Equine Pericardial Patch Research Articles

Pericardial tissue for cardiovascular application: an in-vitro evaluation of established and advanced production processes.

Pericardial tissue is widely used as a biomaterial, especially for cardiovascular application. Tissue processing plays a key role in developing future scaffolds derived from biological material, yet standardized evaluation is still pending. This study presents a comprehensive assessment of different treatment protocols of bovine pericardium and compares those findings to commercially available decellularized bovine (CAB) and equine (CAE) pericardial patches. Native samples were fixed with glutaraldehyde (GA) or decellularized. These decellularized samples were subsequently either treated with GA (DEC-GA) or sterilized (DEC). Treatment effects were assessed by histological evaluation of structural and biomechanical properties. Furthermore, decellularization efficacy and accuracy of the applied sterilization protocol were evaluated. Cell seeding of processed pericardial samples with human endothelial cells constituted as biocompatibility test.GA-fixed tissue revealed structural deterioration, cytotoxicity and opposed to popular believe, GA-treatment did not lead to sterility of the samples. Biomechanical assessment revealed an increase in tensile strength of GA and a decrease of DEC and DEC-GA. DEC samples were successfully sterilized and showed good decellularization results, with a significant decrease in residual DNA. Comparative assessment revealed overall good results of CAE, yet results of CAB varied largely, e.g. decellularization efficacy or tissue thickness. Biocompatibility of DEC, CAB and CAE was confirmed by successful cell adhesion. Substantial differences of native tissue properties were observed, resulting in varying treatment efficacies. This study provides a first overview describing consequential variations among biomaterials and illustrates the necessity of multidimensional assessment and tissue quality management for biological scaffold development.

Xenografts in septic vascular surgery

BackgroundIn general, autologous veins are the optimal replacement material for an infected vascular graft in terms of handling, durability and resistance to reinfection. In the absence of suitable autologous material, several options are available, each of which has specific advantages and drawbacks with regard to these characteristics.MethodsIn recent years, xenogeneic materials (in particular pericardial patches from different species and biosynthetic grafts) have been increasingly used as replacement material in the setting of infections. Bovine and equine pericardial patches are applied in particular as self-made tube grafts in the aortic region and also in infections of iliacofemoral prosthetic grafts and shunt infections.ResultsThe results of small clinical series on durability and resistance to reinfection are promising.ConclusionIt is feasible to use biosynthetic materials to replace infected intracavitary and extracavitary vascular grafts with remarkably low reinfection rates; however, the unique mechanical properties of the grafts as well as the initially increased thrombogenicity, need to be taken into consideration.

Off-Pump Multilayered Sutureless Repair for a Left Ventricular Blowout Rupture after Aortic Dissection Repair

A left ventricular (LV) free wall rupture is a highly lethal condition. A 75-year-old female who experienced chest pain was diagnosed as having an acute aortic dissection Stanford type A and underwent emergent surgery. Under cardiopulmonary bypass with LV venting through the right superior pulmonary vein, a proximal aortic stamp was formed. The patient was cooled, selective antegrade brain perfusion was performed, and a hemiarch repair was performed. After the patient was transferred to the intensive care unit, her blood pressure suddenly fell to 50 mmHg. She had a blowout rupture in the left ventricular anterolateral free wall. Since the bleeding hall was not large and the damage to the surrounding left ventricular tissue was not very wide, an off-pump multilayered sutureless repair was performed by using three layers of collagen fleece squares with fibrinogen-based impregnation (TachoComb; CSL Behring, Tokyo, Japan) and three layers of gelatin-resorcin-formalin glue reinforced by an equine pericardial patch (Xenomedica; Edwards Lifesciences, LLC, Irvine, CA). The blow-out rupture seemed to be caused by perioperative myocardial infarction generated by the compression of the left ventricular vent to the LV lateral wall. The patient was free from re-rupture or aneurysm enlargement. The thickness of the hemostatic material seemed to help control the bulging of the aneurysm and to prevent further LV aneurysm enlargement and re-rupture.

