PubMed Health⌕ Search

Biomedical subjects

C M Duran

Publications and source records attributed to C M Duran.

At least 91 records · Page 5Linked to original sources

Leaflet embolisation from Duromedics valves: a report of two cases.

Embolization of parts of mechanical valves has been reported since the inception of prosthetic valve implantation. We report here two cases of embolization of one hemileaflet of a Duromedic bileaflet prosthesis in the mitral position due to a pivot fracture. Both presented with moderately severe mitral regurgitation and pulmonary edema and were successfully managed by replacement of the malfunctioning prostheses. The embolised disc was located in the left common iliac artery by abdominal ultrasound and removed by an inguinal, retroperitoneal approach with low morbidity. Both patients left hospital and are doing well to-date.

Adult↗

A feasibility study of valve repair in rheumatic mitral regurgitation.

Valve repair is an established form of treatment for mitral valve regurgitation. In order to elucidate the feasibility and results of aggressive repair in a young rheumatic population, all consecutive patients operated on between July 1988 and July 1990 for mitral regurgitation were reviewed. There were 203 patients with a mean age of 29 years; 91% were in functional classes III-IV. Pure regurgitation was present in 47.8%. Associated valvular surgery was performed in 56.2%. Forty-nine (24.1%) patients had a straight valve replacement (MVR), 18 (8.9%) had an unsuccessful attempt at repair and in 136 (67%) the repair was considered successful. Overall hospital mortality was 3.4%: 4% for MVR, 16.6% for the attempts, 1.4% for repairs. The thromboembolic rate for replacement was 6.0% pt-yr and for repair 0.87% pt-yr. There were five late deaths in the replacement group and one in the repair group. Seventeen patients required reoperation in the repair group (12.6%) with a mean age of 17 years. Six of these patients had active rheumatic carditis, either at first operation or in the postoperative period. The postoperative functional status of all patients was excellent. In conclusion, valve repair although possible in a high percentage of rheumatic regurgitation patients carried a penalty of unsuccessful attempts and reoperations. However, in the follow-up period the rate of thromboembolism and late mortality among the patients with prostheses offsets these disadvantages.

Adolescent↗

Decrease in pulmonary artery pressure with slow release nifedipine in Saudi patients with primary pulmonary hypertension.

We studied the acute and short-term hemodynamic effects of vasodilators in three Saudi patients with primary pulmonary hypertension. The study protocol included the measurement of pulmonary artery pressure, resistance and cardiac output at baseline and at 15, 30, 45 and 60 minutes after 10 mg sublingual nifedipine. These hemodynamic studies repeated at 3 and 6 months follow-up. A 24 hour profile of pulmonary artery and aortic pressures were recorded to evaluate the effect of 20 mg of slow release nifedipine, after 25 mg of captopril and 5 mg of sublingual isordil. After nifedipine there was a marked reduction in systolic pulmonary artery pressure from 85 +/- 18 to 55 +/- 8 mmHg and the pulmonary resistance decreased from 1422 +/- 367 to 954 +/- 69 dynes-sec/cm-5. The cardiac output increased from 2.9 +/- 0.2 to 0.2 to 4.0 +/- 0.4 l/min after nifedipine. The patients were discharged on nifedipine 10 mg qid, except for patient #3 who was a non-responder. At follow-up there was a symptomatic improvement and a favourable hemodynamic response was maintained, though patient #2 required a higher dose of nifedipine. The pulmonary artery 24 hour pressure profile revealed that 20 mg slow release adalat reduced pulmonary artery pressure for a 6 hour period. Whereas, regular nifedipine decreased pulmonary artery pressure for a period of less than 90 minutes. There was no favourable hemodynamic response to either captopril 25 mg oral of isordil 5 mg administered sublingually. We conclude that slow release nifedipine decreases the pulmonary artery pressure for longer periods compared to regular nifedipine in patients with primary pulmonary hypertension.

