Hyponatraemia and hypernatraemia: Disorders of Water Balance in Neurosurgery

Urea transporter UT-A1 as a novel drug target for hyponatremia

Hyponatremia is the most common disorder of electrolyte imbalances. It is necessary to develop new type of diuretics to treat hyponatremia without losing electrolytes. Urea transporters (UT) play an important role in the urine concentrating process and have been proved as a novel diuretic target. In this study, rat and mouse syndromes of inappropriate antidiuretic hormone secretion (SIADH) models were constructed and analyzed to determine if UTs are a promising drug target for treating hyponatremia. Experimental results showed that 100 mg/kg UT inhibitor 25a significantly increased serum osmolality (from 249.83 ± 5.95 to 294.33 ± 3.90 mOsm/kg) and serum sodium (from 114 ± 2.07 to 136.67 ± 3.82 mmol/L) respectively in hyponatremia rats by diuresis. Serum chemical examination showed that 25a neither caused another electrolyte imbalance nor influenced the lipid metabolism. Using UT-A1 and UT-B knockout mouse SIADH model, it was found that serum osmolality and serum sodium were lowered much less in UT-A1 knockout mice than in UT-B knockout mice, which suggest UT-A1 is a better therapeutic target than UT-B to treat hyponatremia. This study provides a proof of concept that UT-A1 is a diuretic target for SIADH-induced hyponatremia and UT-A1 inhibitors might be developed into new diuretics to treat hyponatremia.

Quantitative 23Na magnetic resonance imaging in the abdomen at 3 T

OBJECTIVES

To assess the feasibility of sodium-23 MRI for performing quantitative and non-invasive measurements of total sodium concentration (TSC) and relaxation in a variety of abdominal organs.

MATERIALS AND METHODS

Proton and sodium imaging of the abdomen was performed in 19 healthy volunteers using a 3D cones sequence and a sodium-tuned 4-rung transmit/receive body coil on a clinical 3 T system. The effects of B1 non-uniformity on TSC measurements were corrected using the double-angle method. The long-component of 23Na T2* relaxation time was measured using a series of variable echo-times.

RESULTS

The mean and standard deviation of TSC and long-component 23Na T2* values were calculated across the healthy volunteer group in the kidneys, cerebrospinal fluid (CSF), liver, gallbladder, spleen, aorta, and inferior vena cava.

DISCUSSION

Mean TSC values in the kidneys, liver, and spleen were similar to those reported using 23Na-MRI previously in the literature. Measurements in the CSF and gallbladder were lower, potentially due to the reduced spatial resolution achievable in a clinically acceptable scan time. Mean long-component 23Na T2* values were consistent with previous reports from the kidneys and CSF. Intra-population standard error was larger in smaller, fluid-filled structures due to fluid motion and partial volume effects.

Management of neurological complications related to aneurysmal subarachnoid hemorrhage: A comparison of the bedside therapeutic algorithms

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is of the most serious emergencies in neurosurgical practice and continues to be associated with high morbidity and mortality. Beyond securing the ruptured aneurysm to prevent a rebleed, physicians continue to be concerned about potential complications such as cerebral vasospasm-delayed cerebral ischemia (DCI), an area where management remains highly variable. This study aimed at reviewing the most recent literature and assessing any up-to-date schemes for treating the most common aSAH neurological complications in adults that can be applied in daily clinical practice towards optimising outcomes.

METHODS

A systematic review was performed according to PRISMA guidelines on the management of aSAH neurological complications in adults. The literature surveyed was between 2016 and 2022 inclusive, using the Pubmed search engine. Comparisons between the methods suggested by existing therapeutic algorithms were discussed.

RESULTS

Six stepwise algorithms assisting the decision-making for treating cerebral vasospasm-DCI were recognised and compared. No algorithm was found for the management of any other neurological complications of aSAH. Despite differences in the algorithms, induced hypertension and endovascular therapy were common treatments in all approaches. Controversy in the therapeutic process of these complications surrounds not only the variability of methods but also their optimal application towards clinical outcome optimisation.

