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Biomedical subjects

H Weerda

Publications and source records attributed to H Weerda.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Tissue expansion. Part 1: Technical and physiologic principles].

The technique of tissue expansion can now be used to prepare skin for reconstructive operations. This method has been propagated during the last 15 years, but its use has varied from great enthusiasm with exaggerated expectations to disillusion due to high complication rates. For an efficient and successful application of skin expansion an understanding of skin reactions and their control is mandatory. In this review, the biological principles of expansion, various expansion protocols and their objectives, control during the filling phase and preventive measures to avoid complications are described. For clinical use it is important that there is not one but three distinct types of expansion: an intraoperative, intermittent expansion for gentle subcutaneous skin mobilization, a short time period for expansion (between 1-2 weeks) to increase the dermal microcirculation and the "classic" prolonged period of expansion to create new skin for the reconstruction required.

Cell Division↗
PubMed1993

Clinical and experimental evaluation of intermittent intraoperative short-term expansion.

To assist in the closure of defects in the region of the head lack and neck, a number of surgeons recommend intermittent intraoperative short-term expansion to exploit the biomechanical properties of the skin. It was the aim of this study to assess quantitatively the amount of intraoperative "tissue gain," to analyze its origin, and to throw light on its underlying biomechanical processes. A total of 285 expansions in 5-minute intervals under a constant tissue pressure of 100 mmHg were performed on 30 patients with severe microtia. The volumes achieved were protocolled, and microcirculation was monitored with the help of a laser-Doppler flowmeter. Expanders exerting a tissue pressure of 100 mmHg for more than 80 cycles lasting 20 minutes also were employed in five dogs. Apart from determining the volumes, changes in distance between the skin tattoos and the diameter of the expander base were recorded. A volume increase of about 10 percent per hour was recorded for the human patients and an increase of about 30 percent per hour for the animals. After reaching a maximal increase in length of 15 to 20 percent, there was no further skin elongation despite increasing volumes. Instead, the expander began to move into the subcutaneous tissue so that its diameter showed a continuous increase. We can conclude on the basis of these results that the increase in volume during intermittent intraoperative short-term expansion is not caused by the proclaimed "creep" behavior of the skin.

Animals↗
PubMed1993

[Pressure-volume analysis of wound suction drainage systems and their importance in otorhinolaryngologic surgery].

Four low-vacuum systems and 6 high-vacuum systems were examined concerning their pressure-volume relationships. For each type the maximum filling volume for sufficient drainage of wound secretions was determined. The use of a wound fluid substitute instead of water resulted in a lower aspiration volume. Enlargement of the tube diameter showed a reduction in the initial vacuum for the low-vacuum systems, whereas the high-vacuum systems were not affected. The amounts of postoperative wound fluid lost in selected ENT operations were determined. Considering the volume capacity of the wound drainage systems, the type of container can be chosen that eliminates the necessity for later bottle exchange on the wards, thus avoiding a potential risk for wound infection. The high-vacuum systems with a volume capacity of 150 or 200 ml are sufficient for parotidectomies, costal cartilage resections and reconstructions of the auricle, resulting in good postoperative wound adaptation and also preventing the need for postoperative bottle exchanges.

Animals↗
PubMed1993

[Revascularized over-long jejunum segments in single stage reconstruction of voice and deglutition function after total laryngopharyngectomy].

After surgery of advanced larynx and pharynx malignancies, a main problem is reconstruction of swallowing and voice. With microvascular small bowl transplantation, we have been able to use a 30 cm segment of jejunum in a one-stage procedure to reconstruct extended defects of the oropharynx, and total by hypopharynx, as well as to create a speaking-syphon as devised by Ehrenberger. The surgical technique is described and we now report the results achieved in our first five patients. This new method enables pharyngectomized and laryngectomized patients to speak and to eat without any aspiration after about two weeks. This rapid and functionally encouraging rehabilitation means a significant improvement in a patient's quality of life and is further justification for the great effort required in using this method.

Adult↗
PubMed1989

[Measures for reducing the rate of complications in endoscopic surgery of Zenker's diverticulum].

In the treatment of the pharyngeal pouch diverticulectomy and endoscopic diverticulotomy are generally accepted. The latter can lead to severe bleeding and mediastinitis. --Therefore the authors have extended the preoperative diagnostic procedure to include a DSA of the aortic arch. The simultaneous contrast filling of the pouch enables the exact position of the blood vessels relative to the bar to be established. --With the spreadable diverticuloscope developed by the authors, the use of a CO2 laser and an operating microscope, optimum endoscopic working conditions are assured. Postoperative sealing of the wound margin with fibrin reduces the likelihood of postoperative bleeding and mediastinitis, the risk of which have been further reduced by antibiotic prophylaxis and tube feeding for eight days. During and after the treatment of ten patients not a single complication has arisen.

Angiography, Digital Subtraction↗
PubMed1986

[Treatment of stenoses of the laryngotracheal junction and the cervical trachea].

In the past 20 years we have operated on 187 patients for tracheal stenoses. Dilatation, tracheopexy with ring support, sleeve resection, and the gutter procedure are described. In recent years we have replaced open treatment of the tracheal gutter with our closed method. After expanding the posterior wall, the anterior tracheal wall is closed with a myocutaneous island flap, rib cartilage or a myomucosal flap. The merits of the different methods are discussed. Dilatation of the trachea and reconstruction of the anterior tracheal wall over a silicone tube in a one stage procedure creates a sturdy trachea, which is better able to resist scar contracture and pressure from the soft parts of the neck than an open U-shaped gutter. The number of operations and days of treatment per patient are materially reduced by the closed method.

Adolescent↗
PubMed1986

[Removal of the iliac crest bone].

The paper covers diagnoses indicating removal of bone from the iliac crest, positioning, an approach to the iliac crest, and techniques for removing bone. The hazards incident to the removal of spongiosa, cortical substance, or spongeous-cortical bone chips are described. Haemorrhages from the spongiosa must be staunched carefully with wax plugs or fibrin glue (Tissucol1). Complications such as perforation, hernia, hyperaesthesia, muscular atrophy, and changes in contour are discussed, as well as suitable measures to avoid complications.

Bone Cysts↗