An economic appraisal of lower extremity bypass graft maintenance

AbstractObjective: Infrainguinal graft surveillance leads to intervention on the basis of duplex-identified stenoses. We have become increasingly concerned about the high frequency with which such revisions are required to maximize graft patency and limb salvage rates. The economic implications of these procedures have not been carefully analyzed or justified. Methods: We retrospectively reviewed 155 consecutive autogenous infrainguinal bypass grafts performed for chronic leg ischemia in 141 patients. All patients were enrolled in a prospective surveillance program using color flow duplex imaging. Full economic appraisal (cost analysis, cost-effect analysis, and cost-benefit analysis) was performed for all graft surveillance and limb salvage–related interventions through use of standard accounting and valuation techniques. Results: Mean follow-up was 27 months. Five-year assisted primary patency (72%) and limb salvage rates (91%) were calculated by means of life table analysis. A total of 61 grafts required 86 revisions. Within 1 year of implantation, 36% of the grafts required revision. During this first year, the mean cost per graft enrolled was $9417. Time intervals after the initial year demonstrated a reduced annual revision rate (6$1725 per graft). The mean 5-year cost of graft maintenance ($16,318) approached that of the initial bypass graft ($19,331). The sum of the initial cost of bypass graft and 5-year graft maintenance cost ($35,649) was similar to the cost of amputation ($36,273). Grafts revised for duplex-detected stenoses (n = 46), in comparison with those revised after thrombosis (n = 15), had an improved 1-year patency (93% vs 57%; P <.01), required fewer amputations (2% vs 33%; P <.01), less frequently required multiple graft revisions (P =.06), and generated fewer expenses (at 12 months after revision, $17,688 vs$45,252, P <.01). Conclusion: The cost associated with graft maintenance is significant, particularly within the first year, and demands consideration. Revision of a duplex-identified stenosis was significantly less costly than revision after graft thrombosis. Compared with the cost of limb amputation, limb salvage–related expenses appear to be justified. (J Vasc Surg 2000;32:1-12.

The correlation of early flow disturbances with the development of infrainguinal graft stenosis: A 10-year study of 341 autogenous vein grafts

AbstractPurpose: Although duplex surveillance of infrainguinal bypass grafts is widely accepted, the optimal frequency and intensity of graft surveillance remains controversial. Earlier reports have suggested that grafts can be stratified into high-risk and low-risk groups based on the presence or absence of early graft flow disturbances. The purpose of this study was to provide long-term data in determining whether early graft flow disturbances detected by means of duplex scanning can predict the development of intrinsic vein graft stenosis. Methods: We reviewed a series of patients undergoing prospective duplex graft surveillance after autogenous infrainguinal bypass grafting procedures from 1987 to 1997. Patients included in the study underwent at least one duplex scan within 3 months of graft implantation and were observed for a minimum of 6 months. Grafts were categorized as abnormal when a focal flow disturbance with a peak systolic velocity greater than 150 cm/s was identified within 3 months of graft implantation. Results: Of 341 vein grafts in 296 patients who met inclusion criteria, 89 grafts (26%) required revision for intrinsic stenosis; the mean follow-up period was 35 months (range, 6 months to 10 years). Early flow disturbances were detected in 84 (25%) grafts. Grafts with early flow disturbances were more likely to ultimately require revision (43% vs 21%; P = .0001) and required initial revision earlier (8 months vs 16 months; P = .019). Eighty-two percent of initial graft revisions occurred in the first 2 postoperative years; 69% occurred in the first year. However, an annual 2% to 4% incidence of late-appearing graft stenosis persisted during long-term follow-up. An additional 24 patients (7% of grafts) required an inflow or outflow reconstruction. Conclusion: Grafts with early postoperative flow disturbances detected by means of duplex scanning have nearly three times the incidence of graft-threatening stenosis and an earlier requirement for revision, when compared with normal grafts. This suggests that the biology and etiology of these lesions may differ. These data support not only aggressive efforts to detect early graft lesions to stratify grafts at highest risk, but also continued lifelong graft surveillance to detect late-appearing lesions, inflow and outflow disease progression, and maximize graft patency. (J Vasc Surg 1999;30:8-15.