Sir Victor Horsley: pioneer craniopharyngioma surgeon

Evolution and Revolution of Imaging Technologies in Neurosurgery

We understand only a small fraction of the events happening in our brains; therefore, despite all the progress made thus far, a whole array of questions remains. Nonetheless, neurosurgeons invented new tools to circumvent the challenges that had plagued their predecessors. With the manufacturing boom of the 20th century, technological innovations blossomed enabling the neuroscientific community to study and operate upon the living brain in finer detail and with greater precision while avoiding harm to the nervous system. The purpose of this chronological review is to 1) raise awareness among future neurosurgeons about the latest advances in the field, 2) become familiar with innovations such as augmented reality (AR) that should be included in education given their ready applicability in surgical training, and 3) be comfortable with customizing these technologies to real-life cases like in the case of mixed reality.

Cushing's dogged struggle against death: the astonishing case of a patient under cardiac arrest surviving craniopharyngioma surgery

The decisive role Dr. Harvey Cushing (1869-1939) played in medicine goes far beyond the development of neurosurgery. His scientific devotion and commitment to patient care made him an ethical model of strict professionalism. This paper seeks to analyze the decisions Cushing made with the challenging case of HW, an adolescent boy with a craniopharyngioma (CP) involving the third ventricle. Cushing's earlier failure to successfully remove two similar lesions alerted him to the proximity of HW's tumor and the hypothalamus. Consequently, he decided to use the chiasm-splitting technique for the first time, with the aim of dissecting the CP-hypothalamus boundaries under direct view. Unexpectedly, HW suffered cardiac arrest during the surgery, but Cushing did not give up. He continued with the operation while his assistants performed resuscitation maneuvers. Such determined and courageous action allowed Cushing to succeed in an apparently hopeless case. Cushing's unwavering willingness to save patients' lives, even under extreme circumstances, was a fundamental trait defining his identity as a neurosurgeon. Analyzing the way Cushing dealt with HW's case provides valuable lessons for neurosurgeons today, particularly the importance of assuming proactive attitudes and, in certain cases, making painstaking efforts to overcome daunting situations to save a life.

Craniopharyngiomas primarily affecting the hypothalamus

The concept of craniopharyngiomas (CPs) primarily affecting the hypothalamus, or "hypothalamic CPs" (Hy-CPs), refers, in a restrictive sense, to the subgroup of CPs originally developing within the neural tissue of the infundibulum and tuber cinereum, the components of the third ventricle floor. This subgroup, also known as infundibulo-tuberal CPs, largely occupies the third ventricle and comprises up to 40% of this pathological entity. The small subgroup of strictly intraventricular CPs (5%), lesions wholly developed within the third ventricle above an anatomically intact third ventricle floor, can also be included within the Hy-CP category. The remaining types of sellar and/or suprasellar CPs may compress or invade the hypothalamic region during their growth but will not be considered in this review. Hy-CPs predominantly affect adults, causing a wide range of symptoms derived from hypothalamic dysfunction, such as adiposogenital dystrophy (Babinski-Fröhlich's syndrome), diabetes insipidus (DI), abnormal diurnal somnolence, and a complex set of cognitive (dementia-like, Korsakoff-like), emotional (rage, apathy, depression), and behavioral (autism-like, psychotic-like) disturbances. Accordingly, Hy-CPs represent a neurobiological model of psychiatric disorders caused by a lesion restricted to the hypothalamus. The vast majority (90%) of squamous-papillary CPs belong to the Hy-CP category. Pathologically, most Hy-CPs present extensive and strong adhesions to the surrounding hypothalamus, usually formed of a thick band of gliotic tissue encircling the central portion of the tumor ("ring-like" attachment) or its entire boundary ("circumferential" attachment). CPs with these severe adhesion types associate high surgical risk, with morbidity and mortality rates three times higher than those for sellar/suprasellar CPs. Consequently, radical surgical removal of Hy-CPs cannot be generally recommended. Rather, Hy-CPs should be accurately classified according to an individualized surgery-risk stratification scheme considering patient age, CP topography, presence of hypothalamic symptoms, tumor size, and, most importantly, the CP-hypothalamus adhesion pattern.

