Alistair Royse

Prospective randomized trial of high thoracic epidural analgesia for coronary artery bypass surgery

BACKGROUND Postoperative pain may be severe after coronary artery bypass surgery. High thoracic epidural analgesia (HTEA) provides intense analgesia. METHODS Eighty patients were randomized to HTEA or intravenous morphine analgesia (control). Patients received coronary artery bypass surgery (CABG) with cardiopulmonary bypass. Pain was measured by visual analogue scale 0 to 10. Psychologic morbidity, intraoperative hemodynamics, ventricular function, lung function, and physiotherapy cooperation were also assessed. On the third postoperative day HTEA and morphine were ceased and only oral medications were used. Acetaminophen, indomethacin, and tramadol were allowed as supplemental analgesics in both groups. RESULTS The primary endpoint of pain scores was significantly less with HTEA on postoperative days 1 and 2 at rest, 0.02 +/- 0.2 versus 0.8 +/- 1.8 (p = 0.008) and 0.1 +/- 0.4 versus 1.2 +/- 2.7 (p = 0.022), respectively, and with coughing 1.2 +/- 1.7 versus 4.4 +/- 3.1 (p < 0.001) and 1.5 +/- 2.0 versus 3.6 +/- 3.1 (p = 0.001), respectively. When HTEA and morphine were ceased on day 3, there were no significant differences. The secondary endpoints of postoperative depression (p = 0.033) and posttraumatic stress subscales (p = 0.021) of the Minnesota Multiphasic Personality Inventory were lower with HTEA. Extubation occurred earlier with HTEA, 2.6 versus 5.4 hours (p < 0.001). HTEA showed improved physiotherapy cooperation (p < 0.001), arterial oxygen tension (p = 0.041), and peak expiratory flow rate (p = 0.001). Mean arterial pressure was lower with HTEA (p = 0.036), otherwise there were no differences in intraoperative hemodynamics or ventricular function. CONCLUSIONS Epidural analgesia reduces pain after coronary operation and is associated with improved physiotherapy cooperation, earlier extubation, and reduced risk of depression and posttraumatic stress.

Total arterial coronary revascularization: techniques and results in 3,220 patients

BACKGROUND To overcome the problems of late vein graft atherosclerosis, occlusion and need of coronary reoperations, we have adopted a strategy of total arterial coronary revascularization. We evaluated our experience with this strategy to establish its safety and efficacy. METHODS All 3,220 consecutive patients who had total arterial coronary revascularization from January 1988 to June 1998 were evaluated. Data were collected prospectively. The mean age was 62.2 years. Of the patients, 595 (18.8%) had diabetes; 739 (23%) had a left ventricular ejection fraction of less than 0.50; and 484 (15%) were classified unstable/urgent. The conduits included 3,140 left internal thoracic arteries, 1,224 right internal thoracic arteries, and 2,417 radial arteries, 654 of which were bilateral. A Y or T graft with the left internal thoracic artery was used in 467 patients. Patients were followed up at 1 month, 3 months, and yearly thereafter. Postoperative angiography was performed for symptoms or as part of an ethics committee-approved prospective study. RESULTS The operative mortality rate was 0.7% (21 patients). Complications included stroke in 26 patients (0.8%), myocardial infarction in 27 (0.8%), sternal infection in 35 (1.1%), and reoperation for hemorrhage in 23 (0.7%). The peak level of the myocardial enzyme of creatine kinase was 16.4+/-14.9 IU/L. Twenty-five patients (0.8%) required intraoperative or postoperative intraaortic balloon pump support. Mortality and stroke rates were higher in patients having reoperation (0.6% versus 1.8%; p = 0.11; and 0.7% versus 2.2%; p = 0.07, respectively). Postoperative angiographic patency was 97% at 5 years for the left internal thoracic artery (620 grafts), 89% at 5 years for the right internal thoracic artery (276 grafts), and 91% at 1 year for the radial artery (65 grafts). CONCLUSIONS Total arterial coronary revascularization can be performed safely with good patency rates in a large number of patients and may potentially avoid the sequelae of vein graft atherosclerosis.

