Incidence, clinical manifestations, and course of water and electrolyte metabolism disturbances following transsphenoidal pituitary adenoma surgery: a prospective observational study

Endoscopic endonasal pituitary surgery: How we do it. Consensus statement on behalf of the EANS skull base section

Introduction and research question

The use of an endoscope in skull base surgery provides a panoramic close-up view over the intracranial structures from multiple angles with excellent illumination, thus permitting greater extent of resection of tumors arising at sellar area, mostly represented by PitNet - Pituitary neuroendocrine tumors, with higher likelihood of preserving vital/intact gland tissue. For this refined specialty of neurosurgery, unique skills need to be acquired along a steep learning curve.

Material and methods

EANS (European Association of Neurosurgical Societies) skull base section panelists were enrolled and 11 completed the survey: the goal was to provide a consensus statement of the endoscopic endonasal approach for pituitary adenoma surgery.

Results

The survey consisted of 44 questions covering demographics data (i.e., academic/non-academic center, case load, years of experience), surgical techniques (i.e., use of neuronavigation, preoperative imaging), and follow-up management.

Discussion and conclusions

In this paper we identified a series of tips and tricks at different phases of an endoscopic endonasal pituitary surgery procedure to underline the crucial steps to perform successful surgery and reduce complications: we took in consideration the principles of the surgical technique, the knowledge of the anatomy and its variations, and finally the importance of adjoining specialties experts.

Development and validation of a nomogram for assessment postoperative sodium disturbance in PAs patients: a retrospective cohort study

Background

Pituitary adenomas (PAs) are neuroendocrine tumors located in the sellar region. Surgery, being the primary treatment option for most PAs, is known to cause disruptions in sodium metabolism.

Objective

To develop and validate a nomogram for assessment the incidence of postoperative sodium disturbance (SD) in patients with PAs.

Methods

In this retrospective study, 208 patients with PAs who underwent resection surgery between 2013 and 2020 were included. Various demographic characteristics, clinical features and laboratory data were analyzed as potential predictors of postoperative sodium disturbance (SD). LASSO regression were used to identify independent preoperative variables associated with SD. Logistic regression was employed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). A nomogram was constructed to visualize these results and evaluated using metrics such as the area under the curve (AUC) for discrimination, the Hosmer-Lemeshow test for calibration and decision curve for usefulness assessment.

Results

The incidence of SD was 44.23% (92 cases out of 208). Six preoperative factors, including sex, types of PAs, phosphocreatine kinase (CK), serum iron (Fe), free fatty acids (NEFA) and mean corpuscular volume (MCV), were identified for constructing a predictive nomogram. The nomogram showed high accuracy, with AUC values of 0.851 (95% CI [0.799-0.923]) and 0.771 (95% CI [0.681-0.861]) in the training and validation datasets, respectively. Calibration assessment and decision curve analysis confirmed its good agreement and clinical utility.

Conclusion

A practical and effective nomogram for predicting SD after PAs surgery is presented in this study.

A Conspectus of Euvolemic Hyponatremia, Its Various Etiologies, and Treatment Modalities: A Comprehensive Review of the Literature

Hyponatremia is the most prevalent electrolyte imbalance encountered among hospitalized patients, athletes, the elderly, patients with chronic ailments, postoperative patients, and a few asymptomatic individuals. Clinical manifestations of hyponatremia can be diverse, with characteristic neurological symptoms. Depending on in-depth medical history, physical examination (including volume status assessment), laboratory investigation, and drug history, patients can be classified broadly as undergoing hypervolemic, euvolemic, or hypovolemic hyponatremia. However, patients with hypervolemic hyponatremia often present with distinctive signs such as edema or ascites, and the clinical presentation of hypovolemic and euvolemic hyponatremia poses significant challenges for clinicians. The convolution in clinical manifestations of patients is due to the varied etiologies of euvolemic hyponatremia, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH), adrenocortical insufficiency, hypothyroidism, psychogenic polydipsia, different classes of drugs (chemotherapeutics, antipsychotics, antidepressants), endurance exercise events, and reset osmostat syndrome (ROS). The management of hyponatremia depends on the rate of hyponatremia onset, duration, severity of symptoms, levels of serum sodium, and underlying comorbidities. Over the last decade, the clinical understanding of hyponatremia has been scattered due to the introduction of innovative laboratory markers and new drugs. This article will be a conspectus of all the recent advancements in the field of diagnosis, investigations, management, and associations of hyponatremia, along with traditional clinical practices. Subsequently, a holistic overview has been laid out for the clinicians to better understand and identify knowledge deficiencies on this topic.

The Potential of Self-Assessment and Associated Factors for Delayed Symptomatic Hyponatremia Following Transsphenoidal Surgery: A Single Center Experience

(1) Background: We identified screening parameters and associated factors for delayed, symptomatic hyponatremia (DSH) following inpatient discharge after transsphenoidal surgery (TSS). (2) Methods: In this prospective, monocentric study, 108 patients who underwent TSS for pituitary pathologies were included, provided with a questionnaire and instructed to document urine specific gravity, fluid intake/urine output, body weight and clinical symptoms for every of five days following discharge from hospital. (3) Results: The overall incidence of DSH within 14 days following discharge from the hospital was 14.8% (n = 9). Symptomatic patients presented on average 8.6 days after surgery. Mild DSH was present in 3.3% of the patients, moderate in 1.6% and severe hyponatremia in 9.8% of patients. Female sex (p = 0.02) and lower BMI (p = 0.02), as well as nausea (66.7%; p < 0.01) and emesis (33.3%; p < 0.05), were associated with DSH. A significant weight delta between morning and afternoon weight two days before the event of DSH between both groups (1.26 kg (n = 5) vs. 0.79 kg (n = 52), p < 0.05) was detected. (4) Conclusions: Handing out a symptom questionnaire at discharge seems to be an easy and feasible tool for the detection of DSH after hospital discharge.

Disorders of Salt and Water Balance After Pituitary Surgery

Transsphenoidal surgery is the first-line treatment for many clinically significant pituitary tumors and sellar lesions. Although complication rates are low when performed at high-volume centers, disorders of salt and water balance are relatively common postoperatively. Both, or either, central diabetes insipidus (recently renamed arginine vasopressin deficiency - AVP-D), caused by a deficiency in production and/or secretion of arginine vasopressin, and hyponatremia, most commonly secondary to the syndrome of inappropriate antidiuresis, may occur. These conditions can extend hospital stay and increase the risk of readmission. This article discusses common presentations of salt and water balance disorders following pituitary surgery, the pathophysiology of these conditions, and their diagnosis and management.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Serum copeptin levels at day two after pituitary surgery and ratio to baseline predict postoperative central diabetes insipidus

PURPOSE

Central diabetes insipidus is a complication that may occur after pituitary surgery and has been difficult to predict. This study aimed to identify the cutoff levels of serum copeptin and its optimal timing for predicting the occurrence of central diabetes insipidus in patients who underwent transsphenoidal surgery.

METHODS

This was a prospective observational study of patients who underwent transsphenoidal surgery for pituitary gland or stalk lesions. Copeptin levels were measured before surgery, 1 h after extubation, and on postoperative days 1, 2, 7, and 90.

RESULTS

Among 73 patients, 14 (19.2%) and 13 (17.8%) patients developed transient and permanent central diabetes insipidus, respectively. There was no significant difference in copeptin levels before surgery and 1 h after extubation; copeptin levels on postoperative days 1, 2, 7, and 90 were significantly lower in patients with permanent central diabetes insipidus than in those without central diabetes insipidus. Copeptin measurement on postoperative day 2 exhibited the highest performance for predicting permanent central diabetes insipidus among postoperative days 1, 2, and 7 (area under the curve [95% confidence interval] = 0.754 [0.632-0.876]). Serum copeptin level at postoperative day 2(< 3.1 pmol/L) showed a sensitivity of 92.3% and a negative predictive value of 97.1%. The ratio of copeptin at postoperative day 2 to baseline (< 0.94) presented a sensitivity of 84.6% and a negative predictive value of 94.9%. The copeptin levels > 3.4 and 7.5 pmol/L at postoperative day 2 and 7 may have ruled out the occurrence of CDI with a negative predictive value of 100%.

CONCLUSION

The copeptin level at postoperative day 2 and its ratio to baseline can predict the occurrence of permanent central diabetes insipidus after pituitary surgery.

Cirugía endoscópica transnasal de base de cráneo: Análisis de las complicaciones en los primeros 120 procedimientos

Antecedentes:

El abordaje endoscópico endonasal (AEE) presenta ventajas potenciales a los abordajes abiertos tradicionales. Sin embargo, se han descrito complicaciones como la fístula de líquido cefalorraquídeo (LCR), trastornos visuales y meningitis postquirúrgica. El objetivo de este trabajo es presentar la experiencia acumulada en 120 casos de cirugía endoscópica de base de cráneo realizadas por un mismo equipo quirúrgico, y describir y analizar las principales complicaciones postoperatorias según la complejidad de los casos.

