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At least 37 records · Page 2Linked to original sources
PubMed1988

Early experience with a new collagen-impregnated aortic graft.

Standard knitted Dacron prosthetic grafts in the aortic position have performed well in terms of patency and durability, but require preclotting and lose their pliability with use. In an effort to overcome these problems, a collagen-impregnated double-velour knitted Dacron graft has been developed. This graft is impervious to blood, does not require preclotting, and maintains its pliability. During a 2 and one half year period, 590 of these grafts have been used at our institution for abdominal aortic replacement in both emergent and elective cases. Indications have included aneurysmal disease (67%), occlusive disease (30%), and failed previous aortic graft (3%). A bifurcated graft has been used in most cases (68%). The patient population has included 449 men and 141 women. Their median age is 68 years, with a range from 15 to 91 years. Seventy nine per cent of the patients experienced no perioperative complications. The remaining twenty one per cent have had a variety of complications, most of them cardiac or pulmonary, but none related directly to the graft. Twenty nine patients died in the perioperative period, for a mortality of 4.9 per cent. Late complications have been infrequent and in no cases directly related to the graft. There have been no graft-related late deaths. It is concluded that, at least in this early experience, there are no problems inherent in the use of this graft. Its pliability and the fact that it does not require preclotting are distinct advantages over previous Dacron grafts.

Adolescent↗
PubMed1995

[Progression of senile aortic valve calcification: echocardiographic and clinical assessment].

Factors involved in the progression of senile aortic valve calcification were evaluated by analyzing the clinical and echocardiographic characteristics of patients older than 69 years with senile aortic valve calcification. The patients were divided into three groups; group 1: 46 male and 40 female patients with calcification of one cusp and almost normal pliability of three cusps, group 2: 48 males and 55 female patients with calcification of two or three cusps, mildly reduced pliability of calcified cusps, and aortic valve area (AVA) > or = 2.0 cm2, group 3: 26 male and 31 female patients with calcification of two or three cusps, significantly reduced pliability of calcified cusps, and AVA < or = 1.5 cm2. There were no significant differences in age, weight, height, left ventricular dimension, or left ventricular wall thickness between these three groups. For male patients, the end-diastolic maximum left ventricular outflow tract dimensions (LVOT) in groups 1, 2, and 3 were 20 +/- 2 mm, 19 +/- 2 mm (p < 0.01 vs group 1), and 17 +/- 3 mm (p < 0.001 vs group 1, p < 0.01 vs group 2), respectively. For female patients, the LVOTs of groups 1, 2, and 3 were 18 +/- 2 mm, 16 +/- 2 mm (p < 0.001 vs group 1), and 16 +/- 2 mm (p < 0.001 vs group 1), respectively. Reduction in LVOT was not associated with left ventricular hypertrophy or decrease in dimension of aortic annulus. In female patients, the frequency of mitral annular calcification of group 3 was 61% [p < 0.05 vs group 1 (35%), p < 0.01 vs group 2 (25%)].(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2000

The effect of stimulus form and dimensions on the oral size illusion in humans.

Previous work has shown that individuals overestimate the diameter of holes presented to the tongue when they use their fingers to select matching holes from a range of comparators. This disparity is known as the oral size illusion. The hypothesis that this illusion arises from the greater pliability of the tongue surface compared with that of the fingertip was tested here. Two experiments were carried out on 64 participants. In experiment 1 (n=32), the stimuli were two sets of holes, 1 and 5 mm deep and 2.4, 5.6, 8.2, 12 mm dia. , which were presented to the tongue. The comparator was a series of holes 5 mm deep and 0.8-15 mm dia., which were explored manually. Participants significantly overestimated all diameters of the 1- and 5-mm deep stimulus holes (p<0.05). Apart from the 2.4-mm dia. holes, there were no significant differences between the illusions produced with the holes 1 mm and 5 mm deep (p0.7). In experiment 2 (n=32) individuals were tested with small cylinders ('pegs') 1 mm high and 2.6, 5.2. 7.6, 12.6 mm dia. and also with the four 5-mm deep stimulus holes used in experiment 1. The 'peg' stimuli presented to the tongue were matched against a similar set of 1-mm pegs, 2-18 mm dia., explored with the fingers. The comparator series for the 5-mm deep holes was the same as for experiment 1. Participants consistently overestimated the size of the 5-mm holes (p<0.001). However, there was no illusion with the peg stimuli (p=0.08), except for the 7.6-mm dia. stimulus (p<0.05). The results of experiment 1 did not support the experimental hypothesis that the oral size illusion was due to the greater pliability of the tongue surface. The result of experiment 2 suggests that the oral size illusion does not occur when peg stimuli are used instead of holes. The form and diameter of the stimulus is thus important in determining the magnitude of the oral size illusion.

