A method for producing a polyoxyalkylene polyol which comprises subjecting propylene oxide and ethylene oxide to ring-opening addition polymerization with an initiator in the presence of a catalyst,. An axial pressing force is generated by the engagement of screws 1a and 5d of the rotating shaft 1 and the hub 5. Portions of the body tissue may be pressed into linear apposition with each other and held in place by cooperation between the suture and the suture retainer.