[Stingray injury: A case in French Polynesia]. / Piqûre de raie pastenague : un cas en Polynésie française.

INTRODUCTION: Stingray injuries occur when people inadvertently step on these fish. Penetration of the barb results in puncture and/or laceration wounds and lesions related to the venom. PATIENTS AND METHODS: We report the case of a 76-year-old woman in French Polynesia who was stung on her right ankle by a stingray. She initially had a hypertensive episode with encephalopathy and a haemorrhagic wound due to an indwelling fragment of the barb. Necrosis due to the poison required medical-surgical management with debridement, which yielded a favourable outcome. DISCUSSION: Stingray injuries are rare and not well-known by doctors. They can be serious due to injury by the barb and to venom poisoning, leading to enzymatic tissue destruction, ischaemia and intense pain. The initial treatment consists in immersion in hot water, as the venom is thermolabile; antibiotics and surgery may be necessary, depending on the condition of the wound.

[Evaluation of a Micro-Manipulator for Middle Ear Surgery: A Preclinical Trial]. / Evaluation eines Mikromanipulators für die Mittelohrchirurgie: Eine präklinische Studie.

BACKGROUND: Microsurgical preparation is limited by geometric and mechanical constraints. In preparation for clinical use, this study investigates performance, ease of handling and precision of a novel manipulator concept for microsurgery. MATERIAL AND METHODS: A group of 15 ENT experienced doctors, as well as a group of 17 medical students with low/non surgical experience participated in the study. Each of the subjects carried out 4 trials of simulated surgeries on a phantom with built-in force sensors. The task was to apply a defined force between 1.5 and 2 N using a Fisch micro perforator, 16 cm length, 0.4 mm (Storz) targeting holes with a diameter of 0.5 mm. For comparison, the Fisch micro perforator was moved manually or with the manipulator. RESULTS: Assessing the total number of errors proved a significantly lower error number (p<0.0001) and an improvement of the accuracy of 76% with the manipulator. The time requirement for the procedure with the micro manipulator is on average 2-3 times higher than with manual control (p<0.0001). But it is notable that this time requirement significantly decreases with training (p<0.0001). CONCLUSION: The study shows a significant reduction in the number of errors by using a new manipulator concept compared to the non-augmented human hand in an experimental setup. We observed a significant learning effect when subjects applied the micro manipulator, resulting in reduction of the time requirement while maintaining a constant number of errors.

[Clinical experience with navigation functions for temporal bone surgery : interim result after 40 patients]. / Klinischer Einsatz von Navigationsfunktionen in der Felsenbeinchirurgie : Zwischenbilanz nach 40 Patienten.

PROBLEM: Although robust algorithms for registration and segmentation are available, the majority of surgical approaches to the temporal bone are nowadays made without navigation assistance. Beside instrument navigation (IN), functions such as distance control (DC) and navigated control (NC) can be used. This study analyzes the application of these navigation functionalities in lateral skull base and middle ear surgery. PATIENTS AND METHODS: A total of 41 patients with an indication of temporal bone approaches were included. The navigation was realized with an optoelectric navigation system with both non-invasive and invasive markers. Parameters such as surgical time, Level of Quality (LoQ) index, and Change of Surgical Strategy (COS) index were evaluated. RESULTS: In 14.6% of patients, the conventional mode of IN was used. In 70.7% of cases, the function DC was also used. In another 14.6% of cases, the function NC was used to control the speed of the drill. The facial nerve was the dominant segmented risk structure for active navigation. The time for setup was on average 7.78 min. The LoQ index score was on average 66 points. In 17% of the patients, surgeons evaluated the assistance mode as "necessary for the surgery". No technical-related complications were recorded. CONCLUSION: This study proves the usability of navigation technology for temporal bone surgery in clinical routine. DC and NC are two additional features for higher acceptance of navigation in microscopic surgery.

Fixation of split anterior tibialis tendon transfer by anchorage to the base of the 5th metatarsal bone.

