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

Current and Future Advances in Surgical Therapy for Pituitary Adenoma

The vital physiological role of the pituitary gland, alongside its proximity to critical neurovascular structures, means that pituitary adenomas can cause significant morbidity or mortality. While enormous advancements have been made in the surgical care of pituitary adenomas, numerous challenges remain, such as treatment failure and recurrence. To meet these clinical challenges, there has been an enormous expansion of novel medical technologies (eg, endoscopy, advanced imaging, artificial intelligence). These innovations have the potential to benefit each step of the patient's journey, and ultimately, drive improved outcomes. Earlier and more accurate diagnosis addresses this in part. Analysis of novel patient data sets, such as automated facial analysis or natural language processing of medical records holds potential in achieving an earlier diagnosis. After diagnosis, treatment decision-making and planning will benefit from radiomics and multimodal machine learning models. Surgical safety and effectiveness will be transformed by smart simulation methods for trainees. Next-generation imaging techniques and augmented reality will enhance surgical planning and intraoperative navigation. Similarly, surgical abilities will be augmented by the future operative armamentarium, including advanced optical devices, smart instruments, and surgical robotics. Intraoperative support to surgical team members will benefit from a data science approach, utilizing machine learning analysis of operative videos to improve patient safety and orientate team members to a common workflow. Postoperatively, neural networks leveraging multimodal datasets will allow early detection of individuals at risk of complications and assist in the prediction of treatment failure, thus supporting patient-specific discharge and monitoring protocols. While these advancements in pituitary surgery hold promise to enhance the quality of care, clinicians must be the gatekeepers of the translation of such technologies, ensuring systematic assessment of risk and benefit prior to clinical implementation. In doing so, the synergy between these innovations can be leveraged to drive improved outcomes for patients of the future.

New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance)

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

Diagnosis and Management of Central Diabetes Insipidus in Adults

Central diabetes insipidus (CDI) is a clinical syndrome which results from loss or impaired function of vasopressinergic neurons in the hypothalamus/posterior pituitary, resulting in impaired synthesis and/or secretion of arginine vasopressin (AVP). AVP deficiency leads to the inability to concentrate urine and excessive renal water losses, resulting in a clinical syndrome of hypotonic polyuria with compensatory thirst. CDI is caused by diverse etiologies, although it typically develops due to neoplastic, traumatic, or autoimmune destruction of AVP-synthesizing/secreting neurons. This review focuses on the diagnosis and management of CDI, providing insights into the physiological disturbances underpinning the syndrome. Recent developments in diagnostic techniques, particularly the development of the copeptin assay, have improved accuracy and acceptability of the diagnostic approach to the hypotonic polyuria syndrome. We discuss the management of CDI with particular emphasis on management of fluid intake and pharmacological replacement of AVP. Specific clinical syndromes such as adipsic diabetes insipidus and diabetes insipidus in pregnancy as well as management of the perioperative patient with diabetes insipidus are also discussed.

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.

Costs and Its Determinants in Pituitary Tumour Surgery

PURPOSE

Value-based healthcare (VBHC) provides a framework to improve care by improving patient outcomes and reducing healthcare costs. To support value-based decision making in clinical practice we evaluated healthcare costs and cost drivers in perioperative care for pituitary tumour patients.

METHODS

We retrospectively assessed financial and clinical data for surgical treatment up to the first year after surgery of pituitary tumour patients treated between 2015 and 2018 in a Dutch tertiary referral centre. Multivariable regression analyses were performed to identify determinants of higher costs.

RESULTS

271 patients who underwent surgery were included. Mean total costs (SD) were €16339 (13573) per patient, with the following cost determinants: surgery time (€62 per minute; 95% CI: 50, 74), length of stay (€1331 per day; 95% CI 1139, 1523), admission to higher care unit (€12154 in total; 95% CI 6413, 17895), emergency surgery (€10363 higher than elective surgery; 95% CI: 1422, 19305) and postoperative cerebrospinal fluid leak (€14232; 95% CI 9667, 18797). Intradural (€7128; 95% CI 10421, 23836) and combined transsphenoidal/transcranial surgery (B: 38494; 95% CI 29191, 47797) were associated with higher costs than standard. Further, higher costs were found in these baseline conditions: Rathke's cleft cyst (€9201 higher than non-functioning adenoma; 95% CI 1173, 17230), giant adenoma (€19106 higher than microadenoma; 95% CI 12336, 25877), third ventricle invasion (€14613; 95% CI 7613, 21613) and dependent functional status (€12231; 95% CI 3985, 20477). In patients with uncomplicated course, costs were €8879 (3210) and with complications €17551 (14250).

CONCLUSIONS

Length of hospital stay, and complications are the main drivers of costs in perioperative pituitary tumour healthcare as were some baseline features, e.g. larger tumors, cysts and dependent functional status. Costs analysis may correspond with healthcare resource utilization and guide further individualized care path development and capacity planning.

