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Biomedical subjects

J L Pomar

Publications and source records attributed to J L Pomar.

At least 55 records · Page 3Linked to original sources
PubMed1985

Early results with intraoperative transluminal coronary artery balloon dilatation.

We used intraoperative transluminal coronary balloon dilatation, together with coronary artery bypass grafting, to obtain complete myocardial revascularization in extensively diseased coronary arteries. Our patient population consisted of ten males and two females, with a mean age of 58 years. The left anterior descending artery was dilated in five patients, the posterior descending artery was dilated in three, the obtuse marginal artery in two, the left circumflex artery in one, and the right coronary artery in one. Additionally, a mean of 2.81 grafts per patient were placed. Hospital mortality was one patient (8.33%). There was also one case of perioperative myocardial infarction. Postoperative angiography was done in seven patients: five were shown to be improved, one had a vessel that appeared unchanged, and one had an occluded vessel. We found intraoperative transluminal coronary balloon dilatation to be a simple and efficient technique that offers potential improvement in myocardial revascularization.

Journal Article↗
PubMed1984

Late tears in leaflets of porcine bioprostheses in adults.

Of 836 patients with a mitral or aortic bioprosthesis who were followed over an 8-year period, 32 required reoperation for prosthetic dysfunction. Of the 26 prostheses removed at operation, 18 (12 mitral and 6 aortic prostheses) showed tears in the valve leaflets. In 7 of the 12 patients with rupture of "mitral" leaflets and in 1 of the 6 patients with torn "aortic" leaflets, the onset of symptoms was sudden, requiring urgent reoperation. Two of the 18 patients died early after reoperation; both had progressive disability and underwent elective operation. In 5 of the 7 patients with torn leaflets in a mitral prosthesis who had acute onset of symptoms, a single tear was found and no gross evidence of calcification was detected. Macroscopic calcification was found in only 8 of the 18 (44.4%) prostheses with torn leaflets (mitral and aortic). Microscopic examination revealed calcific deposits in 9 of the 12 mitral and in all of the aortic bioprostheses. Of the 54 leaflets examined, 29 had tears: 10 were type I; 6, type II; 7, type III; and 6, type IV. Tears in porcine valve leaflets are not an uncommon cause of dysfunction. These tears often lead to acute hemodynamic changes, particularly in the mitral position, and usually require emergency reoperation. They may occur in prostheses that appear grossly normal.

Adult↗
PubMed1984

Early and late prognosis after reoperation for prosthetic valve replacement.

From 1969 to 1983, 89 patients underwent replacement of a prosthetic heart valve, an average of 66 months after initial implantation, because of primary failure of the prosthesis in 39 patients (44%), endocarditis in 16 (18%), systemic valve-related complications in 16 (18%), and periprosthetic leaks in 13 (15%). In the remaining five patients (5%), a prosthesis was removed concomitantly with the replacement of another native heart valve. A mechanical valve was replaced in 64 cases (72%) and a bioprosthesis in 25 (28%). Forty-six of the prostheses (52%) were in the mitral position, 37 (42%) were in the aortic position, and six patients (6%) underwent replacement of two prostheses. Preoperatively, four patients were in Functional Class I, 21 in Class II, 37 in Class III, and 27 in Class IV. There were 19 early deaths (21.3%). Early mortality was significantly higher with aortic (35.1%) than with mitral prosthetic valve replacement (8.7%, p less than 0.01). Preoperative diagnosis had a significant correlation with mortality, which was higher with infective endocarditis (62.5%) than with all other indications for operation (12.3%, p less than 0.001). No correlation was found with the preoperative clinical class of the patients. During the time period of this study, there was a marked decline in the mortality rate, which decreased from 29.2% prior to 1979 to 7.4% during the last 2 years (p less than 0.05). Actuarial survival was 60% at 5 years and 38% at 10 years after reoperation. Among the 53 survivors followed up for an average of 39 months, 47 (88.9%) remained in Class I or II and six were in Class III (11.3%) at last follow-up. A second prosthetic valve replacement (third valve replacement) was required in eight patients, three of whom died at re-replacement. Recent improvements in myocardial protection techniques, in the treatment of prosthetic valve endocarditis, and increased surgical experience have contributed to decrease the risk of reoperation for prosthetic valve replacement. Late results are similar to those of a first valve implantation.

