Diagnostic Accuracy of Perioperative Measurement of Basal Anterior Pituitary and Target Gland Hormones in Predicting Adrenal Insufficiency After Pituitary Surgery

Pituitary Stalk Morphology as a Predictor of New-Onset Adrenocortical Insufficiency and Arginine Vasopressin Deficiency after Transsphenoidal Resections of Pituitary Macroadenomas: A Retrospective Single-Center Study with a Focus on iMRI

BACKGROUND

A new-onset adrenocortical insufficiency (NAI) is the most critical postoperative endocrinological complication after transsphenoidal surgery for macroadenomas. Because of increased mortality risk, arginine vasopressin deficiency (AVP-D) is also a relevant postoperative complication. This study aimed to identify easy-to-acquire magnet resonance imaging (MRI) aspects of the pituitary stalk to predict these insufficiencies after transsphenoidal surgery.

METHODS

Pituitary stalk morphology was reviewed intraoperatively and three months postoperatively in the MRIs of 48 transsphenoidal surgeries for macroadenomas. NAI was validated in endocrinological follow-up controls 10-14 months post-surgery.

RESULTS

Intraoperative pituitary stalk diameters were 0.5 mm larger in patients who developed NAI and AVP-D. The odds ratio was 29 for NAI and 6 for AVP-D in binary regression analysis. A value of 2.9 mm was identified as the optimal cut-off for the minimal pituitary stalk diameter regarding NAI, with a high specificity of 89%. There was no difference in pituitary stalk diameter regarding these insufficiencies three months post-surgery.

CONCLUSIONS

We identified an increased pituitary stalk diameter in intraoperative MRIs as a predictive factor of NAI and AVP-D after transsphenoidal surgery. These findings might improve the early detection of NAI and, thus, optimal management. However, validating these retrospective findings in prospective studies is obligatory.

Early Morning Cortisol Level as a Predictive Factor for Long-Term Glucocorticoid Replacement After Pituitary Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

A reliable strategy for predicting long-term adrenal insufficiency after pituitary surgery can reduce the risk of glucocorticoid overexposure or missing patients with pituitary insufficiency. For this purpose, we aimed to assess the predictive value of early postoperative morning serum cortisol level for the detection of hypothalamic-pituitary-adrenal axis dysfunction in patients who underwent pituitary surgery.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-based systematic review was conducted to include articles investigating morning blood cortisol levels after pituitary surgery for lesions of the pituitary gland as a determinant for administration of long-term supplemental glucocorticoids. Bayesian statistics were used to pool the sensitivity and specificity rates. Sensitivity and specificity were also determined for each potential cortisol level on postoperative day (POD) 1 and POD 2.

RESULTS

The study included 17 articles encompassing 1648 patients. Morning cortisol levels on POD 1 and POD 2 showed pooled sensitivity rates of 86.4% and 86.6% and pooled specificity rates of 73.1% and 78.2%, respectively, for predicting long-term glucocorticoid replacement after surgery. A cortisol level of 2.1 μg/dL showed the highest sensitivity rate (98.78%), and 22.5 μg/dL showed the highest specificity rate (72.5%) on POD 1.

CONCLUSIONS

In this review and Bayesian meta-analysis, we found that postoperative serum cortisol measurement may have high accuracy in prediction of the long-term need for glucocorticoid administration in patients who underwent pituitary surgery.

Clinical application of the “sellar barrier’s concept” for predicting intraoperative CSF leak in endoscopic endonasal surgery for pituitary adenomas with a machine learning analysis

Background

Recently, it was defined that the sellar barrier entity could be identified as a predictor of cerebrospinal fluid (CSF) intraoperative leakage. The aim of this study is to validate the application of the sellar barrier concept for predicting intraoperative CSF leak in endoscopic endonasal surgery for pituitary adenomas with a machine learning approach.

