Cardiopulmonary bypass for adult patients: a survey of equipment and techniques.

OBJECTIVES: The techniques and equipment used for cardiopulmonary bypass for adult cardiac surgery vary among institutions and may change over time. This study sought to document the changing patterns of practice. DESIGN: Voluntary survey of meeting participants. SETTING: 13th Annual San Diego Cardiothoracic Surgery Symposium (February 1993). PARTICIPANTS: There were 331 responses from perfusionists (79.5%), cardiac surgeons (11.2%), and anesthesiologists (6.3%). The majority of these participants were from institutions where more than 1,000 cardiac operations were performed annually. MEASUREMENTS AND MAIN RESULTS: It was found that 91.5% of the respondents used membrane oxygenators currently, compared with 5% in 1982 (as reported in a previous survey). Over 80% of the institutions surveyed used some type of perioperative cell-salvaging technique. Arterial line filters were used by 92% of the respondents compared with 64% in 1982. Also, 80% of the respondents were aware of the availability of leukocyte-depleting filters. CONCLUSIONS: The probable reasons for the increased utilization of membrane oxygenators and arterial line filters include less damage to the formed elements of blood, fewer gaseous microemboli, and better control of carbon dioxide elimination and oxygenation. The authors anticipate that future surveys will document increased use of leukocyte-depleting filters because of the literature implicating neutrophils as mediators of tissue destruction in various disease processes, including myocardial reperfusion injury.

The natural history of thoracic aortic aneurysms.

Because improved understanding of the natural history of thoracic aneurysms would enhance our ability to determine in which cases the risk of surgical treatment is justified, the rate of enlargement of thoracic aneurysms and thoracoabdominal aneurysms was studied in 67 patients by means of serial computer-generated three-dimensional reconstructions of computed tomographic scans. Patients were followed for a mean of 1.5 +/- 0.15 years (0.2 to 5.35 years) with an average interval between examinations of 0.9 +/- 0.1 year (0.2 to 5.0 years). Thirty-nine patients continue to be followed; 7 were lost to follow-up; 14 died during follow-up (4 after aneurysm rupture), and 10 underwent an operation. Indications for operation included the presence of pain, an absolute aortic diameter larger than 8 cm, an increase in aortic diameter of more than 1 cm per year, or marked irregularity of aneurysm contour. Aortic diameter and volume data were generated from the aortic silhouette obtained by tracing each computed tomographic slice with a translucent digitizing tablet. Estimated change in aortic diameter after 1 year was 0.43 cm; estimated change in aortic volume was 88.1 ml. The impact of possible risk factors on the enlargement of aneurysms was examined by analysis of variance (p < 0.05). A significantly higher rate of aneurysm expansion was found in patients with a larger aortic diameter (> 5 cm) at diagnosis (change in diameter = 0.17 cm versus 0.79 cm; change in volume = 40 ml versus 141.8 ml), and in smokers (change in diameter = 0.35 cm versus 0.70 cm; change in volume = 78.3 ml versus 120.8 ml). Changes in diameter and volume for aneurysms of different initial diameters and volumes was predicted by exponential regression by the equations: change in diameter = 0.0167 (initial aortic diameter)2.1; change in volume = 0.0356 (initial aortic volume)1.322. No correlation was noted between the rate of enlargement and age, sex, or the presence of dissection. A history of hypertension correlated with a greater aortic diameter at diagnosis but did not significantly affect the rate of enlargement.(ABSTRACT TRUNCATED AT 250 WORDS)