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Biomedical subjects

N-C Gellrich

Publications and source records attributed to N-C Gellrich.

17 recordsLinked to original sources
PubMed2007

[Navigated "targeted surgery" for skull base malignomas: additional space for surgical manipulation by neoadjuvant tumor downsizing].

BACKGROUND: Multimodal strategies are required due to the poor prognosis for locally advanced frontal skull base tumors staged as T4. Therefore, a further increase in the degree of invalidity caused by therapy should be avoided, if possible, to preserve the quality of life. As the incidence of these tumors is low, there are no evidence-based, generally accepted therapeutic strategies. METHODS: We evaluated the clinical results of three patients with extended frontal skull base malignomas staged as T4 tumors. The clinical course as well as the surgical technique were analyzed. RESULTS: High dose neoadjuvant therapy for tumor downsizing was performed in all three patients within a multimodal therapy concept. The additional space for surgical manipulation close to the tumor borders, non-traumatically produced by tumor remission, permitted a safely navigated, controlled resection of the tumor under endoscopic or microscopic viewing using an approach associated with reduced trauma as "targeted surgery". CONCLUSIONS: Surgical radicality is limited by the direct vicinity of locally progressive T4 tumors to the frontal brain and other vital structures. A controlled tumor downsizing allows the resection of such tumors using a minimally invasive approach assisted by instrumental navigation leading to less traumatization.

Adult↗
PubMed2007

[Posttraumatic amaurosis after complex frontobasal fracture. Differential diagnosis and therapy].

BACKGROUND: Whether surgical nerve decompression is indicated for the treatment of posttraumatic reduced vision with optic nerve compression in the bony canal has been a subject of controversy for decades. On balance, the recent literature suggests that this procedure is indeed indicated, as a supplement to high-dosed cortisone therapy. The risk of surgery-related side effects is usually rated low in the literature. CASE REPORT: We report on a woman patient in whom craniocerebral trauma involved a fracture of the left optic canal with unilateral loss of vision. In the decompression operation, intraoperative symptoms gave rise to the suspicion of an arteriovenous fistula, which had not been revealed by computer tomography and which was seen as sufficient grounds for discontinuing the procedure. In addition to a carotid artery-sinus cavernosus fistula (CCF Barrow type A), subsequent angiography revealed a dissected aneurysm at the branching of the occluded ophthalmic artery. DISCUSSION AND CONCLUSIONS: In decisions on whether surgical relief of pressure on the optic canal is indicated after trauma-related visual loss, the possibility of secondary lesions near the tip of the orbita and the optic canal must be taken into account. These are not always revealed by computer tomography. The indications should be critically weighed up in each individual case, with additional imaging examinations, such as MR-angiography, CT-angiography, or conventional angiography, performed as needed. The options and indications for imaging are discussed. The procedure can by no means be rated as "minimally invasive", as is postulated by some authors.

Adult↗
PubMed2006

Topographical CT-data analysis of the human orbital floor.

The aim of this study was to evaluate the topographical anatomy of the human orbital floor for the production of prefabricated implants on the basis of computer tomography data. A database of 279 CT scans of Caucasian patients without traumatic deformation of the midface was analysed. 3D-image segmentation of the midfacial skeleton was performed using a computer-assisted protocol. A virtual plane (50 x 50 mm (2)) was constructed using defined landmarks above the orbital floor. An automated procedure was used to measure the distance between the orbital floor and the constructed plane at 400 distinct points. A mathematical algorithm was used to analyse the data, and to calculate a map of the orbital floor. Statistical analysis of the data revealed that orbital floor topography could be classified as distinct clusters. There were 12 variations of orbital floor anatomy: three unique patterns of the orbital floor for the right orbit and three corresponding patterns for the left side, all of which varied between the sexes. The 12 patterns were constructed with a statistical confidence interval of 1.36+/-0.6mm.

Adult↗
PubMed2006

[Skull base chondrosarcoma. An interdisciplinary challenge].