Methods

We conducted a prospective cohort study, from June 2019 to September 2020: data from 155 patients with pituitary subdiaphragmatic adenoma operated through endoscopic approach at the Division of Neurosurgery, Università degli Studi di Napoli “Federico II,” were included. Preoperative magnetic resonance images (MRI) and intraoperative findings were analyzed. After processing patient data, the experiment was conducted as a novelty detection problem, splitting outliers (i.e., patients with intraoperative fistula, n = 11/155) and inliers into separate datasets, the latter further separated into training (n = 115/144) and inlier test (n = 29/144) datasets. The machine learning analysis was performed using different novelty detection algorithms [isolation forest, local outlier factor, one-class support vector machine (oSVM)], whose performance was assessed separately and as an ensemble on the inlier and outlier test sets.

Results

According to the type of sellar barrier, patients were classified into two groups, i.e., strong and weak barrier; a third category of mixed barrier was defined when a case was neither weak nor strong. Significant differences between the three datasets were found for Knosp classification score (p = 0.0015), MRI barrier: strong (p = 1.405 × 10⁻⁶), MRI barrier: weak (p = 4.487 × 10⁻⁸), intraoperative barrier: strong (p = 2.788 × 10⁻⁷), and intraoperative barrier: weak (p = 2.191 × 10⁻¹⁰). We recorded 11 cases of intraoperative leakage that occurred in the majority of patients presenting a weak sellar barrier (p = 4.487 × 10⁻⁸) at preoperative MRI. Accuracy, sensitivity, and specificity for outlier detection were 0.70, 0.64, and 0.72 for IF; 0.85, 0.45, and 1.00 for LOF; 0.83, 0.64, and 0.90 for oSVM; and 0.83, 0.55, and 0.93 for the ensemble, respectively.

Conclusions

There is a true correlation between the type of sellar barrier at MRI and its in vivo features as observed during endoscopic endonasal surgery. The novelty detection models highlighted differences between patients who developed an intraoperative CSF leak and those who did not.

Sevoflurane anesthesia rather than propofol anesthesia is associated with 3-month postoperative hypocortisolism in patients undergoing endoscopic transsphenoidal surgery for non-functional pituitary adenoma with preoperative normal hypothalamic-pituitary-adrenal axis

PURPOSE

The effects of anesthetic technique on intermediate-term postoperative adrenocorticotropic hormone (ACTH) functional outcomes have not been fully determined in non-functioning pituitary adenoma (NFPA) patients. Postoperative hypocortisolism is potentially life-threatening and requires steroid replacement after pituitary surgery. The present study determined whether sevoflurane anesthesia was predictive of 3-month postoperative hypocortisolism in NFPA patients with preoperative normal hypothalamic-pituitary-adrenal (HPA) axis.

METHODS

Demographics, preoperative pituitary hormone status, intraoperative data, and tumor characteristics were retrospectively collected from 429 NFPA patients, who had preoperative normal HPA axis and underwent endoscopic transsphenoidal surgery. Patients were divided into two groups based on intraoperative anesthetic technique: sevoflurane-based inhalation anesthesia group (n = 74) and propofol-based intravenous anesthesia group (n = 355). After propensity score matching, 73 patients were selected in each group and the incidence of 3-month postoperative hypocortisolism (primary outcome measure) was compared between the two groups.

RESULTS

The incidence of 3-month postoperative hypocortisolism was higher in the sevoflurane anesthesia group than the propofol anesthesia group before (n = 20[27.0%] vs. n = 49[13.8%], P = 0.008) and after (n = 20 [27.4%] vs. n = 5 [6.8%], P = 0.002) propensity score matching, respectively. Sevoflurane anesthetic use (odds ratio [95% CI] 5.37[1.80-15.98], P = 0.003) and postoperative steroid administration (2.89 [1.06-7.92], P = 0.039) were predictors of 3-month postoperative hypocortisolism.