Radial artery harvest technique, use and functional outcome

OBJECTIVE To develop a simple harvest technique for radial artery (RA). To investigate the morbidity and functional outcome of RA harvest. METHODS The neurovascular fascia surrounding the RA is divided. Only loose areolar tissue surrounds this artery making harvest of RA simple and allowing minimal trauma to the RA and surrounding muscles. Topical and intraluminal vasodilators but no systemic vasodilators are used. RESULTS RA harvest commenced in December 1994. Between 1996 and 30 June 1998, 2167 RA were harvested and used to construct 3105 coronary anastomoses. A dramatic rise in RA use occurred during 1996. More than 80% of patients undergoing coronary artery bypass surgery (CABG) have RA harvested since this time. Total arterial revascularization rate also rose dramatically and is currently 80% of all CABG. This rate has been assisted by a rapid rise in the use of composite arterial grafting where aortic anastomoses can be avoided and currently represents 40% of all CABG. Hand strength was tested in 328 non-selected patients and was not reduced by RA harvest when hand dominance was taken into account. Objective sensation loss was present in 0.3% for the superficial radial nerve and 2.1% for the lateral cutaneous nerve of forearm. Pulse oximetry observations detected statistically significant but clinically irrelevant differences. Scar hypersensitivity occurred in 20%. Only two patients of all patients undergoing RA harvest reported late hand ischaemia. CONCLUSIONS Harvest of the RA within the neurovascular plane is simple and associated with low morbidity.

Blood Flow in Composite Arterial Grafts and Effect of Native Coronary Flow

BACKGROUND Total arterial coronary revascularization can be achieved by joining arteries together as a composite graft with the proximal left internal mammary artery as the only source of blood inflow. Proof of the capacity of this composite conduit to provide adequate blood flow to the coronary circulation is required. METHODS The radial artery was anastomosed to the left internal mammary artery as a Y graft in 17 patients and all coronary arteries grafted. Intraoperative blood flow through the composite grafts was evaluated by the transit-time Doppler technique. RESULTS Against no resistance, blood flow in the left internal mammary artery alone was 99 +/- 9 mL/min and rose to 173 +/- 16 mL/min when the radial artery was anastomosed as a Y graft. Composite-graft flow following grafting was 88 +/- 9 mL/min, 49 +/- 6 mL/min when the aortic clamp was removed and native coronary flow restored and 82 +/- 13 mL/min following weaning from cardiopulmonary bypass. The maximal potential flow through the composite graft was 2.3-fold (95% CI 1.6 to 3.2) greater than that after cardiopulmonary bypass. CONCLUSIONS Total arterial revascularization, using a composite graft, provided a 2.3-fold reserve of blood flow to the coronary vascular bed through the grafts.

Routine immediate extubation after cardiac operation: a review of our first 100 patients

BACKGROUND Early extubation after cardiac operation is an important aspect of fast-track cardiac anesthesia. Immediate extubation is an extension of this concept. We describe a technique that allows immediate extubation in the majority of patients. METHODS To allow rapid emergence, anesthesia was modified from a high-dose opioid technique to intravenous propofol anesthesia supplemented with sevoflurane. Normothermic cardiopulmonary bypass was used with routine intermittent antegrade and retrograde tepid blood cardioplegia. High thoracic epidural analgesia was used to facilitate immediate extubation in the majority of patients. Contraindications to immediate extubation were prolonged cardiopulmonary bypass (CPB) (>2.5 hours), hemodynamic instability, uncontrolled bleeding, morbid obesity, severe pulmonary hypertension, congestive cardiac failure, or if the operation was emergent. RESULTS Of 109 consecutive patients, 100 were immediately extubated (92%). No patient required reintubation within the first 24 hours after operation. One patient required reintubation 3 days after operation for sputum retention, and 2 patients required reoperation. There was no mortality and the incidence of perioperative morbidity was low. CONCLUSIONS Immediate extubation after cardiac operation can be safely achieved and is possible in a majority of patients.

Rationale and design of the Left Atrial Appendage Occlusion Study (LAAOS) III

BACKGROUND Occlusion of the left atrial appendage (LAA) is a promising approach to stroke prevention in atrial fibrillation (AF). However, evidence of its efficacy and safety to date is lacking. We herein describe the rationale and design of a definitive LAA occlusion trial in cardiac surgical patients with AF. METHODS We plan to randomize 4,700 patients with AF in whom on-pump cardiac surgical procedure is planned to undergo LAA occlusion or no LAA occlusion. The primary outcome is the first occurrence of stroke or systemic arterial embolism over a mean follow-up of four years. Other outcomes include total mortality, operative safety outcomes (chest tube output in the first post-operative 24 hours, rate of post-operative re-exploration for bleeding in the first 48 hours post-surgery and 30-day mortality), re-hospitalization for heart failure, major bleed, and myocardial infarction. RESULTS Left Atrial Appendage Occlusion Study (LAAOS) III is funded in a vanguard phase by the Canadian Institutes for Health Research (CIHR), the Canadian Network and Centre for Trials Internationally, and the McMaster University Surgical Associates. As of September 9, 2013, 162 patients have been recruited into the study. CONCLUSIONS LAAOS III will be the largest trial to explore the efficacy of LAA occlusion for stroke prevention. Its results will lead to a better understanding of stroke in AF and the safety and efficacy of surgical LAA occlusion.

