Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PERICARDIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1993

Regional finite deformations of in situ canine pericardium.

The purpose of this study was to determine in situ regional pericardial strains over a wide range of conditions. In five open-chest, anesthetized dogs we examined deformations from biplane cineradiographs of three sets of four 1-mm diameter steel beads glued to basal, midanterior, and apical regions of the pericardium during extremes of pericardial sac sizes (inferior vena caval occlusion, baseline, and tamponade). Finite deformation theory was used to determine the planar components of the Green's strains referenced to the completely unloaded, excised pericardium at the end of each experiment. From the Green's strains the principal components, EI and EII, and the principal direction of strain were determined. The first strain invariant, I1 = EI + EII, in the basal, anterior, and apical regions during caval occlusion (1.27, 0.73, and 0.67) did not differ significantly from those in the baseline state (1.43, 0.86, and 0.76) but increased significantly (P < 0.01) during tamponade to 1.54, 1.30, and 1.08, respectively. Using end systole during inferior vena cava occlusion as a reference, the directions of principal strain in each region during each condition were aligned parallel to the spine pointing toward the tail except at the base during tamponade when there was a 70 degree rotation toward the left limb. The in situ dog pericardium is considerably strained by the underlying heart even during inferior vena cava occlusion, suggesting that a completely unloaded state cannot be achieved in situ. The regional differences in the direction but not the value of principal strain suggest that there are either regional variations in loading or material properties.

Animals↗
PubMed1975

Mathematical and mechanical modeling of stress-strain relationship of pericardium.

Several mathematical expressions (models) were compared for use in describing the stress-strain (sigma - epsilon) relationship of pericardium. The expression sigma = alpha[ebeta epsilon - 1] was preferred because of its simpler form, theoretical consistency, and "good fit" of experimental data. A method was developed for estimating the precisions of the estimates of the parameters alpha and beta. This approach can have general usefulness in assessing the significance of a change in stress-strain relationship of various soft tissues following different interventions. A mechanical model was formulated for the pericardium which consisted of springs representing the collagen and elastin fibers connected in parallel. It could be simulated by the above equation and could describe the behavior of the pericardium.

Elasticity↗
PubMed1976

Echocardiography in congenital and acquired absence of the pericardium. An echocardiographic mimic of right ventricular volume overload.

The purpose of this study was to investigate the echocardiographic effects of absence of the pericardium. Five patients with congenital complete absence of the left pericardium were studied. All had typical chest X-rays, four had cardiac catheterization which excluded any intracardiac shunts, and one had diagnostic pneumothorax. All five had an enlarged right ventricular dimension (RVD): 1.9 +/- 0.1 cm/m2 (normal: less than 1.3 cm/m2) and abnormal interventricular septal (IVS) motion (three Type A, two Type B). Sixteen additional patients were studied after pericardial stripping for a variety of conditions. In none was cardiopulmonary bypass used. Eight of these patients had preoperative echocardiograms; all showed normal IVS motion. After surgery RVD was large in all 16 patients, increasing from 1.0 +/- 0.2 cm/m2 preoperatively to 1.7 +/- 0.1 cm/m2 postoperatively, P less than 0.01. Fourteen of the 16 patients had abnormal IVS motion, nine Type A, and five Type B. We conclude that absence of the pericardium results in echocardiographic abnormalities which mimic those seen in right ventricular volume overload. This may be due to altered cardiac position and motion within the thorax resulting from loss of normal pericardial restraint.

Cardiomegaly↗
PubMed1978

Alteration of the left ventricular diastolic pressure-segment length relation produced by the pericardium. Effects of cardiac distension and afterload reduction in conscious dogs.

Left ventricular pressure and segment length were measured in seven conscious chronically instrumented dogs with the pericardium intact and 3-9 days after pericardiectomy. Diastolic pressure-length plots were obtained under control conditions and after acute volume loading followed by sodium nitroprusside infusion. In all dogs with intact pericardium, volume loading displaced the entire diastolic pressure-length curve upwards and sodium nitroprusside shifted it toward control. After pericardiectomy the pressure-segment length data during control, volume loading and sodium nitroprusside fell on a single curve (intercepts and slopes not statistically different); After dextran infusion, intrapericardial pressure rose from control 1.5 +/- 0.7 mm Hg to 8.2 +/- 0.5 mm Hg, and it fell to 4.8 +/- 0.1 mm Hg after nitroprusside. Therefore, in acute cardiac dilatation the pericardium contributed significantly to the increased left ventricular diastolic pressure and to the fall during sodium nitroprusside infusion and appeared responsible for shifts in the diastolic pressure-segment length relation.

