38 endoscopic approach to the sella ronald b. willemse ......pituitary adenomas are by far the most...

736

Summary .....................................................................736

Introduction ................................................................736

Indications/Patient Selection ......................................737

Craniopharyngiomas ........................................................737

Meningiomas ...................................................................737

Rathke cleft cysts .............................................................737

Pituitary Adenomas ..........................................................737

Goals of Surgery ...............................................................738

Preoperative Planning .................................................739

Ophthalmological Assessment .........................................739

Endocrinological Assessment ...........................................739

Imaging ............................................................................740

Patient Information/Informed Consent ..................... 743

Anesthesia and Positioning ......................................... 743

Operative Steps ........................................................... 744

Sellar and Parasellar Anatomy ..........................................744

Cavernous Sinus/Intercavernous Sinus .............................745

Image Guidance ...............................................................745

Nasal Phase ......................................................................745

Sphenoidal Phase .............................................................746

Sellar Phase ......................................................................746

Complications .............................................................749

Postoperative Care ......................................................751

Disorders of Water Balance ..............................................752

Hypopituitarism ...............................................................752

Outcomes ....................................................................752

Radiotherapy ....................................................................753

Review Questions ........................................................754

Summary

The endoscopic endonasal approach is currently the approach of choice for most sellar tumors, including pitu-itary adenomas, craniopharyngiomas, meningiomas, and Rathke cysts. Improved visualization, avoidance of brain retraction, faster recovery, lack of external scars, and the ability to directly access tumors with minimal damage to critical neurosurgical structures are among its obvious benefi ts. This is refl ected in improved outcomes in terms of higher rates of gross macroscopic tumor removal and normalization of hormones (in secreting adenomas) and reduced hospitalization requirements. However, it pre-sents surgeons with several challenges, including a steep learning curve, complicated reconstruction requirements, and the need for a true team approach.1

Introduction

Anatomically, it is obvious that the route via the sphenoid sinus is the more direct way to access the sellar region. The transsphenoidal approach to the sella evolved from a subla-bial transseptal to a transnasal approach with the use of the

operating microscope. Although otolaryngologists were the fi rst to use the endoscope in the nasal cavity, Gerard Guiot 2 was the fi rst neurosurgeon to perform an endoscopic trans-sphenoidal approach to the skull base in 1963; however, he had to abandon the procedure because of poor visualiza-tion. Subsequently it was felt that the endoscope was to be used as a visual aid, in addition to the microscope, rather than as the primary means of visualization. Jankowski and coworkers from the Central Hospital of the University of Nancy reported in 1992 the fi rst removal of hypophysial tu-mors in three patients using a purely endoscopic transna-sal, transsphenoidal approach to the sella. 3 Several pioneers in transnasal endoscopic skull base surgery subsequently emerged, including Jho, 4 Cappabianca et al, 5 and Frank and Pasquini,6 who extended the limits of what can be achieved via a transnasal endoscopic approach.

The endoscopic endonasal, transsphenoidal approach provides an excellent panoramic view of the sphenoid sinus and of the sellar and parasellar regions, with intra- and extracapsular visualization using straight and angled endoscopes, preservation of sinonasal function, reduced hospital stay, and increased patient comfort. More impor-tantly, there is increasing evidence that the endoscopic transsphenoidal approach is associated with improved patient outcomes compared with the traditional micro-scopic approach. 7–10

38 Endoscopic Approach to the Sella Ronald B. Willemse, Wouter R. van Furth, Wytske Fokkens, and Christos Georgalas

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Indications/Patient Selection 737

insuffi ciency, failure to thrive, or (rarely) signs and symp-toms of increased intracranial pressure. Despite their be-nign nature, they tend to infi ltrate and adhere to adjacent structures, making their complete removal diffi cult.

■ Meningiomas

Meningiomas usually arise from the tuberculum sellae or diaphragma sellae and may cause headaches or visual disturbances due to the close relationship to the optic nerves and chiasm (see DVD/Thieme Media Center ) .

■ Rathke cleft cysts

Rathke cleft cysts are usually small cystic lesions derived from Rathke pouch remnants, causing headaches.

■ Pituitary Adenomas

Pituitary adenomas are by far the most common tumors of the sellar region, comprising 90 to 95% of all such tu-mors. Pituitary adenomas are benign epithelial tumors derived from secretory cells of the anterior pituitary gland (adenohypophysis), which are classifi ed according to the immunohistochemical expression patterns of hormones. They are divided into microadenomas ( tumors � 10 mm in size) and macroadenomas ( � 10 mm).

The vast majority of pituitary adenomas are asymp-tomatic and occur in �10% of the general population ( incidentalomas), as shown by autopsy and magnetic reso-nance imaging (MRI) studies. 12,13 If clinical symptoms are present, they are due to cranial nerve compression, hor-monal hyper- or hyposecretion, or a combination of these.

Nonfunctioning/Inactive Adenomas

Pituitary adenomas without hormonal overproduction are referred to as nonfunctioning or inactive. Treatment is determined by their size and clinical manifestations. Mechanical compression of the normal pituitary can cause pituitary dysfunction, and pressure on the surrounding structures may be associated with a variety of symptoms: pressure on the optic chiasm, for example, often produces the classic bitemporal hemianopsia. Adenomas with lat-eral extension and invasion of the cavernous sinus may cause symptoms from cranial nerve [CN] III (oculomotor), CN IV (trochlear), and CN VI (abducens), or a combination, leading to ophthalmoplegia. Extensive suprasellar exten-sion can lead to obstruction of the foramen of Monro, resulting in obstructive hydrocephalus. Headaches occur frequently and may be caused by compression or stretch-ing of the sellar diaphragm or dura. 14

However, operating with the use of an endoscope has a defi nite learning curve, 11 while the improved rates of complete tumor removal are associated with larger skull base defects and the potential for cerebrospinal fl uid (CSF) leaks. 10

Indications/Patient Selection

The diff erential diagnosis of sellar lesions is presented in Table 38.1 and consists of primary and metastatic tumors, cysts, and infl ammatory and vascular lesions. The most common are pituitary adenomas, craniopharyngiomas, meningiomas, Rathke cleft cysts, and pituitary apoplex-ies. The main aims of surgery for pituitary adenomas are

1. Normalization of excess hormone secretion 2. Elimination of mass eff ect 3. Preservation or restoration of normal neurologic func-

tion, including visual acuity and fi elds 4. Preservation or restoration of normal pituitary function 5. Prevention of tumor recurrence 6. Achievement of a complete pathologic diagnosis

■ Craniopharyngiomas

Craniopharyngiomas are slow-growing tumors origi-nating from remnants of the Rathke pouch (see DVD/Thieme Media Center ). They usually occur in children and young adults. Depending on their location and size, they may present with headaches, visual loss, pituitary

Table 38.1 Diff erential diagnosis of sellar lesions

Tumor Pituitary adenomaCraniopharyngiomaMeningiomaGlioma (hypothalamic, optic nerve)MetastasisChordomaLymphoma

Cyst Rathke cleft cystDermoid cyst

Infl ammatory and granulomatous disorders

Bacterial abscessLangerhans cell histiocytosisSarcoidosisTuberculosisGranulomatous hypophysitis

Hamartoma Hypothalamic hamartoma

Vascular lesions Carotid aneurysm

Pituitary apoplexy


38 Endoscopic Approach to the Sella738VI

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y Cushing disease

Adrenocorticotropic hormone (ACTH)–producing pituitary adenomas causing the clinical picture of Cushing disease are relatively rare, occur mostly in women, and have a poor prognosis if left untreated (see DVD/Thieme Media Cen-ter ). Note that Cushing disease refers exclusively to ex-cess ACTH of a pituitary origin, usually a (micro)adenoma, whereas all other causes of nonphysiologic hypercorti-solism are grouped under the term Cushing syndrome. The clinical eff ects of hypercortisolism are the same: truncal obesity, hypertension, muscle weakness, amenorrhea, hir-sutism, abdominal striae, glycosuria, osteoporosis, and in some cases psychosis. Sellar enlargement, visual symptoms, and cavernous sinus extension are rare. Demonstrating in-creased concentration of plasma and urinary cortisol makes the diagnosis. Plasma cortisol levels are not suppressed by the administration of small doses of dexamethasone.

