Conflicts, Compromises, and Common Sense

In this issue, Gansera et al demonstrated excellent early outcome results with bilateral thoracic artery (BITA) revascularization in a large cohort of almost 6,500 patients.[1] Aside from a moderately higher re-exploration rate, they did not find relevant differences between patients who received BITA in contrast to those receiving only one thoracic artery. Interestingly, a subgroup of patients receiving pedicled BITA grafts demonstrated a higher rate of deep sternal wound infections than those with only one ITA, while patients who received a skeletonized BITA did not.

Coronary artery bypass graft (CABG) surgery is increasingly challenged by the percutaneous coronary angioplasty successes of our cardiologist partners and numbers have been continuously falling in Germany from 51,000 to 40,000 procedures since 2006 while PTCA is enjoying steady growth.[2] [3] Fortunately, the SYNTAX trial provided evidence that patients still do profit from surgical revascularization regarding long-term patency and absence of reintervention.[4] Surgical revascularization still offers a much longer patency rate than any other current interventional method. Arterial grafts can even exceed 15 years patency in more than 90%, while the often chided vein graft is “good” for 10 years in 60 to 70% of our patients.[5] This advantage, however, is also an obligation for us considering that our patients do suffer from the surgical procedure itself. Fortunately, complications in isolated bypass surgery are rare but they exist and the patient who happens to endure them may think twice as to whether having surgery was a particularly wise idea instead of having a “quick” PTCA. (Remember the famous quote by Dr. Gruentzig: “I can have Dr. Guyton crack your chest or I can fix that little blockage with a catheter.”)

Statistics provide us with up to 7% sternal instabilities in isolated CABG surgery, particularly in diabetic patients undergoing BITA grafting.[6] When they occur, they are a real burden for the patient prolonging hospitalization time and requiring repeated surgery and vacuum therapy. They may result in the need for plastic surgery and can even be fatal. Furthermore, one should keep in mind that after extensive and repeated sternal surgery including plastic measures, this “door” to the heart is as a matter of fact closed, thereby markedly reducing the options for further therapy on the cardiac vessels and valves. Although clearly being the best available graft, the use of the internal thoracic artery increases sternal healing problems, bilateral use more than single use, and in diabetic patients more than in the nondiabetics. In view of the dire circumstance of deep sternal healing problems, one should always weigh risks and benefits of the use of ITA or BITA grafting. Only the superior long-term patency rate of the ITA graft justifies the early risks. A diabetic patient may thus very well profit from a mixed arterial and venous revascularization and may even profit from veins only or the use of the radial artery instead of the ITA when having surgery at an advanced age.[7]

Gansera et al demonstrated the relative perioperative safety of bilateral ITA use. They also show us the benefits of a meticulous, tissue conserving dissection technique. They did, however, not demonstrate the long-term patency advantage—which is the one and only reason for using the ITA.

• References

• 1 Gansera B, Deutsch O, Gansera L, Wunderlich M, Eichinger W. Does bilateral ITA-grafting increase perioperative complications? Outcome of 6476 patients with bilateral versus 5020 patients with single ITA-bypass. Thorac Cardiovasc Surg 2015; [this issue]
• 2 Beckmann A, Funkat AK, Lewandowski J , et al. Cardiac surgery in Germany during 2014: A Report on Behalf of the German Society for Thoracic and Cardiovascular Surgery. Thorac Cardiovasc Surg 2015; 63 (4) 258-269
• 3 Deutscher Herzbericht. Deutsche Herzstiftung e.V. (Hrsg.). Frankfurt/M; 2014. ISBN: 978-3-9811926-6-7
• 4 Iqbal J, Zhang YJ, Holmes DR , et al. Optimal medical therapy improves clinical outcomes in patients undergoing revascularization with percutaneous coronary intervention or coronary artery bypass grafting: insights from the Synergy Between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery (SYNTAX) trial at the 5-year follow-up. Circulation 2015; 131 (14) 1269-1277
• 5 Kieser TM, Head SJ, Kappetein AP. Arterial grafting and complete revascularization: challenge or compromise?. Curr Opin Cardiol 2013; 28 (6) 646-653
• 6 Ogawa S, Okawa Y, Sawada K , et al. Continuous postoperative insulin infusion reduces deep sternal wound infection in patients with diabetes undergoing coronary artery bypass grafting using bilateral internal mammary artery grafts: a propensity-matched analysis. Eur J Cardiothorac Surg 2015; pii: :ezv106
• 7 Hoffman DM, Dimitrova KR, Lucido DJ , et al. Optimal conduit for diabetic patients: propensity analysis of radial and right internal thoracic arteries. Ann Thorac Surg 2014; 98 (1) 30-36 , discussion 36–37