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Objectives The PROSE trial purpose is to investigate whether the incidence of thromboembolic—related complications is reduced with a current generation mechanical prosthesis (On-X Life Technologies/CryoLife Inc.—On-X) compared with a previous generation mechanical prosthesis (St Jude Medical—SJM). The primary purpose of the initial report is to document the preoperative demographics, and the preoperative and operative risk factors by individual prosthesis and by Western and Developing populations. Methods The PROSE study was conducted in 28 worldwide centres and incorporated 855 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The preoperative demographics incorporated age, gender, functional class, etiology, prosthetic degeneration, primary rhythm, primary valve lesion, weight, height, BSA and BMI. The preoperative and operative evaluation incorporated 24 risk factors. Results The total patient population (855) incorporated On-X population (462) and the St Jude Medical population (393). There was no significant difference of any of the preoperative demographics between the On-X and SJM groups. The preoperative and operative risk factors evaluation showed there was no significant difference between the On-X and St Jude Medical populations. The preoperative and operative risk factors by valve position (aortic and mitral) also documented no differentiation. The dominant preoperative demographics of the Western world population were older age, male gender, sinus rhythm, aortic stenosis, congenital aortic lesion, and mitral regurgitation. The dominant demographics of the Developing world population were rheumatic etiology, atrial fibrillation, aortic regurgitation, mixed aortic lesions, mitral stenosis and mixed mitral lesions. The Developing world group had only one significant risk factor, congestive heart failure. The majority of the preoperative and operative risk factors were significant in the Western world population. Conclusions The preoperative demographics do not differentiate the prostheses but do differentiate the Western and Developing world populations. The preoperative and operative risk factors do not differentiate the prostheses BUT do differentiate the Western and Developing world populations.

In patients with severe aortic stenosis at increased risk for surgery, self-expanding transcatheter aortic valve replacement (TAVR) is associated with improved 2-year survival compared with surgery.This study sought to determine whether this clinical benefit was sustained over time.Patients with severe aortic stenosis deemed at increased risk for surgery by a multidisciplinary heart team were randomized 1:1 to TAVR or open surgical valve replacement (SAVR). Three-year clinical and echocardiographic outcomes were obtained in those patients with an attempted procedure.A total of 797 patients underwent randomization at 45 U.S. centers; 750 patients underwent an attempted procedure. Three-year all-cause mortality or stroke was significantly lower in TAVR patients (37.3% vs. 46.7% in SAVR; p = 0.006). Adverse clinical outcome components were also reduced in TAVR patients compared with SAVR patients, including all-cause mortality (32.9% vs. 39.1%, respectively; p = 0.068), all stroke (12.6% vs. 19.0%, respectively; p = 0.034), and major adverse cardiovascular or cerebrovascular events (40.2% vs. 47.9%, respectively; p = 0.025). At 3 years aortic valve hemodynamics were better with TAVR patients (mean aortic valve gradient 7.62 ± 3.57 mm Hg vs. 11.40 ± 6.81 mm Hg in SAVR; p0.001), although moderate or severe residual aortic regurgitation was higher in TAVR patients (6.8% vs. 0.0% in SAVR; p0.001). There was no clinical evidence of valve thrombosis in either group.Patients with severe aortic stenosis at increased risk for surgery had improved 3-year clinical outcomes after TAVR compared with surgery. Aortic valve hemodynamics were more favorable in TAVR patients without differences in structural valve deterioration. (Safety and Efficacy Study of the Medtronic CoreValve(®) System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement; NCT01240902).

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.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.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.Eligible patients were randomly assigned (1:1) to self-expanding TAVR or to SAVR.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.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).Self-expanding TAVR compares favorably with SAVR in high-risk patients with STS PROM scores traditionally considered intermediate risk.Clinicaltrials.gov Identifier: NCT01240902.

