Faculty Bibliography

OBJECTIVE:This study evaluated the smooth muscle functional response and viability of human saphenous vein (HSV) grafts after harvest and explored the effect of mechanical stretch on contractile responses of porcine saphenous vein (PSV). METHODS:The contractile responses (stress, 10(5) N/m(2)) of deidentified, remnant HSV grafts to depolarizing potassium chloride and the agonist norepinephrine were measured in a muscle organ bath. Cellular viability was evaluated using a methyl thiazole tetrazolium (MTT) assay. A PSV model was used to evaluate the effect of radial, longitudinal, and angular stretch on smooth muscle contractile responses. RESULTS:Contractile responses varied greatly in HSV harvested for autologous vascular and coronary bypass procedures (0.04198 ± 0.008128 × 10(5) N/m(2) to 0.1192 ± 0.02776 × 10(5) N/m(2)). Contractility of the HSV correlated with the cellular viability of the grafts. In the PSV model, manual radial distension of ≥ 300 mm Hg had no impact on the smooth muscle responses of PSV to potassium chloride. Longitudinal and angular stretch significantly decreased the contractile function of PSV by 33.16% and 15.26%, respectively (P < .03). CONCLUSIONS:There is considerable variability in HSV harvested for use as an autologous conduit. Longitudinal and angular stretching during surgical harvest impairs contractile responsiveness of the smooth muscle in saphenous vein. Avoiding stretch-induced injuries to the conduits during harvest and preparation for implantation may reduce adverse biologic responses in the graft (eg, intimal hyperplasia) and improve patency of autologous vein graft bypasses.

BACKGROUND:A simplified minimally invasive mitral valve surgery (MIMVS) approach avoiding cross-clamping and cardioplegic myocardial arrest using a small (5 cm) right antero-lateral incision was developed. We hypothesized that, in high-risk patients and in patients with prior sternotomy, this approach would yield superior results compared to those predicted by the Society of Thoracic Surgeons (STS) algorithm for standard median sternotomy mitral valve surgery. METHODS:Five hundred and four consecutive patients (249 males/255 females), median age 65 years (range 20-92 years) underwent MIMVS between 1/06 and 8/09. Median preoperative New York Heart Association function class was 3 (range 1-4). Eighty-two (16%) patients had an ejection fraction ≤35%. Forty-seven (9%) had a STS predicted mortality ≥10%. Under cold fibrillatory arrest (median temperature 28°C) without aortic cross-clamp, mitral valve repair (224/504, 44%) or replacement (280/504, 56%) was performed. RESULTS:Thirty-day mortality for the entire cohort was 2.2% (11/504). In patients with a STS predicted mortality ≥ 10% (range 10%-67%), the observed 30-day mortality was 4% (2/47), lower than the mean STS predicted mortality of 20%. Morbidity in this high-risk group was equally low: 1 of 47 (2%) patients underwent reexploration for bleeding, 1 of 47 (2%) patients suffered a permanent neurologic deficit, none had wound infection. The median length of stay was 8 days (range 1-68 days). CONCLUSIONS:This study demonstrates that MIMVS without aortic cross-clamp is reproducible with low mortality and morbidity rates. This approach expands the surgical options for high-risk patients and yields to superior results than the conventional median sternotomy approach.

OBJECTIVE:In this study, the therapeutic use of pacing pulmonary artery catheters in association with minimally invasive cardiac surgery was evaluated. DESIGN/METHODS:A retrospective study. SETTINGS/METHODS:A single institutional university hospital. PARTICIPANTS/METHODS:Two hundred twenty-four consecutive patients undergoing minimally invasive cardiac surgery through a small (5-cm) right anterolateral thoracotomy using fibrillatory arrest without aortic cross-clamping. MEASUREMENTS AND MAIN RESULTS/RESULTS:Two hundred eighteen patients underwent mitral valve surgery (97%) alone or in combination with other procedures. Six patients underwent other cardiac operations. In all patients, the pacing pulmonary artery catheter was used intraoperatively to induce ventricular fibrillation during the cooling period, and in the postoperative period it also was used in 37 (17%) patients who needed to be paced, mainly for bradyarrhythmias (51%). There were no complications related to the insertion of the catheters. Six (3%) patients experienced a loss of pacing capture, and 2 (1%) experienced another complication requiring the surgical removal of the catheter. Seven (3%) patients needed postoperative implantation of a permanent pacemaker. CONCLUSIONS:In combination with minimally invasive cardiac surgery, pacing pulmonary artery catheters were therapeutically useful to induce ventricular fibrillatory arrest intraoperatively and for obtaining pacing capability in the postoperative period. Their use was associated with a low number of complications.

