[First experience in endonasal surgery using a new 3D-Chipendoscope]. / Erste Erfahrungen in der endonasalen Chirurgie mit einem neuen 3D-Chipendoskop.

BACKGROUND: Endoscopic surgery for treatment of nasal, paranasal and anterior skull base pathologies is an established treatment modality. Available rigid endoscopes with angled views provide a 2-dimensional view with restriction of depth perception. In this study we report about our first experience with a new 3D-Chipendoscope in surgery at the nose, paranasal sinuses und anterior skull base. MATERIAL AND METHODS: 30 patients were enrolled in this study with chronic rhinosinusitis, inverted papilloma, frontal sinus mucocele, frontal sinus osteoma, chronic dacryocystitis and pituitary adenoma. All patients were subjected to standard endonasal endoscopic surgery using 3D-endoscopes. RESULTS: Surgery was performed by the use of the 3D-endoscope in all patients. The operative handling of the 3D-endoscopes was user friendly in regard to design and weight of the endoscopes. The problem of fogging during endoscopic surgery diminishing the quality of view was not observed. Blood crusts on the endoscope tip however was able to changed the 3D-view to a 2D-view. To close positioning of the 3D-endoscopes to the surgical field reduced image quality. The visualisation of the frontal sinus was limited. CONCLUSION: 3D-endoscopic surgery is an interesting development in endonasal surgery of pathologies at the nose, paranasal sinuses and anterior skull base.

[Endoscopic frontal sinus revision following transcutaneous endoscopic puncture and diaphanoscopy]. / Die endonasale Stirnhöhlenrevision nach transkutaner endoskopischer Punktion und Diaphanoskopie.

BACKGROUND: Endoscopic revision sinus surgery in case of frontal sinus pyocele may poses a great surgical challenge for various reasons. Due to the often troublesome anatomical changes caused by prior resection and findings of scaring with new bone formation, the identification of the frontal sinus in revision surgery is frequently a challenge for the surgeon. An easy endoscopic technique for a safe endonasal identification of the frontal sinus in revision surgery is therefore of major importance. MATERIAL AND METHODS: 4 patients (3 men, 1 female) were enrolled with an acute frontal pyocele following prior open frontal sinus surgery over an external access. All patients were subjected to standard endonasal endoscopic frontal sinus surgery. The frontal sinus was endonasally approached after endoscopic transcutaneous frontal sinus puncture through the pre-existing bone defect achieving a diaphanoscopy with endonasal identification of the frontal sinus floor. RESULTS: The external endoscopic puncture and illumination of the frontal sinus was performed in all 4 patients with a modular endoscopic system (Sinus View). A visual exploration of the frontal sinus was easily carried out after irrigation. A clear endonasal identification of the frontal sinus floor by diaphanoscopy was achieved in all patients and guided a direct opening of the frontal sinus. A stable frontal sinus drainage type IIb according to Draf was reached in all cases. CONCLUSION: Transcutaneous frontal sinus puncture with an modular endoscope allows not only to verify frontal sinus pyocele diagnosis, but also provides the option to open the frontal sinus directly guided by the diaphanoscopy at the frontal sinus floor even in situations of complex anatomy.

[Ultrasound of foreign bodies in the head and neck. Cases compared with an in vitro model]. / Ultraschallphänomene von Fremdkörpern der Kopf-, Halsweichteile. Vergleich von Kasuistik und Phantom.

BACKGROUND: High resolution ultrasound is an accepted method in identification and classification of various head and neck alterations. Foreign bodies are a seldom encountered entity and are supposed to have a characteristic echogenicity. In literature there are numerous publications describing diagnosing foreign bodies in other specialities like gynaecology or surgery with ultrasound. The aim of the study was to examine these findings and to reproduce them in the head and neck area. MATERIALS AND METHODS: The study includes the retrospective analysis of 6 cases. 3 cases have been reconstructed in a cadaver dissection model and a selfmade gel model. The findings were compared to the clinical cases and interpreted. RESULTS: In ultrasound foreign bodies have characteristic reflexions and artefacts. The diagnosis foreign body could be made in every case. The foreign body could not only be identified but also precisely localized. The findings were reproducable in both the cadaver and gel model. CONCLUSION: High resolution ultrasound is a dynamic, 3-dimentional, inexpensive, portable and readily available imaging method, facilitating the identification of lesions in the superficial soft tissues. In the hands of an experienced operator ultrasound may be the first imaging modality to be used for detection of radiolucent foreign bodies in head and neck area.