CONCLUSION

In patients with preoperative normal HPA axis undergoing endoscopic transsphenoidal surgery for NFPA, sevoflurane anesthesia and postoperative steroid administration were associated with the development of 3-month postoperative hypocortisolism. A large-scale prospective study is needed to confirm the negative association between sevoflurane anesthesia and postoperative ACTH functional outcome.

Pituitary function after transsphenoidal surgery including measurement of basal morning cortisol as predictor of adrenal insufficiency

INTRODUCTION

Patients with pituitary adenomas undergoing transsphenoidal surgery require pre- and post-surgery examination of pituitary hormones. There is currently no consensus on how to evaluate the adrenal axis post-surgery. The aims of this study were to investigate factors that may predict postoperative adrenal insufficiency (AI) and to investigate the overall effect of transsphenoidal surgery on pituitary function.

METHODS

One hundred and forty-three consecutive patients who had undergone transsphenoidal surgery for pituitary adenomas were included. Data on tumour size, pituitary function pre-surgery, plasma basal cortisol measured within 48 h post-surgery and pituitary function 6 months post-surgery were collected. Patients with AI prior to surgery, perioperative glucocorticoid treatment, Cushing's disease and no re-evaluation after 1 month were excluded (n = 93) in the basal cortisol analysis.

RESULTS

Low plasma basal cortisol post-surgery, tumour size and previous pituitary surgery were predictors of AI (all P < 0.05). A basal cortisol cut-off concentration of 300 nmol/L predicted AI 6 months post-surgery with sensitivity and negative predictive value of 100%, specificity of 81% and positive predictive value of 25%. New gonadal, thyroid and adrenal axis insufficiencies accounted for 2, 10 and 10%, respectively. The corresponding recovery rates were 17, 7 and 24%, respectively.

CONCLUSION

Transsphenoidal surgery had an overall beneficial effect on pituitary endocrine function. Low basal plasma cortisol measured within 48 h after surgery, tumour size and previous surgery were identified as risk factors for AI. Measurement of basal cortisol post-surgery may help to identify patients at risk of developing AI.

Investigation of the Hypothalamo-pituitary-adrenal (HPA) axis: a contemporary synthesis

The hypothalamo-pituitary-adrenal (HPA) axis is one of the main components of the stress system. Maintenance of normal physiological events, which include stress responses to internal or external stimuli in the body, depends on appropriate HPA axis function. In the case of severe cortisol deficiency, especially when there is a triggering factor, the patient may develop a life-threatening adrenal crisis which may result in death unless early diagnosis and adequate treatment are carried out. The maintenance of normal physiology and survival depend upon a sufficient level of cortisol in the circulation. Life-long glucocorticoid replacement therapy, in most cases meeting but not exceeding the need of the patient, is essential for normal life expectancy and maintenance of the quality of life. To enable this, the initial step should be the correct diagnosis of adrenal insufficiency (AI) which requires careful evaluation of the HPA axis, a highly dynamic endocrine system. The diagnosis of AI in patients with frank manifestations is not challenging. These patients do not need dynamic tests, and basal cortisol is usually enough to give a correct diagnosis. However, most cases of secondary adrenal insufficiency (SAI) take place in a gray zone when clinical manifestations are mild. In this situation, more complicated methods that can simulate the response of the HPA axis to a major stress are required. Numerous studies in the assessment of HPA axis have been published in the world literature. In this review, the tests used in the diagnosis of secondary AI or in the investigation of suspected HPA axis insufficiency are discussed in detail, and in the light of this, various recommendations are made.

Second-Day Morning Cortisol Levels after Transsphenoidal Surgery Are Accurate Predictors of Secondary Adrenal Insufficiency with Diagnostic Cut-Offs Similar to Those in Non-Stressed Conditions

INTRODUCTION

Multiple studies tried to identify cortisol cut-offs after pituitary surgery that could accurately assess hypothalamic-pituitary-adrenal (HPA) axis function; however, there is no consensus nowadays. This study aimed to evaluate the accuracy of morning cortisol after transsphenoidal surgery in predicting long-term secondary adrenal insufficiency.

