Endoscopic endonasal trans-sphenoid management of craniopharyngiomas Y R Yadav, Vijay Parihar, Shailendra Ratre, Yatin Kher, Jitin Bajaj, Anurag Pateriya Department of Neurosurgery NSCB (Government) Medical College Jabalpur MP India 482003 Recipient of Charak award (IMA MP state 2011) Chairman fellowship program of one week brain and spine endoscopic training www.neuroendoscopyjbp.org Executive member of Neurological surgeons society of India E mail yadavyr@yahoo.co.in, yadramyr@yahoo.com, Web site www.yadavyr.com Tel: +91 9893711193, +91 761 2673644.  

Endoscopic endonasal trans-sphenoid management of craniopharyngiomas Introduction: Craniopharyngiomas frequently arise in the pituitary stalk and project into the hypothalamus. Can extend anteriorly, posteriorly, superiorly or laterally.

Advantages of endonasal route: Improved visualization, Avoidance of brain retraction. Lack of external scars. Most of lesions including sellar, suprasellar with or without sellar component, intraventricular lesions can be better approached by endonasal technique as compared to any single open trans-cranial technique.

Advantages of endoscopic endonasal technique:   Prechiasmatic/preinfundibular,and retrochiasmatic/retroinfundibular lesions can be removed by this approaches. More benefits in patients who had undergone prior transcranial surgery. Tumor can be removed using bimanual techniques.

Advantages: Severe adverse events: less frequent after transsphenoidal technique (5.6%) as compared to transcranial approach (37%) Good infrachiasmatic exposure without the need for manipulation of surrounding neurovascular structures. (chiasm, infundibulum, hypothalamus and third ventricle) Better endocrine function preservation

Advantages: Higher rate of visual improvement. Reduced post-operative hospital stay Low cost of management. Surgeon and the patient comfort Better total resection rate (nearly 10% in Kadri et al series)

Limitations: Steep learning curve 2 D image Lateral extensions Dural repair Involvements of vascular structures, brain infiltration

Limitations of the procedure: Control of the hemorrhage, Postoperative CSF leak, Tension pneumocephalus, Meningitis

Limitations of the procedure: Constant need for manual control of the endoscope Narrow surgical corridor, Need good endoscopic experience of surgeon to remove this tumor and repair of dura.

Limitations of the procedure: Restricted lateral suprasellar access More demanding cranial base repair Large vascular and dense fibrous tumors are difficult to remove.

Endoscopic endonasal trans-sphenoid management of craniopharyngiomas Indications: Sellar Supra sellar with or without sellar component.

Indications: Selected intraventricular craniopharyngiomas arising from sellar or suprasellar region. Space created after tumor removal can provide exposure to the third ventricle

Indications: Clival craniopharyngioma Nasopharyngeal lesions Recurrent or symptomatic residual craniopharyngiomas Adults and children both Staged or combined technique

Imaging: Detailed evaluation of the anatomy of: Sinuses, Position of carotid artery, Pituitary with stalk Optic pathways. High definition CT scan: for bony detail and calcification MRI: for soft tissues.

Imaging: 3D fast imaging employing steady state acquisition (3D-FIESTA) or constructive interference in steady state (CISS) MR imaging provides high resolution of small structures within the cisterns.

Head elevation Nasal cavity towards surgeon

Endotracheal tube on the patient’s left side The head is kept toward the right and laterally bent to the left shoulder

Technique: Lateralization and resection of middle turbinate

Naso-septal Flap raised Reversed flap

Technique: Ethmoidectomy for extended approach to anterior cranial fossa Posterior clinoid process along with clivus excision for retrochiasmatic and posterior fossa extension .

Extent of dural exposure Dural opening anterior and posterior to SIS

Tumor removal Complete tumor removal

Multilayer closure including nasoseptal flap

Technique: Transplanum transtuberculum corridor offers direct midline access to the retrochiasmatic space.

