Disproportionate enlargement of the pulmonary autograft in the aortic position in the growing pig.

PURPOSE: This study was aimed to demonstrate growth in the pulmonary autograft after transplantation to the aortic position. METHODS AND MATERIALS: In 20 piglets (weight 25.4 +/- 3.5 kg) (mean +/- standard deviation) a Ross operation was performed and in five piglets (weight 9.3 +/- 0.7 kg) (mean +/- standard deviation) the ascending aorta was replaced with a valveless pulmonary autograft. Animals were allowed to grow as much as possible. Postmortem explanted autografts were studied by direct measurements of the valve cusps in the Ross group and of the wall segments in the valveless autograft group. Measurements of the first group were compared with the values of a separate control group, and values of the second group were compared with values of samples taken at operation. RESULTS: In the Ross group, cuspal weight, height, and width increased significantly by comparison with body weight (p < or = 0.003). The rate of increase did not differ significantly from that of the control group with a native pulmonary valve. However, there was a rapid adaptation of the autograft valves resulting in a significantly higher mean cuspal weight, height, and width. In the valveless autograft group, wall circumference, thickness, and height increased significantly (p < or = 0.001). The circumference increased significantly more than that of the native pulmonary wall. Compared with the native aortic wall, the pulmonary autograft media showed retained pulmonary architecture on microscopic study. CONCLUSION: These data suggest that the dimensional increase of the pulmonary autograft in the aortic position in the growing pig is determined by growth and dilatation, that the valve mass increases more than that of the native pulmonary valve, and that the characteristic pulmonary microscopic architecture is retained.

Intraoperative physiologic variables and outcome in cardiac surgery: Part I. In-hospital mortality.

BACKGROUND: Risk stratification schemes have been developed to predict outcome of coronary artery bypass grafting (CABG) procedures, which are predominately based upon unalterable preoperative patient characteristics. The purpose of this study was to determine if minimum intraoperative hematocrit, maximum glucose concentration, mean arterial pressure on cardiopulmonary bypass, or duration of bypass influence risk-adjusted in-hospital mortality after CABG. METHODS: Outcome data from 2,862 CABG patients were merged with intraoperative physiologic data. A preoperative mortality risk index was calculated for each patient. Variables found significant (p<0.05) by univariate logistic regression were tested in a multiple variable model to determine risk-adjusted association with mortality. RESULTS: Overall mortality rate was 1.85%. The preoperative risk index was significantly associated with mortality (p = 0.0001). No significant association was present between mortality and intraoperative variables. Preexisting hypertension was an independent predictor of mortality after controlling for risk index and bypass duration. CONCLUSIONS: Preexisting hypertension proved to be an independent predictor of mortality in our patient population. This study found no evidence to support the hypothesis that mean arterial pressure less than 50 mm Hg, lower hematocrit, or elevated glucose while on bypass increases in-hospital mortality.

Intraoperative physiologic variables and outcome in cardiac surgery: Part II. Neurologic outcome.

BACKGROUND: The impact of alterable physiologic variables on neurologic outcome after coronary artery bypass grafting procedures is unknown. The purpose of this study was to determine whether minimum intraoperative hematocrit, maximum glucose concentration, or mean arterial pressure during cardiopulmonary bypass influences risk-adjusted neurologic outcome after coronary artery bypass grafting. METHODS: Outcome data from 2,862 patients undergoing coronary artery bypass grafting were merged with intraoperative physiologic data. A preoperative stroke risk index was calculated for each patient. Variables found significant by univariate logistic regression were tested in a multivariable model to determine association with outcome. RESULTS: The incidence of stroke or coma in the study population was 1.3%. After controlling for stroke risk and bypass time, only an index of low mean arterial pressure during bypass retained a significant inverse association with outcome (p = 0.0304). CONCLUSIONS: This study found no evidence that glucose concentration or minimum hematocrit are associated with major adverse neurologic outcome. The association between lower pressure during bypass and decreased incidence of stroke or coma persisted in all risk groups. This points to mechanisms other than hypoperfusion as the primary cause of neurologic injury associated with cardiac surgery.

[Diagnostic image (171). A man with a painful red ear. Relapsing polychondritis]. / Diagnose in beeld (171). Een man met een pijnlijke, rode oorschelp. Recidiverende polychondritis.

A 50-year-old man presented with a painful and red swollen right ear, fever, iridocyclitis and a peripheral facial nerve palsy, due to relapsing polychondritis. Immunosuppressive therapy was successful.

A comparison of intra- versus post-operatively acquired electrically evoked compound action potentials.

The objective of this study was to compare the electrically evoked compound action potentials, intra- versus post-operatively, in cochlear implant patients. In a prospective study twenty-five consecutively implanted adult patients received a multichannel cochlear implant. In all patients, electrically evoked compound action potentials were recorded immediately after cochlear implantation and in a post-operative setting nine months later. The threshold of the electrically evoked compound action potential was determined in both settings. A high success rate (97.4%) was found in the intra-operative setting when recording the electrically evoked compound action potential threshold per patient. The success rate per patient was significantly lower (53.4%) in the post-operative setting. Correlations between the intra- versus the post-operative ECAP thresholds were statistically significant for all electrodes tested. The ECAP thresholds were not significantly different for the two settings. The intra-operative setting is preferable for acquisition of the ECAP threshold.