Author + information
- Robert H. Jones, MD⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Robert H. Jones, Duke University Medical Center/Duke Clinical Research Institute, Surgery, P. O. Box 2986, DUMC, Durham, North Carolina 27710
Internal thoracic artery (ITA) use played a prominent role in the development of surgical treatments for coronary artery disease (1). In 1935, Claude S. Beck sutured a pedicle containing internal mammary vessels onto the anterior heart wall of a 48-year-old gardener who 7 months later returned to work without future pain (2). In 1967, Kolessov, a Russian cardiac surgeon, reported the first successful use of the left ITA in 6 patients without preoperative coronary angiography. A left thoracotomy permitted palpation to identify a non-calcific zone of the left anterior descending (LAD) coronary artery in each patient to which an end-to-side anastomosis of the ITA was made. Five of the 6 patients survived (3).
News of these successful first direct ITA to coronary artery bypass operations prompted Favaloro to use saphenous vein to construct an ascending aorta to right coronary artery anastomosis in 1967 (4). Dr. George Green (5) described his careful experimental work with ITA to LAD bypass grafts in dogs and reported 2 patients operated on February 29 and March 12, 1968, who received an ITA to LAD operation without need for clamping the aorta. Dr. Green emphasized the need for optical magnification to precisely construct the ITA to coronary anastomosis.
Given the choice between an operation that could be done using venous conduit with hemodynamic support of cardiopulmonary bypass for an arrested heart or use of a small delicate ITA coronary bypass on a beating heart, it is not surprising that an ITA to LAD was not the coronary bypass procedure of choice of the CASS (Coronary Artery Surgical Study) trial investigators. Although use of artery or vein for bypass conduit was not specified by the CASS protocol, only 16% of patients randomized to the surgical arm of the CASS trial between August 1975 and May 1979 received an ITA bypass to the LAD coronary artery (6). Leading cardiac surgeons of that era were not convinced ITA use added value to coronary artery bypass grafting (CABG).
The minority of cardiac surgeons who continued to champion ITA use were those who had observed gradual development of collateral blood flow using the Vineberg modification of the Beck operation that tunneled the ITA pedicle through the anterior myocardium (7). The addition of a direct anastomosis between the end of a tunneled ITA and the side of the LAD was a logical extension of an operation that otherwise required time to gradually maximize coronary blood flow by development of systemic to coronary collaterals. The Cleveland Clinic investigators became champions of routine ITA to LAD bypass, and in 1985 Lytle et al. (8) produced data convincing the broad cardiac surgical community that the long-term patency of the ITA bypass was superior to that of saphenous vein. Moreover, the high ITA graft patency conveyed a substantial survival advantage over saphenous vein grafts. Routine use of ITA to LAD arterial bypass graft is now an accepted quality indicator for CABG.
The paper by Sabik et al. (9) in this issue of the Journal continues the long list of contributions the Cleveland Clinic surgeons and scientists have made in confirming the added value of routine use of ITA bypass grafting to patients with coronary artery disease. A well-designed matched propensity analysis effectively neutralizes differences in baseline clinical characteristics that otherwise might confound extending observations from the Cleveland Clinic experience to care decisions made for patients at other centers. In light of prior demonstrated increase in survival associated with routine ITA use, readers may wonder why so many matched pairs of patients with similar baseline risk had not received an ITA conduit at their first operation. Perhaps major categories of information that might influence the preoperative CABG plan, such as LAD size, were not consistently available in the medical record.
As a medical student at Johns Hopkins in 1964, I was privileged to read the first operative notes of William Stewart Halsted, the father of modern American surgery. His 1-page notes, often illustrated with sketches of pathologic specimens and operative anatomy, detailed his preoperative diagnosis, treatment plan, and the reason for any change from his pre-procedure plan. His operative notes contained sufficient detail to both validate the appropriateness of any subsequent customization of pre-intraoperative decisions and also to permit any surgical colleague to adopt specific steps of a Halsted operative plan into their own practice.
If the medical record information content tradition of Halsted had been continued by the cardiac surgery profession into the era of conducting millions of CABG and redo CABG procedures notes worldwide, the list of available responses for structured reporting of reasons for use of saphenous vein and not the ITA at time of redo CABG might include: 1) massive bleeding associated with median sternotomy; 2) peristernal wire from prior CABG occluding left internal thoracic artery; 3) aortic dissection at inflow cannulation site; 4) intramyocardial LAD; 5) ventricular fibrillation before institution of ITA takedown; 6) damage to ITA during takedown from chest wall; 7) patent prior saphenous vein graft to LAD; 8) left internal thoracic artery needed for bypass to more dominant coronary artery; and 9) other reason, specify.
Once begun, such lists could be refined to evaluate the appropriateness of ITA use decisions based on outcome results of intraoperative decisions and actions. The current manuscript provides convincing evidence that use of an ITA is reasonable in patient populations with a broad spectrum of baseline risk and indications for a redo CABG. However, most of the intraoperative events listed that may have led to nonuse of an ITA are more likely to have influenced a death outcome more than any difference in baseline characteristics.
Lack of more detail about why approximately one-third of Cleveland Clinic patients coming to reoperation with an intact ITA did not have an ITA conduit used during a redo CABG operation represents a major information deficit that cannot be replaced by modeling of preoperative data. Perhaps some patients experienced 1 or more of the intraoperative complications listed previously that raised the risk of ITA use above its expected benefit. Perhaps certain nonemergency scenarios actually justify use of saphenous vein grafting during elective redo CABG. Only by prospectively acquiring medical records using structured information describing common reasons to deviate from the preoperatively planned care scenarios will clinical databases grow to include actual data that most determine the relationship of care decisions and processes to outcomes of care delivery. Perhaps future operative note templates will provide structured data of carefully defined reasons for deviation from routine use of ITA in sufficient detail to establish which intraoperative decisions optimize outcomes of cardiac surgical care.
As healthcare providers migrate to use of a uniform lexicon for describing healthcare delivery, our greatest need is to acquire future clinical data in standardized structured formats that facilitate provider reimbursement based on the value the care decisions and processes bring to each individual patient. Careful documentation of the reasons for and outcomes of defined processes of care is itself care given. Good care delivery is never complete until it is documented simultaneously with creation of care information that accurately documents care given with sufficient structure to database for quality improvement of future care and as a coherent medical record for each patient encounter.
Dr. Jones has reported that he has no relationships relevant to the contents of this paper to disclose.
↵⁎ Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
- American College of Cardiology Foundation
- Alderman E.L.,
- Bourassa M.G.,
- Cohen L.S.,
- et al.
- Sabik J.F. III.,
- Raza S.,
- Blackstone E.H.,
- Houghtaling P.L.,
- Lytle B.W.