It is not uncommon to detect unruptured aneurysms in preoperative examination of pituitary tumors, among which paraclinoid aneurysms account for a large proportion.1,2 There are many therapeutic strategies for such tumors appearing concurrent with aneurysms. The staging plan is mainly to remove pituitary adenoma after interventional aneurysm treatment. The concurrent strategy includes craniotomy for aneurysm clipping combined with pituitary adenoma removal, craniotomy for aneurysm clipping and transsphenoidal surgery for pituitary adenoma removal, and endoscopic endonasal surgery for simultaneous tumor resection and aneurysm clipping.3 A minimally invasive method with low cost and subsequent no-drug treatment for patients is the best, and the most consistent with this principle is the endoscopic endonasal approach for simultaneous removal of pituitary adenoma and clipping of aneurysm. There were few reports about the concurrent surgical strategy.4 The indications, operation details, and safety and efficacy of this method are worth discussing.
Illustrative Case
A 51-year-old woman was admitted with the chief report of vision loss for 2 years and headache for 2 months. Preoperative evaluation found mild visual loss (20/25 in the left eye and 20/20 in the right eye) with temporal hemianopsia in the left eye. Endocrine examination showed normal pituitary function. Cranial nerve test also found no abnormalities. Preoperative magnetic resonance imaging (MRI) showed a sellar mass with heterogeneous enhancement 2.2 × 2.5 cm and a lesion suspicious for an aneurysm. Digital subtraction angiography (DSA) confirmed a paraclinoid aneurysm measuring 3.5 mm in the neck and 2.2 mm in the body, with the dome pointing medially and inferiorly. After comprehensive consideration of the patient’s economic situation, acceptance of craniotomy, postoperative treatment compliance, and the characteristics of the lesion itself, we recommended the endoscopic endonasal approach for simultaneous resection of the tumor and clipping of the aneurysm.
Operative Technique
VIDEO 1. Clip showing surgical procedure. Click here to view.
Preoperative MRI (A and B) showed a sellar mass with heterogeneous enhancement 2.2 × 2.5 cm. Preoperative DSA (C and D) confirmed a paraclinoid aneurysm measuring 3.5 mm in neck and 2.2 mm in body, with the dome pointed medially and inferiorly. The arrows indicate the location of the aneurysm. Postoperative MRI (E and F) demonstrated total tumor removal. Postoperative computed tomography angiography (G and H) demonstrated total aneurysm clipping without parent vessel stenosis.
Intraoperative view after tumor removal and aneurysm clipping. An = aneurysm; ON = optic nerve; SHA = superior hypophyseal artery.
Discussion
Observations
Endoscopic endonasal clipping of intercranial aneurysms, which has been shown to be feasible in many anatomical studies and clinical applications,5–14 is not the principal strategy of the aneurysm-clipping surgery. Meanwhile, among the reports of planned endoscopic endonasal clipping surgery, paraclinoid aneurysm accounted for most.6,9 Nowadays, endovascular surgery is developing rapidly in the treatment of paraclinoid aneurysms, most of which are treated by interventional therapy, but it is expensive and requires long-term antiplatelet therapy after the operation. A small number of patients who are not suited for endovascular surgery or cannot afford it choose transcranial clipping. Surgical corridors include ipsilateral and contralateral approaches. Ipsilateral approaches require complex manipulations such as exposing the cervical ICA and removing the anterior clinoid process, whereas contralateral approaches have poor control over the proximal end of the parent artery. Paraclinoid aneurysms are always a challenge for microsurgical clipping. With the advantages of a panoramic view of aneurysm, direct route to the aneurysm and parent artery, avoidance of brain retraction, better cosmetic effect, and easy proximal control of the ICA, endoscopic endonasal clipping has been reported as an alternative approach for clipping paraclinoid aneurysms.
