Search PubMed⌕ Search

Biomedical subjects

M Dahan

Publications and source records attributed to M Dahan.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Video-guided surgical resection of solitary pulmonary nodules. Significance of thoraco-conversion in cancer cases. Apropos of 34 cases].

The use of video-guides surgery for major pulmonary resections in cancer patients raises a problem of safety and oncological quality. The aim of this prospective study was to demonstrate the oncological contribution of systematic thoracotomy in suspected stage I cancer patients. Between February 1993 and December 1996, we operated 34 consecutive patients with a solitary primary neoplastic lung nodule using normal fibroscopy and preoperative CT scan to detect mediastinal nodes. The nodules measured a mean 18.5 mm. Diagnosis was confirmed at peroperative pathology examination of the video-guided surgical resection, generally leading to thoracotomy for lobectomy-dissection. The final tumoral stage affirmed the initial diagnosis (stage I) in only 19 cases (56%). Peroperative findings showed that the other patients had more advance disease: 2 stage II (T1N1) (6%), 11 stage IIa (T1N2) (32%) and 2 stage IIIb (satellite nodule in the remaining lobe measuring 6 and 7 cm) (6%). These findings emphasize the importance of complete node dissection as well as the need to carefully palpate the entire lung. Thoracotomy remains the most reliable and reproducible method for safely fulfilling the oncological requirements.

Adenocarcinoma↗
PubMed1997

[Physiopathology of closed thoracic trauma].

Any thoracic trauma causes more or less severe hypoxia, due to pain, pleural effusion, mechanical ventilation disorders and pulmonary contusion. These four factors lead to bronchial congestion, which in turn aggravates hypoxia. More or less rapidly a vicious circle of respiratory failure is created. It can be broken only by early treatment of the cause. Without such treatment, respiratory failure quickly becomes autonomic and treatment of the cause is no longer sufficient.

Adult↗
PubMed1997

Prevention of air leaks after pulmonary wedge resection.

Prolonged air leak after a lung volume reduction operation for pulmonary emphysema is a major cause of morbidity and prolonged hospital stay. Staple line reinforcement is recognized as an effective adjunctive technique for decreasing the occurrence of air leaks after pulmonary wedge resection. Numerous materials have been used for staple-line reinforcement. We use expanded polytetrafluoroethylene sleeves that fit over the arms of surgical staplers to facilitate staple-line reinforcement in both thoracoscopic and open lung volume reduction procedures. The expanded polytetrafluoroethylene sleeves do not require rinsing or special handling; they are easy to use and effective in preventing air leaks. We had no prolonged air leaks or infections in any of the cases in which we used the sleeves.

Humans↗
PubMed1997

Relationship between left ventricular hypertrophy, myocardial contractility, and load conditions in hemodialysis patients: an echocardiographic study.

Left ventricular hypertrophy (LVH) is common and is an independent cardiac risk factor in dialysis patients. The aim of this study was to assess hemodynamic determinants of LVH and, more particularly, the relationship between left ventricular mass, myocardial contractility, and load conditions. Eighty dialysis patients aged 51 +/- 15 years were prospectively studied by echocardiography. LVH was detected in 62 patients (78%). Left ventricular mass was significantly correlated to both end-diastolic volume (r = 0.54; P < 0.001) and end-systolic stress/end-systolic volume, an index of contractility (r = -0.66; P < 0.001), but not to systolic blood pressure or end-systolic stress, both indexes of afterload. Thus, in dialysis patients, the degree of LVH is significantly correlated with the severity of both left ventricular dilatation and contractile myocardial failure, but not with left ventricular afterload.

Adolescent↗
PubMed1997

Amoxicillin and clavulanic acid concentrations in gingival crevicular fluid.

