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Biomedical subjects

Martin J Citardi

Publications and source records attributed to Martin J Citardi.

At least 19 recordsLinked to original sources
PubMed2007

Intraoperative surgical navigation for endoscopic sinus surgery: rationale and indications.

PURPOSE OF REVIEW: The present review discusses the rationale and indications for image-guided surgery through a critical discussion of registration concepts as well as clinical reports. RECENT FINDINGS: The surgical navigation accuracy achieved by commercially available image-guided surgery systems is best reported as target registration error. Clinically achievable target registration error is probably in the 1.5-2.0 mm range. Dry lab studies of registration serve to highlight the principles of registration, the process through which image-guided surgery systems calculate the one-to-one mapping relationship between the preoperative imaging data and the intraoperative surgical volume. Reports on image-guided surgery have highlighted its usefulness in primary and revision endoscopic sinus surgery, osteoplastic frontal sinusotomy, transsphenoidal hypophysectomy, endoscopic cerebrospinal fluid leak repair and endoscopic pterygomaxillary fossa biopsy. Both three-dimensional computed tomography angiography and computed tomography-magnetic resonance fusion images have been incorporated into IGS for advanced minimally invasive endoscopic skull base procedures. The American Academy of Otolaryngology-Head and Neck Surgery policy statement accurately summarizes the current consensus for image-guided surgery applications. SUMMARY: Image-guided surgery has emerged as an important technology, which both general otolaryngologists and subspecialty rhinologists can employ for a wide variety of procedures.

Endoscopy↗
PubMed2006

Computer aided surgery: concepts and applications in rhinology.

Computer-aided surgery (CAS) has become relevant in a growing number of disciplines. This article will describe the history and principals of CAS and explain some of the technical issues, applications, and outcomes for CAS in the domain of rhinology.

Electromagnetic Phenomena↗
PubMed2006

Endoscopic management of sinonasal malignancy.

The advent of rigid telescopes has revolutionized the management of rhinologic disease. These instruments have been used as a diagnostic and therapeutic tool for paranasal sinus inflammatory diseases since the 1970s. Endoscopic techniques have been used for treating increasingly complex intranasal pathology, including nasolacrimal duct obstruction, cerebrospinal fluid leaks/encephaloceles, dysthyroid orbitopathy, and optic neuropathy. Recently, endoscopic techniques have also been used successfully to manage selected tumors, including inverted papilloma, angiofibromas, and hypophyseal tumors. This article reviews patient evaluation strategies, surgical techniques, and outcomes data for the minimally invasive endoscopic resection.

Craniotomy↗
PubMed2006

CT-MR image fusion for the management of skull base lesions.

OBJECTIVE: Image fusion software creates composite images from computed tomography (CT) and magnetic resonance (MR) images. STUDY DESIGN AND SETTING: CT-MR fusion studies between August 2004 to July 2005 were reviewed. CT scan images (1-mm axial) were obtained on a multi-detector CT scanner. MR images (1-mm axial) were obtained with a T1-weighted, volume acquisition technique. CT-MR fusion images were created on the Instatrak 3500 Plus or CBYON Suite. RESULTS: A total of 25 patients had 27 CT-MR image fusion studies. CT-MR fusion accuracy was 2 mm or better. During preoperative planning and intraoperative navigation, CT-MR fusion facilitated the delineation of the anatomic relationships between the lesion and the skull base. CONCLUSIONS: CT-MR image fusion yields composite images that combine features of each component imaging modality. Image fusion, when combined with surgical navigation, further enhances potential skull base applications for minimally invasive endoscopic surgery.

Adult↗
PubMed2006

Comparison of frontal pneumatization patterns between Koreans and Caucasians.

