Treatment of Craniopharyngioma: Transcranial Approach

Fig. 6.1

This was a case of a 7-year-old boy. The tumor cyst expands to the mid-lower portion of the clivus. The operation uses a lateral fissure transtentorial approach. The posterior fossa tumor is fully exposed through the cerebellar hiatus. The schematic diagrams in the black box in the upper right corner show that the bone window is enlarged backwards to expose the posterior tumor part (gray shadow in the pictures). (a) Intraoperative picture showed the anatomy around right side of the cerebellar hiatus; (b, c) pre- and postoperative MR sagittal images. (1) Right-side ICA, (2) optic chiasm, (3) right-side oculomotor nerve, (4) tentorial margin, (5) basal artery, (6) tumor exposed through the cerebellar hiatus

6.3.2 The Midline Approaches

The midline approach mainly includes the frontobasal anterior interhemispheric approach and the interhemispheric transcallosal approach. Some scholars advocate the removal of the craniopharyngioma that invades the third ventricle through the transcallosal approach. However, the authors believe that this approach is difficult to dissect the tumor at the original site of infundibular tuberculum, so it is not described in this atlas.

The following focuses on the surgical techniques in the frontobasal anterior interhemispheric approach:

When the frontobasal anterior interhemispheric approach is used, the exposure of the tumor is mainly through two major surgical spaces: the prechiasmatic space and the lamina terminal space.

In this chapter, we mainly discuss two major surgical techniques in frontobasal anterior interhemispheric approach: (1) drilling of tuberculum bone to increase prechiasmatic space and intrasellar tumor exposure; (2) detachment of anterior communicating artery to increase space at the lamina terminal.

6.3.3 Increase Intrasellar Tumor Exposure by Drilling Bone at the Tuberculum Sellae

The prechiasmatic space is sometimes narrow in craniopharyngioma. Some patients belong to prefixed optic chiasm (the short optic nerve, anatomical variation), and more patients are due to the retrochiasmatic tumor (type T tumors). Drilling the bones of the tuberculum sellae and the sphenoidal platform can increase the space for surgical manipulation and reduce the traction on the optic chiasm. More importantly, through bone removal, the intrasellar tumor can be exposed under direct vision. It is particularly meaningful for the removal of type Q tumor (subdiaphragmatic CP), which can improve the total resection rate and of the possibility of pituitary stalk preservation (Fig. 6.2).


Fig. 6.2

The picture shows the surgical procedure for tuberculum sellae removal to increase exposure of the intrasellar tumor. This technique was used in a patient with a 3-year-old boy who harboring a type Q craniopharyngioma. Although this type of tumor is suitable for endoscopic transsphenoidal transtuberculum approach, we used a transcranial anterior interhemispheric approach. By removing bone at the tuberculum sellae, the tumor was totally removed while retaining the continuity of the pituitary stalk and neurohypophysis. The left two columns showed the bone removal and the procedure to dissect tumor along the tumor boundary, as well as the procedure repairing the sellae bone defection. Right column is the MR scan of the child before and after surgery. As to show the reservation of the pituitary stalk, we specially selected the sagittal sequence which clearly shows the structure of the pituitary stalk (white arrow on the figure i). (a) After tumor exposure through anterior interhemispheric fissure, a curved incision was made on the dual covering tuberculum sellae, (b) after drilling of the bone of tuberculum sellae, an incision was made longitudinally at the dural fold to expose the tumor boundary underneath diaphragm. (c) The tumor was separated along the interface between the tumor wall and the dura mater (dilated diaphragm), which ensures complete resection of the tumor and preservation of the pituitary stalk fibers that fuse with the dilated diaphragm, (d) the picture showed the thinned and dilated pituitary stalk, diaphragm, and intrasellar pituitary gland and neurohypophysis after tumor resection. (e) Bone defect at the sella was repaired by using a small piece of autologous muscle, (f) dura defect of the diaphragm was covered with artificial dura to prevent possible recurrence of the tumor from expanding intracranially. (gj) Pre- and postoperative MR images showed total tumor removal and the preservation of the pituitary stalk

6.3.4 Division of the Anterior Communicating Artery to Exposure of Cistern at the Lamina Terminal

Lamina terminal space is the main corridor for T-type craniopharyngioma through the anterior interhemispheric approach. The lamina terminal is often crowded by the blood vessels of the anterior communicating artery complex. Therefore, dividing of AcoA becomes the choice. Dividing of the artery will provide adequate exposure of the lamina terminal space, making the surgical manipulation more convenient and safer (Fig. 6.3).


