Faculty Bibliography

BACKGROUND AND AIM OF THE STUDY: Although minimally invasive aortic valve replacement (MIAVR) is becoming an accepted technique, additional outcome evaluation is required. To correct for non-randomized treatment, the propensity score was used to analyze the present authors' experience with MIAVR compared to standard sternotomy (SS). METHODS: Between January 1995 and December 2002, a total of 921 consecutive patients underwent isolated AVR; 438 of these patients had MIAVR. Two matched cohorts each of 233 patients, and with comparable distributions of risk factors, were constructed using propensity analysis of prospectively collected data. Matching variables included left ventricular ejection fraction <30%, previous myocardial infarction, congestive heart failure, previous cardiac surgery, renal insufficiency, age, gender, chronic obstructive pulmonary disease (COPD), peripheral vascular disease, previous stroke or carotid disease, urgent/emergent operation, valvular pathophysiology, and atheromatous aortic disease. RESULTS: Hospital mortality and major morbidity were similar in the MIAVR and SS groups: 5.6% versus 7.3% (p = 0.45) and 13.3% versus 14.2% (p = 0.79), respectively. Multivariable analysis of all patients revealed increased mortality with severe atheromatous aortic disease (p = 0.001), COPD (p = 0.002), and urgent operation (p = 0.02). Freedom from any major perioperative morbidity was similar in both groups (86.7% versus 85.8%; p = 0.79). However, the median length of stay was shorter with MIAVR (6 versus 8 days; p <0.001). During the past three years, a greater percentage of MIAVR patients than SS patients was discharged home rather than sent to rehabilitation facilities or nursing homes (65.7% versus 52.9%; p = 0.05). CONCLUSION: MIAVR can be performed safely, with morbidity and mortality outcomes similar to those of standard sternotomy. MIAVR is associated with a decreased length of hospital stay, and a greater proportion of patients are discharged home directly

OBJECTIVE: Vascular injury results in activation of the mitogen-activated protein kinases-extracellular-signal regulated kinases, c-jun N-terminal kinase, and p38(MAPK)-which have been implicated in cell proliferation, migration, and apoptosis. The goal of this study was to characterize mitogen-activated protein kinase activation in arterialized vein grafts. METHODS: Carotid artery bypass using reversed external jugular vein was performed in 29 dogs. Vein grafts were harvested after 30 minutes and 3, 8, and 24 hours, and 4, 7, 14, and 28 days. Contralateral external jugular vein and external jugular vein interposition vein-to-vein grafts were used as controls. Vein graft extracts were analyzed for extracellular-signal regulated kinases, c-jun N-terminal kinase, and p38(MAPK) activation. Proliferating cell nuclear antigen expression was investigated as a parameter of cell proliferation. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling staining and intimal hyperplasia by morphometric examination of tissue sections. RESULTS: Significant intimal hyperplasia was observed at 28 days. Over the time points studied, vein graft arterialization resulted in bimodal activation of both extracellular-signal regulated kinase and p38(MAPK) (30 minutes through 3 hours; 4 days) but did not induce activation of c-jun N-terminal kinase. Proliferating cell nuclear antigen expression increased from days 1 through 28, and apoptosis increased between 8 and 24 hours. CONCLUSION: Vein graft arterialization induces bimodal activation of extracellular-signal regulated kinase and p38(MAPK); however, in contrast with what is described in arterial injury, it does not induce c-jun N-terminal kinase activation. These results provide the first comprehensive characterization of the mitogen-activated protein kinase signaling pathways activated in vein graft arterialization and identify mitogen-activated protein kinases as potential mediators of vein graft remodeling and subsequent intimal hyperplasia

BACKGROUND: Recent evolution of minimally invasive technology has expanded the application of the right thoracotomy approach for mitral valve surgery. These same technological advances have also made the left posterior minithoracotomy approach attractive in complex mitral procedures. METHODS: From 1996 to 2003, 921 isolated mitral valve procedures were performed without sternotomy; 40 (4.3%) of these were performed via left posterior minithoracotomy. In the left posterior minithoracotomy group, ages ranged from 18 to 84 years; 36 patients had had previous cardiac surgery (9 on > or =2 occasions). Other factors precluding right thoracotomy included mastectomy/radiation and pectus excavatum. RESULTS: Arterial perfusion was via femoral artery (n = 26) or descending aorta (n = 14); long femoral venous cannulas with vacuum-assisted drainage were used in 39 procedures. Two patients had direct aortic crossclamping, 18 had hypothermic fibrillation, and 20 had balloon endoaortic occlusion. The mean crossclamp and bypass times were 81.9 and 117.2 minutes, respectively. Hospital mortality was 5.0% (2/40); both deaths occurred in octogenarians. There were no injuries to bypass grafts or conversions to sternotomy. Complications included perioperative stroke (2/40; 5.0%), bleeding (2/40; 5.0%), and respiratory failure (1/40; 2.5%); 28 patients (70%) had no postoperative complications. There was no incidence of perioperative myocardial infarction, renal failure, sepsis, or wound infection. The median length of stay was 7 days. CONCLUSIONS: Advances in minimally invasive cardiac surgery technology are readily adaptable to a left-sided minithoracotomy approach to the mitral valve. The left posterior minithoracotomy approach is a valuable option in complicated reoperative mitral procedures with acceptable perioperative morbidity and mortality