Technique: Transposition of the pituitary gland and its stalk: provide a valuable corridor to the retroinfundibular space and interpeduncular cistern Transposition preserves pituitary function in the majority Only after significant experience. Space created by the tumor allows corridor from the side of stalk.

Technique: Angled scope helps in detection of anterior cranial fossa structures, residual lesion and in inspection of larger residual cavities.

Technique: Navigation and intra operative Doppler: to recognize important neurovascular structures especially in large and recurrent craniopharyngiomas. Intraoperative MRI: helpful in detecting residual craniopharyngioma.

Technique: Flexible fiber CO2 laser could be quick, safe and effective for cutting and coagulation of tumor. The ultrasonic bone curette for bone removal. Side cutting tissue resector for internal debulking of nonvascularized firm tumors.

Technique: Binostril technique provides more space for manipulations of instruments. Although single nostril approach has been used even in children without turbinate or septum resection to minimize postoperative discomfort.

Technique: Multilayered closure using vascularized pedicled septal flap is helpful in reducing postoperative CSF leaks in larger bony and dural defects.

Technique: Intradural fat to obliterate dead space, with tagged suture to prevent migration. Intradural fascia lata with stay sutures to hold it back (Gasket closure partly extradural) Another layer of fascia lata Nasoseptal flap

Age: Piriform aperture (anterior nasal opening) is likely a limit in children under 2 years of age. Sphenoid pneumatization start at 3 years and complete by age 10 years. Septum less developed in less than 10 yrs. Intercarotid distances do not change significantly with any age.

Technique: Pedicled nasoseptal flap may not be a viable option for reconstruction in children less than10 years of age. Reliable option in more than14 years, as septum is comparable to adults. Between 10 -13 years of age require careful preoperative evaluation for the adequacy of the flap. Bilateral nasoseptal flaps when one flap does not completely seal the entire defect.

Results of endonasal approach:   Subtotal excision: Subtotal resection along with radiotherapy: equivalent tumor control rates with lower morbidity, Gross total resection is superior.

Pre op CT case 1 Pre op MRI case 1

Post op MRI Case 1

Pre op CT case 2 Pre op MRI case 2

Post op MRI case 2

Case 3

  Tumor removal: The endoscopic group usually has a significantly greater resection compared to the microscopic group (10 % better). Complete resection of the lesions 70% to 85%. Gross total or near total removal (more than 95 %) in 75 to 93% patients

Case 4

  Tumor removal: Endoscopic cyst drainage, 4-6 weeks prior to definitive surgery, is helpful in improving subsequent surgical excision of large cystic tumors.

Visual outcome: The endoscopic group usually has a significantly greater rate of improvement compared to open group. Improvement in visual field defects is usually better than visual acuity. Vision improves in 77 to 93% patients Visual worsening though rare can be observed.

Endocrine outcome: Partial hypopituitarism: when two axes had deficiencies Panhypopituitarism when three or more axes are deficient.

Endocrine outcome: Pituitary stalk can be preserved in majority Diabetes insipidus along with other endocrine deficiencies are common complications. Preoperative pituitary dysfunction usually does not show improvement On the contrary new postoperative endocrine deficiency may occur.

Endocrine outcome: Posterior pituitary dysfunctions are more common than anterior pituitary malfunction. Diabetes insipidus develops in about 40% patients Panhypopituitarism may be seen in 38% patients (Panhypopituitarism without preexisting hypopituitarism)

Endocrine outcome: Endocrine functions are better preserved in cyst fenestration surgeries compared to subtotal excision procedures, Recurrence rate after cyst fenestration combined with Gamma Knife surgery (GKS) is higher.

Recurrence rate: Recurrence depends on the amount of tumor excision. Recurrence rate in gross total, subtotal and partial excision group is about 13%, 19% and 51% respectively at 5 year follow up. Addition of post operative radiotherapy reduces recurrence in subtotal or partial excision group.

