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Biomedical subjects

A Riberi

Publications and source records attributed to A Riberi.

At least 19 recordsLinked to original sources
PubMed2001

Systemic embolism: a serious complication after cardiac transplantation avoidable by bicaval technique.

OBJECTIVE: Systemic embolism is a serious complication after classical orthotopic transplantation, presumably originating from enlarged left atrium. We specifically studied this problem after classical and modified bicaval transplantation. METHODS: Between December 1985 and March 1999 we consecutively performed 72 classical and 106 modified heart transplantation. Modification included bicaval anastomosis and recipient left atrium maximal reduction. Mean age was 47 years. All the patients received an antiplatelet therapy and were routinely followed. When clinical signs of systemic embolism were present, a neurological evaluation and transesophageal echocardiography were done. Sixty matched patients (30 of each group) had comparative transesophageal echocardiography study, at least 6 months after transplantation. RESULTS: Perioperative mortality was 17.4%. Mean follow-up was 6.8 2+/47 years. All patients were in sinus rhythm. Among 147 survivors, 11 patients who underwent classical transplantation had a systemic embolism, 1 month to 12 years after transplantation, 15.3%, (11/72). Two limb ischemia and one mesenteric ischemia (needing surgery), seven strokes (one death, two permanent neurological deficit). There was no systemic embolism in the modified technique group (P=0.013). Left atrial comparative transesophageal echocardiography study showed a larger left atrial surface in classical transplantation. 33+/-4 cm(2) versus 20+/-3 cm(2) in a modified technique, P=0.01. Spontaneous echo contrast was present in 56% of classical technique group associated with atrial thrombosis in nine patients, there were no atrial thrombosis in modified technique group and spontaneous echocontrast was present in 0.5% (P=<0.001). CONCLUSION: The occurrence of systemic embolism, left atrial spontaneous echocontrast and thrombosis when using classical technique, and the absence of these complications with the bicaval technique justified the use of this method. Our experience with atrial thrombosis and spontaneous echocontrast rises the question of anticoagulation in classical transplantation.

Adolescent↗
PubMed1999

Lung infections in pediatric lung transplantation: experience in 49 cases.

OBJECTIVES: Pulmonary infections, and particularly cytomegalovirus (CMV) infections, are a major cause of morbidity after lung transplantation. We report here our results in 49 pediatric lung transplantations. METHODS: Between may 1988 and 1997, we have done 49 lung transplantations in 42 children (en bloc double lung transplantation (DLT):10, HLTx:7, sequential bilateral sequential-lung transplantation (BSLT):31, single-lung transplantation (SLT): 1). In seven, it was a retransplantation. Among these, 34 were cystic fibrosis (CF) patients, all with multiresistant organisms (Pseudomonas aeruginosa, Burkholderia cepacia, Achromobacter xylososydans, Staphylococcus aureus). All patients were treated with multiantibiotic prophylaxy adapted to the preoperative cultures. Donor-recipient CMV matching was possible in only 31 cases. CMV prophylaxy and immunosuppression protocols have evolved with time, with a current protocol of IV Gancyclovir prophylaxy for 3 months and triple drug immunosuppression without post-operative rabbit anti-thymocyte globulin (RATG) induction. There was no perioperative mortality in the primary transplantations and three early deaths in the whole group (6.1%). RESULTS: Only five patients had no pulmonary infection. The patients presented 3.2 infection episodes per year, 75% localized on the lungs, 41% during the first 3 months. Among the 13 deaths in the 1st year, 10 were directly related to infection, 60% due to CMV. After the 1st year, in all patients dying of pulmonary dysfunction or obliterative bronchiolitis (OB), bacterial infections were associated. There was no serious fungal infection. Actuarial survival at 3 months, 1, 3, 5 years were 85, 65.7, 47.5 and 28.5%, respectively. There was a significant difference in 3 year survival between patients receiving CMV negative organs (40%) and CMV positive organs (17%). CONCLUSION: In our experience, as in other's, pulmonary infection risk is important in lung transplantation. Bacterial infections were mainly an aggravating factor of secondary pulmonary dysfunction or OB, and were not the primary cause of death. CMV infections have been very severe and lead us, despite the scarcity of donors, to avoid positive donors in negative recipients, this leads to disastrous mid-term results in our experience, despite prophylaxis.