METHODS

In our tertiary center, we prospectively determined first- and second-day cortisol after transsphenoidal surgery in 92 patients without preoperative adrenal -insufficiency and not treated with glucocorticoids perioperatively. Definitive diagnosis of secondary adrenal insufficiency was obtained with re-evaluation 3 months after trans-sphenoidal surgery and clinical follow-up of at least 1 year.

RESULTS

Ten patients (10.8%) developed long-term postoperative secondary adrenal insufficiency. The ROC curves demonstrated that first-day cortisol had a moderate diagnostic accuracy, while a second-day cortisol ≤9.3 µg/dL (257 nmol/L) showed the best performance in predicting adrenal insufficiency (sensitivity [Se] 88.9%, specificity [Sp] 86.9%, AUC 0.921). Moreover, a second-day cortisol ≤3.2 µg/dL (89 nmol/L) was able to diagnose adrenal insufficiency in 100% of cases (Se 22.2%, Sp 100%) and >14 µg/dL (386 nmol/L) was able to exclude ACTH deficiency (Se 100%, Sp 57.4%).

CONCLUSIONS

Adrenal function can be carefully studied on the second day after pituitary surgery, using cut-off values that international guidelines suggested for non-stressed conditions. In fact, second-day cortisol levels ≤3.2 μg/dL (89 nmol/L) and >14 μg/dL (386 nmol/L) are diagnostic of secondary adrenal insufficiency and normal function, respectively. We also suggest performing a definitive re-evaluation with an HPA axis stimulation test when second-day cortisol values are between 3.3 and 14 μg/dL (90-386 nmol/L).

Early postoperative HPA-axis testing after pituitary tumor surgery: reliability and safety of basal cortisol and CRH test

PURPOSE

To assess the reliability and safety of a postsurgical evaluation strategy of adrenal function using CRH stimulation and basal cortisol concentrations after transsphenoidal pituitary surgery.

METHODS

Retrospective cohort study of all patients undergoing endoscopic transsphenoidal surgery from 2010 to 2017, in whom early postoperative basal cortisol and/or CRH-stimulated cortisol secretion were available, including confirmation of adrenal function during follow-up. Patients with Cushing's disease were excluded. Optimal test performances were assessed using ROC analysis.

RESULTS

A total of 156 patients were included. Sensitivity and specificity of the CRH test were 78% and 90%, respectively, and 86% and 92% for basal cortisol, respectively, using an optimal cutoff of 220 nmol/L. Eight patients had false-negative test results with the CRH test (normal test but adrenal insufficient at follow-up), and six patients with basal cortisol, the majority of which had multiple pituitary hormone deficiencies and fluid imbalances. No clinical adverse events occurred in patients with false-negative test results. The diagnostic performance of a single basal cortisol measurement was superior to the CRH test.

CONCLUSIONS

The early postoperative basal cortisol is a safe and simple measurement to guide (dis)continuation of hydrocortisone replacement. However, disturbing factors, e.g., sodium balance disorders, contraceptives, untreated hypopituitarism, and illness impact the interpretation and in those cases this measure is unreliable. We propose an algorithm in which hydrocortisone replacement at discharge is based on basal cortisol <220 nmol/L on postoperative day 2 or 3 in a stable condition.

Preoperative risk factors for postoperative complications in endoscopic pituitary surgery: a systematic review

BACKGROUND

The ability to preoperatively predict postoperative complication risks is valuable for individual counseling and (post)operative planning, e.g. to select low-risk patients eligible for short stay surgery or those with higher risks requiring special attention. These risks however, are not well established in pituitary surgery.

METHODS

We conducted a systematic review of associations between preoperative characteristics and postoperative complications of endoscopic transsphenoidal surgery according to the PRISMA guidelines. Risk of bias was assessed through the QUIPS tool.

