Iatrogenic intracranial pseudoaneurysms: neuroradiological and therapeutical considerations, including endovascular options

Abstract

Intracranial pseudoaneurysms represent a potentially fatal complication of intracranial surgery. Our purpose is to describe their neuroradiological characteristics, prognostic features and possible treatment. Eight cases of postsurgical intracranial pseudoaneurysms have been observed at our institution since 1988. Four were observed following transsphenoidal (TS) surgery and four after pterional craniotomies. Two types of iatrogenic pseudoaneurysms were observed: "fusiform", probably due to weakening of the adventitia during surgical peeling of the tumour from the artery (three cases) and "saccular", occurring after a more focal or complete laceration of the vessel (five cases), more often after TS surgery. A thorough preoperative neuroradiological examination may identify anatomical conditions at risk for development of this severe complication. Postoperative neuroradiological follow-up is mandatory in cases in which unusual bleeding has occurred during the perioperative period, but absence of bleeding does not exclude the possible development of a pseudoaneurysm. Endovascular treatment of pseudoaneurysms represents a safe and durable procedure, specifically in those cases in which damage to the carotid siphon occurred during TS surgery.

Endovascular Management of Vascular Injury during Transsphenoidal Surgery

“…These lesions have been reported in patients after TSS [4][5][6] . This is without clinical consequences due to the overpacking.…”

“…Fortunately, vascular injuries are uncommon in TSS, estimated to occur in just 1.1% of all cases 5 . Other conditions associated with increased risks of vascular injury include anatomic variants of the sphenoid bones, tumor invasion of the cavernous sinus, tumor adhesion to the ICA, and distortion of the local anatomy 6 . As such, it is critical to remain in the midline during TSS, and the vomer ridge can be used as an important landmark.…”

“…In the event of intraoperative carotid injury, the carotid artery is compressed to give sufficient time for tamponade with a variety of materials (including Surgicel, muscle plugs, tissue adhesives), which are held in place by closing the sellar window with a piece of cartilage or bone. If significant bleeding occurs during or after a TSS, even after successful intraoperative tamponade, immediate vascular imaging should be obtained and the clues of vessel wall damage must be sought 2,4,6 . Moreover, if intraoperative packing was utilized for hemorrhage control, any radiographic studies that appeared normal with the packing in place should be repeated later regardless of pack removal 4 .…”

Use of the Pipeline embolization device in the treatment of iatrogenic intracranial vascular injuries: a bi-institutional experience

“…iatrogenic injury of the basilar artery, anterior cerebral artery, posterior cerebral artery, and middle cerebral artery occur less commonly but have also been reported. 4,9,10,12,18 Recently, the use of flow-diverting stents has been reported in the treatment of iatrogenic intracranial vascular injuries. Nerva et al 13 presented 2 cases in which pseudoaneurysms were encountered following transsphenoidal pituitary tumor resection.…”

A Case of Pseudoaneurysm of the Internal Carotid Artery Following Endoscopic Endonasal Pituitary Surgery: Endovascular Treatment with Flow-Diverting Stent Implantation

“…In addition to the normal intimate relationship of the ICA with the parasellar region, underlying anatomic variations of the sphenoid bones, an abnormally short distance between ICAs, ICA displacement by the lesion, tumor invasion of the cavernous sinus, tumor adhesion to the ICA, acromegaly with distortion of the local anatomy, and unusual tortuosities in the ICA can all result in an increased risk of vascular injury (8). Previous surgery, previous external radiotherapy (risk may be higher after proton or stereotactic radiation), chemoradiotherapy, or prior treatment with bromocriptine for pituitary tumors have also been linked to ICA injury (4).…”