Changes in vein interstitium following distension for aortocoronary bypass
Kennedy, J.H.; Lever, M.J.; Addis, B.J.; Paneth, M.
Journal of Cardiovascular Surgery 30(6): 992-995
1989
ISSN/ISBN: 0021-9509 PMID: 2600135 Document Number: 333417
Some patients who undergo aortocoronary bypass develop lesions in the graft and recurrence of symptoms. Hydraulic distension is used for preparation of veins. We have studied properties of vein interstitium, before and after peroperative distension, in 30 consecutive unselected patients. Segments of vein were studied for water content, swelling behaviour, tracer distribution, and uronic acid content. Initial water content was the same in distended and undistended vein; initial uronic acid content was slightly lower in distended veins, 8.7 (SD = 2.3) .mu.g/m, n = 4 vs 10.5 (SD = 5.1) .mu.g/mg dry weight, n = 6, not significant. The initial ratio, uronate/hydroxyproline was less in distended veins, 0.14 (SD = 0.05) n = 4 vs 0.19 (SD = 0.07), n = 6 in controls, not significant. Distended veins swelled less during incubation in saline. Average weight gain/initial weight was 0.65 (SD = 0.45), n = 27, and 1.1 (SD = 0.66), n = 25 in controls (p < 0.01); change in water content/dry weight was 1.2 (SD = 1.1), n = 22, and 1.7 (SD = 1), n = 23 (p < 0.02), in controls. Distended veins desorbed less uronic acid into the bath; 0.40 (SD = 0.2) .mu.g/mg wet tissue, n = 26 and 0.59 (SD = 0.3), n = 25 in controls (p < 0.01). The pattern of uptake of two tracers 125I Serum albumin and 51Cr EDTA, was similar in both groups. These findings suggest alteration of the interstitial matrix of veins during distension. Histologic examination of gluteraldehyde-fixed tissue by light and electron microscopy revealed mural thinning and endothelial cell damage in distended veins. Of 29 patients who survived surgery, follow-up information is available in 25 (86%); of these, 10 (40%) have symptoms of ischemic heart disease an average of 13.2 (SD = 5.7) months postoperatively. Similar water contents, swelling behaviour, and uronic acid elution were seen in distended and undistended vein in this subgroup.