[Soft tissue navigation and image-guided removal of foreign bodies in head and neck surgery]. / Weichteilnavigation im Kopf-Hals-Bereich und navigierte Fremdkörperentfernung.

BACKGROUND: Soft tissue navigation has traditionally been neglected in computer-aided surgery (CAS) because of unpredictable margins of error. In our study, we examined clinical cases in which standard CAS was applied in soft tissue surgery in the head and neck region. Its extended applicability, margins of error, and general performance are described and discussed. MATERIALS AND METHODS: CAS was applied in surgical procedures for six patients. Five patients had foreign bodies in the head and neck region, and one patient displayed uncertain cervical lymph node enlargement. An optoelectrical navigation system (VectorVision(2), BrainLAB) was used in all cases. RESULTS: Using CAS, 10 out of 11 total foreign bodies were identified. Only one glass splinter attached to the eyeball could not be detected by the navigation system. One glass splinter that was deeply buried within the sphenoid bone was easily found but was left untouched. The parapharyngeal lymph node was identified and extracted in a minimally invasive transpalatinal approach. CONCLUSIONS: Soft tissue navigation was successfully applied in all but one case; the success was due to the altered demands in soft tissue navigation as opposed to skull-base surgery. Easy identification of foreign bodies and lymph nodes was possible in the soft tissues of the head and neck, with an acceptable margin of error.

[Update on computer- and mechatronic-assisted head and neck surgery in Germany]. / Update in der navigiert kontrollierten und mechatronisch assistierten Kopf-Hals-Chirurgie in Deutschland.

A consequence of the ongoing advances in medical navigation is the development of so-called mechatronic assistant systems. Up to now, medical navigation had been used only for additional intrasurgical orientation. But improvements in accuracy in imaging and medical navigation can exceed the surgeon's possible manual accuracy of surgical manipulation. In such cases, mechatronic assistant systems can supplement certain surgical procedures in order to obtain the required precision, such as for positioning of implants. The development and possible use of such mechatronic assistant systems in the head and neck, as well as improvements in the accuracy of medical navigation, are the focus of several working groups. For coordinating and adapting the various research projects, different research groups were called to present their current projects and results in the context of ASKRA (working group for skull-base and craniofacial surgery of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery) workshops at the German Society for Computer- and Robot-Assisted Surgery (CURAC) convention on 14 October 2006 in Hanover. Different projects were presented, with topics including navigated controlled assistant systems for the frontal and lateral skull base, possibilities for sonographic-induced bone measurement, and requirements for high-precision surgery of the skull base.

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.

[Development of an active robot system for multi-modal paranasal sinus surgery]. / Entwicklung eines aktiven Robotersystems für die multimodale Chirurgie der Nasennebenhöhlen.

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.

Increased safety in robotic paranasal sinus and skull base surgery with redundant navigation and automated registration.

We present an advanced version of our robotic setup for paranasal sinus surgery that was developed at the Department of Otorhinolaryngology, Head and Neck Surgery in Erlangen, Germany. The system was interconnected with a redundant navigation system for increasing intraoperative safety while performing telemanipulatory as well as fully automated maneuvers.In contrast to the previous "all in one" version, we built a modular three component setup. The basic feature of the computer navigation system is the "CAPPA ENT" station. The system references by automatically detecting a referencing frame mounted on a non-invasive upper jaw mouthpiece. Software components of both systems, navigation and robotics were combined on one user interface. Accuracy as well as clinical applicability studies were carried out. For better surveillance and increased safety, we decided to evaluate the robots reproducibility errors and overall stereotactic accuracy by means of redundant navigational control on a phantom model for paranasal sinus and skull base surgery. Multiple measurements from 14 CT-markers were taken representing different surgical approaches.A modular setup was designed and was deemed feasible in its size and weight dimensions as well as its maneuvrability for application in a routine operating room environment. The navigational feedback is integrated in real time in the robots user interface. In case of blocked visibility to the Dynamic Referencing Frame the robot powers down and activates the force torque sensor, thus softening all articulating joints. We found only adequate accuracies in pinpointing a specific CT-marker both in telemanipulatory and fully automated maneuvers. No significant offsets were observed evaluating accuracies for different surgical approaches.By using redundant navigation feedback, we were able to add another safety feature, the "loss of control" function, which shuts down any robotic action. However, no increase of the absolute accuracy was observed by adding this feature. We conclude that redundant navigational control does not make the robot more accurate, but it adds a potent safety feature to the system.

