David A. Latter

Temperature during cardiopulmonary bypass for coronary artery operations does not influence postoperative cognitive function: A prospective, randomized trial

OBJECTIVE The objective was to examine the effect of temperature (28 degrees vs 36 degrees C) during cardiopulmonary bypass on postoperative cognitive functions in a prospective, double-blind, and randomized manner. METHODS Sixty-two patients scheduled for coronary operations were randomized to warm or cold cardiopulmonary bypass. Preoperative and postoperative (7 days) neuropsychologic evaluations were performed by an observer unaware of cardiopulmonary bypass temperature. RESULTS Fifty-four patients completed the study (cold bypass, n = 24; warm bypass, n = 30). Significant (p < 0.01) postoperative deterioration for tests of psychomotor coordination and verbal memory was noted in both warm and cold groups, but no differences were observed between groups. CONCLUSION Temperature during cardiopulmonary bypass for coronary operations does not influence postoperative cognitive function.

Impact of transfusion of mediastinal shed blood on serum levels of cardiac enzymes

BACKGROUND Infusion of shed mediastinal blood using an autotransfusion system is a widely applied technique of blood conservation in cardiac surgery. Serial determinations of serum creatine kinase (CK), its MB isoenzyme (CK-MB), and lactate hydrogenase (LDH) levels have been used to monitor perioperative myocardial injury. We investigated the impact of postoperative autotransfused blood infusion on serum levels of these enzymes. METHODS We performed a retrospective analysis of postoperative serum CK, CK-MB, and LDH levels of 300 patients who had elective uncomplicated aortocoronary bypass grafting. Shed mediastinal blood samples from 26 patients were analyzed for CK, CK-MB (enzymatic activity and mass), and LDH levels before infusion. RESULTS High postoperative serum levels of CK and LDH were observed after infusion of autotransfused blood. Shed mediastinal blood contained extremely high levels of these enzymes, particularly from patients who had internal mammary artery dissection. There was a strong correlation (r = 0.96) between measured CK-MB enzyme activities and those calculated from the CK-MB mass units. CONCLUSIONS Infusion of autotransfused blood containing high concentrations of CK and LDH results in elevated serum levels of these enzymes. Hemolysis, frequently present in shed blood, does not interfere with the routine biochemical assays for CK and CK-MB enzyme activities. Caution should be taken when postoperative cardiac enzyme levels are used to determine myocardial injury after aortocoronary bypass grafting if autotransfusion is used as a method of blood conservation.

Reinfusion of Mediastinal Blood in CABG Patients: Impact on Homologous Transfusions and Rate of Re‐exploration

Abstract Background: Reinfusion of mediastinal shed blood after cardiac surgery has been used in some centers to reduce exposure to homologous blood transfusions. The method has not been widely applied mostly because some studies have failed to demonstrate a significant benefit. Methods: A group of 675 consecutive patients undergoing first‐time, isolated coronary artery bypass surgery (CABG) was studied. Prospective data was collected on the first 375 patients receiving autotransfusion (ATS) of mediastinal shed blood. The charts of 338 patients immediately preceding the institution of the ATS program at our institution (NO ATS group) were retrospectively reviewed. Transfusion of homologous blood products and rate of re‐exploration for bleeding were closely monitored. Results: The two groups were identical. The net blood loss was significantly less in the ATS group than in the NO ATS group (1013 ± 431 cc vs 1371 ± 631 cc, p < 0.0001). Rate of exploration for postoperative bleeding was 1.5% in the ATS group and 5.0% in the NO ATS group (p < 0.01). In the ATS group, 51.9% of patients were not exposed to any homologous blood product (vs 17.8% in the NO ATS group, p < 0.0001). The ATS patients received on the average 2.9 ± 7.2 units of blood products versus 6.4 ± 9.7 units in the NO ATS group (p < 0.0001). Conclusion: Reinfusion of mediastinal shed blood significantly reduces exposure to homologous blood transfusions and rate of re‐exploration. The ATS system reduces the number of re‐explorations for coagulopathy‐related postoperative hemorrhage.

Vascular Injury and Thrombotic Potential: A Note of Caution About Recombinant Factor VIIa

Postoperative hemorrhage following cardiac surgery increases morbidity, mortality, and costs. Several case reports have described the successful use of recombinant factor VIIa to decrease or stop bleeding in patients undergoing cardiac surgery. The mechanism of action of recombinant factor VIIa is thought to be increased site-specific thrombin generation by tissue factor—mediated activation of coagulation or from activated platelets. However, there have also been many reports of thrombotic complications after recombinant factor VIIa administration. Randomized clinical trials and further laboratory studies should help better clarify the efficacy, safety, cost-effectiveness, and optimal dosing of recombinant factor VIIa in the cardiac surgical setting.

