Effect of Internal Thoracic Artery Side Branches On Distal Flow

Abstract

Amaç: İnternal torasik arter (İTA) koroner bypass cerrahisinde rutin olarak kullanılan arteryel grefttir. Açık olan ITA yan dallarına olan akım nedeni ile çalma fenomeni tanımlanmış ve myokardiyal perfüzyon bozukluğunun nedeni olarak gösterilmiştir. Minimal invaziv koroner cerrahisinde kullanılan sınırlı İTA diseksiyonunun yan dalların açık kalmasına neden olması sonucu çalma fenomeni önem kazanmıştır. Literatürde ise açık kalan İTA yan dallarının koroner bypass sonrası myokardiyal iskeminin tek nedeni olduğunu gösteren kesin bulgu yoktur. Yöntem: İTA yan dallarının akım patternine olan etkisini ortaya koymak amacıyla, koroner bypass cerrahisi için başvuran 22 hasta randomize olarak çalışmaya alındı. İTA, birinci interkostal ve timik dalları korunarak, proksimalde subklavian artere, distalinde de bifurkasyona kadar pediküllü olarak serbestleştirildi. İTA'nın önce distal kısmından yan dallar klempli ve klempsiz, sonra 1/3 distal kısım kesilerek yan dallar klempli ve klempsiz akım ölçümleri yapıldı. Bulgular: İTA yan dallarının klempli ve klempsiz akım ölçümlerinde, distal (20.7±10.1 mL/dk - 20.3±11.1 mL/dk) veya proksimal (55.6±26.0 mL/dk - 55.1±29.0 mL/dk) akımlarında anlamlı fark bulunmamıştır (p>0.05). Ancak proksimal kısımda akım distale göre yan dallar klempli veya klempsiz ölçümlerde daha yüksek bulunmuştur (p<0.01). Sonuç: Bu çalışmada İTA yan dallarının distal akıma anlamlı etkisinin olmadığı gösterilmiştir. Açık kalan yan dallar anastamoz stenozu, yetersiz kalibrasyonda İTA ve yeterli distal yatak olmaması gibi nedenler olmadıkça myokardiyal iskemiye neden olmamaktadır. İTA akımlarının proksimale çıkıldıkça artması, İTA'in anastamoz sırasında mümkün olduğunca proksimalden kullanılması gerektiğini göstermiştir. Anahtar Kelimeler: İnternal torasik arter, Yan dallar

Keywords

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İnternal Torasik Arterin Yan Dallarnn Distal Akıma Etkisi

Öz

Objective: Internal thoracic artery (ITA) is routinely used as an arterial greft for coronary artery bypass grafting (CABG). Steal phenomenon is described as a culprit causing myocardial low perfusion due to ITA side branch patency. Steal phenomenon due to limited dissection of ITA side branches in minimally invasive CABG method resulting in patency of ITA side branches has gained popularity. There is no definite evidence in the literature regarding the side branches of the ITA as the only cause of myocardial ischemia in CABG. Material and Methods: In order to document the effects of ITA side branches on the flow pattern, 22 patients applying for CABG were randomly involved in the study. ITA was dissected with pedicle until the subclavian artery proximally and the bifurcation distally, protecting first intercostal and thymic side branches. ITA flow measurements were done from the distal part and after resecting the 1/3 distal part, clamping and unclamping the side branches for each part. Results: There was no significant difference in flow measurements for clamped and unclamped side branches in neither the distal (20.7±10.1 mL/min vs. 20.3±11.1 mL/min) nor the proximal (55.6±26.0 mL/min vs. 55.1±29.0 mL/min) parts of ITA (p>0.05). On the other hand, flow measurements were higher at the proximal part than the distal part regardless of the side branches being clamped or not (p<0.01). Conclusion: In this report we found that ITA side branches have no significant effect on distal flow. Therefore, patent side branches of ITA do not cause myocardial ischemia unless accompanying lesions such as stenosis of anastomosis, inadequate caliber of ITA and inadequate distal run off of the coronary vessels are present. Flow measurments were higher when ITA was resected more proximally, suggesting that ITA must be used as proximally as possible in anastomosis. Key Words: Internal thoracic artery, Side branches

Anahtar Kelimeler

• İnternal torasik arter, Yan dallar

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