BACKGROUND: Chondrosarcoma is a rare differential diagnosis of malignant tumours of the skull base. The prognosis was rated as unfavourable in articles for many years. It has, however, improved considerably in recent years. The objective of this study was to evaluate and current, new optimised treatment strategies. PATIENTS AND METHODS: We retrospectively analysed the case histories and course of four patients whom we treated for chondrosarcoma of the skull base over the past 5 years at the Freiburg Skull Base Centre. RESULTS: Because of initially mild symptoms, the patients first came for examination at an advanced stage of the tumour. All patients underwent surgery, whereby an R0-resection was barely or only questionably present. Three patients underwent radiation therapy postoperatively. All patients are currently tumour free. CONCLUSIONS: Surgical treatment with curative intent is basically the therapy of choice. Due to the usually large size of the tumour and its close relationship to relevant structures, complete resection is, however, not always possible despite advances in surgical procedures. Taking the possibility of modern adjuvant radiotherapeutic procedures into account, an incomplete, function-preserving resection is preferred to a radical and mutilating resection.

Adult↗
PubMed2006

[Objectivity of therapeutic results following skull base surgery using virtual model analysis].

BACKGROUND: Virtual model analysis of patient head tracking allows for objectivity and the monitoring of therapeutic results of pathologies in the skull base region. The introduction of these models in clinical routine has been impaired by the extended time needed for the preparation of radiological data. METHODS: Quality control analysis was carried out for seven cases with different pathological findings in the skull base region in patients who had undergone virtual model analysis. RESULTS: Preparation time of radiological data for the process of segmentation required, under optimal conditions, a minimum of 30 min. Virtual model analysis enables spatial visualization of regions of interest and adjacent anatomical structures. This improves case-specific pathoanatomical understanding as well as preoperative planning of surgical strategies. CONCLUSIONS: Virtual model analysis improves the physician's spatial comprehension of localized pathological findings at the dysmorphic interface of bone and soft tissue across the skull base. Therefore, it seems to be an adequate tool for quality control analysis of therapeutic results after extended skull base surgery.

Adolescent↗
PubMed2006

[Single and temporally displaced second nerve lesions in an animal model and their clinical significance].

BACKGROUND: Surgical optic decompression after trauma has been discussed controversially. The surgical trauma is supposed to produce an additional nerve lesion with the danger of complete loss of vision. Alternatively, conservative high dose cortisone therapy has been recommended. METHODS: The functional and morphological consequences of a lesion after calibrated optic compression in one or two sessions were examined in an animal model using 29 Wistar rats. RESULTS: Depending on the duration and intensity of the lesion, we observed a linear decline in the number of neurons in the RGC (retinal ganglion cell) layer as well as an increasing reactivity to GFAP (glial fibrillary acidic protein) as an indication of central gliosis of astrocytes; however, this was independent on whether optic compression was performed in one or two sessions. CONCLUSIONS: To reduce secondary damage to the visual nerve and the central visual system that might increase with a persisting lesion, the indication for surgical relief of an eye affected by afference should be considered liberally, especially in view of the low morbidity of rhinosurgical intervention.

Animals↗
PubMed2005

[Computer assisted methods in reconstructive and function-preserving orbital surgery. New capabilities of computer assisted preoperative surgical planning (CAPP) and computer assisted surgery (CAS)].

BACKGROUND: Orbital reconstruction after tumor or trauma makes high demands on the surgeon when restoring the optic axis and cosmetic features. Computer-assisted preoperative planning surgery (CAPP) and computer-assisted surgery (CAS) allow calculation of the form of the orbital cavity to be reconstructed preoperatively as well as the process of its realization intraoperatively. METHODS: We developed new planning software methods for this surgical procedure. For validation the deviation of accuracy was assessed between the virtual and the real model in eight patients with surgical reconstruction of the orbit. RESULTS: The check of accuracy of the reconstructions compared to the planning of the surgery by fusion of preoperative and postoperative data resulted in a mean deviation of 1.74 mm. The volumetric measurements presented a mean deviation of 0.2 cm(3) with an accuracy of >99%. The accuracy of linear measurements with the techniques of image fusion of the "feature-based" method was 0.38 mm and thus close to the technical threshold of effective data accuracy of 0.35 mm. The enophthalmus could be assessed more objectively with this method compared to using the Hertel index. CONCLUSIONS: CAPP and CAS are helpful in reconstructive orbital surgery to verify the position of the optic axis and the cosmetic result intraoperatively.

Adult↗
PubMed2005

Search for ideal biomaterials to cultivate human osteoblast-like cells for reconstructive surgery.

