Biomedical subjects

A C Galloway

Publications and source records attributed to A C Galloway.

At least 55 records · Page 3Linked to original sources

PubMed1998

Recent developments and evolving techniques of mitral valve reconstruction.

Experiences with 1,000 patients undergoing mitral valve reconstruction at New York University over the past 18 years are summarized. A continuing follow-up (98% complete) demonstrated that 88% of patients are free from recurrent insufficiency 10 years after the operation. Reconstruction is feasible in nearly 90% of patients with mitral valve prolapse, with an operative mortality near 2%. Accordingly, operation is now recommended at an early stage with the first sign of left ventricular systolic dysfunction, while the patient is still in sinus rhythm. Most operations have been done with the Carpentier techniques of segmental resection with annuloplasty and insertion of a Carpentier ring. Recently, two other repair techniques and a minimally invasive operative approach have been evaluated. A triangular resection of a prolapsing anterior leaflet has been done in more than 100 patients with excellent results. Also, a posterior "folding plasty" has been employed in more than 40 patients with a large redundant posterior leaflet, minimizing the need for annular plication. A minimally invasive approach to the mitral valve has now been employed in 130 patients over the past year, using a right mini-thoracotomy and the Port-Access (Heartport, Inc, Menlo Park, CA) approach. This technique employs catheters introduced through femoral vessels to institute cardiopulmonary bypass and cardioplegic arrest. The operative approach and techniques for mitral valve reconstructive operations continue to evolve, with excellent results and improved patient benefits.

Cardiac Surgical Procedures↗

PubMed1998

Modulation of matrix metalloproteinase activity in human saphenous vein grafts using adenovirus-mediated gene transfer.

BACKGROUND: Neointima formation after human saphenous vein grafting (hSVG) involves several matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). This study assessed the feasibility of modulating MMP activity in hSVGs by adenovirus-mediated gene transfer. METHODS: First, 1 x 10(9) plaque-forming units (pfu) of replication-deficient recombinant adenoviruses encoding either beta-galactosidase (ad beta gal), MMP-3 (AdMMP-3), or TIMP-1 (AdTIMP-1) were added into the lumen of hSVGs for 1 hour. After incubation at 37 degrees C for 24 hours, specimens were analyzed by immunohistochemistry, in situ zymography, and X-gal staining. RESULTS: By X-gal staining ad beta gal-infected hSVGs stained positively in the intima and occasionally in the media. Immunohistochemistry of AdMMP-3- and AdTIMP-1-infected hSVGs localized these proteins to the intima. In situ zymography showed increased MMP activity in the intima of AdMMP-3-infected hSVGs relative to AdTIMP-1- or Ad beta gal-infected vessels. CONCLUSIONS: MMP-3 and TIMP activity can be regulated in hSVGs by replication-deficient recombinant adenoviruses. We have previously demonstrated that MMP-3 or TIMP-1 transduction, or both, inhibit SMC migration in an in vitro reconstituted vessel wall. Modulation of MMP activity may thus afford high patency rates in genetically engineered hSVGs. However, adenovirus-mediated gene delivery is limited to the vessel's intima; strategies to infect medial smooth muscle cells need to be developed.

Adenoviridae↗

PubMed1998

Activation of tumor cell matrix metalloproteinase-2 by neutrophil proteinases requires expression of membrane-type 1 matrix metalloproteinase.

