Biomedical subjects

W Millesi

Publications and source records attributed to W Millesi.

At least 19 recordsLinked to original sources

PubMed2001

Impact of hemoglobin level and use of recombinant erythropoietin on efficacy of preoperative chemoradiation therapy for squamous cell carcinoma of the oral cavity and oropharynx.

PURPOSE: We assessed the influence of hemoglobin level and r-HuEPO administration on response to chemoradiotherapy, locoregional tumor control, and overall survival in patients treated with neoadjuvant chemoradiotherapy and surgery for a squamous cell carcinoma of the oral cavity or oropharynx. METHODS AND MATERIALS: The 191 study patients were treated with mitomycin C (15 mg/m(2) day 1), 5-fluorouracil (750 mg/m(2)/day, days 1-5), and radiotherapy (50 Gy in 25 fractions weeks 1-5), followed by resection of the primary tumor bed and neck dissection at the General Hospital Vienna, Austria, between November 1989 and October 1998 for a T2-4, N0-3, M0 SCC of the oral cavity or oropharynx. Starting in May 1996, patients with a low hemoglobin (Hgb) before or during chemoradiotherapy received r-HuEPO 10,000 IU/kg s.c. 3-6 times/week until the week of surgery. RESULTS: On multivariate analysis, Hgb level and use of r-HuEPO were independent prognostic factors for response to chemoradiotherapy and locoregional tumor control (p < 0.01). Pathologic response to neoadjuvant therapy was also predictive of locoregional control (p < 0.001). Patients with a pretreatment Hgb > or = 14.5 g/dL had significantly higher complete response, locoregional control, and survival rates than the patients with a pretreatment Hgb < 14.5 g/dL who did not receive r-HuEPO (p < 0.05). The response, control, and survival rates in patients with a pretreatment Hgb < 14.5 g/dL given r-HuEPO were significantly higher than in low Hgb patients not given r-HuEPO (p < or = 0.001) and equivalent to patients with a pretreatment Hgb > 14.5 g/dL (p > or = 0.3). CONCLUSION: Low pretreatment Hgb is a negative prognostic factor for oral cavity and oropharyngeal SCCA patients, but was completely abrogated by r-HuEpo administration during neoadjuvant chemoradiotherapy. Randomized trials of radiation and/or chemotherapy with or without r-HuEPO for patients whose Hgb level is either low at the start of therapy or is anticipated to become low during therapy are indicated.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

Immune competent cells in non-irradiated autologous jejunal grafts used for reconstruction of the oral cavity and oropharynx.

Autologous jejunal grafts used for primary reconstruction in cases of extensive soft tissue defects following tumor resection in the upper aerodigestive tract were investigated by immunohistochemistry (APAAP technique). Biopsies from eight patients were taken intra-operatively, at the time of transplantation and 2, 4, and 6 months post-operatively. A panel of monoclonal antibodies directed against surface antigens of the major subpopulations of the immune system was used. In all of the patients, a remarkable increase of all antigens investigated was detected 2 months post-operatively, which remained unchanged in the following biopsies (4 and 6 months postoperatively). Significantly higher numbers of CD45RA+ and CD45RO+ (P<0.05) leukocytes were detectable. This increase was due to both subsets of T and B cells, but only for CD19+ B cells was the increase significant. In addition, NK cells (CD16+ lymphocytic cells, P<0.01) and mature macrophages (25F9+ cells, P<0.01) increased. The first post-operative biopsy showed a significantly higher expression of activation-associated antigens (ICAM-1, VCAM, and HLA-DR) on monocytes/macrophages and endothelial cells. Our findings indicate that autologous jejunal grafts facilitate immunological function in the new microenvironment.

Aged↗

PubMed2001

Preprosthetic vertical distraction osteogenesis of the mandible using an L-shaped osteotomy and titanium membranes for guided bone regeneration.