Adolescent↗

Mitral balloon valvotomy using the Inoue balloon technique for selected patients with severe pliable rheumatic mitral valve stenosis: immediate and short-term results.

We selected 40 patients with severe symptomatic rheumatic mitral stenosis for balloon valvotomy using the Inoue balloon technique. The patients' mean age was 31 +/- 14 years and there were 24 females and 16 males. The patients were selected according to the following echo/Doppler criteria; 1. Severe mitral stenosis, i. e. mitral valve area (MVA) less than 1.1 cm2; 2. pliable anterior mitral valve leaflet; 3. absence of calcification of the mitral commissures and 4. absence of significant subvalvular mitral valve disease (Block echo score less than 8). We failed to cross the mitral valve in three cases and repeat attempts in two patients with higher transeptal puncture was successful. Thirty-nine procedures were technically successful (98%). There were no complications. We used an Inoue balloon size 24-30 mm using echo/Doppler guided stepwise mitral dilatation. After mitral balloon valvotomy, the MVA increased from 0.8 +/- 0.2 to 1.7 +/- 0.5 cm2 (p less than 0.001). Five patients developed mild mitral regurgitation and in one patient the degree of mitral regurgitation increased from mild to moderate. The mean mitral valve area 48 hours after the procedure measured 1.9 +/- 0.4 cm2 (echo/Doppler); one patient (2.5%) had residual mitral stenosis (MVA less than 1.5 cm2). At six weeks follow-up study the mean mitral valve area was 1.9 +/- 0.5 cm2 (Echo/Doppler), with no restenosis. We conclude that in selected cases of severe pliable mitral stenosis, the Inoue balloon technique achieves a greater than 100% increase of the MVA, without inducing significant iatrogenic mitral regurgitation or residual stenosis.

Catheterization↗

Valve repair in rheumatic mitral disease.

Emerging evidence indicates that etiology plays an essential role in the results of mitral valve repair. In an attempt to evaluate the possibilities and problems of repair in a rheumatic population, all consecutive patients treated between July 1988 and July 1990 were reviewed. Three hundred and four patients at risk of undergoing a repair were studied. The mean age was 31.3 years. In 78 patients (25.6%) the valve was considered beyond repair and immediately replaced (MVR). In 26 patients (8.5%) an unsuccessful attempt at repair was followed by replacement (attempts), and 200 (65.7%) underwent a successful repair (repair). The repair group was younger (p less than 0.001) and had less tricuspid involvement (p less than 0.005). The repair rate was highest in regurgitant lesions (79.4% repaired, p less than 0.005). The attempts group was very similar to the MVR group. The total hospital mortality was 3.2%. For MVR it was 3.8%, for attempts 19.2%, and for repairs 1.0%. The incidence of embolism was 3.34%/patient/yr for the mechanical, 3.06%/patient/yr for bioprosthesis, and 2.19%/patient/yr for repairs. Only 7.5% of repairs were anticoagulated. A reoperation was needed in 26 patients: one for bioprosthesis, one for aortic repair failure, and 24 for mitral repair dysfunction (12.1% of all surviving repairs). The reoperation incidence after repair was 26.8% in patients with an age under 20 years and 4.5% in those over 20. Eight patients had active carditis and 10 severe hemolysis. There were eight late deaths (six prosthesis and two repairs), with an actuarial total survival at 30 months of 72.46 +/- 8.45% for prosthesis and 94.41 +/- 3.74% for repairs (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Regression of infundibular pulmonary stenosis after successful balloon pulmonary valvuloplasty in adults.