OBJECTIVE: To evaluate the prevalence of specific frontal recess cells in Korean and Caucasian populations; to evaluate and compare the relationship between anterior skull base length and frontal recess pneumatization in these two populations. MATERIALS AND METHODS: Frontal recess anatomy was studied with high resolution sinus CT scans obtained in 60 Korean adults and 41 Caucasian adults. None of the subjects had a history of frontal sinus disease or trauma. The anterior cranial base length (ACBL, distance between the nasion and center of the pituitary fossa) and anterior ethmoid length (AEL, distance between the nasion and upper attachment of basal lamella) was also measured on each side. RESULTS: Supraorbital ethmoid cells were more common in Caucasians whereas suprabullar cells and recessus terminalis were more common in Koreans. The prevalence of some frontal recess pneumatization patterns (specifically supraorbital ethmoid cell, suprabullar cell, and recessus terminalis) were more commonly associated with race rather than with ACBL or AEL. CONCLUSION: Frontal recess pneumatization patterns differ in the Korean and Caucasian adult populations. Because corresponding differences in skull base length were not identified, these differences seem likely to reflect other factors. Such information has clinical significance for frontal recess surgery in these patient populations.

Adult↗
PubMed2006

Contour and paired-point registration in a model for image-guided surgery.

OBJECTIVES/HYPOTHESIS: This study assesses target registration error (TRE) of contour-based registration (CBR) and paired-point registration (PPR) for endoscopic sinus surgery. STUDY DESIGN: The experimental registration model consisted of a replica of a human head (Sawbones #1345-27; Pacific Research Laboratories, Vashon, WA). Twelve surface fiducial markers were affixed to the simulated skin on the model, and titanium screws were placed in the regions of the anterior ethmoid (AE) and sphenoid face (SF). An axial computed tomography scan (1-mm slice thickness) was then obtained. METHODS: Registration was then performed on the InstaTrak 3500 Plus (GE Surgical Navigation & Visualization, Lawrence, MA) with the standard PPR protocol with 12 points and CBR protocol with 500, 250, 125, 50, and 4 points. TRE was then calculated at the AE and SF targets. RESULTS: Target registration error was significantly lower for paired-point registration compared with contour-based registration (AE, 0.5 mm vs. 1.5 mm, P < .0001; SF, 0.8 mm vs. 1.5 mm, P < .0001). Among contour-based registration protocols, target registration error at the sphenoid face was lowest with 50 points (1.5 mm, P < .02). At the anterior ethmoid, contour-based registration with 50 points produced a lower target registration error than contour-based registration with 125 points (1.5 vs. 1.8 mm, P < .01). Other target registration error values for CBR were similar at both regions. The target registration error interquartile range was lowest with CBR-125 at both regions. CONCLUSIONS: Paired-point registration provided significantly lower target registration error. Contour-based registration with 125 points (and possibly as few as 50 points) produces clinically acceptable target registration error. This registration model elucidates important concepts about registration for surgical navigation for sinus surgery.

Bone Screws↗
PubMed2005

Image-guided sinus surgery: current concepts and technology.

Image-guided surgery (IGS) has gained considerable acceptance in rhinologic surgery. Principles of registration paradigms and registration error serve to define certain intrinsic limitations of this technology. Real-world experiences have further elucidated other concepts that may guide the appropriate use of IGS. With such knowledge, the rhinologic surgeon may incorporate IGS into a wide range of procedures.

Humans↗
PubMed2005

Isolated sphenoid sinus disease: etiology and management.

OBJECTIVE: To evaluate the diagnosis and management of isolated sphenoid sinus disease by using the current rhinologic standard of care. STUDY DESIGN: Retrospective chart review. RESULTS: Fifty sequential, symptomatic patients were studied. Presenting symptoms included headache or facial pain (88%), rhinorrhea (46%), and nasal congestion (26%). All patients underwent CT imaging, demonstrating bony changes or dehiscences (42%), a mass (24%), or complete opacification of the sphenoid sinus (22%). Eighty percent required surgical intervention. The most frequent diagnoses were as follows: sinusitis (38%), fungal ball (20%), neoplasm (16%), and mucocele (12%). Treatment resulted in clinical or endoscopic improvement or resolution in 87% of the patients. CONCLUSION: The presenting symptoms of isolated sphenoid sinus disease can be nonspecific and may result in an inordinate delay in diagnosis. Nasal endoscopy and radiologic imaging are central to making an accurate and timely diagnosis. Medical treatment or minimally invasive surgical techniques can successfully manage the majority of patients with persistent or refractory symptoms.

Adolescent↗
PubMed2005

Comparison of delivery of topical medications to the paranasal sinuses via "vertex-to-floor" position and atomizer spray after FESS.

