Biomedical subjects

E Polykandriotis

Publications and source records attributed to E Polykandriotis.

12 recordsLinked to original sources

PubMed2006

[Vacuum-assisted closure as temporary coverage in the "problem zone hand"].

INTRODUCTION: Vacuum therapy of hand defect problematic due to the interdigital folds and in particular due to the small surface. As a temporary cover in staged procedures, e. g. following excision of tumor-suspicious skin alterations at the hand, and/or at the fingers, the application of vacuum therapy results not only in a sterile, temporary cover of the wound, furthermore it promotes wound conditioning and reduction of the wound area as well as lymph and edema reduction. PATIENTS AND METHODS: A 75 year old female patient presented herself with a skin alteration at the right dorsal ring finger and the tentative diagnosis of a Morbus Bowen like lesion was raised. Due to the unclear histological status, a staged procedure with excision of the tumour and temporary defect coverage by means of vacuum therapy until final histological evaluation was indicated. We accomplished the radical excision of the unclear skin tumour at the proximal phalanx under preservation of the synovial sheath of the tendon. Subsequently, the wound was temporarily closed with vacuum therapy. Histological examination revealed the complete removal of a solar keratosis. Finally, after 7 days of vacuum therapy as a sterile dressing, with obvious reduction of wound area and simultaneous decrease of edema, the defect was finally covered with a reversed cross finger flap from the adjacent middle finger. The donor site was covered with a full thickness skin graft harvested from the right forearm. The further course was without complication after flap dissection and complete healing. DISCUSSION: Vacuum therapy represents a usefull procedure for temporary wound coverage. Especially at hand defects, when nerves, tendons or bones following trauma or staged procedures are exposed, vacuum therapy can be successfully applied utilizing the special surgical "hand glove" technique.

Aged↗

PubMed2006

[Modified gloving technique for vacuum therapy in the hand].

INTRODUCTION: During the last 10 years sub-atmospheric pressure dressings (Topical Negative Pressure Therapy = TNP) has become a well accepted standard therapeutic modality in the management of acute and chronic wounds. However, in the hand and the fingers TNP treatment is not as an established method as elsewhere in the body. This is mostly due to difficulties in the technique of sealing wounds near the interdigital folds, especially when the interdigital folds are affected themselves. MATERIALS AND METHODS: Over a period of 36 months we treated 9 extensive open wounds of the hand with the TNP dressing procedure. To optimize the effective sealing procedure several methods of closure were applied: sterile vinyl gloves, split V.A.C. gel-straps and the "Sandwich"-principle. RESULTS: In all cases we were able to achieve a tight vacuum sealing with the use of our vinyl or latex free surgical glove as an aid to cover the interdigital spaces. There was a rapid and complete remission of the symptoms in terms of edema, redness, tenderness and range of motion. The indication spectrum encompassed infection control, temporary coverage of exposed bone or tendons, intermittent irrigation with local antiseptics as well as wound preconditioning before skin grafting or flap coverage. For the definite closure or coverage a second operation was necessary in all cases. CONCLUSIONS: The TNP-dressing can be securely achieved even in wounds encompassing the interdigital folds or adjacent to the in digital spaces with a modified surgical gloving technique to aid the standard sealing foil. It is a suitable principle for the management of severe hand infections with a reduction of clinical symptoms, reduction of the frequency of dressing changes compared to open approaches and a significant amelioration in the quality of life both for patients and health care personnel.

Amputation, Surgical↗

PubMed2006

[Prevascularisation strategies in tissue engineering].

INTRODUCTION: Experiments on animals have underlined the importance of vascularisation for biointegration and functionality of any given tissue engineering device. The aim of this investigation was to dissect the angiogenetic process in the frame of axial neovascularisation of a xenogenic solid matrix. The ultimate goal of this series of studies is the application of cells onto a prevascularised matrix, with the ambition to enhance cell survival after transplantation in vivo. MATERIALS AND METHODS: We performed a study in the rat with different vascular configurations in an isolation chamber. A disc-formed biogenic hard matrix (9 x 5 mm) was encased into an isolation chamber made of Teflon. In group 1, an arteriovenous fistula (AV loop) between the femoral vessels was microsurgically constructed and was placed around the matrix (n = 15). In group 2, the vascular carrier had the form of an arteriovenous ligated pedicle (n = 15). Evaluation intervals were two, four and eight weeks after implantation. The modes of evaluation included histology, scanning electron microscopy of corrosion casts as well as intravital micro-magnetic resonance imaging (MRI). RESULTS: The arteriovenous loop as vascular carrier revealed a higher capacity for angiogenesis over the bundle configuration. The neo-fibrovascular tissue displayed minimal inflammatory elements but dense vascularisation. Scanning electron microscopy demonstrated a vivid angiogenesis with rapid evolution of the vascular bead into mature, hierarchically organised network. Micro-MRI could be used for serial investigation in terms of flow measurements and detection of thrombosis. DISCUSSION: The presence of a vascular bed prior to cell transplantation might protect against hypoxia-induced cellular death, especially at central portions of the matrix, and therefore ensure physiological function of the device. The generation of vascularised bioartificial tissue substitutes might offer new modalities of surgical reconstruction for use in reparative medicine.

