How I do it: proximal control in parkinson’s triangle for a very large paraclinoid aneurysm

Background Paraclinoid aneurysms, especially when they are large, can be quite difficult to treat, both endovascularly and through microsurgical clip reconstruction. There are many possibilities to approach this region surgically, and most hinge on total or partial removal of the anterior clinoid process. Gaining proximal control may be a challenge when space is limited, which is why Parkinson’s triangle may be a viable alternative in some cases. Methods We describe in a stepwise fashion the steps used to reconstruct a very large paraclinoid aneurysm. We first attempted to gain proximal control in the carotid cave and later in Parkinson’s triangle because of limited manoeuvrability. Conclusion Proximal control in Parkinson’s triangle can be a safe alternative when the post-clinoidal segment of the internal carotid artery (ICA) is short and working space is limited in paraclinoid aneurysm microsurgical clip reconstruction.

Direct Clipping of Paraclinoid Aneurysm in Conjunction with Extradural Anterior Clinoidectomy: Technical Nuance and Functional Outcome

Objective Because of their anatomical features, treatment for paraclinoid aneurysms has remained to be challenging. Thus, the aim of this report is to prove the validity of our surgical method for unruptured paraclinoid aneurysms, together with surgical videos. Study Design Between August 2017 and November 2019, we were able to perform surgical clipping for 11 patients with unruptured paraclinoid aneurysm using a completely unified method. This study investigated the effect of surgery on multiple measures, including visual impairment, brain contusion, temporalis muscle atrophy, and multiple neurocognitive functions. Results Of the 67 unruptured aneurysms treated at our hospital, 17 were identified to be paraclinoid aneurysm, and 11 of them were treated by direct clipping using anterior clinoidectomy. Three were ophthalmic artery aneurysms, three were superior hypophyseal artery aneurysms, and five were anterior carotid wall aneurysms without branch projection. Only one patient had asymptomatic mild enlargement of the Marriott blind spots postoperatively. No brain contusion and temporalis muscle atrophy were observed in any cases. Only the Trail Making test (TMT) showed a significant worsening in the acute postoperative period: mean pre- and postoperative TMT scores were 59.1 ± 29.1 and 72.7 ± 37.3 for Part A (p = 0.018) and 80.5 ± 35.5 and 93.8 ± 39.9 for Part B (p = 0.030), respectively. However, it improved in the chronic phase. Conclusion We can conclude that our surgical method is safe and can be considered an acceptable treatment. Although surgical stress can cause temporary executive dysfunction shortly after surgery, this decline is temporary.

A Combined Microsurgical and Endovascular Approach to Giant Paraclinoid Aneurysm: 2-Dimensional Operative Video

Giant paraclinoid aneurysm remains a treatment challenge because of their complex anatomy and surgical difficulties stems frequently from a calcified or atherosclerotic aneurysmal neck and compression of the optic pathways.1-9 To improve exposure, facilitate the dissection of the aneurysm, assure vascular control, reduce brain retraction and temporary occlusion time, and enable simultaneous treatment of possible associated aneurysms, we combined the cranio-orbital zygomatic (COZ) approach9 with endovascular balloon occlusion of the internal carotid artery (ICA) and suction decompression of the aneurysm.4 The patient is a 50-yr-old female who presented with headache and hemianopsia. MRI, CT, and 4-vessel angiography revealed a giant right ophthalmic paraclinoid partially thrombosed aneurysm. Surgery was performed via right COZ approach with removal of the anterior clinoid. Unroofing the optic canal and opening the falciform ligament and the optic sheath, allowing the dissection and mobilization of the optic nerve from the aneurysm and the origin of ophthalmic artery. The endovascular team placed a deflated, double lumen balloon catheter in the ICA 2 cm above the common carotid bifurcation. Proximal control is achieved by inflating the balloon. Distal control is then gained by temporary clipping just proximal of the origin of PcomA.4 Retrograde suction decompression through the catheter partially collapses and softens the aneurysm.1,4,6-8 Carotid occlusion was applied twice, 2:47 and 2:57 min. Intraoperative angiogram revealed the obliteration of the aneurysm and the patency of the carotid and ophthalmic artery. The patient recovered well, and visual deficit resolved and was neurologically intact. Patient consented for surgery. Illustrations in video reprinted with minimal modification from Surgical Neurology, vol 50, issue 6, Arnautović KI, Al-Mefty O, Angtuaco E, A combined microsurgical skull-base and endovascular approach to giant and large paraclinoid aneuroysms, 504–518,4 Copyright 1998, with permission from Elsevier Science Inc.