In this study we cultured human osteoblast-like cells on 16 different biomaterials to find an optimal biomaterial for subsequent use in reconstructive surgery. The tested biomaterials can be divided into five groups: collagen-based membranes of bovine, equine or calf origin, tricalcium phosphate based membranes (alpha and beta), hyaluronic acid based, anorganic bovine bone and anorganic silicone-based membranes. Cell proliferation and cell colonization (Environmental Scanning Electron Microscope, ESEM) analysis were performed. The results of the study demonstrated that four of the examined biomaterial/cell constructs showed a very good proliferation rate and cell density: No. 3 (Tissue Vlies), No. 7 (Sepra film), No. 16 (Biobrane) and No. 17 (Biomend). No favourable group of biomaterials was noticeable. Moreover, the results indicate that these four biomaterials as a part of bone constructs are the best tools for engineering new bone tissue. In contrast, biomaterials No. 19a (Bio-Oss) and 19b (Bio-Oss Collagen) showed the lowest proliferation rates. The result of No. 19b was improved by treatment in the perfusion chamber for 48 h as well as by additional use of vacuum. The present study is an important base for further analysis of biomaterials and consequently for the development of tissue engineering.

Bioartificial Organs↗
PubMed2005

[CAS in rhino-surgical procedures in the growing age].

BACKGROUND: Rhinosurgery in children and adolescents meets special requirements: Limited cooperation and reduced limits for the organ dose for ionizing radiological examinations aggravate diagnostics. On the other side, bone sutures and bone growth areas have to be respected intraoperatively, and regions of bones not yet calcified have to be distinguished from possible tumor infiltration. Computer assisted surgery (CAS) can help to identify these areas safely. METHOD: 5 patients, from the first to the 20 (th) year of life, suffering from tumors, malformation syndromes or therapy resistant nasal polyposis were treated with CAS in rhinosurgery. RESULTS: In addition to radiological diagnostics, we performed 3D computed tomography of the skull for CAS. CAS enabled us to intraoperatively respect possible areas of bone growth, to identify regions with thin, not bonily developed cranial vault and to safely distinguish bone sutures from ethmoidal cells. CAS helped the surgeon to navigate in the not yet developed paranasal sinus system. CONCLUSIONS: CAS is a useful complementary method in rhinosurgery of the developing skull of the child. In spite of the additional 3D computed tomography, the calculated organ dose of the ocular lense amounted to 5 millisievert, so a recommended maximal organ dose for the ocular lense of 15 millisievert was not exceeded.

Adolescent↗
PubMed2004

[Markers in patients with squamous cell carcinoma of the oral cavity. Expression and long-term follow-up of VEGF, FLT-1 and Tie2 in serum].

OBJECTIVE: The quantification of serum or plasma levels of angiogenic factors in patients with malignancies aims at the description of these factors or their receptors and allows a tissue independent study of biological tumor behavior. METHODS: In 51 patients with untreated squamous cell carcinoma of the oral cavity (SCCOC) and 10 healthy controls, plasma levels of VEGF and serum levels of the VEGF-receptor FLT-1 and the Ang1-receptor Tie2 were measured. Using an ELISA technique, the concentration of these factors was measured preoperatively and postoperatively over a period of 5 weeks. RESULTS: No statistically significant correlation could be found between the serum and plasma levels and the clinical or pathological parameters. There was no difference between the patients with SCCOC and healthy controls. CONCLUSIONS: In patients with SCCOC, plasma levels of VEGF and serum levels of FLT-1 and Tie-2 do not provide any further information on the biological tumor behavior like proliferation or expression of metastases.

Biomarkers, Tumor↗
PubMed2004

[Neurophysiologic intraoperative monitoring to preserve cranial nerve function in base of skull surgery].

BACKGROUND: Neurophysiologic intraoperative monitoring (NIM) has gone through a renaissance since the advent of computer technology. Currently, both motor and sensory cranial nerves, including the IInd and VIIIth cranial nerves, can be intraoperatively controlled by means of small and mobile systems. PATIENTS AND METHODS: In order to estimate the value of NIM using the new generation of computer systems, we analyzed the records of 379 patients who underwent skull base surgery since 1996. These comprised NIM of the IInd, VIIth, VIIIth cranial nerves in most cases and of the IXth, Xth, XIth, and XIIth cranial nerves in selected cases. RESULTS: Whereas 72% of these cases demonstrated changes in the recorded intraoperative NIM signals, only 29% of them gave evidence of either clinical or electrophysiological neural function alterations during the postoperative follow-up. CONCLUSIONS: NIM is the only available system capable of providing the surgeon with instant intraoperative neural status-related feedback.

Computer Systems↗
PubMed2004

Endoscopic assistance in the removal of a foreign body in the condylar process.

