Bovine pericardium retail preserved in glutaraldehyde and used as a vascular patch

Current trends in vena cava reconstructive techniques with major liver resection: a systematic review

PURPOSE

Historically, invasion of the inferior vena cava (IVC) represented advanced and often unresectable hepatic disease. With surgical and anesthetic innovations, IVC resection and reconstruction have become feasible in selected patients. This review assesses technical variations in reconstructive techniques and post-operative management.

METHODS

A comprehensive literature search was performed according to PRISMA. Inclusion criteria were (i) peer-reviewed articles in English; (ii) at least three cases; (iii) hepatic IVC resection and reconstruction (January 2015-March 2020). Primary outcomes were reconstructive technique, anti-thrombotic regimen, post-operative IVC patency, and infection. Secondary outcomes included post-operative complications and malignant disease survival.

RESULTS

Fourteen articles were included allowing for investigation of 351 individual patients. Analysis demonstrated significant heterogeneity in surgical reconstructive technique, anti-thrombotic management, and post-operative monitoring of patency. There was increased utilization of ex vivo approaches and decreased use of venovenous bypass compared with previously published reviews.

CONCLUSION

This review of literature published between 2015 and 2020 reveals persistent heterogeneity of hepatic IVC reconstructive techniques and peri-operative management. Increased utilization of ex vivo approaches and decreased use of venovenous bypass point towards improved operative techniques, peri-operative management, and anesthesia. In order to gain evidence for consensus on management, a registry would be beneficial.

FLIm-Guided Raman Imaging to Study Cross-Linking and Calcification of Bovine Pericardium

Bovine pericardium (BP) is a vascular biomaterial used in cardiovascular surgery that is typically cross-linked for masking antigenicity and enhance stability. There is a need for biochemical evaluation of the tissue properties prior to implantation to ensure that quality and reliability standards are met. Here, engineered antigen removed BP (ARBP) that was cross-linked with 0.2% and 0.6% glutaraldehyde (GA), and further calcified in vitro to simulate graft calcifications upon implantation was characterized nondestructively using fluorescence lifetime imaging (FLIm) to identify regions of interest which were then assessed by Raman spectroscopy. We observed that the tissue fluorescence lifetime shortened, and that Raman bands at 856, 935, 1282, and 1682 cm-1 decreased, and at 1032 and 1627 cm-1 increased with increasing GA cross-linking. Independent classification analysis based on fluorescence lifetime and on Raman spectra discriminated between GA-ARBP and untreated ARBP with an accuracy of 91% and 66%, respectively. Pearson's correlation analysis showed a strong correlation between pyridinium cross-links measured with high-performance liquid chromatography and fluorescence lifetime measured at 380-400 nm (R = -0.76, p = 0.00094), as well as Raman bands at 856 cm-1 for hydroxy-proline (R = -0.68, p = 0.0056) and at 1032 cm-1 for hydroxy-pyridinium (R = 0.74, p = 0.0016). Calcified areas of GA cross-linked tissue showed characteristic hydroxyapatite (959 and 1038 cm-1) bands in the Raman spectrum and fluorescence lifetime shortened by 0.4 ns compared to uncalcified regions. FLIm-guided Raman imaging could rapidly identify degrees of cross-linking and detected calcified regions with high chemical specificity, an ability that can be used to monitor tissue engineering processes for applications in regenerative medicine.

Mammalian Pericardium-Based Bioprosthetic Materials in Xenotransplantation and Tissue Engineering

Bioprosthetic materials based on mammalian pericardium tissue are the gold standard in reconstructive surgery. Their application range covers repair of rectovaginal septum defects, abdominoplastics, urethroplasty, duraplastics, maxillofacial, ophthalmic, thoracic and cardiovascular reconstruction, etc. However, a number of factors contribute to the success of their integration into the host tissue including structural organization, mechanical strength, biocompatibility, immunogenicity, surface chemistry, and biodegradability. In order to improve the material's properties, various strategies are developed, such as decellularization, crosslinking, and detoxification. In this review, the existing issues and long-term achievements in the development of bioprosthetic materials based on the mammalian pericardium tissue, aimed at a wide-spectrum application in reconstructive surgery are analyzed. The basic technical approaches to preparation of biocompatible forms providing continuous functioning, optimization of biomechanical and functional properties, and clinical applicability are described.

Surgical removal of part of an occluder to treat iatrogenic coarctation of the aorta: a case report

Background

Iatrogenic aortic stenosis is a serious complication and potentially fatal due to erosion of the aortic wall. Timely management is necessary to prevent complications.