BACKGROUND: Matrix metalloproteinase-2 (MMP-2), an enzyme involved in tumor invasion, is secreted as an inactive proenzyme and requires interaction with membrane-type 1 MMP (MT1-MMP) for activation. We have previously demonstrated that polymorphonuclear neutrophils (PMNs) release a soluble factor(s) that activates pro-MMP-2. Therefore, we tested the hypothesis that PMN-derived proteinases act in concert with MT1-MMP to activate pro-MMP-2. METHODS: Human HT-1080 cells transfected with MT1-MMP cDNA (HT-SE) or the corresponding antisense cDNA (HT-AS) or an empty vector (HT-V), which expressed differing levels of MT1-MMP, were incubated with serum-free, human PMN-conditioned medium with or without proteinase inhibitors. The culture supernatants were analyzed by gelatin zymography. RESULTS: Ht-1080 cells expressing basal (HT-V) or low levels (HT-AS) of MT1-MMP secreted MMP-2 in proenzyme from (72 kd). Ht-1080 cells with high levels of MT1-MMP (HT-SE) secreted pro MMP-2 and a 68 kd intermediate activation product. Addition of PMN-conditioned medium to either HT-SE or HT-V clones resulted in dose-dependent generation of active, 62 kd MMP-2. In contrast, when PMN-conditioned medium was added to HT-AS clones, no MMP-2 activation occurred. CONCLUSIONS: PMN-derived serine proteinases act in concert with MT1-MMP to activate proMMP-2. This finding indicates a potential role for inflammatory cells in promoting extracellular matrix breakdown during tumor invasion.

Aprotinin↗

PubMed1997

Lexipafant inhibits platelet activating factor enhanced neutrophil functions.

Platelet activating factor (PAF) enhances polymorphonuclear leukocyte (PMN) superoxide (.O2-) production, CD11b expression, and elastase release, all essential components in the pathophysiology of multiple-organ failure. This study was designed to determine the effects of Lexipafant, a PAF receptor antagonist, on PAF-mediated PMN functions. PMNs from 10 healthy volunteers were isolated and pretreated with various concentrations of Lexipafant (0-100 microM). PMNs were then incubated for 5 min with 200 nM PAF for .O2- detection or 2000 nM PAF for elastase measurement and activated with 1 microM N-formylmethionylleucylphenylalanine. The mean rate of .O2- production was determined by a cytochrome c reduction assay (nmole .O2-/min/1.33 x 10(5) PMN +/- SEM). Elastase release was measured by the cleavage of the synthetic elastase substrate Meo-Suc-Ala-Ala-Pro-Val-pNA (mean elastolytic activity +/- SEM). In parallel experiments, PMNs were incubated with 200 nM PAF for 30 min following pre-treatment with Lexipafant and CD11b expression was determined by flow cytometry (mean fluorescence intensity +/- SEM). Statistical analysis was performed using repeated-measures ANOVA (P < 0.05). Lexipafant inhibited PAF-enhanced PMN .O2- generation, CD11b expression and elastase release in a dose dependent fashion. The IC50 of Lexipafant for .O2- production, CD11b expression, and elastase release was 0.046, 0.285, and 0.05 microM, respectively. Lexipafant attenuated the PAF-mediated upregulation of PMN .O2- production, CD11b expression, and elastase release in a dose dependent fashion. These data support the hypothesis that Lexipafant may reduce the severity of the inflammatory response to injury produced by PAF-enhanced activation of PMNs.

Dose-Response Relationship, Drug↗

PubMed1997

Single and multivessel port-access coronary artery bypass grafting with cardioplegic arrest: technique and reproducibility.

OBJECTIVES: Although minimally invasive coronary artery bypass grafting is now feasible, using this technique to perform anastomoses on the beating or fibrillating heart may yield poorer graft patency than the standard open techniques that use cardioplegic arrest. This study tested the feasibility and anastomotic reproducibility of minimally invasive coronary bypass using newly developed port-access coronary artery bypass technology (Heartport, Inc., Redwood City, Calif.), which allows endovascular cardiopulmonary bypass, cardiac venting, aortic occlusion, and cardioplegic arrest for internal thoracic artery-coronary artery anastomoses. METHODS: Nineteen dogs had thoracoscopic takedown of either single (n = 14) or bilateral (n = 5) internal thoracic arteries followed by minimally invasive coronary bypass with cardioplegic arrest, done by means of the port-access system. The anastomotic technique was modified after the fourth animal by switching from a microscope to a 2.5 cm oval port and performing a conventional anastomosis with operative loupes. The adequacy of delivery of cardioplegic solution, ventricular decompression, and anastomotic patency was assessed. RESULTS: The crossclamp and bypass times were 50 +/- 15 minutes and 87 +/- 28 minutes (mean +/- standard deviation), respectively. The mean myocardial temperature after cardioplegia was 17 degrees +/- 1 degree C and the aortic pressure (-3 +/- 9 mm Hg) and pulmonary artery pressure (4 +/- 1 mm Hg) were low throughout the procedure. All animals were weaned from bypass without inotropic agents. Angiograms and autopsies demonstrated successful thoracic artery takedown and anastomotic patency in 18 of 19 animals, with 100% anastomotic patency after the technique had been modified after the fourth animal. CONCLUSION: This study describes a reproducible technique for minimally invasive coronary bypass that allows myocardial protection, anastomotic precision, and predictable thoracic artery graft patency. Clinical trials are indicated.

