Employing computational fluid dynamics technique for analyzing the PACK-1300XY with methanol and isopropanol mixture.

In this study, an innovative wire gauze structured packing, namely PACK-1300XY with a specific surface area of 1300 m2/m3 has been characterized by performing computational fluid dynamics (CFD) approach. Indeed, different features of this packing (height equivalent to a theoretical plate, wet/dry pressure drop, and mass transfer efficiency) were analyzed by analyzing the flow regime using the three-dimensional CFD approach with the Eulerian-Eulerian multiphase scenario. The results showed the mean relative deviation of 16% (for wet pressure drop), 14% (for dry pressure drop), and 17% (for mass transfer efficiency) between the CFD predictions and experimental measurements. These excellent levels of consistency between the numerical findings and experimental observations approve the usefulness of the CFD-based approach for reliable simulation of separation processes.

Results of percutaneous double-balloon mitral commissurotomy in one medical center in Tunisia.

Percutaneous balloon mitral commissurotomy was attempted in Tunisia, where rheumatic fever is still endemic, in 463 consecutive patients with severe rheumatic mitral valve stenosis. Their mean age +/- SD was 33 +/- 12 years (range 8 to 68), 324 patients (70%) were women, and 327 (71%) were in sinus rhythm. Valvotomy was technically successful in 454 patients (98%). The mean mitral valve gradient decreased from 20 +/- 7 to 6 +/- 4 mm Hg, mean left atrial pressure decreased from 27 +/- 8 to 15 +/- 6 mm Hg, cardiac index increased from 3.0 +/- 0.7 to 3.6 +/- 0.8 L/min/m2, and Gorlin mitral valve area, from 0.97 +/- 0.19 to 2.2 +/- 0.4 cm2 (all p < 0.001). Two-dimensional echocardiographic mitral valve area increased from 1.03 +/- 0.18 to 2.15 +/- 0.36 cm2 (p < 0.00001). A final valve area of > or = 1.5 cm2 was achieved in 98% of patients. Multivariate analysis identified a pre-mitral valve area < 0.8 cm2 and an echocardiographic score (echo score) > or = 12 as the strongest predictors of residual stenosis (final mitral valve area < 1.5 cm2). Major procedural complications included mortality (0.4%), tamponade (0.7%), thromboembolism (2.0%), severe mitral regurgitation (4.6%), significant (pulmonary to systemic flow ratio > or = 1.5) interatrial shunt (4.8%). Four hundred thirty patients were followed up between 6 and 82 months (mean 37 +/- 22): 95% were in functional class I to II without reintervention, and 7 patients died (1.6%); restenosis (echocardiographic mitral valve area < 1.5 cm2) occurred in 10.4% of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Closed versus open mitral commissurotomy in pure noncalcific mitral stenosis: hemodynamic studies before and after operation.

Controversy persists regarding whether the efficacy of closed instrumental mitral commissurotomy compares well enough with that of open commissurotomy to warrant its continued use. The purpose of this study was to compare the results of operation as determined by catheterization studies in 63 patients with pure, severe, and noncalcified mitral stenosis. The patients were randomly assigned to one of two groups: thirty-two patients were operated on by the closed technique (group I) and 31 by the open technique (group II). All patients underwent left-sided and right-sided catheterization before and 4 months after operation. Preoperatively the two groups were statistically similar with regard to major clinical data and hemodynamic findings. There were no deaths at operation or systemic embolism in the two groups. The prevalence of surgically induced mitral regurgitation was similar in the two groups (12.4% versus 12.9%). Pulmonary arterial pressure and arteriolar and total pulmonary vascular resistance decreased significantly in the two groups. Pulmonary capillary wedge pressure decreased from 23.3 +/- 8.5 to 15.8 +/- 7 mm Hg in group I (p less than 0.001) and from 23.7 +/- 6 to 14 +/- 5.8 mm Hg in group II (p less than 0.001). Cardiac index increased from 2.86 +/- 0.84 to 3.14 +/- 0.78 L/min/m2 in group I, but this increase did not reach statistical significance. In group II cardiac index increased from 2.89 +/- 0.6 to 3.6 +/- 0.6 L/min/m2 (p less than 0.005). The mean and end-diastolic transmitral pressure gradients decreased significantly in the two groups, but the decrease was statistically greater in the open mitral commissurotomy group (p less than 0.001). Mitral valve area increased from 0.82 +/- 0.18 to 1.4 +/- 0.40 cm2 in group I (p less than 0.01) and from 0.84 +/- 0.15 to 2.14 +/- 0.53 cm2 in group II (p less than 0.001). The mean increase in mitral valve area was 0.61 cm2 in group I and 1.34 cm2 in group II (p less than 0.001). At exercise, in patients with resting pulmonary capillary wedge pressures of 18 mm Hg or less, cardiac index increased by 36% in group I (23 patients) and 48% in group II (24 patients), because of a smaller mitral valve area in group I (1.61 +/- 0.39 cm2) than in group II (2.45 +/- 0.65 cm2). Thus open commissurotomy improved hemodynamic values to a greater extent than closed commissurotomy at both rest and exercise.(ABSTRACT TRUNCATED AT 400 WORDS)

