The sellar nonneoplastic cystic lesions include Rathke’s cleft cysts and arachnoid cysts [
In this paper, we present 8 cases of Rathke’s cleft cysts and arachnoid cysts, managed with endoscopically transsphenoidal surgery by applying intentional fenestration to the subarachnoid space and closing the sellar floor using delicate dural suturing technique. This method is minimally invasive and the surgical results were favorable.
All patients were included in the prospective database between October 2009 and August 2013 who underwent endoscopic endonasal transsphenoidal surgery for treating symptomatic Rathke’s cleft cysts and arachnoid cysts. The sample of 8 patients comprised 2 males and 6 females, with ages ranging from 37 to 73 years. In all of the subsequent patients, no packing of fat or other grafts was performed, wide fenestration of the cyst cavity to the SAS was intentionally conducted, and the sellar dura was closed meticulously using sutures and fibrin glue.
Patient clinical notes, operative notes, imaging studies, and hormonal studies were reviewed. In addition, data on lesion characteristics, detailed intraoperative observations, intra- and postoperative complications, and clinical outcomes were collected. A single surgeon, Yudo Ishii, performed all of the procedures.
Pituitary function was assessed using standard hormonal assays, including the levels of thyroid-stimulating hormones (TSHs) and thyroxine (Free-T3, Free-T4), growth hormones (GHs) and IGF-I, plasma adrenocorticotropic hormones (ACTHs) and serum cortisol, prolactin, luteinizing hormones (LHs), follicular-stimulating hormones (FSHs), and testosterone in men. In the early postoperative period, the patients were monitored for DI based on urine volume and urine-specific gravity. The hormone levels of the patients were monitored every 2 days after the operation.
The preoperative and postoperative visual function assessment involved measuring visual acuity using formal visual field testing. Visual function was considered improved if the visual acuity assessed using the handheld eye card improved by at least 2 lines or if the visual field defects, assessed using field confrontation or by having an ophthalmologist conducting a formal visual field test review, were resolved or improved.
All of the patients underwent pre- and postoperative pituitary MR imaging with and without Gadolinium enhancement, including early postoperative MR imaging on day 7 and subsequently within 3–6 months after operation. One of the female patients, the sixth patient, received a preoperative MR exam, but during the preoperative evaluation, a cardiac pacemaker was prescribed and, therefore, the postoperative image study was replaced with a brain CT scan.
A direct endoscopic endonasal transsphenoidal surgery (ETSS) was performed in all of the cases in this study. The surgical procedure used for treating the RCCs and ACs in this study is summarized briefly, as follows.
After performing a wide sphenoidotomy and sellar floor opening (Figure
Three arachnoid cyst and 5 Rathke’s cleft cyst cases were included in this series. All of the patient symptoms were visual disturbances. The patients did not exhibit headache or pituitary dysfunction, except for the fifth patient who had a headache, and the headache dissipated after the operation. The visual function of all of the patients was improved after the surgery. The preoperative MR image and the postoperation 3-4-month image are shown in Table Patient demographics, clinical data in 8 cases of AC and RCC. AC: arachnoid cyst, RCC: Rathke’s cleft cyst.Patient number Age (yr)/sex Diagnosis Maximum diameter (mm) Headache Visual disturbance Pituitary/hypothalamus disfunction 1 45/F RCC 23.15 Nil Positive Nil 2 64/F AC 51.88 Nil Positive Nil 3 71/F RCC 22.54 Nil Positive Nil 4 37/M AC 37.01 Nil Positive Nil 5 53/F AC 26.68 Positive Positive Nil 6 56/M RCC 28.02 Nil Positive Nil 7 73/F RCC 25.48 Nil Positive Nil 8 59/F RCC recurrence 23.45 Nil Positive Nil Previous with fat packing
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(1) (RCC) |
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(2) (AC) |
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(3) (RCC) |
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(4) (AC) |
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(5) (AC) |
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(6) (RCC) |
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(7) (RCC) |
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Preoperative image and postoperative image in recurrence RCC patient.
