A study on the surgical approach of trans frontonasal keyhole

Zhang Xiaopeng; Gong Fanghe; Yang Shuai; Wang Weimin

doi:10.11850/j.issn.1009-122X.2017.08.008

Abstract：Objective To design the surgical approach for the tumor located in the suprasellar region, anterior area of the third ventricle, even over the interventricular foramen. Methods Three patients received bone anatomical measurement for the width of the frontonasal suture the distances between the bilateral supraorbital notches and the distance from the midpoint of the frontonasal suture to the midpoint of the line between the bilateral supraorbital notches. The angle of the horizontal line at the bottom of the frontal sinus and the line from the bottom of the frontal sinus to the interventricular foramen and the distance between the bottom of the frontal sinus and the interventriculare foramen were measured by MRI. The resection of the tumor in the anterior third ventricle region in the 3 patients validated the feasibility of the approach clinically. Results ①The width of the frontonasal suture was 2.8 cm in average. The space between the bilateral supraorbital notches was 5.2 cm in average. The distance from the midpoint of the frontonasal suture to the midpoint of the line between the bilateral supraorbital notches was 1.4 cm in average.②MRI results showed that the average angle was 24° between the horizontal line at the bottom of the frontal sinus and the line from the bottom of the frontal sinus to the interventricular foramen, and the average distance was 6.5 cm.③"U"shaped incision was designed for the surgery. Through the keyhole approach the tumor could be completely removed. Conclusions The frontonasal suture is the bony landmark for trans-frontonasal keyhole. The relevant local anatomy meets the requirements of the keyhole microsurgery. The third ventricle and the interventricular foramen area can be accessed by means of the natural gap. The surgical approach can decrease the risk and surgical damage and achieve optimal surgical outcome.