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PubMed1994

Does early micromotion of femoral stem prostheses matter? 4-7-year stereoradiographic follow-up of 84 cemented prostheses.

Roentgen stereophotogrammetry was used to measure the migration of the centre of the femoral head in 84 cemented Lubinus SP I hip arthroplasties (58 primary operations, 26 revisions). Four to seven years later, seven femoral components had been revised because of painful loosening. These implants showed greater subsidence, medial migration and posterior migration during the first two postoperative years than did the hips which had not been revised. Six months after operation, subsidence of more than 0.33 mm combined with a total migration of more than 0.85 mm predicted an increased risk of subsequent revision; the amount of subsidence at two years was an even better predictor. The probability of revision was greater than 50% if the subsidence at two years was 1.2 mm or more.

Adult↗
PubMed2005

Implant-supported facial prostheses provided by a maxillofacial unit in a U.K. regional hospital: longevity and patient opinions.

PURPOSE: The aim of this study was to acquire information on the types and longevity of implant-retained facial prostheses and the opinions of patients on several factors related to their prostheses. MATERIALS AND METHODS: A survey of 75 maxillofacial prosthetic patients currently under treatment and review at the Maxillofacial Unit, Morriston Regional Hospital was conducted through a 23-question postal questionnaire. These patients were selected as representative of a group of individuals receiving treatment or under review for the fabrication of maxillofacial prostheses. RESULTS: Of the prosthetic replacements, 83% were ear prostheses, 8% nose, 6% eye, and 2% combination prostheses. Of the 47 respondents, 8 (17%) reported that they were currently wearing their original prostheses. The remaining 39 (83%) respondents had all been provided with at least 1 replacement prosthesis. The mean lifetime of the prostheses was found to be 14 months (range: 4-36 months). The majority of replacement prostheses in this study were provided as a result of color fade or wear of the silicone material of the previous prosthesis. Individuals with no previous experience wearing a prosthesis had an unrealistic expectation of their prosthesis longevity, with a mean value of 17.8 months. In comparison, individuals with previous experience had reduced expectations, with a mean of 14.4 months. In terms of the patients' opinions of the overall quality of their prostheses, the results demonstrated that a large number of patients were satisfied. Thirty-five patients rated their prostheses as excellent and 9 as good. At 7-12 months, 4 patients rated their prostheses as excellent and 8 as good. At 13 months, 4 patients rated their prostheses as excellent and 5 as good. CONCLUSIONS: It is important that advice be given to patients on the expected average longevity of their prostheses, together with information on factors affecting the longevity (i.e., environmental staining, cosmetics, and cleaning regimes). In this study, 26% of the replacement prostheses were provided due to color fading of the original prosthesis. This highlights the need for continuing research in the development of materials used for the construction of facial prostheses with improved properties, and in particular, improved color stability.

Adolescent↗
PubMed2006

Valve replacement surgery in end-stage renal failure: mechanical prostheses versus bioprostheses.

BACKGROUND: The 1998 American College of Cardiology/American Heart Association Guidelines recommend mechanical prostheses for valve replacement in patients with end-stage renal disease requiring dialysis. The aim of the study is to evaluate the combined experience at two academic centers. METHODS: Sixty-nine valve replacements (aortic 40; mitral 22; multiple 7; 47 bioprostheses, 22 mechanical prostheses) were performed. Total follow-up was 128.7 patient-years (bioprostheses, 68.4; mechanical prostheses, 60.4). RESULTS: Patient populations were homogeneous, except for age (bioprostheses greater than mechanical prostheses, p = 0.012), previous myocardial infarction (bioprostheses greater than mechanical prostheses, p = 0.040), and concomitant CABG (bioprostheses greater than mechanical prostheses, p = 0.019). A survival advantage was observed in favor of mechanical prostheses (p = 0.0299) at 5 years. Freedom from valve-related complications at 5 years was calculated for thromboembolism plus thrombosis plus hemorrhage (bioprostheses, 93.0% +/- 3.9%; mechanical prostheses, 76.4% +/- 12.7%), thromboembolism excluding thrombosis (bioprostheses, 93.0% +/- 3.9%; mechanical prostheses, 88.9% +/- 10.5%), and hemorrhage (bioprostheses, 100%; mechanical prostheses, 95.2% +/- 4.7%). One case of structural valve deterioration occurred in the bioprostheses group at 95 months after surgery. Five-year freedom from all valve-related complications was 82.8% +/- 8.1% for bioprostheses and 76.4% +/- 12.7% for mechanical prostheses. CONCLUSIONS: Overall survival was poor. Differences between populations were related to age at operation and coronary artery disease. Structural valve deterioration was not accentuated with bioprostheses. Considering lack of homogeneity between prostheses groups there was no superiority of mechanical prostheses over bioprostheses in terms of freedom from composites of complications. Bioprostheses should be considered in the management of valvular disease in end-state renal disease patients.