Assessment of left ventricular function in severe scorpion envenomation: combined hemodynamic and echo-Doppler study.

OBJECTIVE: To assess left ventricular function in patients presenting with pulmonary edema following scorpion envenomation. DESIGN: Cohort study. SETTING: Medical intensive care unit of a teaching hospital. PATIENTS: Nine consecutive adult patients stung by Androctonus australis and presenting with pulmonary edema entered the study. Fourteen normal volunteers comprised the control group. INTERVENTIONS: Upon admission, all patients had right heart catheterization and, within the first 8 h, a Doppler echocardiographic study. Results of Doppler echocardiographic studies were compared to those of controls. MEASUREMENTS AND RESULTS: Usual hemodynamic information (heart and vascular pressures, derived data and tissue oxygenation parameters), left ventricular dimensions and indicators of systolic function, and Doppler-derived parameters of left ventricular filling and diastolic function were obtained upon admission. Serial echocardiographic measurements were repeated daily until full clinical recovery (eight patients) or death (one patient). All patients had a hemodynamic profile of acute congestive heart failure (mean PAOP = 24 +/- 2 mmHg; mean SVI = 22 +/- 7 ml/m2; mean CI = 2.5 +/- 0.5 l/min/m2). However, SVR were not increased (mean = 22 +/- 3 U/m2). Left ventricle was hypokinetic in all patients with transient mitral regurgitation present in five patients. Left ventricular systolic function was markedly depressed (FS = 12 +/- 6%; EF = 26 +/- 12%). An associated diastolic dysfunction is suggested by Doppler records of mitral inflow. Left ventricular systolic function evolved toward normalization within 6 +/- 2 days preceded by full clinical recovery. CONCLUSIONS: These data suggest that pulmonary edema in scorpion envenomation is of hemodynamic origin and is related to a severe and prominent impairment of left ventricular systolic function.

Successful percutaneous double balloon valvuloplasty for congenital mitral stenosis.

A 19-month-old infant had an isolated severe 'typical' congenital mitral stenosis with dysplastic valves and two symmetric papillary muscles. He underwent successful double balloon mitral valvuloplasty via the right femoral vein. Left atrium pressure decreased from 30 to 20 mmHg and end diastolic mitral gradient from 12 to 0 mmHg. Cardiac index increased from 4.4 to 6.3 l/min per m2. Gorlin's mitral valve area increased from 1 to 1.7 cm2/m2 and Doppler mitral valve area from 0.9 to 2.2 cm2/m2. At 16 months follow-up, the infant showed sustained clinical improvement.

[Long-term results of heterografts in the mitral position]. / Evolution à long terme des hétérogreffes en position mitrale.

