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PubMed1990

Immunogenicity of glutaraldehyde-tanned bovine pericardium.

Glutaraldehyde-tanned bovine pericardium was tested for its ability to induce immunologic responses in vivo. Sections of glutaraldehyde-tanned bovine pericardium were implanted between the abdominal muscles of rats and guinea pigs. Control animals received Dacron implants. Lymphocytes and sera from animals were isolated at 2 and 4 weeks after implantation (four animals per group per time). Tritiated thymidine incorporation and an enzyme-linked immunosorbent assay were used to measure T- and B-lymphocyte responses to glutaraldehyde-tanned bovine pericardium antigens. At the same time points, implants and surrounding tissue from all animals were processed for histologic data. Results show that T-lymphocytes from animals with glutaraldehyde-tanned bovine pericardium implants responded significantly (p less than 0.001) to glutaraldehyde-tanned bovine pericardium antigens in vitro but not to Dacron. In contrast, lymphocytes from animals with Dacron implants failed to respond to glutaraldehyde-tanned bovine pericardium or Dacron preparations. Results of enzyme-linked immunosorbent assay show that animals with glutaraldehyde-tanned bovine pericardium implants produced antibody directed against glutaraldehyde-tanned bovine pericardium antigens. Histologic study revealed a dense mononuclear and multinuclear giant cell infiltrate at the interface between glutaraldehyde-tanned bovine pericardium and surrounding host tissues, with focal degradation of implant collagen. Dacron elicited a nonspecific lymphocytic and foreign body-type reaction. These results indicate that glutaraldehyde-tanned bovine pericardium can induce immunologic responses in vivo consistent with a host-versus-graft reaction.

Abdominal Muscles↗
PubMed2006

Determination of the force necessary for the propagation of tears in ostrich and calf pericardium.

The durability of prosthetic heart valve leaflets made of biological materials is limited. A tear in the biomaterial accelerates their early failure, but microtearing of the collagen fibers may be responsible for their medium-term failure. We studied the force necessary to propagate tearing in two biomaterials: ostrich and calf pericardium. One hundred twenty samples of each tissue were tested in an Elmendorf pendulum capable of measuring the force required to tear a tissue in which a predefined slit had been made. The forces required to produce tears, ranging between 2.5 and 0.25 cm in length, were determined. For ostrich pericardium, this force ranged between 67.67 and 4.80 newton, while that required to tear the same lengths of calf pericardium ranged between 70.67 and 4.70 newton. The function that relates the tearing force to the length of the tear was expressed as follows: y = 20.62x + 1.77x(2) (R(2) = 0.923) for ostrich pericardium and y = 45.57x - 7.21x(2) (R(2) = 0.936) for calf pericardium, where y is the force in newton and x is the length in centimeter. Calf pericardium was found to have a greater resistance to tearing. However, these results should be interpreted with caution owing to the fact that the thickness of the majority of the samples of ostrich pericardium was significantly less than that of calf pericardium. A more careful selection and utilization of adult ostrich pericardium would probably improve these results.

Animals↗
PubMed2001

Influence of the selection of the suture material on the mechanical behavior of a biomaterial to be employed in the construction of implants. Part 2: Porcine pericardium.

