1.1 Introduction

When we consider the current state of the art in many areas of surgery, it is instructive and humbling to glance occasionally in the rearview mirror of history. Where we are now has only been reached because of the achievements of those who went before. Bernard of Chartres in the 12th century pointed out “that we see more and further than our predecessors not because we have keener vision or greater height, but because we are lifted up and borne aloft on their gigantic stature.” While it is true that we may look back on some of the ideas and misconceptions from the past with incredulity or even, at times, amusement, one has to put the efforts of our predecessors into the context of the state of knowledge and technology of the day. We may rest assured that future generations of surgeons will look back at our early 21st century efforts with the same emotions.

1.2 Presurgical “Diagnostic” Era

The first date in the vestibular schwannoma (VS) saga is 1777, when Eduard Sandifort of Leiden recorded the first postmortem description of such a tumor, in a paper entitled “De duro quodam corpusculo, nervo auditorio adherente” (“Regarding a certain hard body adherent to the auditory nerve”). It was “not only connected to the lower part of the said nerve, but also to the nearest part of the medulla oblongata from which the two seventh nerves emerge, penetrating as far the foramen in the inner part of the petrous section of the temporal bone.” The tumor was externally hard like cartilage, but soft inside. He concluded that this cause of deafness was beyond the reach of medication or surgery and was thus incurables. Literatur (Fig. 1‑1 ).

The 18th century saw the dawn of the Age of the Enlightenment and can be seen as the start of the era of scientific medicine. Central to this was the abandonment of the belief that disease was a God-given punishment and was to be suffered as the price of redemption. Anatomy had been studied for several hundred years (e.g., the detailed dissection of the middle ear by Vesalius in the 16th century), but there was no serious attempt to understand physiology, until the groundbreaking work by William Harvey on the circulation of the blood. Galenic theories were gradually being challenged, and many of the great thinkers of the day presented their own concepts of the function of the human body and its relationship with the mind. Diagnostic medicine was fueled by the study of the relationship of disease to postmortem findings. In particular, neuroanatomy advanced through the outstanding contribution of Soemmerring on the origin and classification of the 12 cranial nerves and the doctrine of localization of the senses, notably through the work of Hughlings Jackson, Eduard Hitzig, and David Ferrier in the 19th century. Neurologists, like doctors in all specialties, were increasingly attempting to correlate pathological anatomy with clinical presentation—diseased structure with disorders of function. There are many elegant accounts of these efforts in the early literature on VS, and Leveque-Lasource, in 1810 in the French Literature, was one of the first who described a case of blindness and deafness with voice changes and partial paralysis.s. Literatur

Cruveilhier’s 1835 report cannot be bettered as an account of the progression of the symptomatology of VS, from deafness to postmortem, in a young woman. He describes “Complete amaurosis; no less complete loss of taste and smell; partial deafness. Violent headache, numbness of the skin of the face, and at times sharp pain in the left thigh, which seems to alternate with the cephalgia. Intelligence remained unimpaired to the last; passionate wish to die, as the sole means of ending her sufferings … for the last two weeks of life she refused nourishment, and for the first time there was practically continuous nausea; violent efforts to vomit, which raised phlegm; … the patient lost consciousness and died after 24 hours of agony. My diagnosis had been this: compression of the brain by an expanded tumor, either at the expense of the meninges or in the thickness of the brain itself; the probability of the seat of this tumor being at the base of the skull.” Cruveilhier describes the application of 16 leeches to the mastoid, bloodletting from the feet, electropuncture, and the use of moxas–downy vegetable material used in Oriental medicine as a counterirritant by igniting it on the skin.s. Literatur It is clear that at that time diagnostic skills were progressing at a greater rate than therapeutic remedies.

Sir Charles Bell in Edinburgh provided one of the most detailed early accounts in the English language in his 1830 description of a young woman who presented to him with total anesthesia of the second and third divisions of the trigeminal nerve so that “the end of a feather passed three inches into the nostril gives her no sensation and does not produce sneezing.” She went on to develop a hearing loss on the same side, giddiness, headache, and vomiting, and eventually died with brainstem failure, with clenching of her teeth, slurred speech, respiratory failure, and dysphagia. At postmortem, a tumor “the size of a pigeon’s egg” was found occupying the cerebellopontine angle and indenting the pons and cerebellum. It was described as cystic and contained fluid the color of urine. The solid capsule resembled vitreous humor. The auditory nerve could not be identified and only the most medial quarter inch of the facial nerve and half inch of the trigeminal nerve could be seen to be free of tumor.s. Literatur Throughout the 19th century, further important contributions to the localization of posterior fossa tumors and to cerebellar pathology were made by Hughlings Jackson,s. Literatur Joseph Toynbee,s. Literatur and William Gowerss. Literatur in England; Ludwig Brunss. Literatur and Hermann Oppenheims. Literatur in Germany; and by Joseph Babinskis. Literatur in France, eventually giving surgeons the confidence to locate and to attempt removal of posterior fossa lesions.