Repair of gastric defects with an equine pericardial patch.

The objective of this study was to test the efficacy of an equine pericardial patch for repairing full-thickness defects of the stomach wall. Circular defects, 1.5 cm in diameter, were created on the anterior wall of the stomach of 12 female New Zealand rabbits. The defects were repaired by an equine pericardial patch. After euthanasia at different time intervals (3 days to 8 weeks) a macroscopic evaluation of the abdominal cavity (including adhesion scoring), mechanical testing and a histological examination of the stomach were performed. The animals survived the surgical procedure and underwent an uneventful recovery until euthanasia. None of the patches failed. Adhesions were observed in all animals and were significant in 3/12 animals. Bursting pressure testing indicated that the repair was durable and that adequate strength to prevent patch failure was achieved by the second week. A histological examination showed gradual narrowing of the perforation site by mucosal and limited muscular regeneration. The equine pericardial patch was successfully used to repair a gastric defect in our experimental model, and it seems that it could have potential as a material suitable for further research concerning the repair of upper gastrointestinal defects.

Successful implantation of a decellularized equine pericardial patch into the systemic circulation

BackgroundIn the past, successful use of decellularized xenogenic tissue was shown in the pulmonary circulation. This study, however, evaluates a newly developed decellularized equine pericardial patch under high pressure circumstances.Material/MethodsSeven decellularized equine pericardial scaffolds were implanted into the descending aorta of the juvenile sheep. The implanted patches were oversized to evaluate the durability of the decellularized tissue under high surface tension (Law of Laplace). After 4 months of implantation, all decellularized patches were inspected by gross examination, light microscopy (H&E, Serius red, Gomori, Weigert, and von Kossa straining), and immunohistochemical staining.ResultsThe juvenile sheep showed fast recovery after surgery. There was no mortality during follow-up. At explantation, only limited adhesion was seen at the surgical site. Gross examination showed a smooth and pliable surface without degeneration, as well as absence of aneurysmatic dilatation. Light microscopy showed a well preserved extracellular scaffold with a monolayer of endothelial cells covering the luminal side of the patch. On the outside part of the patch, a well developed neo-vascularization was seen. Host fibroblasts were seen in all layers of the scaffolds. There was no evidence for structural deterioration or calcification of the decellularized equine pericardial scaffolds.ConclusionsIn the juvenile sheep, decellularized equine tissue showed no structural deterioration, but regeneration and remodeling processes at systemic circulation.

Repeated mitral valve replacement in a patient with extensive annular calcification

BackgroundMitral valve replacement in the presence of severe annular calcification is a technical challenge.Case reportA 47-year-old lady who had undergone mitral and aortic valve replacement for rheumatic disease 27 years before presented with dyspnea. At reoperation, extensive mitral annular calcification was hindering the disc motion of the Starr-Edwards mitral prosthesis. The old prosthesis was removed and a St Jude Medical mechanical valve was implanted after thorough annular debridement. Postoperatively the patient developed paravalvular leak and hemolytic anemia, subsequently undergoing reoperation three days later. The mitral valve was replaced with an Edwards MIRA valve, with a bulkier sewing cuff, after more aggressive annular debridement. Although initially there was no paravalvular leak, it recurred five days later. The patient also developed a small cerebral hemorrhage. As the paravalvular leak and hemolytic anemia gradually worsened, the patient underwent reoperation 14 days later. A Carpentier-Edwards bioprosthetic valve with equine pericardial patches, one to cover the debrided calcified annulus, another as a collar around the prosthesis, was used to eliminate paravalvular leak. At 7 years postoperatively the patient is doing well without any evidence of paravalvular leak or structural valve deterioration.ConclusionMitral valve replacement using a bioprosthesis with equine pericardial patches was useful to overcome recurrent paravalvular leak due to severe mitral annular calcification.