Charles H. Frazier's craniopharyngioma treatment: the pivotal role of the transfrontal approach

Charles H. Frazier (1870-1936), one of the pioneers of neurosurgery in the US, is known worldwide for devising surgical procedures to relieve trigeminal neuralgia and intractable pain. Less well-known are his substantial contributions to understanding and treating pituitary and parahypophyseal lesions. Along with Bernard Alpers, he defined Rathke's cleft tumors as a different pathological entity from adenomas and hypophyseal stalk tumors (craniopharyngiomas [CPs]). The surgical challenge posed by CPs piqued Frazier's interest in these lesions, although he never published a complete account of his CP series. An examination of the Charles Frazier papers at the College of Physicians of Philadelphia allowed the authors to identify 54 CPs that he had treated during his career. In the early 1910s, Frazier developed the subfrontal approach, which would become the primary surgical route to access these lesions, providing better control of the adjacent vital neurovascular structures than the transsphenoidal route hitherto used. Nevertheless, strong adhesions between CPs and the third ventricle floor, the major reason underlying Frazier's disappointing results, moved him to advocate incomplete tumor removal followed by radiotherapy to reduce both the risk of hypothalamic injury and CP recurrence. This conservative strategy remains a judicious treatment for CPs to this day.

Craniopharyngioma treatment: an updated summary of important clinicopathological concepts

INTRODUCTION

Craniopharyngiomas (CPs) are benign histological tumors that may develop at different positions along the hypothalamic-pituitary axis. Their close, heterogenous relationship to the hypothalamus makes surgical removal challenging even though this remains the primary treatment strategy.

AREAS COVERED

This article presents a critical overview of the pathological and clinical concepts regarding CPs that should be considered when planning treatment. Thus, we have performed a comprehensive review of detailed CP reports published between 1839 and 2020.

EXPERT OPINION

CP surgery should pursue maximal tumor resection while minimizing the risk of injuring the hypothalamus. Therefore, surgical strategies should be individualized for each patient. Accurate assessment of presenting symptoms and preoperative MRI has proven useful to predict the type of CP-hypothalamus relationship that will be found during surgery. CPs with dense and extensive adhesions to the hypothalamus should be highly suspected when MRI shows the hypothalamus positioned around the mid-third of the tumor and an amputated upper portion of the pituitary stalk. Symptoms related to functional impairment of the infundibulo-tuberal area of the third ventricle floor, such as obesity/hyperphagia, Fröhlich's syndrome, diabetes insipidus, and/or somnolence, also indicate risky CP-hypothalamic adhesions. In these cases, limited tumor removal is strongly advocated followed by radiation therapy.

Harvey Cushing's craniopharyngioma treatment: Part 1. Identification and clinicopathological characterization of this challenging pituitary tumor

OBJECTIVE

Harvey Cushing (1869-1939) coined the term "craniopharyngioma" (CP) in 1929 to describe a kaleidoscopic group of epithelial tumors involving the hypothalamic-pituitary axis. Throughout his career, he endured a long struggle to accurately diagnose and safely remove these complex lesions, and his resulting surgical series has never before been analyzed in depth. The authors here conduct such an analysis.

METHODS

In this study, the authors retrospectively examined the CP patient records available in the Cushing Brain Tumor Registry, as well as those CP cases reported by Cushing in medical monographs and scientific reports.

