Dr. Supreet Singh Nayyar, AFMC
2011
Approaches to the Sphenoid (for more ENT topic & ppts, visit www.nayyarENT.com www.nayyarENT.com ) )
Anatomy
Sphenoid sinuses originate fourth fetal month as evaginations in the sphenoethmoidal recess Pnuematization 3 yrs Adult size 18 yrs Volume 7.5 ml Congdon classified three types of pneumatizations in respect to the sella. o Conchal (5%) posterior extent of the sphenoid sinus is well anterior to the sella turcica Presellar type (23%) posterior wall of the sphenoid sinus reaches o the anterior face of the sella turcica o Sellar or postsellar type (67%) sphenoid sinus extends past the level of the sella turcica to approach the pons posteriorly, allowing the sella to make a superior indentation in the sinus Midline bony septum 0.6 mm Walls irregular ; Bony septae partially separate Dehiscences in the bony sinus wall, especially laterally and superiorly, where it is only about 1 mm thick result in direct contacts between the sinus mucosa and the overlying dura Superior o Pitutary hypophysis o Olfactory tract o Frontal lobes of the brain o Extensive intercavernous venous network Anterosuperiorly o Optic chiasma Anteriorly o Anterior margin of the sphenoid bone forms a small segment of the posterior orbital wall Inferiorly o Nasopharynx Blood vessels and the nerve of the pterygoid canal o Posteriorly o Thick, bony posterior wall o Basilar artery Pons o Anteriorly, an o Incomplete bony wall separates the sinus mucosa from Nasal mucosa Posterior ethmoid sinuses
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Dr. Supreet Singh Nayyar, AFMC
2011
If the sphenoid sinus is larger, it may extend over the pterygopalatine fossa with its contents, and it may be located directly posterior to the maxillary sinus Laterally o Thin, bony wall with occasional dehiscences Meckels’s cave o o Cavernous sinus Internal carotid artery (which may leave a depression in the bony o wall or even be in direct contact with the sinus mucosa) o Maxillary division of the trigeminal nerve Ostium of the sphenoid located high on the anterior sinus wall approximately 1/3 to ½ up the face of the sinus Sinus drains into the posterior most portion of the sphenoethmoid recess, above the level of the superior turbinate o
Approaches History o o o
Krause - first transfrontal approach to the pituitary (1905) Schloffer - first transnasal route (1907) Cushing - sublabial transseptal operation (1910)
Transsphenoidal hypophysectomy hypophysectomy Transeptal approaches o
Sublabial transseptal o Septoplasty steps Transfixion incision along the left nasal septum Left mucoperichondrial & mucoperiosteal tunnel elevated over quadrangular cartilage, perpendicular plate of the ethmoid, and vomer Inferior tunnels elevated bilaterally in a submucoperiosteal plane lateral to the nasal spine Mucosa not elevated along right side of quadrangular cartilage Post. osseocartilagenous jn. dislocated Mucoperiosteum right elevated Cartilaginous septum separated from nasal spine and maxillary crest and translocated to the right o Further steps Bony septum taken down to the sphenoid rostrum Sublabial incision between canine fossae bilaterally Sublabial and transnasal exposures are connected
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Dr. Supreet Singh Nayyar, AFMC
o
2011
Hypophysectomy speculum is then inserted through the sublabial incision between the mucosal flaps to sphenoid rostrum Anterior wall of the sphenoid and intersinus septum is removed Neurosurgeon begins the hypophysectomy After completion cartilaginous septum must be secured into the prespine fossa with suture Septal and sublabial incisions are closed Quilting stitch
Endoscopic transseptal Use of rigid nasal 0-degree endoscope o Operation carried out through one nostril o Lateralization the middle turbinate, exposing the sphenoethmoidal recess, and natural ostia of the sphenoid sinuses o If nasal cavity very narrow, options : septal deviation septoplasty Superior turbinate identified and removed with a through-cutting forceps o
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Posterior portion of the middle turbinate can also be removed by use of a microscissor After identification of the middle and superior turbinates, the posterior region of the nasal septum and the choanal arch, the ostium of the sphenoid sinus is probed with the seeker/palpator Semilunar incision is made posteriorly on vomer Mucoperiosteal flaps are elevated bilaterally Vomer is resected saving the inferior portion as a landmark for midline Anterior wall of sphenoid sinus is removed starting at the natural ostia The initial opening of the sphenoid sinus is made with a micro-Kerrison punch, beginning at the ostium. Sphenoidotomy is enlarged inferiorly, carefully avoiding or cauterizing the septal artery that crosses the anterior wall of the sphenoid sinus in that region
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Dr. Supreet Singh Nayyar, AFMC