Actuarial Analysis↗
PubMed1984

Reoperation in patients with patent atherosclerotic coronary vein grafts. A different approach to a different disease.

Atherosclerotic changes are often noted in vein grafts at angiography 8 to 10 years after coronary artery grafting. Reoperation in these patients is hazardous, as manipulation of the grafts may loosen atheromatous debris and cause coronary embolization and myocardial infarction. A technique is described to avoid embolization of atheromatous material during reoperation in patients with patent atherosclerotic coronary vein grafts. This technique was carried out in six patients and compared to the standard technique of reoperation in similar patients. The incidence of complicated perioperative myocardial infarction (0/6 versus 5/12) and perioperative death (zero versus three) was lower when our new technique was used. This approach consists of minimal dissection for access to the right atrium and ascending aorta for cannulation, prompt ligation of all patent grafts at the start of cardiopulmonary bypass, cardioplegic infusion through the ascending aorta and subsequently also through newly inserted grafts using larger infusions until myocardial temperatures reach less than or equal to 15 degrees C, and single aortic clamping for distal and proximal anastomoses.

Aged↗
PubMed1983

Influence of partial sympathetic denervation on the results of myocardial revascularization in variant angina.

Poor results of the aortocoronary bypass graft operation in the treatment of variant angina have been ascribed to recurrent vasospastic activity due to autonomic imbalance. Cardiac sympathetic denervation (plexectomy) may represent a rational approach in the prevention of vasospasm. To test the value of plexectomy in the treatment of variant angina, 31 patients were studied, 17 of whom (Group 1) underwent conventional coronary artery grafting whereas the remaining 14 (Group 2) underwent cardiac sympathetic denervation also. The 2 groups were similar with respect to age (54 +/- 8 versus 50 +/- 7 years), sex distribution (male/female ratio 12/5 versus 9/5), prevalence of coexisting effort angina (10 versus 12 patients), previous myocardial infarction (7 versus 4 patients), and duration of variant angina (3.3 +/- 5.4 versus 2.4 +/- 2.7 months). The left ventricular ejection fraction was comparable in both groups (60 +/- 11 versus 60 +/- 4%) as were left ventricular end-diastolic pressure (15 +/- 4 versus 13 +/- 5 mm Hg) and extent of coronary artery disease (65 versus 71% prevalence of multivessel disease). The average duration of follow-up was 23 +/- 15 months in Group 1 and 22 +/- 18 months in Group 2 (p = not significant [NS]). There were no operative deaths. Four patients, 2 in each group, had a perioperative myocardial infarction. Seven patients in Group 1 and 1 patient in Group 2 had recurrent variant angina. There was sudden death and 2 infarcts in Group 1. Actuarial curves showed the cumulative probability of recurrent variant angina to be significantly lower (p less than 0.05 and p less than 0.001 at 6 and 10 months, respectively) in Group 2. This study suggests that cardiac sympathetic denervation may prevent recurrent vasospastic activity in variant angina.

Adult↗
PubMed1981

Coronary arteriography and atrial thrombosis in mitral valve disease.

The arteriographic findings of neovascularity and fistula formation from the coronary arteries to the left atrium have occasionally been reported in association with atrial thrombosis in patients with mitral valve disease. To establish the diagnostic value of these findings, the preoperative coronary angiograms of 507 patients who underwent open mitral valve surgery were reviewed. Atrial thrombosis was present in 76 patients (14.9 percent). In the 30 patients with angiographic neovascularity and fistula formation, the thrombi were always observed to arise from the circumflex coronary artery. None of these 30 patients had atherosclerotic coronary lesions. In 25 of these patients an atrial thrombus was found at operation. These coronary arteriographic findings, in this selected group of patients, had a predictive accuracy of 83.3 percent, a specificity of 98.8 percent and a sensitivity of 32.8 percent for the diagnosis of the presence of thrombus in the left atrium. No relation was found between these signs and the size and histologic age of the thrombi examined.

Adult↗
PubMed1980

Conservative operation for mitral insufficiency: critical analysis supported by postoperative hemodynamic studies of 72 patients.

