P2-P3 junction aneurysm of the posterior cerebral artery

Aneurysms in the P2 segment arise between the junction of the posterior communicating artery (PCoA) with the PCA and the posterior part of the midbrain. The pterionalsubtemporal, temporopolar, transpetrous and transcortical transchoroidal fissure are the surgical approaches which have been used to gain access to P2 segment aneurysms.

Endovascular coil occlusion has rapidly evolved as a competing therapeutic alternative to surgical clipping in the treatment of P2 segment aneurysms.

However, surgery is still a well-established option for P 2 segment aneurysms and complete closure of the aneurysm can be achieved by surgical clipping 1).

Treatment

Proximal occlusion of PCA represents a treatment option. However, this procedure carries a high risk of ischemic complication

The STA-P3/PTA bypass through the subtemporal approach is a feasible option to maintain blood flow in cases of PCA fusiform aneurysms requiring trapping of the P2 segment 2).


Progressive deconstruction with flow diversion using a Pipeline embolization device (PED; Medtronic) can be utilized to promote thrombosis of broad-based fusiform aneurysms. Current flow diverters require a 0.027-inch microcatheter for deployment. Vakharia et al., presented a patient with a fusiform P2P3 junction posterior cerebral artery aneurysm in which they demonstrate the importance of haptics in microwire manipulation to recognize large-vessel anatomy versus perforator anatomy that may overlap, especially when access is needed in distal tortuous circulations. In addition, the authors demonstrate the need for appropriate visualization before PED deployment. Postembolization runs demonstrated optimal wall apposition with contrast stasis within the aneurysm dome.The video can be found here: https://youtu.be/8kfsSvN3XqM

 3).

References

1)

Zhitao J, Yibao W, Anhua W, Shaowu O, Yunchao B, Renyi Z, Yunjie W. Microsurgical subtemporal approach to aneurysms on the P(2) segment of the posterior cerebral artery. Neurol India. 2010 Mar-Apr;58(2):242-7. doi: 10.4103/0028-3886.63806. PubMed PMID: 20508343.
2)

Kawashima A, Andrade-Barazarte H, Jahromi BR, Oinas M, Elsharkawy A, Kivelev J, Kubota Y, Kawamata T, Hernesniemi JA. Superficial Temporal Artery: Distal Posterior Cerebral Artery Bypass through the Subtemporal Approach: Technical Note and Pilot Surgical Cases. Oper Neurosurg (Hagerstown). 2017 Jun 1;13(3):309-316. doi: 10.1093/ons/opw033. PubMed PMID: 28521345.
3)

Vakharia K, Munich SA, Waqas M, Setlur Nagesh SV, Levy EI. Deployment of distal posterior cerebral artery flow diverter in tortuous anatomy. Neurosurg Focus. 2019 Jan 1;46(Suppl_1):V9. doi: 10.3171/2019.1.FocusVid.18481. PubMed PMID: 30611181.

Direct carotid cavernous fistula

Type A Direct carotid cavernous fistula (CCF) are high flow fistulas occurring due to a tear in the carotid artery most commonly from either penetrating or non-penetrating head trauma.

Direct CCF also occur secondary to cavernous aneurysmrupture and from iatrogenic trauma following oromaxillofacial and neurosurgical procedures.

The most common (70%-90%) etiology of direct CCF is trauma from a basal skull fracture resulting in tear in the internal carotid artery (ICA) within the cavernous sinus.


video of Liao et al., from the Chung Shan Medical University, Institute of Medicine, Taichung. Departments of Neurosurgery and Department of Neuroradiology, Taichung Veterans General Hospital, Neurology, Neurological Institute, and Department of Neurosurgery, Tri-Service General Hospital, National Defense Medical Center, TaipeiTaiwan presents a case of new-onset visual blurring, diplopia, and conjunctival injection after head injuryCTA of the brain revealed a direct carotid-cavernous fistula (dCCF) of the right side. Careful evaluation of CTA source images revealed that the fistula point was at the ventromedial aspect of the right cavernous internal carotid artery (ICA), about 3.6 × 3.6 mm2 in size, with 3 main outflow channels (2 intracranial and 1 extracranial) (CTA-guided concept). DSA of the brain also confirmed the diagnosis but was unable to locate the fistula point in a large-sized dCCF. Through a transfemoral artery approach, 3 microcatheters were navigated to each peripheral channel to initiate outflow-targeted embolization. Intracranial refluxes were blocked first to avoid cerebral hemorrhages, followed by the extracranial outflow. During embolization, accidental dislodge of one coil into the sphenoparietal vein occurred, but no attempt of coil retrieval was made. Complete obliteration of the dCCF was achieved, and the patient recovered well without new neurological deficits. 4D MRA at the 3-month follow-up showed no residual dCCF.The video can be found here: https://youtu.be/LH2lNVRZSPk

 1).