Animals↗
PubMed1981

Ventricular diastolic pressure-volume relations and the pericardium. Effects of changes in blood volume and pericardial effusion in dogs.

We investigated the role of the pericardium in the mechanism of shifts in the left ventricular (LV) diastolic pressure-volume relation produced by changes in circulating blood volume and by pericardial effusion. Twelve closed-chest anesthetized dogs were instrumented with pericardial and pleural balloons and intracardiac catheters for pressure measurements. We measured the volumes of the pericardium and the left and right ventricles by computed tomography (CT), integrating the area of CT cross-sections measured at 1-cm intervals from the cardiac apex to the aortic arch. The volumes of the pericardium and the cardiac chambers were changed by infusing 40 and 80 ml of dilute contrast medium into the pericardial space, by bleeding, and by rapidly infusing saline intravenously. Pericardial effusions of 80 ml reduced mean right ventricular volumes to 59% of control, whereas LV volumes were less severely compromised (81% of control). Total pericardial volume and pressure increased. Intravenous saline infusions, which raised right atrial pressure 10-15 mm Hg, produced increases of this magnitude in pericardial pressure. This was also the magnitude of the upward displacement in the LV diastolic pressure-volume relation after infusion. However, LV diastolic transmural pressure-volume coordinates fell along a single curve. Similar behavior was observed for the right ventricular diastolic pressure-volume relation. Pericardial transmural pressure-volume curves were described. When cardiac volume was altered by volume load and pericardial effusion, acute shifts in the LV diastolic pressure-volume relation were caused by changes in pericardial pressure, which, in turn, corresponded to changes in pericardial volume.

Animals↗
PubMedDate not supplied

Pseudoaneurysm of the saphenous vein graft related to artificial rubber pericardium--a case report.

Pseudoaneurysm is an unusual complication of coronary artery bypass grafting. Such aneurysms are caused by technical surgical failures, or inflammation of the sternum and mediastinum following sternotomy observed as an early or mid-term complication of cardiac surgery. This case was an 80-year-old man with a piece of artificial rubber pericardium used for complete closure of the pericardium. A large pseudoaneurysm developed in the body of the saphenous vein graft 15 years after surgery. The old rubber synthetic pericardium was severely degenerative, which induced inflammation and disrupted the saphenous vein graft.

Aged↗
PubMed2006

Modifications on collagen structures promoted by 1,4-dioxane improve thermal and biological properties of bovine pericardium as a biomaterial.

Collagen is a widely used raw material for biomaterial manufacture, which generally depends on chemical modifications of this fibrillar protein with cross-linking agents to improve biocompatibility and mechanical properties. However, cross-linking reduces the natural properties of collagen, such as low immune response, low toxicity as well as the ability to promote cellular growth and attachment. In this work, the modifications promoted by 1,4-dioxane solvent on the collagen present in native bovine pericardium (NBP) matrix routinely used in bioprosthesis manufacture, with or without subsequent cross-linking by glutaraldehyde, has been studied. The structural changes of NBP evaluated by scanning electron microscopy show that 1,4-dioxane induces a more homogeneous material by increasing aggregation of collagen fibers, while transmission scanning electron microscopy shows that natural collagen fibril arrangement, integrity, and the D-periodicity pattern are maintained by solvent treatments. Measurements of thermal stability and resistance to collagenase enzymatic digestion of NBP matrices treated with 1,4-dioxane show an increase in melting temperature and decrease in biodegradability, as compared to native pericardium. Cross-linking with glutaraldehyde improves all the analyzed NBP properties, which are not impaired by previous treatment with 1,4-dioxane. Histological evaluation of NBP submitted to 1,4-dioxane treatment shows lower lipid and cell contents and improvement in other morphologic characteristics compared to native pericardium. Altogether, these results suggest the use of 1,4-dioxane organic solvent as an alternative non-cross-linking treatment for direct utilization on rich collagen matrices, resulting in materials with improved biocompatibility and physicochemical properties suitable for tissue engineering.