Métodos:

Estudio retrospectivo sobre nuestra base de datos de pacientes operados de AEE de base de cráneo por diversas patologías entre julio de 2011 y marzo de 2022.

Resultados:

Se analizaron 120 cirugías con AEE de base de cráneo. El 57.14% fueron realizadas en mujeres. La mediana de edad fue de 44 años. El 26.66% fueron reintervenciones. La patología más frecuente fue el adenoma hipofisario (49.17%) seguida de la fístula de LCR (8.33%). El AEE más utilizado fue el transelar 65.83%. Se registraron 26 complicaciones, sin diferencias según la complejidad. Se constataron 13 casos de diabetes insípida (DI) y 8 de fístula de LCR. Esta fue más frecuente en pacientes con fístula intraoperatoria de LCR. La mediana de internación fue de 5.5 días.

Conclusiones:

El AEE de base de cráneo se ha vuelto una opción cada vez más utilizada para el manejo quirúrgico de la patología de la base de cráneo, con una baja frecuencia de complicaciones postoperatorias inmediatas y baja mortalidad. El perfeccionamiento de la técnica como la mejoría en los cuidados postoperatorios se asocian a una menor estancia hospitalaria.

Impact of surgical factors on delayed hyponatremia in patients with nonfunctioning pituitary adenoma after endonasal endoscopic transsphenoidal procedure

PURPOSE

Delayed hyponatremia can occur after pituitary surgery, resulting in prolonged hospitalization. However, the influence of surgical factors after such a procedure has not been well established. The impact of surgery and related factors on delayed hyponatremia was investigated.

METHODS

This was a retrospective analysis of 137 consecutive patients who underwent transsphenoidal surgery for a nonfunctioning pituitary adenoma between 2008 and 2019. Preoperative (demographics, comorbidities), intraoperative (resection extent, operation time, blood loss volume, cerebrospinal fluid leak, tumor consistency), and postoperative [hematoma, meningitis, diabetes insipidus (DI), hormonal assessment] data were collected, with statistical analysis of each factor performed.

RESULTS

Among the 137 patients, delayed hyponatremia occurred in 31 (22.6%). Multivariate analysis revealed that those with hypertension had a significantly higher likelihood of avoiding delayed hyponatremia (p = 0.004). Although no correlations of direct surgical factors with delayed hyponatremia were found, multivariate analysis of indirect surgical factors showed that presence of a firm tumor, transient DI, and meningitis were significantly associated with delayed hyponatremia (p = 0.014, 0.001, and 0.047, respectively). There was also a significant association of severe hyponatremia with appearance of symptoms (p = 0.002).

CONCLUSION

There was a tendency for hypertension to be associated with delayed hyponatremia avoidance, with indirect surgical factors including tumor consistency, transient DI, and meningitis found to have an influence on delayed hyponatremia. It was concluded that attention should be given to non-hypertensive patients with a firm tumor, transient DI, or meningitis after pituitary surgery, as delayed hyponatremia may occur.

Effect of vasopressin V2-receptor antagonist tolvaptan on syndrome of inappropriate antidiuresis (SIAD) after transsphenoidal pituitary surgery: recovery of measured osmolality

Background

Delayed hyponatremia after pituitary surgery can be treated with the V2-receptor antagonist, oral tolvaptan. We investigated the pharmacological effect of oral tolvaptan against SIAD in patients with hyponatremia after pituitary surgery.

Methods

Thirty-nine patients with pituitary adenoma treated by endoscopic transsphenoidal surgery developed SIAD according to the major guidelines, and 7 patients (17.9%) were treated with tolvaptan. Tolvaptan was administrated orally half a tablet (3.75 mg) once in the first two cases, and half a tablet twice in the other five cases. Serum osmolality, urinary osmolality, urinary sodium concentration, urinary volume, and serum sodium and potassium concentration were evaluated before administration, and after the last oral administration of tolvaptan. Serum osmolality and urine osmolality were physically measured.

Results

Serum sodium concentration was significantly increased from 132.1 ± 4.0 to 143.0 ± 2.9 mmol/L (mean ± standard deviation, n = 7, P < 0.001). Serum osmolality was significantly increased from 266.3 ± 7.7 to 289.6 ± 6.7 mOsm/kg (n = 7, P < 0.001). Urine osmolality was significantly reduced from 607.1 ± 240.4 to 262.7 ± 115.6 mOsm/kg (n = 7, P = 0.01). Urinary sodium concentration was significantly decreased from 121.3 ± 48.4 to 36.9 ± 35.0 mOsm/kg (n = 7, P = 0.001). Urine output (24-hour including the first administration) was significantly increased from 1384.2 ± 550.7 to 3291.3 ± 1710.9 mL/day (n = 6, P = 0.026).

Conclusions

Oral tolvaptan administration corrects SIAD after pituitary surgery. Hyponatremia after pituitary surgery was confirmed to be due to SIAD.

Identifying risk factors for postoperative diabetes insipidus in more than 2500 patients undergoing transsphenoidal surgery: a single-institution experience

OBJECTIVE

Diabetes insipidus (DI) following transsphenoidal surgery can adversely impact quality of life and be difficult to manage. This study sought to characterize pre- and perioperative risk factors that may predispose patients to DI after pituitary surgery.

METHODS

A retrospective review of patients treated at a single institution from 2007 to 2019 was conducted. DI was defined as postoperative sodium > 145 mEq/L and urine output > 300 ml/hr and/or postoperative desmopressin (ddAVP) use. DI was further characterized as transient or permanent. Uni- and multivariate analyses were performed to determine variables associated with postoperative DI.

RESULTS

The authors identified 2529 patients who underwent transsphenoidal surgery at their institution. Overall, DI was observed in 270 (10.7%) of the 2529 patients, with 114 (4.5%) having permanent DI and 156 (6.2%) with transient symptoms. By pathology type, DI occurred in 31 (46.3%) of 67 craniopharyngiomas, 10 (14.3%) of 70 apoplexies, 46 (14.3%) of 322 Rathke's cleft cysts, 77 (7.7%) of 1004 nonfunctioning pituitary adenomas (NFPAs), and 62 (7.6%) of 811 functioning pituitary adenomas (FPAs). Final lesion pathology significantly affected DI rates (p < 0.001). Multivariate analysis across pathologies showed that younger age (odds ratio [OR] 0.97, p < 0.001), intraoperative CSF encounter (OR 2.74, p < 0.001), craniopharyngioma diagnosis (OR 8.22, p = 0.007), and postoperative hyponatremia (OR 1.50, p = 0.049) increased the risk of DI. Because surgery for each pathology created specific risk factors for DI, the analysis was then limited to the 1815 pituitary adenomas (PAs) in the series, comprising 1004 NFPAs and 811 FPAs. For PAs, younger age (PA: OR 0.97, p < 0.001; NFPA: OR 0.97, p < 0.001; FPA: OR 0.97, p = 0.028) and intraoperative CSF encounter (PA: OR 2.99, p < 0.001; NFPA: OR 2.93, p < 0.001; FPA: OR 3.06, p < 0.001) increased DI rates in multivariate analysis. Among all PAs, patients with DI experienced peak sodium levels later than those without DI (postoperative day 11 vs 2). Increasing tumor diameter increased the risk of DI in FPAs (OR 1.52, p = 0.008), but not in NFPAs (p = 0.564).

CONCLUSIONS

In more than 2500 patients treated at a single institution, intraoperative CSF encounter, craniopharyngioma diagnosis, and young age all increased the risk of postoperative DI. Patients with postoperative hyponatremia exhibited higher rates of DI, suggesting possible bi- or triphasic patterns to DI. Greater vigilance should be maintained in patients meeting these criteria following transsphenoidal surgery to ensure early recognition and treatment of DI.

Evaluation of the etiological and clinical characteristics of pediatric central diabetes insipidus

OBJECTIVES

Central diabetes insipidus (CDI) is a rare but important disease of varying etiology that poses challenges in diagnosis and follow-up. Identifying diagnostic difficulties in patients with CDI will help ensure an optimal approach to their management and follow-up. This study aimed to characterize the clinical and etiological characteristics of CDI in pediatric patients.

METHODS

We analyzed the admission and follow-up data of CDI patients aged 0-18 years who were followed in our center between 2010 and 2019.

RESULTS

The study included 56 patients with a mean age at diagnosis of 7.92 ± 5.11 years and symptom duration of 8.65 ± 21.3 months. The patients were grouped by etiology into those with organic causes, such as structural anomalies, tumors, and trauma (group 1, n=41) and other causes (group 2, n=15). The prevalence of idiopathic CDI was 16%. At least one pituitary hormone deficiency was detected in 60.7%, the most common being thyroid stimulating hormone deficiency. Patients in group 1 had a higher mean age at diagnosis, shorter symptom duration, and higher frequency of other pituitary hormone deficiencies compared to group 2. Additionally, germinoma was detected 1 year subsequent to normal MRI findings at diagnosis and another patient was diagnosed with Langerhans cell histiocytosis (LCH) 5 years after diagnosis. All patients responded well to replacement therapies, but two patients with germinoma died during follow-up.

