Thomas Pfeffer

Intraoperative autotransfusion reduces blood loss after cardiopulmonary bypass

BACKGROUND A combination of several techniques is necessary to minimize the transfusion requirements for open heart operations. The benefit of plasmapheresis remains in doubt because of smaller and less effective platelets obtained with this technique. Therefore, we evaluated the effects of whole blood intraoperative autotransfusion as part of a blood conservation protocol. METHODS One hundred patients undergoing coronary artery bypass graft operations were randomized to an autotransfusion group (group A) or control group (group C). Group A patients had a 10 mL/kg of whole blood removed before cardiopulmonary bypass; they had retransfusion at the termination of cardiopulmonary bypass and heparin reversal. Both groups had intraoperative cell saving and autotransfusion of shed mediastinal blood postoperatively. The indications for blood transfusion were standardized, and the physicians ordering blood products were blinded to the study. RESULTS Compared with the control group, patients in the autotransfusion group had a 28% reduction of chest tube drainage at 8 hours and a 45% reduction in the total homologous blood units transfused. CONCLUSIONS Autotransfusion during cardiopulmonary bypass provides benefit in addition to other techniques in reducing blood loss and the need for blood products in the postoperative period.

Pulmonary abnormalities after coronary arterial bypass grafting operation: cardiopulmonary bypass versus mechanical stabilization.

BACKGROUND Cardiopulmonary bypass has been implicated in causing poor pulmonary gas exchange postoperatively in patients undergoing coronary artery bypass grafting procedures. This randomized prospective study was conducted to determine whether patients undergoing coronary artery bypass grafting operations using cardiac stabilization and thereby avoiding cardiopulmonary bypass will have improved pulmonary function postoperatively. METHODS Fifty-eight patients were randomized to one of two groups: coronary artery bypass grafting operation with stabilization or coronary artery bypass grafting operation with cardiopulmonary bypass. Preoperative and postoperative pulmonary gas exchange measurements were performed on intubated patients, including the arterial partial pressure of oxygen on 100% inspired oxygen, the alveolar-arterial oxygen gradient, and pulmonary shunt. Static and dynamic lung compliance measurements were performed postoperatively. Hemodynamic variables (including creatine kinase-MB and troponin levels), intubation time, postoperative bleeding, and blood transfusions were compared. RESULTS Both study groups had a large decrease in arterial partial pressure of oxygen on 100% inspired oxygen (p < 0.0001) and a significant postoperative increase in the alveolar-arterial oxygen gradient (p < 0.0001). There was no statistical difference in the postoperative gas exchange between the two groups; however, the postoperative pulmonary shunt was significantly better in the stabilization group (24% versus 31%, p = 0.03). The patients were extubated in the intensive care unit earlier in the stabilization group (8.2 hours versus 9.2 hours, not significant). The mean static and dynamic lung compliance postoperatively was lower in the stabilization group, although not statistically significant (p = 0.06). CONCLUSIONS Coronary artery bypass grafting operation using cardiac stabilization technique is safe and avoids the risk of cardiopulmonary bypass. The pulmonary gas exchange postoperatively is comparable to standard cardiopulmonary bypass procedures, but a reduced postoperative pulmonary shunt was seen in the stabilization group.

Mitral valve replacement: Technique to preserve the subvalvular apparatus

A technique is described for retaining the entire subvalvular apparatus in an anatomic fashion during mitral valve replacement that has resulted in no ventricular outflow tract obstruction or interference by retained chordal structures with prosthetic valve function in 128 patients.

