|Ahead of print
Spontaneous or iatrogenic? Postoperative pseudo aneurysm in craniopharyngioma: Case report
Apinderpreet Singh1, Tejasvi Singh Randhawa1, Kirti Gupta2, Chirag Ahuja3, Pravin Salunke1
1 Department of Neurosurgery, PGIMER, Chandigarh, India
2 Department of Histopathology, PGIMER, Chandigarh, India
3 Department of Radio Diagnosis Division of Neuroradiology, PGIMER, Chandigarh, India
|Date of Submission||10-Oct-2020|
|Date of Decision||11-Feb-2021|
|Date of Acceptance||24-Mar-2021|
|Date of Web Publication||07-Jan-2022|
Department of Neurosurgery, PGIMER, Sector 12, Chandigarh 160012.
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Caniopharyngiomas pose significant surgical challenge because of their location and close proximity to major neurovascular structures. Early and delayed vascular complications associated with Craniopharyngioma and its surgery have been documented. Various mechanisms have been postulated for the origin of aneurysms in Craniopharyngioma. Though the surgery and minor injuries to the vessel wall might predispose the aneurysm formation, exact mechanism and relation is lacking. We report a case of a psedoaneurysm of the distal ACA AT A2`-A3 junction in a case of cystic Craniopharyngioma who presented with rupture, 2 weeks after primary surgery. Insight into the probable causes of aneurysm formation and its subsequent rupture and management have been described.
Keywords: Craniopharyngioma, fusiform dilatation, pseudoaneurysm
| Introduction|| |
Caniopharyngiomas though histologically benign, are notorious for their typical deep seated, central location, and close proximity to critical neurovascular structures. Though rare, vascular involvement like dissecting and blister aneurysms have been described with these tumors., The vessels may be lacerated or handled while operating these tumors causing ischemic stroke, vasospasm, stenosis, or pseudo aneurysms. Though the vascular complications are known, the overall incidence is quite low. The index of suspicion should be high so that these complications are picked up early and not missed. We report here a case of a 15-year-old child, who was uneventfully operated for cystic Craniopharyngioma. Three weeks later, he presented with SAH due to ruptured pseudoaneurysm that was clipped and managed successfully. Possible mechanisms and management issues have been elucidated and discussed.
| Case Report|| |
A 15-year-old male child presented to emergency department with progressive vision loss for 2 months and altered sensorium for 2 days. Patient was unconscious. NCCT brain showed predominantly cystic suprasellar lesion with peripheral calcification reaching up to the third ventricle and right frontal lobe. There was no evidence of hypopituitarism or any metabolic derangement and patient did not show any improvement in sensorium after initial resuscitation. Considering the mass effect as the cause, the cyst was tapped and approximately 25 ml of machine oil fluid was drained. Patient improved following the tap. Post tap CT showed air inside the cyst with no blood. Contrast MRI showed solid cystic mass in the same location. The Anterior cerebral arteries were stretched and subsequent surgery was performed [Figure 1]. The tumor was resected completely through trans-sylvian corridor. The surgery was uneventful with no inadvertent injury to any neurovascular structure. Patient had uneventful postoperative period except transient Diabetes insipidus and was discharged on postoperative day 10. On postop day 15, he came back to emergency with sudden onset headache. NCCT brain revealed SAH in anterior interhemispheric fissure and along corpus callosum. CT angiography revealed a saccular aneurysm, 4.6 × 4.4 mm arising from right A2 at the origin of callosmarginal artery [Figure 2]. There was no angiographic evidence of dissection. There was no proceeding history of fever or any evidence of meningitis. Retrospective analysis of the previous MR study did not reveal any pre-existing aneurysm. However, because of acute compression of vessels by the tumor, the possibility of pre-existing aneurysm cannot be ruled out. Clipping of aneurysm was performed by interhemispheric approach. Histopathological examination of the aneurysm revealed pseudoaneurysm with wall formed by fibrin and media remnants with fibrin rich thrombi in it [Figure 3]. There was no evidence of its mycotic origin. The patient was discharged on postoperative day 7 and is doing well till the last follow up of 1 year.
