PubMed Health⌕ Search

Biomedical subjects

C M Duran

Publications and source records attributed to C M Duran.

At least 19 recordsLinked to original sources
PubMed1995

From aortic cusp extension to valve replacement with stentless pericardium.

Between 1988 and 1994, 82 consecutive patients (median age 24 years) underwent reconstruction of the aortic valve with glutaraldehyde-treated pericardium. Simultaneously, 29 of 30 mitral valves were repaired. The first 27 patients underwent resection of the free edges and suture of a single strip of bovine pericardium. Transient ischemic changes suggested the need for a change in technique. The subsequent 55 patients underwent total valve reconstruction with an autologous pericardium fixed with glutaraldehyde in the appropriate shape and size according to the patient's aortic annulus. There were one in-hospital and three late deaths. No patient received anticoagulation, and no embolic events were detected. Nine patients required reoperation as a result of failure of mitral valve repair in 4 and severe aortic regurgitation in 5 (endocarditis [n = 2], commissural tear [n = 1], root dilation [n = 1], calcification of one bovine cusp [n = 1] at 58 months). There were no reoperative deaths. Complete linear echocardiographic follow-up of these patients showed low gradients, valve competence, and no progressive deterioration. No difference between techniques was detected.

Adolescent↗
PubMed1995

Autologous glutaraldehyde-treated pericardial valved conduit: an experimental study.

Extracardiac conduits in the form of allografts and synthetic tubes containing heterograft valves have been used widely in the management of ventricular outflow abnormalities and for establishing ventriculoarterial continuity. These procedures are limited by long-term calcification as well as by formation of neointimal peel, necessitating reoperation. In an effort to continue the search for an alternative conduit, we designed and evaluated a valved sinus-bearing conduit fashioned out of autologous pericardium treated with glutaraldehyde. The construction of the conduit is described. The results of implantation of these conduits in 12 sheep showed no progression of gradients, fresh regurgitation, or evidence of wall or cusp calcification 9 months after implantation.

Animals↗
PubMed1995

Pulmonary autograft for aortic valve replacement in rheumatic disease: a caveat.

Pulmonary autograft replacement of the aortic valve offers an attractive option in the younger patient with growth potential and long-term survival. In our institution between January 1990 and August 1994, 78 patients have undergone this procedure. The mean age was 18.6 +/- 7.36 years (range, 1 to 41 years). The etiology was rheumatic in 63 patients (80.7%). Aortic regurgitation was the predominant lesion in 60 patients (76.9%). Significant mitral regurgitation requiring operation was present in 22 patients (28.2%). All patients underwent pulmonary autograft replacement of the diseased aortic valve and the mitral valve was repaired in 22 patients. There were no hospital mortality, endocarditis, or thromboembolism in the series up to date. There have been two late non-cardiac deaths. Five patients (6.4%) required reoperation, one for mitral repair failure and four for autograft failure. Acute rheumatic valvulitis was demonstrated in one of the reoperated patients. Echocardiography of 68 patients followed up more than 2 months show progression of aortic regurgitation more than 2/4+ in 12 patients (15.4%). Four of these patients have been reoperated without mortality. In conclusion, although the Ross procedure remains a safe and attractive alternative in aortic valve operation, the progression of aortic regurgitation, especially in the younger patient with rheumatic etiology, remains a concern.

Adolescent↗
PubMed1995

Extended transseptal versus conventional left atriotomy: early postoperative study.

BACKGROUND: Mitral valve operations require excellent exposure. The description of an extended vertical transseptal atriotomy by Guiraudon and associates promises to provide optimal exposure of the mitral valve. A prospective study was carried out to evaluate the merits of the extended vertical transseptal atriotomy in comparison with the conventional left atriotomy for mitral valve operations. METHODS: Conventional atriotomy was performed in 24 patients (group I) whereas 65 patients underwent the extended vertical transseptal offroach (group II). They were similar in age, sex, cause of disease, New York Heart Association functional class, left atrial size, and left ventricular function. The early postoperative rhythm changes in these two groups were compared. Statistical studies to analyze the significance of incidence of junctional arrhythmia in these two groups were carried out. RESULTS: Of the 24 patients in group I, 3 had development of transient junctional rhythm after operation, lasting less than 24 hours. None had this arrhythmia at the time of discharge. Of the 65 patients in group II, junctional rhythm was documented in 25, with a rate of occurrence of 38% (95% confidence interval, 27.6% to 52.2%). At the 6-week follow-up, 3 patients still had this junctional rhythm, with a failure to recover rate of 12% (3 of 25). CONCLUSIONS: The surgical exposure was considered excellent and closure of the atriotomy was thought to be easy in group II. However, this should be balanced against a significant (38%) incidence of transient junctional rhythm in the early postoperative period in group II, probably from injury to sinus node artery or atrial conduction pathways.