Combined hepatic resection with the inferior vena cava and diaphragm and reconstruction using an equine pericardial patch: Report of a case

We herein report a case of combined hepatic resection with inferior vena cava (IVC) and diaphragm resection, and reconstruction using an equine pericardial patch. A 54-year-old woman showed hepatic cancer recurrence on radiological imaging, with invasion to the caudate lobe of the liver, IVC, diaphragm, and adrenal gland. We resected 10 × 5 cm of the diaphragm. After dissecting the hepatic parenchyma, the caudate lobe was connected only to the IVC. Clamping of the IVC was performed between the IVC below the confluence of the hepatic vein and the suprarenal IVC. A 6 × 3-cm segment of the IVC was then resected. The IVC and diaphragm were reconstructed using an equine pericardial patch, as both defects were too large to repair without a patch. The equine pericardium represents a suitable graft material for repairing both the IVC and diaphragm. Further investigation is needed to determine the durability and anti-infection properties of equine pericardial grafts.

A Modified Infarct Exclusion Repair of Posterior Postinfarction Ventricular Perforation: Triple-patch Technique for Postinfarction Ventricular Septal Perforation in 2 Female Patients

We describe a new technique for the early surgical repair of a posterior postinfarction ventricular septal perforation (VSP) in two consecutive female patients. The occurrence of a posterior VSP is rare, and its repair is technically difficult because the posteromedial papillary muscle is located adjacent to the intraventricular septum. This modification appears to prevent leaks to the right ventricle through the VPS with a single direct patch and the use of two equine pericardial patches to form a single endocardial pouch. The women were 77 and 62 years old, and the time between the onset of acute MI and surgery was 3 and 6 days. On preoperative catheterization, Qp/Qs was 4.18 and 4.01. Neither operative death nor residual shunting was observed.

Ventricular Septal Defect and Left Ventricular Aneurysm After Acute Myocardial Infarction

The combination of an acute ventricular septal defect (VSD) and left ventricular aneurysm (LVA) is a rare, life-threatening complication which usually occurs within the first week following acute myocardial infarct- tion (AMI). We describe the case of an apical VSD and LVA in a 77-year-old diabetic and dyslipidemic male patient after anterior AMI. The patient was an active smoker and had a history of chronic obstructive pulmonary disease, arterial hypertension and atrial fibrillation. The patient underwent ventriculotomy for VSD repair using a large equine pericardial patch followed by intraventricular patch remodelling of the LVA. He was discharged 2 months after surgery and underwent a successful hip replacement 10 months later.

Double patch technique for closing acute ventricular septal perforation

Ventricular septal perforation (VSP) is a rare but life-threatening complication of acute myocardial infarction (AMI). Even with assisted circulation heart failure often progresses quickly, and urgent surgical intervention is required to close the VSP. For several years, we have been performing a double patch closure technique using an equine pericardial patch. In this report, we present details of our patch closure technique and the VSP surgical results; we also examine the problems we encountered. The present study was a review of nine patients who underwent our patch closure of VSP secondary to AMI. We used a large double-layered equine pericardial patch to close the VSP and did not exclude the infarction area from the left ventricular cavity. No necrotic myocardium was excised to avoid simultaneous excision of stunned myocardium. No patients died within 30 days of the surgery, and there were no in-hospital deaths. Over a mean clinical follow-up period of 4.5 years, no residual shunts were detected, and all patients were alive and had New York Heart Association functional class II. Our patch closure technique was effective for closing VSPs securely. The operating times and cardiopulmonary bypass times were short, and blood loss was minimal. Our patch closure technique may improve the prognosis of VSP.

Early obstruction of decellularized xenogenic valves in pediatric patients: involvement of inflammatory and fibroproliferative processes

