Martin J. Citardi

Implementation, calibration and accuracy testing of an image-enhanced endoscopy system

This paper presents a new method for image-guided surgery called image-enhanced endoscopy. Registered real and virtual endoscopic images (perspective volume renderings generated from the same view as the endoscope camera using a preoperative image) are displayed simultaneously; when combined with the ability to vary tissue transparency in the virtual images, this provides surgeons with the ability to see beyond visible surfaces and, thus, provides additional exposure during surgery. A mount with four photoreflective spheres is rigidly attached to the endoscope and its position and orientation is tracked using an optical position sensor. Generation of virtual images that are accurately registered to the real endoscopic images requires calibration of the tracked endoscope. The calibration process determines intrinsic parameters (that represent the projection of three-dimensional points onto the two-dimensional endoscope camera imaging plane) and extrinsic parameters (that represent the transformation from the coordinate system of the tracker mount attached to the endoscope to the coordinate system of the endoscope camera), and determines radial lens distortion. The calibration routine is fast, automatic, accurate and reliable, and is insensitive to rotational orientation of the endoscope. The routine automatically detects, localizes, and identifies dots in a video image snapshot of the calibration target grid and determines the calibration parameters from the sets of known physical coordinates and localized image coordinates of the target grid dots. Using nonlinear lens-distortion correction, which can be performed at real-time rates (30 frames per second), the mean projection error is less than 0.5 mm at distances up to 25 mm from the endoscope tip, and less than 1.0 mm up to 45 mm. Experimental measurements and point-based registration error theory show that the tracking error is about 0.5-0.7 mm at the tip of the endoscope and less than 0.9 mm for all points in the field of view of the endoscope camera at a distance of up to 65 mm from the tip. It is probable that much of the projection error is due to endoscope tracking error rather than calibration error. Two examples of clinical applications are presented to illustrate the usefulness of image-enhanced endoscopy. This method is a useful addition to conventional image-guidance systems, which generally show only the position of the tip (and sometimes the orientation) of a surgical instrument or probe on reformatted image slices.

IL-33–Responsive Innate Lymphoid Cells Are an Important Source of IL-13 in Chronic Rhinosinusitis with Nasal Polyps

RATIONALE Chronic rhinosinusitis (CRS) without nasal polyps (CRSsNP) and CRS with nasal polyps (CRSwNP) are associated with Th1 and Th2 cytokine polarization, respectively; however, the pathophysiology of CRS remains unclear. The importance of innate lymphoid cells in Th2-mediated inflammatory disease has not been clearly defined. OBJECTIVES The objective of this study was to investigate the role of the epithelial cell-derived cytokine IL-33 and IL-33-responsive innate lymphoid cells in the pathophysiology of CRS. METHODS Relative gene expression was evaluated using quantitative real-time polymerase chain reaction. Innate lymphoid cells in inflamed ethmoid sinus mucosa from patients with CRSsNP and CRSwNP were characterized using flow cytometry. Cytokine production from lymphoid cells isolated from inflamed mucosa of patients with CRS was examined using ELISA and intracellular cytokine staining. MEASUREMENTS AND MAIN RESULTS Elevated expression of ST2, the ligand-binding chain of the IL-33 receptor, was observed in inflamed sinonasal mucosa from CRSwNP compared with CRSsNP and healthy control subjects. An increased percentage of innate lymphoid cells was observed in inflamed sinonasal mucosa from CRSwNP compared with CRSsNP. ST2(+) innate lymphoid cells are a consistent source of IL-13 in response to IL-33 stimulation. Significant induction of IL-33 was observed in epithelial cells derived from patients with CRSwNP compared with patients with CRSsNP in response to stimulation with Aspergillus fumigatus extract. CONCLUSIONS These data suggest a role for sinonasal epithelial cell-derived IL-33 and an IL-33-responsive innate lymphoid cell population in the pathophysiology of CRSwNP demonstrating the functional importance of innate lymphoid cells in Th2-mediated inflammatory disease.

Management of carotid artery rupture by monitored endovascular therapeutic occlusion (1988‐1994)

The reported mortality (40%) and neurologic morbidity (25%) rates for carotid rupture remain unacceptably high. This study was conducted to assess the impact of endovascular detachable balloon occlusion and the changing characteristics of carotid rupture in head and neck surgery. Between January 1, 1988, and June 30, 1994, 18 carotid ruptures were identified in 15 patients. Etiologic factors included radical surgery, radiation therapy, wound complications, and recurrent or persistent carcinoma. In 15 of 18 instances of carotid rupture, patients survived without major neurologic sequelae. After the introduction of endovascular techniques in 1991, the 12 patients whose hemorrhage was definitively managed through permanent balloon occlusion survived without significant neurologic sequelae. Endovascular occlusion techniques in the monitored patient may significantly improve the outcome after carotid rupture.