Animals↗
PubMed1999

The antithrombotic versus calcium antagonistic effects of polyethylene glycol grafted bovine pericardium.

Cardiovascular calcification, the formation of calcium phosphate deposits in cardiovascular tissue, is a common end stage phenomenon affecting a wide variety of bioprosthesis. This study proposes a novel approach of reducing pericardial calcification and thrombosis via coupling polyethylene glycols (PEG) to glutaraldehyde treated bovine pericardium via acetal linkages. The calcification of the PEG modified tissue and the control pericardium (extracted and glutaraldehyde treated) was investigated by in vivo rat subcutaneous implantation models and by in vitro meta stable calcium phosphate solutions. Scanning electron microscopy showed that calcification primarily involved the surface of collagen fibrils and the intrafibrillar spaces. However, the grafting of pericardium with PEG-20,000 had dramatically modified the surface and subsequently inhibited the deposits of calcium. Further, the modified tissue had also reduced the platelet surface attachment. Such a reduced calcification of PEG modified tissues can be explained by decrease of free aldehyde groups, a space filling effect and therefore improved biostability and synergistic blood compatible effects of PEG after coupling to the tissues. This simple method can be a useful anticalcification treatment for implantable tissue valves.

Animals↗
PubMed1993

The effect of the pericardium on right and left ventricular diastolic functions during isoflurane anesthesia.

We examined the effects of the pericardium on diastolic function of the right and left ventricles during isoflurane anesthesia. The diastolic properties of the ventricles were assessed by indices of isovolumetric relaxation such as -dP/dt, -dP/dt25, and time constant for relaxation, and by end-diastolic pressure. In seven mongrel dogs, anesthesia was initially induced by the administration of pentobarbital and maintained with alpha-chloralose. Two 7F microtipped pressure transducers were inserted into the right and left ventricles, and a flow-directed pulmonary artery catheter was placed in the pulmonary artery. After a left thoracotomy, opening and closing the pericardium was performed at 0% isoflurane, 1.3% isoflurane, and 2.6% isoflurane. Isoflurane 1.3% and 2.6% produced a decrease in cardiac output in association with a decrease in -dP/dt and an increase in time constant for relaxation of both ventricles, suggesting that isoflurane may depress isovolumetric relaxation of both ventricles. Isoflurane also increased end-diastolic pressure of the left ventricle. With 0% isoflurane, pericardial opening did not significantly change the diastolic properties of either ventricle and other hemodynamics. Pericardial opening at 1.3% and 2.6% isoflurane increased cardiac output without any significant changes in -dP/dt and time constant of either ventricle, but with significant decreases in end-diastolic pressures of both ventricles. We conclude that the pericardium may have a constraining effect on the diastolic properties, especially end-diastolic pressure, but not on isovolumetric relaxation of both ventricles during isoflurane anesthesia.

Anesthesia, Inhalation↗
PubMed1996

Reconstruction of the mitral annulus with porcine pericardium--report of a case with mitral annular disruption due to staphylococcal endocarditis.

A 60-year-old man was admitted to our hospital for investigation of dyspnea and disorientation with right hemiplegia. Echocardiography showed thickened mitral valve leaflets with vegetations and severe mitral regurgitation. Blood cultures grew Staphylococcus aureus. During the operation, perforation and destruction of the mitral valve leaflets and vegetations were confirmed. Debridement of the infected tissues resulted in segmental disruption of the posterior mitral fibrous annulus. Reconstruction of the mitral annulus with porcine pericardium treated with glutaraldehyde and mitral valve replacement were successful. The patient's postoperative course was complicated with metastatic cerebral and splenic abscesses. After splenectomy on the 8th postoperative day, he gradually recovered without major neurologic sequelae. We believe that reconstruction of the mitral valve annulus with pericardium, especially autologous pericardium, is reliable and useful for the treatment of patients with disruption of the mitral valve annulus.

Animals↗
PubMed1992

The role of the pericardium in conditioning the effects of physical training.

More work needs to be done on the extent to which the pericardium can modulate the cardiovascular response to exercise and the mechanisms whereby this modulation is brought about. Studies are needed to differentiate the effects of the pericardium on the cardiovascular exercise response, comparing trained with untrained subjects. Evidence is accumulating that exercise training in patients with heart failure improves not only the performance of exercising muscles, but also has some beneficial effects on central hemodynamics. The extent to which these beneficial effects can be attributed to conditioning the pericardium remains speculative.

