Impact of age on ultrastructural changes in internal thoracic artery in patients undergoing coronary artery bypass grafting

Öz

Aim: Age is a known risk factor for cardiovascular disease and plays a role in the atherosclerotic process. The purpose of this study was to look at the impact of aging and associated risk factors on the ultrastructure of internal thoracic arteries in patients undergoing coronary artery bypass grafting. Material and Methods: We enrolled 27 patients undergoing elective coronary artery bypass grafting at our institute between August-October 2018. Age groups were classified into three: 50-59, 60-69, and 70-79 years. A 2-mm distal portion of the vessel was excised when the ITA was surgically harvested. Transmission electron microscopy was used to investigate the ultrastructural changes. Cell structure, tissue edema, and endothelial mitochondria were all assessed and rated by using semiquantitative analysis. Results: The ultrastructure of the vessel wall exhibited no significant changes in Group-I. Endothelial wall irregularity with endothelial cells of varying thickness was seen in Group-II. Group-III showed subendothelial edema and localized endothelial wall discontinuity. These changes were particularly severe in the elderly and patients with comorbidities. The greatest permanent cell alterations, such as massive vacuoles and organelle loss, were identified in two patients with kidney failure and hypertension. The average scores assessing the severity of changes in endotohelial cell structure (P  .001), tissue edema (P  .001), and mitochondria (P  .001) were significantly different between groups showing more severe changes with aging. Conclusions: In elderly patients with comorbidities, the ITA endothelium may exhibit severe ultrastructural alterations, with the most permanent abnormalities reported in those with hypertension and kidney failure. However, The ITA remains the gold standard in CABG with its native resistance to atherosclerosis.

Anahtar Kelimeler

• Internal thoracic artery
• transmission electron microscopy
• coronary artery disease
• aging

Koroner arter baypas greftleme yapılan hastalarda yaşın internal torasik arterdeki ultrastrüktürel değişiklikler üzerine etkisi

Öz

Amaç: Yaş, kardiyovasküler hastalık için bilinen bir risk faktörüdür ve aterosklerotik süreçte rol oynar. Bu çalışmanın amacı, koroner arter baypas greftlemesi yapılan hastalarda yaşlanmanın ve ilişkili risk faktörlerinin internal torasik arterlerin altyapısı üzerindeki etkisini incelemektir. Gereç ve Yöntemler: Ağustos-Ekim 2018 tarihleri arasında birimimizde elektif koroner arter bypass ameliyatı geçiren 27 hasta çalışmaya dahil edildi. Yaş aralıkları 50-59, 60-69 ve 70-79 olmak üzere üç gruba ayrıldı. ITA cerrahi olarak çıkarıldığında damarın 2 mm'lik distal kısmı eksize edildi. Ultrastrüktürel değişiklikleri araştırmak için transmisyon elektron mikroskobu kullanıldı. Hücre yapısı, doku ödemi ve endotelyal mitokondri yarı kantitatif analiz kullanılarak değerlendirildi ve derecelendirildi. Bulgular: Grup-I'de damar duvarında ultrastrüktürel anlamlı bir değişiklik görülmedi. Grup-II'de değişen kalınlıklarda endotel hücreleri içeren endotel duvar düzensizliği görüldü. Grup-III'de subendotelyal ödem ve lokalize endotel duvar süreksizliği görüldü. Bu değişiklikler özellikle yaşlılarda ve eşlik eden hastalıkları olan hastalarda şiddetliydi. Büyük vakuoller ve organel kaybı gibi en büyük kalıcı hücre değişiklikleri, böbrek yetmezliği ve hipertansiyonu olan iki hastada tespit edildi. Endotelyal hücre yapısındaki (P = 0,001), doku ödemi (P = 0,001) ve mitokondrideki (P = 0,001) değişikliklerin ciddiyetini değerlendiren ortalama puanlar, yaşlanmayla birlikte daha ciddi değişiklikler gösteren gruplar arasında anlamlı derecede farklıydı. Sonuç: Eşlik eden hastalıkları olan yaşlı hastalarda, ITA endoteli ciddi yapısal değişiklikler sergileyebilir; en kalıcı anormallikler hipertansiyon ve böbrek yetmezliği olanlarda rapor edilmiştir. Ancak ITA, ateroskleroza karşı doğal direnci nedeniyle KABG'de altın standart olmaya devam etmektedir.