Adolescent↗
PubMed1980

Rheumatic mitral stenosis:cross-sectional echocardiographic analysis.

Twenty-one patients with rheumatic mitral stenosis diagnosed by both M-mode echocardiography and hemodynamic findings were subjected to detailed cross-sectional echocardiographic studies. The age of the patients ranged from 27 to 79 years with 76% females. Left ventricular longitudinal, short axis, and apical four-chamber cross-sectional echocardiographic views were obtained in each patient. Three predominant patterns of anterior mitral leaflet motion on left ventricular longitudinal view were observed and correlated with the severity of mitral stenosis: Pattern A (eight patients) with diastolic leaflet doming and restricted leaflet tip motion. Pattern B (eight patients) tip and body leaflet motion, and Pattern C (five patients) with the entire leaflet motion restricted. Mitral valve prolapse as a rebound phenomenon was observed in three patients who had marked leaflet doming in Pattern A and two had severe obstruction. The longitudinal cross-sectional echocardiography was superior to the apical view in assessing the diastolic doming motion of the anterior mitral leaflet. Thus, longitudinal cross-sectional echocardiographic analysis of the pliability and degree of doming of the anterior of the pliability and degree of doming of the anterior mitral leaflet is valuable in estimating the severity of mitral stenosis.

Adult↗
PubMed1976

Ghost cells as a cause of glaucoma.

Clinical and investigative evidence indicated a glaucoma caused mainly by degenerated red blood cells, or ghost cells. These ghost cells, with altered shape, color, and pliability, accumulated in the vitreous cavity after hemorrhage. Following disruption of the anterior hyaloid face, they passed into the anterior chamber and caused severe glaucoma. In the anterior chamber, the tiny, khakicolored cells, circulating slowly, were frequently mistaken for white blood cells. They covered the trabecular meshwork or filled the inferior angle with a pathognomonic khaki-colored layer. They were identified by phase-contrast microscopic examination of anterior chamber aspirates. The decreased pliability of these degenerated cells seemed to account for their inability to pass easily through the human trabecular meshwork and, therefore, to cause severe glaucoma.

Aged↗
PubMed2003

Laser scar revision: comparison study of 585-nm pulsed dye laser with and without intralesional corticosteroids.

BACKGROUND: Hypertrophic scars affect 1.5% to 4.5% of the general population and remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with treatment. Pulsed dye laser (PDL) treatment and intralesional corticosteroids have individually been reported to be effective in reducing hypertrophic scar bulk and symptoms. OBJECTIVE: To determine whether combination PDL and intralesional corticosteroid treatment produces better hypertrophic scar improvement than PDL treatment alone. METHODS: Bilateral hypertrophic inframammary scars in 22 females were randomly assigned to receive treatment with 585-nm PDL alone or in combination with intralesional corticosteroid. Clinical evaluations and scar pliability scores were determined before each of the two treatment sessions and 6 weeks after the final treatment. Histologic evaluation of skin biopsies obtained before and after treatment was performed in four patients. RESULTS: All scars showed clinical improvement with increased pliability and decreased symptoms (pruritus) after each of the two treatments. Clinical improvement scores were not significantly better with the concomitant use of corticosteroids. Side effects were limited to mild purpura and transient hyperpigmentation. Decreased sclerosis was seen in scars after PDL treatment (with or without concomitant corticosteroids). CONCLUSIONS: Treatment of hypertrophic inframammary scars with 585-nm PDL irradiation alone effected substantial clinical and histologic improvement. The adjunctive use of intralesional corticosteroids did not significantly enhance clinical outcome except in those scars that were most symptomatic.

