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Biomedical subjects

M S Sweeney

Publications and source records attributed to M S Sweeney.

At least 37 records · Page 2Linked to original sources
PubMed1989

Improved cardiac function with glucose-insulin-potassium after aortocoronary bypass grafting.

To assess the effectiveness of metabolic support for the heart in patients with refractory heart failure after hypothermic ischemic arrest for aortocoronary bypass grafting we assigned 22 patients to receive either intravenous glucose (50%), insulin (80 IU/L), and potassium (100 mEq/L) at a rate of 1 mL/kg/h for up to 48 hours (GIK) or glucose (5%) and NaCl (0.225%) at the same rate (control). All patients started out with a mean cardiac index of less than 3.0 L/min/m2, were on intraaortic balloon pump assistance, and required inotropic drugs. At 12 and 24 hours cardiac index had increased significantly in the GIK group when compared with the control group (3.6 and 3.4 versus 2.5 and 2.7 L/min/m2, respectively). Time on the intraaortic balloon pump (39 versus 61 hours) and requirements for inotropic drug support were significantly less in GIK group than in the control group. All 11 GIK patients could be weaned from intraaortic balloon pump assistance. At 30 days after operation survival was 10/11 in the GIK group, compared with 7/11 in the control group. We conclude that GIK is both safe and effective in the treatment of refractory left ventricular failure after aortocoronary bypass grafting. The exact mechanism for the beneficial effect of GIK on myocardial contractility remains to be elucidated.

Aged↗
PubMed1989

Bioprosthetic versus mechanical valve replacement in patients with infective endocarditis.

During the 5-year period, 1979-1984, at the Texas Heart Institute, 4,598 patients underwent cardiac valve replacement procedures of which 185 were for acute infective endocarditis. Staphylococcus and streptococcus accounted for 80% of the cases and congestive heart failure was a leading indication in 63%. The purpose of this article is to evaluate the recurrence of endocarditis dependent upon whether the patient had an Ionescu-Shiley bioprosthetic pericardial valve or a mechanical valve (St. Jude Medical). Actuarial freedom from both early and late reoperation was higher for prosthetic valves than bioprosthetic valve patients. We conclude that mechanical valves are the valves of choice in acute infective endocarditis which apparently is the results of less biologic tissue available for exposure to infection by the offending organisms.

Actuarial Analysis↗
PubMed1989

Cardiac surgical emergencies.

Cardiac surgical emergencies are broken down into three categories: cardiac trauma, aortic dissection, and surgery for acute myocardial infarctions. Emphasis is given to describing the presentation of patients with such problems, and to the salient aspects of the clinical strategies for managing each problem. An important goal of each section is focusing the critical care physician on the early recognition of cardiac surgical emergencies and providing him with some rationale for instituting an expeditious plan of therapy.

Aged↗
PubMed1988

The treatment of advanced cardiac allograft rejection.

Severe cardiac allograft rejection remains a serious problem despite the advances of cyclosporine-based immunosuppression. This study analyzes our experience with 202 recipients of cardiac allografts who were treated primarily with cyclosporine and prednisone. Failure of such therapy in 86 patients (43%) resulted in 105 episodes of advanced cardiac allograft rejection as diagnosed by endomyocardial biopsy. Of 101 rejection episodes that were initially treated with intravenous pulse therapy, 48 (48%) were successfully resolved, yet 60% of these successes were associated with major infections. Patients in whom steroid therapy failed or was contra-indicated received intravenous antithymocyte globulin (ATG) or intravenous monoclonal antibody (OKT3). ATG and OKT3 successfully reversed severe rejection in 26 (81%) of 32 and in 13 (93%) of 14 episodes, respectively. Infectious complication rates were 54% and 21%, respectively. Because the majority (87%) of these rejection episodes occurred within the first 30 days after treatment, many of them may have resulted from inadequate immunosuppressive induction therapy. Based on our results, we believe that advanced cardiac allograft rejection may be managed best by individualizing immunosuppressive therapy, thus enhancing prevention, and by adding OKT3 to the regimen when rejection occurs.

Adolescent↗
PubMed1988

Infections in patients receiving OKT3 monoclonal antibody for cardiac rejection: results of a small clinical trial.

