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At least 19 recordsLinked to original sources
PubMed1977

Failure of knitted dacron as an arterial prosthesis.

The incidence of failure of knitted Dacron arterial prostheses is thought to be significantly greater than that reported in the literature. Five cases of immediate and late defects in grafts of various manufacture are reported and a sixth case is discussed. The development of increased porosity to achieve more complete graft healing is thought to play a role in both early and late graft failure. Although the precise etiologic mechanisms are yet to be determined, the Dacron fibers were noted to become separated with subsequent widening of the graft interstices with resulting hemorrhage through the "intact" prosthetic material. Related theories of explanation are reviewed, and guidelines for study of these defective prostheses are suggested. It is essential that this complication of arterial grafting be recognized and that pertinent clinical experiences be documented in the surgical literature.

Aged↗
PubMed1979

Arthrodesis of the knee following failed total knee arthroplasty.

In forty-five patients, who had an arthrodesis because of failed total knee arthroplasty, the cause was infection in forty, instability in two, failure of the prosthesis in two, and loosening in one. The arthrodesis succeeded in twenty-nine (81%) of thirty-six patients who had had a minimally or partially constrained arthroplasty and in five (56%) of nine who had had a hinge-type prosthesis inserted. The reasons for failure were severe bone loss, persistent sepsis, and loss of bone apposition after manipulation. The technique of arthrodesis did not seem to influence the final result. External fixation most commonly had to be used because of the infections and the device was kept in place for an average of ten weeks, after which immobilization in a cast was used until the arthrodesis healed.

Adult↗
PubMed2026

Convergent methodologies in prosthetic joint infection research: integrating transdisciplinary approaches to understand and prevent biofilm-driven failure of orthopaedic prostheses.

Prosthetic joint infections (PJIs) remain among the most devastating complications of arthroplasty, imposing substantial clinical, economic and patient burdens. Although culture-based diagnostics underpin current clinical practice, PJIs are biofilm-driven infections shaped by taxonomic diversity, spatial organization, host responses and surface interactions, meaning conventional approaches provide only a partial and often decontextualized view of the infection process. We examine how convergent methodologies can transform PJI research by integrating approaches that have traditionally been studied in isolation, including sequencing, transcriptomics, metabolomics, advanced imaging and culture-based characterization. We discuss how whole-genome sequencing, shotgun metagenomics, transcriptomic and metabolomic approaches resolve pathogen identity, functional activity and adaptive persistence and how cross-scale imaging and spatial biology techniques reveal where microbes colonize, interact and survive across implant surfaces. We highlight emerging opportunities to unify these datasets into coherent frameworks that capture both the molecular and physical dimensions of PJIs. Integrating these complementary approaches will enable a multi-layered understanding of PJIs that link composition, function and spatial organization. Ultimately, this provides a foundation for predictive diagnostics, precision antimicrobial strategies and improved implant design and supports a shift towards more effective, mechanism-informed management of implant-associated infection.

Prosthesis-Related Infections↗
PubMed1978

Experience with the Melbourne knee prosthesis, based on the first 35 operations over a three-year period.

The Melbourne knee prosthesis is an improved hinge prosthesis. Its component parts are constructed of a chrome cobalt alloy and ultrahigh molecular weight polyethylene. The hinge has a range of flexion of 120 degrees, and while flexed, can rotate 15 degrees in either direction. Over the past three years a total of 45 prostheses have been inserted in patients with chronic degenerative arthritis of the knee joints. This survey covers the first 35 operations. The most gratifying result has been a dramatic relief of pain in 87.5% of patients. There have been few complications, and no prosthesis has had to be removed. There have been no mechanical failures of the prosthesis itself.

Adult↗
PubMed1976

[Results of isolated aortic valve replacement].

