Endovascular treatment for saccular aneurysms of the proximal (M1) segment of the middle cerebral artery

Feasibility, Safety, and efficacy of endovascular treatment for M1 hilltop Aneurysms: A retrospective study

OBJECTIVE

This retrospective study aimed to evaluate the feasibility, safety, and efficacy of endovascular treatment (EVT) for M1 hilltop aneurysms, a specific M1 segment subtype located at the highest point of the middle cerebral artery (MCA).

METHODS

The study included 54 patients with M1 hilltop aneurysms who underwent EVT between December 2017 and [end date]. Treatment decisions were based on angiographic findings and patient characteristics. Clinical and radiological data were reviewed, and outcomes were assessed using the Raymond-Roy classification (RRC) and modified Rankin Scale (mRS). Follow-up radiological examinations were conducted at specific intervals.

RESULTS

EVT was successful in all 54 cases. Immediate postprocedural angiograms showed favorable occlusion (RRC I or II) in 59.3% and aneurysm remnants (RRC III) in 40.7%. Procedure-related complications occurred in 7.4% of patients, including thromboembolism and ICA dissection, with no permanent neurological impairment. During a mean 18.2-month follow-up, no neurological deterioration or aneurysmal rupture occurred. Most patients showed stable/improved occlusion on follow-up imaging, with a 14% recurrence rate. Retreatment was required in 2% of cases.

CONCLUSIONS

EVT appears feasible, safe, and effective for treating M1 hilltop aneurysms. It resulted in favorable occlusion and low recurrence/retreatment rates. Neck diameter and stent usage influenced immediate outcomes and recurrence. Larger studies with longer follow-ups are needed to validate these findings further.

Prognostic nomogram for predicting lower extremity deep venous thrombosis in ruptured intracranial aneurysm patients who underwent endovascular treatment

Background

Lower extremity deep vein thrombosis (DVT) is one of the major postoperative complications in patients with ruptured intracranial aneurysms (RIA) who underwent endovascular treatment (EVT). However, patient-specific predictive models are still lacking. This study aimed to construct and validate a nomogram model for estimating the risk of lower extremity DVT for RIA patients who underwent EVT.

Methods

This cohort study enrolled 471 RIA patients who received EVT in our institution between 1 January 2020 to 4 February 2022. Perioperative information on participants is collected to develop and validate a nomogram for predicting lower extremity DVT in RIA patients after EVT. Predictive accuracy, discriminatory capability, and clinical effectiveness were evaluated by concordance index (C-index), calibration curves, and decision curve analysis.

Result

Multivariate logistic regression analysis showed that age, albumin, D-dimer, GCS score, middle cerebral artery aneurysm, and delayed cerebral ischemia were independent predictors for lower extremity DVT. The nomogram for assessing individual risk of lower extremity DVT indicated good predictive accuracy in the primary cohort (c-index, 0.92) and the validation cohort (c-index, 0.85), with a wide threshold probability range (4-82%) and superior net benefit.

Conclusion

The present study provided a reliable and convenient nomogram model developed with six optimal predictors to assess postoperative lower extremity DVT in RIA patients, which may benefit to strengthen the awareness of lower extremity DVT control and supply appropriate resources to forecast patients at high risk of RIA-related lower extremity DVT.

Distal stenting technique for coil embolization of early branch aneurysms of middle cerebral artery

BACKGROUND AND PURPOSE

Stent-assisted coil embolization of early branch aneurysms of the middle cerebral artery (MCA) can sometimes be challenging due to the small diameter and acute angle of the branches. This study aimed to analyze the treatment results and report the feasibility and outcomes of the distal stenting technique for these aneurysms.

MATERIALS AND METHODS

The distal stenting technique was used for 15 wide-neck MCA aneurysms (females, 10; males, 5; mean age, 65.1 years) originating from the early branch between December 2018 and October 2021. The average sizes of the dome, depth, and neck of the aneurysms were 4.17 mm (range: 2.99-6.21 mm), 2.86 mm (range: 1.82-3.72 mm), and 3.42 mm (range: 2.44-4.32 mm), respectively.

RESULTS

The average diameter of the stents was 4.0 mm (3.0 mm, 3; 4.0 mm, 6; 4.5 mm, 6). Stents were successfully deployed in all 15 aneurysms (100%). The average length of the procedure was 69 min (range: 45-117 min). On postoperative angiography, nine (60.0%) aneurysms were completely occluded, four (26.7%) had neck remnants, and two (13.3%) had contrast flow in the sac. During the procedure, vasospasm and thrombus formation occurred in one case each, but no neurological sequelae were observed. On follow-up digital subtraction angiography of the 10 aneurysms after an average of 13.7 months (range: 12-18 months), the branches were well preserved, and neck remnants were noted in four aneurysms (40.0%). No thromboembolic events occurred during the clinical follow-up.

CONCLUSION

The distal stenting technique using an open-cell stent can be a good option for coil embolization of early branch MCA aneurysms.

