Diagnostic reliability of the Berlin classification for complex MCA aneurysms—usability in a series of only giant aneurysms

Acta Neurochirurgica (2020) 162:2753–2758

The main challenge of bypass surgery of complex MCA aneurysms is not the selection of the bypass type but the initial decision-making of how to exclude the affected vessel segment from circulation. To this end, we have previously proposed a classification for complexMCA aneurysms based on the preoperative angiography. The current study aimed to validate this new classification and assess its diagnostic reliability using the giant aneurysm registry as an independent data set.

Methods We reviewed the pretreatment neuroimaging of 51 patients with giant (> 2.5 cm) MCA aneurysms from 18 centers, prospectively entered into the international giant aneurysm registry. We classified the aneurysms according to our previously proposed Berlin classification for complex MCA aneurysms. To test for interrater diagnostic reliability, the data set was reviewed by four independent observers.

Results We were able to classify all 51 aneurysms according to the Berlin classification for complex MCA aneurysms. Eight percent of the aneurysm were classified as type 1a, 14% as type 1b, 14% as type 2a, 24% as type 2b, 33% as type 2c, and 8% as type 3. The interrater reliability was moderate with Fleiss’s Kappa of 0.419.

Conclusion The recently published Berlin classification for complex MCA aneurysms showed diagnostic reliability, independent of the observer when applied to the MCA aneurysms of the international giant aneurysm registry.

Bypass surgery for complex middle cerebral artery aneurysms: an algorithmic approach to revascularization

J Neurosurg 127:463–479, 2017

Management of complex aneurysms of the middle cerebral artery (MCA) can be challenging. Lesions not amenable to endovascular techniques or direct clipping might require a bypass procedure with aneurysm obliteration. Various bypass techniques are available, but an algorithmic approach to classifying these lesions and determining the optimal bypass strategy has not been developed. The objective of this study was to propose a comprehensive and flexible algorithm based on MCA aneurysm location for selecting the best of multiple bypass options.

METHODS Aneurysms of the MCA that required bypass as part of treatment were identified from a large prospectively maintained database of vascular neurosurgeries. According to its location relative to the bifurcation, each aneurysm was classified as a prebifurcation, bifurcation, or postbifurcation aneurysm.

RESULTS Between 1998 and 2015, 30 patients were treated for 30 complex MCA aneurysms in 8 (27%) prebifurcation, 5 (17%) bifurcation, and 17 (56%) postbifurcation locations. Bypasses included 8 superficial temporal artery–MCA bypasses, 4 high-flow extracranial-to-intracranial (EC-IC) bypasses, 13 IC-IC bypasses (6 reanastomoses, 3 reimplantations, 3 interpositional grafts, and 1 in situ bypass), and 5 combination bypasses. The bypass strategy for prebifurcation aneurysms was determined by the involvement of lenticulostriate arteries, whereas the bypass strategy for bifurcation aneurysms was determined by rupture status. The location of the MCA aneurysm in the candelabra (Sylvian, insular, or opercular) determined the bypass strategy for postbifurcation aneurysms. No deaths that resulted from surgery were found, bypass patency was 90%, and the condition of 90% of the patients was improved or unchanged at the most recent follow-up.

CONCLUSIONS The bypass strategy used for an MCA aneurysm depends on the aneurysm location, lenticulostriate anatomy, and rupture status. A uniform bypass strategy for all MCA aneurysms does not exist, but the algorithm proposed here might guide selection of the optimal EC-IC or IC-IC bypass technique.

Management of complex intracranial aneurysms with bypass surgery


Complex aneurysms bypass surgery_93 patients

Neurosurg Rev (2015) 38:109–120

Despite advances in microsurgery and the development of new endovascular techniques, the treatment of complex intracranial aneurysms remains a daunting challenge for neurosurgeons. In the present study, we retrospectively reviewed our experience of bypass surgery in the treatment of 93 cases of complex intracranial aneurysms.

