Detection of pathological aortic tissues by infrared multispectral imaging and chemometrics.

Processing of multispectral images is becoming an important issue, especially in terms of data mining for disease diagnosis. We report here an original image analysis procedure developed in order to compare 42 infrared multispectral images acquired on human ascending aortic healthy and pathological tissues. Each image contained about 2500 infrared absorption spectra, each composed of 1641 variables (wavenumbers). To process this large data set, we have restricted the spectral window used to the 1800-950 cm(-1) spectral range and selected 100 spectra from the aortic media, which is the most altered part of the aortic tissue in aneurysms. Prior to this selection, a spectral quality test was performed to eliminate 'bad' spectra. Our data set was first subjected to a discriminant analysis, which allowed separation of aortic tissues in two groups corresponding respectively to normal and aneurysmal states. Then a K-means analysis, based on 20 groups, allowed reconstruction of infrared images using false-colours and discriminated between pathological and healthy tissues. These results demonstrate the usefulness of such data processing methods for the analysis and comparison of a set of spectral images.

Analysis of structural changes in normal and aneurismal human aortic tissues using FTIR microscopy.

Aortic aneurisms are frequently asymptomatic but can induce dramatic complications. The diagnosis is only based on the aortic diameter and not on a structural and compositional basis. In this preliminary study, we propose infrared microspectroscopy to nondestructively probe normal and aneurismal human aortas. Spectra from 19 human ascending aortic biopsies (10 normal and 9 aneurismal) were acquired using infrared microspectroscopy. A 1500 x 150 microm(2) area of each 7-microm thick cryosection was investigated using a 30-microm spatial resolution with a total of about 200 spectra per sample. Spectral differences between normal and aneurismal tissues were mainly located in spectral regions related to proteins, such as elastin and collagen, and proteoglycans (1750-1000 cm(-1)). Tissue heterogeneity and sample classification have been evaluated using hierarchical cluster analysis of individual or mean spectra and their second derivative. Using spectral range related to proteins, 100% of good classification was obtained whereas the proteoglycan spectral range was less discriminant. This in vitro study demonstrates the potential of such technique to differentiate between normal and aneurismal aortas using selected spectral ranges. Future investigations will be focused on these specific spectral regions to determine the role of elastin and collagen in the discrimination of normal and pathological aortas.

[Endovascular treatment of aortic isthmus ruptures: medium term results]. / Traitement endovasculaire des ruptures de l'isthme aortique: résultats à moyen terme.

UNLABELLED: Despite an improvement in the surgical management of aortic isthmus ruptures, the observed morbidity and mortality rates remain high. The use of aortic endoprostheses could improve these results, but there are not yet many medium term studies on ruptures of the isthmus. Between January 2000 and December 2005, we treated endovascularly 9 patients (7 males and 2 females) presenting with a rupture of the aortic isthmus, acute in 8 of them and chronic in one case. The average age was 46 years. All of the patients presented with significant traumatic co-morbidity. Ten endoprostheses were used in these 9 patients, and no immediate conversion was necessary. Complete excision of the lesions lasted on average 112 +/- 27 min and there were no per-operative deaths. Hospital mortality was 22% (2 patients: multiple organ failure on day 3, and a CVA on day 10). The mean length of hospital stay was 16 +/- 20 days. The mean follow up of the 7 surviving patients was 38 +/- 17 months. No complications relating to the endoprostheses were reported. In all of the patients an almost complete disappearance of lesions on CT scan was noted: by 6 months for the acute ruptures and at 1 year for the chronic rupture. CONCLUSION: the medium term results of endovascular treatment of isthmus ruptures are good.

In-vitro analysis of normal and aneurismal human ascending aortic tissues using FT-IR microspectroscopy.

FTIR microspectroscopy has shown to be a proven tool in the investigation of many tissue types. We have used this spectroscopic approach to analyse structural differences between normal and aneurismal aortic tissues and also aortas from patients with congenital anomalies like aortic bicuspid valves. Spectral analysis showed important variations in amide I and II regions, related to changes in alpha-helix and beta-sheet secondary structure of proteins that seem to be correlated to structural modifications of collagen and elastin. These proteins are the major constituents of the aortic wall associated to smooth muscular cells. The amide regions have thus been identified as a marker of structural modifications related to these proteins whose modifications can be associated to a given aortic pathological situation. Both univariate (total absorbance image and band ratio) and multivariate (principal components analysis) analyses of the spectral information contained in the infrared images have been performed. Differences between tissues have been identified by these two approaches and allowed to separate each group of aortic tissues. However, with univariate band ratio analysis, the pathological group was found to be composed of samples from aneurismal aortas associated or not with an aortic bicuspid valve. In contrast, PCA was able to separate these two types of aortic pathologies. For other groups, PCA and band ratio analysis can differentiate between normal, aneurismal, and none dilated aortas from patients with a bicuspid aortic valve.