This case report describes the application of the endoscopic technique in the removal of a metallic foreign body in the condylar process in an 81-year-old man. The patient's history indicated 60 years of pain in the left preauricular region as well as complaints of localized headaches. Physical examination revealed multiple scars on the patient's left preauricular region. No limitation of mandibular movement and no joint clicking were detected. Maximal mouth opening was 45 mm. According to the patient, masticatory function was normal. Digital palpation of the temporomandibular joint did not produce pain. Radiographic diagnosis was performed, which showed a pointed metallic foreign body lodged in the left condylar process. The removal of the foreign body was performed under endoscopic visualization via an intraoral approach. A 30 degrees-angled 4-mm diameter endoscope (Karl Storz, Tuttlingen, Germany) with a xenon light source was used.

Aged↗
PubMed2003

[Transvestibular closure with an autologous bone graft as surgical repair of a nasoseptal defect due to Le Fort-I osteotomy].

Defects of the nasal septum are a common complication after nasal surgery. Affected patients frequently suffer from bleeding, crusting and impaired nasal air flow. The surgical closure of septal defects remains a distinctive challenge. Though many different techniques have been described, the failure rate of this procedure remains high. In the case presented here, a large basal septum defect occurred after a prosthetic Le Fort-I osteotomy. The attempt to cover the distance between the bony nasal floor and the nasal septum with pedicled mucosal flaps failed due to extensive scar formation of the nasal mucosa. Therefore a nasal floor elevation by insertion of an autologous bone graft from the iliac crest was conducted. The bone graft was connected with the hard palate via two titanium screws. Other than with an autologous cartilage graft, no major resorption of the bone graft is to be expected. This indirect method for the closure of a basal nasal septum defect is new.

Alveolar Ridge Augmentation↗
PubMed2003

Swallowing and speech function after intraoral soft tissue reconstruction with lateral upper arm free flap and radial forearm free flap.

Swallowing, speech, and morbidity were assessed postoperatively in 25 patients, 18 of whom had had intraoral defects reconstructed by lateral upper arm free flaps (LUFF) and 7 by radial forearm free flaps (RFFF). Video fluoroscopy was used to assess swallowing, the Freiburger audiometric test to assess speech; and measurement of arm circumference to assess donor site morbidity. A questionnaire was used to evaluate swallowing, speech, and donor site morbidity subjectively. The degree of impairment in swallowing depended on the site of resection. Anterior and posterior resections affected swallowing more than lateral resections. Anterior resection and the use of LUFFs reduced intelligibility. There was no significant difference in impairment between LUFF and RFFF. We conclude that the LUFFs are superior to RFFFs because they can be closed primary and the incidence of donor site morbidity is slight.

Adult↗
PubMed2003

Evaluation of swallowing function after intraoral soft tissue reconstruction with microvascular free flaps.

This study assessed swallowing function after tumour resection and reconstruction utilizing free vascularized flap closures in patients with oral cancer. Swallowing function was evaluated postoperatively in 23 patients (21 men and 2 women) who had undergone reconstruction with either a lateral upper arm free flap (LUFF, n=16) or a radial forearm free flap (RFFF, n=7). Videofluoroscopy was used to assess tongue mobility and abnormalities of swallowing function. All patients who underwent reconstruction with LUFF or RFFF free flaps had decreased tongue mobility, except for the tip of the tongue. Patients who underwent anterior or posterior resection had greater decreases in tongue mobility than those who underwent medial resection. Swallowing impairment was similar in patients with LUFFs and those with RFFFs. Anterior resection of the oral cavity had a significant negative effect on swallowing function. Silent aspiration occurred in five patients. In conclusion the resection site affected swallowing function, but the type of flap did not, in patients with oral carcinoma, who underwent tumour resection with reconstruction

Adult↗
PubMed2002

Calvarial sclerosing osteomyelitis.

We report a 15-year-old boy who suffered from calvarial sclerosing osteomyelitis and presented with painful head swelling. X-rays of the skull revealed areas of irregular radiolucency. MR imaging and CT showed a well-demarcated intradiploic lesion with thickening of the skull extending from the frontal to the parietal calvarium with a low signal on T1-weighted images, strong but heterogeneous enhancement after gadolinium application and a mixed signal on T2-weighted images. Computer-navigated neurosurgery was planned, and the craniotomy defect was reconstructed by a preformed titanium implant. Sclerosing osteomyelitis of the calvarium has to be included in the differential diagnosis of osteolytic and sclerosing lesions of the skull coinciding with persistent swelling of the head.

Adolescent↗