RESULTS

Cushing's CP series comprises a total of 124 tumors (CP124) compatible with a CP diagnosis. Among this series are 92 cases that could be pathologically verified (CP92). This subcohort showed a bimodal age distribution (41% aged ≤ 19 years old) and a balanced sex distribution. Clinical evolution up to diagnosis was longer than 3 years in half of the patients. Typical symptoms found at diagnosis were severe headache (94%), visual deficits (97%), panhypopituitarism (76%), psychiatric disturbances (47%), and abnormal somnolence (47%). The highest rate of endocrine deficits occurred in patients younger than 19 years of age (p < 0.001), whereas hypothalamic disturbances were observed mainly in adults between 30 and 49 years (p = 0.02). Hydrocephalus was present in 63% of the patients, predominantly involving the younger subgroup (p < 0.001). Preoperative diagnosis was based on clinical signs, funduscopic exams, and skull radiographs, the latter study showing suprasellar calcifications in 64% of cases. The majority of tumors (61%) had developed within the third ventricle (3V) or had invaded it. The adamantinomatous histological variant was the predominant one (73%). Squamous-papillary CPs occurred only in adults older than 40 years of age (p < 0.001). Strong CP adherences to the hypothalamus were demonstrated in 63% of cases. The infundibulo-tuberal and sellar/suprasellar-3V CP topographies were associated with the highest rates of hypothalamic dysfunction before surgery (p < 0.001), surgical hypothalamic injury (p < 0.001), and severe postoperative morbidity and/or mortality (p = 0.009). Both topographies showed the strongest adherences to the hypothalamus and 3V (p < 0.001).

CONCLUSIONS

Cushing's CP series comprises severely ill patients with tumors in the late stages of progression, with a high rate of tumors developing primarily within the hypothalamus (infundibulo-tuberal CPs) or invading this structure from the sellar/suprasellar regions. Craniopharyngioma topography was the fundamental variable influencing the clinical manifestations, tumor features, and patient outcomes in this series.

Measurements and Clinical Application of Anatomical Space for Transfrontal Pituitary Surgery Through Magnetic Resonance Imaging Reconstruction

OBJECTIVE

This study aims to clarify the relative position of the normal important structures and anatomical spaces formed by the structures passed through during the transfrontal pituitary surgery, and discuss how to avoid some eloquent structures.

METHODS

A total of 120 cases of magnetic resonance imaging images from normal adult brains were selected as the object of study and divided into male and female groups. The important adjacent structures of the pituitary passed through during the transfrontal pituitary surgery were marked on the reconstructed images. In all planes of the spaces passing through successively during the pituitary surgery, the morphological parameters such as the size, boundary, structure, and spatial extent of the spaces were measured.

RESULTS

The size, boundary, structure, and spatial extent of the space between the 2 optic nerves, the space between the optic nerves and the pituitary stalk, and the space between the tuber cinereum and the interal carotid artery in the plane of the pituitary stalk were measured, the anterior part and the posterior part in male were shorter than those in female (P = 0.021; P = 0.029); no statistically significant difference was found in the measurements of the lengths and angles of these spaces.

CONCLUSIONS

The authors' findings provide the surgeons with the detailed anatomical data and help to provide a morphological basis for intraoperative protection of the pituitary and vital adjacent structures and surgical approach.

American views of Sir Victor Horsley in the era of Cushing

Sir Victor Horsley was a pioneering British neurosurgeon known for his numerous neurosurgical, scientific, and sociopolitical contributions. Although word of these surgical and scientific achievements quickly spread throughout Europe and North America in the late 19th century, much of modern neurosurgery's view of Horsley has been colored by a single anecdote from John Fulton's biography of Harvey Cushing. In this account, Cushing observes a frenetic Horsley hastily removing a Gasserian ganglion from a patient in the kitchen of a British mansion. Not long after, Cushing left Britain saying that he had little to learn from British neurosurgery. The authors of this paper examined contemporary views of Horsley to assess what his actual reputation was in the US and Canada. The authors conducted a thorough search of references to Horsley using the following sources: American surgical and neurosurgical textbooks; major biographies; diary entries and letters; PubMed; newspaper articles; and surgical and neurosurgical texts. The positive reception of his work is corroborated by invitations for Horsley to speak in America. Research additionally revealed that Horsley had numerous personal and professional relationships with prominent Americans in medicine, including William Osler, John Wheelock Elliot, Ernest Sachs, and (yes) Harvey Cushing. Horsley's contributions to medicine and science were heavily reported in American newspapers; outside of neurosurgery, his strong opposition to the antivivisectionists and his support for alcohol prohibition were widely reported in popular media. Horsley's contributions to neurosurgery in America are undeniable. Writings from and about prominent Americans reveal that he was viewed favorably by those who had met him. Frequent publication of his views in the American media suggests that medical professionals and the public in the US valued his contributions on scientific as well as social issues. Horsley died too young, but not without the international recognition that was rightly his.