Image-Guided Functional Endoscopic Sinus Surgery

INTRODUCTION: Computer-aided surgery (CAS) technology in functional endoscopic sinus surgery (FESS) has engendered considerable discussion. OBJECTIVE: The goals of this study were to describe CAS preoperative planning (software-based CT image analysis) and to develop intraoperative CAS strategies for endoscopic sinus surgery. STUDY DESIGN: Between October 1, 1997, and December 31, 1998, the StealthStation (Sofamor Danek, Memphis, TN) was used in 61 FESS cases, and a retrospective review of the findings was performed. The indication for surgery in all instances was chronic rhinosinusitis refractory to medical management. The StealthStation was used to review all CT scans before surgery. Anatomic fiducial registration supplemented by contour mapping was used. RESULTS: Localization accuracy was estimated to be within 2 mm or better. The StealthStation was used for both CT image review and intraoperative localization. CAS was useful in the frontal recess, sphenoethmoid region, posterior ethmoid system, and skull base area. CAS was deemed helpful in situations where the surgical anatomy was altered by previous surgery and extensive inflammatory disease (polyposis, fungal sinusitis, and pansinusitis). CONCLUSION: The paradigm of image-guided FESS surgery, which integrates CAS into FESS, will serve to increase surgical effectiveness and decrease surgical morbidity. (Otolaryngol Head Neck Surg 2000; 123:188-94.)

Topical antimicrobials in the management of chronic rhinosinusitis: a systematic review.

Background Chronic rhinosinusitis (CRS) is a common disease that can significantly impact health. The mainstay of medical treatment is topical steroids and oral antibiotics, but little is known about the efficacy of topical antibiotics. The purpose of this study was to identify evidence for the use of topical antibiotics in the treatment of CRS and exacerbations of CRS. Methods Systematic review of literature with a search of the MEDLINE, EMBASE, and CINAHL databases; Cochrane Central Register of Controlled Trials (Third Quarter 2007); and Cochrane Database of Systemic Reviews (3rd Quarter 2007) databases were performed. The dates of search were from December 1, 1949 to September 30, 2007. Results Fourteen studies that fulfilled the inclusion criteria were identified: seven were controlled trials and of these, five were double blinded and randomized. Only one of the randomized studies showed a positive outcome. Overall, there was low-level corroborative evidence for the use of antibacterials. No definite conclusions could be made regarding the use of antifungals. Currently, there is evidence for the use of nasal irrigation or nebulization rather than delivery by nasal spray. For the antibacterial studies, the highest level of evidence currently exists for studies that have used postsurgical patients and culture-directed therapy. Both stable and acute exacerbations of CRS appear to benefit from topical antimicrobials. Conclusion Topical antibiotics appear effective in the management of CRS. Given the combination of low-level evidence (level III, with inherent potential confounders of natural progression of disease and placebo effect) and the level IIb evidence being limited to the cystic fibrosis group of patients, topical antibiotics should not be first-line management but may be attempted in patients refractory to the traditional topical steroids and oral antibiotics. Larger and better-designed randomized double-blind placebo-controlled trials are required to more fully evaluate this emerging modality of treatment.

Resection of anterior skull base tumors: Comparison of combined traditional and endoscopic techniques

Background Traditional craniofacial resection (tCFR) has been used successfully for resection of anterior skull base (ASB) tumors. Minimally invasive endoscopic resection (MIER) also has been used recently; this strategy facilitates superior visualization, avoids facial incisions, and preserves local structures. The goal of this study was to compare the outcome for these two approaches. Methods Retrospective chart analysis was conducted to identify patients undergoing resection of ASB tumors between January 1995 and January 2003. Demographic data, tumor characteristics, and the surgical approach used were determined. The mean operative time, estimated blood loss, hospital stay, and complications were analyzed. Recurrence and mortality rates were calculated. Results Nine patients were managed with the MIER approach, and 16 patients were treated with the traditional open approach. No significant difference was observed between groups on operative time, estimated blood loss, or hospital stay. Major complications were encountered in 2/9 (22%) and 7/16 (44%) patients in the MIER and tCFR groups, respectively. Recurrence was observed in 3/9 (33%) and 5/14 (36%) of the patients in the MIER and tCFR groups, respectively. Mortality rates in the MIER and tCFR groups were 0/9 (0%) and 4/15 (27%), respectively. Conclusion In this preliminary study, MIER of ASB neoplasia did not differ significantly from tCFR in operative time, estimated blood loss, hospital stay, or complication rate. Survival and recurrence rates were similar also. This early experience suggests that MIER is a viable alternative for the surgical management of ASB lesions in appropriately selected patients.