Using a hydraulic stress simulator, the mechanical behavior of the porcine pericardium used in the construction of cardiac valve leaflets was characterized following the same procedure employed with calf pericardium in Part 1 of this study. One hundred fifty pairs of tissue samples were subjected to tensile testing to rupture. One of the two samples from each of 120 pairs (four series of 30 pairs each) was saturated with commercially available threads made of nylon, silk, Prolene or Gore-Tex, while the other sample in each of these pairs was left unsewn. The remaining 30 pairs were employed as controls in which neither of the two samples was subjected to suturing. The sutured tissue samples showed a significant decrease in tensile strength at rupture (range: 11.61 to 21.22 MPa) when compared with unsutured samples (range: 50.80 to 89.45 MPa; p < 0.01). When these results were compared with their equivalent in calf pericardium, no significant differences were observed (the mean values at rupture in calf pericardium ranged between 211.61 MPa and 26.04 MPa). Again, the application of morphological and mechanical selection criteria to ensure the homogeneity of the samples provided excellent fit with respect to the stress/strain curves. The interaction of the different suture materials with the pericardial tissue was also assessed by comparing the mechanical behavior of the sutured samples with that of the control samples. At the working stress of a cardiac valve leaflet, 0.250 MPa, samples sewn with Gore-Tex were found to show the least difference in behavior with respect to the controls, indicating that this material presented the lowest degree of interaction with the pericardium. In conclusion, the suture clearly has deleterious effects on the resistance of both calf and porcine pericardium, which showed no statistically significant differences in terms of resistance to rupture when their respective sutured or unsutured samples were compared, except in the case of porcine pericardium sewn with silk, which presented lower resistance to rupture in all the zones studied. These findings suggest that the hypothesis that porcine pericardium is less resistant is erroneous. The Gore-Tex suture also presented a lower degree of interaction with the porcine pericardium, with values similar to the working stress of a cardiac valve leaflet. This methodology and the results should be evaluated in dynamic studies, such as fatigue testing, that not only confirm the resistance of the material but establish the durability of the samples being assayed.

Animals↗
PubMed1976

Closure of pericardium after open heart surgery. A way to prevent postoperative cardiac tamponade.

Between July 1968 and December 1975, 821 patients underwent open heart operations. In 596 cases the pericardium was left open and in 225 the pericardium was closed. Forty-one patients in the open pericardium group required reoperation and 23 of these had tamponade. Four patients in the closed pericardium group had reoperation but there was not a single case of tamponade. In most cases that required reoperation the bleeding was from extrapericardial sources. Absence of tamponade in the closed pericardium group can be explained by the fact that blood from extrapericardial sources of bleeding cannot collect round the heart because the pericardium is closed. Thus closure of pericardium helps to prevent tamponade. Reoperations some months or years after the original operation are technically easier and less hazardous if the pericardium has been closed because the closed pericardium prevents the heart from becoming adherent to the back of sternum and also because there are fewer adhesions in the pericardial cavity.

Cardiac Surgical Procedures↗
PubMed1990

[Regional irrigation of the pericardium in children].

PURPOSE: To investigate the irrigation of both fibrous pericardium and the parietal layer of serosal pericardium in children. PATIENTS AND METHODS: The cadavers of 10 children of both sexes, under the age of one. In this study we adopted the regional divisions described by DI Dio, which considers a plane between the two phrenic nerves that divides the areas of pericardium into ventral and dorsal regions. We also refer to these regions as antephrenic and retrophrenic respectively. In addition, we consider the inferior pericardium to be that portion of pericardial sac related to the diaphragm. RESULTS: The pericardium ventralis was more frequently irrigated by branches of the following arteries: thoracicae internae dextra and sinistra, pericardiacophrenica dextra in 9 cases; pericardiacophrenica sinistra in 8 cases; and less frequently, by branches of the arteriae phrenicae inferiores dextra and sinistra, epigastrica superior sinistra, thimica, rami thimici of the a. thoracica interna dextra, and rami thimicus and esophagealis of the a. subclavia dextra. The pericardium dorsalis was more frequently supplied b the following arterial branches: bronchiales in 9 cases; esophagealis of the aorta in 8 cases; and in a frequency inferior than 4 cases, we observed the following arteries: thyroidea inferior sinistra, intercostalis suprema, pericardiacophrenicae dextra and sinistra, subclavia sinistra, coronariae dextra and sinistra, phrenicae superior and inferior sinistra, thoracica interna dextra, intercostales posteriores primae dextra and sinistra, truncus costocervalis and rami esophageales of the a. gastrica sinistra. The pericardium inferior was irrigated by branches of the arteriae phrenicae inferiores dextra in 10 cases and sinistra in 9 cases. CONCLUSION: Analysis of the results demonstrated that similar behavior in the pericardium regional irrigation offers a standard for intervention in the pericardium.

