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Biomedical subjects

H Iro

Publications and source records attributed to H Iro.

At least 19 recordsLinked to original sources
PubMed2005

[Submandibular sialoliths. Stone removal with organ preservation].

BACKGROUND: Sialolithiasis as a cause of sialadenitis within Wharton's duct accounts for more than 80% of all cases. In the past extirpation of the gland was carried out in nearly all cases. Gland-preserving therapies such as transoral removal have so far been seldom examined. PATIENTS AND METHODS: In 683 patients suffering from submandibular lithiasis with a mean age of 45 years (8-87 years) transoral removal of the stones were carried out. The follow-up period was 1-7 years. The stone location was distal to the edge of the mylohyoid muscle in 283 cases and more proximal to the gland within the hilum in 296 patients (single concrements). Fifty-nine patients had two separate stones, one within the area of the hilum and other smaller ones proximal within the gland. RESULTS: All patients with distal stone location, 89% of patients with single stones of the perihilar region, and 63% of the patients with two separate stones in the hilum and parenchyma were free of stones. Another 8 and 23%, respectively, had small residual concrements without any complaints. Recurrence of lithiasis or damage of the lingual nerve remained below 1%. CONCLUSION: Transoral removal in palpable sialoliths should be considered as the treatment of choice in patients suffering from submandibular stones located within the floor of the mouth or within the perihilar region of the gland. Ultrasound imaging is important for exact location of the stones.

Adolescent↗
PubMed2005

[HNORAD].

BACKGROUND: New media are gaining importance in undergraduate as well as postgraduate and continued medical education. We aimed to create an interactive educational program for imaging diseases of the ear, nose and throat (ENT). MATERIALS AND METHODS: Cases and images representing clinical routine were collected, arranged by content and graphically presented according to instructional criteria. Undergraduate students participating in the project used an authoring system to generate case studies, which were then published at http://www.HNORAD.de. RESULTS: HNORAD is an interdisciplinary teaching program offering more than 100 classical disease presentations. Three systematic indices offer a choice of instructional approach. Apart from typical images, the information presented includes patient history, clinical findings, imaging findings as described by a board-qualified radiologist, diagnosis, differential diagnosis and internet links. Elements of the radiologist's report are linked with the images in such a way that the structure or finding described can be interactively highlighted. An evaluation index allows proficiency testing in self study and as a part of taught courses. CONCLUSION: HNORAD is a valuable resource for students, ENT surgeons and radiologists at the undergraduate, postgraduate and CME level for self study as well as for course work.

Computer-Assisted Instruction↗
PubMed2005

[Magnetic Drug Targeting--a new approach in locoregional tumor therapy with chemotherapeutic agents. Experimental animal studies].

BACKGROUND: Advanced squamous cell carcinomas of the head and neck region were often treated with combined radio-chemotherapy. Radiotherapy allows a focused treatment of the tumor, and healthy tissue can be protected from radiation. Chemotherapy, however, is mostly given systemically and the unwanted negative side effects also develop in many other organs. AIM OF THE STUDY: Locoregional application of chemotherapeutic agents with Magnetic Drug Targeting on an animal experimental study. METHODS AND RESULTS: Magnetic Drug Targeting is a new approach to the locoregional treatment of tumors. Ferrofluids (colloidal dispersion of magnetic nanoparticles) were reversibly bound to chemotherapeutic agents and injected intra-arterially, while focused with an external magnetic field to a certain body compartment (i.e. the tumor). With only 20% or 50% percent of the regular systemic chemotherapeutic dose, we achieved an up to 26 times higher concentration in the tumor region with this application compared to the usual systemic administration. CONCLUSION: Magnetic Drug Targeting offers an unique opportunity to treat tumors locoregionally with chemotherapeutic agents.

Animals↗
PubMed2005

[Development of an active robot system for multi-modal paranasal sinus surgery].

