of the venous wall 20 or the vein wall 20 including both surfaces along the zero degree wall line 75 can be attached to another vein wall 20 in a similar manner a 90 degree wall 80 can be identified for the distended vein segment 5 at a location of intersection between a 90 degree radian 85 and the vessel wall 20 the 90 degree radian 85 is rotated clockwise 90 about the centerline 40 an angle 95 of 90 degrees from the zero degree radian 35 and with respect to an antegrade flow direction 100 a 90 degree wall line 105 can then be identified in a manner similar to that described for the zero degree wall line 75 and the vein wall 20 that extends between the zero 75 and 90 105 degree wall lines is considered the first quadrant 110 similarly a 180 115 and 270 120 degree wall a 180 125 and 270 130 degree wall line and a second 135 third 140 and fourth 145 quadrant can be identified in a manner similar to that discussed earlier an inner surface 90 150 180 155 and 270 160 degree point and an outer surface 90 165.