Computer simulation to estimate the effectiveness of carotid endarterectomy

Cost-effectiveness of Intraoperative Imaging in Carotid Endarterectomy

OBJECTIVE:

There has never been a large, randomized controlled trial to assess the impact of intraoperative imaging on the success of carotid endarterectomy (CEA). This comparison involves cost-effectiveness analysis.

METHODS:

We constructed a decision-analytic model to compare effectiveness and costs of intraoperative ultrasound (IUS) and completion angiography as adjuncts to CEA. Data on procedural mortality, morbidity, and costs were obtained from the English-language literature. The review included a total of 52 reports, encompassing more than 22,000 patients. The main components of costs were those of the monitoring interventions and the care of perioperative stroke.

RESULTS:

Mean perioperative outcome without completion imaging is approximately 96.7% of what it would be in the absence of perioperative stroke or death. IUS and completion angiography each result in approximately 2% improvement in expected outcome. Mean perioperative costs are $396.50 for IUS, $721.30 for no monitoring, and $840.90 for completion angiography. Because IUS is significantly more effective at detecting technical errors that would likely result in perioperative stroke than no imaging and is significantly less costly than angiography, this strategy dominates the other two (i.e., it provides greater effectiveness at lower cost).

CONCLUSION:

Although surgical complications are uncommon, IUS substantially lowers the rate of perioperative stroke and mortality and thus is significantly more cost-effective than either completion angiography or no operative imaging.

Costs and benefits of carotid endarterectomy and associated preoperative arterial imaging: a systematic review of health economic literature

BACKGROUND AND PURPOSE

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with severe stenosis of the internal carotid artery. However, the cost implications of this procedure have not yet been satisfactorily addressed. The objective of this systematic review was to critically appraise the studies addressing the economic implications of CEA and the associated preoperative arterial imaging.

METHODS

A systematic search strategy was developed to identify research articles related to the economic evaluation of CEA and the associated preoperative imaging. MEDLINE, EMBASE, and BIOSIS were electronically searched, and reference lists from identified studies were searched manually. Methods used to critically appraise these studies followed proposed guidelines for an economic evaluation that addresses 10 distinct aspects under 3 separate headings.

RESULTS

Studies identified were either partial economic or full economic evaluations, with the majority coming from the United States. The methodological quality seems to have improved over time. The studies that assessed cost-effectiveness of CEA were all modeling studies; although the same baseline parameters were used, divergent conclusions were reached. Variation in the cost estimates of CEA ($9500 to $11 500) in the same health care system was also observed in the studies reporting only on the cost of carotid surgery. For a symptomatic patient, the benefit of CEA ranged from 0.35 quality adjusted life years (QALYs) (4.2 months) at a cost of $4100 per QALY to 0.93 QALYs (11.2 months) at a cost of $434 per QALY. For an asymptomatic patient, the cost-effectiveness of CEA varied from 0.15 QALYs (1.8 months) at a cost of $52 700 per QALY to 0.25 QALYs (3 months) at a cost of $8004 per QALY.

CONCLUSIONS

Divergent conclusions of the cost-effectiveness of CEA were reported from studies that addressed the same questions and using similar parameters in their models. The cost estimates of the procedure and the different time periods used in the studies might explain these inconsistencies. Modeling studies in hypothetical cohorts might also be to blame. The cost-effectiveness of CEA will only definitively be assessed when real patient data are used.