CONCLUSIONS

A universal approach to managing aSAH complications is lacking. Despite advances in the techniques to secure a ruptured aneurysm, there persist a high rate of neurological deficit and mortality, and several unanswered questions. More research is required towards stratification of current treatment algorithms as per the quality of their evidence.

Association between preoperative serum sodium and postoperative 30-day mortality in adult patients with tumor craniotomy

BACKGROUND

Limited data exist regarding preoperative serum sodium (Na) and 30-day mortality in adult patients with tumor craniotomy. Therefore, this study investigates their relationship.

METHODS

A secondary retrospective analysis was performed using data from the ACS NSQIP database (2012-2015). The principal exposure was preoperative Na. The outcome measure was 30-day postoperative mortality. Binary logistic regression modeling was conducted to explore the link between them, and a generalized additive model and smooth curve fitting were applied to evaluate the potential association and its explicit curve shape. We also conducted sensitivity analyses and subgroup analyses.

RESULTS

A total of 17,844 patients (47.59% male) were included in our analysis. The mean preoperative Na was 138.63 ± 3.23 mmol/L. The 30-day mortality was 2.54% (455/17,844). After adjusting for covariates, we found that preoperative Na was negative associated with 30-day mortality. (OR = 0.967, 95% CI:0.941, 0.994). For patients with Na ≤ 140, each increase Na was related to a 7.1% decreased 30-day mortality (OR = 0.929, 95% CI:0.898, 0.961); for cases with Na > 140, each increased Na unit was related to a 8.8% increase 30-day mortality (OR = 1.088, 95% CI:1.019, 1.162). The sensitivity analysis and subgroup analysis indicated that the results were robust.

CONCLUSIONS

This study shows a positive and nonlinear association between preoperative Na and postoperative 30-day mortality in adult patients with tumor craniotomy. Appropriate preoperative Na management and maintenance of serum Na near the inflection point (140) may reduce 30-day mortality.

Postoperative Dysnatremia in Pediatric Patients Undergoing Palatoplasty

OBJECTIVE

Identifying predisposing factors to dysnatremia to improve perioperative care after cleft surgery.

DESIGN

Retrospective case series. Patient data were obtained through the electronic medical records of the hospital.

SETTING

Tertiary care university hospital.

PATIENTS

The inclusion criterion was the measurement of an abnormal natremia value, defined as Na >150 or <130 mmol/l after a cleft lip or cleft palate repair procedure. The exclusion criterion was natremia between 131 and 149 mmol/l.

RESULTS

Natremia measurements were available for 215 patients born between 1995 and 2018. Five patients presented with postoperative dysnatremia. Several predisposing factors to dysnatremia have been identified: drugs, infection, administration of intravenous fluids, and postoperative syndrome of inappropriate antidiuretic hormone secretion. Although the hospital environment contributes to dysnatremia development, the fact that only patients undergoing cleft palate repair develop natremia anomalies suggests that this surgery may be itself a risk factor.

CONCLUSION

Children undergoing palatoplasty may be at higher risk to develop postoperative dysnatremia. Early recognition of symptoms and risk factors, postoperative monitoring, and prompt treatment of dysnatremia diminish the risk of neurological complications.

Quality of life and surgical outcomes in incidental pituitary adenomas undergoing endoscopic endonasal resection

OBJECTIVE

Incidental, asymptomatic pituitary adenomas require nuanced, shared decision-making, which is limited by a poor understanding of their natural history and effects on quality of life (QOL). A greater understanding of the effects of surgery would inform evidence-based care.

METHODS

A multicenter review of consecutive pituitary adenomas resected via an endoscopic endonasal approach (EEA) between late 2016 and mid-2021 was performed, with prospective, longitudinal QOL assessment (at 3 and 6 weeks and at 3, 6, and 12 months) postoperatively using the 35-item Anterior Skull Base Questionnaire.