Adolescent↗
PubMed1995

Aortic valve replacement with freehand autologous pericardium.

Fifty-one patients with a mean age of 31.2 years underwent aortic valve replacement with glutaraldehyde-treated autologous pericardium. Pure aortic regurgitation was present in 28 (54.9%), stenosis in 9, and mixed disease in 14. Simultaneous mitral valve repair was done in 17 patients and replacement in 1. There were no hospital and two late deaths. Three patients required reoperation because of failure of the pericardial valve as a result of infective endocarditis in two (5 and 31 months after operation) and commissural tear at 8 months in another. One patient underwent reoperation at 24 months because of failure of the mitral valve repair. The pericardial aortic valve, which had 2+ regurgitation since the first operation, was also replaced. Macroscopic and microscopic examination findings in the excised pericardium were excellent. No thromboembolic events have been detected and no patient received anticoagulation therapy except one after mitral valve reoperation and replacement with a mechanical valve. The actuarial survival was 84.53% +/- 12.29% at 60 months, freedom from failure of the aortic reconstruction 83.83% +/- 8.59%, and freedom from any event 72.59% +/- 12.79%. Doppler echocardiographic study at most recent follow-up showed a mean gradient of 12.56 +/- 8.10 mm Hg and mean regurgitation on a scale from 0 to 4+ of 0.80 +/- 0.66. Although the maximum follow-up is only 5 years, the results obtained so far encourage us to continue replacing the aortic valve with stentless autologous pericardium.

Adolescent↗
PubMed1995

Aortic valve replacement with autologous pericardium: surgical technique.

The surgical technique of aortic valve replacement with freehand glutaraldehyde-treated autologous pericardium is described. Forty-nine patients underwent this procedure without hospital mortality and no thromboembolic episodes without anticoagulation. Three patients underwent reoperation: for infective endocarditis in two; and tear of one commissure 8 months after surgery in another. This technique because of its excellent hemodynamics and low thrombogenicity might be a valid alternative particularly in patients with a small aortic annulus.

Adolescent↗
PubMed1995

Comparison of fresh and glutaraldehyde-treated autologous stented pericardium as pulmonary valve replacement.

The use of fresh autologous pericardium in valve surgery has shown poor results in the past mainly due to thickening and retraction. Recently, it has been suggested that a short treatment with glutaraldehyde might radically change its behavior. In an attempt to determine whether this disparity in results is due to the glutaraldehyde treatment or to a better present-day surgical technique, fresh and glutaraldehyde-treated autologous pericardium was mounted in a frame and implanted in the pulmonary position of adult sheep. Six survivors obtained in each group were sacrificed between 2 and 8 months in the "fresh" group and between 2 and 6 months in the "glutaraldehyde-treated" group. Macroscopically, the fresh pericardium became thickened and retracted in all specimens, eventually resulting in severe regurgitation, while the glutaraldehyde-treated, although slightly thickened, retained its pliability without significant retraction. Microscopically, viability of the central core of the collagen was more often preserved in the fresh pericardium. Endothelialization was irregular. In conclusion, short glutaraldehyde treatment seems to improve the results of autologous pericardium mounted on a valve stent. Its effect on calcification remains to be ascertained.

Animals↗
PubMed1995

In situ mitral valve stabilization with glutaraldehyde.

