Ann Thorac Surg 1996;61:1722-1723
© 1996 The Society of Thoracic Surgeons
Invited Commentary
Invited Commentary
Stephen R. Large, FRCS
Transplant Unit, Papworth Hospital, Papworth Everard, Cambridgeshire CB3 8RE, England
See also page 1721.
Doctors Tewari and Aggarwal have presented a series of patients who have suffered neurologic impairment associated with their coronary artery bypass grafts. These were left recurrent laryngeal and phrenic nerve lesion. The association was with the use of large amounts of ice slush that fell into the open left pleural cavity after internal mammary artery harvesting. There is no doubt that frostbite is effective at producing damage to phrenic nerve function, and on occasion this may be permanent. It seems likely that cold is the cause here as both these nerves have a superficial mediastinal pleural route in the left chest but, of course, there are other potential causes. Direct trauma from the operation, certainly as far as the phrenic nerve is concerned, has been implicated, as has stretch. The phrenic nerve is also at risk of sharp trauma from central venous cannulation. There is a lot of circumstantial evidence in the medical press from our own work and others implicating cold in both the development of partial and complete loss of function of the phrenic nerve, but here we see laryngeal nerve involvement as well. It is encouraging to see that the vast majority of phrenic nerve lesions will resolve with time. It will be interesting to see the fate of these combined injuries in these reports. However, there are sporadic reports of bilateral phrenic nerve palsy that threatens the patient's survival. With increased harvesting of both left and right internal mammary arteries let us hope that reports remain sporadic and do not increase in frequency, and that we do not see a body of literature emerge describing bilateral laryngeal lesions. This seems unlikely because of the peculiar asymmetry of left and right recurrent laryngeal nerve anatomy.
In summary, this is a report emphasizing the danger of using this form of myocardial protection. Precautions to avoid direct cold injury to left and right phrenic nerves meet with a reduction in the incidence of phrenic nerve paralysis or paresis. We can thank Tewari and Aggarwal for raising this issue again, highlighting the vulnerability of all exposed nerves to frostbite, and note that it is particularly timely with the increased incidence of bilateral pleural opening for left and right internal mammary arteries.
Related Article
-
Combined Left-Sided Recurrent Laryngeal and Phrenic Nerve Palsy After Coronary Artery Operation
- Prabhat Tewari and Surendra Kumar Aggarwal
Ann. Thorac. Surg. 1996 61: 1721-1722.
[Abstract]
[Full Text]