Orthoclone OKT3 (muromonab-CD3), a murine monoclonal antibody that virtually eliminates circulating T cells and inhibits medullary lymphocyte function, has recently been found effective in reversing stubborn severe allograft rejection after heart transplantation. To determine the influence of OKT3 therapy on the development of infections in cardiac allograft recipients, we compared the frequency and severity of infection in 16 patients who underwent treatment for cardiac allograft rejection at our institution from July 1985 through November 1986. these included 11 patients on OKT3 therapy and 5 patients on a conventional immuno-suppressive regimen. With 2 exceptions late in the trial, OKT3 was used only as a rescue therapy, for patients who did not respond to standard adjunctive therapy consisting of high doses of corticosteroids or antithymocyte globulin, or both. The 5 patients who did not receive OKT3 responded to adjunctive therapy and were in general not as ill as the OKT3 recipients. Our protocol specified that patients in both groups be studied during the 6 weeks (42 days) immediately following transplantation. During this period of study, 6 patients in our 11 member OKT3 group experienced 25 infectious processes, 22 of which occurred in only 3 patients and 14 of which were considered life-threatening (2 of the 3 very ill patients died during the study period). These infections were found most often in the gastrointestinal and genitourinary tracts, involved both bacterial and nonbacterial pathogens, and developed about 2 weeks after the initiation of therapy. By comparison, 2 patients in our 5-member non-OKT3 group experienced 3 infectious processes during the study period, and these were not life-threatening. Because of the occurrence in the OKT3 group of 22 of the 25 infections in only 3 patients, these early results were skewed, but a trend was noted towards a higher incidence of bacterial infection in the OKT3 group. A larger and longer-term trial is under way to evaluate the trend.

Journal Article↗
PubMed1987

The Puig-Massana-Shiley annuloplasty ring for mitral valve repair: experience in 126 patients.

Between October, 1982, and December, 1984, 126 patients at the Texas Heart Institute underwent mitral valve repair for mitral insufficiency utilizing the Puig-Massana-Shiley annuloplasty ring. Resection of a triangular-shaped wedge of the mural leaflet and direct suture repair was done in 42 patients, and anterior leaflet repair was used in 2 patients. There were 79 male (63%) and 47 female (37%) patients with a mean age of 58 years. Preoperatively, 95% were in New York Heart Association (NYHA) Functional Class III or IV. Concomitant cardiac operations were performed in 82 patients and included coronary artery bypass grafting (49%), aortic valve replacement (16%), repair of ventricular septal defect (2%), resection of left ventricular aneurysm (2%), and repair of atrial septal defect (1%). There were 8 early deaths (6.3%) and 11 late deaths (8.7%). In 44 patients undergoing mitral valve repair as an isolated primary procedure, operative mortality was 2.3%. Murmurs of mitral insufficiency were present in 5 patients postoperatively, but only 1 required early reoperation for mitral valve replacement. Follow-up data have been obtained on 80% of the patients. Postoperative Functional Class was obtained for 63 of the 82 surviving patients and showed 92% of these patients to be in NYHA Functional Class I or II. Mitral valve repair incorporating the Puig-Massana-Shiley annuloplasty ring and valve leaflet revision is a reliable technique that is not technically demanding. We believe these methods should be attempted for correction of pure mitral insufficiency, particularly in circumstances where other cardiac repairs are required.

Adolescent↗
PubMed1986

Apicoaortic conduits for complex left ventricular outflow obstruction: 10-year experience.

We interposed valved conduits between the left ventricular apex and aorta in 38 patients over a 10-year period. Indications included tunnel subaortic stenosis, aortic annular hypoplasia, tubular supravalvular aortic hypoplasia, and severe calcification of the ascending aorta. Operative mortality was 11%, but 78% of the survivors were alive at 5 years, and 70% had had no major complication. The results were better in adolescents and adults than in young children. Although complications included calcific degeneration of the valve and disruption of the conduit at the site of insertion into the ventricular apex, we continue to believe in the utility of this procedure in a few patients with complex left ventricular outflow tract obstruction.

Adolescent↗
PubMed1985

Hypothermic circulatory arrest for cardiovascular lesions: technical considerations and results.