Decellularization of pulmonary valve substitutes is believed to eliminate immunogenicity and improve conduit durability. This study focused on a detailed histopathological and immunohistochemical analysis of explanted Matrix P plus valves, following their early obstruction in pediatric patients. Occurrence of fibrosis, scar formation, neovascularization, and inflammatory infiltrates were determined in longitudinal sections of four valve specimens explanted after 12-15 months. Valves were immunohistochemically analyzed for presence of different subtypes of inflammatory cells. The expression of smooth muscle actin and connective tissue growth factor was determined. We observed a foreign body-type reaction accompanied by severe fibrosis and massive neointima formation around decellularized porcine valve wall, whereas the equine pericardial patch remained separated from porcine layer and acellular. Re-cellularization of decellularized matrix was low, and neovascularization was observed only in the neointima and scar tissue. Inflammatory infiltrates, composed mainly of T cells, B cells, and plasma cells, as well as the presence of dendritic cells, macrophages, and mast cells were detected in the tissue surrounding the porcine matrix. In the fibrous tissue, overexpression of connective tissue growth factor was observed. The leaflets remained functional, with normal endothelialization and no degenerative changes. Control pre-implant samples of Matrix P plus valve revealed incomplete decellularization of porcine matrix, which may have contributed to increased immunogenicity of these conduits. Early obstruction of decellularized Matrix P plus valve is associated with massive inflammatory reaction and exaggerated fibrotic scaring around porcine conduit wall. Detailed studies will be necessary to determine factors that contribute to remnant immunogenicity of decellularized grafts.

Right hemi-reconstruction of the left atrium using two equine pericardial patches for recurrent malignant fibrous histiocytoma: Report of a case

We report a case of recurrent malignant fibrous histiocytoma (MFH) in the left atrium, treated by removal of the tumor and the right half of the left atrium, which was reconstructed with two equine pericardial patches. Postoperative echocardiography showed patent right pulmonary veins and a properly shaped left atrium. The patient survived for 3 years after the operation with no cardiac symptoms.

Regeneration potential of decellularized equine pericardial patches implanted into the aortic position of the juvenile sheep model

Objectives: In the past several studies showed the successful use of decellularized tissue in the pulmonary circulation. This study, however was performed to evaluate if a newly developed decellularized equine pericardial patch can be used in the systemic circulation.

Bland‐white‐garland syndrome demonstrated by multislice computed tomography

In a 44-year-old woman admitted due to exertional anginasymptoms, diagnostic coronary angiography (Fig. 1) demon-strated an enlarged right coronary artery with profuse septalcollaterals communicating with the left anterior decendingand left circumflex arteries, and finally draining into the pul-monary artery (PA) via the left main coronary artery (LMCA).Multislice computed tomography (Fig. 2) showed an anoma-lous connection between the LMCA and the PA, further con-firming the diagnosis of Bland-White-Garland syndrome. Thepatient later received bypass surgery and the orifice of LMCAwas repaired with an equine pericardial patch from inside ofthe main PA. Finally, the patient recovered uneventfully.

Ross procedure in an infant weighing 4.5 kg

A 6 month-old male infant (weight: 4.5 kg) with congenital aortic stenosis underwent aortic valve replacement with a pulmonary autograft (Ross procedure). The right ventricular outflow tract (RVOT) was reconstructed with a polytetrafluoroethylene (PTFE) -valved equine pericardial conduit. At the age of 5, re-RVOT reconstruction with an equine pericardial patch bearing a PTFE monocusp was required because of severe pulmonary stenosis resistant to 2 attempts of percutaneous transluminal pulmonary valvotomy. Currently, at the age of 8, the degree of aortic regurgitation is trivial and the pulmonary autograft is free of functional deterioration despite somatic growth.