Patient number | Preoperative image | Postoperative image |
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(8) (RCC recurrence) |
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(8) (Recurrence after fenestration) |
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An arachnoid cyst is a collection of CSF-like fluid, the walls of which comprise an arachnoid structure. The cyst can develop at any site in the subarachnoid space along the cerebrospinal axis. Two theories on the pathogenesis of intrasellar arachnoid cysts have been postulated [
Intended fenestration of the cystic wall balances the pressure between the outside and inside of the cyst and can subsequently relieve the symptoms. The other way is that one of the pathogeneses of arachnoid cyst is the ball-valve mechanism. Once fenestration of the cyst with the subarachnoid space was performed, no pressure gradient occurred and, thus, the recurrence of arachnoid cyst was less likely. The wider the fenestration is, the faster the communication of subarachnoid space with the cyst is. The size of the fenestration was variable, depending on the relation between the small perforating arteries and the pituitary gland. We usually make fenestration until the flow of CSF becomes the to-and-fro oscillations of the arachnoid membrane like the 3rd ventriculostomy.
We recommend that the fenestration site be located at the arachnoid membrane of the dorsum sellae, just above the posterior clinoid process. For Rathke’s cleft cyst, the anterior pituitary gland is mostly located at the ventral sella, and the posterior lobe is at the dorsal sella. In endoscopic transsphenoidal surgery, we could verify the location of normal pituitary gland and the perforators supplying it. We make fenestration-avoiding injury to these vessels by direct vision under endoscope. In case of arachnoid cysts, pituitary gland would be located in the dorsal or caudal sella. In such cases, fenestration would be made at the frontal part of cyst as described by Oyama et al. Before the surgery, the surgeon should carefully examine the sagittal view of the MR image of the brain to determine the relationship of the trunk and tip of the basilar artery behind the dorsum sellae and possible location of pituitary stalk (Figure
Surgical therapy is the most commonly used method for treating symptomatic primary and recurrent Rathke’s cleft cysts, and transsphenoidal approach is the preferred approach [
Consequently, most neurosurgical centers limit the use of this complete resection method [
In the treatment of Rathke’s cleft cysts, fenestration of the cyst cavity to the subarachnoid space after removing the cyst content relieved the cyst pressure. The symptoms may thus be remedied. However, because the cyst wall was not completely removed, some residual ciliated epithelial cells may form the cyst content. The epithelial cell might be with a mucus secreting function, and the communication of subarachnoid space may prevent this secretion from accumulating. In the literature, studies have reported that “chemical meningitis” had occurred when removing the cystic craniopharyngioma [
The postoperative recurrence rate and complication rate are high for these 2 diseases. The literature review and our result were summarized (Table
AC or RCC | Author and year | Case numbers | Decompression method | Packing or reconstruction method | Complications | Recurrence |
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AC | Dubuisson et al. (2007) [ |
9 | Microscopically, cyst removed totally (2) and partially (7), communicating with SAS | Adipose tissue (4/9), bone pieces, biological glue, lumbar puncture drainage | 1 permanent diabetes insipidus (11%); 2 CSF fistula (22%) | FU from 2 months to 324 months, 0 recurrence |
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AC + RCC | Cavallo (2008) [ |
AC: 10 RCC: 20 | AC: microscopic or endoscopic, no cyst wall removal; RCC: endoscopic (20), cyst removed totally in purely suprasellar lesion, partially in sellar lesion | AC: adipose tissue and/or collagen sponge; RCC: 7 with reconstruction, 13 left open | AC: 2 CSF fistula (20%); RCC: 1 thalamic infarction (5%), 2 diabetes insipidus (10%), 1 CSF fistula (5%) | AC: FU 10 to 94 months, 1 recurrence (10%); RCC: FU 7 to 70 months, 2 recurrence (10%) |
