An open electrosurgical forceps for sealing tissue, comprising: a pair of first and second shaft members (12a, 12b) each having a jaw member (110, 120) disposed at a distal end thereof, the jaw members (110, 120) being movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members (110, 120) cooperate to grasp tissue therebetween; each of the jaw members (110, 120) including an electrically conductive sealing plate for communicating electrosurgical energy through tissue held therebetween to effect a tissue seal; one of the sealing plates including a stop member configured to maintain a gap distance between about 0.001 inches (0.003 cm) to about 0.006 inches (0.02 cm); a curved knife channel defined along a length of at least one of the jaw members, the curved knife channel being dimensioned to reciprocate a cutting mechanism therealong; a ratchet including first and second ratchet interfaces (31a, 31b) disposed on the first and second shaft members (12a, 12b), respectively, the ratchet configured to maintain a pressure between jaw members (110, 120) within the range of about 3 kg/cm 2 to about 16 kg/cm 2, the ratchet including a stop disposed on one of the shaft members to prevent over pressurizing of the jaw members (110, 120) beyond the first and second ratchet interfaces (31a, 31b), and an actuator operatively connected to one of the shaft members for selectively advancing the cutting mechanism from a first position wherein the cutting mechanism is disposed proximal to tissue held between the jaw members (110, 120) to at least one subsequent position wherein the cutting mechanism is disposed distal to tissue held between the jaw members (110, 120), characterised in that the cutting mechanism includes a generally hourglass-shaped flexible blade having a notch disposed generally midway therealong which facilitates distal translation of the knife within the knife channel. a pair of first and second shaft members (12a, 12b) each having a jaw member (110, 120) disposed at a distal end thereof, the jaw members (110, 120) being movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members (110, 120) cooperate to grasp tissue therebetween; each of the jaw members (110, 120) including an electrically conductive sealing plate for communicating electrosurgical energy through tissue held therebetween to effect a tissue seal; one of the sealing plates including a stop member configured to maintain a gap distance between about 0.001 inches (0.003 cm) to about 0.006 inches (0.02 cm); a curved knife channel defined along a length of at least one of the jaw members, the curved knife channel being dimensioned to reciprocate a cutting mechanism therealong; a ratchet including first and second ratchet interfaces (31a, 31b) disposed on the first and second shaft members (12a, 12b), respectively, the ratchet configured to maintain a pressure between jaw members (110, 120) within the range of about 3 kg/cm 2 to about 16 kg/cm 2, the ratchet including a stop disposed on one of the shaft members to prevent over pressurizing of the jaw members (110, 120) beyond the first and second ratchet interfaces (31a, 31b), and an actuator operatively connected to one of the shaft members for selectively advancing the cutting mechanism from a first position wherein the cutting mechanism is disposed proximal to tissue held between the jaw members (110, 120) to at least one subsequent position wherein the cutting mechanism is disposed distal to tissue held between the jaw members (110, 120), characterised in that the cutting mechanism includes a generally hourglass-shaped flexible blade having a notch disposed generally midway therealong which facilitates distal translation of the knife within the knife channel.