Physician experience with an optical image guidance system for sinus surgery

OBJECTIVES/HYPOTHESIS: Intraoperative guidance systems have been developed which use infrared tracking technology to assist with anatomical localization during sinus surgery. Although the introduction of this technology is intended to increase the safety and efficacy of sinus surgery, little is known about its actual impact in the clinical setting. The objective of this report was to study the application and utilization of an image guidance system shared by multiple sinus surgeons in a specialty hospital. STUDY DESIGN: Combined prospective case study and retrospective analysis of physician surveys. METHODS: An optical-based image guidance system (LandmarX, Xomed, Inc., Jacksonville, FL) was used by 34 physicians to perform 754 sinonasal surgeries over a 2.5-year period at Massachusetts Eye and Ear Infirmary. In 19 cases, system registration was repeated during surgery to measure the effect of fiducial placement on system accuracy. RESULTS: The measured accuracy of anatomical localization at the start of surgery (mean value, 1.69 +/- 0.38 mm) was comparable to the perceived accuracy of 1 to 3 mm that was reported by 79% of surgeons surveyed. Operating room time (mean period, 130.6 +/- 41.1 min) correlated with the surgical procedure performed (P < .05), but not with the disease stage or revision rate. According to a majority of surgeons, use of the image guidance equipment increased operating room time by 15 to 30 minutes during initial cases and by 5 to 15 minutes once experience with the equipment had been acquired. More than 90% of surgeons anticipated their continued use of the image guidance equipment for sinus surgery at a similar or greater level in the future. CONCLUSION: An optical-based image guidance system can be successfully integrated into a multisurgeon operating room environment. Use of the system provides accurate anatomical localization during sinus surgery and results in a relatively high level of physician satisfaction.     

Fabrication of tissue engineered tympanic membrane patches using computer-aided design and injection molding

Objectives/Hypothesis: The goal of the current study was to use computer‐aided design and injection molding technologies to tissue engineer precisely shaped cartilage in the shape of butterfly tympanic membrane patches out of chondrocyte‐seeded calcium alginate gels. Methods: Molds were designed on SolidWorks 2000 and built out of acrylonitrile butadiene styrene (ABS) using fused deposition modeling (FDM). Tympanic membrane patches were fabricated using bovine articular chondrocytes seeded at 50 × 10⁶ cells/mL in 2% calcium alginate gels. Molded patches were cultured in vitro for up to 10 weeks and assessed biochemically, morphologically, and histologically. Results: Unmolded patches demonstrated outstanding dimensional fidelity, with a volumetric precision of at least 3 μL, and maintained their shape well for up to 10 weeks of in vitro culture. Glycosaminoglycan and collagen content increased steadily over 10 weeks in culture, demonstrating continual deposition of new extracellular matrix consistent with new tissue development. Conclusions: The use of computer‐aided design and injection molding technologies allows for the fabrication of very small, precisely shaped chondrocyte‐seeded calcium alginate structures that faithfully maintain their shape during in vitro culture. In vitro fabrication of tympanic membrane patches with a precisely controlled geometry may have the potential to provide a minimally invasive alternative to traditional methods for the repair of chronic tympanic membrane perforations.     

Use of computer-aided surgery for frontal sinus ventilation

OBJECTIVES: To review our experience and evaluate the utility of computer-aided surgery for frontal sinus and frontal recess disease. STUDY DESIGN: A retrospective review of 31 consecutive patients undergoing computer-aided surgery for frontal sinus ventilation. METHODS: The hospital charts of 31 patients were reviewed. Previous sinonasal procedures, etiology of sinonasal disease, preoperative computed tomography (CT) scan findings, preoperative symptoms, endoscopic and intraoperative findings, type of frontal sinus ventilation procedure, complications, imaging system registration method or accuracy, and postoperative course were noted. RESULTS: In all 31 patients the surgery was successfully completed, and no intracranial or orbital complications were encountered during or after surgery. Six patients required additional surgery including revision transnasal endoscopic frontal sinus ventilation or osteoplastic flaps with fat obliteration. In the six cases requiring additional surgery, disease severity, most commonly, aspirin triad disease, predisposed to failure of frontal sinus ventilation. CONCLUSIONS: Computer-aided surgery is a useful adjunctive device for safe, efficient identification and surgery of the frontal sinus. However, it is not a replacement for sound surgical technique, anatomical knowledge, and experience. In particular, patients with aspirin triad disease with frontal recess and frontal sinus involvement are highly suited for computer-aided surgery and thorough removal of disease, although failures occur despite this technique. The long-term benefit of computer-aided surgery of the frontal sinus has not yet been demonstrated by this or other studies.     