Mitral valve repair in the young rheumatic patient carries a high reoperation rate due to progression of the disease. In an attempt to halt or at least slow down this process, the possibility of fixing in situ the valve tissues with glutaraldehyde was explored. Six weanling sheep underwent tanning of their anterior mitral leaflet for two minutes with 0.5% buffered glutaraldehyde. The non-treated posterior mitral leaflet served as control. The animals were sacrificed at varying intervals between 2.5 and 6 months. At sacrifice, Doppler echocardiography and hemodynamic studies were done. The leaflets were subjected to histopathologic examination and calcium and glutaraldehyde contents were estimated. Glutaraldehyde treatment of the anterior leaflet caused thickening of the cusp and chordae associated with partial devitalization of its core tissue, partial loss of endothelium and intense fibrocellular reaction with abundant elastic fibers without altering its functional integrity. It did not induce calcification. There were no detectable levels of glutaraldehyde at explantation. The posterior mitral leaflets were normal. Although the absence of calcification and partial viability of the tissue are encouraging, it does not necessarily follow that this treatment would arrest progression of the underlying disease. This process may have clinical application in the future, but it is not yet recommended.

Animals↗
PubMed1992

Percutaneous mitral valvotomy with the Inoue balloon catheter in children and adults: immediate results and early follow-up.

Percutaneous mitral balloon valvotomy (PMV) using the Inoue balloon catheter was attempted in 60 consecutive patients with severe symptomatic mitral stenosis. There were 10 children (mean age 13 years) and 50 adults (mean age 31 years). Forty patients were females and 20 were males; 53 were in sinus rhythm. The procedure was technically successfully performed in 57 (95%) patients. There were no deaths or thromboembolic complications. Balloon valvotomy was done using a 22 to 30 mm diameter catheter with the echo/Doppler guided stepwise mitral dilatation technique. After PMV the mean left atrial pressure decreased from 23.0 +/- 5.0 to 14.0 +/- 4.0 mm Hg (p less than 0.001). The mean mitral valve gradient (MVG) decreased from 15.0 +/- 4.0 to 6.0 +/- 2.0 mm Hg (p less than 0.001). The mitral valve area (Gorlin formula) increased from 0.7 +/- 0.2 to 1.6 +/- 0.4 cm2 (p less than 0.001). The mitral valve area as determined by echocardiography increased from 0.8 +/- 0.1 to 1.9 +/- 0.3 cm2 (p less than 0.001). Mild mitral regurgitation (MR) developed in six patients (11%) and increased by one grade in another five patients (9%). No patient developed severe mitral regurgitation. Mitral valve area at mean follow-up of 4.8 months remained unchanged at 1.9 +/- 0.3 cm2. We conclude that PMV, using the Inoue balloon catheter, is safe and effective in the treatment of severe mitral stenosis in children and adults, without inducing significant mitral regurgitation.

Adolescent↗
PubMed1992

Balloon coarctation angioplasty in adolescents and adults: early and intermediate results.

Twenty-three adolescent and adult patients with native coarctation of the aorta underwent balloon dilatation. Dissection of the aorta developed in one patient. Data were collected on the remaining 22 patients. They ranged in age from 15 to 55 years (mean 23 +/- 9.2 years). Invasive measurement of the peak systolic gradient (PSG) and biplane angiography were performed before and immediately after angioplasty and at follow-up 4 to 48 months (mean 15 months) later. PSG before dilatation was 37 to 100 mm Hg (mean 66.9 +/- 19.9 mm Hg) and decreased to 0 to 30 mm Hg (mean 9.1 +/- 11 mm Hg) immediately after dilatation (p less than 0.001). Restenosis occurred in two patients 6 months after dilatation, and one patient had an incomplete dilatation. These three patients underwent successful redilatation and remained improved 12 to 19 months later. There was no significant change in gradient at repeat catheterization in the remaining 20 patients. PSG was 0 to 20 mm Hg (mean 5.8 +/- 7.2 mm Hg). Angiography showed that a small aneurysm developed in one patient immediately after dilatation and in another 6 months later. Eleven patients were restudied more than once, and no change in gradient or size of the aneurysm was noted at mean follow-up 25 months after dilatation. This study demonstrated that balloon angioplasty is an effective method of treating adolescent and adult patient with native coarctation of the aorta. However, because of the uncertain natural history of aneurysm after dilatation, this procedure should be considered investigational until much longer follow-up times are available.

Adolescent↗
PubMed1992

New surgical technique for type B aortic interruption.