PURPOSE: Vertical osteodistraction is a new alternative method for alveolar ridge augmentation of the mandible. The purpose of this article is describe a technique using an L-shaped osteotomy and titanium membranes for guided bone regeneration (GBR) in the distraction gap. PATIENTS AND METHODS: Ten patients with severe atrophy of the edentulous molar region of the mandible underwent vertical callus distraction in 13 sites using intraoral microplate distractors. An L-shaped osteotomy with a short vertical part mesially and a longer horizontal part ending in the retromolar region was made, and the osteotomized segment was fixed to the mandibular ramus at its distal edge by a microplate, which became the center of rotation when distraction began. In this way, more callus generation could be achieved mesially than in the distal molar region. Follow-up computed tomography (CT) scans reconstructed axially to the axis of the mandible revealed semilunar excavations of the generated bone buccally in the distraction gap in the first cases. Clinical inspection on removal of the distractors showed fibrous connective tissue in the gap. Therefore, to prevent this from happening, titanium membranes covering the distraction gap were applied in subsequent cases. RESULTS: Ten patients (13 sites) were treated by vertical callus distraction. In 4 cases, GBR was achieved using titanium membranes. In all cases, the increase in alveolar height was sufficient to make dental implantation possible. In 1 patient, a fracture of the distractor occurred, and dehiscence was observed in 2 cases. These complications did not change the plan of therapy nor did they influence the results. The CT scans showed a homogenous surface on the regenerated mandible in the cases of GBR application. CONCLUSION: Both an L-shaped osteotomy and the application of titanium membranes for GBR in the distraction gap are of great value for mandibular augmentation, producing a physiologically shaped alveolar ridge.

Adult↗

PubMed2001

Muscle-nerve-muscle neurotization of the orbicularis oris muscle.

INTRODUCTION: A denervated half of the orbicularis oris muscle is not reinnervated spontaneously by axon sprouting from the intact contralateral side. The borderline between the facial nerve territories seems to act as a barrier. The muscle-nerve-muscle technique was advocated as a technique to reneurotize a denervated half of the orbicularis oris muscle in cases of marginal mandibular paralysis. MATERIAL AND METHODS: This muscle-nerve-muscle neurotization was tried to induce reinnervation of a denervated angle of the mouth in four patients. Grafts were harvested from the sural nerve. Functional recovery was assessed by measurement of facial movements and by electrophysiological examination. RESULTS: In three of the four cases presented, this technique helped to improve function of the lower lip. The clinical relevance of the results is discussed.

Electromyography↗

PubMed2001

The influence of deliberate hypotension on splanchnic perfusion balance with use of either isoflurane or esmolol and nitroglycerin.

UNLABELLED: Various techniques to induce deliberate hypotension (DH) have different influences on splanchnic perfusion. The aim of our study was to determine whether splanchnic perfusion is clinically impaired during DH by using either isoflurane (ISO) or a combination of esmolol and nitroglycerin (E/N). We randomized 16 patients undergoing elective maxillofacial surgery to receive either ISO (0.7%-1.8%) or E (105 g x kg(-1) x min(-1)) and N (1-6 mg/h) to induce DH. General anesthesia was performed in both groups by IV midazolam 0.07 mg/kg, fentanyl 0.003 mg/kg, propofol 1.5 mg/kg, and vecuronium 0.1 mg/kg followed by a propofol infusion with 6 mg x kg(-1) x h(-1). After the induction of anesthesia, a gastric tonometer (TRIP NGS Catheter) and a radial artery catheter were inserted. Baseline values of gastric intramucosal pH (pHi) were determined 60 min after placement of the catheter and before the induction of DH. The pHi values were calculated every 60 min until DH was discontinued. In both groups, DH was satisfactorily established. None of the pHi values calculated was less than 7.37 in the E/N or 7.41 in the ISO group. Arterial blood lactate levels did not increase in any of the patients. We conclude that neither method of producing DH compromises splanchnic tissue oxygen balance in healthy patients. Furthermore, overall organ perfusion was sufficient in both groups, because none of the patients showed an increase in blood lactate. IMPLICATIONS: Neither the isoflurane nor the esmolol/nitroglycerin method of producing deliberate hypotension compromises splanchnic tissue oxygen balance in healthy patients. Furthermore, overall organ perfusion was sufficient in both groups, because none of the patients showed an increase in blood lactate.

