Biomedical subjects

R Laszig

Publications and source records attributed to R Laszig.

At least 19 recordsLinked to original sources

PubMed2007

[Conventional tomographic investigations of the reconstructed middle ear in temporal bone specimen].

BACKGROUND: In modern reconstructive middle ear surgery imaging plays an essential role as a diagnostic tool, especially in pre-operative planning. Nowadays imaging of surgical results as a matter of quality control in post-operative follow-up becomes more important. MATERIAL AND METHODS: Conventional tomography was performed in 10 temporal bone specimen using the CommCat IS 2000-system in order to evaluate anatomical structures and inserted middle ear prostheses (PORP/TORP). This imaging technique has not been used in middle ear surgery beforehand. RESULTS: Using conventional tomography characterization of anatomical structures of the temporal bone as e. g. the semicircular canals appeared to be of superior quality to comparable conventional radiographic imaging. Concerning imaging quality (contrast; resolution) conventional tomography allowed similar findings like computed tomography (CT)-scans in some of the investigated specimen while showing inferior sharpness quality due to technical reasons. Further advantages of conventional tomography in contrast to CT were the requirement of just 2.5 % of the CT's irradiation exposure, lack of metallic artefacts caused by implanted prostheses and the feasibility of distance- and angle-measurement of inserted prostheses towards the tympanic membrane which coincided extensively with the temporal bone preparation. CONCLUSIONS: Conventional tomography enables detailed anatomical imaging of the temporal bone region which outperforms conventional radiographic imaging, requires less irradiation dose than CT and helps avoid problems like metallic artefacts. This technique enhances immediate quality-control and seems to be therefore a promising tool for postoperative evaluation after reconstructive middle ear surgery.

Contrast Media↗

PubMed2007

Ericksonian hypnosis in tinnitus therapy: effects of a 28-day inpatient multimodal treatment concept measured by Tinnitus-Questionnaire and Health Survey SF-36.

For the first time, the therapeutic effects on subacute and chronic tinnitus of an inpatient multimodal treatment concept based on principles of Ericksonian hypnosis (EH) were examined by standardized criteria of the Tinnitus Questionnaire (TQ) and Health Survey (SF-36) within a controlled prospective, longitudinal study. A total of 393 patients were treated within an inpatient closed-group 28-day-setting based on a resource-oriented, hypnotherapeutic concept. The severity of tinnitus was assessed by TQ at times of admission, discharge and also at a 6- and 12-month follow-up. Health-related quality of life was evaluated before and after therapy using the SF-36. After therapy, a decrease in TQ score was seen in 90.5% of the patients with subacute tinnitus and in 88,3% of those with chronic tinnitus. Assessment of the TQ score at the end of therapy revealed highly significant improvements of 15.9/14.1 points in mean. Effect sizes in the treatment groups (0.94/0.80) were superior to those in the waiting-list controls (0.14/0.23). The TQ score remained stable in the follow-up controls. Significant improvement in health-related quality of life has been observed within the treatment groups depending on initial level of tinnitus serverity I-IV according to TQ. Using a multimodal treatment concept with emphasis on resource-activating approaches of EH the annoyance of tinnitus can be significantly reduced while health-related quality of life is enhanced within a comparatively short treatment period of 28 days.

Adolescent↗

PubMed2006

Rotational tomography of the normal and reconstructed middle ear in temporal bones: an experimental study.