The long term results in 43 patients who underwent mitral valve replacement with a bioprosthesis are reported. The average age of the patient was 25, and nearly half of them were under fifteen. The underlying valvular disease was rheumatic in the great majority. Small bioprostheses were used in 40 p. 100 of cases. Hospital mortality was nil. Two patients developed atrioventricular block and needed permanent pacing; this was the principal complication observed in this study. After 34 months, 17 serious complications were recorded including two episodes of thromboembolism. The main problem arose from restenosis of the bioprosthesis, either because of its small size (3 cases) or because of degeneration (6 cases), all in children (33 p. 100 of our paediatric cases). The actuarial survival rate without degeneration shows only 48,2 p. 100 of patients to be without this problem at 5 years. Late mortality reached 29 p. 100 and the five year survival rate showed only 57 p. 100 of patients to be still alive, and only 35 p. 100 with their bioprosthesis. The haemodynamic profile of these prostheses with regards to transvalvular pressure gradient and mitral surface area, was very good for the large size valves, in contrast to the small size. In the absence of degeneration, the gradient was found to be stable. This study has shown that small bioprosthetic valves should be avoided in mitral valve replacement because of the risk of stenosis. Despite the low incidence of thromboembolism, they should not be used in children because of the high incidence of degeneration in paediatric patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Surgical treatment of fixed subvalvular aortic stenosis. Immediate and long-term hemodynamic results]. / Cure chirurgicale des rétrécissements aortiques sous-valvulaires fixes. Résultats hèmodynamiques immédiats et à long-terme.

Forty patients operated on for fixed subvalvular aortic stenosis underwent cardiac catheterization preoperatively, immediately after coming off cardiopulmonary bypass and at long-term (1 to 14 years later, average 7 +/- 3.9 years). The age range was 3 to 50 years (average 15 +/- 12 years) with 27 (68%) aged under 18 years. Twenty-seven patients were male. The stenosis was the thin membranous type in 29, the fibromuscular collar type in 5, the tunnel type in 5 others and related to supernumerary mitral tissue in the remaining patient. Significant other pathology was associated in 13 cases. In addition to excision of the membrane or the fibromuscular ring, the surgeons performed myotomy in 6 cases, myomectomy in 12 cases, large resection of muscular and fibrous tissue in tunnels, and aortic valve replacement in 3 cases. There was no operative fatality. Permanent cardiac pacing was required in 1 patient for complete atrioventricular block. The peak systolic pressure gradient fell from 87 +/- 32 to 31 +/- 10 mmHg (p < 0.0001) at the immediate control: it remained > 30 and even 50 mmHg in 3 patients (7.5%), 2 of whom had tunnel types and the other the supernumerary mitral tissue. The gradient increased in the long-term to 42 +/- 11 mmHg, 1 patient with a membrane developed a gradient of 40 mmHg and 4 others (10%) developed a gradient > 50 mmHg (3 tunnels and 1 membrane). The 5 patients with tunnel types either had a residual stenosis or restenosis and underwent aorto-ventriculoplasty by Konno's procedure 1 to 8 years later. This operation should be the procedure of first intention, even in small children: the large resection is only acceptable when it cannot be performed or when aortic ring hypoplasia is mild. There is no residual stenosis and restenosis is rare (2.5%) in the membranous and fibromuscular types, probably because of the widespread use of myotomy and myomectomy. In the absence of severe associated malformations, surgery in only justified when peak systolic pressure gradients are > or = 50 mmHg.

[Percutaneous pulmonary valvuloplasty in children and adults: immediate results]. / La valvuloplastie pulmonaire percutanée chez l'enfant et l'adulte; résultats immédiats.

