Surgical approach and application of adult craniopharyngioma

Surgical approach and application of adult craniopharyngioma.  Many open surgical approaches can be used for resection of craniopharyngioma. The choice of surgical approach depends on the location and texture of the tumor.

At present, there is no clear consensus on the treatment of craniopharyngioma. Its natural course has not been studied carefully. Craniopharyngioma is a benign tumor, so theoretically it can be cured by complete resection. But before the development of microneurosurgery, active surgical resection brought a high rate of complications. This leads to a period of time, many people think that palliative surgery combined with postoperative radiotherapy is the best treatment. However, advances in neuroimaging, surgical techniques and hormone replacement therapy have caused many people to re-adopt the concept of active surgery.

The concept of active surgery must be plagued by the realization that surgery in this area will cause serious complications. In addition to possible complications, many people pointed out that there is evidence that even complete removal of the tumor can not prevent tumor recurrence, so more conservative treatment strategies should be adopted. The understanding of these characteristics of craniopharyngioma makes the previous treatment lack of uniformity. Many neurosurgeons have even adopted a variety of different treatment concepts in their careers.

Many open surgical approaches can be used for tumor resection. The choice of surgical approach depends on the location and texture of the tumor. The treatment of huge cystic tumors is often completely different from that of huge solid tumors. Various surgical approaches benefit from the removal of the skull to be flush with the skull base. A surgical approach parallel to the base of the anterior or middle cranial fossa can reduce the amount of brain tissue that needs to be retracted. In many cases, different surgical approaches are used for tumors in the same or different locations.

Subfrontal approach

The subfrontal approach is the most commonly used surgical method for patients with this type of tumor. This method requires the patient to lie supine and maintain a neutral position so that the anterior skull base is perpendicular to the ground. Beautiful double coronal scalp incisions are often used for this approach. The skull periosteum is often separated as a separate layer, because subsequent craniectomy may damage the frontal sinus. Extend the frontal bones on one or both sides. If the mucosa of the frontal sinus is ruptured, the mucosa should be removed and the sinus contents should be removed. Fat and muscle can be used to fill the frontal sinus, and suture the periosteal sheet to seal the frontal sinus.

Inter-hemispheric approach

Although many neurosurgeons prefer the subfrontal approach, some others have proposed the double frontal interhemispheric approach. This surgical approach is very suitable for removing huge tumors, or tumors located in the midline or behind the optic chiasm that may extend to the posterior sella. Although it may have many technical challenges, this approach provides a broader exposure to the visual path and the front of the Wills ring.

Supporters of this kind of human access praised it for avoiding the blind spots that may be encountered with unilateral access. The recognition of a series of problems such as the separation of the bilateral anterior bridging veins and the retraction of the frontal lobes and the increased possibility of bilateral frontal lobes have restricted the use of this approach. This technique also requires dissection of the anterior communicating artery to maximize the removal of the tumor located behind the optic chiasm.

Wing point approach

The pterional approach is often used to remove craniopharyngiomas. This approach has two advantages. One is that neurosurgeons are particularly familiar with this approach, and the other is that it is the shortest access to the parasaddle space. This approach often requires removal of the anterior clinoid process to completely remove the tumor. It provides neurosurgeons with more exposure to the outside of the tumor rather than to the front, and most tumors are removed in the optic chiasm-internal carotid artery space. In addition, this approach can reveal tumors on the side of the surgical approach.

Subtemporal approach

The subtemporal approach is mainly used to remove a unilateral tumor occupying the posterior part of the optic chiasm. Those who believe that the use of the subfrontal approach to remove the optic cross and tumor will damage the visual organs promoted the development of this approach.

Transsphenoidal approach

When craniopharyngioma is located in the saddle, with or without growth on the saddle, the transsphenoidal approach can often be used. For tumors that grow below the sella septum, if the sphenoid sinus is gasified normally, this is the best surgical approach. In a case group of craniopharyngioma, which is predominantly adult, the percentage of patients treated with transsphenoidal approach first is 25%-60%.

Prefrontal cortical fistula approach

Craniopharyngiomas that enter the ventral area of ​​the third ventricle and cause non-communicating hydrocephalus can often be removed by upper surgery. Make a small parasagittal craniectomy just in front of the coronal suture. After removing a small part of the cortex in the middle frontal gyrus, it can enter the ventricular system. Small-scale cortical resection reduces the risk of postoperative epilepsy, and this surgical approach can theoretically reduce the possibility of vein damage. In addition, this kind of human path will also reduce the possibility of memory loss.

Via hydrazine callosum

Unlike the transcortical approach, a standard transhydrazine callosal approach can also be used. After entering the lateral ventricle, the lateral anatomical relationship between the hypothalamic striatal vein and the choroid plexus can be located by neurosurgeons. The tumor can then be removed from the lateral ventricle and the third ventricle. When the interventricular foramina is so small that the tumor cannot be removed, the interfornix fissure or choroidal fissure can be opened to maximize the exposure of the third ventricle.

Stereotactic tumor decompression

In many cases, we will encounter craniopharyngiomas whose main manifestations are cysts. Decompression of these huge cystic tumors can be used as a preliminary or final treatment. This method often quickly alleviates the patient’s symptoms, such as visual impairment, hypothalamic hypofunction, and increased intracranial pressure.

We can simply put the catheter into the tumor sac through the ventricular system, and then connect the catheter to a collection sac. When the cyst is decompressed, the solid part of the tumor can be removed.

Because most of the sac fluid will recur within two months, the final surgical resection is usually performed within 4 weeks of intra-sac decompression.

Other options include: repeated puncture and drainage after clinical or imaging evidence suggests recurrence, and the use of a connecting tube inside and outside the capsule for intraluminal radiotherapy or chemotherapy.

(source:internet, reference only)

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