Fig. 6.3

This was a case of a 27-year-old male patient with craniopharyngioma. The left pictures were the preoperative sagittal and coronal MR scan (a, b). The intraoperative pictures showed the structure of the lamina terminal cistern after the longitudinal fissure is opened. Division of the anterior communicating artery provided a sufficient surgical space (cf). The right pictures showed the postoperative sagittal and coronal MR scans suggesting total tumor resection, and the lateral wall of the third ventricle was preserved (g, h)

Because of the difference in anatomical development, the vascular architecture of the anterior communicating artery complex is diverse (Fig. 6.4). Therefore, it is important to evaluate the vascular structure of the anterior communicating artery before and during the operation for the division of the artery.


Fig. 6.4

The differences in anatomical development of the anterior communicating artery complex in patients with craniopharyngioma

The evaluation methods mainly include: (1) preoperative angiography to understand the development of bilateral A1 and A2 segments and the morphology of the anterior communicating artery; (2) intraoperative microscopic exploration of the development of bilateral anterior cerebral arteries; (3) intraoperative experimental blockade using temporary aneurysm clip, and the blood supply of bilateral A2 segments and the perforating vessels were observed. If necessary, intraoperative phthalocyanine green angiography is a useful method (Figs. 6.5 and 6.6). It is worth emphasizing that dividing of anterior communicating artery is not a necessary step in the treatment of T-type craniopharyngioma through the trans-laminal terminal approach. In addition to assessing its feasibility, the growth characteristics of the tumor itself are more important factor. In the authors experience, only those cases where the tumor is located in a high position in the direction of the third ventricle (for example, 2/3 of the tumor exceeds the anterior communicating artery complex, the tumor significantly exceeds the anterior commissure, etc.) are the potential indication of the artery division.


Fig. 6.5

This was a case of a 34-year-old man with recurrent craniopharyngioma. After temporary blockage of the anterior communicating artery (c), the indocyanine green angiography showed that bilateral A1 and A2 were well filled (d). The ascending pictures showed the extent of the laminal terminal cistern before and after the division of the anterior communicating artery (a, b). Division of the vessel provides adequate exposure of the lamina terminal cistern


Fig. 6.6

This was a case of a 5-year-old girl with craniopharyngioma. Intraoperative findings showed the dual trunk anterior communicating artery. The right pictures showed the filling of the indocyanine green angiography before and after division of the anterior communicating artery

6.4 Illustrate Cases

Here, we will discuss three types of tumors (type QST), which were removed using transcranial approaches; the surgical procedures and techniques for each type of tumor will be described and illustrated.

6.4.1 Type Q Case 1

Medical History

This was the case of a 9-year-old girl with a 12-month history of headache and decreased vision for 1 month. Her height was 115 cm, which is lower than average for her age and sex by 2 SD, and she was under the third percentile of average height for Chinese girls. Endocrinological examination revealed hypo-thyroxine and growth hormone axis and increased levels of prolactin (31 ng/μL).

Analysis Before Surgery

The tumor was a typical type Q tumor, and the patient’s primary complaint was vision disturbance, and she presented with growth retardation.


Surgical consideration: Type Q tumor growth began below the diaphragm and arachnoid. The suprasellar part was covered by the diaphragma sellae (DS) and arachnoid above the DS, and therefore this kind of tumor is considered the optimal tumor type for the transsphenoidal approach. However, there are several difficulties associated with selection of the transsphenoidal approach for the management of this type Q tumor (Fig. 6.7).

  1. 1.

