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Introduction Identifying the internal carotid artery (ICA) when managing petroclival and infratemporal fossa pathology is essential for the skull base surgeon. The vidian nerve and eustachian tube (ET) cartilage come together at the foramen lacerum, the vidian--eustachian junction (VEJ). The ICA position, relative to the VEJ is described. Methods Endoscopic dissection of adult fresh-frozen cadaver ICAs and a case series of patients with petroclival pathology were performed. The relationship of the VEJ to the ICA horizontal segment, vertical segment, and second genu was assessed. The distance of the ICA second genu to VEJ was determined in coronal, axial, and sagittal planes. The length of the vidian nerve and ET was measured from the pterygopalatine fossa (PPF) and nasopharyngeal orifice to the VEJ. Results In this study, 10 cadaver dissections (82.3 ± 6.7 years, 40% female) were performed. The horizontal petrous ICA was at or behind VEJ in 100%, above VEJ in 100%, and lateral to VEJ in80%. The vertical paraclival segment was ator behindVEJ in 100%, above in 100%, and medial in 100%. The second genu was at or behind VEJ in 100% (3.3 ± 2.4 mm), at or above in 100%(2.5 ± 1.6mm), andmedial in100%(3.4 ± 2.0mm). The VEJwas successfully used to locate the ICA in nine consecutive patients (53.3 ± 13.6 years, 55.6% female) where pathology was also present. The VEJ was 15.0 ± 6.0 mm from the ET and 17.4 ± 4.1 mm from the PPF. Conclusion The VEJ is an excellent landmark as it defines both superior and posterior limits when isolating the ICA in skull base surgery. [ABSTRACT FROM AUTHOR]

Abstract: The anterior transclival route to basilar artery aneurysms is not widely performed. The objective of this study was to carry out a feasibility assessment of the transclival approach to basilar aneurysms with advanced endonasal techniques on 11 cadaver heads. Clival dura was exposed from the sella to the foramen magnum between the paraclival segments of the internal carotid arteries (ICA) laterally. An inverted dural “U” flap was reflected inferiorly to expose the basilar artery. The maximal dimensions from operative measurements were recorded. Surgical manoeuvrability of multiple instruments and the proficiency to place proximal and distal vascular clips were evaluated. The mean operative depth (± standard deviation), measured from the anterior choanae to the basilar artery, was 110±6mm. The lateral corridors were limited distally by the medial pterygoids (mean width 21±2mm) and paraclival ICA (mean width 20±2mm). The mean transclival craniectomy dimensions were 19±2mm (width) and 23±4mm (height). Exposure of the basilar–anterior inferior cerebellar artery junction, superior cerebellar artery, and the basilar caput were possible in 100%, 91%, and 64% of instances, respectively. Placements of proximal and distal aneurysm clips were achieved in all instances. Based on our findings, the transclival endoscopic endonasal surgery approach provides excellent visualisation of the basilar artery. Clip application and manoeuvrability of instruments was considered adequate for basilar aneurysm surgery. Surgical skills and instrumentation to control significant haemorrhage can potentially limit the clinical applicability of this technique. [Copyright &y& Elsevier]

Abstract: Although postoperative seizure is an acknowledged risk following transcranial surgery, the incidence of seizure after removal of intradural pathology via an expanded endoscopic endonasal approach is not well defined. The current study was performed to systematically review the risk of seizure in patients undergoing endoscopic endonasal skull base (EESB) surgery. Embase (1980 to 9 March 2012) and Medline (1950 to 9 March 2012) were searched using a search strategy designed to include any studies that report the perioperative outcomes following EESB surgery. Outcomes of patients undergoing a simple closure of cerebrospinal fluid fistulae or encephaloceles and transellar approaches for pituitary or intrasellar lesions were excluded because this review is focused on large skull base defects. A title search selected those articles relevant to clinical series on expanded endoscopic approaches. A subsequent search of abstracts selected for manuscripts of any report that documented the presence or absence of postoperative seizure. A total of 2234 manuscripts were selected initially and full text analysis produced 67 studies with extractable data regarding the perioperative outcomes for EESB surgery. Of these manuscripts, seven reported the incidence of seizure following EESB procedures. Two of these studies were excluded due to duplication of authorship and institutional data. The overall risk of postoperative seizure following EESB surgery was estimated at 1.1% (six of 530). Subgroup analyses of data revealed that the risk of seizure following an endoscopic endonasal to the anterior cranial base was 2.3% (one patient of 43). For a posterior cranial base approach, the risk of seizure was indeterminate due to deficiency of reporting in the current literature. We concluded that the risk of seizure following an EESB procedure appears to be low (1%). However, the lack of reporting on the incidence of seizures or the use of antiepileptic prophylaxis following EESB procedure is a key limitation. Future EESB studies will need to include seizure as an outcome to accurately define this risk. [Copyright &y& Elsevier]

Background Osteitic bone is a feature of chronic rhinosinusitis (CRS), potentially playing a role in pathogenesis. Although seen after previous endoscopic sinus surgery (ESS), it is also a de novo feature in patients without prior interventions. In these patients, osteitis is associated with high tissue and serum eosinophilia. However, the impact of osteitis on prognosis is unclear. This study investigates the clinical and endoscopic outcomes between patients with and without osteitis after primary ESS. Methods A prospective study of a cohort of previously unoperated patients with CRS undergoing ESS was performed. The sinuses were scored radiologically for osteitis using the Global Osteitis Score (GOS) and Kennedy Osteitis Score (KOS) preoperatively and were also scored dichotomously for the presence or absence of osteitis. Disease-specific quality of life (22-item Sino-Nasal Outcomes Test [SNOT-22]), nasal symptom score (NSS), endoscopic score (Lund-Kennedy), and clinical outcomes-including oral steroid use, frequency of nasal steroid irrigation, and infective exacerbations-were collected at baseline and 1 year postsurgery. The presence and extent of osteitis was assessed relative to clinical outcome. Results Fifty-three patients were included (41.5% female, age 47.4 ± 13.8 years), 42.9% of which had radiologic osteitis. There was no significant association between the presence or severity of osteitis at the time of surgery and SNOT-22, NSS, or endoscopy scores at 12 months postsurgery. However, the presence of osteitis was associated with the need for a course of oral steroid postsurgery (odds ratio [OR]=4.17; p = 0.026). High tissue eosinophilia could not predict this alone ( p = 0.55). There was no significant relationship between osteitis and the frequency of steroid irrigations or infective exacerbations. Conclusion Osteitis in CRS is associated with the degree of eosinophilia and as a independent process it was associated with the need for a course of systemic corticosteroid over a 12-month period, but did it not affect overall disease control. [ABSTRACT FROM AUTHOR]