Animals↗

PubMed1997

Minimally invasive mitral valve replacement: port-access technique, feasibility, and myocardial functional preservation.

OBJECTIVE: This experiment examined the feasibility of minimally invasive port-access mitral valve replacement via a 2.5 cm incision. METHODS: The study evaluated valvular performance and myocardial functional recovery in six mongrel dogs after port-access mitral valve replacement with a St. Jude Medical prosthesis (St. Jude Medical, Inc., St. Paul, Minn.). Femoro-femoral cardiopulmonary bypass and a balloon catheter system for myocardial protection with cardioplegic arrest (Heartport, Inc., Redwood City, Calif.) were used. The mitral valve was replaced through a 2.5 cm port in the left side of the chest, and the animals were weaned from bypass. Cardiac function was measured before and at 30 and 60 minutes after bypass. Left ventricular pressure and electrical conductance volume were used to calculate changes in load-independent indexes of ventricular function. RESULTS: Each procedure was successfully completed. Recovery of left ventricular function was excellent at 30 and 60 minutes after bypass compared with the prebypass values for elastance (30 minutes = 4.04 +/- 0.97 and 60 minutes = 4.27 +/- 0.57 vs prebypass = 4.45 +/- 0.96; p = 0.51) and for preload recruitable stroke work (30 minutes = 76.23 +/- 4.80 and 60 minutes = 71.21 +/- 2.99 vs prebypass = 71.23 +/- 3.75; p = 0.45). Preload recruitable work area remained at 96% and 85% of baseline at 30 and 60 minutes (p = not significant). In addition, transesophageal echocardiography demonstrated normal prosthetic valve function, as well as normal regional and global ventricular wall motion. Autopsy revealed secure annular-sewing apposition and normal leaflet motion. CONCLUSIONS: These results suggest that minimally invasive mitral valve replacement using percutaneous cardiopulmonary bypass with cardioplegic arrest is technically reproducible, achieves normal valve placement, and results in complete cardiac functional recovery. Minimally invasive mitral valve replacement is now feasible, and clinical trials are indicated.

Animals↗

PubMed1997

Thoracic aorta: comparison of gadolinium-enhanced three-dimensional MR angiography with conventional MR imaging.

PURPOSE: To evaluate gadolinium-enhanced three-dimensional magnetic resonance (MR) angiography for thoracic aortic disease and to compare this technique with conventional thoracic MR imaging. MATERIALS AND METHODS: One hundred eight consecutive patients underwent 122 thoracic MR examinations, including conventional MR imaging followed by enhanced three-dimensional MR angiography. A gradient-echo sequence was used at 1.5 T (116 examinations) and 1.0 T (6 examinations) during infusion of 0.2 mmol/kg gadopentetate dimeglumine. Two independent readers (A and B), with varied experience in thoracic MR angiography, retrospectively evaluated the images for presence of aortic dissection, aneurysm, arch vessel disease, and protruding atheroma. Correlation with findings of surgery or other imaging modalities was available in 98 cases. RESULTS: Enhanced MR angiography was sensitive (92%-96%) and specific (100%) for acute and chronic aortic dissection (n = 26) and was as useful as conventional MR imaging in the diagnosis of aneurysm (n = 43) and arch vessel disease (n = 7). One of two intramural hematomas were overlooked at MR angiography by reader A, and both were overlooked by reader B. CONCLUSION: Enhanced three-dimensional MR angiography is a rapid and accurate imaging modality in diagnosis of thoracic aortic disease but is insensitive to intramural hematoma.

