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National and international tendencies to avoid nasal packing after FESS are closed related to the surgical surgery (atraumatic endoscopic surgery, avoidance of resection of turbinates, meticulose coagulation). At the end of each operation a benefit-risk-analysis should be performed, whether nasal packing is indicated and which one. In endonasal surgery only those conventional nasal packing materials should be used - if necessary - which have a smooth surface and minimize mucosal damage, potential worsening of wound healing and negative impact on patient comfort. So called hemostatic/resorbable materials are a first step to these direction. But they are critical, because these materials cause increased synechiae and sometimes foreign body reactions because of incorporation into the mucosa. Occlusion of the nose via simple taping of the nasal entrance is a simple and very effective method to create a moist environment to optimize endonasal wound healing or management of a dry nose.

The synthesis of pharmaceutically relevant (R)-benzoins catalyzed by the benzaldehyde lyase is almost exclusively described for aqueous monophasic systems. In such systems the number of convertible hydrophobic substrates is limited, the turn over number is partly unsatisfactory and additives which are commonly used for the improvement of the substrate solubility have a negative influence on the enzyme activity and the product quality. This thesis describes the development of a gel-stabilized two-phase system that enabled the application of the recombinantly produced benzaldehyde lyase derived from Pseudomonas fluorescens in organic solvents for the synthesis of novel, strongly hydrophobic (R)-benzoins. The benzaldehyde lyase was homogeneously purified and immobilized into a PVA matrix for the carboligation of hydrophobic, aromatic or heterocyclic aldehydes in n-hexane. The conversion of the different aldehydes was already up to 77% without prior optimization of the system. (R)-benzoins were synthesized with an enantiomeric excess of predominantly >99%. With respect to the (R)-2,2'-furoin synthesis the enzyme productivity was considerably higher with the gel-stabilized system than with an aqueous monophasic system described in the literature. Furthermore the gel-stabilized two-phase system was investigated and optimized for the synthesis of (R)-3,3-furoin whereas the conversion of 3-furaldehyde was increased to 90%. The product extraction could be improved in a specially engineered, continuously operating fluidized-bed reactor whereby the space-time yield was increased and unwanted side reactions were minimized. Furthermore the physico-chemical properties of the system were investigated. The 9% containing PVA matrix was highly compression-proof and elastic. Even the contact of organic solvents did nearly not influence the stability of the PVA immobilizates. Homogeneous partition of the enzyme in the round-shaped immobilizates was proven. Proteins with a molecule mass of more than 154 kDa were completely retained by the matrix. Besides for n-hexane the substrate specific partition coefficient and diffusion were determined for others solvents as well.

At present the vacuum sealing technique is acknowledged as a therapy for acute and chronic wounds. An acceleration of the healing process, due to the vacuum suction with occlusive wound dressing, leads to the shortening of a cost-effective medical treatment. This can be applied to wound treatment and infections of soft tissues, but even today there is only sparse information in this context about joint infections.The results of therapy with the vacuum sealing technique in 68 patients with infections of the joints of an extremity or the trunk were analysed in a retrospective study without a control group. The importance of several patient-related factors for the medical treatment have been analysed.An adequate treatment of joint infections can be achieved even in the presence of endoprostheses or osteosynthetic material. The following factors have been found to be of significance for a prolonged medical treatment: diabetes mellitus (p=0.0052), obesity (BMI25) (p=0.0458) and a preceding trauma (p=0.0457).The results confirm the value of the vacuum sealing technique following surgical debridement in combination with resistance tested antibiotic treatment, as a sufficient therapy for joint infections, even in patients with an endoprosthesis. This procedure leads to a safe treatment of the joint infection, combined with a good function of the treated joint, good patient comfort and a short duration of the therapy.

Summary Modern wound therapy is developing continuously. Vacuum therapy is an estab-lished procedure to treat wounds. Available on the market is, among others, the V.A.C.® (Vacuum Assisted Closure) therapy system. Here, we report the various effects of the vacuum therapy on wounds such as reducing the bacterial contamination, improving granulation and microcirculation and focus on the practical use of the V.A.C.®, possible complications, contraindications and the economic aspects of the therapy. Since V.A.C.® therapy allows rapid mobilization of patients especially with postoperative or posttraumatic wounds, infrequent dressing changes and relative analgesia, this treatment modality is well-accepted by patients with acute or chronic wounds. One explanation for the high acceptance on part of the therapists and the widespread use of the method are the excellent clinical results.

