Anterior Pituitary Research Articles

Immune checkpoint inhibitor induced hypophysitis: a specific disease of corticotrophs?

The aim of this study was to define functional and anatomical pituitary disease at the time of presentation following immune checkpoint inhibitor (ICI) therapy and to describe any changes in pituitary function over time. We conducted a retrospective observational audit of patients on ICI therapy at our centre between January 2013 and September 2023. We reviewed all patients on ICI therapy under the care of the oncology department at University Hospital Plymouth, a 1000-bedded hospital serving a population of 500,000 people. From this group, we identified all individuals referred to the endocrinology department with a suspected diagnosis of adrenal insufficiency. Patients were established on adrenal steroid replacement and subsequently underwent formal pituitary testing. People were included if they had pituitary disease, as evidenced by low ACTH, other pituitary dysfunction and/or abnormalities on pituitary imaging. Nine hundred and fifty-four patients received ICI therapy during the study period, and 37 (a prevalence of 3.9%) developed hypothalamic-pituitary-adrenal axis dysfunction. Their mean age was 65 years, and 70% were male. About 86.5% of the total patients affected were treated for metastatic malignancies. Ten of the 37 patients died during follow-up as a direct consequence or complication of their primary cancer diagnosis. The median interval for the onset of symptoms was 4 months. Following repeated testing, there was no recovery in cortisol or ACTH levels for any individual. Other permanent anterior pituitary hormone defects were unusual. Hypophysitis associated with immunotherapy appears to specifically target the corticotrophs, with no evidence of recovery over time. There was a specific abnormality seen in MRI scans of 7 of 27 patients who had scans, which appeared to be a particular feature of immune-mediated hypophysitis. These were confined to the anterior aspect of the pituitary gland, appearing as striations, and were not visible on any of the scans performed more than 3 months after the likely onset of the disease. These data show that immune-related hypophysitis is a common complication of immune checkpoint inhibitor therapy. This may result in an imaging abnormality within the areas of the pituitary that are richest in corticotrophs. The endocrine consequence of this is a permanent defect in ACTH and, therefore, cortisol production.

Associations of the AVPR1A RS1 Microsatellite Locus with the Level of Hormones of the Anterior Pituitary Gland and Personality Traits.

The arginine vasopressin receptor gene (AVPR1A) is one of the genes affecting mental processes. The aim of this study was to search for associations of microsatellite locus RS1, which is related to the AVPR1A expression level, with the level of hormones of the anterior pituitary gland and personality traits. The study sample included Yakut men aged 18-26years (n = 121). The analysis of RS1 locus was carried out using the PCR method and sequencing of the primary nucleotide sequence. Serum hormonal levels of thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin were determined by the time-resolved fluorescence immunoassay (DELFIA), plasma adrenocorticotropic hormone (ACTH) levels were determined by enzyme-linked immunosorbent assay (ELISA). In the Yakut population "short" (S) alleles of the AVPR1A RS1 locus containing ≤ 10 repeats (63%) and the corresponding SS genotypes (44.6%) were more frequent, while individuals with "long" (LL) and "heterozygous" (SL) genotypes accounted for 18.2 and 37.2%, respectively. The range of concentrations of ACTH and TSH in the group of SS genotype carriers was significantly lower than that observed in the group of LL genotype carriers (p = 0.042 and p = 0.048, respectively); the LH level was significantly higher (p = 0.029). The trend towards higher neuroticism in SS genotype carriers compared to the individuals with LL genotypes (p = 0.05) is revealed. The results obtained indicate the modulating effect of genetic variants of the AVPR1A gene on the level of anterior pituitary hormones, which could slightly affect the level of neuroticism in humans.

Estrogen-dependent oxytocin expression in the hypothalamus and estrogen-dependent vasopressin in the median eminence.