Anahtar Kelimeler

• İnternal torasik arter
• transmisyon electron mikroskobu
• koroner arter hastalığı
• yaşlanma

Kaynakça

1. Gogulamudi VR, Cai J, Lesniewski LA. Reversing age-associated arterial dysfunction: Insight from preclinical models. J Appl Physiol (1985) 2018; 125: 1860-70.
2. Dhingra R, Vasan, RS. Age as a risk factor. Med Clin North Am 2012; 96: 87-91.
3. Bakuy V, Unal O, Gursoy M, Kunt A, Ozisik K, et al. Electron microscopic evaluation of internal thoracic artery endothelial morphology in diabetic coronary bypass patients. Ann Thorac Surg 2014; 97: 851-57.
4. Barthelmes J, Nägele MP, Ludovici V, Ruschitzka F, Sudano I, et al. Endothelial dysfunction in cardiovascular disease and Flammer syndrome-similarities and differences. EPMA J 2017; 8: 99-109.
5. Rodgers JL, Jones J, Bolleddu SI, Vanthenapalli S, Rodgers LE, et al. Cardiovascular risks associated with gender and aging. J Cardiovasc Dev Dis 2019; 6: 19.
6. Sajja LR. Strategies to reduce deep sternal wound infection after bilateral internal mammary artery grafting. International Journal of Surgery 2015; 16: 171-78.
7. Fonseca DA, Antunes PE, Cotrim MD. Ultrastructural and histomorphologic properties of the internal thoracic artery. Coron Artery Dis 2017; 28: 518-27.
8. Deo SV, Altarabsheh SE, Shah IK, Cho YH, McGraw M, et al. Are two really always better than one? Results, concerns and controversies in the use of bilateral internal thoracic arteries for coronary artery bypass grafting in the elderly: A systematic review and meta-analysis. Int J Surg 2015; 16: 163-70.

9. Sattartabar B, Ajam A, Pashang M, Jalali A, Sadeghian S, et al. Sex and age difference in risk factor distribution, trend, and long-term outcome of patients undergoing isolated coronary artery bypass graft surgery. BMC Cardiovasc Disord 2021; 21(1): 460.
10. Alpat S, Yilmaz M, Onder S, Sargon MF, Guvener M, et al. Histologic alterations in tetralogy of Fallot. J Card Surg 2017; 32(1): 38-44.
11. Emir M, Gol MK, Ozisik K, Bakuy V, Sargon MF, et al. Harvesting techniques affect the integrity of the radial artery: an electron microscopic evaluation. Ann Thorac Surg 2004; 78: 1319-25.
12. Fonseca DA, Antunes PE, Antunes MJ, Cotrim MD. Histomorphometric analysis of the human internal thoracic artery and relationship with cardiovascular risk factors. PLoS One 2019; 14: e0211421.
13. Otsuka F, Yahagi K, Sakakura K, Virmani R. Why is the mammary artery so special and what protects it from atherosclerosis? Ann Cardiothorac Surg 2013; 2: 519-26.
14. Harskamp RE, Alexander JH, Ferguson TB, Hager R, Mack MJ, et al. Frequency and predictors of internal mammary artery graft failure and subsequent clinical outcomes. Circulation 2016; 133: 131-38.
15. Kinoshita T, Asai T, Suzuki T, Van Phung D. Histomorphology of right versus left internal thoracic artery and risk factors for intimal hyperplasia. Eur J Cardiothorac Surg 2013; 45: 726-31.
16. Ruengsakulrach P, Sinclair R, Komeda M, Raman J, Gordon I, et al. Comparative histopathology of radial artery versus internal thoracic artery and risk factors for development of intimal hyperplasia and atherosclerosis. Circulation 1999; 100(Supplement 2): 139-44.
17. Borović ML, Borović S, Marinkovic-Eric J, Perić M, Vuković P, et al. A comprehensive morphometric analysis of the internal thoracic artery with emphasis on age, gender and left-to-right specific differences. Histol Histopathol 2013; 28: 1299-1314.
18. Arciniegas E, Fermín E, Tortoledo F, Va ́squez JR, Bello A. Characterization of the atherosclerotic plaque in the internal mammary artery. Cathet Cardiovasc Diagn 1998; 43: 413-20.
19. Perrotta I, Sciangula A, Concistre G, Mazzulla S, Aquila S, Agnino A. Internal mammary artery atherosclerosis: an ultrastructural study of two cases. Ultrastruct Pathol 2014; 38: 199-203.
20. Tyrrell DJ, Goldstein DR. Ageing and atherosclerosis: vascular intrinsic and extrinsic factors and potential role of IL-6. Nat Rev Cardiol 2020; 18: 58–68.