Adolescent↗

PubMed1997

Sterol 27-hydroxylase: expression in human arterial endothelium.

Human endothelium obtained from both the aorta and the pulmonary artery has been evaluated for the presence of the messenger RNA coding for the expression of sterol 27-hydroxylase. Unique oligomers were designed to detect the mRNA by reverse transcription followed by the polymerase chain reaction. The amplified product was sequenced and was found to be identical to the published sequence for nucleotides 491 to 802 of the human sterol 27-hydroxylase cDNA. Northern blot analysis confirmed the presence of 27-hydroxylase mRNA in pulmonary artery and aortic endothelium. As part of these studies, enzymatic activity was assayed in cultured arterial endothelium using cholesterol as a substrate and isotope ratio gas-liquid chromatography-mass spectrometry to identify the metabolites, 27-hydroxycholesterol and 3 beta-hydroxy-5-cholestenoic acid, in the medium. Localization of sterol 27-hydroxylase to vascular endothelium indicates intracellular production of the biologically active metabolite 27-hydroxycholesterol.

Aorta↗

PubMed1997

Port-Access coronary artery bypass grafting.

New techniques for minimally invasive cardiac surgery have recently emerged. This report describes the Port-Access technique for coronary artery bypass grafting, which involves a small left anterior thoracotomy, femoral cannulation for endovascular cardiopulmonary bypass, and cardioplegic arrest using an endoaortic occlusion catheter and cardioplegia delivery system. This technique allows for minimally invasive single or multivessel revascularization in an arrested, protected heart, while maintaining a high level of anastomotic precision. The Port-Access surgical techniques are described, along with the indications and contraindications for this procedure. The initial New York University clinical results with Port-Access coronary bypass grafting are presented.

Adult↗

PubMed1996

Selective approach to descending thoracic aortic aneurysm repair: a ten-year experience.

BACKGROUND: A variety of surgical techniques has been developed to attempt to minimize the risk of paraplegia after descending thoracic aortic aneurysm repair. This study reviews our institutional experience with several basic techniques over a period of 10 years. METHODS: Seventy-eight consecutive patients underwent repair of descending thoracic aortic aneurysm between 1983 and 1993. Two basic repair strategies were used: (1) distal perfusion with somatosensory evoked potential monitoring (n = 54) and (2) cross-clamping (n = 24), alone (n = 6) or with controlled distal exsanguination (n = 18). RESULTS: The operative mortality rate was 6.5% for elective repair (n = 62), 25.0% for emergent repair (n = 16), and 10.3% overall. Univariate predictors of increased operative risk were emergent operation, rupture, and shock. Neither death nor paraplegia was related to the operative technique used. The incidence of paraplegia was 3.7% in perfused patients and 4.2% in cross-clamping patients (p > 0.05). Paraplegia did not occur after any elective operation (zero of 62) but occurred in 18.6% of emergent cases (p < 0.01). In perfused patients, paraplegia did not occur when the distal pressure was maintained above 55 mm Hg and somatosensory evoked potentials remained intact. When somatosensory evoked potentials were lost (n = 7) in perfused patients, the operative technique was altered successfully in 5 patients, whereas in 2 patients (28.6%), paraplegia developed. CONCLUSIONS: The risks associated with elective descending thoracic aortic aneurysm repair were extremely low using an operative strategy that was flexible but skewed toward perfusion with somatosensory evoked potential monitoring. In perfused patients, paraplegia did not occur when distal pressure was greater than 55 mm Hg and somatosensory evoked potentials remained intact. However, the risks of death and paraplegia were primarily related to emergent presentation, not to technique, and the technique of cross clamping with controlled distal exsanguination was found to be valuable in unstable or in anatomically complicated subsets of patients.

Adolescent↗

PubMed1996

Minimally invasive cardiopulmonary bypass with cardioplegic arrest: a closed chest technique with equivalent myocardial protection.