Surgical therapy for cardiovascular disease carries excellent long-term outcomes but it is relatively invasive. With the development of new devices and techniques, modern cardiovascular surgery is trending toward less invasive approaches, especially for patients at high risk for traditional open heart surgery. A hybrid strategy combines traditional surgical treatments performed in the operating room with treatments traditionally available only in the catheterization laboratory with the goal of offering patients the best available therapy for any set of cardiovascular diseases. Examples of hybrid procedures include hybrid coronary artery bypass grafting, hybrid valve surgery and percutaneous coronary intervention, hybrid endocardial and epicardial atrial fibrillation procedures, and hybrid coronary artery bypass grafting/carotid artery stenting. This multidisciplinary approach requires strong collaboration between cardiac surgeons, vascular surgeons, and interventional cardiologists to obtain optimal patient outcomes.

Combined coronary artery valvular heart disease is a major cause of morbidity and mortality in the adult patient population. The standard treatment for such disease has been open heart surgery in which coronary artery bypass grafting (CABG) is performed concurrently with valve surgery using a median sternotomy and cardiopulmonary bypass. With the increasing complexity of patients referred to surgery, some patients may prove to be poor surgical candidates for combined valve and CABG surgery. In certain selected patients who fall into this category, valve surgery and percutaneous coronary intervention (PCI) have been considered a feasible alternative. Conventionally, valve surgery is performed in the cardiac surgical operating room, whereas PCI is carried out in the cardiac catheterization laboratory. Separation of these two procedural suites has presented a logistic limitation because it impedes the concomitant performance of both procedures in one setting. Hence, PCI and valve surgery usually have been performed as a "two-stage" procedure in two different operative suites, with the procedures being separated by hours, days, or weeks. Technologic advancements have made possible the construction of a "hybrid" procedural suite that combines the facilities of a cardiac surgical operating room with those of a cardiac catheterization laboratory. This design has enabled the concept of "one-stage" or "one-stop" PCI and valve surgery, allowing both procedures to be performed in a hybrid suite in one setting, separated by minutes. The advantages of such a method could prove to be multifold by enabling a less invasive surgical approach and improving logistics, patient satisfaction, and outcomes in selected patients.

A 33-year-old, previously healthy male presented with respiratory distress and underwent intubation. A physical examination revealed a holosystolic murmur and pupillary abnormalities. Echocardiography revealed a flail anterior mitral valve leaflet with ruptured chordae and severe mitral regurgitation. The patient underwent urgent mitral valve replacement and tolerated the procedure well. The mitral valve leaflet was myxomatous and calcified -- an unusual find in such a patient. An ophthalmology consultation was obtained and the patient diagnosed with Axenfeld-Rieger syndrome, a disorder of the anterior ocular chamber that has been associated with cardiac malformations. The present case report adds to the body of literature which suggests a correlation between Axenfeld-Rieger syndrome and valvular abnormalities. Hence, it is believed prudent that patients with Axenfeld-Rieger syndrome should undergo echocardiographic screenings for valvular abnormalities.

A hybrid strategy combines the treatments traditionally available only in the catheterization laboratory with those traditionally available only in the operating room to offer patients the best available therapies for any given set of cardiovascular lesions. Examples include hybrid coronary revascularization (coronary artery bypass grafting [CABG]/percutaneous coronary intervention [PCI]) wherein a left internal mammary artery graft is placed on the left anterior descending artery (left anterior descending coronary artery [LAD]) either by minimally invasive or open technique and combined with PCI of non-LAD vessels. Other examples include minimally invasive valve surgery combined with PCI to coronary lesions (valve/PCI), to convert a high-risk valve/CABG into a lower-risk isolated minimally invasive valve procedure. Several questions remain unresolved, such as the order in which surgery and PCI should be performed, the duration of the staging of the 2 procedures, antiplatelet strategies, the costs, and the logistics. Other areas in which hybrid approaches are being developed include hybrid endomyocardial/epicardial atrial fibrillation procedures and hybrid aortic arch debranching combined with endovascular grafting for thoracic aortic procedures. The key requirement in all of these approaches is the need for collaboration between cardiac surgeons, vascular surgeons, and interventional cardiologists to obtain optimal patient outcomes.

Limited donor availability for orthotopic cardiac transplantation has led surgeons to develop surgical alternatives to treat congestive heart failure as a result of ischemic cardiomyopathy. Coronary revascularization plays a clear role in patients with ischemic cardiomyopathy, substantial viable myocardium subtended by coronary stenoses, and presence of anginal symptoms. It is unclear whether patients with heart failure symptoms but no angina benefit from bypass surgery. Some of these patients present with left ventricular dilatation and akinetic/dyskinetic scars, and are therefore candidates for surgical ventricular restoration. Current evidence is lacking as to whether ventricular reconstruction should be performed along with coronary revascularization. Functional mitral regurgitation is often seen in patients with end-stage cardiomyopathy, and its presence portends decreased survival. Mitral valve repair has been shown to improve quality of life, functional class, and to contribute to left ventricle reverse remodeling; however, it has been insufficient in improving survival.