BACKGROUND: Severe complications in endoscopic paranasal sinus surgery are rare, however, when they occur they are often fatal. Injuries to the optic nerve or the internal carotid artery mostly occur after penetration of the sphenoid sinus' anterior wall. METHODS: We present the robot system "A 73" with its newly designed 4-canal-microendoscope and special instruments that meets the demands of endoscopic paranasal sinus surgery. A fully automated perforation of the sphenoid sinus' anterior wall was performed in five cadaveric specimens. RESULTS: The sphenoid sinus' anterior wall could be perforated without damaging the surrounding structures in all cases. Subsequently, the approach was enlarged to the desired diameter using telemanipulation mode. The analysis of both the transformation error and intraopertive accuracy showed values in the submillimeter range. CONCLUSIONS: Using a newly developed robotic system, a fully automated perforation of the sphenoid sinus' anterior wall was performed precisely and reproducibly. This approach can be enlarged in a telemanipulation mode.

Cadaver↗
PubMed2005

[Endonasal removal of a large recurrent craniopharyngioma using intraoperative navigation].

In recent years computer-navigation systems have been commonly used in the field of otorhinolaryngology. Taking its limitations and possible failures into account, this technology is considered reasonable and helpful in routine paranasal sinus surgery, particularly in revision cases and complex approaches to the lateral skull base. We report on a patient with a large recurrent craniopharyngioma, and show that the use of intraoperative navigation might even be necessary to accomplish the desired postoperative outcome in certain cases. Future developments will demonstrate whether computer assisted surgery can extend the indications for operative procedures in complex anatomical regions.

Child↗
PubMed2005

Management of spontaneous enophthalmos due to silent sinus syndrome: a case report.

Silent sinus syndrome (SSS) is a rare disease exhibiting unilateral enophthalmos and hypoglobus. A 26-year-old white female presented with right side enophthalmos and hypoglobus. There was no history of previous trauma or maxillary sinus diseases. A CT scan showed an opacified right maxillary antrum with decreased volume and downward bowing of the right orbital floor. From clinical and radiological findings the diagnosis SSS was made. Biopsies were collected from the maxillary sinus for the exclusion of malignancy. Two months later orbital floor reconstruction was carried out. Before antrostomy of the affected maxillary sinus, a relative enophthalmos of 4mm was determined. Five days after antrostomy the value reduced to 2.3mm. During the following 2 months the enophthalmos remained constant. At the end of the operation for orbital floor reconstruction it was 0.1mm. Five days after surgery the relative enophthalmos increased to 0.8mm. The value remained constant during the following 3 months. Initial antrostomy of the affected maxillary sinus may lead to a relevant, spontaneous reduction of enophthalmos. After a minimum period of 2 months a re-evaluation should be made, if a reconstruction of the orbital floor is still necessary for the correction of the globe position.

Adult↗
PubMed2005

[Lymph node metastasis of glottic laryngeal carcinoma].

UNLABELLED: The incidence of lymph node metastases in glottic cancer is assumed to be lower than in other head and neck cancers. In a retrospective study this statement was investigated. MATERIAL AND METHODS: This analysis was based on 910 consecutive patients with glottic carcinoma treated between 1970 and 1990 by means of surgery with special interest on regional lymph node metastases. RESULTS: 8.6 % patients had clinically positive necks (N+) and 5.9 % pathohistologically positive necks (pN+). The incidence of lymph node metastases showed correlation with pT category and vocal cord mobility. Lymph node metastases were found in 5 % of pT2, in 18 % of pT3 and in 32 % of pT4 tumors. Only one patient with pT1 cancer had metastatic lymph node involvement. The incidence of occult lymph node metastases was 18 %. Lymph node involvement, extracapsular spread and lymphangiosis carcinomatosa proved to be relevant prognostic factors. The 5 year recurrent free survival rate was 86.7 % for the whole group, 81.6 % for patients with negative nodes (pN0), and 61.8 % for patients with pN+ nodes (p < 0.001 according to logrank test). CONCLUSIONS: Clinical lymph node staging plays an important prognostic role in the staging procedure also in glottic carcinoma. At least in T3 carcinomas, elective treatment of the cervical lymph nodes seems to be necessary. T2 carcinomas with impaired cord mobility have a significant higher risk for metastatic spread; therefore neck dissection should be discussed also in these cases.