Thoracoscopic cardiac surgery is presently under intense investigation. This study examined the feasibility and efficacy of closed chest cardiopulmonary bypass and cardioplegic arrest in comparison with standard open chest methods in a dog model. The minimally invasive closed chest group (n = 6) underwent percutaneous cardiopulmonary bypass and cardiac venting, as well as antegrade cardioplegic arrest through use of a specially designed percutaneous endovascular aortic occluder and cardioplegic solution delivery system. The control group (n = 6) underwent standard sternotomy and conventional open chest cardiopulmonary bypass, aortic crossclamping, and antegrade cardioplegia. Ischemic arrest time was 1 hour in each group. Ventricular pressures and sonomicrometer segment lengths were recorded before bypass and at 30 and 60 minutes after bypass. Left ventricular function did not differ significantly between the two groups, as demonstrated by measurements of elastance and end-diastolic stroke work. Also, the preload recruitable work area was 69% and 60% of baseline at 30 and 60 minutes after bypass in the minimally invasive group versus 65% and 62% in the conventional control group (p = not significant); the stroke work end-diastolic length relationship was 78% and 71% of baseline in the minimally invasive group at these intervals versus 77% and 74% in the conventional control group (p = not significant). Myocardial temperatures were similar throughout bypass in the two groups, and ultrastructural examination of prebypass and postbypass biopsy specimens showed no differences between groups. These results demonstrate that minimally invasive cardiopulmonary bypass with cardioplegic arrest is as feasible, safe, and effective as conventional open chest cardiopulmonary bypass. Thus current technology may allow wider clinical application of closed chest cardiac surgery.

Analysis of Variance↗

PubMed1995

Endoventricular remodeling of left ventricular aneurysm. Functional, clinical, and electrophysiological results.

BACKGROUND: Recent advances in surgical techniques for the repair of left ventricular aneurysms (LVAs) include the use of an endoventricular patch to exclude the aneurysm cavity. This technique has replaced conventional linear plication of the aneurysm. The endoventricular patch technique remodels the left ventricular cavity to a more physiological geometry that improves function. METHODS AND RESULTS: From December 1989 through November 1993, 45 patients underwent an LVA repair with an endoventricular patch. This procedure was performed in association with coronary artery bypass grafting in 40 patients. Twenty-eight patients (62.2%) also had nonguided encircling subendocardial incisions. Operative procedures included 7 emergency operations, 3 concomitant valve procedures, and a mean of 2.2 bypass grafts per patient. Eight patients had previous cardiac operations. Hospital mortality was 15.6% (7/45) for all patients and 9.1% (3/33) for nonemergent revascularization and LVA repairs. Ejection fraction improved from a mean of 25.8% preoperatively to 37.8% postoperatively; the mean New York Heart Association classification improved from 3.5 to 1.5. Of patients known to have preoperative arrhythmias (inducible or sudden death), 69% were not inducible postoperatively without antiarrhythmic medication. Survival from late cardiac death (including death of unknown origin) was 86.5% at 2 years. Freedom from documented ventricular arrhythmias was 94.3% at 2 years. CONCLUSIONS: These results indicate that the patch endoaneurysmorrhaphy technique can provide an excellent functional and physiological outcome in patients with LVAs and severely impaired ventricular function.

Aged↗

PubMed1995

Effect of cannula length on aortic arch flow: protection of the atheromatous aortic arch.

Atheromatous disease in the transverse aortic arch is associated with an increased incidence of perioperative stroke. In addition, tissue erosion in the aortic arch is caused by the high-velocity jet emerging from an aortic cannula during cardiopulmonary bypass (CPB), termed the "sandblast effect". To quantify this phenomenon, flow in the aortic arch was measured intraoperatively by epiaortic ultrasonography in 18 patients undergoing CPB. All were cannulated in the ascending aorta, 10 with a short (1.5 cm) cannula and 8 with a long (7.0 cm) cannula. The peak forward aortic flow velocities (mean +/- standard deviation) measured on the caudal luminal surface of the aortic arch were 0.80 +/- 0.23 m/s off CPB and 2.42 +/- 0.69 m/s on CPB (p < 0.001) for the short cannula and 0.53 +/- 0.20 m/s off CPB and 0.18 m/s on CPB for the long cannula. Thus, during CPB the peak forward aortic flow velocity with the short cannula was significantly greater (p < 0.001) than before CPB, whereas the long cannula produced a lower peak forward aortic flow velocity during CPB. Furthermore, Doppler examination revealed severe turbulence in the aortic arch in all patients with a short cannula. No arch turbulence, however, was seen in 7 patients with a long cannula, and only mild turbulence appeared in the remaining patient with a long cannula. These results show that use of a long aortic cannula results in a significant decrease in peak forward aortic flow velocity and turbulence in the aortic arch during CPB, which may reduce the risk of erosion or disruption of existing atheroma and ensuing embolic complications.

