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At least 145 records · Page 8Linked to original sources
PubMed1997

Cross sectional echocardiographic demonstration of the mechanisms of abnormal interventricular septal motion in congenital total absence of the left pericardium.

OBJECTIVE: To investigate the influence of the absence of the pericardium on the left ventricular wall, particularly on interventricular septal motion, using M mode and cross sectional short axis echocardiography in patients with congenital total absence of the left pericardium. METHODS: 21 patients with, congenital total absence of the left pericardium were divided into three groups according to the interventricular septal motion; systolic type (n = 6) with paradoxical motion during systole, diastolic type (n = 11) with abnormal posterior motion during mid to late diastole, and mixed type (n = 4) with paradoxical motion during systole and abnormal posterior motion during diastole. RESULTS: On cross sectional short axis echocardiograms of the left ventricle, in the diastolic type the degree of angular displacement of the papillary muscles during end diastole to end systole showed excessive anticlockwise rotation about the long axis of the left ventricle without marked anteroposterior displacement. In the systolic type, there was shift of the left ventricle towards the anteromedial portion in systole and towards the posterolateral portion in diastole without significant rotation. There was a significantly positive correlation between the degree of angular displacement and the amplitude of diastolic interventricular septal motion during mid to late diastole in all patients. CONCLUSIONS: There was abnormal interventricular septal motion during systole and diastole in patients with total absence of the left pericardium. Abnormal systolic motion was induced by anteroposterior displacement of the left ventricle, and abnormal diastolic motion by left ventricular rotation about the long axis of the heart during the cardiac cycle. Analysis using cross sectional echocardiography was useful for elucidating the mechanisms of abnormal interventricular septal motion.

Adult↗
PubMed1986

Creep of the canine pericardium in vivo.

In eight open chest dogs we assessed the creep of the pericardium by measuring the increase in surface area of the pericardium, occurring after pericardial surface pressure (Ppe) was rapidly increased by inflating an air-containing balloon positioned between the pericardium and the left ventricular (LV) epicardium. We observed an increase in LV end diastolic pressure (EDP) of 3.6 +/- 3.4 mmHg (1 mmHg = 133.3 Pa) (p less than 0.05) (mean +/- SD) and a reduction in LV anteroposterior (AP) diameter of 8.8 +/- 6.1 mm (p less than 0.01), both of which were stable after 10 s. Mean Ppe increased 11.6 +/- 3.3 mmHg (p less than 0.001). Pericardial surface lengths at 45 and 135 degrees to the long axis of the LV were measured with two pairs of ultrasonic crystals attached to the outer surface of the pericardium. The beam of ultrasound travelling between each pair was directed parallel to the pericardial surface through a film of conducting medium. Initial increase in surface area (calculated as the product of two pericardial lengths) occurring during the first 15 s after balloon inflation was 5.8 +/- 2.5% (p less than 0.001). During the next 30 min, while mean pericardial pressure did not change, pericardial surface area increased another 2.8% (p less than 0.005). This time-dependent 2.8% increase in pericardial surface area (equivalent to an increase in volume of approximately 5%) is due to creep.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Influence of the pericardium on right and left ventricular filling in the dog.

We compared the influence of the pericardium on left and right ventricular (LV, RV) filling by measuring LV and RV pressures and segment lengths (SL, LV free wall, and RV inflow and outflow tracts) in six open-chest, pentobarbital sodium-anesthetized dogs before and after pericardiectomy. End-diastolic pressure (EDP) was varied by partial caval occlusion and dextran infusion. At each site the ln EDP-SL relation was fitted by linear regression and characterized by its slope and 1-Torr EDP intercept. The slope and 1-Torr intercept of the LV ln EDP-SL relation changed variably after pericardiectomy, but in each dog a change occurred that shifted this relation downward. In contrast, the RV inflow tract slope invariably decreased significantly after pericardiectomy, whereas its intercept was unchanged in all but one dog. The RV outflow tract results were similar to the inflow tract but less consistent. By the use of the raw EDP-SL data points, we calculated that the absolute contribution of the pericardium to EDP (i.e., the effective pericardial surface pressure) was similar at the three sites. However, as EDP values increased the proportional contribution of the pericardium to right ventricular end-diastolic pressure (RVEDP) increased, whereas that to left ventricular end-diastolic pressure (LVEDP) remained relatively constant. As a result, at the higher EDP values tested, the pericardium was responsible for a larger proportion of RVEDP than LVEDP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effect of the pericardium on atrial systolic function.

