Endoscopic Orientation of Juxta-pituitary Carotid in Transsphenoidal Approaches: Critical Considerations for Clinical Applications

Abstract Introduction In sphenoid sinuses with ill-defined carotid bony landmarks, accidental injury of the internal carotid artery (ICA) remains one of the most challenging complications, which is particularly reported in the endoscopic endonasal transsphenoidal approaches (EETAs). Objectives To describe an anatomical model for the endoscopic orientation of the juxta-pituitary segment of the ICA in relation to the lateral opticocarotid recess (OCR) as a nearby bony landmark. Methods Dissection was performed progressively, simulating the EETA, in twenty fresh adult cadavers. After reducing the posterior and lateral walls of the sphenoid sinuses, various measurements were taken from both lateral OCRs to "contact points" on the juxta-pituitary segment of the ICA and lateral margins of the pituitary gland. Results The current results have enabled us to divide the region between the lateral OCRs into 3 compartments: 2 lateral parasellar compartments contain juxta-pituitary segments of the ICA with a mean width of 8 mm and a narrow range from 7 mm to 10 mm; and a central intercarotid sellar compartment represents the safe region for bone drilling, showing widely variable widths ranging from 9 mm to 20 mm. In all specimens, the variation in the width of the intercarotid compartment correlated with the distance between both lateral OCRs. Conclusion The present study improves surgeon awareness of the variations in the course of the ICA through the EETA along sphenoid sinuses with ill-defined bony landmarks. An appreciation of the measurements taken in the present study can help in operative training, and can also provide a base for future studies to confirm ICA courses associated with a higher risk of injury.

Endoscopic Orientation of Juxta-pituitary Carotid in Transsphenoidal Approaches: Critical Considerations for Clinical Applications.

Introduction In sphenoid sinuses with ill-defined carotid bony landmarks, accidental injury of the internal carotid artery (ICA) remains one of the most challenging complications, which is particularly reported in the endoscopic endonasal transsphenoidal approaches (EETAs). Objectives To describe an anatomical model for the endoscopic orientation of the juxta-pituitary segment of the ICA in relation to the lateral opticocarotid recess (OCR) as a nearby bony landmark. Methods Dissection was performed progressively, simulating the EETA, in twenty fresh adult cadavers. After reducing the posterior and lateral walls of the sphenoid sinuses, various measurements were taken from both lateral OCRs to "contact points" on the juxta-pituitary segment of the ICA and lateral margins of the pituitary gland. Results The current results have enabled us to divide the region between the lateral OCRs into 3 compartments: 2 lateral parasellar compartments contain juxta-pituitary segments of the ICA with a mean width of 8 mm and a narrow range from 7 mm to 10 mm; and a central intercarotid sellar compartment represents the safe region for bone drilling, showing widely variable widths ranging from 9 mm to 20mm. In all specimens, the variation in the width of the intercarotid compartment correlated with the distance between both lateral OCRs. Conclusion The present study improves surgeon awareness of the variations in the course of the ICA through the EETA along sphenoid sinuses with ill-defined bony landmarks. An appreciation of the measurements taken in the present study can help in operative training, and can also provide a base for future studies to confirm ICA courses associated with a higher risk of injury.

Endoscopic Orientation of Juxta-Pituitary Carotid in Transsphenoidal Approaches: Critical Considerations for Clinical Applications.

Accidental injury of the internal carotid artery (ICA) remains one of the most challenging complications reported in the endoscopic endonasal transsphenoidal approaches (EETA) particularly, in sphenoid sinuses with ill-defined carotid bony landmarks. The purpose of this study was to describe an anatomical model for the endoscopic orientation of juxta-pituitary segment of ICA in relation to the lateral optico-carotid recess (OCR) as a nearby bony landmark. Cadaveric dissection was conducted progressively in twenty fresh adult cadavers simulating the EETA. After reducing posterior and lateral walls of sphenoid sinuses, various measurements were taken from both lateral OCRs to "contact points" of the juxta-pituitary segment of ICA and lateral margins of the pituitary gland. Current results have enabled us to divide the region between lateral OCRs into three compartments. Two lateral parasellar compartments contain juxta-pituitary segments of ICA showing a mean width of 8 mm; with a narrow range of 7-10 mm; and a central inter-carotid sellar compartment represents the safe region for bone drilling showing widely variable widths ranging between 9 to 20 mm. In all specimens; variation in the width of the inter-carotid compartment correlated with the distance between both lateral OCRs. This study improves surgeons' awareness of the ICA course variations in the EETA through sphenoid sinuses with ill-defined bony landmarks. An appreciation of the measurements gathered from this study can help in operative training, and can also provide a base for future studies to confirm ICA courses associated with higher risk of injury.

