Dear Dr. Venelin Gerganov,

There are many factors which determine the surgical approach for craniopharyngioma: anatomical site, size, extent , and the nature of the tumor. Of course endoscopic resection of the tumour has more advantageous than craniotomy if its applicable and was done by a well expert surgeon who have a great practice in this field.

Kind regards

Raid

Dear Dr. Venelin Gerganov,

The endoscopic endonasal approach (EEA) for craniopharyngiomas offers great advantanges in terms of improved visualization and gross-total resection with reduced brain retraction and complications compared to fronto-lateral approach. EEA is generally indicated for midline tumors (sellar, suprasellar and third ventricle). If cranio extends laterally, a fronto-lateral craniotomy would be needed. It would be interesting to analyse long-term outcomes between EEA and interhemispheric subfrontal approach.

Best,

Emanuele

References:

1. Komotar, R. J. et al. (2012) ‘Endoscopic Endonasal Compared with Microscopic Transsphenoidal and Open Transcranial Resection of Craniopharyngiomas’, World Neurosurgery, 77(2), pp. 329–341. doi: 10.1016/j.wneu.2011.07.011.

2. Moussazadeh, N. et al. (2016) ‘Endoscopic endonasal versus open transcranial resection of craniopharyngiomas: a case-matched single-institution analysis’, Neurosurgical Focus, 41(6), p. E7. doi: 10.3171/2016.9.FOCUS16299.

Dear Dr Gerganov,

The paramount factor is the location of the craniopharyngioma, when it is located in retrochiasmatic with or without extension into the 3rd ventricule it will be an excellent indication for the endoscopic aproach. However if the cranio extends laterally, a interhemispheric subfrontal approach is for my opinion the best alternative.

Best

MM

Dear Dr. Venelin Gerganov:

My opinion agrees with the detailed explanation given by Drs. Raid M. Al-Ani, Emanuele La Corte and Mahmoud Messerer.

Microscopic transsphenoidal surgery has been performed with good surgical outcomes and minimal morbidities. Nevertheless, an endoscope carries advantages over the operating microscope such as its ability to visualize through a narrow surgical corridor and to provide angled, close- up views. As mentioned earlier, endoscope- assisted microscopic surgery is a reasonable first step taken when a neurosurgeon desires to adopt endoscopy into skull base surgery surgery. In this case, an endoscope can provide certain advantages in microscopic skull base surgery surgery by providing panoramic views as well as visualizing angled, close- up views.

However, the surgeon should be aware that the speculum will restrict maneuverability of the endoscope, and create a potential hindrance between the endoscope and other surgical instruments

Regards

Aderito De Sousa F.

Dear Dr. Venelin Gerganov:

Endoscopic endonasal surgical removal of craniopharyngiomas it's really advantageous to the patient. Is not a fashion approach.

Advantages

Wide-angle view

Placement of the surgeon’s eye at the site of surgery

Angled scopes look around the periphery of the operative field

Increased volume of visualization at the site of surgery

Disadvantages

Lack of binocular vision with current technology

Endoscope occupies space in surgical corridor

Requires adequate learning curve in endoscopic sinus surgery of all surgical team (

Assistant or holder for scope is required for bimanual surgery to be performed

Lack of instrumentation to work through operative channel

Dear Dr. Venelin Gerganov:

Endoscopic skull base surgery is advantageous compared  with  conventional microscopic surgery in terms of less invasiveness, but it also has some limitations and disadvantages, especially for neurosurgeons, inexperienced in handling endoscopes. Nevertheless microscopic surgery is used by many authors, especially neurosurgeons. Magnification, stereoscopy and the freedom for two-handed techniques are all cited as advantages of the microscopic technique.

In microscopic surgery of tumors of the base of the skull there is a greater possibility of not completely resecting the lesion and residual tumor fragments can be precursors to recurrence and persistent disease. However the endoscope has a wider functional field of view and superior focal length.

The dynamic optical qualities of the endoscope should allow for more careful intraoperatory observatio through the very constrained cavities of the skull base, for more detailed appreciation of critical surgical anatomy, and for more thorough surgical intervention with fewer complications due to better visualization. Pure endoscopic approaches provide excellent access to the ethmoid roof, cribriform plate, and most of the sphenoid sinus.

With currently available operating microscopes, depth of focus has been improved but the “straight” vision still limits visualization of hidden presellar and parasellar recesses and lateral recesses of the sphenoid bones in pituitary surgery.

Angled endoscopes are able to expose lateral recesses of intracranials where these fragments were missed during microscopic surgery.

Therefore these observations do provide evidence that endoscopic view of the intrasellar, parasellar, and suprasellar spaces is more comprehensive than that provided by the operative microscope. The potential impact upon the efficacy of tumor resection and subsequent rates of tumor recurrence is significant when endoscopy is implemented as an imaging modality in the surgical management of skull base tumors.

