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PubMedDate not supplied

[Comparison of the results of sclerotherapy of esophageal varices using a rigid esophagoscope and fiber-optics esophagoscope].

The authors compared the results of 20 emergency and 100 elective varicosclerotisations with rigid esophagoscope and the same number of obliterations with the use of esophagofiberoscope. Haemorrhage was stopped in 90% of patients injected through the rigid esophagoscope and in 80% of patients in whom esophagofiberoscope was used. Hospital mortality rate in patients with bleeding esophageal warices was 25% in both groups. Complications were seen in 4.2% of procedures carried out with the rigid esophagoscope, and 5.8% of obliterations with esophagofiberoscope. The authors recommend rigid esophagoscope for emergency sclerotherapy and for the initial 2-3 series of injections in patients with large varices. Esophagofiberoscope is prefered in case of repeated, elective varicosclerotisations, first injections and recurrence of esophageal varices following obliterative therapy.

Adolescent↗
PubMed1989

The role of rigid skeletal fixation in bone-graft augmentation of the craniofacial skeleton.

The type of fixation (rigid skeletal vs. wire) was assessed against embryologic origin (membranous vs. endochondral) and recipient site (depository vs. resorptive) as variables affecting inlay and onlay bone-graft survival in 20 mature dogs. Wet weight and volume measurements were made at operation and at sacrifice (16 weeks). The results were as follows: (1) Rigid skeletal fixation increased bone-graft volume survival over wire fixation (p less than 0.05). (2) Fixation (i.e., rigid skeletal) and embryologic origin (i.e., membranous) were equal determinants of bone-graft volume survival (p less than 0.001); the recipient site was not significant for onlay bone graft survival. (3) Embryologic origin was the only significant determinant of weight survival (p less than 0.001). (4) Inlay bone grafts demonstrated greater weight and volume survival than onlay bone grafts (p less than 0.05). (5) Histologic and microradiographic studies demonstrated bony union of bone grafts fixed with rigid skeletal fixation, while fibrous union predominated in bone grafts fixed with wire technique.

Alveolar Ridge Augmentation↗
PubMed1989

Knee orthoses for valgus protection. Experiments on 11 designs with related analyses of orthosis length and rigidity.

Recent years have seen the introduction of a great many knee orthosis designs prescribed for protection against ligamentous injury or reinjury of the knee. The configurations and materials incorporated in these designs vary greatly, but all claim to be very effective. A leg model and 11 different commercially available knee orthoses were tested with static loading to obtain objective data on the relative effectiveness of the 11 designs to protect the knee from externally applied valgus moments. From these data, the effectiveness of each orthosis was calculated in terms of the rigidity contributed to the leg/orthosis combination. At a static valgus loading of 78 Nm, there was an eightfold variation in the rigidities contributed by the various knee orthoses, ranging from a low of 0.9 Nm per degree valgus to a maximum of 7.2 Nm per degree. The authors related analyses of two aspects of knee orthosis design (orthosis length and orthosis rigidity) to effectiveness in protecting against knee valgus overload injuries. Correlations were found between design inadequacies noted theoretically and efficacy problems evident from the laboratory tests. Orthosis length and orthosis rigidity must both be adequate, or the orthosis will not be biomechanically effective.

Humans↗
PubMed1987

[Multiminicore disease in a rigid spine syndrome].

The case of a 15 year-old girl, who had difficulties in walking from early childhood is reported. The clinical picture was that of the rigid spine syndrome, spine rigidity being associated with retractions and diffuse amyotrophy of the upper limbs. Histochemical and ultra-structural studies of the muscle showed typical multiminicores. The multiminicore myopathy has not particular clinical features. In the rigid spine syndrome various histological changes can be found. For these reasons, we think that the rigid spine syndrome should be classified within the group of congenital myopathies.

Adolescent↗
PubMed1986

Erythrocyte rigidity in healthy patients and patients with cardiovascular disease risk factors.

The normal values for erythrocyte rigidity as measured by the "Selective Erythrocyte Rigidometer" were derived from a group of 275 apparently healthy subjects without risk factors. These individuals were randomly selected from an address book. The normal values ranged from 0.83-1.19 (median: 1.01). Quality control was conducted throughout the study and the analytical reliability was verified (day-to-day coefficient of variation VCd was 7.5%; coefficient of variation in series VCs was 3.1%). Inter- and intraindividual fluctuations in erythrocyte rigidity in the 8.3% and 6.1% ranges respectively were found in 20 apparently healthy subjects in the course of a 6-month study. No relationship was found between either age or sex and erythrocyte rigidity. Significantly higher erythrocyte rigidity values were found in patients with risk factors however; this applies to hypertensive patients, patients with diabetes mellitus, but also to apparently healthy subjects who were either overweight or smokers. Patients with disordered lipometabolisms on the other hand did not show any change in erythrocyte deformability when compared with healthy subjects.