Aorta, Thoracic↗

PubMed1995

Effects of a single administration of fibroblast growth factor on vascular wall reaction to injury.

Expansion of the vascular wall through formation of neointimal fibromuscular lesions is the basic mechanism underlying stenosis of vascular grafts, restenosis of arteries treated by balloon angioplasty, and other major cardiovascular problems. This study examined the effect of a single, systemic, low dose of basic fibroblast growth factor (bFGF) on formation of neointimal fibromuscular lesions in response to injury. New Zealand white rabbits (n = 76) were subjected to balloon injury of the abdominal aorta. Forty-five rabbits were given a single intravenous dose of bFGF (0.5 microgram/kg) immediately after injury, and 31 rabbits were given only the vehicle solution as controls. After 2 (n = 15), 5 (n = 21), 14 (n = 29), or 28 (n = 11) days the rabbits were sacrificed. Those rabbits receiving the single administration of bFGF exhibited significantly greater intimal thickening (intima/media ratio) than the control group at 5 days (mean +/- standard error of the mean, 0.091 +/- 0.009 versus 0.058 +/- 0.006; p < 0.002), but not at 14 or 28 days. These results were achieved without any significant differences in mitotic indices, as determined by a mitostatic method, between the two groups at any postinjury interval examined. The findings suggest that a single systemic dose of exogenous bFGF has a relatively long term effect on enhancing the neointimal response to vascular injury. Therefore, local control of endogenous bFGF may be useful in limiting formation of vascular neointimal fibromuscular lesions, thus improving the long-term results of vascular grafts, balloon angioplasty, and other cardiovascular procedures.

Animals↗

PubMed1995

Heparin bonding of bypass circuits reduces cytokine release during cardiopulmonary bypass.

BACKGROUND: Heparin bonding of the cardiopulmonary bypass (CPB) pump circuit decreases complement activation and fibrinolysis. It is not known whether inflammatory cytokines produced during CPB can also be modulated by the more biocompatible heparin-coated circuit. METHODS: This initial study evaluated the impact of heparin-bonded CPB circuits on production of the cytokines interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-a), IL-6, and IL-8 in adults undergoing complex cardiac operations with prolonged CPB. Twenty patients had blood samples drawn immediately before and at hourly intervals after the start of CPB using either a conventional oxygenator and circuit (n = 14) or a covalently bonded heparin oxygenator and circuit (n = 6). Levels of IL-1, TNF-a, IL-6, and IL-8 were measured in all serum samples using a "sandwich" enzyme-linked immunosorbent assay. RESULTS: The levels of IL-6 and IL-8 increased in a time-dependent fashion in both groups, but the response was significantly less over time in the heparin-bonded group (p < 0.05) for both IL-6 and IL-8. Levels of IL-1 and TNF-a were not significantly elevated with lengthening bypass interval in either group. CONCLUSIONS: These data indicate that the use of heparin-coated bypass pump circuits results in lower serum levels of the inflammatory cytokines IL-6 and IL-8 than standard circuits. Biocompatible materials that decrease the inflammatory response to CPB may ultimately reduce the morbidity associated with cardiac operations.

Adult↗

PubMed1995

Anterior leaflet procedures during mitral valve repair do not adversely influence long-term outcome.