The effect of pericardial constraint on atrial systolic function was investigated in nine acutely instrumented anesthetized dogs. Left and right atrial pressures were recorded by high-fidelity catheters; auricular diameters and free wall segment lengths were measured by sonomicrometry. Atrial function curves were constructed by relating atrial systolic dimensional shortening to atrial end-diastolic pressure during progressive volume loading. With the pericardium closed, the function curves were shifted markedly downward and rightward, such that atrial systolic shortening was reduced at any given pressure. There was a concomitant leftward and upward shift of the atrial end-diastolic pressure-dimension relationship. The relationship between atrial systolic shortening and atrial end-diastolic dimension was not shifted. These results suggest that the apparent depression of atrial systolic function with the pericardium closed is due to a restrictive effect of the pericardium on atrial filling. In conclusion, in the acutely dilated heart, the pericardium restricts atrial filling and thus causes a reduction in atrial systolic contribution to ventricular filling.

Animals↗
PubMed1995

Isolated systolic and diastolic ventricular interactions in pacing-induced dilated cardiomyopathy and effects of volume loading and pericardium.

BACKGROUND: Interactions between the closely coupled right and left ventricles are known to play important roles as determinants of ventricular function, and the purpose of this study was to evaluate their effects in a model of heart failure. METHODS AND RESULTS: A dilated cardiomyopathy resulting in congestive heart failure (CHF) was produced in pigs by rapid ventricular pacing at 230 beats per minute for 1 week. Blood was rapidly withdrawn from the left ventricular (LV) apex into a prosthetic ventricle, and the instantaneous effects on the right ventricle were studied during volume loading and before and after pericardiectomy. The systolic interaction gain between the right and left ventricles (Gs) was calculated as the ratio of changes in mean systolic pressure during isolated systolic LV unloading. Diastolic ventricular interaction gain (Gd) was calculated as the ratio of changes in mean diastolic pressures during LV unloading in the last 150 ms of diastole. With the pericardium closed, all interaction gains were significantly increased during volume loading from a right ventricular end-diastolic pressure of 3 to 9 mm Hg: Gs from 0.045 +/- 0.014 to 0.063 +/- 0.020 mm Hg/mm Hg (normal pigs) and from 0.077 +/- 0.040 to 0.103 +/- 0.019 (CHF pigs) and Gs from 0.196 +/- 0.116 to 0.493 +/- 0.117 mm Hg/mm Hg (normal pigs) and from 0.174 +/- 0.101 to 0.341 +/- 0.165 (CHF pigs). When the pericardium was opened, Gd was significantly reduced to 0.145 +/- 0.071 and 0.129 +/- 0.026 mm Hg/mm Hg (normal and CHF pigs, respectively), but Gs showed no significant change (0.067 +/- 0.027 and 0.109 +/- 0.012 mm Hg/mm Hg for normal and CHF pigs, respectively), and both were also significantly increased during volume loading. Gs was significantly greater in CHF versus normal pigs under all conditions, but there were no differences in Gd between CHF and normal pigs. CONCLUSIONS: These results suggest that dilated cardiomyopathy increases systolic but not diastolic interactions, that the pericardium increases diastolic but not systolic ventricular interactions, and that volume loading with and without the pericardium opened increases both systolic and diastolic interactions.

