The cost-effectiveness of repairing ruptured abdominal aortic aneurysms

BACKGROUND: Although advances in technology have reduced the operative risk of elective abdominal aortic aneurysm (AAA) repair, the surgical repair of ruptured AAAs is associated with a much poorer prognosis and a higher cost. Accordingly, it has been suggested that patients with predictably high rates of morbidity and mortality from ruptured AAA may not benefit from surgical intervention.Methods and Results: A cost-effectiveness analysis was performed with the use of a Markov decision-analytic model to compute long-term survival in quality-adjusted life years and lifetime costs for a hypothetical cohort of patients with ruptured AAAs managed with either a strategy of open surgical repair or no intervention. Probability estimates for the various outcomes were based on a review of the literature. Average costs of (1) the immediate hospitalization ($28,356) and (2) complications resulting from the procedure were based on the average use of resources as reported in the literature and from a hospital's cost accounting system. Our measure of outcome was the incremental cost-effectiveness ratio. For our base-case analysis, the repair of ruptured AAAs was cost-effective with an incremental cost-effectiveness ratio of $10,754. (Society is usually willing to pay for interventions with cost-effectiveness ratios of less than $60,000; for example, the costeffectiveness ratios for coronary artery bypass grafting and dialysis are $9500 and $54,400, respectively.) In sensitivity analyses, the cost-effectiveness of repairing ruptured AAAs was influenced only by alterations in the operative mortality. If the operative mortality exceeded 88%, repair of ruptured AAAs was no longer cost-effective. As an independent variable, increasing age had no substantial impact on the cost-effectiveness, although it is reported to be associated with increased operative mortality. It was necessary that the patient's cost of the initial hospitalization for ruptured AAA exceed $195,000 before repairing ruptured AAAs was no longer cost-effective. CONCLUSIONS: Our analysis suggests that despite the high cost and poor outcomes, the surgical repair of ruptured AAAs is still cost-effective when compared with no intervention. The cost of repairing ruptured AAAs falls within society's acceptable limits and therefore should not be a consideration in the management of patients with AAAs.     

Elective surgery for small abdominal aortic aneurysms.

BACKGROUND AND PURPOSE: Surgical repair for abdominal aortic aneurysm has become more frequent and the mortality associated with elective surgery has been reduced, but the overall mortality for ruptured aneurysm remains unacceptably high. The dilemma for the vascular surgeon is whether to operate early and electively on asymptomatic small aneurysms, less than 5 cm in diameter, or to delay surgery, adopting a wait-and-see attitude. The purpose of this retrospective study was to review a recent 5-year experience of elective aneurysm surgery, with special emphasis on the perioperative outcome of surgical repair of asymptomatic small aneurysms, in order to evaluate whether early mortality and morbidity justify an aggressive approach. METHODS: The report concerns a series of 141 consecutive patients who underwent aneurysm repair for small (n = 65, group I) and large aneurysms (n = 76, group II). For each group, the age, sex, risk factors and associated diseases, operative and aortic cross-clamping times, estimated blood loss, blood transfusion volume, type of operation and graft, perioperative morbidity and mortality, and causes of death were recorded and compared. RESULTS: The majority of patients were males. The mean age of the patients was lower in group I than in group II. No statistically significant difference was found from the comparison of the risk factors and associated diseases in groups I and II. The mean operating time was 82 minutes in group I, 98 minutes in group II, and the aortic cross-clamping time was also shorter in group I (37 min versus 52 min), whereas blood loss was greater, with a statistically significant difference (P < 0.05). The operative mortality rate was higher in group II than in group I (1.3% versus 0%, P = NS). CONCLUSIONS: Elective small aneurysm repair is recommended in good-risk patients for the following reasons: (i) the operative mortality and morbidity rates are lower in small than in large aneurysm patients, and (ii) the small aneurysm repair is technically easier and safer to perform. In addition, there are two other considerations that are more difficult to quantify, but may support an aggressive approach: the cost-benefit ratio is better with early diagnosis and elective surgery, before an emergency operation is required, and personal choice and psychological reasons can induce patients to prefer early elective repair to periodic monitoring by ultrasound or computed tomography scans.     