Outcome and Complications of Frontal Sinus Stenting: A Case Presentation and Literature Review.

INTRODUCTION: Frontal sinus surgery remains challenging to manage because of its complex anatomy and narrow outflow tract. A number of studies suggest the success of frontal sinus stenting to reduce postoperative complications in endoscopic frontal sinus surgery. However, failure and complications of frontal sinus stenting may occur. METHOD: We present a case of frontal sinus stenting with migration of the stent and erosion of the lamina papyracea together with a granulomatous reaction around the stent. PubMed and Medline search was also conducted to study the current evidence on frontal sinus stenting benefits and complications. RESULTS: Still there are no guidelines or universally accepted indications for the use of frontal sinus stenting in the literature. A limited number of studies suggest the success of frontal sinus stenting to reduce postoperative stenosis in endoscopic frontal sinus surgery. However, failure and complications of frontal sinus stenting may occur. Infection, pain, edema, and stent obstruction may also occur. Our case report also highlights the potential of orbital complications as well as the consequences of inducing a granulomatous reaction. CONCLUSION: The value of frontal sinus stenting is still a subject of debate. Complications of frontal sinus stenting are not uncommon and thus necessitate regular follow-up.

Bilateral Simultaneous Endoscopic Dacryocystorhinostomy: Outcome and Impact on the Quality of Life of the Patients.

Introduction Bilateral simultaneous endoscopic dacryocystorhinostomy (endo-DCR) has received little attention in the literature, thus many surgeons continue to address bilateral nasolacrimal duct obstruction at two stages, rather than in the same setting. Objective To evaluate the feasibility and the outcome of simultaneous bilateral Endo-DCR and its impact on the quality of life of the patients. Methods We have conducted a retrospective analysis of patients who underwent bilateral simultaneous endo-DCR between March 2013 and February 2017 at our tertiary care institution. The reviewed data included clinical presentation; operative details; success rate; pre and postoperative evaluation of the symptoms of the patients, using the Nasolacrimal Duct Obstruction Symptom Score Questionnaire; satisfaction of the patients, and improvement in the quality of life, assessed by the Glasgow Benefit Inventory (GBI) questionnaire. Results Out of 128 cases in which endo-DCRs were performed, 13 were bilateral (26 sides). Postoperative success was documented in 24 of the 26 sides (92.3%), with a mean follow-up duration of 16.2 months. The two failed sides were reported in the same case. The preoperative symptom score ranged between 12 and 80 (mean ± standard deviation [SD]: 38.23 ± 15.7). The postoperative symptom score was significantly lower (mean ± SD: 5.4 ± 12.9). The success rates in unilateral and bilateral cases were comparable, with no statistically significant difference. A notable improvement in the quality of life of the patients was also reported, with a mean GBI score of 81.38 ± 12.37. Conclusion Our results support that a simultaneous bilateral endo-DCR is a safe procedure that offers a high success rate, spares the patient from the stress of a second surgery, provides the patient with a bilateral resolution of the symptoms, and confers an immediate improvement in the quality of life of the patients.

Endoscopic and Radiologic Findings in Failed Dacryocystorhinostomy: Teaching Pearls for Success.

