Single aortic cross-clamp technique in coronary surgery: a prospective randomized study

EUROPEIIN ,O”P.NAL OF CARDIO-THORACIC SURGERY European Journal of Cardio-thoracic Surgery 12 (1997) 413-418 Single aortic cross-clamp technique in coronary surgery: a prospective randomized study’ Department of Cardiovascular Surgery, Renzo Pessotto, University of Verona Medical School, OCM Borg0 Trento, Piazzale Stefani 1, 37126 Verona, Italy Received 4 December 1996; received in revised form 7 April 1997; accepted 25 April 1997 Abstract Objective: To test the lrypothesis of an improved myocardial and cerebral prqtection by combining blood cardioplegia and the single aortic cross-clamp technique, 100 patients were enrolled in a prospectively randomized study and stratitied for preoperative conditions. Methods: In Group I, 55 patients underwent myocardial revascularization using crystalloid cardioplegia and the conventional partial occluding clamp technique to perform proximal anastomoses, whereas in Group II, 45 patients were operated on combining blood cardioplegia and the single aortic cross-clamp technique. Unstable angina, emergency procedures, reoperations and preoperative counterpulsation accounted for an higher risk score in group II patients (P < 0.03). Operations were performed by the same surgical team. Aortic cross-clamp time was significantly longer in group II patients (59 + 22 vs. 47 + 18 min.) (P < 0.001). Other intraoperative variables were not significant. Results: A 70-year-old male in group I died on post-operative day 5 as a consequence of a major neurological event. Length of ventilatory dependency, post-operative bleeding, need for blood transfusions, ICU stay, and hospital stay were similar between the two groups (P = NS). Patients in group I showed a strict correlation between the duration of surgical ischemia and post-operative myocardial necrosis. Analysis of combined mortality and morbidity events (adverse events) between the two groups, led to a significant prevalence in group I patients (P < 0.03) in spite of an higher pre-operative risk score and longer iscaemic times in group II patients. Neurological lesions remained confined to group I patients. Conclusions: The combined use of blood cardioplegia, delivered via the antegrade and retrograde routes, and the single-clamp technique to perform myocardial revascularization, might enhance myocardial and cerebral protection when compared to conventional methods. Larger groups of patients are needed to support this trend. 0 1997 Elsevier Science B.V. Keywords: Cardioplegia; Myocardial protection 1. Introduction In the last few years, indication for myocardial revascularization has been progressively extended to include sicker patients with severely diseased coronary arteries, poor left ventricular function; and often diffuse *Corresponding author. Tel.: + 39 45 8072476; fax: + 39 45 8073308. ’ Presented at the 10th Annual Meeting of the European Association for Cardio-thoracic Surgery, Prague, Czech Republic, 6-9 October 1996. IOIO-7940/97/%17.00 0 1997 Elsevier Science B.V. All rights reserved. PZZSlOlO-7940(97)00148-6 atherosclerotic disease of the ascending aorta. Similarly, the spreading utilization of percutaneous transluminal coronary angioplasty (F’TCA) has indirectly selected for surgical treatment those patients, often in poor clinical conditions, with more diffuse coronary lesions. Facing the challenge of operating on a more demanding cohort of patients, the development of highly efficacious systems of myocardial protection soon appeared to be mandatory. To this aim, a relatively recent advance was represented by the use of a combination of antegrade and retrograde routes for infusion of the cardioplegic solution in order to achieve a more homogeneous distri- Paolo Bertolini *, Francesco Santini, Giuseppe Montalbano, Alessandro Mazzucco 414 P. Bertolini et al. /European Journal of Cardio-thoracic Surgery 12 (1997) 413-418 Table I Patients population Age Weight NYHA IV Mainstem lesions 3 Vessels disease Emergency Unstable angina Re-do operation Pre-op IABP Diabetes LVEF <30% GII P value 63 48 72 + 9 12 (22%) 9 (16%) 33 (16%) 2 (3.6%) 1(13%) 2 (3.6%) 1 (1.8%) 16 (29%) 3 (3.5%) 62 * 8 76k 10 10 (22%) 5 (11%) 5 (11%) 5 (11%) 15 (33%) 4 (9%) 3 (6.7%) 9 (20%) 5 (11%) Ns NS NS NS NS NS <0.03 NS NS NS NS of coronary disease. However, patients in GII had a prevalence of unstable angina approaching statistical significance. Patients undergoing emergency operations, redo revascularization procedures, and those with preoperative intraaortic balloon counterpulsation were also more frequent in GII (P = NS). Patients with carotid artery disease were excluded from the study. In our series, we adopted a stratification of the pre-operative risk according to the criteria described for patients undergoing coronary surgery at the Cleveland Clinic [Ill. According to these criteria, 76% of all patients were in the low risk class (score O-5), whereas 24% were in the high risk (score 6-10) (Fig. 1). Six patients in GI and 18 in GII belonged to the high risk class (P < 0.03). 2.1. Operative technique Median sternotomy was followed by harvesting of the internal mammary artery, when indicated. After institution of cardiopulmonary by-pass using a double stage venous cannula and venting the left ventricle, rectal temperature was lowered down to 28°C in all 2. Patients and methods A total of 100 patients who underwent myocardial revascularization at the Department of Cardiovascular Surgery of the University of Verona Medical School (Italy) between November 1994 and December 1995 entered this study. There were 78 males and 22 females, with a mean age of 62.2 + 8.2 years (range, 36-76 years). Informed consent was obtained from each patient prior to the enrollment in the study. Patients with a recent history of myocardial infarction and those needing associated procedures were excluded. Pre-operative variables of patients in Group I (GI) (no. = 55) and Group II (GII) (no. = 45) are reported in Table 1. There were no statistically significant differences between the two groups in age, sex and extension GI pre-operative risk score 50 45 40 35 30 25 20 15 10 5 0 I-5 26 Fig. 1. Pre-operative risk score. bution in the presence of diffuse coronary lesions [l-3]. In addition, different cardioplegic solutions were developed among which the use of blood cardioplegia, utilized according to different protocols, soon gained wide popularity [4]. However, although the superiority of myocardial protection provided by the use of blood cardiplegia alone was clearly demonstrated in experimental studies, its superiority in controlled clinical series appears still to be controversial [5]. Indeed, also a prospective randomized trial developed at our Institution in the past four years, where two group of patients underwent revascularization using conventional surgical technique and blood versus crystalloid cardioplegia for myocardial protection, failed to show any statistically significant difference be (...truncated)