Objective: In some surgical specialties (eg, orthopedics), robots are already used in the operating room for bony milling work. Otological surgery and otoneurosurgery may also greatly benefit from the enhanced precision of robotics. Study Design: Experimental study on robotic milling of oak wood and human temporal bone specimen. Methods: A standard industrial robot with a six-degrees-of-freedom serial kinematics was used, with force feedback to proportionally control the robot speed. Different milling modes and characteristic path parameters were evaluated to generate milling paths based on computeraided design (CAD) geometry data of a cochlear implant and an implantable hearing system. Results: The best-suited strategy proved to be the spiral horizontal milling mode with the burr held perpendicular to the temporal bone surface. To reduce groove height, the distance between paths should equal half the radius of the cutting burr head. Because of the vibration of the robot's own motors, a high oscillation of the SD of forces was encountered. This oscillation dropped drastically to nearly 0 Newton (N) when the burr head made contact with the dura mater, because of its damping characteristics. The cutting burr could be kept in contact with the dura mater for an extended period without damaging it, because of the burr's blunt head form. The robot moved the burr smoothly according to the encountered resistances. Conclusion: The study reports the first development of a functional robotic milling procedure for otoneurosurgery with force-based speed control. Future plans include implementation of ultrasound-based local navigation and performance of robotic mastoidectomy.
The reconstruction of lip defects presents a challenge to the surgeon. Apart from attaining a good aesthetic result, preserving the function of the oral sphincter is an essential objective. A variety of techniques and modifications of procedures for reconstructing lip defects have been reported in the literature. It is up to the surgeon to select the reconstruction procedure ensuring optimum functional and cosmetic results, depending on the location, size, and depth of the defect. The division of the lips into aesthetic subunits can prove very beneficial in designing lip reconstruction procedures. The upper lip is divided into three aesthetic subunits: two lateral subunits and a median subunit, the philtrum. The lower lip constitutes a single subunit. In this study established reconstruction techniques are discussed, and a concept serving to facilitate the appropriate choice of technique is introduced. This concept differentiates between vermilion defects on the one hand and partial-thickness and full-thickness lip defects on the other hand. For the lower lip the full-thickness defects are classified as defects involving one third and one third to two thirds of the lower lip width and between two thirds and complete loss of lip tissue. For the upper lip a distinction is made between isolated defects of the central and lateral subunits and combined defects of the central and lateral subunits. Important principles of surgery and the advantages and disadvantages of different reconstruction techniques are discussed.
The pharmacokinetics of gentamicin, tobramycin, and amikacin in inner ear fluids, serum, cerebrospinal fluid, and the compartments of the eye were studied and compared in guinea pigs. The concentrations of antibiotic were determined by microbiologic methods and were confirmed by the use of 14C-labeled gentamicin. Retention was clearly demonstrated in perilymph, in which the half-lives of gentamicin, tobramycin, and amikacin were 12, 11, and 10 hr, respectively. The concentrations of drug in perilymph were symmetrical and were many times higher than the concentrations of antibiotic in the brain. There was no difference between the concentration of drug in endolymph and that in perilymph. A linear relation between concentrations in the perilymph and the dosage of gentamicin was ascertained. Long-term treatment did not influence the pharmacokinetics of the three antibiotics in the inner ear. However, increased levels of drug in the inner ear in animals with uremia and in some animals with otitis media explained the increased ototoxicity that occurs in treatment of these two conditions. Suboccipital puncture and diuresis did not change the concentrations of aminoglycoside antibiotics in the inner ear. Antibiotics applied locally in the middle ear had high degrees of ototoxicity.
Objective: The treatment strategy of squamous cell carcinoma of the nasal vestibule (SCCNV) is controversial. The objective of this study is to investigate the role of surgery, which is the preferred treatment option at our institution. Design: This was a monocentric prospective study of patients that were diagnosed with SCCNV between 2005 and 2013. Material and Methods: Twenty-six patients were included. Tumors were staged using the UICC (7th edition) TNM classification of nasal cavity cancer and the classification proposed by Wang. The primary treatment was surgery in all patients. Survival data were statistically analyzed using the Kaplan-Meier method. The median follow-up time was 6 years. Results: Using the UICC classification, 9/26 tumors were staged as pT1 (35%), 7/26 as pT2 (27%), and 10/26 as pT4a (39%). Using the classification by Wang, 9/26 tumors were staged as pT1 (35%), 15/26 as pT2 (58%), and 2/26 as pT3 (8%). Reconstruction was performed using an implant-retained prosthesis in 50% of patients and by plastic surgery in the remaining 50%. Only 2/26 patients (8%) needed adjuvant radiation therapy. The five-year recurrence-free survival (RFS) was 86.7%, disease-specific survival was 96.2% and overall survival was 91.8% after five years. Conclusion: Surgery in SCCNV gives an excellent prognosis and minimized the need for radiotherapy.
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