    The suprasellar part of the tumor breaks through the diaphragma sellae into the anterior cranial fossa, which might present a significant challenge to GTR.


  2. 2.

    The PS always inflates and fuses with the tumoral cystic walls. The absence or interruption of the PS is very often associated with posterior pituitary gland anomalies and hormonal dysfunction. As a result, these tumors are difficult to treat surgically with the transsphenoidal approach with preservation of the PS and pituitary function.



Fig. 6.7

Presurgical axial (a), sagittal (b), and coronal (c) studies revealed a large intra- and suprasellar, predominantly cystic mass with enlargement of the pituitary fossa and a rounded, symmetrical cystic suprasellar extension; on the sagittal and axial views, the suprasellar tumor cyst had expanded anteriorly to the anterior cranial fossa. No obstructive hydrocephalus was observed on presurgical radiological images

The midline interhemispheric approach was selected for gross total or maximum possible safe resection and to maintain the intactness of normal nervous tissues, especially the infundibulum-pituitary stalk tract. The ultimate goal of surgery is to pursue a certain quality of life while removing the tumor, specifically the endocrine function dominated by the hypothalamic-hypophyseal axis.

The operative steps involving craniotomy utilized for the removal of type Q craniopharyngiomas can be summarized as follows: (1) standardized skull base craniotomy (frontobasal interhemispheric craniotomy), (2) separation of the tumor from suprasellar structures and the stretched, attenuating DS, (3) resection of the bone at the tuberculum sellae to provide direct vision on the intrasellar tumor portion, (4) T-shaped incision of the elevated DS, and (5) tumor dissection along the true capsule while attempting to preserve the neurohypophysis and continuity of the PS.

Intraoperative Findings

Figures 6.8, 6.9, 6.10, 6.11, 6.12, 6.13, 6.14, and 6.15.


Fig. 6.8

After careful dissection of the anterior interhemispheric cistern, the planum sphenoidale, bilateral optic nerves, and prechiasmatic cistern were exposed. The tumor was dissected mainly through the prechiasmatic space. Dura mater was arc-shapely incised to remove the bone at the planum sphenoidale and tuberculum sellae and expose the intrasellar space. (1) Dual flap of the planum sphenoidale, (2) bone of the planum sphenoidale, (3) tumor, (4) bilateral olfactory nerves


Fig. 6.9

A high speed drill was used to remove the bone at the planum sphenoidale in order to expose the intrasellar tumor portion. (1) Dual flap of the planum sphenoidale, (2) bone of the planum sphenoidale, (3) tumor, (4) bilateral olfactory nerves


Fig. 6.10

After bone removal, the dural fold anterior to the pituitary fossa was exposed. (1) Dual fold of the planum sphenoidale, (2) sphenoid sinus mucosa, (3) tumor, (4) bilateral olfactory nerves


Fig. 6.11

A “T-shaped” incision was made on the diaphragm to expose the tumor wall underlining the diaphragmatic cover. (1) Dual fold of the planum sphenoidale, (2) sphenoid sinus mucosa, (3) tumor wall, (4) bilateral olfactory nerves


Fig. 6.12

After careful dissection, the boundary of the intrasellar tumor was identified; there was thinning membranous separation (black asterisk) between the stretched diaphragm and tumor wall, considered to be the remnant of the pituitary gland. (1) Dual fold of the planum sphenoidale, (2) tumor, (3) sphenoid sinus mucosa, (4) bilateral olfactory nerves


Fig. 6.13

The intrasellar tumor portion was dissected along the real tumor cystic wall to facilitate GTR and to preserve the pituitary stalk. (1) Dual fold of the planum sphenoidale, (2) tip of the stripper, (3) sphenoid sinus mucosa, (4) intrasellar tumor wall


Fig. 6.14

The distal portion of the PS diverged and fused with the upper posterior part of the tumor capsule and elevated diaphragma sellae (DS). (1) Diaphragma sellae, (2) proximal part of the PS, (3) left optic nerve, (4) Liliequist membrane