Endoscopic skull base approach improved visualization of surrounding optic bulbs, brainstem, and carotid prominences. In contrast, the telescopic vision of the nasal endoscopes has an unlimited depth of focus with the angled telescopes providing added visualization of previously hidden recesses.

Endoscopy provides distinct advantages over microscopy in intraoperative imagings of skull base structures, including intrasellar and parasellar structures, as surrounding optic bulbs, brainstem, and carotid prominences, during skull base surgery. In microscopic surgery of tumors of the base of the skull there can also increases the possibility of not completely resecting the lesion and residual tumor fragments can be precursors to recurrence and persistent disease.

The potential impact upon the efficacy of resection the skull base tumors and subsequent rates of recurrence is significant when endoscopy is implemented as an approach modality. Likewise improved ability to differentiate tumor from normal tissue.

In the same way endoscopic endonasal surgery can be employed for treating skull base tumors without septal or sublabial complications, naso-oral fistulae and lip seen with the transseptal approach. Postoperative  suffering was  reduced  and hospitalization was shortened by this minimally invasive procedure.

Several  reports  as  well as our  experience  suggest  that  the endonasal  endoscopic  approach  is a safe and effective alternative to the conventional microscopic surgery for the treatment of skull base lesions.

The  image-guided  systems  are also advantageous during endoscopic surgery in terms of safety, less invasiveness as well as the good overall results and reduce even more intraoperative complications.

I recommend several papers that can clarify these points of view:

1. Krischek B, Carvalho FG, Godoy BL, Kiehl R3, Zadeh G, Gentili F: From craniofacial resection to endonasal endoscopic removal of malignant tumors of the anterior skull base. World Neurosurg. 2014 Dec;82(6 Suppl):S59-65. doi: 10.1016/j.wneu.2014.07.026.

2. Liu JK, Sevak I, Carmel PW, Eloy JA: Microscopic versus endoscopic approaches for craniopharyngiomas: choosing the optimal surgical corridor for maximizing extent of resection and complication avoidance using a personalized, tailored approach. Neurosurg Focus. 2016 Dec;41(6):E5.

3. Koutourousiou M, Fernandez-Miranda JC, Stefko ST, Wang EW, Snyderman CH, Gardner PA: Endoscopic endonasal surgery for suprasellar meningiomas: experience with 75 patients. J Neurosurg. 2014 Jun;120(6):1326-39. doi: 10.3171/2014.2.JNS13767. 

4. Zimmer LA, Theodosopoulos PV: Anterior skull base surgery: open versus endoscopic. Curr Opin Otolaryngol Head Neck Surg. 2009 Apr;17(2):75-8

5. Buchmann L, Larsen C, Pollack A, Tawfik O, Sykes K, Hoover LA: Endoscopic techniques in resection of anterior skull base/paranasal sinus malignancies. Laryngoscope. 2006 Oct;116(10):1749-54.

6. Carrabba G, Dehdashti AR, Gentili F: Surgery for clival lesions: open resection versus the expanded endoscopic endonasal approach. Neurosurg Focus. 2008;25(6):E7. doi: 10.3171/FOC.2008.25.12.E7.

7. Ceylan S, Koc K, Anik I: Extended endoscopic approaches for midline skull-base lesions. Neurosurg Rev. 2009 Jul;32(3):309-19; discussion 318-9. doi: 10.1007/s10143-009-0201-9.

8. Almeida JP, De Albuquerque LA, Dal Fabbro M, Sampaio M, Medina R, Chacon M, Gondim J: Endoscopic skull base surgery: evaluation of current clinical outcomes.  Neurosurg Sci. 2015 Nov 23.

8. Little AS, Kelly DF, Milligan J, Griffiths C, Prevedello DM, Carrau RL, Rosseau G, Barkhoudarian G, Jahnke H, Chaloner C, Jelinek KL, Chapple K, White WL: Comparison of sinonasal quality of life and health status in patients undergoing microscopic and endoscopic transsphenoidal surgery for pituitary lesions: a prospective cohort study. J Neurosurg. 2015 Sep;123(3):799-807. doi: 10.3171/2014.10.JNS14921.

9. Helal MZ. Combined micro-endoscopic trans-sphenoid excisions of pituitary microadenomas. Eur Arch Otorhinolaryngol 1995;252:186-9.

There are two main issues to discuss in my opinion:

- Does everybody agree that the extended endonasal approach is less traumatic than a small frontolateral (supraorbital) approach?

We are discussing the management of an intradural lesion. The advantages of the EEA in chordomas or other tumors destroying the skull base are obvious.

- Is the radicality rate higher and the morbidity lower if the endonasal approach is utilized?

The literature and my experience- both personal and institutional - do not support these statements

endoscopic  nasal approach