Adult↗
PubMed1980

The rigidity of human fingernails: a biophysical investigation on influencing physical parameters.

(A) The property of withstanding bending and buckling in a composite material such as the nail is best described by such terms as rigidity or stiffness. (B) The physical property of rigidity can be understood from the macromolecular orientation of the keratin filaments and the cellular architecture of the dorsal and ventral nail plates. (C) The rigidity is influenced by factors such as the water content of the nail material. Specimens investigated must therefore be well equilibrated prior to the measurements. (D) Detergents, organic solvents, oils etc. are factors which are likely to influence nail rigidity.

Biomechanical Phenomena↗
PubMed1983

Rigidity of pure lag-screw fixation as a function of screw inclination in an in vitro spiral osteotomy.

The rigidity of lag-screw fixation of experimental tibial fractures was tested in 27 anatomic specimens. Spiral osteotomies with a 60 degree angle of ascent were produced using a Gigli saw. Three screws with an axial force of 100 kp were inserted at 90 degree, 80 degree, or 70 degree of longitudinal inclination. The 70 degree group was stable in axial compression up to 88 kp and the 80 degree group up to 151 kp. Rigidity in bending was 50% in the 70 degree and 80 degree groups and 27% in the 90 degree group, while rigidity in torsion was 20% as compared with the intact bone. Screws tightened with 50 kp and 150 kp showed increased rigidity as axial screw force increased. There were only small gains in torsion and bending, whereas there was a 200% gain in compression. This confirms the view that in long spiral fractures of the tibia three lag screws alone can maintain sufficient stability to permit early limb mobility. If the screws are inserted perpendicular to the bone, the high resistance to axial compression may permit early partial weight-bearing.

Biomechanical Phenomena↗
PubMed1982

Osteolysis after rigid fixation. The possible role of periosteal neural mechanoreceptors in bone remodeling.

Rigid intramedullary fixation in the rat tibiofibular bone of a tibial fracture caused the development of nonunion in the associated fibular fracture, with marked osteolytic resorption of the fibular fragments. In contrast, with flexible fixation, the associated fibular fracture healed normally. The tibial fractures healed uneventfully in both cases. Histologic examinations showed that there exists a plexus of encapsulated nerve endings (Pacinian corpuscles) in the periosteum of the fibula, at the distal tibiofibular junction. The rat fibula forms a bony contact with the lower midshaft of the anteriorly curved tibia, acting as a supporting shaft. The periosteal neural mechanoreceptors probably sense the fibular loading when the tibia is bent during weight-bearing. Fibular resorption in rigid fixation could be attributed to the rigid intramedullary nail preventing tibial bending and loading of the receptor area. In other words the neural elements could detect the stress protection due to rigid fixation and coordinate the adverse remodeling process.

Animals↗
PubMed1994

Comparison of craniofacial growth after rigid fixation with autogenous bone plates and with metal plates.

This study was undertaken to determine whether rigid fixation using autogenous cranial bone grafts restricts craniofacial growth less than metal plates in 7-week-old Yorkshire pigs. A rectangular 10 x 20 mm segment of bone centered on the right coronal suture was resected. Animals were randomly assigned to one of three experimental groups: (1) rigid fixation across the defect using the bone graft rotated 90 degrees and attached with four microscrews; (2) rigid fixation across the defect using two microplates attached with four microscrews; or (3) no rigid fixation, with four microscrews placed to serve as radiologic markers. All animals were followed up with serial radiographs, and 8 months after the surgery direct measurements were performed on dry skull preparations. The greatest lengths were in the control group, followed by the bone plate and then the metal plate groups, but these differences were not statistically significant. The cranial width was significantly greater in the bone plate group, suggesting that a growth center may have been reoriented.

Animals↗
PubMed1994

Rigid gas permeable extended wear (RGPEW) for the postoperative patient: a review and clinical observations.

BACKGROUND: Contact lenses are often the indicated method of correction following cataract extraction without implantation of an intraocular lens and following penetrating keratoplasty. Unfortunately, many patients who stand to benefit from contact lens wear are unable or lack the motivation to perform proper lens hygiene. Thus, extended lens wearing schedules using soft and rigid lens designs are often utilized. METHODS: Following a review of the literature regarding extended wear rigid lenses (PMMA and oxygen permeable) for the aphakic patient, this paper presents results of fitting high DK (92 x 10-11) rigid contact lenses worn from 1-2 months prior to removal on 11 patients (six with aphakia, five following penetrating keratoplasty). All subjects with aphakia were considered to be unsuccessful with soft aphakic extended wear (SEW). Subjects in the penetrating keratoplasty group were new to contact lens wear. RESULTS: These data show that 60 percent of aphakic patients considered to be unsuccessful with SEW may be successful with rigid gas permeable extended wear (RGPEW). The predicted success with RGPEW following penetrating keratoplasty was lower at 20-40 percent. CONCLUSIONS: RGPEW should be considered for the postoperative patient who stands to benefit from the optical advantages of contact lenses but is unable or not motivated to perform the necessary lens hygiene. Patients who experience lens awareness or become intolerant to SEW due to corneal edema are potential candidates for RGPEW.