Cystic tumors of the pituitary infundibulum: seminal autopsy specimens (1899 to 1904) that allowed clinical-pathological craniopharyngioma characterization

A heterogeneous group of epithelial cystic tumors developed at the infundibulum and the third ventricle disconcerted pathologists at the dawn of the twentieth century. Very little was known at that time about the physiological role played by the pituitary gland, and there was almost complete ignorance regarding the function of the hypothalamus. Acromegaly, or enlargement of acral body parts, described in 1886 by Pierre Marie, was the only disease linked to primary hypertrophies of the pituitary gland, known as "pituitary strumas". A growing number of young patients manifesting an unexplained combination of physical and mental symptoms, including absent or delayed sexual maturation, progressive obesity, abnormal somnolence, and dementia-like changes in behavior were reported to present large solid-cystic tumors which characteristically expanded within the infundibulum and third ventricle, above an anatomically intact pituitary gland. Between 1899 and 1904, five seminal autopsy studies from different countries thoroughly described the anatomical relationships and histological features of this newly recognized type of infundibular tumors. These cases were instrumental in fostering the systematic investigation of similar lesions by the Austrian pathologist Jakob Erdheim (1874-1937), who in 1904 was able to classify these infundibulo-tuberal cysts under the common category of hypophyseal duct tumors. The pioneering American neurosurgeon Harvey Cushing (1869-1939) unsuccessfully attempted to surgically remove one of these cysts, for the first time in history, in 1902. The term "craniopharyngioma", chosen by Cushing in 1929 to designate these lesions, would eventually prevail over Erdheim's more accurate denomination, which linked their origin to squamous cell remnants derived from the embryological structures that give rise to the pituitary gland. This paper presents a comprehensive, renewed account of the five clinical-pathological reports which laid the groundwork for the proper clinical diagnosis, topographic conceptualization and pathological categorization of craniopharyngiomas.

Jean Camus and Gustave Roussy: pioneering French researchers on the endocrine functions of the hypothalamus

At the beginning of the twentieth century, the hypothalamus was known merely as an anatomical region of the brain lying beneath the thalamus. An increasing number of clinicopathological reports had shown the association of diabetes insipidus and adiposogenital dystrophy (Babinski-Fröhlich's syndrome), with pituitary tumors involving the infundibulum and tuber cinereum, two structures of the basal hypothalamus. The French physicians Jean Camus (1872-1924) and Gustave Roussy (1874-1948) were the first authors to undertake systematic, controlled observations of the effects of localized injuries to the basal hypothalamus in dogs and cats by pricking the infundibulo-tuberal region (ITR) with a heated needle. Their series of surgical procedures, performed between 1913 and 1922, allowed them to claim that both permanent polyuria and adiposogenital dystrophy were symptoms caused by damage to the ITR. Their results challenged the dominant doctrine of hypopituitarism as cause of diabetes insipidus and adiposogenital dystrophy that derived from the experiments performed by Paulescu and Cushing a decade earlier. With their pioneering research, Camus and Roussy influenced the experimental work on the hypothalamus performed by Percival Bailey and Frederic Bremer at Cushing's laboratory, confirming the hypothalamic origin of these symptoms in 1921. More importantly, they provided the foundations for the physiological paradigm of Neuroendocrinology, the hypothalamus' control over the endocrine secretions of the pituitary gland, as well as over water balance and fat metabolism. This article aims to credit Camus and Roussy for their groundbreaking, decisive contributions to postulate the hypothalamus being the brain region in control of endocrine homeostasis and energy metabolism.

