Francis P. Sutter

Optimizing intraoperative cerebral oxygen delivery using noninvasive cerebral oximetry decreases the incidence of stroke for cardiac surgical patients.

BACKGROUND A recent study demonstrated that almost 75% of strokes after coronary artery revascularization surgery occur in patients classified preoperatively as low to medium risk. Thus, despite the use of risk classification, most strokes can occur when not expected. We hypothesized that optimization of cerebral oxygen delivery variables by using noninvasive cerebral oximetry could reduce the incidence of stroke. METHODS Cerebral oximetry was used by all surgeons to monitor cerebral oxygen saturation in all cardiac surgery patients from January 1, 2002, until June 30, 2003 (n = 1034; 18 months, treatment group). Cerebral oxygen delivery was optimized during surgery by modifying oxygen delivery and consumption variables to maintain oximetry values at or near the patients preinduction baseline. Stroke was defined according to guidelines of the Society of Thoracic Surgeons. The incidence of stroke in the treatment group was compared with that for patients who underwent cardiac surgery between July 1, 2000, and December 31, 2001, (n = 1245; 18 months, control group) before cerebral oximetry was incorporated. RESULTS Age and sex distribution were similar in the 2 groups. The study group had significantly more patients in New York Heart Association (NYHA) classes III and IV than the control group, and patients in the study group were sicker overall. Despite this difference, the study group overall had fewer permanent strokes (10 [0.97%] versus 25 [2.5%]; P < .044). This difference remained significant when the results were controlled for NYHA class and on-pump or off-pump surgery. When the patients were examined by NYHA class, the proportion of patients requiring prolonged ventilation was significantly smaller in the study group (6.8% versus 10.6%; P < .0014), as was the length of hospital stay (P < .046). CONCLUSIONS The treatment group, which underwent all cardiac surgeries with optimized cerebral oxygen delivery using cerebral oximetry monitoring, demonstrated a significantly lower incidence of permanent stroke. Because our study is retrospective, a prospective randomized trial is warranted.

Axillary artery cannulation in acute ascending aortic dissections

BACKGROUND Standard cannulation of the femoral artery in preparation for repair of a dissection involving the ascending aorta carries a high risk of malperfusion. Arterial perfusion through the right axillary artery is more likely to perfuse the true lumen and should be advantageous in acute dissections involving the ascending aorta. METHODS Thirteen patients underwent repair of acute ascending aortic dissections and were perfused through the right axillary artery. All had deep hypothermic circulatory arrest. RESULTS There was one mild intraoperative cerebrovascular accident with complete recovery and one operative death secondary to low cardiac output. There were no intraoperative problems with perfusion through the axillary artery, and there were no postoperative problems or complications involving the axillary artery, axillary vein, or brachial plexus. CONCLUSIONS Arterial perfusion through the right axillary artery is a safe and effective means of more reliably perfusing the true lumen. In this regard, it may be superior to femoral artery perfusion and could lead to improved outcomes with repair of acute deBakey type I and II aortic dissections.

Coronary artery bypass grafting in patients who require long-term dialysis ☆

BACKGROUND Should coronary artery bypass grafting (CABG) be performed in patients on long-term dialysis? This subject has been debated for several years. We retrospectively reviewed the charts of all patients who had CABG from August 1989 to October 1997. METHODS We identified 70 patients who were on long-term dialysis and had CABG during that time period. Patients were evaluated by chart review and telephone survey. Forty-nine patients (70%) had unstable angina and 37 patients (52%) had triple vessel disease. Patient risk factors included 60 patients with hypertension (85%), 40 patients with diabetes mellitus (57%), 35 patients who had congestive heart failure (50%), 35 patients who had a previous myocardial infarction (50%), and 31 smokers (44%). Operative procedures included 49 patients who had CABG only and 21 patients who had concomitant CABG with valve replacement or repair. During the postoperative period, complications developed in 50% of patients. RESULTS Review of these complications showed that 25% of patients required prolonged mechanical ventilation, and 10% of patients had septicemia. Operative mortality was high, with 10 patient deaths (14.3%) within 30 days of the procedure. Six (60%) of these deaths occurred in patients who had CABG and valve repair or replacement. Long-term follow up at 50.3 months showed no improvement in survival in patients who had CABG compared with the known mortality rate of 22% per year in dialysis patients regardless of comorbid conditions. Quality of life subjectively improved in only 41% of patients in follow-up telephone survey. CONCLUSIONS Patients requiring long-term dialysis with coexistent severe cardiac disease should be thoroughly evaluated preoperatively. One must weigh the high morbidity and mortality risk against the limited long-term resolution of angina and ultimate survival.

Does routine use of aortic ultrasonography decrease the stroke rate in coronary artery bypass surgery

PURPOSE The purpose of this study is to determine whether the routine use of intraoperative surface aortic ultrasonography decreases the stroke rate in coronary artery bypass graft surgery (CABG). METHODS One hundred ninety-five consecutive patients undergoing CABG between July 1, 1992, and June 30, 1993 (study group), were evaluated by intraoperative surface aortic ultrasonography. Based on information obtained, changes in the operative technique were made in an effort to decrease the incidence of embolic stroke from unsuspected atherosclerotic disease of the ascending aorta. The outcome of these patients was compared with that of 164 consecutive patients who underwent CABG between July 1, 1991, and June 30, 1992 (control group), in whom the ascending aorta was assessed by inspection and palpation only. RESULTS Significant disease was detected in three (2.0%) of 164 patients in the control group. Modifications in their operative technique consisted of hypothermic fibrillatory arrest with no cross-clamping of the aorta and left ventricular venting in two patients and single cross-clamping in one patient. There were five strokes overall in this group (3.0%), and six patients died (3.6%), one in whom the stroke contributed directly to the cause of death. In the study group the ultrasonic findings were normal to mild in 168 patients, moderate in 20 patients, and severe in seven patients. These results led to a modification of the technique in 19 patients, (10%): hypothermic fibrillatory arrest with no cross-clamping of the aorta and left ventricular venting in 14 patients, modification in the aortic cannulation site or single cross-clamping in three patients, and modification in placement of proximal anastomoses or all arterial grafts in two patients. No strokes occurred in this group (p < 0.02, Fishers exact test). Five patients died, for an operative mortality rate of 2.6%. CONCLUSION These data indicate that intraoperative ultrasonography of the ascending aorta with simple modifications in operative technique reduces the stroke rate in CABG.