Adult↗
PubMed2005

Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after mitral valve replacement.

OBJECTIVE: Predominant concerns of patients undergoing valve replacement surgery are risks of death, stroke, antithrombotic bleeding, and reoperation related to the replacement prosthesis. The purpose of this study was to compare valve-related reoperation, morbidity (permanent impairment), and mortality between bioprostheses and mechanical prostheses for mitral valve replacement. METHODS: Between 1982 and 1998, a total of 959 bioprostheses were implanted in 943 patients, and a total of 961 mechanical prostheses were implanted in 839 patients. Total follow-ups were 5730 years for bioprostheses and 5271 years for mechanical prostheses. Eight variables were considered as predictors of risk for the composites of valve-related complications. RESULTS: The linearized occurrence rates for valve-related reoperation were 3.7 events/100 patient-years for bioprostheses and 0.5 events/100 patient-years for mechanical prostheses ( P < .001), with all age groups differentiated except older than 70 years. Valve-related morbidity was undifferentiated for bioprostheses and mechanical prostheses. Valve-related mortalities were 1.7 events/100 patient-years for bioprostheses and 0.7 events/100 patient-years for mechanical prostheses ( P < .001). Predictors of valve-related reoperation were age and valve type. The only predictor of valve-related morbidity was age, whereas age and valve type were predictors for valve-related mortality. Actual freedom from valve-related reoperation favored mechanical prostheses in all age groups except older than 70 years (91.7% +/- 2.0% for bioprostheses at 15 years and 96.7% +/- 1.5% at 12 years for mechanical prostheses). Actual freedom from valve-related morbidity was not different between bioprostheses and mechanical prostheses. Actual freedom from valve-related mortality favored mechanical prostheses in all groups except older than 70 years. CONCLUSION: Comparative evaluation gives high priority in mitral valve replacement for mechanical prostheses relative to bioprostheses for freedom from valve-related reoperation and valve-related mortality but not valve-related morbidity. Freedom from valve-related reoperation and valve-related mortality favors mechanical prostheses for all age groups except older than 70 years. Valve-related morbidity, due to neurologic or functional impairments, does not differentiate between bioprostheses and mechanical prostheses.

Adult↗
PubMedDate not supplied

Regurgitant flow in apparently normal valve prostheses: improved detection and semiquantitative analysis by transesophageal two-dimensional color-coded Doppler echocardiography.

In 128 patients with apparently normally functioning prosthetic valves (n = 136) in the aortic position (n = 79) and the mitral position (n = 57), the prevalence of transprosthetic regurgitant flow was studied by use of transthoracic and transesophageal two-dimensional color-coded Doppler echocardiography. With the transthoracic approach, regurgitant flow was detected in early systole or diastole for 28% of the mitral prostheses and for 29% of the aortic prostheses. With transesophageal color-coded Doppler echocardiography, regurgitant jets were visualized for 95% of the mitral prostheses and for 44% of the aortic prostheses. In 40% of the Björk-Shiley prostheses and 88% of the St. Jude Medical prostheses in the mitral position, more than one jet with an eccentric origin was detected, whereas in bioprostheses only one centrally localized regurgitant jet was noted. The regurgitant jet length was 22 +/- 2 mm in mitral prostheses and 12 +/- 2 mm in aortic prostheses. The jet area was 154 +/- 31 mm2 in mitral prostheses and 61 +/- 26 mm2 in aortic prostheses. Jets of this size and frequency have to be considered a normal finding and the equivalent of regurgitant flow known from in vitro studies. We conclude that only transesophageal color-coded Doppler echocardiography seems to be a reliable method for following up mitral valve prostheses to detect and differentiate regurgitant jets. For aortic valve prostheses the advantage of transesophageal color-coded Doppler echocardiography does not seem to be as obvious as the advantage for mitral prostheses.