Fig. 6.15

After total tumor removal, continuity of the hypothalamus–pituitary stalk axis was preserved. The intact proximal segment of the pituitary stalk was identified. Note that the pituitary stalk and part of the diaphragm were preserved. (1) Diaphragma sellae, (2) proximal part of the PS, (3) remaining neurohypophysis, (4) left optic nerve, (5) Liliequist membrane

Perioperative Treatment

Postoperative MRI (10a–c) obtained after 24 months revealed total tumor removal with preservation of the pituitary stalk (Fig. 6.16). Endocrinological detection performed 6 months after surgery indicated no new hormone deficiencies. The PRL level was normal, although the levels of several sexual hormones remained low.


Fig. 6.16

A postoperative MRI study after 2 years confirmed total tumor removal and maintenance of an intact third ventricle floor and preserved pituitary stalk

Long-Term Follow-Up

The patient’s visual symptoms had recovered by the time of the last official follow-up, which was conducted at 24 months postoperatively. Her diabetes insipidus (DI) recovered gradually. She was able to attend school and did not require hormone replacement therapy at the time of the last follow-up study. Case 2

Medical History

This was the case of a 6-year-old male patient with a 12-month history of intermittent headache and vomiting. He also exhibited growth failure, emaciation, and partial hypopituitarism. He presented with visual deterioration (right eye: 0.4, left eye: 0.08) and bitemporal hemianopia.

Physical and Experimental Examination

The patient’s routine blood and urine analysis results were normal; however, he had low levels of plasma thyroxine and free thyroxine (fT4). An insulin stimulation test for cortisol and growth hormone (GH) revealed subnormal responses.

Radiological Images Before Surgery

A predominantly cystic intra- and suprasellar mass was identified both on CT and MRI (Fig. 6.17). The anterior communicating (AcoA) and anterior carotid arteries (ACA) formed a snowman shape at the top of the cystic tumor. On enhanced MRI, the cystic tumor wall was significantly enhanced roundly. On a coronal scan, a solid tumor was observed on the right side of the pituitary fossa near the medial wall of the CS. No obstructive hydrocephalus consequent to the tumor growth pattern and expansion was observed.


Fig. 6.17

Presurgical magnetic resonance images indicating a predominantly cystic tumor in the suprasellar region with upward expansion of a daughter cyst behind the anterior communicating artery. The cystic wall and solid part of the tumor were enhanced significantly (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018)

Analysis Before Surgery

  1. 1.

    Surgical and topographic tumor classification: Type Q tumor (intra- and suprasellar Id-CP).


  2. 2.

    Relationship with the AcoA: The AcoA complex was displaced upwards.


  3. 3.

    Tumor growth began below the diaphragm and arachnoid. The suprasellar part was covered by the diaphragma sellae and arachnoid above the DS.


  4. 4.

    Surgical excision should be the first-line therapy. A frontobasal interhemispheric approach was ultimately selected to reach the lesion.


Intraoperative Findings

After general anesthesia induction, the patient was placed in the supine position with the head fixed in a Mayfield three-pin head-holder. The head was extended slightly downward (approximately 15°), allowing the frontal lobe to spontaneously fall downward because of gravity during surgery. A standard frontobasal interhemispheric craniotomy (FIH) was performed (Fig. 6.18). A square of forehead periosteum was maintained for further frontal sinus repair. The bone flap extended beyond the median line, with the lowest margin as near as possible to the nasion. The mucosa inside the frontal sinus was removed carefully after opening the bone window. The bone of the posterior sinus wall was removed and drilled to increase exposure. Next, bone wax with antibiotic powder was used to fill the sinus cavity completely and reduce the risk of intracranial infection. A curved incision was made to open the bilateral dura mater beside the superior sagittal sinus; this incision was made close to the skull base. Subsequently, the anterior part of the superior sagittal sinus was ligated, followed by removal of the cerebral falx. The dural flap was turned rearward.