Adolescent↗
PubMed1998

Association of mild hyperhomocysteinemia with cardiac graft vascular disease.

In non-transplant patients mild hyperhomocysteinemia is an independent risk factor for vascular disease. The aim of this study was to determine whether hyperhomocysteinemia is associated with graft vascular disease. Fasting total plasma homocysteine was assessed in 18 patients with graft vasculopathy and 18 transplanted patients without graft vasculopathy matched for age, sex and the time since transplant. All were on cyclosporin. Graft vasculopathy was defined at coronary angiography as stenoses > or = 25%, or aneurysms. We found that hyperhomocysteinemia ( > or = 15 micromol/l) is common among transplanted heart recipients and significantly more frequent in the patients with graft vasculopathy (17/18 versus 11/18). Accordingly, the mean homocysteinemia was significantly higher in the group with graft vasculopathy (23.6+/-7.8 versus 16.9+/-7.1 micromol/l, P=0.01). The elevation of homocysteine plasma levels in the heart transplant recipients has probably multiple causes. The main cause seems to be renal failure. Additional causes could be azathioprine treatment or genetic polymorphisms. These results suggest that besides the immunological factors, homocysteine can play an additional role in the pathogenesis of graft vascular disease.

Adult↗
PubMed1998

Anatomic repair of corrected transposition or atrio-ventricular discordance: report of 8 cases.

BACKGROUND: It is well recognized that a right ventricle (RV) may eventually fail if working as systemic. This has led to arterial switch operation for transposition of the great arteries (TGA), but more recently to anatomic correction of 'corrected transposition' or atrio-ventricular discordance (AVD) combining an atrial switch and a ventricular outflow repair (arterial switch or Rastelli type). METHODS: We report here 8 cases of such anatomic correction of AVD in patients from 3 months to 10 years. Of these patients, 6 had situs solitus, and 2 situs inversus; 7 patients had a ventricular septal defect (VSD); 5 had an increased pulmonary flow, and 3 had a decreased pulmonary flow with pulmonary stenosis (PS) or pulmonary atresia (PA). In all, 6 had discordant and 1 had concordant ventriculo-arterial (VA) relations, and 1 had double-outlet RV, 2 had an associated coarctation, and 1 had a cor triatriatum. Of the 8 patients, 5 had pulmonary artery hypertension, 3 a moderate to severe tricuspid insufficiency and 6 had undergone one or more previous operations. Correction was done between 3 months and 10 years of age, with 7 having a Senning procedure (twice left-sided) and 1 a Mustard type operation. VA outflows were repaired with: 4 arterial switches, 1 left ventricle to aorta rerouting, 1 right ventricular outflow tract (RVOT) repair and 2 Rastelli. A tricuspid annuloplasty was done once. RESULTS: All patients survived the operation, but 2 patients needed a reoperation (both successful): late obstruction of pulmonary venous channel after a left-sided Senning, and residual VSD closure. Mean follow-up is 45 months (3-122). Of the 8 patients, 6 patients are in sinus rhythm, 2 have junctional rhythm. A patient with junctional rhythm and occasional tachycardia died suddenly 18 months after surgery 1 week after satisfactory evaluation. All have a normal left ventricle function as evidenced by echocardiography. CONCLUSIONS: Despite a more demanding procedure, the 'anatomic repair' of hearts with AVD is possible, even in infancy, with good early and mid-term result. Despite the potential late rhythmic problems of the Senning operation (somehow more frequent with AVD in our experience), it may become, with increasing experience, the procedure of choice in corrected transposition.