RESULTS

Of 366 adenomas resected during the study period, 52 (14.2%) were incidentally discovered, of which 51 (98.1%) were macroadenomas. Preoperative QOL in patients with these incidentalomas was better than in those with adenomas presenting with endocrinopathy (p < 0.01), visual failure (p = 0.02), or headache (p = 0.03). Surgery was performed due to visual field deficits (13.5%, n = 7); ophthalmoplegia (1.9%, n = 1); radiological compression or contact of the optic apparatus (63.5%, n = 33); functional status (growth hormone-secreting tumor) (5.8%, n = 3); and clinically significant growth (15.4%, n = 8). Surgical outcomes were excellent, with vision improved in 100% (7/7) and complete resection in 84.6% (44/52). There were 2 (3.8%) cases of new cortisol deficiency, 3 (5.8%) cases of transient postoperative diabetes insipidus, and 4 (7.7%) cases of postoperative hyponatremia. There were no perioperative complications and no cases of postoperative CSF leakage. QOL transiently decreased during the first 3 weeks after surgery, then improved to above baseline levels by 3 months (p = 0.03) and continued to improve throughout the first postoperative year (p = 0.03). All surgical indications demonstrated an overall mean improvement in QOL at 3 months. QOL benefits were not affected by age or tumor size.

CONCLUSIONS

Resection of pituitary adenomas via the EEA provided a tangible benefit for patients within 3 months. Surgery via the EEA is safe, effective, and beneficial for patients with pituitary incidentalomas meeting accepted criteria for intervention.

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.

Influence of cardioplegic solution on incidence of delirium after CABG surgery: Use of Calafiore blood cardioplegia versus HTK - Bretschneider - solution in a single-center retrospective analysis from 2017 to 2021

BACKGROUND

Purpose of the present study is an evaluation of postoperative incidence for delirium after coronary artery bypass surgery (CABG). Study addressed whether application of Histidine-Tryptophan-Ketoglutarate (HTK) solution (Bretschneider) or blood cardioplegia (Calafiore) is associated with increased of postoperative delirium cases.

MATERIALS AND METHODS

In a retrospective, single center evaluation a total number of 273 patients were enrolled in the study from January 2017 to October 2021. There were 124 patients assigned to the Calafiore group blood cardioplegic solution (BCC) and 149 patients were included in the Bretschneider group (HTK). The primary endpoint was the postoperative delirium rate in its frequency of occurrence. Definition of the dilirium status was performed using the Confusion Assessment Method in the Intensive Care Unit (CAM-ICU) score during the first three postoperative days. Secondary endpoints were the time intervals of intensive care duration of stay, mechanical ventilation, total extracorporeal circulation, ischemia and reperfusion. Serum levels of the electrolytes Sodium, Potassium, ionized Calcium, and Chloride were monitored.

RESULTS

Although no significant difference in delirium status between the groups were noticed, on third postoperative day, delirium rate dependent on cardioplegia solution used (HTK 12.0%; BCC 3.0%; p = .024) and duration of intensive care stay differed (HTK 4.5 vs. BCC 3.0 days; p = .001). Although Ischemic time (HTK 73.0 vs. BCC 83.0 min; p < .001) and reperfusion time (HTK 35.0 vs. Calafiore 24.0 min; p < .001) were extended in the BCC group less cases of delirium were diagnosed. Serum sodium levels after HTK cardioplegic infusion were decreased (HTK 129.68 vs. BCC 138.96 mmol/l; p < .001). The significant difference persists up to the hundredth extracorporeal circulation circuit min (p = .005).

CONCLUSION

The present data suggest an impact of the cardioplegic solution used upon postoperative delirium rates. Optimization of cardiac arrest protocols is needed. Present data encourage further prospective studies regarding the impact of cardioplegic solutions on electrolyte imbalance for postoperative delirium rates in CABG surgery.