Animals↗
PubMed1997

Influence of polyethylene glycol graftings on the in vitro degradation and calcification of bovine pericardium.

Calcification is a frequent cause of the clinical failure of bio-prosthetic heart valves fabricated from glutaraldehyde pretreated bovine pericardium (GATBP). This article reports on various chemical techniques for grafting polyethylene glycol (PEG) on bovine pericardium, their biostability, and calcification. The process of calcification profile was studied by in vitro experiments via the incubation of pericardial samples in a metastable solution of calcium phosphate. The calcification profile of PEG-modified bovine pericardium through glutaraldehyde linkages was significantly reduced compared to other methods of grafting. The mechanical property of these PEG-modified tissues after enzyme (collagenase) digestion and calcification were also investigated. PEG grafting of BP via glutaraldehyde or hexamethylene diisocyanate had shown better mechanical stability compared to other grafting methods used. In conclusion, it seems that the surface modification of bovine pericardium through high molecular weight PEGs via glutaraldehyde linkages may provide new ways of controlling tissue biodegradation and calcification.

Animals↗
PubMed1998

Polyethylene glycol (PEG) modified bovine pericardium as a biomaterial: a comparative study on immunogenicity.

Bioprosthetic heart valves made from glutaraldehyde (GA)-fixed porcine aortic valves or bovine pericardium (BP) are having some advantages over mechanical valves. However, their durability is low due to the calcification and immunological rejection. Study on immunogenicity is an important part in understanding the biocompatibility of materials. Polyethylene glycol (PEG) on pericardium can control biodegradation and calcification. Also, PEG exhibits low immunogenicity. We have studied the complement activation potential and the contribution of complement factors (biologic factors) on the calcification of PEG grafted pericardium samples and compared with standard (control) glutaraldehyde-treated pericardium samples. PEG-grafted BP activated using GA and carbodiimide (EDC) could be selected for further studies since complement activation and calcification observed on these samples has been relatively low.

Animals↗
PubMed1993

[Biocompatibility of materials used in cardiovascular prostheses: a comparison between bovine pericardium and Dacron].

During the past 25 years, numerous studies relating to medical device biocompatibility have appeared world-wide. Development of biomaterials for grafting cardiovascular applications has contributed to an increase in knowledge of the compatibility between synthetic or biological surfaces and blood. The biocompatibility of one of the materials most commonly used in the fabrication of xenograft heart valves, bovine pericardium, treated with glutaraldehyde and formaldehyde is assessed comparison to a synthetic material, Dacron tricot. An in vitro tissue culture assay, by the agar overlay method, using RC-IAL and Hela cell lines, was applied to treated pericardium and attested the intense toxicity of the treating agents. The subcutaneous grafting of treated pericardium and Dacron was carried out in Wistar rats of 1 to 3 months of age. After the use of the usual histological methods, an evaluation of hematoxylin-eosin stained specimens demonstrated an absence of histocompatibility, mainly as regards for the formaldehyde treated pericardium. Comparatively, the evaluation of implanted Dacron confirmed it's perfect biocompatibility. In conclusion, some improvement in xenograft heart valves is necessary, before the surgical implantation procedure takes place.

Animals↗
PubMed2005

[Comparative study of the biocompatibility of the porcine intestinal submucosa and bovine pericardium used as grafts in the inferior cava vein of dogs].

PURPOSE: To compare the biocompatibility of the bovine pericardium and the small intestine submucosa (SIS) when used to repair a created defect in the inferior vena cava of dogs. METHODS: Sixteen male mongrel dogs were submitted to a midline laparotomy incision. An elliptical segment (1.5 x 3.0 cm) of the inferior vena cava, below the renal veins, was excised. In 8 dogs, the A group, a patch of porcine small bowel submucosa was used to repair the defect. In the 8 remaining dogs, the B group, a bovine pericardium was implanted in the vena cava. On the 30th post-operative day an ultrasound was performed in order to identify stenosis. The euthanasia was accomplished in the 40th post-operative day. Stenosis of the vein was observed in 1 dog of A group and in 2 of the B group. RESULTS: Partial thrombosis with collateral circulation was evidenced in 1 dog of the bovine pericardium group. A moderated chronic inflammatory process was evidenced in both groups. Microscopic evaluation, regarding endothelization of the implant, collagen deposition, smooth muscle growth, was similar in both groups. CONCLUSION: SIS proved to be a functional graft patch for possessing local vena cava remodeling and its biocompatibility was similar to bovine pericardium.