Adolescent↗
PubMed2005

An automated robotic approach with redundant navigation for minimal invasive extended transsphenoidal skull base surgery.

BACKGROUND: The aim of this work was to determine the feasibility of a robotic-assisted and fully automated approach to the sphenoid sinus. An image-guided robotic system was designed to address potential human errors in performing transsphenoidal sinus surgery by combining the reproducible accuracy of a robotic system with standard computer navigation. METHODS: A six-degrees of freedom robotic assistance system and an opto-electrical navigation system were combined for image-guided assistance with redundantly controlled robotics. Newly designed endoscopic instruments for robotic surgery have been developed and are described. Telemanipulatory, as well as fully automated procedures, were tested on cadaveric heads as part of a preclinical trial. RESULTS: A fully automated sphenoidotomy as well as a telemanipulatory sphenoidectomy were performed successfully on cadaveric heads. Intraoperative performance, accuracy assessment studies, as well as possible sources of stereotactic offsets are described. The mean measured robotic reproducibility accuracy was 0.056 mm (range: 0.02 - 0.14 mm) and the mean overall navigated robotic accuracy, including all transformation and registration errors was 1.53 mm (range: 1.13 - 1.89 mm) respectively. CONCLUSION: A system for robot-guided surgery in combination with redundant navigational control was developed. It allows highly accurate maneuvers, performed either in a telemanipulation mode as master-slave system or in a fully automated fashion. A sphenoidectomy on cadaveric heads was performed in both telemanipulation and fully automated modes. The overall intraoperative accuracy was in the range of the resolution of the CT images and stereotactic offsets were caused mainly due to deflections of the endoscopic operating instrument.

Cadaver↗
PubMed2004

[Complications with inflammatory diseases of the nasal sinuses].

The close localization of the paranasal sinuses both to the brain and the orbit can even today lead to severe and potentially lethal complications in patients with sinusitis. These incidents are rare, however, they should be duly diagnosed and treated since fatal outcome is described in 5-10% of cases. Current diagnosis and therapy for acute inflammatory complications and mucoceles of paranasal sinuses are presented in this article.

Eye Infections↗
PubMed2004

Sialoscopy--initial experiences with a new endoscope.

BACKGROUND: After the introduction of mini-endoscopes for the diagnosis of swelling of the major salivary glands there has been further development of materials and techniques. A new highly flexible semirigid sialoendoscope with high quality imaging (6000 pixels), an outside diameter of 1.1 mm, a working channel of 0.4 mm, and a separate channel for irrigation has been developed and we examined its clinical value. METHODS: We used the endoscope in 22 patients for diagnosis and treatment. RESULTS: Sialoendoscopy was achieved after dilatation of the papilla in all cases. The image (both in contrast and resolution) was excellent. We found sialolithiasis in 13, stenosis in 3, and sialodochitis in 3. Through the working channel we were able to insert instruments with success in seven cases with pathological findings. One patient developed a complication.

Adult↗
PubMed2004

Adaptation of a hexapod-based robotic system for extended endoscope-assisted transsphenoidal skull base surgery.