Late Perforation of the Aortic Root by an Atrial Septal Defect Occlusion Device

A 55-year-old woman was admitted to the emergency unit with severe dyspnea. Oral history revealed acute chest pain and collapse at home, which led to the tentative diagnosis of an acute aortic dissection. The electrocardiogram was normal. Transthoracic echocardiography showed a massive pericardial effusion (PE), no dissection flap, and a competent aortic valve. A computed tomographic scan was initiated. Meanwhile, evaluation revealed that the patient had undergone a percutaneous catheter occlusion of a persistent foramen ovale with an atrial septal defect occluder system device (D) 4 years before. The device could be located by computed tomographic scan through intensive roentgenogram reflection from its metal struts (Fig 1A; LA = left atrium; RA = right atrium). During scanning, the patient's hemodynamics deteriorated rapidly, necessitating mechanical resuscitation. An immediate paraxiphoidal pericardiocentesis was performed. The drainage showed fresh arterial blood. After hemodynamic recovery the patient was transferred immediately to the operating room. Intraoperative transesophageal echocardiography displayed an echogenic structure projecting on the cranial aspect of the interatrial septum in close proximity to the aorta (AO; Fig 1B). After pericardiotomy and removal of clots and fresh blood, arterial bleeding originating from a small perforation (2 mm) of the aortic root at the noncoronary sinus of Valsalva could be identified (Fig 2A). Moreover, the tip of a metal strut (S) penetrating the roof of the left atrium (LA)—without bleeding—directly opposite from the aortic perforation was visible. The aortic perforation was closed by a suture reinforced with autologous pericardium (P). By a second operation 1 week later, the device was removed (Fig 2B) electively by using cardiopulmonary bypass. For avoiding massive tissue damage, special tools provided by the manufacturer to disconnect the device were necessary. The atrial septal defect was closed with an equine pericardial patch. After an uneventful course, the patient was discharged home on the eighth postoperative day.

Traumatic pericardial rupture involved with complication by blunt chest trauma

A 65-year-old man who had sustained a blunt chest trauma in a traffic accident demonstrated a mass in the left hilum by chest radiography. Emergency surgery demonstrated a rupture of the left-side pericardium with herniation of the heart into the left pleural cavity along with a right ventricular rupture. The tear in the right ventricle was sutured using 4-0 polypropylene with felt and the pericardial rupture was repaired with an expanded polytetrafluoroethylene sheet. A 31-year-old man who had been crushed against a tree while skiing 5 years and 6 months earlier was diagnosed as having severe tricuspid valve regurgitation and tricuspid valve replacement was performed. Large left pericardial defect was found and repaired with an equine pericardial patch. In both cases, a bridging of phrenic nerve was found in the pericardial defect that was regarded as a traumatic rupture.

Cyanosis Caused by a Huge Obstructive Right Ventricular Fibroma.

Cardiac fibromas are rare lesions which occur more often in infants and children than in adults. These tumors are benign proliferations of connective tissue most often found in the left ventricular myocardium or septum. In an 8-month-old infant with cyanosis and progressive exertional dyspnea, a huge cardiac tumor obstructing the right ventricular outflow tract (RVOT) was diagnosed by means of 2-dimensional echocardiography and cardiac catheterization. At surgery, a whitish gray solitary tumor measuring 5.0 x 4.5 cm could be well visualized. It was nearly totally resected, and the RVOT was reconstructed with an Equine pericardial patch. Histologic examination classified the tumor as a fibroma. Although surgical mortality in cardiac fibroma with RVOT obstruction is extremely high, early diagnosis and prompt excision of the tumor is mandatory in relieving its dangerous symptoms.

As originally published in 1992: updated in 1999 by

A new technique is described to repair aortopulmonary window with total defect in an 8-day-old baby. Because we expected the future growth of aorta, we used the anterior wall of the pulmonary artery as a large flap to reconstruct the posterolateral aortic wall. An equine pericardial patch was used to repair the defect in the pulmonary artery. This is a logically effective method for aortic reconstruction in a neonate with a large aortopulmonary septal defect.

Sandwich repair with two sheets of equine pericardial patch for acute posterior post-infarction ventricular septal defect.

A 74-year-old man, who had posterior post-infarction ventricular septal defect, was treated successfully by early surgical repair with a sandwich technique involving two sheets of equine pericardial patch. In this technique the ventricular septal defect (VSD) was exposed through a trans-infarction approach. The inside patch covered the VSD and ventriculotomy from the inside. The outside patch generously covered the infarcted myocardium. The two patches completely sandwiched the infarcted myocardium including the VSD and ventriculotomy with eighteen interrupted sutures. This technique ensures strong fixation of the VSD, reducing the risk of bleeding and recurrence of VSD, and also maintains the proper shape and size of the left ventricle without the danger of ventricular aneurysm formation.