The posterior pituitary (PP) hormones oxytocin (OXT) and arginine vasopressin (AVP) are synthesized within the hypothalamic nucleus and released from the PP into systemic circulation. Hypothalamic AVP projects its axons into the external layer of median eminence (eME) and regulates anterior pituitary hormone secretion during stress responses. Although similar as PP hormones, we demonstrate distinct regulatory roles of estrogen in hypothalamic OXT and AVP dynamics. OXT dynamics in the hypothalamus exhibit sex-dependent variations and that estrogen may influence dynamic OXT level changes, as observed in OXT-mRFP1 transgenic rats. Estrogen was also observed to modulate dynamic changes in AVP levels in the axon terminals of eME in female AVP-eGFP transgenic rats. Although OXT and AVP are produced within the similar hypothalamic region, both exhibit distinct dynamics within the hypothalamus. Estrogen acts on the hypothalamus, and further effects of estrogen replacement therapy can be expected.

Expression of the apelin system in the porcine pituitary during the oestrous cycle and early pregnancy and the effect of apelin on LH and FSH secretion

Reproductive success requires considerable energy investment. Research has shown that some adipokines, i.e. the hormones produced in adipose tissue, affect reproductive functions by influencing all structures of the hypothalamic-pituitary-ovarian axis. Apelin is a recently identified member of the adipokine family. To the best of the authors' knowledge, this is the first study to investigate the gene and protein expression of the apelin system (the apelin hormone and the apelin receptor, APJ) in the anterior (AP) and posterior (PP) pituitary lobes of the domestic pig during different phases of the oestrous cycle (days 2 to 3, 10 to 12, 14 to 16, and 17 to 19) and in early pregnancy (days 10 to 11, 12 to 13, 15 to 16, and 27 to 28). It was also assumed that apelin participates in the regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion and influences Akt, MAPK/Erk1/2, and AMPK signalling pathways in the AP during the oestrous cycle. Apelin, APJ mRNAs and proteins were detected in both pituitary lobes. Apelin was identified in gonadotropes, somatotropes, lactotropes, and thyrotropes. The study also revealed that apelin and APJ mRNA/protein levels fluctuate during the oestrous cycle and early gestation. Apelin affects basal, GnRH- and/or insulin-stimulated gonadotropin secretion in some phases of the cycle, as well as the phosphorylation of Akt, MAPK/Erk1/2, and AMPK proteins in AP cells. These findings suggest that apelin may be produced locally in the pituitary and that this gland is receptive to apelin's action. The study also suggest that apelin may influence female reproductive functions by controlling the release of LH and FSH from AP cells, and that it affects Akt, MAPK/Erk1/2, and AMPK signalling pathways.

Paracrine FGF1 signaling directs pituitary architecture and size

Organ architecture is established during development through intricate cell-cell communication mechanisms, yet the specific signals mediating these communications often remain elusive. Here, we used the anterior pituitary gland that harbors different interdigitated hormone-secreting homotypic cell networks to dissect cell-cell communication mechanisms operating during late development. We show that blocking differentiation of corticotrope cells leads to pituitary hypoplasia with a major effect on somatotrope cells that directly contact corticotropes. Gene knockout of the corticotrope-restricted transcription factor Tpit results in fewer somatotropes, with less secretory granules and a loss of cell polarity, resulting in systemic growth retardation. Single-cell transcriptomic analyses identified FGF1 as a corticotrope-specific Tpit dosage-dependent target gene responsible for these phenotypes. Consistently, genetic ablation of FGF1 in mice phenocopies pituitary hypoplasia and growth impairment observed in Tpit-deficient mice. These findings reveal FGF1 produced by the corticotrope cell network as an essential paracrine signaling molecule participating in pituitary architecture and size.

Deciphering the Presentation and Etiologies of Hypophysitis Highlights the Need for Repeated Systematical Investigation