Split anterior tibialis transfer is a procedure, frequently performed in combination with triceps surae lengthening, to treat equinovarus foot deformity in adult hemiplegia patients. The authors present their surgical technique, with tendon fixation by an anchor to the base of the fifth metatarsal. Although bone-tendon anchor fixation is widespread in orthopedic surgery, it is original in this type of indication. It is simpler, and less traumatic for the bone than a bone tunnel and less traumatic for the sole than transplantar fixation. The very distal attachment to the base of the 5th metatarsal bone solves the common problem of adjusting the tension of tendon transfer. The authors report their experience of 22 split transfers from 2005 to 2008.

[Clinical use of a micromanipulator system: preliminary clinical experience in middle ear surgery]. / Klinischer Einsatz eines Mikromanipulators : Erste Erfahrungen in der Mittelohr- und Felsenbeinchirurgie.

PROBLEM DESCRIPTION: Nowadays all procedures in tympanoplasty are performed using conventional instrumentation without any mechatronic based manipulators. A micromanipulator system (MMS) holds microinstruments and transmits the surgeon's hand movements to a monitor, thus, improving precision and ergonomics. MATERIALS AND METHODS: Using the Cartesian principle, a telemanipulator with three linear degrees of freedom controlled with a joystick was designed. The three axes are powered by a servomotor. The manipulator is equipped with a sterilizable instrument holder, which is placed on a sterile covered system. On this instrument holder, sterile surgical instruments can be clipped and can be easily changed during surgery. In the scope of this study, the MMS was used to perform a tympanoplasty III in 20 patients. A workflow expert protocol, a video of the surgery, and a questionnaire completed by all surgeons were evaluated. RESULTS: Clinical use of the MMS 2.0 was performed in all 20 patients as planned. A partial/total ossicular replacement prosthesis (PORP/TORP) was used in all cases with the MMS as planned. Significantly more time was necessary not only to prepare for surgery but also to prepare the equipment intraoperatively, and the incision to suture time was longer. The number of intraoperative changes of instruments decreased by 24%. The frequency of contact between the instrument and the prosthesis was significantly decreased. All questionnaires indicated that further improvement of the MMS is needed. CONCLUSION: The manipulator MMS 2.0 was successfully used in the clinical setting for the first time. The tool offers great potential for middle ear surgery (e.g., tympanoplasty III, stapes surgery and cochlear implant insertion). The principal of telemanipulation (master-slave) could be transferred to middle ear surgery. However, numerous technical improvements are still required.

Manual accuracy in comparison with a miniature master slave device--preclinical evaluation for ear surgery.

Manual accuracy in microsurgery is reduced by tremor and limited access. A surgical approach through the middle ear also puts delicate structures at risk, while the surgeon is often working at an unergonomic position. At this point a micromanipulator could have a positive influence. A system was developed to measure "working accuracy", time and precision during manipulation in the middle ear. 10 ENT-surgeons simulated a perforation of the stapedial footplate on a modified 3D print of a human skull in a mock OR. Each trial was repeated more than 200 times aiming manually and using a micro-manipulator. Data of over 4000 measurements was tested and graphically processed. Work strain was evaluated with a questionnaire. Accuracy for manual and micromanipulator perforation revealed a small difference. Learning curves showed a stronger decrease both in deviation and time when the micromanipulator was used. Also a lower work strain was apparent. The micromanipulator has the potential as an aiding device in ear surgery.

[Clinical experiences with an automatic collision warning system: instrument navigation in endoscopic transnasal surgery]. / Klinische Erfahrungen mit einem Kollisionswarnsystem: Instrumentennavigation in der endo- und transnasalen Chirurgie.