Systematic Review of Enhanced Recovery After Surgery in Patients Undergoing Cranial Surgery

BACKGROUND

Enhanced Recovery after Surgery (ERAS) pathways are increasingly being integrated in neurosurgical patient management. The full extent of ERAS in cranial surgery is not well studied. We performed a systematic review examining ERAS in cranial surgery patients to 1) identify the extent to which ERAS is integrated in cranial neurosurgical procedures and 2) assess effectiveness of ERAS interventions for patients undergoing these procedures.

METHODS

A systematic review of MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Scopus, PsychInfo, and Google Scholar was conducted according to PRISMA guidelines (CRD42020197187). Studies eligible for inclusion assessed patients undergoing any cranial surgical procedure using an ERAS or ERAS-like pathway, defined by ≥2 ERAS protocol elements per the ERAS Society's RECOvER Checklist and the recommendations of Hagan et al. 2016 (not including patient education, criteria for discharge, or tracking of postdischarge outcomes).

RESULTS

Nine studies were included in qualitative synthesis, 2 of which were randomized controlled trials. All studies showed a moderate risk of bias. The most common ERAS elements used were screening and/or optimization and formal discharge criteria. The least common ERAS elements used were fasting/carbohydrate loading and antithrombotic prophylaxis. Complication rates were similar in studies comparing ERAS with non-ERAS groups. ERAS interventions were associated with reduced length of stay, with comparable and/or improved patient satisfaction.

CONCLUSIONS

ERAS is a safe and potentially favorable perioperative pathway for select patients undergoing cranial surgery. Future studies of ERAS in cranial surgery patients should emphasize postoperative optimizations and patient-reported outcome measures as key features.

Same day discharge for craniotomy

PURPOSE OF REVIEW

Same-day protocols for craniotomy have been demonstrated to be feasible and safe. Its several benefits include decreased hospital costs, less nosocomial complications, fewer case cancellations, with a high degree of patient satisfaction. This paper reviews the most recent publications in the field of same-day discharge after craniotomy.

RECENT FINDINGS

Since 2019, several studies on same-day neurosurgical procedures were published. Ambulatory craniotomy protocols for brain tumor were successfully implemented in more centers around the world, and for the first time, in a developing country. Additional information emerged on predictors for successful early discharge, and the barriers and enablers of same-day craniotomy programs. Moreover, the cost benefits of same-day craniotomy were reaffirmed.

SUMMARY

Same- day discharge after craniotomy is feasible, safe and continues to expand to a wider variety of procedures, in new institutions and countries. There are several benefits to ambulatory surgery. Well-established protocols for perioperative management are essential to the success of early discharge programs. With continued research, these protocols can be refined and implemented in more institutions globally, ultimately to provide better, more efficient care for neurosurgical patients.

Towards precision medicine for clinically non-functioning pituitary tumours

OBJECTIVE

Clinically non-functioning pituitary tumours (NFPT) are a heterogenous group of neoplasms with diverse outcomes. The purpose of this narrative review was to summarize available data on predictive factors, both in routine practice and research settings.

DESIGN

A literature review was conducted for papers published in peer-reviewed journals, investigating clinical, radiological, pathological and genetic predictive factors in NFPT.

RESULTS

Several clinical and radiological factors have been associated with NFPT recurrence and/or aggressiveness, including larger size and pre-/post-operative growth rates. Application of transcription factor immunohistochemistry has given rise to improved subtype identification, including 'higher-risk' subtypes, in routine clinical practice. Numerous other pathological and genetic biomarkers have demonstrated promise for prognostication in the research setting.

CONCLUSION

NFPT are a heterogenous group of tumours, characterized by diverse presentation, pathogenesis and outcomes. Ongoing refinements in understanding of tumour biology are likely to pave the way to improved integrative prognostication and precision medicine for NFPT.

Outcome Squares Integrating Efficacy and Safety, as Applied to Functioning Pituitary Adenoma Surgery

CONTEXT

Transsphenoidal surgery is standard care in the treatment of hormone-secreting pituitary adenomas. Current clinician-reported surgical outcome measures are one-dimensional, typically focusing primarily on complete or partial resection, and secondarily on complication rates. However, outcomes are best reflected by the delicate balance of efficacy and complications at patient level.

OBJECTIVE

This study proposes a novel way to classify and report outcomes, integrating efficacy and safety at the patient level.

METHODS

Retrospective chart review of all pure endoscopic transsphenoidal surgical procedures for acromegaly, Cushing's disease, and prolactinoma between 2010 and 2018 in a single tertiary referral center. We present our results in a classic (remission and complications separate) and in a novel outcome square integrating both outcomes, focusing on intended and adverse effects (long-term complications). This resulted in 4 outcome groups, ranging from good to poor. We use this approach to present these outcomes for several subgroups.