Adaptation, Physiological↗
PubMed2004

Urethroplasty using a bovine pericardium graft: an experimental study using normal urethras from dogs.

The use of bovine pericardium as a urethral patch to substitute a ventral segment of canine urethras was studied. Healing, epithelial growth, urethral permeability, fistulas, and calcification were analyzed. Thirty male mongrel dogs of medium and large size underwent resection of a ventral segment of the medial urethra measuring 2.0 x 0.5 cm, which was replaced with a bovine pericardium graft, treated with buffered glutaraldehyde and preserved in formaldehyde. Two running sutures of polygalactin 5-0 were applied, one on each side of the patch. The corpus spongiosum was closed with uninterrupted suture and the skin with interrupted suture of polygalactin 5-0. Six months later, the animals were examined and sacrificed under anesthesia. Retrograde urethrograms showed that the urethral healing was complete in six of the 30 animals, without stenosis, fistulas or dilations. Microscopic examination showed complete epithelization of these six urethras. The remaining 24 animals presented urethrocutaneous fistulas without stenosis, demonstrated by urethral catheterism using a 10-Fr plastic catheter. These data show that a successful urethral reconstruction of the penile urethra was possible in only 20% of the operated animals. Infection and leakage may be the cause of the urethrocutaneous fistulas present in 80% of cases. Further studies are necessary to determine whether such fistulas are avoidable. If they are, the bovine pericardium may well be an option in the treatment of urethral lesions in dogs.

Animals↗
PubMed1988

MR imaging of the transverse sinus of the pericardium.

On MR images of the chest, a low-signal-intensity band is often seen between the ascending aorta and left atrium in the transverse plane, and between the right pulmonary artery and left atrium in the coronal and sagittal planes. CT and MR of cadavers, with injection of contrast media into the pericardial space, confirmed that this structure was the transverse sinus of the pericardium. Retrospective review of MR studies in 45 patients without evidence of pericardial disease showed the transverse sinus of the pericardium in 80% (32/40) of transverse ECG-gated images, 78% (7/9) of sagittal ECG-gated images, and 67% (14/21) of coronal ECG-gated images. Nongated studies showed the sinus infrequently. Knowledge of the three-dimensional anatomy of the transverse sinus of the pericardium and of its typical MR appearance should allow its recognition and preclude misinterpretation.

Adolescent↗
PubMedDate not supplied

Thoracoabdominal wall repair with glutaraldehyde-preserved bovine pericardium.

Glutaraldehyde-preserved bovine pericardium (GPBP) is evaluated as a bioprosthesis for the reconstruction of surgical defects in the thoracoabdominal wall. The mechanical properties of bovine pericardium preserved at different concentrations of glutaraldehyde were studied. Samples preserved in 0.5% glutaraldehyde showed a significantly higher tensile strength (11.7 +/- 0.8 N/mm2) than samples preserved in 2.5, 5, or 10% (similar to pericardium preserved in normal saline). The percentage of elongation was significantly lower than samples preserved in 1, 2.5, and 5% glutaraldehyde. GPBP at 0.5% was used to repair experimentally induced defects of the abdominal wall (n = 9), chest wall (n = 6), diaphragm (n = 6), and sternum (n = 7). All animals presented adequate tolerance to the material used and no case of infection or rejection of the material was seen in any of the animals. Finally, 0.5% GPBP was used clinically in a series of 40 patients: postincisional abdominal hernia (n = 30), inguinal hernia (n = 8), diaphragmatic hernia (n = 1), and congenital pelvic defect with prolapse of abdominal organs (n = 1). Surgical use showed that GPBP was a very manageable material and long-term results were good in 37 patients with a mean follow up of 18 months (range 5-35 months). Six patients presented seroma formation (all abdominal hernia patients), three of which eventually developed infection and had the GPBP patch removed at 3, 5, and 7 months postoperatively. The rest of the patients presented good scar formation with adequate resistance at the area of implantation. GPBP is a biological material with sufficient resistance to be used surgically in the repair of thoracoabdominal defects. Ideal concentration of glutaraldehyde to be used in the preparation-preservation of the material is 0.5% since higher concentration negatively affect its tensile rupture strength and elongation.