Tissue-engineered calcium alginate patches in the repair of chronic chinchilla tympanic membrane perforations

OBJECTIVE: Chronic tympanic membrane perforations are a common problem in the United States. A high number of these cases results from placement of pressure equalization tubes. These perforations may initially be treated with paper patch techniques and although safe and well tolerated, the procedure demonstrates poor efficacy. The ideal treatment for small perforations should be rapid, minimally invasive, and efficacious. Calcium alginate-based tissue engineered tympanic membrane patches represent an attractive option, but in vivo data are required. METHODS: A controlled prospective study of tympanic membrane perforation repair using a well-known chinchilla model of chronic tympanic membrane perforation was performed. Calcium alginate-based tympanic membrane patches were created using computer-aided design techniques. A previously described chinchilla model of chronic tympanic membrane perforations was used to create stable perforations ranging from 2 to 5 mm. Ears with chronic perforations were divided into three groups: control (no patch), paper patch, and calcium alginate plugs. At 10 weeks postimplantation, all animals were killed and inspected both grossly and histologically for healing. RESULTS: In the chinchilla model, the alginate grafts demonstrated significantly improved healing rates over both the untreated control group (spontaneous repair) and the paper patch group; nine of 13 healed in the alginate group versus two of nine healed in the paper patch group (P < .05) versus one of 11 healed in the control group (P < .05). CONCLUSION: Calcium alginate tympanic membrane perforation patches offer a significant advantage in the repair of chronic perforations over traditional techniques in the chinchilla perforation model and may offer attractive opportunities in the clinical setting.     

计算机智能导航系统在鼻科和耳科手术中的应用

目的：探讨计算机智能导航系统在鼻科和耳科手术中应用的有关问题。方法：霉菌性蝶窦炎1例，巨大额筛窦囊肿1例，先天性外耳道闭锁3例，均在影像导航系统下进行鼻内窥镜手术和显微镜手术。结果：术前准备时间16-30min，平均27min，配准系数在1.3-2.0之间，平均1.92。影像与实体指示之间误差小于1mm的是中耳，颅底，乳突，误差小于1.3mm的区域是鼻腔鼻窦，5例手术均顺利，无术中，术后并发症，手术时间与传统的鼻内窥镜手术和耳显微手术相比差异无显著性意义。结论：导航手术可以帮助医师在手术中确认鼻，耳及与之相连接的高危解剖区域的标志，即提高了手术的精确性，又提高了手术的安全性，是未来耳鼻咽喉微创外科的方向之一。     

Three-dimensional computed tomography angiography of the internal carotid artery for preoperative evaluation of sinonasal lesions and intraoperative surgical navigation

