Biomedical subjects

G Semb

Publications and source records attributed to G Semb.

At least 19 recordsLinked to original sources

PubMed1992

Strut fracture with Björk-Shiley 70 degrees convexo-concave valve. An international multi-institutional follow-up study.

Between 1980 and 1983, 831 Björk-Shiley 70 degrees convexo-concave prosthetic heart valves were implanted at five institutions in Sweden, Germany. The Netherlands, and Canada. As of January 1991, there were 34 outlet strut fractures occurring from 0.2 to 10.1 years (median = 4.6 years) after implantation. In addition, there were 28 sudden, unexplained deaths. The mortality after strut fracture was 84%. The mortality after emergency valve replacement for strut fracture was 50%. The 10-year actuarial fracture rate (standard error) was 10.5 (2.4)% for large (29-33 mm) valves vs. 3.3 (1.2)% for 21-27 mm valves (P less than 0.001). Within valve size groups, fracture rates for aortic and mitral valves were similar. Cox regression analysis found only valve size to be significantly associated with strut fracture. There is a further subgrouping of the valves according to the manufacturer: group I are the earlier large 29-33 mm) valves; group II are the later large valves; group III are the small size (21-27 mm) valves. The risk of strut fracture was highest in group I (12.3% at 10 years) with an approximatively constant hazard (1.4% per year). A comparison was made with a statistical model incorporating all cases reported to the manufacturer. This model estimates fracture rates approximately 63%-73% of those found in the present study. These findings lead us to recommend that group I patients should be considered for elective reoperation on an individual basis, giving careful attention to risk factors and contraindications.

Adolescent↗

PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 1. Principles and study design.

This article describes the design of an intercenter comparative study of treatment outcome in the treatment of children with a unilateral complete cleft of the lip and palate. The rationale and aims of this study are defined and treatment schemes of the participating centers are described. The findings are presented in a series of three papers (Parts 2, 3, and 4) dealing with the comparison of craniofacial form, dental arch relationships, and nasolabial appearance. In Part 5, conclusions and general recommendations regarding future research are discussed.

Child↗

PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 2. Craniofacial form and soft tissue profile.

The craniofacial morphology and the soft tissue profile were evaluated in this part of the intercenter study of the European Cleft Lip and Palate Research Group. The sample was comprised of cephalometric x-rays of the full cohort of 151 cases from the six European cleft palate centers. The facial morphology in complete unilateral cleft lip and palate patients was evaluated by means of roentgen cephalometry. Approximately 25 consecutive cases from each of six European cleft palate centers were compared. Only one center showed notable and consistent differences from the others. A contributing factor for these differences may be an inconsistent treatment regimen with many surgeons involved. Analysis of the soft tissue profile between the centers showed more pronounced differences than analysis of the skeletal profile. The treatment outcome in centers with more complex or expensive programs was no better than those centers using simpler management approaches.

Analysis of Variance↗

PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 3. Dental arch relationships.

One hundred and forty-nine dental casts of subjects with complete unilateral clefts of the lip and palate from six European cleft palate centers were assessed by means of the Goslon Yardstick. The Yardstick proved capable of discriminating between the quality of the dental arch relationships between the six centers. Two centers showed especially poor results. Three centers obtained satisfactory results although differing surgical techniques were used in these centers. One of the centers showing satisfactory dental arch relationships employed a more complex and expensive treatment program than the other two centers, which both used simpler centralized treatment regimens.

Analysis of Variance↗

PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 4. Assessment of nasolabial appearance.

One hundred and fifteen frontal and profile photographs of the nasolabial area of subjects with complete unilateral clefts of the lip and palate from six European centers were assessed. Four components of the nasolabial area were rated separately by a panel of judges using a five-point scale of attractiveness. The Tukey multiple comparison test showed significant differences between the centers. The relative position of the six centers in this study followed a similar pattern to their respective positions in the cephalometric and dental cast studies.

Child↗

PubMed1992

Craniofacial development in children with unilateral clefts of the lip, alveolus, and palate treated according to three different regimes. Assessment of nasolabial appearance.

From extraoral photographs taken from the front and in profile of 61 16-year old children with unilateral cleft lip, alveolus, and palate (UCLAP) who had been treated by three different treatment regimes, the nasolabial appearances were assessed by a panel. The photographs were masked, leaving only the mid face including the nose and lips. The following features were assessed using a five point scale: nasal form, symmetry of the nose, vermilion of the upper lip, shape of the vermilion border, total symmetry of upper lip, and nasal profile including the upper lip. The number and type of secondary operations required were recorded. Intraobserver reliability was good but interobserver agreement was poor, some observers systematically scoring more severely than others. A panel of six was therefore set up to establish an acceptable mean assessment. The treatment regime that included secondary bone grafting, and the one that included primary bone grafting and presurgical orthopaedic-T-traction, scored better on all features assessed compared with the group that underwent primary bone grafting but no T-traction. The latter group required fewer secondary revisionary procedures, however, which could explain these results.

