Study Of Applied Anatomy For Transaction Of Petroclival Region Tumor Through Presigmoid Retrolabyrinth Approach

Objective:Petroclival region is deep, surrounded by a number of imp ortant blood vessels and nerve tissue, surgery is difficult,especially for larg er tumors removed,neurosurgeons have been a great challenge,mainly related to the more complex anatomy,especially those related to rock bone, neurosurgeons are not familiar with,so far limited to the petroclival region tumor surgery,the experiment by measuring the data,these data were ground for the safe operation of the petrous bone,a reasonable choice of operation and expansion of petroclival space the scope of surgical field exposure and pro-vide a reliable basis to further explore and improve the bone back into the road by the rock method of operation,the clinical application of the appro-ach and provide anatomical information. And clearly presigmoid retrolaby-rinthine approach could reveal the extent of the operation, in order to disse-ct the data through this surgery can provide some clinical guidance.Methods:six cases of 12 sides in 10% formalin fixed adult specimens of fresh wet head frame fixed to simulate the sigmoid sinus approach before surgery,after getting lost, as close to the actual surgical procedure.Head po-sition:lateral position,head turned to the contralateral surgery,the top level bit lower than the 15°-20°,slightly lower frontal position,so mastoid at the highest point along the visual pathway of the temporal bone to keep the De-partment of the direction of rock. Take a big question mark around the ear in cision, the incision from the ear from the front before the mid-point of zygo matic arch, up around the ear from the auricle of about 3-4cm,back row in the papilla after the 2-3cm,limited to the mastoid tip of about 1cm (Figure 1).Can be flexibly adjusted according to lesion location, if the middle cra-nial fossa lesions larger,then cut forward to expand,if a larger posterior fos sa lesions,then the incision in the transverse sinus on the midline by som e,extending down more,so that the range of exposure after the nest increase ed.Opened along the lower deck of the subgaleal flap,flap turned the directi on of the external ear canal,the superficial temporal fascia,periosteum and sternocleidomastoid with nothing at attachment points.There are two holes in the choice of bone:The first 4 hole method, basically a star point as the center of radial drilling 4 holes. With a hole in the top corner before sewing Ru (key hole); two holes in a hole parallel lines (parallel to the transverse sinus) back close to the skin edge;3 hole 2 hole in the bottom of about 1.5 cm (cross-transverse sinus);4 hole in a hole about 1.5cm below the office. Temporal bone drilling three holes,drill a posterior fossa bone hole, the first along with the temporal bone cutter milling holes open,and then along the posterior bone milling holes open, carefully grind the last open cross-sinus bone,the bone valve opened. (Figure 3) The second two hole method, that is,the key hole in a hole drilled along the transverse sinus and drill a hole parallel to the line backwards. Under the first temporal bone milling, and then in front of the rear transverse sinus transverse sinus sulcus carefully peel off from the brain under the protection plate in the bone flap,the post-erior flap cutter milling, the formation of temporal, posterior 2 block of bo-ne. (Figure 5) were ground with a micro-burr the Department of temporal bone rock wall.In addition to the mastoid bone cortex surface grinding, the gradual emergence of mastoid (Figure 6). 1cm from the sigmoid sinus and start at the rear were ground bone, consistent with the depth up to reveal the sigmoid sinus and mastoid in here to see the lead vessel connected with the sigmoid sinus,cut the blood vessels.With a diamond grinding along the sigm oid sinus to the jugular bulb,so that the surface of a thin layer of cortical bo ne remaining. Contour of the sigmoid sinus,forward, top to remove the mas-toid a small room, revealing the middle cranial fossa dura.Further forward than mastoid ground until it has tympanic sinus,were ground carefully to the surrounding bone, drum sinus wall appeared hard,light yellow color when the bone area, suggesting that close to the lateral semicircular canal;as clear to see to the quality of hard ivory