CONCLUSIONS

In the pediatric age group, intracranial organic pathologies are an important etiology of CDI, and despite a short symptomatic period, determining the cause may be challenging and prolonged. Patients presenting at a young age with a long history of symptoms and no other pituitary hormone deficiency are unlikely to have organic CDI. However, organic causes such as LCH should be evaluated at all ages. Patients with idiopathic disease are candidates for further etiological studies, and repeated cranial imaging is important during follow-up.

Postoperative water and electrolyte disturbances after extended endoscopic endonasal transsphenoidal surgery

Introduction

Water and electrolyte disturbances are common after pituitary surgery and can generally be classified into transient hypotonic polyuria and transient or permanent diabetes insipidus (DI). The prevalence varies in the literature between 31-51% for transient hypotonic polyuria, 5.1-25.2% for transient DI, and 1-8.8% for permanent DI.

Objective

The aim of this study was to identify the prevalence of water and electrolyte disturbances with polyuria and the preoperative and postoperative predictive factors in patients undergoing surgery with an extended endoscopic endonasal approach.

Material and methods

This retrospective observational descriptive study included 203 patients with a diagnosis of pituitary adenoma who underwent their first transsphenoidal surgery via the extended endoscopic endonasal approach between April 2013 and February 2020. The diagnosis of water and electrolyte disturbances was based on the criterion for polyuria (>4 ml/kg/h). Postoperative polyuria was defined as those cases diagnosed during the immediate postsurgical period that resolved prior to discharge. Transient DI included all cases with a duration of less than 6 months but still present at hospital discharge, and permanent DI included cases lasting more than 6 months.

Results

The overall prevalence of water and electrolyte disorders was 30.5% (62), and the prevalence of postoperative polyuria was 23.6% (48). The median number of desmopressin doses administered to patients with postoperative polyuria was one dose (interquartile range [IQR] 1-2), and thus the median duration of treatment was 0 days. The median initiation of desmopressin was the second day after surgery (IQR 1-2). The overall prevalence of DI was 6.89%. Among the patients with transient DI, the duration was less than 3 months in three patients (1.47%), and between 3 and 6 months in two (0.98%). Nine patients had permanent DI (4.43%). (4.43%).

Conclusions

The prevalence of electrolyte disturbances in our study was high, although similar to that found in the literature. Most of the cases were transient hypotonic polyuria that resolved within one day. The prevalence of transient DI in our cohort was lower than that described in the literature, while permanent DI was similar.

Glucocorticoid Withdrawal Syndrome following treatment of endogenous Cushing Syndrome

PURPOSE

Literature regarding endogenous Cushing syndrome (CS) largely focuses on the challenges of diagnosis, subtyping, and treatment. The enigmatic phenomenon of glucocorticoid withdrawal syndrome (GWS), due to rapid reduction in cortisol exposure following treatment of CS, is less commonly discussed but also difficult to manage. We highlight the clinical approach to navigating patients from GWS and adrenal insufficiency to full hypothalamic-pituitary-adrenal (HPA) axis recovery.

METHODS

We review the literature on the pathogenesis of GWS and its clinical presentation. We provide strategies for glucocorticoid dosing and tapering, HPA axis testing, as well as pharmacotherapy and ancillary treatments for GWS symptom management.

RESULTS

GWS can be difficult to differentiate from adrenal insufficiency and CS recurrence, which complicates glucocorticoid dosing and tapering regimens. Monitoring for HPA axis recovery requires both clinical and biochemical assessments. The most important intervention is reassurance to patients that GWS symptoms portend a favorable prognosis of sustained remission from CS, and GWS typically resolves as the HPA axis recovers. GWS also occurs during medical management of CS, and gradual dose titration based primarily on symptoms is essential to maintain adherence and to eventually achieve disease control. Myopathy and neurocognitive dysfunction can be chronic complications of CS that do not completely recover.

CONCLUSIONS

Due to limited data, no guidelines have been developed for management of GWS. Nevertheless, this article provides overarching themes derived from published literature plus expert opinion and experience. Future studies are needed to better understand the pathophysiology of GWS to guide more targeted and optimal treatments.

Complications in Endoscopic Endonasal Pitiuitary Adenoma surgery: An institution experience in 310 patients

Objective: Endoscopic Endonasal approaches (EEA) have shown excellent results for majority of hypophyseal tumors. The aim of this study was to evaluate and report the complications of EEA in patients with Pituitay Adenoma (PA) who underwent surgery between 2013 and 2018. Methods: We performed a retrospective review of 310 consecutive patients/325 procedures with PA treated with an Endoscopic Endonasal (EEA) approach from May 2013 to January 2018. Minor complications including transient diabetes insipidus (DI) or new anterior pituitary hormone insufficiency in one axis and major complications including CSF leakage, hematoma needing reoperation, vascular damage, brain infection, new pan-hypopituitarism permanent DI, new visual impairment, neurological deficits, and mortality were recorded. Results: We encountered 58 complications in 310 patients (18.7%) and in 325 procedures (17.7%). Minor complications were 43 (13.9% and 13.2%) in 310 patients and in 325 procedures respectively; whereas, major complications were 28 (9% and 8.6% respectively). Total complications were associated with diameter group 2 (>30 mm), diaphragm sella violation, suprasellar extension, paraselar involvement, nonfunctional secretory type, intraoperative arachnoid tearing Conclusion: EEA can be considered as a safe surgical treatment with acceptable complications in the management of pituitary adenomas.

Central diabetes insipidus after total abdominal hysterectomy and bilateral salpingo-oophrectomy: A case report

Postoperative polyuria due to diabetes insipidus (DI) is commonly reported complication of pituitary surgery. However, central DI postabdominal surgery is rare and related to unmasking of pre-existing DI or prolonged surgery with significant intraoperative blood loss. A thorough workup needs to be performed to exclude central DI in such patients.

Predicting the Need for Desmopressin Treatment During Inpatient and After Discharge Following Endoscopic Sellar Surgery

Introduction

Postoperative diabetes insipidus (DI) is a common complication following endoscopic sellar surgery. However, the requirement of desmopressin treatment for patients with DI are heterogenous. Although the predictors of postoperative DI have been reported, whether these patients required desmopressin treatment remained uninvestigated. Predicting the need of desmopressin can benefit clinical decision making more directly than predicting the occurence of postoperative DI. This study aimed to identify variables that predict the need for desmopressin treatment following sellar surgery.

Methods

Patients undergoing endoscopic sellar surgery between 2016 and 2019 were retrospectively reviewed. Twenty-three variables, characterized as potential predictors for requiring desmopressin treatment, were analyzed. To assess the capability to generalize the identified predictors, external validation with receiver operating characteristic (ROC) analysis was performed using a second series from 2019 to 2020.

Results

Postoperative DI occurred in 40 of 159 included patients. Twelve patients required inpatient desmopressin treatment and 20 patients needed desmopressin prescription after discharge. The potential predictors of requiring any desmopressin use included higher peak sodium (Na) level (p = 0.007), lower minimum Na level (p = 0.043), and higher peak urine output (p = 0.006), but these were not supported by external validation. The predictors of requiring desmopressin after discharge included higher peak Na (p = 0.040) and minimum Na levels (p = 0.048), which were supported by external ROC validation showing areas under curve of 0.787, 0.611, and 0.898 for peak Na (p = 0.036), minimum Na (p = 0.460), and peak Na – minimum Na levels (p < 0.001), respectively. A criterion of peak Na ≥ 150 mmol/L or peak Na – minimum Na ≥ 10 predicted the need of desmopressin prescription after discharge. A postoperative management algorithm was proposed.

Conclusion

The required treatments for patients with postoperative DI following endoscopic sellar surgery are heterogenous. Elevated peak Na and large peak Na—minimum Na levels in the perioperative period predicted requiring desmopressin after hospital discharge. Patients with peak Na <150 mmol/L and peak Na—minimum Na <10 can be safely discharged without desmopressin prescription.

Predictive factors of postoperative diabetes insipidus in 333 patients undergoing transsphenoidal surgery for non-functioning pituitary adenoma

PURPOSE

Diabetes insipidus (DI) following transsphenoidal surgery (TSS) is a common complication. Although postoperative DI often occurs in patients with craniopharyngioma and Rathke's cleft cyst, postoperative DI in patients with non-functioning pituitary adenoma (NFPA) has not been fully examined. We clarified the clinical characteristics and magnetic resonance imaging (MRI) findings predicting postoperative DI in NFPAs.

