The posterior inferior cerebellar artery (PICA) is a vessel located between the intra- and extracranial circulation. The artery is characterized by a complex embryological development and numerous anatomical variants. The authors present a case of the PICA supplied by both a hypertrophic anterior spinal artery and a hypoplastic bulbar artery. This unusual arrangement somehow completes the list of previously published variants, and the spontaneous rupture of a related aneurysm confirmed the fragility of this network. The authors discuss anatomical and treatment considerations.
Joseph Gabrieli, Nader-Antoine Sourour, Dorian Chauvet, Federico Di Maria, Jacques Chiras and Frédéric Clarençon
Eimad Shotar, Matthieu Debarre, Nader-Antoine Sourour, Federico Di Maria, Joseph Gabrieli, Aurélien Nouet, Jacques Chiras, Vincent Degos and Frédéric Clarençon
The authors aimed to design a score for stratifying patients with brain arteriovenous malformation (BAVM) rupture, based on the likelihood of a poor long-term neurological outcome.
The records of consecutive patients with BAVM hemorrhagic events who had been admitted over a period of 11 years were retrospectively reviewed. Independent predictors of a poor long-term outcome (modified Rankin Scale score ≥ 3) beyond 1 year after admission were identified. A risk stratification scale was developed and compared with the intracranial hemorrhage (ICH) score to predict poor outcome and inpatient mortality.
One hundred thirty-five patients with 139 independent hemorrhagic events related to BAVM rupture were included in this analysis. Multivariate logistic regression followed by stepwise analysis showed that consciousness level according to the Glasgow Coma Scale (OR 6.5, 95% CI 3.1–13.7, p < 10−3), hematoma volume (OR 1.8, 95% CI 1.2–2.8, p = 0.005), and intraventricular hemorrhage (OR 7.5, 95% CI 2.66–21, p < 10−3) were independently associated with a poor outcome. A 12-point scale for ruptured BAVM prognostication was constructed combining these 3 factors. The score obtained using this new scale, the ruptured AVM prognostic (RAP) score, was a stronger predictor of a poor long-term outcome (area under the receiver operating characteristic curve [AUC] 0.87, 95% CI 0.8–0.92, p = 0.009) and inpatient mortality (AUC 0.91, 95% CI 0.85–0.95, p = 0.006) than the ICH score. For a RAP score ≥ 6, sensitivity and specificity for predicting poor outcome were 76.8% (95% CI 63.6–87) and 90.8% (95% CI 81.9–96.2), respectively.
The authors propose a new admission score, the RAP score, dedicated to stratifying the risk of poor long-term outcome after BAVM rupture. This easy-to-use scoring system may help to improve communication between health care providers and consistency in clinical research. Only external prospective cohorts and population-based studies will ensure full validation of the RAP scores' capacity to predict outcome after BAVM rupture.
Joseph Gabrieli, Frédéric Clarençon, Federico Di Maria, Robert Fahed, Anne-Laure Boch, Vincent Degos, Jacques Chiras and Nader-Antoine Sourour
Intracranial aneurysms are relatively frequently encountered in patients with brain arteriovenous malformations (BAVMs). They may be located on the circle of Willis, on arterial feeders, or even inside the nidus. Because BAVM-associated aneurysms represent a risk factor of bleeding, the question of the timing and modality of their management remains a matter of debate in unruptured BAVMs. The authors present a case of fatal periprocedural rupture of a flow-related aneurysm (FRA) during the removal of the microcatheter after injection of a liquid embolic agent. A 40-year-old man was treated at the authors' institution for the management of a Spetzler-Martin Grade III left unruptured frontal BAVM, revealed by seizures and a focal neurological deficit attributed to flow steal phenomenon. After a multidisciplinary meeting, endovascular treatment was considered to reduce the flow of the BAVM. A proximal FRA located on the feeding internal carotid artery (ICA) was purposely left untreated because it did not meet the criteria of the authors' institution for preventative treatment (i.e., small size [2.5 mm]). During embolization, at the time of microcatheter retrieval, and after glue injection, the aneurysm unexpectedly ruptured. The aneurysm's rupture was attributed to the stress (torsion/flexion) on the ICA caused by the microcatheter removal. Despite the attempts to manage the bleeding, the patient eventually died of the acute increase of intracranial pressure related to the massive subarachnoid hemorrhage. This case highlights a previously unreported mechanism of FRA rupture during BAVM embolization: the stress transmitted to the parent artery during the removal of the microcatheter.