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2011
Intersinus septum is removed Hardy speculum is placed deep between the mucoperiosteal flaps as far down as the open sinus From this point on the operation proceeds as normal with the operating microscope
External rhinoplasty o Advantages of enhanced exposure while limiting the problems with sublabial dissection (gingival numbness, denture problems, contamination of the field with oral flora) o A standard external rhinoplasty incision employing the inverted V o Columellar flaps are raised to the midportion of the lower lateral cartilages o Complete exposure of the lateral crura and the upper lateral cartilages is unnecessary o Caudal edge of quadrilateral cartilage is exposed by dividing the intercrural ligaments between the medial crura o Mucoperichondrial flap on one side of the quadrilateral cartilage is developed and continued over the perpendicular plate of the ethmoid and vomer o Dissection proceeds onto the maxillary crest and the floor of the nose connecting the medial and inferior tunnels o The quadrilateral cartilage is detached posteriorly at the bony cartilaginous junction and and the mucoperioste mucoperiosteum um on the opposite opposite side side of the ethmoid ethmoid and vomer is elevated o Cartilage is then disarticulated from the maxillary crest o Mucoperiosteal elevation is continued on maxillary crest and floor of the nose on the opposite side o Hardy speculum is inserted, displacing the septal leaflets laterally o Perpendicular plate of the ethmoid is resected, taking care to preserve the vomer, which serves as a midline guide to the anterior face of the sphenoid
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Dr. Supreet Singh Nayyar, AFMC
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2011
Anterior sinus wall is opened, the intersinus septum is removed, and the sinus mucosa is exenterated An additional procedure described by Peters and Zitsch Modification of the columellar flap Complete transfixion incision at caudal septum Incision is made at base of columella Quadrangular cartilage is accessed via this incision Requires no separation of the medial crura Operation then proceeds in the previous manner
Previous septal surgery o Prior septal surgery areas of missing bone or cartilage where septal mucosa on one side is directly adherent to mucosa on the opposite side o Methods to avoid septal perforations Area of missing bone or cartilage is small septoplasty with avoidance of the problem area Problem area superior sublabial approach Problem area inferior external rhinoplasty approach Problem area mid part Septoplasty with dissection through adherent mucosal areas o Time since previous surgery, thickness of the tissue, and skill of the surgeon influence practicality of this option Septum can be laterally displaced, thus going around the problem area o Incision paralleling septum made laterally in the mucosa of the floor of the nose, near the inferior turbinate o Complete transfixion incision is made, extending laterally around the pyriform margin and connecting with the first incision in the floor of the nose o Mucoperiosteum along the floor of the nose is elevated with a Freer elevator upto septum o Anterior septum is dissected free of any remaining maxillary crest and nasal spine o Dissection progresses posteriorly until residual solid bone is encountered o Once the anterior septum is free of the maxillary crest, the mucosa on the other nasal floor is elevated Self-retaining retractor is placed just short of the o remaining posterior bony septum and the septum with attached floor mucosa is retracted laterally o An incision is made on the existing bony septum and the operation proceeds as normal
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Dr. Supreet Singh Nayyar, AFMC
2011
Transantral Transantral approach o o o o o
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Caldwell-Luc approach Medial wall of antrum taken down Anterior and posterior ethmoidectomies Anterior wall of sphenoid sinus is reached and removed Intersinus septum is next taken down and removal of the tumor is begun Disadvantage oblique angle taken toward the sphenoid which doesn’t allow for easy orientation with midline structures
Transethmoidal approach
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Lynch incision for external ethmoidectomy Subperiosteal elevation posteriorly Anterior ethmoid artery exposed and ligated Lamina papyracea penetrated and enlarged Under direct vision ant and post ethmoid cells removed up to ant wall of sphenoid sinus Using operating microscope ant wall of the sphenoid sinus entered Intersinus septum removed
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One third shorter than the transseptal route Lack of oral communication Avoidance of nasal complications (septal perforation, etc.)