Between July 1985 and March 1988, 22 adult patients with congenital pulmonary stenosis underwent balloon pulmonary valvuloplasty. There were 10 males and 12 females aged 16-45 (average 25 +/- 9.9) years. All patients had additional mild to severe infundibular stenosis; 16 were restudied 6-36 (mean 12.6) months later by repeat catheterization. Student's t-test was used for comparison of data. Right ventricular (RV) systolic pressure before dilatation was 84-196 (mean 129 +/- 32.3) mm Hg, and the peak pulmonary gradient (PPG) was 60-176 (mean 111 +/- 33.2) mm Hg immediately after dilatation. The RV systolic pressure dropped to 32-140 (mean 59.2 +/- 27) (P less than 0.001); and PPG dropped to 10-113 (mean 37.8 +/- 26.4) (P less than 0.001), and the infundibular gradient ranged from 8 to 113 (mean 35.1 +/- 25.8) mm Hg. The infundibular diameter, before dilatation, ranged from 2 to 15 (mean 9.5 +/- 4) mm Hg. At repeat catheterization, the RV systolic pressure dropped further to 33-66 (mean 42.8 +/- 9.7) mm Hg and the PPG was reduced to 0-48 (mean 18.4 +/- 10.9) mm Hg (P less than 0.001). The infundibular gradient regressed to 0-34 (mean 15 +/- 8.8) mm Hg (P less than 0.001). The infundibular diameter increased to 8-25 (mean 15.8 +/- 5.4) (P less than 0.001). It is concluded that moderate to severe infundibular stenosis, in adults, can regress after successful pulmonary valvuloplasty.

Adult↗

Early clinical results with the Xenomedica porcine bioprosthesis.

All patients undergoing heart valve replacement with a glutaraldehyde-preserved Xenomedica xenograft from June 1983 through November 1983, were reviewed. This analysis included 75 patients: 37 having undergone aortic valve replacement, 23 mitral valve replacement, and 15 mitral and aortic valve replacement. Of 70 patients discharged from the hospital, there were 5 late deaths, which represents an incidence of 1.06% per patient-year. Twenty-six patients were recatheterized between 3 and 6 months postoperatively. The mean mitral valve orifice area was 1.57 +/- 0.37 cm2. The average mitral valve gradient was 9.8 +/- 2.9 mmHg. No differences in hemodynamic behavior were found between standard and composite mitral prostheses. The average aortic valve peak systolic gradient was 11 +/- 6 mmHg. Fourteen out of the 34 mitral (41%) and 5 out of 52 aortic (9.6%) prostheses have some degree of incompetence. We have discontinued the use of this cardiac bioprosthesis due to the frequent appearance of incompetence in mitral valves, and high transvalvular gradients in mitral prostheses.

Adult↗

Expanded polytetrafluoroethylene surgical membrane for pericardial closure. An experimental study.

This experimental study summarizes our experience with the use of a new polytetrafluoroethylene surgical membrane as a pericardial substitute in 24 dogs. Group I consists of 10 dogs who underwent simple pericardial closure with this membrane, and in Group II, 14 dogs had pericardial closure with this membrane after cardiac procedures. There were three early deaths. Two dogs that had undergone an associated right heart procedure developed endocarditis at 4 and 7 months, respectively. Postmortem examinations were performed in all 21 surviving dogs. The pericardial membranes were found to be acellular and to have maintained their initial characteristics. The epicardium was normal and the coronary arteries easily visible. Seven of the eight 0.2 mm thick membranes caused filmy pericardial adhesions. None of the 0.1 mm thick membranes formed adhesions or had any structural change. We conclude that this new 0.1 mm thick polytetrafluoroethylene surgical membrane should be clinically tested to see if it will reduce or eliminate pericardial adhesions and facilitate cardiac reoperation.

Animals↗

Reconstruction of right ventricular outflow and pulmonary artery with a composite pericardial monocusp patch: an experimental study.

A composite bovine pericardial monocusp patch was implanted in the right ventricular outflow tract of 30 dogs. The monocusp patch incorporates a molded sinus of Valsalva designed according to a computer-analyzed study of the normal anatomy. Twenty-two dogs survived the operation and were killed between 1 and 34 months postoperatively (mean, 19.5 +/- 3.5 months). Two implants showed signs of infective endocarditis 2 and 2.5 months, respectively, after operation; 1 was thrombosed at 7 months, and 1 was calcified 8 months postoperatively. In the remaining 18 animals, there was no stenosis, thrombosis, or degeneration of tissue in the monocusp. Macroscopic and microscopic studies of these grafts showed normal structure and pliability of the monocusp valve up to 34 months after operation.