Fig. 6.18

Illustrations of the operating position and incision via a frontobasal interhemispheric approach (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018)

Dissection of the Interhemispheric Fissure

A self-retaining retractor was used to retract the bilateral frontal lobe. The bilateral frontal lobes were separated along the interhemispheric corridor and the cerebrospinal fluid (CSF) was drained to the extent possible. Occasionally, dissection of the frontal interhemispheric fissure is much more complex than that used in a lateral transsylvian approach, especially in patients with increased intracranial pressure (ICP). Continuous lumbar CSF drainage during dissection is a valid method of ICP release. The planum sphenoidale, optic chiasm, and cisterna lamina terminalis were exposed in a stepwise fashion after allowing the frontal lobe to fall.

Tumor Removal

The enlarged prechiasmatic space was the major corridor for surgical manipulation. Because of diaphragmatic septation, the suprasellar cystic tumor could be separated via slight pulling from the circle of Willis vascular ring. In this case, the suprasellar cystic tumor protruded in front of the AcoA complex to form a snowman sign (Fig. 6.17). However, this type of snowman sign can be separated easily via intracystic decompression while following the cystic wall interface. At the posterosuperior part of the tumor, the proximal PS could be exposed. The distal PS fused with the tumor capsule at the border of the diaphragmatic foramen. Here, the pituitary appeared to be inflated as an umbrella rather than displaced by compression, and thus it was difficult to preserve PS continuity. As a result, the distal segment of the PS was seceded where the stalk and tumor capsule had fused. Upon total separation of the suprasellar tumor cyst, a circular incision was made in the diaphragm at the bony opening of the pituitary fossa to locate the true subdiaphragmatic tumor capsule. Following this interface, the intrasellar part of the tumor was removed in a stepwise manner. When separating bilateral tumor walls, brisk venous bleeding is often encountered from the bilateral CS. This can be readily controlled via gentle packing with a small piece of Gelfoam (Fig. 6.19).


Fig. 6.19

Tumor exposure via the frontobasal interhemispheric approach. (a) The bilateral frontal lobes and hemispheric fissure were visible after completing the craniotomy. (b) The suprasellar tumor capsule along with the evaluated DS was identified through the prechiasmatic space. (c) Intraoperative photographs showing the tumor–stalk relationship; the lower part of the stalk had fused with the superoposterior part of the tumor capsule. The third ventricle floor (third VF) remained intact. (d, e) The protruding suprasellar tumor encased the anterior communicating artery (AcoA) complex, necessitating sharp dissection to release. (1) Infradiaphragmatic tumor portion, (2) dome of the tumor protruding from the diaphragma sellae, (3) pituitary stalk, (4) third ventricular floor, (5) Liliequist membrane, (6) anterior communication artery. Abbreviations: ASPS arachnoid sleeve of pituitary stalk (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018)

Pathology Study

A typical adamantinomatous CP was identified on the pathological slides.

Postoperative course: The third VF remained intact (Fig. 6.20). Postoperatively, the patient developed mild transient DI. Hyponatremia was the major manifestation of electrolyte disturbance. The symptoms were relieved with fluid and electrolyte replacement. Endocrinological detection revealed evidence of panhypopituitarism. The patient’s visual function recovered significantly.


Fig. 6.20

Postoperative sagittal T1-weighted magnetic resonance image confirming total tumor removal (a). The tumor was removed completely en bloc (b). Pathological examination (c) revealed that the tumor was covered by a layer of fiber tissue, resembling the structure of the diaphragma sellae (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018) Case 3

Medical History

This was the case of an 8-year-old female patient. She had undergone a prior craniotomy via a right pterional approach to address a significant reduction in visual acuity at a local hospital in December 2011. However, a follow-up series of MRIs indicated tumor recurrence. The patient subsequently had intermittent vomiting and constant headache.

Physical and Experimental Examination

No significant positive symptoms were observed except right eye blindness.