Adolescent↗

PubMed1992

Craniofacial development in children with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes. III. The soft tissue profile at 16-18 years of age.

The soft tissue profiles of 85 16-18 year old children with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes were studied using lateral skull radiographs. Regimes that included secondary bone grafting to the alveolus in the mixed dentition gave better convexity of the soft tissue profile (excluding the nose) and better soft tissue sagittal jaw relationships compared with treatment regimens that included primary bone grafting. The soft tissue profile in regimes that excluded bone grafting was almost as favourable as those in regimes in which bone grafting was done during the mixed dentition.

Adolescent↗

PubMed1992

Craniofacial development in children with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes. II. Mandibular and vertical development.

Lateral skull radiographs of 85 patients with unilateral clefts of the lip, alveolus and palate treated according to four different regimes were compared longitudinally, at three different ages, regarding mandibular and vertical facial development. It was found that there were no lasting differences in mandibular morphology resulting from regimes including primary or early secondary bone grafting. The non grafted group, however, showed increased mandibular length and anterior height. The jaw angle was increased and there was a more favourable sagittal jaw relationship. Regimes that included primary bone grafting were associated with reduced upper anterior facial height, which resulted in less harmonious facial proportions compared with treatment regimes including early secondary bone grafting done during the mixed dentition, or no bone grafting at all. Vertical development was greatest where bone grafting was excluded.

Alveolar Process↗

PubMed1992

Five-year results after valve replacement with the Björk-Shiley 70 degrees convexo-concave prosthesis.

In the 18 months up to July 1983, 120 Björk-Shiley convexo-concave prostheses with 70 degrees opening angle were implanted in 47 women and 61 men aged 19-78 (mean 58.6) years. The prosthetic valves were aortic in 65 cases, mitral in 23 and both aortic and mitral in 20 cases. Emergency operation was required in ten cases, and concomitant surgery was performed in 43 (39.8%). The early mortality was 5.5%. A follow-up study, comprising 498 patient years, revealed 73.1% 5-year survival. There were three mechanical failures of prosthesis, in one of which re-replacement was successful. Elective prosthesis replacement was performed in four other cases judged to be at high risk of strut fracture.

Adult↗

PubMed1992

Reduced complement activation with heparin-coated oxygenator and tubings in coronary bypass operations.

Complement activation after cardiopulmonary bypass is correlated with postoperative organ dysfunction. Heparin coating of the entire blood-contact surface of the cardiopulmonary bypass circuit has proved to reduce complement activation in vitro. A membrane oxygenator and tubing setup coated with functionally active heparin was compared with an uncoated, otherwise identical setup in 20 patients undergoing routine coronary bypass operations. The concentrations of C3 activation products and the terminal complement complex were measured in sensitive and specific enzyme immunoassays. Peak concentrations of C3 activation products were 90.1 (74.7 to 107.4) AU/ml (medians and 95% confidence intervals) and 52.4 (35.7 to 76.4) AU/ml with the uncoated and coated setups, respectively (p = 0.02). The corresponding concentrations of the terminal complement complex were 26.2 (20.1 to 37.5) AU/ml and 13.7 (11.1 to 25.1) AU/ml (p = 0.03). Blood loss from the mediastinal drains during the first 12 postoperative hours was 533 (416 to 975) ml in patients treated with the uncoated setup and 388 (313 to 579) ml in the coated treatment group (p = 0.06) and was significantly correlated with peak concentrations of the terminal complement complex (p = 0.01). There were no differences in neutrophil counts nor platelet numbers between the treatment groups. The approximate 45% reduction in complement activation with the heparin-coated cardiopulmonary bypass device indicates a substantial improvement of biocompatibility.

Aged↗

PubMed1992

Results of multidisciplinary management of bilateral cleft lip and palate at the Iowa Cleft Palate Center.

Bilateral cleft of the lip and palate is by many standards the most complex and severe form of the defect. The complexity and severity of the defect require an unusual degree of cooperation among all specialists and especially between the surgeon and the orthodontist. There are no published findings that we know about in which comprehensive data from a number of disciplines are reported for the same group of bilateral cleft patients. Fifty randomly selected patients with bilateral complete clefts were examined by the Iowa team and two orthodontists from other institutions. The evaluations revealed that a large number of patients over the age of 10 have multiple residual problems requiring further treatment. Only 23 percent of the older patients studied were judged to have had treatment completed by the surgeon, speech pathologist, and orthodontist. It is very difficult to state whether the results obtained by our team can be considered satisfactory because there are no comparable studies that have attempted to evaluate the same parameters in multidisciplinary management.

Adolescent↗

PubMed1991

[Accidental hypothermia. Risk factors in 29 patients with body temperature of 30 degrees C and below].

