Management Strategy of a Grade-3 Cerebrospinal Fluid Leak Repair Following Endoscopic Endonasal Transsphenoidal Excision of Pituitary Macroadenoma

Abstract

A skull- base defect with grade-3 cerebrospinal fluid (CSF) leak following a pituitary macroadenoma removal is rare and challenging. We provide a simple sample model of multilayer closure with naturally available hard and soft tissue components. Tamponade was provided to the reconstructed site with a simple inflated Foley’s catheter bulb. There was no repair failure and cavities were well mucosalised on follow-up. Mucosal and turbinate preservation was fully achieved in this method as no turbinate flaps were raised or large raw surface exposure was there.

Introduction

Pituitary adenomas constitute 10–15% of all intracranial tumours [1] and are generally slowly growing, benign neoplasms of epithelial origin arising from the adenohypophysis [2]. Adenomas of 10–30 mm are macroadenomas [1]. The nasal cavity and paranasal sinuses are contaminated spaces which communicate to the exterior. The complications arising from inadequate sellar floor reconstruction after a trans-nasal pituitary excision can cause morbidities like low pressure headaches,CSF rhinorrhea,meningitis and pneumocephalus [3]. Chances of leak repair failure and meningitis are significantly higher in a grade-3 [4] leak- leak arising from a large defect in diaphragma sellae that opens into the floor of third ventricle [4]. We present a case of functional macroadenoma with acromegalic features and no mass effects which on removal resulted in a grade-3 CSF leak. A multilayer closure with hard and soft tissue components repaired the defect successfully.

Case Report

A 24 year old male presented with recurrent headaches and acromegalic features of enlarged facial bones and protruding jaw. There was no history of visual disturbances, clear liquid leaking from nose or nasal bleeding. A gadolinium enhanced magnetic resonance imaging (MRI) of the brain revealed a 1.34 cm × 1.23 cm × 1.31 cm heterogenous contrast enhancing mass in sella extending superiorly through diaphragma sellae up to pre-chiasma (Fig. 1). Patient was diagnosed with a growth hormone secreting pituitary macroadenoma. On ophthalmological examination, vision was 6/6 with no field defects, papilledema or diminished colour vision. An endoscopic endonasal transsphenoidal median approach to pituitary tumour was done. On removal of anterior wall of sphenoid sinuses, the sellar floor appeared bulged. All the key landmarks on posterior wall of sphenoid sinus were systematically identified. The sellar floor craniotomy was done using a Kerrison’s punch and the dura was incised in a ‘V’ shaped fashion to prevent immediate drop of the diaphragm. Adequate exposure of prechiasmatic space was achieved. A piece-meal removal of the tumour performed using a ring curette and suction. The sellar diaphragm was allowed to drop. A remnant defect was 0.5 cm × 0.5 cm approximately with a diaphragmatic defect and grade-3 CSF leak. Grafts of abdominal fat, temporalis fascia and a nasal septal cartilage were harvested. The nasal margins of the defect were refreshed. A large fat plug was inserted like a dumbbell into the bony defect with elimination of dead space between the diaphragm and sellar floor. The temporalis fascia graft was placed by onlay technique. A sculpted septal cartilage was placed as a gasket-sealing for the defect. A left-based sphenoid mucosal flap raised and draped over the reconstructed site. Tissue glue was applied over the entire reconstructed area. A watertight seal was ensured with Valsalva manoeuvre. A gel foam was used as an interface and pressure tamponade was provided with the inflated bulb of a size 12 Foley’s catheter (Fig. 2). In the postoperative period, the patient was advised bed rest for 3 days. Foley’s catheter in the sinus was removed after 48 h. He was administered oral cephalosporins and stool softeners for 2 weeks. He was advised not to lift heavy weights for 2 months. The first follow-up visit was 1 week following the surgery and consecutive follow-ups were scheduled weekly for one month, and from then on, once in two weeks for 3 months. Regular endoscopic nasal cleaning was done and gentle saline nasal irrigation was initiated after 1 week. Afterwards, the patient was followed-up once in two months for 2 years. Following this, the patient has undergone multiple nasal endoscopies for an additional 1 ½ years for allergic rhinitis. The surgical site is well mucosalized with no visible pulsations or CSF leak.

Fig. 1.

a, b Gadoinium enhanced MRI showing contrast enhancing pituitary macroadenoma () extending superiorly into pre-chiasmatic space, laterally upto right cavernous sinus and inferiorly into sphenoid sinus () cavity

Fig. 2.

Strategy of multilayer skull-base reconstruction showing (a) Defect in diaphragma sellae, b Fat plug, c Temporalis fascia, d Nasal septal cartilage, e Sphenoid mucosal flap, f Gelfoam and g Inflated bulb of Foleys catheter

Discussion

The repair of a skull-base defect with grade-3 csf leak is challenging. Esposito et al. [4] studied a large cohort with all grades of intraoperative CSF leak. This study had 58 grade-3 cases and showed a higher repair failure rate and meningitis rate (12% and 3.4% respectively) as compared with all other grades combined (1.6% and 0.16% respectively) which was statistically significant (p-0.0003 & p-0.021 respectively). In this case, we used a fat plug of larger size plugged the bony defect in a dumbbell fashion and eliminated the intrasellar dead space during intracranial pressure rise. The temporalis fascia acted as a thin interface between the fat and the septal cartilage that also draped over the edges of the defect to provide scaffolding for easy vascularisation. A gasket-closure was achieved using a septal-cartilage. Since our closure was in a layered fashion and the septal-cartilage sandwiching was done with the edges snugly-fit like a gasket on the sellar-floor which was also topped-up with a sphenoid-mucosal flap, the possibility of septal cartilage migration with pulsation is considerably reduced. The ideal technique to facilitate faster healing of the reconstruction site is to use of a local vascularised pedicle mucosal flap. The nasoseptal flap is the work-horse flap for skull base defects but it can result in large raw surfaces on posterior part of septum. Studies have shown the effectiveness of sphenoid mucosal flap in low output CSF leaks [5]. To our knowledge, this is the first study where a sphenoid mucosal flap is used for a high-output CSF leak. We believe the use of sphenoid mucosal flaps are a good alternative to nasoseptal flaps and free flaps as these are easy to transpose and prevent wound dehiscence. A skull base defect with grade-3 CSF leak should ideally be managed with a watertight seal that withstands high intracranial pressure. Thus it requires a multilayer closure with hard and soft tissue components [5] and promotion of rapid healing. Different standardized techniques of closure with various biomaterials [4, 6] are proposed but in our opinion, the approach should be customised base on the shape and size of defect and the availability of these resources.

Declarations

Conflict of interest

No conflicts of interest. There are no material, financial or non-financial interests to disclose by the authors for this publication. No funds, grants or other supports were received.

Consent to publish

The study is in compliance with institutional ethics committee policies and patient provided informed/ written consent for publication of the case study.