Endocrine Disorders in Children with Brain Tumors: At Diagnosis, after Surgery, Radiotherapy and Chemotherapy

INTRODUCTION

Brain tumors are the second most frequent type of all pediatric malignancies. Depending on their localization, patients with brain tumors may present neurological or ophthalmological symptoms, but also weight anomalies and endocrine disorders ranging from growth hormone deficiency, anomalies of puberty, diabetes insipidus to panhypopituitarism. Immediately at diagnosis, all patients with brain tumors require a complete assessment of the hypothalamic-pituitary function in order to address eventual endocrine disorders. Moreover, children and adolescents undergoing brain surgery must receive peri- and postoperative hydrocortisone stress therapy. Post-operative disorders of water homeostasis are frequent, ranging from transient diabetes insipidus, as well as syndrome of inappropriate antidiuretic hormone secretion to persistent diabetes insipidus. Late endocrine disorders may result from surgery near or within the hypothalamic-pituitary region. Pituitary deficits are frequent after radiotherapy, especially growth hormone deficiency. Thyroid nodules or secondary thyroid cancers may arise years after radiotherapy. Gonadal dysfunction is frequent after chemotherapy especially with alkylating agents.

CONCLUSION

Early detection and treatment of specific endocrine disorders at diagnosis, perioperatively, and during long-term follow-up result in improved general and metabolic health and quality of life.

Surgical outcomes and longitudinal quality of life after endoscopic endonasal surgery for anterior skull base meningioma

OBJECTIVE

The objective of this study was to establish the effect of endoscopic endonasal surgery on longitudinal quality of life (QOL) in patients with anterior skull base meningioma.

METHODS

A prospectively collected cohort of consecutively operated anterior skull base meningiomas was analyzed. All cases were performed using the endoscopic endonasal approach (EEA). Sinonasal-specific and overall QOL were measured using the 22-Item Sinonasal Outcome Test and the Anterior Skull Base Questionnaire longitudinally (at 3 weeks, 6 weeks, and 3, 6, and 12 months) across the first postoperative year. The relationship between surgical and QOL outcomes to clinical and radiological characteristics was analyzed using multivariate regression.

RESULTS

Fifty cases were available, with a mean age of 61.5 years and female predominance (74.0%). Visual dysfunction and headache were the most common presenting symptoms, and tumors commonly took origin from the planum (46.0%), tuberculum (44.0%), and olfactory groove (24.0%). Median tumor volume was 4.6 cm3. Visual improvement was noted in 73.1% of cases with preoperative field deficits, while nonimprovement was associated with greater tumor height (p = 0.04). Gross-total resection was not possible in patients with 360° vessel encasement and high-grade cavernous sinus extension with ophthalmoplegia. Postoperative diabetes insipidus was observed only in cases with suprasellar extension. Sinonasal-specific QOL worsened transiently after surgery but returned to baseline levels after 3 weeks. Olfaction and taste scores returned to preoperative baseline scores within the year. Overall QOL at presentation was worse in those with larger tumors (p = 0.04) and visual failure (p = 0.04) and better in those presenting with headache (p = 0.04). Transient worsening of QOL was seen in the first 3 weeks, which returned to baseline by 6 weeks, and then improved to above preoperative levels at 6 months and beyond. Worse QOL at baseline (p = 0.01) and visual improvement (p = 0.01) predicted QOL improvement after surgery.

CONCLUSIONS

Longitudinal QOL in anterior skull base meningioma has been examined for the first time. Endoscopic endonasal surgery improves overall QOL after a transient 3-week worsening due to the sinonasal morbidity of the approach. Visual function is intimately tied to QOL, with worse vision associated with worse preoperative QOL, and QOL improving in parallel with visual restoration after surgery. The EEA is associated with better visual outcomes and should be the preferred approach in accessible tumors.