Animals↗
PubMed1990

The postnatal development of the mouse pericardium; the time and mechanism of formation of pericardial pores.

The mouse pericardium is a continuous serous membrane, up to postnatal day 6 (P6), that consists of pericardial and pleural mesothelia with sparse connective tissue sandwiched in between. This study shows that on P7 the pericardium becomes fenestrated, and the pericardial and pleural cavities become continuous. We found that the number of pores per pericardium increased continuously with the advance of age and reached as many as 3000 on P21. Transmission electron microscopy of the pericardium revealed various structures of the pericardial and pleural mesothelia that may relate to the formation of the pericardial pores. The pericardial and pleural mesothelia were adjoined with cytoplasmic processes that extended toward the base of the opposing mesothelium. As a result of the adjoinment, a pair of U-shaped folds were formed. The two U-shaped folds were connected with tight junctions at their apices, and separation of these junctions may give rise to the pericardial pores.

Animals↗
PubMed1996

Ovine pericardium: a new material for duraplasty.

The authors report on their 2 1/2-year clinical experience using a dural substitute, ovine pericardium, stabilized with 0.3% glutaraldehyde, flat freeze-dried, and sterilized with gamma-irradiation. Packaging of the ovine pericardium in double-plastic transparent bags allows simple storage in operating rooms and the opportunity for the surgeon to choose an ideal graft according to its shape, size, and plasticity. The ovine pericardia were examined histologically and by transmission and scanning electron microscopy in their native, freeze-dried, and irradiated forms. The final product is composed solely of pericardium fibrosum interwoven with artificially formed extracellular microcavities that serve as natural pores for the ingrowth of host tissue. The surfaces of the grafts appear smooth on the inner and rough on the outer sides. Sixteen grafts were examined macroscopically at autopsy and four of these were also examined histologically to illustrate their successful healing with no adhesion to the underlying brain. As a new dural substitute, ovine pericardium proved to be superior to bovine and allogeneic pericardia because of its workability, flexibility, and reduced thickness. In a study of 120 grafts, all but one healed without complications.

Adolescent↗
PubMed1999

[The pericardium: a heterogeneous tissue. Anatomic and morphometric considerations].

BACKGROUND AND AIMS OF THE STUDY: Short-term glutaraldehyde fixed autologous pericardium is widely used in cardiac valve repair or in autologous pericardial bioprosthesis construction. The thinner the tissue, the better the fixation. The aim of this study was to determine thickness and useful surface area of pericardium in relation to harvesting site using a digital thickness counter (0.01 mm precision). Parietal pericardium fragments were obtained from the pericardial sac of six fresh cadavers (group I). In the other groups, pericardial strips (80 x 30 mm) were obtained from patients undergoing surgery: group II patients (n = 5 females) and group III (n = 10 males) were non-cardiomegalic (cardiothoracic ratio (CTR) < 0.5)), while group IV patients (n = 5) were all cardiomegalic (CTR > 0.5). Results were reported on a coloric scale according to measurement position. In group I, mean surface area was 93 +/- 18 cm2, and thickness gradually increased from 0.1 to 0.6 mm, maximally on the diaphragm, along the left heart side. In other groups, a gradual increase in thickness was identified towards the diaphragmatic zone. Significant differences in tissue thickness appear as a result of cardiomegaly, but are not related to the sex of the patients. Pericardium taken from the right anterior aspect of the pericardial sac in patients without cardiomegaly is the most appropriate tissue for valve reconstructive surgery, due to its thin nature and hence better fixation properties.