BACKGROUND: Although several studies have commented on causes of dacryocystorhinostomy (DCR) failure, detailed description of anatomical findings in such cases remains insufficient. OBJECTIVE: Our objective was primarily to analyze radiologic, endoscopic, and intraoperative findings in patients presenting with failed DCR and secondarily to assess the outcome of revision endoscopic DCR (endo-DCR) carried out at our institution. METHODS: Twenty-four failed DCRs presenting to our tertiary care center were retrospectively analyzed. Data collection included patients' history, diagnostic, and management data, as well as thorough analysis of sinonasal CT scans, along with endoscopic and intraoperative findings. Outcome was also assessed in 21 cases with revision endo-DCR performed. RESULTS: The anterior part of uncinate process was not previously removed in 15 sides (62.5%), with unopened agger nasi in 13 sides (54.2%). The lacrimal bone was detected covering the posterior sac despite removal of the anterior ascending process of maxilla in 9 sides (37.5%). Rhinostoma was anterior to lacrimal sac in 2 sides (8.3%) and was below the sac in 7 sides (29.2%). Fibrous membrane covered the rhinostoma despite removal of all sac-overlying bones in 6 sides (25%). Other findings included intranasal adhesions, septal deviation, lateralized middle turbinate, granulation tissue, foreign body reaction, and chronic sinusitis. Nineteen of the 21 revision endo-DCRs were successful (90.5%). CONCLUSION: This study provides a precise anatomical description of findings in cases of failed DCR. Such information is paramount in helping surgeons enhance their learning curve, refine the surgical technique, and improve patients' outcome.

Bilateral simultaneous endoscopic dacryocystorhinostomy: outcome and impact on the quality of life of the patients

Introduction: Bilateral simultaneous endoscopic dacryocystorhinostomy (endo-DCR) has received little attention in the literature, thus many surgeons continue to address bilateral nasolacrimal duct obstruction at two stages, rather than in the same setting. Objective: To evaluate the feasibility and the outcome of simultaneous bilateral Endo- DCR and its impact on the quality of life of the patients. Methods: We have conducted a retrospective analysis of patients who underwent bilateral simultaneous endo-DCR between March 2013 and February 2017 at our tertiary care institution. The reviewed data included clinical presentation; operative details; success rate; pre and postoperative evaluation of the symptoms of the patients, using the Nasolacrimal Duct Obstruction Symptom Score Questionnaire; satisfaction of the patients, and improvement in the quality of life, assessed by the Glasgow Benefit Inventory (GBI) questionnaire. Results: Out of 128 cases in which endo-DCRs were performed, 13 were bilateral (26 sides). Postoperative success was documented in 24 of the 26 sides (92.3%), with a mean follow-up duration of 16.2 months. The two failed sides were reported in the same case. The preoperative symptom score ranged between 12 and 80 (mean ± standard deviation [SD]: 38.23 ± 15.7). The postoperative symptom score was significantly lower (mean ± SD: 5.4 ± 12.9). The success rates in unilateral and bilateral cases were comparable, with no statistically significant difference. A notable improvement in the quality of life of the patients was also reported, with a mean GBI score of 81.38 ± 12.37. Conclusion: Our results support that a simultaneous bilateral endo-DCR is a safe procedure that offers a high success rate, spares the patient from the stress of a second surgery, provides the patient with a bilateral resolution of the symptoms, and confers an immediate improvement in the quality of life of the patients (AU)

Acute rhinosinusitis during Hajj season 2014: Prevalence of bacterial infection and patterns of antimicrobial susceptibility.

BACKGROUND: The presence of large number of pilgrims during Hajj in Makkah region increases the risk of respiratory diseases. In this study, we aimed to assess the bacteriology of acute rhinosinusitis (ARS) during Hajj season and to demonstrate the antimicrobial susceptibility patterns that should guide the clinicians towards more appropriate antibiotic use. METHODS: Patients with ARS presenting during Hajj season of 2014 were prospectively enrolled. According to EPOS2012 criteria. Sampling of sinus secretions was performed from the middle meatus adjacent to the maxillary sinus ostium via endoscopic guidance. Over all, the study has covered all ENT, emergency and outpatient departments in Hajj. RESULTS: Two hundred and twenty six patients with ARS were enrolled in the study. Pathogenic bacteria were identified in 93 (41.2%) patients. Of the 93 patients with bacterial ARS, Staphylococcus aureus was isolated in 46 (49.5%) patients, out of which 13 (28.3%) were methicillin-resistant Staphylococcus aureus (MRSA).The second most common group of bacterial isolates was Enterobacteriaceae such as Escherichia coli, and various Klebsiella species. Antibiotic sensitivity showed that methicillin-sensitive Staphylococcus aureus (MSSA) was also sensitive to cephalosporins, quinolones and clindamycin, while exhibiting relatively less sensitivity rates to amoxicillin-clavulinic acid and macrolides. CONCLUSION: Our study demonstrates the importance of assessing the bacteriology of ARS to help implement guidelines for proper treatment and prevention protocols during Hajj season.

