Impaired contractility of left-over vein grafts used for CABG and the possible trauma caused by air exposure.
OBJECTIVE
The patency of vein grafts limits the long-term results after bypass surgery. Vein graft trauma may contribute to the clinical results.


METHODS
Left-over pieces of vein after routine coronary bypass surgery were compared with references of the same vein that were stored with maximum care. Blood perfusion (20 h, 37 degrees C) was also tested to evaluate possible recovery. Vessel rings were measured by isometric tone recordings.


RESULTS
Left-over veins showed a contractile dysfunction compared to reference (p < 0.01-0.001, n = 13), and that did not recover after blood perfusion. Four trauma models were tested, using saphenous vein graft (SVG)-references (n = 5). Chemical exposures (0-90 min) to NaCl-papaverin or cardioplegic medium affected the baseline (p < 0.05-0.01). With mechanical distension, up to 450 mmHg leak testing, an increased norepinephrine (NE) reactivity appeared. Air contact, 20 min, reduced the NE reactivity to half maximum (p < 0.05). Longer exposures (40-60 min) completely abolished the contractility.


CONCLUSIONS
The saphenous vein smooth muscle function appeared permanently traumatized following routine harvesting and handling. Air exposure gave dramatic deterioration and could in theory contribute to hamper the long-term results after bypass surgery.
Engström
K G
KG
Department of Surgery and Perioperative Science, Caidiothoracic Division, Umeå University Hospital, Sweden. Gunnar.Engstrom.us@vll.se
Szentkiralyi
I
I
D000368:Aged; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology*; D011184:Postoperative Period; D012501:Saphenous Vein / Q000503:physiopathology / Q000637:transplantation*; D020858:Tissue and Organ Harvesting / Q000009:adverse effects*; D014654:Vascular Patency; D014666:Vasomotor System / Q000503:physiopathology*