A 3D high resolution MRI method for the visualization of cardiac fibro-fatty infiltrations.

Modifications of the myocardial architecture can cause abnormal electrical activity of the heart. Fibro-fatty infiltrations have been implicated in various cardiac pathologies associated with arrhythmias and sudden cardiac death, such as arrhythmogenic right ventricular cardiomyopathy (ARVC). Here, we report the development of an MRI protocol to observe these modifications at 9.4 T. Two fixed ex vivo human hearts, one healthy and one ARVC, were imaged with an Iterative decomposition with echo asymmetry and least-square estimations (IDEAL) and a magnetization transfer (MT) 3D sequences. The resulting fat fraction and MT ratio (MTR) were analyzed and compared to histological analysis of the three regions ("ARVC triangle") primarily involved in ARVC structural remodeling. In the ARVC heart, high fat content was observed in the "ARVC triangle" and the superimposition of the MTR and fat fraction allowed the identification of fibrotic regions in areas without the presence of fat. The healthy heart exhibited twice less fat than the ARVC heart (31.9%, 28.7% and 1.3% of fat in the same regions, respectively). Localization of fat and fibrosis were confirmed by means of histology. This non-destructive approach allows the investigation of structural remodeling in human pathologies where fibrosis and/or fatty tissue infiltrations are expected to occur.

Multiple aneurysm of saphenous vein graft with low symptoms 16 years after coronary artery bypass grafting.

Aneurysms of saphenous vein graft are a known but rare complication of coronary artery bypass grafting (CABG). In this report, we present a case of a 59-year-old man who presented 16 years after CABG, three aneurysms of the saphenous vein graft to the right coronary artery compressing right atrium but with low symptoms. Transoesophageal echocardiography and CT scan were used to identify the aneurysm which was confirmed by cardiac catheterization. A favourable course was obtained after surgical treatment. We also review the literature on saphenous vein graft aneurysms interesting symptoms, diagnosis, pathophysiology and treatments.

Mobile thrombus of the thoracic aorta: diagnosis and treatment in 9 cases.

Detection of mobile thrombus of the thoracic aorta has become increasingly common thanks to routine exploration using transesophageal echography (TEE) after any embolic event. Although the indication for treatment remains controversial, there is a growing interest in understanding this potential source of arterial emboli and in defining proper diagnostic and therapeutic approaches. The purpose of this study was to evaluate the utility of different diagnostic and therapeutic modalities used in our department over the last 6 years. Between 1995 and 2000, mobile thrombus of the thoracic aorta was diagnosed in 9 patients (5 men, 4 women) with a mean age of 49.2 years (range, 28 to 68 years). In all patients, aortic thrombus was suspected after a peripheral (n = 4) or cerebral (n = 5) vascular event. Treatment using intravenous heparin was attempted in all patients and allowed complete dissolution of thrombus in four. In the remaining five patients, repeat TEE demonstrated persistent thrombus and operative treatment was undertaken. In three patients with thrombosis in the aortic arch, thrombectomy was performed with cardiopulmonary bypass, and deep hypothermic circulatory arrest. In two patients presenting thrombosis in the descending thoracic aorta, thrombectomy was performed with an atriofemoral shunt. Thrombectomy was associated with repair of a wall defect in two patients and resection of atheromatous plaque in one patient. Postoperative recovery was uneventful but recurrence was noted in one patient because anticoagulation therapy was stopped too soon. On the basis of our experience and previous reports, we have defined the following therapeutic strategy. All patients are first treated with heparin. In case of failure, thrombectomy may be undertaken in young patients. Because of the highly invasive nature of the procedure, careful work-up including TEE should be performed to rule out any other cause of embolism and to determine that the lesion presents a high potential for embolism. Follow-up must include long-term coumadin therapy and routine surveillance using TEE or magnetic resonance imaging, since long-term outcome is unclear.

Surgery for post infarction ventricular septal defect (VSD): risk factors for hospital death and long term results.

OBJECTIVE: Repair of post infarction ventricular septal defect (VSD) is still a challenging procedure with a high risk of recurrence of the VSD and subsequent mortality. The aim of this retrospective study was to assess if technical change in the surgical procedure was followed by an improvement in recurrence of the VSD and operative results. METHOD: This retrospective study from 1971 to 2001 included 85 patients operated on early (<15 days) after the occurrence of a post infarction VSD. Double patch technique was introduced in 1986. A total of 44 variables were studied by a uni- and multivariate analysis. RESULTS: Hospital death occurred in 36 patients. Significant factors for hospital mortality included: preoperative and evolution of the clinical status, right ventricular function and type of repair (one or two patches). Moreover, no recurrence was observed in patients repaired with the double patch technique (P=0.09). None of the studied variables were significant for long term survival. Concomitant CABG was not associated with higher hospital mortality and long-term survival rate was similar in patients with or without concomitant CABG. CONCLUSION: The use of the double patch technique and glue by avoiding recurrence of the VSD played a role in the reduction of the hospital mortality. This technique has to be recommended in the early repair of post infarction VSD. Concomitant CABG can be done safely to control the added risk of an associated coronary artery lesion.