METHODS

A total of 333 patients undergoing initial TSS for NFPA were included in this retrospective study. Hyperintensity (HI) in the posterior pituitary lobe was evaluated on preoperative T1-weighted MRI. Based on the findings of HI patients were divided into three groups as follows: HI was not detected (Disappearance group), HI located intrasellarly (Intrasellar group), and HI located suprasellarly (Suprasellar group).

RESULTS

The overall rate of DI was 21.9%, including permanent DI in 0.6%. DI occurred at postoperative day 1 (72.6%) or day 2 (19.2%) and improved within 7 days in most cases (87.7%). Univariable and multivariable analyses showed that the predictive factors of DI were a younger age (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.95-0.99, P = 0.0037) and larger tumor diameter (OR 1.04, 95% CI 1.01-1.08, P = 0.0155). The rate of DI was highest in the Disappearance group (43.8%) followed by the Intrasellar group (26.0%). The OR was 2.17 in the Intrasellar group compared with the Suprasellar group (95% CI 1.17-4.02, P = 0.0141).

CONCLUSIONS

Factors predicting DI following TSS for NFPA were a younger age, larger tumor size, and the location of intrasellar HI on preoperative T1-weighted MRI.

Predictive factors for delayed hyponatremia after transsphenoidal surgery in patients with pituitary adenomas

Objective

The aim of this study was to evaluate the incidence and duration of delayed hyponatremia and to assess the factors influencing the development of delayed hyponatremia after transsphenoidal surgery (TSS) in pituitary adenomas.

Methods

We retrospectively analyzed the clinical data of patients with pituitary adenoma who underwent TSS. Univariable and multivariable statistics were carried out to identify factors independently associated with the occurrence of delayed hyponatremia.

Results

Of the 285 patients with pituitary adenoma who underwent microscopic TSS, 44 (15.4%) developed postoperative-delayed hyponatremia and 241 (84.6%) did not. The onset of delayed hyponatremia occurred an average of 5.84 days post-surgery and persisted for an average of 5.36 days. Logistic regression analysis showed the highest risk of delayed hyponatremia in patients with significant change in tumor cavity height (odds ratio (OR), 1.158; 95% CI, 1.062, 1.262; P = 0.001), preoperative hypothalamus-pituitary-thyroid axis hypofunction (OR, 3.112; 95% CI, 1.481, 6.539; P = 0.003), and significant difference in blood sodium levels before and 2 days after TSS (OR, 1.101; 95% CI, 1.005, 1.206; P = 0.039).

Conclusions

Preoperative hypothyroidism, difference in blood sodium levels before and 2 days after TSS, and the change in tumor cavity height after TSS played important roles in predicting postoperative-delayed hyponatremia onset in patients with pituitary adenomas.

Novel Nomograms to Predict Delayed Hyponatremia After Transsphenoidal Surgery for Pituitary Adenoma

OBJECTIVE

This study aimed to develop a nomogram of clinical variables and magnetic resonance imaging scans to predict delayed hyponatremia after transsphenoidal surgery for pituitary adenoma.

METHODS

Patients who underwent transsphenoidal surgery for pituitary adenoma in Fuzong Clinical Medical College of Fujian Medical University between January 2012 and December 2020 were retrospectively investigated. Medical records, MRI findings, and laboratory examination results were recorded as candidate variable predictors of delayed hyponatremia. A nomogram to predict delayed hyponatremia was formulated based on the multivariable model of risk factors. The predictive accuracy and discriminative ability of the nomogram were assessed using the receiver operating characteristic (ROC) curve, calibration plot, and decision curve analyses. The model underwent prospective validation in three medical centers with patients who underwent transsphenoidal surgery for pituitary adenoma between January 2021 and February 2022.

RESULTS

The model that incorporated the postoperative length of "measurable pituitary stalk," pituitary stalk deviation angle difference, postoperative diabetes insipidus, sinking depth of diaphragma sellae, and blood sodium level on the second postoperative day was developed and presented as the nomogram of the training cohort. The nomogram achieved area under the ROC curve (AUCs) of 0.806 and 0.849 for the training cohort and the testing cohort, respectively, and displayed good calibration. Decision curve analysis showed that the nomogram was clinically useful when the threshold probability was 13-96%.

CONCLUSIONS

We developed a nomogram to evaluate the individualized prediction of delayed hyponatremia after transsphenoidal surgery for pituitary adenomas.

Grading Central Diabetes Insipidus Induced by Immune Checkpoint Inhibitors: A Challenging Task

Central diabetes insipidus (CDI) is a rare endocrine disease deriving from an insufficient production or secretion of anti-diuretic hormone. Recently, CDI has been reported as a rare side effect triggered by immune checkpoint inhibitors (ICI) in cancer patients. Despite its current rarity, CDI triggered by ICI is expected to affect an increasing number of patients because of the expanding use of these effective drugs in a growing number of solid and hematologic malignancies. An appropriate assessment of the severity of adverse events induced by anticancer agents is crucial in their management, including dosing adjustment and temporary withdrawal or discontinuation treatment. However, assessment of the severity of CDI induced by ICI may be challenging, as its main signs and symptoms (polyuria, dehydration, weight loss, and hypernatremia) can be incompletely graded. Indeed, the current grading system of toxicity induced by anticancer treatments does not include polyuria. Additionally, dehydration in patients affected by diabetes insipidus, including ICI-induced CDI, is different in certain aspects from that due to other conditions seen in cancer patients, such as vomiting and diarrhea. This prompted us to reflect on the need to grade polyuria, and how to grade it, and to consider a specific grading system for dehydration associated with CDI induced by ICI. Here we propose a new grading system for polyuria and dehydration, as critical symptoms of the CDI syndrome occurring in patients on ICI treatment, to obtain better management of both the adverse event and the triggering drugs.

Plasma sodium and potassium concentrations after hypophysectomy in dogs with corticotroph adenomas

Background

Electrolyte abnormalities, especially hypernatremia, are frequent complications after transsphenoidal hypophysectomy in dogs with pituitary‐dependent hypercortisolism.

Objectives

To describe electrolyte abnormalities after transsphenoidal hypophysectomy and to investigate possible associations between postoperative hypernatremia and clinical and surgical variables as well as with postoperative outcome.

Animals

One hundred and twenty‐seven client‐owned dogs.

Methods

Dogs with pituitary corticotroph adenomas that underwent transsphenoidal hypophysectomy were retrospectively included. Plasma sodium and potassium concentrations were measured −2, +2, +8, +24, and +48 hours from hypophysectomy. Clinical (breed, age, body weight, skull type, urinary cortisol/creatinine ratio, percentage of suppression to dexamethasone) and surgical variables (duration of anesthesia and surgery, pituitary dimensions) were compared to the development of hypernatremia.

Results

Postoperative hypernatremia developed in 46.5% (57/127) of dogs and hyponatremia in 6.3% (8/127). Plasma sodium concentration increased after surgery and peaked at 8 hours after surgery, normalizing after 24 to 48 hours. Plasma potassium concentration increased without exceeding the reference limit.

No significant associations were found between clinical and surgical variables and hypernatremia, or between hypernatremia and postoperative death, long‐term survival or recurrence.

Surgery time was significantly longer in dogs that developed persistent diabetes insipidus (P = .02) and persistent diabetes insipidus occurred more frequently in dogs with enlarged pituitary glands (P = .01).

Conclusion and Clinical Importance

Hypernatremia remains a frequent postoperative complication after transsphenoidal hypophysectomy but did not appear to have an impact on postoperative outcome. No predisposing factor to postoperative hypernatremia was identified. Variations in plasma potassium concentrations do not seem to influence postoperative outcome.

Diaphragma sellae sinking can predict the onset of hyponatremia after transsphenoidal surgery for pituitary adenomas

PURPOSE

Sinking of the diaphragma sellae (DS) may stretch the pituitary stalk, which in turn impairs neurohypophyseal function; thus, it may play a role in the development of postoperative hyponatremia. We aimed to assess the factors influencing the development of hyponatremia after transsphenoidal surgery (TSS) for pituitary adenomas and analyze the effect of DS sinking on hyponatremia.

METHODS

After applying the inclusion and exclusion criteria, we retrospectively analyzed the clinical data of patients with pituitary adenoma who underwent TSS. The pituitary gland was scanned using a 3.0-T magnetic resonance imaging, and sagittal and coronal images were acquired. We evaluated the following: preoperative and postoperative hypothalamus‒pituitary‒thyroid axis function, hypothalamus‒pituitary‒adrenal axis function, intra-operative cerebrospinal fluid leaks, diabetes insipidus, hyponatremia, time from the day of surgery to the day of discharge, and time of hyponatremia onset.

RESULTS

Of the 460 patients who had microscopic TSS for pituitary adenoma, 83 experienced postoperative hyponatremia. Hyponatremia occurred approximately 5.25 days postoperatively and persisted for 5.54 days. The lowest average blood sodium level was 123.9 mEq/L, which occurred at 7.49 days after surgery. Logistic regression analysis showed that the risk of hyponatremia was greater for patients with a significant DS sinking depth, a large pituitary stalk deviation angle difference, and a longer postoperative "measurable pituitary stalk". The difference in blood sodium levels between pre-TSS and 2 days post-TSS was also an independent predictor of postoperative hyponatremia onset.