Between April 1987 and December 1993, 60 consecutive patients with valvular pulmonary stenosis underwent percutaneous balloon valvuloplasty in the cardiology department of Monastir. The average age was 13.9 +/- 10.9 years (3 days-44 years). Fifteen patients were over 17 years of age and 4 were less than one year old. The right ventricular systolic pressure fell from 116.5 +/- 39.5 mmHg to 55 +/- 19.7 mmHg (p < 0.0001) immediately after the procedure. The peak-to-peak systolic gradient between the right ventricle and pulmonary artery fell from 95.4 +/- 40.2 mmHg to 30.4 +/- 19.0 mmHg (p < 0.00001), the valvular-gradient fell from 87.5 +/- 39.6 mmHg to 14.7 +/- 11.1 mmHg (p < 0.00001) and the infundibular pressure gradient increased slightly from 8.0 +/- 14.0 mmHg to 15.6 +/- 18.6 mmHg (p = 0.06). The systolic pulmonary artery pressure increased from 21.6 +/- 6.0 mmHg to 25.2 +/- 6.3 mmHg (p = 0.0015). The mean pulmonary artery pressure from 15.6 +/- 4.8 mmHg to 17.3 +/- 4.9 mmHg (p = 0.028). There were no changes in pulmonary diastolic pressures (10.6 +/- 3.7 mmHg vs 9.2 +/- 3.5 mmHg, p = 0.6). There were 4 primary failures (6.4%) with residual valvular gradients > or = 30 mmHg, including one due to valvular dysplasia. No predictive factors of primary failure could be identified. An infundibular gradient > or = 20 mmHg was observed in 11 patients, 4 of whom had gradients > or = 50 mmHg (6.6%); two gradients were residual and 2 were created by pulmonary valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

[Complications of percutaneous mitral commissurotomy. Personal experience and review of the literature]. / Complications de la commissurotomie mitrale percutanée. Expérience personnelle et revue de la littérature.

Percutaneous mitral commissurotomy was performed in 484 patients by the double balloon technique and by Inoue's technique in 33 patients. The average age of the patients was 33.6 +/- 13 years (range: 8 to 72 years); 30% were in atrial fibrillation. A primary failure was observed in 10 patients (2%). The acute mortality was 0.4% and first month mortality 0.6%, the main cause being perforation of the left ventricle. The incidence of systemic embolism was 2%, related to atrial fibrillation (p < 0.016); this complication disappeared after systematic utilisation of transoesophageal echocardiography. Grade 4+ mitral regurgitation was created in 5 patients (1%) and grade 3+ in 20 others (3.9%). A score > 8 (p < 0.006) and preexisting grade 1+ mitral regurgitation (p < 0.005) were predictive factors of these severe regurgitations. They were also more frequent with Inoue's technique (10.5%; p < 0.05). Surgical intervention was necessary during the first month in 5 patients and at long-term (38 +/- 24 months) in 15 others. A tear in the anterior leaflet and ruptured chordae tendinae were the main mechanisms. The most common minor complication was the creation of a small interatrial shunt (16%) without any immediate or long-term complications. With a major complication rate of 4.2%, the mitral surface area increased from 0.97 to 2.2 cm2 and the cardiac index from 3 to 3.6 l/min/m2; left atrial pressure fell from 27 to 15 mmHg (p < 0.0001): the incidence of residual stenosis was only 2%. Seventy nine per cent of patients were asymptomatic and 16% were paucisymptomatic (class II) at long-term. Systematic transoesophageal echocardiography to detect thrombi, the use of pig-tail or Inoue catherters, effective heparinisation during a prolonged procedure and improved experience of the medical teams, should result in a further reduction of the risks of percutaneous mitral commissurotomy.

[Thromboembolic accidents in patients with mechanical prostheses and heterografts]. / Accidents thrombo-emboliques (ATE) chez les porteurs de prothèses mécaniques et d'hétérogreffes.

759 patients with a prosthetic valve replacement (335 mitral prostheses, 184 aortic prostheses and 240 double or triple valve replacements) were regularly followed-up for a total duration of 3 715 patient years. The mean age of these patients was 30 years. 681 (90%) of these patients were treated by long term anticoagulants, which were effective in only 320 patients. 78 patients did not receive anticoagulant treatment. 97 patients presented a total of 129 thrombo-embolic episodes (TEE), i.e. a frequency of 12.7 p. cent or 3.4 embolisms per 100 patients-year. The rate of TEE was influenced by the site of the prosthesis and by the presence or absence of complete arrhythmia due to atrial fibrillation, but it was not influenced by the quality of the anticoagulant treatment. In the patients with a heterograft, the rate of TEE varied according to the site of the prosthesis. In the aortic position, the rate of TEE in our series of prostheses was essentially similar to that reported in series of heterografts by Davila, Oyer and lonescu. This rate is generally higher for the mechanical prostheses in the mitral position and in the case of double valve replacement. The aim of this study was to deduce the current operative indications in relation to the choice of the type of valve replacement.