PROBLEM: The goal of this work is the extension of instrument navigation with a collision warning function. With the help of an additional distance display and warning system the performance of surgical navigation systems should be improved. MATERIAL AND METHODS: The collision warning system (DCS) is an extension of an optoelectric navigation system (NPU, Karl Storz GmbH&Co.KG, Tuttlingen, Germany). The measurement of situation awareness was performed on phantom models of functional endoscopic surgery of the paranasal sinuses (FESS; Phacon, Leipzig). Altogether 450 measurement pairs for the analysis of surgical accuracy to the risk structure (frontal skull base, lamina papyracea, internal carotid artery) were available. To examine the influence on the clinical process, a prospective analysis of intraoperative complications was carried out. Of the 104 FESS patients, two groups, one of 56 patients with only navigation (NAV) and one of 48 patients (NAV+DCS), were examined. Efficiency was evaluated on the basis of times for system preparation and intraoperative application. RESULTS: A significant increase in the assumed and actual distance values between instrument tip and risk structure using the collision warning system was seen at 76%. The complication rate was more favorable for the NAV+DCS group. The time needed for preparation of the navigation system with the application of the collision warning system increased on average by 48%, or 1.2 min. However, the relation between preparation time and utilization time was approximately the same at 53.5% in the NAV group and 57.4% in the NAV+DCS group. CONCLUSIONS: This work supports the clinical use and efficiency of a collision warning system as an addition to well-known instrument navigation in endo- and transnasal surgery. The segmenting algorithm is suitable for clinical requirements.

[Conception, realization and analysis of a modern operating theatre workplace for ENT surgery]. / Konzeption, Realisierung und Analyse einer neuartigen OP-Konzeption für die HNO-Chirurgie.

BACKGROUND: The requirements of ENT (ear, nose and throat) surgery, i. e. operating theatre, have changed dramatically in recent years, e. g. by high definition video endoscopy, navigation, neuromonitoring, intraoperative imaging, navigated and navigation-controlled instruments and intraoperative imaging and video documentation. For this reason a specialized operating theatre is necessary for ENT. The aim of this work was to compare this operating theatre with the previous standard. MATERIAL AND METHODS: The scientific basis of this work represents a surgical workflow analysis. Over 200 completely documented operations in conventional operating theatres were available for comparison. In addition the log files of the medical technical devices, software analysis modules of the clinical documentation and ergonomics questionnaires (NASA TLX standard) were available. In the period from 1(st) June 2009 to 31(st) September 2009 a total of 139 standard procedures (9 different ENT surgeons) were analyzed in the new ly integrated operating theatre system "Surgical Deck1-ENT". RESULTS: In the newly developed operating theatre system four work areas are specified: preparation area, technical cockpit, surgical cockpit and anesthesia cockpit. The medical technical components are permanently installed. The surgical cockpit incorporates five permanently arranged monitors, two main screens, two navigation screens and a surgical dashboard. A suitable high definition video routing system is installed and procedure-specific light profiles are developed. Documentation is automatically carried out in the picture archive and communication system (PACS). The comparison to the conventional operating theatre system the slot time was reduced from 73.8 min to 65.6 min (-11%), the preoperative time was reduced on average by 31% (8 min) per case and the documentation time was decreased on average by 6 min (67%). The interaction steps of the surgeon with the system were reduced by 70% (from 17 to 5 steps). No significant differences in complications could be observed. In the total evaluation of all 16 questions on the ergonomics there was a significant improvement of the workplace layout. DISCUSSION: The presented operation unit can significantly improve safety and efficiency as well as the ergonomics for ENT surgery and related procedures.

[Intraoperative volumetry in ENT surgery. Objectivation of surgical success by the volume control system]. / Intraoperative Volumetrie in der HNO-Chirurgie. Objektivierung des Operationserfolgs mit Volume-Control-System.