Imaging is an essential diagnostic tool in reconstructive middle ear surgery, especially in pre-operative planning. Due to ongoing improvement of imaging quality and development of new imaging techniques like e.g. rotational tomography (RT) post-operative follow-up and immediate evaluation of surgical results may become more important. The aim of this experimental study was to evaluate RT as a new tool for postoperative determination of middle ear anatomy and implant position in temporal bones. RT was performed in ten temporal bone specimen after insertion of different middle ear prostheses concerning material, shape and length (PORP; TORP; Stapes piston). An implantable hearing device (Symphonix Soundbridge) was also implanted and visualized. For comparison some specimen additionally underwent conventional computed tomography (CT), including the newest technology. Characterization of anatomical structures of the temporal bone using RT was of comparable quality to conventional CT-scans in all investigated specimen while requiring approximately 30% of the CT's irradiation exposure. Unlike CT the RT showed almost no problems due to metallic artefacts of the implanted prostheses. Furthermore RT enabled a 3-dimensional view of the temporal bone and angle determination of inserted prostheses towards the tympanic membrane and/or the malleus handle. Detailed imaging of the prostheses allowed determination of shape, material and localization within the specimen's reconstructed middle ear. The new imaging technique of RT allows precise presentation of anatomical structures and middle ear implants in temporal bones. Following these experimental results it will be our future work to evaluate this method in clinical practise.

Ear, Middle↗

PubMed2005

[Relapsing facial erysipelas caused by nickel allergy. Significance of allergy diagnostics in ENT practice].

This case report shows a typical complication of allergic contact dermatitis as it is often seen in hand and foot eczema: relapsing erysipelas. To our knowledge the occurrence of such a complication in the face has never been reported. In the case presented, relapsing facial erysipelas were treated four times in a period of 2 years symptomatically without having identified or eliminated the causing allergen. This clearly indicates how important it is to have a sound knowledge of allergology and its diagnostic procedures, especially in ENT-practice.

Adult↗

PubMed2005

[Information assisted surgery as a transdisciplinary surgical procedure].

BACKGROUND: Information assisted surgery (IAS) is a further development of the computer assisted surgery (CAS) exclusively for intraoperative localization serving as basis for future technologies such as mechatronic and robotic. It requires of the surgeon a turnaround from traditional surgical proviso as well as transdisciplinary knowledge in the areas of surgical medicine, radiological imaging and information. The advantage of IAS is the predictability of the surgical procedure according to the specifications of modern quality assessment. METHOD: We analyzed the possibilities for the application of IAS in interdisciplinary transfacial surgery of the frontobasis in 9 patients with different pathologies of the central skull base and the cranio-cervical junction and compared this to conventional CAS. RESULTS: We determined retrospectively with a quality assessment analysis that surgery planning is too time consuming in the moment, and that the necessary transdisciplinary knowledge for IAS cannot be taken for granted yet. IAS has not been consequently applied for the entire surgery process in any of the 9 cases. This was due to technical difficulties as well as large intraoperative accuracy deviations of more than 5 mm. CONCLUSION: Even though the highly-developed technology of IIAS -- intelligent information assisted surgery -- is available, with the possibility of half or fully automatic implementation of IIAS including a automatic re-referencing, this technology will not be used in medical navigation for strategic reasons.

Adenoma↗

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↗

PubMed2005

[LED autoregistration in navigated endonasal sinus surgery].

BACKGROUND: In endonasal sinus surgery, computer aided surgery (CAS) is a generally accepted method. Applying CAS, there are basic problems with the constancy of accuracy at a free mobile patient head as well as with extended referencing time. The navigation system manufacturer Stryker-Leibinger invented together with our working group a non-invasive, frameless, automatic patient registration and simultaneous tracking system for navigated endonasal sinus surgery. With this new user-friendly system it concerns an active, LED-based, self-adhesive on the surface of splanchnocranium autoregistration mask. MATERIAL AND METHOD: The LED autoregistration mask was tested in an anatomic cadaver study and an ongoing clinical patient study regarding manageability, applicability and accuracy. Accuracy measurements were accomplished on different control points of the head in the cadaver study. The determination of accuracy was calculated with the metric Euclidean distance. Further we report on our experiences with a total of 20 patients applying the new mask. To control the accuracy, anatomic landmarks of the patients were adducted. Goal of our study was to determine the accuracy of the LED mask and to compare it with titanium screw markers, the valid reference gold standard. RESULTS: The LED autoregistration mask convinced by a high precision with relatively simple useability. Total accuracy amounted to 2.22 +/- 0.91 mm. The LED system proved to be a valuable orientation guide mainly at revision surgeries with modified anatomy. CONCLUSIONS: LED surface autoregistration is especially suitable for endonasal sinus surgery and represents a very helpful tool for the rhinosurgeon. Our accuracy studies have shown that the LED autoregistration mask is comparable to the gold standard titanium screw markers and, in addition, very reliable.