Adrenergic beta-Antagonists↗

PubMed2000

Guided bone regeneration with titanium membranes: a clinical study.

Guided bone regeneration using barrier membranes is useful in bone augmentation. Because the commonly used polytetrafluoroethylene (PTFE, Gore-Tex (R), WL Gore, Flagstaff, AZ, USA) membranes or resorbable membranes tend to collapse, more stable membranes are desirable. A titanium membrane (FRIOS(R) BoneShield, Friatec, Mannheim, Germany) was evaluated in a clinical study of 52 patients. Most of them had particulate bone grafts or phycogene hydroxyapatite (Algipore(R), Friatec, Mannheim, Germany) or both stabilized with titanium membranes. In 78 procedures, 23 membranes (29%) became exposed, but only seven of these (9%) led to failure of the graft with a considerable loss of augmented material. The time interval between operation and possibly exposure was responsible for the result. Early exposures (within a few weeks) led to poor formation of new bone within the grafts, whereas if exposure was later, results were as good as in procedures in which the membranes did not become exposed.

Adult↗

PubMed2000

The L-shaped osteotomy for vertical callus distraction in the molar region of the mandible: a technical note.

The following report refers to a well described surgical procedure using a prototype vertical distractor developed in Cologne in cooperation with Martin Medizintechnik GmbH. The surgical technique has been refined by an L-shaped osteotomy stabilized posteriorly by a miniplate to limit the amount of callus regeneration in the molar region where no increase in vertical height is required. The surgical technique with its advantages and one complication is described as used in four patients undergoing six distraction treatments.

Adult↗

PubMed2000

Experimental study of muscle-nerve-muscle neurotization.

A laboratory model for the study of possible reinnervation by muscle-nerve-muscle (MNM) neurotization is presented. Preliminary studies revealed that MNM neurotization occurs in synergistically closely-related facial muscles. However, for larger antagonistic somatic muscle (flexor and extensor), this phenomenon could not be reproduced. The potential clinical relevance of these findings is presented and discussed.

Animals↗

PubMed2000

Multifocal eosinophilic granuloma of the jaw: long-term follow-up of a novel intraosseous corticoid treatment for recalcitrant lesions.

Eosinophilic granuloma of the jaws is a rather benign and localized form of Langerhans' cell histiocytosis. Treatment is usually required in larger lesions that cause local pain and swelling and pose the risk of spontaneous fractures. There are several accepted forms of treatment, which include surgery, radiation therapy, systemic and local therapy with corticoids, and systemic chemotherapy. No studies exist that compare the effectiveness of these treatment modalities. We report a novel therapeutic regimen that uses repeated intraosseous injections of triamcinolone-1 16 alpha 21-diacetat, a synthetic corticoid, which led to a rapid, complete, and durable treatment. The patient had a multilocal eosinophilic granuloma of the mandible in which radiation therapy, systemic corticoid therapy, and systemic chemotherapy had failed.

Adult↗

PubMed1999

Clinical experience with interactive teleconsultation and teleassistance in craniomaxillofacial surgical procedures.