Coronary Angiography↗
PubMed1997

Extending the concept of the autograft for complete repair of transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction: a report of ten cases of a modified procedure.

BACKGROUND: In most cases of transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction, a Lecompte procedure (réparation à l'étage ventriculaire) is possible without interposition of a conduit between the right ventricle and pulmonary artery. However, the anterior location of the pulmonary arteries after the Lecompte maneuver may be a potential cause for right ventricular outflow obstruction, which continues to be reported in 5% to 25% of cases. We have used a tubular segment of aortic autograft to connect the pulmonary artery, left in the orthotopic posterior position (without the Lecompte maneuver), to the right ventricle in 10 consecutive patients with transposition, ventricular septal defect, and left ventricular outflow tract obstruction. METHODS: Ten consecutive patients aged 2 months to 11 years (mean 32 months) have undergone a modified Lecompte operation. Eight had severe pulmonary stenosis, two had pulmonary atresia, and four had a restrictive ventricular septal defect at the time of the operation. Two had multiple ventricular septal defects. Seven had undergone one (n = 5) or two (n = 2) previous modified Blalock-Taussig shunts. All patients underwent a total correction with left ventricular-aortic intraventricular connection (four needed a ventricular septal defect enlargement), connection between the right ventricle and pulmonary arteries with a tubular segment of autograft aorta, without the Lecompte maneuver (anterior location of the bifurcation of the pulmonary arteries) on the right (n = 6) or the left (n = 4) of the aorta. No valvular device was used for the right ventricular outflow repair. RESULTS: No early or late deaths occurred. One patient with multiple ventricular septal defects needed an early (2 weeks) reoperation for a residual muscular ventricular septal defect. All patients are currently in New York Heart. Association class I, without medications, in sinus rhythm, at a mean follow-up of 30 months. Late results up to 3.6 years show no calcification on the chest roentgenogram, and at the most recent echocardiogram, right ventricular pressures were low (25 to 40 mm Hg, mean 33 mm Hg) and no significant gradient (over 10 mm Hg) was found between the right ventricle and pulmonary arteries. Left and right ventricular function was satisfactory. CONCLUSION: This modification of the Lecompte operation using a segment of autograft allows an excellent early and late result, with no danger of compression of anteriorly placed pulmonary arteries, no significant right ventricular outflow obstruction, and normal appearance of the tubular autograft. In view of laboratory and clinical evidence, normal growth of the autograft can be anticipated. It allows an elective correction of transposition, ventricular septal defect, and left ventricular outflow tract obstruction without a previous Blalock-Taussig shunt (three patients) and correction at a young age (three patients younger than 1 year).

Aorta↗
PubMed1997

Aortic valve or root replacement with cryopreserved homograft for active infectious endocarditis.

Active aortic endocarditis is a serious condition that carries a high mortality and morbidity. The aim of this study was to analyse results obtained from 24 patients who underwent aortic valve or root replacement with cryopreserved homograft for aortic endocarditis. Eleven patients had native valve endocarditis, and 13 had prosthetic valve endocarditis. The mean age was 47.7 years: there were seven women and 17 men. Causative organisms were staphylococci (12), streptococci (four), serratia (one), candida (one), pneumococci (one), while no organisms were isolated in the remaining five patients. Complete reconstruction of the aortic annulus with homograft conduits was necessary in 20 patients (six total root and 14 mini-root). Infracoronary homograft aortic valve replacement was performed in the remaining patients. One patient died 1 day after the operation from ventricular failure, and two others died after 4 and 6 months as a result of arrhythmia. One patient died of recurrent endocarditis 1 year after surgery. The actuarial survival rate at 3 years was 83.4%. All survivors are symptom-free, with no evidence of recurrent endocarditis. Doppler echocardiography showed minimal aortic regurgitation in four patients.

Adult↗
PubMed1997

Growth potential of aortic autografts and allografts: effects of cryopreservation and immunosuppression in an experimental model.