Computer Graphics↗

PubMed2005

[Methods for evaluation of perimodiolar ci electrode arrays in human temporal bones].

BACKGROUND: Cochlear implants (CI) are the established treatment for cochlear deafness. Recently, indications for cochlear implantation have been expanded to include severely hearing-impaired patients. The use of bilateral implants seems to provide additional benefit. Moreover, new electrode designs, i. e. perimodiolar electrode arrays, aim at improving benefit for patients. However, in addition to providing functional improvements, modern electrode array development must also address safety aspects, because damage to the cochlear morphology (especially the osseous spiral lamina) may lead to degeneration of residual neuronal structures and bony obliteration or scarring within the cochlear ducts. METHODS: Therefore, insertion trauma of the newly developed electrode arrays in human temporal bones must be evaluated before applied to patients. Several methods for testing electrode location and intracochlear trauma are described. RESULTS: Combining cross-sectional imaging, histological analysis and elements of risk-assessment valid information about trauma and possible consequences for use in patients can be determined, based on our experience in 57 temporal bones. CONCLUSIONS: Following our results, safety studies with prototype electrode arrays should, in addition to radiological examination, always include careful histomorphological evaluation.

Adult↗

PubMed2005

[The influence of insertion depth on the preservation of residual hearing after cochlear implantation].

BACKGROUND: Cochlear implantation may be indicated in patients with bilateral severe sensory hearing loss. Patients with minimal residual hearing have more benefit from cochlear implantation than from optimal fitted hearing aids. However, it has to be considered that inner ear structures might be damaged during electrode insertion. METHODS: We analysed the influence of insertion depth on the preservation of residual hearing in 47 cochlear implant patients (type of implant: Nucleus 22 M or 24 M) by using the pure tone audiometry. Frequency-specific analyses of pre- and postoperative audiograms on the implanted side were performed, evaluating only frequencies above 500 Hz. The insertion depth was documented by stiffening rings outside the cochlea. RESULTS: Residual hearing was more obtained in cases with complete insertion of the electrode array than in those cases with incomplete insertion. In the frequencies 1000 and 4000 Hz these results are significant. CONCLUSION: In our opinion, the perceived resistance producing intracochlear damages and preventing the complete electrode-insertion at the same time is an explanation for the significantly poorer results of the patients with incomplete insertion.

Audiometry, Pure-Tone↗

PubMed2005

[The freiburg incision for cochlear implantation -- initial results].

BACKGROUND: Cochlear implant surgery is a well standardized therapy for rehabilitation of congenital or acquired deafness at all ages. Mastoidectomy, posterior tympanotomy, cochleostomy and electrode insertion are performed consistently worldwide. Recently newly developed types of incision are taken into account. In our experience over more than 15 years the extended endaural incision has proven to be reliable with a low complication rate. OBJECTIVE: To evaluate a modified retroauricular incision for clinical use and complication rate in cochlear implant surgery with devices of different manufacturers. MATERIAL AND METHODS: We performed a prospective analysis of cochlear implant surgeries between 03/2003 and 03/2004. In all cases a modified retroauricular incision was used. Necessary adaptations of incision, depending on the device used, and postoperative complications were evaluated. RESULTS: In 76 ears a retroauricular incision was performed. Depending on the shape and size of receiver/stimulator an extension of the incision was necessary. The mean observation time was 6.3 months. Intra- or postoperative complications were not observed. In one case a skin dehiscence following trauma 28 days after surgery was reported without dehiscence of fascia or implant failure with uneventful healing after secondary suture. CONCLUSIONS: With regard to the results with the extended endaural incision the modified retroauricular incision allows a safe access for cochlear implant surgery. Observation of long term results and outcomes in revision surgery is mandatory.