Alexis Guédon, Frédéric Clarençon, Federico Di Maria, Charlotte Rosso, Alessandra Biondi, Joseph Gabrieli, Patricia Rojas, Jacques Chiras and Nader Sourour
The authors evaluate the rate and discuss the pathomechanisms of very late (≥ 4-month) ischemic complications after flow-diverter stent (FDS) placement for intracranial aneurysms.
The authors retrospectively reviewed the clinical data of the patients treated at Pitié-Salpêtrière Hospital between January 2010 and September 2014, who underwent FDS placement for intracranial aneurysm. The patients received dual-antiplatelet therapy (clopidogrel and aspirin) 5 days before and 3–6 months after the procedure and then aspirin alone for 6–9 months. An ischemic complication was defined as a sudden focal neurological deficit documented on diffusion-weighted images.
Eighty-six consecutive patients were included. Three (3.5%) patients treated with the Pipeline embolization device experienced a delayed acute ischemic stroke (2 cases of perforator/side-wall branch infarction and 1 case of thromboembolic stroke) with an average delay of 384 days (4 months, 20 months, and 13 months, respectively). The aneurysm locations were the left superior cerebellar artery, the right anterior choroid artery, and the left internal carotid artery (paraclinoid segment), respectively. The complications occurred after the patients had completed the antiaggregation protocol, except for Patient 1, who was receiving aspirin alone because of a spontaneous hematoma. At the acute phase, no in-stent thromboses were found on digital subtraction angiography. In Patient 2, the treated anterior choroid artery was occluded 20 months after the procedure. In Patient 3, a focal stenosis (approximately 40%) of the distal aspect of the FDS, probably caused by intimal hyperplasia, was seen.
Very late ischemic complications after FDS treatment were observed in 3.5% of the cases in the authors' series, some of which occurred as late as more than 1 year after placement.
Robert Fahed, Frédéric Clarençon, Nader-Antoine Sourour, Dorian Chauvet, Lise Le Jean, Jacques Chiras and Federico Di Maria
One of the procedural risks in arteriovenous malformation (AVM) embolization is possible migration of the embolic agent into the venous drainage with an incomplete nidus occlusion, which may lead to severe hemorrhagic complications.
This report presents the case of a 29-year-old man who presented with a deep intraparenchymal hematoma on the left side secondary to the spontaneous rupture of a claustral AVM. Upon resorption of the hematoma, the patient underwent an initial therapeutic session of N-butyl-2 cyanoacrylate endovascular embolization, with the purpose of reducing the AVM volume and flow before performing Gamma Knife radiosurgery. After glue injection into one of the arterial feeders, the control angiography showed a partial migration of the glue cast into the straight sinus, with most of the nidus still visible. Because of the bleeding risk due to possible venous hypertension, it was decided to try to retrieve the glue from the vein by using a stent retriever via jugular access. This maneuver allowed a nearly complete removal of the glue cast, thereby restoring normal venous flow drainage. The patient showed no clinical worsening after the procedure.
To the authors’ knowledge, this is the first report of the use of the Solitaire FR device as a rescue glue retriever. This method should be considered by physicians in cases of unintended glue migration into the venous circulation during AVM embolization.
Frédéric Clarençon, Federico Di Maria, Evelyne Cormier, Nader-Antoine Sourour, Eric Enkaoua, Frédéric Sailhan, Christina Iosif, Lise Le Jean and Jacques Chiras
Presurgical devascularization of hypervascular spinal metastases has been shown to be effective in preventing major blood loss during open surgery. Most often, embolization can be performed using polyvinyl alcohol (PVA) microparticles. However, in some cases, the close relationship between the feeders of the metastases and the feeders of the anterior spinal artery (ASA) poses a risk of spinal cord ischemia when PVA microparticle embolization is performed.
The authors present their early experience in the treatment of spinal metastases close to the ASA; in 2 cases they injected Onyx-18, by direct puncture, into hypervascular posterior arch spinal metastases situated close to the ASA.
Two women, one 36 and the other 55 years of age, who presented with spinal lesions (at the posterior arch of C-4 and T-6, respectively) from thyroid and a kidney tumors, were sent to the authors' department to undergo presurgical embolization. After having performed a complete spinal digital subtraction angiography study, a regular angiography catheter was positioned at the ostium of the artery that mainly supplied the lesion. Then, with the patient in the left lateral decubitus position, direct puncture with 18-gauge needles of the lesion was performed using roadmap guidance. Onyx-18 was injected through the needles under biplanar fluoroscopy.