1.3 The Start of the Surgical Era and the Birth of Neurosurgery

The literature from the second half of the 19th century contains details, albeit somewhat scanty, of unsuccessful attempts at removal of what were most probably VSs. A patient was operated on by von Bergmann in Oppenheim’s clinic in 1890, but the tumor was not actually found until after the patient’s death.s. Literatur Charles McBurney in New York unsuccessfully explored the posterior fossa of a patient of M. Allen Starr in 1891,s. Literatur and Guldenarm operated for Winkler in Amsterdam in 1893, but the patient died soon after the operation.s. Literatur

The literature has widely attributed the distinction of the first successful surgical removal of a VS in 1894 to the London-based neurosurgeon Sir Charles Ballance.s. Literatur Harvey Cushing, however, disputes this, on the grounds that Ballance’s tumor was broad based and attached to the posterior surface of the petrous bone and therefore more likely to be a meningioma. Furthermore, deafness was not mentioned as a symptom. Fig. 1‑2 is taken from Ballance’s own operative note and does indeed show the tumor to be broad based. The internal meatus is not widened and does not contain tumor and there is minimal compression of the brainstem. Ballance himself describes it as “a solid tumor found attached to dura over inner part of posterior surface of petrous – somewhat firmly fixed.” Taken together, it does indeed seem to have been a meningioma, rather than a VS. In Cushing’s view, the accolade should go to the Edinburgh surgeon, Thomas Annandale, in 1895: “a brilliant surgical result the first recorded.”s. Literatur Annandale studied medicine in Edinburgh, Scotland, where he eventually succeeded Joseph Lister as Regius Professor in 1877. Like all general surgeons of the day, he could turn his hand to anything, although most of his practice seems to have been orthopedic (Fig. 1‑3 ).

His famous case described by Gibson (1896)s. Literatur and by Stewart (1895),s. Literatur who was the resident physician at Edinburgh Royal Infirmary, was Isabella, aged 25 years and pregnant, with a 10-month history of frontal headache, giddiness, and difficulty walking. She was unable to hear the ticking of a watch in her right ear or a tuning fork placed on the vertex. Examination of the eyes revealed optic neuritis (papilledema) and both horizontal and vertical nystagmus. There was dilation of the contralateral pupil, palatal weakness with nasal regurgitation of fluids, and changes in her voice. She had exaggerated tendon reflexes on both sides and ankle clonus. Her gait was broad based and she had a tendency to fall to the right side especially when standing with the feet together and the eyes closed. There was therefore strong clinical evidence of a large posterior fossa lesion, and Stewart made the perspicacious observation “the labyrinthine deafness would be consistent with a lesion either of an auditory pathway in the cerebellum, or in the auditory nucleus or nerve itself.” The differential diagnosis was tumor, gumma, or tuberculoma. Treatment with inunction of blue ointment and the antisyphilitic potassium iodide (her husband was a sailor “absent for protracted periods in distant parts of the world”) proved ineffective and, on May 3^rd 1895, Annandale trephined the skull over the right lobe of the cerebellum and removed a semicystic tumor the size of a pigeon’s egg from “the lateral lobe of the cerebellum.” Microscopic investigation showed it to be of the nature of a fibrosarcoma, at that time a rather imprecise term, but from the clinical description of the case it was most certainly a VS. Postoperatively, progress was “eminently satisfactory.” Her headache was immediately better, her sickness ceased, and her nystagmus settled almost completely. The swallowing became perfect even for fluids. Her gait improved and her optic neuritis almost disappeared. Surprisingly, there is no mention in the clinical record of the postoperative function of the facial nerve. It is hard to imagine that it remained intact and it may just be that in 1895, a facial paralysis was not regarded as much of a price to pay for the successful removal of an intracranial tumor. Five months later, Isabella delivered a baby girl and the note from the general practitioner makes it clear that both mother and child were in excellent health. The author could find no reference in the literature to any further sorties into the cerebellopontine angle (CPA) by Annandale. It may well be that he decided to quit while he was ahead!

During the early decades of the 20th century, there were increasing numbers of attempts at tumor removal. The results were almost always apocalyptically dreadful. Krause reported an 84% operative mortality,s. Literatur Borchardt reported 72%,s. Literatur and Eiselsberg reported 75%.s. Literatur Such statistics did nothing to encourage early intervention, and perpetuated the ominous outcome figures. Digital enucleation was common, with brain stem retraction and no understanding of the importance of the blood supply to the brainstem. Indeed, Ballance suggested that surgical outcomes could be improved if the anteroinferior cerebellar artery could be ligated prior to tumor removal. The need for speed driven by the still embryonic state of general anesthesia was a further contributing factor to the dire prognoses. At that time, the accepted approach to the tumor was via a large unilateral suboccipital craniotomy, often with resection of part of the cerebellum for access, and often as planned two- (or more) stage procedure. Furthermore, although localization was improving, it was still imperfect. Uncertainty as to the side of lesion would often mean that surgeons were obliged to remove all the bone from one lateral sinus to the other in search of the tumor.

Interestingly, the translabyrinthine approach to the tumor was first proposed in 1904 by Panse,s. Literatur avoiding the need for brainstem retraction. He defined the limits of that approach as the lateral sinus, the jugular bulb, the internal carotid artery, and the temporal lobe, but felt that the facial nerve would usually have to be sacrificed, although he also suggested that it could be mobilized from the geniculate ganglion to the stylomastoid foramen, anticipating Ugo Fisch by several decades. It is unclear whether Panse ever used the approach himself, but operations were carried out by Kümmel in Heidelberg in 1909s. Literatur and by Quix in Utrecht in 1911,s. Literatur although Quix was not able to remove the tumor. Success was primarily limited because of the cramped access. The approach was cursorily dismissed by Ballance as “objectionable for obvious reasons” and for at least half a century was relegated to obscurity, although Cushing himself stated “it may in time become the operation of choice.” Some surgeons did experiment with a combined suboccipital and transpetrosal approach removing bone as far as the internal meatus, but the results were just as disastrous.