Coronary Circulation↗
PubMed2004

Resistance to tearing of calf and ostrich pericardium: Influence of the type of suture material and the direction of the suture line.

The tearing of the valve leaflet of a cardiac bioprosthesis can cause early failure of this device, which is employed to replace a diseased native valve. This report involves the study of the behavior of 312 tissue samples (152 of calf pericardium and 160 of ostrich pericardium) treated with glutaraldehyde and subsequently subjected to tear testing. The samples were cut in the two principal directions: longitudinally, or root to apex, and transversely. They included a series of control samples that were left unsutured, and the remaining samples were repaired with the use of two different suture techniques: a running suture in the direction of the load and a telescoping suture perpendicular to the load. Four commercially available suture materials were employed: Pronova, nylon, Gore-Tex, or silk. The unsutured control samples of both types of pericardium exhibited a similar anisotropic behavior in the tear test. The mean resistance to tearing of the calf pericardium was 24.29 kN m in samples cut longitudinally and 34.78 kN m in those cut transversely (p =.03); the values were 28.08 kN m and 37.12 kN m (p =.002), respectively, in ostrich pericardium. The series repaired with the telescoping suture always exhibited greater resistance to tearing, with values that ranged between 44.34 and 64.27 kN for the samples of calf pericardium and from 41.65 to 47.65 kN for those obtained from ostrich. These assays confirm the anisotropic behavior of calf and ostrich pericardium treated with glutaraldehyde when subjected to tear testing, as well as the loss of this behavior in ostrich pericardium after suturing. Suturing techniques, such as the telescoping model, that provide a greater resistance to tearing should be studied for use in the design of the valve leaflets of cardiac bioprostheses made of biological materials.

Animals↗
PubMed2001

The effects of the pericardium on length-dependent regulation of left ventricular function in coronary artery surgery patients.

OBJECTIVE: To analyze the effects of the pericardium on the length-dependent regulation of myocardial function in coronary artery surgery patients. DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Patients scheduled for elective coronary artery surgery. INTERVENTIONS: In 10 patients, a combined micromanometer transducer conductance catheter was inserted into the left ventricle for measurement of left ventricular pressures and volumes. MEASUREMENTS AND MAIN RESULTS: Consecutive data were obtained during a progressive increase in left ventricular pressures and volumes obtained by leg elevation in closed chest-closed pericardium and open chest-open pericardium conditions. Pericardiotomy did not alter baseline left ventricular hemodynamics. The effects of leg elevation were different, however. In closed chest-closed pericardium conditions, stroke volume and stroke work remained unchanged, whereas these parameters increased in open chest-open pericardium conditions. This increase was related to the increase in end-diastolic volume that was observed in open chest-open pericardium conditions and not in closed chest-closed pericardium conditions. CONCLUSIONS: In coronary artery surgery patients, pericardiotomy does not alter baseline left ventricular function. When cardiac load is increased by leg elevation, however, use of the Frank-Starling mechanism is enhanced in open chest-open pericardium conditions.

Coronary Vessels↗
PubMed1982

The effect of pericardium on the diastolic properties of the heart--experimental studies on volume load and on acute ischemia in open chest dogs.