Case presentation

A 2-year-old boy underwent surgery to remove part of an Amplatzer occluder after patent ductus arteriosus (PDA) device embolization in the thoracic aorta. He exhibited moderate to severe obstruction with erosion of the intimal layer of the aorta caused by the device, part of which was retrieved surgically with restructuring of the thoracic aorta segment and occluder remnant. The patient’s postoperative course was uneventful.

Conclusions

When possible, retrieving only part of an embolized device can be advocated because it reduces the risk of aortic and pulmonary artery damage.

Bovine pericardial extracellular matrix niche modulates human aortic endothelial cell phenotype and function

Xenogeneic biomaterials contain biologically relevant extracellular matrix (ECM) composition and organization, making them potentially ideal surgical grafts and tissue engineering scaffolds. Defining the effect of ECM niche (e.g., basement membrane vs. non-basement membrane) on repopulating cell phenotype and function has important implications for use of xenogeneic biomaterials, particularly in vascular applications. We aim to understand how serous (i.e., basement membrane) versus fibrous (i.e., non-basement membrane) ECM niche of antigen-removed bovine pericardium (AR-BP) scaffolds influence human aortic endothelial cell (hAEC) adhesion, growth, phenotype, inflammatory response and laminin production. At low and moderate seeding densities hAEC proliferation was significantly increased on the serous side. Similarly, ECM niche modulated cellular morphology, with serous side seeding resulting in a more rounded aspect ratio and intact endothelial layer formation. At moderate seeding densities, hAEC production of human laminin was enhanced following serous seeding. Finally, inflammatory marker and pro-inflammatory cytokine expression decreased following long-term cell growth regardless of seeding side. This work demonstrates that at low and moderate seeding densities AR-BP sidedness significantly impacts endothelial cell growth, morphology, human laminin production, and inflammatory state. These findings suggest that ECM niche has a role in modulating response of repopulating recipient cells toward AR-BP scaffolds for vascular applications.

Fiber-based fluorescence lifetime imaging of recellularization processes on vascular tissue constructs

New techniques able to monitor the maturation of tissue engineered constructs over time are needed for a more efficient control of developmental parameters. Here, a label-free fluorescence lifetime imaging (FLIm) approach implemented through a single fiber-optic interface is reported for nondestructive in situ assessment of vascular biomaterials. Recellularization processes of antigen removed bovine pericardium scaffolds with endothelial cells and mesenchymal stem cells were evaluated on the serous and the fibrous sides of the scaffolds, 2 distinct extracellular matrix niches, over the course of a 7 day culture period. Results indicated that fluorescence lifetime successfully report cell presence resolved from extracellular matrix fluorescence. The recellularization process was more rapid on the serous side than on the fibrous side for both cell types, and endothelial cells expanded faster than mesenchymal stem cells on antigen-removed bovine pericardium. Fiber-based FLIm has the potential to become a nondestructive tool for the assessment of tissue maturation by allowing in situ imaging of intraluminal vascular biomaterials.

The use of bovine pericardial patch for vascular reconstruction in infected fields for transplant recipients

Infectious vascular complications affecting transplant recipients may lead to severe morbidity and graft loss. This is a retrospective review of vascular repair with bovine pericardial patch (BPP) in infected fields for immunosuppressed patients. BPP was used as either a patch or an interposition graft. Five cases of arterial reconstruction in infected fields using BPP were performed. There were no complications related to bleeding, thrombosis, or recurrent infection. In our limited experience, the use of BPP as a vascular patch is successful, and it represents an alternative when vascular reconstruction is needed in the context of infected fields.

Effect of bovine pericardial extracellular matrix scaffold niche on seeded human mesenchymal stem cell function

Numerous studies have focused on generation of unfixed bovine pericardium (BP) extracellular matrix (ECM) for clinical application. However, the extent to which maintenance of native ECM niche is capable of directing behavior of repopulating cells remains relatively unexplored. By exploiting the sidedness of BP scaffolds (i.e., serous or fibrous surface), this study aims to determine the effect of ECM niche preservation on cellular repopulation using different scaffold generation methods. BP underwent either sodium dodecyl sulfate (SDS) decellularization or stepwise, solubilization-based antigen removal using amidosulfobetaine-14 (ASB-14). SDS scaffolds were toxic to repopulating human mesenchymal stem cells (hMSC). Scanning electron microscopy revealed distinct surface ultrastructure of ASB-14 scaffolds based on native BP sidedness. Basement membrane structures on the serous side stimulated hMSC cell monolayer formation, whereas fibrous side facilitated cell penetration into scaffold. Additionally, serous side seeding significantly increased hMSC adhesion and proliferation rate compared to the fibrous side. Furthermore, scaffold ECM niche stimulated sidedness dependent differential hMSC human leukocyte antigen expression, angiogenic and inflammatory cytokine secretion. This work demonstrates that ECM scaffold preparation method and preservation of BP side-based niches critically affects in vitro cell growth patterns and behavior, which has implications for use of such ECM biomaterials in clinical practice.

