Optimal pediatric dosing of anti-platelet agents for pipeline stent embolization -a case report and review of the literature.

BACKGROUND: Various strategies are emerging for dosing antiplatelet therapies in preparation for pipeline stent embolization in adults. Hyper-response is associated with hemorrhagic complications. Hypo-response is associated with thromboembolic events. Dosing of antiplatelet agents is highly variable, with little consensus among experts for adults-and even more so for children. To date, pipeline stents have been deployed in 11 pediatric patients, ages 4-15. A variety of clopidogrel and aspirin dosing regimens have been used, with response tested in only three patients, who were all therapeutic. Thrombotic events occurred in two patients, neither of whom were tested. CASE: We describe here the first case of a hemorrhagic complication in a hyper-responsive pediatric patient undergoing placement of a pipeline stent. DISCUSSION: As the use of endovascular therapies requiring dual anti-platelet agents becomes more established, there is an increasing need to develop titration protocols that minimizes the risk of thrombotic and hemorrhagic events.

Intra-aneurysmal thrombus modification after flow-diversion.

Flow diversion has been successfully used to treat large and giant intracranial aneurysms that present with mass effect. We conducted a retrospective review, evaluating the modification of thrombi in this aneurysm type after treatment with the Pipeline Embolization Device (ev3 Endovascular, Plymouth, MN, USA) and the effects of these modifications on symptoms. Eight patients, seven of whom were female, harbored eight partially thrombosed large or giant aneurysms. Five of the eight aneurysms presented with symptomatic mass effect. At 1 year follow-up, complete occlusion occurred in 75% (6/8) of patients. On average, the longest thrombus diameter measured 22.31 mm before treatment and 14.05 mm 1 year afterwards. Seven of the eight thrombi regressed, as did their aneurysms. All six patients with shrunken thrombi had tremendous symptom improvement and became asymptomatic in the following year. The current findings seem to reflect the size variation of the intra-aneurysmal thrombus rather than the size of the aneurysm itself.

Saving the ischemic penumbra: endovascular thrombolysis versus medical treatment.

Endovascular thrombolysis may allow rapid arterial recanalization in patients with acute ischemic stroke. We present the first study to our knowledge comparing the ischemic penumbra saved with endovascular versus medical therapy. A retrospective review of 21 patients undergoing endovascular intervention for stroke from 2010 to 2011 was contrasted with 21 consecutive patients treated with antiplatelet agents alone. Immediate computed tomography perfusion (CTP) scan of the head and neck was obtained in all patients. Patients with lacunar and posterior circulation infarcts, and those who were medically unstable for MRI post-operatively were excluded. CTP and MRI underwent volumetric calculation. CTP penumbra was correlated with diffusion restriction volumes on MRI, and an assessment was made on the volume of ischemic burden saved with either endovascular treatment or antiplatelet agents. The median age was 70 years (interquartile range 62-80). Median National Institutes of Health Stroke Scale score was 18 and 14 in the control and endovascular groups, respectively. Intravenous tissue plasminogen activator was administered in 22 of 42 patients (52%). Median penumbra calculated was 32,808 mm(3) in the control group and 46,255 mm(3) in the endovascular group. Median penumbra spared was 9550 mm(3) (4980-18,811) in the control group versus 38,155 mm(3) in the endovascular group (p=0.0001). Endovascular thrombolysis may be more efficient than medical therapy alone in saving ischemic penumbra. Future advances in recanalization techniques will further improve the efficacy of endovascular therapy.

Microsurgical clipping of large and giant cerebral aneurysms: a single-center contemporary experience.

Several treatment strategies are available to manage large and giant cerebral aneurysms, including surgical, endovascular and combined approaches. We present our experience with microsurgical clipping of large and giant aneurysms. A total of 138 patients with 139 aneurysms of which 128 were large (≥10mm) and 11 were giant (≥25mm) were treated at our institution between 2004 and 2011. Data were collected from a prospectively maintained neurovascular database. Of 138 patients, 53 (38.4%) patients presented with subarachnoid hemorrhage (SAH). Peri-operative complications occurred in 16.7% of patients causing permanent morbidity in 4.4% and death in 0.7%. Complete occlusion, as evident on intra-operative angiography, was achieved in all clipped aneurysms (100%). Long-term follow-up angiography showed no recurrence (mean follow-up time, 43.9 months; range: 1-72 months). Favorable outcomes at discharge (Glasgow Outcome Scale score 4 or 5) were noted in 64.1% of SAH patients and 93% of non-SAH patients. Favorable outcomes at follow-up (mean follow up time, 42.5 months) were seen in 96% of patients. In our experience, microsurgical clipping of large and giant aneurysms carries low rates of morbidity and mortality with high rates of favorable outcomes. The excellent durability of surgical treatment stands in stark contrast with the high recurrence rates observed with coiling for this subset of aneurysms. These data suggest that microsurgical clipping continues to be a viable option that can be offered for patients with large and giant aneurysms.