Background In a prospective, randomized trial involving 263 patients who would be incompletely revascularized by coronary artery bypass grafting (CABG) alone, CABG plus transmyocardial revascularization (CABG/TMR) provided an early mortality benefit with similar angina relief compared with CABG alone at 1 year. We evaluated the long-term outcome of patients randomized to CABG/TMR or CABG alone. Methods Thirteen centers that enrolled 83% (218/263) of the patients in the original trial participated in this longitudinal study. Between 1996 and 1998, these centers randomized 218 patients who would be incompletely revascularized by CABG alone because of diffusely diseased target vessels to either holmium:yttrium-aluminum-garnet (holmium:YAG) CABG/TMR (n = 110) or CABG alone (n = 108). Baseline demographics and operative characteristics were similar between groups. Follow-up (mean 5.0 ± 1.7 years) included survival and blinded angina class assessment. Results At this 5-year follow-up both groups experienced significant angina improvement from baseline, however, the CABG/TMR group had a lower mean angina score (0.4 ± 0.7 vs 0.7 ± 1.1, p = 0.05), a significantly lower proportion of patients with severe angina (class III/IV: 0% [0/68] vs 10% [6/60], p = 0.009), and a trend towards greater number of angina-free patients (78% [53/68] vs 63% [38/60], p = 0.08), compared with CABG alone patients. Kaplan-Meier survival at 6 years was similar between CABG/TMR and CABG alone patients (76% vs 80%, p = 0.90). Conclusions Five-year follow-up of prospectively randomized patients who would be incompletely revascularized because of diffuse coronary artery disease indicates that the addition of TMR to conventional CABG provides superior angina relief compared to CABG alone.

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.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.Both study groups had a large decrease in arterial partial pressure of oxygen on 100% inspired oxygen (p0.0001) and a significant postoperative increase in the alveolar-arterial oxygen gradient (p0.0001). 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).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.

OBJECTIVE Cardiac surgical mortality has improved during the last decade despite the aging of the population. An integrated US health plan developed a heart valve registry to track outcomes and complications of heart valve operations. This database was used for longitudinal evaluation of mitral valve (MV) outcomes from 1999 to 2008 at four affiliated hospitals. METHODS We identified 3130 patients in the Apollo database who underwent 3180 initial MV procedures. Internal administrative and Social Security Administration databases were merged to determine survival rates. Electronic health records were searched to ascertain demographics, comorbidities, and postoperative complications. Cox regression was used to evaluate mean survival and identify risk factors. RESULTS The procedures included 1160 mechanical valve replacements, 1159 tissue valve replacements, and 861 annuloplasties. The mean age of patients undergoing these procedures was 58 ± 11 years, 69 ± 12 years, and 62 ± 12 years, respectively. Mean survival was 8.9 ± 0.1 years for mechanical valve replacement, 7.0 ± 0.1 years for tissue valve replacement, and 7.7 ± 0.1 years for annuloplasty. Early in the study, there was a preference for implanting mechanical MVs. Beginning in 2003, more patients received tissue valve replacements rather than mechanical valves. Over time, there was an increasing trend of annuloplasty. Cox regression analysis identified the following risk factors for increased ten-year mortality: tissue valve implantation; advanced age; female sex; nonelective, nonisolated procedure; diabetes; postoperative use of banked blood products; previous cardiovascular intervention; dialysis; and longer perfusion time. Hospital location, reoperation, preoperative anticoagulation, and cardiogenic shock were not statistically significant risk factors. CONCLUSIONS When controlling for other risk factors, we observed a lower long-term survival rate for tissue valve replacement compared with mechanical valve replacement. Integrating electronic health records with existing electronic databases provided near-real-time analysis of longitudinal cardiac surgical outcomes.

At present no consensus exists regarding the timing of surgical revascularization after acute myocardial infarction. Patients admitted with acute myocardial infarction between January 1990 and April 1993 underwent early cardiac catheterization if they had postinfarction ischemia or positive results on a low-level exercise stress test. If indications for surgical intervention were found at the time of catheterization, patients were operated on within 1 or 2 days or were discharged and returned for the operation within 2 to 3 weeks. During this period, we performed 2175 isolated coronary artery bypass graft procedures; 23 patients were operated on within 24 hours of acute myocardial infarction with an operative mortality of 4.4 %, 30 patients underwent surgery between 24 and 72 hours after infarction with no deaths, 193 patients were operated on between 3 and 7 days after infarction with an operative mortality of 2.1%, 284 patients underwent revascularization between 1 week and 1 month after infarction with an operative mortality of 1.4%, and the 1645 patients without a recent infarction had a mortality rate of 1.9%. Multivariate statistical analysis was performed to evaluate mortality with these independent variables: reoperative surgery, sex, age, diabetes, timing of infarction, location of infarction, and type (transmural versus subendocardial). Myocardial infarction at any time interval less than 1 month before the operation was not associated with mortality when adjusted by these other risk factors. In addition, no differences were noted in length of stay, stroke rate, or prevalence of renal failure or pulmonary insufficiency. We conclude that nonemergency surgical revascularization can be done safely at any time interval after acute myocardial infarction,, certainly after 72 hours, with no increase in operative mortality and acceptable morbidity.