The fi rst line of treatment is transsphenoidal removal of the adenoma. Radiotherapy can be an alternative in patients who failed surgery or if surgery is not possible. Another op-tion is bilateral adrenalectomy with steroid replacement. 19

Gonadotropin-secreting adenoma

Gonadotropin-secreting (luteinizing hormone [LH], follicle-stimulating hormone [FSH]) adenomas are usually clini-cally silent. Symptoms may arise in cases of large tumors with chiasmal compression or hormonal defi ciency of one or more hormones due to compression of the normal pitu-itary gland.

Thyrotropin-producing adenoma

Thyrotropin-secreting adenomas are the rarest type of adenomas. Patients usually present with hyperthyroidism (palpitations, tremor, weight loss, and sweating) and goiter in combination with compression symptoms. Patients can be treated with somatostatin analogues, while surgery is reserved in cases of chiasmal compression.

Pituitary Apoplexy

Pituitary apoplexy is caused by a pituitary hemorrhage or a hemorrhage in an adenoma causing sudden visual loss with headache and vomiting.

■ Goals of Surgery

A management algorithm based on the “European Position Paper on the Endoscopic Management of Tu-mours of the Nose, Paranasal Sinuses, and Skull Base” is presented in Fig. 38.1 . 19 The goal of surgery is always complete tumor removal (and subsequent normalization

Hypersecreting Adenomas

Prolactinoma

Prolactin-secreting adenomas (prolactinomas) are the most common type of hypersecreting adenomas. The majority of such patients are women presenting with secondary oligoamenorrhea, infertility, and (less often) galactorrhea. Men present with galactorrhea, headache, impotence, and visual abnormalities. The size of pitu-itary adenomas is usually proportional to the degree of prolactin elevation. Prolactin is under inhibitory control by dopamine from the hypothalamus; therefore, any mass eff ect in this area may produce increased prolactin levels, called the stalk eff ect (due to disruption of dopa-mine transport down the pituitary stalk). However, in such cases, prolactin levels tend to be � 100 μ g/L, while the majority of macroprolactinomas present with levels � 200 μ g/L.

The treatment of prolactinomas is primarily medical (dopamine agonists), with good results ( � 90% response rates). Dopamine agonists (bromocriptine, cabergoline) normalize prolactin levels and reduce tumor size, thereby restoring vision even in the case of large tumors with severe visual loss. 15,16 Surgery is indicated only

1. If visual fi elds fail to improve, and there is ongoing chiasmal compression despite medical treatment

2. In cases of intolerance to dopamine agonists 17

Acromegaly

Overproduction of growth hormone (GH) in adults results in deformity and thickening of the bones and soft tissues; the most striking feature is the enlargement of the nose and chin and of the hands and feet. This syndrome is called acromegaly and frequently presents in combina-tion with several endocrine disorders (hypermetabolism, diabetes mellitus). The diagnosis of acromegaly, which is often long delayed, is made on the basis of the char-acteristic clinical changes, the fi nding of elevated serum GH and insulinlike growth factor (IGF) � 1 values, and the failure of the serum GH concentration to rise in response to the administration of glucose (oral glucose tolerance test). Surgical removal is the treatment of choice for GH-producing tumors and results in biochemical cure in 75 to 95% of patients, although this is markedly lower in tumors � 2 cm or with cavernous sinus invasion. 18

The medical treatment of acromegaly includes soma-tostatin receptor ligands (SRLs), GH receptor antagonists, and dopamine agonists. SRLs can be used before and after surgery and have been shown to be moderately eff ective in tumor control and controlling GH/IGF-1 hypersecretion. Radiation therapy is usually given only as a last resort and consists of conventional or stereotactic radiotherapy. The main disadvantage is loss of pituitary function in � 50% of patients, which compares unfavorably with the rates of hypopituitarism (10–20%) after surgery.


Preoperative Planning 739

Preoperative Planning

Every patient with a sellar lesion should have a preopera-tive radiological, endocrinological, and (when indicated) ophthalmological work-up.

■ Ophthalmological Assessment

In patients with chiasmal compression, ophthalmologi-cal assessment should include a measurement of visual acuity and fi elds with the Goldman perimeter, as visual compromise necessitates rapid treatment.

■ Endocrinological Assessment

Patients with sellar nonhypersecreting lesions have po-tentially varying degrees of hypopituitarism, occasionally requiring substitution therapy. The decision to use peri-operative glucocorticoids in patients undergoing pituitary surgery can be based on the results of the preoperative screening tests. 20 If preoperative cortisol is subnormal, the patient should start with hydrocortisone replacement (15–30 mg daily) with an increase to cover surgery and the fi rst 48 hours postoperatively. Our standard perioperative

of the hormone levels) in hormone-secreting adenomas. The same goal is mostly true for nonsecreting adeno-mas and meningiomas, although patients with pressure symptoms can be improved by tumor debulking (de-compression of the chiasm in patients with hemianop-sia; cavernous sinus decompression in patients with occulomotor dysfunction and headaches). Rarely, a biopsy may be performed in case of uncertain diagnosis to plan further management. There is controversy re-garding the management of Rathke cleft cysts. However, simple drainage and subtotal cyst removal are usually eff ective with minimal risk of recurrence; the opposite is true for craniopharyngiomas, where complete resection is normally the goal of surgery except in circumstances where adherences to critical neurovascular structures preclude complete resection.

NoteSurgery is the mainstay of management for nonsecreting adenomas with compressive symptoms, as well as ACTH- and GH-producing adenomas. Patients with prolactinomas should be treated primarily medically.

!

NoteComplete surgical resection should be the aim with all hor-mone-secreting tumors. Simple drainage is usually suffi cient for Rathke cleft cysts and apoplexy; in nonsecreting adenomas, craniopharyngiomas, and meningiomas, complete resection should be balanced against the expected associated morbidity.

!

Pituitary tumors

Symptoms and Signs

Imaging MRI (contrast)

Non functioning

Neuroendocrinologist

Suprasellar(optic system compression)

Non HPR HPR>100μg/ml


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y the navigation system and be used for surgical planning, particularly with respect to tumor invasion in the cavern-ous sinus ( Fig. 38.3 ). 21 Localization of the pituitary gland is best done by following the pituitary stalk from superior to inferior on a T1-weighted axial MRI with 1-mm slices. With macroadenomas, it can be remarkably diffi cult to see the gland on contrast-enhanced T1-weighted MRI, although usually a brighter enhancing rim will provide a clue to its location. The posterior lobe of the pituitary gland can be best seen as a hyperintense signal on sagittal T1-weighted MRI without contrast. Sometimes following the enhancing pituitary stalk from the third ventricle down can help in identifying the gland. Failure to identify the gland prior to tumor removal can result in damage, or even resection, of the pituitary gland.

