Ann Thorac Surg 2005;80:2372-2374
© 2005 The Society of Thoracic Surgeons
Case report
Neurological Monitoring and Off-Pump Surgery in a Very High-Risk Stroke Patient
Mark F. Berry, MD
a
,
Michael L. McGarvey, MD
b
,
Li Zeng, MD
c
,
Y. Joseph Woo, MD
a
,
*
a Division of Cardiothoracic Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
b Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
c Department of Anesthesia, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania
Accepted for publication June 16, 2004.
* Address correspondence to Dr Woo, 3400 Spruce St, 6 Silverstein Pavilion, Philadelphia, PA19104–4227 (Email: wooy{at}uphs.upenn.edu).
 |
Abstract
|
|---|
Stroke remains a high risk of coronary artery bypass grafting. We present a patient with progressively symptomatic coronary disease and severe four-vessel cerebrovascular disease not amenable to revascularization. This patient underwent coronary revascularization without neurologic complication using off-pump coronary surgery to avoid aortic manipulation and intraoperative electroencephalographic monitoring of cerebral perfusion. This management strategy may reduce the stroke risk in similar patients.
|
Introduction
|
|---|
Stroke complicates coronary artery bypass grafting in 1.1% to 3.8% of cases and significantly increases mortality and prolongs hospitalization [1–6]. Reduced ejection fraction, carotid artery disease, and peripheral vascular disease increase the stroke risk [1–3, 6]. We present a patient with progressively symptomatic coronary disease and severe nonrevascularizable four-vessel cerebrovascular disease who underwent uncomplicated coronary revascularization with off-pump coronary artery bypass (OPCAB), a modified anesthetic regimen, and intraoperative electroencephalographic (EEG) monitoring.
A 58-year-old man with hypertension, diabetes, hyperlipidemia, and an ejection fraction of 35% had dyspnea on exertion and a positive stress test. Coronary angiography showed a stenotic left anterior descending coronary artery not amenable to percutaneous intervention and occluded right coronary and circumflex arteries, with a very small reconstituted distal obtuse marginal and no right-sided distal target. The patient also had peripheral vascular disease with multiple prior lower extremity operations. Preoperative magnetic resonance angiogram revealed severe four-vessel cerebrovascular disease, including an occluded left internal carotid artery, a severely stenotic intracranial right internal carotid artery, and moderate stenoses at the origin of the left vertebral artery and at the right distal intracranial vertebral artery, none of which were amenable to surgical or percutaneous intervention (Fig 1). Coronary artery bypass grafting was considered but not performed after the initial presentation due to the patient's high stroke risk. The patient returned with progressive dyspnea symptoms despite maximal medical therapy, and after extensive discussion regarding the extremely high risk of both stroke and myocardial infarction given his tenuous coronary anatomy, he agreed to coronary artery bypass grafting because of his life-limiting symptoms.
View larger version (114K):
[in this window]
[in a new window]
|
Fig 1. Magnetic resonance angiogram showing severe cerebrovascular disease, including (left) an occluded left internal carotid artery (white arrow) and (right) a severely stenotic intracranial right carotid artery (white arrow).
|
|
Because of the patient's cerebrovascular disease, intraoperative EEG neuro-monitoring and OPCAB were used to monitor brain perfusion, maintain hypertensive pulsatile cerebral blood flow, and avoid aortic manipulation and potentially neurologically devastating atheroma embolization. Instead of using a more typical anesthetic regimen with long-acting agents to keep the patient sedated until postoperative hemodynamics and bleeding could be adequately assessed, only short-acting paralytics and narcotics were used with an inhalational agent to allow full postoperative neurologic evaluation as quickly as possible. The patient underwent median sternotomy and OPCAB with a single left internal mammary artery to the left anterior descending coronary artery graft. A sternotomy was used rather than a less invasive approach to allow evaluation for other potential distal targets in the occluded right coronary and circumflex territories. The patient showed EEG waveform slowing when his mean arterial blood pressure fell below 100 mm Hg, so pharmacologic support was used to keep mean arterial blood pressures greater than 100 throughout the case, resulting in EEG normalization (Figs 2A–2C). The patient also had diffuse EEG slowing during heart manipulation and evaluation of other potential targets, which returned to baseline with heart repositioning (Fig 2D). As expected, other targets were unsuitable for grafting. Postoperatively, the patient was awake and neurologically intact immediately on arrival to the intensive care unit. He was discharged home by postoperative day 3. Even though complete revascularization was not possible, the patient has no chest pain or dyspnea. He climbs the stairs daily to his second story apartment multiple times without difficulty 2 years after surgery.