We studied the effect of the pericardium on the end-diastolic pressure-segment length (P-L) relation in volume loading (Experiment I) and in acute ischemia (Experiment II). Experiment I: In 6 open chest dogs, segment length of left and right ventricles were measured using ultrasonic crystals during blood infusion. Drawing end-diastolic pressure (P, on ordinate) against segment length (L, on abscissa), the P-L curve with pericardium positioned upward compared to that without pericardium. The slopes (b) of the exponential curve (P = aebL) with pericardium were steeper than those without pericardium in both ventricles. The difference between the slopes with and without pericardium was significantly larger in the right ventricle (RV, 0.30 +/- 0.10, mean +/- SEM) than in the left ventricle (LV, 0.05 +/- 0.02, p less than 0.05). These results show that the pericardium inhibits the distensibility of the free wall more in RV than in LV, and enhances a mechanical coupling of both ventricles during volume over-load. Experiment II: In 8 open chest dogs, segment lengths of ischemic and non-ischemic regions in LV were measured after left circumflex coronary occlusion. When the segment lengths and LV pressure became stable, a pericardiectomy was performed. After the pericardiectomy, whereas heart rate and LV systolic pressure did not change, end-diastolic segment length in the ischemic region further lengthened (12.0 +/- 0.2 to 12.5 +/- 0.2 mm, p less than 0.01) and that in the non-ischemic region did not change despite the concomitant fall in LV end-diastolic pressure (EDP, 11.9 +/- 0.6 to 9.8 +/- 0.6 mmHg, p less than 0.01). These results suggest that the pericardium alters the LV end-diastolic pressure-volume relation and is one of the factors contributing to an increase in LVEDP during acute ischemia.

Animals↗
PubMed2004

[Experimental study on guiding bone regeneration with bovine pericardium membrane].

OBJECTIVE: To explore the feasibility of bovine pericardium used as a material for guiding bone regeneration. METHODS: 1 cm x 1 cm x 0.5 cm defects were created on both buccal sides of the mandibles of 11 dogs. One side was covered with Glutaraldehyde (GA) cross-linking bovine pericardium; no membrane covered side was used as control. The animals were sacrificed in 2 weeks, 4 weeks, 8 weeks and 16 weeks after operation to observe the repair of the bone defects. RESULTS: (1) Wounds healed well in 10 dogs. Meanwhile, wounds in dogs of 16 weeks group healed badly and severe inflammatory response was found in bovine pericardium treated area. (2) The pericardium can be maintained in vivo for 16 weeks without absorption, there were only mild inflammatory cells invading. (3) The bone defects covered with bovine pericardium repaired better than control groups significantly. CONCLUSION: (1) GA bovine pericardium have the effect on guiding bone regeneration in the repair of dog experimental bone defects and it is possible that the bovine pericardium will be used as a new kind of GBR material; (2) GA bovine pericardium has good biocompatibility.

Animals↗
PubMed1998

The use of pericardium in acquired heart disease: a review article.

Pericardium is an excellent material for reconstruction of the heart during the surgical management of certain acquired heart defects. This review details our experience with pericardium as a patch material for various parts of the left ventricle. MITRAL ANNULUS: Extensive calcification of the mitral annulus, abscess, multiple previous mitral valve replacements and rupture of the posterior wall of the left ventricle are challenging surgical problems that can be satisfactorily managed by reconstructing the mitral annulus with either fresh autologous or glutaraldehyde-fixed bovine pericardium. The mitral valve prosthesis is secured to the newly reconstructed mitral annulus. This procedure has proven to be durable and has provided very good long-term results. LEFT VENTRICULAR OUTFLOW TRACT: We have used bovine pericardium to enlarge the aortic annulus in patients with small aortic annulus undergoing aortic valve replacement with bioprosthetic valves. Patch enlargement of the aortic annulus probably increases the operative mortality of aortic valve replacement but it may favorably effect the clinical outcome and late survival. Another problem in the aortic root that frequently requires reconstruction with pericardium is aortic root abscess. We believe that radical resection of the abscess is the single most important component to eradicate infection in these patients. Pericardium is an excellent material to reconstruct all parts of the left ventricular outflow tract and the results have been excellent. RECONSTRUCTION OF THE LEFT VENTRICULAR WALL: We have also used pericardium to repair the left ventricle in patients with postinfarction ventricular septal defect. We have used a technique of infarct exclusion by suturing a properly tailored bovine pericardium to the endocardium of the left ventricle all around the infarct, excluding the left ventricular cavity from the infarcted wall. This technique has improved the outcome of surgery for this mechanical complication of myocardial infarction, particularly in patients with posterior interventricular septal rupture.