Identifying the optic nerves on contrast-enhanced T1-weighted MRI can be diffi cult. The contrast reduces resolution somewhat; therefore, sometimes optic nerves can be best seen on a thin-slice coronal T1-weighted MRI, without intravenous (IV) contrast ( Fig. 38.2a ).

Large adenomas or macroadenomas ( � 1 cm) are usu-ally hypo- or isointense to gray matter on noncontrast T1-weighted images and exhibit homogeneous contrast enhancement, whereas microadenomas ( � 1 cm) appear as hypointense areas compared with the normal pituitary gland and enhance only on delayed images. Macroadeno-mas frequently extend superiorly with compression of the optic chiasm. Some tumors pass through the diaphragma sellae (“dumbbell” adenomas) ( Figs. 38.2 and 38.3 ). Lateral growth into or beyond the cavernous sinus can occur ( Fig. 38.4 ), while erosion of the sellar fl oor causes anteroinferior extension into the sphenoid sinus.

regimen includes 50 mg hydrocortisone at induction of an-esthesia, 50 mg 4 dose dense (DD) for the fi rst day, 20 mg 4 DD for the second day, then return to regular replacement. Patients with normal cortisol levels preoperatively do not require perioperative replacement provided that basal cor-tisol levels are tested immediately after surgery.

■ Imaging

MRI using a pituitary protocol with delayed postcontrast images is the imaging modality of choice for patients with sellar lesions. Important anatomical structures of the sel-lar region that are visualized on MRI include the pituitary gland, optic chiasm, cavernous sinus, and intracavernous internal carotid artery (ICA). The pituitary gland has an anterior (adenohypophysis) and posterior (neurohy-pophysis) part showing signal intensity diff erences. The neurohypophysis usually has a high signal intensity on noncontrast T1-weighted MRI. The cavernous sinus lies lateral to the pituitary gland and is essentially a venous space containing the ICA and cranial nerves. The domi-nant structure within the cavernous sinus is the ICA, which, when patent, appears as a signal void on a T2-weighted coronal MRI. High-resolution MRI can demon-strate CN III (oculomotor) and CN IV (trochlear) above and lateral to the ICA. The ophthalmic division of CN V 1 (tri-geminal) and CN VI (abducens) is below and lateral to the ICA. CN V 2 (maxillary) is in the inferior part of the cav-ernous sinus ( Figs. 38.2a and 38.10a,b ). High-resolution (three-dimensional) MRI can also be incorporated into

A

B

C

a

Chiasm

Body

Anterior cerebral artery Middle cerebralartery

Superiororbital fissure

Foramen rotundumPterygoid process

Vidian canalForamen ovale

Carotid artery

Lesser wing

Greater wing

CN IICN IIICN IVCN VIV1V2

Vidian nerveV3

bFig. 38.2a, ba T1-weighted magnetic resonance imaging (MRI) after injection of contrast in a patient with a suprasellar adenoma. Note the optic chiasm/optic nerve (C) and the third cranial

nerve (CN III, B) above and lateral to the internal carotid artery (A).b Anatomy of the sella and parasellar region.


Preoperative Planning 741

CT scan provides information on paranasal bony struc-tures, including the presence of concha bullosa, and the size and septations of the sphenoid sinus. 22 Three types of sphenoid sinus have been described, depending on the degree of pneumatization. 23,24 First, the conchal type, in which the area below the sella is bony without any air cavity, is common in children before puberty. Second, the sellar type, is the most common type of sphenoid sinus and is present in 98% of adults. 23 In this type, the air cav-ity extends into the body of the sphenoid below the sella

Craniopharyngiomas present as heterogeneous masses on MRI, but the presence of calcifi cations on computed to-mography (CT) makes the diagnosis more likely ( Fig. 38.5 ). Meningiomas mostly have diff use contrast enhancement and a characteristic dural tail (contrast enhancement along the dura) on MRI ( Fig. 38.6 ).

We perform a standard CT scan of the paranasal si-nuses and the skull base for the assessment of calcifying lesions such as craniopharyngiomas, as well as for CT/MRI fusion during intraoperative navigation. A thin-slice

Fig. 38.3a–c Neuronavigation images with computed tomography (CT) and MRI fusion showing important bony, vas-cular, and neuronal structures in relation to a pituitary macroadenoma with suprasellar extension. Note the “dumbbell” sign as the adenoma extends above the sellar diaphragm.a Axial image.b Coronal image.c Sagittal image.

a, b c

a bFig. 38.4a, ba MRI in a patient who presented with hemianopsia and diplopia caused by a large adenoma compressing the optic chiasm and CN III. Note the encasement of the carotid artery on the right side (A) and the invasion of the cavernous sinus on the left (B).

b The same patient 24 hours postoperatively: The tumor was completely removed, while a small amount of dissolv-able material (Spongostan [Ethicon, Somerville, NJ]) with air is seen in the sellar cavity (C).



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Fig. 38.5a, b, ca A retrochiasmatic craniopharyngioma (A) extending into the third ventricle in a child pre-senting with delayed growth and pituitary insuf-fi ciency.b The same child 24 hours postoperatively after complete tumor removal following a pituitary transposition approach. Dissolvable material is seen in the sphenoid cavity (B).c Endoscopic view of the third ventricle after complete tumor removal.

a b

c

Fig. 38.6a–d A tuberculum sella meningioma (note the dural tail arteri-orly [A]).a Before endoscopic removal.b, c After endoscopic removal.d Endoscopic view of anterior communicating artery, optic chiasma, and anterior cerebral artery after tumor removal.

a,b c

Nasoseptal flapDecompressed chiasma

d


Anesthesia and Positioning 743

Fig. 38.7a, ba Sellar-type sphenoid sinus, with air cavity extending below the sella and posteriorly to the clivus.b Presellar-type sphenoid sinus, with pneumatization limited to the anterior sellar wall.

a b

and as far posteriorly as the clivus ( Fig. 38.7a ). Third, the presellar type, in which pneumatization is limited to the anterior sellar wall ( Fig. 38.7b ), occurs in �2% of adults.

NoteWe strongly feel that the preoperative assessment, the sur-gical indication, the choice of approach, and postoperative care should be done jointly by the neurosurgeon and the otolaryngologist in a multidisciplinary setting, including an endocrinologist and neuroradiologist.

!

Patient Information/Informed Consent

The standard procedure at the Endoscopic Skull Base Center in Amsterdam, a multidisciplinary skull base clinic, with the otolaryngologist, the neurosurgeon, and the endocrinologist present, is to discuss with the pa-tient the options available to him or her (watchful wait-ing, radiotherapy, and medical treatment as applicable), the goals of surgery (decompression or complete re-moval), and the expected outcome, including the post-operative recovery period and the risks and potential complications. We explain the role of each surgeon and discuss briefl y the technical aspects of the operation, including the use of endoscopes, intraoperative naviga-tion, and reconstruction. Nasal packing, splints, and the harvest of fascia lata (as applicable) are discussed, as well as the expected length of the hospital stay, which depends on the size of the tumor and the endocrinologi-cal profi le of the patient, and is usually 2 or 3 days in the case of small tumors when no intraoperative CSF leak or

pituitary insuffi ciency is expected. The time needed for the healing of nasal mucosa (typically 2 or 3 months) and the associated crusting expected during that period are explained. Patients are advised to refrain from stressful activities and blowing their nose for 6 weeks and to use nasal saline sprays for the fi rst 4 weeks and subsequently nasal douching. Finally, the postopera-tive follow-up schedule is planned, and postoperative imaging is outlined.