The beta-lactams are bactericidal antibiotics, but some of them may be inactivated by bacterial beta-lactamases which destroy the beta-lactam ring. The inactivation of amoxicillin by beta-lactamases of gram negative anaerobic bacteria can be circumvented by the addition of clavulanic acid, a beta-lactamases inhibitor. Thus, most of these bacteria are susceptible to this combination. The aim of this study was to investigate the concentrations of amoxicillin and clavulanic acid in gingival crevicular fluid (GCF). These concentrations were measured in 20 patients with rapidly progressive periodontitis 1 h after a dose of 500 mg (1 tablet Augmentin) on day 0 and 1 h after the 10th intake on day 3. For the sampling of GCF, Periopapers were introduced in 16 gingival sites per subject and time. The GCF volumes collected were estimated using the Periotron 6000. A high performance liquid chromatography method has been developed for the determination of amoxicillin and clavulanic acid in microsamples (1 to 10 microliters) of GCF. The concentrations of amoxicillin and clavulanic acid were respectively, 14.05 micrograms ml-1 and 0.40 microgram ml-1 at day 0, 13.93 micrograms ml-1 and 0.37 microgram ml-1 at day 3. Effective levels of amoxicillin and clavulanic acid, well above the minimal inhibitory concentrations of some susceptible periodontal anaerobes (P. intermedia) involved in destructive periodontal diseases, are achieved following the multiple administration of amoxicillin combined with clavulanic acid.

Adult↗
PubMed1997

Prevalence of six periodontal pathogens detected by DNA probe method in HIV vs non-HIV periodontitis.

OBJECTIVE: The aim of the study was to examine the prevalence of selected periodontal pathogens associated with HIV and non-HIV related periodontal lesions. METHODS: Subgingival plaque samples were obtained from both HIV-seropositive and HIV-seronegative patients affected with periodontal disease. DNA probes were used to detect Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Eikenella corrodens and Campylobacter rectus. RESULTS: A actinomycetemcomitans, P. intermedia and B. forsythus (P < 0.05) were more prevalent in HIV-seronegative patients with rapidly progressive periodontitis. Only C. rectus was slightly more prevalent in HIV-seropositive subjects with periodontal diseases, but this was not significant.

AIDS-Related Opportunistic Infections↗
PubMed1996

Complications of video-assisted thoracic surgery: a five-year experience.

BACKGROUND: Although thoracoscopy was originally described in 1910, recent developments in video-assisted surgical techniques and endoscopic equipment has expanded the application of video-assisted surgical procedures in the field of thoracic surgery. METHODS: In an effort to define both high-risk patients for video-assisted thoracic procedures and high-risk video-assisted thoracic surgical procedures, we reviewed the experience of four surgical institutions from June 1991 through May 1995. We looked specifically at complications resulting from the 937 video-assisted thoracic procedures performed during this period. RESULTS: Perioperative incidents or complications occurred in 35 patients (3.7%), and 116 procedures (12.4%) were converted to a thoracotomy. The in-hospital mortality rate was 0.5%, and death occurred principally in patients operated on for malignant pleural effusion. The overall incidence of postoperative complications was 10.9%, and the most prevalent complications were prolonged air leak (6.7%) and pleural effusion (0.7%). CONCLUSIONS: The incidence of complications was acceptable and, except for that of prolonged air leak, did not differ significantly from that resulting from analogous open procedures. Video-assisted thoracic surgery appears safe and particularly useful for some indications. However, the possibility of dramatic life-threatening perioperative complications requiring emergency conversion to thoracotomy justifies the fact that only trained thoracic surgeons should perform video-assisted thoracic surgical procedures.

Adolescent↗
PubMed1996

Imaging of hyperparathyroidism: US, CT, MRI and MIBI scintigraphy.

Hyperparathyroidism is a rare condition although recently the incidence has increased, particularly the asymptomatic form, as a result of routine serum calcium measurements. A definitive diagnosis can be made using modern bio-assays giving direct measurements of parathormone (PTH). Various methods are currently available for pre-operative localisation of pathological parathyroid glands. Ultrasound is sufficient prior to the initial surgery. However, if primary surgical exploration fails to localise the parathyroid glands then the surgeon faces a more complex problem and requires precise localisation prior to repeat surgery to reduce operating time and risk. No radiological method is available to localise pathological glands in 100% of cases. The surgeon is usually satisfied when two different methods are positive and in concordance. The non-invasive methods such as ultrasound, CT, MRI and scintigraphy are initially performed and if the result remains equivocal then more invasive methods such as arterial or venous sampling are undertaken. Our preliminary results in secondary hyperparathyroidism, before repeat surgery, indicate that associated and complementary tests, morphological and functional, MRI (fat-sat, T1, gadolinium) and MIBI scintigraphy, have greater efficacy.