Myocardial hypothermia is an essential component of myocardial preservation for most cardiac operations. Because of multiple causes of rewarming, it is necessary to monitor temperatures at specific sites (right and left ventricular epicardium and endocardium or cavity). Thus, plastic temperature probes have been designed and fabricated to facilitate temperature monitoring at these sites. Using a bare thermocouple as a standard, in vitro comparison of metallic probes and plastic probes revealed differences of 4.0 degrees +/- 0.9 degrees C and 0.7 degrees +/- 0.6 degrees C, respectively (p less than 0.005). Consequently, metallic probes do not have sufficient accuracy to detect transmural temperature gradients because of "stem effect." Using the plastic probes to evaluate temperature changes in porcine hearts after cardioplegia-induced hypothermia revealed a temperature rise of 1 degree C/min at all sites if control of systemic and venous return and local myocardial cooling are not provided. The use of temperature monitoring at multiple sites permits identification and prevention of various causes of myocardial rewarming and is facilitated by the use of plastic probes described herein which contain dual thermocouples.

Objective: The merits of retaining the subvalvular apparatus during mitral valve replacement for chronic mitral regurgitation have been demonstrated in numerous retrospective clinical investigations but not in a randomized study. In this report we analyzed the early and late effects of complete versus partial chordal preservation on left ventricular mechanics. Methods: Forty-seven patients undergoing isolated surgical correction of mitral insufficiency were prospectively randomized to either total or partial chordal-sparing mitral valve replacement. Complete data from 36 patients were available for analysis. Of these individuals, 15 had preservation of the posterior leaflet only (P-MVR group), and 21 had complete preservation of all chordal structures (C-MVR group). Echocardiography was performed preoperatively, at the time of discharge, and after 1 year to determine dimensions, wall stress, left ventricular mass, and ejection function. Results: End-diastolic volume decreased in both groups initially but continued to decline only in the C-MVR cohort. Similarly, although end-systolic volume decreased over time with total chordal preservation, no notable changes were observed in the P-MVR group. In the C-MVR group, end-systolic stress decreased initially but rose slightly by 1 year. In contrast, end-systolic stress remained unchanged at discharge in the P-MVR group and increased at 1 year. In terms of systolic performance, ejection fraction declined after surgical intervention with partial chordal-sparing techniques and did not improve by 1 year. Ejection fraction returned to the preoperative level after an initial decrease in the C-MVR group. Finally, left ventricular mass was reduced in the C-MVR cohort versus no change in the P-MVR group. Conclusion: Complete retention of the mitral subvalvular apparatus during mitral valve replacement confers a significant early advantage by reducing left ventricular chamber size and systolic afterload compared with partial chordal preservation. Furthermore, left ventricular ejection performance continues to improve over time, probably because of more favorable left ventricular remodeling. J Thorac Cardiovasc Surg 2002;123:707-14

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.