Craniopharyngioma adherence: a comprehensive topographical categorization and outcome-related risk stratification model based on the methodical examination of 500 tumors

OBJECTIVE Craniopharyngioma (CP) adherence strongly influences the potential for achieving a radical and safe surgical treatment. However, this factor remains poorly addressed in the scientific literature. This study provides a rational, comprehensive description of CP adherence that can be used for the prediction of surgical risks associated with the removal of these challenging lesions. METHODS This study retrospectively analyzes the evidence provided in pathological, neuroradiological, and surgical CP reports concerning 3 components of the CP attachment: 1) the intracranial structures attached to the tumor; 2) the morphology of the adhesion; and 3) the adhesion strength. From a total of 1781 CP reports published between 1857 and 2016, a collection of 500 CPs providing the best information about the type of CP attachment were investigated. This cohort includes autopsy studies (n = 254); surgical studies with a detailed description or pictorial evidence of CP adherence (n = 298); and surgical CP videos (n = 61) showing the technical steps for releasing the attachment. A predictive model of CP adherence in hierarchical severity levels correlated with surgical outcomes was generated by multivariate analysis. RESULTS The anatomical location of the CP attachment occurred predominantly at the third ventricle floor (TVF) (54%, n = 268), third ventricle walls (23%, n = 114), and pituitary stalk (19%, n = 94). The optic chiasm was involved in 56% (n = 281). Six morphological patterns of CP attachment were identified: 1) fibrovascular pedicle (5.4%); 2) sessile or patch-like (21%); 3) cap-like (over the CP top, 14%); 4) bowl-like (around the CP bottom, 13.5%); 5) ring-like (encircling central band, 19%); and 6) circumferential (enveloping the entire CP, 27%). Adhesion strength was classified in 4 grades: 1) loose (easily dissectible, 8%); 2) tight (requires sharp dissection, 32%); 3) fusion (no clear cleavage plane, 40%); and 4) replacement (loss of brain tissue integrity, 20%). The types of CP attachment associated with the worst surgical outcomes are the ring-like, bowl-like, and circumferential ones with fusion to the TVF or replacement of this structure (p < 0.001). The CP topography is the variable that best predicts the type of CP attachment (p < 0.001). Ring-like and circumferential attachments were observed for CPs invading the TVF (secondary intraventricular CPs) and CPs developing within the TVF itself (infundibulo-tuberal CPs). Brain invasion and peritumoral gliosis occurred predominantly in the ring-like and circumferential adherence patterns (p < 0.001). A multivariate model including the variables CP topography, tumor consistency, and the presence of hydrocephalus, infundibulo-tuberal syndrome, and/or hypothalamic dysfunction accurately predicts the severity of CP attachment in 87% of cases. CONCLUSIONS A comprehensive descriptive model of CP adherence in 5 hierarchical levels of increased severity-mild, moderate, serious, severe, and critical-was generated. This model, based on the location, morphology, and strength of the attachment can be used to anticipate the surgical risk of hypothalamic injury and to plan the degree of removal accordingly.

Harvey Cushing and pituitary Case Number 3 (Mary D.): the origin of this most baffling problem in neurosurgery

