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Biomedical subjects

K Vinzenz

Publications and source records attributed to K Vinzenz.

At least 19 recordsLinked to original sources

The dermis-prelaminated scapula flap for reconstructions of the hard palate and the alveolar ridge: a clinical and histologic evaluation.

Ideal reconstructions of complex defects in the midface require the restitution not only of bone and soft tissue, but also of a thin and durable lining of the oral cavity. So far, split-thickness skin grafts, intestinal grafts, and in vitro cultured mucosal grafts have been used for the reconstruction of the oral lining. The use of skin as a substitute for oral mucosa is controversial because contraction, hair growth, maceration, and dysplastic changes can occur. This clinical and histologic study was performed to evaluate the suitability of dermis as a substitute for oral lining. Twelve complex defects of the midface were reconstructed with dermis-prelaminated scapula flaps. A bony flap from the lateral border of the scapula was prepared, and osseointegrated implants were placed. The bone flap was then prelaminated with dermis and covered with a Gore-Tex membrane to prevent adhesions. The composite flap was transferred to the midface 2 to 3 months later. The oral lining of the flap was evaluated clinically and histologically at 2, 4, and 6 weeks and at 3 to 41 months after the reconstruction. In all patients, the reconstructed bone was covered with a thin and lubricated surface without hair growth. None of the patients showed any signs of maceration. Histologically, these findings corresponded to a keratinized stratified squamous epithelium with highly developed connective-tissue papillae. These features closely resemble those of the normal mucosa of the hard palate and the gingiva. Thus, dermis prelamination is an effective method for reconstructing the mucosa of the alveolar ridge and the hard palate.

Adolescent↗

The prefabricated scapula flap consists of syngeneic bone, connective tissue, and a self-assembled epithelial coating.

The reconstruction of maxillary defects is a challenge in plastic surgery. The so-called prefabricated scapula flap consists of syngeneic bone covered with syngeneic dermis and is used to reconstruct maxillary defects. After placing these flaps into the oral cavity, they are reepithelialized within a short time period, raising the question of the cellular origin of the "neomucosa." We therefore obtained sequential biopsy samples of the prefabricated flap and of the flap after being placed into the oral cavity and analyzed the keratin expression profile of epithelial cells. We expected that after placing the prefabricated flap into the oral cavity, keratinocytes from adnexal structures of the dermal component of the graft would migrate onto the surface and reepithelialize the flap. Unexpectedly, reepithelialization occurred earlier. The flap had acquired a mucosa-like epithelium at the interface between the Gore-Tex coating and the dermis while still being positioned within the scapular region. The keratin expression profile of this epithelium was very similar to that of mucosal epithelium. Thus, the prefabricated scapula flap not only consisted of bone covered with connective tissue, but was also covered with epithelial cells derived from adnexal structures of the dermal graft. This seems to be the reason for the rapid restoration of an intact mucosa and the excellent outcome achieved with this surgical technique.

Adult↗

The external oblique muscle free flap.

To date, the external oblique muscle has been considered to have a purely segmental vascular supply and therefore has been used surgically only as a pedicled flap. To better define the vascular anatomy and nerve supply of the muscle, we performed arterial injection studies and dissected the nerves that entered the muscle in 35 human cadavers. We found that in addition to the segmental arteries, one or two large branches of the deep circumflex iliac artery contributed significantly to the blood supply of the external oblique muscle in 33 of the 35 cadavers. We also found that the lateral cutaneous branches of the intercostal nerves entered and supplied the muscle near its origin from the rib in a strictly segmental pattern. These anatomic findings enabled us to transplant the external oblique muscle successfully as a free flap based on the deep circumflex iliac vessels in six patients. The muscle flap is thin, pliable, and can be combined with an iliac bone or an abdominal skin transplant. Its vascular pedicle is long (mean 12 cm) and of adequate diameter for microvascular repair. The donor scar of the flap is inconspicuously situated along the inguinal ligament and the iliac crest. Finally, since the muscle has a multiple nerve supply, it has the potential to provide several functional units at the recipient site when transplanted as a functional free flap.