RESULTS

In total 23 articles were included, containing 5491 patients (96% pituitary adenoma). There was a wide variety regarding the nature and number of risk factors, definitions, measurement and statistics employed, and overall quality of mainly retrospective studies was low. Consistent significant associations were older age for complications in general, and intraventricular extension for cerebrospinal fluid (CSF) leaks. Associations identified in some but not all studies were younger age, increased BMI, female gender, and learning curve for CSF leaks; increased tumor size for complications in general; and Rathke's cleft cysts for diabetes insipidus. Mortality (incidence rate 1%) was not addressed as a risk factor.

CONCLUSION

Based on current literature, of low to medium quality, it is not possible to comprehensively quantify risk factors for complications. Nevertheless, older age and intraventricular extension were associated with increased postoperative complications. Future research should aim at prospective data collection, reporting of outcomes, and uniformity of definitions. Only then a proper risk analysis can be performed for endoscopic pituitary surgery.

Circadian disruption: New clinical perspective of disease pathology and basis for chronotherapeutic intervention

Biological processes are organized in time as innate rhythms defined by the period (τ), phase (peak [Φ] and trough time), amplitude (A, peak-trough difference) and mean level. The human time structure in its entirety is comprised of ultradian (τ < 20 h), circadian (20 h > τ < 28 h) and infradian (τ > 28 h) bioperiodicities. The circadian time structure (CTS) of human beings, which is more complicated than in lower animals, is orchestrated and staged by a brain central multioscillator system that includes a prominent pacemaker - the suprachiasmatic nuclei of the hypothalamus. Additional pacemaker activities are provided by the pineal hormone melatonin, which circulates during the nighttime, and the left and right cerebral cortices. Under ordinary circumstances this system coordinates the τ and Φ of rhythms driven by subservient peripheral cell, tissue and organ clock networks. Cyclic environmental, feeding and social time cues synchronize the endogenous 24 h clocks and rhythms. Accordingly, processes and functions of the internal environment are integrated in time for maximum biological efficiency, and they are also organized and synchronized in time to the external environment to ensure optimal performance and response to challenge. Artificial light at night (ALAN) exposure can alter the CTS as can night work, which, like rapid transmeridian displacement by air travel, necessitates realignment of the Φ of the multitude of 24 h rhythms. In 2001, Stevens and Rea coined the phrase "circadian disruption" (CD) to label the CTS misalignment induced by ALAN and shift work (SW) as a potential pathologic mechanism of the increased risk for cancer and other medical conditions. Current concerns relating to the effects of ALAN exposure on the CTS motivated us to renew our long-standing interest in the possible role of CD in the etiopathology of common human diseases and patient care. A surprisingly large number of medical conditions involve CD: adrenal insufficiency; nocturia; sleep-time non-dipping and rising blood pressure 24 h patterns (nocturnal hypertension); delayed sleep phase syndrome, non-24 h sleep/wake disorder; recurrent hypersomnia; SW intolerance; delirium; peptic ulcer disease; kidney failure; depression; mania; bipolar disorder; Parkinson's disease; Smith-Magenis syndrome; fatal familial insomnia syndrome; autism spectrum disorder; asthma; byssinosis; cancers; hand, foot and mouth disease; post-operative state; and ICU outcome. Poorly conceived medical interventions, for example nighttime dosing of synthetic corticosteroids and certain β-antagonists and cyclic nocturnal enteral or parenteral nutrition, plus lifestyle habits, including atypical eating times and chronic alcohol consumption, also can be causal of CD. Just as surprisingly are the many proven chronotherapeutic strategies available today to manage the CD of several of these medical conditions. In clinical medicine, CD seems to be a common, yet mostly unrecognized, pathologic mechanism of human disease as are the many effective chronotherapeutic interventions to remedy it.