1)

Liao CH, Chen WH, Liao NC, Tsuei YS. CTA-guided outflow-targeted embolization of direct carotid-cavernous fistula. Neurosurg Focus. 2019 Jan 1;46(Suppl_1):V11. doi: 10.3171/2019.1.FocusVid.18447. PubMed PMID: 30611182.

Middle cerebral artery aneurysm stent assisted coiling

Extra intracranial bypass surgery is a well-established procedure for the treatment of chronic ischemic diseases of the carotid artery. Rarely de novo aneurysms can develop at the site of anastomosis. The treatment of these aneurysms can be very challenging due to various factors, including the presence of graft, previous craniotomyatherosclerosis, and lack of direct access. In a video Joshi et al., from the Department of Neurological Surgery, Rush University Medical CenterLoyola University Medical Center and Cerebrovascular Neurosurgery and Comprehensive Stroke Center, ChicagoIllinois, report and discuss the management of a right middle cerebral artery (MCA) wide-necked de novo aneurysm by stent assisted coiling through a retrograde trans-posterior communicating artery access.The video can be found here: https://youtu.be/MBKolPvOErU

 1).


57 patients with MCA trifurcation wide-necked aneurysms underwent stent-assisted coiling embolization using a solitaire AB stent. All 57 patients completed the surgery successfully. Embolization efficacy was graded according to the Modified Raymond-Roy Classification.

There were 52 cases of complete embolization, 4 cases of residual aneurysm neck, and 1 case of residual aneurysm body. 50 patients participated in a 6-36-month follow-up. There has not been observed any aneurysm rupture and hemorrhage. 50 patients received digital subtraction angiography (DSA) re-examination; 46 patients presenting complete embolization had no aneurysm relapses; 3 patients had residual aneurysm neck demonstrated; 1 patient had no aneurysm neck and others 2 were in stable condition. Finally, the patient with residual aneurysm body showed no sign during follow-up reexamination.

Stent-assisted coiling embolization of intracranial wide-necked aneurysms using the solitaire AB stent was safe and effective 2).


From November 2003 to October 2009, 49 patients (27 men, 22 women; mean age, 52 ± 12 years) harboring 52 complex unruptured MCA aneurysms (11 ruptured previously and coiled but recanalized and 41 unruptured) were treated by EVT by using self-expandable intracranial stents. Procedural complications, clinical outcome, and initial and midterm angiographic results were evaluated. Initial treatment status and aneurysm sac size were tested as potential risk factors for recurrence.

After successful stent deployment, coiling was performed in 50 aneurysms (96.2%) in 47 patients; however, 2 failures (3.8%) occurred in 2 patients. Ten intrastent clot formations (20%) observed on final control angiography induced 2 permanent moderate disabilities (GOS score = 2). Mortality and permanent neurologic morbidity were 0% and 4.3%, respectively. At a mean period of 14 ± 9 months, among 48 aneurysms in 45 patients eligible for follow-up, 34 complete (71%) and 14 partial treatments (29%) were observed, 7 recurrences (14.6%) occurred, and 5 patients (10.4%) needed retreatment. No aneurysm bleeding or symptomatic intrastent stenosis was observed. Aneurysm sac size ≥7 mm and incomplete initial treatment were associated with more recurrences without a statistically significant difference.

For complex unruptured MCA aneurysms, EVT by using a self-expandable intracranial stent was feasible, safe, and durable and could be considered as the first-option treatment 3).

References

1)

Joshi KC, Heiferman DF, Beer-Furlan A, Lopes DK. Stent-assisted coil embolization of MCA aneurysm via a trans-posterior communicating artery access. Neurosurg Focus. 2019 Jan 1;46(Suppl_1):V3. doi: 10.3171/2019.1.FocusVid.18444. PubMed PMID: 30611185.
2)

Chen Y, Zhang Y, Chao YJ, Gao G, Ni CS, Fu XM, Wei JJ, Gu DQ, Yu J. Stent-assisted coiling embolization of middle cerebral artery trifurcation wide-necked aneurysms. Eur Rev Med Pharmacol Sci. 2017 Oct;21(19):4346-4349. PubMed PMID: 29077162.
3)

Vendrell JF, Costalat V, Brunel H, Riquelme C, Bonafe A. Stent-assisted coiling of complex middle cerebral artery aneurysms: initial and midterm results. AJNR Am J Neuroradiol. 2011 Feb;32(2):259-63. doi: 10.3174/ajnr.A2272. Epub 2010 Oct 21. PubMed PMID: 20966055.
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