Adenoma↗
PubMed1996

[Clinical course and treatment of pleural empyema in children].

BACKGROUND: Purulent pleurisy has become rare. It is often masked by previous antibiotic treatment so that functional prognosis may be poor. PATIENTS AND METHODS: Twenty children with purulent pleurisy of the large cavity admitted from 1987 to 1993 were included in the study: there were nine infants (age 5 to 18 months) with pleuro-pulmonary staphylococcal infection (group I) and 11 children (4-13 years) (group II). Clinical, biological, bacteriological and radiologic findings were analysed retrospectively as was the outcome. RESULTS: Patients of group I were admitted in poor general condition. X-ray showed moderate effusion and characteristic signs of staphylococcal infection. The bacteria identified in seven patients (77%) was S aureus. Recovery was rapid with antibiotics and simple local treatment. X-rays were normal two months after hospital discharge in seven patients (77%). One infant presented cicatricial bullous emphysema which required segmental resection. Patients of group II were admitted for moderate respiratory signs after a relatively long delay (14 days) since the onset of symptoms. X-rays showed considerable effusion in all and mediastinal shift in five patients (45%). Streptococcus pneumoniae was identified in one patient only. Local treatment of empyema was difficult; the effusion, already fibrinous, required repeated use of chest tubes in eight cases and surgical decortication in three. X-rays, performed 2 months after hospital discharge, were normal in only three patients. Long-term course was nevertheless favorable since chest X-rays at 5 months were normal in all children of both groups. CONCLUSIONS: Early recognition of purulent pleurisy is important in children aged over 3 years to ensure effective drainage before the effusion becomes fibrinous. All patients in whom the first tube was inserted after more than 10 days had a difficult follow-up requiring repeated chest drainages or surgery. Ultrasonography was a useful aid for diagnosis and local treatment. Computed tomography was useful for adapting treatment after several days of course.

Adolescent↗
PubMed1996

[Incidents and complications of therapeutic thoracoscopy. Apropos of 898 operated patients].

The exceptional interest in endoscopic surgery, both in laparoscopic surgery and video-assisted thoracoscopic surgery have led many teams to widen their indications. This movement has developed into a revolution in techniques demanded by patients, the public, and the medias, requiring many practicians to use these techniques more and more often and consequently to attempt very delicate operations. This "explosion" of endoscopic techniques has largely benefited from advances in equipment development (optics, video instrumentation) but has also required that operators acquire rigorous procedures for the proposed techniques. With the development of new thoracoscopic techniques for therapeutic indications, there are an unavoidable number of incidents and complications. These incidents and complications are related both to the use of instruments undoubtedly not well enough adapted to the procedures used and also to "forced" indications. We humbly recognize that a certain number of incidents are related to the necessarily inadequate experience of the operators during the "run in" period. We emphasize that video-assisted thoracoscopic surgery is a complementary technique among the available therapeutic armamentarium. We evaluated the mid and long term results of cancerology exeresis with these two techniques and underscore that morbidity and complications are rare but sometimes unacceptable. In conclusion, whatever the form of the technique used, it is an important evolution in surgery which must abide by the classical rules, in particular for indications in cancer surgery.

Endoscopy↗
PubMed1995

Influence of preload reserve on stroke volume response to exercise in patients with left ventricular systolic dysfunction: a Doppler echocardiographic study.