Aneurysm geometry in predicting the risk of rupture. A review of the literature.

The management of unruptured aneurysms (UAs), whose incidence is increasing, is still a controversial issue. Many studies have been investigating the link between the geometry of the aneurysm and the risk of future rupture in order to bring forth a clear decision plan. The different estimators studied are the aneurysm's geometry and hemodynamic features on one hand, and the patient's clinical characteristics on the other. We reviewed the literature while focusing on the different geometrical parameters that have been used in estimating the future risk of rupture. These include mainly the size ratio (SR), the aspect ratio, the non-sphericity index (NI), the undulation index (UI), and the vessel aneurysm inclination angle (AA), to name a few.

Stereotactic radiosurgery with neoadjuvant embolization of larger arteriovenous malformations: an institutional experience.

OBJECTIVE: This study investigates the safety and efficacy of a multimodality approach combining staged endovascular embolizations with subsequent SRS for the management of larger AVMs. METHODS: Ninety-five patients with larger AVMs were treated with staged endovascular embolization followed by SRS between 1996 and 2011. RESULTS: The median volume of AVM in this series was 28 cm(3) and 47 patients (48%) were Spetzler-Martin grade IV or V. Twenty-seven patients initially presented with hemorrhage. Sixty-one patients underwent multiple embolizations while a single SRS session was performed in 64 patients. The median follow-up after SRS session was 32 months (range 9-136 months). Overall procedural complications occurred in 14 patients. There were 13 minor neurologic complications and 1 major complication (due to embolization) while four patients had posttreatment hemorrhage. Thirty-eight patients (40%) were cured radiographically. The postradiosurgery actuarial rate of obliteration was 45% at 5 years, 56% at 7 years, and 63% at 10 years. In multivariate analysis, larger AVM size, deep venous drainage, and the increasing number of embolization/SRS sessions were negative predictors of obliteration. The number of embolizations correlated positively with the number of stereotactic radiosurgeries (P < 0.005). CONCLUSIONS: Multimodality endovascular and radiosurgical approach is an efficacious treatment strategy for large AVM.

Endovascular treatment of carotid cavernous aneurysms: complications, outcomes and comparison of interventional strategies.

The best treatment modality for cavernous carotid aneurysms (CCA) remains unclear. We treated 82 CCA in 79 patients with endovascular coiling (n=14), stent assistance (n=53), and carotid vessel deconstruction (CVD) (n=15). Favorable outcomes were defined as a Glasgow Outcome Scale of 4 to 5 without worsening signs or symptoms. Mean CCA size was 13.3±9.2 mm, and CCA treated with CVD were larger (p=0.010). Fourteen patients had incidental CCA, 40 (50.6%) had cranial nerve palsies (CNP), and 25 (31.7%) had pain leading to diagnosis. Immediate occlusion (>95%) occurred in 91.5% of aneurysms. Ischemic or hemorrhagic complications developed following eight treatments (9.8%) and three were permanent (3.7%). There were no deaths, and favorable discharge outcome occurred following 87.8% of procedures. Although there was no difference in immediate occlusion or complications amongst treatment cohorts, fewer permanent complications (0% versus 10.3%, p=0.041) and favorable discharge outcomes (p=0.039) were associated with stent assisted treatment. Follow-up was available following 75 procedures (mean 21.4±17.4 months). Recanalization occurred in 36% of patients and retreatment in 25%. Patients presenting with CNP improved over time (p<0.001); 54% of patients presenting with CNP remained unchanged while 46% improved; there was no difference in improvement rates stratified by treatment. Favorable follow-up outcome occurred after 96% of treatments and those receiving stents were more likely to have favorable outcome in multivariate analysis (p=0.039). Endovascular therapy is a safe and effective therapy for CCA. When possible, stent assisted therapy may be the best option with fewer complications and low recanalization rates.

Short-term outcome for saccular cerebral aneurysms treated with the Orbit Galaxy Detachable Coil System.

