Vein compliance: A preoperative indicator of vein morphology and of veins at risk of vascular graft stenosis

Abstract

Compliance measurements of 53 long saphenous veins before femorodistal bypass have been performed using a duplex scanner with venous occlusion for distension. These have been compared with the histological features of the veins. There was significantly more moderate or severe focal hyperplasia and circular muscle hypertrophy in distal long saphenous vein than in its proximal counterpart (P < 0.01 and P < 0.05 respectively). The mean (95 per cent confidence interval) compliance of distal vein with moderate or severe hyperplasia was 0.16 (0.13-0.19) compared with 0.29 (0.22-0.36) for that with no, minimal or mild hyperplasia (P = 0.001). The mean compliance of distal vein with moderate or severe muscle hypertrophy was 0.19 (0.17-0.21) and of vein with no, minimal or mild hypertrophy 0.25 (0.21-0.29) (P = 0.14). The mean lowest compliance in seven patients who developed stenosis was 0.10 (0.07-0.13) compared with 0.21 (0.16-0.26) in the rest (P < 0.001). Preoperative measurement of vein compliance can be used to identify vein with marked pre-existing intimal hyperplasia and as a predictor of future graft stenosis.

Ultrastructural Analogies between Intimal Alterations in Veins from Diabetic Patients and Animals with STZ-Induced Diabetes

“…On the basis of these findings we speculate in accordance with Davies et al 20 and Marin et al 10 that diabetes affects venous physiology and may contribute to graft failure. Intimal hyperplasia, 10,14,15 preexisting disease, 18,19 and thick or calcified walls 10 are among the numer- ous factors that increase the risk of intragraft lesions. Our results also validate the usefulness of experimentally induced diabetes in animals as a model for further study to clarify the fate of the diabetic venous wall when used as a graft in patients with peripheral vascular disease.…”

“…16,17 It has also been suggested that preexisting disease in the saphenous vein may contribute to graft stenosis and some bypass graft failures. 18,19 Greater saphenous vein with thick and calcified walls or hypercellular intima at the time of grafting are at increased risk for graft failure due to stenotic lesions. 10 In a recent report, Davies et al 20 examined the outcome of experimental bypass using jugular vein grafts in alloxan-induced diabetic rabbits and found that the endothelium of the vein grafts from diabetic animals showed marked ultrastructural changes compared to that of the controls.…”

Tissue engineering of vascular conduits

“…Compliance mismatch may cause excessive stretching of SMCs, resulting in their proliferation. Further evidence for this is the finding in humans that preoperative ultrasonographic measurement of human saphenous vein compliance is a predictor of femorodistal bypass stenosis 74 . The only limitation of this study was that it did not measure host artery compliance to assess the degree of mismatch between vein graft and artery.…”

Venous compliance and clinical implications

“…This may explain the finding of a linear pressure/diameter relationship in the filled veins ( Figure 6). 13,17 The shape of the compliance curve is determined, therefore, by the physical characteristics of the material involved [18][19][20] in the system, as well as by the volumetric extension of the system and its geometric configuration. The actual value of compliance is, instead, correlated, as we mentioned, with the filling volume of the system.…”