OBJECTIVES: This study evaluated the role of preload reserve in the stroke volume response to exercise in patients with left ventricular systolic dysfunction by assessing the relation between stroke volume and late left ventricular diastolic filling during exercise. BACKGROUND: In patients with left ventricular diastolic dysfunction, the absence of left ventricular distension is the fundamental mechanism explaining the nonaugmentation of stroke volume during exercise. METHODS: In 32 patients with left ventricular systolic dysfunction and 16 healthy control subjects, mitral and aortic velocities were recorded by Doppler echocardiography at rest and during submaximal supine bicycle exercise. Stroke volume, peak early (E) and late (A) mitral velocities, A/E ratio and end-diastolic filling were measured at rest and during exercise. RESULTS: Stroke volume increased significantly in control subjects but did not change in patients. Peak early mitral velocity increased significantly and to the same extent in both groups, whereas peak late mitral velocity and end-diastolic filling increased significantly in both groups but more so in control subjects; the A/E ratio increased significantly in control subjects but did not change in patients. In addition, stroke volume correlated significantly with peak late mitral velocity during exercise in patients (r = 0.72, p < 0.001). CONCLUSIONS: Compared with control subjects, patients with left ventricular systolic dysfunction exhibited limited increases in both stroke volume and late left ventricular filling during exercise. Furthermore, their stroke volume response correlated with the capacity of the left ventricle to increase late diastolic filling, that is, preload reserve.

Adolescent↗
PubMed1995

Videothoracoscopic excision of thoracic neurogenic tumors.

BACKGROUND: Videothoracoscopic surgery is a new procedure for treating neurogenic tumors of the thorax. Feasibility and utility of this technique are not yet well defined. METHODS: Over a 26-month period, 26 neurogenic tumors of the thorax were treated in five general thoracic surgery centers performing videothoracoscopic surgery. Indications and contraindications for this new procedure and initial results were retrospectively studied. RESULTS: Contraindications to videothoracoscopy included intraspinal extension of the tumor (n = 3), spinal artery involvement (n = 2), tumors more than 6 cm in diameter borderline located within the thorax (n = 2), and middle mediastinal location (n = 1). Videothoracoscopy was performed in 18 patients. Conversion to thoracotomy was required in 3. In 1 patients, subsequent chest wall resection was performed because of malignancy. Postoperative hospital stay was uneventful. It was shorter after videothoracoscopy. Postsurgical pain was more acute in patients who had thoracotomy or conversion to thoracotomy. CONCLUSIONS: Videothorascopy is a good alternative for managing neurogenic tumors of the thorax when deemed feasible. There is a tendency toward a shorter hospital stay with less pain in patients treated by this new procedure.

Adolescent↗
PubMed1995

[Diagnostic value of myocardial thallium stress scintigraphy in the detection of coronary artery disease in patients undergoing chronic hemodialysis].

Atherosclerotic heart disease is the leading cause of death in patients with end stage renal disease, but its non invasive detection remains difficult because of a low efficacy of exercise testing. The aim of the study was to evaluate diagnostic accuracy of thallium myocardial imaging after dipyridamole combined with exercise. Forty two chronic dialysis patients (34 men, 8 women) aged 55 +/- 11 years (range: 36 to 75) without symptom of angina nor myocardial infarction were studied. In each patient, an echocardiography, a myocardial scintigraphy with dipyridamole combined with symptom-limited exercise, and coronarography were performed. A coronary heart disease was diagnosed by coronarography in 10 patients (4.5 and 1 respectively with 1, 2 and 3 vessels diseased). Echocardiography detected a left ventricular hypertrophy (LVH) in 26 patients and a regional asynergia in 14 patients. A positive scintigraphy was present in 11 patients. Three false-positive and 2 false-negative on scintigraphy were noted. Sensibility, specificity, positive predictive value and negative predictive value were respectively evaluated at 80, 73, 73 and 93%. All the five patients with either false-positive or false-negative scintigraphy exhibited a LVH. CONCLUSION. In chronic dialysis patients, coronary heart disease may be detected by thallium myocardial imaging after dipyridamole combined with exercise.

Adult↗
PubMed1995

[Palliative percutaneous treatment under x-ray computed tomographic control of inoperable pulmonary aspergilloma. Apropos of 30 cases].

The authors report 30 cases of the percutaneous treatment of symptomatic pulmonary aspergilloma by injection of amphotericine paste in patients who were not considered to be operable. The treated aspergillomas had developed as a sequel to bacilliary infection and pulmonary fibrosis. Surgery was contraindicated in these patients on account of severe respiratory failure. The authors specify the technique for the preparation of the paste and for the type of percutaneous injection, the aim being to obtain complete filling of the cavity and creating an anaerobic environment for the aspergillus. The contribution of this technique for the non-surgical treatment of patients appears interesting but should be carried on a larger series to identify the exact indications and the interaction with other new treatments which have just appeared.

