Expanded Endoscopic Endonasal Approach

39 Expanded Endoscopic Endonasal Approach

Zachary Litvack, Cristian Gragnaniello, Alan Siu, and Ameet Singh

39.1 Indications

• Craniopharyngioma.

• Tuberculum sellae meningioma.

• Planum sphenoidale meningioma.

• Olfactory groove meningioma.

• Esthesioneuroblastoma.

• Paranasal sinus malignancies.

39.2 Cautions and Contraindications

• Extension of the pathology lateral to the medial edge of the optic canal/orbit.

• Extension of the pathology lateral to the paraclinoid/supraclinoidal carotid.

• Extension of the pathology ventral to the subfrontal region.

• Caution should be exercised for pathology that circumferentially encases critical structures including the carotid or its major branches, and the optic nerve.

• Caution regarding sinonasal morbidity including atrophic rhinitis, chronic sinusitis, nasal septal perforations, and tooth numbness.

39.3 Room Layout (Fig. 39.1)

• Bed is spun 180° from anesthesia.

• A right-handed surgeon will stand on patient’s right side.

• The first assist/co-surgeon can stand at the patient’s head to the surgeon’s left, or across from the surgeon.

• The scrub nurse stands across from the surgeon at the torso, such that instruments are passed across the sterile field.

• The back table of instruments is arranged as an “L” off the left side of patient’s head.

• A Mayo Stand is positioned at patient’s head on the side opposite the first assist/co-surgeon.

39.4 Equipment Considerations

• Surgical equipment includes the following:

◦ HD Endoscopic Tower, 4 mm × 18 cm rod lenses (0°, 30°, 45°).

◦ Ultrasonic aspirator with long (transsphenoidal) bone cutting and tumor ablating attachments.

◦ Endonasal bipolar instrumentation.

◦ Sinus microdebrider.

◦ Neurosurgical microdebrider (NICO Myriad).

39.5 Patient Positioning (Fig. 39.2)

• Position: Patient is positioned in semi-recumbent position (supine with bed reflexed) with head held on a cerebellar headrest or in 3-point Mayfield fixation.

• Body: The body is placed supine. (Fig. 39.2)

◦ Shoulders should be kept above the break in the bed prior to removing the headboard to place the cerebellar horseshoe/Mayfield.

◦ The bed is reflexed to torso up 20°, and the legs are placed downward 20°.

◦ Ipsilateral arm is reverse tucked at the side.

◦ Contralateral arm is left accessible on an arm board.

◦ Abdomen or thigh is draped out for a possible fat/fascia graft.

Fig. 39.1 Intraoperative photograph of the room layout demonstrating the position of the patient with the head of the bed 180° from anesthesia and the position of the surgeons and tech as well as the monitors and instrument tables.

Fig. 39.2 Patient positioning. Patient is placed supine, head in a cerebellar headrest with the torso elevated 20° and the legs lowered 20°. The ipsilateral arm is tucked at the side to increase surgeon’s ergonomics. The contralateral arm is kept on an arm board. The abdomen is draped for possible graft harvesting.

• Head: (Fig. 39.3)

◦ The head is flexed 10–15° (bridge of nose approximately parallel to floor), rotated 5° to the right, and tilted 10–15° to the contralateral side.

• Padding:

◦ Arms are padded with foam or gel pads prior to tucking.

◦ Care is taken to ensure hands are supported at the sides, and not hanging free at the wrists. Intravenous (IV) sites are double padded with gauze between the plastic of the IV or stop-cock and the patient’s skin.

◦ A pillow is placed behind patient’s knees. It is combined with the leg-panel of the bed down 20°, which removes pressures from the heels.

◦ Heels are padded/wrapped with gel pads.

◦ Sacrum is padded with gel or disposable pad.

• The nasal tip is the highest point in the surgical field.

39.6 Skin Incision (Fig. 39.4)

• The only external incisions for this portion are the harvest sites.

• Alternatives include

◦ Lower quadrant abdominal.

◦ Sub-umbilical.

◦ Lateral thigh (fascia lata).

39.7 Endonasal Dissection

• Nasal passage (typically completed by an ENT/sinus surgeon)

◦ Inferior turbinates are outfractured/reduced.

◦ Right middle turbinate is resected. Left turbinate is optionally resected depending on anatomy and type of pathology.

◦ Septal flap is harvested according to Hadad-Bassagasteguy and stored in the nasopharynx (Fig. 39.5).

◦ Superior/posterior septectomy is performed.

◦ Bilateral posterior ethmoidectomy, occasional complete ethmoidectomy depending on pathology and anatomy is performed.

Fig. 39.3 Patient positioning. The head is flexed 10–15°, bringing the bridge of the nose parallel to the floor with a slight 5° rotation to the right and a 10–15° tilt to the opposite side.

◦ Wide bilateral sphenoidotomies with removal of horizontal, vertical, or oblique septations are carried out.

◦ (Optional) Modified Lothrop approach (for pathology extending up to or ventral to the Crista Galli) (see Chapter 40).

Fig. 39.4 Photograph of the abdomen showing the possible harvesting incision.

• Bone exposure

◦ Contents of sphenoid from clivus to planum sphenoidale, including carotid prominences, optic-carotid recesses, tuberculum sella, fovea ethmoidalis should be clearly identified. This often requires drilling or ultrasonic bone curettage of intra-sphenoidal septations and ethmoidal septations (Fig. 39.6).

◦ Variants

– Removal of endonasal olfactory apparatus via trans-ethmoidal route to reveal the fovea ethmoidalis and cribriform plate for approach to pathology between the planum sphenoidale and the Crista Galli.

– Modified Lothrop/Draf III approach to expose the sub-frontal bone for approach to pathology at or ventral to the Crista Galli.