Retromaxillary Pneumatization of Posterior Ethmoid Air Cells: Novel Description and Surgical Implications.

OBJECTIVE: Retromaxillary pneumatization of posterior ethmoid (PE) air cells is an area that is yet to have appropriate description in rhinologic literature. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care hospital. SUBJECTS AND METHODS: First, 524 sides in 262 paranasal sinus computed tomography scans were analyzed: 350 normal sides were examined for PE pneumatization lateral to the sagittal plane of the medial wall of maxillary sinus posteriorly, and 174 diseased sides were similarly reviewed to check how pathology may affect identification and measurements. Following that, 153 operated sides in 84 cases prepared for revision endoscopic sinus surgery (ESS) were studied for residual diseased cells at different anatomic locations. RESULTS: Overall, retromaxillary PE pneumatization was identifiable in 416 of the 524 sides (79.4%). Lateral retromaxillary extension varied from 0.5 to 12.3 mm (mean ± SD, 4.8 ± 2.3 mm). This area of pneumatization is bounded anteroinferiorly by the junction between the posterior and superior walls of the maxillary sinus. Three cell types were described depending on the degree of lateral extension (type I, <3 mm; type II, 3-6 mm; type III, >6 mm). This cell, which we refer to as the Herzallah cell, was distinguishable from the anterior ethmoid Haller cell and was found to have residual disease in 50.3% of cases prepared for revision ESS. CONCLUSION: Retromaxillary extension of PE air cells varies considerably and requires attention during ESS. Residual undissected retromaxillary cell is a common finding in revision ESS and can contribute to inadequate disease clearance.

Mucosal contact points and paranasal sinus pneumatization: Does radiology predict headache causality?

OBJECTIVES/HYPOTHESIS: The goal of this study was to evaluate the prevalence of mucosal contact points (MCP), concha bullosa (CB), and variable paranasal sinus (PNS) volumes among patients sent for rhinogenic headache workup as compared with controls. STUDY DESIGN: Retrospective study with case and control groups. METHODS: Fifty-three adults with clear PNS computed tomography (CT) scans were included: 28 patients who have originally undergone PNS CT scan as part of sinus (rhinogenic) headache workup, and 25 controls in whom PNS CT scans were obtained for other purposes. All subjects were asked to report their symptoms using a headache scoring system. CT scans of all subjects were analyzed for presence of MCP, CB, as well as for volumes of maxillary, frontal, and sphenoid sinuses. RESULTS: MCP was found in 40% of controls, and in 50%, 50%, and 40% of mild, moderate, and severe headache groups, respectively. CB was found in 24% of controls, and in 33.3%, 58.3%, and 20%, of mild, moderate, and severe headache groups, respectively. Total volume of the measured PNS ranged from 23.9 to 81.4 cm(3) (mean ± standard deviation [SD], 48.3 ± 15.8) in the control group and from 5.31 to 87.4 cm(3) (mean ± SD, 43.6 ± 16) in the patient group. No statistically significant difference was found between groups regarding all studied variables. CONCLUSIONS: Radiological identification of MCP, CB, or hyperpneumatized sinuses does not seem to be a predictor of headache causality. Further studies are required to identify clinical scenarios in which these variations may contribute to pain symptoms. LEVEL OF EVIDENCE: 3b.

