The endonasal paraseptal approach is most often used to remove pathology within the sella turcica. The technique has been used to remove intradural pathology extending anterior to the tuberculum sellae and above the sellar turcica.
Step 6. Repair the paraseptal mucosal flap (Fig. 5.22)
Surgical Tips
As the surgeon is operating in a deep narrow hole, hemostasis should be established at each step. Bleeding can be controlled with oxidized cellulose and bipolar cautery. The key instruments for tumor removal are curettes of various sizes and angles. A plane should be established between the tumor and the normal flattened pituitary gland. The tumor is then systematically removed by first gutting the tumor and then dissecting the walls of the tumor toward the midline. Brisk venous cavernous sinus bleeding is controlled by elevation of the head, oxidized cellulose, and gentle pressure. It is not uncommon for a lip of arachnoid to protrude in front of the superior edge of the pituitary tumor. This is a possible site for cerebral spinal fluid leaks.
Illustrated Steps with Commentary
Fig. 5.1 Approach through the left nostril.The right-handed surgeon is more comfortable operating through the left nostril. The surgeon’s view is oblique to the right. For lesions extending to the left cavernous sinus, the surgeon’s view of the lesion is improved by operating through the right nostril. (IT, inferior turbinate)Fig. 5.2 (Step 1) Identify the middle turbinate through the left nostril.The floor of the nasal cavity is first identified. The inferior nasal turbinate is found and the middle nasal turbinate is seen above the inferior nasal turbinate. This methodical technique will avoid erroneous identification of this important landmark. (MT, middle turbinate)Fig. 5.3 Identification of the middle turbinate.(IT, inferior turbinate; MT, middle turbinate; NS, nasal septum)Fig. 5.4 Nasal septum opposite to the middle turbinate.A microscope is tilted toward the nasal septum to start a mucosal incision. (MT, middle turbinate; NS, nasal septum)Fig. 5.5 (Step 2) Paraseptal mucosal incision.An incision is made in the mucosa of the nasal septum with a cautery approximately 1 cm anterior to the sphenoid sinus. This will create a mucosal flap that can be reapproximated to the nasal septum at the end of the case. (MT, middle turbinate; NM, nasal mucosa; NS, nasal septum)Fig. 5.6 Paranasal mucosal elevation.The mucosal flap is raised from the vomer, perpendicular plate of the ethmoid, and anterior wall of the sphenoid sinus. (MT, middle turbinate; NM, nasal mucosa; NS, nasal septum)Fig. 5.7 Creation of the paranasal mucosal pocket.The vomer is cracked anterior to the ala vomer, and the vomer and perpendicular plate of the ethmoid are pushed to the right. The mucosa over the right side of the anterior sphenoidal wall is stripped from that bone. The mucosa is held laterally by a nasal speculum. (NM, nasal mucosa; NS, nasal septum)Fig. 5.8 Identification of the bilateral natural ostia of the sphenoid sinus bilaterally.The ostia of the sphenoid sinus are identified bilaterally. (fVo, fractured vomer; OSS, ostium of the sphenoid sinus)Fig. 5.9 Exposure of the ala vomer remnant (keel bone).The ala vomer covers the spine of the sphenoid bone. When the medial nasal septum is dislocated laterally, the ala vomer remains attached to the sphenoid bone and produces a characteristic teardrop shaped landmark. (aVo, ala of the vomer; fVo, fractured vomer; OSS, ostium of the sphenoid sinus)Fig. 5.10 Downward tilting of the microscope.As a surgical trajectory viewing the ostium of the sphenoid sinus is slightly high for the approach to the sella floor, the microscope should be tilted downward, putting the tip of the keel bone in the center of the surgeon’s field. Stripping mucosa high off the ethmoid sinus risks injury to the bundles of the olfactory nerve. (aVo, ala of the vomer; fVo, fractured vomer)Fig. 5.11 (Step 3) Exposure of the mucosa of the sphenoid sinus.The ala vomer and the anterior wall of the sphenoid sinus are removed with a diamond drill. The opening is made as wide as possible. (mSS, mucosa of the sphenoid sinus)Fig. 5.12 Opening of the sphenoid sinus.The mucosa within the sphenoid sinus is removed. Troublesome bleeding from the mucosa can be controlled with bipolar cautery or temporary compression with Gelfoam (Pfizer Inc., NY, NY). The surgeon should note the position of the intrasinus septa on the preoperative imaging studies and match them to the anatomy found at the time of surgery. (CP3, carotid