Analysis of Variance↗
PubMed1975

Influence of primary closure of the pericardium after open-heart surgery on the frequency of tamponade, postcardiotomy syndrome, and pulmonary complications.

Experiences with primary closure of the pericardium in a series of 100 patients undergoing open-heart operations are described. The pericardium was kept under tension during the operation to minimize shrinkage and permit closure at the end of the procedure. In 28 patients one pleural space was opened for drainage, whereas in 72 patients intra- and extrapericardial sumps alone were used for drainage. Measurements of sump drainage revealed that most postoperative bleeding originates from outside the pericardium. There were no instances of cardiac tamponade although 19 patients lost more than 1 L. of blood after operation and 5 required reoperation for hemorrhage. Transpleural drainage tubes were shown to be ineffective and in addition were associated with a fourfold increase in postcardiotomy syndrome and a significantly greater frequency of pleural effusion and atelectasis when compared to the use of mediastinal sump drainage alone. We have concluded that closing the pericardium and using mediastinal sump drainage minimizes the risk of cardiac tamponade and allows early localization of the site of postoperative bledding. Another advantage of pericardial closure and drainage is that postoperative adhesions and postcardiotomy syndrome will be less significant. As a consequence the danger of injuring the heart in a subsequent operation is lessened.

Adult↗
PubMed2001

[Diagnosis and surgical strategy in injuries of the heart and pericardium].

Results of the emergency diagnosis and surgical treatment of wounds of the heart and pericardium were summed up in 207 wounded during twenty years of work. It was found that injuries of the heart and pericardium were diagnosed in 42% of cases according to clinical symptoms, while emergency thoracotomy during the first minutes after admission to the surgical hospital was performed in 55-60% of wounded to the heart. About half wounded at the moment of admission to the hospital were at the state of relative stabilization of hemodynamic indices and had no clinical symptoms of wounds to the heart. In this group of patients injuries of the heart and pericardium were diagnosed on the basis of additional investigations, extrapleural pericardiotomy (fenestration of the pericardium) being most reliable. The results of treatment of wounded to the heart can be improved at the expense of acute surgical strategy which is determined by the stable state of the wounded, character of the myocardium injury and associated wounds.

Adolescent↗
PubMed2004

[Reconstruction of descending aorta with adhesive pericardium patch: the experimental study].

OBJECTIVE: Tissue adhesive is one of the recognized methods to stop bleeding from aorta. The aim of this experimental work was to use pericardium patch and long chain n-butil-2-cyanoacrilic tissue adhesive for the strengthening of descending aorta wall. MATERIAL AND METHODS: Seven mongrel dogs were operated under general anesthesia and artificial ventilation support. Left side thoracotomy was done and descending aorta reached. The aorta was clamped from both side and opened by longitudinal incision. Pericardium patch, coated with cyanoacrilic adhesive (Hystacryl), was glued to aorta intimate layer. The aorta was sutured and normal blood flow restored. Morphological investigation was performed after 2, 4, and 24 hours and after 1 week. RESULTS: In all cases interior of aorta looked normal; there were no evidence of tissue color changes, thrombosis or inflammation. Pericardial patch was tightly fixed to the aortic wall. Histological examination showed normal aorta wall and pericardium structure with glue layer between of them. There were no evidence of tissue cells necrosis, interstitial oedema or leukocytes penetration on examinated samples. CONCLUSIONS: Long chain n-butyl-2-cyanoacrilic glue has inert properties on the aortic wall tissue. Pericardium patch, fixed with cyanoacrilic glue in aortis lumen, has no significant influence on the blood flow.

Anesthesia, General↗
PubMed2006

[Perivenous support with autologous pericardium inhibits neointimal thickening in canine vein grafts].