During a six-year period (1979 to 1984), the technique of hypothermic circulatory arrest was used to operate on 128 patients. Our technique included induction of hypothermia (20 degrees to 24 degrees C) by femoral artery cannulation for return of oxygenated blood, "open" aortic reconstruction, and brief periods of circulatory arrest (range, 5 to 31 minutes; mean, 13 minutes). Eighty patients had dissecting aneurysms of the ascending aorta (42 acute, 38 chronic), 28 had fusiform aortic arch aneurysms, and 13 had annulo-aortic ectasia. Seven had other procedures. Ages ranged from 14 to 79 years (mean, 54 years). Of the 113 patients (88%) who survived the operation and were discharged, 107 are currently alive and well. Only 15 of the 21 deaths occurred within 30 days of operation, and 5 (33%) were in severely hypotensive patients whose operations were begun during active resuscitation. Of the 80 patients admitted with ascending aortic or arch dissection, an in-hospital mortality of 7.5% was achieved. A marked reduction was observed in such complications as postoperative hemorrhage, renal failure, and pulmonary insufficiency with our current hypothermic perfusion methods. Moreover, none of the five neurological complications could be attributed to anoxic cerebral injury during the period of circulatory arrest. This experience indicates that moderate levels of hypothermia provide adequate cerebral protection for most cardiovascular procedures, and our results encourage continued use of this method.

Adolescent↗
PubMed1985

Reoperation for aortic coarctation: techniques, results, and indications for various approaches.

To define the safety and efficacy of operation for recurrent thoracic aortic coarctation, we reviewed the hospital records and subsequent courses of 53 patients who underwent such procedures over a 23-year period. Previous operations included end-to-end anastomosis, prosthetic patch or subclavian flap aortoplasty, and prosthetic interposition or bypass grafts, performed in patients ranging from 1 day to 44 years old. Several different reoperative procedures were used, including an ascending-descending aortic bypass graft in 4 patients who had had two previous repairs. There were no hospital or late deaths and only 3 relatively minor complications. Only 2 patients have hypertension requiring drug therapy at follow-up, which now averages 7 years. We conclude that operative management of severe, recurrent coarctation is both safe and effective, and that several techniques of reconstruction may have a place in such therapy.

Adolescent↗
PubMed1985

Total anomalous pulmonary venous return: report of 201 patients treated surgically.

Between 1956 and June 1984, 201 patients with uncomplicated total anomalous pulmonary venous return (TAPVR) were operated on at the Texas Heart Institute and Texas Children's Hospital. Two groups were previously reported that included periods from 1955 to 1964 and from 1964 to 1972. From 1972 until 1984, 76 patients were operated on for uncomplicated TAPVR. The mortality was 11/19 (57%) for patients less than 1 month old, 2/27 (7%) for patients 1 month to 1 year old, and 0/21 (0%) for patients older than 1 year. Forty-five percent (5/11) of the infants who died in the less than 1-month-old category were operated on when they were less than 24 hours old and in extremis when presented for correction.

Journal Article↗
PubMed1985

Comparison of bioprosthetic and mechanical valve replacement for active endocarditis.

The choice between bioprosthetic or mechanical prosthetic valve replacement for active valvular endocarditis has been controversial. To establish the role of each, we reviewed the case histories of 185 patients who underwent valve replacement for active valvular endocarditis during the past 5 years. All patients had life-threatening, active bacterial endocarditis of a native or prosthetic valve. Group I (88 patients) had replacement with the Ionescu-Shiley pericardial valve and Group II (97 patients) with the St. Jude Medical valve. The male/female distribution, age range, and functional classification were the same in the two groups. Mean follow-up was approximately 20 months for both groups. Valve replacement was done because of native valve endocarditis in 76 patients in Group I and 49 patients in Group II. Of the remainder of the Group I patients, six had endocarditis of a bioprosthesis and six of a mechanical valve; of the remainder of Group II patients, 30 had endocarditis of a bioprosthesis and 18 of a mechanical valve. Early mortality was not significantly different between the two groups (14 deaths in each group). Of the 74 survivors in Group I, 15 underwent valve reoperation, 10 because of recurrent endocarditis and five because of sterile perivalvular leakage. The frequency of reoperation was significantly different (p less than 0.01) from that in Group II, in which only five patients underwent valve reoperation, four for recurrent endocarditis and one for sterile perivalvular leakage. The actuarial rate for freedom from reoperation was also significantly higher in Group II patients; 94.6% were free from reoperation at 4 years compared to 75% at 4 years in Group I patients (p less than 0.01). The actuarial survival rate, which also differed significantly between groups, was 78.7% at 4 years in Group I and 87.4% at 4 years in Group II (p less than 0.05). Patients receiving a bioprosthesis for active endocarditis had a significantly higher reoperation rate and a significantly greater incidence of recurrent endocarditis (p less than 0.01). Therefore, we prefer to use a mechanical valve for valve replacement in most patients who have active endocarditis.

Adolescent↗
PubMed1984

Primary aortoduodenal fistula: manifestation, diagnosis, and treatment.