Evaluation of an established pericardium patch for delivery of mesenchymal stem cells to cardiac tissue

The present study has evaluated a commercial pericardial material for its capacity to assist as a natural extracellular matrix (ECM) patch for the delivery and retention of mesenchymal stem cells for cardiac repair. The repair of cardiac tissue with cells delivered by an appropriate bioscaffold is expected to offer a superior, long-lasting treatment strategy. The present material, CardioCel®, is based on acellular pericardium that has been stabilized by treatments, including a low concentration of glutaraldehyde, that eliminate calcification after implantation. In the present study, we have assessed this material using human bone marrow mesenchymal stem cells at various cell densities under standard, static cell culture conditions. The initial seeding densities were monitored to evaluate the extent of cell attachment and cell viability, with subsequent cell proliferation assessed up to 4 weeks using an MTS assay. Cell morphology, infiltration, and spreading were tracked using scanning electron microscopy and phalloidin staining. The efficacy of long-term cell survival was further assessed by examining the extent and type of new tissue formation on seeded scaffolds at 70 days; both type I and type III collagens were present in fibrillar structures on these scaffolds indicating that the seeded stem cells had the capacity to differentiate into collagen-producing cells necessary to repair damaged ECM. These data show that the CardioCel® scaffold is an appropriate substrate for the stem cells and has the potential to both retain seeded stem cells and to act as a template for cell propagation and new tissue formation.

The use of biological grafts for reconstruction of the inferior vena cava is a safe and valid alternative: results in 32 patients in a single institution

BACKGROUND

Resection and reconstruction of the inferior vena cava (IVC) is occasionally required in the surgical treatment of intra-abdominal tumours. IVC reconstruction can be performed with biological or synthetic graft material, with most centres preferring synthetic grafts. In spite of the potential advantages of biological grafts in terms of handling characteristics, and safety, very limited data are available about their use in patients requiring an IVC resection.

METHODS

Medical records of 32 patients who underwent an IVC resection and reconstruction from 1990 and 2011 with autogenous peritoneo-fascial (N = 22) and bovine pericardial (N = 10) grafts were reviewed.

RESULTS

A tangential resection with patch repair was performed in 10 patients, whereas in the remaining 22 it was necessary to resect and replace a segment or all of the retrohepatic IVC. A concomitant liver resection was performed in 14 patients, nephrectomy in 10 and pancreaticoduodenectomy in 2 patients. There were no acute or late complications related to graft thrombosis or infection. Three patients died as a consequence of multi-organ failure. Overall survival at 1 and 5 years was 78% and 48%, respectively.

CONCLUSIONS

The preferential use of synthetic grafts in IVC replacement is not evidence based. Selection of an appropriate prosthetic graft for IVC reconstruction should be based on the safety and its handling features. The use of biological grafts for IVC repair is a valid alternative to current synthetic materials and may in fact be superior in terms of biocompatability, ease of handling, reduced rate of infection and improved long-term patency without permanent anticoagulation.

[Glutaraldehyde-preserved and lyophilized bovine pericardium as materials for medialization of the vocal folds in an animal model]

INTRODUCTION

Glutaraldehyde-preserved bovine pericardium (GBP) and lyophilized GBP (LGBP) have been used successfully in repairing several anatomical defects, but their effectiveness and safety as implants to vocal cords (VC) have not been reported.

OBJECTIVE

The aim of this study was to evaluate the use of GBP and LGBP as materials for medialization thyroplasty, as well as to assess the endoscopic, macroscopic and microscopic VC changes after medialization in an experimental canine model.

MATERIAL AND METHODS

In 12 healthy mongrel dogs, the right VC were medialized using pericardium and the left with polytetrafluoroethylene (PTFE). Group 1 (n=6): GBP and Group 2 (n=6): LGBP. The surgical manoeuvrability of the implants was compared. The animals were evaluated clinically and endoscopically. Three months after surgery, the larynges were assessed macro- and microscopically.

RESULTS

Both GBP and LGBP implants showed better surgical manoeuvrability (Kruskal-Wallis, P=.005). Endoscopic and macroscopic studies showed no evidence of granulomas, absorption or extrusion of the implant. At the end of the study, greater thickness was observed in VC implanted with PTFE. Microscopically, all the VC developed fibrous capsules surrounding the implants and similar chronic inflammation reaction. The VC implanted with PTFE presented eosinophilic infiltration (Kruskal-Wallis, P<.05).

CONCLUSION

Both GBP and LGBP can be used as implants for VC medialization because they are biocompatible, have easy surgical manoeuvrability, do not suffer absorption, migration or extrusion and produce inflammation reactions similar to those of PTFE.