Adolescent↗

PubMed2005

Influence of ionizing radiation on nucleus 24 cochlear implants.

HYPOTHESIS: To evaluate the influence of conventional or hyperfractionated radiotherapy on Nucleus CI24M or CI24R(CS) implant systems. BACKGROUND: As a consequence of more than 70,000 cochlear implant recipients worldwide, the potential need for radiotherapy is an issue requiring consideration by both implantees and implantation centers. Conditions requiring radiotherapy of the head may include head, neck, or brain tumors. METHODS: The study examines the effect of ionizing radiation on cochlear implant function. The implanted devices examined were the Nucleus CI24M and Nucleus CI24R(CS). In a modeled study, two implants of each type were treated with fraction schemes most frequently used in clinical routine (e.g., conventional fractionation [total dose, 120 Gy] and hyperfractionation [total dose, 116 Gy]). Parameters quantified were the implant output amplitude changes at high and low current level (current levels 255 and 100, respectively), the charge balance of the biphasic pulse, and the accuracy of the impedance telemetry function. RESULTS: Within the clinically relevant dose range (< 80 Gy), implant function in all four devices was normal. Failure occurred in one Nucleus CI24R(CS) device treated with hyperfractionation. A dramatic drop in the output amplitude at 106 Gy was observed, and the impedance measurement failed at a total dose of 111 Gy. CONCLUSION: The results suggest that conventional or hyperfractionated radiotherapy can be applied safely at Nucleus CI24M or CI24R(CS) implant systems in a patient-like setting. Therefore, the authors propose that the results of the study can be applicable in clinical practice.

Cochlear Implants↗

PubMed2004

[Psychological stress and impaired quality of life in patients with tinnitus].

OBJECTIVES: The majority of patients with chronic decompensated forms of tinnitus have comorbid psychological disorders, possibly accompanied by restricted quality of life and participation in everyday activities. There is no standardized tool to measure these clinically relevant dimensions. SAMPLE AND METHOD: Both the Hospital Anxiety and Depression Scale (HADS) and the Short Form 36 (SF-36) were administered to a consecutive sample of patients ( n=110) who were recruited from the tinnitus outpatient service in the department of psychiatry and psychotherapy. Using the Tinnitus Questionnaire (TF), associations of the HADS and SF-36 scales with tinnitus grading were determined and the classification of patients (mild-medium-severe-very severe) was evaluated. RESULTS: A severe tinnitus grading is correlated to a high extent of anxiety and depression and a low quality of life. With the exception of the SF-36 subscale on physical functioning, all scales discriminated between the extreme groups (mild vs severe/very severe), but less between the two medium groups. CONCLUSIONS: Patients with severe decompensated tinnitus (grades III and IV) should be seen for diagnosis of psychiatric comorbidity and supportive psychotherapy/psychopharmacotherapy used when necessary.

Activities of Daily Living↗

PubMed2004

[Current developments in cochlear implantation].

Over the last 20 years, cochlear implantation has become a well accepted treatment in patients suffering from hearing loss or congenital deafness. Results have been impressive,and indications for a cochlear implant have been extended continuously. Thanks to a sophisticated diagnostic procedure, optimization of the surgical technique, and the progression of interdisciplinary cooperation in the field of rehabilitation, the acceptance of cochlear implantation is growing significantly. The manufacturers of the devices are making great efforts to miniaturize the external components of the system, and new developments in electrode arrays, combined with new speech coding strategies, result in better speech understanding. The new developments in electrode design, however, are not necessarily improvements over recent years. Nevertheless, a very well functioning network of physicians, scientists, and manufacturers has acted and reacted in an outstanding manner to identify possible causes of post-implantation meningitis, have taken immediate counter measures and presented possibilities of prevention.

