Microsurgery is a general term for surgery requiring an operating microscope. The most obvious developments have been procedures developed to allow anastomosis of successively smaller blood vessels and nerves (typically 1 mm in diameter) which have allowed transfer of tissue from one part of the body to another and re-attachment of severed parts. Microsurgical techniques are utilized by several specialties today, such as general surgery, ophthalmology, orthopedic surgery, gynecological surgery, otolaryngology, neurosurgery, oral and maxillofacial surgery, plastic surgery, podiatric surgery and pediatric surgery. History Otolaryngologists were the first physicians to use microsurgical techniques. A Swedish otolaryngologist, Carl-Olof Siggesson Nylén (1892–1978), was the father of microsurgery. In 1921, in the University of Stockholm, he built the first surgical microscope, a modified monocular Brinell-Leitz microscope. At first he used it for operations in animals. In November of the same year he used it to operate on a patient with chronic otitis who had a labyrinthine fistula. Nylen's microscope was soon replaced by a binocular microscope, developed in 1922 by his colleague Gunnar Holmgren (1875–1954). Gradually the operating microscope began to be used for ear operations. In the 1950s many otologists began to use it in the fenestration operation, usually to perfect the opening of the fenestra in the lateral semicircular canal. The revival of the stapes mobilization operation by Rosen, in 1953, made the use of the microscope mandatory, although it was not used by the originators of the technique, Kessel (1878), Boucheron (1888) and Miot (1890). Mastoidectomies began to be performed with the surgical microscope and so were the tympanoplasty techniques that became known in the early 1950s. The stapes mobilization operation had varying results and was soon replaced by stapedectomy, first described by John Shea, Jr.; this was an operation that was always performed with the microscope. Today neurosurgeons are very proud to use microscopes in their procedures. But it was not always so: many prestigious centers did not accept that idea and it had to be developed in relative isolation. In the late 1950s William House began to explore new techniques for temporal bone surgery. He developed the middle fossa approach and perfected the translabyrinthine approach and began to use these techniques to remove acoustic nerve tumors. The first neurosurgeon to make use of the surgical microscope was a Turkish emigrant, Gazi Yasargil. In 1953 he studied neurovascular surgery during work with Prof. Hugo Krayenbühl in Switzerland. His ideas