In cases where the fallopian tubes are blocked, surgery performed to unblock the tubes, on peritubal adhesions requires great sensitivity to prevent new adhesions or occlusions. In some instances, the damaged parts of the tubes are excised and functioning ends are sown back together. Before 1980, tubal surgery was the only option for patients with tubal infertility. Since that time IVF has become more successful, surgery is performed much less frequently. Surgery to open the Fallopian tubes is most commonly performed on patients who have had tubal ligation done to prevent pregnancy.