Adult↗
PubMed2001

Energy density and numbers of treatment affect response of keloidal and hypertrophic sternotomy scars to the 585-nm flashlamp-pumped pulsed-dye laser.

BACKGROUND: The 585-nm flashlamp-pumped pulsed-dye laser (PDL) has proven to be the treatment of choice for certain keloids and hypertrophic scars, but the precise fluence, numbers of treatment, and treatment interval remain anecdotal. OBJECTIVE: This study was performed to determine whether the therapeutic outcome of the PDL varies with the energy density (fluence) of the laser pulses and numbers of treatment. METHOD: Ten previously untreated, erythematous, keloidal or hypertrophic median sternotomy scars of 10 patients were divided into 4 segments and were randomly treated with a 585-nm PDL at a fluence of 3, 5, and 7 J/cm(2) to 3 of 4 segments every 4 weeks for a total of 6 treatment sessions. One segment of each patient's scars was untreated and served as a control. Clinical improvement including scar height, erythema, and pliability was evaluated before treatment and every 8 weeks for a total period of 32 weeks. Self-assessment was also determined by patients on a 25% increment of improvement scale comparing week 0 and week 32. RESULTS: A significant improvement in scar height, erythema, and pliability was noted in all laser-treated scar areas. There was no significant difference in treatment outcome versus the fluence of the laser (3, 5, and 7 J/cm(2)), although there was a trend for lower fluences to show more improvement. Objective clinical improvement was seen as early as week 16, after more than two treatments were given. Multiple treatments (>2) appeared to provide a greater percentage of scar resolution. CONCLUSIONS: The clinical improvement of scars after PDL treatment demonstrates no statistically significant fluence dependence in this study, but a trend toward better response with lower fluences is seen. In addition, multiple treatment sessions are suggested for achieving greater response.

Adult↗
PubMed2001

Influence of dacron tissue thickness on the performance of the Pintucci biointegrable keratoprosthesis: an in vitro and in vivo study.

PURPOSE: In 1979 Pintucci developed a biointegrable keratoprosthesis with polymethylmethacrylate optical cylinder integrated with a Dacron tissue-colonizable supporting element to avoid the complications caused by the interaction between the haptic element and the eye. The purpose of this article is to compare the colonization of three Dacron fabrics (thicknesses of 0.25 mm, 0.6 mm, and 1.4 mm) in vitro and in vivo to optimize the device performance. METHODS: In vitro three different Dacron fabrics were cultured for 3 days with 3.5 x 10(5) human fetal lung fibroblasts and observed with a scanning electron microscope. In vivo three different Dacron fabrics were implanted on the sclera near the superior rectus insertion in the right eye of six albino rabbits and were observed after 4 days with light and scanning electron microscopy. RESULTS: In the in vitro experiments, the cells were preserved and their structure was found to be normal. The 0.25-mm thick fabric was coated only on the surface, and the other fabrics were colonized in three dimensions. In the in vivo experiments, the 0.25-mm thick fabric appeared coated only on its surface. The other fabrics were three-dimensionally colonized and the Dacron filaments appeared embedded in neovascularized connective tissue with minimal foreign body reaction. The 1.4-mm thick colonized fabric showed a substantial loss of pliability. CONCLUSION: Given that the 0.25-mm thick fabric was coated only by connective tissue, that the 0.6-mm and 1.4-mm thick fabrics were perfectly colonized, and that the 1.4-mm thick fabrics showed a substantial loss of pliability, the 0.6-mm thick fabric haptic part of the Pintucci keratoprosthesis is preferred. For 19 years, the 0.6-mm Dacron fabric Pintucci keratoprosthesis was implanted in 159 eyes with good results, overcoming the apparently inseparable difficulties represented by mechanical anchorage and biointegrability of a keratoprosthesis.

