Microanatomical Study Of The Anterior Infratemporal Approach In The Cavernous Sinus Area

Objective: The cavernous sinus area is deep,and its surrounding bone structures,important blood vessels and nerves adjacent and running relationship are complicated.Therefore,the surgery there has always been one of the hot topics of research for neurosurgeons.The infratemporal anterior petrosal approach is one of the commonly used surgical approaches for neurosurgical removal of tumors in the sphenoidal-anterior region-slope area.Some larger tumors on the clinical slope area and in the middle slope squeeze the brain stem backwards.At the same time,it will also protrude into the cavernous sinus area to harass and compress important cranial nerves and blood vessels,which will produce a series of clinical symptoms.The purpose of this study is to: 1.Observe and measure the important structures and adjacent relationships of the cavernous sinus area exposed by the anterior infratemporal approach under the microscope,and quantify the relationship between them with a more accurate grasp Microsurgical anatomical structure of the middle and posterior cranial fossa(cavernous sinus region and rock oblique region);2.Provide reliable data support for the operational safety range exposed by the anterior subtemporal approach through the cavernous sinus region This approach has advantages and disadvantages when the skull fossa protrudes into the cavernous sinus area after resection.Methods:1.Randomly select 3 cases of Chinese adult dry head(6 sides),using the plane from the upper edge of the eyebrow arch to the upper edge of the extraoccipital bulge as the limit,cut the skull with a hacksaw,and cut off the visual bundles on both sides after the vision crosses Only the exposed midbrain,pons and medulla are retained,and the cerebrum and cerebellum are removed,so that the middle and posterior cranial fossa can be fully exposed.Distinguish important anatomical structures such as foramen spinosum(FS),eminentia arcuata(AE),trigeminal nerve impression,greater superfici M petrosal nerve(GSPN)groove.Measure the important anatomical structure of the temporal bone rock and the adjacent spatial position relationship,and then statistically measure the data.2.Randomly select 3 specimens of 6 adult Chinese cadaver heads,and treat them with 10% formalin and 75% alcohol before infusion with red(arterial)and blue(venous)latex.Under the microscope(4 to 25 times),the microsurgical process of the anterior infratemporal approach was simulated,and the important anatomical structures and adjacent relationships revealed during the operation were photographed and accurate and multiple data measurements were performed.The measurement results of the statistical analysis of the measurement distance in this study are expressed as mean ± standard deviation(x ± s).Result:1.Infratemporal approach After entering the middle cranial fossa to raise the temporal lobe,the spinal foramen is used as a mark.The superficial petrosal nerve,trigeminal nerve,and arched bulge can be seen from the perforation of the canal;Can gradually reveal the middle and back of the cavernous sinus.Ablation of the apex of the rock bone and opening of the cerebellum can increase the exposure range of the posterior cranial fossa in the operation area.You can see the upper,middle and ventral side of the rock oblique area backward,and can be exposed to the anterior bed and All temporal lobe.2.The trigeminal nerve,rock bone crest,and rock superficial nerve sulcus form a Kawase triangle.The inner ear canal can be divided into two parts,the front and the back.The anterior part is surrounded by the inner auditory canal,the superficial petrosal nerve and the trigeminal nerve,and the posterior part is composed of petrosal crest,arched hump,and inner auditory canal.The anterior medial half of the anterior region is generally free of important blood vessels and nerves.Therefore,this approach is usually the first choice for abrasion of the apex of the rock when the approach is in the direction of the inferior petrosal sinus.Kawase Triangular Measurements:1)The intersection of the trigeminal foramen-superficial petrosal nerve and the mandibular nerve is 12.45 ± 1.25mm(10.52~13.90)mm2)Intersection point of arched ridges and rock crests-Trigeminal nerve hole 30.58 ± 4.05 mm(25.32~35.70)mm3)Intersection of arched bulge and superficial petrosal nerve-Intersection of superficial petrosal nerve and mandibular nerve 19.78± 4.14 mm(13.59~25.63)mm4)Intersection point of arched ridges and rock crests-Knee-shaped ganglia 19.19 ± 3.91mm(13.10~24.21)mm5)The intersection of the geniculate ganglion-superficial petrosal nerve and mandibular nerve is 16.00 ± 2.14 mm(12.88~18.60)mm6)Projection of the anterior portal of the inner ear on the rock ridge-Trigeminal foramen 5.47 ± 1.22 mm(3.65~7.14 mm)3.It is important to pay attention to the three important anatomical