CONCLUSION

DS sinking plays an important role in predicting hyponatremia onset after TSS for pituitary adenomas.

Management of Diabetes Insipidus following Surgery for Pituitary and Suprasellar Tumours

Central diabetes insipidus (CDI) is a common complication after pituitary surgery. However, it is most frequently transient. It is defined by the excretion of an abnormally large volume of dilute urine with increasing serum osmolality. The reported incidence of CDI after pituitary surgery ranges from 0–90%. Large tumour size, gross total resection and intraoperative cerebrospinal fluid leak usually pose an increased risk of CDI as observed with craniopharyngioma and Rathke’s cleft cysts. CDI can be associated with high morbidity and mortality if not promptly recognised and treated on time. It is also essential to rule out other causes of postoperative polyuria to avoid unnecessary pharmacotherapy and iatrogenic hyponatremia. Once the diagnosis of CDI is established, close monitoring is required to evaluate the response to treatment and to determine whether the CDI is transient or permanent. This review outlines the evaluation and management of patients with CDI following pituitary and suprasellar tumour surgery to help recognise the diagnosis, consider the differential diagnosis, initiate therapeutic interventions and guide monitoring and long-term management.

Changes in copeptin levels before and 3 months after transsphenoidal surgery according to the presence of postoperative central diabetes insipidus

Copeptin levels reflect arginine vasopressin (AVP) release from the hypothalamus. Pituitary surgery often impairs AVP release and results in central diabetes insipidus (CDI). Here, we aimed to investigate how serum copeptin level changes 3 months after pituitary surgery and whether it has a diagnostic value for postoperative permanent CDI. Consecutive patients who underwent endoscopic transsphenoidal surgery at a single tertiary hospital were recruited. Serum copeptin levels were measured preoperatively and 3 months postoperatively. Among 88 patients, transient and permanent CDI occurred in 17 (19.3%) and 23 (26.1%), respectively. Three-month postoperative copeptin levels significantly declined from preoperative levels in permanent CDI group (P < 0.001, percentage difference =  - 42.2%) and also in the transient CDI group (P = 0.002, - 27.2%). Three months postoperative copeptin level < 1.9 pmol/L under normal serum sodium levels was the optimal cutoff value for diagnosing permanent CDI with an accuracy of 81.8%, while 3-month postoperative copeptin level ≥ 3.5 pmol/L excluded the CDI with a negative predictive value of 100%. Conclusively, 3 months postoperative copeptin levels significantly decreased from preoperative levels in the transient CDI group as well as the permanent CDI group. Three-month postoperative copeptin levels ≥ 3.5 pmol/L under normal serum sodium levels may be diagnostic for excluding postoperative CDI.

High Incidence of Hyponatremia in Patients Operated for Nonsellar/Suprasellar Supratentorial Tumors—A Prospective Observational Study

Background The incidence of hyponatremia is high in supratentorial tumors. However, most studies of supratentorial tumors have included patients with sellar/suprasellar tumors. It is common knowledge that sellar tumors have higher incidence and severity of hyponatremia. Incidence of hyponatremia is not known if we exclude sellar/suprasellar tumors. Therefore, this study was designed to evaluate the incidence of hyponatremia in supratentorial tumors after excluding sellar/suprasellar tumors.

Methods After institutional ethics committee approval and written informed consent, adult patients with supratentorial tumors (nonsellar/suprasellar) were recruited, and data were collected prospectively. In all patients, serum electrolytes were measured every 2 to 3 days. Hyponatremia was defined as serum sodium of <135 mEq/L. All the patients were followed up till death or discharge from the hospital.

Results A total of 61 patients’ data were analyzed. There were 31 male and 30 female patients with an average age of 44 years. There were 23 meningiomas, 36 gliomas, and 2 other tumors. Forty patients (66%) developed hyponatremia during hospital stay. There were 29 mild cases (serum sodium 131–134 mEq/L), 7 were moderate (serum sodium 126–130 mEq/L), and 4 were severe (serum sodium <126 mEq/L). Three hyponatremic meningioma patients died, of which two had mild hyponatremia and one had severe hyponatremia. Duration of hospital stay was longer in hyponatremic patients.

Conclusion The incidence of hyponatremia is high in supratentorial tumor patients after excluding sellar/suprasellar lesions. In the majority of patients, the disturbance is mild. Hyponatremic patients has a longer hospital stay and higher mortality.

Is it possible to predict the development of diabetes insipidus after pituitary surgery? Study of 241 endoscopic transsphenoidal pituitary surgeries

PURPOSE

To identify presurgical and surgical factors associated with the development of diabetes insipidus (DI) after pituitary adenoma (PA) resection through an endoscopic endonasal transsphenoidal approach.

METHODS

Data from 231 patients with functioning and non-functioning PAs who underwent an endoscopic endonasal transsphenoidal approach in the last ten years.

RESULTS

231 patients with 241 pituitary surgeries were included. Eighty-five percent harbored macroadenomas and 38.1% of them were invasive. After pituitary surgery, 12.5% (n = 30) developed transient DI and 5.0% (n = 12) permanent DI. The global risk of DI was higher in patients younger than 65 years (OR = 2.94, p = 0.029), with total tumoral resection (OR = 2.86, p = 0.007) and with diaphragm opening during pituitary resection (OR = 3.63, p = 0.0003). Once postoperative DI developed, the risk of permanent DI increased in those patients with larger PA (OR = 1.07 for each mm of craniocaudal diameter, p = 0.020), especially in those greater than 30 mm (OR = 8.33, p = 0.004). Moreover, diaphragm opening during pituitary resection (OR = 28.3, p = 0.018) predicted long-term DI independently of pituitary tumor size. The risk of permanent DI increased as PA craniocaudal diameter increased (r = 0.20, p = 0.002).

CONCLUSION

In patients with PAs younger than 65 years, in whom diaphragm has been opened during pituitary surgery and/or with a total tumor resection, special hydric balance monitoring should be maintained in the postoperative period due to the increased risk of developing DI. The risk of permanent DI increases as PA craniocaudal diameter increased.

Increased oxytocin release precedes hyponatremia after pituitary surgery

PURPOSE

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a well-known complication of transsphenoidal pituitary surgery, related to inappropriate secretion of arginine vasopressin (AVP). Its diagnosis is based on hyponatremia, with a peak of occurrence around day 7 after surgery and, to date, no early marker has been reported. In particular, copeptin levels are not predictive of hyponatremia in this case. Oxytocin (OXT) is secreted into the peripheral blood by axon terminals adjacent to those of AVP neurons in the posterior pituitary. Besides its role in childbirth and lactation, recent evidences suggested a role for OXT in sodium balance. The contribution of this hormone in the dysnatremias observed after pituitary surgery has however never been investigated.

METHODS

We analyzed the urinary output of OXT in patients subjected to transsphenoidal pituitary surgery.

RESULTS

While OXT excretion remained stable in patients who presented a normonatremic postoperative course, patients who were later diagnosed with SIADH-related hyponatremia presented with a significantly increased urinary secretion of OXT 4 days after surgery.

CONCLUSION

Taken together, these results show for the first time that urinary OXT output remains normally stable after transsphenoidal pituitary surgery. OXT excretion however becomes abnormally high on or around 4 days after surgery in patients later developing hyponatremia, suggesting that this abnormal dynamics of OXT secretion might serve as an early marker for transsphenoidal surgery-related hyponatremia attributed to SIADH.

Effectiveness of dietary diabetes insipidus bundle on the severity of postoperative fluid imbalance in pituitary region tumours: A randomized controlled trial

AIM

To test the effectiveness of nurse-led dietary diabetes insipidus (DI) bundle on the severity of postoperative fluid imbalance in pituitary region tumours.

DESIGN

Blinded randomized controlled trial.

METHODS

Patients aged 18-65 operated for sellar-suprasellar tumours in an Indian tertiary care centre were enrolled through total enumeration sampling and underwent randomization with allocation concealment during Sep 2018-Feb 2019. Pre-operative DI, postoperative ventilation, renal failure or decompensated diabetes mellitus were excluded. Patients in the intervention group received a nurse-led DI bundle (validated by three Delphi rounds) with four dietary components: intake of only water during thirst and avoidance of the following-added salt, high-protein foods and caffeinated drinks. Treating clinicians and the investigator assessing outcome were blinded about enrolment. Urine output, serum sodium, vasopressin requirement and hospital stay were assessed as primary outcomes. The outcome measures were monitored daily till the 6th postoperative day. Analyses were performed on 'intention-to-treat' basis, irrespective of compliance. Independent t-test and Chi-square test were used.