A series of 93 consecutive cases of complex intracranial aneurysms were treated with bypass surgery between April 2004 and July 2013. Radial artery (RA) grafts were used in 58 cases, saphenous vein (SV) grafts in 16 cases, and occipital artery (OA) grafts in 6 cases, while the remaining 13 cases were managed with superficial temporal artery (STA) grafts. In this series, the aneurysms were excised after trapping in 32 cases with mass effect and neural compression. Proximal occlusion of the parent artery was performed in 22 cases of fusiform or giant dissecting aneurysms with subsequent retrograde flow to avoid compromise of the perforators nearby. Trapping was performed after bypass surgery in the remaining 39 cases. Postoperative angiographies were performed in 91 patients and patency of the bypass graft and obliteration of the aneurysms were confirmed in 89 patients. Patency of the bypass could not be confirmed in the remaining two patients, of which one presented with cerebral infarction due to graft occlusion, and the other remained asymptomatic. Within 1 month after surgery, 88 patients had good outcome, four patients needed assistance for daily living, and one death occurred due to brainstem infarction. In 77 patients with a mean follow-up of 3.0 years, 72 patients had good outcome, 4 patients needed assistance for daily living, and 1 death occurred unrelated to surgery.

Complex intracranial aneurysms present unique therapeutic challenges that require thorough surgical planning, individualized treatment strategies, and refined neurovascular techniques for successful outcome. Proper use of bypass surgery is imperative in preserving the parent artery and its major perforators. The internal maxillary artery, used as a donor in a bypass, is an effective method due to its shorter distance from the recipient vessels and relatively large diameter with resulting higher flow rate.

Bypass surgery for complex middle cerebral artery aneurysms

By-pass surgery in MCAA

J Neurosurg 120:398–408, 2014

The object of this study was to describe the authors’ institutional experience in the treatment of complex middle cerebral artery (MCA) aneurysms necessitating bypass and vessel sacrifice.

Methods. Cases in which patients with MCA aneurysms were treated with a combination of bypass and parent artery sacrifice were reviewed retrospectively.

Results. The authors identified 24 patients (mean age 46 years) who were treated with bypass and parent artery sacrifice. The aneurysms were located in the M1 segment in 7 patients, MCA bifurcation in 8, and more distally in 9. The mean aneurysm diameter was 30 mm (range 7–60 mm, median 26 mm). There were 8 saccular and 16 fusiform aneurysms. Twenty-one extracranial-intracranial and 4 intracranial-intracranial bypasses were performed. Partial or total trapping (only) of the parent artery was performed in 17 cases, trapping with resection of aneurysm in 3, and aneurysm clipping with sacrifice of an M2 branch in 4. The mean follow-up period was 27 months. The aneurysm obliteration rate was 100%. No recanalization of the aneurysms was detected during follow-up. There was 1 perioperative death (4% mortality rate) and 6 cerebrovascular accidents, causing permanent morbidity in 5 patients. The median modified Rankin Scale score of patients with an M1 aneurysm increased from 0 preoperatively to 2 at latest follow-up, while the score was unchanged in other patients. Most of the permanent deficits were associated with M1 aneurysms. Twenty-one patients (88%) had good outcome as defined by a Glasgow Outcome Scale score of 4 or 5.

Conclusions. Bypass in combination with parent vessel occlusion is a useful technique with acceptable frequencies of morbidity and mortality for complex MCA aneurysms when conventional surgical or endovascular techniques are not feasible. The location of the aneurysm should be considered when planning the type of bypass and the site of vessel occlusion. Flow alteration by partial trapping may be preferable to total trapping for the M1 aneurysms.

Anatomy and morphology of giant aneurysms

Giant aneurysms

Acta Neurochir (2014) 156:1–10

Giant intracranial aneurysms are rare and heterogeneous lesions with complex vascular anatomy. The aim of this retrospective study was to provide a comprehensive description of the anatomical features of giant aneurysms.

Methods We identified 125 patients with 129 giant aneurysms (≥25 mm) who were treated between 1987 and 2007 at the Department of Neurosurgery of Helsinki University Central Hospital (HUCH). All the imaging studies and medical records were reviewed for relevant information.

Results The distribution of the giant aneurysms among regions was as follows: internal carotid artery (ICA) 39 %, middle cerebral artery (MCA) 32 %, vertebrobasilar and posterior cerebral artery (VB-PCA) region 25 %, and anterior cerebral artery (ACA) including the anterior communicating artery 5%. The cavernous ICA segment (n =21, 16 %) and the MCA bifurcation (n =25, 19 %) were the most frequent specific locations. Half (n =11) of all fusiform aneurysms were found in the VB-PCA region. As many as 41 % of the giant MCA aneurysms were ruptured. Major anatomic variations were found in three (2 %) and multiple giant aneurysms in three (2 %) patients.Wall calcification was noted in 24 % and intraluminal thrombosis in 33 % of ruptured giant aneurysms (n =42).

