Endovascular Treatment Of Vertebrobasilar Dissecting Aneurysms

Part one:Efficacy and safety of Endovascular Treatment of Vertebrobasilar Dissecting AneurysmsObjective:Evaluate the efficacy and safety of endovascular strategies for vertebrobasilar dissecting aneurysms (VBDAs) through long-term follow-up. Analyze advantages and disadvantages of different endovascular strategies for the treatment of VBDAs.Methods:The study included 35 VBDA patients that underwent endovascular treatment between January 2007 and December 2013.The data of presenting symptoms, endovascular strategies, perioperative complications, and long-term postoperative clinical and angiographic follow-up of the patients were retrospectively analyzed.All the 35 patients had clinical symptoms and were confirmed by digital subtraction angiography (DSA) that accorded with the inclusion criteria. Different endovascular treatment was performed, including reconstructive techniques (preserving blood flow through the parent artery) and destructive techniques (involving sacrifice of the parent artery). Reconstructive techniques included stent-assisted coil embolization (20 patients) and placement of single or multiple overlapping stents (5 patients). Destructive technique referred to coil embolization combined with proximal coil trapping of the dissected segment of the parent artery (CE+PT,10 patients).After explaining the pros and cons of these three endovascular strategies to the patients and their family members in detail, different method was adopted according to the preoperative hemodynamic and their choices. Before operation, different antiplatelet aggregation methods were adopted according to various presenting symptoms and endovascular strategy. The effectiveness of the treatment was evaluated by the degree of occlusion, which was measured by Raymond scale. Modified Rankin scale (mRS) was used to evaluate the patients’clinical outcomes. Clinical and angiographic follow-up were performed in 1 month,3 months,6 months, 12 months and 24 months after the treatment, and review interval were adjusted according to perspective condition. The average follow-up time was 12.0 months, the mRS of the last time of follow-up was regarded as the final score. When there was a recurrence, retreatment was performed if necessary. The data of the patients’general information, immediate postoperative occlusion degree, perioperative complications, such as ischemia or rerupture, mRS score and the degree of occlusion of long-term follow-up were recorded.According to different endovascular strategies, the patients were divided into reconstructive group and destructive group; according to the presenting symptoms, the patients were divided into ruptured and non-ruptured groups. Related indicators of perioperative complications, mRS score and the occlusion degree of long-term follow-up were analyzed.Results:Of the 25 cases with ruptured VBDAs,14 underwent stent-assisted coil embolization,2 underwent multiple overlapping stents placement and 9 underwent CE +PT. Of the 14 patients with ruptured VBDAs underwent stent-assisted coil embolization,10 exhibited Raymond grade I complete occlusion,3 exhibited Raymond grade II occlusion and 1 exhibited Raymond grade III partial occlusion. The two patients with ruptured VBDAs underwent multiple over-lapping stents placement procedures exhibited Raymond grade III partial occlusion. Of the 9 patients that underwent CE+PT,6 patients exhibited Raymond grade I complete occlusion, two patients exhibited Raymond grade II occlusion and one patient exhibited Raymond grade III partial occlusion. The three patients with Raymond grade II and III occlusions had PICA involved VBDAs. Perioperative complications occurred in four cases (16.0%), including one aneurysm rupture and one parent artery thrombosis during the procedure and two incidences of brainstem ischemia after the procedure. Clinical outcome evaluations were performed using the modified Rankin scale and resulted in the following scores:0-2 for 22 patients (22/25,88.0%),3-6 for 3 patients (3/25,12.0%). No cerebral bleeding events or deaths occurred during the follow-up period.Of the 10 cases with unruptured VBDAs, six underwent stent-assisted coil embolization, three underwent single or multiple overlapping stents placement and one patient underwent CE+PT. All 10 of the patients with unruptured VBDAs had favorable clinical and radiologic outcomes without procedure-related complications.In the present study, perioperative complications occurred in only four cases (11.4%), and procedure-associated complications occurred in only one case (2.9%). The death rate associated with these complications was 5.7%. One aneurysm rupture and one parent artery thrombosis were happened in reconstructive group and two incidences of brainstem ischemia after the procedure were happened in destructive group. All the complications and deaths occurred in patients with ruptured VBDAs. The incidence of perioperative complications in reconstructive group was lower than in destructive group, there are statistical differences (P<0.001),but there were no significant differences in mRS scores at follow-up