Animals↗

Pulse duplicator study of the right ventricular outflow tract: changes induced by surgery.

Thirty-one adult pig hearts were studied in a pulse duplicator to observe the changes induced by right ventricular outflow tract reconstruction. Six were normal hearts, 7 had a transannular outflow patch and 18 a composite monocusp patch inserted. Abnormal movements and distortion of the posterior pulmonary leaflets were observed when a patch had been inserted. The monocusp patch achieved a competent pulmonary valve although the bovine pericardial cusp had slower movements than the normal leaflet, resulting in a mild regurgitation.

Animals↗

Clinical experience with the Carpentier-Edwards porcine bioprosthesis: short-term results (from 2 to 4.5 years).

All patients undergoing a heart valve replacement with a glutaraldehyde Carpentier-Edwards xenograft from April 1978 through December 1980 were reviewed. This analysis included 189 patients: 117 having a mitral valve replacement (MVR), 45 having an aortic valve replacement (AVR), and 27 having mitral and aortic valve replacements (MAVR). Out of 174 patients discharged from the hospital, one was lost to follow-up and is excluded from the analysis. There were 11 late deaths, which represent an incidence of 1.89% per patient-year for the MVR (6/106), 0.83% per patient-year for the AVR (1/41), and 5.83% per patient-year for the MAVR (4/26). There were 6 instances of infective endocarditis (4 MVR, 2 MAVR), which represent a linearized incidence o 1.26% and 2.91% per patient-year for the MVR and MAVR respectively. All were successfully treated with medication. There were 10 thromboembolic events in 7 patients (6 MVR had 9 events and 1 AVR had 1 event). This represents a linearized incidence of 2.84% and 0.83% per patient-year for MVR and AVR, respectively. Primary tissue failure was observed in 3 patients (2 MVR, 1 MAVR), who required reoperation for explantation of the mitral valves. This represents an overall linearized incidence of mitral failures of 0.78% per patient-year. The probability of being free from primary tissue failure is 95.9 +/- 4.9% for all mitral prostheses at 4.5 years of follow-up. These current results indicate that the Carpentier-Edwards porcine xenograft valve can be considered as a valid alternative for heart valve replacement.

Adolescent↗

Five- to eight-year follow-up of patients with the Hancock cardiac bioprosthesis.

All patients undergoing a heart valve replacement with a glutaraldehyde-preserved Hancock xenograft from June, 1974, through June, 1977, were reviewed. This analysis included 403 patients: 202 having mitral valve replacement (MVR), 131 having aortic valve replacement (AVR), and 70 having mitral and aortic valve replacement (M/AVR). The hospital mortality was 9.9% (40/403): 10.8% (22/202) for MVR, 4.5% (6/131) for AVR, and 17.1% (12/70) for M/AVR. Of 363 patients discharged from the hospital, six were lost to follow-up at 24 and 37 months and they are excluded from the figures. There were 41 late deaths, which represents an incidence of 1.47% per patient-year for MVR (16/177), 1.95% per patient-year for AVR (14/122), and 3.35% per patient-year for the M/AVR (11/58). There were 37 thromboembolic events in 32 patients. This represents a linearized incidence of 1.93%, 0.97%, and 2.74% per patient-year for MVR, AVR, and M/AVR, respectively. None of the accidents was fatal, and four of the 32 patients were on a regimen of controlled anticoagulation at the time of embolism. Primary tissue failure was observed in 34 patients (231 MVR, eight AVR, and five MAVR). The probability of being free from primary tissue failure at 8 years is 85.3% +/- 3.7% for MVR, 85% +/- 11.6% for AVR, and 81% +/- 8.9% for M/AVR. These current results indicate that the Hancock xenograft valve can be considered as a valid alternative in heart valve replacement.