From the very beginning of his career, Harvey Williams Cushing (1869-1939) harbored a deep interest in a complex group of neoplasms that usually developed at the infundibulum. These were initially known as "interpeduncular" or "suprasellar" cysts. Cushing introduced the term "craniopharyngioma" for these lesions, which he believed represented one of the most baffling problems faced by neurosurgeons. The patient who most influenced Cushing's thinking was a 16-year-old seamstress named "Mary D.," whom he attended in December 1901, exactly the same month that Alfred Fröhlich published his seminal article describing an adiposogenital syndrome in a young boy with a pituitary cyst. Both Cushing's and Fröhlich's patients showed similar symptoms caused by the same type of tumor. Notably, Cushing and Fröhlich had met one another and became good friends in Liverpool the summer before these events took place. Their fortunate relationship led Cushing to realize that Fröhlich's syndrome represented a state of hypopituitarism and provided a useful method of diagnosing interpeduncular cysts. It is noteworthy that Cushing's very first neurosurgical procedure on a pituitary tumor was performed in the case of Mary D.'s "interpeduncular cyst," on February 21, 1902. Cushing failed to remove this lesion, which was later found during the patient's autopsy. This case was documented as Pituitary Case Number 3 in Cushing's masterpiece, The Pituitary Body and Its Disorders, published in 1912. This tumor was considered "a teratoma"; however, multiple sources of evidence suggest that this lesion actually corresponded to an adamantinomatous craniopharyngioma. Unfortunately, the pathological specimens of this lesion were misplaced, and this prompted Cushing's decision to retain all specimens and documents of the cases he would operate on throughout his career. Accordingly, Mary D.'s case crystallized the genesis of the Cushing Brain Tumor Registry, one of Cushing's major legacies to neurosurgery. In this paper the authors analyze the case of Mary D. and the great influence it had on Cushing's conceptions of the pituitary gland and its afflictions, and on the history of pituitary surgery.

Norman M. Dott, master of hypothalamic craniopharyngioma surgery: the decisive mentoring of Harvey Cushing and Percival Bailey at Peter Bent Brigham Hospital

Norman McOmish Dott (1897-1973) developed surgical neurology in Edinburgh, Scotland, and was a scholar of worldwide renown. One of Dott's most notable contributions to neurosurgery was his understanding of hypothalamic physiology, mostly acquired through the comprehensive study of patients with lesions involving this region of the diencephalon, particularly craniopharyngiomas (CPs). Recognition of symptoms caused by hypothalamic disturbances allowed him to predict the accurate anatomical relationships between CPs and the hypothalamus, despite the rudimentary radiological methods available during the 1930s. His sophisticated knowledge permitted Dott to perform radical removals of CPs originating within the third ventricle floor with acceptable success. Between 1934 and 1937, he operated on 4 CP cases originating in the hypothalamus, achieving a satisfactory postoperative outcome in 3 of the 4 patients. Aware of the strong attachment of hypothalamic CPs to the infundibulo-tuberal area, Dott used a double transbasal and transventricular approach to these lesions, a strategy providing an optimal view and control of the tumor boundaries. The decisive mentorship of several legendary figures of physiology and neurosurgery greatly influenced Dott's surgical evolution. The experimental pituitary gland work he performed with Sir Edward Sharpey-Schäfer at the beginning of his career stirred Dott's curiosity about the issue of hypothalamus-pituitary relationships. As a result, he decided to move to Peter Bent Brigham Hospital (Boston, Massachusetts) in 1923, to train in neurosurgery and neuropathology under the guidance of the leaders in these fields, Harvey Williams Cushing (1869-1939) and Percival Sylvester Bailey (1892-1973). They inspired the young Dott and shared with him their clinical and pathological expertise, in addition to their surgical strategies for best approaching and removing these challenging tumors. In time, Dott would come to surpass his mentors. This paper aims to credit Norman M. Dott for his decisive, modern contributions to hypothalamic CP surgery.

Pathological and Topographical Classification of Craniopharyngiomas: A Literature Review

Craniopharyngiomas (CPs) are clinically relevant tumors of the sellar region and are associated with high morbidity and occasional mortality. There are two different subtypes of CPs that differ clinically and pathologically: adamantinomatous CP and papillary CP. The differential diagnosis is still challenging even with developments in preoperative imaging as several tumors of the sellar/parasellar region share a continuum of clinical characteristics and imaging similarities. Several topographical classifications of CPs have been mentioned in literature, but to date, there has not been a consensus on a standard reference classification system and there is need to a develop such a model.