Adolescent↗
PubMed2003

Implant-supported fixed cantilever prostheses in partially edentulous arches. A seven-year prospective study.

The purpose of the following study was to evaluate the medium- to long-term prognosis of implant-supported cantilever fixed prostheses, and to establish to what degree this is influenced by factors such as length, type of cantilever (mesial or distal), and opposite dentition versus cantilever prostheses. This study was performed on a sample of 38 partially edentulous patients treated between January 1994 and March 2001 with 49 partial cantilever fixed prostheses supported by 100 implants. Marginal bone resorption (MBL) has been studied and used as a reference parameter to define therapeutic success. The MBL measurement was made possible by transposing X-ray images of patients selected on a PC and then using a software program. Statistical analysis was carried out for possible correlation between peri-implant bone resorption and the parameters considered in this study: length and type (mesial or distal) of cantilever and opposite dentition to cantilever prostheses. Seven years after loading cantilever prostheses, the overall cumulative implant survival rate (OCSR) was 97%, and the prostheses success rate is 98%. Mesial cantilever prostheses registered a lower success rate (97.1%) than distal cantilever prostheses (100%). Furthermore, a better prognosis was not observed when the opposite dentition of the prostheses comprised natural teeth, or fixed prostheses on natural teeth, when compared with the cases in which opposite teeth were implant-supported fixed prostheses. The authors concluded that medium-term prognosis of implant-supported cantilever fixed prostheses and traditional implant-supported fixed prostheses was comparable. However, a thorough pre-treatment analysis of risk factors regarding implant-supported prosthesis survival is important.

Adult↗
PubMed1992

Seeding of enzymatically derived and subcultivated canine endothelial cells on fibrous polyurethane vascular prostheses.

Fibrous polyurethane (FPU) prostheses with or without fibronectin coating and gelatin impregnation and FPU prostheses with or without fibronectin coating were seeded with 4.8 x 10(5) subcultivated dog endothelial cells per cm2 prosthesis. Expanded polytetrafluoroethylene (ePTFE) prostheses with and without fibronectin coating served as controls. The numbers of cells retained on uncoated polyurethane prostheses were minimal but increased with fibronectin coating and/or gelatin impregnation. Adhering cells were predominantly round in shape and few cells were seen stretched over the prosthetic fibres. Optimum numbers of cells were found in prostheses impregnated with gelatin and coated with fibronectin, where almost all the cells were stretched forming a confluent monolayer. In ePTFE prostheses only minimal numbers of cells were retained but in the fibronectin-coated prostheses a high cell count was noted. Gelatin-impregnated and fibronectin-coated FPU prostheses, as well as ePTFE prostheses coated with fibronectin, were additionally perfused in vitro after seeding under nearly physiological conditions for 1 h. Cells in the FPU prostheses were still present after perfusion, whereas all the cells in the ePTFE prostheses were lost from the inner surface. It is concluded that FPU prostheses impregnated with gelatin and coated with fibronectin are a suitable substrate for subcultivated endothelial cells to be seeded on. The cells remained at the surface even after 1 h in vitro perfusion with tissue culture medium under nearly physiological conditions. Further research including in vivo implantations is indicated.

Animals↗
PubMed2005

Cinefluoroscopic assessment of mechanical disc prostheses: its value as a complementary method to echocardiography.

