (13.2 versus 5.2 days; P =.006). No gender differences were identified for patients after open AAA repair regarding readmission-free survival rate (P =.09) or LOS on readmission (P =.98). CONCLUSION: Although initial LOS was shorter for the patients who underwent endovascular as compared with conventional AAA repair, this advantage was lost during the follow-up interval because of frequent readmission for the treatment of procedure-related complications, chiefly endoleak. These readmissions frequently involved the performance of additional invasive procedures. Gender differences existed regarding LOS and the likelihood of complications after open and endovascular AAA repair.     

Endovascular abdominal aortic aneurysm repair is more profitable than open repair based on contribution margin per day

BACKGROUND: Earlier studies have reported that endovascular abdominal aortic aneurysm (EAAA) repair yields lower total profit margins than open AAA (OAAA) repair. This study compared EAAA versus OAAA based on contribution margin per day, which may better measure profitability of new clinical technologies. Contribution margin equals revenue less variable direct costs (VDCs). VDCs capture incremental resources tied directly to individual patients' activity (eg, invoice price of endograft device, nursing labor). Overhead costs factor into total margin, but not contribution margin. METHODS: The University of Michigan Health System's cost accounting system was used to extract fiscal year 2002-2003 information on revenue, total margin, contribution margin, and duration of stay for Medicare patients with principal diagnosis of AAA (ICD-9 code 441.4). RESULTS: OAAA had revenues of $37,137 per case versus $28,960 for EAAA, similar VDCs per case, and thus higher contribution margin per case ($24,404 for OAAA vs $13,911 for EAAA, P < .001). However, OAAA had significantly longer mean duration of stay per case (10.2 days vs 2.2 days, P < .001). Therefore, mean contribution margin per day was $2948 for OAAA, but $8569 for EAAA ( P < .001). CONCLUSIONS: On the basis of contribution margin per day, EAAA repair dominates OAAA repair. The shorter duration of stay with EAAA allows higher throughput, fuller overhead amortization, better use of scarce inpatient beds, and higher health system profits. Surgeons must understand overhead allocation to devices, especially when new technologies cut duration of stay markedly.     

腹主动脉瘤形态学特点及临床意义

目的了解腹主动脉瘤的形态学特点对腔内修复术(EVR)治疗方法的影响.方法应用螺旋CT血管造影检测了30例腹主动脉瘤并收集解剖学数据.结果动脉瘤平均最大直径5.9cm(4.0～12.2cm),腹主动脉瘤直径与瘤颈的角度呈正相关(r=0.47,P＜0.05);与瘤颈长度呈负相关(r=-0.41,P＜0.05).本组病例中有12例(40%)符合EVR要求的解剖条件,18例不适合EVR手术,其中16例(53.3%)因瘤颈角度过大(平均88.8°,范围70°～110°,其中4例合并髂总动脉瘤),1例(3.3%)因瘤颈过短,另1例(3.3%)单侧髂总动脉闭塞伴瘤颈附壁血栓.结论影响腹主动脉瘤EVR手术最主要的单一因素是瘤颈角度过大.这是与欧美腹主动脉瘤病例不同的形态学特点.     

Hospital resource use and costs among abdominal aortic aneurysm repair patients admitted to the intensive care unit

BackgroundAbdominal aortic aneurysm (AAA) repair is associated with significant morbidity and mortality. As a result, many of these patients are monitored postoperatively in the intensive care unit (ICU). However, little is known about resource utilization and costs associated with ICU admission in this population. We sought to evaluate predictors of total costs among patients admitted to the ICU after repair of nonruptured or ruptured AAA.MethodsWe retrospectively analyzed prospectively collected data (2011-2016) of ICU patients admitted after AAA repair. The primary outcome was total hospital costs. We used elastic net regression to identify pre-ICU admission predictors of hospitalization costs separately for nonruptured and ruptured AAA patients.ResultsWe included 552 patients in the analysis. Of these, 440 (79.7%) were admitted after repair of nonruptured AAA, and 112 (20.3%) were admitted after repair of ruptured AAA. The mean age of patients with nonruptured AAA was 74 (standard deviation, 9) years, and the mean age of patients with ruptured AAA was 70 (standard deviation, 8) years. Median total hospital cost (in Canadian dollars) was $21,555 (interquartile range, $17,798-$27,294) for patients with nonruptured AAA and $33,709 (interquartile range, $23,173-$53,913) for patients with ruptured AAA. Among both nonruptured and ruptured AAA patients, increasing age, illness severity, use of endovascular repair, history of chronic obstructive pulmonary disease, and excessive blood loss (≥4000 mL) were associated with increased costs, whereas having an anesthesiologist with vascular subspecialty training was associated with lower costs.ConclusionsPatient-, procedure-, and clinician-specific variables are associated with costs in patients admitted to the ICU after repair of AAA. These factors may be considered future targets in initiatives to improve cost-effectiveness in this population.     