Anesthesia and Positioning

Most people with pituitary adenomas are not high risk anesthesia patients. However, there are exceptions, in-cluding those with thyrotoxicosis due to thyrotropin- secreting adenomas who are at an increased risk of tachyarrhythmias and should be treated prior to surgery. Patients with Cushing syndrome from excess ACTH pro-duction are at risk for severe hypertension and hyper-glycemia during surgery. Those with acromegaly can have airway-related complications, including obstructive sleep apnea.

Patients undergo general anesthesia with orotracheal intubation with a Foley catheter and arterial line. Pro-phylactic antibiotics (normally ceftriaxone) are given intravenously prior to surgery. Controlled hypotension with adequate analgesia and total intravenous anesthe-sia (TIVA) are favored, as they have been shown to reduce bleeding.

The patient is positioned supine in an anti-Trendelen-burg position to facilitate venous drainage and reduce mucosal bleeding. The head can be fi xated in a three-pin



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y 200 mg (total) cocaine powder in cotton buds soaked in 1:1000 adrenaline, placed in the sphenopalatine, anterior ethmoidal, and greater palatine region. (See Chapter 30 for more details.) The nose and face are prepared with chlorhexidine solution in water, and the patient is draped with the nose exposed.

Operative Steps

Traditionally, “team” surgery was defi ned as surgeons working sequentially. However, both technically as well as conceptually, this approach is not valid in extended endonasal approaches to the sella: the anatomical knowl-edge, dissection principles, and manual dexterity of all members of the team ( otolaryngologists and neurosur-geons) are required throughout the whole procedure. In practical terms, and in most of our cases, this takes the form of a “two nostrils, four hands technique” as a way of optimizing visualization and tissue handling. This so-called two nostrils-four hands technique 11 requires good collaboration between two surgeons who should be per-fectly tuned, alternating in holding the endoscope as well as providing traction and another handling two surgical instruments inside the surgical fi eld ( Figs. 38.8 and 38.9 ).

■ Sellar and Parasellar Anatomy

The average pituitary gland lies within the sella turcica, with the diaphragma sellae attached �3 mm below the tuberculum sellae, which is a double layer of dura that separates the pituitary from the brain. This layer may be incomplete, which allows tumor to erupt into the

fi xator or placed on a horseshoe cushion, depending on the neuronavigation system used, and is slightly turned to the surgeon on the right side. Placement on the horse-shoe has the advantage of intraoperative manipulation of the head. To optimize the space next to the patient, one or both arms are completely adducted with soft restraints. Depending on the potential for intraopera-tive CSF leak and need for reconstruction, the left thigh is prepared for fat or fascia lata graft harvesting. Endo-neurosurgery requires a binarial approach to allow for a two-surgeon, three- or four-hand technique. Bimanual dissection is facilitated by bilateral nasal access, as it pro-vides the necessary space for instrument manipulation, allows for dynamic movement of the scope, and improves the angle for dissection. Usually both surgeons stand on the right side of the patient, although the operating side depends on the surgeon’s dominant hand (right-handed surgeon on the right side of the patient [Fig. 38.9]). We routinely use local anesthesia and vasoconstriction with

Fig. 38.8 The two nostrils, four-hand approach is possible, even in narrow noses, as in this 11-year-old child

Fig. 38.9 Standard setting for the combined three-four hands technique.


Operative Steps 745

■ Nasal Phase

We routinely outfracture both the inferior and middle turbinates to maximize available space (see DVD/Thieme Media Center ). Any anatomical abnormalities that restrict our approach (deviated septum, concha bullosa) are treated at this stage. We do not routinely remove the middle turbinate, although, depending on available space, this may occasionally be necessary. The ostium of the sphenoid is identifi ed �1.5 cm above the nasal choanae and medial to the superior turbinate ( Fig. 38.11 ). Both sphenoid ostia are sequentially exposed. If an intraopera-tive CSF leak is expected (usually in giant adenomas or craniopharyngiomas with signifi cant suprasellar exten-sion or extension into the third ventricle), a nasoseptal fl ap is prepared. If in doubt whether a fl ap is needed, the pedicle can be prepared while the septal part of the fl ap

suprasellar space with increased risk of intraoperative CSF leak. The bony confi nes of the sella govern the direc-tion in which a tumor grows. The anterior wall, the sellar fl oor, is shared with the sphenoid sinus. The anterior wall is usually thin and therefore easily breached by an erod-ing sellar tumor. If the sphenoid septum is thick, such erosion may be prevented, and the pressure may be redi-rected superiorly through the diaphragm.

The lateral walls of the sella are the cavernous sinus and its contents.

■ Cavernous Sinus/Intercavernous Sinus

The cavernous sinus is a venous chamber within the lay-ers of the dura. The right and left cavernous sinuses are usually connected with a superior and inferior intercav-ernous sinus. Due to tumor compression, these venous anastomoses may deviate from their common loca-tion and involve the whole dura of the face of the sella. Within the cavernous sinus runs the ICA and CN VI, while CN III, CN IV, and CN V 1 course through the lateral wall. Because of its location within the cavernous sinus, CN VI is particularly vulnerable when tumors invading the cav-ernous sinus are resected ( Figs. 38.10 ).

Within the cavernous sinus, the ICA gives rise to the meningohypophysial trunk, which supplies the pituitary gland.

■ Image Guidance

We routinely use fusion CT/MRI image guidance for every sellar approach as a way to confi rm rather than to identify anatomical structures.

Fig. 38.10a, ba Anatomical dissection of the sella region. (Courtesy of Albert L. Rhoton, Jr. MD.)b Coronal cut of the hypophysis gland and the cavernous sinus. Note the location of CN III, CN IV, and CN VI in relation to the internal carotid artery (see also Fig. 38.1).

b

Pituitarygland

Sphenoid sinus

Carotid artery

CN VI

CN IV

CN III

V1

V2V3

Venousspace

a

Fig. 38.11 Identifi cation of the sphenoid ostium, medial to the superior turbinate and 1.5 cm above the choanae (*).



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all corners, as opposed to the purely tactile control pro-vided by a smaller opening. Tumors invading the cavern-ous sinus and those with large suprasellar extensions can be safely resected under direct vision; under tactile con-trol, radical resection is often deemed too risky.

NoteWide exposure of the sella facilitates visualization of its con-tents, including the normal pituitary gland, and complete dissection of the tumor around the cavernous sinuses and above the diaphragm sellae. Spending enough time on the adequate removal of bone from the face of the sella is almost always worthwhile.

!

Bone removal is typically done by thinning the bone with a coarse diamond drill and then outfracturing it. With larger tumors, bone can already be eggshell thin and can be gently removed with a dissector placed between the bone and the dura. The tuberculum sellae is typically thicker, and an osteotomy medial to the me-dial OCR has to be performed with the drill to allow bone outfracture ( Fig. 38.14 ). The temptation to remove bone with a Kerrison rongeur should at all times be resisted, especially when removing bone over the cavernous sinus or the planum sphenoidale. The dura can be very thin and easily torn when the rongeur is used to bite, instead of using it as a strong leverage to outfracture the bone.