Abdominal Muscles↗

[Tissue preparation in combined scapula flap for microsurgical reconstruction of defects of the oromaxillofacial area].

Nowadays, in congenital or acquired large oro-maxillofacial defects microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aim of reconstruction includes not only restoration of stable continuity and esthetic contour, but also the restoration of a functioning "chewing organ". For reconstruction in maxillary and midface defects, we prefer the scapular flap for a single-step reconstruction. Tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable soft tissue conditions at the time of microsurgical reconstruction. Following dental restoration, full oral function is given. This single-stage procedure improves the psychosocial situation of the patient considerably when compared with conventional multi-stage reconstruction.

Adult↗

The prefabricated combined scapula flap for bony and soft-tissue reconstruction in maxillofacial defects--a new method.

A concept for improving the precision of reconstruction of the maxilla in terms of form and function, including gnathologic, functional, and prosthetic aspects, is presented with a prefabricated combined scapula flap. In four cases, a bony flap from the lateral border of the scapula with osseointegrated titanium implants, covered with skin grafts and encapsulated with a Goretex sheet to create a stable soft-tissue coverage, was performed. Three months later, the prefabricated combined scapula flap was harvested and transferred to reconstruct a maxillary bony and soft-tissue defect in the face using microsurgical vascular anastomoses to the facial vessels. One flap was lost because of vascular thrombosis and was repeated successfully 1 year later. In each of the four cases, full dental rehabilitation and marked improvement of the facial contour was achieved in a single surgical intervention of the face. For this purpose, new radiodiagnostic methods for precise correlation between the maxillofacial defect and the donor area were use. With this new concept, an organ-specific reconstruction of soft-and bony-tissue defects of the alveolar ridge and the hard palate, with a pseudogingiva and teeth, is possible in an optimal way.

Adolescent↗

[Postoperative physical rehabilitation. Therapeutic goals and procedures in head and neck cancer].

The objective of postoperative physical rehabilitation of patients with head and neck carcinoma is to re-establish their physical, emotional, and social capabilities as far as possible. It is the task of the specialist in physical medicine to diagnose on musculoskeletal system-related problems, to establish concepts for rehabilitation treatment, and to define the aims of therapy. Depending on the clinical situation, pain has to be reduced, edemas eliminated, muscle balance re-established and endurance improved. Special emphasis must be put on correct breathing and to the training of the activities of daily living.

Combined Modality Therapy↗

Investigations into shoulder function after radical neck dissection.

In order to determine shoulder function after radical neck dissection, and to evaluate the outcome of postoperative physical treatment, 43 patients were investigated 10 days up to 1 month after this procedure. Shoulder function was judged by means of (a) clinical investigation of the shoulder girdle and by (b) electromyographic testing of the trapezius muscle. Our results demonstrated a correlation between the extent of atrophy and clinical parameters such as abduction and lateral displacement of the scapula. Electromyography revealed damage present mainly in the descending part of the trapezius, while in the majority of patients the ascending part was only slightly damaged or normal. Electromyography proved a valuable tool for the determination of the clinical state after neck dissection. There was also evidence supporting the efficacy of physical therapy in case of irreversible shoulder disability.

Adult↗

Natural cytotoxicity in draining lymph nodes of squamous cell cancer in the maxillofacial region.

There is at present very little information available, including the presented preliminary data, concerning NK activity in patients with head and neck cancer. The objective of the present investigation was to study NK activity in peripheral blood (PB) and regional lymph nodes (LNs) in patients with different stages of head and neck cancer. Furthermore, phenotypic characterization of lymph node cells was performed. Finally, the in vitro response of mononuclear cells isolated from blood and lymph nodes to interferon was investigated.