Aortic Valve↗
PubMed1998

Treated bovine and autologous pericardium for aortic valve reconstruction.

BACKGROUND: To determine the differences in clinical behavior of bovine versus autologous pericardium, all consecutive patients undergoing aortic valve reconstruction were reviewed. METHODS: Between October 1988 and December 1995, 91 patients (mean age 30 years) underwent reconstruction with bovine (n = 27) or autologous (n = 64) pericardium. RESULTS: There were 2 hospital deaths, 5 late deaths, and no embolic events. Dysfunction of the aortic reconstruction required reoperation in 6 bovine (infection 1, fibrocalcific 5) and in 5 autologous (infection 3, annulus dilatation 1, commissural tear 1). Actuarial survival and freedom from structural deterioration at 8 years were 82.2%+/-9.6% and 76.2%+/-10.7% for bovine and 91.05%+/-3.96% and 96.8%+/-2.25% for autologous pericardium, respectively. The last Doppler echocardiographic study showed a mean regurgitation (1 to 4+) and gradient in the bovine pericardium of 1.25+/-and 20.7 mm Hg and in the autologous pericardium of 1+ and 7.7 mm Hg. CONCLUSIONS: Aortic valve reconstruction with pericardium can be safely performed with low thromboembolic rate. At 8 years follow up, there is a difference in favor of the autologous pericardium.

Actuarial Analysis↗
PubMed2003

Comparison of the mechanical behaviors of biological tissues subjected to uniaxial tensile testing: pig, calf and ostrich pericardium sutured with Gore-Tex.

The purpose of this study was to compare the mechanical behavior of calf pericardium, pig pericardium and ostrich pericardium when subjected to tensile testing. Tensile stress was applied to 108 tissue samples, 36 of each type of tissue, until rupture. Groups of three adjacent strips measuring 12 x 2 cm(2) were cut longitudinally. Each group consisted of an unsutured center sample, or control, and the two contiguous samples, that on the right sutured with Gore-Tex at a 90 degrees angle with respect to the longitudinal axis and that on the left sewn with the same suture material at 45 degrees angle. The sutured samples showed a statistically significant loss of resistance (p<0.001) when compared with the corresponding unsutured tissue. The mean stresses at rupture for sutured ostrich pericardium were 21.81 and 20.81 MPa in the samples sewn at 45 degrees and 90 degrees, respectively, higher than those corresponding to unsutured calf and pig pericardium, 14.0 and 11.49 MPa, respectively, at rupture. The analysis of the stress/strain curve shows a smaller difference between sutured and unsutured ostrich pericardium than those observed in the other two biomaterials. These results demonstrate that, in addition to its greater resistance, ostrich pericardium also presents a less pronounced interaction with the suture material. Its capacity to absorb the shearing stress produced by the suture is greater. This report also confirms that the method of selection using paired samples ensures their homogeneity and makes it possible to predict the behavior of a sample by determining that of the other half of the pair.

Animals↗
PubMed2002

Usefulness of the transgastric view by transesophageal echocardiography in evaluating thickened pericardium in patients with constrictive pericarditis.

Detection of thickened pericardium in patients with constrictive pericarditis is essential for pericardiectomy because restrictive cardiomyopathy and severe tricuspid regurgitation show similar hemodynamic data. The purpose of this study was to clarify whether transesophageal echocardiography can evaluate thickened pericardium. We investigated 7 patients with constrictive pericarditis who underwent pericardiectomy. Thickened pericardium over the right atrium was detected in 6 patients, but the borders were not clear. Thickened pericardium over the left ventricle was not detected in any patients in the standard longitudinal and horizontal views. On the other hand, thickened pericardium over the ventricles was detected in all patients in the transgastric view as an echogenic area between the liver and ventricular wall. Tissue characteristics of the thickened pericardium could be evaluated because of the high-quality images in the transgastric view. The transgastric view by transesophageal echocardiography allows high-quality images of the pericardium, which might be useful in diagnosing constrictive pericarditis.