PURPOSE: The objective of this study was to evaluate the clinical value and feasibility of surgical telenavigation and teleassistance technology in the field of craniomaxillofacial surgery. MATERIALS AND METHODS: The technology is based on the principles of augmented reality environment technology and remote stereotactic visualization. A consultant surgeon in a remote location receives video, audio, and stereotactic navigation data from the operation site almost in real-time and, using a head-mounted display, is emerged in the surgical augmented reality environment. By telepresence or teleconsultation, the composite images and superimposed graphics (instruments, target structures, landmarks, contours) can be seen and discussed in connected clinics with the possibility of interactive manipulation and assistance. RESULTS: Interactive teleassistance was used in 27 cases of various types craniomaxillofacial surgery. The principles of computer-aided telenavigation were applied successfully. Technical problems in 6 cases did not cause a breakdown of overall system performance. CONCLUSION: Teleconsultation with remote experts is a useful tool, although some shortcomings exist. The financial and personal effort involved is considerable.

Computer Graphics↗

PubMed1999

Positioning of dental implants using computer-aided navigation and an optical tracking system: case report and presentation of a new method.

A navigation system for computer-aided surgery (Virtual Patient System, VPS) has been described in previous studies for different indications in oral and maxillofacial surgery. The aim of the system is the intraoperative transfer of preoperative planning on radiographs or CT scans on the patient, in real-time, and independent of the position of the patient's head. Until now an electromagnetic tracking system has been used for intra-operative position measurement. For placement of dental implants, the electromagnetic tracking system is not suitable since the motor of the implant drill leads to a considerable distortion of the magnetic field, thus direct visualization of drilling the implant socket was not possible. To overcome this problem, an optical tracking system which is not disturbed by conductive materials was integrated in the VPS system. The first patient operated on with this system had a posttraumatic loss of the upper incisors; three implants have been placed according to the prosthetic axis previously planned on radiographs and CT scans. The experience gained in this intervention led to the conclusion that computer-aided surgery provides a valuable tool in implant dentistry.

Adult↗

PubMed1999

Neuromucosal prelaminated flaps for reconstruction of intraoral lining defects after radical tumor resection.

To reconstruct intraoral lining defects after radical tumor resection by reinnervated vascularized mucosa, eight distal radial forearm flaps and two fibula flaps were prelaminated. Prelamination was performed by exposing the vascularized fascia, onto which the split distal end of a sural graft was fixed. The fascia and the sural nerve graft were covered by device-meshed mucosa or small full-thickness mucosa pieces. These structures again were covered by a Silastic sheet as large as the future flap, and the wound was closed by the elevated skin and subcutaneous tissue. Coverage by a Silastic sheet enabled mucosal spreading on the fascia, and the final flaps were thin, mucus-producing, and larger than the originally inserted mucosa. The 10 neuromucosal prelaminated flaps were harvested together with the inserted sural nerve graft after 8 to 10 weeks. During this time, the patient underwent radiotherapy and chemotherapy. Donor sites were closed directly by the preserved skin and subcutaneous tissue. Intraoral defects were reconstructed successfully by eight neuromucosal prelaminated distal radial forearm flaps and two neuromucosal prelaminated fibula flaps. The sural nerve grafts, inserted between the fascia and the mucosa, were coaptated eight times with the lingual nerve and two times with the inferior alveolar nerve. Intended reinnervation of the mucosa could already be proved clinically and histologically in the first two patients after 11 and 9 months. Preservation of skin and subcutaneous tissue considerably lowered donor-site morbidity. Neuromucosal prelamination enables reconstruction of intraoral lining defects by reinnervated mucus-producing tissue. Reconstruction of other mucosa-lined structures by this method seems feasible. Avoidance of skin islands for reconstruction lowers donor-site morbidity.

Adult↗

PubMed1999

Computer-aided surgery in distraction osteogenesis of the maxilla and mandible.