Randomised trial of mitral valve repair with leaflet resection versus leaflet preservation on functional mitral stenosis (The CAMRA CardioLink-2 Trial)

Background The gold-standard treatment of severe mitral regurgitation (MR) due to degenerative disease is valve repair, which is surgically performed with either a leaflet resection or leaflet preservation approach. Recent data suggest that functional mitral stenosis (MS) may occur following valve repair using a leaflet resection strategy, which adversely affects patient prognosis. A randomised comparison of these two approaches to mitral repair on functional MS has not been conducted. Methods and analysis This is a prospective, multicentre randomised controlled trial designed to test the hypothesis that leaflet preservation leads to better preservation of mitral valve geometry, and therefore, will be superior to leaflet resection for the primary outcome of functional MS as assessed by 12-month mean mitral valve gradient at peak exercise. Eighty-eight patients with posterior leaflet prolapse will be randomised intraoperatively once deemed by the operating surgeon to feasibly undergo mitral repair using either a leaflet resection or leaflet preservation approach. Secondary end points include comparison of repair strategies with regard to mitral valve orifice area, leaflet coaptation height, 6 min walk test and a composite major adverse event end point consisting of recurrent MR ≥2+, death or hospital readmission for congestive heart failure within 12 months of surgery. Ethics and dissemination Institutional ethics approval has been obtained from all enrolling sites. Overall, there remains clinical equipoise regarding the mitral valve repair strategy that is associated with the least likelihood of functional MS. This trial hopes to introduce high-quality evidence to help surgical decision making in this context. Trial registration number NCT02552771.

Axillary versus innominate artery cannulation for antegrade cerebral perfusion in aortic surgery: design of the Aortic Surgery Cerebral Protection Evaluation (ACE) CardioLink-3 randomised trial

Introduction Neurological injury remains the major cause of morbidity and mortality following open aortic arch repair. Systemic hypothermia along with antegrade cerebral perfusion (ACP) is the accepted cerebral protection approach, with axillary artery cannulation being the most common technique used to establish ACP. More recently, innominate artery cannulation has been shown to be a safe and efficacious method for establishing ACP. Inasmuch as there is a lack of high-quality data comparing axillary and innominate artery ACP, we have designed a randomised, multi-centre clinical trial to compare both cerebral perfusion strategies with regards to brain morphological injury using diffusion-weighted MRI (DW-MRI). Methods and analysis 110 patients undergoing elective aortic surgery with repair of the proximal arch requiring an open distal anastamosis will be randomised to either the innominate artery or the axillary artery cannulation strategy for establishing unilateral ACP during systemic circulatory arrest with moderate levels of hypothermia. The primary safety endpoint of this trial is the proportion of patients with new radiologically significant ischaemic lesions found on postoperative DW-MRI compared with preoperative DW-MRI. The primary efficacy endpoint of this trial is the difference in total operative time between the innominate artery and the axillary artery cannulation group. Ethics and dissemination The study protocol and consent forms have been approved by the participating local research ethics boards. Publication of the study results is anticipated in 2018 or 2019. If this study shows that the innominate artery cannulation technique is non-inferior to the axillary artery cannulation technique with regards to brain morphological injury, it will establish the innominate artery cannulation technique as a safe and potentially more efficient method of antegrade cerebral perfusion in aortic surgery. Trial registration number NCT02554032.

Year in review: mitral valve surgery.

Purpose of review In the past year, there has been progress on several fronts in the field of mitral valve surgery and intervention. Here, we review key publications regarding the surgical and transcatheter management of mitral valve disease. Recent findings This past year heralded the publication of the 2014 American Heart Association (AHA)/American College of Cardiology (ACC) Guidelines for the Management of Patients With Valvular Heart Disease. Regarding degenerative mitral regurgitation, low risk of operative mortality and data demonstrating clinical benefit for early surgery are prompting renewed calls for early intervention before guideline-based triggers. For functional mitral regurgitation, the precise roles of chordal-sparing replacement versus repair and the optimal management of moderate disease at the time of surgical revascularization are unclear. Sternal-sparing minimally invasive mitral valve surgery has become a mature procedure in experienced centers and offers comparable surgical morbidity and mortality with superior cosmesis and faster return to baseline function. Transcatheter interventions for mitral regurgitation continue to undergo development and testing. Mounting experience and ongoing clinical trials with the MitraClip endovascular edge-to-edge repair device will provide important data on the optimal target population for this device. Summary This past year has seen important advances in the surgical treatment of degenerative and functional mitral regurgitation as well as continued refinement of transcatheter interventions.

In collaboration with the Canadian Anesthesiologists’ Society, the Canadian Journal of Anesthesia is proud to publish the best abstracts presented at the Annual Meeting of the Canadian Anesthesiologists’ Society held in Quebec City, Quebec, June 18–22, 2004

tion by a member of the Society. The Richard Knill competition was instituted in memory of Dr. Richard Knill, a foremost researcher in anesthesiology and prominent collaborator to the Canadian Journal of Anesthesia (CJA). The Annual Meeting Committee selects the top abstracts submitted for presentation by members of the Society at the Annual Meeting. The authors are invited to present their results at the Richard Knill competition. Presentations are marked by a jury composed of the members of the Editorial Board of the CJA. In 2004, the Richard Knill Award was presented to Dr. David C. Campbell for his work on Patient Controlled Epidural Analgesia during labour.