Disadv o o o
Midline not followed and loss of orientation External scar Inaccessibility of the suprasellar region
Endoscopic sphenoid approaches o
Intranasal sphenoethmoidectomy o Middle turbinate is fractured medially o Ethmoid air cells are taken down working posteriorly Middle turbinate is the medial border and the lamina papyracea is the o lateral border of the dissection o Once the posterior attachment of the middle turbinate is reached, the turbinate is pushed laterally and the sphenoid ostium is identified posterior and slightly superior to the posterior attachment of the middle turbinate o Ostium is enlarged medially before removing the posterior attachment of the middle turbinate and the posterior ethmoid cells creating a common cavity
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Dr. Supreet Singh Nayyar, AFMC
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2011
Stankiewicz modification o Medialize middle turbinate o Remove ant & post ends of the middle turbinate with endoscopic scissors Posterior ethmoid sinuses entered through the ground lamella o o Expose anterior wall of the sphenoid sinus o Entered medially adjacent to the septum approximately 1/3 of the way up the anterior wall, at 30 degrees from the nasal spine o Sinus then opened inferiorly, medially, and laterally o Care taken superiorly possibility of CSF leak
Transpalatal Transpalatal approaches
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Midline palatal split through the medial raphe Once the hard palate is reached, it is removed as necessary for exposure along with the posterior vomer Allows direct access to rostrum of sphenoid and nasopharynx Closure performed in two layers
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Disadv
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Shortening of the palate Velopharyngeal insufficiency
Infratemporal fossa approach o o o
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For extensive sphenoid sinus neoplasms Is actually a combined middle cranial fossa-infratemporal fossa approach Skin incision from vertex of the scalp into the neck and flaps are elevated from the angle of the mandible to the lateral orbital rim to the calvarial vertex Temporalis muscle is elevated into infratemporal fossa where it inserts on the coronoid process Zygomatic osteotomies are made on the zygomatic arch, lateral orbital wall, and malar eminence Soft tissues then completely dissected from the medial end of the glenoid fossa, to the foramen spinosum, foramen ovale, and base of the lateral pterygoid plate Craniotomy is made and elevated along the dura Craniotomy usually fractures across the eustachian tube which is the key maneuver in finding the internal carotid artery Carotid further defined with the a cutting burr V3 next identified as it crosses the carotid Dissection will then lead to the cavernous sinus and parasellar region Tumor dissection then proceeds
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Dr. Supreet Singh Nayyar, AFMC
2011
Anterior approach o o o o o o o
Lateral rhinotomy or Weber-Fergusson incision Lateral osteotomy lateral nasal skeleton out-fractured Anterior and medial maxillary walls excised Ethmoids exenterated Tumor removed piecemeal Anterior wall of the sphenoid sinus taken down Rest of walls
Complications o
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Neurovascular complications o Carotid artery injury o Venous hemorrhage from cavernous sinus o Air embolism o Third, fourth, fifth, and sixth cranial nerve palsy o Optic chiasma Trauma Prolapse into decompressed sella Chiasmal compression by fat or muscle that has been packed into the sinus o CSF leaks Rhinologic complications o Septal perforation Epistaxis o o Synechiae o Anosmia o Cosmetic deformity o Loss of nasal tip projection & decrease in nasolabial angle (sublabial approach damage to ant. nasal spine) o Saddle-nose deformities (excessive resection of cartilaginous septum)
(for more ENT topic & ppts, visit www.nayyarENT.com www.nayyarENT.com ) )
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