Hyperlactatemia and other perioperative metabolic disturbances in neuroanesthesia

PURPOSE OF REVIEW

The concept of 'brain-body cross-talking' has gained growing interest in the last years. The understanding of the metabolic disturbances (e.g., hypernatraemia/hyponatraemia and hyperlactatemia) in neurosurgical patients has improved during the last years.

RECENT FINDINGS

The impact of elevated lactate without acidosis in neurosurgical patients remains controversial. The pathophysiology of inappropriate secretion of antidiuretic hormone (SIADH) has become clearer, whereas the diagnosis of cerebral salt wasting should be used more carefully.

SUMMARY

These findings will contribute to a better understanding of the pathophysiology involved and enable better prevention and therapy where possible in clinical practice.

Quality of Life in Craniopharyngioma: A Systematic Review

BACKGROUND

Craniopharyngiomas are morbid tumors that significantly reduce patients' quality of life (QoL). The lifelong burden of endocrine, visual, hypothalamic, and limbic dysfunction can have disastrous consequences for the physical and psychosocial health of patients. Elucidating the factors that influence QoL could guide therapeutic interventions to improve patient well-being.

METHODS

A systematic review was performed in accordance with the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement using the PubMed and Medline databases. Studies that had reported patient QoL using validated metrics in both adult and pediatric populations were included. Bias and methodological rigor were assessed using the MINORS (methodological index for nonrandomized studies) criteria.

RESULTS

A total of 25 studies, including 2025 patients, were available for review. Most studies were small, retrospective, cohort studies with a high risk of bias. The QoL of the patients with craniopharyngioma was lower than that of the general population. Hypothalamic involvement was consistently the strongest predictor of QoL. Endocrinopathy contributed to morbidity but could be ameliorated by hormone replacement therapy. Social and emotional dysregulation and a poor memory are common complaints after surgery, and iatrogenic damage to the infundibulum, hypothalamus, limbic system, and frontal lobes might underlie these concerns. Sleep-wake cycle dysfunction and hypothalamic obesity are serious consequences of hypothalamic damage.

CONCLUSIONS

An experienced multidisciplinary team is necessary to optimally manage the complex cases of these patients. The poor QoL of patients with craniopharyngioma is multifactorial. However, the contribution of iatrogenesis is not insubstantial. Improved surgical techniques, focusing on hypothalamic preservation, and adjuvant treatment options are required to improve the well-being of these patients.

Surgical outcomes and quality of life in Rathke's cleft cysts undergoing endoscopic transsphenoidal resection: a multicentre study and systematic review of the literature

OBJECTIVE

To establish the effect of endoscopic endonasal surgery (EES) on quality-of-life (QoL) in symptomatic Rathke cleft cyst (RCC).

METHODS

Analysis of 38 patients with RCC treated by EES, with regular overall (ASBQ-35) and sinonasal-specific (SNOT-22) QoL assessment during the first postoperative year. A systematic literature review of large case series was performed with pooled analysis.

RESULTS

In our series, mean age was 53.6 years with a female predominance (73.7%). Larger cysts were seen in males (p < 0.01), those with hypogonadism (p = 0.04), and visual dysfunction (p = 0.04). Complete normalisation of vision was seen in 83.3%. Persistence of visual dysfunction postoperatively was associated with diabetes (p = 0.005), hypertension (p = 0.02), suprasellar only location (p = 0.001), and monocular field cut (p = 0.02). Surgery did not significantly effect hormonal function. Sinonasal QoL transiently worsened after surgery, resolving within 3 weeks. A parallel transient worsening of overall QoL normalised by 6 weeks, and remained at preoperative baseline thereafter. These results were comparable to the literature, where 76.4% demonstrated improvement of vision and 13.1% had recurrence after treatment. There was no significant difference in outcomes between EES and microscopic approaches.

CONCLUSIONS

We report longitudinal QoL outcomes in RCC for the first time. Vision commonly improves with surgery, but endocrinopathy is likely to persist. Microvascular risk-factors may compromise visual improvement. Surgery causes a transient worsening of sinonasal symptoms that resolves within 3-6 weeks, but patients may not experience significant improvement in QoL within the first postoperative year.