Abstract Context Hypophysitis is defined as an inflammation of the pituitary gland and/or infundibulum. Objective Our aim was to characterize the initial course and evolution of patients with hypophysitis according to the different etiologies. Methods Retrospective observational study conducted in a university referral hospital center. Patients over 15 years of age were included if they had a diagnosis of hypophysitis between January 2014 and October 2023, with the exclusion of hypophysitis secondary to immune checkpoint inhibitors. Results Sixty-one patients (64% women; median age, 34 years) were included. Polyuria–polydipsia, headache, and asthenia were present in 64%, 48%, and 44% of cases respectively. At diagnosis, at least 1 anterior pituitary deficiency was present in 91.5% of cases and vasopressin deficiency in 56%. Magnetic resonance imaging was abnormal in 97% of cases. Secondary hypophysitis was found in 46% of cases (n = 28), including sarcoidosis in 28% (n = 17) and L (Langerhans) group histiocytoses in 13.1% (n = 8). Among patients with secondary hypophysitis, pituitary deficiency preceded systemic manifestations in 23% and occurred concomitantly in 23% of cases. Patients were treated in 36% of cases (glucocorticoids, surgery), without improvement of pituitary hormone deficits. Conclusion A systemic etiology of hypophysitis was found in almost half of the patients. Pituitary disorders preceded the systemic disease in a quarter of the cases. This emphasizes the importance of a systematic repeated workup looking for a secondary etiology of hypophysitis in these patients.

Structural Basis for Antagonist Binding to Vasopressin V1b Receptor Revealed by the Molecular Dynamics Simulations.

The human V1b receptor (V1bR) is primarily expressed in the corticotropic cells of the anterior pituitary where it is involved in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. The activation of V1bR induces the secretion of adrenocorticotropin hormone (ACTH) from the anterior pituitary cells which, in turn, stimulates the production of cortisol via the adrenal cortex. Clinical studies have demonstrated the chronic dysfunction of the HPA axis in patients with several psychiatric disorders. Thus, the inhibition of the V1b receptor and normalizing the HPA axis hyperactivity is a promising approach to the treatment of many stress-related disorders such as anxiety and depression. Nelivaptan is a selective V1bR antagonist that can be used for this purpose and an excellent molecule to study how antagonists interact with V1bR, especially since in recent years the experimental structures of vasopressin V2 and oxytocin receptors were solved, providing high-similarity templates for homology modeling of V1bR. Therefore, in this work, six independent molecular dynamics simulations of a V1bR-nelivaptan complex in a fully hydrated lipid bilayer, yielding a total simulation time of 6.0 μs, have been conducted. In the lowest-energy complexes obtained in this work and proposed to be the most probable structure of the V1bR-nelivaptan complex, the location of the ligand inside the receptor pocket is very similar to that of the other ligands observed in the experimental structures of the vasopressin/oxytocin receptor family. The receptor-ligand interaction has been analyzed and described, revealing the details of the molecular mechanism of this antagonist binding to V1bR and a probable contribution of L2005×40 and T2035×43 to binding selectivity.

Isolated hypoprolactinemia: The rarest of the rare?

Isolated hypoprolactinemia (IHP) can be defined as the presence of consistently low serum levels of prolactin in the absence of other anterior pituitary hormone abnormalities. It is an extremely rare condition, and consequently incompletely understood and unrecognized. A recent study has reported the first cases of IHP caused by mutation in the PRL gene. There are also cases where the pathogenesis of IHP is likely secondary to an autoimmune response against the PRL-secreting cells. But most published cases are acquired and idiopathic. The best characterized function of PRL is to facilitate milk production in the puerperium. Analysis of the GTEX data repository, however, shows that PRL is the most abundantly expressed gene in the human pituitary, independently of gender and age, suggesting the presence of additional roles for PRL. Newer studies have indeed revealed a much larger spectrum of PRL functions and will likely uncover novel clinical phenotypes associated with severe PRL deficiency.

Anterior pituitary hormone dysfunction among individuals with complete heart block requiring pacemaker.