Conclusions The majority of giant aneurysms are located in the ICA and MCA regions, while the ACA region is an exceptional site. The MCA region is the most common site for ruptured giant aneurysms. Associated anatomic variations and the multiplicity of giant aneurysms are a rare finding.

Visual outcomes for surgical treatment of large and giant carotid ophthalmic segment aneurysms

Vision after aneurysm clipping with suction decompression

J Neurosurg 118:937–946, 2013

The authors report their results in a series of large or giant carotid ophthalmic segment aneurysms clipped using retrograde suction decompression.

Methods. A retrospective review of clinical data and treatment summaries was performed for 18 patients with large or giant carotid artery ophthalmic segment aneurysms managed operatively via retrograde suction decompression. Visual outcomes, Glasgow Outcome Scale (GOS) scores, and operative complications were determined. Postoperative angiography was assessed.

Results. During a 17-year period, 18 patients underwent surgery performed using retrograde suction decompression. The mean aneurysm size was 26 mm. Three patients presented with subarachnoid hemorrhage. Fourteen of 18 patients presented with visual symptoms. Eleven (79%) of these 14 patients experienced visual improvement and the remaining 3 (21%) experienced worsened vision after surgery. Of 3 patients without visual symptoms and a complete visual examination before and after surgery, 1 had visual worsening postoperatively. One aneurysm required trapping and bypass, and all others could be clipped. Postoperative angiography demonstrated complete occlusion in 9 of 17 clipped aneurysms and neck remnants in the other 8 clipped aneurysms. One (5.5%) of 18 patients experienced a stroke. Eighteen patients had a GOS score of 5 (good outcome), and 1 patient had a GOS score of 4 (moderately disabled). There were no deaths. There was no morbidity related to the second incision or decompression procedure. Prolonged improvement did occur, and even in some cases of visual worsening in 1 eye, the overall vision did improve enough to allow driving.

Conclusions. Retrograde suction decompression greatly facilitates surgical clipping for large and giant aneurysms of the ophthalmic segment. Visual preservation and improvement occur in the majority of these cases and is an important outcome measure. Developing endovascular technology must show equivalence or superiority to surgery for this specific outcome.

Giant Intracranial Aneurysms: Evolution of Management in a Contemporary Surgical Series

Neurosurgery 69:1261–1271, 2011 DOI: 10.1227/NEU.0b013e31822bb8a6

Many significant microsurgical series of patients with giant aneurysms predate changes in practice during the endovascular era.

OBJECTIVE: A contemporary surgical experience is presented to examine changes in management relative to earlier reports, to establish the role of open microsurgery in the management strategy, and to quantify results for comparison with evolving endovascular therapies.

METHODS: During a 13-year period, 140 patients with 141 giant aneurysms were treated surgically. One hundred aneurysms (71%) were located in the anterior circulation, and 41 aneurysms were located in the posterior circulation.

RESULTS: One hundred eight aneurysms (77%) were completely occluded, 14 aneurysms (10%) had minimal residual aneurysm, and 16 aneurysms (11%) were incompletely occluded with reversed or diminished flow. Three patients with calcified aneurysms were coiled after unsuccessful clipping attempts. Eighteen patients died in the perioperative period (surgical mortality, 13%). Bypass-related complications resulted from bypass occlusion (7 patients), aneurysm hemorrhage due to incomplete aneurysm occlusion (4 patients), or aneurysm thrombosis with perforator or branch artery occlusion (4 patients). Thirteen patients were worse at late follow-up (permanent neurological morbidity, 9%; mean length of follow-up, 23 6 1.9 months). Overall, good outcomes (Glasgow Outcome Score 5 or 4) were observed in 114 patients (81%), and 109 patients (78%) were improved or unchanged after therapy.

CONCLUSION: A heavy reliance on bypass techniques plus indirect giant aneurysm occlusion distinguishes this contemporary surgical experience from earlier ones, and obviates the need for hypothermic circulatory arrest. Experienced neurosurgeons can achieve excellent results with surgery as the ‘‘first-line’’ management approach and endovascular techniques as adjuncts to surgery.