Patency in canine inferior vena cava grafting: Effects of graft material, size, and endothelial seeding

Herring, Malcolm B.; Gardner, A.B.; Peigh, Pamela S.; Madison, David; Baughman, Sally; Brown, John M.; Glover, John

doi:10.1067/mva.1984.avs0010877

Cited by 12 publications

(7 citation statements)

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“…The appropriate porosity, allowing for cell migration and supporting natural ECM (extracellular matrix) secretion, is important to graft patency as is a healthy endothelial layer. A canine study, which examined the effects of biomaterial and endothelial cell seeding revealed that simply applying endothelial lining in dacron and e-PTFE (expanded-Polytetrafluoroethylene) grafts was not a deciding factor for patency, but, the biomaterial used to construct the vessel played a significant role [6]. The study results concluded that isodiametric naturally harvested scaffolds performed best to maintain patency [6].…”

Section: Biomaterials For Vascular Tissue Engineeringmentioning

confidence: 99%

“…A canine study, which examined the effects of biomaterial and endothelial cell seeding revealed that simply applying endothelial lining in dacron and e-PTFE (expanded-Polytetrafluoroethylene) grafts was not a deciding factor for patency, but, the biomaterial used to construct the vessel played a significant role [6]. The study results concluded that isodiametric naturally harvested scaffolds performed best to maintain patency [6]. Graft porosity allows for cell adherence as well as migration and diffusion of important healing factors critical to the remodeling responses [7–9].…”

Section: Biomaterials For Vascular Tissue Engineeringmentioning

confidence: 99%

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Animal models of cardiovascular disease as test beds of bioengineered vascular grafts

Row

Swartz²,

Andreadis

2017

Drug Discovery Today: Disease Models

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The last two decades have seen many advances in regenerative medicine, including the development of tissue engineered vessels (TEVs) for replacement of damaged or diseased arteries or veins. Biomaterials from natural sources as well as synthetic polymeric materials have been employed in engineering vascular grafts. Recently, cell-free grafts have become available opening new possibilities for the next generation, off-the-shelf products. These TEVs are first tested in small or large animal models, which are usually young and healthy. However, the majority of patients in need of vascular grafts are elderly and suffer from comorbidities that may complicate their response to the implants. Therefore, it is important to evaluate TEVs in animal models of vascular disease in order to increase their predictive value and learn how the disease microenvironment may affect the patency and remodeling of vascular grafts. Small animals with various disease phenotypes are readily available due to the availability of transgenic or gene knockout technologies and can be used to address mechanistic questions related to vascular grafting. On the other hand, large animal models with similar anatomy, hematology and thrombotic responses to humans have been utilized in a preclinical setting. We propose that large animal models with certain pathologies or age range may provide more clinically relevant platforms for testing TEVs and facilitate the clinical translation of tissue engineering technologies by increasing the likelihood of success in clinical trials.

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Section: Biomaterials For Vascular Tissue Engineeringmentioning

confidence: 99%

Section: Biomaterials For Vascular Tissue Engineeringmentioning

confidence: 99%

Animal models of cardiovascular disease as test beds of bioengineered vascular grafts

Row

Swartz²,

Andreadis

2017

Drug Discovery Today: Disease Models

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“…Of these, one reported clinical patency at 5 months [19], one clinical and radiological patency at 8 months [20] and one an occlusion [21]. One animal study [22] involving 117 dogs compared the patency of Dacron with PTFE. All of the Dacron grafts occluded by 30 days, but the patency of the PTFE grafts was surprisingly low, at 28%.…”

Section: Commentmentioning

confidence: 99%

“…Both in vitro [23] and in vivo [24] studies comparing the thrombogenicity of Dacron with PTFE have shown that Dacron leads to the deposition of more fibrin and platelets. In animal studies with Dacron over the last 18 years, some have tried seeding the graft with endothelial cells to enhance patency in the venous system, with some statistically significant success recently, but no clinical trials as yet [22,25–27].…”

Section: Commentmentioning

confidence: 99%

Transitional cell carcinoma of the kidney invading the inferior vena cava, treated by excision and grafting, with a review of vena cava replacement