signs of the superficial petrosal nerve,trigeminal nerve,and arched bulge when removing the tip of the rock bone.The trigeminal nerve is the boundary of the medial side,the arched bulge is the boundary of the outside,and the superficial petrosal nerve is the boundary of the front.The internal carotid artery travels obliquely forward from the rupture mouth into the skull and parallel to the direction of the superficial petrosus and enters the cavernous sinus.Therefore,the abrasion range should be before the superficial petrosal nerve to avoid injuring the internal carotid artery with unpredictable consequences.Arched bulge,the position of the vertical semicircular canal of the labyrinth of bone,can affect hearing after injury.4.The medial side of the cavernous sinus is the outer wall of the cavernous sinus after the apex is removed.The measurement results of the size range of each anatomical triangle surrounded by the cranial nerve and bone structure are as follows(using the SPSS 21.0 software for statistical description using the mean ± SD):1)Outer triangle: the inner side length(11.26 ± 0.98)mm,the outer side length(12.55 ± 0.77)mm,and the bottom side length(7.18 ± 0.52)mm.2)Inside and inside triangle: the inner side length(10.65 ± 0.85)mm,the outer side length(11.37 ± 0.75)mm,and the bottom side length(6.38 ± 0.72)mm.3)Anterior and lateral triangle: the inner side length(13.28 ± 1.10)mm,the outer side length(7.65 ± 0.54)mm,and the bottom side length(5.42 ± 0.93)mm.4)Far and outer triangle: the inner side length(11.86 ± 0.67)mm,the outer side length(6.07 ± 0.63)mm,and the bottom side(11.62 ± 0.87)mm.5)The posterolateral triangle: the inner side length(12.16 ± 0.78)mm,the outer side length(12.85 ± 0.78)mm,and the bottom side length(7.50 ± 0.44)mm.6)Posterior medial triangle: the inner side length(12.33 ± 1.28)mm,the outer side length(11.96 ± 1.50)mm,and the bottom side length(12.34 ± 1.30)mm.Conclusions:1.The infratemporal transcranial anterior approach is a classic approach recognized by the academic community for the treatment of oblique tumors in the rock.The identification of spinous holes,superficial petrosal nerves,trigeminal nerves,and arched bulges is very important.Important anatomical landmarks can preliminarily estimate the approximate location of important structures such as the facial auditory nerve,cochlea,and internal carotid artery,thereby avoiding injury during surgery.The tumor resection of the posterior cranial fossa into the cavernous sinus often needs to be performed through one or more anatomical triangles,so it is important to be familiar with the structure of the cavernous sinus revealed by the anatomical triangle and the range of available cavities.Proper surgical approach provides important references.2.Advantages of the anterior infratemporal approachThe infratemporal approach is short and the overall damage is small.The structure of the middle and posterior cavernous sinus can be carefully explored along the petrosal condyle and exposed in order.The cerebellar membrane can be opened to further increase the surgical field.,Can be explored forward to the front bed process,backward to the side of the ring pool.At this time,the entire lateral wall of the cavernous sinus,the lateral cranial nerve,the trigeminal crescent and the apical area of bone can be clearly revealed.In summary,this approach is more suitable for the removal of lesions on the outer wall of the cavernous sinus,the middle,posterior portion of the cavernous sinus and the apex area.3.Deficiencies of the anterior infratemporal approach1)The approach is the sequence from the middle and posterior portion of the cavernous sinus to the front exposure.The exposure of the anterior portion of the cavernous sinus is poor,and due to the path and sight,the abrasion of the anterior bed process is also It is extremely limited,so for the lesions of the anterior wall of the cavernous sinus,such as tumors that occur in the optic canal and lesions involving the anterior bed process,this approach is not easy to achieve the purpose of surgery.2)The surgical approach reveals insufficient internal carotid arteries.The protection of the internal carotid arteries is extremely limited when removing lesions surrounding the neck or pinching an associated aneurysm,so the internal carotid artery system of the cavernous sinus area This approach is also inappropriate for vascular diseases.By dissecting the cavernous sinus area under the microscope,the internal structure of the upper and middle slopes of the rocky slope and the cavernous sinus and the range of the anatomical triangular area of the lateral wall can be clearly and intuitively displayed.Sinus tumors can theoretically guide us to open the cavernous sinus safely using the data measured in the experiment,so that we can safely enter the oblique area and cavernous sinus for surgical operations without damaging important nerve vessels.