Progress in surgical technique and decreased early and late postoperative risk should lead to a modification in the indications for aortic valve replacement, before irreversible myocardial changes have definitively compromised the result of surgery. One hundred and seventy aortic valve replacements (100 pure or predominant aortic stenoses, 70 cases of aortic insufficiency) were carried out by the same surgeon over a period of 4 years with a minimum follow-up of one year and average of 25.4 months, using à Bjork prosthesis or a homograft. Early postoperative mortality was 5.3%, not differing from that associated with other types of valve replacement (mitral, polyvalvular). It is related more directly to surgical technique than to preoperative prognostic factors. Late mortality was 8.1%. Almost one third of these late deaths were related to the surgical technique or to the model of aortic prosthesis used. Stage IV cardiac failure plays a pejorative role in this late mortality, whilst no prognostic role could be demonstrated with respect to angina, meancardiac surface, Sokolow index, mean pulmonary artery pressure or diastolic pressure in the left ventricule. One year after surgery there was found to be a significantly important decrease in the Sokolow index and a modest decrease in mean radiological cardiac surface area. Beyond one year, no further improvement was seen. The majority of the patients surviving surgery had a good functional result since only 1% of the aortic stenosis patients and 7% of the aortic insufficiency group remained in stage III or IV cardiac failure. 78% of the patients who were working before operation were able to resume their professional activity after an average period of 6.2 months. However only 40% of the patients with stage IV failure who underwent surgery could return to work.

Aortic Valve↗
PubMed1978

Failure of Dacron prostheses caused by structural defect.

Intrinsic prosthetic failure is quite uncommon since the advent of Dacron prostheses. Only 24 cases of arterial prosthetic failure have been described in the literature. Our experience consists of two additional failures of knitted Dacron prostheses. The first patient developed aortojejunal fistula due to a defect of the aortic prosthesis 6 years after resection and replacement of an abdominal aortic aneurysm. The analysis of the graft revealed a defect in the form of a dropped stitch, which caused a weak spot where the prosthesis was able to be torn apart longitudinally. The second patient had femoropopliteal bypass and 6 years later developed degeneration with aneurysmal formation of the entire length of the prosthesis. Optical microscopy of this prosthesis exhibited mostly transverse failures which were coincident with valleys of the corrugated prosthesis. This was indicative of a defect that rendered the corrugation root too weak to withstand normal arterial pressures. This presentation emphasizes the seldom and serious complication of prosthetic failure due to defect of the prosthetic material. Details of scanning electron microscopy of the prosthesis, clinical presentation, angiography, and pathological findings with treatment also are discussed.

Aorta, Abdominal↗
PubMed1976

Challenge to conventional treatment for myocardial failure-mechanical assist.

Use of a prosthesis for temporary or permanent circulatory support in left ventricular failure has been investigated by our group for over 12 years. Experiences with both a U-shaped mechanical auxiliary ventricle (MAV) and the intraaortic balloon pump showed that in-series devices can stabilize the failing circulation. Studies with a MAV based on the balloon pump, the dynamic aortic patch (DAP) indicated that this system too is hemodynamically effective. In addition, data from extensive in vivo studies indicated that when its intravascular surface is made of Electrolour (Dacron velour backed by polyurethane with a negative electrical charge), the frequency of thromboembolism is greatly diminished. Following initial activation of the DAP in a patient with advanced chronic congestive failure, his hemodynamic parameters rapidly approached normal values: mean pulmonary artery and end-diastolic pressures were reduced, cardiac output increased, and myocardial metabolism changed from anaerobic to aerobic. The patient's cardiac function gradually improved, allowing his return to his home. The patient died on the 96th postoperative day after three months of improved cardiac function. Autopsy disclosed the DAP to be functional. A stable fibrin layer had formed on its intravascular surface; there were no signs of embolization. The DAP represents a promising approach to long-term ventricular support. For more than twelve years, our group has been interested in the possibility of using a mechanical prosthesis, not for total heart replacement, but rather for partial temporary or permanent circulatory support. In the first several years of work following this approach, we concentrated on the development of a permanently implantable system for in-series ventricular assistance. This work led to the study of several configurations of a mechanical auxiliary ventricle which gave effective circulatory support in laboratory and clinical studies [1,2]. The problem of achieving satisfactory interaction between blood and prosthesis was not resolved in these studies, but we were sufficiently encouraged by the hemodynamic effects to look into the possibility of working with the temporary support system initially proposed by Moulopoulos, Topaz, and Kolff [3].

Animals↗
PubMed1978

Valve placement in the ventricular apex for complicated left ventricular outflow obstruction.