[Primary cardiac lymphoma: diagnosis and treatment. Report of 6 cases and review of the literature]. / L ymphome cardiaque primitif: démarche diagnostique et thérapeutique. A propos de 6 cas et revue de la littérature.

Primary cardiac lymphoma (PCL) is the rarest primary cardiac tumour and carries a poor prognosis. Early diagnosis, often difficult, to introduce appropriate treatment as soon as possible, seems to have a positive impact on prognosis. The authors report their experience of 6 patients with PCL. None of the patients had immune depression. The presentations were tamponade (N= 2), right heart failure (N= 1), general ill health (N= 3). A PCL was suspected on echocardiography and thoracic CT scan showing tumour invading the right heart chambers in all cases. The diagnosis of PCL was confirmed by surgical biopsy in 5 patients and by endomyocardial biopsy in 1 patient. A diffuse large cell type B lymphoma was found in 5 patients and an anaplastic lymphoma in 1 patient. One patient died of right heart failure 4 days after diagnosis and before starting chemotherapy. All the other patients received chemotherapy. Two patients died during their first course. The other three patients had several courses of chemotherapy: there are two survivors 17, 5 months later and one patient died 62 months after diagnosis. The diagnosis of PCL should be suspected in patients with a cardiac tumour associated or not with pericardial effusion. Early, appropriate chemotherapy seems to have a positive impact on the prognosis, justifying aggressive approaches to obtain a rapid histological diagnosis.

[Chronic dissection of the aorta after coronary bypass surgery]. / Dissection aortique chronique après pontages coronaires. Une stratégie chirurgicale difficile.

Dissection of the aorta is a potential complication of all forms of cardiac surgery. It occurs after a variable interval. When observed in the long term, surgery may be complex with greater technical difficulties resulting in increased postoperative morbidity and mortality compared with other types of dissection. These difficulties are all the more marked when the initial surgery is coronary bypass grafting and when the grafts, especially internal mammary artery grafts, remain patent. A surgical strategy has to be elaborated to prevent certain per- and postoperative complications. The authors report the case of a patient who developed a chronic dissection of the aorta 9 months after coronary bypass surgery with patent internal mammary artery grafts. In this situation, a strategy associating anterograde cerebral perfusion before the sternotomy and endovascular control of the internal mammary grafts was proposed.

[Infectious endocarditis in cerebral death: implications for explantation of tissues and organs]. / Endocardite infectieuse chez les patients en état de mort cérébrale: implications pour le prélèvement de tissus et d'organes.

Allograft valve replacement is the preferred treatment for infectious endocarditis With severe annular destruction. Explantation of the valve in patients with cerebral death requires preliminary cardiac investigations and strict surgical procedures. The authors report two cases of right atrial endocarditis discovered at the time of explantation of the valvular allografts. In view of the infectious nature of the lesions, no tissues were resected. In both cases, transthoracic echocardiography had not diagnosed these lesions. The sensitivity of transoesophageal echocardiography in the diagnosis of these lesions should lead to systematic referral for this investigation. The infectious nature of these endocarditic lesions should raise suspicion about the presence of a central venous catheter. In addition, careful inspection of the chambers, septa and cardiac valves should be performed at surgery. The detection of potentially infectious endocarditic lesions should, in accordance with present recommendations, lead to renouncing the explantation of valvular allografts.

[Fibroelastoma of the tricuspid valve presenting with syncope]. / Fibroélastome de la valve tricuspide révélé par des syncopes.

Cardiac fibroelastomas are rare benign tumours. Initially observed as a chance finding at autopsy or during cardiac surgery, the diagnosis has become more common since the introduction of echocardiography. These tumours are usually asymptomatic. When the left heart valves are involved, embolic complications may be threatening. When the right heart valves are affected they are usually asymptomatic. The authors report the case of a fibroelastoma of the tricuspid valve responsible for several syncopal attacks. The tumour was excised with preservation of the native valve. There has been no recurrence of syncope since surgery. The authors believe this to be the second reported case of fibroelastoma of the tricuspid valve presenting with syncope.

Fistula between a saphenous vein graft aneurysm and the pulmonary artery trunk.

We report the case of a 52-year-old man who was admitted for atypical thoracic pain 18 years after a saphenous vein bypass graft of the left anterior descending coronary artery. Investigations demonstrated an aneurysm of the middle portion of the vein graft with a fistulous communication to the pulmonary artery trunk. The aneurysm was excised surgically, and the fistula was closed with an autogenous pericardial patch.