When Is Diagnostic Subtraction Angiography Indicated Before Clipping of Unruptured and Ruptured Intracranial Aneurysms? An International Survey of Current Practice

Introduction: The goal of this survey is to investigate the indications for preoperative digital subtraction angiography (DSA) before clipping of ruptured and unruptured intracranial aneurysms in an international panel of neurovascular specialists.Methods: An anonymous survey of 23 multiple-choice questions relating to indications for DSA before clipping of an intracranial aneurysm was distributed to the international panel of attendees of the European-Japanese Cerebrovascular Congress (EJCVC), which took place in Milan, Italy on 7–9 June 2018. The survey was collected during the same conference. Descriptive statistics were used to analyze the data.Results: A total of 93 surveys were distributed, and 67 (72%) completed surveys were returned by responders from 13 different countries. Eighty-five percent of all responders were neurosurgeons. For unruptured and ruptured middle cerebral artery (MCA) aneurysms without life-threatening hematoma, approximately 60% of responders perform surgery without preoperative DSA. For aneurysms in other locations than MCA, microsurgery is done without preoperative DSA in 68% of unruptured and in 73% of ruptured cases. In cases of ruptured MCA or ruptured non-MCA aneurysms with life-threatening hematoma, surgery is performed without DSA in 97% and 96% of patients, respectively. Factors which lead to preoperative DSA being performed were: aneurysmal shape (fusiform, dissecting), etiology (infectious), size (>25 mm), possible presence of perforators or efferent vessels arising from the aneurysm, intra-aneurysmal thrombus, previous treatment, location (posterior circulation and paraclinoid aneurysm) and flow-replacement bypass contemplated for final aneurysm treatment. These are all factors that qualify an aneurysm as a complex aneurysm.Conclusion: There is still a high variability in the surgeons’ preoperative workup regarding the indication for DSA before clipping of ruptured and unruptured intracranial aneurysms, except for ruptured aneurysms with life-threatening hematoma. There is a general consensus among cerebrovascular specialists that any angioanatomical feature indicating a complex aneurysm should lead to a more detailed workup including preoperative DSA.

Microneurosurgery for Paraclinoid Aneurysms in the Context of Flow Diverters

The advent of flow diverter (FD) stents has apparently reduced the role of microneurosurgery for paraclinoid aneurysms despite sparse high-quality evidence about their long-term effects.The present study critically reviews the overall results of a microneurosurgical series of 57 paraclinoid aneurysms.Of these aneurysms, 47.4% were regular in size while 19.3 were giant. Barami type I was predominant. In 21 aneurysms a hemorrhagic onset occurred. Pterional approach with intradural anterior clinoidectomy was preferred by far. Clipping was possible in 91.2% of aneurysms and a high-flow bypass was the choice in five cases. An mRS of 0–2 was achieved in 77.3% of patients, typically <50 years old.Visual field appeared improved or unchanged in 36.3% and 63.6% of the symptomatic patients, respectively. In 76.1% of incidental aneurysms, campimetry was unaffected by surgery.A complete aneurysm exclusion was achieved in 93% of cases using a single procedure. No recurrences were documented on an average follow-up of 54.1 ± 34 months.Microneurosurgery is still a valuable, definitive, and durable option for Barami type Ia, Ib, or II paraclinoid aneurysm, especially in patients <50 years old and visually symptomatic. Conditions other than these are ideal candidates for FD stents.

Predictor of Visual Impairment Following Paraclinoid Aneurysm Surgery: Special Consideration of Surgical Microanatomy Related to Paraclinoid Structures

BACKGROUND Microsurgical clipping with extradural anterior clinoidectomy (EDAC) for paraclinoid aneurysm is an established technique with good angiographic outcomes, although postoperative worsening of visual acuity remains a concern. Multiple reports show visual acuity deteriorating after clipping, yet the cause remains unclear. OBJECTIVE To analyze results of asymptomatic paraclinoid aneurysm surgeries treated with EDACs, specifically focusing on the microanatomy of paraclinoid structure dissection. This determined the causes of delayed visual impairment and microsurgical indications. METHODS Results of the treatment with EDAC of 94 patients with cerebral aneurysm and normal preoperative visual acuity but also full visual fields were retrospectively analyzed. RESULTS The mean aneurysm size was 6.2 (±3.3) mm. Clipping was performed in 87 cases and trapping in 7 cases. Complete angiographic occlusion was observed in 91 patients. In 26 cases, a postoperative visual deficit occurred. A total of 20 cases exhibited partial visual field deficits, including 5 who were asymptomatic. Visual deficits were only detectable by postoperative ophthalmologic testing. Six showed light perception impairment or blinding. Of the 15 patients with symptomatic partial visual field deficits, 5 showed improvement at follow-up. Visual deficits persisted in 22 patients at the last follow-up. Multivariate logistic regression analysis revealed that medial projecting aneurysm (adjusted odds ratio [OR]: 10.43) and the opening of the carotidoculomotor membrane (adjusted OR: 5.19) were significantly related to visual impairment. CONCLUSION Excess dissection of carotidoculomotor membranes causes postoperative delayed visual worsening. For treating small, asymptomatic paraclinoid aneurysms, carotidoculomotor membranes should not be opened, and microsurgical clipping should not be performed for preoperative asymptomatic medial projecting aneurysms.