BACKGROUND AND AIM OF THE STUDY: Many types of mechanical prostheses are used for heart valve replacement, but it is difficult to distinguish between them using transthoracic echocardiography. Hence, cinefluoroscopy complements the echocardiographic evaluation of cardiac prostheses. The aims of the present study were to: (i) describe the contribution of cinefluoroscopy in identifying different prostheses; (ii) compare gradients obtained by Doppler echocardiography with the opening angle of the discs assessed by cinefluoroscopy; and (iii) assess the ability of cinefluoroscopy to distinguish normal from dysfunctional prostheses. METHODS: A total of 229 mechanical disc prostheses was prospectively evaluated with cinefluoroscopy. Eight prosthetic valves (six aortic, two mitral) were excluded due to the coexistence of severe left ventricular dysfunction. Thus, the final analysis comprised 221 prosthetic valves (146 aortic, 75 mitral). RESULTS: Based on the characteristics of the ring and the discs, cinefluoroscopy identified 87 single-leaflet and 134 bileaflet prostheses. Disc motion allowed distinction to be made between normal and dysfunctional prostheses (opening angle: 74 +/- 13 degrees versus 49 +/- 18 degrees). Fluoroscopy could not define disc profile or the ring in 6% of aortic valves and in 26% of mitral prostheses. The technique could be used to identify the TriTechnologies and HP-Biplus valves, but could not provide data on prosthetic function due to radiolucency of the discs. Among the 146 aortic prostheses, Doppler echocardiography helped to identify 109 normal valves and 37 dysfunctional valves. Among 75 mitral prostheses, 54 normal and 21 dysfunctional prosthetic valves were identified. When both methods were correlated, the sensitivity, specificity and positive and negative predictive values of fluoroscopy to distinguish normal from malfunctioning prostheses were 83%, 80%, 89%, and 71%, respectively. CONCLUSION: Each prosthesis type has radioscopic characteristics that allow its identification. Fluoroscopy permitted rapid and easy evaluation of mechanical prosthetic valve function, and in most cases allowed a distinction to be made between normal and dysfunctional prostheses. The presence of high gradients by Doppler echocardiography, with normal opening angles by fluoroscopy, and without pannus on transesophageal echocardiography, is indicative of patient-prosthesis mismatch. Fluoroscopy was superior to echocardiography in identifying disc motion, whilst Doppler study allowed the measurement of gradients and areas, and semiquantification of regurgitation. Thus, cinefluooscopy rapidly provides valuable information which is complementary to that obtained by echocardiography.

Aged↗
PubMed1990

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.

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)

Adipose Tissue↗
PubMed1993

[Doppler echocardiographic evaluation of functional parameters of mechanical and biological valve prostheses].

We studied and compared functional parameters in 314 valvular prostheses. The following parameters have been calculated: mean transvalvular gradients for aortic and mitral prostheses and functional area by Pht (pressure half time) for mitral prostheses. All patients with important depression in myocardial function, tachycardia or malfunctioning prostheses were excluded. 173 prostheses were in aortic position and 141 in mitral position. Mitral prostheses were: 31 biological and 110 mechanical. We subdivided mechanical prostheses in monoleaflet (Omnicarbon, Sorin-Carbocast and Allcarbon, Medtronic, Bjork-Shiley) and bileaflet (Sorin-Bicarbon, St. Jude). These three groups were compared: mean transvalvular gradients and area showed no differences. Aortic prostheses were: 33 biological and 140 mechanical; mechanical prostheses were subdivided in two groups: monoleaflet (Sorin Allcarbon e Carbocast, Bjork-Shiley, Medtronic, Omnicarbon) and bileaflet (Sorin-Bicarbon, St. Jude). Mean transvalvular gradients of these three groups were compared within each group for every size: bileaflet prostheses demonstrated inferior gradients than biological and monoleaflet for 19-21 and 23 sizes; in superior sizes there were no significant differences. Further analysis showed a significant correlation among gradients and body surface area in the 21 size prostheses (p = 0.004). Bileaflet prostheses in this subgroup showed less increase in mean gradient with surface area than mechanical and biological ones.

Aortic Valve↗
PubMed1998

Coating PTFE vascular prostheses with a fibroblastic matrix improves cell retention when subjected to blood flow.

