Use of computed tomography to assess volume change after endoscopic orbital decompression for Graves' ophthalmopathy.

BACKGROUND: Orbital decompression is frequently performed in the management of patients with sight-threatening and disfiguring Graves' ophthalmopathy. The quantitative measurements of the change in orbital volume after orbital decompression procedures are not definitively known. Furthermore, the quantitative effect of septal deviation on volume change has not been previously analyzed. OBJECTIVES: To provide quantitative measurement of orbital volume change after medial and inferior endoscopic decompression and describe a straightforward method of measuring this change using open-source technologies. A secondary objective was to assess the effect of septal deviation on orbital volume change. METHODS: A retrospective review was performed on all patients undergoing medial and inferior endoscopic orbital decompression for Graves' ophthalmopathy at a tertiary care academic medical center. Pre-operative and post-operative orbital volumes were calculated from computed tomography (CT) data using a semi-automated segmenting technique and Osirix™, an open-source DICOM reader. Data were collected for pre-operative and post-operative orbital volumes, degree of septal deviation, time to follow-up scan, and individual patient Hertel scores. RESULTS: Nine patients (12 orbits) were imaged before and after decompression. Mean pre-operative orbital volume was 26.99 cm(3) (SD=2.86 cm(3)). Mean post-operative volume was 33.07 cm(3) (SD=3.96 cm(3)). The mean change in volume was 6.08 cm(3) (SD=2.31 cm(3)). The mean change in Hertel score was 4.83 (SD=0.75). Regression analysis of change in volume versus follow-up time to imaging indicates that follow-up time to imaging has little effect on change in volume (R=-0.2), and overall mean maximal septal deviation toward the operative side was -0.5mm. Negative values were attributed to deviation away form the operative site. A significant correlation was demonstrated between change in orbital volume and septal deviation distance site (R=0.66), as well as between change in orbital volume and septal deviation angle (R=0.67). Greater volume changes were associated with greater degree of septal deviation away from the surgical site, whereas smaller volume changes were associated with greater degree of septal deviation toward the surgical site. CONCLUSION: A straightforward, semi-automated segmenting technique for measuring change in volume following endoscopic orbital decompression is described. This method proved useful in determining that a mean increase of approximately 6 cm in volume was achieved in this group of patients undergoing medial and inferior orbital decompression. Septal deviation appears to have an effect on the surgical outcome and should be considered during operative planning.

Criterion-based (proficiency) training to improve surgical performance.

OBJECTIVE To investigate whether training otorhinolaryngology residents to criterion performance levels (proficiency) on the Endoscopic Sinus Surgery Simulator produces individuals whose performance in the operating room is at least equal to those who are trained by performing a fixed number of surgical procedures. DESIGN Prospective cohort. SETTING Two academic medical centers in New York City. PARTICIPANTS Otorhinolaryngology junior residents composed of 8 experimental subjects and 6 control subjects and 6 attending surgeons. INTERVENTION Experimental subjects achieved benchmark proficiency criteria on the Endoscopic Sinus Surgery Simulator; control subjects repeated the surgical procedure twice. MAIN OUTCOME MEASURES Residents completed validated objective tests to assess baseline abilities. All subjects were videotaped performing an initial standardized surgical procedure. Residents were videotaped performing a final surgery. Videotapes were assessed for metrics by an expert panel. RESULTS Attendings outperformed the residents in most parameters on the initial procedure. Experimental and attending groups outperformed controls in some parameters on the final procedure. There was no difference between resident groups in initial performance, but the experimental subjects outperformed the control subjects in navigation in the final procedure. Most important, there was no difference in final performance between subgroups of the experimental group on the basis of the number of trials needed to attain proficiency. CONCLUSIONS Simulator training can improve resident technical skills so that each individual attains a proficiency level, despite the existence of an intrinsic range of abilities. This proficiency level translates to at least equal, if not superior, operative performance compared with that of current conventional training with finite repetition of live surgical procedures.

Use of intraoperative CT scanning in endoscopic sinus surgery: a preliminary report.

BACKGROUND: Image-guided functional endoscopic sinus surgery (IG-FESS) using preoperatively acquired CT images for navigation has been proven to facilitate complicated endoscopic sinus procedures and decrease the need for revision procedures. However, this system does not render the intraoperative anatomic changes that occur throughout the procedure. The purpose of this study is to show the technical feasibility and the potential impact of intraoperative CT scanning in conjunction with real-time update of computer-assisted navigation during ESS. METHODS: Intraoperative CT scanning was performed in selected patients undergoing FESS. A scan was taken before the conclusion of surgery performed by skilled endoscopic sinus surgeons. The scans were evaluated for residual disease or cellular partitions. Where indicated, intraoperative scan was then loaded into the image guidance system and intraoperative scans were then used for additional IGS. The scan findings were documented. RESULTS: Intraoperatively acquired CT scans were obtained successfully in <40 seconds and able to be loaded into the image guidance system within minutes. All surgeries were preformed without complication. New information obtained from the intraoperative CT scan led to alteration in the surgical plan in 30% of patients. CONCLUSION: Intraoperative CT scanning can be preformed with currently available technology and has the potential to improve the extent of surgery in patients with complicated anatomy and extensive disease.

Radiographic and histologic analysis of the bone underlying inverted papillomas.