RESULTS

Of the initial 63 patients, 50 fulfilling criteria were randomized to two groups and assessed over six days yielding 150 patient-days per group. There were no significant baseline differences between groups. The mean daily urine output was significantly lower in the DI bundle group than in control, both overall and among endonasal operated pituitary adenomas [3000.09(462.7) vs. 4095.71(896.4)ml & 2987.14(419.5) vs. 4064.73(1051)ml], with the greatest difference on the second postoperative day. Though hypernatraemia in controls became most prominent during days 2-3 and resolved in a week, it was significantly lower in the intervention group (12.7% vs. 30.7% overall, 11.4% vs. 29.4% endonasal adenomas). The need for vasopressin analogues and hospital stay were also significantly lower with DI bundle (p < 0.001).

CONCLUSION

This is probably the first ever report of dietary DI bundle among operated pituitary patients, which seem to flatten the DI trend with significant benefits in polyuria, hypernatraemia, vasopressin requirement and hospital stay.

TRIAL REGISTRATION

CTRI/2018/07/015127 of ICMR.

IMPACT

The nurse-led dietary DI bundle has effectively reduced the severity of DI among operated pituitary patients with significant benefits in polyuria, hypernatraemia, vasopressin requirement and hospital stay. Its implementation is simple and easy to carry out, especially in resource-constrained institutions, where continuous monitoring and repeated serum sodium estimation are difficult.

Postoperative diabetes insipidus: how to define and grade this complication?

PURPOSE

Although transient diabetes insipidus (DI) is the most common complication of pituitary surgery, there is no consensus on its definition. Polyuria is the most overt symptoms of DI, but can also reflect several physiological adaptive mechanisms in the postoperative phase. These may be difficult to distinguish from and might coincide with DI. The difficulty to distinguish DI from other causes of postoperative polyuria might explain the high variation in incidence rates. This limits interpretation of outcomes, in particular complication rates between centers, and may lead to unnecessary treatment. Aim of this review is to determine a pathophysiologically sound and practical definition of DI for uniform outcome evaluations and treatment recommendations.

METHODS

This study incorporates actual data and the experience of our center and combines this with a review of literature on pathophysiological mechanisms and definitions used in clinical studies reporting of postoperative DI.

RESULTS

The occurrence of excessive thirst and/or hyperosmolality or hypernatremia are the best indicators to discriminate between pathophysiological symptoms and signs of DI and other causes. Urine osmolality distinguishes DI from osmotic diuresis.

CONCLUSIONS

To improve reliability and comparability we propose the following definition for postoperative DI: polyuria (urine production > 300 ml/hour for 3 h) accompanied by a urine specific gravity (USG) < 1.005, and at least one of the following symptoms: excessive thirst, serum osmolality > 300 mosmol/kg, or serum sodium > 145 mmol/L. To prevent unnecessary treatment with desmopressin, we present an algorithm for the diagnosis and treatment of postoperative DI.

Guidelines in the management of CNS tumors

INTRODUCTION

Evidence-based, clinical practice guidelines in the management of central nervous system tumors (CNS) continue to be developed and updated through the work of the Joint Section on Tumors of the Congress of Neurological Surgeons (CNS) and the American Association of Neurological Surgeons (AANS).

METHODS

The guidelines are created using the most current and clinically relevant evidence using systematic methodologies, which classify available data and provide recommendations for clinical practice.

CONCLUSION

This update summarizes the Tumor Section Guidelines developed over the last five years for non-functioning pituitary adenomas, low grade gliomas, vestibular schwannomas, and metastatic brain tumors.

Comparison of intraoperative cortisol levels after preoperative hydrocortisone administration versus placebo in patients without adrenal insufficiency undergoing endoscopic transsphenoidal removal of nonfunctioning pituitary adenomas: a double-blind randomized trial

OBJECTIVE

In this double-blind randomized trial, the necessity of preoperative steroid administration in patients without adrenal insufficiency (AI) undergoing endoscopic transsphenoidal surgery (ETSS) for pituitary adenoma was evaluated.

METHODS

Forty patients with and without AI, defined as a peak cortisol level > 18 µg/dl on the insulin tolerance test or rapid adrenocorticotropic hormone (ACTH) test, undergoing ETSS for nonfunctioning pituitary adenomas were randomly allocated to treatment with either 100 mg of preoperative hydrocortisone (group HC, n = 20) or normal saline (group C, n = 20). The patients with pituitary apoplexy, the use of a drug within the last 3 months that could affect the hypothalamic-pituitary-adrenal axis, or a previous history of brain or adrenal surgery were excluded. Intraoperative cortisol and ACTH levels were measured after anesthesia induction, dura incision, and tumor removal, and at the end of surgery. Intraoperative hypotension, early postoperative AI, and postoperative 3-month pituitary function were investigated.

RESULTS

Intraoperative serum cortisol levels were significantly higher in the HC group than in the C group after anesthesia induction (median 69.0 µg/dl [IQR 62.2-89.6 µg/dl] vs 12.7 µg/dl [IQR 8.4-18.2 µg/dl], median difference 57.5 µg/dl [95% CI 33.0-172.9 µg/dl]), after dura incision (median 53.2 µg/dl [IQR 44.9-63.8 µg/dl] vs 6.4 [IQR 4.8-9.2 µg/dl], median difference 46.6 µg/dl [95% CI 13.3-89.2 µg/dl]), after tumor removal (median 49.5 µg/dl [IQR 43.6-62.4 µg/dl] vs 9.2 µg/dl [IQR 5.75-16.7 µg/dl], median difference 39.4 µg/dl [95% CI 0.3-78.1 µg/dl]), and at the end of surgery (median 46.9 µg/dl [IQR 40.1-63.4 µg/dl] vs 16.9 µg/dl [IQR 12.1-23.2 µg/dl], median difference 32.2 µg/dl [95% CI -42.0 to 228.1 µg/dl]). Serum ACTH levels were significantly lower in group HC than in group C after anesthesia induction (median 3.9 pmol/L [IQR 1.7-5.2 pmol/L] vs 6.9 pmol/L [IQR 3.9-11.9 pmol/L], p = 0.007). No patient showed intraoperative hypotension due to AI. Early postoperative AI was observed in 3 and 5 patients in groups HC and C, respectively. The postoperative 3-month pituitary hormone outcomes including ACTH deficiency were not different between groups.

CONCLUSIONS

Preoperative steroid administration may be unnecessary in patients without AI undergoing ETSS for nonfunctioning pituitary adenomas. However, a further large-scale study is needed to determine whether preoperative steroid administration has a significant impact on clinically meaningful events such as perioperative AI and postoperative 3-month ACTH deficiency in these patients.Korean Clinical Trial Registry no.: KCT0002426 (https://cris.nih.go.kr/cris/).

Tolvaptan in the Management of Acute Euvolemic Hyponatremia After Transsphenoidal Surgery: A Retrospective Single-Center Analysis

INTRODUCTION

Syndrome of inappropriate antidiuresis (SIAD) can be a complication of hypothalamus-pituitary surgery. The use of tolvaptan in this setting is not well established, hence the primary aim of this study was to assess the sodium correction rates attained with tolvaptan compared with standard treatments (fluid restriction and/or hypertonic saline). Furthermore, we compared the length of hospital stay in the two treatment groups and investigated the occurrence of overcorrection and side effects including osmotic demyelination syndrome.

METHODS

We retrospectively reviewed 308 transsphenoidal surgical procedures performed between 2011 and 2019 at our hospital. We selected adult patients who developed post-operative SIAD and recorded sodium monitoring, treatment modalities and outcomes. Correction rates were adjusted based on pre-treatment sodium levels.

RESULTS

Twenty-nine patients (9.4%) developed post-operative SIAD. Tolvaptan was administered to 14 patients (median dose 15 mg). Standard treatments were employed in 14 subjects (fluid restriction n=11, hypertonic saline n=1, fluid restriction and hypertonic saline n=2). Tolvaptan yielded higher adjusted sodium correction rates (12.0 mmolL^-1/24h and 13.4 mmolL^-1/48h) than standard treatments (1.8 mmolL^-1/24h, p<0.001, and 4.5 mmolL^-1/48h, p=0.004, vs. tolvaptan). The correction rate exceeded 10 mmolL^-1/24h or 18 mmolL^-1/48h in 9/14 and 2/14 patients treated with tolvaptan, respectively, and in no patient who received standard treatments. No side effects including osmotic demyelination occurred. Tolvaptan was associated with a shorter hospital stay (11vs.15 days, p=0.01).

CONCLUSIONS

Tolvaptan is more effective than fluid restriction (with or without hypertonic saline) and allows for a shortened hospital stay in patients with SIAD after transsphenoidal surgery. However, its dose and duration should be carefully tailored, and close monitoring is recommended to allow prompt detection of overcorrection.