Abdominal Muscles↗
PubMed2000

The anticalcification effect of polyethylene glycol-immobilized on hexamethylene diisocyanate treated pericardium.

Pathologic calcification is thought to be the main cause of failure in the present generation tissue valves fabricated from glutaraldehyde pretreated bovine pericardium (BP). The present investigation describes the in vitro calcification and enzymatic degradation of bovine pericardia after hexamethylene diisocyanate (HMDIC) crosslinking and subsequent modification with polyethylene glycol. The enzymatic degradation of these treated surfaces were monitored by scanning electron micrography and tensile strength measurements. Various proteases, such as alpha-chymotrypsin, bromelain, esterase, trypsin and collagenase were investigated for tissue stability. Incubation of these enzymes with crosslinked pericardia had variably reduced their tensile strength. Among these treated surfaces, polyethylene glycol (PEG) grafted BP via isocyanate functionalities had retained maximum strength. The PEG modified tissues had also indicated a substantial reduction in calcification, when compared to other treated tissues. Further, the biocompatibility of various pericardial tissues were established by platelet adhesion and octane contact angle measurements. It is assumed that the PEG modification of pericardium may interfere with the cellular activation of injury (platelets) to reduce tissue associated calcification. In conclusion, it seems the PEG modification of bovine pericardium via HMDIC may provide new ways of controlling tissue biodegradation and calcification. However, more in vivo studies are needed to develop applications.

Animals↗
PubMed1989

Xenogeneic pericardium as a dural substitute in reconstruction of suboccipital dura mater in children.

A 5-year experience with the glutaraldehyde-stabilized freeze-dried radiation-sterilized calf pericardium used as a dural substitute is reported. The structure of pericardium xenograft is compared with other collagenous materials used for duraplasty (allogeneic fascia lata and dura mater) by light and electron microscopy. The special neurosurgical techniques involved in using pericardium xenografts in the reconstruction of suboccipital dura mater in children are presented in detail.

Animals↗
PubMed1976

[Congenital defects of the left-sided pericardium].

Three patients with congenital absence of the left pericardium and one patient with a partial left pericardial defect are described. Congenital absence of the left pericardium is characterized roentgenologically by levoposition of the heart, a prominent pulmonary artery segment and cardiac apex, interposition of lung between the left hemidiaphragm and the base of the heart, and unusual mobility of the heart. The electrocardiogram frequently shows right axis deviation, an incomplete right bundle branch block and leftward displacement of the transition zone in the precordial leeds. The anomaly has often been mistaken for other heart disease. As an isolated anomaly it is benign and does not require any treatment. Patients with a partial defect of the left pericardium can only be diagnosed lcinically if the left atrial appendage herniates through the defect. The herniation produces a protruding shadow along the left heart border and can be demonstrated angiographically and by fluoroscopy. In isolated cases death caused by herniation and strangulation of larger parts of the heart through a partial left pericardial defect has been described.

Adolescent↗
PubMed1999

The human pericardium in vibroacoustic disease.

INTRODUCTION: One of the main features of vibroacoustic disease (VAD) is the proliferation of the extra-cellular matrix which induces cardiovascular morphological and dynamic changes, and has been evaluated through echo-Doppler. While all subjects exposed to large pressure amplitude (> or =90 dB SPL) and low frequency (< or =500 Hz) (LPALF) for at least 15 yr have thickening of some cardiac structure, most frequently the pericardium, no significant diastolic changes accompany these observations. Echocardiography has become the diagnostic method of choice for the VAD. However, there have been no studies relating the echo-images of pericardial thickening to gross anatomy. METHODS: We present the histology and ultrastructure of the pericardia of four patients who underwent cardiac surgery. RESULTS: The most important findings concern the real thickening of the pericardium (values: 1.11, 1.35, 2.19, and 2.33 mm vs. norm: < or = 0.5 mm), the dynamic arrangements of mesothelial cells in the serosa layer, and the plasticity of the cells found among the multifascicular waveform collagen fibers. We found that the fibrosa of VAD patients has three layers: sandwiched between two thickened layers of normal fibrosa there is a loose tissue layer with vascular, nervous, and adipose structures. CONCLUSION: These features may partially explain why no important diastolic changes are observed in VAD patients in spite of the pericardium thickening.

Adult↗