Variations of lamina papyracea position from the endoscopic view: a retrospective computed tomography analysis.

BACKGROUND: Accidental injury of lamina papyracea (LP) remains one of the most common complications reported in endoscopic sinus surgery (ESS) even in most recent studies. The purpose of this study was to categorize the LP position radiologically and from an endoscopic perspective. METHODS: A total of 207 computed tomography (CT) scans (414 sides) including both diseased and control groups were retrospectively reviewed by 2 examiners. Inferior turbinate attachment to the lateral nasal wall and the inferior margin of the planned middle meatal antrostomy (MMA) were identified anteriorly. Position of LP in relation to the vertical line passing through MMA inferior margin was reported. LP was categorized to lie either within 2 mm on either side of the MMA inferior margin (type I), more than 2 mm medial to the MMA line (type IIa: 2 to 4 mm; type IIb: >4 mm), or more than 2 mm lateral to the MMA line (type IIIa: 2 to 4 mm; type IIIb: >4 mm). RESULTS: Of the 221 sides in the control group, 69.7% were classified as type I, 24.9% as type II, and 5.5% as type III. Among the 193 diseased operated sides examined, 60.1% were classified as type I, 20.2% as type II, and 13.5% as type III. Weighted kappa coefficient showed good interexaminer reliability. Five sides (2.6%) in the case group had accidental LP penetration intraoperatively, 4 of them were type II and type III LP. CONCLUSION: This study improves surgeons' awareness of LP variations in the endoscopic field and can be of help for residents in training.

Endoscopic localization of the sphenopalatine foramen: do measurements matter?

The objective of this study was to evaluate different methods and measurements for localization of the sphenopalatine foramen (SPF) during endoscopic transnasal exposure. The study design consisted of descriptive anatomical study and the setting was in Microsurgical Cadaver Dissection Lab. Sixteen lateral nasal walls were dissected endoscopically to identify and localize the SPF. Multiple measurements were obtained from nasal sill (NS) to SPF, ethmoid crest (EC), and other related landmarks. The results showed that EC was identified in all sides with different degrees of projection. SPF extended below the inferior edge of EC, i.e., lying both in the superior and middle meatus, in 12 sides (75 %), while it was laying only in the superior meatus in 4 sides (25 %). An accessory foramen was identified in 3 sides (18.7 %), all of which were located in middle meatus. The distance from NS to SPF ranged widely from 55 to 76 mm (mean ± SD 64.4 ± 6 mm). The average angle of elevation formed between SPF to NS and nasal floor was 11.4° (range 11-12°). Although many previous studies have reported measurements to SPF, we do not believe these measurements are of practical help due to the wide range of measurements and the lack of standard reference points. The main constant landmark for SPF remains the EC. Since SPF frequently extends below EC, the mucoperiosteal flap should be extended below the inferior edge of this crest to avoid missing the middle meatal part of SPF or any accessory foramina.

Olfactory bulb volume changes in patients with sinonasal polyposis: a magnetic resonance imaging study.

OBJECTIVES: The olfactory bulb (OB) is thought to be a plastic structure with highly active afferent neurons. The aim of this study was to evaluate the effect of olfactory deprivation caused by sinonasal polyps on OB volume. STUDY DESIGN: Cross-sectional study. SETTING: Tertiary university hospital, Department of Otolaryngology. SUBJECTS AND METHODS: Twenty-two subjects were included: 11 adult patients with bilateral allergic sinonasal polyposis (patient group) and 11 adult healthy controls (control group). Both study groups were matched for age and sex. OB volumes in all study subjects were evaluated in T2-weighted coronal MRI images by planimetric manual contouring. RESULTS: In the patient group, OB volume measurements ranged from 5.2 to 19.5 mm(3) (mean ± SD, 10.14 ± 3.8). In the control group, volume measurements ranged from 35 to 75.8 mm(3) (mean ± SD, 47.66 ± 10.75). The difference in OB volumes between patient and control groups was statistically significant (P < .001). CONCLUSION: Our study highlights the significant reduction in OB volume in patients with bilateral sinonasal polyposis as compared with its volume in healthy controls. Further studies are required to evaluate the impact of OB volume reduction on olfactory recovery postoperatively.