Early and long term results of coronary artery bypass grafts in patients with dialysis dependent renal failure.

OBJECTIVE: Coronary artery disease is the main cause of mortality and morbidity in patients on renal therapy replacement. The aim of this study was to define peri-operative risk and long term results of coronary artery bypass grafts (CABG) in dialysis patients. METHODS: this retrospective study included 82 patients in chronic dialysis who underwent CABG between 1978 and 1997. The mean age was 61+/-10 years (range 28-81 years), 84% of the patients were male and the average duration of dialysis was 57 months (range 1-148 months). Combined procedures were carotid endarterectomy in one case, left ventricular aneurysm resection in one and valvular replacement in 10 (nine aortic and one mitral replacements). The operation was elective in 42 patients (51 %) and urgent in the others. Previous myocardial infarction was found in 37 patients (45%) and left ventricular ejection fraction (LVEF) at less than 45% in 15 patients (18%); 23 patients (28%) were in NYHA class III or IV and regarding angina functional status, 77% in CCS class 3 or 4. Follow-up was complete. Statistical analysis included 30 and pre and peri-operative data. Statistical analysis used Chi-square analysis or Fisher's exact test, and the Mann-Whitney test when appropriate. The estimated probability of survival, including postoperative mortality, was calculated by the method of Kaplan-Meyer, and the Log-Rank test used to compare the results. RESULTS: the hospital mortality was 14.6 % (n = 12). Ischemic time and ECC time were significantly lengthened in dead patients (P = 0.01). Moreover, use of internal mammary artery was directly related to lower hospital mortality (P = 0.02). For previous myocardial infarction, LVEF at less than 45%, diabetes and combined procedure, a P-value of < or = 0.1 was calculated. The follow-up ranged from 1 to 140 months (mean 36 months). There were 39 late deaths. The survival rates (included hospital mortality) were 71+/-5%, 56+/-6% and 39+/-6% at 1, 3 and 5 years, respectively. All surviving patients improved their functional status and had symptomatic relief. Statistical analysis showed significant difference in favor of long term survival for patients younger than 60 years, LVEF > 45% and NYHA class I or II. CONCLUSION: these data confirm that CABG in patients with renal replacement therapy is associated with an high operative and long term mortality. However it allows an improvement of functional status, and so, let possible duration of dialysis. It may be expected that more active prevention and detection of coronary disease might improve these results.

Updating visual space during passive and voluntary head-in-space movements.

The accuracy of our spatially oriented behaviors largely depends on the precision of monitoring the change in body position with respect to space during self-motion. We investigated observers' capacity to determine, before and after head rotations about the yaw axis, the position of a memorized earth-fixed visual target positioned 21 degrees laterally. The subjects (n=6) showed small errors (mean=-0.6 degrees) and little variability (mean=0.9 degrees) in determining the position of an extinguished visual-target position when the head (and gaze) remained in a straight-ahead position. This accuracy was preserved when subjects voluntary rotated the head by various magnitudes in the direction of the memorized visual target (head rotations ranged between 5 degrees and 60 degrees). However, when the chair on which the subjects were seated was unexpectedly rotated about the yaw axis in the direction of the target (chair rotations ranged between 6 degrees and 36 degrees ) during the head-on-trunk rotations, the performance was markedly decreased, both in terms of spatial precision (mean error=5.6 degrees ) and variability (mean=5.7 degrees). A control experiment showed that the prior knowledge of chair rotation occurrence had no effect on the perceived target position after head-trunk movements. Updating an earth-fixed target position during head-on-trunk rotations could be achieved through both cervical and vestibular signals processing, but, in the present experiment, the vestibular output was the only signal that had the potentiality to contribute to accurate coding of the target position after simultaneous head and trunk movements. Our results therefore suggest that the vestibular output is a noisy signal for the central nervous signal to update the visual space during head-in-space motion.

Infrarenal abdominal aortic aneurysm repair: detection and treatment of associated carotid and coronary lesions.