[Dobutamine doppler echocardiography in severe aortic stenosis with left ventricular dysfunction. Comparison with postoperative examination]. / Apport de l'échocardiographie Doppler sous dobutamine dans le rétrécissement aortique serré avec dysfonction ventriculaire gauche. Comparaison aux données postopératoires.

The association of left ventricular dysfunction with aortic stenosis worsens the spontaneous prognosis and increases operative mortality. The aim of this prospective study was to assess the predictive value of dobutamine Doppler echocardiography on the indices of left ventricular contractile function in patients with aortic stenosis and left ventricular dysfunction (LVEF < 0.45) undergoing aortic valve replacement. Eighteen patients, including 9 with coronary artery disease, were included in a protocol consisting of analysis of left ventricular function and of the severity of aortic stenosis before, during dobutamine infusion, and after valvular replacement. The dobutamine was given in progressive increments of 5 micrograms/Kg up to a maximum of 20 micrograms/Kg. During pharmacological stress, the functional aortic valve area increased from 0.46 +/- 0.15 to 0.56 +/- 0.23 cm2. Tolerance of the procedure was good. All but 2 patients improved their postoperative ejection fraction with values equivalent to those observed during the last increment of dobutamine (r = 0.73; p < 0.003). The patients with initial mean pressure gradients > 50 mmHg normalised their LVEF after valve replacement. The authors conclude that dobutamine echocardiography is useful for predicting the values of postoperative left ventricular contractile indices when severe aortic stenosis is associated with systolic dysfunction. It allows evaluation of the expected short term benefits to these indices after aortic valve replacement.

Carotid arterial stenosis: evaluation at CT angiography with the volume-rendering technique.

PURPOSE: To determine whether computed tomographic (CT) angiography with the volume-rendering technique (VRT) can be used to accurately quantify carotid arterial stenosis and to identify occlusions. MATERIALS AND METHODS: Spiral CT was performed in 23 patients who were referred for carotid stenosis evaluation. VRT images and shaded-surface display (SSD) images of 46 carotid arterial bifurcations were compared with findings from digital subtraction angiography (DSA). RESULTS: Agreement on stenosis category between VRT CT angiography and DSA was found in 39 (85%) of the 46 carotid arteries studied. VRT CT angiography was 92% (49 of 53) sensitive and 96% (82 of 85) specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). Agreement on stenosis category between SSD CT angiography and DSA was found in 38 (83%) of the 46 carotid arteries studied. SSD CT angiography was 91% (48 of 53) sensitive and 93% (79 of 85) specific for the detection of grade 2-3 stenoses. Calcified stenoses were correctly graded at VRT CT angiography in 10 of the 10 cases with heavy mural calcified plaques, while eight of the 10 stenoses were accurately quantified at SSD CT angiography. CONCLUSION: These results indicate that VRT CT angiography is as accurate as SSD CT angiography in the evaluation of carotid arterial bifurcations.

[Incidental discovery of asymptomatic Loeffler fibroplastic endocarditis. Report of a case]. / Découverte fortuite d'une endocardite fibroplastique de loeffler asymptomatique. A propos d'un cas.

The authors report a case of fibroplastic endocarditis discovered during echocardiography in an asymptomatic patient in the context of assessment of systematized electrocardiographic modifications. The diagnosis, strongly suspected on the basis of the cardiac MRI findings, was finally confirmed by endocardial biopsy.

[Combination of colorectal tumor and Streptococcus bovis endocarditis. Apropos of 3 cases]. / Association d'une tumeur colo-rectale et d'une endocardite à Streptococcus bovis. A propos de trois observations.

The authors report about 3 cases of bovis endocarditis revealing a colic carcinoma. This morbidity confirms the need for routine digestive investigations in endocarditis due to group D streptococci and eventually a liver disease.

[Carcinoid thymus tumor at an advanced age: diagnostic value of mediastinal needle biopsy with computerized tomography]. / Tumeur carcinoïde du thymus à un âge avancé: intérêt diagnostique de la ponction-biopsie médiastinaie sous tomodensitométrie.

Carcinoid tumour of the thymus is a rare neuroendocrine tumour particularly at an advanced age. The authors report a case of a mediastinal mass in a man aged 85, the mass had remained asymptomatic for a long time. It was decided to achieve a diagnosis because the tumour was causing local compression: a mediastinal needle biopsy under computerised tomographic control confirmed that this was a carcinoid tumour and a study of the biopsy material using an electron microscope showed neurosecretory granules. A sternotomy enabled the tumour to be excised but a post-operative Pseudomonas pneumonia led to the death of the patient. This case underlines the diagnostic place of mediastinal needle biopsy in the presence of a mediastinal tumour. The technique can be carried out under computerised tomography or ultrasonography and this can be associated with a study of the biopsy specimen using electron microscopy which enables the diagnosis to be made before any therapeutic decisions. The treatment of choice of a carcinoid tumour of the thymus is surgery which confirms the tumour limits and also its thymic origin. Tumour excision can be completed using radiotherapy or even chemotherapy.