PROBLEM: At present no procedure exists to measure distances or volumes in endoscopic or otherwise limited surgical approaches directly and with high accuracy. Here a laser measuring system is evaluated for the first time as a clinical application in ENT surgery. MATERIAL AND METHODS: The volume control system (VCS) measures with the help of automatic recognition of laser measuring points in the surgical situs. A lab test examines the accuracy and the precision at anatomically accurate paranasal sinus and tympanic cavity models under flexible endoscopic visualization. The true values are known in each case as calibrated distances. Thus 90 values were available for evaluation. The clinical trial serves as proof of the intraoperative applicability and includes 32 patients. RESULTS: The measurements in the lab test resulted in an average deviation from the true value at a maximum of 7.1%. The precision was between 0.2 and 0.5 mm. In the clinical setting the system could be used in all 32 patients. Altogether 97 measured values could be included. The VCS functioned without system failures. The additional time required for setting up amounted to less than 2 min. The manageability of the flexible endoscope was reduced because of the length and the difficulty in controlling the adjustment. The additional intraoperative time required for collection of the measured values was less than 4 min in each case. Many results led to clinically relevant interpretations with intraoperative consequences. DISCUSSION: The VCS shows for the first time an intraoperatively applicable measuring function for distances, surfaces and volumes. There is a multiplicity of meaningful applications in ENT and in other surgical disciplines. The available study has proved the concept.

[Evaluation of a daily used navigation system for FESS]. / Untersuchungen zur Effizienz eines Navigationssystems für die HNO-Chirurgie: Auswertungen von 300 Patienten.

PROBLEM: The aim of this study is to proof the clinical efficiency by using a modern navigation system for Functional Endoscopic Sinus Surgery (FESS). MATERIAL AND METHODS: An optical navigation system was used in clinical routine of 300 patients. Two groups with 150 patients each were examined. Group A was treated with navigation assistance (Karl Storz Navigation Panel Unit NPU), Group B was treated without navigation by conventional FESS. Examination period was limited to 12 months. Median follow-up is 22 and 26 weeks. Perioperative, intraoperative and postoperative parameters were recorded by workflow-analysis, clinical and radiological findings and standardized questionnary. RESULTS: Application of the navigation system needs 1.1 min additional perioperative time in average. Intraoperative time reduction by the navigation system was about 10 min per case (Group A 32.6 (SD 11.2) min, Gruppe B 42.7 (SD 9.5) min). Specific information by the navigation system was evaluated in all surgical areas as usefull and additional to a-priori-knowledge. Postoperatively patients from group A (10/89) show lower rate of re-polyposis then in group B (24/71). Fenestration of the sphenoid sinus were sufficient by CT-evaluation in 100% (group A) and 23% (group B). CONCLUSIONS: The advantages of the examined navigation system in comparison to the gold standard of FESS are proven. Navigation assistance led to an reduced intraoperative time consumption, increased postoperative results and lowered the workload of the surgeons.

[Evaluation of a training system for middle ear surgery with optoelectric detection]. / Evaluation eines Trainingssystems für die Felsenbeinchirurgie mit optoelektrischer Detektion.

PROBLEM: This work presents a new training concept for surgery of the temporal bone. It is based on a model of gypsum plastic with optoelectric detection of risk structures. A prototypical evaluation is given. MATERIAL AND METHODS: The training models are based on high-resolution computed tomographic data of a human skull. The resulting data set was printed by a three-dimensional (3D) printer. A 3D phantom is created from gypsum powder and a bonding agent. Risks structures are the facial nerve, semicircular canal, cochlea, ossicular chain, sigmoid sinus, dura, and internal carotid artery. An electrically conductive metal (Wood's metal) and a fiber-optic cable were used as detection materials for the risk structures. For evaluating the training system, a study was done with eight inexperienced and eight experienced ear surgeons. They were asked to perform temporal bone surgery using two identical training models (group A). In group B, the same surgeons underwent surgical training with human cadavers. In the case of injuries, the number, point in time, degree (facial nerve), and injured structure were documented during the training on the model. In addition, the total time needed was noted. RESULTS: The training systems could be used in all cases. Evaluation of the anatomic accuracy of the models showed results that were between 49.5% and 90% agreement with the anatomic origin. Error detection was evaluated with values between 79% and 100% agreement with the perception of an experienced surgeon. The operating setting was estimated to be better than the previous"gold standard." The possibility of completely replacing the previous training method, which uses cadavers, with the examined training model was affirmed. CONCLUSIONS: This study shows that the examined system fulfills the conditions for a new training concept for temporal bone surgery. The system connects the preliminary work with printed and sintered models with the possibilities of microsystem engineering. In addition, the model's digital database permits a complete virtual representation of the model with appropriate further applications ("look behind the wall," virtual endoscopy).