When using unidirectional intraoral distraction devices, it is desirable to be able to determine the final position of the bone fragment after the distraction procedure. However, additional constraining forces from adjacent tissues render the prediction of the distraction direction difficult. We have utilised computer-aided surgery in three patients for intraoperative control of the distraction direction. In one cleft palate patient, suffering from maxillary hypoplasia and anterior open bite, a modified Le Fort I osteotomy and maxillary distraction was performed. Despite a ventrocaudal position of the distraction device, intraoperative computer visualisation showed an unfavourable caudal vector of distraction without any anterior movement. The final result confirmed the direction indicated by the computer. Maxillary advancement remained insufficient. In two patients suffering from mandibular hypoplasia, intraoperative assessment revealed a favourable direction of distraction. The distraction procedure led to a satisfactory result in both cases. Computer-aided surgery is helpful in assessing the vector of distraction intraoperatively, making the result of the distraction procedure more predictable and allowing instant correction by adequate reapplication of the device.

Adolescent↗

PubMed1998

Continuous hyperfractionated accelerated radiotherapy with/without mitomycin C in head and neck cancer.

PURPOSE: To evaluate the effect of mitomycin C to an accelerated hyperfractionated radiation therapy. The aim was to test a very short schedule with/without mitomycin C (MMC) with conventional fractionation in histologically verified squamous cell carcinoma of the head and neck region. METHODS AND MATERIALS: From October 1990 to December 1996, 188 patients entered the trial. Tumors originated in the oral cavity in 54, oropharynx in 82, larynx in 20, and hypopharynx in 32 cases, respectively. Patients' stages were predominantly T3 and T4 (158/188, 84%) and most patients had lymph node metastases (144/188, 77%) at diagnosis. Only 22 patients were female, 166 were male, the median age of patients was 57 years (range 34 to 76 years). Patients were randomized to one of the following three treatment options: conventional fractionation (CF) consisting of 70 Gy in 35 fractions over 7 weeks (65 patients) or continuous hyperfractionated accelerated radiation therapy (V-CHART; 62 patients) or continuous hyperfractionated accelerated radiation therapy with 20 mg/sqm MMC on day 5 (V-CHART + MMC; 61 patients). By the accelerated regimens, the total dose of 55.3 Gy was delivered within 17 consecutive days, by 33 fractions. On day 1, a single dose of 2.5 Gy was given, from day 2 to 17 a dose of 1.65 Gy was delivered twice: the interfraction interval was 6 hours or more. RESULTS: Mucositis was very intense after accelerated therapy, most patients experiencing a grade III/IV reaction. The mucosal reaction did not differ whether MMC was administered or not. Patients treated by accelerated fractionation experienced a confluent mucosal reaction 12-14 days following start of therapy and recovered (no reaction) within 6 weeks. The skin reaction was not considered different in the three treatment groups. Those patients treated with additional chemotherapy experienced a grade III/IV hematologic toxicity in 12/61 patients. Initial complete response (CR) was recorded in 43% following CF, 58% after V-CHART, and 67% after V-CHART + MMC, respectively (p < 0.05). Actuarial survival (Kaplan-Meier) was significantly improved in the combined treated patients. Local tumor control was 28%, 32%, and 56% following CF, V-CHART, and V-CHART + MMC, respectively (p < 0.05). CONCLUSION: We conclude that our continuous hyperfractionated accelerated radiation therapy regimen is equal to conventional fractionation, suggesting that by shortening the overall treatment time from 7 weeks to 17 days a reduction in dose from 70 Gy to 55.3 Gy is possible, with maintenance of local tumor control rates. The administration of MMC to the accelerated regimen is tolerable and improves the outcome for patients significantly.

Adult↗

PubMed1998

Magnetic cell separation for purification of human oral keratinocytes: an effective method for functional studies without prior cell subcultivation.