OBJECTIVE: To adapt a hexapod-based robotic system for use in extended endoscope-assisted transsphenoidal skull base surgery. METHODS: A robotic system (Evolution 1, Universal Robot Systems, Schwerin, Germany) based on a hexapod design with an attached seventh axis is used as instrument holder. The instrument interface is operated via a joystick control. An endoscope is applied to the instrument interface, which is tracked by a navigation system (Stealth, Medtronic, USA). RESULTS: The instrument holder was modified so that it could be applied in transsphenoidal surgery. Furthermore, translation and pivoting movements of the system were implemented, also a quick change between microscope and robotic-controlled endoscope was made possible. After extensive phantom testing two patients with large invasive pituitary adenomas were operated on using the robotic endoscope assistance during transsphenoidal surgery. The robotic assistance allowed the use of two additional instruments under endoscopic view. For example, drilling, suctioning, application of punches, as well as microsurgical tumor removal could be performed under endoscopic view. CONCLUSION: A robotic system could be adapted for use in endoscope-assisted transsphenoidal skull base surgery allowing simultaneous use of two instruments under endoscopic view. This opens new possibilities to extend transsphenoidal skull base surgery.

Adenoma↗
PubMed2003

[Facial nerve schwannoma in the inner auditory canal and geniculate ganglion].

BACKGROUND: Schwannoma of the vestibular nerve is the most common tumor found in the inner auditory canal. If a schwannoma of the facial nerve is found unexpectedly during surgery, the original surgical plan may have to be changed. In our series, we describe the symptoms, diagnostic procedures and therapy of this infrequent, benign tumor. In particular, we want to analyse the influence of diagnostic techniques, such as magnetic resonance tomography and electrophysiology, on the diagnosis of these tumors. PATIENTS: Between 1975 and 2001, we diagnosed 17 cases of facial nerve schwannoma in the inner auditory canal or the geniculate ganglion. All patients were treated surgically. In 16 cases, we used the enlarged middle fossa approach and in the remaining patient the translabyrinthine approach was used. RESULTS: In 11 cases, the facial nerve could be saved but in six the nerve had to be rebuilt with a transplant. During the first years of our study, palsy of the facial nerve was a frequent finding. In the later years, a hearing impairment and tinnitus became the most frequent symptoms. CONCLUSIONS: Advances in magnetic resonance imaging have, in many cases, facilitated the differentiation between schwannomas of the facial nerve and the vestibular nerve over the last years. Signal enhancement at the geniculate ganglion is important for the diagnosis of facial nerve schwannoma. In individual cases, we found significant findings using electrophysiological procedures. In three cases, the temporal delay was elongated. Based on these findings, the therapeutic procedures can be discussed together with the patients.

Adolescent↗
PubMed2003

[Advanced transfacial approach to extensive sellar adenoma of the pituitary gland].

The excision of tumors of the pituitary gland is usually achieved via a transsphenoidal transnasal approach. In the past, alternative approaches were described for macroadenomas. Especially in tumors surrounding the internal carotid artery (ICA) and the optic nerve, the selection of the appropriate approach is of importance. We demonstrate the case of a second extensive relapse of a macroadenoma after primary transsphenoidal resection and radiation therapy. As the tumor enclosed both the ICA and left optic nerve, a median external approach via the upper midface was chosen. After the median skin incision and translocation of the upper parts of the nasal structure, the papyraceous lamina was removed bilaterally. The orbital tissue was laterally exposed with retractors, achieving a wide access to both carotids and optic nerves. The functional and aesthetic results were satisfactory. Compared with other approaches, this one provides a good exposure of both the ICA and optic nerve.

Adenoma↗
PubMed2003

[Surgical therapy of Madelung's disease in the head and neck area].

PATIENTS AND METHODS: Between 1995 and 2001 we treated 12 patients with benign symmetric lipomatosis in the head and neck. The group comprised 11 men and 1 woman aged 34-62 (M=47). The most frequent complaints were diminished range of motion of the head and obstruction when eating or speaking. Combined lipectomy and liposuction were performed in all patients, with liposuction being carried out in a second session. RESULTS: The mean follow-up period was 3 years. The functional results were very satisfactory in all patients. Of the 12 patients, 9 were also satisfied with the aesthetic outcome.A recurrence occurred in three patients 1.5, 2, or 3 years after the operation. Severe complications were not observed. CONCLUSIONS: According to our experience, combined lipectomy and liposuction represents a successful procedure in treating benign symmetric lipomatosis in the head and neck region.Nevertheless, advantages and drawbacks of the two techniques should be equally considered prior to surgery.

