ANAESTHESIA FOR ENDOSCOPIC ENDONASAL TRANSPHENOIDAL RESECTION OF PITUITARY ADENOMA: INITIAL EXPERIENCE OF A SINGLE NIGERIAN CENTER

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O.K. Idowu¹, J.A Balogun² , T.A Adigun¹

1. Department of Anaesthesia, College of Medicine, University of Ibadan/University College Hospital, Ibadan, Oyo State, Nigeria.
2. Department of Surgery, College of Medicine, University of Ibadan/University College Hospital, Ibadan, Oyo State, Nigeria.

Abstract

Introduction: Endoscopic endonasal transsphenoidal surgery (EETSS) is an established technique for the resection of pituitary tumors and is well-domesticated in our center due to its numerous benefits. This study aimed to provide insights into the anaesthetic management of patients with pituitary tumors for EETSS, analyze the perioperative complications, and associations between demographic data, perioperative complications, intensive care unit (ICU) management, and outcomes.

Methods: This prospective descriptive study includes all patients who underwent EETSS for pituitary adenoma under general anaesthesia in a tertiary center. Data collected through a semi-structured proforma from patients and patient medical records included socio-demographic data, peri-operative complications, ICU management, and outcome.

Results: There was a total of 60 patients (Male: Female was 1:1), an age range between 18 to 76 years, and the mean age was 30.9 (± 12.8 years). Most patients (65%) presented with visual complaints. Hypertension (30%) was the most common intercurrent illness. The American Society of Anesthesiologists (ASA) physical status II and III were 56.7% and 43.3% respectively. Intraoperative complications were hypertension 30%, hypotension 5%, and bradycardia 15%. 30% (15) of the patients were admitted into the ICU and 13 (21.7%) of those admitted were ventilated. ICU length of stay was between 1-6 days. Overall mortality was 10%. Bivariate analysis revealed a significant association was observed between mortality and tumor size (p=0.046), ventilator use (p=0.05), and ICU admission (p=0.008).

Conclusion: The tumor size, postoperative complications that necessitated ICU admission, and ventilator use in the ICU significantly impact the overall perioperative outcome.

Keywords: Transsphenoidal, Pituitary, Anaesthesia

Introduction

Pituitary adenomas are described as the third most common brain tumors constituting 10–15% of all intracranial tumours¹ They are classified as either clinically functioning pituitary adenomas such as prolactinomas, adrenocorticotropic hormone-secreting, growth hormone-secreting, or thyroid-stimulating hormone-secreting adenomas or clinically non-functioning pituitary adenomas causing pressure on adjacent structures, leading to vision field impairment, hypopituitarism and sometimes ophthalmoplegia.²

Surgical removal can be done endoscopically or by transcranial approach³. The endoscopic transsphenoi-dal approach for the resection of pituitary tumors dates to over 100 years ago and offers some advantages over the transcranial approach considering the direct approach to the pathology in the sellar/suprasellar region with no brain retraction under dynamic endoscopy, minimal blood loss, fewer complications, shorter hospital stays, better patient comfort and low mortality rate.⁴

However, endoscopic endonasal transsphenoidal (EETSS) pituitary surgery poses unique challenges for neuro-anesthetists in the peri-operative period. Preoperatively, airway management may be challenging in up to 4% of patients undergoing resection of the pituitary lesion, and retrospective data from the University of Virginia showed an increased risk of unexpectedly difficult airway in acromegalic patients at over 9%. They may have sleep apnea with an increased risk of perioperative airway compromise⁵. Medical diseases such as hypertension, diabetes, and ischaemic heart disease a major causes of perioperative mortality.^6,7 Furthermore, the procedure causes intensive noxious stimuli at various stages of surgery which may result in difficulty maintaining intraoperative hemodynamic stability.⁸

Anaesthetic goals for EETSS include optimizing cerebral oxygenation, maintaining hemodynamic stability, providing conditions to facilitate surgical exposure, managing intraoperative complications, allowing for rapid smooth emergence, and assessing neurologic function.⁹