Simultaneous carotid endarterectomy and coronary revascularization.

BACKGROUND Combined cardiac operation and carotid endarterectomy using our technique is an acceptable approach to simultaneous correction of both carotid and cardiac disease. METHODS From August 1989 to March 1998, 121 consecutive patients underwent combined operations. Of these patients, 112 had coronary artery bypass grafting and carotid endarterectomy, and 9 had coronary artery bypass grafting, carotid endarterectomy, and valve repair or replacement. All patients had a critical stenosis of 85% or more of the carotid artery. Mean age of the patients was 69.2 years; 80 patients were 65 years old or older. There were 88 men and 33 women. Notable risk factors included chronic obstructive pulmonary disease (19.8%), congestive heart failure (28%), preoperative myocardial infarction and unstable angina (66.9%). Of the patients, 20.7% had a stenosis of greater than 50% of the left main coronary artery. The technique used was correction of both the carotid and coronary lesions during a single aortic cross-clamp period using retrograde continuous blood cardioplegia for myocardial protection. Systemic hypothermia to 25 degrees C was used for cerebral protection. RESULTS Mean cross-clamp time was 118 minutes. Seven patients (5.8%) sustained perioperative cerebrovascular accidents. Two patients had transient ischemic attacks. The procedure-related mortality rate was 5.8%. CONCLUSIONS The described technique is a good method for simultaneous repair of coronary and carotid lesions in a high-risk group of patients with concomitant disease. We will continue to use it.

Combined cardiac operation and carotid endarterectomy during aortic cross-clamping

We present a surgical technique that we believe provides superior cerebral protection for simultaneous correction of carotid and cardiac pathology with low operative mortality and stroke rate. Our study population consists of 23 consecutive patients undergoing cardiac operation between August 1989 and April 1991 who also had associated critical (greater than 85%) carotid artery stenosis. Using 20 degrees C systemic hypothermia for cerebral protection, we performed simultaneous correction of both lesions during the aortic cross-clamp period, using continuous retrograde blood cardioplegia for myocardial protection. Mean patient age was 69.4 years; 83% were 65 years or older. Eighty-seven percent had angina, 35% had recent myocardial infarctions (within 30 days), and 52% had congestive heart failure. Asymptomatic bruit was found in 39%, and 61% had previous strokes, neurologic symptoms, or both. All had 85% or greater luminal narrowing on cerebral angiography, with 65% having severe or critical contralateral disease as well. Sixty-one percent had associated other vascular pathology, including peripheral vascular occlusive disease, renal artery stenosis, or abdominal aortic aneurysm. There were no postoperative strokes or neurologic events. One early vein graft occlusion resulted in postoperative myocardial infarction and subsequent death (4.3%).

Spontaneous late rupture of an aortocoronary saphenous vein graft

Abstract A case is presented of vein graft rupture leading to myocardial infarction and subsequent pseudoaneurysm formation.

Augmented femoral venous return

We present a technique of femoral cardiopulmonary bypass that allows excellent venous drainage. This is accomplished by augmenting the venous return with a centrifugal pump.

Plasma concentrations of soluble tumor necrosis factor receptor I and tumor necrosis factor during cardiopulmonary bypass.

BACKGROUND Tumor necrosis factor-alpha (TNF) has been implicated in the development of postoperative morbidity after cardiopulmonary bypass for myocardial revascularization. Despite their postulated roles as modulators of TNF bioavailability, soluble TNF receptors have not been characterized in patients undergoing this procedure and is the focus of this study. METHODS Soluble tumor necrosis factor receptor I (sTNFRI) and TNF were measured by immunoassay in plasma samples collected from 36 patients at events before, during, and after cardiopulmonary bypass. RESULTS Plasma concentrations of sTNFRI averaged 1.39 ng/mL at the start of the operation. Preoperative sTNFRI concentrations were found to significantly correlate with a preoperative morbidity assessment score, age, duration of bypass, duration of supplemental oxygen, and length of hospital stay. Plasma sTNFRI increased in all of the patients during the procedure. Plasma concentrations of sTNFRI and TNF did not correlate at any time. CONCLUSIONS Preoperative measurement of sTNFRI could potentially serve as a reliable indicator for prophylactic treatment with an anti-TNF therapy. Such a therapeutic approach might help attenuate inflammatory processes thought to underlie postoperative morbidity associated with cardiopulmonary bypass.

Events associated with rupture of intra-aortic balloon counterpulsation devices

Nineteen intra-aortic balloon (IAB) ruptures occurred in sixteen patients during a three-year period. Perforation occurred secondary to abrasion with material failure or mishandling of the device during insertion. To avoid serious sequelae, it is important to be aware of the possibility of IAB rupture and to remove any defective device immediately upon recognition of an event.