Biomedical subjects

C W van der Hoeven

Publications and source records attributed to C W van der Hoeven.

4 recordsLinked to original sources

PubMed1995

The influence of anaesthetic drugs on the lower oesophageal sphincter in propofol/nitrous oxide anaesthetized dogs. Pressure profilometry in an animal model.

The lower oesophageal sphincter (LES) is the main barrier against gastro-oesophageal reflux. Various anaesthetic drugs have been reported to affect the LES pressure. In this study, the effects of cisapride, atropine, suxamethonium, vecuronium and pancuronium on the LES pressure of six mongrel dogs anaesthetized with propofol and nitrous oxide were investigated. By means of eight-channel pressure profilometry the LES pressure was measured in consecutive sessions before and after administration of each drug. Compared to basal values, atropine and suxamethonium significantly decreased LES pressure, pressure vector volume and sphincter length. Cisapride significantly increased all sphincter parameters, vecuronium significantly increased LES pressure and pressure vector volume while pancuronium had no significant effects. A significant decrease of the LES pressure and pressure vector volume was observed when nitrous oxide was omitted from the ventilation mixture. Three-dimensional imaging showed an asymmetric shape of the LES pressure which resulted from radial differences of the LES pressure. The results from this study show that both the anaesthetic animal model and the eight-channel pressure profilometry are useful procedures in studying the effects on sphincter function of different drugs during anaesthesia.

Anesthesia↗

PubMed1994

Treatment of faecal incontinence in a child with sacral agenesis: the use of biofeedback training.

The case of a 14-year-old girl is presented who was born with sacral agenesis and severe, chronic constipation not responding to laxative treatment. Biofeedback was employed in the treatment of the constipation and soiling. After six treatment sessions over four months, the constipation and soiling ceased and there was no relapse during follow-up of 12 months. Although this child had an absence of S3-S5 and the coccyx, with possible innervation abnormalities, this case illustrates that biofeedback training might be a useful adjunct to existing therapies.

Adolescent↗

PubMed1994

Manometry, profilometry, and endosonography: normal physiology and anatomy of the anal canal in healthy children.

Normal and manometric and profilometric values and normal endosonographic features of the anal canal are required for evaluation of pathological conditions such as slow-transit constipation, anorectal outlet obstruction, and Hirschsprung's disease, status after surgery for imperforate anus, and other anal abnormalities. Anorectal manometry, profilometry (rapid-pull-through, three-dimensional, eight-channel radial manometry), and endosonography were carried out in 13 healthy children. A significant correlation was demonstrated between conventional manometric and profilometric maximal squeeze pressure of the external anal sphincter (EAS). However, the maximal and resting tone of the sphincter complex in profilometry was twice as high as in manometry due to reflexive contraction of a pelvic floor muscle, probably the EAS. With profilometry a positive correlation was found between age and sphincter length. Endosonographically assessed thickness of the EAS, puborectal muscle, and levator ani complex showed a significant correlation with age. However, no correlation was demonstrated between age and internal anal sphincter thickness. Thus, the development of the essential structures of the anal canal in children is age dependent. In addition, these measurements of normal physiology and anatomy of the anal canal provide the basis for detecting pathological conditions of the anorectal region in children.

Adolescent↗

PubMed1990

The lower esophageal sphincter shown by a computerized representation.

The clinical application of manometry of the lower esophageal sphincter (LES) remains controversial. This is because of the large variability in recorded lower esophageal sphincter pressure (LESP). In this paper a computerized method providing a three-dimensional image of the LES is described. In 12 healthy subjects end-expiratory rapid pull-through LESP recordings were performed for 1 h, using a perfused 8-channel probe. A cylindric model of the sphincter was calculated by means of a graphics program. The graphic representation of the LES demonstrated a circular pressure zone that was affected by the gastric migrating motility complex. This pressure zone was located proximal to a persistent indentation in the posterior and right posterolateral direction. Three-dimensional visualization of the LES provides additional information that cannot be obtained by the usually used techniques of analysis of sphincter manometry.

Adolescent↗