[Treatment of chronic refractory cardiac insufficiency with enalapril]. / Traitement de l'insuffisance cardiaque chronique réfractaire par l'enalapril.

The objective is here to study the long and intermediate term clinical and haemodynamic effects of enalapril during chronic heart failure resistant to the classic digitalis-diuretics treatment. The study involves 16 patients (12 males and 4 females), with a mean age of 50 years. Before being given enalapril, 12 patients were at stage IV and 4 patients at stage II of the NYHA; the mean capillary pressure was quite elevated (30 +/- 6.3 mmHg), the cardiac index has collapsed (2.12 +/- 0.38 l.min.m2) and the stroke fraction (SF) is 0.28 +/- 0.08. At the 1st month control, there is a definite functional and haemodynamic improvement of the pre-charge as well as the post-charge. This improvement is still present at 6 months. The ventricular function is improved (SF = 0.38 +/- 0.13; p less than 0.001). The clinical tolerance of enalapril is excellent and the only adverse reaction is a transient deterioration of the renal function in a patient with diabetic glomerulopathy.

[Pulmonary embolism and paradoxical embolism in a patient with chronic respiratory insufficiency treated with mechanical ventilation]. / Embolie pulmonaire et embolie paradoxale chez un insuffisant respiratoire chronique en ventilation mécanique.

The authors report a case of paradoxical embolism associated with pulmonary embolism in a male patient under mechanical ventilation for chronic respiratory failure. They review the present diagnostic criteria of paradoxical embolism and insist on the determinant contribution of contrast echocardiography to the diagnosis. They also discuss the factors which make this type of patient liable to reopening of the foramen ovale and to paradoxical embolism. The clinical and gasometric characteristics of pulmonary embolism occurring in patients under mechanical ventilation are detailed.

[Abdominal tuberculosis: a retrospective series of 90 cases]. / Tuberculose abdominale : étude rétrospective de 90 cas.

PURPOSE: The aim of this study was to analyze the clinical, bacteriological, radiological and therapeutic features of abdominal tuberculosis in a series of 90 patients. METHODS: This was a retrospective and descriptive multicentre study of 90 cases of abdominal tuberculosis conducted from June 1997 to June 2008. Diagnosis of tuberculosis was based on bacteriologic evidence in 12 cases, histological evidence in 55 cases and on clinical and radiologic features with favorable outcomes under specific treatment in the 23 remaining cases. RESULTS: Thirty-one patients were male and 59 were female. The mean age of the patients was 41.5 years. Family history of tuberculosis was reported in three cases. Associated risk factors were: diabetes mellitus (five cases), ethylism (one case), post-hepatitis C cirrhosis (one case), systemic lupus erythematosus treated by corticosteroids (one case). Sites of involvement were: peritoneum (78 cases), liver (14 cases), gut (nine cases) and spleen (eight cases). Forty-eight patients (53,3%) had only an abdominal involvement, nine others patients (10%) had an abdominal involvement associated with intra-abdominal lymph nodes, 16 patients (17,8%) had a respiratory involvement (pulmonary, pleural and mediastinal lymph nodes), eight patients (8,8%) presented with an extra-abdominal and extra-respiratory involvement and 10 patients (11,1%) had respiratory and extra-respiratory disease associated with abdominal involvement. Among the 54 patients who underwent laparoscopy or laparotomy, diagnosis was evoked on macroscopic examination in 51. CONCLUSION: Laparoscopy and laparotomy are still helpful for the diagnosis of abdominal tuberculosis, especially in the presence of peritoneal involvement.