or long-term angiographic out-comes between these two groups. When compared with patients with unruptured VBDAs, procedure-associated complications and worse clinical outcomes have commonly been associated with patients with ruptured VBDAs. However, we found no significant differences in mRS scores at follow-up or long-term angiographic out-comes between the ruptured and non-ruptured groups (P>0.05).Also, there were no significant differences in procedure-associated complications,mRS scores at follow-up or long-term angiographic out-comes between different endovascular method (P>0.05).Conclusions:1. Endovascular treatment is effective and safe for VBDAs. For patients with ruptured VBDAs, the complication rate associated with endovascular treatment is acceptable. For unruptured VBDAs, endovascular treatment is associated with good clinical outcome without perioperative complication.2. The incidence of perioperative complication in reconstructive group is lower than destructive group.3. Stent-only therapy, especially with multiple stents, achieved satisfactory VBDA treatment outcome.Part two:Incidence and risk factors for recurrence after endovascular treatment of VBDAsObjective:Evaluate the incidence and risk factors for recurrence after endovascular treatment of VBDAs.Methods:The study included 35 VBDA patients that underwent endovascular treatment at the Department of Neurosurgery of the Second Hospital of Shandong University between January 2007 and December 2013.The data of general information, presenting symptoms, endovascular strategies, long-term postoperative clinical and angiographic follow-up of the patients were retrospectively analyzed.All the 35 patients had clinical symptoms and were confirmed by digital subtraction angiography (DSA) that accorded with the inclusion criteria. Different antiplatelet aggregation methods were adopted before treatment according to various presenting symptoms. Hemodynamic of each patient was analyzed by intra-arterial DSA, and then different endovascular treatment was performed, including reconstructive techniques (preserving blood flow through the parent artery) and destructive techniques (involving sacrifice of the parent artery). Reconstructive techniques included stent-assisted coil embolization (20 patients) and placement of single or multiple overlapping stents (5 patients). Destructive technique referred to coil embolization combined with proximal coil trapping of the dissected segment of the parent artery (CE+PT,10 patients).After explaining the pros and cons of these three endovascular strategies to the patients and their family members in detail, different method was adopted according to the preoperative hemodynamic and their choices. The effectiveness of the treatment was evaluated by the degree of occlusion, which was measured by Raymond scale. Modified Rankin scale (mRS) was used to evaluate patients’clinical outcomes. Clinical and angiographic follow-up were performed in 1 month,3 months,6 months, 12 months and 24 months after the treatment, and review interval were adjusted according to perspective condition. The average follow-up time was 12.0 months, the mRS of the last time of follow-up was regarded as the final score. When there was a recurrence, retreatment was performed if necessary.According to whether recurrence occurred, the patients were divided into recurrence group and no recurrence group. The data of the patients’age, sex, hypertension, smoking history, aneurysmal size, presenting symptoms, degree of embolization, GCS scores, aneurysmal localization and treatment methods were analyzed to evaluate the incidence and risk factors for recurrence after endovascular treatment of VBDAs.Results:There were 31 patients performed long-term angiographic follow-up, and the recurrence rate after endovascular VBDA treatment was 25.8%(8/31) in the present study, and they all occurred in reconstructive group. Among the 20 patients who underwent stent-assisted coil embolization, recurrence in the aneurysmal body occurred in 3 patients, and recurrence in the aneurysmal neck occurred in 4 cases. In 5 of these cases, recurrence occurred with complete embolization, and in 2 cases, recurrence occurred with partial embolization. Recurrence occurred in 1 case that underwent single stent placement. No recurrence occurred in patients that underwent CE+PT.4 cases underwent retreatment, of which 3 cases were totally embolized,1 case was subtotally embolized.T test and χ2 test showed that aneurysmal recurrence was not associated with patient age, sex, hypertension, smoking history, aneurysmal size, presenting symptoms, degree of embolization, GCS scores, aneurysmal localization or treatment methods (p> 0.05). Patients with aneurysms that involved the basilar artery (P=0.056) or reconstructive surgery (P=0.053) had a tendency toward a high incidence of recurrence.Conclusions:1. The high postoperative recurrent aneurysm risk suggests the necessity of long-term angiographic follow-up of VBDA patients who undergo endovascular treatments.2. Basilar artery involvement and reconstructive surgery were associated with a tendency toward a high incidence of recurrence.