Carcinoma, Squamous Cell↗

Diagnosis of head and neck carcinomas by means of immunological tumour markers (Beta-2-microglobulin, immunoglobulin E, ferritin, N-acetyl-neuraminic acid, phosphohexose-isomerase).

In a great number of patients with squamous cell cancer of the head and neck, tumour markers in the serum were determined before any therapy, in order to evaluate their possible usefulness as parameters for monitoring therapy as well as for early detection of cancer. Patients with primary tumours (n = 101) were distributed to groups TI-II and TIII-IV according to the UICC classification 1978, and investigated together with a group of recurrences (n = 105). 50 age-matched healthy individuals served as controls. Substances investigated were beta 2-Microglobulin (beta 2-M), Immunoglobulin E (IgE), Ferritin, N-Acetyl-Neuraminic Acid (sialic acid; NANA), Phosphohexose-Isomerase (PHI). Not only were the mean values of the groups compared with each other, but also the percentages of the respective groups displaying increases above the upper norm limit (95. percentile) were calculated. Critical evaluation of the results led to the conclusion that in particular IgE, NANA and--with some reservations--ferritin should be further investigated as biological serum markers in serial determination with special regard to their possible relevance for cancer treatment.

Biomarkers, Tumor↗

Modulation of NK activity in regional lymph nodes by preoperative immunotherapy with OK-432 in patients with cancer of the oral cavity.

The influence of preoperative perilesional therapy with the potent bacterial biological response modifier (BRM) OK-432 on natural killer (NK) cell activity in peripheral blood and tumor draining lymph nodes (LNs) of patients with head and neck cancer (HNC) has been investigated. Pretreatment NK activity in peripheral blood (PB) was comparable within the group of HNC patients. However, after perilesional OK-432 therapy, a significant increase in cytotoxicity was observed by day 8. Furthermore, postoperative suppression of PB NK activity was less pronounced in patients with OK-432 therapy. In tumor draining LNs, NK activity was significantly higher in patients receiving OK-432 therapy than in those treated by surgery alone. No differences were detected concerning the in vitro stimulatory capacity of interferon (IFN) and/or Staphylococcus protein A (SPA) on LN NK activity in both the OK-432 treated and untreated group. Furthermore, by immunoperoxidase technique, LNs of OK-432 treated patients were found to express a higher number of cells reacting with the monoclonal antibody HNK-1 compared to LNs of the untreated group. Both these results suggest that perilesional OK-432 therapy leads to an increase in number and function of NK cells in regional LNs, together with an increase in NK activity in PB in some but not all patients.

Adult↗

Systemic and regional natural cytotoxicity in patients with head and neck cancer.

Forty patients with squamous carcinoma of the oral cavity (head and neck cancer) were investigated for natural killer-cell (NK) activity in peripheral blood (PB) and tumour-draining lymph nodes (LNs). For measuring NK activity a 4 hrs 51Cr release assay and K 562 target cells were used. Mononuclear cells of PB (PBMNC) and LNs (LNMNC) were separated by Ficoll Hypaque gradient centrifugation. NK activity was determined before tumour surgery. LNs were obtained either at the time of surgery of the primary tumour (en bloc neck dissection)--"immediately dissected LNs (ID-LNs)" or some time after removal of the primary tumour, especially for prophylactic purposes,--"delayed dissected LNs (DD-LNs)". Preoperatively, NK activity was clearly stage-dependent, patients with stages T1-2 displaying mean values similar to those of a control group without malignant disease, whereas values were significantly lower in patients with stages T3-4. Spontaneous cytotoxicity was significantly lower in LNMNC than in PBMNC of identical donors. NK activity was significantly lower in ID-LNs than in DD-LNs. These results suggest some negative influence of the primary tumour in the spontaneous cytotoxicity in both PB and tumour-draining LNs. In vitro incubation at +37 degrees together with addition of lymphoblastoid interferon (IFN-alpha) achieved a significantly stimulation of NK activity in both PBMNC and LNMNC.

Cytotoxicity, Immunologic↗