Optico-carotid recess and anterior clinoid process pneumatization â€" proposal for a novel classiï¬cation and uniï¬ed terminology: an anatomic and radiologic study.

BACKGROUND: The aims of this study were to propose a novel and uniï¬ed classiï¬cation system of the optico-carotid recess (OCR) and anterior clinoid process (ACP) pneumatization, determine their frequency in a Caucasian population and measure the size of the OCR. METHODOLOGY: A total of 200 specimen (400 sphenoid sinuses) were evaluated in a separate anatomic cadaveric study (n=100) and radiologic study (n=100) by using sphenoidal sinus cast and computed tomography (CT) scan. OCR was divided according to its location to the optic nerve into sub-optical and latero-optical OCR grade I-III. RESULTS: An OCR was found in 39% of the samples (78/200) and in 19% (38/200) it occurred bilaterally. Both, sub-optical and latero-optical OCR were identiï¬ed in 14% of the sides (58/400), with a mean length and depth of 6.9 mm; 7.7 mm and 2.3 mm, 7.1 mm, respectively. We determined the pneumatized ACP frequency with 23% (46/200) and deï¬ned 3 uniï¬ed different types of pneumatization. CONCLUSIONS: The OCR is a reliable landmark to identify the optico-carotid region in endoscopic sphenoid sinus surgery, and can even be visualized by CT. Hence, preoperative investigation of the sphenoid region is mandatory. In our opinion, the classiï¬cation presented in this study can be useful in order to avoid surgical complications.

Gender-specific differences in feasibility of pre-lacrimal window approach.

The feasibility and surgical effort of a pre-lacrimal window approach (PLWA) depends on the width of the bony window anterior to the nasolacrimal duct. This study aimed to investigate gender-specific differences in feasibility of PLWA. A consecutive series of paranasal computed tomography scans from 50 females (n = 100) and 50 males (n = 100) were retrospectively analyzed. The primary outcome measure was the antero-posterior length of the bony pre-lacrimal window (BPLWA). The secondary outcome measure was the distribution of Simmen's PLWA feasibility types (major, moderate and minor surgical effort). On average, males had a 1.5 mm (95% CI 0.8-2.2) significantly higher BPLW length in comparison to females [t(198) = 4.4, p < 0.0001]. The requirement of major surgical effort occurred 29% more frequently in females [χ2(1) = 17.7, p < 0.0001], whereas the necessity of moderate surgical effort was 21% more prevalent in males [χ2(1) = 8.8, p = 0.003]. The need of only minor surgical effort was twice as high in males compared to females [χ2(1) = 3, p = 0.081]. Our data indicates that females require more significant surgical effort during a PLWA to gain access to the maxillary sinus. These results are highly informative as a high amount of bone removal and nasolacrimal duct dislocation are associated with a higher likelihood of complications.