Effect of internal mammary artery mobilization on sternal blood flow.

Use of the internal mammary artery as a conduit for coronary artery bypass has enhanced this procedure in terms of prolonged graft patency. An earlier warning that use of both arteries would devascularize the sternum was based on postmortem radiologic imaging. This was complemented by a subsequent animal study employing isotopic microspheres. In the present clinical study, laser Doppler flowmetry was adapted to identify changes in blood supply to the left half of the divided manubrium sternum during separation of the left internal mammary artery from its chest wall attachment. Our finding of continued blood flow after this event suggests that complete devascularization of the sternum does not take place. Quality of sternal bone and surrounding tissues and clinical indications should remain as factors influencing use of one or both internal mammary arteries.

Reoperation without medical records: avoidable?

Coronary bypass graft reoperations are performed at increased risk if prior operative records are unavailable. A durable record of the operation, carried by the patient, may offer the most rapid access to this information.

Simplified placement of retrograde cardioplegic catheter.

A method is described for rapid placement of a retrograde cardioplegia catheter at a precise location in the coronary sinus. Palpation of the posterior cardiac surface is not required, thus facilitating use of retrograde coronary sinus cardioplegia in cardiac reoperations.

Vascular evaluation for balloon pumping.

The effectiveness of intraaortic balloon counterpulsation is reduced frequently by arterial insufficiency following balloon insertion and occasionally by inability to pass the balloon centrally from a peripheral site. From a series of patients undergoing cardiac catheterization, a subgroup with increased likelihood of needing balloon counterpulsation can be selected. Patients so chosen have received one aortoiliac injection of contrast material at the time of cardiac catheterization. Impressive degrees of vessel irregularity and stenosis on an atherosclerotic basis and of tortuosity of normal lumen size have been noted. Such information, gathered at little additional risk or irradiation, is considered to be important in the subsequent choice of sides for transfemoral insertion and may rule out attempted passage of the balloon by this route, directing the surgeon to a deliberate, prompt, transabdominal or thoracic aortic insertion if necessary.

The surgeon as gatekeeper.

The author pays tribute to three deceased members of the North Pacific Surgical Association who directed his own career. The gatekeeper function of surgical specialists is discussed, and surgeons are urged to become more active in this role. Increased involvement in managed care planning and cost control, particularly in smaller communities, is encouraged.

Repair of tracheal intubation injuries.

Occult tracheal injuries occurring at the time of intubation frequently leave a posterior defect and lead to the rapid development of mediastinal infection. Some protection is provided by the endotracheal tube, which may further contribute to delay in diagnosis. Current descriptions of tracheal reconstruction emphasize circumferential excision and reanastomosis, but advanced infection and a probable need for ventilatory support are considered contraindications. Two cases of tracheal injury are reported in which a considerable delay in diagnosis resulted in severe mediastinal infection and respiratory failure. Use of an earlier method of tracheal repair, with pedicled intercostal muscle, resulted in control of mediastinal infection. Respiratory failure was treated effectively with a volume ventilator. It is recommended that the operation be given first consideration for such posterior injuries when they are accompanied by infection or respiratory failure.

Pericardial closure.

Closure of the pericardium after operation for coronary bypass is recommended. It affords protection for the right ventricle and overlying bypass grafts if repeat sternotomy is necessary, and may decrease the incidence of tamponade. A mild compressive effect on the heart has been noted at the time of pericardial closure that does not appear to affect clinical outcome. Hemodynamic studies support this impression. The supracardiac portion of this layer is not closed, and permits use of internal mammary artery conduits. Pericardial closure is not feasible in all instances, however. The need for increased filling pressures, the anticipation of cardiac rather than mediastinal postoperative bleeding, and occasional interference with the course of internal mammary pedicles may preclude closure.