Quality of Life After Endoscopic Surgical Management of Pituitary Adenomas

BACKGROUND

Patient-reported quality of life (QOL) is a vital metric for surgical success.

OBJECTIVE

To assess the effect of surgery on QOL in the largest prospectively collected, longitudinal cohort of surgically managed pituitary adenomas.

METHODS

A consecutive surgical adenoma cohort (n = 304) between late 2016 and mid-2020 underwent a scheduled overall (Anterior Skull Base Questionnaire-35) and sinonasal-specific (Sinonasal Outcome Test-22) QOL assessment. Scores were stratified by adenoma subtype and analyzed for clinical predictors of QOL changes.

RESULTS

The average age was 53.8 ± 16 yr, and 53% of participants were female. 60.9% of adenomas were nonfunctioning while adrenocorticotropic hormone adenomas (16.4%), growth hormone adenomas (14.1%), and prolactinomas (5.9%) were the most prevalent secreting adenomas. Baseline overall QOL differed between tumor types (P = .006), with adrenocorticotropic hormone adenomas worse than growth hormone adenomas (P = .03) and nonfunctioning pituitary adenomas (NFPA) (P < .001). Sinonasal QOL worsened in the 3 wk after surgery but returned to baseline by 6 wk and beyond. Overall QOL worsened at 3 wk after surgery (P < .001) but significantly improved from baseline by 3 mo (P = .009) and beyond (P < .001). Emotional functioning improved soon after surgery, followed by performance and pain, and then, by 6 mo, physical function and vitality. Predictors of improved QOL were sellar/suprasellar lesions (P = .01), prolactinomas (P = .003), and NFPA (P = .04). Conversely, new postoperative hypopituitarism (P = .04) and larger adenoma volume (P = .04) predicted QOL worsening.

CONCLUSION

QOL is worsened after surgery at early time points. Prolactinomas and NFPA enjoy significant QOL improvements from surgery as early as 3 mo postoperatively. Other functional tumors may experience early benefits in younger patients without hypopituitarism and when isolated to the sellar/suprasellar region. These findings provide valuable information for counseling patients and setting expectations for surgery.

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.

Frailty does not preclude surgical success after endoscopic transsphenoidal surgery for pituitary adenomas

INTRODUCTION

Frailty is a state of physiological vulnerability that negatively influences surgical outcomes. The effect of frailty on pituitary adenoma surgery, however, is not clear, and patients may be wrongly denied surgery because they are "too frail". We examined the effects of frailty on surgical outcome and quality-of-life (QoL) in patients undergoing endoscopic transsphenoidal resection of pituitary adenomas.

METHODS

A prospective, consecutive cohort of surgically managed pituitary adenoma was analysed. Frailty was defined by the 5-factor modified Frailty Index (mFI-5) and the Charlson Comorbidity Index (CCI). QoL was measured by the anterior skull base questionnaire (ASBQ) and sinonasal outcomes test (SNOT).

RESULTS

Of 304 patients with pituitary adenomas, 42 (13.8%) were frail (mFI5 of > 1). Frail patients tended to have smaller adenomas (p < 0.0001) with less suprasellar extension (p < 0.0001). Both overall (ASBQ) and sinonasal-specific (SNOT) QoL were not affected by frailty on multivariate analysis. Endocrine and visual outcomes were similarly not worsened by frailty. Overall, medical complications were uncommon, and perioperative morbidity or mortality was not significantly greater in the frail group.

CONCLUSION

Frail patients experience the same QoL benefits from surgery as their non-frail counterparts, and have equivalently successful visual and endocrine outcomes. Frailty should not be seen as a barrier to successful surgical management of pituitary adenomas.