Diagnosis, Differential↗
PubMed1983

Role of the pericardium in the regulation of myocardial blood flow and its distribution in the normal and acutely failing left ventricle of the dog.

The effects of the pericardium on the amount and distribution of left ventricular myocardial blood flow were studied. In 10 normal dogs, transfusion of blood from a donor dog resulted in modest increases in coronary flow and ventricular diameter that were greater with an open than a closed pericardium. The ratio of subendocardial to subepicardial flow remained normal with or without the pericardium, at low and high diastolic ventricular pressure, and before and after pharmacological vasodilation with chromonar. In 18 dogs, cardiac failure was induced by constant infusion of the metabolic inhibitor, phenformin. Modest ventricular dilatation occurred if the pericardium was open. A progressive rise in myocardial blood flow developed in those with the pericardium open (1.06 rising to 3.02 ml . g-1 . min-1). A lesser increase (0.62 to 1.75 ml . g-1 . min-1) was seen in dogs with the pericardium closed; they selectively increased subendocardial flow, producing an average subendocardial to subepicardial flow ratio of 2.25. Pharmacological vasodilatation then resulted in uniform transmural flow. The pericardium can influence myocardial flow indirectly by influencing myocardial metabolic demand, when the heart is stressed. It may have a beneficial role in preventing the increased oxygen and coronary flow requirements produced by ventricular dilatation.

Animals↗
PubMed2006

A 2D FE model of the heart demonstrates the role of the pericardium in ventricular deformation.

During pulmonary artery constriction (PAC), an experimental model of acute right ventricular (RV) pressure overload, the interventricular septum flattens and inverts. Finite element (FE) analysis has shown that the septum is subject to axial compression and bending when so deformed. This study examines the effects of acute PAC on the left ventricular (LV) free wall and the role the pericardium may play in these effects. In eight open-chest anesthetized dogs, LV, RV, aortic, and pericardial pressures were recorded under control conditions and with PAC. Model dimensions were derived from two-dimensional echocardiography minor-axis images of the heart. At control (pericardium closed), FE analysis showed that the septum was concave to the LV; stresses in the LV, RV, and septum were low; and the pericardium was subject to circumferential tension. With PAC, RV end-diastolic pressure exceeded LV pressure and the septum inverted. Compressive stresses developed circumferentially in the septum out to the RV insertion points, forming an arch-like pattern. Sharp bending occurred near the insertion points, accompanied by flattening of the LV free wall. With the pericardium open, the deformations and stresses were different. The RV became much larger, especially with PAC. With PAC, the arch-like circumferential stresses still developed in the septum, but their magnitudes were reduced, compared with the pericardium-closed case. There was no free wall inversion and flattening was less. From these FE results, the pericardium has a significant influence on the structural behavior of the septum and the LV and RV free walls. Furthermore, the deformation of the heart is dependent on whether the pericardium is open or closed.

Animals↗
PubMed1982

Mechanical interactions between four heart chambers with and without the pericardium in canine hearts.