[Endonasal removal of a large recurrent craniopharyngioma using intraoperative navigation]. / Endonasale Entfernung eines ausgedehnten Kraniopharyngeomrezidivs mit Hilfe der intraoperativen 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.

Sperm protein 17 (Sp17) in multiple myeloma: opportunity for myeloma-specific donor T cell infusion to enhance graft-versus-myeloma effect without increasing graft-versus-host disease risk.

We recently found that sperm protein 17 (Sp17), a spermatozoa-restricted protein, is aberrantly expressed on the tumor cells in patients with multiple myeloma (MM). It may therefore be possible to generate donor-derived Sp17-specific CTL for administration following allogeneic stem cell transplant to augment graft-versus-myeloma (GVM) effect without inducing a global GVHD. To assess this approach, we have produced recombinant Sp17 protein and used Sp17 protein-pulsed dendritic cells to generate HLA class I-restricted Sp17-specific CTL from a previously unimmunized healthy donor. These CTL were able to lyse autologous Epstein-Barr virus-transformed lymphoblastoid cells in a Sp17-dependent manner. Target lysis was HLA-A1 and HLA-B27 restricted. Cytotoxicity could be blocked by antibodies against monomorphic HLA class I, HLA-A1 and HLA-B27 molecules but not HLA class II molecules. Most importantly, the CTL lysed HLA class I-matched Sp17-positive tumor cells, suggesting that Sp17 is processed and presented in association with the HLA class I molecules in Sp17-positive tumor cells in a concentration and configuration that could be recognized by recombinant protein-primed CTL. Analysis by flow cytometry of the CTL indicated that they were predominantly CD8 in phenotype and they produced IFN-gamma and very little IL-4. Our results suggest the potential for the generation and administration of donor-derived Sp17-specific CTL to augment GVM without inducing GVHD following allogeneic stem cell transplant for MM.

High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH.

Multiple myeloma (MM) is a hypoproliferative malignancy yielding informative karyotypes in no more than 30% of newly diagnosed cases. Although cytogenetic and molecular deletion of chromosome 13 is associated with poor prognosis, a MM tumor suppressor gene (TSG) has not been identified. To localize a minimal deleted region of chromosome 13, clonotypic plasma cells from 50 consecutive patients with MM were subjected to interphase fluorescence in situ hybridization (FISH) analysis using a panel of 11 probes spanning the entire long arm of chromosome 13. Whereas chromosome 13 abnormalities were absent in plasma cells from 25 normal donors, 86% of patients with MM demonstrated such aberrations. Heterogeneity, both in deletion frequency and extent, was confirmed by simultaneous FISH with 2 chromosome 13 probes. Deletion hot spots were noted at D13S272 (70%) and D13S31 (64%), 2 unlinked loci at 13q14. Homozygous deletions at these loci occurred in 12% (simultaneously in 8%) of the cases. Molecular deletions were found in all 14 patients with morphologic deletions, in 21 of 24 with uninformative karyotypes, and 8 of 12 patients with karyotype abnormalities lacking chromosome 13 deletion. Homozygous deletion of any marker was noted in 4% with low and in 36% with higher plasma cell labeling index greater than 0. 4% (P =.01). The absence of increasing deletion incidence and extent with therapy duration suggests that the observed lesions are not induced by treatment. The high incidence and extent of chromosome 13 deletions require the correlation of specific deletion(s) with poor prognosis. These analyses will provide valuable guidance toward cloning of an MM-TSG. (Blood. 2000;96:1505-1511)

Minimally invasive head holder to improve the performance of frameless stereotactic surgery.

Frameless stereotactic procedures crucially depend on the firmness of immobilization. Once registered, shifting of the patient leads to inaccuracy, and the patient registration has to be realigned. To overcome the drawbacks of conventional invasive fixation for neurosurgery and the widely accepted fixation with surgical tape in ENT, the Vogele-Bale-Hohner (VBH) head holder has been developed. It permits rigid, noninvasive fixation of the head by using an individualized dental cast attached to the upper jaw by vacuum. Oral intubation is uncomplicated. In addition, a special registration device providing well defined reference points can be mounted to the mouthpiece. We report the first promising clinical applications of this device.