Management of carotid or coronary lesions associated with abdominal aortic aneurysm (AAA) remains controversial. To determine the influence of these lesions on the outcome of elective infrarenal AAA repair, we review our experience between January 1978 and December 1992. A total of 345 consecutive patients underwent infrarenal AAA repair. Procedures were performed under emergency conditions in 62 patients (18%) and electively in 283 patients (82%). Carotid and coronary risk was assessed in all 283 patients undergoing elective operations. There were 259 men (91.5%) with a mean age of 68 years (range: 45-88 years) and 24 women (8.5%) with a mean age of 76 years (range: 59-92 years). Previous cardiac manifestations included myocardial infarction in 57 patients (20%), angina in 50 patients (17.6%), coronary bypass grafting in 14 patients (14.9%), and coronary transluminal angioplasty in two patients. Cerebral ischemic attacks had been observed in 11 patients (3.8%) including transient events in two cases. Carotid endarterectomy had been performed in two patients. Assessment of carotid artery risk using Doppler ultrasonography led to selective carotid angiography in six patients and carotid endarterectomy in two patients. Assessment of coronary risk using a cardiac stress test was performed in 204 patients. Results were normal or subnormal in 132 patients (46.6%), abnormal in 21 patients (7.4%), and uninterpretable in 51 patients (18%). Coronary arteriography was performed in 151 patients (53.3%) for secondary assessment after the cardiac stress testing in 72 patients (25%) and for primary assessment in 79 patients (27.9%). Significant coronary lesions were demonstrated in 52 patients (18% of the overall population; 34% of coronary arteriography procedures). In 12 cases the lesions were not considered as threatening. In four cases the lesions were deemed inoperable. In the remaining 36 cases the lesions were treated either by aortocoronary bypass grafting (34 cases) or percutaneous transluminal angioplasty (two cases). In 11 of the 36 treated cases the patient was asymptomatic and had no history of coronary disease. In all cases AAA was treated by resection graft. Eight patients (2.8 +/- 1%) died during hospitalization including two deaths related to preexisting cardiac insufficiency. No death was attributed to preoperative work-up or treatment of associated lesions. With a mean follow-up of 62 months (range: 1-14 years), late mortality involved 96 patients (33.9 +/- 3%) including 16 deaths due to cardiac causes (16.7 +/- 4%) and 10 due to stroke (10.4 +/- 3%). Actuarial survival including deaths during hospitalization was 70.5 +/- 3% at 5 years and 41.4 +/- 5% at 10 years. Comparison of these results with those previously reported supports our policy of performing carotid or coronary angiography in patients selected by noninvasive tests.

[Surgical repair of postinfarction left ventricular lesion type I]. / Riparazione chirurgica della lesione postinfartuale di I tipo del ventricolo sinistro.

Left ventricular rupture is the most frequent cause of death following myocardial infarction after ventricular arrhytmias and cardiogenic shock. Under these circumstances, only a prompt diagnosis and urgent surgical treatment can be lifesaving. A review of the literature is made and a simple surgical technique with GRF glue application is presented.

Ex vivo leucocyte adhesion and protein adsorption on TiN.

Titanium nitride (TiN) is regarded as a potential biomaterial for blood-contact applications. Its in vitro haemocompatibility has been evaluated already and gave promising results. The purpose of this study was to continue studying its 'biological' behaviour through an ex vivo evaluation. The material was a physical vapour deposition elaborated TiN coating and the phenomena observed were leucocyte adhesion and albumin and fibrinogen adsorption. These ex vivo results were compared with in vitro results obtained previously. Two reference medical grade silicone elastomer and three TiN arterio-arterial extra-corporeal circuits were tested. No leucocyte was retained by TiN, as in in vitro experiments; the ex vivo fibrinogen adsorbed quantity was higher and albumin adsorption was about the same in in vitro and in ex vivo situations. TiN can be considered as a suitable blood-contacting material.

Expanding wire stents in benign tracheobronchial disease: indications and complications.

Prosthetic tracheobronchial stents provide palliative treatment for narrowed airways where surgical resection is inadvisable. Over a 1-year period, 28 Gianturco expanding wire stents were used in 15 patients for nonneoplastic indications: pure fibrous airway stenosis (6), fibroinflammatory stenosis (4), and tracheobronchial malacia (5). Insertion was technically straightforward. A satisfactory airway lumen with immediate improvement in ventilatory function was obtained in all patients. After insertion all patients had an irritation-type cough that either subsided spontaneously (10 patients) or was successfully suppressed with inhaled corticosteroid therapy (5 patients). The most common complication (12 patients) was granuloma formation leading to stent removal in 3 patients with fibroinflammatory stenosis. Other complications were dysphagia (1), suction catheter entrapment (1), and fatal massive hemoptysis (1). At a mean follow-up of 13 months (range, 3 to 19 months) all remaining stents are functioning well with no displacement or infection. Overall results were satisfactory in pure fibrous stenoses and tracheobronchial malacia but poor in the presence of inflammation. Tracheobronchial wire stents can be successfully used in selected patients.