Vacuum therapy is a routine and successful method for wound treatment and for the temporary covering of soft-tissue defects. It is an occlusive method that can be used for treating acute, chronic and infected wounds. To date, no data are available regarding secretion transit times and pressure conditions in lesions treated with vacuum therapy. The present study had as its objectives to examine the mechanisms of vacuum therapy and determine the effects of physical forces on the wound surface with the purpose of formulating recommendations for pressure settings using the various available vacuum pumps.Using an appropriate model, we measured secretion transit times and pressures using two different vacuum therapy pads. We then conducted pressure measurements during dressing change in eight patients with wound surfaces greater than 20 cm(2).The secretion transit times remained unchanged with the polyvinyl alcohol (PVA) pad and a negative pressure of 40 kPa, but decreased by about 50 % when the black polyurethane (PU) pad was used. Pressure measurements showed that, at this negative pressure, there was only a slight positive external pressure of 31 mmHg on the wound surface.When the PVA pad is used, negative pressures greater than 40 kPa should be applied in order to effect a maximum transit of wound secretion and prolongation of the use of the vacuum dressing. When the PU pad is used, the applied negative pressure can be lower due to the pad's larger pores, as recommended by Argenta and Morykwas. An excessive external pressure on the wound surface does not occur.

The aim of this study was to determine the pressure conditions in the tissue beneath and on the surface of wounds. This was done in vitro both on a plain surface and on a bovine muscle. In comparison we measured the pressure of the anterior tibial muscle of a patient with compartment syndrome. Besides, we applied negative pressure using just one drape connector and measured the pressure in different distances to look if the pressure is constant in large V.A.C.(R) dressings. Both polyurethane and polyvinyl alcohol foams were used.

Treatment of open abdomen following secondary peritonitis is a challenge for surgery and intensive care units (ICU). The aim of this study was to compare three different concurrent treatment strategies.Patients suffering an open abdomen following surgery for secondary peritonitis at the Department of General Surgery from 01/01 to 12/03 were investigated. Factor studied: duration of open abdomen, incidence of multi-organ failure, need for surgical revisions, length of stay (LOS) in ICU, nursing requirements (change of dressing/day), survival and integrity of abdominal wall after discharge. Treatment strategies included: open packing (OP), classic vacuum assisted (V.A.C.(R))-therapy with silicone net protection for the intestine (CV) and V.A.C.(R)-therapy with "abdominal dressing" a newly developed meshed polyvinyl wrap (AD).21 patients were studied: 5 patients were treated with OP, 8 patients with CV and 8 patients with AD. Mean LOS was 65 (OP) vs. 53 (CV) vs. 42 (AD) days (NS), peritonitis related death was 3 (OP) vs. 1 (CV) vs. 0 (AD) (p0.05 Chisquare test). Median nursing effort was 4 dressings/day (OP), 0.5 (CV) and 0.5 (AD) (p0.005 OP vs CV, AD Kruskal-Wallis test).The "abdominal dressing"-therapy seems to be a more efficient treatment option in patients suffering from open abdomen following secondary peritonitis. A trend towards shorter ICU-LOS, lower mortality rates and reduced nursing requirements support our hypothesis.

Tissue engineering research has demonstrated the potential of a variety of different matrix materials to enable cell adhesion, diffusion of nutrients, vascular ingrowth, nutrition and growth promotion. Therefore it appears attractive to apply these features also to topical negative pressure therapy. The article discusses several aspects of foam materials and their possible interactions with the wound surface.

Infections after hip arthroplasty can lead to protracted and complicated treatments. A great problem is thereby the persistant secretion after surgical revision. 8 patients (3 x after acetabulum cup replacement, 2 x after Girdlestone hip, 2 x after spacer implantation and one case of rearthroplasty) have been treated with a V.A.C.-therapy after bacterial infection and persistant wound secretion. In all cases a pathogen organism could be identified during the frustrated attempts of sanitation. After meticulous debridement and jet lavage in each case, 1-3 polyvinyl sponges have been placed either periprosthetic or in the resection cavity with a transcutan tube outgoing. The wounds have been closed in layers. Initially a pressure of 200 mm Hg via V.A.C. has been attached. After 48-72 h an alteration from haemorrhagic to serous secret could be observed and afterwards the pressure has been reduced to 150 mm Hg. After a mean period of 11 days (8-13) the infection parameters have been retrogressive, the wound secretion was obviously reduced and the sponges were removed. During the remaining hospitalization of each patient no complications occured. In the mean follow-up of 21 months (2-46) no reinfections have been observed. Although the V.A.C.-therapy does not count to the primary therapy concepts of periprosthetic hip infections, it stands for an effective therapy option in exclusive cases.

