History and Neurosurgery Collide: The Evolution of Neurosurgery in Germany
History, politics and economics often have significant impact on science and medicine, and thus on the evolution of neurosurgery. For Germany, this included the broad influences impacting all of Europe in the early stages and then a unique impact of World Wars I and II as well as the Cold War. Since unification, neurosurgery in Germany has grown significantly and become fully integrated with and influential upon international neurosurgical progress.
Ancient Grecian, Egyptian and Indian sources contributed both ideas and devices influential to modern medicine. These concepts would have been lost to the Christian West had Islamic scholars not preserved them and then extended them with their own discoveries and concepts. During the Middle Ages, Europe contributed very little to this body of knowledge, since ecclesiastical dogma excluded surgery from medicine. Consequently, the doctrines of ancient medicine – including erroneous ones – remained in force until the 17th century, when the Age of Enlightenment inspired a new thirst for knowledge. In Germany, Lorenz Heister (1683-1758) became the first academic surgeon. His textbook Chirurgie was, in part, based on his own detailed anatomic studies. To that, Albrecht von Haller (1708-1777) added his own observations on the physiology of sensation and the muscle-nerve relationship.
The foundations of modern surgery were laid in the middle of the 19th century, notably:
- General anesthesia in the United States;
- Local anesthesia in Austria and Germany; and
- The principles of antisepsis in the United Kingdom.
By 1880, the specific prerequisite of neurosurgery – knowledge of the topical organization of brain function – had been established by a Briton, David Ferrier, and two Germans, Gustav Fritsch and Eduard Hitzig.
Ernst von Bergmann (1836-1907), the father of modern German surgery, was the first German to deal systematically with cranial surgery. As a military surgeon, he recognized the significance of increased intracranial pressure in head injuries. In 1880 and 1889, he wrote the first textbooks on neurosurgery and, more importantly, he introduced the principle of asepsis. Given the disastrous results of brain tumor surgery at the time, he warned against any uncritical enthusiasm, constraining progress of the new subspecialty.
Working independently, Fedor Krause (1857-1937) became a true pioneer of neurosurgery in Germany. Employed as a general surgeon in Altona and, after 1900, at Augusta Hospital, a small, non-teaching hospital in Berlin. He developed some of the main approaches to deep-seated intracranial regions:
- 1893 – the Gasserian ganglion, (independently from the American Frank Hartley)
- 1898 – the cerebellopontine angle
- 1900 – subfrontal approach to the sellar region
- 1913 – the supracerebellar (Krause) approach to the pineal region
His textbook on neurosurgery (1908-1911) remained a standard work for decades. Apart from Krause, a few surgeons focused on neurosurgical topics, among them:
- Moritz Borchardt (1868-1948), who, in 1905, was one of the first surgeons who successfully operated on vestibular schwannomas.
- Ernst Unger (1875-1938) introduced surgical suction techniques in brain tumor operations as early as 1910, but did not receive due recognition from his colleagues.
The Great War
When Krause retired in 1921, the Great War had left Germany in a state of total defeat, encumbered by economic disaster and political turmoil. In addition, German surgeons were excluded from international meetings for a decade and the German language was banned from medical journals. As a result, Germany was no longer able to keep abreast of international scientific progress. Significant technological breakthroughs, such as blood pressure monitoring (1901), silver clips (1911) and surgical suction (1925), were not properly disseminated to the wider scientific community.
Nevertheless, there was a gradual increase in neurosurgical activity in the post-war period, involving both general surgeons and neurologists. Of the latter, Otfrid Foerster (1873-1941) became the most renowned in Breslau (now Wroclaw), Poland. Following extensive training in neuroanatomy, neurology and rehabilitation, Foerster began neurosurgical interventions as early as 1908, when he introduced selective dorsal rhizotomy to mitigate spasticity (Foerster’s procedure). Although he had never received any basic surgical training, during and after the war he extended his surgical activity to the entire nervous system. Fluent in several languages, he became the most internationally renowned German neuroscientist, visited by many colleagues from all over the world. His pupils later established a particular school of neurosurgery, known as “surgical neurology,” rather than “neurological surgery.”
Emil Heymann (1878-1936), Foerster’s contemporary, is less known today, although, in his time, he was internationally recognized for outstanding surgical skills. Heymann joined Krause’s team in 1903, became his deputy and eventually succeeded him in 1921. He dealt intensively with the surgical problems of vestibular schwannomas and gained particular expertise in tumors of the spinal canal. He was the first German to adopt Cushing’s technique
of electrocautery in brain tumor surgery and worked to improve technical equipment to improve outcomes.