OBJECTIVE: An animal model has been used to evaluate the potential of growth of vascular autografts and allografts, and the effects of cryopreservation, rejection and immunosuppression on this growth. METHODS: In 35 animals (seven groups of five female NZW rabbits; age 5-6 weeks; weight 1.1 kg), a graft interposition was performed at the level of the infrarenal aorta. Different groups included fresh autografts, fresh and cryopreserved consanguineous allografts (donor: litter sister), fresh and cryopreserved immunosuppressed (IS) consanguineous allografts (receiving cyclosporin 10 mg/kg per day) and fresh and cryopreserved allografts. Animals were allowed to grow normally and were sacrificed at the mean weight of 2.89 kg. We studied the growth of the native aorta and of the graft and calculated the growth ratio (growth of the graft/growth of native vessel). Grafts and adjacent aorta were histologically studied. RESULTS: Growth of the graft was normal (mean ratio 1.08; S.D. = 0.21) for autografts, and for fresh and cryopreserved IS consanguineous grafts. Growth was absent (mean ratio 0.12; S.D. = 0.15) for fresh and cryopreserved allografts (P = 0.0001). In consanguineous grafts without IS, growth was absent or normal, presumably according to genetic compatibility, but never intermediate. Histological study showed normal optic microscopic aspects when growth was normal and, when growth was absent, aspects compatible with rejection including mainly intimal hyperplasia and medial thinning. CONCLUSIONS: (1) Normal growth of arterial autografts was confirmed; (2) cryopreservation did not prevent potential growth of an arterial graft; and (3) in an allogenic situation, without IS, an aortic graft, fresh or cryopreserved, never showed any growth potential.

Animals↗
PubMed1997

[A comparative study of standard and total orthotopic cardiac transplantation].

The classical orthotopic heart transplant modifies size and geometry of the atria, may affect mitral and tricuspid function, and ventricular filling. A technical modification with subtotal excision of the recipient's heart, with anastomosis of a cuff of left atrium and of venae cavae has been used and compared with 2 consecutive series of transplantations : 70 classical (group I) 1986-1991, and 50 modified (group II) 1992-1994. The patients were similar for age, pretransplant characteristics, postoperative treatment. The aortic cross-clamping in the recipient (duration of cardiac excision and graft implantation) has been longer in group II (87 +/- 19 mm vs 65 +/- 15: p < 0.001). No surgical complication due to the technique was observed. Mortality was similar in the 2 groups (14% group I, 18% group II; NS). Five patients of group I has a systemic embolism (1 month to 5 years after transplant), none in group II. Two comparable groups of 30 patients were studied at least 6 months after transplantation with: surface EKG, Holter, transthoracic and esophageal echodoppler. A larger number of EKG anomalies, a significant increase in the size of atria, a significantly larger number of mitral and tricuspid insufficiencies, an increase in the variability of E/A ratio (left ventricular filling parameter) were noted after classical transplantation. Spontaneous contrast echo and thrombus in the left atrium were also noted after classical transplant. We conclude that these technical modifications result in a geometry and anatomy closer to normal. Less anomalies of the cardiac function were found. Due to the absence of left atrial thrombus and of systemic embolism we think that there is a definite advantage in this technically rather simple approach.

Actuarial Analysis↗
PubMed1996

False aneurysm: a rare and potentially severe complication after pulmonary autograft operation.

A case of a false aneurysm arising at the proximal suture of an aortic root replacement with a pulmonary autograft is presented. This complication did not occur in the first postoperative month but was discovered late, and the female eight-year-old patient was in an extremely serious condition. She was reoperated on an emergency basis but died of acute pulmonary artery hypertension. The mechanism of the occurrence of such a case is discussed. In the absence of infection, structural weakness of the right ventricular muscle with progressive tearing is suggested. Strict and prolonged echocardiographic surveillance after the Ross procedure and early reoperation are mandatory.

Aneurysm, False↗
PubMed1996

[Value of echocardiography in the study of aortic valve homografts and autografts].