Aged↗
PubMed1993

The performance of the Rigiscan in the measurement of penile tumescence and rigidity.

The validity of the Rigiscan as a measure of both penile circumference and rigidity was assessed. In the first study, the Rigiscan was used simultaneously with a mercury-in-rubber strain gauge to monitor nocturnal penile tumescence. The Rigiscan was found to underestimate the circumference proportional to the degree of erection. In a second study a calibration system was developed which allowed independent variation of circumference and rigidity. Assessment of the Rigiscan with this system confirmed that circumference was underestimated, particularly at lower levels of rigidity, and also that different devices consistently recorded different degrees of rigidity. The use of this type of system for regular calibration is recommended, and other potential improvements in the device for research purposes are discussed.

Adult↗
PubMed1993

Bending rigidity of composite resin coating clasps.

The purpose of this study is to examine the bending profiles of composite resin coating cast clasps. The cobalt-chromium alloy cast clasps were made using tapered wax pattern. Silane coupling method (Silicoater MD, Kulzer Co.) was used to attach composite resin to metal surface. The breakage and the bending rigidity of composite resin coating clasps were evaluated. Results were as follows: 1) After the repeated bending test to the tips of clasp arm at 10,000 times in 0.25 mm deflection, neither crack on composite resin surface nor separation at resin/metal interface was observed in any specimen. 2) There was no significant difference in the bending rigidity of clasp arms between before and after composite resin coating. From these results, it was demonstrated that the composite resin coating cast clasp was available in clinical cases and coating with composite resin had little influence on the bending rigidity of clasp arms. Therefore, it was suggested that our clasp designing and fabricating system to control the bending rigidity of clasp arms could be applied to composite resin coating clasps.

Chromium Alloys↗
PubMed1997

Randomized, prospective, double-blind study of the effects on pain perception of lidocaine jelly versus plain lubricant during outpatient rigid cystoscopy.

PURPOSE: There is no clear evidence that intraurethral lidocaine jelly decreases pain and/or makes rigid cystoscopy more tolerable for patients. Since lidocaine jelly is significantly more expensive than plain lubricant, we attempted to assess the true benefit of this agent. MATERIALS AND METHODS: We performed a randomized, prospective, double-blind study to compare the anesthetic effects of intraurethral 2% lidocaine jelly versus plain lubricant in patients undergoing rigid cystoscopy. Unlike previous studies, we ensured adequate urethral filling by using 30 cc of each agent and we waited 20 minutes after instillation of the agent before performing cystoscopy to allow adequate absorption. Cystoscopy was performed using a 17 to 21F rigid instrument. A total of 189 patients was entered into the study but 10 were excluded from analysis due to incomplete questionnaires. A 10-point scale (1-least to 10-most painful) was used to measure pain perception. RESULTS: In men pain perception was significantly decreased when lidocaine jelly was used (mean plus or minus standard error 3.00 +/- 0.21 versus 4.36 +/- 0.37 points, p = 0.002). In women there was no observed difference in pain perception when lidocaine jelly or plain lubricant was used (3.21 +/- 0.38 versus 3.11 +/- 0.30 points, p = 0.823). Patient race, performance of a related procedure, cystoscope size or history of cystoscopy did not significantly affect reported pain scores. There was a slight decrease in pain perception with increasing age (-0.23 +/- 0.10 points per decade, p = 0.021). The level of patient anxiety before cystoscopy was also significantly associated with pain perception (p < 0.001). CONCLUSIONS: Lidocaine jelly offers no advantage over plain lubricant in regard to pain control during rigid cystoscopy in women. However, when used in adequate amounts and allowed to dwell in the urethra for 20 minutes before cystoscopy, lidocaine jelly can significantly decrease pain in men.

Adult↗
PubMed1996

Rigid bronchoscopy and jet ventilation in an extremely low birthweight infant.

Until recently, rigid bronchoscopy was considered too risky for premature infants. We report a 658 g infant with life-threatening mediastinal shift due to right pulmonary atelectasis. Rigid bronchoscopy revealed tenacious mucous plugs in the right main bronchus. The collapsed lung was successfully reinflated after bronchial lavage with a rigid bronchoscope, with the help of intermittent high-frequency jet ventilation (HFJV). The infant's mediastinal shift was reversed and the vital signs became stable. In our experience, rigid bronchoscopy combined with HFJV is a valuable diagnostic and therapeutic procedure for very small premature infants.