et al. 2003

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surgeon to remove part or all of the IVC [2]. In one case with complete obstruction of the IVC on venography before surgery the vena cava was excised from the level of the left renal vein down to the common iliac veins, and the natural collateral circulation via paravertebral and lumbar veins relied upon [3]. No comment was made about limb swelling after surgery, apart from the patient being alive and well 1 year afterward. In one case involving thrombectomy only with thrombus extending to the hepatic veins, a cardiopulmonary bypass and hypothermic circulatory arrest was used [4]. IVC INVOLVEMENTRenal cell cancers may involve the IVC in up to 10% of cases and the experience of operating on the IVC in a urological context arises from this area of surgery. It is seldom necessary to graft the IVC [5], but if the caval wall is invaded and there are few collaterals it may be required. Some indication as to whether or not the wall of the IVC is invaded may be gained from the diameter of the thrombus. A small study on 18 patients found that in all seven with an IVC diameter of ≥ 40 mm on CT there was extensive macroscopic and microscopic tumour invasion of the caval vessel wall at operation. In these cases the caval wall was resected with or without a synthetic PTFE patch graft. By comparison, in only two of 11 patients with a caval diameter of <40 mm was there vessel wall invasion requiring patch-grafting [6]. IVC GRAFTSThe first experimental attempts at grafting the vena cava were by Carrel and Guthrie in the early 1900s. In an extensive review in 1974, Scherck et al. [7] noted that prosthetic replacement of veins was too unreliable for routine clinical application, because the patency rates in animal models were inconsistent or low. The lowest success rates were in the infrarenal IVC and maintaining patency at this level became the focus of experimental work. The best success rates in experimental models in the 1950s and 1960s were with autologous artery and vein grafts, 46% of which were patent at follow-up. Synthetic grafts of Dacron or unexpanded PTFE had a 62% patency rate if an arteriovenous fistula was used. The latter were introduced by Stansel [8] in 1964, as a way of increasing flow through the graft. By contrast polyester or unexpanded PTFE grafts with no fistulae had patency rates of only 15% and 9%. However, this 15% patency rate for polyester was based on only 10 animals, and all these patency rates were based on numerous small and uncontrolled experiments. The article concluded that caval replacement was still a difficult and unsolved problem. PTFEIn 1972 the first animal experiments with expanded PTFE (Gore-Tex™) in the venous system appeared; in the arterial system the early ordinary PTFE grafts had aneurysmal dilatation. Gore-Tex has the inner extrusion supported by a thin outer membrane of higher density PTFE that gives greater bunting and suture holding strength [9]. No arteriovenous anastomosis or long-term anticoagulation was used. Patency rates in the IVC were high, in seven of nine piglets at 2...

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“…1°13 Another problem is low retention of seeded ECs on grafts; as few as 17% of seeded ECs reportedly remain adherent to implanted vascular prostheses 24 hours after implantation when the preclotting method of seeding is used} 4,~s Perhaps because of some or all of these problems, one study of EC seeding of polytetrafluoroethylene (PTFE) inferior vena cava (IVC) prostheses in dogs found no reduction of thrombus-free surface area after seeding. 16 In another study low-density seeding (with 2.5 to 4.5 × 104 EC/cm 2 of PTFE graft sur-face) was used on PTFE, and thrombus-ftee area was significantly improved when compared to unseeded PTFE conduits, yet complete EC coverage and freedom from grossly visible thrombus formation was not seen even 4 weeks after surgery, i7…”

mentioning

confidence: 99%

Rapid cellular luminal coverage of Dacron inferior vena cava prostheses in dogs by immediate seeding of autogenous endothelial cells derived from omental tissue: Results of a preliminary trial

Wang

Du²,

Li³

et al. 1990

Journal of Vascular Surgery

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Endothelial cell seeding methods might reduce the high failure rates of venous vascular prostheses, but low flow rates in venous vascular prostheses impose a need to protect early patency and to attain early endothelial cell coverage without waiting several weeks for relatively small endothelial cell innocula from autologous veins to form confluent linings. To obtain large number of autologous endothelial cells for high-density seeding, canine omental microvascular endothelial cells were harvested by collagenase digestion and density gradient centrifugation, with yields of 1.34 +/- 0.24 (SD) X 10(6) cells/gm of omentum (N = 8 harvests). Primary culture of a subfraction from each harvest showed the cell population to be dominated by factor VIII-related antigen-positive endothelial cells with only a few nonstaining cells (estimated to be 10% or less of total cell number) visible. Freshly harvested omental cells were seeded onto double velour knitted Dacron prostheses at densities of 5 X 10(5) cells/cm2 of graft luminal surface in an autologous plasma suspension by use of prior preclotting with cell-free autologous plasma, followed by endothelial cell seeding in autologous plasma, with plasma recalcification during endothelial cell instillation. Six seeded and two control (sham-seeded) vascular prostheses 5 cm long with 10 mm inner diameter were used as inferior vena cava interposition grafts. A distal arteriovenous fistula and aspirin (300 mg) and dipyridamole (50 mg orally every day) starting 3 days before surgery were used to protect early patency of all grafts. Seeded venous vascular prostheses were explanted for study at intervals of 1,5, and 10 days after surgery (N = 2 prostheses at each time); the two control venous vascular prostheses were explanted at 10 days. All venous vascular prostheses were patent at time of removal. In seeded venous vascular prostheses, light, scanning, and transmission electron microscopy showed emergence of numerous flattened endothelial cell-like cells on the luminal surface 24 hours after surgery, followed by formation of a confluent cellular lining without adherent platelets by 5 to 10 days after surgery. Control venous vascular prostheses, in contrast, remained covered by an irregularly thickened fibrin and red cell thrombus, which sometimes encroached on the lumen. Our results suggest that (1) omental tissue can furnish endothelial cells for high-density immediate seeding of venous vascular prostheses, and (2) that the method we used to combine features of both so-called high density "seeding" and "sodding" techniques offers both more rapid prosthesis coverage than the former and shorter intraoperative times for cell attachment to prostheses than the latter.(ABSTRACT TRUNCATED AT 400 WORDS)

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Patency in canine inferior vena cava grafting: Effects of graft material, size, and endothelial seeding

Cited by 12 publications

References 0 publications

Animal models of cardiovascular disease as test beds of bioengineered vascular grafts

Animal models of cardiovascular disease as test beds of bioengineered vascular grafts

Transitional cell carcinoma of the kidney invading the inferior vena cava, treated by excision and grafting, with a review of vena cava replacement

Rapid cellular luminal coverage of Dacron inferior vena cava prostheses in dogs by immediate seeding of autogenous endothelial cells derived from omental tissue: Results of a preliminary trial

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