Although increasingly used, the echocardiographic parameters of aortic valve homografts and autografts have not been extensively investigated. The aim of this study was to assess the value of transthoracic (TTE) and transoesophageal (TOE) echocardiography in the preoperative assessment of these patients, especially with regards to prediction of homograft size and to describe the normal and pathological echocardiographic appearances of this type of prosthesis. Thirty-seven consecutive patients were studied. Before surgery, the diameter of the aortic ring (24.1 +/- 3 mm), correlated well with the value measured by the surgeon (24.4 +/- 2 mm; r = 0.9), but in 2 cases, this measurement was impossible and in 3 cases inaccurate, the difference between the 2 measurements being greater than 2 mm. It was possible to measure the aortic ring diameter in all cases by TOE. After surgery, TTE showed normal function of 33 of the 37 prosthetic valves with minimal or no obstruction (mean gradient 5.9 +/- 4 mmHg, aortic surface area = 2.8 +/- 0.5 cm2) with no significant difference between the homografts and autografts. Better visualisation of the homograft leaflets was possible by TOE and detected minimal central regurgition in 16 (84%) of the homografts examined, the persistence of an annular abscess in 2 patients and a minimal aorto-left atrial fistula in 1 patient. In conclusion. TTE coupled with Doppler examination is usually adequate for preoperative selection of the homografts and haemodynamic evaluation and follow-up of these patients. TOE should be performed preoperatively in patients with unsatisfactory TTE studies but is mainly useful for preoperative evaluation and postoperative follow-up of patients operated for aortic endocarditis with paravalvula abscess.

Adolescent↗
PubMed1995

Orthotopic heart transplantation with preservation of the left heart.

In December 1992, cardiac transplantation (for right heart failure with partially occluded pulmonary arteries but with a normal left ventricle) was accomplished with partial resection of right atrium and ventricle but with preservation of the left heart, obtaining a three-ventricle heart. The short-term result (27 months) is good, with normal native and grafted heart rhythms and functions, allowing us to conceive of the possible application of this procedure in some other selected cases.

Adult↗
PubMed1995

Bilateral single-lung transplantation in children.

BACKGROUND: This study examined our experience with bilateral single-lung transplantation in pediatric patients. METHODS: Between 1988 and 1995, we have performed 32 double-lung transplantations in children. The first 10 were performed en bloc, the following 22 by bilateral single-lung transplantation. Indications for bilateral single-lung transplantation were cystic fibrosis in 16 patients, primitive obliterative bronchiolitis in 1, pulmonary artery hypertension in 1, and retransplantation in 4. Patients' ages ranged from 7 to 16 years (mean, 12 years). Four patients underwent a parenchymal reduction (lobectomy or bilobectomy). Bilateral single-lung transplantation was performed with a "clam-shell" incision, normothermic cardiopulmonary bypass, and a beating heart. RESULTS: There was one postoperative death (heart failure in a retransplantation patient). Bleeding was moderate, and 4 patients had a bloodless procedure. Bronchial healing was satisfactory, with 3 patients receiving temporary left main bronchus stenting. There were two hospital deaths (recurrent cytomegalovirus infection in a retransplantation patient and multiorgan failure at 2 months) and seven late deaths, caused by infection (mostly cytomegalovirus), obliterative bronchiolitis, or both. Actuarial survival was 75% at 1 year, 56% at 2 years, and 36% at 3 years. CONCLUSIONS: We conclude that bilateral single-lung transplantation appears to be an acceptable technique, even in small children. Bronchial healing is satisfactory, and no revascularization procedure appears necessary. Midterm and long-term results are comparable with those of heart-lung transplants, and in view of the current problems with organ donation, we think it is an adequate strategy in pediatric lung parenchymal disease.

Adolescent↗
PubMed1995

Experimental basis for autograft growth and viability.