■ Sellar Phase

In this chapter, we focus on removal of macroadenoma of the pituitary gland. Other sellar lesions, such as cra-niopharyngiomas, Rathke cleft cysts, and tuberculum

remains in place (see Chapter 41). Subsequently, and after storage of the fl ap, the sphenoidotomies are widened lat-erally, inferiorly, and superiorly to expose the sphenoid lateral recesses, the planum–tuberculum junction, and opticocarotid recesses (OCRs). If needed, the posterior ethmoidal cells are exenterated to expose the medial orbital wall and posterior cribriform plate. The anterior wall of the sphenoid is drilled down. On the nonnasosep-tal fl ap side, the nasoseptal branch of the sphenopalatine artery crosses the inferior part of the anterior sphenoid wall and has to be cauterized before drilling the anterior sphenoid wall. Adequate superior and inferior sphenoid wall removal enhances the rostrocaudal trajectory into the suprasellar and retrosellar space.

NoteOptimizing the access at the level of the anterior sphenoid wall to the level of the pterygoid plates laterally, to the fl oor of the sphenoid inferiorly, and to the planum sphenoidale/cribriform plate superiorly facilitates greatly the subsequent dissection by avoiding “sword fi ghting” of instruments and maximizing visualization.

!

The location of the intersinus septa is highly variable; however, more often than not, laterally positioned septa are attached to the bulge of the ICA and should be gen-tly drilled out rather than fractured. The mucosa over the sella is retracted laterally to avoid unnecessary mucosal bleeding and facilitate reepithelialization, unless the use of a nasoseptal fl ap is planned. At this stage, the impor-tant surgical landmarks of the sphenoid sinus are seen, including the sellar prominence in the center, the bony strut covering the superior intercavernous sinus above, the clival recess below, the carotid prominences lateral to the sella and more superiorly the optic nerves, and the medial and lateral OCRs ( Fig. 38.12 ).

■ Sphenoidal Phase

When the transition was fi rst made from the traditional microscopic transsphenoidal approach to an endoscopic approach, the surgery remained more or less unchanged (see DVD/Thieme Media Center ). Bony removal of the sella was typically a rather small quadrangle at the face of the sella, the area typically visualized with a speculum and a microscope. With growing experience, the advan-tage of larger bony removal became clear. With large tu-mors, bony removal now includes the bone covering the superior and inferior intercavernous sinus, as well as both cavernous sinuses ( Fig. 38.13 ). In the case of tumors with signifi cant suprasellar extension, the approach can be extended by removing the tuberculum sellae or planum sphenoidale. The main advantage of a larger bony win-dow is that it allows visual control of tumor resection in

S

ICA

mOCR

OC

lOCR TC

Fig. 38.12 Anatomy of the face of the sella/posterior wall of the sphenoid: IC, internal carotid artery; iOCR, lateral opti-cocarotid recess; mOCR, median opticocarotid recess; OC, optic canals; S, sella; TC, tuberculum sellae.


Operative Steps 747

a b

NoteA key point in surgery is to identify the pituitary gland on preoperative MRI prior to opening the dura of the sella, as occasionally the pituitary gland may be displaced anteriorly by the tumor and found lying immediately under the dura.

!

We prefer to make a U-shaped opening, starting by placing the horizontal cut low on the face of the sella, just above the inferior intercavernous sinus and extending laterally up to the two cavernous sinuses ( Fig. 38.15 ). The dura layer is then dissected free from the contents of the sella and retracted superiorly. In the case of a tumor with large suprasellar extension, it can be useful to open the dura all the way up to the planum sphenoidale. Prior to cutting the dura at the fold, the superior intercavernous sinus needs to be coagulated to prevent venous bleeding during or after surgery. The pituitary gland can be the fi rst structure encountered in the sella if the tumor has displaced it anteriorly. In that case, the tumor needs to be removed by dissecting the gland free from the tumor. More commonly, the gland is located in the posterosuperior corner. Subsequently, the tumor is dissected from the dura of the fl oor of the sella, and tumor removal starts with resecting the in-ferior part fi rst. The tumor is resected up to the medial walls of the cavernous sinus. When the tumor invades the cavernous sinus, it is removed preferably by suc-tion. Often what is described on MRI as cavernous sinus invasion is just compression of the medial wall of the cavernous sinus by the tumor. Brisk venous bleeding once the fi nal plug is removed marks complete tumor

sellae meningiomas, can also be resected with the sellar approach described here (see DVD/Thieme Media Center

), although the tumor removal technique can be quite diff erent ( Fig. 38.14 ).

A two- (or occasionally three-) hand dissection tech-nique is used, with the second surgeon providing visu-alization with the endoscope and facilitating dissection with the use of suction or occasionally a dissector. The main instruments used are a small suction tube, micro-surgical grasping forceps, various angled ring curets, small scissors, and dissectors.

Fig. 38.14 Removal of the tuberculum sella in a patient with an adenoma with signifi cant suprasellar and anterior skull base extension. ON, optic nerve; TS, tuberculum sella.

Fig. 38.13a, ba Ventral view of the sella taken with 0-degree endoscope through the right nostril of a patient who had previous mi-croscopic transsphenoidal surgery. The small oval is around scar tissue, showing the maximal extent of the opening with a microscopic approach. In a microscopic approach, the small oval is all that can be seen of the sella. The large oval shows

the extent of bony resection that can be performed with an endoscopic approach.b Ventral view of the sella after bone removal for recurrent nonfunctioning pituitary macroadenoma. Scar tissue from the previous microscopic approach can be seen centrally in the sella.



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take a 30-degree scope and inspect all corners of the sella for tumor remnants.

Dura closure depends on the presence of CSF leakage during surgery. When there is no intraoperative CSF leak, the face of the sella is closed with dissolvable artifi cial materials, such as Spongostan and tissue glue. When CSF leak is demonstrated during surgery, a watertight clo-sure is mandatory (see Chapter 41). In the case of a high-fl ow leak (open third ventricle, suprasellar cistern), we routinely use as underlay fascia lata and seal with small pieces of fat, with a pedicled nasoseptal mucosa fl ap as overlay, which is harvested during the nasal phase of the surgery (see DVD/Thieme Media Center ). In the case of a low-fl ow leak (small arachnoid breaches), there is typi-cally no need for a dura substitute (underlay). The fl ap is carefully placed over the dura defect, with the rims cov-ered with tissue glue ( Fig. 38.18 ). The fl ap is supported with antibiotic and steroid-impregnated Vaseline gauze (Jelonet). We do not routinely use nasal packs, although we place them (as well as septal splints) when there has been a nasoseptal fl ap reconstruction.

removal from the cavernous sinus. This bleeding can easily be controlled with a hemostatic agent, such as FlowSeal (Baxter Healthcare SA, Zurich, Switzerland). In the case of a tumor with large parasellar extension (lateral to the carotid), we fi nd useful the complete mobilization of the carotid through the removal of the overlying bone.