Adolescent↗

Clinical experience with glutaraldehyde-preserved heterologous pericardium for the closure of the pericardium after open heart surgery.

A limited series of 58 patients had their pericardial cavity closed with a patch of heterologous glutaraldehyde-preserved pericardium. No patients have been lost to follow-up, which extends between 3 hours and 50 months with a mean of 21 months. No problems related to the patch have been detected. Nine specimens have been available for macroscopic examination and 5 for microscopic study with a maximum postimplant time of 6 months. The patch maintained its initial structure, remained acellular and offered a retrosternal and intrapericardial plane of cleavage.

Animals↗

Open mitral commissurotomy.

We analyzed the results obtained in 163 consecutive patients with "pure" mitral stenosis who underwent operation by the open approach exclusively. Calcification was found in the mitral valve leaflets in 11% of the patients and left atrial thrombus, in 13.2%. A statistically significant relationship was discovered between history of previous systemic embolism and cardiac rhythm (p less than 0.005). The subvalvular apparatus was affected in 66.6% of patients; most of them were in New York Heart Association Functional Class III (p less than 0.005). The frequency with which annuloplasty had to be performed because of mitral insufficiency after commissurotomy was statistically higher (p less than 0.025) among patients in Functional Class III. Early mortality was 1.2% and late mortality, 0.2% per patient-year. Two patients required late reoperation (0.4% per patient-year). One was in Functional Class III and the other, Functional Class IV before the first operation. Three patients sustained a late systemic embolism (0.6% per patient-year). All survivors but 1 are in Functional Class I (84.4%) or II (14.9%).

Adolescent↗

A safe technique for removal of massive left atrial thrombus.

Open mitral operation in patients with massive left atrial thrombus still carries a high mortality due to intraoperative embolism. To prevent this danger, we have standardized a surgical technique that includes careful handling of the heart and use of suction, blockage of the mitral orifice, and excision of subendocardial thrombus. Our total experience with massive left atrial thrombosis comprises 30 patients. Seven out of 8 patients operated on before our present technique was used died in the hospital of irreversible cerebral damage. The other 22 patients underwent operation with this technique, and the thrombus was removed without mortality or morbidity.

Heart Atria↗

Heart valve replacement with the Hancock bioprosthesis: a 6-year review.

All patients who had a mitral or aortic Hancock valve replacement between June, 1974, and June, 1979, were reviewed. A total of 734 bioprostheses were implanted in 632 patients: 291 had mitral (MVR), 239 had aortic (AVR), and 102 had both mitral and aortic valve replacement (MVR + AVR). In 228 patients, an associated surgical procedure was necessary. It involved conservative valve operation in 205 of them. The hospital mortality was 9.6% (28) for MVR (11.5% with associated operation), 4.6% (11) for AVR (8.7% with associated operation), and 13.7% (14) for MVR + AVR (13.0% with associated operation). The follow-up period was between 1 and 6 years with a total follow-up of 934.6, 714.6, and 288.3 patient-years for MVR, AVR and MVR + AVR, respectively. The late mortality was 0.96% (9), 1.53% (11), and 2.08% (6) per patient-year for MVR, AVR, and MVR + AVR, respectively. The thromboembolic rate was 1.49%, 0.14%, and 2.08% per patient-year for MVR, AVR, and MVR + AVR, respectively. There were twelve valve failure (six wer due to rupture; four, thrombosis; one, insufficiency because of intrinsic failure; and one, stenosis without evident cause at reoperation). This represents a failure rate of 0.53%, 0.13%, and 2.08% per patient-year for MVR, AVR, and MVR + AVR, respectively. These results encourage us to continue our routine use of the glutaraldehyde xenografts as the safest valve substitute at present.

Adolescent↗