Outcomes in the Randomized CoreValve US Pivotal High Risk Trial in Patients With a Society of Thoracic Surgeons Risk Score of 7% or Less

Importance Transcatheter aortic valve replacement (TAVR) is now a well-accepted alternative to surgical AVR (SAVR) for patients with symptomatic aortic stenosis at increased operative risk. There is interest in whether TAVR would benefit patients at lower risk. Objective The Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) has trended downward in US TAVR trials and the STS/American College of Cardiology Transcatheter Valve Therapy Registry. We hypothesized that if the Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM) alone is sufficient to define decreased risk, the contribution to survival based on the degree of invasiveness of the TAVR procedure will decrease, making it more difficult to show improved survival and benefit over SAVR. Design, Setting, and Participants The CoreValve US Pivotal High Risk Trial was a multicenter, randomized, noninferiority trial. This retrospective analysis evaluated patients who underwent an attempted implant and had an STS PROM of 7% or less. The trial was performed at 45 US sites. Patients had severe aortic stenosis and were at increased surgical risk based on their STS PROM score and other risk factors. Interventions Eligible patients were randomly assigned (1:1) to self-expanding TAVR or to SAVR. Main Outcomes and Measures We retrospectively stratified patients by the overall median STS PROM score (7%) and analyzed clinical outcomes and quality of life using the Kansas City Cardiomyopathy Questionnaire in patients with an STS PROM score of 7% or less. Results The mean (SD) ages were 81.5 (7.6) years for the TAVR group and 81.2 years (6.6) for the SAVR group. A little more than half were men (57.9% in the TAVR group and 55.8% in the SAVR group). Of 750 patients who underwent attempted implantation, 383 (202 TAVR and 181 SAVR) had an STS PROM of 7% or less (median [interquartile range]: TAVR, 5.3% [4.3%-6.1%]; SAVR, 5.3% [4.1%-5.9%]). Two-year all-cause mortality for TAVR vs SAVR was 15.0% (95% CI, 8.9-10.0) vs 26.3% (95% CI, 19.7-33.0) (log rank P = .01). The 2-year rate of stroke for TAVR vs SAVR was 11.3% vs 15.1% (log rank P = .50). Quality of life by the Kansas City Cardiomyopathy Questionnaire summary score showed significant and equivalent increases in both groups at 2 years (mean [SD] TAVR, 20.0 [25.0]; SAVR, 18.6 [23.6]; P = .71; both P < .001 compared with baseline). Medical benefit, defined as alive with a Kansas City Cardiomyopathy Questionnaire summary score of at least 60 and a less than 10-point decrease from baseline, was similar between groups at 2 years (TAVR, 51.0%; SAVR, 44.4%; P = .28). Conclusions and Relevance Self-expanding TAVR compares favorably with SAVR in high-risk patients with STS PROM scores traditionally considered intermediate risk. Trial Registration Clinicaltrials.gov Identifier: NCT01240902.

Freestyle Valve Experience: Technical Considerations and Mid-term Results

Abstract Background: Many studies have demonstrated the superior hernodynamics of stentless porcine aortic valves compared to stented valves. This article describes the operative techniques and reviews our 5‐year experience with the Medtronic Freestyle stentless valve. Methods: Between January 1993 and November 1997, 95 patients underwent implantation of the Medtronic Freestyle valve at a mean age of 76 years. All patients were seen at 6 months, 1 year, and annually thereafter for clinical assessment and Doppler echocardiography. Results: There were three operative and ten late deaths (two cardiac and eight noncardiac). Three strokes and four transient ischemic attacks occurred in the follow‐up period. Four patients had bacteremia that was treated successfully with antibiotics. No patient required reoperation for valve‐related problems. Serial echocardiograms revealed a decrease in mean systolic gradients across the valve during the first year and an increase in effective orifice areas. Ninety‐one percent of patients had no, or trace, aortic insufficiency at the time of discharge and this has not increased over time. Conclusion: The Medtronic Freestyle valve has excellent hemodynamics and good clinical results. In our experience, no patient has required reoperation in a 5‐year follow‐up.

Effective median sternotomy closure in high-risk open heart patients.

We describe a novel surgical technique with a median sternotomy closure in high-risk open heart patients. In contrast to conventional sternal closure, in which sternal wires are passed through the intercostal space, the novel technique in sternal closure passes sternal wires transcostally or through costo-chondral joints.