Background & objectives Neuronal hypoxia associated with conditions like traumatic brain injury and cardiac tachyarrhythmia has been implicated in causing hypopituitarism. Individuals with complete heart block (CHB) may be predisposed to develop anterior pituitary hormone dysfunction in the long term. The objective of this study was to investigate anterior pituitary hormone functions in individuals after CHB. Methods This prospective cohort study included 30 individuals (21 men and 9 women) with CHB requiring pacemaker implantation, who were evaluated at admission and then at a mean follow up of 12.4 ± 2.2 months to look for development of any degree of hypopituitarism. In addition to the measurement of hormones like follicle-stimulating hormone (FSH), luteinising hormone (LH), thyroid stimulating hormone (TSH), total tetra iodothyronines (TT4), free tetraiodothyronines (FT4), cortisol, insulin-like growth factor-1 (IGF-1), testosterone and estradiol, a fixed-dose glucagon stimulation test (GST) was performed to assess growth hormone (GH) and adrenocorticotrophic hormone (ACTH) axis. Results The mean age of the participants was 64.9 ± 11.3 yr. At follow up evaluation, 17 (56.7%) had low serum IGF-1, and among them, seven (23%) had growth hormone deficiency (GHD) (peak GH <1.0 ng/ml after GST). Six participants (20%) had ACTH deficiency (peak cortisol <9 ug/dl after GST) and one had TSH deficiency. None had prolactin (PRL) or gonadotropin deficiency. Overall, hormone deficiencies were observed in nine patients (30%). Interpretation & conclusions This pilot study detected loss of anterior pituitary hormones in a significant number of individuals of CHB at 12 months follow up. Unrecognised hypopituitarism may have resulted in significant morbidity and mortality in these individuals.

Rathke's cleft cysts: from pathophysiology to management.

Rathke's cleft cysts (RCCs) are benign, non-neoplastic lesions located in the sellar and suprasellar regions of the brain, originating from remnants of Rathke's pouch, an embryonic precursor to the anterior pituitary gland. Although RCCs are frequently asymptomatic and discovered incidentally during imaging studies, they can present with a variety of symptoms, including headaches, visual disturbances, and endocrine dysfunction due to the compression of adjacent neural structures. The management of RCCs is particularly challenging, as the decision to pursue conservative monitoring or surgical intervention depends heavily on the cyst's size, growth potential, and the severity of symptoms. Transsphenoidal surgery is the primary treatment for symptomatic RCCs, offering effective relief from symptoms through decompression of the cyst. However, recurrence remains a significant issue, with rates reported up to 33%, prompting debates about the extent of cyst wall removal during surgery. Recent advancements in minimally invasive endoscopic techniques have improved surgical outcomes, yet the risk of postoperative complications such as hypopituitarism and cerebrospinal fluid leaks persists. Additionally, stereotactic radiosurgery has emerged as a potential alternative for patients with recurrent RCCs or those who are not suitable candidates for repeat surgery. Despite its promise, the long-term safety and efficacy of radiotherapy in RCC management require further investigation. This narrative review aims to provide a comprehensive overview of RCCs, integrating the latest research and clinical guidelines to discuss pathophysiology, clinical presentation, and management strategies, emphasizing the need for a personalized approach to treating this complex condition.

Eje hipotálamo-hipofisario. Regulación neurohormonal, implicaciones patológicas, pruebas funcionales hipofisarias, indicaciones e interpretación

The hypothalamic-pituitary axis is a crucial system for maintaining homeostasis by integrating hormonal and neuronal inputs and outputs. Almost all bodily functions are regulated directly or indirectly by this axis. The hypothalamus, a small but vital brain region, monitors various inputs and maintains physiological set points through hormonal secretion, coordinating with the pituitary gland. This regulation involves multiple feedback mechanisms and interactions with other brain areas.The hypothalamus is anatomically divided into several regions and nuclei, each with specific functions. It produces a variety of hormones, including growth hormone-releasing hormone, corticotropin-releasing hormone, thyrotropin-releasing hormone, and gonadotropin-releasing hormone. These hormones regulate the secretion of corresponding hormones from the anterior pituitary gland, which control several physiological processes, including growth, metabolism, reproduction, and stress response.Pathological implications of hypothalamic-pituitary axis dysfunctions include endocrine disorders such as hyperprolactinemia, growth hormone deficiency, and hypogonadism. In addition, hypothalamic damage can lead to neurological and behavioral problems such as sleep disturbances and thermoregulation.