|Figure 1: (A–C) Non-contrast CT scan axial view demonstrating suprasellar solid cystic SOL with peripheral calcification involving frontal lobe. (D–F) Axial contrast MRI (post tap) showing lesion with peripheral contrast enhancement and pushed ACA complex without any evidence of aneurysmal dilatation. (G and H) Coronal and sagittal view of the same lesion showing normal ACAs. (I) Postoperative axial CT scan demonstrating Gross Total Excision|
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|Figure 2: (A–C) Postoperative CT angiography (coronal, sagittal, axial view) of the same patient revealing a saccular aneurysm arising from right A2 at the origin of callosomarginal artery (yellow arrows)|
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|Figure 3: (A) Scanning image depicting the vessel with pseudoaneurysm with central organising thrombus (H and E ×20). (B) Low magnification image (B ×100). (C) High magnification image (C ×200) depicting pseudo aneurysmal wall covered with fibrin. (D) High magnification of the edge of the lesion demonstrates remnant of media (arrow) highlighted with elastic van Gieson stain (EVG ×200)|
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| Discussion|| |
Craniopharyngioma surgery remains challenging because of proximity to anterior circulation and its branches. Intra-operative vascular injury might lead to its thrombosis or may complicate as dissecting /pseudoaneurysm. The pseudoaneurysm can develop immediately after surgery but sometimes might present later in the course. Therefore, serial angiography is recommended in case of high index of suspicion. Apart from that, fusiform dilatation of ICA has been reported in a delayed fashion after surgery and radiotherapy, years after the treatment.
In our case, the saccular aneurysm was discovered after 2 weeks of the primary surgery when the patient presented with rupture of aneurysm. The aneurysm was located in the distal ACA where cyst wall was present. There was no evidence of vascular injury during the tap or surgical excision. Absence of aneurysm on pre-operative imaging confirmed that aneurysm had developed after surgery. The development of such aneurysm without any evident vascular insult instigated us to look for the possible cause and mechanism behind its formation.
The role of inflammation and inflammatory markers including interlukin-6 has been potentially associated with aneurysm genesis and progression. Similar markers have been detected in the cystic fluid contents of Craniopharyngioma, inducing inflammation and cytotoxic reactions. These reactions lead to gliosis, chemical meningitis, and oxidative damage. This inflammatory cascade results in vessel wall remodeling and smooth muscle weakness and inducing aneurysm formation. This process of remodeling and aneurysm formation supposingly takes a longer time. The earliest documented time period between aneurysm formation and surgery till date is 4–6 months. Therefore, this mechanism of aneurysm formation seems less likely in our case.
Vascular injury during surgery may give rise to pseudoaneurysm formation at a later date. This has been reported immediately to months after the injury., It is recommended to obtain angiograms on regular intervals in cases with apparent vascular injury. This would pick up the aneurysms early and managed. In our case, there was no apparent vascular injury. It is possible that injury went unnoticed. There was no bleeding because of vasospasm. Later the sealed area ballooned to form a pseudoaneurysm. Vasospasm masking the pseudoaneurysm has also been reported in the past. It is possible that the combination of the above two factors would have played a role in our case.
Though the exact mechanism of pseudoaneurysm formation without any evident injury remains unclear, the need for pre-operative angiographic screening and regular postoperative angiography remains the key to diagnose such entity particularly in cases with large Caniopharyngiomas requiring dissection from the major vessels.
| Statement of Ethics|| |
The standard treatment protocol was followed. Ethical clearance was not applicable. Written informed consent was taken from the parents for the publication of this case report and the accompanying images.
Financial support and sponsorship
No funding source was used.
Conflict of interest
The authors have conflict of interest to declare.
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[Figure 1], [Figure 2], [Figure 3]