Endoscopic identification of the pharyngeal (palatovaginal) canal: an overlooked area.

Objective The pharyngeal or palatovaginal canal (PC) is a small tunnel that lies between the sphenoid process of the palatine bone and the vaginal process of the sphenoid bone. Currently, little endoscopic information is available about this region. Design and Setting Endoscopic endonasal cadaveric study. Subjects and Methods Twenty sides in 10 adult cadaver heads were studied endoscopically. The sphenopalatine foramen (SPF) and the adjacent pterygopalatine fossa were exposed. Dissection medial to the vidian canal demonstrated a tunnel that runs posteromedially in the sphenoid floor. Endoscopic data were documented. Additionally, canal measurements were obtained on 20 sides from coronal CT scans of paranasal sinuses. Results The PC was identifiable in 85% of the sides, although thickness of its bony wall was variable. The endoscopic relationship of the canal and its artery with other landmarks is described. Radiologically, the diameter of the PC averaged 1.7 mm, and the mean distance from the PC to the vidian canal was 3.78 mm. Conclusion The current study provides a novel endoscopic identification of an overlooked canal. The pharyngeal artery can be a source of bleeding during extended endoscopic procedures. The PC itself could be a place for finger-like projections of anatomically related neoplasms.

Endoscopic orientation of the parasellar region in sphenoid sinus with ill-defined bony landmarks: an anatomic study.

The sphenoid bony landmarks are important for endoscopic orientation in skull base surgery but show a wide range of variations. We aimed to describe an instructional model for the endoscopic parasellar anatomy in sphenoid sinuses with ill-defined bony landmarks. Five preserved injected cadaveric heads and four sides of dry skulls were studied endoscopically via transethmoid, transsphenoidal approach. The parasellar region was exposed by drilling along the maxillary nerve (V2) canal [the length of the foramen rotundum (FR) between the middle cranial fossa and the pterygopalatine fossa]. This was achieved by drilling in the inferior part of the lateral wall of posterior ethmoids immediately above the sphenopalatine foramen. Cavernous V2 was traced to the paraclival internal carotid artery (ICA). Cavernous sinus (CS) apex was exposed by drilling a triangle bounded by V2 and its canal inferiorly, bone between FR and superior orbital fissure (SOF) anteriorly, and ophthalmic nerve (V1) superiorly. Drilling was continued toward the annulus of Zinn (AZ) and optic nerve superiorly and over the intracavernous ICA posteriorly. Endoscopic measurements between V2, SOF, AZ, and opticocarotid recess were obtained. Endoscopic systematic orientation of parasellar anatomy is presented that can be helpful for approaching sphenoid sinus with ill-defined bony landmarks.

Endoscopic transnasal study of the infratemporal fossa: a new orientation.

INTRODUCTION: The medial portion of the infratemporal fossa (ITF) is not infrequently involved in sinonasal and skull base pathologies. However, endoscopic view of the ITF remains unclear with lack of studies addressing this region from the endoscopic perspective. METHODS: Using an extended endoscopic approach, the pterygopalatine and infratemporal fossae were dissected in 10 sides of five adult cadaver heads. A plane of dissection along the pterygoid base and the infratemporal surface of the greater sphenoid wing was developed. High-quality images were produced by coupling the video camera to a digital recording system. RESULTS: The foramen rotundum, ovale, and spinosum were accessed and new landmarks were described from the endoscopic point of view. The sphenomandibularis muscle was also highlighted. Maxillary and mandibular nerves and middle meningeal artery were all identified. Columellar measurements to the foramen rotundum and ovale ranged from 6.1 to 8.0 cm for the former and 7.0 to 9.1 cm for the latter, with a mean of 6.75 cm and 7.78 cm respectively. CONCLUSION: The current study provides a novel endoscopic orientation to the medial ITF. Such knowledge should provide an anatomical basis for experienced surgeons to endoscopically address this region with more safety and efficacy.

Endoscopic reconstruction of large anterior skull base defects using acellular dermal allograft.