INTRODUCTION: Topical nasal medications are frequently employed for persistent sinonasal symptoms after functional endoscopic sinus surgery (FESS) in chronic rhinosinusitis patients. The optimal means for the delivery of these medications is unclear. In this study, the efficacy of the vertex to floor (VF) position compared to atomizer spray was evaluated in post-FESS patients. METHODS: Three trials were performed: two trials in which patients maintained the VF position for 1 and 5 minutes, respectively, after nasal drop administration were compared to a third trial utilizing an atomizer spray in the upright position. Two independent observers rated the distribution of fluorescein-dyed dexamethasone drops at 5 sinonasal sites: maxillary sinus (MS), ethmoid cavity (EC), frontal recess (FR), sphenoid sinus (SS), and olfactory cleft (OC). RESULTS: VF position consistently delivered nasal drops to the MS, EC, SS, and OC. The atomizer distributed drops to the MS, EC, SS, and FR. The greatest difference was noted with the nasal drops in the olfactory cleft in the VF position; statistical significance was achieved with ANOVA testing (P = 0.012). Student's paired t test comparing trial 1 to 2, 1 to 3, and 2 to 3 demonstrated greater distribution in the OC at 5 minutes compared with 1 minute and spray (P = 0.042 and 0.003). CONCLUSIONS: The VF position and atomizer spray were both effective in delivery of the dexamethasone drops to the paranasal sinuses. This has significant implications for management of patients suffering from recalcitrant chronic rhinosinusitis and/or sinonasal polyposis through the delivery of topical medications to the paranasal sinuses and olfactory cleft. EBM RATING: C.

Administration, Intranasal↗
PubMed2005

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.

Adolescent↗
PubMed2005

Outcomes for endoscopic resection of sinonasal squamous cell carcinoma.

OBJECTIVES: Preliminary data suggest efficacy for the endoscopic approach for sinonasal malignancy. The purpose of this study is to evaluate the effectiveness of the endoscopic approach for the resection of sinonasal squamous cell carcinoma (SCC). STUDY DESIGN: Retrospective analysis of patients undergoing endoscopic resection of sinonasal SCC from August 1996 to May 2004. METHODS: Eleven patients were treated with curative intent. Demographic data, histopathology, extent of tumor involvement, and need for adjunctive radiation or chemotherapy were determined. Local recurrence (LR), distant metastasis, overall survival (OS), and disease-free survival (DFS) rates were calculated. RESULTS: The mean age for the patient population was 62.5 (52-85) years with a male:female ratio of 8:3. Multimodality therapy including radiation or chemotherapy was used in 8 of 11 (73%) patients. Seven patients were resected using strictly an endoscopic approach, whereas four required combined endoscopic and neurosurgical resection. LR and distant metastatic rates were 20% and 0%, respectively. OS and DFS were both 91%, with mean follow-up of 31.5 (range 6-88) months. CONCLUSIONS: Endoscopic resection in combination with multimodality therapy is an effective method for curative resection of sinonasal SCC. In this preliminary study, it facilitated complete resection with acceptable LR and DFS rates.

Aged↗
PubMed2004

Considerations against concurrent functional endoscopic sinus surgery and rhinoplasty.

Over the last decade, functional endoscopic sinus surgery (FESS) has become the surgical modality of choice in the treatment of inflammatory sinus disease refractory to medical therapy. During the same interval, interest in cosmetic surgery procedures, including rhinoplasty, has exploded. Some of the published literature endorses the performance of concurrent FESS and rhinoplasty. This article addresses some of the concerns regarding the combined approach and its limitations. It offers the reader a framework for surgical risk assessment when concurrent procedures are considered.

Combined Modality Therapy↗
PubMed2004

The impact of fiducial distribution on headset-based registration in image-guided sinus surgery.