Anterior perforated substance region aneurysms: review of a series treated with microsurgical technique

Aneurysms arising from the distal carotid, proximal A1, and proximal M1 that project posteriorly and superiorly toward the anterior perforated substance (APS) are rare. Their open surgical treatment is particularly difficult due to poorly visualized origin of the aneurysm and the abundance of surrounding perforators. We sought to analyze the anatomical and clinical characteristics of APS aneurysms and discuss surgical nuances that can optimize visualization, complete neck clip obliteration, and preservation of adjacent perforators. Thirty-two patients with 36 APS aneurysms were surgically treated between November 2000 and September 2017. Patients were prospectively enrolled in a cerebral aneurysm database and their clinical, imaging, and surgical records were retrospectively reviewed. Twenty-seven aneurysms originated from the distal ICA, 7 from the proximal A1, and 2 from the proximal M1; 15 patients presented with subarachnoid hemorrhage. Careful intraoperative dissection revealed 4 aneurysms originating at the takeoff of a perforator; another 25 had at least 1 adherent perforator. All aneurysms were clipped except for one that was trapped. Postoperatively, 3 patients had radiographic infarctions in perforator territory with only 1 developing delayed clinical hemiparesis. Good outcome (modified Rankin Scale, 0-2) was achieved in 28 patients (88%). APS aneurysms present a challenging subset of aneurysms due to their complex anatomical relationship with surrounding perforators. These should be identified on preoperative imaging based on location and projection. Successful microsurgical clipping relies on optimization of the surgical view, meticulous clip reconstruction, preservation of all perforators, and electrophysiological monitoring to minimize ischemic complication.

Endovascular Treatment for Middle Cerebral Artery Aneurysms: Single-Center Experience and Review of Literatures

Objective

The efficacy of endovascular treatment for middle cerebral artery (MCA) aneurysms remains controversial. However, recent studies have reported the safety of endovascular treatment for MCA aneurysms. In this study, we studied the efficacy and clinical outcomes of endovascular treatment for MCA aneurysms in our hospital and the morphology and anatomy of MCA aneurysms that were suitable for endovascular treatment.

Methods

We retrospectively analyzed 26 cases of MCA aneurysms which had undergone endovascular treatment at our institution between January 2015 and October 2018. We studied sizes and shapes of the aneurysms, clinical and angiographical outcomes one year after the treatment, and complications in these 26 patients. We also compared the differences in these parameters of the 26 patients with those of 61 other patients who were treated with clipping during the same period.

Results

The median aneurysm size was 6.1 mm (1.8-29.9 mm), with the shapes of the aneurysms irregular in 8, and round in the other 18 cases. Four cases (15.4%) had ruptured aneurysms. All aneurysms were treated with assist techniques; 8 (30.8%) were treated by stent-assisted technique and 18 (69.2%) were treated by balloon-assisted technique and endovascular treatment was successfully performed in all (100%) cases. While the aneurysms were completely obliterated in 22 of them (84.6%), the remaining 4 cases (15.4%) had neck remnants. We observed periprocedural complications in 5 of the 26 (19.2%) aneurysms, all of which were transient and completely recovered during the follow-up period. The efficacy and complication rates were not different from the MCA aneurysms treated with clipping. All MCA aneurysms arising from the M1 trunk were treated with endovascular treatment, and those with a round shape with the axis not deviating from M1 were also treated with endovascular treatment.

Conclusion

Endovascular treatment for MCA aneurysms is safe and effective together with adjunctive techniques such as balloon-assisted technique or stent-assisted technique. Thus, M1 trunk aneurysms and MCA bifurcation aneurysms with a round shape along the same axis of MCA may be good indications for endovascular treatment. However, long-term clinical and angiographical outcomes remain unknown. Thus, further studies are needed to address the existing limitations.

Proximal Middle Cerebral Artery Aneurysms: Microsurgical Management and Therapeutic Results

BACKGROUND

Management of proximal (M1) middle cerebral artery (MCA) aneurysms can be challenging. Because of the diversity of aneurysm morphology and location of M1 aneurysms, the surgical strategy should be tailored to each individual case, especially for complex cases. We assessed the safety and efficacy of an algorithmic strategy for the management of M1 aneurysms.

METHODS

A prospective single-center study of M1 aneurysms treated with microsurgery was performed. Our algorithmic strategy was determined by the location and complexity (e.g., size, shape) of the aneurysms. The surgical modalities included neck clipping, aneurysm resection and/or trapping, and proximal occlusion with revascularization. The clinical and radiographic data were analyzed.

RESULTS

From January 2007 to March 2017, 92 proximal MCA aneurysms in 92 patients were treated microsurgically. Aneurysm treatment techniques included clipping in 55, proximal occlusion in 21, aneurysm resection in 11, and trapping in 4. Bypass techniques included 2 anterior temporal artery reconstructions, 5 middle cerebral bifurcation reconstructions, 4 parent artery reanastomoses, 2 interpositional bypasses, 25 high-flow bypasses, and 7 medium-flow bypasses. Overall, good outcomes (modified Rankin scale score, 0-2) were seen in 49 of 92 patients (53.3%) at discharge and in 79 of 91 (86.8%) at the last follow-up visit. On the latest angiogram, 78 of 90 aneurysms (86.7%) had been completely occluded without a remnant. Bypass patency was confirmed in 38 of 43 bypass procedures.

