Faculty Bibliography

OBJECTIVE: Although it has been postulated that minimally invasive cardiac surgery using the port access method would reduce operative stress and postoperative pain and accelerate postoperative recovery to a good quality of life, few data are currently available to document this intuitively appealing claim. Therefore, this study was designed to examine differences in stress response, postoperative pain, rapidity of recovery, and quality of life after port access (PA) isolated coronary artery bypass surgery compared with standard sternotomy (STD) isolated coronary bypass surgery. METHODS: Fourteen PA and 15 STD coronary bypass patients were studied postoperatively for pain score, FEV, catecholamine and cortisol levels, resumption of activity, and Duke Activity Scale ratings. The surgical approach was based on the surgeon's preference. Although the PA patients were younger, there were no other differences between the groups in gender or preoperative risk factors. RESULTS: There were no operative deaths and no differences between the groups in perioperative complications. Repeated measures analysis of variance showed lower pain scale ratings over the first 4 postoperative weeks in the PA group (P < 0.001). The PA patients also had less muscle soreness, shortness of breath, fatigue, and poor appetite at 1, 2, 4, and 8 weeks (P < 0.05), better FEV at 1 day (1.59 vs. 0.97 l/s; P < 0.02) and 3 days (2.20 vs. 1.49 l/s; P < 0.03), and lower norepinephrine levels at days 1, 2, and 3 (P = 0.005). The Duke Activity Scale questionnaire results demonstrated that more PA patients were able to walk 1-2 blocks at 1 week, climb stairs at 1 and 2 weeks, perform light or moderate housework at 1 and 2 weeks, and engage in moderate recreational activities and perform heavy housework at 4 and 8 weeks (P < 0.05). CONCLUSIONS: These results show that compared with STD coronary bypass patients PA patients enjoyed significant postoperative physiologic and quality of life advantages with less pain, less early stress response, better pulmonary function, and superior Duke Activity scores during the first 2 postoperative months

BACKGROUND: We reviewed the initial patient series of three institutions performing large volume port-access (PA) coronary artery bypass grafting (CABG) to evaluate the efficacy of this new procedure. METHODS: From October 1996 until June 1998, 302 consecutive patients underwent isolated CABG using the PA approach. Patients (mean age 60.7 years) were predominantly male (77.5%) and received a mean of 2.3 distal anastomoses; few were New York Heart Association class III or IV (15.9%). The distribution of the number of grafts was: 76 (25.2%) single, 110 (36.4%) double, 73 (24.2%) triple, and 43 (14.2%) four or more bypass grafts. The Society of Thoracic Surgeons (STS) Database data collection form was used prospectively by all three institutions to define patient risk factors and record outcomes. RESULTS: Total 30-day hospital mortality was 0.99% compared to the STS-database-model-predicted risk of 1.2%. Complication rates for the PA CABG patients compared with risk-matched morbidity rates from the STS data for CABG alone were: reoperation for bleeding, 3.3% versus 1.9%; ventilatory support more than 1 day, 1.7% versus 3.8%; stroke, 1.7% versus 1.2%; and perioperative transmural myocardial infarction 0% versus 1.3%. CONCLUSIONS: The STS CABG risk-adjusted model demonstrates that the 30-day mortality for patients undergoing PA CABG is lower than predicted for traditional CABG patients (confidence intervals not available). Likewise, the morbidity was low, with minimal ventilatory support, pulmonary complications, and atrial fibrillation. The port-access technique is an acceptable strategy for multivessel bypass grafting