Sheehan's syndrome. A descriptive study of 4 cases at the main hospital of Dakar

Sheehan's syndrome or postpartum anterior pituitary necrosis results in pan hypopituitarism. This is an ischemic necrosis of the anterior pituitary gland secondary to a state of sudden shock during a postpartum hemorrhage. It is a serious complication of the postpartum period. Advances in obstetric care in developed countries have reduced the incidence of this disease. In black Africa its frequency is unknown with a few reported cases. The authors report 4 cases of Sheehan's syndrome treated at the Hôpital Principal de Dakar. This is a retrospective study carried out in the medical departments of the main hospital of Dakar over 5 years. Secondary amenorrhea of variable duration 1 to 10 years was noted in 3 patients. Clinical presentation consisted of a worsening in the general condition in all patients. Low cortisol levels were noted in most patients associated with an empty sella turcica on pituitary MRI. The outcome was favorable under treatment.

Practical approaches to diagnosing PitNETs/adenomas based on cell lineage.

The evolution of classification systems of pituitary adenomas (now PitNETs) has culminated in the use of transcription factor (TF) immunohistochemistry (IHC), forming a cell lineage-based system. However, several issues remain to be addressed, including the additional financial and logistic burden of undertaking the complete array of anterior pituitary hormones and TF IHC. To that end, several groups have suggested algorithms to minimise the number of tests performed, with varying levels of diagnostic accuracy. Although the proportion of null cell tumours has decreased following the use of TFs, "multilineage" tumours have been reported and characterised using transcriptomic signatures, most prominently the PIT1-SF1 co-expressing PitNETs, which do not bear a position in the present system of classification. In this review, we examine the proposed practical approaches to the diagnosis of PitNETs. We review the literature on reported PitNET types that challenge the existing classification system, such as those that express multiple TFs, with their potential clinical implications. Finally, we assess limitations in the present system, such as the lack of a standardised system for IHC interpretation, that need to be addressed in the future.

The Association between Vitamin D Status and the Impact of Metformin on Hypothalamic-Pituitary-Thyroid Axis Activity in Women with Subclinical Hypothyroidism.

Metformin inhibits enhanced secretion of anterior pituitary hormones. Its impact on prolactin and gonadotropin concentrations is absent in individuals with hypovitaminosis D. The aim of this prospective cohort study was to investigate whether vitamin D status determines the effect of metformin on hypothalamic-pituitary-thyroid axis activity in levothyroxine-naïve women. The study included three groups of women of reproductive age with subclinical non-autoimmune hypothyroidism, which were matched for age, thyroid-stimulating hormone (TSH) concentration, and insulin sensitivity: untreated women with vitamin D deficiency/insufficiency (group A), women effectively supplemented with exogenous calciferol (group B), and untreated women with normal 25-hydroxyvitamin D concentrations (25OHD) (group C). Owing to concomitant type 2 diabetes or prediabetes, all subjects were treated with metformin. Concentrations of 25OHD, TSH, total and free thyroid hormones, glucose, insulin, glycated hemoglobin (HbA1c), prolactin, and peripheral markers of thyroid hormone action were assayed before metformin treatment and six months later. Based on hormone concentration, structure parameters of thyroid homeostasis were calculated. Except for 25OHD concentrations, there were no between-group differences in baseline values of the measured variables. Metformin reduced glucose, the homeostatic model assessment 1 of insulin resistance ratio (HOMA1-IR), and HbA1c in all study group, but these effects were less pronounced in group A than in the remaining groups. The reduction in TSH and Jostel's index was observed only in groups B and C, and its degree correlated with baseline TSH concentrations, baseline 25OHD concentrations, and the degree of improvement in HOMA1-IR. The drug did not affect circulating levels of 25OHD, free and total thyroid hormones, prolactin, other structure parameters of thyroid homeostasis, and markers of thyroid hormone action. The obtained results allow us to conclude that low vitamin D status in young women mitigates the impact of metformin on thyrotroph secretory function.

Dysregulated zinc homeostasis and microadenomas in the anterior pituitary: pathological insights into suicide risk.

