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.
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.
Because of the diversity of aneurysm morphology, complicated arterial anatomy and hemodynamic characteristics, tailored surgical treatments are required for cases of individual complex middle cerebral artery (MCA) aneurysms.
Methods During an 8-year period, 59 complex MCA aneurysms in 58 patients were treated microsurgically in our department. Complex aneurysms were defined as having large (10–24 mm in diameter) or giant (diameter≥25 mm) size or non-saccular morphology (fusiform, dissecting or serpentine).
Results Direct clipping of the aneurysmal necks was achieved in eight patients, while reconstructive clipping was performed in 25 patients. Indirect aneurysm occlusion was performed in 25 cases, including trapping or resecting the aneurysm in four cases, trapping or resecting the aneurysm with extraintracranial (EC) or intra-intracranial (IC) bypass in 21 cases and internal carotid artery (ICA) sacrifice with EC-IC bypass in one case. Forty-eight aneurysms (81.4 %) were completely obliterated. Graft patency was confirmed in 20 of 21 cases (95.2 %) with bypass. A recurrent aneurysm was detected in one case and a re-operation was performed. Two patients with Hunt-Hess grade IV aneurysms died during the perioperative period. Overall, 52 cases (88.1 %) had good outcomes (Glasgow Outcome Scale≥4) during the late follow-up period.
Conclusion The surgical modality and strategy for treating complex MCA aneurysm are decided according to the morphology of the aneurysm, vascular anatomy and the hemodynamic characteristics of each case. Thus, we developed a new classification based on the angioarchitecture. Favorable outcomes can be achieved by treating complex MCA aneurysms with appropriate surgical modalities, strategies and techniques.
Currently, there is an ongoing debate regarding the best treatment option for ruptured aneurysms. The International Subarachnoid Aneurysm Trial study suggests that an endovascular procedure is the best treatment. In some complex cases, or in patients with an additional large intracerebral hemorrhage, aneurysms require further microsurgical clipping.
OBJECTIVE:We introduce a new clip system to improve clipping procedures in especially complex aneurysms.
METHODS: The inverted opening mechanism of the clip in combination with the special clip applier provides the surgeon with a good overview in the operating field. The new design also enables a wider opening of the clip jaws in contrast to all other well-known titanium aneurysm clips. This should provide a better and safer application and decrease the danger of premature rupture.
RESULTS: From January 2006 to July 2008, 55 aneurysms were clipped in 45 patients. The most common aneurysm location was the anterior communicating artery (20 patients) followed by the M1 segment of the middle cerebral artery (16 patients). Four patients had 2, one had 3, and one had 5 aneurysms. Two clipping procedures were performed for an ateriovenous malformation-associated aneurysm. All aneurysms were clipped without any technical complication.
CONCLUSION: The use of the new clip system, especially in complex aneurysm surgery, has potential benefits because of the better surgical vision during clip application and the wider opening of the clip jaws. It is easy to handle and compatible with magnetic resonance imaging.
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