3D computed tomographic analysis of frontal recess anatomy in patients without frontal sinusitis

OBJECTIVE: Describe frontal sinus pneumatization in patients with no history of frontal sinus disease. STUDY DESIGN AND METHODS: All 1-mm axial sinus CT scans performed from 2001 through 2003 were eligible for review on a CBYON Suite workstation (CBYON, Mountain View, CA). Exclusion criteria included frontal sinusitis, sinonasal polyposis, age < 18 years, sinus malignancy, fibroosseous lesions, maxillofacial trauma, congenital anomaly, and sinus surgery. RESULTS: A total of 50 patients met the inclusion criteria. The prevalence of each structure was: agger nasi cell (89%), type 1 frontal cell (37%), type 2 frontal cell (19%), type 3 frontal cell (8%), type 4 frontal cell (0%), supraorbital ethmoid cell (62%), suprabullar cell (15%), frontal bullar cell (9%), interfrontal septal cell (14%), and recessus terminalis (22%). CONCLUSIONS: This study describes frontal pneumatization in patients without a history of conditions that influence frontal pneumatization. The results characterize normal frontal recess/sinus pneumatization patterns.

Sequence-dependent cytotoxic effects due to combinations of cisplatin and the antimicrotubule agents taxol and vincristine

The antineoplastic activity that taxol has demonstrated in advanced ovarian cancer and other neoplasms in which the platinum analogues are among the most active agents has been the impetus for the development of taxol/platinum combination regimens. Since both classes of agents are known to induce cell-cycle-dependent effects and to delay cell-cycle traverse in specific phases of the cycle, an evaluation of drug sequence dependence was incorporated into initial clinical studies of the drug combination. To complement clinical studies, sequence-dependent interactions were assessed in vitro using L1210 leukemia. Cytotoxicity resulting from the combination of taxol and cisplatin was significantly increased over that achieved with cisplatin alone only when cisplatin was administered after taxol. This sequence was significantly superior to both the reverse sequence and to simultaneous drug treatment. Results achieved with sequence iterations of vincristine and cisplatin were nearly identical. In addition, alkaline-elution studies, using the optimal sequence of cisplatin and either taxol or vincristine, demonstrated that these antimicrotubule agents do not increase the formation of cisplatin-induced DNA interstrand and DNA-protein crosslinking over that produced by cisplatin alone. Although the mechanisms for the sequence-dependent cytotoxic interactions between cisplatin and the antimicrotubule agents have not been determined, it is likely that antagonistic interactions occur with the suboptimal sequences, probably because of cell-cycle-dependent phenomena.

Esthesioneuroblastoma: 25-year experience at a single institution

Objectives To evaluate outcomes for patients with esthesioneuroblastoma treated at a single institution during a 25-year period. Design Eighteen patients with pathologic diagnosis of esthesioneuroblastoma between 1980 and 2004 were retrospectively identified. Results Two patients had Kadish A, seven had Kadish B, and nine had Kadish C disease. The mean follow-up was 71 months. Treatment regimens consisted of surgery alone (four patients), surgery followed by postoperative radiation (six patients), surgery followed by postoperative chemoradiotherapy (three patients), preoperative radiotherapy (two patients), preoperative chemoradiotherapy (one patient), chemoradiotherapy (one patient), and surgery plus chemotherapy (one patient). Surgical approaches (n = 17) consisted of 13 traditional craniofacial resections, one endoscopic-assisted cranionasal resection, and three minimally invasive endoscopic resections. The 10-year disease-specific survival was 80%. The overall recurrence-free survival at five and 10 years was 62% and 46%, respectively. Positive surgical margins and TNM staging predicted survival. Conclusion Both endoscopic and open surgical approaches have been successful in treating a small number of esthesioneuroblastoma patients with high survival and low rate of surgical complications.

Sinonasal Wegener granulomatosis: A single-institution experience with 120 cases

Wegener granulomatosis (WG) is intimately associated with the sinonasal tract, with involvement reported in 85% of patients during the course of the disease process. The objectives of the study were: 1) to describe sinonasal symptoms and signs at the time of initial otolaryngologic evaluation; and 2) to review indications and outcomes for rhinologic surgery in WG at our institution.