Endoscopic transsphenoidal surgery of skull base tumors (7514 cases): 25-year experience, evolution of surgical views

Background . Currently, pituitary adenomas, also known as neuroendocrine pituitary tumors, are one of the most common intracranial tumors in adults, accounting for up to 15 % of all tumors of the central nervous system. Transsphenoidal removal using endoscopic or microscopic surgery remains the main and the most widely used method for their treatment. However, some questions remain regarding the optimal surgical technique and the reducing of complications incidence. Aim . To analyze the features of endoscopic transsphenoidal access in tumors of the chiasmal sellar region as well as surgical complications and strategies for their prevention and treatment; also this article describes the latest technical developments in this field and the issues identifications requiring constant and future development. Materials and methods . The technique of transsphenoidal endoscopic removal of chiasmal sellar tumors is described as well as the structure of this approach complications, methods of their prevention and treatment are analyzed based on personal experience over the past 25 years and the experience of foreign colleagues. Results . A variety of medical and surgical complications may occur after endoscopic transsphenoidal surgery, but it is important to note that their number has been steadily decreasing over the past decade. So, if in our first series of endoscopic operations the percentage of postoperative relapses was 26 %, complications - 78 %, mortality - 2.1 %, then gradually the recurrence rate was 9-11 %, complications - 2-7 %, and mortality is approaching zero, now amounting to 0.12 % in the total series. The operation time has also significantly decreased from 1.5-3 hours with the first endoscopic surgeries to 15-25 minutes in the modern period. Conclusion . In pituitary tumors surgery, the introduction of endoscopic techniques has allowed to solve the main problem of transsphenoidal operations - to expand the overview and lighting of the surgical field as well as to detail the structures of the chiasmal sellar region and to perform the selective intervention. The analysis of all errors and complications, the dynamics of the learning curve allows us to conclude that the development of transsphenoidal endoscopic surgery should be carried out in a large specialized center with extensive experience in such interventions, and the first surgeries should be performed by a training surgeon only with the mandatory assistance of an experienced specialist.