A non-resective therapy for abdominal aortic aneurysm: intravascular thrombosis by dropping inflatable balloons.

A case of subrenal abdominal aortic aneurysm treated by unipolar exclusion and axillobifemoral bypass is reported. The exclusion was performed by inserting inflatable balloons through a femoral access and obstructing the iliac arteries. This technique may be useful in poor-risk patients with a symptom-free aneurysm.

[Transesophageal echocardiographic diagnosis of left ventricular parietal rupture, a complication of myocardial infarction]. / Diagnostic par échographie transoesophagienne d'une rupture pariétale du ventricule gauche sur infarctus du myocarde.

The authors report the case of postero-lateral myocardial infarction complicated by free wall rupture at the 48th hour. The diagnosis was suspected clinically and transoesophageal echocardiography showed the appearance of pericardial effusion in a patient difficult to examine by conventional echocardiography. Transoesophageal echocardiography was performed and well tolerated. The transgastric view showed a thrombus adjacent to a thinned and lacerated postero-lateral wall. The clinical outcome was favourable after surgical repair.

[Mitral surgery by superior biatrial septotomy]. / Chirurgie mitrale par bi-atrio-septotomie supérieure.

The superior biatrial septotomy approach consists of two semicircular right atrial and septal incisions joined at the superior end of the interatrial septum and extended across the dome of the left atrium, allowing exposure of the mitral valve by reflecting the ventricular side using stay sutures. From 1991 to 1993, 81 patients underwent mitral valve surgery by this technic. Mitral valve operation was combined with other cardiac procedures in 30 patients (37%) and was performed as a second operation in 21 patients (25.9%). Duration of cardiopulmonary bypass and aortic occlusion was not significantly different from that of patients operated via a conventional left atrial approach. The five hospital deaths (6.2%) were not related to this operative approach. Only 2 patients (3.3%) with preoperative in sinus rythm were discharged in atrial fibrillation after operation. In one patient (1.6%), atrioventricular block appeared at late follow-up. There were no cases of bleeding, atrioventricular nodal dysfunction or intra-atrial shunting related to the approach. This approach provides excellent exposure of the mitral valve even in unfavorable situations such as a small left atrium, dense adhesions from previous procedures or a previously implanted aortic prosthesis, without damage to various cardiac structures due to excessive traction. No retractor or vena cava repair are required. These data support a wide application of the superior biatrial septotomy approach in mitral valve surgery.

[Recurrent mobile thrombus of the ascending aorta diagnosed by transesophageal echocardiography]. / Thrombus mobile récidivant de l'aorte ascendante diagnostiqué par échocardiographie transoesophagienne.

The authors report the case of a 32 year old woman with no risk factors for thromboembolism apart from a raised Lipoprotein (a) level, in whom a mobile thrombus of the ascending aorta was diagnosed only by transoesophageal echocardiography after multiple episodes of systemic embolism. After surgical excision the thrombus recurred and death ensued on the 17th postoperative day after multiple visceral embolism despite adequate anticoagulant therapy. This is a rare condition, the outcome of which seems often to be fatal, due to early recurrence irrespective of the treatment (anticoagulant or platelet antiaggregant therapy). This case illustrates the value of systematic transoesophageal echocardiography for the investigation of cerebral or peripheral ischaemic episodes without carotid artery disease and raises the problem of the best way of treating this pathology.

[Value of transesophageal echography in the detection of left intraventricular masses. Apropos of a case of apical thrombus]. / Intérêt de l'échographie transoesophagienne biplan dans la détection des masses intra-ventriculaires gauches. A propos d'une observation de thrombus apical.

The authors report a case of left intraventricular thrombus investigated by two-dimensional transesophageal echocardiography (TEE). Three longitudinal views obtained by rotation, left lateral inclination and by advancing the probe, enabled the precise evaluation of a mass situated at the apex of the left ventricle, together with ventricular morphology and kinetics. Two-dimensional TEE is electively indicated for confirmation of the diagnosis of left intraventricular apical masses, in particular in hypoechogenic patients and to guide possible surgery. The two-plane probe provides a certain number of sections which remain relatively limited but this problem is resolved with the development of multidimensional probes.