Adult↗
PubMed2003

[Growth of sporadic vestibular schwannomas correlates with Ki-67 proliferation index].

BACKGROUND: Sporadic vestibular schwannoma show a wide variability of their growth rate. Some tumors might remain quiescent for a long time without symptoms and other tumors might suddenly enlarge. Sometimes during surgical removal of tumors, it is useful to have a parameter for the prediction of the further growth potential of the schwannoma, especially if tumor resection results in functional impairment of the facial nerve. An often used histological parameter for growth rate of tumor cells is the proliferation index. METHODS AND PATIENTS: In our study we observed a series of 50 patients with neurinoma of the vestibular nerve by "wait and scan". After the first magnetic resonance imaging (MRI) all patients were controlled by a second MRI. The time between the MRIs ranged between 3 and 26 months (median 9). In 45 of 50 patients a surgical removal of the tumor by transtemporal approach followed. RESULTS: The proliferation index (Ki-67) was identified in the histological tumor specimens. The next step was the correlation of proliferation index and "tumor doubling time" (TDT). The volume of the tumors was provided by measuring three diameters of the tumors in MRI and calculating the volume with a formula. The volume of the tumors were used to calculate tumor growth and TDT. 10 patients showed no tumor growth during follow up. The average TDT in 40 cases was 22 months (SD 16). In 33 cases we were able to determine a proliferation index, which showed an average score of 1.99 %. Statistical analysis showed a correlation between proliferation index and TDT with a coefficient of - 0.42 (s: 0.014). In two cases with relevant clinical tumor growth (TDT: 12 months), the MIB-1 index was nearly 0 % in different areas of the tumor specimen. May be in these cases, the cell proliferation declined just before operation. On the other hand we found one patient with a high proliferation index of 3.3 % and a rather long TDT of 19 months. CONCLUSIONS: The determination of proliferation can serve as a further decision guidance during surgery of vestibular schwannoma.

Cell Division↗
PubMed2003

Patterns of failure following radiation with and without chemotherapy in patients with nasopharyngeal carcinoma.

PURPOSE: Aim of this study was to retrospectively evaluate patterns of failure, results, and prognostic factors for patients with nasopharyngeal cancer (NPC) following radiotherapy (RT) with and without concurrent chemotherapy (RCT). PATIENTS AND METHODS: Between 1978 and 1999, a total of 101 patients with NPC were treated in our hospital, of whom 53 received external megavoltage RT alone with a median total dose of 76 Gy (1978-1988), and 48 patients had RCT (1989-1999). For RCT a combination of 5-FU and cisplatin was used together with a median total dose of 72 Gy. Patterns of relapse, survival rates and toxicity as well as prognostic factors were evaluated retrospectively. RESULTS: RCT was associated with a marked reduction in distant metastases: 6/48 (13%) vs. 17/53 (32%) after RT alone. Locoregional tumor persistence was only marginally lower with RCT: 10/48 (21%) vs. 17/53 (32%) following RT. Patients with RCT demonstrated a survival advantage compared to those with RT alone (5-year overall survival (OS): 64% vs. 44%, p = 0.1). OS, disease-specific survival and locoregional control rates were 53, 57, and 78% at 5 years and 47, 51 and 78% at 10 years, respectively. OS was significantly affected by histology (p = 0.007), the patients' age (p = 0.009) and gender (p = 0.01). CONCLUSION: This retrospective study provides further evidence that both reduction of distant metastasis and enhanced local tumor control by combined radiochemotherapy may be associated with improved survival rates in NPC compared to radiation alone. Concurrent RCT is therefore considered the preferable treatment option, however, confirmation in randomized trials is still warranted.

Adolescent↗