Exclusive Y graft operation for multivessel coronary revascularization

BACKGROUND The pedicled (in-situ) left internal mammary artery grafted to the left anterior descending artery has a very high late patency and reduces late mortality following coronary artery bypass surgery. A technique is described which achieves total arterial revascularization in patients with multivessel coronary disease and which is also entirely pedicled. METHODS Using the left internal mammary artery and radial artery joined as a composite Y graft, all coronary territories may be grafted. RESULTS One in-hospital death from 464 patients (0.2%) occurred. Age (mean +/- standard error) was 64.7 +/- 0.5 years and number of distal anastomoses 3.4 +/- 0.04. Of 1,681 patients from Royal Melbourne Hospital, 346 had this operation. Comparison found no preoperative selection bias and no postoperative differences in complications. Actuarial survival was 0.98 +/- 0.01 at 36.1 +/- 0.3 months. CONCLUSIONS Total arterial revascularization may be performed using the left internal mammary artery and radial artery as a composite Y graft. There was no increase in complications. This technique preserves the left internal mammary artery to left anterior descending artery graft.

The influence of propofol or desflurane on postoperative cognitive dysfunction in patients undergoing coronary artery bypass surgery

We investigated the influence of either propofol or desflurane on the incidence of postoperative cognitive dysfunction in a randomised trial of 180 patients undergoing coronary artery bypass surgery. The primary outcome was incidence of postoperative cognitive dysfunction at 3 months, defined as ≥ 1 SD deterioration in two or more of 12 neurocognitive tests. Secondary outcomes included early postoperative cognitive dysfunction (between days three and seven), delirium on day one, morbidity and length of hospital stay. Early postoperative cognitive dysfunction was significantly higher with propofol compared with desflurane (56/84 (67.5%) vs 41/83 (49.4%), respectively, p = 0.018), but this effect was not seen at 3 months (10/87 (11.2%) vs 9/90 (10.0%), respectively. There was no difference in delirium (7/89 (7.9%) vs 12/91 (13.2%), respectively, length of hospital stay (median (IQR [range]) 7 (6‐9 [4‐15]) vs 6 (5‐7 [5‐16) days, respectively or other morbidities. Desflurane was associated with reduced early cognitive dysfunction.

The impact of focused transthoracic echocardiography in the pre‐operative clinic

Patients with suspected or symptomatic cardiac disease, associated with increased peri‐operative risk, are often seen by anaesthetists in the pre‐assessment clinic. The use of transthoracic echocardiography in this setting has not been reported. This prospective observational study investigated the effect of echocardiography on the anaesthetic management plan in 100 patients who were older than 65 years or had suspected cardiac disease. Echocardiography was performed by an anaesthetist, and was validated by a cardiologist. Overall, the anaesthetic plan was changed in 54 patients. Haemodynamically significant cardiac disease was revealed in 31 patients, resulting in a step‐up of treatment in 20 patients, including: cardiology referral (four patients); altered surgical (two) and anaesthetic (four) technique; use of invasive monitoring (13); planned use of vasopressor infusion (10); and postoperative high dependency care (five). Reassuring negative findings in 69 patients led to a step‐down in treatment in 34 patients: altered anaesthetic technique (six); procedure not cancelled (10); cardiology referral not made (10); use of invasive monitoring not required (seven); and high dependency care not booked (11). We conclude that focused transthoracic echocardiography in the pre‐operative clinic is feasible and frequently alters management in patients with suspected cardiac disease.

The impact of pre-operative focused transthoracic echocardiography in emergency non-cardiac surgery patients with known or risk of cardiac disease

This prospective observational study investigated the effect of focused transthoracic echocardiography in 99 patients who had suspected cardiac disease or were ≥ 65 years old, and were scheduled for emergency non‐cardiac surgery. The treating anaesthetist completed a diagnosis and management plan before and after transthoracic echocardiography, which was performed by an independent operator. Clinical examination rated cardiac disease present in 75%; the remainder were asymptomatic. The cardiac diagnosis was changed in 67% and the management plan in 44% of patients after echocardiography. Cardiac disease was identified by echocardiography in 64% of patients, which led to a step‐up of treatment in 36% (4% delay for cardiology referral, 2% altered surgery, 4% intensive care and 26% intra‐operative haemodynamic management changes). Absence of cardiac disease in 36% resulted in a step‐down of treatment in 8% (no referral 3%, intensive care 1% or haemodynamic treatment 4%). Pre‐operative focused transthoracic echocardiography in patients admitted for emergency surgery and with known cardiac disease or suspected to be at risk of cardiac disease frequently alters diagnosis and management.