OBJECTIVES: This study was done to assess the impact of anterior mitral leaflet reconstructive procedures on initial and long-term results of mitral valve repair. BACKGROUND: It has been suggested that involvement of the anterior leaflet in mitral valve disease adversely affects the long-term outcome of mitral valve repair. Our policy has been to aggressively repair such anterior leaflets with procedures that include triangular resections in some cases. METHODS: From June 1979 through June 1993, 558 consecutive Carpentier-type mitral valve repairs were performed. The anterior mitral leaflet and chordae tendineae were repaired in 156 patients (mean age 58 years). The procedures included anterior chordal shortening in 78 patients (50%), anterior leaflet resections in 44 (28%), resuspension of the anterior leaflet to secondary chordae in 42 (27%) and anterior chordal transposition in 27 (17%). Concomitant cardiac surgical procedures were performed in 75 patients (48%). RESULTS: The operative mortality rate was 2.5% (2 of 81) for isolated mitral valve anterior leaflet repair and 3.8% (6 of 156) for all mitral valve anterior leaflet repair. Freedom from reoperation at 5 and 10 years was, respectively, 89.7% (n = 160) and 83.4% (n = 24) for the entire series of 558 patients, 91.9% (n = 51) and 81.2% (n = 10) for patients with anterior leaflet procedures, 88.8% (n = 109) and 84.4% (n = 14) for patients without anterior leaflet procedures and 91.7% (n = 118) and 88.9% (n = 18) for patients without rheumatic disease. Logistic regression showed that rheumatic origin of disease (odds ratio 2.99), but not anterior leaflet repair, increased the risk for reoperation. CONCLUSIONS: These results demonstrate that expansion of mitral valve techniques to include anterior leaflet disease yields immediate and long-term results equal to those seen in patients with posterior leaflet disease.

Follow-Up Studies↗

PubMed1995

Resuscitative retrograde blood cardioplegia. Are amino acids or continuous warm techniques necessary?

This experiment was designed to determine the relative degree of cardiac functional recovery provided by various forms of resuscitative retrograde blood cardioplegia after global ischemic injury. Twenty-four dogs were subjected to 20 minutes of normothermic global myocardial ischemia followed by 60 minutes of cardioplegic arrest by one of three methods: group 1, standard cold blood cardioplegia with a cold terminal dose (n = 8); group 2, aspartate-glutamate-enhanced blood cardioplegia with warm induction and terminal enhancement (n = 8); and group 3, continuous warm blood cardioplegia (n = 8). Sonomicrometry was used to analyze left ventricular function for maximal elastance and preload recruitable stroke work area. Data were recorded at baseline and after 30 and 60 minutes of unloaded reperfusion. The results showed improved early recovery of preload recruitable stroke work area, but not of maximal elastance, after reperfusion of ischemic hearts with warm resuscitative blood cardioplegic solution enhanced with amino acids. The functional improvement provided by this technique was transient, however, and no significant differences were detectable among the groups after 60 minutes of unloaded reperfusion. Neither amino acid enhancement nor continuous warm cardioplegia offered a significant advantage in functional recovery over the standard method of cold blood cardioplegia reperfusion.

Animals↗

PubMed1995

Operative therapy for mitral insufficiency from coronary artery disease.

This report reviews the results of combined coronary bypass and Carpentier-type mitral valve reconstruction in 115 patients with ischemic mitral insufficiency. Overall operative mortality was 15.7%. Factors that increased operative risk in the overall valve repair population of 638 patients included ischemic etiology, previous cardiac surgery, NYHA functional classification, and age. Variables predicting increased risk of late cardiac death were ischemic etiology, concomitant procedures, and pulmonary hypertension. Late survival was diminished in ischemic patients, but 10-year freedom from reoperation was 93%, suggesting excellent durability after repair for ischemic mitral insufficiency. These results are compared with published reports of operative treatment for mitral insufficiency from coronary artery disease. Guidelines for use of coronary bypass alone versus coronary bypass in association with valve repair or replacement are developed. In most patients with moderate to severe mitral insufficiency secondary to coronary artery disease, the valvular pathology must be corrected, and valve repair with ring annuloplasty is the preferred method. Preoperative planning based on transesophageal echocardiography and cardiac catheterization data is essential for proper operative strategy, and attention to cardioplegia delivery and techniques to minimize reperfusion injury are necessary for optimal results. With these guidelines, late results are excellent after operative treatment for ischemic mitral insufficiency.

Coronary Artery Bypass↗