prominence formed by the C3 portion of the internal carotid artery; SF, sella floor; SS, sphenoid sinus)Fig. 5.13 Identification of the left C3 and C5 carotid prominences.The C3 portion of the carotid artery makes an impression that protrudes into the sphenoid sinus lateral to the pituitary gland. The C3 segment protrudes lateral to the medial clivus. (CP3, carotid prominence formed by the C3 portion of the internal carotid artery; CP5, carotid prominence formed by the C5 portion of the internal carotid artery; CL, clivus; SF, sella floor)Fig. 5.14 Identification of the right C3 and C5 carotid prominence.The prominence of the C5 carotid artery can be seen below the sella turcica. The C3 carotid artery lies under the protuberance of bone over the optic nerve. The perisellar protuberance is the outpouching of bone over C3. (CP3, carotid prominence formed by the C3 portion of the internal carotid artery; CP5, carotid prominence formed by the C5 portion of the internal carotid artery; CL, clivus; SF, sella floor)Fig. 5.15 Viewing of the sella turcica.The anterior sella protrudes into the sphenoid sinus in most cases. In the concha type sella (3%) cancellous bone covers the sella turcica. In these cases, the sella is not obvious when looking through the sphenoid sinus. (SF, sella floor)Fig. 5.16 (Step 4) Drilling of the sella floor with an endonasal drill.The anterior wall of the sella turcica is removed with a diamond drill or Kerrison rongeur. Care is taken not to injure the carotid arteries, the venous channels that run in the dura, or the cavernous sinuses. Opening of the intercavernous sinuses in the underlying dura leads to annoying bleeding that can be controlled with oxidized cellulose and bipolar cautery. (SF, sella floor)Fig. 5.17 (Step 5) Exposure of the dura of the pituitary gland.A large intercavernous sinus frequently runs through the inferior anterior aspect of the sella dura. Bleeding from this sinus can be avoided by cauterizing the walls of the sinus before cutting through the sinus. (DSF, dura of the sella floor; ICS, intercavernous sinus)Fig. 5.18 Obtaining maximal exposure of the dura of the pituitary gland on the right side.The dura should be exposed until the cavernous sinus is seen bilaterally. The cavernous sinus is identified by its blue color. It usually protrudes anterior to the dura covering the pituitary gland and covers C3. (C3, C3 portion of the internal carotid artery; DSF, dura of the sella floor; ICS, intercavernous sinus)Fig. 5.19 Exposure of the medial cavernous sinus wall on the left side.The anatomical relationship between the pituitary gland, the intercavernous sinus, and the C3 and C5 portions of the internal carotid artery is demonstrated. (C3, C3 portion of the internal carotid artery; C5, C5 portion of the internal carotid artery; ICS, intercavernous sinus; PG, pituitary gland)Fig. 5.20 Separation of the dura of the pituitary gland from the true medial cavernous wall.The normal pituitary gland can be separated from the true medial cavernous wall that is very thin. (C3, C3 portion of the internal carotid artery; C5, C5 portion of the internal carotid artery; ICS, intercavernous sinus; PG, pituitary gland)Fig. 5.21 Opening of the right cavernous sinus for an extended transsphenoidal approach.The covering of the cavernous sinus can be opened to expose the C3 carotid artery. Venous bleeding can be controlled with a hemostatic agent such as oxidized cellulose. There are no neural structures between the carotid artery and the pituitary gland. Care should be taken not to injure the fine branches of the carotid artery. (C3, C3 portion of the internal carotid artery; C4, C4 portion of the internal carotid artery; PG, pituitary gland)Fig. 5.22 (Step 6) Renovation of the paraseptal mucosal flap.If a CSF fistula develops, fat is placed into the sella turcica. It is held in place with fibrin glue and an absorbable cranial fixation plate. In the case of a large CSF fistula, a piece of fascia is used to reconstruct the anterior sellar wall. Once the speculum is removed, the medial nasal septum is pushed back to the midline. The ipsilateral mucosal flap is approximated to the nasal septa. (MT, middle turbinate; NM, nasal mucosa)Fig. 5.23 Renovation of the paraseptal mucosal flap.A pledget of absorbable hemostatic agent approximates the mucosal flap to the midline septum. The flap is held against the midline with fibrin glue. (AHA, absorbable hemostatic agent)
Only gold members can continue reading. Log In or Register to continue
