Supraclinoid internal carotid artery blister-like aneurysms:hypothesized pathogenesis and microsurgical clipping outcomes

Background:Blister-like aneurysms(BLAs)on the supraclinoid segment of the internal carotid artery(ICA)are an enigma of cerebrovascular disease.Neither has a definite pathogenesis been so far identified,nor have uniform treatment guidelines been established for them.Our aim was to develop a hypothesis regarding the evolution of BLAs according to their macroscopic morphologies and to evaluate the efficacy of microsurgical clipping.Methods:The clinical data and morphological features of 15 consecutive patients with 16 BLAs on the supraclinoid ICA were retrospectively reviewed.The treatment strategies were analyzed,and functional outcomes were evaluated using the modified Rankin scale(mRS).Favorable outcomes were defined as a mRS score of 0-2.Results:Morphologically,aneurysm growth with expansion of the aneurysm neck before the surgical procedure occurred in two ruptured and one unruptured aneurysm.Daughter bleb formation was observed in two ruptured and five unruptured aneurysms.A varied degree of parent artery sclerosis was observed in nine patients.Thirteen patients were treated with direct surgical clipping,one patient was treated with clipping and wrapping,and the remaining patient was treated with an encircling clipping graft.Favorable and unfavorable outcomes were observed in 13 and two cases,respectively.Follow-up angiograms revealed 4 cases of stenosis with respective degree of mild,30%,50%,and 80%without any neurological dysfunction.Conclusions:We suggest a hypothesis that BLAs on the supraclinoid ICA may share different evolving mechanisms between ruptured and unruptured lesions.A majority of them can be reliably and safely obliterated by direct clipping technique,except for the aneurysms accompanied with severely atherosclerotic parent walls.

Application of hybrid operating rooms for clipping large or giant intracranial carotid-ophthalmic aneurysms

BACKGROUND A hybrid operating room(Hybrid-OR)is a surgical theatre that combines a conventional operating room with advanced medical imaging devices.There are still plenty of limitations when endovascular treatment or microsurgical treatment is used individually to treat large or giant carotid-ophthalmic aneurysms.AIM To explore and summarize the technical features and effectiveness of the application of a Hybrid-OR in managing major intracranial carotid-ophthalmic aneurysms.METHODS The Department of Neurosurgery treated 12 cases of large or giant intracranial carotid-ophthalmic aneurysms between March 2013 and December 2019 in a Hybrid-OR.All cases were treated with clipping and parent vessel reconstruction.RESULTS With the assistance of the Hybrid-OR,the rate of incomplete intraoperative aneurysm clipping decreased from 25%(3/12)to 0%,while the rate of vessel stenosis decreased from 16.7%(2/12)to 8.35%(1/12).In terms of thromboembolic events,ischemic infarction complication occurred in only one patient,and none of the patients experienced embolic infarction complications.All 12 patients were followed for an average of 3 years,and no aneurysms recurred.The postoperative recovery was evaluated with the modified Rankin Scale(mRS):11 patients showed no symptoms(mRS=0),1 patient showed slight disability(mRS 1-2),and none of the patients had severe disability(mRS=5)or died(mRS=6).CONCLUSION The Hybrid-OR provides new ideas for the surgical clipping of large or giant intracranial carotid-ophthalmic aneurysms and decreases the rate of intraoperative vessel stenosis and unsuccessful clipping.

Intraoperative microvascular Doppler monitoring in intracranial aneurysm surgery

Background Surgical treatment of intracranial aneurysms is often compromised by incomplete exclusion of the aneurysm or stenosis of parent vessels. Intraoperative microvascular Doppler （IMD） is an attractive, noninvasive, and inexpensive tool. The present study aimed to evaluate the usefulness and reliability of IMD for guiding clip placement in aneurysm surgery. Methods A total of 92 patients with 101 intracranial aneurysms were included in the study. IMD with a 1.5-mm diameter, 20-MHz microprobe was used before and after clip application to confirm aneurysm obliteration and patency of parent vessels and branching arteries. IMD findings were verified postoperatively with digital subtraction angiography （DSA） or dual energy computed tomography angiography （DE-CTA）. Ninety consecutive patients, harboring 108 aneurysms, who underwent surgery without IMD was considered as the control group. Results The microprobe detected all vessels of the Circle of Willis and their major branches. Clips were repositioned in 24 （23.8%） aneurysms on the basis of the IMD findings consistent with incomplete exclusion and/or stenosis. IMD identified persistent weak blood flow through the aneurismal sac of 11 of the 101 （10.9%） aneurysms requiring clip adjustment. Stenosis or occlusion of the parent or branching arteries as indicated by IMD necessitated immediate clip adjustment in 19 aneurysms （18.8%）. The mean duration of the IMD procedure was 4.8 minutes. The frequency of clip adjustment （mean： 1.8 times per case） was associated with the size and location of the aneurysm. There were no complications related to the use of IMD, and postoperative angiograms confirmed complete aneurysm exclusion and parent vessel patency. About 8.3% （9/108） aneurysms were unexpectedly incompletely occluded, and 10.2% （11/108） aneurysms and parent vessel stenosis without IMD were detected by postoperative DSA or DE-CTA. IMD could reduce the rate of residual aneurysm and unanticipated vessel stenosis which demonstrated statistically significant advantages compared with aneurysm surgery without IMD. Conclusion IMD is a safe, easily performed, reliable, and valuable tool that is suitable for routine use in intracranial surgery, especially in complicated, large, and giant aneurysms with wide neck or without neck.