Animals↗
PubMedDate not supplied

Fabrication of pliable biodegradable polymer foams to engineer soft tissues.

We have fabricated pliable, porous, biodegradable scaffolds with poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) blends using a solvent-casting and particulate-leaching technique. Our study investigated the effects of four different processing parameters on pliability and pore morphology of the biodegradable scaffolds. The parameters investigated were the PLGA copolymer ratio, the PLGA/PEG blend ratio, the initial salt weight fraction, and the salt particle size. A wide range of shear moduli (0.59 to 9.55 MPa), porosities (0.798 to 0.942), and median pore diameters (71 to 154 microns) was able to be achieved by varying the combination of these parameters. Our study indicates that initial salt weight fraction and PLGA/PEG blend ratio have the most significant effects on the physico-mechanical properties of the scaffolds. Enhanced pliability of the three dimensional foams made with blends of PLGA and PEG is evidenced by the ability to roll them into a tube without macroscopic damage to the scaffold. Pliable polymer substrates hold great promise for regeneration of soft tissues such as skin, or those requiring a tubular conformation such as intestine or vascular grafts.

Biodegradation, Environmental↗
PubMedDate not supplied

Massage in hypertrophic scars.

Various attempts have been made to intervene with the formation of hypertrophic scarring (HTS) or to ameliorate it once it has developed, but none have yet proved effective. Massage therapy is routinely used by therapists for the treatment of various conditions, and there have been reports of increased scar pliability and decreased scar banding with the use of massage. This study examines the use of friction massage over a 3-month period in a group of 30 pediatric patients with HTS. The patients were randomly assigned to receive either therapeutic massage sessions of 10 minutes per day in combination with treatment with pressure garments or they were treated with pressure garments alone. A modified Vancouver Burn Scar Assessment Scale was used to measure the characteristics of the identified scars (10 cm by 10 cm) before and after the implementation of massage therapy. The study failed to demonstrate any appreciable effects of massage therapy on the vascularity, pliability, and height of the HTS studied, although there were reports of a decrease in pruritus in some patients. Further studies, with prolonged treatment intervals, are necessary to conclusively demonstrate the ineffectiveness of this therapy for HTS.

Burns↗
PubMed1979

Water deprivation test in the dog: maximal normal values.

Studies were undertaken to determine maximal urine osmolality and urine specific gravity following water deprivation for 20 dogs with normal renal function. In addition, the reliability of body weight, skin pliability, total plasma protein concentration, and packed cell volume as indices of negative water balance was assessed. Following water deprivation for periods sufficient to induce dehydration, the mean maximal urine osmolality was 2,289 mOsm/kg. The corresponding mean maximal urine specific gravity was 1.062 and ranged from 1.050 to 1.076. The ratio of mean maximal urine osmolality to mean serum osmolality at the time of peak urine concentration was 7.3. There was no detectable difference in urine concentration indices between males and females. Changes in skin pliability and packed cell volume proved unreliable as estimates of dehydration. Weight loss and increases in total plasma protein concentration proved to be more consistent indicators of hydration status. Abnormal increases in serum urea nitrogen and serum creatinine concentrations occurred rarely, even though some dogs had water withheld for periods of up to 96 hours.

Animals↗
PubMed1979

An evaluation of 8-0 polyglycolic acid braided synthetic absorbable suture in cataract surgery.

This study describes the operative and postoperative performance of 8-0 polyglycolic acid braided suture, trademarked Dexon "s", in cataract surgery. The evaluation consists of a clinical comparison of 8-0 Dexon to the same suture in 7-0 size in 109 cataract surgical procedures. The 8-0 Dexon, like 7-0, gave high tensile strength, good knot security, batch-to-batch uniformity, relatively good pliability, and provoked minimal reaction while disappearing at a predictable rate of around 35 days. When compared to 7-0 Dexon, 8-0 produced less tissue drag, fibrillation, and reaction, while providing better pliability. However, the smaller suture possessed less tensile strength, and had an increased tendency to cut through tissue when tied too tightly.