Suicide is a significant public health problem influenced by various risk factors, including dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. Zinc (Zn), essential for pituitary function in hormone synthesis and release, has been linked to suicide, with studies noting reduced serum levels and altered brain transport mechanisms. Despite Zn's crucial role in pituitary function and its involvement in suicidal behavior, information on pituitary Zn in suicide is scarce. Tumor cells modify Zn dynamics in tissues, and a previous report suggests microadenomas in the anterior pituitary as a risk factor for suicide. Histopathological analysis with hematoxylin-eosin stain and histochemical techniques to assess Zn homeostasis were carried out on anterior pituitary postmortem samples from 14 suicide completers and 9 non-suicidal cases. Pituitary microadenomas were identified in 35% of suicide cases and none in the non-suicidal cases. Furthermore, compartmentalized Zn (detected via dithizone reactivity), but not free Zn levels (detected via zinquin reactivity), was lower in the suicide cases compared to the non-suicidal group. This is the first report of a potential association between disrupted Zn homeostasis and microadenomas in the anterior pituitary as a feature in suicide and provides critical insights for future neuroendocrine Zn-related research.

PACS-1 Interacts with TRPC3 and ESyt1 to Mediate Protein Trafficking while Promoting SOCE and Cooperatively Regulating Hormone Secretion.

Corticotropic cells of the anterior pituitary gland release adrenocorticotropic hormone (ACTH) in a regulated manner to promote the production of cortisol and androgens. The process of ACTH secretion is partly mediated by the phosphofurin acidic cluster sorting protein 1 (PACS-1); however, the underlying mechanisms behind this regulation remain unclear. Herein, we demonstrated PACS-1 interactions with the short transient receptor potential channel 3 (TRPC3) calcium transporter and the extended synaptotagmin-1 (ESyt1) endoplasmic reticulum-plasma membrane tethering protein. Importantly, PACS-1 promoted interactions between TRPC3 and ESyt1 and regulated their plasma membrane localization. Lastly, we demonstrated that PACS-1 is required for a proper store-operated calcium entry (SOCE) response and that ESyt1 regulates ACTH secretion through an unknown mechanism regulated by PACS-1. Overall, our study provides new insights into the physiological role PACS-1 plays in modulating intracellular calcium levels and regulating ACTH secretion in corticotropic cells.

Differentiation potential of SOX2-positive stem cells in the bovine pituitary gland

The pituitary gland is the master endocrine gland, harboring stem cells with various genetic characteristics; however, data from non-rodent and non-human sources are scarce. In this study, we isolated putative stem cells from the bovine pituitary gland and investigated their potential for differentiation into hormone-producing cells. Immunohistochemical analysis revealed that in calves and heifers, stem cell marker sex-determining region Y-box 2 (SOX2)-positive cells were widely present in the pituitary gland and partially co-localized with anterior pituitary hormones. Next, a single-cell suspension of primary anterior lobe cells from bovines aged 0 and 12 months was subjected to two-dimensional culture. Consequently, some cells proliferated in the culture dishes. The expression levels of Sox2 and several other stem cell markers were higher in these cells after culture. In addition, almost all proliferating cells were positive for SOX2, whereas all were negative for hormones. In three-dimensional cultures, SOX2-positive cells presented a spheroid-like morphology and differentiated into endocrine cells. These results provide evidence that SOX2-positive cells are pituitary stem cells with the potential to differentiate into hormone-producing cells, regardless of age. Our data lay a theoretical foundation for further studies on controlling fundamental processes, such as body growth, reproduction, and lactation.

Localization of β-Nerve Growth Factor in the Stallion Reproductive Tract.