[Modified procedure for patient registration for navigation control instruments in ENT surgery]. / Ein modifiziertes Verfahren zur bissschienenbasierten Patientenregistrierung für die HNO-Navigation.

PROBLEM: Surgical navigation and navigation-controlled instruments demand a robust and precise patient registration process. For navigation in the skull, a bite-splint-based registration method has been widely applied, which had to be manufactured by dental technicians. The additional cost and time could be avoided by directly using the manufactured imprint, which is prepared by the ENT surgeon in one step. MATERIAL AND METHODS: This study examined the re-positioning accuracy for three silicon materials in a laboratory study with a 3D measuring device (Faro-arm) after several re-positioning cycles (simulating erosion) in comparison to the gold standard. RESULTS: The mean deviation after two cycles was lower for all three materials compared to the gold standard. Only C-Silikon Optosil was better then the gold standard after all cycles and with a deviation of 0.17 mm it well below that of the conventional bite-splint (0.28 mm). The additional cost benefits of 10 euro per imprint compared to the bite-splint with >100 euro favor this material for clinical application. CONCLUSIONS: As a consequence of this investigation Optosil was successfully used in 6 patients during the period from 01.09.2007 to 30.11.2007. The bite-splint was manufactured completely in the ENT department and could be used during the planning CT and surgery. The resulting accuracy corresponded to the experiences gained in previous surgery with a maximum deviation of 0.87 mm. The favorable ergonomic characteristics for patient and surgeon could be confirmed. As a result of this study this clinic now exclusively uses the procedure described in this article for bite-splint-based registration.

No improvement in renal cell carcinoma survival: a population-based study in the Netherlands.

BACKGROUND: The increased finding of kidney 'incidentalomas' and more frequent surgery in patients with renal cell cancer (RCC) metastases may have improved survival from the disease. However, recent data on survival of unselected population-based series of patients with RCC are sparse. METHODS: We collected the follow-up data for all the patients registered with RCC in the population-based cancer registry held by the Comprehensive Cancer Centre East, the Netherlands. RESULTS: Patients (1504) diagnosed with RCC between 1989 and 2002 were included. Eighty-three percent of all tumours were histologically confirmed; 17% of all diagnoses were based on clinical examination only. The latter group was older, had a worse stage distribution, often did not receive any kind of therapy and showed a 5-year relative survival of 8%. Five-year relative survival for patients with a histologically confirmed RCC was 60% and did not improve over the last 15 years. A low resection rate in patients with metastasis was observed, most pronounced in elderly, without a tendency of increase in more recent years. CONCLUSION: The relative survival of RCC did not improve over the years. The resection rate in patients with metastasised disease did not increase over time, despite current knowledge concerning its benefit on tumour complications, time to progression and response to immunotherapy.

[Integration of the functional signal of intraoperative EMG of the facial nerve in to navigation model for surgery of the petrous bone]. / Integration des intraoperativen EMG-Signals des N. facialis in das Navigationsmodell der Felsenbeinchirurgie.