RESULTS

A total of 198 surgical procedures were included (44 reoperations). Remission was achieved in 127 operations (64%). Good outcome was observed after 121 (61%), and poor outcome after 6 (3%) operations. When intended effect of surgery was applied (instead of remission), good outcome as intended was achieved after 148 of 198 surgeries (75%) and poor outcome after 4 (2%).

CONCLUSION

Quality of a surgical intervention can be presented in 4 simple categories, integrating both efficacy and safety with flexibility to adapt to the individualized situation at patient, disease, and surgical strategy and to the outcome of interest.

Use of a Surgical Stepdown Protocol for Cost Reduction After Transsphenoidal Pituitary Adenoma Resection: A Case Series

OBJECTIVE

No established standard of care currently exists for the postoperative management of patients with surgically resected pituitary adenomas. Our objective was to quantify the efficacy of a postoperative stepdown unit protocol for reducing patient cost.

METHODS

In 2018-2020, consecutive patients undergoing transsphenoidal microsurgical resection of sellar lesions were managed postoperatively in the full intensive care unit (ICU) or an ICU-based surgical stepdown unit based on preset criteria. Demographic variables, surgical outcomes, and patient costs were evaluated.

RESULTS

Fifty-four patients (27 stepdown, 27 full ICU; no difference in age or sex) were identified. Stepdown patients were also compared with 634 historical control patients. The total hospital length of stay was no different among stepdown, ICU, and historical patients (4.8 ± 1.0 vs. 5.9 ± 2.8 vs. 4.4 ± 4.3 days, respectively, P = 0.1). Overall costs were 12.5% less for stepdown patients (P = 0.01), a difference mainly driven by reduced facility utilization costs of -8.9% (P = 0.02). The morbidity and complication rates were similar in the stepdown and full ICU groups. Extrapolation of findings to historical patients suggested that ∼$225,000 could have been saved from 2011 to 2016.

CONCLUSIONS

These results suggest that use of a postoperative stepdown unit could result in a 12.5% savings for eligible patients undergoing treatment of pituitary tumors by shifting patients to a less acute unit without worsened surgical outcomes. Historical controls indicate that over half of all pituitary patients would be eligible. Further refinement of patient selection for less costly perioperative management may reduce cost burden for the health care system and patients.

Endoscopic, Endonasal Transsphenoidal Surgery for Tumors of the Sellar and Suprasellar Region: A Monocentric Historical Cohort Study of 369 Patients

BACKGROUND

The endoscopic endonasal transsphenoidal approach (EETA) is an established technique for the resection of a large variety of benign sellar and suprasellar lesions, mostly pituitary adenomas. It has clear advantages over the microscopic approach, like a superior close-up view of the relevant anatomy and the tumor-gland interface, an enlarged working angle, as well as an increased panoramic vision inside the surgical area. We have been performing the EETA for over a decade, and this study will focus on perioperative and postoperative outcomes and complications and their association with the learning curve.

MATERIAL AND METHODS

All patients in our tertiary referral center (n = 369) undergoing an EETA for a lesion of the sellar and suprasellar region between January 1st 2008 and December 31st 2018 were included, and data were retrospectively retrieved from the electronic patient records.

RESULTS

Median follow-up after surgery was 55 months. Pituitary adenomas (n = 322) were the most frequent pathology. Headache (43.4%) and loss of vision (29.3%) were the most common presenting symptoms. Median procedure duration was significantly longer during the initial 5 years (106 versus 79 minutes; p <0.0001), but incidence of peri- and postoperative CSF leaks in the early years was not significantly higher. Knosp grade >2 was associated with perioperative CSF leak (p =0.002), and perioperative CSF leak was associated with postoperative CSF leak (p <0.001). Almost all cases of meningitis were preceded by a postoperative CSF leak. In 22.4% of patients, tumor recurrence required additional therapy. Perioperative (iatrogenic) mortality was 0.8%. The overall hospital stay decreased over time from an average of 7 to 5 days, and the case load increased yearly (p =0.015).

CONCLUSION

The EETA is an excellent technique with complication rates comparable to or even lower than those in large microsurgical series in the literature. EETA has a significant learning curve affecting the procedure duration. Throughout the first 10 years following the transition from the microscopic approach to the EETA in our cohort, the caseload increased and hospital stay was reduced, while no increase in peri- and postoperative complications was observed.

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.

Endoscopic Surgery for Pituitary Tumors

Endoscopic transsphenoidal surgery for pituitary adenoma is a safe and highly effective first-line treatment that is well tolerated by patients. Potential complications are plenty, and there is a large variation in complexity of surgery. This article presents the philosophy, surgical techniques, and outcomes of a high-volume pituitary adenoma center. Three surgical videos illustrate some procedures. The experience has reinforced the authors' belief that experience and surgical volume are key to high quality of care.