Primary aortoduodenal fistulas are an especially lethal part of the spectrum of arterioenteric fistulas. The lethal nature is due to the subtleties in manifestation, leading to delays in diagnosis and institution of prompt operative repair. A review of the 118 primary aortoduodenal fistulas in the world's literature reveals that pain (32%), palpable abdominal mass (25%), and bleeding (64%) are inconsistently present as initial symptoms and that routine abdominal films, barium studies, and endoscopy have been ineffective as diagnostic aids. Attention is called to the importance of recognizing the "herald bleed." Operation is usually undertaken emergently and has been successful in only 21 cases in addition to the case reported here. Repair of the duodenal rent and replacement of the aorta with a Dacron prosthesis, rather than an extra-anatomic bypass, is advised.

Abdomen↗
PubMedDate not supplied

Blunt trauma to the heart: the pathophysiology of injury.

Blunt injuries to the heart are common and potentially lethal. These injuries often go undetected while more obvious problems are treated. A cardiac injury should be suspected in any patient who sustains severe chest trauma. The spectrum of cardiac trauma ranges from injuries with no actual cellular damage (myocardial concussion) to cardiac chamber rupture. The pathophysiology, diagnosis, and treatment of these injuries are discussed.

Animals↗
PubMedDate not supplied

Bacterial mediastinitis after heart transplantation.

Bacterial mediastinal abscess or mediastinitis developed in nine (2.5%) of 361 consecutive patients who underwent isolated heart transplantation at the Texas Heart Institute. All nine patients had at least one predisposing factor that may have contributed to the development of mediastinitis. These included insulin-dependent diabetes mellitus, repeat operation for postoperative mediastinal hemorrhage, Staphylococcus aureus pneumonitis, and cardiac allograft rejection in the early postoperative period (less than 30 days), necessitating steroid pulse therapy alone or in combination with murine-derived monoclonal antibody (OKT3). In six of the nine patients, the diagnosis of mediastinitis was made on the basis of clinical findings (unstable sternum and incisional erythema, with or without gross purulence), and in the other three patients, diagnosis was confirmed by computed tomography of the chest. Culture data were unequivocal in all patients; S. aureus was the most frequent (five patients), followed by S. epidermidis (two patients), and Enterobacter cloacae (two patients). Computed tomography-directed percutaneous drainage and systemic antibiotics were successful in treating two of three patients who had stable sternums with mediastinal abscess. In the remaining seven patients, sternal and mediastinal debridement with rewiring of the sternum was successfully applied. No patient required muscle or omental flap coverage, and no patient experienced a recurrence of mediastinitis during an average follow-up period of 35 months (range, 12 to 46 months).

Female↗
PubMedDate not supplied

Adjuvant native heart surgery during heterotopic heart transplantation: two case reports.

The results of heterotopic heart transplantation may be further improved if repairs on native heart abnormalities are performed just before implantation of the allograft. Such procedures increase the potential for the recipient's own heart to recover function and, thus, to maintain circulation if the heterotopic heart malfunctions or fails. The native hearts of two of our patients, both women, showed signs of greater contractility and ejection after repair and were able to provide adequate circulatory support during periods of donor heart failure. The first patient required ventricular aneurysmectomy and coronary artery bypass grafting, and the second, native mitral valve repair. Moreover, when persistent ventricular fibrillation occurred in the donor heart of the first patient, a donor cardiectomy was performed, and the recipient heart functioned well thereafter. As more adjuvant operations are performed and the results evaluated, we may find that heterotopic operations would be suitable in a greater variety of heart transplant candidates.

Coronary Artery Bypass↗
PubMedDate not supplied

Use of a new device in cannulation of the great vessels: cannula introducer.

To improve the existing complications of the arterial cannulation technique, an introducer was developed that could minimize the trauma to the vessel wall and intima, simplify the operation and avoid the usual complications such as air or emboli strokes, misdirection and malrotation of the cannula tip within the artery. The Introducer consists of an extendable blade proportionate to the size of the cannula to be inserted. The movement of the blade is accomplished by a trigger in the handle of the device. The cannula is also released by another trigger in the handle. Ninety heart patients in whom this device was used underwent open heart surgery, and there were no single case of a major stroke, air or thrombo-embolism, or undue blood loss. One patient developed a transient right hand paresis that subsided after removal of the arterial line. The results were compared to 65 patients with the current method of cannulation and in whom this device was not used. In this latter group there were five cases of major neurological deficits, one aortic dissection, one case of embolism to the leg and four cases of abnormal bleeding which necessitated takebacks in the first 24 hours of post-operative period.

Aged↗