APROTININ AND DEEP HYPOTHERMIC CIRCULATORY ARREST - THERE ARE NO BENEFITS EVEN WHEN APPROPRIATE AMOUNTS OF HEPARIN ARE GIVEN

Objective: To evaluate retrospectively the effect of 'high-dose' aprot inin on blood losses, donor blood requirements and morbid events on pa tients undergoing ascending aorta and/or aortic arch procedures with t he employ of deep hypothermic circulatory arrest (HCA). Methods: Durin g the period 1987-1994, 39 patients underwent a thoracic aorta procedu re with the employ of circulatory arrest; of these 18 (46.2%) were ope rated on during the period 1990-1994 and were given aprotinin intraope ratively following the 'high-dose' protocol (group I), while 21 (53.8% ) who underwent surgery during the years 1987-1989, did not receive in traoperative aprotinin and served as historical controls (group II). T wenty-seven (69.2%) patients were male, 18 (46.2%) were operated on on an emergency basis, 15 (38.5%) were acute type A dissections, and two (5.1%) were redo-operations. Circulatory arrest times were not signif icantly different between the two groups (40 +/- 4 (S.E.) group I vs. 43 +/- 4 min group II, P = 0.62) likewise cardiopulmonary bypass (CPB) times (181 +/- 9 vs. 201 +/- 20 mm, P = 0.74) and the amount of hepar in administered (32 056 +/- 1435 vs. 31 691 +/- 1935 IU, P = 0.56). Re sults: Postoperative blood loss was comparable between the two groups (1213 +/- 243 (median 850) group I vs. 1528 +/- 377 (median 880) mi gr oup II, P = 0.87), as well as the number of units of donor blood trans fused (9.4 +/- 3.0 (median 6) vs. 9.9 +/- 3.6, (median 5) P = 0.87), a nd revisions for bleeding (2/18, 11.1% vs. 3/21, 14.3%, P = 0.77). In- hospital mortality rate was not statistically different (5/18, 27.7% g roup I vs. 6/21, 28.6% group II, P = 0.92). There were no significant differences between the two groups in myocardial infarction (2/18, 11. 1% vs. 0/21, 0%, P = 0.21), and postoperative renal failure rates (3/1 8, 16.7% vs. 2/21, 9.5%, P = 0.65). On the other hand, there was a tre nd towards an increased incidence of permanent neurological deficit (5 /18, 27.7% group I vs. 1/21, 4.8% group II, P = 0.07) and towards a mo re complicated postoperative course (perioperative renal failure and/o r myocardial infarction and/or neurological deficit either transient o r permanent) (8/18, 44.4% group I vs. 4/21, 19% group II, P = 0.09) in group I patients. Forward stepwise logistic regression analysis, perf ormed on the whole group of patients, identified chronic obstructive p ulmonary disease (P = 0.010, Odds ratio (OR) = 5.7), aprotinin use (P = 0.017, OR = 5.1), and the number of units of blood collected intraop eratively by the cellsaver (P = 0.045, OR = 1.3/unit) as independent p redictors of complicated postoperative course in the whole group of pa tients. CPB time (P = 0.040, OR = 1.032/min), circulatory arrest time (P = 0.053, OR = 1.22/min), and overall donor blood units transfused ( P = 0.067, OR = 1.37/unit) emerged as independent risk factors for in- hospital mortality at multivariate analysis. Conclusions: Even when ap propriate amounts of heparin are administered, 'high-dose' aprotinin p robably is not an effective blood-sparing drug in deep HCA. Aprotinin should be employed cautiously in this clinical setting because of its possible correlation with an increased rate of postoperative morbid ev ents. Copyright (C) 1997 Elsevier Science B.V.