Expanding use of emergency endovascular repair for ruptured abdominal aortic aneurysms: disparities in outcomes from a nationwide perspective

BACKGROUND: Endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) has become widely accepted in the elective setting but remains controversial for emergency repair of ruptured aneurysms (rAAA). We sought to examine the national trends in use and associated outcomes with EVAR. METHODS: The Nationwide Inpatient Sample (NIS) was used to analyze all admissions for rAAA from 2001 through 2004. Nationwide temporal trends and demographics using weighted samples were evaluated. Focused univariate and multivariate analyses comparing outcomes from open repair and EVAR were done for the years 2003 and 2004. RESULTS: There were 28,123 admissions for rAAA, with a stepwise decline in admissions from 2001 to 2004. Use of EVAR increased significantly from 6% of all emergency repairs in 2001 to 11% in 2004 (P < .01). Mortality for EVAR declined significantly from 43% to 29% (P < .01), but mortality with open repair showed no change (40% to 43%). From the 2003 to 2004 data set, 949 EVAR and 8982 open repairs were identified. Compared with open repair, the EVAR patients had lower mortality (31% vs 42%), shorter hospital stay (6 vs 9 days), and were more likely to be discharged to home (59% vs 37%, all P < .01). The total hospital charges for EVAR and open repair were similar (dollars 71,428 vs $74,520, P = .59). Mortality for EVAR was significantly higher at nonteaching hospitals compared with teaching centers (55% vs 21%, P < .01) and at nonteaching centers, even exceeding that of open repair (46%). Regression modeling confirmed the overall benefits of EVAR as well as the worse outcomes at nonteaching facilities after adjusting for patient comorbidities, disease severity, and hospital or system covariates. CONCLUSIONS: Endovascular repair is being increasingly used in the emergency management of ruptured AAA, with steadily decreasing mortality during the study period. Endovascular AAA repair is associated with improved mortality and outcomes compared with open repair, but results in nonteaching centers are substantially worse than those in teaching hospitals.     

THE COST OF ELECTIVE AND EMERGENCY REPAIR OF AAA IN PATIENTS UNDER AND OVER THE AGE OF 80

Background : As Australia’s population ages, the number of elderly patients presenting for surgery of abdominal aortic aneurysms (AAA), both elective and ruptured, will increase. The aim of the present study was to compare the costs of treatment of patients with AAA, under and over the age of 80, in the elective and emergency settings in a hospital with a divisional structure in which the true costs can be accurately obtained. Methods : A total of 40 patients were selected at random from a series of 267 patients treated with open surgery for AAA between January 1987 and December 1994, 10 in each of four groups: group A, elective repair in patients aged < 80 (171/267); group B, elective AAA repair in patients aged > 80 (25/267); group C, emergency AAA repair in patients aged < 80 (50/267); and group D, emergency AAA repair in patients aged > 80 (11/267). A retrospective analysis of the hospital costs of treatment of these patients at St George Hospital was conducted. These true costs were then compared to Australian National Diagnostic Related Group (AN-DRG) costs. Results : Group A and B had no mortality. In Group C and D the mortality was 20 and 60%, respectively. The emergency treatment groups also had longer lengths of stay. A statistically significant difference in cost of AAA repair between elective and emergency groups in both age groups was seen; that is, group A cost less than group C and group B cost less than group D. Costs per survivor, however, showed a dramatic difference between the cost of group C patients ($30 000) and group D patients ($60 000). In comparison with AN-DRG calculated costs, the true costs of groups A and B were equivalent to AN-DRG costs. In the emergency groups, how- ever, there were marked discrepancies between the true cost ($61 000) and that calculated by the DRG ($25 000) in group D, with similar differences seen in group C to a lesser extent. Conclusion : Emergency repair of AAA is significantly more expensive and has a high mortality in the over-80 age group. Also, there is a substantial shortfall between the true costs of treating these patients and the funds allocated for treatment in this group.