In studying human oral keratinocytes, it would be very helpful to obtain a pure population of cells without prior in vitro expansion. An immunomagnetic separation technique, or magnetic cell separation (MACS), was modified for efficient purification of human oral keratinocytes. Subsequent to two-step enzymatic digestion, the cell suspension was labelled with a mouse anti-CD45 (pan-leukocyte) monoclonal antibody (MoAb) to stain mononuclear cells. In a second step a rat anti-mouse antibody conjugated with colloidal superparamagnetic particles was used. Labelled cells were retained in the magnetic field of a permanent magnet on columns containing a ferromagnetic matrix. The unlabelled, unretained cells were further examined by flow cytometry analysis, enzyme-linked immunosorbent assay and polymerase chain reaction. After the MACS procedure, unretained cells showed a strong positivity for the lu-5 MoAb (as a marker for pan-cytokeratin) and were negative for anti-vimentin (to mark mesenchymal cells), for anti-CD45 MoAb and for melanocyte-detecting antibodies, thus representing pure keratinocytes (> 98%). Purified keratinocytes maintained full viability (> 91%) and functional capacities. [3H]thymidine uptake and epidermal growth factor (EGF) receptor expression were unaltered when compared with the non-separated cell population. Furthermore, interleukin-1 alpha was detected at the protein and RNA levels in keratinocytes immediately after MACS enrichment. Our findings show that MACS appears to be a useful tool for purification of oral keratinocytes and allows for further functional studies without prior subcultivation of cells.

Animals↗

PubMed1998

Contrast-enhanced computed tomography of freely transplanted jejunal patches after surgery in the oral cavity and oropharynx.

Thirty-two patients with jejunal patches in the oral cavity and oropharynx were examined with contrast-enhanced computed tomography (CT). The morphology of the intestinal wall, the mesenteric fatty tissue, mesenteric lymph nodes and the region of the anastomosis were evaluated and correlated with clinical findings. The size and number of mesenterial lymph nodes, which were found in 16 cases, did not correlate with tumour recurrence. The benign alterations of the intestinal wall ranged from flat surfaces with no enhancement to significant enhancement with persisting folds. In cases with persisting intestinal folds, separation of tumour recurrence was achieved by identification of a typical double-layer configuration of the enhancing mucosa, and the restriction of alterations to the intestinal wall compartment. Tumour recurrences occurred at patch margins and were reliably distinguished from normal patches. For differentiation of findings, an exact localization of jejunum-patch compartments and margins with contrast-enhanced CT was, therefore, necessary.

Adult↗

PubMed1998

Reconstruction of the floor of the mouth with a fascial radial forearm flap, prelaminated with autologous mucosa.

To circumvent the disadvantages of extraoral skin within the oral cavity and to cover mucosal defects by mucosa, we successfully prelaminated the radial forearm flap by insertion of buccal mucosa in ten patients. In a first-step operation, free grafts of buccal mucosa were fixed to the forearm fascia and covered with an alloplastic sheet, separating the mucosa grafts and the dissected fascia between and around the grafts from the overlaying subcutaneous tissue. The dimension of the alloplastic sheet in the subcutaneous pocket was chosen according to the size of the desired flap. Underneath the alloplastic sheet, the mucosal grafts merged and the mucosal surface increased by advancing of epithelial cells under in vivo culture conditions. After two months, mucosal prelamination of the distal radial forearm fascia had led to thin, pliable and resistant fasciomucosal flaps with a mucosal surface up to 7x4 cm, allowing physiological intraoral reconstruction. The preservation of skin and subcutaneous tissue of the forearm also enabled primary wound closure, reducing donor-site morbidity.

Adult↗

PubMed1998

Preoperative stereolithographic model planning for primary reconstruction in craniomaxillofacial trauma surgery.

High precision anatomical facsimile models of the patient's skull, individually produced by stereolithography, have been used in the preoperative planning in 16 patients with acute craniomaxillofacial trauma. In late primary repair, when open reduction and internal fixation had to wait for a decrease in facial swelling or cerebral oedema, computer-aided surgery has proven to be useful in terms of facilitating anatomical reduction, minimizing surgical approaches, saving operating time and leading to improved postoperative results, which may reduce the number of secondary corrections of post-traumatic deformities.

Acrylic Resins↗