The radial artery for coronary artery bypass grafting

Coronary artery bypass grafting (CABG) is the standard surgical procedure for the treatment of advanced coronary artery disease. CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts used for myocardial revascularisation, compared with internal mammary artery grafts. Recently, the use of radial artery for CABG has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent reports of encouraging mid-term and long-term patency rates of the radial artery, supports its continued use as a bypass conduit. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.Hirurška revaskularizacija miokarda je standardna procedura u tretmanu uznapredovale koronarne bolesti. Dokazano je da koronarna hirurgija uklanja simptome i produžava život određenih kategorija koronarnih bolesnika. Dugotrajni rezultati hirurške revaskularizacije miokarda u velikoj meri ovise o promenama koje se vremenom javljaju na upotrebljenom graftu. Studije dugoročnog praćenja operisanih bolesnika potvrdile su izuzetan kvalitet i prednost grafta unutarnje torakalne arterije u odnosu na venski graft. U skorije vreme obnovljeno je interesovanje za graft radijalne arterije, sa uverenjem da će njegova primena omogućiti bolje dugoročne rezultate. U poslednje vreme prikazani su radovi koji potvrđuju izuzetnu kratkoročnu i dugoročnu prohodnost grafta radijalne arterije i govore u prilog intenzivnije primene toga grafta u hirurškoj revaskularizaciji miokarda. Na prikaz je pregled sadanjih saznanja o radijalnoj arteriji kao graftu u kardiohirurgiji, sa posebnim osvrtom na kliničke rezultate

Endotel-zavisna relaksacija unutrašnje torakalne arterije prouzrokovana rezveratrolom

Resveratrol, a polyphenol present in wine, has been thought to be responsible for cardiovascular benefits associated with moderate wine consumption. It is also present in the plant Polygonum Cuspidatum. The mechanism of cardiovascular benefits probably includes vasorelaxation, antioxidant and anti-platelet effects of resveratrol. The mechanisms by which resveratrol causes vasodilatation are uncertain. The aim of this study was to investigate the mechanism(s) of resveratrol induced vasorelaxation in human internal mammary artery (HIMA) with endothelium. HIMA rings were precontracted by phenylephrine. Resveratrol induced relaxation of the HIMA rings with endothelium. LNAME, an inhibitor of NO synthase, and methylene blue, an inhibitor of guanylate cyclase, abolished relaxation of HIMA induced by resveratrol. Highly selective blocker of ATP-sensitive K channels, glibenclamide as well as a nonselective blocker of big Ca-sensitive K+ channels, charybdotoxin did not block resveratrol-induced relaxation of HIMA. 4-Aminopyridine and margatoxin, blockers of voltage-gated K+ (KV) channels, abolished endothelium-dependent relaxation of HIMA, induced by resveratrol. In conclusion, we have shown that resveratrol induces relaxation of HIMA with endothelium. It seems that NO and smooth muscle KV channels are included in this relaxation.Smatra se da rezveratrol kao jedna polifenolna komponenta prisutna u značajnim količinama u crnom vinu, smanjuje rizik od razvoja ateroskleroze i koronarne bolesti. U mehanizam kardioprotektivnog delovanja verovatno su uključ eni antioksidativno, antitrombocitno i vazodilatatorno delovanje rezveratrola. Mehanizam vazodilatacije još uvek nije poznat, pa je cilj ovog rada bio da se ispitaju efekti i mehanizam vazorelaksantnog delovanja rezveratrola na humanoj unutraš njoj torakalnoj arteriji sa endotelom. Unutrašnja torakalna arterija je prekontrahovana fenilefrinom. Rezveratrol je koncentracijski-zavisno relaksirao unutrašnju torakalnu arteriju čoveka. L-NAME, inhibitor NO sintaze, i metilensko plavo, inhibitor solubilne gvanilat ciklaze, su antagonizovali relaksaciju unutrašnje torakalne arterije sa intaktnim endotelom, prouzrokovanu rezveratrolom. Visoko selektivni blokator ATP-senzitivnih K+ kanala, glibenklamid, kao i neselektivni blokator velikih Ca-senzitivnih K+ kanala, karibdotoksin nisu antagonizovali rezveratrolom indukovanu relaksaciju unutrašnje torakalne arterije. 4-Aminopiridin i margatoksin, blokatori voltažnih K+ kanala su antagonizovali relaksaciju prouzrokovanu rezveratrolom. Na osnovu ovih činjenica se može zaključiti da je endotel-zavisna relaksacija unutrašnje torakalne arterije čoveka, prouzrokovana rezveratrolom, verovatno posredovana NO. Izgleda, da su 4-aminopiriin- i margatoksin-senzitivni K-kanali smešteni u membrani vaskularnih glatko-mišićnih ćelija humane unutrašnje torakalne arterije, uključeni u mehanizam endotel-zavisne relaksacije prouzrokovane rezveratrolom