Background —The merits of retaining the subvalvular apparatus during mitral valve replacement for chronic mitral regurgitation have been demonstrated in numerous clinical and laboratory investigations. In this preliminary report, we analyzed the early effects of complete versus partial chordal preservation on left ventricular mechanics. Methods and Results —Fifty patients undergoing isolated surgical correction of mitral insufficiency were prospectively randomized to either total or partial chordal-sparing mitral valve replacement. Of the first 19 patients studied, 8 had preservation of the posterior leaflet only, and 11 had complete preservation of all chordal structures. A comparison group consisted of 6 patients who had primary mitral valve repair. Echocardiography was performed preoperatively and at discharge from the hospital to determine dimensions, wall stress, and ejection fraction. Preservation of the posterior leaflet only resulted in a reduction in end-diastolic volume, an increase in end-systolic volume ( P =0.058), a rising trend in end-systolic stress, a decrease in long-axis fractional shortening, and a fall in ejection fraction from 0.68±0.16 to 0.46±0.19 ( P =0.001). Although patients who had preservation of all chordal structures also had decreased end-diastolic volume, long-axis fractional shortening, and ejection fraction (0.60±0.13 to 0.52±0.07, P =0.01), end-systolic stress fell and end-systolic volume decreased instead of increased. Compared with the posterior leaflet preservation group, those in the group with completely preserved chordal structures had a larger decline in end-diastolic volume and smaller decreases in long-axis fractional shortening and ejection fraction. Changes in end-systolic volume and stress were also statistically different between the 2 cohorts. No differences were detected between the group with total preserved chordal structures and the mitral repair group in any of the measured parameters. Conclusions —Compared with posterior chordal preservation only, complete retention of the subvalvular apparatus during mitral valve replacement resulted in improved ejection performance and smaller chamber volumes due to reduced systolic wall stress. These hemodynamic advantages are comparable to those observed with primary mitral reconstruction.

Background —Stentless aortic valves were designed to provide a more physiological flow pattern and lower transvalvular gradient, which may have an important bearing on postoperative left ventricular function and remodeling. In this study, we prospectively analyzed the 5-year clinical results with the Freestyle valve (Medtronic, Inc) and its hemodynamic performance by serial echocardiography. Methods and Results —Between January 1993 and August 1997, 95 patients with a mean age of 75 years underwent aortic valve replacement with the Freestyle prosthesis. Sixty-four percent of patients received valves ≤23 mm, and 37% had concomitant coronary artery bypass grafting. Average follow-up was 44±18 months (mean±SD), and echocardiography was performed preoperatively, at discharge, at 3 to 6 months, and annually thereafter. The 30-day operative mortality rate was 3%, with an overall actuarial survival rate of 80±6% (mean±SEM) at 5 years. Of the 10 late deaths, only 2 were cardiac related, thereby yielding a freedom from cardiac mortality of 94±3% after 5 years. No patient required reoperation on the aortic valve for any reason, including structural degeneration, nonstructural dysfunction, or prosthetic valve endocarditis. There were 9 thromboembolic and 3 anticoagulant-related bleeding events, none of which was fatal. The actuarial freedom from valve-related morbidity and mortality was 79±4% at 5 years. Hemodynamically, the mean transvalvular gradient significantly decreased after valve replacement and was reduced further by 41% by 6 months with a corresponding increase in effective orifice area. Left ventricular mass index fell to 75% of the preoperative value by 2 years. Conclusions —The Freestyle stentless valve can be implanted safely in the elderly with excellent midterm clinical results. It has superb hemodynamics in terms of residual transvalvular gradient, effective orifice area, and regression of left ventricular hypertrophy.

Background . Due to improved operative techniques, myocardial preservation, and perioperative care, open heart procedures are now being performed in older and sicker patients. As a result, the quality of life has become an important issue in the decision making process. Methods . Between January 1993 and October 1994, 604 patients above 65 years of age who underwent non-emergent open heart operations were followed prospectively over a 2-year period. The Health Status Questionnaire forms were distributed to all patients preoperatively and to hospital survivors at 3, 12, and 24 months. The questionnaire contains 36 questions and is divided into eight categories. Follow-up was 100% complete with 99.6% of questionnaires returned. Results . Significant quality of life improvements were noted in all categories after surgery. After reaching a peak at 12 months, there were small, but significant declines in scores relating to physical health and health perception at 24 months. In contrast, measurements for mental attributes continued to increase with time. By multivariate analysis, diabetes, older age, and female gender had a relatively adverse influence on quality of life despite improvement after operation. Similarly, patients with chronic obstructive pulmonary disease or having redo operations had lower health perception with some physical limitations. While procedure type (coronary artery bypass grafting) was associated with preoperative bodily pain, congestive heart failure symptoms were not an independent factor affecting quality of life. Conclusions . Quality of life improves with cardiac surgical interventions in this studied age group and should not be denied even in the elderly population.

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.

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 auto-transfusion 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 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.