Absorption↗
PubMedDate not supplied

[A nasal reconstruction via the expansion of the tissue].

The techniques that offer the best results in total nasal reconstruction are those that use frontal skin. Even if traditional procedures meet most of the reconstructive needs, they are often limited by the size of the tissues to be transplanted and by the scarring they leave in the donor area. The stiffness and scarce pliability of the frontal skin hinder fine modelling of the alae, of the columella and of the nasal tip. Expanded forehead flaps to day offer a substantial advantage. In the period from 1986 to 1991 total nasal reconstruction was performed in 12 patients (4 males and 8 females). Their ages ranged from 4 to 69 years. Four patients presented a recurrence of a basal cell carcinoma, 1 patient presented a trichoepithelioma. In 3 cases an arteriovenous vascular malformation was present, in 1 there were radiodermatitic lesions while in another 3 cases there was extensive scarring. In all cases a rectangular skin expander without base and with a remote filling port was used. The nominal volume ranged from 100 cc to 260 cc. All expanders were introduced through a vertical hair incision in the subgaleal plane, except in 1 case in which it was placed over the frontal muscle. The mean time of expansion was 79 day. The mean volume at the end of the expansion was 283 cc. The results obtained are presented and the advantages of the technique are exposed. These are: 1) the possibility of obtaining forehead flaps wide enough to cover large defects, 2) the direct closure of the donor area even if large flaps are raised, and 3) the improved pliability of the expanded frontal skin. A minor complication present in all the patients treated was moderate pain during inflation of the expander, easily controlled with common analgesics. A bony crest was frequently observed around the base of the skin expander which, however, was easily removed with a curette. Only in one case was a major complication observed; that of a preoperative infection necessitating removal of the expander, which was reapplied a few months later in order to complete the initial reconstructive program.

Adolescent↗
PubMed1993

A compliant biological vascular prosthesis.

One requirement of the mechanical parameters for an acceptable vascular prosthesis is compliance. The compliance of a vascular prosthesis is defined as the fractional change in luminal volume per unit change in applied pressure. A compliant prosthesis has been correlated to prosthesis patency and long-term efficacy in an animal study. However, there have been very few reports on how to manufacture a compliant prosthesis. It is the objective of this study to research the processing methods to manufacture a reasonably compliant vascular prosthesis. A new fixative, polyepoxy compound, was used to fix an artery. The arteries were fixed under different degrees of longitudinal retraction. By locking in the collagen micro-structure at an overly relaxed state and then crosslinking said collagen, the resulting biological prosthesis exhibited extreme compliance and pliability. A prosthesis matching its arterial origin in tensile modulus was achieved by crosslinking an artery at its 45% retraction longitudinally. This flexible prosthesis showed a volumetric compliance index of 18.4 +/- 0.9 % delta/100 mmHg and a longitudinal tensile modulus of 942 grams/cm2. Our current study indicated that a prosthesis fixed with polyepoxy compounds has shown more pliability than that with glutaraldehyde. Further animal study to correlate prostheses patency to different degrees of compliance is needed to confirm this proposed manufacturing approach.

Bioprosthesis↗
PubMed1997

Evaluation of a vaginal moisturizer in baboons with decreasing ovarian function.

Decrease of estrogen concentrations in postmenopausal women leads to many urogenital problems including vaginal dryness, atrophy, stenosis, itching, and irritation, along with sexual dysfunction. Systemic estrogen replacement is effective in many women but may not be effective in others because estrogen therapy may be contraindicated for medical reasons. The reproductive tract in nonhuman female primates has been used successfully as a model for a variety of research including, but not limited to, anatomy and physiology, reproduction, cancer, infectious disease, and menopause. The baboon is especially valuable because of the similarity of its menstrual cycle to women's, prior research with this animal, and its adaptability to captivity. A nonhormonal, nonsystemic, bio-adhesive vaginal moisturizer was evaluated in baboons as a possible alternative to hormonal therapy for vaginal symptoms due to a decrease in estrogen concentrations. Eight baboons with decreasing ovarian function were used in a two-part study to evaluate vaginal health with pliability, elasticity, mucosal secretion, pH, and histologic features as criteria. The first study involved a single intravaginally administered dose of test product, with evaluation at 20 min and 24 h later. The second study consisted of five doses given at 24-h intervals, with daily evaluations for 9 consecutive days. There was marked improvement in vaginal pliability, elasticity, and secretions, with decreased pH and thickness of the vaginal epithelium. These effects appeared 1 or 2 days after drug administration, reached the maximum on day 4, and mostly decreased by day 8. However, increased secretions, vaginal elasticity, and vacuolization of the epithelium in biopsy specimens persisted to the last day of observation. The study results indicate the efficacy of the test product and the value of the baboon as a model to study decreasing ovarian function and vaginal health.

