A cannula comprises a main body for accommodating both an endoscopic lumen and a working lumen. The main body of the cannula ends at a point proximal to the distal end of the cannula. Extending distally from the point at which the main body end is an endoscopic dissection shaft of decreased diameter, which houses the endoscopic lumen, but not the working lumen. A transparent tapered tip is positioned on the distal end of the endoscopic dissection shaft. Due to the decreased diameter of the endoscopic dissection shaft, the transparent tapered tip has a small diameter, The main body of the cannula ends in a smoothly contoured face that provides minimal trauma to vessel and other tissue that comes in contact with the face as the cannula is advanced through the surgical site. The endoscope is sealed in the endoscopic lumen by the transparent tapered tip to prevent smudging of the endoscope by surrounding blood or tissue during dissection and during surgical procedures performed by surgical tools housed in an auxiliary lumen. A flexible hood extends from the distal end of the working lumen to the proximal edge of the transparent tapered tip to form a tapered profile to facilitate low dissection force and improved maneuverability, and the flexible hood also prevents blood or tissue from entering into the working lumen.