OBJECTIVE: The objective of this study was to assess registration error due to fiducial configuration for the ENT headsets for the CBYON Suite (CBYON, Mountain View, CA) and InstaTrak (GEMS Navigation and Visualization, Waukesha, WI). STUDY DESIGN: Axial CT scans (1-mm slice thickness) were obtained of for 24 cadaveric heads using the CBYON headset and for 23 cadaveric heads using the GEMS headset. The CBYON and GEMS NAV software were used to calculate the fiducial registration error (FRE). Fiducial localization error (FLE) was estimated from FRE. Theoretical target registration error (TRE) was calculated at 11 targets. RESULTS: The FRE for CBYON and GEMS NAV was 0.69 mm and 0.27 mm, respectively. The theoretical TRE for CBYON and GEMS NAV was 0.41 mm and 0.30 mm, respectively. The theoretical TRE was greater at targets posterior in the sinus cavities. CONCLUSION: Theoretical TRE values for both ENT headsets are less than clinically observed TRE. Clinically observed TRE is likely due to repositioning accuracy. EBM RATING: B-2.

Cadaver↗
PubMed2004

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%), suprabullarcell (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.

Adolescent↗
PubMed2004

Software-enabled CT analysis of optic nerve position and paranasal sinus pneumatization patterns.

OBJECTIVE: Delineate the relationships among the optic nerve (CN II), the sphenoid sinus, and the sphenoethmoid cell. STUDY DESIGN: High-resolution CT scans of 64 frozen human cadavers were obtained on a Siemens VolumeZoom CT scanner (Munich, Germany) and transferred to a CBYON Suite Doctor Station version 2.6 (CBYON, Mountain View CA) for standardized review. RESULTS: Pneumatization around CN II was categorized into 5 types: no adjacent pneumatization (type 0), pneumatization adjacent to CN II (type 1), adjacent pneumatization with indentation (type 2), pneumatization of <50% CN II circumference (type 3), and pneumatization of >50% CN II circumference (type 4). The prevalence of types 0 to 4 CN II position relative to the sphenoid sinus was 4.7%, 25.8%, 39.8%, 14.1%, and 15.6%, respectively. The prevalence of sphenoethmoid cells was 28.1%. The prevalences of types 0, 1, 2, 3, and 4 CN II positions relative to the sphenoethmoid cell was 5.6%, 58.3%, 25%, 2.8%, and 8.3% respectively. CONCLUSIONS: Software-enabled CT review facilitated precise study of the anatomic relationships of CN II. Caution must be exercised during sinonasal surgery to minimize the risk of inadvertent CN II injury. EBM RATING: D.

Adult↗
PubMed2003

Endoscopic reconstruction of anterior and middle cranial fossa defects using acellular dermal allograft.

OBJECTIVE: To report our experience in reconstructing defects of the anterior and middle cranial fossa skull base using endoscopic placement of acellular dermal allograft (AlloDerm, LifeCell Corp., The Woodlands, TX). STUDY DESIGN: Retrospective chart review. METHODS: In all cases, the skull base repair was completed with a similar technique. After identification of the defect boundaries, endoscopic transnasal repair was performed through placement of a layered reconstruction of acellular dermal allograft, septal bone/cartilage, and acellular dermal allograft, which were all placed on the intracranial side of the defect. A mucosal free graft was draped over the reconstruction. Fibrin glue was used to hold the mucosal graft in place, and the reconstruction was supported by both absorbable and nonabsorbable nasal packing. RESULTS: Eight patients with nine skull base defects underwent the procedure for repair of cerebrospinal fluid rhinorrhea. All defects were successfully repaired. One patient underwent successful reconstruction of bilateral ethmoid roof defects that resulted from endoscopic resection of ethmoid adenocarcinoma. Twenty-four patients underwent primary resection of hypophyseal adenomas. Twenty-three patients had macroadenomas, and intraoperative cerebrospinal fluid leaks were noted in 11 patients. Sellar repairs after trans-sphenoidal hypophysectomy were successful in 22 of 24 patients. One patient with hypophysectomy required reoperation (1 of 24 [4%]) for secondary closure of a cerebrospinal fluid leak. Serious complications were avoided in all patients. Patients were followed for a period ranging from 5 to 57 months (mean period, 34 mo). CONCLUSIONS: Acellular dermal allograft can be successfully used for the reconstruction of anterior and middle cranial fossa skull base defects. This allograft, which is easy to manipulate endoscopically, provides an effective seal and barrier in skull base reconstruction and avoids the need for a donor site.

Adenocarcinoma↗
PubMed2002

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.

Adolescent↗