Statistical or clinical improvement? Determining the minimally important difference for the vascular quality of life questionnaire in patients with critical limb ischemia.

OBJECTIVE: Interpreting whether changes in quality of life (Qol) in patients with peripheral arterial disease (PAD) are not only statistically significant but also clinically relevant, may be difficult. This study introduces the concept of the minimally important difference (MID) to vascular surgeons using Qol outcomes of patients treated for chronic critical limb ischemia (CLI). METHODS: The Vascular Quality of Life (VascuQol) questionnaire was recorded at baseline before treatment and after 6 months follow-up in consecutive patients with CLI treated between May 2007 and May 2010. Statistical significance of change in VascuQol score was tested with the Wilcoxon Signed Rank test. The MID for the VascuQol score was determined using a clinical anchor-based method and a distribution-based method. RESULTS: A total of 127 patients with CLI completed the VascuQol after 6 months. The VascuQol sum scores improved from 3.0 (range 1.1-5.9) at baseline to 4.0 (range 1.2-6.7) at 6 months (p < .001). The MID on the VascuQol sumscore indicating a clinically important change determined with the anchor-based method was 0.36, and with the distribution-based method was 0.48. On an individual level, depending on the method of determining the MID, this resulted in 60% to 68% of the patients with an important benefit. CONCLUSIONS: Expression of changes in Qol by means of the MID provides better insight into clinically important changes than statistical significance.

Extra-anatomical reconstruction in the case of an inaccessible groin: the axillopopliteal bypass.

Axillopopliteal bypass is a relatively unknown and uncommon therapeutic option for patients with critical limb ischemia in the presence of an inaccessible groin due to infection or excessive scar formation. In our center, this procedure is performed several times a year. The results of all axillopopliteal bypass reconstructions over an 11-year period were analyzed. Thirty axillopopliteal bypass grafts were performed on 24 patients (16 men, mean age 67 years). In 23 limbs, the indication was persistent groin infection after previous vascular surgery and a threatened limb. In seven limbs, the possibility to anastomose in the groin was absent. There were eight patients (27%) with diabetes mellitus, hypertension was present in 43% (n = 13), and 90% (n = 27) were current or previous smokers. During 5 years of follow-up, 11 patients died, eight during the first year after operation. The primary patency after 1 year was 64% (n = 9). The secondary patency after 1 year was 77%. Seven amputations (23%) were needed: six for ischemia and one for persistent infection. Limb salvage after 1 year was 84%. A limitation of the study is the small number of patients, which was not enough for uni- and multivariate risk analyses with sufficient statistical power. The results of axillopopliteal bypass surgery in patients with critical limb ischemia and an inaccessible groin demonstrate a high mortality rate of 29% after 1 year. However, surviving patients may benefit from the operation in terms of limb salvage because the primary patency was 64% and the secondary patency 77% at 1-year follow-up. We conclude that extra-anatomical axillopopliteal bypass is a valuable therapeutic option for limb salvage in this specific patient population.