By using excised postmortem hearts obtained from 15 mongrel dogs with the pericardium intact, we investigated mechanical interactions between the four heart chambers from the standpoint of ventricular pressure-volume relationships. The interactions investigated were those between (1) the atrium and the ventricle, (2) the right ventricle and left ventricles, (3) the atrium and one ventricle vs. the other ventricle, and finally (4) the left and right atrium and the right ventricle vs. the left ventricle. For these purposes, we inserted compliant balloons into the four heart chambers without injuring the pericardium, i.e., we incised the base of the atria which was not covered with the pericardium. We obtained the right and/or left ventricular pressure-volume relationships under a constant pressure in three other heart chambers by changing the height of the reservoir connected to each balloon. As a result, both ventricular pressure-volume relationships were hardly affected by an increase in the atrial pressure ranging from 5 to 30 cm H2O with the pericardium removed, although the ventricle became less compliant due to an increase of the same magnitude of the opposite ventricular pressure. On the other hand, the effect of an increase in atrial pressure was distinct with the pericardium intact. Also, all mechanical interactions were enhanced dramatically with the intact pericardium. Thus, the pericardium plays an important role in these mechanical interactions, especially when the filling pressures of all heart chambers increase simultaneously. Clinically, these findings may be important to understanding ventricular functions as related to various heart disease-especially acute heart failure.

Animals↗
PubMedDate not supplied

[Ventricular function curves with and without pericardium: analysis of pericardial pressures].

Simultaneous right and left ventricular function curves (VFC, R, L) were obtained in a canine model, (open chest preparation), with and without pericardium. Preload and afterload conditions for the right and left ventricles were controlled. VFC were constructed from zero to 25 mmHg of ventricular end-diastolic pressures and by increasing the cardiac output from 50 to 250 mL/kg-1min-1. Both, right and left VFC showed an initial steep rise at low filling pressures and then flattened off to a plateau at high filling pressures. The best mathematical model that fitted with the VFC, with and without the pericardium was the parabola (r2 = 0.71, 0.72 respectively). After pericardiectomy R and L VFC were displaced to the left of the VFC with pericardium and a decrease in filling pressures were noted at the same points of cardiac output, findings that suggest a restraining effect of the pericardium. By subtracting the filling pressures obtained with pericardium from those without pericardium at the same levels of cardiac output, pericardial pressures were derived. In all the range of the VFC the pericardial pressures were positive, and this pressure increase as cardiac output increase. Thus the transmural pressure was never cero, for both right and left ventricles. The observed relation for the R and L filling pressures, derived from a polynomial equation of second order suggest a small although not unimportant effect of the pericardium at normal filling pressures, and a very substantial influence at high levels of cardiac output. The demarcation between small and major effects appears in the upper range of normal filling pressures in this dynamic approach of the pericardial pressures.

Algorithms↗
PubMed2002

Evaluation of kangaroo pericardium as an alternative substitute for reconstructive cardiac surgery.

BACKGROUND: Bioprosthetic materials (human, bovine and porcine) are used in various cardio-thoracic repair and replacement procedures because of excellent performance and low thrombogenicity. These bioprosthetic substitutes fail due to degeneration and calcification. This study examines the morphology, tensile properties and calcification potential of kangaroo pericardium in vitro and in vivo. METHODS: Bovine (control tissue) and kangaroo pericardium, fixed in 0.625% buffered glutaraldehyde, were examined by light and scanning electron microscopy. A standard method was used for biaxial testing. Pericardial strips (10 x 5 mm) were implanted subcutaneously into male Wistar rats and retrieved after 4, 6 and 8 weeks and examined by Von Kossa's stain technique and atomic absorption spectrophotometry. RESULTS: Histology revealed serosa and fibrosa cell layers in both tissues. Electron microscopy showed a densely arranged collagen matrix in kangaroo pericardium. Kangaroo pericardium calcified significantly less than bovine pericardium at 4 weeks (0.80+/-0.28 versus 21.60+/-4.80 microg/mg) at 6 weeks (0.48+/-0.08 versus 32.80+/-14.4 microg/mg) and at 8 weeks (2.40+/-1.20 versus 30.40+/-17.20 microg/mg), respectively. CONCLUSIONS: Kangaroo pericardium has a densely arranged collagen matrix with a higher extensibility and significantly lower calcification potential. Therefore, kangaroo pericardium could be used as an alternative substitute in cardiac surgery because of its low calcification potential.

Animals↗