The selective management of small abdominal aortic aneurysms: the Kingston study.

The management of small abdominal aortic aneurysms less than 5.0 cm maximum diameter remains controversial particularly in patients who are medically fit. All patients referred with abdominal aortic aneurysms less than 5.0 cm maximum diameter were prospectively followed regardless of their fitness for operation. Two hundred sixty-eight patients had been entered into the study by December 31, 1988, and monitored until December 31, 1990, by at least two aneurysm sizings by ultrasonography, CT scanning, or both. The mean follow-up was 42 months. Operations were performed on 114 patients (if they were fit for operation) when the aneurysm reached 5.0 cm, expanded more than 0.5 cm in a 6-month period, or when the patient had significant occlusive disease requiring repair. In this group the mean annual increase in diameter was 0.9 cm. One hundred fifty-four patients were monitored without operation for a mean period of 42 months. One rupture occurred in this group. The average annual increase in diameter in the group not undergoing operation was 0.24 cm. This study supports a policy of observation for abdominal aortic aneurysms less than 5.0 cm in maximum diameter.     

Endovascular management of abdominal aortic aneurysms

An estimated 1.5 million people in the United States have abdominal aortic aneurysms (AAAs) with more than 200000 American diagnosed each year. The natural history of AAAs is to expand and rupture, accounting for an estimated 15000 deaths per year. Thus, the major impetus for AAA repair is for prophylaxis against aneurysm-related death. The standard open surgical repair of AAAs is a well-established and durable procedure. However, as with all other major abdominal surgical operations, associated significant morbidity and mortality exist, along with prolonged recovery and various late complications. Furthermore, both mortality and morbidity increase significantly with advanced patient age and associated co-morbid disease states. Endovascular AAA repair using covered stent-grafts offers a significantly less invasive alternative to conventional open-surgical repair. A considerable reduction in hospital stay has been demonstrated, with early return to preoperative levels of activity. Patients previously considered unsuitable for open repair can often receive treatment for aneurysms with endovascular techniques. Current estimates are that more than 1/2 all infrarenal AAAs will be repaired using endovascular approach in the future. Despite the minimally-invasiveness of this new treatment, there are unanswered questions as to the durability and efficacy of devices, which results in concerns about their ability to successfully protect the patient from subsequent rupture. Three devices are commercially available and have been extensively used for implantation in the United States with a 4th device recently receiving approval from the Food and Drug Administration (FDA). In this review article, endovascular management of AAAs with these devices is described, as are the design and deployment techniques of the currently available endografts.     

Laparoscopic surgery for abdominal aortic aneurysms

Background: Laparoscopic surgery for infrarenal aortic aneurysms is based on the principle of retroperitoneal exclusion of the aneurysm sac with aortofemoral or aortoiliac bypass. Methods: Of 22 patients who met the selection criteria, 20 successfully underwent laparoscopic aortic surgery at Morristown Memorial Hospital between February and October 1997. Technical elements and steps of this operation are described and illustrated. Results: Within 30 days of surgery, 2 patients died and 9 had various major and minor perioperative complications. As a group, the laparoscopic patients had less postoperative pain, needed fewer hours of ventilator support, had shorter intensive care unit (ICU) and hospital lengths of stay, and resumed diet and normal activity earlier than the historical norms for patients undergoing transabdominal or retroperitoneal aortic resections at the same institution. Conclusions: These early observations suggest that the laparoscopic treatment of infrarenal abdominal aneurysms may have several significant potential benefits. Long-term results and randomized prospective studies with patients matched by risk stratification will be needed to confirm these impressions. Received: 23 June 1997/Accepted: 11 December 1997     

The cost-effectiveness of a "quick-screen" program for abdominal aortic aneurysms