An investigation was made into the effect of blood flow on endothelial cells (EC) and mesothelial cells (MC) seeded on a vascular expanded polytetrafluoroethylene (ePTFE) prosthesis coated with a fibroblastic matrix. Endothelial cells were obtained from the external jugular vein and MC from the omentum. To test the performance of prostheses, a custom designed, femoral "ex vivo" circuit was developed in mongrel dogs. Four study groups were established: a control group, A1, where prostheses were uncoated and seeded with EC; a second control group, A2, where prostheses were uncoated and seeded with MC; group B1 where prostheses were coated with a fibroblastic matrix and seeded with EC; and group B2 where coated prostheses were seeded with MC. All cells were labeled with 111Indium oxine (10 microCi/mL) before seeding. After the seeded cells had formed a monolayer on the ePTFE prostheses (which took approximately 24 h) the prostheses were placed in the "ex vivo" circuit. The rates of blood flow to which prostheses were exposed were measured at the point of inflow (117.5 +/- 12.50 mL/min, mean +/- SD) and outflow (72.6 +/- 14.3 mL/min). MC showed a greater baseline radionuclide uptake than did EC. The cells of groups B1 and B2 adhered sufficiently to the fibroblastic matrix and covered enough of the prosthetic surface to be positioned in the "ex vivo" circuit (76.90 +/- 8.24% surface covered in EC-seeded prostheses and 71.65 +/- 6.23% in MC-seeded prostheses). After exposure to blood flow the quantity of radionuclide-labeled cells and the prosthetic surface covered by them were greatly reduced though the fibroblast-coated prostheses showed greater cell retention.

Animals↗
PubMed2001

The acute phase response following implantation of triclosan-bonded vascular prostheses.

OBJECTIVE: Infection of prosthetic material is a major complication of vascular surgery. Therapy for it includes implantation of antimicrobial prostheses bonded with different antimicrobial agents. These agents may, however, induce an acute phase reaction following implantation in the host, thus compromising follow-up of the infection. It is not known whether the antimicrobial agent triclosan induces a significant acute phase reaction when bonded to vascular prostheses. METHODS: To study this, 34 adult swine weighing 20-30 kg were allotted randomly to the following groups: (1) controls with untreated prostheses, (2) control group with triclosan-bonded prostheses, (3) therapy group with untreated prostheses, local infection with Staphylococcus aureus surgical revision, and exchange with new, untreated prostheses, and (4) therapy group with untreated prostheses, local infection with S. aureus, surgical revision, and exchange with triclosan-bonded prostheses. Serum C-reactive protein (CRP) and haptoglobin values were determined during the 28-day period after surgery. The study was performed at the Institute for Surgical Research of the Ludwig Maximilian University School of Medicine in Munich. RESULTS: Normal ranges of serum CRP and haptoglobin values were 10.7+/-1.4 microg/ml and 2.5+/-0.3 mg/ml, respectively. Following implantation of untreated and triclosan-bonded vascular prostheses, significantly elevated serum CRP and haptoglobin values were observed. No significant differences between results with triclosan-bonded and untreated prostheses were observed in control or treatment groups. No correlation was found between acute phase reaction and the absence or presence of infection. CONCLUSIONS: Triclosan is the only antimicrobial agent that bonds to vascular prosthetic material without the need of a sealant. Our data indicate that vascular prosthesis implantation, whether untreated and triclosan-bonded, results in a significant acute phase reaction. No differences between antimicrobial and untreated prostheses were observed, independently of the absence or presence of infection. The antimicrobial agent itself did not induce a severe acute phase response and may, therefore, be used in patients at risk of infection.

Acute-Phase Proteins↗
PubMed1992

Ultrastructural analysis of pseudo-intimal hyperplasia of polytetrafluoroethylene prostheses implanted into the venous and arterial systems.

To evaluate and compare the pathogenesis of pseudo-intimal hyperplasia (PH) of venous and arterial prostheses, a segment of the inferior vena cava (n = 16) or abdominal aorta (n = 16) was substituted by a 3 mm internal diameter polytetrafluoroethylene tube graft (PTFE, 3 cm long, 30 microns in nodal distance) in albino rabbits. At designated time intervals (3-28 days) after the replacement, graft patency was examined and the dry weights of the intraluminal deposits measured as an indicator of the degree of PH. The harvested grafts were then subjected to an ultrastructural analysis by means of light microscopy (LM), and scanning electron and transmission electron microscopy (SEM, TEM). All the grafts remained patent during the entire observation period. The PH judged by the dry weight was significantly more extensive in the venous than in the arterial prostheses. The PH on day 28, observed by light microscopes was apparently most extensive in the mid-portion of venous prostheses but in the arteria prostheses it was mostly seen at the anastomotic sites. The lining of the intraluminal surface of the prostheses with endothelial-like cells observed by SEM was faster and more extensive in venous than in arterial prostheses. The process of PH in venous prostheses observed by TEM may be divided into the following steps: early thrombosis, phagocytosis of the thrombus, appearance of fibroblasts, growth of endothelial-like cells, appearance of smooth muscle cells, and pseudointimal thickening and proliferation of fibroblasts producing collagen fibrils. The process in arterial prostheses was essentially identical to that in venous prostheses but was much slower and less extensive. From these observations, it was concluded that the formation of PH occurs much faster in venous than in arterial prostheses, although the mechanism of PH is mostly identical in venous and arterial prostheses.