Animals↗

PubMed2005

The composite vastus medialis-patellar complex osseomuscular flap as a salvage procedure after complex trauma of the knee--an anatomical study and clinical application.

BACKGROUND: In the setting of severe perigenicular trauma or complicated endoprosthetic knee surgery, primary knee fusion may be the last resort for salvage of the limp. In this case, the patella looses its destination as an anterior knee stabilizer and can become a substantial donor of bone substance, especially if osseous defects are involved. PATIENTS AND METHODS: 12 formalin fixated cadavers were studied in terms of vascular anatomy, pedicle reliability, arc of rotation and their relation to sex, age, and height. Moreover, the operation was performed on a suitable patient. RESULTS: The quadriceps with the vastus medialis and the patella can be raised from the tibial tuberosity up to the entrance of the osteoarticular branch of the superficial femoral artery into the vastus medialis muscle ca 16 cm (15-19 cm) from the inferior patellar pole. This distance correlated well to the overall height of the cadavers (P=0.009). The vascular prerequisites were always present. In the clinical case, there was a favorable outcome with knee fusion after 4 months, despite of the lateral condylar defect. DISCUSSION: The composite vastus medialis-patellar complex osseomuscular flap can be safely used as a source of vascularized femoral condyle substitute in the setting of primary knee fusion.

Arteries↗

PubMed2004

[Breast-reduction surgery--a long-term survey of indications and outcomes].

Between 1986 and 2003, breast-reduction surgery was performed in a total of 814 women. The indication was established on the basis of physical complaints, chronic back pain, stiff neck or recurrent intertrigo in the foldbeneath the breasts. A proportion of the patients were interviewed postoperatively using a questionnaire, to determine the impact of the operation on their quality of life. 91% of those surveyed reported a postoperative improvement in the perception of their own body, and 80% were satisfied with the reduced size of their breasts. In conclusion, in the hands of an experienced breast surgeon, breast-reduction surgery for the proper indication results in a reliable and safe diminishment in breast size and tightening of slack tissue, leading to a significant enhancement in the patient's quality of life.

Adolescent↗

PubMed2004

[Use of vacuum therapy during defect coverage of the upper extremity with microsurgically grafted arterialized venous flaps].

Arterialized venous soft tissue flaps are defined as tissue portions usually harvested from the anterior and distal third of the forearm over a venous pathway to be transplanted to another recipient area. Basically, they are composed of skin, subcutaneous tissue, and subdermal venous plexus. At the recipient site flaps are perfused by a nourishing artery while the other veins are connected to one or more regional veins. The retrograde blood perfusion often results in edema, temporary epidermolysis, or even some degree of skin necrosis that disappear during subsequent treatment. To circumvent these drawbacks grafting of arterialized flaps was combined with local application of vacuum to overcome the venous initial stasis, resulting in improved healing and survival of these flaps.

Adult↗

PubMed2004

[Salvage of exposed alloplastic materials in irradiated wounds - a case report].

BACKGROUND: Modern multimodal concepts of complex reconstructions and advanced wound management enlarge strategies for surgical oncological therapies. One of the mainstays of classical surgical therapy in case of exposed alloplastic materials in irradiated wounds was to remove the foreign body due to the risk of infection. This loss of integrity and function of the contaminated host bed was to allow wound healing and closure. METHOD: We report the management of a 56-year-old female patient who developed a lyomyosarcoma at her left shoulder girdle 8 years after radiation of the left thorax because of breast cancer. After radical tumor resection and exarticulation of her left arm in the shoulder joint a necrosis of the soft tissue envelope developed, leading to an exposed alloplastic mesh. Staged debridement and continuous application of negative pressure was performed three times. Ultimate plastic coverage was performed by means of a pectoralis myocutaneous island flap from the other breast. RESULTS: After staged debridement and repeated vacuum application excellent wound cleaning, neovascularisation, wound contraction and formation of granulation tissue within the previously irradiated tissue zone was observed. Until fourteen months postoperative wound coverage remained stable and no signs of infection were observed. DISCUSSION: By means of negative pressure therapy even in radiated wounds excellent wound cleaning and sufficient formation of granulation tissue can be achieved. In some cases negative pressure therapy together with staged debridement allows reintegration of exposed and therefore potentially contaminated alloplastic meshes into new formed granulation tissue in radiated wounds respectively radiation ulcers. Thus leading to the possibility of ultimate plastic coverage.