Animals↗
PubMed1998

Autograft from quadrangular resection for floppy valve repair in endocarditis.

We present a case of reconstruction of the anterior leaflet in mitral valve prolapse and subacute bacterial endocarditis in which the resected prolapsing segment of the posterior leaflet was used as patch material. Competence of the valve was achieved with no recurrence of infection. Quadrangular resection of the posterior leaflet supplies presumably viable patch material for valve repair, which is particularly useful in bacterial endocarditis and when pliability is required.

Aged↗
PubMed1997

Use of a bovine jugular vein graft with natural valve for right ventricular outflow tract reconstruction: a one-year animal study.

OBJECTIVE: We evaluated a bovine jugular vein graft with a natural trileaflet valve for right ventricular outflow tract reconstruction in a canine study for an entire year. METHODS: Heparinized bovine jugular vein grafts with a natural valve cross-linked with a hydrophilic polyepoxy compound of 18 to 20 mm in internal diameter were implanted in the right ventricular-pulmonary arterial position in eight dogs, and the main natural pulmonary artery was ligated. Anticoagulants were not used after implantation. Five grafts were retrieved on day 182 after implantation and the other three grafts on days 196, 375, and 385, respectively, and were inspected by macroscopic and microscopic observation. Cardiac catheterization, followed by angiography and echocardiography, was done just before graft retrieval. RESULTS: No graft kinking or regurgitation of the valve was observed. Echocardiography showed natural valve motion without thickening of the leaflets. Blood pressure in the conduits ranged from 18/9 to 31/4 mm Hg, in the right ventricle from 18/4 to 40/0 mm Hg, and the gradient varied from 0 to 14 mm Hg. The explanted conduits maintained their original shape, softness, and pliability with good coaptation of valves, without calcification or degenerative changes, except for one leaflet with slight deformation. In microscopic observation, endothelial cells lined the luminal surface of the conduit except for the areas adjacent to the valve. CONCLUSION: The graft worked perfectly as a right ventricular-pulmonary arterial valved conduit without anticoagulant therapy for a long time.

Animals↗
PubMed1995

Comparison of fresh and glutaraldehyde-treated autologous stented pericardium as pulmonary valve replacement.

The use of fresh autologous pericardium in valve surgery has shown poor results in the past mainly due to thickening and retraction. Recently, it has been suggested that a short treatment with glutaraldehyde might radically change its behavior. In an attempt to determine whether this disparity in results is due to the glutaraldehyde treatment or to a better present-day surgical technique, fresh and glutaraldehyde-treated autologous pericardium was mounted in a frame and implanted in the pulmonary position of adult sheep. Six survivors obtained in each group were sacrificed between 2 and 8 months in the "fresh" group and between 2 and 6 months in the "glutaraldehyde-treated" group. Macroscopically, the fresh pericardium became thickened and retracted in all specimens, eventually resulting in severe regurgitation, while the glutaraldehyde-treated, although slightly thickened, retained its pliability without significant retraction. Microscopically, viability of the central core of the collagen was more often preserved in the fresh pericardium. Endothelialization was irregular. In conclusion, short glutaraldehyde treatment seems to improve the results of autologous pericardium mounted on a valve stent. Its effect on calcification remains to be ascertained.

Animals↗