OBJECTIVE: To observe the effect of perivenous support with autologous pericardium on neointimal thickening in canine vein grafts. METHODS: An autologous pericardium graft of 7 cm x 4 cm was harvested in right anterolateral thoracotomy. Two equal segments of the jugular vein were transplanted to both sides of the femoral arteries in 12 dogs, and on one side of the vein graft, perivenous support with autologous pericardium was applied. The vein grafts were harvested 2 and 4 weeks after operation and the thickness and area of the neointima calculated using computerized image analysis system. Scanning electron microscopy and PCNA immunohistochemistry were also performed. RESULTS: The thickness and area of the neointima were significantly greater in the control grafts than in the grafts with perivenous support (P<0.05), and the proliferation of vascular smooth muscle cells in the supported graft was less active (P<0.05). Electron microscopy showed extensive destruction of the endothelium in the control graft, but only slight damage was found in the graft with perivenous support. CONCLUSION: Perivenous support of the vein graft with autologous pericardium can reduce intimal and medial hyperplasia in the graft.

Animals↗
PubMed2006

A multi-step approach in anti-calcification of glutaraldehyde-preserved bovine pericardium.

AIM: Bioprosthetic cardiovascular substitutes, manufactured from glutaraldehyde-preserved bovine or porcine tissues, are prone to calcification after implantation. The aim of the study was to evaluate the ultrastructure, material stability and calcification behaviour of glutaraldehyde-preserved bovine pericardium, treated with a multi-step anti-calcification process which addresses each of the major causes of calcification and tissue degeneration. METHODS: Bovine pericardium samples were divided into 2 groups. Group I (control) consisted of tissue fixed with 0.625% glutaraldehyde and Group II (study group) consisted of tissue fixed with 0.625% glutaraldehyde and exposed to a multi-step anti-calcification process. Ultrastructure was examined by scanning electron microscopy and material stability was assessed by mechanical testing, shrinkage temperature and enzymatic degradation. Calcification was assessed by histology (Von Kossa stain) and by atomic absorption spectrophotometry in the subcutaneous rat model. RESULTS: Bovine pericardium in the study group revealed less visible changes in the ultrastructure of the collagen matrix, improved material stability (P<0.05) and significantly (P<0.001) reduced calcification compared to control tissues (4.5+/-1.2 versus 136.03+/-11.39 ug/mg tissue). CONCLUSIONS: In conclusion, results demonstrate that the multi-step anticalcification process improved the material stability and reduced the calcification potential of bovine pericardial tissue. These improvements in the quality of the bovine pericardium should enhance the long-term durability of the tissue as a bioprosthetic substitute for cardiovascular application.

Animals↗
PubMed1991

Lymphatics and pre-lymphatics of the rabbit pericardium and epicardium with special emphasis on particulate absorption and milky spot-like structures.

The lymphatics and pre-lymphatic connective tissue of rabbit pericardium and epicardium were examined by light and electron microscopy under normal conditions and after the injection of India ink and latex particles into the pericardial cavity. A characteristic lattice structure of connective tissue was present between the small mesothelial cells and the submesothelial lymphatic capillaries in the basal region of the pericardium, but not in the epicardium. Milky spot-like structures bulging toward the pericardial cavity were found in the pericardium, similar to those in the omentum and mediastinal pleura. Within 60 minutes after injection, carbon and latex particles were directly absorbed through the intercellular clefts of the adjacent small mesothelial cells into the submesothelial layer particularly at sites of characteristic lattice structure. Carbon particles were already present in the lumens of lymphatic capillaries at this time. Macrophages in the pericardial cavity and submesothelial layers of the pericardium engulfed both carbon and latex particles. Our results suggest two possible routes of drainage of particulate matter from the pericardial cavity into the lymphatics: direct absorption and indirect absorption after phagocytosis by macrophages. Macrophages probably migrate from the milky spot-like structures described in this study. Epicardial lymphatics, in contrast, drain tissue fluid primarily from the myocardium.

Absorption↗