β-Nerve growth factor (β-NGF) is a protein produced in the reproductive tract of camelids (camels, llamas, and alpacas) that has been identified as the ovulation inducing factor in seminal plasma. β-NGF from seminal plasma deposited into the reproductive tract of the female camelid acts systemically to stimulate the secretion of luteinizing hormone (LH) from the anterior pituitary, which in turn induces follicle maturation and ovulation. The objectives of the present study were to determine if β-NGF is present in the reproductive tract of the stallion and identify the specific site(s) of production. The hypotheses were that β-NGF would be present in the stallion reproductive tract and would primarily be localized in Sertoli cells of the testes and the prostate gland. Immunohistochemistry on paraffin-embedded paraformaldehyde-fixed tissues was performed using a rabbit polyclonal anti-β-NGF antibody on a total of six male equine reproductive tracts, including a one-day old colt, a one-year-old colt, and four adult stallion tracts. Strong immunostaining was observed in the efferent ducts of the testes and the epithelial cells of the prostate, seminal vesicles, bulbourethral glands, and ampullae. Weaker β-NGF staining was noted in Leydig cells, Sertoli cells, and spermatogonia within the testes and in epithelial cells of the epididymis. In conclusion, immunohistochemistry revealed that β-NGF is present in the stallion reproductive tract, and the protein is primarily present in the efferent ducts of the testes and in all accessory sex glands.

Video-Based Performance Analysis in Pituitary Surgery - Part 2: Artificial Intelligence Assisted Surgical Coaching

Superior surgical skill improves surgical outcomes in endoscopic pituitary adenoma surgery. Video-based coaching programs, pioneered in professional sports, have shown promise in surgical training. In this study, we developed and assessed a video-based coaching program using artificial intelligence (AI) assistance. An AI-assisted video-based surgical coaching was implemented over 6months with the pituitary surgery team. The program consisted of 1) monthly random video analysis and review; and 2) quarterly 2-hour educational meetings discussing these videos and learning points. Each video was annotated for surgical phases and steps using AI, which improved video interactivity and allowed the calculation of quantitative metrics. Primary outcomes were program feasibility, acceptability, and appropriateness. Surgical performance (via modified Objective Structured Assessment of Technical Skills) and early surgical outcomes were recorded for every case during the 6-month coaching period, and a preceding 6-month control period. Beta and logistic regression were used to assess the change in modified Objective Structured Assessment of Technical Skills scores and surgical outcomes after the coaching program implementation. All participants highly rated the program's feasibility, acceptability, and appropriateness. During the coaching program, 63 endoscopic pituitary adenoma cases were included, with 41 in the control group. Surgical performance across all operative phases improved during the coaching period (P < 0.001), with a reduction in new postoperative anterior pituitary hormone deficit (P= 0.01). We have developed a novel AI-assisted video surgical coaching program for endoscopic pituitary adenoma surgery - demonstrating its viability and impact on surgical performance. Early results also suggest improvement in patient outcomes. Future studies should be multicenter and longer term.

Video-Based Performance Analysis in Pituitary Surgery—Part 1: Surgical Outcomes

Endoscopic pituitary adenoma surgery has a steep learning curve, with varying surgical techniques and outcomes across centers. In other surgeries, superior performance is linked with superior surgical outcomes. This study aimed to explore the prediction of patient-specific outcomes using surgical video analysis in pituitary surgery. Endoscopic pituitary adenoma surgery videos from a single center were annotated by experts for operative workflow (3 surgical phases and 15 surgical steps) and operative skill (using modified Objective Structured Assessment of Technical Skills [mOSATS]). Quantitative workflow metrics were calculated, including phase duration and step transitions. Poisson or logistic regression was used to assess the association of workflow metrics and mOSATS with common inpatient surgical outcomes. 100 videos from 100 patients were included. Nasal phase mean duration was 24minutes and mean mOSATS was 21.2/30. Mean duration was 34minutes and mean mOSATS was 20.9/30 for the sellar phase, and 11minutes and 21.7/30, respectively, for the closure phase. The most common adverse outcomes were new anterior pituitary hormone deficiency (n= 26), dysnatremia (n= 24), and cerebrospinal fluid leak (n= 5). Higher mOSATS for all 3 phases and shorter operation duration were associated with decreased length of stay (P= 0.003 &P < 0.001). Superior closure phase mOSATS were associated with reduced postoperative cerebrospinal fluid leak (P < 0.001), and superior sellar phase mOSATS were associated with reduced postoperative visual deterioration (P= 0.041). Superior surgical skill and shorter surgical time were associated with superior surgical outcomes, at a generic and phase-specific level. Such video-based analysis has promise for integration into data-driven training and service improvement initiatives.