BACKGROUND. Angiogenesis requires degradation of the vessel's basal lamina and endothelial cell migration into the tissue stroma. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play important roles in this process. MMP activity is tightly regulated during vessel growth. This work was designed to characterize the effect of TIMP-1 upregulation on endothelial cell invasion of the extracellular matrix. METHODS. We constructed replication-deficient recombinant adenoviruses that encode either TIMP-1 (Ad.TIMP-1) or Escherichia coli lac Z (Ad.beta gal) cDNA. Bovine aortic endothelial (BAE) cells were infected with 100 infectious particles/cell. Gene expression was assessed by Northern and Western blotting. TIMP-1 activity in cell-conditioned media was measured by a resorufin-labeled casein protease assay. BAE cell migration was measured by Boyden chamber assays with 0.2% gelatin-coated, 8. 0-mcm polycarbonate membranes. RESULTS. TIMP-1 was overexpressed by Ad.TIMP-1-infected BAE cells relative to control, Ad. beta gal-infected or uninfected cells. TIMP-1 activity in Ad.TIMP-1 cell-conditioned medium was 2.8-fold higher than in control cells. By Boyden chamber assays with gelatin-coated membranes, Ad. TIMP-1-infected BAE cells showed 89.97 +/-1.64% (mean +/- SEM) reduction in migration relative to Ad.beta gal-infected cells (P < 0. 02) and 90.53 +/- 1.12% relative to uninfected cells (P < 0.02). Without gelatin coating, migration was equivalent in all groups. CONCLUSION. The replication-deficient recombinant adenovirus we constructed affords rapid and efficient upregulation of functional TIMP-1 in endothelial cells. Infection results in a dramatic decrease in cell migration and invasion of extracellular matrix. Thus, such a recombinant vector may provide a useful tool for the gene therapy of vascular remodeling and inhibition of angiogenesis.

BACKGROUND: Although minimally invasive techniques for valvular surgery have rapidly come into widespread use, whether such an approach can be safely applied to elderly patients remains an open question. To help resolve this issue, we reviewed our experience with minimally invasive port access (MIPA) valve surgery in elderly patients and compared it to the results obtained with the standard sternotomy (STD) approach in the same age group. METHODS: From January 1994 through December 1998, 370 consecutive patients at least 70 years of age underwent isolated aortic or mitral valve surgery at our institution. The standard sternotomy operative approach was used in 259 patients (mean age 77.5 years) and the minimally invasive port access approach was used in 111 patients (mean age 76.0; p=.006). A mitral valve procedure was performed more often in the MIPA patients than in the STD patients (49.5% vs. 35.9%; p < .001). RESULTS: Hospital mortality was comparable in the two groups, 9.7% (25/259) in the STD group and 7.2% (8/111) in the MIPA group (p = .50), as was the incidence of many perioperative complications. The MIPA group, however, had a significantly lower incidence of sepsis or wound complications (1.8% vs 7.7%; p = .027), required less fresh frozen plasma transfusion (median 1.0 unit vs 2.0 units; p =.04), and had a shorter length of hospital stay (11.6 days vs 17.6 days; p = .001). CONCLUSIONS: These results indicate that with appropriate surgical techniques the MIPA approach for isolated valve surgery can be safely applied to the elderly patient population with excellent results. In our initial experience the MIPA approach is associated with significantly less plasma transfusion, fewer postoperative complications, and shorter length of hospital stay

The recent development of endovascular catheters that are placed via the femoral artery and vein has enabled patients to be placed on cardiopulmonary bypass without the need for direct visualization of the heart or great vessels via sternotomy. This has allowed cardiac surgery to be performed through smaller, thoracotomy incisions. Placement of these catheters initially was performed under fluoroscopic guidance, which has major imaging limitations. Now, transesophageal echocardiography (TEE) has replaced fluoroscopy as the primary imaging technique to assist in the placement of endovascular catheters during minimally invasive, port-access cardiac surgery. In our institution, 449 port-access procedures have been performed from May 1996 through July 1998. We found that TEE is able to adequately visualize the cardiac structures and assist in the placement of the endovascular catheters in all patients. Fluoroscopy is helpful only as an aid to the use of TEE for placement of the coronary sinus catheter

The port-access approach for coronary artery bypass grafting is an excellent technique for minimal access, multivessel coronary revascularization. Patient selection criteria, technical aspects, and clinical results are reviewed