An equally famous specialist for VS at Johns Hopkins in Baltimore was Walter E. Dandy (1886–1946), a former pupil of Cushing who advocated total tumor removals. In 1931, he reported a complete removal with preservation of the facial nerve. Imaging
A major problem for the pioneers in VS neurosurgery was the lack of adequate imaging for spotting small tumors. Treating tumors that grew overly large in the cerebellopontine angle resulted in poor outcomes for the goals of facial nerve and hearing preservation. For imaging, conventional X-rays began to be used in the 1920s and CT scanners were introduced in the 1960s, but all were superseded by gold standard MRIs in the 1980s. Facial nerve monitoring was added in 1979. William F. House (1923–2012) pioneered the use of the operating microscope, and (with William Hitselberger) popularized the translabyrinthine and middle fossa surgery approaches for VS. The operating microscope would be used in virtually all operations by 1998. Houses son, John W. House, proposed (1983) and, with Derald E. Brackmann, developed the House-Brackmann grading system for reporting facial nerve outcomes following VS surgery. Treatment
Surgical treatment
In 1986, at a meeting for neurosurgeons in San Francisco, the House group endorsed a guideline for the surgical treatment of VS: "The best opportunity for successful removal of an acoustic neuroma is when it is small: when first diagnosed." At the time of the NIH Consensus Development Conference for Acoustic Neuroma in 1991, microsurgery was definitely the predominant management strategy for VS.
The Introduction to the Guidelines stated: "The evolution in treatment over the last century has ultimately led to an environment where functional outcome has taken precedence over disease eradication. With multiple noninvasive management options available, the tolerance of cranial neuropathy in patients with small and medium-sized tumors is low. Today, hearing preservation, facial nerve function, and tumor control remain the primary benchmarks used to evaluate treatment effectiveness and compare outcomes." In other words, tumor management was able to give greater attention to preserving quality of life. The three main surgical approaches to the tumor were the translabyrinthine (incision behind the ear to reach the bony labyrinth), the retrosigmoid (incision behind the ear to reach cerebellopontine angle) and the middle cranial fossa (incision in front of the ear to access the IAC from above). Tumor size was a major factor in determining approach selection. Adjunctive use of the endoscope for enhanced visualization during surgery for IAC tumors gained attention as an emerging technique with advancing technology. For large tumors, a facial nerve sparing surgery evolved offering partial removals, to be followed (as needed) by stereotactic radiosurgery or radiotherapy for residuals. The rate of tumor control appeared to be similar to that for gross total removal surgeries. For small to medium size tumors, the appropriateness of so-called hearing preservation surgery via either the Middle Fossa or Retrosigmoid approach remained controversial. Data from Denmark indicated that primary observation offered the best chance to preserve good hearing the longest.