INTRODUCTION: Three-dimensional computed tomographic angiography (3DCTA) demonstrates the spatial relationships of the internal carotid artery (ICA) and adjacent skull base. This imaging modality may be incorporated into intraoperative surgical navigation during endoscopic skull base surgery. METHODS: The charts of patients who had undergone 3DCTA imaging between July 2002 and February 2005 were reviewed. For 3DCTA, 1 mm axial computed tomography (CT) scan images were obtained with simultaneous intravenous contrast bolus on a multidetector CT scanner (Somatom Sensation 16, Siemens, Munich, Germany). The CBYON Suite version 2.6 to 2.8 (Med-Surgical Services, Mountain View, CA) was also used for creating CTA images through its volume-rendering protocols. RESULTS: A total of 22 3DCTA studies were performed for diagnostic evaluation or preoperative planning. In 18 instances, the 3DCTA images were used during intraoperative surgical navigation. The specific indications for obtaining the 3DCTA study included neoplasm (11 cases), cerebrospinal fluid leak (3 cases), fibro-osseous lesion (2 cases), mucocele (2 cases), and other (4 cases). Images generated by 3DCTA facilitated the definition of the anatomic relationships between the ICA and skull base lesion. During intraoperative surgical navigation, the 3DCTA provided critical information about the ICA location and adjacent skull base anatomy in the operative field. CONCLUSIONS: 3DCTA is a useful means for assessing the ICA and its relationship to skull base lesions. Incorporation of 3DCTA into intraoperative surgical navigation facilitates the comprehension of operative field anatomy in the ICA region. As a result, this imaging technique, especially when combined with intraoperative surgical navigation, may extend the applications of minimally invasive endoscopic approaches to the skull base.     

Image-guidance for endoscopic sinus surgery

Objectives/Hypothesis: Image‐guided surgery (IGS) is a critical tool. However, its clinical validity remains controversial. A review of indications and a consensus based on literature are presented. Methods: Literature review. Results: Traditional indications remain valid. Novel applications have emerged, and the reliability of IGS has been consistently endorsed. Although evidence is based on scattered reports and expert opinions, the use of IGS in approved instances is regarded as the state of the art. Conclusions: IGS is reliable, and a scientific validation of outcomes would entail unethical strategies. An expanding spectrum of indications is anticipated, although IGS does not replace proper training.     

Quantitative computer‐assisted digital‐imaging upper airway analysis for obstructive sleep apnoea*

This was a prospective study of a new objective method which quantitatively analyses the upper airways in patients with obstructive sleep apnoea (OSA). Video‐nasopharyngoscopic examinations of the upper airways of 45 patients were carried out with an endoscopic calibrator. Images of the upper airway during quiet respiration and Mueller's manoeuvre in erect and supine positions were digitized by computer to generate the actual dimensions of obstructive sites. Measurements by the new method were validated by comparing 90 pairs of videoendoscopic images with upper airway magnetic resonance imaging (MRI) measurements at two identical levels. Quantitative precision is 100% for the retropalatal level and 95.6% for the retrolingual level with a tolerance of 0.5 cm² between the two methods. The absolute mean of the difference between the two methods of measurement is 0.08 cm² at the retropalatal level and 0.18 cm² at the retrolingual level. The agreement between the digital‐imaging videoendoscopic and MRI measurements was 93.3% for the retropalatal level and 95.6% for the retrolingual level. Quantitative computer‐assisted digital imaging is a reliable, cost‐effective clinical method of upper airway evaluation in OSA patients. This method allows us to examine the dynamic and static morphology objectively, measure surgical outcomes of upper airway, opening up new avenues for OSA management.     

Blepharokymographic analysis of eyelid motion in Bell's palsy

OBJECTIVE: To present characteristics of eyelid motion measured by blepharokymography in Bell's palsy patients and to discuss possible roles and limitations of blepharokymography. STUDY DESIGN: Retrospective analysis. METHODS: The study included 72 patients with Bell's palsy who presented to the Department of Otolaryngology at Asan Medical Center, Seoul, Korea, between April 2002 and March 2005, and who underwent both electroneuronography and blepharokymography. Parameters of eyelid motion were measured using revised blepharokymography. Correlations between blepharokymography and electroneuronography or House-Brackmann grade were examined by Spearman rank correlation and Kendall's tau-b correlation, respectively. RESULTS: Compared with the normal side, all parameters of eyelid motion except opening time were decreased on the palsy side, with peak closing velocity showing the greatest difference (40.2%). On average, paralytic eyelids moved down 6.5 mm in 277 ms with a peak velocity of 55.4 mm/s, whereas normal eyelids moved down 9.7 mm in 214 ms, with a peak velocity of 142.6 mm/s. Subtle paralytic eyelid motion or "lid lag" could be objectively documented by blepharokymography to have longer and gentler downward slopes in displacement curves. Most blepharokymographic parameters correlated with ocular electroneuronography and House-Brackmann grade. CONCLUSIONS: Slow or incomplete closure of paralytic eyelids can be graphically and numerically analyzed by blepharokymography. Blepharokymography may be useful for evaluating status, predicting prognosis, and assessing effects of rehabilitative procedures, including gold weight implants in patients with facial palsy.     