Diabetes insipidus after endoscopic transsphenoidal surgery: multicenter experience and development of the SALT score

OBJECTIVE

To identify risk factors for the development of postoperative diabetes insipidus (DI) in a modern cohort of endoscopic endonasal transsphenoidal surgery.

METHODS

Analysis of prospectively collected data of 449 consecutive patients operated on for anterior skull base pathology. DI was defined as a polyuria (> 250 ml/h for ≥ 2 consecutive hours) polydipsia syndrome associated with hypotonic urine with or without hypernatraemia. Multivariate logistic regression was used to identify predictors of postoperative DI. A simple scoring system was then created.

RESULTS

Postoperative DI occurred in 46 (10.2%) patients. The development of DI did not affect quality of life. Predictors of DI on multivariate analysis included suprasellar extension (OR 2.2; p = 0.04), age < 50 years (OR 2.8; p = 0.003), craniopharyngioma histology (OR 6.7; p = 0.002), and Kelly grade 3 intraoperative CSF leak (OR 2.1; p = 0.04). The SALT score was created based on these characteristics, with one point awarded for each feature present, and predicted DI with fair to good predictive value in our cohort (AUROC 0.735 (95%CI 0.65-0.82)). The rates of postoperative DI were 4.0%, 6.5%, 15.0%. 36.8% and 85.7% for SALT scores of zero, one, two, three, and four, respectively.

CONCLUSIONS

The SALT score predicts postoperative DI with fair to good accuracy, and now requires prospective external validation. Improved prediction of DI could optimize resource allocation and facilitate individualised preoperative patient counselling. We also provide our algorithm for diagnosis and treatment of DI.

Predictors of visual and endocrine outcomes after endoscopic transsphenoidal surgery for pituitary adenomas

Surgery for pituitary adenoma is indicated for relief of mass effect and control of endocrinopathy. Setting benchmarks for visual and hormonal outcomes is important for monitoring performance of surgical centres, while understanding the preoperative factors that predict endocrine cure and visual improvement facilitates tailored counselling for patients prior to surgery. A prospective, consecutive cohort of surgically managed (endoscopic transsphenoidal) pituitary adenoma (n = 304) were analysed. Preoperative and postoperative endocrine and visual field assessments were performed and compared to demographic, imaging and pathological data. Larger adenomas tended to have preoperative endocrine deficiency (p < 0.001) and visual field defects (p < 0.001). The largest tumours did not experience normalisation of their endocrinopathy or visual fields with surgery. Of the adenomas with normal preoperative endocrine function, 92.0% (126/137) maintained this postoperatively; only 2 of the 11 patients with new hypopituitarism required long-term hormone replacement. Functional tumour cure was achieved in 65.2% (86/116) after surgery; 74.4% (32/43) of acromegalics and 70.0 (35/50) of Cushing's disease patients achieved hormonal control. All patients with isolated hyperprolactinaemia from stalk effect normalised with surgery, while only 15.9% (7/44) with hypopituitarism recovered normal endocrine function. New hypopituitarism was predicted by younger age and functional adenoma, particularly Cushing's disease. Resolution of endocrinopathy was less likely with reoperative cases and those with cavernous sinus invasion (Knosp grade > 2) or preoperative ophthalmoplegia. One-third of the cohort (102/304, 33.6%) had a preoperative field cut, most commonly an incomplete (51.0%) or complete (31.4%) bitemporal hemianopsia. Only two patients (2/304, 0.7%) had visual field worsening after surgery, while 71.6% (73/102) experienced partial or complete resolution of their field cut after surgery. Complete resolution of visual field defect was predicted by younger age and incomplete bitemporal hemianopsia. Surgery is a safe and effective therapy for pituitary adenomas. Nearly all patients experience improvement in visual fields, especially the young and those with incomplete bitemporal defects. Reoperative cases and those with cavernous sinus involvement (high Knosp grade/ophthalmoplegia) are less likely to have resolution of endocrinopathy. Visual worsening, new ophthalmoplegia or endocrinopathy were rare complications of surgery.