The previous reports were mainly pure aneurysm clipping without combined lesions. In the present case, the interaction effects between pituitary adenoma and paraclinoid aneurysm should be comprehensively contemplated. Considering the effect caused by aneurysm to pituitary adenoma, the paraclinoid aneurysm contacted the pituitary tumor but did not occupy the route to expose the tumor, so securing the aneurysm should be done prior to resecting tumor to prevent intraoperative rupture. We achieved satisfactory space for proximal control after removing the bone embracing the paraclival ICA and rehearsing temporary trapping. Removal of the lingual process and petrous process of the sphenoid bone was the crucial step for acquiring adequate room for temporary occlusion. Generally, in larger medial carotid aneurysms, the best segment of the carotid for proximal occlusion was thought to be the cavernous segment, while opening the cavernous sinus may cause massive venous bleeding. We took the extracavernous segment of ICA as the occlusive site, which was helpful for reducing bleeding from the cavernous sinus. The branches of the trigeminal nerve, gasserian ganglion, abducens nerve, and ICA were not in danger if the dura posterior to lingual process and petroclival fissure were kept intact, as cautioned in anatomical study.5 In the case of pituitary adenomas invading the cavernous sinus, the extradural paraclival ICA exposure cannot be omitted because using the cavernous segment of ICA as the site of proximal occlusion may result in cranial nerve injury, and this site can only be exposed after resection of most of the tumor, which is not a good option for preventing aneurysm rupture during surgery.
Considering the effect caused by pituitary adenoma to aneurysm, the endoscopic endonasal clipping may require pituitary gland transposition in the absence of pituitary adenoma, which is also a complex procedure, but in combined tumor surgery, removal of the tumor provides room for clipping the aneurysm as needed. We did not open the dura covering the dome of the aneurysm as described in the first report of endoscopic endonasal clipping of paraclinoid aneurysm by Kassam et al.,13 because after removing tumor, the dura edge was proper for clipping and further dissection of dura only involved more risk. In summary, exposure of the paraclival ICA, tumor removal, and aneurysm clipping should be completed step by step. At the end of the operation, the clip breached level of base reconstruction in solo tumor resection. The end of the clip was wrapped by multilayer reconstruction performed without cerebrospinal fluid leakage. The principles of aneurysm clipping were also obeyed in endoscopic endonasal clipping: (1) ability to gain proximal and distal control, (2) exposure of vessels and their respective perforators, and (3) possibility of clip placement, as described before.
In reports of a pituitary adenoma coexisting with an aneurysm, the rates have ranged from 2.3% to 8.3%.1,2,15 Endoscopic endonasal clipping is not suitable for all aneurysms. Medial and inferior projection with not large size are indications for endoscopic endonasal clipping. The limitations of the procedure include difficulty in exposing the neck of aneurysms projecting laterally, difficulty in large aneurysms hindering visualization and control of the aneurysm neck and the distal ICA, and impossibility of bypass. However, ruptured aneurysms are not contraindications.11,16,17 The most common postoperative complications were cerebrospinal fluid leak, stroke, meningitis, and transient hemiparesis.7
The drawbacks in our treatment included MRI of the wall not being performed to assess the likelihood of aneurysm rupture18 and intraoperative endoscopic fluorescence not being available to confirm whether the clipping was complete and whether the parent artery was unobstructed.
Lessons
The advantages of personalized therapy have been introduced by technological advances. When confronted with pituitary adenoma coincidental with paraclinoid aneurysm, in a team that harbors the experience of the endoscopic endonasal approach and cerebrovascular surgery, owns adequate instruments and equipment, and ensures that patient selection is made with extreme caution, surgery for small, superiorly or medially projecting aneurysms could be best achieved with endoscopic endonasal tumor removal and aneurysm clipping. This strategy has the advantage of saving medical resources, promoting a patient’s rapid postoperative recovery, and reducing possible antiplatelet therapy after interventional therapy.
Acknowledgments
This work was sponsored by Hunan Provincial Health Commission (202204045210).
Disclosures
The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
Author Contributions
Conception and design: He, Gu, Zhong. Acquisition of data: Zhong, Gao. Analysis and interpretation of data: He, Zhong, Gao. Drafting the article: He, Gu. Critically revising the article: He, Gu. Study supervision: He, Gu.
Supplemental Information
Video
Video 1. https://vimeo.com/703303858.
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