Hypothalamus-Pituitary Dysfunction as an Independent Risk Factor for Postoperative Central Nervous System Infections in Patients With Sellar Region Tumors

OBJECTIVE

The purpose of this study was to verify that hypothalamus-pituitary dysfunction is one of the risk factors for postoperative central nervous system infections (PCNSIs).

METHOD

We performed a retrospective analysis of all patients with sellar region lesions who underwent surgery between January 2016 and November 2019 at Peking Union Medical College Hospital. In total, 44 age- and sex-matched controls were enrolled. Univariate and multivariate analyses were performed to identify risk factors for PCNSIs.

RESULT

We enrolled 88 patients, 44 of whom had PCNSIs. Surgical approach (TCS) (P<0.001), previous surgery on the same site (P=0.001), intraoperative cerebral spinal fluid (CSF) leakage (P<0.001), postoperative adrenal insufficiency (P=0.017), postoperative DI (P=0.004) and the maximum Na⁺ levels(<0.001) correlated significantly with PCNSIs. Multivariate analysis showed that Surgery approach (TCS)(OR: 77.588; 95%CI: 7.981-754.263; P<0.001), intraoperative CSF leakage (OR: 12.906; 95%CI: 3.499-47.602; P<0.001), postoperative DI (OR: 6.999; 95%CI:1.371-35.723; P=0.019) and postoperative adrenal insufficiency (OR: 6.115; 95%CI: 1.025-36.469; P=0.047) were independent influencing factors for PCNSIs.

CONCLUSION

TCS, intraoperative CSF leakage, postoperative DI and postoperative adrenal insufficiency are risk factors for PCNSIs in patients with sellar region tumors.

Delayed Postoperative Hyponatremia Following Endoscopic Transsphenoidal Surgery for Non-Adenomatous Parasellar Tumors

Little is known about delayed postoperative hyponatremia (DPH) accompanied with transsphenoidal surgery for non-adenomatous skull base tumors (NASBTs). Consecutive data on 30 patients with parasellar NASBT was retrospectively reviewed with detailed analyses on perioperative serial sodium levels. Serological DPH (sodium ≤ 135 mmol/L) was observed in eight (27%), with four (13%) of them being symptomatic. DPH developed on postoperative day 7-12 where the mean sodium levels were 134 mmol/L (a mean of 7 mmol/L drop from the baseline) in asymptomatic and 125 mmol/L (a mean of 17.5 mmol/L drop from the baseline) in symptomatic DPH. Serological DPH was accompanied with "weight loss and hemoconcentration (cerebral salt wasting type)" in four (50%), "weight gain and hemodilution (syndrome of inappropriate antidiuretic hormone secretion type)" in three (38%), and no significant weight change in one. Intraoperative extradural retraction of the pituitary gland was the only significant factor for serological DPH (p = 0.035; odds ratio, 12.25 (95% confidence interval, 1.27-118.36)). DPH should be recognized as one of the significant postsurgical complications associated with TSS for NASBTs. Although the underlying mechanism is still controversial, intraoperative extradural compression of the pituitary gland and subsequent dysregulation of the hypothalamo-hypophyseal axis may be responsible.

Feasibility of machine learning based predictive modelling of postoperative hyponatremia after pituitary surgery

PURPOSE

Hyponatremia after pituitary surgery is a frequent finding with potential severe complications and the most common cause for readmission. Several studies have found parameters associated with postoperative hyponatremia, but no reliable specific predictor was described yet. This pilot study evaluates the feasibility of machine learning (ML) algorithms to predict postoperative hyponatremia after resection of pituitary lesions.

METHODS

Retrospective screening of a prospective registry of patients who underwent transsphenoidal surgery for pituitary lesions. Hyponatremia within 30 days after surgery was the primary outcome. Several pre- and intraoperative clinical, procedural and laboratory features were selected to train different ML algorithms. Trained models were compared using common performance metrics. Final model was internally validated on the testing dataset.

RESULTS

From 207 patients included in the study, 44 (22%) showed a hyponatremia within 30 days postoperatively. Hyponatremic measurements peaked directly postoperatively (day 0-1) and around day 7. Bootstrapped performance metrics of different trained ML-models showed largest area under the receiver operating characteristic curve (AUROC) for the boosted generalized linear model (67.1%), followed by the Naïve Bayes classifier (64.6%). The discriminative capability of the final model was assessed by predicting on unseen dataset. Large AUROC (84.3%; 67.0-96.4), sensitivity (81.8%) and specificity (77.5%) with an overall accuracy of 78.4% (66.7-88.2) was reached.

CONCLUSION

Our trained ML-model was able to learn the complex risk factor interactions and showed a high discriminative capability on unseen patient data. In conclusion, ML-methods can predict postoperative hyponatremia and thus potentially reduce morbidity and improve patient safety.

Feasibility, safety, and outcomes of a stratified fast-track care trajectory in pituitary surgery

OBJECTIVE

Discharge policies concerning hospitalization after endoscopic pituitary tumor surgery are highly variable. A few studies support fast-track discharge; however, this is not commonplace. Our goal was to report the transition to and evaluate the feasibility, safety, clinical- and patient-reported outcomes and costs of fast-track care in pituitary surgery.

METHODS

This observational study included 155 patients undergoing pituitary surgery between December 2016 and December 2018. Fast-track care consisted of planned discharge 2-3 days after surgery, followed by daily surveillance by a case manager. All outcomes were compared with patients not eligible for fast-track discharge. The total group (fast-track and non-fast-track) was compared with historic controls (N = 307).

RESULTS

A total of 79/155 patients (51%) were considered eligible for fast-track discharge, of whom 69 (87%) were discharged within 3 days. The total group was discharged more often within 3 days compared with historic controls (49 vs. 20%, p < 0.001), the total length of stay did not differ (5.3 vs. 5.7 days, p = 0.363). Although the total group had more readmissions compared with historic controls (17 vs. 10%, p = 0.002), no life-threatening complications occurred after discharge. On average, clinical- and patient-reported outcomes improved over time, both in the fast-track and non-fast-track groups. The mean overall costs within 30 days after surgery did not differ between the total group € 9992 (SD € 4562) and historic controls € 9818 (SD € 3488) (p = 0.649).

CONCLUSION

A stratified fast-track care trajectory with enhanced postoperative outpatient surveillance after pituitary tumor surgery is safe and feasible. As expected, costs of the fast-track were lower than the non-fast-track group, however we could not prove overall cost-effectiveness compared with the historic controls.

Isolated second-phase diabetes insipidus post-transsphenoidal surgery

A 57-year-old woman presented with severe lethargy, dizziness and nausea 1 week after transsphenoidal resection of a growth hormone secreting pituitary adenoma. She was found to have severe hyponatremia of 115 mmol/L. Importantly, she was neurologically intact and clinically euvolaemic. Her fluid intake was restricted and her sodium levels increased to 131 mmol/L over 4 days. She made a full recovery.She was diagnosed with isolated second-phase diabetes insipidus, a state of symptomatic hypoosmolar hyponatremia that usually occurs 7-10 days after transsphenoidal surgery. The sodium levels improve with fluid restriction.

Diabetes insipidus and syndrome of inappropriate antidiuresis (SIADH) after pituitary surgery: incidence and risk factors

Electrolyte disorders are relatively frequent and potentially serious complications after pituitary surgery. Both DI (diabetes insipidus) and SIADH (syndrome of inappropriate antidiuresis) can complicate and prolong hospital and intensive care unit stay, and the latter may even be preventable. We aim to assess the incidence of both electrolyte disorders and their risk factors. From a prospective registry of patients who underwent endoscopic transnasal transsphenoidal surgery (TSS) for pituitary adenoma, patients with postoperative DI and SIADH were identified. Univariable and multivariable statistics were carried out to identify factors independently associated with the occurrence of either DI or SIADH. A total of 174 patients were included, of which 73 (42%) were female. Mean age was 54 years (range 20-88). During postoperative hospital stay, 13 (7.5%) patients presenting with DI and 11 (6.3%) with SIADH were identified. Patients who developed DI after surgery had significantly longer hospital stays (p = 0.022), as did those who developed SIADH (p = 0.002). Four (2.3%) patients were discharged with a diagnosis of persistent DI, and 2 (1.1%) with the diagnosis of SIADH. At the last follow-up, 5 (2.9%) patients presented with persistent DI, while none of the patients suffered from SIADH. Younger age (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.94-1.01, p = 0.166) and pituitary apoplexy (OR 2.69, 95% CI 0.53-10.65, p = 0.184) were weakly associated with the occurrence of DI. We identified younger age (OR 0.96, 95% CI 0.92-0.99, p = 0.045) and lower preoperative serum sodium (OR 0.83, 95% CI 0.71-0.95, p = 0.008) as independent risk factors for SIADH. Although we found a weak association among age, pituitary apoplexy, and the occurrence of DI, no independent predictor was identified for DI. For postoperative SIADH however, lower age and preoperative serum sodium were identified as significant predictors. None of these findings were sufficiently supported by preexisting literature. Both electrolyte disorders are exquisitely hard to predict preoperatively, and further research into their early detection and prevention is warranted.