BACKGROUND: Endoscopic repair of small- to medium-sized anterior skull base (ASB) defects using bone, cartilage, fascia, fibrin glue, lipolized dura, and, more recently, acellular dermal allograft have all been described with equal efficacy. The purpose of this study was to review our experience with the use of acellular dermis as the sole graft material in endoscopic reconstruction of large ASB defects. METHODS: A retrospective chart review of all patients who underwent endoscopic repair of ASB defects at the University of Miami between the years of 2001 and 2006 was conducted. Fifty-six patients were identified who met these criteria. All repairs were performed by a transnasal, endoscopic approach. Outcome measures included success of graft take and incidence of major and minor complications. Dural defect size was defined as small (<0.4 cm), intermediate (0.4-2.0 cm), and large (>2.0 cm). RESULTS: AlloDerm (AlloDerm. LifeCell Corp. Woodlands, TX) was used as the primary graft material in 30/55 (55%) cases; 16/55 (29%) of the repaired defects were classified as large. Graft success was 97% in the AlloDerm group and 92% in the non-AlloDerm group. The incidence of major and minor complications in the AlloDerm group was 0 and 3.3%, respectively. In the non-AlloDerm group, the incidence of major and minor complications was 4 and 12%, respectively. There were no statistical differences in the complication rates based on the type of repair or defect size. CONCLUSION: Alloderm can be used successfully to repair ASB defects, including large defects that are >2 cm in size with little or no morbidity.

Endoscopic endonasal study of the maxillary nerve: a new orientation.

BACKGROUND: Endoscopic endonasal procedures for advanced lesions involving the pterygopalatine fossa (PPF) and its various communications are increasingly performed. The maxillary division of the trigeminal nerve (V2) passes through the foramen rotundum and crosses the upper part of the PPF, with a risk of partial or complete injury during surgery in this complex region. Despite the available knowledge of the sinonasal anatomy, the endoscopic orientation of the V2 remains unclear and requires further analysis from this unique view. METHODS: Using an extended endoscopic approach, the PPF was dissected in 20 sides of 10 adult cadaver heads. The V2 also was followed anteriorly from the trigeminal ganglion, toward the infraorbital canal. The course and the neurovascular relationships of the V2 were studied. High-quality endoscopic images have been produced by coupling the video camera to a digital video recording system. RESULTS: The endoscopic course and relations of the V2 were carefully described. Important landmarks to identify and avoid injury of the nerve were discussed in relation to this unique view. CONCLUSION: This study updates our understanding of the V2 anatomy from an endoscopic perspective. The medial to lateral inclination and drooping of the V2, as well as different relationships of the V2 with the vascular structures are important findings to be taken into consideration while endoscopically addressing related lesions.

Endoscopic endonasal study of the internal carotid artery course and variations.

BACKGROUND: With the advance in endoscopic sinus surgery, more procedures are being performed to address challenging lesions and, of particular concern, those around the internal carotid artery (ICA). Despite the current progress in the understanding of endoscopic paranasal sinus anatomy, little information is available about the course and variations of the closely related ICA as seen endoscopically. In this study, we show an endoscopic analysis of the ICA course in a series of advanced endoscopic dissections METHODS: Ten cadaver heads (20 sides) have been endoscopically dissected. Using an extended approach, a wide sphenoidotomy has been performed as far laterally as the pterygoid base. The latter also has been drilled posteriorly and the ICA was fully exposed from its petrous part up to its termination below the anterior perforated substance of the brain. High-quality endoscopic pictures were produced by coupling the video images with a digital recording system. RESULTS: The ICA course, landmarks, and segments have been defined and analyzed. The ICA was found to have a variable course that was well appreciated using the multiangled, magnified endoscopic view. The importance of such variation was established in relation to the nearby anatomic structures as well as possible lesions involving this area. CONCLUSION: The results of this study provide the endoscopic sinus and skull base surgeon with a better understanding of the endoscopic course and variations of the ICA. In experienced hands, such endoscopic orientation should allow safer as well as more effective management of closely related lesions.