Successful correction of severe valvular calcific aortic stenosis is described in which a stented porcine aortic heterograft was placed in the ventricular apex. Creation of a double outlet is a valid alternative approach to relieve left ventricular hypertension, and indication for such a procedure may be encountered unexpectedly. Intramyocardial placement of a durable tissue valve provides a simple and effective option for the cardiac surgeon.

Aged↗
PubMed1978

Primary reconstruction of the mandible with a wire mesh prosthesis.

A stainless steel wire mesh prosthesis was used as a primary mandibular replacement in 102 patients following resection of malignant neoplasms arising in the head and neck. In 67 patients the prosthesis was considered successful. Failure of the host to tolerate the prostheses was associated with history of previous irradiation, extensive resections, and the loss of distant skin flaps used for coverage of the prosthesis. But the prosthesis is tolerated by the host in 90% of the cases if it is inserted in a non-irradiated bed, covered with local tissues, and the resection is limited to the maxillo-oral complex only.

Follow-Up Studies↗
PubMed1977

Phonocardiographic and echocardiographic features of Lillehei-Kaster mitral prosthesis.

Fifteen patients were studied with phonocardiography (phono) and echocardiography (echo) three to 13 months after mitral valve replacement with Lillehei-Kaster mitral valve prostheses. Echo measurements in all patients included prosthesis excursion (DE), opening velocity (OV), closing velocity (CV), and Q-to-mitral prosthesis closure (Q-MPC). In five patients, further, echo measurements included isometric contraction period (ICP), left ventricular ejection time (LVET), and time to completion of aortic valve opening (TCAO). Phono measurements in all patients included pre-ejection period (PEP), LVET, and PEP/LVET. Further phono measurements in the same five patients in whom further echo measurements were performed included Q to first heart sound (Q-S1), ICP, and isometric relaxation period (IRP). Phono and echo measurements were done sequentially. The echo results showed widespread values for DE, OV and CV with no correlation between clinical state, size of prosthesis, or postoperation duration. There was a positive correlation between CV and OV, r + 0.65. Q-MPC by echo averaged 72 msec, which is longer than reported values for Q-to-mitral valve closure in normal people. Similarly, ICP by echo was shorter than ICP by phono in every patient. Of the phono measurements IRP was shortest (45 msec) in one patient in congestive heart failure with a possible prosthesis malfunction. We conclude that echo- and phonocardiography are useful tools in evaluating mitral prosthesis function, but because normal values are widespread, individual measurements may be useful for followup in the same individual. Precise measurement of subdivisions of systolic intervals are now possible with these techniques.

Adult↗
PubMed2026

Influence of endodontic access on the fracture resistance, retention and microleakage of full-coverage restorations in vitro: A systematic review and meta-analysis.

BACKGROUND: Endodontic access through retained full-coverage restorations (FCRs) is a preferred option for patients because of its high cost-effectiveness. However, the clinical performance of FCRs after repaired access cavity remains insufficiently characterized. This systematic review investigates the effects of endodontic access cavity preparation through retained FCRs on fracture resistance, retention, and microleakage based on in vitro studies. METHODS: A comprehensive search was performed in PubMed, Web of Science, and Scopus databases. Studies investigating the influence of endodontic access on the fracture resistance, retention, and microleakage of FCRs were included. Two independent reviewers conducted study selection, data extraction, and risk-of-bias assessment using the QUIN tool. Meta-analysis was employed to estimate fracture resistance and retention, with sensitivity analysis and subgroup evaluation also performed. Microleakage was summarized qualitatively. RESULTS: Twentythree studies were included: fracture resistance (n = 15), retention (n = 5), and microleakage (n = 3). Endodontic access significantly reduced fracture resistance for zirconia (p = 0.0002) and lithium disilicate (LD) restorations (p = 0.007), but not for resin-matrix ceramic (RMC) restorations (p = 0.25). Abutment tooth type contributed to heterogeneity within the LD and RMC subgroups. Retention was significantly reduced when access cavities were left unrepaired (p = 0.03), whereas appropriate repair protocols restored or enhanced retention relative to baseline. Accelerated aging increased microleakage in retained FCRs. Surface pretreatments and flowable resin liners tended to reduce microleakage, but findings were inconsistent. CONCLUSIONS: Endodontic access significantly reduces fracture resistance of zirconia and LD FCRs, whereas RMC restorations show no significant change. Appropriate repair protocols can restore or improve retention, potentially exceeding original values. Limited evidence suggests that effective sealing is achievable with appropriate materials. However, well-designed and in-vivo researches are needed to provide more detailed clinical guidance. CLINICAL SIGNIFICANCE: When performing endodontic access through retained FCRs, reduced fracture resistance must be carefully considered for zirconia and LD restorations, while RMC restorations may be exempt from this concern. Loss of retention with access can be restored after repair. Surface pretreatment and flowable resin liners help decrease microleakage.