View larger version (107K):
[in this window]
[in a new window]
|
Fig 2. (A) Baseline electroencephalographic (EEG) tracings. (B) The EEG tracings slowed (black arrow) when blood pressure decreased. (C) The EEG waveforms returned to baseline after pharmacologic support increased blood pressure. (D) Heart manipulation during evaluation for additional coronary targets caused diffuse EEG slowing.
|
|
|
Comment
|
|---|
Stroke after coronary artery bypass grafting results from an embolus in 60% of cases, and is otherwise due to hypoperfusion or a mixture of embolus and hypoperfusion [3, 4]. This patient's management method protected against both causes. Although the results concerning whether OPCAB reduces the risk of stroke compared with coronary artery bypass grafting with cardiopulmonary bypass are mixed, the avoidance of aortic manipulation in this high-risk patient likely did significantly reduce the chance of an embolic stroke [3, 7, 8]. Considering this patient's cerebrovascular disease, any emboli from atheroma dislodgement during aortic cannulation and cross-clamping could have had potentially devastating neurologic consequences. OPCAB also allowed the anesthesiologists to manipulate hemodynamics to maintain pulsatile hypertensive flow to the brain, as nonpulsatile pump flow could have resulted in brain hypoperfusion given this patient's cerebrovascular anatomy.
Electroencephalographic monitoring also helped protect against hypoperfusion in this case. Electroencephalographic monitoring quickly identified relative cerebral hypoperfusion, allowing the use of fluid, pressors, or inotropic agents to increase perfusion before permanent neurologic damage occurred. Electroencephalographic monitoring was especially important considering the use of OPCAB in this patient. Heart manipulation during OPCAB can impair cardiac output and induce hypotension, with significant brain hypoperfusion in patients with cerebrovascular disease. In this case, EEG monitoring immediately detected brain hypoperfusion during heart manipulation and allowed repositioning of the heart to reverse the hypoperfusion before a stroke occurred. Electroencephalographic monitoring could have objectively guided blood pressure management and allowed careful completion of the distal anastomoses had this patient's anatomy been amenable for additional bypasses.
The use of short-acting anesthetic agents in conjunction with EEG monitoring in this case enabled almost continuous neurologic monitoring intraoperatively and immediately postoperatively. Most perioperative strokes (65%) occur after an initial, uneventful neurologic recovery from cardiac surgery with the rest occurring intraoperatively [4]. Having the patient wake up immediately postoperatively allows immediate detection of neurologic dysfunction and institution of therapy. As intraoperative EEG had shown that this patient's cerebral perfusion was directly related to blood pressure, the mean arterial blood pressure could have been immediately raised pharmacologically to try and prevent any temporary deficit from becoming permanent. If neurologic function did not normalize with increased mean arterial blood pressure, an emergent cerebral angiogram and catheter-based intervention could have been attempted if appropriate lesions were identified to try and salvage the patient's status.
|
References
|
|---|
- Likosky DS, Leavitt BJ, Marrin CA, et al. Intraoperative and postoperative predictors of stroke after coronary artery bypass grafting Ann Thorac Surg 2003;76:428-434.[Abstract/Free Full Text]
- Bucerius J, Gummert JF, Borger MA, et al. Stroke after cardiac surgerya risk factor analysis of 16,184 consecutive adult patients. Ann Thorac Surg 2003;75:472-478.[Abstract/Free Full Text]
- Ascione R, Reeves BC, Chamberlain MH, Ghosh AK, Lim KH, Angelini GD. Predictors of stroke in the modern era of coronary artery bypass graftinga case control study. Ann Thorac Surg 2002;74:474-480.[Abstract/Free Full Text]
- Hogue Jr CW, Murphy SF, Schechtman KB, Davila-Roman VG. Risk factors for early or delayed stroke after cardiac surgery Circulation 1999;100:642-647.[Abstract/Free Full Text]
- D'Ancona G, Saez de Ibarra JI, Baillot R. Determinants of stroke after coronary artery bypass grafting Eur J Cardiothorac Surg 2003;24:552-556.[Abstract/Free Full Text]
- Stamou SC, Hill PC, Dangas G, et al. Stroke after coronary artery bypassincidence, predictors, and clinical outcome. Stroke 2001;32:1508-1513.[Abstract/Free Full Text]
- Mack MJ, Pfister A, Bachand D, et al. Comparison of coronary bypass surgery with and without cardiopulmonary bypass in patients with multivessel disease J Thorac Cardiovasc Surg 2004;127:167-173.[Abstract/Free Full Text]
- Sabik JF, Gillinov AM, Blackstone EH, et al. Does off-pump coronary surgery reduce morbidity and mortality? J Thorac Cardiovasc Surg 2002;124:698-707.[Abstract/Free Full Text]
Top
Abstract
Introduction