white tips to the bone the last Department of posterior semicircular canal.Posterior semicircular canal in the direction parallel to the posterior wall of petrous part of temporal bone,the inside of the outer half of its pre-regulation,while the facial nerve canal horizontal semicircular canal is located outside the post below.Careful outline of bony labyrinth and facial nerve canal,to continue to grind down the mastoid tip area than the small room,so that pre-sigmoid sinus dural,middle fossa dura and sinus dural angle are fully exposed, the transverse sinus and the horiz-ontal transfer of sigmoid sinus petrosal sinus can be seen (Figure 67). Paral-lel to the anterior sigmoid sinus dural incision posterior to the jugular bulb at the top, pull to the front of the dura,sigmoid sinus exposure before the gap;along the middle cranial fossa transverse incision in the cranial fossa dura (Figure 8), raised his temporal lobe; in petrosal sinus,sigmoid sinus ligation meeting point in front of 0.5cm Department,cut off petrosal sinus;cut off from the petrosal sinus tentorial Department cut inward to the trochlear nerve into the dural side of the screen later notch Office,will push the rear tentorium.Further up the temporal lobe,cerebellum,and slightly retracted sigmoid sinus,petroclival exposure,observation and measurement data.Results:1. the distance between the skull surface markers:Star point reach the peak milk from the joint front foot 28.9±3.7mm;star point to the external ear canal from the posterior crest of 43.2±1.6mm;top milk after sewing on the front foot to the ear canal from the crest of 25.8±4.2 mm.2. sinus dural angle to the landmarks distance:sinus dural angle to the posterior semicircular canal from 18.6±3.1mm;sinus dural angle to the jugular bulb in the range 27.9±1.9 mm;sinus dural angle to the posterior external auditory canal ridge from 28.8±3.8mm.3. intracranial length of the cranial nerves and the major gap between the cranial nerves:oculomotor intracranial far cry from 14.4±1.9mm;trigem-inal nerve intracranial far cry from 12.1±1.4mm;the facial nerve intracr-anial far cry from 11.3±1.8 mm;intracranial glossopharyngeal vagus nerve, far below the 17.7±1.9mm;oculomotor and trigeminal nerve from 12.9±3.2 mm;the facial nerve and glossopharyngeal vagus nerve from 10.2±2.9mm.4. petroclival region by the exposed areas of measurement:In this study,to the middle cranial fossa revealed most visible carotid artery supr- aclinoid segment,measured petrous apex to its distance, representing the operative field can be revealed in the middle cranial fossa area, petrous apex to the supraclinoid carotid artery,far below as:10.2±1.7mm. Petrocli-val exposure can see the bottom of glossopharyngeal,vagus nerve, so the sco pe of the posterior fossa,which pointed to the rock glossopharyngeal,vagus nerve distance,petrous apex to the vagus nerve glossopharyngeal distance: 30.8±5.9mm.Conclusion:1. Markers of body:external eye canthus, the upper edge of the external auditory canal and the external occipital protuberance to connect to mark location of transverse sinus;2. Craniectomy:Star point can locate transverse sinus location, the top milk seam front key hole positioning as sigmoid sinus on the song. According to the dual positions of transverse sinus craniotomy safety, save time;3. Papilla and bone were ground rock when the signs:For non-sclerosing papillary, according to bone, color, positioning posterior semicircular canal. Sclerotic mastoid sinus wall based primarily on indirect positioning drum posterior semicircular canal;4. Tentorial surgery can be a very good margin of the upper and lower exposure areas can be exposed to the middle cranial fossa parasellar, supraclinoid internal carotid artery segment, posterior cranial fossa can be exposed to the vertebral artery, the glossopharyngeal, vagus nerve high. As the angle of the problem, the bone behind the rock exposed from the poor before the arcuate eminence;5. Preoperative line of the necessary checks must clear position of transverse sinus venous return Labbe, a high jugular bulb, semicircular canals, the location of sigmoid sinus, otherwise, these anatomical position deviation will seriously affect the operation area of the exposed areas;6. Screen up and down the joint presigmoid retrolabyrinthine approach is well exposed in the fissures on the slopes and tentorial area.