Recurrence risk: Presence of residual tumor on the first postoperative MR imaging, Male sex, Without postoperative radiation therapy

Treatment of Recurrence: Radiotherapy for residual or recurring disease Repeat surgery, Combination of both

CSF leak: CSF leak varies from 3.8 % to 58% . Incidence in endoscopic transsphenoid (18.4%), microscopic transsphenoidal techniques (9.0%), transcranial approach (2.6%). CSF leak higher in larger tumors, Reconstruction with the vascularized nasoseptal flap: reduces incidence.

Bleeding: Bleedings in craniopharyngioma surgery can occur from the venous sinuses, small arteries, tumor bed and internal carotid artery. Prevention by avoiding pulling of tumor tissue.

Bleeding: Management of intradural bleeding may be challenging, Application of thrombin gelatin haemostatic matrix ( FloSeal Hemostatic Matrix, Surgiflow Hemostatic Matrix) can be useful in oozing, focal hemorrhage and even in high flow bleeding. Head end elevation.

Practical tips In less than 10 Years patients, there may be problems of inadequate nasoseptal flap, and improper pneumatization of Sella Good judgment about extent of excision (morbidity versus recurrence) CSF leak remains a problem Multi layer closure Intradural placement of flap or graft. Sufficient bony opening.

Best results Good results Best approach or technique Experienced surgeon in that technique Best results Alternate Technique Experienced surgeon in that technique Good results Best technique Poor results Inexperienced surgeon Poor approach selection Inexperienced surgeon Bad results

Summary: Indicated: Sellar, Supra sellar (prechiasmatic, sub chiasmatic, transinfundibular, and retrochiasmatic), Selected intra ventricular, Petroclival, Nasopharyngeal, Recurrent craniopharyngiomas In adults and children both.

Indications: It can be used in large craniopharyngioma in association with other staged or combined endoscopic or microscopic transcranial approach or as an adjuvant to Gamma Knife surgery to reduce tumor sizes.

Advantages: High definition wide angle improved visualization Without brain retraction, Good infrachiasmatic exposure, Minimally invasive nature, Greater tumor resection rate, Better visual outcome, Less severe adverse events Better endocrine results Lack of external scars

Limitations Large tumors with significant parasellar extension, Pure intraventricular lesion without sellar or suprasellar component, Lack of stereoscopic visualization, Steep learning curve, Narrow surgical corridor, Neurovascular encasement, Difficulty in control of hemorrhage, Problems in dural and bony defect closure, CSF leak.

Multilayer dural closure using vascular flap has reduced CSF leak rate significantly. Preoperative pituitary dysfunctions usually do not show any improvement. New posterior pituitary dysfunctions are more common than anterior pituitary. Uses of angled scope, navigation, Doppler, ultrasonic bone curette, intraoperative MRI and binostril approach etc. have improved safe and effective tumor removal.

Tumor recurrence depends on the amount of excision. Although proponents of subtotal resection argue less aggressive approach along with radiotherapy because of equivalent tumor control with lower morbidity, others suggest gross total resection. Gross total removal without chasing densely adherent tissue to neurovascular seems to be superior in reducing endocrine and visual morbidity.

References Yadav YR, Nishtha Y, Vijay P, Shailendra R, Yatin K. Endoscopic endonasal trans‐sphenoid management of craniopharyngiomas. Asian J Neurosurg 2015;10:10‐6. Yadav YR, Parihar V, Kher Y. Complication  avoidance and its management in endoscopic neurosurgery. Neurol India 2013;61:217-25. Yadav YR, Parihar V, Ratre S, Iqbal M. Microneurosurgical skills training. J Neurol Surg A Cent Eur Neurosurg 2015 Apr 27. [Epub ahead of print] DOI: 10.1055/s-0034-1376190

Thankful to my teachers

Thankful To My colleagues