Anatomic Evaluation of the Ophthalmic Artery in Optic Canal Decompression: A Cadaver Study of 20 Optic Canals.

AIM: A relationship was shown in this study between the optic canal and the ophthalmic artery by cadaver study. It is intended that the anatomical and histological values which we obtained can be used as a guide in surgery MATERIAL and METHODS: A surgical anatomical evaluation was made of twenty optic canals in ten cadavers fixed in 10% formaldehyde. These were evaluated together with measurements of the ophthalmic artery and histological sections of the surrounding structure. RESULTS: The ophthalmic artery separated from the carotid at different positions. In our material, eight (40%) left the carotid from the upper internal part, six (30%) from the front internal part, four (20%) from the upper central part, and two (10%) emerged at the end of the cavernous segment of the middle of the carotid at a steep angle. In none of the material did the ophthalmic artery originate from any other vascular structure than the carotid. Whatever position the ophthalmic artery was in within the canal on entry, it followed the outer walls of the canal and left the canal in the lower external section of the optic nerve. In the literature, work on this area has been limited to examining the anatomical values and variations in the optic canal. The results in the present study have been obtained by combining the data with surgical anatomy. CONCLUSION: This is a method of transcranial decompression of the optic canal which is safe for the vascular structures in and around the optic canal providing certain points are kept in mind.

Breakage of an Epidural Catheter Inserted for Labor Analgesia.

The breakage of an epidural catheter, which is usually not noticed, is a rare but important complication encountered while inserting or removing the catheter during epidural blockade. While the epidural catheter was being inserted for labor analgesia, despite no problem being encountered in advancing the catheter, it was drawn back to verify the location; it was observed that 2 cm of the distal end of the catheter was missing. A neurosurgical consultation was requested; it was reported that the broken piece would not create any problems and reintervention could be performed for labor analgesia. An epidural catheter was reinserted and was used for analgesia without any problem until delivery. Although nine months have passed, no problem was defined by the patient. If epidural catheter has to be removed while the Tuohy needle is still in place, we recommend that they should be removed together to minimize the risk of a possible breakage. We think that the decision for surgery and imaging can be performed based on the individual patient's clinical picture.

Morphometric analysis of human occipital condyle.

OBJECTIVE: The human occipital condyle is the unique bony structure connecting the cranium and the vertebral column. The progress in neuroimaging techniques has increased interest for aggressive craniovertebral surgery. Such surgery requires the knowledge regarding anatomical aspects of the craniovertebral junction. The aim of the present study is to analyze the occipital condyle morphometrically. MATERIAL AND METHODS: 404 occipital condyles of 202 dry skulls were used for this study. Twenty-seven parameters were measured, including length, width and height of occipital condyle, the distances between the occipital condyle and hypoglossal canal, as well as some important condyle-related angles. RESULTS: The length, width and the height of the occipital condyle were found to be 23.4, 10.6, and 9.2 mm, respectively. The anterior and posterior intercondylar distances are 21.0 and 41.6 mm, respectively. Sagittal intercondylar angle was 59.3 degrees. The intracranial orifice of the hypoglossal canal was found in the junction of the second and third quarter on the condyle in more than 55% of specimens. The shape of occipital condyles was classified into eight types as follows--type 1: oval-like condyle; type 2: kidney-like condyle; type 3: S-like condyle; type 4: eight-like condyle; type 5: triangle condyle; type 6: ring-like condyle; type 7: two-portioned condyle and type 8: deformed condyle. The most common type was type 1 (50%), whereas the most unusual type was type 7 (0.8%). CONCLUSION: It is concluded that the occipital condyle may present various shapes, length, width, and orientation, requiring a careful radiological analysis before craniovertebral junction surgery.