Expanded Endonasal Approaches  of the skull base tumors guided by neuronavigation: Our expirience from 2015 – 2018

INTRODUCTION

To present the technique used and the results obtained in the first 17 patients diagnosed with tumors of the skull base treated by transnasal endoscopic guided by neuronavigation

It is a minimally invasive technique for the resection of tumors in the sellar and parasellar region. Initially it was used for tumors in the sellar region with suprasellar extension, the advent of the neuronavigator allowed to extend sagittally from the cribrosa sheet to the cranio-spinal junction and in the coronal plane cavernous sinus, orbital and petrosal apex.

All patients underwent simple and contrasted magnetic resonance imaging (IRM s / c), CT simple scans of paranasal sinuses with neuronavigation protocol. These images were integrated into the neuronavigation system, making the planning of the approach and registration with Z touch technique under general anesthesia. The patient’s head is turned slightly towards the surgeons and the body laterally so that the head is vertically aligned with the surgeon, with slight flexion to the clival plane and extension to the sphenoid. Trendelenburg position (> 15 degrees) decreases venous pressure and aids hemostasis.

The endoscopic technique used corresponds to the nasal, sphenoidal and sellar phases, described in several publications, the last stage of the approach changes in relation to the location of the tumor extension.

   MATERIALS AND METHOD

A retrospective analysis of 17 transnasal endoscopic surgeries guided by a neuronavigation system in skull base tumors was carried out during the period from October 2015 to March 2018. The demographic characteristics were analyzed of the patients, the basic pathology and the morbidity and mortality associated with the surgery. Surgical resection was performed with optical endoscope of 0 – 30 degrees x 4 mm in diameter guided by neuronavigation system (Curve ™ Image Guided Surgery)

RESULTS

Fig. 1: A.- Observe dural of sella turcica protruded by the tumor (white star), B.- lateral residual tumor near the medial wall of the cavernous sinus (long arrow), C.- Suprasellar surgical resection, identifying the sealing diaphragm (black star) and laterally tumor-free diaphragmatic recesses (curved arrows), D.- CT scan in axial, coronal and sagittal sections with acquisition of 3D volume of tumor lesion, E.- CT scan in axial section of intrasellar portion, pre-surgical (red arrow) and postoperative without tumor residue (yellow arrow), F.- CT scan in axial section of suprasellar portion, pre-surgical (red arrow) and postoperative without tumor residue (yellow arrow)

Fig. 2: A.- Observe partial sphenoidectomy with exposure of sphenoid portion of the tumor through the sella turcica floor (short arrow), B.- dural exposure of the sealing region (black point) and cavernous sinus floor (Estrella), (circle with intercut lines) corresponds to standard approach, (parallellogram with intercut lines) corresponds to extended approach, scale in millimeters, C.- tumoral resection in the sealing region (white point), internal carotid artery intracavernosal segment (white star), D .- CT scan with acquisition of volume in 3D of tumor lesion, E.- MRI axial, coronal and sagittal cuts with acquisition of 3D volume of tumor lesion, F and G.- MRI in axial and sagittal section

Fig. 3: A.- Observe the ethmoid portion of the tumor (intermittent circle), B.- intradural tumor bed (black star) and remnant of dural (black point), C.- trepano hole in the nasium region for flap transposition from galea pericranial to the base of the skull (long arrow), D.- closure with galea pericranial defect in postoperative bone (short arrow), E.- MRI with volume acquisition in 3D of tumor lesion, F.- MRI axial sections pre-surgical intracranial tumor lesion (red arrow), CT scan postoperative axial slice partial resection (yellow arrow), G.- MRI axial sections of tumor lesion presurgical ethmoidal portion (red arrow), CT scan postoperative axial section complete resection (yellow arrow).

CONCLUSIONS

The results of surgery in extended endoscopic approaches based on the skull, including the pituitary gland with assistance from the neuronavigation system, have allowed a higher percentage of complete resections that increase endocrinological and visual healing.

The anatomical detail is clearly superior to other minimally invasive techniques in resections in this type of tumors.

We can objectify more conclusive results in future work for the moment endoscopy in transnasal resection surgery guided by neuronavigation as any technique has a learning curve.

REFERENCES

  1. Berker M, Hazer DB, YücelT, Gürlek A, Cila A, Aldur M, Onerci M. Complications of endoscopic surgery of the pituitary adenomas: Analysis of 570 patients and review of the literature. Pituitary. 2011 Dec 8; [PubMed]
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