Cochlear Implantation↗

PubMed2004

[Navigation-controlled cochleostomy. Is an improvement in the quality of results for cochlear implant surgery possible?].

BACKGROUND: The correct positioning of the electrode, which is the limiting factor for the functional integrity of cochlear implants, is decisively influenced by the cochleostomy. Localisation and form of the drilling canal have been solely defined by the surgeon during the operation and an enlargement of the drilling canal is often necessary. Thanks to the improved resolution of new slice imaging techniques, computed tomography allows an exactly defined optimal point for cochleostomy. MATERIAL AND METHODS: In a cadaver study, we examined whether the target defined with computed tomography can be reached in a reproducible way with the help of navigated computer assisted surgery. We chose titanium screw markers as the gold standard for referencing. RESULTS: There was a real deviation of 1.6 mm in the target field. Thus, in a cochleostomy with a diameter of 0.5 mm the goal was not reached in a reproducible way. With this deviation a target of 2.56 mm(2) is defined. CONCLUSIONS: A target assessed by navigation is better than one reached without navigation in view of reproducibility and accuracy. With further technical progress navigated cochleostomy will be possible.

Cadaver↗

PubMed2004

[Tumour staged surgery of endolymphatic sac tumors (ELST)].

BACKGROUND: Endolymphatic sac tumours (ELST) have only been known as own tumour entities since 1984. ELST might occur solitarily and sporadically as well as hereditary connected to von Hippel-Lindau disease (VHL). This connection has been observed in 1992 for the first time and confirmed by molecular genetic analyses of the VHL gen. There is no agreement yet concerning diagnostics and therapy. METHODS: Our attempt of classifying this type of tumour is the first one. According to our own experience and to literature, we suggest the following classification: ELST type A is locally confined without erosions of the temporal bone nor infiltration of the subarachnoidal area; ELST type B with bony infiltration of the labyrinth block and clinical hearing loss, and ELST type C with additional infiltration of the sigmoid sinus and the vein of jugular bulb. Preoperative diagnostics are performed according to defined radiological criteria in CT and MRI scans including MR-angiography. RESULTS: In 6 patients, including two with a VHL syndrome, ELST was completely sanitized by stage-compatible surgery, using translabyrintine to infratemporal approaches, according to the tumour classification that we developed. The VII (th) nerve could be saved in all tumour stages, and in stage ELST type A the VIII (th) nerve as well. All patients remained without local recurrence in MRI check during the observation period of 4 to 38 months. CONCLUSION: Our stage-compatible surgery of ELST allows total tumor removal with minor morbidity. In contrast to the antero-, retrosigmoidal and suboccipital approaches, the tumour matrix can be safely removed via transmastoidal approach to exclude local recurrences.

Adult↗

PubMed2004

[Results with the Contour cochlear implant in patients with cochlear otosclerosis].

BACKGROUND: Results after cochlear implant surgery may be complicated by postoperative facial nerve stimulation. Aim of the study presented was to evaluate postoperative results in implanting the straight Nucleus electrode array and the preformed Contour array in patients with deafness due to cochlear otosclerosis. METHODS: A retrospective analysis of intra- and postoperative reports of all patients with cochlear otosclerosis was carried out. Results with the Nucleus straight electrode array and the Contour array were compared with regard to postoperative facial nerve stimulation. RESULTS AND CONCLUSION: None of the Contour patients (n = 7) presented with postoperative facial nerve stimulation. This is in contrast to the majority (4 of 6) of patients being implanted with the straight electrode array. Our results indicate that the use of the Contour array is advantageous in patients being at risk for facial nerve stimulation. In addition intraoperative reports suggest a more reliable insertion of the Contour electrode array in cochlear otosclerosis with partial obliteration.

Cochlear Implants↗

PubMed2004

[Subtemporal approach according to house versus Wigand in intrameatal CPA tumors type A].