Restoring continuity of the aortic arch in aortic interruption continues to be a problem in terms of both surgical technique and long-term results. We report here a surgical technique using the left subclavian artery along with an aberrant right subclavian artery to form a conduit in a patient with type B interruption, to reestablish aortic continuity.

Aorta, Thoracic↗
PubMed1992

Simultaneous measurement of left atrial pressure by Doppler echocardiography and catheterization.

Simultaneous, continuous wave Doppler echocardiography, left ventricular systolic and mean pulmonary capillary wedge pressure measurements were performed during cardiac catheterization in 54 patients with mitral regurgitation. Doppler-derived left atrial pressure, which was calculated by subtracting mitral regurgitant gradient from brachial artery systolic pressure, correlated well with mean pulmonary capillary wedge pressure by catheter (r = 0.933, SEE = 2.9 mmHg, P < 0.001); a comparison between non-invasive and invasive systolic gradients across the mitral valve yielded a high correlation (r = 0.91, SEE = 6.0 mmHg, P < 0.001); and there was also a high correlation between brachial artery and left ventricular systolic pressures (r = 0.93, SEE = 4.9 mmHg, P < 0.01). It is concluded that Doppler echocardiography provides a reliable and accurate method for complete non-invasive assessment of left atrial pressure in patients with mitral regurgitation.

Adolescent↗
PubMed1992

Total cavopulmonary connection for right ventricular endomyocardial fibrosis.

Endomyocardial fibrosis is an endemic problem in tropical countries and is characterised by ventricular cavity obliteration, decreased ventricular compliance, and atrioventricular valve regurgitation. We report on a patient with right ventricular endomyocardial fibrosis resulting in obliteration of the cavity and tricuspid regurgitation treated successfully by total cavopulmonary connection and exclusion of the right ventricle.

Adult↗
PubMed1992

Right-sided endomyocardial fibrosis with recurrent pulmonary emboli leading to irreversible pulmonary hypertension.

A 26 year old Saudi man with features of both Loeffer's endocarditis and endomyocardial fibrosis presented with mild symptoms and pulmonary emboli. Echocardiographic examination showed obliteration of the right ventricular apex by an attached mass. The results of haemodynamic studies were somewhat abnormal and medical treatment was started. Despite anticoagulation with warfarin the patient's condition deteriorated rapidly over a four month period after a further episode of pulmonary embolism and the development of pulmonary hypertension. Two haemodynamic studies performed four months apart were typical of pulmonary hypertension and later right ventricular failure; they showed none of the characteristics of restriction. Pulmonary embolectomy was attempted but there was no cleavage plane between the organised thrombi and the endothelium of the pulmonary artery. The patient died of severe pulmonary hypertension and right ventricular failure several days after operation. Surgical intervention in the early stages of right-sided endomyocardial fibrosis might have prevented the development of pulmonary embolism and pulmonary hypertension.

Adult↗
PubMed1992

The vanishing tricuspid annuloplasty. A new concept.

A tricuspid De Vega annuloplasty with absorbable 2-0 polydioxanone sutures was performed on 16 sheep supported by cardiopulmonary bypass. The anulus diameter was reduced by 2 to 6 mm. Four sheep died perioperatively. The 12 survivors were electively killed at 2-week intervals during a period of 6 months. Infective endocarditis was not observed. At the time of death no gradient was found on simultaneous pressure measurements of the right atrium and ventricle. Epicardial echocardiography did not reveal tricuspid stenosis or regurgitation. Macroscopically there was no thrombus and the tricuspid leaflets were of a normal appearance. A thin white cord was observed at the anulus in all animals killed after 12 weeks. The annular size remained as surgically induced until the fourth month, but it reverted to its preoperative size after 5 months. Histologically there was granulation tissue initially only around the foreign material, but then progressively it appeared also between the foreign filaments, with the development of multinucleated foreign body giant cells. At approximately 5 months most of the foreign material had been disrupted or absorbed, leaving a tenuous ring of granulation tissue, which allowed expansion of the tricuspid ring to its original circumference. By 6 months most of the foreign material had disappeared and was replaced by loose collagenous tissue. The concept of a "vanishing annuloplasty" is advanced, with particular application in children and in patients with functional tricuspid insufficiency.

Animals↗
PubMed1991

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↗