From May, 1974, through December, 1978, 255 mitral annuloplasties have been performed at our institution. Forty-three Carpentier rings and 212 flexible rings were used. Simultaneously, 307 patients with predominant insufficiency were treated with a Hancock bioprosthesis. A critical analysis of the flexible ring group versus the Hancock group is presented: The average ages were 41.3 versus 43.3 years. Preoperatively, 55% versus 60% were in Functional Class III and 9.6 versus 25.4% were in Class IV. The valve lesion was caused by rheumatic disease in 91.2% versus 93.9%. A multiple valve operation was required by 51% versus 60%. There was a significant difference in the operative mortality rates (1.8% versus 11.4%). This difference was maintained for each preoperative functional class and for the isolated and multiple valve groups. There was no significant difference in the late mortality rates (1.4% versus 3.7%). The total actuarial survival rates were of 96.4% and 81% (maximum follow-up times 4.0 and 4.5 years). The incidence of embolism was 2.4% and 4.1% per patient-year, with both groups being subjected to the same anticoagulation policy. The incidence of dysfunctions was equal (3.9% per patient-year). Postoperative hemodynamic evaluation of 72 patients having annuloplasty and 129 patients having Hancock valve replacement showed basal mean transmitral gradients of 10.98 +/- 3.6 and 9.66 +/- 2.73 mm Hg. The average effective orifice areas were 1.93 +/- 0.74 and 2.25 +/- 0.46 cm2. While the bioprosthesis behaves hemodynamically like a flow-related variable orifice, the reconstructed valve orifice is dependent upon its preoperative anatomy. In conclusion, the comparison of flexible ring annuloplasty and Hancock valve replacement for mitral valve disease shows a lower operative mortality for the former and comparable medium-term postoperative course. Since both techniques have a limited durability, longer follow-up periods will soon resolve this controversial issue.

Adolescent↗
PubMed1980

Is tricuspid valve repair necessary?

In an attempt to clarify the indications for tricuspid valve operations, we studied 150 patients who had preoperative and postoperative full catheterization including biventriculography. Seventy-eight patients had organic and 72 had functional tricuspid insufficiency (TI). One hundred nineteen underwent tricuspid repair (46 commissurotomies and 115 annulopasties), and in 31 the tricuspid disease was surgically ignored. Ninety seven percent of all patients with hemodynamically correct left-side repair were in Class I or II, regardless of the state of the tricuspid valve. Repair of lesions on the left side determined the postoperative cardiac index. In the "repaired group," 38% had residual gradients and 30% residual TI. Eighty percent of patients with low postoperative pulmonary resistance had no TI, compared with 53% with high pulmonary resistance. In the "ignored group," all 14 patients with organic disease had residual TI, as did nine of 17 with functional disease but with elevated pulmonary resistance. The right ventricular end-diastolic volume (RVEDV) decreased 37% in the "repaired" (p < 0.001) and 36% in the "ignored" group (p < 0.01) if tricuspid competence was achieved, but remained high if TI persisted. Because of these data, which emphasize the need for an early and correct repair of the left-side lesions, we believe that (1) functional TI can be ignored only in patients with predictable and significant reduction in pulmonary resistance and (2) organic disease must be repaired.

Adolescent↗
PubMed1978

Intraoperative assessment of mitral valve function.

Clinical, echocardiographic, hemodynamic, and angiographic data can usually assess the preoperative status of the mitral valve quite accurately. However, there is need for an intraoperative method to observe the dynamic function of the mitral valve, particularly after an open commissurotomy, or to determine the efficacy of a valvoplasty. Our experience with more than 250 mitral annuloplasties has led to the development of a safe method for direct observation of the mitral closure mechanism using the left ventricular vent and a slight modification of the usual cardiopulmonary circuit.

Animals↗
PubMed1978

Heterologous pericardium for the closure of pericardial defects.

Patches of glutaraldehyde-preserved porcine pericardium were transplanted orthotopically into 20 dogs to see if they might make a satisfactory pericardial substitute. Two dogs had mediastinal infections and were excluded from this study. All animals were reoperated on at regular intervals between 15 and 300 days. In 15 dogs there were no adhesions between the porcine pericardium and the host's epicardium. Histological study showed healing between both pericardiums and no degenerative changes in transplanted pericardium. Glutaraldehyde porcine pericardium has been utilized in 8 patients to close the pericardial cavity. There have been no problems related to the pericardial grafts after a maximum follow-up of 9 months.

Adult↗