Up to this point, extracapsular tumor removal is usu-ally possible. When removing the more superior portions of the tumor, extracapsular tumor resection may not be possible, or it may be deemed too risky. The tumor is re-moved from the superior corners and middle area while attempting to preserve the pituitary gland ( Fig. 38.16 ). Usually the structure of the gland is fi rmer than that of the tumor, and the yellow/orange color of the gland can be used to discern it from the tumor. With macroad-enomas, the diaphragma sellae is usually very thin or absent. In the last stage, the tumor is removed from the diaphragma sella, and complete tumor removal is marked by symmetrical descending of the suprasellar arachnoid or diaphragma sellae ( Fig. 38.17 ). It can be very useful to

Fig. 38.15 After removal of the eggshell-thin face of the sella in a patient with a large prolactinoma, a small blade is used to perform a U-shaped incision on the dura.


Complications 749

Complications

Endoscopic transsphenoidal surgery of pituitary tumors is a relatively safe operation with low morbidity and mortality. In a large series (including the preendoscopy era), mortality was typically � 0.6%, with � 95% of pa-tients going home after surgery. 25–28 In transsphenoidal pituitary surgery, a relation between experience and complications was demonstrated, with better outcomes in large-volume departments ( � 25 cases/y), and by sur-geons with a larger case load ( � 8 cases/y). A learning curve for the endoscopic approach is well recognized, and this supports subspecialization. 11

The most common complications of resection of mac-roadenomas of the pituitary gland are

• CSF leak • Loss of pituitary function (one or more hormones):

usually transient diabetes insipidus, rarely permanent complete loss of pituitary function

• Nasal complications (chronic or acute recurrent rhino-sinusitis, epistaxis, septal perforation, nasal crusting, anosmia)

• Neurologic complications (rare) • Transient CN VI palsy • Persistent or increased visual fi eld defects • Intracerebral hemorrhage • Stroke due to vascular injury (brainstem) • Nonradical tumor resection (with a chance of tumor

recurrence) • Continuation of overproduction of excess hormone

(when hormone-producing tumor)

Of course, any comparison of complication data must take into account the size and location of the tumor, as well as the radicality of excision. The chance of intraoperative CSF leak and loss of pituitary function is higher when at-tempting radical resection of bigger tumors with signifi cant suprasellar extension. Overall, the incidence of temporary diabetes insipidus is at the level of 10 to 20%, and perma-nent loss of pituitary function occurs in � 5% of patients.

Fig. 38.16 The fi nal remnants of the adenoma are removed under the diaphragm (*, tumor being removed).



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A recent meta-analysis10 comparing the occurrence rate of CSF leak between microscopic and endoscopic approaches to the sella showed that the rate of intraop-erative CSF leak did not diff er signifi cantly between the endoscopic and microscopic group, although there was a trend for higher CSF leak in the endoscopic group (relative risk [RR] 0.99 [95%], confi dence interval [CI] 0.92–1.05; P � .69; 19.5% vs 14.4% in the endoscopic and microscopic group, respectively).

The rate of postoperative CSF leak requiring operative repair was also higher in the endoscopic group without the diff erence between the two study groups being sta-tistically signifi cant (RR 1.98 [95%], CI 0.85–4.63; P � .11, 4,5% vs 2.1% in the endoscopic and microscopic group, respectively) ( Fig. 38.19 ).10

Regarding postoperative diabetes insipidus (temporary or permanent), the number of patients with this adverse eff ect was considerably lower in the endoscopic than in the microscopic group (RR 1.14 [95%], CI 1.04–1.24;

Fig. 38.17 After complete tumor removal, the diaphragma sella has descended. *, diaphragma sella.

Fig. 38.18 Closure with the use of a vascularized nasosep-tal (Haddad) fl ap (in the case of a cerebrospinal fl uid [CSF] leak). * nasoseptal fl ap.


Postoperative Care 751

Performing a baseline MRI within the fi rst 24 hours after extended approaches is useful for the assessment of tumor removal without the artifacts that may complicate interpretation when healing takes place a few months later. The 24-hour MRI can also demonstrate the degree of pneumocephalus and the vitality of the nasoseptal fl ap, so we use it routinely for all extended sellar approaches. For simple adenomas, the 3-month postoperative MRI is usually suffi cient.

P � .003; 15% vs 28% in the endoscopic and microscopic group, respectively).

Interestingly, the nasal morbidity of the endo-scopic approach is less compared with the traditional microscopic approach. 24 The use of a nasoseptal fl ap is associated with additional nasal trauma, and indeed, its harvesting may damage the olfactory epithelium, result-ing in hyposmia or anosmia. Our experience has been that overall, nasal mucosa tends to heal after a period of �3 months, and nasal morbidity is minimally increased with the use of the nasoseptal fl ap. Indeed, in a study comparing extended approaches to the skull base with standard pituitary surgeries using Rhinosinusitis Out-come Measure 31 (RSOM-31) to measure nasal quality of life, we found no signifi cant increase in nasal morbidity with the use of the nasoseptal fl ap, with the exception of slightly worse sense of smell.29 However, signifi cant dif-ferences were found between secreting and nonsecreting tumors regarding most aspects of patients’ quality of life postoperatively ( Fig. 38.20 ).

Postoperative Care

Early recognition and management of postoperative complications are crucial in the treatment of patients with pituitary lesions. The main objective is screening for disorders of water balance and neurologic complications. Immediately after surgery when the patient is awake, they are assessed with respect to visual functions (visual fi elds, acuity, and ocular motility). If these are impaired, immediate imaging (CT or MRI) should be performed and sometimes reexploration.

Fig. 38.19 Meta-analysis of endoscopic versus microscopic approaches to the sella: comparison of CSF leak rates. (From Gou-dakos JK, Markou KD, Georgalas C. Endoscopic versus microscopic trans-sphenoidal pituitary surgery: a systematic review and meta-analysis. Clin Otolaryngol 2011;36(3):212–220.)

Study or Subgroup

Total (95% Cl) 333 366 100.0% 1.98 [0.85, 4.63]

Endoscopic Microscopic Risk Ratio Risk Ratio

White et al.Casler et al.Jain et al.Neal et al.O'Malley et al.Higgins et al.Duz et al.Graham et al.D'Haens et al.

0.01Total eventsHeterogeneity: Chi2 = 4.56, df = 4 (P = .34); l2 = 12%Test for overall effect: Z = 1.59 (P = .11) Favors endoscopic Favors microscopic

0.1 1 10 100

000010833

15 8

200010140

501510352519536660

50151015252940

12260

0.20 [0.01, 4.06]Not estimableNot estimableNot estimable

1.00 [0.07, 15.12]Not estimable

6.04 [0.79, 46.34]1.39 [0.32, 6.01]

7.00 [ 0.37, 132.66]

200420052007200720082008200820092009

31.5%

12.6%

14.3%35.3%

6.3%

Events Total Weight YearM-H, Fixed, 95% Cl M-H, Fixed, 95% ClTotalEvents

Fig. 38.20 Signifi cant diff erence in emotional quality of life (QOL), sleep-related QOL, and total Rhinosinusitis Outcome Measure 31 (RSOM-31) scores were found between patients who had undergone removal of secreting versus nonsecret-ing adenomas, refl ecting the diff erences in the nature of the respective diseases.

3.00

2.00

1.00

0.00NasalQOL

PracticalQOL

SleepQOL

GeneralQOL

TotalRSQMQOL

Error Bars: 95% Cl

Mea

n

Hormonesecreting

NoYes



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y usually stop sweating and have better control of their diabetes mellitus postoperatively. To check if patients with Cushing disease are cured, cortisol levels the next morning in the absence of steroid replacement will usually give the answer. Patients are then dependent on steroid replacement therapy, which should be started immediately.