OBJECTIVE: Three-dimensional motion-capture data offer insight into the mechanical differences of mitral valve function in pathologic states. Although this technique is precise, the resulting time-varying data sets can be both difficult to interpret and visualize. We used a new technique to transform these 3-dimensional ovine numeric analyses into an animated human model of the mitral apparatus that can be deformed into various pathologic states. METHODS: In vivo, high-speed, biplane cinefluoroscopic images of tagged ovine mitral apparatus were previously analyzed under normal and pathologic conditions. These studies produced serial 3-dimensional coordinates. By using commercial animation and custom software, animated 3-dimensional models were constructed of the mitral annulus, leaflets, and subvalvular apparatus. The motion data were overlaid onto a detailed model of the human heart, resulting in a dynamic reconstruction. RESULTS: Numeric motion-capture data were successfully converted into animated 3-dimensional models of the mitral valve. Structures of interest can be isolated by eliminating adjacent anatomy. The normal and pathophysiologic dynamics of the mitral valve complex can be viewed from any perspective. CONCLUSION: This technique provides easy and understandable visualization of the complex and time-varying motion of the mitral apparatus. This technology creates a valuable research and teaching tool for the conceptualization of mitral valve dysfunction and the principles of repair

OBJECTIVE: Atheromatous aortic disease is a risk factor for excessive mortality and stroke in patients undergoing coronary artery bypass grafting. Outcomes of off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass in patients with severe atheromatous aortic disease were compared by propensity case-match methods. METHODS: Routine intraoperative transesophageal echocardiography identified 985 patients undergoing isolated coronary artery bypass grafting with severe atheromatous disease in the aortic arch or ascending aorta. Off-pump coronary artery bypass grafting was performed in 281 patients (28.5%). Propensity matched-pairs analysis was used to match patients undergoing off-pump coronary artery bypass grafting (n = 245) with patients undergoing coronary artery bypass grafting with cardiopulmonary bypass. RESULTS: Univariate analysis revealed decreased hospital mortality (16/245, 6.5% vs 28/245, 11.4%; P =.058) and stroke prevalence (4/245, 1.6% vs 14/245, 5.7%; P =.03) in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass. Freedom from any postoperative complication was higher in off-pump coronary artery bypass grafting compared with coronary artery bypass grafting with cardiopulmonary bypass (226/245, 92.2% vs 196/245, 80.0%; P <.001). Multivariable analysis of preoperative risk factors showed that increased hospital mortality was associated with coronary artery bypass grafting with cardiopulmonary bypass (odds ratio = 2.7; P =.01), fewer grafts (P =.05), acute myocardial infarction (odds ratio = 11.5; P <.001), chronic obstructive pulmonary disease (odds ratio = 2.4; P =.03), previous cardiac surgery (odds ratio = 10.2, P =.05), and peripheral vascular disease (odds ratio = 2.1; P =.05). Cardiopulmonary bypass was the only independent risk factor for stroke (odds ratio = 3.6, P =.03). At 36 months' follow-up, comparable survival was observed in the off-pump coronary artery bypass grafting and coronary artery bypass grafting with cardiopulmonary bypass groups (74% vs 72%). Multivariable analysis revealed that renal disease (P <.001), advanced age (P <.001), previous myocardial infarction (P =.03), and lower number of grafts (P =.02) were independent risks for late mortality. CONCLUSIONS: Patients with severe atherosclerotic aortic disease who undergo off-pump coronary artery bypass grafting have a significantly lower prevalence of hospital mortality, perioperative stroke, and overall complications than matched patients who underwent coronary artery bypass grafting with cardiopulmonary bypass. Routine intraoperative transesophageal echocardiography identifies severe atheromatous aortic disease and directs the choice of surgical technique

BACKGROUND: Traditional mitral annuloplasty devices include both rigid rings, which restrict annular motion, and soft rings and bands, which can locally deform. Conflicting data exist regarding their impact on annular dynamics. We studied mitral annuloplasty with a semirigid partial band and with a nearly complete rigid ring. METHODS: Intraoperative three-dimensional transesophageal echocardiograms (n = 14) and predischarge transthoracic echocardiograms were retrospectively analyzed in patients undergoing mitral valve repair for degenerative disease with either a rigid ring (n = 77) or a semirigid partial band (n = 38). Each transesophageal echocardiogram was analyzed with TomTec three-dimensional software to produce cardiac cycle frame planimetry and to measure device geometry. Actual device sizes provided reference dimensions. Blinded analysis of Doppler data from transthoracic echocardiograms was performed. RESULTS: Validation of the quantitative transesophageal echocardiogram methodology revealed a 1.3% +/- 0.3% (mean +/- standard error of the mean) underestimation of actual linear dimension. With the semirigid partial band, systolic valve orifice area and intertrigonal distance decreased from 6.14 +/- 0.37 to 5.55 +/- 0.24 cm(2) (-9.6%; p = 0.01) and from 2.69 +/- 0.08 to 2.55 +/- 0.13 cm (-5.2%; p = 0.03), respectively. Systolic anterior-posterior distance decreased from 2.1 +/- 0.10 to 1.95 +/- 0.06 cm (-7.1%; p = 0.01) compared with diastole. In contrast, rigid ring orifice area was unchanged (4.12 +/- 0.15 to 4.10 +/- 0.16 cm(2); -0.5%; p = 0.48) during the cardiac cycle. Transthoracic echocardiography revealed significantly lower mitral inflow gradients with semirigid partial band (mean gradients compared with rigid ring, 4.0 +/- 0.3 versus 5.0 +/- 0.3 mm Hg; p = 0.02; peak gradients, 8.9 +/- 0.5 versus 11.1 +/- 0.5 mm Hg; p = 0.01). CONCLUSIONS: Three-dimensional transesophageal echocardiographic measurements of annular dynamics are valid and reliable when discrete annuloplasty devices are present. In contrast to the rigid ring, the semirigid partial band permits more physiologic geometric changes and is associated with lower postoperative mitral valve gradients