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Biomedical subjects

H Iro

Publications and source records attributed to H Iro.

At least 19 recordsLinked to original sources

[Segmental tracheal resection for the treatment of tracheal stenoses].

BACKGROUND: Segmental tracheal resection is considered to be the standard treatment of tracheal stenoses. MATERIALS/METHODS: During the time period 1985-2002, segmental tracheal resection with a primary end-to-end anastomosis was performed in 117 patients with a cervical or upper thoracal stenosis of the trachea. The age distribution of the patients was between 7 and 77 years. Of the patients with a benign tracheal stenosis, sufficient data for a retrospective analysis were available in 101 patients. The length of the resected tracheal segments varied between 2 and 6 cm which required mobilisation of the trachea and the larynx and, if necessary, incision of the pulmonary ligament. RESULTS: In 5 patients a permanent damage of the recurrent laryngeal nerve was seen, of which 4 had undergone revision surgery and 10 months after surgery 93% presented with a large and stable tracheal lumen without any relevant restenosis. Due to a restenosis of 70-80% causing dyspnea at rest, 3% of the 101 patients had to undergo revision surgery. In 4% a mild and asymptomatic restenosis of 30-40% was seen which did not require any further treatment. CONCLUSION: These results demonstrate that segmental tracheal resection can safely and effectively remove stenotic tracheal segments of up to 6 cm and is therefore the treatment of choice.

Adolescent↗

[First experiences with a new nickel-titanium piston with a shape memory feature].

BACKGROUND: The aim of this study was to describe a new stapes prosthesis with memory characteristics for wire crimping (SMart-Piston). PATIENTS AND METHODS: This technique was used in 15 patients (mean age 43.4 years; range 28-71) undergoing routine stapes surgery. SMart-Piston prostheses with a shaft diameter of 0.5 mm and length ranging from 4.25-4.5 mm were used. Heat induced wire crimping was performed by CO2 laser in five patients, and by bipolar diathermy forceps in ten patients. In 15 patients, postoperative audiological testing was performed at an average 21.9 days and in another 10 again after 435 days following surgery. RESULTS: The median observed air-bone-gap (ABG) postoperatively was 8.7 dB+/-7.7 dB. A total of 73% of all patients had an ABG of 10 dB or less, and all patients had less than 20 dB. In the ten patients controlled after 435 days, the ABG was 4.4 dB+/-2.4 dB. It was lower than 10 dB in all individuals. DISCUSSION: A critical point in every stapes surgery, the prosthesis fixation to the incus, is greatly facilitated by this novel technique. Long-term results in a larger group of patients are pending.

Adult↗

[Long-term experiences in the therapy of esthesioneuroblastoma].

BACKGROUND: Esthesioneuroblastoma is a rare and clinically variable tumor of nasal sinus and skull base and challenging for modern multidisciplinary therapy. There are no generally known prognostic factors or generally accepted standard therapy regimens. PATIENTS AND METHODS: Between 1975 and 2001 26 patients were treated after the diagnosis of esthesioneuroblastoma was established. The cases were evaluated retrospectively. According to the classification of Kadish 1 patient (4 %) had stage A, 16 patients (53 %) stage B and 11 cases (43 %) had stage C tumors. Hyams grading could be obtained in 22 cases (81 %). Tumors were in 12 patients (52 %) graded I or II and in 10 cases tumors had grade III or IV (48 %). Operative therapy was performed in 23 patients (88.5 %), being in 5 patients a single mode therapy. In 18 cases combined therapy was performed (surgery and radiotherapy or radiotherapy and chemotherapy). RESULTS: Actuarial survival was 61.5 % (16/26). Disease specific 10- and 15-year-survival according to the estimation of Kaplan-Meier was 76.2 %. Patients with small tumors (Kadish A/B) had a 15-year-survival of 86.7 % compared to 63.6 % in cases with advanced tumors (Kadish C). In 7 cases (26.9 %) recurrences developed. Salvage therapy was performed in 5 cases (71.4 %) with a success rate and a 15-year survival each of 60 %. CONCLUSIONS: Therapy of esthesioneuroblastoma is challenging because of rarity and biologic variability of the tumor and and because of lack of a standard therapy. An interdisciplinary multimodal therapeutic approach is necessary especially in case of advanced tumors with promising results. Histopathological grading according to Hyams and tumor stage are important factors for survival and prognosis. Although recurrence can occur with high frequency even after prolonged time interval, long time survival can be improved after aggressive salvage therapy. Therefore longterm follow up is mandatory.

Adolescent↗

[Digital photography and video archives in ENT].

Digital media have become standard documentation tools in modern ENT clinics. To date, multiple formats are generated by variable data sources. Old fashioned archiving techniques with numerous print-outs, hard copies or even slides would soon generate an unmanageable data flood and require costly manpower for proper and precise maintenance. It has become obvious that data archiving is the prime challenge for modern hospital information technology. Multiple computerized multimedia archives exist and offer promising solutions for collecting and managing these data. From a clinical point of view, not only data centralisation but also interactions with existing network components and hospital information technology systems have to be made available. Here, we describe variable data sources and formats, centralisation techniques, networking options and discuss available digital documentation solutions.

Computer Communication Networks↗

[Styloid syndrome and its treatment].

BACKGROUND: An elongation of the styloid process or an ossification of the stylohyoid ligament can be the cause for a styloid syndrome and may lead to craniocervical pain, globus sensation and dysphagia. Pathophysiologically, the styloid syndrome is related to an irritation of the surrounding nerves, the carotid artery or the pharyngeal mucosa. There are various alternatives for its treatment. PATIENTS AND METHODS: This study analyzed retrospectively the data of eleven patients, who were treated for a styloid syndrome. All patients were placed on a stepwise therapy plan, which began with a medicamentous treatment, followed by a surgical treatment, if the problems persisted. The surgical approach included a transoral styloid fracture and/ or a surgical styloid shortening, which was carried out either transorally or transcervically. RESULTS: Three of the eleven patients presented no complaints after the medical treatment and did not require any further therapy. In two out of five patients, transoral fracturing of the styloid was successful. Six patients underwent surgical resection of the styloid process. In five cases a transoral route was used and in one cases a transcervical route. Postoperatively, four patients were free of symptoms and did not present any functional deficit. Two patients experienced severe complications with an ipsilateral medial cerebral artery infarction. These were related to a dissection of the internal carotid artery (ICA) in one case, and an arrosion bleeding of the ICA after the formation of an abscess of the parapharyngeal space in the other case. CONCLUSION: A stepwise therapy of the styloid syndrome including medicamentous treatment, transoral styloid fracture and resection of the styloid process has proven to be of value. If the styloid process can be palpated submucosally, a transoral resection may be chosen. However, using this route, the possibility of severe complications has to be taken into consideration, such as injury of the internal carotid artery.

Adult↗

[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↗

[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↗

[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↗

[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↗

[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↗

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↗

[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↗

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↗

[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↗

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↗

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↗