Humans↗
PubMed1977

Autogenous veins and velour dacron in femoropopliteal arterial bypass.

Sixty-five patients treated by femoropopliteal bypass in 1974 were surveyed; the mean follow-up time was 10.4 months. The one year cumulative patency rate for velour Dacron was 50 percent; this was less successful than were the results from a comparable group in which vein grafts were used (79 percent). These poor results were due principally to the high failure rate of velour Dacron in patients suffering from clinically severe ischemia. In these only one in four grafts remained patent. If a less than perfect arteriographic runoff was obtained, only one in three still functioned. These results occurred despite high intraoperative graft flows. It appears that velour Dacron may be acceptable in patients treated for claudication if no adequate vein is available. This prosthesis gives an unacceptably high failure rate in patients with severe ischemia.

Adolescent↗
PubMed1979

[Heart valve prostheses in children with reference to 95 cases].

Over a 10 year period, 95 children aged 15 years and less underwent replacement of one or several of their heart valves, usually by a Starr-Edwards ball prosthesis. The predominant pathology was rheumatic heart disease and the most commonly affected valve was the mitral. Severe symptomatology, heart failure, cardiomegaly and high wedged-capillary and pulmonary arterial pressures were practically constant findings. Operative mortality was low (3.2%) and the long-term mortality was 10 patients. With an average follow-up of 40 months, results were excellent in the great majority of patients, with complete regression of symptoms, cardiomegaly and high capillary and pulmonary arterial pressures. Anticoagulant therapy was not systematic and only half the series were so treated. Thromboembolic complications were rare, 5.5% patients, but only affected those without anticoagulant therapy. The problems of evolving rheumatic disease and, above all, of tricuspid incompetence, the persistence of which after surgery on the mitral valve seems to be a sign of advanced myocardial damage, are discussed.

Adolescent↗
PubMed1977

[Re-operations on patients with ball valve prostheses].

Out of 989 cases with a ball-valve prosthesis, 66 have been reoperated (6.7%). 2.9% of the cases reviewed annually have thus been reoperated. The main indications for reoperation were displacement (75.5%), malfunction (10.5%) which was related to a failure of the material of the prosthesis or to the deposition of fibrinous plaques, and associated lesions (14%) which were valvular, coronary or myocardial. There were multiple complications in 36 patients. The operative mortality was 31.8% (21.7% over the last two years). On statistical analysis, the significant risk factors were a previous history of bacterial endocarditis, grouping in Class IV of the NYHA classification, enlargement of the QRS complex (0.12 s), urgency of reoperation, and prolonged extracorporeal circulation (2 hours). The rapid fall in survival time was due in part to late deaths (16 patients). By way of contrast, the clinical result was satisfactory in 71% of the survivors. Analysis of the causes of failures has lead to a search for ways of preventing the necessity for reoperation.

Adult↗
PubMed1976

The sutureless aortic valve prosthesis: experience with and technical considerations for replacement of the early model.

Reoperation was performed in seven (16%) of 43 patients with early models of Magovern sutureless aortic valve prostheses, because of thromboembolism and ball variance. All patients survived reoperation with no major complications. Removal of the sutureless prosthesis was not difficult when an insertion tool of proper size was used. A scarred annulus remained which was favorable for the suturing of a new prosthesis. The incidence of disabling thromboembolism (42%) and poppet failure (21%) is high with these early models. When these complications occur, replacement of the prosthesis is recommended to prevent death or recurrent embolic episodes.

Adult↗