An experimental model has been designed to evaluate the potential of growth of aortic vascular autografts and homografts. In 25 young rabbits a graft interposition was performed at the level of the infrarenal aorta, with micro-surgical techniques. Different groups included fresh autografts, fresh and cryopreserved homografts and controls. Animals were allowed to grow normally and were sacrificed when adult, at the mean weight of 2.99 kg. We studied for each case the growth of the native aorta and that of the graft, and calculated the growth-ratio (growth of the graft/growth of native vessel). Grafts and adjacent aorta were histologically studied. The growth in terms of increase in diameter of the native aorta was identical between the four groups (from 1.97 +/- 0.14 mm to 2.86 +/- 0.23 mm). Growth of the graft was normal (mean growth ratio 1.08 +/- 0.21) for autografts. Growth was absent (mean ratio 0.12 +/- 0.15) for fresh and cryopreserved homografts (p = 0.001). Histologic study showed normal optical microscopic aspects (endothelial layer, intima and media thickness and cellularity) when growth had been normal and, when growth had been absent, aspects compatible with rejection including mainly intima hyperplasia and media attenuation. In conclusion, normal growth of the arterial autografts was confirmed, the histologic features of these grafts were normal, but homologous aortic grafts, fresh or cryopreserved, never showed any growth potential.

Aging↗
PubMed1994

Thallium perfusion and myocardial hypertrophy in transplanted heart recipients with normal or near-normal coronary arteriograms.

In patients with hypertrophic cardiomyopathy or systemic hypertension, exercise thallium perfusion defects have been observed but without significant angiographic stenoses. Hypertension and myocardial hypertrophy are common in transplanted heart recipients, and the aim of this study was to determine if exercise thallium scintigraphy false-positives are frequent in transplanted heart recipients. Thirty-four transplanted heart recipients were evaluated by exercise thallium single emission computed tomography and subsequently had a normal or near normal coronary arteriogram. At the time of the exercise, the patients (28 men and six women) had a mean age of 48.9 +/- 12 years and 29 had been previously treated for systemic hypertension. The mean duration between transplantation and the exercise test was 31.6 +/- 13 months. In all patients left ventricular mass was obtained by echocardiography within 3 months of thallium 201 SPECT and was > or = 130 g.m-2 in nine males and > or = 110 g.m-2 in four females. M-mode septal + posterior end-diastolic thickness was > 23 mm in 14 patients, all of whom had been previously treated for systemic hypertension. These patients were older and endured a longer period during which the heart was kept cold but ischaemic before being grafted ('cold ischaemia') but a shorter exercise duration than patients without left ventricular hypertrophy. During exercise testing, 26 of 34 patients achieved at least 80% of their maximal predicted heart rate and two developed significant ECG changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

A simple approach to takedown of a modified Blalock shunt.

We describe a simple and rapid technique for takedown of right-sided modified Blalock shunts involving a blunt approach between the pericardium and the pleura. We have used this method successfully on either side in 47 cases.

Arteriovenous Shunt, Surgical↗
PubMed1992

Delayed traumatic superior mesenteric arteriovenous fistula after a stab wound: case report.

Eight cases of superior mesenteric arteriovenous fistula (SMAVF) occurring after an abdominal stab wound have been reported. Seven of these patients manifested symptoms within 1 month after the stab wound. We report the case of a 28-year-old man whose SMAVF occurred 31 months after an abdominal stab wound. A SMAVF must be considered even when considerable time has elapsed between penetrating abdominal trauma and symptoms of abdominal pain, unexplained diarrhea, or an abdominal bruit or thrill.

Abdominal Injuries↗
PubMed1992

Evaluation of an absorbable suture for sternal closure in pediatric cardiac surgery.

We conducted a study in a prospective fashion using 1-mm diameter absorbable sutures (polydioxanone [PDS]) for sternal closure in 50 consecutive patients, ages 5 months to 16 years, weighing 5 to 27 kg. Good wound closure and absence of any iatrogenic complications were noted. Potential benefits of this approach include disappearance of sequelae of the closure and better bone healing. This appears to be a safe alternative to standard sternotomy closure.

Child↗