A 68-year-old woman with severe chronic obstructive pulmonary disease, aortic valvular insufficiency, and diffuse thoracic aortic aneurysm underwent aortic valve replacement and separate Dacron graft replacement of the ascending aortic and arch aneurysms using the elephant trunk technique. She was discharged on the tenth postoperative day. Five months later, she underwent endovascular stent-graft repair of the descending thoracic aortic aneurysm. She recovered uneventfully, and was discharged on the third postoperative day. Follow-up computed tomography at 6 months demonstrated exclusion of all flow into the descending thoracic aortic aneurysm. The elephant trunk technique followed by endovascular stent-grafting of the descending thoracic component is a potential therapeutic option in selected high-risk patients with diffuse aortic aneurysmal disease.

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.

The colchicine-binding assay was used to quantitate the tubulin concentration in unfertilized Strongylocentrotus purpuratus eggs and to characterize pharmacological properties of this tubulin. Specificity of colchicine binding to tubulin was demonstrated by apparent first-order decay colchicine-binding activity with stabilization by vinblastine sulfate, time and temperature dependence of the reaction, competitive inhibition by podophyllotoxin, and lack of effect of lumicolchicine. The results demonstrate that the minimum tubulin concentration in the unfertilized egg is 2.71 mg per milliliter or 5.0% of the total soluble cell protein. Binding constants and decay rates were determined at six different temperatures between 8 degrees C and 37 degrees C, and the thermodynamic parameters of the reaction were calculated. delta H0=6.6 kcal/mol, delta S0=46.5 eu, and, at 13 degrees C, delta G=-6.7 kcal/mol. The association constants obtained were similar to those of isolated sea urchin egg vinblastine paracrystals (Bryan, J. 1972. Biochemistry. 11:2611-2616) but approximately 10 times lower than that obtained for purified chick embryo brain tubulin at 37 degrees C (Wilson, L.J.R. Bamburg, S.B. Mizel, L. Grisham, and K. Creswell. 1974. Fed Proc. 33:158-166). Therefore, the lower binding constants for colchicine in tubulin-vinblastine paracrystals are not due to the paracrystalline organization of the tubulin, but are properties of the sea urchin egg tubulin itself.

Currently, numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operations. During cardiac ischemia we have compared myocardial surface cooling with topical cold saline (Group I, N = 9), crystalloid cardioplegia plus topical cold saline (Group II, N = 8) and cardioplegia with a specially designed cooling jacket (Group III, N = 8) in patients undergoing aortic or mitral valve replacement, or both. Temperatures were assessed and recorded continuously in standardized locations for the right and left ventricular epicardium and endocardium. In Group I the rate of cooling was significantly slower than in the other two groups. Also, excessive gradients were developed across the left and right ventricular walls. In Group II the rate and depth of cooling were adequate and initial temperature gradients were eliminated. However, over the period of ischemia, significant rewarming occurred. In Group III temperatures were reduced rapidly and uniformly and maintained at or below 10° C for the duration of the ischemic period. These differences are statistically significant (p

Very little biochemical work has been done on plant cell tubulin. In this study, tubulin was isolated from sperm cell flagella from the fern Marsilea vestita. Electrophoresis of reduced and carboxymethylated Marsilea tubulin on three different gel systems revealed that Marsilea tubulin consisted of α- and β-bands, as do the better-known animal and protist tubulins. Comparison of the electrophoretic mobilities of Marsilea, Aspergillus, Chlamydomonas and bovine tubulin showed that Marsilea tubulin's behavior is unique but is most like that of Chlamydomonas. The effects in vivo of tubulin-specific drugs were also examined. Mitosis of Marsilea microspores was sensitive to colchicine, podophyllotoxin and vinblastine, at concentrations higher than those necessary to obtain comparable effects in animal cells, but equivalent to those which block mitosis in Chlamydomonas. In addition, all three drugs, depending on the stage at which they were administered, either prevented flagellar growth or caused formation of abnormal flagella. It thus appears that Marsilea has microtubules similar in many ways to the better characterized animal microtubules but also demonstrating unique characteristics.