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AC | Mclaughlin et al. (2012) [ |
8 | Microscopically or endoscopic approach, no cyst wall removal | Adipose tissue, titanium micromesh, fat and collagen buttress, acetazolamide for 48 hours | No | FU 6 to 47 months, 2 recurrence (25%) |
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RCC | Benveniste et al. (2004) [ |
62 | Microscopically sublabial (37), endonasal (23), endoscopic endonasal (1) craniotomy (1), cyst wall removed totally (6) | Adipose tissue (19) + bone piece (55) or titanium mesh (1); left open (6) | 1 CSF fistula (1.6%), 1 abdominal fat graft harvest infection | FU 1 to 166 months, 10 recurrence (16%) |
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RCC | Aho et al. (2005) [ |
118 | Microscopically sublabial (118), 114 cyst wall removed totally, | Adipose tissue (43) | 22 diabetes insipidus (19%), 1 CSF fistula (0.8%), 1 meningitis (0.8%) | FU over 60 months, 21 recurrence (18%) |
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RCC | Lillehei et al. (2011) [ |
82 | Microscopically sublabial and endonasal, simple cyst drainage, alcohol cauterization | Gelfoam and bone strut, fibrin glue, spinal drain for intraoperative CSF leakage, 0 adipose tissue packing | 2 CSF fistula (2.4%), 3 transient DI (3.7%) | FU 4 to 163 months, 8 recurrence (9.7%) |
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RCC | Park et al. (2012) [ |
73 | Microscopically and endoscopic assisted, cyst drainage | 34 packing adipose tissue, 22 packing surgically, 17 no packing, sellar reconstruction with bone, porous polyethylene, TachoComb with BioGlue | 2 CSF fistula (2.7%) | FU 12–166 months, 12 recurrence (16%) |
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AC + RCC | Oyama et al. (2014) [ |
AC: 6; RCC: 1 | Microscopically extended approach, cisternostomy | 7 dura stitches, no fat packing | 1 CSF fistula | FU 36 to 49 months, 2 recurrence (28%) |
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AC + RCC | Our series | AC: 3; RCC: 5 | Endoscopically endonasal, cyst drainage cisternostomy | 8 dura stitches, no fat packing, bone and BioGlue | 0 CSF fistula | FU 4 to 50 months, 1 recurrence (12%) |
CSF fistula is a major postoperative complication of endoscopic transsphenoidal surgery, especially in cystic lesions [
Therefore, we recommend not packing the cyst with fat or other materials after fenestration of the RCC with communication of the SAS. Although the flow of CSF may be large, the dura of the sellar floor can be closed using meticulously applied sutures and the synergistic easy slipknot approach, as reported by the senior researcher [
We performed operations, totally 151 Rathke’s cleft cysts and 5 arachnoid cysts from 2004 to 2013 in Nippon Medical School University Hospital with the method of traditional drainage and cyst wall biopsy. Among them, 10 Rathke’s cleft cysts and 2 arachnoid cysts recurred. All the recurrent cases were large cysts with suprasellar extension. We propose the indication of this fenestration procedure for the large cysts with suprasellar extension. This approach would not be too invasive if it is performed in hands of an experienced endoscopic transsphenoidal surgeon with good sellar reconstruction technique, like the dura suturing. Endoscopic transsphenoidal management of the cystic lesions could be as easy as in craniotomy cases.
Managing symptomatic RCC and sellar AC by fenestration of the cyst wall and meticulously applying dural sutures can provide symptom relief and prevent recurrence without increasing the risk of CSF fistula complications. Endoscopic endonasal transsphenoidal surgery to the cyst lesions can achieve more minimally invasive result than the extended approach method using microscope.
This work did not receive any funds from NHI, Welcome Trust, Howard Hughes Medical Institute, or any foundations requiring open access.
All the authors listed in this paper have no direct or indirect conflict of interests about this study method, including secondary financial gain. The authors have no personal or institutional financial interest in drugs, material, or device described in this submission.
This project was partly supported by Health and Welfare Surcharge of Tobacco Products, MOHW103-TD-B-111-01, from the Ministry of Health and Welfare.