BACKGROUND: The incidence of abdominal aortic aneurysm (AAA) is increasing, and the prognosis of ruptured AAA remains dismal. Early diagnosis and intervention are crucial. We designed this study to determine whether selected population screening with a brief "quick-screen" ultrasound could be cost-effective. METHODS: A series of 25 patients with risk factors for AAA were evaluated in a blinded fashion by a quick-screen ultrasound and a full conventional study. Times and accuracy for the 2 approaches were compared. An analysis of the cost-effectiveness of screening for AAA was then performed using a Markov model. We determined the long-term survival in quality-adjusted life years and lifetime costs for a hypothetical cohort of 70-year-old males undergoing either AAA screening or not. Our measure of outcome was the cost-effectiveness ratio (CER). RESULTS: The average time for a quick screen was one-sixth that of a conventional study (4 vs 24 minutes). The accuracy of the quick screen was 100%. In our base-case analysis, screening for AAA was cost-effective with a CER of $11,215. Society usually is willing to pay for interventions with CER of less than $60,000 (eg, CER for coronary artery bypass grafting, $9500; breast cancer screening, $16,000). In sensitivity analysis, reducing the cost of screening from $259 (approximate Medicare reimbursement) to $40 (the quick screen) improved the CER to $6850. Moreover, screening populations with increased prevalence of AAA (eg, male with family history [18%]) further improved the CER. CONCLUSIONS: Our analysis demonstrates that ultrasound screening for AAA should be offered to all males above the age of 60. Widespread screening for AAA should be adopted and reimbursed by Medicare and other insurers.     

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.     

The outcome of endovascular repair of small abdominal aortic aneurysms

OBJECTIVE: To assess the outcome of endovascular repair (EVAR) of small abdominal aortic aneurysms (AAA, 相似文献   

The endovascular management of ruptured abdominal aortic aneurysms.

Endovascular aneurysm repair (EVAR) is a controversial technique, which remains the subject of a number of prospective randomised trials. Although questions remain regarding its long-term durability objective evidence exists which demonstrates its reduced physiological impact compared with conventional open repair. If this technique could be used in patients with ruptured abdominal aortic aneurysm (AAA) it may reduce the high peri-operative mortality. A review of the literature identified a limited experience with EVAR of ruptured AAA. Only a small number of case series with selected patients exist. The majority of patients were haemodynamically stable. However, the selective use of aortic occlusion balloons allowed successful endovascular management in a small number of unstable cases. All investigators had access to an "off the shelf" endovascular stent-graft (EVG). Per-operative mortality ranged from 9 to 45% and may reflect increasing experience and patient selection. A number of patients who underwent successful EVAR were turned down for open repair. A number of important lessons have been learned from these studies but questions remain regarding patient suitability and staffing issues. If these difficulties can be surmounted then the technique may offer an alternative to open repair.     

Technical aspects in the management of abdominal aortic aneurysms

During the past decade, resection of abdominal aortic aneurysms has become common. The technical aspects of the operation are now relatively standardized and simplified. With concomitant improvements in anesthesia and intensive care, the operative mortality for elective resection of these aneurysms has declined progressively; several centres report an operative mortality of less than 5%. The author considers the following principles important in managing patients with abdominal aortic aneurysms: (a) simplicity and limited dissection are critical features of the operative technique; (b) tubular grafts should be used whenever possible; (c) selected patients should be transferred to the intensive care unit preoperatively for "fine-tuning" of the cardiovascular system; (d) patients should be monitored intraoperatively and postoperatively; (e) the surgeon should be aware of special problems such as horseshoe kidney, venous anomalies, adherent duodenum and the presence of major arteries arising from the aneurysm; (f) ruptured aneurysms should be diagnosed promptly and the patient operated upon without delay. Using these principles, the author's group achieved an operative mortality of only 1.8% in 168 patients with abdominal aortic aneurysms resected electively. However, the operative mortality for their patients with ruptured aortic aneurysms was 50%, a rate that has not changed appreciably over the years.     

Current management of infrarenal abdominal aortic aneurysms

Since the concept of endovascular aneurysm repair (EVAR) was introduced more than 15 years ago, many technological advances and multiple generations of aortic stent-graft devices have been used to manage infrarenal abdominal aortic aneurysms. In this rapidly changing environment, the determination of the optimal management of patients with aneurysmal disease can be difficult. In this article, the current management of infrarenal abdominal aortic aneurysms is outlined. Consistent data revealing short-term advantages in morbidity and mortality make EVAR a very appealing option for practitioners and patients. However, mid- and long-term data proving an all-cause mortality benefit are lacking. Open repair has proven durability, and should be strongly considered in younger and lower-risk patients.