Vacuum therapy (vacuum assisted wound closure (V.A.C.(R)) is a non invasive method to promote wound healing. It is based on defined, controlled negative pressure application via medical-grade reticulated polyurethane ether or polyvinyl foam dressing to wound surfaces. The technique is characterized by continuous removal of wound exudates and hence reduction of extravascular, interstitial fluid, subsequently leading to enhanced microcirculation. Experimental studies revealed a positive influence both on local microcirculation and on granulation tissue formation. Local mechanical physical factors, yet not completely understood, similar to tissue expansion, apply to the wound surface and seem to promote cell growth. In our own patients the vacuum technique has been used to pretreat chronic wounds in 139 patients, to fix split thickness skin grafts in 148 patients and to prefabricate or delay free or pedicled flaps in 11 patients so far. Thorough surgical debridement remains the mainstay of wound care. Vacuum therapy however, as an adjunctive procedure, offers significant advantages compared to conventional wound care methods, which call for further clinical and experimental studies to elucidate the basic mechanisms.

Dural carotid sinus cavernous fistulas account for about 12% of intracranial arteriovenous fistulas. These dynamic shunts are dilemmas not only for the clinical diagnosis but also for the management of ocular complications and in the application of diagnostic and therapeutic techniques. The traditional therapy is transarterial embolisation by an interventional neuroradiologist. We report on the management of two fistulas where the classical therapeutic methods were not possible or failed.Two patients underwent an osteoplastic pterional craniotomy with cannulation of a vein of the sylvian fissure and controlled embolisation of the fistula with polyvinyl alcohol particles.Successful closure of both arteriovenous shunts was achieved on angiography with normalisation of clinical symptoms. As a severe complication one patient suffered from a stroke after the postoperative angiography.Arteriovenous fistulas not approachable by traditional therapeutic methods, can be embolised effectively via a superficial vein of the sylvian fissure. This surgical route should only be considered if other therapeutic ways fail or seem impossible.

Evaluation of superselective embolisation of renal tumours in inoperable patients with solitary kidneys.Eight inoperable patients with solitary kidneys bearing tumour nodules underwent 1-3 superselective embolisation procedures with ethibloc (5x) or polyvinyl alcohol (1x). Renal function was monitored with creatinine levels. Tumour size was controlled every three months by means of sonography.Technical success rate was 100%. In 3/3 patients haematuria could be stopped. Post-embolisation renal function was unchanged in 6 patients and deteriorated in two patients; creatinine level rose to a maximum of 2.2 mg%. We observed no other side effects. Seven of eight patients died during a median follow-up period of 9.3 months (4-18 months); in two cases they died due to their underlying malignant disease. One patient had local tumour progress.Superselective embolisation of renal tumours in patients with solitary kidneys may be a helpful, well-tolerated therapeutic option in inoperable, symptomatic patients.

The author reports about his experiences with the polyvinylalcohol (PVAL) method for sampling gunshot residues from the hands of suicides. Traces of blood are no obstacle for the PVAL-method. It is even possible to save gunshot residues with PVAL after sampling with cottonswabs or tape-lifts. High resolution radiography is proposed for the evaluation in addition to the chemographic analysis as a second independent method.

In 1992, 15 of 152 patients with open fractures were treated with vacuum sealing. Drainage tubes are inserted into polyvinyl foam, which is used to fill in the wound or tissue defect. Polyvinyl foam and adjacent skin are covered with a transparent polyurethane dressing which is impermeable to bacteria. The connection of the drainage tubes to a suction device, such as vacuum bottles, produces negative pressure in the polyvinyl foam, which means a high-contact zone of the foam-wound interface. This results in efficient cleaning and conditioning of the wound, with marked proliferation of granulation tissue. Bone infection did not occur in any of our 15 patients; 1 patient sustained a soft tissue infection due to an insufficient sealing technique. When the correct technique was applied the infection cleared up.

