Control of bleeding in endoscopic skull base surgery: current concepts to improve hemostasis.

Hemostasis is critical for adequate anatomical visualization during endoscopic endonasal skull base surgery. Reduction of intraoperative bleeding should be considered during the treatment planning and continued throughout the perioperative period. Preoperative preparations include the optimization of comorbidities and cessation of drugs that may inhibit coagulation. Intraoperative considerations comprise anesthetic and surgical aspects. Controlled hypotension is the main anesthetic technique to reduce bleeding; however, there is controversy regarding its effectiveness; what the appropriate mean arterial pressure is and how to maintain it. In extradural cases, we advocate a mean arterial pressure of 65-70 mm Hg to reduce bleeding while preventing ischemic complications. For dealing intradural lesion, controlled hypotension should be cautious. We do not advocate a marked blood pressure reduction, as this often affects the perfusion of neural structures. Further reduction could lead to stroke or loss of cranial nerve function. From the surgical perspective, there are novel technologies and techniques that reduce bleeding, thus, improving the visualization of the surgical field.