Bronchoalveolar Lavage↗
PubMed1998

Flexible versus rigid ring annuloplasty for mitral valve annular dilatation: a finite element model.

BACKGROUND AND AIMS OF THE STUDY: The study objective was to compare coaptation, and leaflet and chordal stresses in normal and dilated mitral valves (18% annular dilatation) versus valves with flexible (Duran) and rigid (Carpentier-Edwards classic) ring annuloplasty, using a computer model. We have developed a 3D finite element model which allows us to evaluate valvular function in terms of coaptation and stresses in both leaflets and individual chordae. METHODS: The mitral valve was simulated using ANSYS 4.4A software. Normal model geometry, collagen fiber orientation, tissue thickness and material properties were determined from fresh porcine valves. For annular dilatation, the annular circumference was increased by 18% versus normal. For annuloplasty, a simulated flexible ring was attached to the annulus, and a simulated rigid ring then attached. Valves were evaluated during systolic pressure loading, after which timing of coaptation and leaflet and chordal stresses were determined. RESULTS: In the normal valve, the anterior leaflet was subject to higher tensile stresses than the posterior leaflet which was under compression. With annular dilatation, all stresses were increased, particularly in the posterior leaflet. The flexible ring returned leaflet and chordal stresses closer to normal than did the rigid ring. Leaflet coaptation began at 5 ms in the normal state, was delayed by dilatation, and returned towards normal with both rings. The flexible ring returned coaptation and stresses closer to normal than did the rigid ring. CONCLUSIONS: Ring annuloplasty reduces the stresses and improves coaptation relative to annular dilatation. The success of mitral annuloplasty is likely due to the re-establishment of posterior leaflet compressive stresses and near-normal coaptation.

Biomechanical Phenomena↗
PubMed1998

Neonatal/infant rigid bronchoscopy.

OBJECTIVE: The neonatal intensive care unit (NICU) of the Montreal Children's Hospital (MCH) has averaged 358 admissions/ year over the past 10 years. Over the same period, 1.8% of these admissions have required rigid bronchoscopy in either the neonatal or infant time period: 175 rigid bronchoscopies were performed on 76 patients since 1977. METHOD: We retrospectively reviewed the findings at first bronchoscopy. Our cases were analyzed regarding indication for bronchoscopy, primary airway pathology, concomitant secondary airway pathology, management, outcome, and overall prognosis. RESULTS: Normal bronchoscopic findings were seen in 25% of cases. The remaining 75% revealed pathology in sites ranging from the oropharynx to the bronchus. The majority were subglottic (15), esophageal atresia/tracheoesophageal fistula (14), and glottic (11). There was concurrent airway pathology in 41% of the cases, ranging from 0% in the bronchial group to 75% in the oral/pharyngeal group. Thirty three percent of patients with a secondary airway pathology identified required further airway intervention, either therapeutic bronchoscopy at the same time or later airway surgery. There were no major complications from rigid bronchoscopy in our series. The mortality due to airway pathology was highest in the supraglottic/ glottic group (36%). CONCLUSION: Rigid bronchoscopy performed in the neonatal/infant period is safe. The primary and concomitant secondary diagnosis are high (75% and 41%, respectively), while both may require further airway intervention. Finally, it directs early management of these cases for better prognosis.

Bronchoscopes↗
PubMed1976

Evaluation of use of the rigid dressing in amputation of the lower extremity.

Twenty-seven arteriosclerotic amputees were evaluated to determine the value of the rigid dressing technique for amputation wound management. Results were compared with those for patients having conventional stump wound management. The two groups were similar in number, age and incidence of diabetes. All the patients treated with the rigid dressing had primary healing of the amputation wound, while 13 patients treated with the conventional dressing had primary healing. Long term rehabilitation to the use of a prosthesis was not improved by the application of a rigid dressing on the amputation wound. Our current preference is use of the rigid dressing applied in the operating room at the time of amputation. If the wound is satisfactory and the general condition of the patient is such that he can use a temporary pylon, it is attached to the cast at the first change, about two weeks after operation.

Aged↗
PubMed1998

Design and evaluation of a portable rigid forced-air warming cover for prehospital transport of cold patients.

Forced-air warming is promising for use during transport of cold patients. However, the current soft covers may be easily damaged in the nonhospital environment. Two rigid covers were designed to direct heat to the torso and thighs. Five subjects (one female) were heated with an AC powered heater (Bair Hugger 505, Augustine) and either a soft cover or the rigid covers (with heat input at the head or abdomen). Compared to the soft cover, the rigid cover (with heat input at the abdomen) provided similar heat delivery but a higher mean skin temperature. We conclude that the portable rigid covers are efficient for treatment of cold victims during pre-hospital transport.

Air↗