Breast Neoplasms↗

PubMed2004

[Indication and clinical results of buried skin grafting to treat problematic wounds].

In 1920 Braun described a technique of skin grafting particularly designed for areas where shearing forces, high pressure and extensive secretion cause repetitive loss of conventionally transplanted skin. During the last 10 years we successfully used this technique when impaired wound healing was encountered due to various reasons. Clinical examples of application and results are presented. By combining this technique with vacuum therapy, formation of granulation tissue can be accelerated, thereby resulting in successful transplantation of problematic and therapy resistant wounds.

Adult↗

PubMed2001

[Plastic surgery coverage in the dorsal trunk area].

Defects of the trunk are major plastic surgical challenges. In the posterior trunk these defects are congenital or acquired. Most of the defects are due to major tumor resections, rarely after trauma or burns. With regional or local flaps most of the defects can be covered adequately. Presently musculocutaneous and perforator flaps are favoured. An interdisciplinary cooperation is mandatory for a successful result.

Abdominal Injuries↗

PubMedDate not supplied

The windblown hand - diagnosis, clinical picture and pathogenesis.

The syndrome of the windblown hand deformity is a complex constellation of malformations affecting not only the head and the feet but also the hands in a quite distinct manner. In the hand, it involves congenital bilateral flexion contracture with ulnar deviation of the metacarpophalangeal joints. The thumb is characteristically adducted (reaching the palm; "thumb-in-palm deformity") with flexion of the MP joint and hyperextension of the IP joint. The etiology is basically unknown. We present two theories based on knowledge derived from the disciplines of evolution biology and embryology. We believe that the atavistic appearance of phylogenetically primitive muscle groups in conjunction with an impaired rotation of the extremities during embryological development account for this malformation syndrome.

Abnormalities, Multiple↗

PubMedDate not supplied

Tissue engineering of bone: the reconstructive surgeon's point of view.

Bone defects represent a medical and socioeconomic challenge. Different types of biomaterials are applied for reconstructive indications and receive rising interest. However, autologous bone grafts are still considered as the gold standard for reconstruction of extended bone defects. The generation of bioartificial bone tissues may help to overcome the problems related to donor site morbidity and size limitations. Tissue engineering is, according to its historic definition, an "interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function". It is based on the understanding of tissue formation and regeneration and aims to rather grow new functional tissues than to build new spare parts. While reconstruction of small to moderate sized bone defects using engineered bone tissues is technically feasible, and some of the currently developed concepts may represent alternatives to autologous bone grafts for certain clinical conditions, the reconstruction of large-volume defects remains challenging. Therefore vascularization concepts gain on interest and the combination of tissue engineering approaches with flap prefabrication techniques may eventually allow application of bone-tissue substitutes grown in vivo with the advantage of minimal donor site morbidity as compared to conventional vascularized bone grafts. The scope of this review is the introduction of basic principles and different components of engineered bioartificial bone tissues with a strong focus on clinical applications in reconstructive surgery. Concepts for the induction of axial vascularization in engineered bone tissues as well as potential clinical applications are discussed in detail.

Bioartificial Organs↗

PubMedDate not supplied

A new approach to tissue engineering of vascularized skeletal muscle.

Tissue Engineering of skeletal muscle tissue still remains a major challenge. Every neo-tissue construct of clinically relevant dimensions is highly dependent on an intrinsic vascularisation overcoming the limitations of diffusion conditioned survival. Approaches incorporating the arteriovenous-loop model might bring further advances to the generation of vascularised skeletal muscle tissue. In this study 12 syngeneic rats received transplantaion of carboxy-fluorescine diacetate-succinimidyl ester (CFDA)-labelled, expanded primary myoblasts into a previously vascularised fibrin matrix, containing a microsurgically created AV loop. As control cells were injected into fibrin-matrices without AV-loops. Intra-arterial ink injection followed by explantation was performed 2, 4 and 8 weeks after cell implantation. Specimens were evaluated for CFDA, MyoD and DAPI staining, as well as for mRNA expression of muscle specific genes. Results showed enhanced fibrin resorption in dependence of AV loop presence. Transplanted myoblasts could be detected in the AV loop group even after 8 weeks by CFDA-fluorescence, still showing positive MyoD staining. RT-PCR revealed gene expression of MEF-2 and desmin after 4 weeks on the AVloop side, whereas expression analysis of myogenin and MHC(embryo) was negative. So far myoblast injection in the microsurgical rat AV loop model enhances survival of the cells, keeping their myogenic phenotype, within pre-vascularised fibrin matrices. Probably due to the lack of potent myogenic stimuli and additionally the rapid resorption of the fibrin matrix, no formation of skeletal muscle-like tissue could be observed. Thus further studies focussing on long term stability of the matrix and the incorporation of neural stimuli will be necessary for generation of vascularised skeletal muscle tissue.

Animals↗