29 patients with a body temperature below 30 degrees C (mean 26.4 degrees C) were treated during the period 1982-88, both years inclusive. Eight patients were severely hypotensive (systolic blood pressure less than 60 mm Hg) and two had ventricular fibrillation on admission. Bradycardia (less than 60 beats per minute) was noted in ten patients. 12 patients were rewarmed by surface warming, 17 by extracorporeal circulation with femoral cannulation. 22 patients (76%) were discharged alive. Age, sex, body temperature, method and rate of rewarming, serum electrolytes, acidosis and the use of blood components did not influence the outcome. Renal failure was the only complication associated with a fatal outcome. Severe hypotension on admission tended to increase mortality, but logistic regression analysis identified the mode of cooling as the only independent risk factor for death. A patient cooled indoors had an odd risk of 10.6 of hospital mortality compared to one found outdoors. For the sake of convenience, in hospitals with the available resources rewarming by extracorporeal circulation may be used in patients with circulatory arrest, since this is the easiest way to control and support failing circulation. In all other cases carefully monitored surface rewarming should be used as this necessitates less use of hospital resources and produces equally good results.

Accidents↗

PubMed1991

Cephalometric scaling methodology in limited samples.

In longitudinal or cross-sectional cephalometric evaluation there are many factors which make analysis difficult. Samples are often limited in number and include both sexes. Registration may be done at different ages, using different equipment and techniques. By linear scaling size differences between sub-groups may be calibrated. Angular variables may still differ, however, suggesting differences in shape. If not, such sub-groups can be pooled, thus increasing the number of cases in each group and allowing more meaningful comparisons to be made with other groups. Calibration of biological size differences and/or technical effects of image enlargement may also be used to create a suitable baseline independent of growth, from which to study treatment effects.

Adolescent↗

PubMed1991

A study of facial growth in patients with unilateral cleft lip and palate treated by the Oslo CLP Team.

Lateral and frontal cephalometric analysis of a mixed longitudinal survey of 257 individuals with complete unilateral cleft lip and palate from the Oslo CLP Growth Archive is described. All subjects were treated and followed up by the Oslo CLP Team according to strictly defined protocols for treatment and documentation. Craniofacial form for this sample is generally similar to that reported for Caucasian children treated for this condition elsewhere.

Adolescent↗

PubMed1991

A study of facial growth in patients with bilateral cleft lip and palate treated by the Oslo CLP Team.

Lateral and frontal cephalometric analysis of a mixed longitudinal survey of 90 individuals with complete bilateral clefts of the lip and palate from the Oslo Growth Archive is described. All subjects were treated and followed-up by the Olso CLP Team according to strictly defined protocols for treatment and documentation. Craniofacial form in this sample is generally similar to that reported for Caucasian subjects treated for this condition elsewhere.

Adolescent↗

PubMed1991

Simonart's band and facial growth in unilateral clefts of the lip and palate.

A cephalometric analysis was carried out to see if the presence of a Simonart's band at birth was associated with a detectable difference in subsequent craniofacial form. Mixed longitudinal data from 5 through 18 years of age was analyzed for 257 individuals with complete UCLP included in the Oslo CLP Growth Archive, 80 with a Simonart's band and 177 without. No major differences were detected between individuals with or without Simonart's band, though the presence of a Simonart's band was associated with a larger cranial base angle and a slightly more favorable maxillomandibular relationship. The findings are discussed in relation to embryogenesis, primary surgery, and secondary surgery. It is recommended that cephalometric studies of UCLP involving group comparisons should avoid major imbalance with respect to the proportion of individuals with a Simonart's band at birth.

Adolescent↗

PubMed1991

Strategies for the advancement of surgical methods in cleft lip and palate.

This paper examines the clinical research methodologies used for the evaluation of cleft lip and palate therapies. A survey of clinical reports in the Cleft Palate Journal between 1964 and 1988 revealed that almost all used retrospective methods (96%). The authors examine the merits and biases associated with retrospective evaluation of therapies and compared these to prospective randomized clinical trials. The strengths and weaknesses of clinical trials are discussed in relation to the long-term evaluation of primary surgery in cleft patients. For these to be successful, further work is needed to investigate questions such as sample size, possible predictors of long-term outcome, and improved methods of presurgical assessment. The authors conclude that if the uncertainties associated with the choice of primary cleft surgery are to be resolved, the challenge of multicenter prospective clinical trials must be faced by the various disciplines involved in cleft palate clinical research.

Cleft Lip↗

PubMed1991

Craniofacial development in children with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes. I. Maxillary development.

Lateral skull radiographs of 85 patients with unilateral clefts of the lip, alveolus, and palate treated according to four different regimes were compared at three different ages regarding maxillary development. Regimes that included primary bone grafting to the alveolus at six months of age resulted in inhibited anterior maxillary growth and reduced maxillary inclination. Regimes that included secondary bone grafting after eruption of the incisors but before the eruption of the canines, resulted in better maxillary development, but were not as good as regimes that omitted bone grafting altogether.

Adolescent↗