Technological advancement within the field of neuroendovascular therapy may lead to safer and more robust treatment options for patients with lesions traditionally not favorable to coil occlusion. We analyze and report our outcomes with the Orbit Galaxy Detachable Coil System (DePuy Synthes, West Chester, PA, USA) for the treatment of anterior and posterior circulation saccular cerebral aneurysms. Patients treated with Orbit Galaxy coils for primary or recurrent saccular cerebral aneurysms from October 2010 to July 2012 were retrospectively reviewed using medical records, operative reports, and radiographs. Ninety-three patients, 69% unruptured and 31% ruptured, were treated with Orbit Galaxy coils for their anterior (80%) or posterior (20%) circulation saccular cerebral aneurysm. Primary treatment with Orbit Galaxy coils occurred in 84% of patients with an initial 100% occlusion rate of 65% while 16% had Galaxy coils placed into a "secondary" recurrent lesion. The overall incidence of recurrence was 26% with a mean interval of 7 months. Retreatment for recurrence was needed in 20 patients (22%). The mortality rate was 0%. A 2% incidence of rebleed was observed; each was after a secondary treatment. The morbidity of the treatment was low with 1% having a modified Rankin score greater than 3. Primary endovascular treatment of saccular cerebral aneurysms of the anterior and posterior circulation with the Orbit Galaxy Detachable Coil System is safe and effective in the short term.

An extreme case of the syndrome of the trephined requiring the use of a novel titanium plate.

INTRODUCTION: Patients with large cranial defects can manifest a secondary neurological deterioration known as the "syndrome of the trephined." CASE REPORT: This is the case of a 66-year-old female with a left-sided acute subdural hematoma, treated with decompressive craniectomy. Six months later, a cranioplasty was performed. However, it was complicated by an infection requiring removal of the bone plate. A week later, the patient became comatose; her craniectomy flap was sunken. After ruling out all other possible disorders, we suspected an extreme syndrome of the trephined. The patient's neurological status drastically improved after she was placed on a Trendelenburg position regiment. A second cranioplasty was performed only 3 months after the infection using a novel custom designed titanium mesh, the least porous material used in synthetic bone flaps, to decrease the risk of infection. The patient had an excellent recovery; at her 6-month follow-up she was neurologically intact, cosmetically satisfied, and free of infection. CONCLUSIONS: The treatment of extreme cases of syndrome of the trephined in the setting of a recent infection can be challenging; successful treatment can be achieved by using a custom titanium plate.

Safety and efficacy of intraoperative angiography in craniotomies for cerebral aneurysms and arteriovenous malformations: a review of 1093 consecutive cases.

BACKGROUND: In an era of indocyanine angiography, the routine use of intraoperative angiography (IOA) in the surgical treatment of aneurysms and vascular malformations is controversial. OBJECTIVE: To retrospectively assess the safety and efficacy of IOA and to determine predictors of surgical revision. METHODS: Between 2003 and 2011, IOA was performed during surgical treatment of 976 aneurysms, 101 arteriovenous malformations (AVMs), and 16 arteriovenous fistulas. RESULTS: In 80 of 976 aneurysms (8.2%), IOA prompted clip repositioning. The reason for readjustment was residual aneurysm in 54.7%, parent vessel occlusion in 42.9%, and both in 2.4% of cases. In multivariate analysis, increasing aneurysm size (P, .001), ruptured aneurysm (P, .001), and increasing number of vessels injected (P, .001) were strong predictors of clip readjustment. There was a strong trend for posterior circulation aneurysm location to predict clip repositioning (P = .06). IOA revealed residual nidus/ fistula requiring further intervention in 9 of 101 AVMs (8.9%) and 3 of 16 arteriovenous fistulas (18.8%). Of 9 AVMs requiring a surgical revision, 2 (22.2%) were Spetzler-Martin grade II, 5 (55.6%) were grade III, and 2 (22.2%) were grade IV. Mean Spetzler-Martin grade was 3.0 in AVMs requiring surgical revision compared with 2.3 in those not requiring revision (P = .05). IOA-related complications were all transient or minor and occurred in 0.99% of patients; none resulted in permanent morbidity. CONCLUSION: IOA remains a valuable tool in the surgical treatment of brain vascular abnormalities, guiding surgical re-exploration in .8% of cases. Easy access to an angiographer and routine use of IOA are important factors contributing to procedural safety and efficacy.