INTRODUCTION: Inverted papilloma (IP) is a benign but locally aggressive sinonasal tumor. Those localized to the maxillary sinus or medial maxillary wall have classically been removed through an external approach. In recent years, endoscopic removal has been advocated as an effective, minimally invasive approach. Successful endoscopic management is based on accurate intraoperative identification and complete resection of the tumor. The surgical management of the bone underlying the surface of an IP is less clearcut. Controversy exists as to whether the bony undersurface of an IP should be removed. In this article, histopathologic specimens and preoperative radiologic studies are prospectively examined to better understand the involvement of the bone underlying an inverted papilloma. MATERIALS AND METHODS: A prospective study of patients with maxillary sinus IP treated with endoscopic or endoscopic-assisted resection over a 12-month period was conducted. Intraoperatively, the site of tumor attachment was identified, and a 1- to 2-cm wedge of bone with overlying tumor was removed en bloc and analyzed under light microscopy. Preoperative radiographic studies were analyzed with respect to bony changes in the area of the tumor pedicle. RESULTS: On histopathologic analysis, the bony surface underlying the IP was irregular with multiple bony crevices in all nine cases. In two cases (22% of specimens), an isolated rest of normal-appearingsalivary gland and/or mucosal tissue was seen embedded in the underlying bone. Radiographic osteitic bony changes were seen at site of tumor attachment in 100% of cases. CONCLUSION: The irregularity of the bony surface may hinder complete tumor removal because microscopic rests of mucosa can be hidden within the bony crevices. Intraoperative removal of the bony surface at the site of tumor attachment may ensure a more complete removal.

Utility of a three-item smell identification test in detecting olfactory dysfunction.

OBJECTIVE: Physicians rarely assess smell function, largely because of time considerations. Therefore, there is clinical need for very brief cranial nerve I screening tests. Although a few such tests exist, none have been adequately validated. The goal of this study was to empirically assess the utility of a three-item microencapsulated odor identification test in detecting olfactory dysfunction. SETTING: Smell and taste center at a university medical center. METHODS: The test was administered to 224 consecutive patients (98 men and 126 women ranging in age from 15-88 years). As part of their overall assessment, the well-validated 40-item University of Pennsylvania Smell Identification Test (UPSIT) was also administered. Sensitivity, specificity, and both negative and positive predictive values of the three-item test were established relative to UPSIT dysfunction categories. Test-retest reliability was determined in a subset of 39 patients. RESULTS: The three-item test was abnormal in 99% (67/68) of patients with anosmia, 85% (35/41) of those with severe microsmia, 76% (31/41) of those with moderate microsmia, and 50% (17/34) of those with mild microsmia. Of the 40 normosmic patients, 62.5% (25/40) correctly identified all odors, 25% (10/40) two odors, and 12.5% (5/40) one odor. None of the normosmic patients missed all three items. Using a cut-off score of 2, the test's sensitivity and specificity were 99% and 40%, respectively, for detecting total anosmia. The corresponding negative and positive predictive values were 98% and 43%. For detecting anosmia and severe microsmia, these values were 93%, 45%, 88%, and 63%. For detecting any olfactory pathology, they were 82%, 63%, 42%, and 91%. The test-retest reliability was 0.87. CONCLUSION: The brief three-item test used in this study was found to be highly sensitive in identifying olfactory loss in patients with chemosensory complaints, particularly those with severe dysfunction. Although only moderately specific, its high reliability and negative predictive value suggests it may be an appropriate screening test for olfactory loss.

Cranial nerve preservation in surgery for large acoustic neuromas.

Facial nerve outcomes and surgical complication rates for other cranial nerves were evaluated retrospectively after the resection of large acoustic neuromas. The charts of all patients who underwent surgical removal of an acoustic neuroma between 1992 and 2001 at New York University Medical Center were reviewed. Fifty-four patients with tumors measuring 3 cm or larger were included in the study. Four patients had neurofibromatosis type 2, two of whom underwent bilateral removal of acoustic neuromas. Translabyrinthine microsurgical removal of tumor was performed in 47 of 56 cases (84%). In all cases, EMG monitoring, improved sharp microdissection, and ultrasonic aspiration were employed. Facial nerve function was assessed using the House-Brackmann facial nerve grading system immediately after surgery and at follow-up visits. A House-Brackmann grade III or better was achieved in 90% of patients, and a grade II or better was achieved in 84% of patients. Ultimate facial nerve outcome was excellent after the surgical resection of large acoustic neuromas. Preoperative cranial nerve palsies also improved after surgery. The translabyrinthine approach for tumor removal is our treatment of choice for acoustic neuromas 3 cm or larger.

Cochlear implantation in human immunodeficiency virus-infected patients.

OBJECTIVE: To evaluate the efficacy of cochlear implants in human immunodeficiency virus-infected individuals and correlate these results with a proposed pathophysiological mechanism of human immunodeficiency virus-associated hearing loss. STUDY DESIGN: Retrospective case series and temporal bone analysis of deceased human immunodeficiency virus-positive patients. SETTING: Tertiary care hospital. PATIENTS: Seven human immunodeficiency virus-positive individuals with profound sensorineural hearing loss. INTERVENTION: Cochlear implantation at New York University Medical Center. METHODS: The surgical outcomes and complications were analyzed. Additionally, electron microscopic and immunohistochemical findings of cadaver temporal bone specimens of other known human immunodeficiency virus-positive individuals were reviewed. The performance results of the human immunodeficiency virus-positive cochlear implant patients were then correlated with the previously hypothesized pathophysiological mechanism of human immunodeficiency virus-associated hearing loss. RESULTS: The patients had a varied performance with cochlear implantation, and as a group performance was good. There were no surgical complications or postoperative complications. The good performance of these patients supports the hypothesis that the mechanism of human immunodeficiency virus-associated deafness involves infiltration, malfunction, and premature degeneration of the hair cells and supportive cells of the cochlea. CONCLUSIONS: Human immunodeficiency virus-positive individuals benefit from cochlear implantation without increased surgical risk.