Other surgeons, such as Nicolai Guleke (1878-1958) in Jena and Alexander Stieda (1875-1966) in Halle, also focused on the nervous system. Like Heymann, they remained general surgeons and none of them pressed for neurosurgery to be treated as an autonomous subspecialty. In contrast, the first professional neurosurgical association was founded in the USA in1920, followed by a second in 1932, while British neurosurgeons founded their own national society in 1926. It was not until 1925 that Germany became interested in American neurosurgical techniques, as evidenced by an increasing number of study visits and fellowships with leading American neurosurgeons. Emil Heymann and Moritz Borchardt tried to obtain academic recognition of neurosurgery as a subspecialty. They failed, not only because of the resistance of the professors of general surgery, but also because they were Jewish, reflecting the widespread anti-Semitic attitude within academia at that time.
Hitler and World War II
Adolf Hitler and the National Socialist party came to power in January 1933. They soon ousted all practicing doctors of Jewish descent, dramatically reducing the number of physicians active in neurosurgery (about 20). While the Jewish proportion of the overall German population was about 1.5 percent, nearly 16 percent of all German physicians were Jewish. The persecuted brain surgeons included Emil Heymann, Moritz Borchardt and Ludwig Guttmann. Guttman was Otfrid Foerster’s chief resident physician and deputy, who later found refuge in the United Kingdom where he revolutionized the treatment of spinal cord injuries and founded the Paralympic Games. In addition, Carl Felix List (a member of Moritz Borchardt’s staff) and Jost Joseph Michelsen (Leipzig) were forced to emigrate. Both were able to pursue a career in neurosurgery in the United States. Alice Rosenstein, also a trainee of Foerster and, perhaps, the first female neurosurgeon in the world, was forced to flee Germany and could only work as a psychiatrist and neurologist. Others, including Walter Lehmann (Göttingen and Frankfurt) and Franz Schück (Berlin) ultimately failed to establish themselves in exile. The Nazi rulers made every effort to erase all these names from the collective memory. In this, they were supported by surgeons of Aryan descent to an unsettling degree.
The resulting lack of neurosurgical expertise became particularly apparent in Berlin after Heymann’s death in 1936. Wilhelm Tönnis (1898-1978) came to Berlin as his replacement one year later. Tönnis had received basic surgical training with Victor Schmieden in Frankfurt and with Bergmann’s disciple, Fritz König, in Würzburg. In 1932, he was awarded a seven-month fellowship with Herbert Olivecrona in Stockholm, where he was trained in American neurosurgical techniques. Following his return, the political authorities allowed him, in 1934, to establish the first specialized neurosurgical unit in Germany. He was transferred to Berlin in 1937 on the instructions of the political authorities and without the formal involvement of any university institutions. However, his appointment to the first associate professorship for neurosurgery marked the beginning of a new German academic discipline. There was little resistance from general surgeons, since the political rulers, busy with preparations for war, appreciated the military value of the new specialty. Tönnis was also appointed head of a section for tumor research and experimental pathology at the Kaiser Wilhelm Institute for Brain Research. From the outset, Tönnis tried to establish international relationships: in 1936, he founded the first international neurosurgical journal with an international editorial board. In the following year, he (together with Foerster) hosted the British Society of Neurological Surgeons in Berlin and Breslau. Devoid of major competitors (with the possible exception of the younger, extremely well trained Franz Karl Kessel in Munich), Tönnis sent out his own pupils to create new neurosurgical units. By the fall of 1939, the number of neurosurgical units in Germany had reached the same level as in 1932. With few exceptions (e.g. Foerster, Riechert, Sauerbruch), the heads of these units belonged to Nazi organizations. A few weeks before the scheduled foundation of a national neurosurgical society, Nazi Germany launched World War II. During the war, Tönnis was appointed consulting neurosurgeon of the Luftwaffe (Air Force), later of the entire Wehrmacht (Army) and ultimately promoted to the rank of Surgeon-General. Like Hugh Cairns in the United Kingdom, he established mobile surgical teams for the initial treatment of wounded military personnel. He won particular international recognition for his organization of an airborne rescue system.
Post War and Cold War
After the war, Tönnis was allowed to pursue his career at a large miners’ hospital in Bochum. In 1948, he was appointed the first tenured professor of neurosurgery at the University of Cologne, where he remained until his retirement in 1966. In 1950, the Deutsche Gesellschaft für Neurochirurgie (German Neurosurgical Society) was founded. Together with his mentor and friend Herbert Olivecrona, Tönnis edited a 12-volume handbook of neurosurgery. Oncology remained his predominant scientific field. His accumulated experience formed the basis of the first WHO classification of brain tumors drawn up by his longstanding staff member Klaus-Joachim Zülch. While his early career was substantially boosted by the political conditions created by the Nazi regime, he used his power to introduce the American school of neurosurgery into Germany to good effect and establish this subspecialty as an academic discipline and to encourage the development of many neurosurgical units in Germany. Most of these were headed by his own pupils, including:
- Gerhard Okonek (Göttingen);
- Peter Röttgen (Bonn);
- Friedrich Loew (Homburg/Saar);
- Hans Werner Pia (Gießen);
- Kurt Schürmann (Mainz); and
- Wolfgang Schiefer (Erlangen).