Outcomes

In general, the endoscopic approach to the sella is safe and well tolerated. 31 Patients typically do well imme-diately after surgery, and the length of hospital stay is primarily determined by the endocrinological outcome (primarily defi ned by the presence of diabetes insipidus). In the case of an intraoperative CSF leak, a few days of bed rest are recommended to assist in healing and prevent the displacement of the nasoseptal fl ap.

It is our impression that with the improved visualiza-tion associated with endoscopic (extended) approaches, complete tumor removal has become more common than in the microscopic era. Indeed, a meta-analysis suggests 70 to 80% gross tumor removal and �60 to 80% normalization of hormone levels in secreting tumors. 6 Although these results are not dramatically diff erent from surgical results with a microscopic approach, the levels of complications and patient discomfort are sig-nifi cantly less. 32 In a series of 91 patients with a variety of sellar and parasellar tumors, we had an 81.3% rate of gross tumor removal (74/91). Recovery of visual fi eld defects is more common than not. In a recent large se-ries, 88% of patients had improved visual disturbances at discharge, 31 whereas in our series, 35 out of 45 pa-tients with visual defects had an improvement postop-eratively. In a recent meta-analysis, 7 the initial remission rate of hypersecretion of functioning adenomas was not signifi cantly diff erent between the endoscopic and the microscopic group, although there was a trend in favor of endoscopy (OR 1.34 [95%], CI 0.73–2.47; P � .35; 66% remission rate in the endoscopic group vs 60% in the mi-croscopic group) ( Fig. 38.21 ).

In the same meta-analysis, 7 the proportion of patients with gross complete tumor removal was not signifi -cantly diff erent between the endoscopic and microscopic group, although slightly in favor of endoscopy (OR: 0.83 [0.52–1.33], P � .44; 71% removal rate in the endoscopic group versus 69% in the microscopic group) ( Fig. 38.22 ). The rate of patients with preoperative visual impairment (51 patients in the endoscopic group and 82 in the mi-croscopic group) that achieved visual improvement after the surgical procedure was not signifi cantly diff erent be-tween the two study groups (OR 0.81 [95%], CI 0.45–1.46; P � .48; 53% improvement rate in the endoscopic group vs 55% in the microscopic group).

If nasal packs are in situ, it may be diffi cult to as-sess for CSF leak. However, clinical confi rmation of CSF (with or without laboratory tests) necessitates prompt management.

Nausea, vomiting, and headaches are frequent post-operative complaints and can be treated individually. Pain, especially headache, is another frequent complaint in the postoperative period requiring analgesics. Patients are covered with antibiotics as long as nasal packs are in situ, although many experts recommend doing so only in the case of rhinosinusitis. 28 Patients are instructed not to blow their nose. After the nasal packs have been removed, patients are instructed to perform saline irrigations for about 6 weeks. Nasal toilette, including gentle removal of crusts, is done at the outpatient clinic after 10 days and then as needed.

■ Disorders of Water Balance

The most common endocrine disturbance requiring management in the postoperative period is diabetes in-sipidus, usually transient but rarely permanent. 29,30 Pa-tients with diabetes insipidus have an increased urine volume with lowered concentration (hypotonic poly-uria), excessive thirst, electrolyte disturbances (hyper-natremia), and dehydration. Most patients have intact thirst mechanisms and therefore are able to increase fl uid intake. Treatment should be considered when hy-pernatremia and hyperosmolarity occur. The specifi c treatment of diabetes insipidus consists of a synthetic analogue of ADH, desmopressin (DDAVP). When DDAVP is administered, close monitoring of urine output and serum electrolytes is necessary to prevent overshoot hyponatremia, which can cause confusion, epilepsy, and even death.

■ Hypopituitarism

In patients with preoperative hypocortisolism or ex-pected insuffi cient ACTH release upon stress, cortico-steroid therapy should be started at surgery. In these patients, hydrocortisone is typically tapered down and continued in physiologic doses after surgery until proper testing can be done. Postoperative endocrine function of the pituitary gland should be evaluated 4 to 6 weeks after surgery, regardless of the patient’s preop-erative endocrine status. Most patients (90–95%) with normal pituitary function retain this postoperatively, and about one-quarter of the patients with preopera-tive hypopituitarism normalize postoperatively. 28 Pa-tients with hypersecreting tumors such as acromegaly


Outcomes 753

Study or Subgroup

Total (95% Cl) 92 92 100.0% 1.34 [0.73, 2.47]

Endoscopic Microscopic Odds Ratio Odds Ratio

Cho et al.Jain et al.D'Haens et al.

0.01Total eventsHeterogeneity: Chi2 = 1.70, df = 2 (P = .43); l2 = 0%Test for overall effect: Z = 0.93 (P = .35)

Favors microscopic Favors endoscopic0.1 1 10 100

149

38

61 55

169

30

221060

221060

0.66 [0.18, 2.36]1.00 [0.05, 18.57]

1.73 [0.83, 3.58]

200220072009

32.8%5.1%

62.1%


Fig. 38.21 Meta-analysis of endoscopic versus microscopic approaches to the sella: comparison of tumor remission rates (secreting adenomas). (From Goudakos JK, Markou KD, Georgalas C. Endoscopic versus microscopic trans-sphenoidal pituitary surgery: a systematic review and meta-analysis. Clin Otolaryngol 2011;36(3):212–220.

surgery or tumor recurrence. Tumors invading the cav-ernous sinus may need radiotherapy to be controlled. In some patients surgery is associated with a higher risk due to comorbidity, and radiotherapy may be the treatment of choice.

Conventional radiotherapy is generally 45 to 50 Gy in total, fractionated in 5 to 6 weeks.

Higher radiation doses are associated with increased toxicity, particularly of the optic system and pituitary gland. The proximity of the (radiosensititve) optic nerves to the pituitary gland limit the use of stereotac-tic techniques. However, due to high-resolution MRI and improved targeting techniques, stereotactic tech-niques are becoming more popular. For Cushing disease and acromegaly, a small series showed a 50% remission rate, whereas in nonsecreting adenomas, there was 90% tumor control. 33 In 20 to –40% of patients, loss of pitu-itary function occurs after radiotherapy. In another study, stereotactic radiosurgery proved to be well tolerated and reasonably eff ective treatment for residual Cushing adenomas. 34

Patients with panhypopituitarism are unlikely to im-prove after surgery, and patients with normal pituitary function retain their normal function in ~80% of the cases ( Fig. 38.23 ). In patients with preoperative pituitary dys-function, about one-third improve and one-third worsen after surgery. The results of two meta-analyses support the safety and short-term effi cacy of endoscopic pituitary surgery. 6,7 Our quality of life study on patients undergoing removal of secreting and nonsecreting adenomas showed that the nature of the tumor (secreting versus nonsecret-ing) has the greatest impact on the outcome and quality of life (see Fig. 38.20 ).