Barriers to Cochlear Implant Access: Acknowledging the Challenges,Changing the Future: Functional Assessment of Hearing Aid Benefit: Incorporating Verification and Aided Speech Recognition Testing into Routine Practice

Potential cochlear implant (CI) candidates arrive to the clinic with a variety of hearing loss configurations, hearing aid history, and aided capabilities. CI candidacy is primarily determined based on aided speech recognition capability, which relies on benefit derived from use of hearing aids. Therefore, contemporary evaluation for CI candidacy should incorporate a battery of testing to determine abilities and limitations and must be predicated on appropriate verification of the hearing aid fitting. However, recent reports, including a retrospective chart review of patients presenting to Cleveland Clinic for CI evaluation, suggest that a significant subset of patients may be using inappropriately fit or programmed amplification. Thus, a combination of simulated real-ear measurements and aided speech recognition testing is essential for fully assessing the effect of amplification and ultimately determination of CI candidacy. Furthermore, waiting to incorporate these tools until CI candidacy is suspected may delay timely identification of problems or need to change technology. Utilization of evidence-based decision drivers ultimately leads clinicians to timely patient-specific interventions which may include surgical intervention or other amplification options. As audiology moves into a healthcare era in which payers consider the benefit of our services to overall health and well-being, demonstrating timely, optimal outcomes using thorough, multifactorial evaluation is essential.     

Assessing candidacy for bilateral cochlear implants: A survey of practices in the United States and Canada

Abstract

Objectives

There are currently no agreed-upon criteria to establish candidacy for bilateral cochlear implants (CIs). This study categorized practice patterns for establishing bilateral CI candidacy.

Methods

A postal survey was sent to all practices performing CIs in the United States and Canada. The survey queried centers regarding candidacy criteria for bilateral implantation, testing parameters, definition of ‘best aided condition’, use of testing in noise, localization, and quality-of-life questionnaires. The survey was resent to non-responding centers 4 weeks after the initial mailing.

Results

The overall response rate was 40%. ‘Best aided condition’ (70%) and hearing in noise (52%) were used to establish bilateral candidacy, while 45% of centers offered bilateral implants to all candidates. The majority of respondents defined ‘best aided’ as hearing aids only (57% non-exclusive) or CI and hearing aid together (57%). Only 25% considered a CI alone as best aided. Nearly 5% considered no aiding to be the best aided. Sound localization was used by 8% of respondents for candidacy assessment. Reimbursement affected candidacy decision for 45%. There was variability in stimulus levels (60, 50, 45, and 55 dB), signal-to-noise ratios, and speaker orientations used.

Discussion

There are no consistent criteria to assess patients for bilateral CIs. This practice variation makes comparing outcomes across centers challenging and leaves open the possibility of having external standards imposed by regulators or payors. Standardization of candidacy assessment is necessary to develop best practices for bilateral cochlear implantation both to optimize patient outcomes and to ensure the continuity of coverage for these services.     

联合使用多媒体计算机辅助教学与FM调频系统对聋儿选择性听取影响的研究

目的旨在从声学角度研究和分析联合使用多媒体计算机辅助教学与FM调频系统对聋儿选择性听取的影响。结果32名聋儿在使用多媒体计算机辅助教学系统的过程中，使用FM调频系统与不使用FM系统时词汇辨别的差别有显著意义（P〈0．01）。结论FM系统可以改善多媒体计算机辅助教学系统在声音传播中受其内外部传音影响的状况，明显提高聋儿对词汇的识别率。