Tolvaptan Versus Fluid Restriction in the Treatment of Hyponatremia Resulting from SIADH Following Pituitary Surgery

Context

The relevance of hyponatremia has been acknowledged by guidelines from the United States (2013) and Europe (2014). However, treatment recommendations differ due to limited evidence.

Objective

In hyponatremia following pituitary surgery-caused by the syndrome of inappropriate antidiuretic hormone (SIADH) secretion-we compared fluid restriction with the pharmacological increase of water excretion by blocking the vasopressin 2 receptors with tolvaptan at a low and a moderate dose.

Design

Prospective observational study.

Setting

Neurosurgical Department of a University hospital with more than 200 surgical pituitary procedures per year.

Patients

Patients undergoing pituitary surgery and developing serum sodium below 136 mmol/L. The diagnosis of SIADH was established by euvolemia (daily measurement of body weight and fluid balance), inappropriately concentrated urine (specific gravity), and exclusion of adrenocorticotropic and thyroid-stimulating hormone deficiency.

Intervention

Patients were treated with fluid restriction (n = 40) or tolvaptan at 3.75 (n = 38) or 7.5 mg (n = 48).

Main Outcome Measures

Treatment efficacy was assessed by the duration of hyponatremia, sodium nadir, and length of hospitalization. Safety was established by a sodium increment below 10 mmol/L per day and exclusion of side effects.

Results

Treatment with 7.5 mg of tolvaptan resulted in a significant attenuation of hyponatremia and in a significant overcorrection of serum sodium in 30% of patients. The duration of hospitalization did not differ between treatment groups.

Conclusions

Tolvaptan at a moderate dose is more effective than fluid restriction in the treatment of SIADH. Overcorrection of serum sodium may be a side effect of tolvaptan even at low doses.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Clinical Approach to Sodium Homeostasis Disorders in Children with Pituitary-Suprasellar Tumors

Children with pituitary-suprasellar tumors are at high risk of developing sodium metabolism disorders since the tumoral mass itself or surgical and medical treatment can damage AVP release circuits. Additional risk factors are represented by the use of hypotonic fluids, the young age, total parenteral nutrition, and obstructive hydrocephalus secondary to tumor pathology. The most frequent hyponatremic disorders related to AVP in these patients are the syndrome of inappropriate ADH secretion and the cerebral/renal salt wasting syndrome, while hypernatremic conditions include central diabetes insipidus (CDI) and adipsic CDI. The main challenge in the management of these patients is to promptly distinguish the AVP release disorder at the base of the sodium imbalance and treat it correctly by avoiding rapid sodium fluctuations. These disorders can coexist or follow each other in a few hours or days; therefore, careful clinical and biochemical monitoring is necessary, especially during surgery, the use of chemotherapeutic agents, or radiotherapy. This monitoring should be performed by experienced healthcare professionals and should be multidisciplinary, including pediatric endocrinologists, neurosurgeons, and oncologists since maintaining sodium homeostasis also plays a prognostic role in terms of disease survival, therapeutic response, hospitalization rate, and mortality. In this review, we analyze the management of sodium homeostasis disorders in children with pituitary-suprasellar tumors and discuss the main challenges in the diagnosis and treatment of these conditions based on literature data and over 30 years of clinical experience at our Department of Pediatric Endocrinology.

Delayed postoperative hyponatremia after endoscopic transsphenoidal surgery for pituitary adenoma

BACKGROUND

Hyponatremia generally occurs after transsphenoidal surgery (TSS) in a delayed fashion. Most patients with delayed postoperative hyponatremia (DPH) are asymptomatic or only express non-specific symptoms; consequently, DPH is associated with prolonged hospitalization. No consensus has been reached on which patients are at greatest risk of developing DPH. We reviewed patients with DPH and evaluated predictive factors for DPH.

METHODS

We retrospectively analyzed 107 consecutive patients who underwent endoscopic TSS for pituitary adenoma (January 2010-December 2016). Patients with DPH (hyponatremia group) and without DPH (normonatremia group) were compared according to their nadir sodium levels on postoperative days 3 to 10. We documented the patients' demographics, clinical features, and postoperative physiological characteristics.

RESULTS

Twenty-five (23.4%) patients developed DPH after endoscopic TSS. The patients' mean age was 54 ± 17 years, and 63.6% of the patients were female. The overall prevalence of DPH was 23.4%. The non-parametric χ2 test and the Mann-Whitney U test revealed statistically significant differences in age, use of antihypertensive drugs, nonfunctioning pituitary adenoma, and higher yet normal preoperative thyroid-stimulating hormone level between the hyponatremia and normonatremia groups (P < 0.05). Logistic regression analysis revealed that only older age was a useful independent predictive factor for DPH (odds ratio, 1.05; 95% confidence interval, 1.01-1.08; P = 0.01). The serum sodium levels on postoperative day 2 were significantly lower in the hyponatremia than normonatremia group (P < 0.01) and were negatively correlated with age (r = - 0.25, P < 0.05). The cut-off age for predicting DPH was 55 years. The hospital stay was significantly longer in the hyponatremia than normonatremia group (P < 0.01).

CONCLUSIONS

Age of more than 55 years was an independent predictive factor for DPH even after adjusting for potential confounders. Older age was negatively correlated with the serum sodium level on postoperative day 2. Preventing early decreases in the sodium level could reduce the risk of DPH.

TRIAL REGISTRATION

1707-027.

Management and consequences of postoperative fluctuations in plasma sodium concentration after pediatric brain tumor surgery in the sellar region: a national cohort analysis

PURPOSE

Severe fluctuations in plasma sodium concentration and plasma osmolarity, including central diabetes insipidus (CDI), may have significant influence on postoperative morbidity and mortality after pediatric brain tumor surgery.The aim of this study was to describe the frequency, severity and neurological consequences of these fluctuations in pediatric brain tumor survivors.

METHODS

A retrospective, multi-institutional chart review was conducted among all children who underwent brain tumor surgery in the sellar or suprasellar region in seven university hospitals in the Netherlands between January 2004 and December 2013.

RESULTS

Postoperative CDI was observed in 67.5% of 120 included children. Fluctuations of plasma sodium concentration ≥ 10 mmol/L/24 h during the first ten postoperative days were seen in 75.3% of patients with CDI, with a maximum delta of 46 mmol/L/24 h. When compared to patients without CDI, altered mental status occurred more frequently in patients with postoperative CDI (5.1 vs. 23.5% respectively, p = 0.009). Low plasma sodium concentration was related to altered mental status and the occurrence of seizures. Frequency and severity of fluctuations in plasma sodium concentration during the first ten postoperative days were significantly higher in patients with permanent CDI at last follow-up than in patients with transient CDI or without CDI (p = 0.007).

CONCLUSION

Postoperative CDI is a common complication after pediatric brain tumor surgery in the sellar or suprasellar region. Extreme plasma sodium concentrations and large intra-day fluctuations still occur and seem to influence the postoperative neurological course. These results illustrate the need for intensive monitoring in a highly experienced center.

Implementation of a Postoperative Outpatient Care Pathway for Delayed Hyponatremia Following Transsphenoidal Surgery

BACKGROUND

After transsphenoidal surgery, delayed hyponatremia (DH) is the leading cause of 30-d unplanned hospital readmissions.

OBJECTIVE

To determine the impact of a DH care pathway on 30-d readmissions after transsphenoidal surgery.

METHODS

Data from before and after DH care pathway implementation were retrospectively reviewed. Patient demographics and clinical characteristics were compared. Readmission causes, clinical pathway failures, sodium trends, and symptoms were evaluated.

RESULTS

Before the DH care pathway implementation, 229 (55%) patients were treated (group 1); afterward, 188 (45%) were treated (group 2). Baseline characteristics were equivalent between groups, except for glucocorticoid supplementation, which was higher in group 2. The incidence of detected DH was significantly lower in group 1 (16/229, 7%) than group 2 (29/188, 15%) (P = .006) likely due to the impact of routine screening in group 2. Ten group 1 patients (4%) were readmitted for hyponatremia and 6 (3%) were managed as outpatients. Eleven group 2 patients (6%) were readmitted and 17 (9%) were managed as outpatients. Readmission rates between groups were similar (P = .49). Patients readmitted with severe hyponatremia experienced symptoms ≥24 h before presentation. The protocol failed to prevent readmission because outpatient management for mild or moderate DH (n = 4) failed, sodium levels precipitously declined after normal screening (n = 3), and severe hyponatremia developed after scheduled screenings were missed (n = 3).

CONCLUSION

Although more DH patients were identified after care pathway implementation, readmission rates were not reduced and clinical outcomes were not changed. Because DH onset timing varies, some patients have highly acute presentation, and most readmitted patients develop symptoms before reaching their sodium nadir, close symptom monitoring may be a reasonable alternative to routine screening.