The drug release can be improved by incorporation of additional auxiliary substances in extrusion pellets. The experimental results proved evidence, that especially the incorporation of calcium carbonate or polyvinylalcohol leads to an increase of the drug release. Their content must amount to 40%. In preparing thermically unstable drugs in pellets, it is necessary to prepare these products under thermically mild conditions. By using ethylene-vinyl-acetate-copolymers these unstable drugs can be incorporated in extrusion pellets.

Periodontitis is a locally limited disease caused by bacteria. The local application presents itself useful for the indicated medicamentous therapy of periodontitis by means of metronidazole. In preliminary tests the metronidazole liberation from hollow fibres, in gel and from polyvinyl alcohol platelets has been tested by ultraviolet absorption measurement. The hollow fibres have been evaluated no more because of too small agent absorption in the clinical test. In polyvinyl alcohol metronidazole acts definitely over 3 days. However, the prolonged action in the gel form is not definitely (45 min to 24 h). A single one or repeated twice metronidazole/polyvinyl alcohol platelet application results in a sufficient long and high metronidazole concentration in the gingival pocket.

Animal experimental research and clinical experience in polyvinylalcohol formaldehyde foam (PVA) as a temporary skin cover: The usefulness of PVA as a temporary skin cover of burns and infected wounds was studied in animals. On the back of 20 pigs full thickness burns were produced and wounds were infected, then examined macroscopically, histologically and bacteriologically over a period of 18 days. PVA showed a better wound cleansing, a significantly reduced bacterial flora and a more rapid growth of the epithelium in comparison with three other materials. The clinical use of PVA in the treatment of compound fractures with a severe damage of soft tissue, of infected wounds and of burns also demonstrated a quick cleansing of the wound and an induction of a dense and vascularised granulation tissue. Thus considerable infections could be avoided and early grafting was possible.

The aim of this study was to prepare a tablet with acetylsalicylic acid based on hydrophilic matrix form by means of polyvinyl alcohol. The liberation was carried out with the column dissolution-rate method. In contrast to other studies, the percentage of the cumulative liberation is decreased by increasing the drug concentration. Acetylsalicylic acid caused a decrease of the wetting and the rate of swelling.

The optimal qualitative and quantitative identification by microscopy of mycobacteria cultivated in liquid medium in including several problems. Acridine-orange was used for staining in all investigations. Polyvinyl-alcohol (1--2.5%) proved to be the best means for fixing mycobacteria culture suspensions on slides. A reliable sterilization of the sides was possible with peracetic acid (3%). Tween 80 in the culture medium did not impair the adherence of the fixed suspension on the slide under these conditions. Mycobacteria in a suspension of 10(-4) mg (wet weight) per ml could be still found by microscopy with this procedure.

The influences of 8 different beta-blockers on the tear film stability-measured on the breakup time (BUT) of normal and healthy volunteers-was compared. All beta-blockers led to BUT reduction, however, the lowest influence was observed with levobunolol. The duration of this effect was compared with that of levobunolol, timolol and metipranolol. While the minor BUT alterations induced by levobunolol recovered after 30 min and were completely restored after 1 h, those of the two other beta-blockers lasted for over 2 h. The combination of timolol 0.5% with different artificial tears containing mainly polyvinyl alcohol (PVA) 1.4%, methylcellulose and polyacrylic acid initially led also to BUT reduction. The best results were obtained with PVA 1.4%.

By increasing the drug concentration or the porosity of the mouldings, the liberation rate of the drug is increased. Dependently on their wetting behaviour and concentration, insoluble solids may exert varied effects on the liberation rate. The rate of swelling and, thus, the disintegration time and the release can be controlled by the addition of magnesium stearate or potato starch.

In 30 subjects without ophthalmological disease the corneal contact time of a new artificial polyacrylic-based tear gel (Vidisic, produced by Dr. Mann, Berlin) was compared with a well-known artificial polyvinyl alcohol-based tear solution. The Vidisic concentration remained in the corneal tear film 7 times longer than the substance it was compared with. In a second study including 7 normal subjects and 5 patients with keratoconjunctivitis sicca, the influence of Vidisic on break-up time (BUT) and the Schirmer test was demonstrated. It was found that tear secretion improved for 2-4 hours (Schirmer test) and the stability of the tear film (BUT) improved for about 6 hours with Vidisic. These results suggest that application of Vidisic four times a day is sufficient for efficatious therapy even in cases of severe keratoconjunctivitis sicca.