In 1946, Arist Stender (1903-1975) created a neurological and neurosurgical department in Berlin-Charlottenburg. One year later, Ernst Klar and Hans Kuhlendahl opened neurosurgical units in Heidelberg and Düsseldorf respectively. The neurological focus of these units remained recognizable for several decades, but it gradually became less evident. A third center developed in Freiburg, where Traugott Riechert (1905-1983) and his staff had been concentrating on stereotactic procedures and later on hydrocephalus and pediatric neurosurgery. Their colleagues, who had been expelled only ten years before, remained forgotten. They were neither mentioned by the post-war generation of neurosurgeons nor even invited to return to Germany.
In response to Nazi Germany’s monstrous crimes, the allied powers excluded most German scientists from the international scientific community for more than a decade. Tönnis’ staff, as well as Stender and Riechert, made particular efforts to foster cooperation in worldwide. In 1957, Stender became a founding member of the World Federation of Neurosurgical Societies (WFNS). In 1959, the first European neurosurgical meeting took place in Zürich, organized as a joint meeting of the Société de Neuro-Chirurgie de Langue Française and the Deutsche Gesellschaft für Neurochirurgie. This eventually led to the foundation of the European Association of Neurosurgical Societies (EANS) in 1971.
The Iron Curtain divided Germany after the war with differential development of neurosurgery in the two sectors. West Germany (FRG) benefited politically from the establishment of a democratic system of government and economically from the Marshall Plan. East Germany (GDR), which became a satellite of the Soviet Union, was economically stressed by large war reparations as well as politically and intellectually limited by the new totalitarian regimes. Professors of surgery resisted the introduction of neurosurgery as a subspecialty. However, in 1948 the first neurosurgical unit opened in Leipzig, headed by Georg Merrem (1908-1971), a pupil of Emil Heymann. He was the only one to continue the tradition of the Krause-Heymann school, and his unit became the main center for neurosurgery in the GDR. In 1959, Merrem was appointed professor of neurosurgery in the GDR, the only such appointment to be made in that country. Leipzig and the municipal unit in Berlin-Buch (Friedrich Weickmann) remained the only independent neurosurgical units until the reunification of Germany in 1990. The other units, their number eventually increasing to 11, functioned as sections of surgical departments, the
most renowned being Erfurt (Werner Usbeck), Berlin-Charité (Rudolf Unger), Dresden (Peter Schaps) and Magdeburg (Siegfried Vogel and Hans-Joachim Synowitz). Despite all the difficulties, GDR neurosurgeons provided high quality care, in part using technical equipment developed in the GDR itself, e.g. the surgical microscope (1973), the laser scalpel (1980) and the ultrasound aspirator (1983).
Modern Era and Reunification
Neurosurgery was finally recognized as a subspecialty when board certification was instituted in the GDR in 1955 and in West Germany in 1956. At the time of reunification in 1990, the number of active neurosurgeons had increased to nearly 500 in West Germany and to 60 in the GDR. Most of them were affiliated to 85 West German hospital units and 60 in the GDR. They were responsible for providing care for nearly 61 million people in West Germany and 19 million in the GDR. The number of neurosurgeons rose to 2,000 in 2017. Women currently account for 25 percent of all neurosurgeons and are rising. Of the 2,000 neurosurgeons, two-thirds are employed in university or municipal hospitals and, more recently, also in commercial hospitals. The remaining one-third practice in private surgeries, the faster growing sector. The total number of neurosurgical procedures approximates to 320,000 per year. These figures raise concerns about oversupply, since the total population of 82 million has remained essentially stable during the past three decades.
Board certification in Germany requires a minimum of six years of postgraduate training. It is largely bound to hospital services and includes a minimum of four years training in general neurosurgical practice. In accordance with a Europe-wide agreement, this must be documented and supervised on a properly structured basis. Particular experience in diagnostic ultrasound and electrophysiological examination is required, as is a minimum half-year period spent in an intensive care unit. Training in other specialties is accepted to a certain extent. The German Neurosurgical Society assists qualification by organizing annual training courses. In addition, several working groups are engaged in scientific research in particular fields of interest.
Acknowledgement: The authors wish to express their gratitude to Leslie Woodhall for translation and final language editing.
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