CONCLUSIONS

Our present treating strategy might provide a benefit for patients with proximal MCA aneurysms.

Management of Unruptured Saccular Aneurysms of the M1 Segment with Flow Diversion : A Single Centre Experience

PURPOSE

The optimal strategy for the treatment of M1 segment aneurysms has not yet been determined as both standard microneurosurgical and endovascular techniques can pose challenges. We sought to determine the efficacy of flow diverting stents to treat small, unruptured aneurysms of the M1 segment.

METHODS

We retrospectively reviewed our database of prospectively collected information for all patients treated with flow diversion for an unruptured saccular aneurysm of the middle cerebral artery (MCA) between February 2009 and February 2016. The relationship to early cortical branches, aneurysm fundus size, number and type of flow diverting stent (FDS), complications and follow-up data were recorded.

RESULTS

In total 15 patients were identified that matched our inclusion criteria (11 female and 4 male). The average age of the patients was 58.3 years (range 14-76 years). All patients had a single aneurysm affecting the M1 segment of the MCA, 10 (66.6%) of which were related to early cortical branches and 10 aneurysms were located on the left (66.6%). The average aneurysm fundus size was 3 mm (range 2-9 mm) and 13 patients had follow-up angiographic studies. In total, 8 aneurysms were completely excluded, and 6 remained incompletely occluded (3 modified Raymond-Roy classification [mRRC] II and 3 mRRC IIIa). One patient suffered a stroke and another patient had an iatrogenic vessel dissection that was not flow limiting.

CONCLUSION

Flow diversion can be used to treat small, unruptured aneurysms of the M1 segment of the MCA and even though side vessel occlusion can occur clinically relevant infarction occurs infrequently.

Endovascular Treatment of Middle Cerebral Artery Aneurysm with the LVIS Junior Stent

BACKGROUND

Middle cerebral artery (MCA) aneurysms often occur in small parent vessels and are incorporated with the orifice of acute-angled efferent branch vessels. Endovascular treatment for these aneurysms remains technically challenging. This study aimed to assess the clinical safety and efficacy of the Low-profile Visualized Intraluminal Support Junior (LVIS Jr) stent for embolization of MCA aneurysms.

METHODS

Eighteen intracranial aneurysms, including 13 unruptured and 5 ruptured aneurysms, were treated with LVIS Jr stent-assisted coil embolization. The clinical data and technical results are presented.

RESULTS

A total of 18 stents were successfully delivered to the target aneurysms, and the technical success rate was 100%. There was complete occlusion in 8 (44.4%) of 18 cases, neck remnants in 7 (38.9%) cases, and partial occlusion in 3 (16.7%) cases. In-stent thrombosis occurred in 1 case, and the symptoms disappeared after transvenous tirofiban injection. The modified Rankin Scale score at discharge was 0 in 14 patients, 1 in 3 patients, and 2 in 1 patient.

CONCLUSIONS

The LVIS Jr stent provided excellent trackability and deliverability and is safe and effective for the treatment of wide-necked MCA aneurysms with tortuous and smaller parent vessels.

Endovascular coil embolization of middle cerebral artery aneurysms of the proximal (M1) segment

INTRODUCTION

Proximal middle cerebral artery (M1 segment) aneurysms have various configurations and are distinct from middle cerebral artery bifurcation aneurysms. We present the clinical and radiological results of coil embolization of the M1 segment aneurysms.

METHODS

From a prospective database, we retrieved the data for 59 consecutive patients harboring 60 M1 aneurysms that were treated with endovascular coil embolization from January 2006 to May 2012. We assessed the clinical outcomes of the patients and morphological outcomes of the aneurysms using the Raymond classification.

RESULTS

The aneurysms were located on the superior wall of the M1 segment in 43 and on the inferior wall in 17. Superior-wall aneurysms were related to the frontal cortical artery and the lateral lenticulostriate perforator while inferior-wall aneurysms were to the temporal cortical artery. With coil embolization, complete aneurysmal occlusion or residual neck could be achieved in 52 aneurysms (86.7 %) and residual aneurysm in 8. The microcatheter protection technique was most commonly used for coil embolization (41.7 %) followed by single microcatheter (31.7 %), double microcatheter (23.3 %), and stent protection (3.3 %). There was no procedure-related morbidity or mortality. Follow-up angiography more than 6 months after embolization (n = 46; mean 12.4 months) demonstrated stable occlusion in 40 (87.0 %), minor recanalization in 4 (8.7 %), and major recanalization in 2 (4.3 %). One patient experienced delayed cerebral infarction without permanent neurologic deficit.

CONCLUSION

Coil embolization in M1 aneurysms seems to be safe and efficacious, although it may require various technical strategies due to distinct anatomic configurations.