To Örebro University

Coronary artery disease is one of the biggest health issues worldwide; it is estimated that cardiovascular diseases cause around 45% of all deaths in Sweden and in the Western world. In a large proportion of cases, the treatment involves a coronary artery bypass grafting (CABG) operation. One of the most commonly-used grafts is the saphenous vein from the leg, but this has the disadvantage of a predisposition to early obstruction, with inter-national literature showing occlusion rates of 15% in the first year and 40% after 10 years.

At the Department of Cardiothoracic and Vascular Surgery at Örebro University Hospital, a method was developed for harvesting the saphenous vein together with the surrounding fat tissue. This technique, called the no-touch technique (NT), has the advantage of reducing damage to the vein during the harvesting, and carries a substantially reduced risk of future occlusion (5% after 18 months and 10% after 8.5 years).

The aim of this dissertation was to evaluate the results of the no-touch technique in comparison to the conventional (C) technique for venous graft harvesting, focusing on patients who received a percutaneous coronary intervention (PCI) in their NT or C ve-nous graft. This study is the first to examine the long-term results of the no-touch tech-nique after stenting of the venous graft.

Paper I was a systematic review and meta-analysis of the international literature re-garding PCI in vein grafts. It included 36 articles covering nearly 15 000 patients in total. Paper II was a retrospective clinical cohort study including 346 patients (67 NT, 279 C) who underwent PCI in a stenosed vein graft, with a mean follow-up time of 6.4 ± 3.7 years. The primary endpoint was in-stent restenosis, and secondary endpoints were major adverse cardiovascular events (MACE) and 1-year re-hospitalization rate. Paper III was a retrospective cohort study analysing all individuals who required clinically-driven coro-nary angiography after CABG. It included 1520 patients (618 NT, 825 C, 77 arterial graft) with a mean follow-up time of 8.4 ± 5.5 years. The patency rate of the vein grafts was compared between the two techniques as primary outcome. Paper IV was a retro-spective cohort study in which individuals who received a PCI in their vein graft (NT or C) were asked to estimate their quality of life using the RAND-36 survey, which consists of eight domains. A total of 165 patients answered the questionnaire (48 NT, 117 C).

The results showed that in comparison to C grafts, NT vein grafts displayed a statisti-cally significantly higher patency rate and statistically significantly lower rates of long-term in-stent restenoses and MACE. Among patients who later required a PCI in the vein graft, those who received a primary NT graft estimated their quality of life as better than those who received a primary C graft. The NT vein graft results in this dissertation were significantly better than results in the international literature, suggesting that use of this technique will have both clinical and economic benefits at both the individual and the community level. Clinical benefits consist of fewer recurrences of angina and myocardial infarction, less risk of needing a new interventional procedure, and improved quality of life. These in turn will create health-economic benefits for the healthcare system.