■ Radiotherapy

Although pituitary adenomas are relatively sensitive to radiation, transsphenoidal surgery and/or medical treat-ment is the primary treatment for these tumors. Radia-tion therapy is mostly reserved for residual tumor after

Study or Subgroup

Total (95% Cl) 151 233 100.0% 0.83 [0.52, 1.33]

Endoscopic Microscopic Odds Ratio(Non-event) Odds Ratio(Non-event)

Casler et al.Neal et al.Jain et al.Higgins et al.Duz et al.O'Malley et al.Graham etal

0.01

Total eventsHeterogeneity: Chi2 = 3.42, df = 6 (P = 0.75); l2 = 0%Test for overall effect: Z = 0.77 (P = .44) Favors microscopic Favors endoscopic

0.1 1 10 100

1011

517151436

108 161

1210

524201773

15141019282144

151510294022

102

2.00 [0.38, 10.51]0.55 [0.10, 2.89]1.00 [0.17, 5.77]0.56 [0.10, 3.25]0.87 [0.33, 2.28]1.70 [0.44, 6.55]0.56 [0.23, 1.35]

2005200720072008200820082009

5.2%9.9%6.5%9.3%

23.1%8.5%

37.4%


Fig. 38.22 Meta-analysis of endoscopic versus microscopic approaches to the sella: comparison of gross resection rates.



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y 2. Which of the following statements regarding prolacti-nomas is/are correct? a. The presence of elevated prolactin levels and a

hypophysial lesion is diagnostic of prolactinoma. b. Prolactinomas should be treated surgically when

they cause chiasmal compression. c. Prolactinomas rarely respond to medical treatment. d. Prolactinomas are treated primarily with dopamine

agonists. e. Prolactinomas occur more often in men.

3. Surgical management of hypophysial tumors a. Should always include complete excision b. In the case of craniopharyngiomas is facilitated by

the presence of a well-defi ned capsule c. Can be very diffi cult in the case of craniopharyngio-

mas if the capsule is adherent to critical neurovas-cular structures

d. Typically includes debulking in the case of hor-mone-producing adenomas

e. Is never indicated in the case of tumors compress-ing the optic nerve

4. Which of the following statements regarding the anat-omy of the sella region is/are correct? a. There are no anastomotic veins between the two

lateral cavernous sinuses. b. The sixth cranial nerve (CN VI) lies lateral to the inter-

nal carotid artery (ICA), outside the cavernous sinus. c. CN III, CN IV, and CN VI run inferomedially to the ICA. d. CN VI is the only cranial nerve lying within the

cavernous sinus, which places it at risk during dissection of tumors with cavernous extension.

e. The nerves within the cavernous sinus are not visible on magnetic resonance imaging.

5. Endoscopic approaches to the sella for adenomas a. Have generally worse outcomes compared with mi-

croscopic approaches b. Are associated with lower rates of complete tumor

removal c. Result in worse nasal-related quality of life d. Cannot be used for tumor extending above the sella

or tumor invading the cavernous sinus e. Can be extended via the transplanum, transtuber-

culum, or transpterygoid approach for more exten-sive tumors

References

1. Oostra A, van Furth W. Georgalas C. Extended endoscopic en-donasal skull base surgery: from the sella to the anterior and posterior cranial fossa. ANZ J Surg 2012;82(3):122–130

2. Guiot G, Rougerie J, Fourestier M, et al. Une nouvelle technique endoscopique: Explorations endoscopiques intracrâniennes. Presse Med 1963;72:1225–1231

3. Jankowski RD, Auque J, Simon C, Marchal JC, Hepner H, Way-off M. Endoscopic pituitary tumor surgery. Laryngoscope 1992;102(2):198–202

Key Points

• A true multidisciplinary approach (including outpa-tient clinics, patient selection, planning of approach, the operation, and postoperative care) can improve safety and overall quality of care.

• In cases of pituitary adenomas, screening for high prolactin levels preoperatively is mandatory, as their detection is diagnostic of prolactinomas, which should be initially managed medically, even in the presence of severe pressure symptoms.

• Surgical removal is the treatment of choice for GH- and ACTH-producing adenomas, as well as for nonsecreting adenomas and craniopharyngiomas presenting with mass eff ect.

• For large tumors or tumors with suprasellar and cavernous sinus extension, complete drill-out of the anterior sphenoid wall and the face of the sella (extending, as required, to the tuberculum sella and planum sphenoidale) is vital.

• Compared with traditional transsphenoid approaches, endoscopic approaches to the sella are associated with higher rates of complete tumor removal, albeit at a cost of (potentially) higher rates of CSF leak.

• The use of vascularized nasoseptal fl aps has im-proved outcomes for signifi cant skull base defects associated with extended endonasal approaches.

Review Questions

1. The most c ommon tumor of the sella region is a. Rathke cleft cyst b. Meningioma c. Hypophysial adenoma d. Craniopharyngioma e. Metastatic tumor

Fig. 38.23 Endoscopic view of the sphenoid 6 weeks after re-moval of a posterior skull base chordoma. Note the complete healing of the fl ap.


Review Questions 755

21. Wolfsberger S, Ba-Ssalamah A, Pinker K, et al. Application of three-Tesla magnetic resonance imaging for diagnosis and sur-gery of sellar lesions. J Neurosurg 2004;100(2):278–286

22. van Lindert EJ, Ingels K, Mylanus E, Grotenhuis JA. Varia-tions of endonasal anatomy: relevance for the endoscopic endonasal transsphenoidal approach. Acta Neurochir (Wien) 2010;152(6):1015–1020

23. Wang J, Bidari S, Inoue K, Yang H, Rhoton A Jr. Extensions of the sphenoid sinus: a new classifi cation. Neurosurgery 2010;66(4):797–816

24. Hammer G, Radberg C. The sphenoidal sinus: an anatomical and roentgenologic study with reference to transsphenoid hy-pophysectomy. Acta Radiol 1961;56:401–422

25. Cappabianca P, Cavallo LM, de Divitiis E. Endoscopic endonasal transsphenoidal surgery. Neurosurgery 2004;55(4):933–940, discussion 940–941

26. Barker FG II, Klibanski A, Swearingen B. Transsphenoidal sur-gery for pituitary tumors in the United States, 1996-2000: mortality, morbidity, and the eff ects of hospital and surgeon volume. J Clin Endocrinol Metab 2003;88(10):4709–4719

27. Murad MH, Fernández-Balsells MM, Barwise A, et al. Outcomes of surgical treatment for nonfunctioning pituitary adenomas: a systematic review and meta-analysis. Clin Endocrinol (Oxf) 2010;73(6):777–791

28. Graham SM, Iseli TA, Karnell LH, Clinger JD, Hitchon PW, Green-lee JD. Endoscopic approach for pituitary surgery improves rhino-logic outcomes. Ann Otol Rhinol Laryngol 2009;118(9):630–635

29. Georgalas C, Badloe R. van Furth W, Reinartz S, Fokkens W. Quality of life in extended endonasal approaches for skull base tumors. Rhinology 2012;50(3)

30. Dumont AS, Nemergut EC II, Jane JA Jr, Laws ER Jr. Postop-erative care following pituitary surgery. J Intensive Care Med 2005;20(3):127–140

31. Hensen J, Henig A, Fahlbusch R, Meyer M, Boehnert M, Buch-felder M. Prevalence, predictors and patterns of postoperative polyuria and hyponatraemia in the immediate course after transsphenoidal surgery for pituitary adenomas. Clin Endocri-nol (Oxf) 1999;50(4):431–439

32. Kristof RA, Rother M, Neuloh G, Klingmüller D. Incidence, clinical manifestations, and course of water and electrolyte metabolism disturbances following transsphenoidal pituitary adenoma surgery: a prospective observational study. J Neuro-surg 2009;111(3):555–562

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38 endoscopic approach to the sella ronald b. willemse ......pituitary adenomas are by far the most...

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