Animals↗
PubMed1993

Modern cardiac valve devices--bioprostheses and mechanical prostheses: state of the art.

The choice of bioprostheses and mechanical prostheses as valvular substitutes for cardiac valve replacement surgery has existed for over 20 years. The extensive developments over the past three decades have been introduced to reduce or eliminate valve related complications, namely thromboembolism, anticoagulant related hemorrhage, and structural failure, as well as to optimize hemodynamic performance. The biological valvular prostheses, namely porcine aortic or bovine pericardium, have been developed with tissue preservation, together with stent designs, that contribute to preservation of anatomical characteristics and biomechanical properties of the leaflets. The mechanical prostheses have been developed to eliminate structural failure, to facilitate prevention of blood status and thrombus formation, to facilitate radiopacity for evaluation of prosthesis function, and to facilitate intraoperative leaflet positioning. The implantation of the various present generation bioprostheses and mechanical prostheses requires special considerations to avoid technical complications and support ventricular performance. The studies of biological and mechanical prostheses, both randomized and nonrandomized, as well as specific prosthesis assessments, have contributed to the establishment of indications for types of prostheses. Bioprostheses have a high risk of structural failure and reoperation, while mechanical prostheses have a high risk of thromboembolism and anticoagulant hemorrhage. Within the bioprostheses population, the risk factors for structural valve deterioration are younger age and mitral prosthesis. Older patients (> 65 years of age) have a greater risk of valve related complications with mechanical prostheses, while younger patients (< 40 years of age) are at greater risk with bioprostheses. Comparison of large bioprostheses and mechanical prostheses populations by age groups revealed that regardless of the differences in the freedom from structural valve deterioration, the freedom from treatment failure (valve related mortality and permanent impairment from thromboembolism, anticoagulant hemorrhage, and septal emboli from prosthetic valve endocarditis) is essentially the same for mechanical prostheses and bioprostheses at 10 years. The quality of life is superior with bioprostheses, while patient survival and total valve related morbidity/mortality are similar with both types of prostheses.

Adult↗
PubMed2005

Tissue-engineered semi-microporous segmented polyetherurethane vascular prostheses.

We investigated the biocompatibility of semi-microporous segmented polyetherurethane (SPEU) that was coated with human microvascular endothelial cells. Three types of prosthesis were examined: (1) non-porous (control), (2) SPEU without a collagen coating (PNC) and (3) collagen-coated SPEU (PC). The attachment and proliferation of endothelial cells on SPEU (PNC and PC prostheses) was twice as great as in the control prostheses and endothelial cell adhesion in the PC prostheses was 1.4-times greater than in the PNC prostheses. The degree of endothelial cell coverage in the control prostheses was significantly lower than in the PNC and PC prostheses (P < 0.05), and there was no significant difference between the PNC and PC prostheses in the degree of endothelial cell coverage. As regards the retention of endothelial cells under simulated blood-flow conditions, the PNC prostheses exhibited a greater decrease in endothelial cell coverage, as compared to the PC prostheses (P < 0.05). Similarly, the PNC prostheses exhibited less platelet adhesion than the PC prostheses (P < 0.05). In summary, the semi-microporous SPEU offered better surfaces to anchor and culture for endothelial cells, and had superior anti-coagulant properties, as compared to nonporous SPEU. The coating of SPEU with collagen influenced both the attachment of endothelial cells and blood coagulation on the SPEU.

Blood Coagulation↗