Can the Left Internal Mammary Artery Be Used During Coronary Artery Bypass Graft Surgery in Patients Undergoing Bone Marrow Transplant? A First Case Report

1. Introduction

With the increased survival of patients following bone marrow transplant (BMT), new unprecedented issues arise that need to be addressed. Coronary artery occlusion is one of these problems (1, 2). Atherosclerosis exacerbates in patients after BMT (2) and these patients are anticipated to need coronary artery bypass graft (CABG) in the near future (3).

The challenging issue is that the best vascular patency, survival, and quality of life are observed in patients whose left internal mammary artery (LIMA) has been used for CABG (4, 5).

Harvesting the LIMA can, on the one hand, increase the risk of infection, malunion, or surgery complications, and on the other hand, if we do not use the LIMA, the lifespan of grants and their patency is usually up to about five years, after this time the patient will need another intervention. However, this time is about ten years or more with the use of the LIMA (4, 5).

The LIMA is used for CABG surgery with its 2 - 3 times longer lifespan compared to saphenous vein grafts, but its harvest from the sternum affects the sternum blood flow and the outcome of its use is still not identified in patients undergoing bone marrow transplant. This case report is the first report on this issue.

The question is whether we can use the LIMA in these people even though their bone marrow is involved and they have undergone BMT before.

A review of the literature showed no reports on any similar cases, and the present is the first case report on the use of the LIMA in cardiac surgery following BMT and the assessment of sternum-related complications over a six-month follow-up.

We hope that future efforts at collecting data on this subject can help provide a protocol for the treatment of these patients.

2. Case Presentation

A 60-year-old man with diffuse large B cell lymphoma who had undergone a bone marrow transplant a year before had then developed chest pain. Before the visit, no coronary artery examination had been performed on the patient and no information was available on the patient’s coronary artery status.

Examinations following chest pain included angiography, which indicated three-vessel disease (3VD), and the patient was therefore selected for CABG and was transferred to the operating room after some routine examinations.

Having found no reports or articles on the use of the LIMA in BMT patients, we decided to use the LIMA and saphenous vein for CABG in this patient.

When reducing thru the sternum from the middle, it turned into discovered to be quite firm with regular consistency, and the bone marrow was microscopically ordinary inside the sternotomy.

Bone wax was not used for bone marrow homeostasis due to the higher risk of sternum complications in this patient.

When harvesting the LIMA from the sternum environment, this artery had high adhesion in the middle and upper thirds and was only gradually harvested with patience. Overall, compared to other cases of harvesting the LIMA, harvesting time was 80% longer in this case and bleeding was 30% higher as well, but eventually, the LIMA was harvested with good quality and blood flow. CABG procedures were performed as was the routine, and cardiopulmonary bypass was established. A total of five coronary arteries were anastomosed. The LIMA was anastomosed to the left anterior descending artery (LAD) and the saphenous vein was anastomosed separately to obtuse marginatus1 (OM1), the diagonal artery, the posterior descending artery (PDA), and the posterior left ventricle (PLV).

CABG surgery was completed without any major problems. Steel wire size 7 was used to close the sternum bone at the end of the surgery. The wires were placed separately, such that three wires were placed in the manubrium and four in the sternum body.

The patient was discharged with drug tablets ASA 80, Pavix 75, rosevastatin 20, and metoral 50 mg. After discharge from the hospital, the patient recovered without any problems and no chest pain was reported in his 6-month follow-up. The patient’s sternum was quite firm and stable. There was no evidence of complications such as malunion or delayed union or infection of the sternum.

3. Discussion

There have been many advances in the diagnosis and treatment of neoplastic diseases and cancers in recent decades. With the improvements in patients’ life expectancy and the more effective neoplasm treatments developed, we have now entered a new era of having to deal with senile patients’ complications (1, 6).

One of the most common issues is coronary involvement and the resultant need for CABG. This involvement has been reported and its data have been summarized in patients undergoing chemotherapy or radiotherapy (1-3, 6), and the protocols are being changed and revised as the quality of anti-neoplastic drugs and radiotherapy improves (6). Nevertheless, there is still inadequate information on patients who undergo BMT and gradually develop cardiovascular problems similar to other groups with the increase in survival rates.

The patient presented in this study had diffuse large B cell lymphoma, which is one of the most common neoplasms of the lymphatic system (7) and BMT is part of its treatment (8). In patients undergoing BMT, some changes are observed in different organs that had previously been normal (9) or their previous disease gets altered or exacerbated (10) based on follow-ups over several years.

The reported patient also had lymphoma, which was treated with BMT a year before, but no previous examination had been performed before the onset of pain chest and we do not know if the patient’s coronary artery stenosis already existed and worsened or had developed over the preceding year. His CABG surgery was performed normally as in other patients (5), but the question was whether to use the LIMA, which is under the sternum and offers a patency that is 2 - 3 times higher than that of the veins. Since the LIMA is responsible for blood supply to part of the sternum, its removal increases complications related to sternum fusion, and patients who have undergone BMT might develop more of these bone-related complications.

Furthermore, the usefulness of the LIMA has been fully demonstrated as a graft in CABG surgeries and the patency of the LIMA graft is 2 - 3 times longer than that of venous grafts (4, 5).

The usefulness of using a LIMA is so great that even in cases where the LAD has been cut due to an accident, it is effective even a few months later and improves heart function (11).

No information was available on the benefits of using the LIMA during CABG in patients undergoing BMT. Therefore, considering the expected survival of more than ten years for this patient, we decided to harvest his LIMA from the sternum to use as a graft.

After the surgery, six months of follow-up showed no incidents or complications related to sternum nonunion, malunion, or infection.