Aged↗
PubMed1994

Peak oxygen uptake during exercise in mitral stenosis with sinus rhythm or atrial fibrillation: lack of correlation with valve area. A study in 70 patients.

Although the haemodynamic response during submaximal supine exercise in mitral stenosis has been well described, the determinants of peak oxygen uptake during maximal upright exercise are poorly characterized and may differ in sinus rhythm and atrial fibrillation. Seventy patients with isolated mitral stenosis underwent Doppler-echocardiography and bicycle exercise with respiratory gas analysis. Forty-two patients were in sinus rhythm (Group I) and 28 in atrial fibrillation (Group II). Peak oxygen uptake was 21.3 +/- 5.6 ml.min-1.kg-1 in group I and 18.1 +/- 5.1 ml.min-1.kg-1 in group II (P < 0.05). There was no significant correlation between indices of exercise tolerance (exercise duration, ventilatory threshold, peak oxygen uptake, indexed peak oxygen uptake, peak oxygen pulse) and valve area or gradient in either group. Indexed peak oxygen uptake was not correlated to delta oxygen pulse but was linearly related (r = 0.43) to delta heart rate (delta heart rate = peak heart rate/rest heart rate) in Group I but not in Group II. Thus, in patients with mitral stenosis, no correlation was found between the mitral valve area or the gradient at rest and maximal upright exercise tolerance, suggesting that peripheral adaptation and, in sinus rhythm, chronotropic reserve, are important compensatory mechanisms.

Atrial Fibrillation↗
PubMed1994

Balloon dilatation and self-expanding metal Wallstent insertion. For management of bronchostenosis following lung transplantation. The Toulouse Lung Transplantation Group.

Here we report our experience on the use of balloon dilatation or self-expandable metal Wallstent implantation, or both, for the management of twelve bronchial stenoses in ten lung transplant recipients during the past two years. Both techniques were carried out endoscopically, under fluoroscopic guidance and without general anesthesia. Both methods were straightforward, well tolerated, and resulted in immediate symptomatic and functional improvement. The first-line treatment relied on Wallstent insertion (n = 4) or on balloon dilatation (n = 8). Early restenosis occurred in four of eight dilated stenoses and subsequently led to Wallstent insertion. Following Wallstent implantation, growth of granulation tissue occurred in one case and necessitated repeated balloon dilatations inside the stent during the following months. On two occasions, the stenosis was located such that the lower end of the Wallstent overlapped the upper lobe bronchus orifice. This necessitated laser therapy to eliminate the filaments of the stent crossing the lobar orifice, preventing subsequent obstruction. Laser therapy was followed, in one case, by a fibroinflammatory stenosis which was successfully treated by balloon dilatation inside the prosthesis. At the time of writing, the mean +/- SE of the follow-up after Wallstent implantation is 15.3 +/- 2.7 (range: 6 to 32) months. Most Wallstent prostheses are overgrown with bronchial epithelium. We conclude (1) that self-expanding metal Wallstent implantation is a safe procedure and good alternative to silicone stent insertion for the treatment of bronchostenosis following lung transplantation, provided granulomas are not present and (2) that balloon dilatation, although possibly leading to recurrences, can be used to allow inflammatory tissue to mature or to dilate restenoses inside the Wallstent.

Adult↗
PubMed1994

[Refractory hypoxemia caused by transient opening of the foramen ovale after pneumonectomy].

A patient with bronchogenic cancer underwent right pneumonectomy. Surgical and infectious criteria were normal during the postoperative period when immediate postoperative severe hypoxeamia occurred. Pure oxygen only incompletely corrected the situation. Transoesophageal echocardiography with injection of microbulles for contrast imaging demonstrated a right-left shunt due to an open foramen ovale. Reopening the foramen ovale is rare but well documented complication of pneumonectomy. The pathogenics is still debated since hyperpressure in the right atria usually is not present. Echocardiography with contrast test is the best means of making the diagnosis.

Aged↗