Radiological Images Before Surgery

The MRI scan conducted in December 2011 indicated a typical Id-CP in the intra- and suprasellar regions. This lesion was mixed cystic-solid, and the optic chiasm was displaced upward. Postsurgical MRI indicated subtotal tumor removal with residual intrasellar tumor. Follow-up MRI in April 2012 indicated intrasellar tumor recurrence. In September 2012, MRI indicated that this significant recurrent tumor remained an Id-CP with upward displacement of the optic chiasm. However, the tumor was not treated until the patient presented in our department in March 2013. CT indicated an extensive and expanding tumor in the sellar region, anterior basement of the cranial fossa, and upper clivus that also occupied the third ventricular cavity. Broad punctate calcification was observed. MRI revealed a huge mixed cystic-solid tumor in the intra- and suprasellar regions with extensive extension and external growth. The solid part of the tumor was significantly enhanced on T1-weighted enhanced MRI. The ACA and AcoA were entrapped by the cystic tumor. As a result, the tumor exhibited a lobular tumor shape (Fig. 6.21).


Fig. 6.21

Radiological images of this patient. (ac) Magnetic resonance imaging (MRI) before the first craniotomy surgery. (df) MRI after the first surgery. (gi) MRI before the second surgery (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018)

Analysis Before Surgery

This was a case of recurrent CP, and the notable morphological features should be emphasized. Before the primary surgery, the tumor was a typical case of Id-CP. However, the natural “protective membranous structures” such as the diaphragm and suprasellar arachnoid were destroyed by surgery so that no such interface obstructed the invagination of the recurrent tumor into the nervous tissue layer. MRI performed before the secondary surgery indicated tumor penetration through the PS and growth toward the nervous tissue layer of the infundibulum and third VF, leading to severe hypothalamic involvement.

Intraoperative Findings

Although the primary surgery destroyed the normal membranous structures that covered the tumor surface, the inner arachnoid layer continued to separate the tumor from the surrounding neurovascular structures. During surgery, this interface was followed to avoid injury. The most important locations were the site of origin and PS. Intrasellar recurrence is the most frequent issue, and therefore identification of the pituitary capsule was necessary to ensure total intrasellar tumor removal. After total tumor removal, the floor of the pituitary fossa was smooth and contained the neurohypophysis. The involved PS was ruptured to avoid additional recurrences (Figs. 6.22 and 6.23).


Fig. 6.22

Intraoperative findings. (a) The posteriorly located pituitary stalk, which exhibited severe tumor involvement, was identified after dissecting the suprasellar and intrasellar tumor. (b) After total tumor removal, the smooth pituitary fossa floor was visible. (c) Pathological examination (c) of the intrasellar tumor part showed the tightly adhered interface between the tumor and adenohypophysis, which was believed to be the cause of hypopituitarism of this tumor type. (d) Through an opening in the cystic wall, punctate calcification could be observed on the wall of the removed tumor. (e) After tumor removal, the sellar neurovascular structures were exposed (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018)


Fig. 6.23

Postoperative magnetic resonance image confirmed total tumor removal (reproduced with permission from Qi (Ed.), Craniopharyngioma, People’s Medical Publishing House, ISBN 978-7-117-26463-1, 2018)

Perioperative Treatment

The patient developed severe water and electrolyte imbalance disorder and required fluid and sodium substitution and adjustment. Postsurgical endocrinological detection indicated panhypopituitarism. The patient’s right eye was completely blinded.

Long-Term Follow-Up

After a 1.5-year follow-up, the patient’s right eye remained blind. However, vision in the patient’s left eye was restored. She continued receiving oral prednisone, thyroxin, and desmopressin to treat panhypopituitarism and permanent DI. Her BMI increased from a presurgical value of 15.7–20. Case 4

Medical History

This was the case of a 5-year-old male patient with a 1-year history of intermittent headaches that had progressively worsened during the last 2 weeks.

Physical and Experimental Examination

The patient exhibited growth retardation and bitemporal hemianopia but no other positive physical signs. Endocrinological detection indicated hypopituitarism. Deficiencies in fT4, T3, sexual hormones, and GH were present. The PRL level was slightly increased.

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Mar 25, 2020 | Posted by in NEUROSURGERY | Comments Off on Treatment of Craniopharyngioma: Transcranial Approach
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