UNLABELLED: PROBLEM DEFINITION: The goal of this work is the integration of the information of the intraoperative EMG monitoring of the facial nerve into the radiological data of the petrous bone. The following hypotheses are to be examined: (I) the N. VII can be determined intraoperatively with a high reliability by the stimulation-probe. A computer program is able to discriminate true-positive EMG signals from false-positive artifacts. (II) The course of the facial nerve can be registered in a three-dimensional area by EMG signals at a nerve model in the lab test. The individual items of the nerve can be combined into a route model. The route model can be integrated into the data of digital volume tomography (DVT). MATERIAL AND METHODS: (I) Intraoperative EMG signals of the facial nerve were classified at 128 measurements by an automatic software. The results were correlated with the actual intraoperative situation. (II) The nerve phantom was designed and a DVT data set was provided. Phantom was registered with a navigation system (Karl Storz NPU, Tuttlingen, Germany). The stimulation probe of the EMG-system was tracked by the navigation system. The navigation system was extended by a processing unit (MiMed, Technische Universität München, Germany). Thus the classified EMG parameters of the facial route can be received, processed and be generated to a model of the facial nerve route. The operability was examined at 120 (10 x 12) measuring points. RESULTS: The evaluation of the examined algorithm for classification EMG-signals of the facial nerve resulted as correct in all measuring events. In all 10 attempts it succeeded to visualize the nerve route as three-dimensional model. The different sizes of the individual measuring points reflect the appropriate values of Istim and UEMG correctly. DISCUSSION: This work proves the feasibility of an automatic classification of an intraoperative EMG signal of the facial nerve by a processing unit. Furthermore the work shows the feasibility of tracking of the position of the stimulation probe and its integration into amodel of the route of the facial nerve (e. g. DVT). The rediability, with which the position of the nerve can be seized by the stimulation probe, is also included into the resulting route model.

First clinical evaluation of the navigated controlled drill at the lateral skull base.

Surgery on the lateral skull base puts delicate structures at risk. To support the surgeon in identifying and protecting the risk structures the principle of Navigated Control (NC) can be used for preventing iatrogenic injuries. In this paper the application of Navigated Control for surgery on the lateral skull base was investigated for the first time in clinical use. There was no risk structure damage with NC. Navigated Control in lateral skull base surgery seems to have a great potential for safe risk structure protection, a morbidity reduction and in a relief of strain for the surgeon.

[Improvement of registration accuracy for navigated-control drill in mastoidectomy (autopilot)]. / Der Einfluss von unterschiedlichen Registrierverfahren auf die Genauigkeit der navigiert-kontrollierten Fräse (Safety Assistance-Funktion) für die Mastoidektomie.

BACKGROUND: The goal of this study is the improvement of the surgical accuracy of a navigate-controlled drill for mastoidectomy in a lab test. METHODS: For lab tests an artificial model of the temporal bone with color-coded injury identification of the facial nerve (solution of 0.5 mm) was used. Two different registration methods were examined: (group 1) navigation bow with 4 integrated markers at the upper jaw; (group 2) landmark registration with 4 titanium micro screws. An optical navigation system was used. The targets were illustrated by 3 titanium screws within the range of the planum mastoideum. The accuracy of the navigate-controlled drill in drilling the planned cavity were evaluated at 20 temporal bone models. The measurement of the registration accuracy was evaluated by deviation between the target screw and the calculated position in the navigation system. The evaluation of the resulted cavities was done by 5 senior surgeons with the help of the microscope. RESULTS: The registration accuracy shows a maximum deviation between the real position and the calculated position of 1,73 MM in group of 1 and 0.93 MM in group 2. In group 1 the nerve was hurt in 5/20 cases and a maximum deviation of - 1.5 mm (Std 0.25 mm) (drilled beyond the nerve) was measured. In group 2 the nerve was not hurt, a maximum deviation of 0.5 mm (too early stopped before the nerve) was measured. CONCLUSIONS: Significantly better results of the registration and drilling accuracy show up in group group 2. Thus the preconditions for clinical use are fulfilled.

A system for respiratory motion detection using optical fibers embedded into textiles.

In this contribution, a first prototype for mobile respiratory motion detection using optical fibers embedded into textiles is presented. The developed system consists of a T-shirt with an integrated fiber sensor and a portable monitoring unit with a wireless communication link enabling the data analysis and visualization on a PC. A great effort is done worldwide to develop mobile solutions for health monitoring of vital signs for patients needing continuous medical care. Wearable, comfortable and smart textiles incorporating sensors are good approaches to solve this problem. In most of the cases, electrical sensors are integrated, showing significant limits such as for the monitoring of anaesthetized patients during Magnetic Resonance Imaging (MRI). OFSETH (Optical Fibre Embedded into technical Textile for Healthcare) uses optical sensor technologies to extend the current capabilities of medical technical textiles.