BACKGROUND: The subtemporal approach is indicated in intrameatal CPA tumors type A in order to preserve hearing. The exploration of the inner auditory canal for tumor exposure varies. It reaches from a locally limited uncovering of the bony inner auditory canal to a complete removal of the surrounding bony bed with the circular skeletization (360 degrees ) according to Wigand of the 7 (th) and 8 (th) nerve. Concerning the preservation of the function of the cranial nerve as well as an avoidable hyperelevation of the temporal cerebral lobe with a possible consecutive organic brain syndrome, both approaches have often been discussed controversially. METHOD: In a quality assurance analysis, we examined patients suffering from a unilateral, intrameatally limited CPA tumor type A in tumor stages 1 to 5. The functions of the 7 (th) and 8 (th) cranial nerves were assessed according to the consensus conference "Systems for reporting results in acoustic neuroma", Tokyo, November 2001, under consideration of the recommendations of the "American Academy of Otolaryngology, Head and Neck Surgery -- Committee on hearing and equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma", 1995, as well as indications for a possible organic brain syndrome. The results then were compared to current literature. RESULTS: 37 patients with an intrameatal confined CPA tumor after subtemporal tumor exstirpation were evaluated. In these patients, the inner auditory canal was only exposed in the area of the bony tectum (90 degrees - 120 degrees ) adjusted to the volume of the tumor, as described by House: 1 patient with tumor stage 1, 2 patients stage 2, 12 patients stage 3, 16 patients stage 4 and 6 patients with a tumor stage 5. The N. VII was anatomically preserved in 100 %. Immediately after surgery the function of N. VII was assessed in 32 % of the cases as stage I, 43 % stage II, 3 % stage IIIa, 14 % stage IIIb, 3 % stage IV, 0 % stage V, 5 % stage VI. All patients in stage VI had a restricted function of N. VII in stage II or IIIa already before surgery. N. VIII could be preserved anatomically in 78 % of the cases. 1 to 6 months postoperatively the hearing was at stage A in 10 % of the cases, at 25 % in stage B, 33 % in stage C, 16 % in stage D, 5 % in stage E and 11 % in stage F. One patient demonstrated signs of a possible organic brain syndrome postoperatively even after 12 months of latency (headache, unsteady walking, attention disorders). CONCLUSION: When comparing own data with the clinical results from literature, no differences can be found concerning the function of the 7 (th) and 8 (th) cranial nerves. There are no data concerning the incidence of a potential organic brain syndrome. The advantage of the House method is a noticeably reduced drilling time as well as possibly a reduced elevation of the temporal cerebral lobes. The Wigand method, however, allows a better overview and is needed for extrameatally growing tumors anyway.

Cranial Nerve Injuries↗

PubMed2004

[Caloric stimulation of the vestibular organ after cochlear implant surgery].

BACKGROUND: Alterations of the vestibular organ after intracochlear insertion of the electrode array in cochlear implant (CI) surgery are estimated in the literature to be more than 30 % . By performing a most atraumatic electrode insertion following the "soft surgery technique" as described by Lehnhardt , the risk of postoperative vestibular dysfunction should be minimised. METHODS: In the present study we compared pre- and postoperative results of the caloric stimulation test in cochlear implant patients and analysed the influence of untimely opening of the perilymphatic space under cochleostomy. In addition we used a non-validated questionnaire, asking for continuous postoperative vertigo after cochlear implant surgery. RESULTS: From patients with preoperative normal or hyperfunction on the implanted ear (n = 32) approximately 16 % showed a hypofunction or nonfunction on the implanted side postoperatively, independent of the technique of the cochleostomy. Only 12 % (n = 98) of the patients who were without vestibular problems preoperatively described postoperative vertigo longer than two days in the questionnaires. CONCLUSIONS: Although we found no significant difference regarding the influence of the technique of the cochleostomy on the preservation of vestibular function, we conclude that the concept of an atraumatic electrode insertion reduces the risk of vestibular dysfunction after CI-surgery.

Adolescent↗