Objective We sought to compare the 6-month angiographic patency rates of greater saphenous veins removed during coronary artery bypass grafting with the endoscopic vein harvest or open vein harvest techniques. Methods Two hundred patients undergoing nonemergency on-pump coronary artery bypass grafting were prospectively randomized to either endoscopic vein harvest or open vein harvest. Follow-up angiography of all vein grafts was scheduled at 6 months. Graft patency and disease grades were assigned independently by 2 interventional cardiologists. Leg wound healing was evaluated at discharge, 1 month, and 6 months for evidence of complications. Results There were 3 conversions from endoscopic vein harvest to open vein harvest because of vein factors. Leg wound complications were significantly lower in the endoscopic vein harvest group (7.4% vs 19.4%, P = .014). On multivariable analysis, endoscopic vein harvest emerged as the only factor affecting wound complications (odds ratio, 0.33). Three deaths (2 perioperative and 1 late) occurred in the endoscopic vein harvest group that were unrelated to vein graft closure. Twenty-four and 29 patients in the endoscopic vein harvest and open vein harvest cohorts, respectively, refused the follow-up 6-month angiography. Therefore a total of 144 angiograms (73 endoscopic vein harvests and 71 open vein harvests) and 336 vein grafts (166 endoscopic vein harvests and 170 open vein harvests) were available for analysis. The overall occlusion rates at 6 months were 21.7% for endoscopic vein harvest and 17.6% for open vein harvest. Additionally, there was evidence of significant disease (>50% stenosis) in 10.2% and 12.4% of endoscopic vein harvest and open vein harvest grafts, respectively. By means of ordinal hierarchic logistic regression, endoscopic vein harvest was not found to be a risk factor for vein graft occlusion or disease (odds ratio, 1.15). Significant predictors were congestive heart failure (odds ratio, 2.87), graft to the diagonal artery territory (odds ratio, 1.76), larger vein conduit size (odds ratio, 1.32), and graft flow (odds ratio, 0.90). Conclusion Endoscopic vein harvest reduces leg wound complications compared with open vein harvest without compromising the 6-month patency rate. The overall patency rate depends on target and vein-related variables and patient characteristics rather than the method of vein harvesting.

Objective: We sought to assess the safety and efficacy of transmyocardial revascularization combined with coronary artery bypass grafting in patients not amenable to complete revascularization by coronary bypass alone. Methods: A total of 263 patients whose standard of care was coronary artery bypass grafting and who had one or more ischemic areas not amenable to bypass grafting were prospectively randomized to receive coronary bypass of suitable vessels plus transmyocardial revascularization to areas not graftable (n = 132) or coronary bypass alone with nongraftable areas left unrevascularized (n = 131). Group preoperative demographics and operative characteristics were similar. Results: The operative mortality rate after coronary bypass/transmyocardial revascularization was 1.5% (2/132) versus 7.6% (10/131) after coronary bypass alone ( P = .02). Patients undergoing both coronary bypass and transmyocardial revascularization required less postoperative inotropic support (30% vs 55%, P = .0001) and had a trend toward fewer insertions of intra-aortic balloon pumps (4% vs 8%, P = .13) than did patients having coronary bypass alone. Multivariable predictors of operative mortality were coronary artery bypass alone (odds ratio, 5.3; 95% confidence interval, 1.1-25.7; P = .04) and increased age (odds ratio, 1.1; 95% confidence interval, 1.0-1.2; P = .03). One-year Kaplan-Meier survival (95% vs 89%, P = .05) and freedom from major adverse cardiac events defined as death or myocardial infarction (92% vs 86%, P = .09) favored the combination of coronary bypass and transmyocardial revascularization. Baseline to 12-month improvement in angina and exercise treadmill scores was similar between groups. Conclusions: In a prospective, randomized, multicenter trial, transmyocardial revascularization combined with coronary artery bypass grafting in patients not amenable to complete revascularization by coronary bypass alone was safe; however, angina relief and exercise treadmill improvement were indistinguishable between groups at 12 months of follow-up. Operative and 1-year survival benefits observed after adjunctive transmyocardial revascularization require confirmation by a larger validation study, which is ongoing. (J Thorac Cardiovasc Surg 2000;119:540-9)

Survival estimates of patients with aortic dissection commonly come from tertiary care centers; such estimates may be biased by referral and selection bias. The survival of unselected patients with aortic dissection by gender in the community remains poorly defined. Aortic dissection cases were