Satisfactory devascularization of the lesions was obtained; the ASA remained patent in both cases. The metastases were surgically removed in both cases within the 48 hours after the embolization and major blood loss did not occur.
Presurgical devascularization of hypervascular spinal metastases close the ASA by direct puncture with Onyx-18 seems to be an effective technique and appears to be safe in terms of the preserving the ASA's patency.
Robert Fahed, Federico Di Maria, Charlotte Rosso, Nader Sourour, Vincent Degos, Sandrine Deltour, Flore Baronnet-Chauvet, Anne Léger, Sophie Crozier, Joseph Gabrieli, Yves Samson, Jacques Chiras and Frédéric Clarençon
Contrary to acute ischemic stroke involving the anterior circulation, no randomized trial has yet demonstrated the safety and effectiveness of endovascular management in acute basilar artery occlusion (BAO). Recently developed thrombectomy devices, such as stentrievers and aspiration systems, have helped in improving the endovascular management of acute ischemic stroke. The authors sought to assess the impact of these devices in the endovascular treatment of acute BAO.
A retrospective analysis of 34 consecutive patients treated in Pitié-Salpêtrière Hospital for acute BAO was carried out. All patients had undergone an endovascular procedure. In addition to the global results in terms of safety and effectiveness (recanalization rate and 3-month clinical outcome based on the modified Rankin Scale [mRS]), the authors aimed to determine if the patients treated with the most recently developed devices (i.e., the Solitaire stentriever or the ADAPT catheter) had better angiographic and clinical outcomes than those treated with older endovascular strategies.
The overall successful recanalization rate (thrombolysis in cerebral infarction score 2b–3) was 50% (17 of 34 patients). A good clinical outcome (mRS score 0–2 at 3-month follow-up) was achieved in 11 (32.3%) of 34 patients. The mortality rate at 3-month follow-up was 29.4% (10 of 34 patients). Patients treated with the Solitaire stentriever and the ADAPT catheter had a higher recanalization rate (12 [92.3%] of 13 patients vs 5 [23.8%] of 21 patients, p = 0.0002) and a shorter mean (± SD) procedure duration (88 ± 31 minutes vs 126 ± 58 minutes, p = 0.04) than patients treated with older devices.
The latest devices have improved the effectiveness of mechanical thrombectomy in acute BAO. Their use in further studies may help demonstrate a benefit in the endovascular management of acute BAO.
Alberto Di Somma, Jorge Torales, Luigi Maria Cavallo, Jose Pineda, Domenico Solari, Rosa Maria Gerardi, Federico Frio, Joaquim Enseñat, Alberto Prats-Galino and Paolo Cappabianca
The extended endoscopic endonasal transtuberculum transplanum approach is currently used for the surgical treatment of selected midline anterior skull base lesions. Nevertheless, the possibility of accessing the lateral aspects of the planum sphenoidale could represent a limitation for such an approach. To the authors’ knowledge, a clear definition of the eventual anatomical boundaries has not been delineated. Hence, the present study aimed to detail and quantify the maximum amount of bone removal over the planum sphenoidale required via the endonasal pathway to achieve the most lateral extension of such a corridor and to evaluate the relative surgical freedom.
Six human cadaveric heads were dissected at the Laboratory of Surgical NeuroAnatomy of the University of Barcelona. The laboratory rehearsals were run as follows: 1) preliminary predissection CT scans, 2) the endoscopic endonasal transtuberculum transplanum approach (lateral limit: medial optocarotid recess) followed by postdissection CT scans, 3) maximum lateral extension of the transtuberculum transplanum approach followed by postdissection CT scans, and 4) bone removal and surgical freedom analysis (a nonpaired Student t-test). A conventional subfrontal bilateral approach was used to evaluate, from above, the bone removal from the planum sphenoidale and the lateral limit of the endonasal route.
The endoscopic endonasal transtuberculum transplanum approach was extended at its maximum lateral aspect in the lateral portion of the anterior skull base, removing the bone above the optic prominence, that is, the medial portion of the lesser sphenoid wing, including the anterior clinoid process. As expected, a greater bone removal volume was obtained compared with the approach when bone removal is limited to the medial optocarotid recess (average 533.45 vs 296.07 mm2; p < 0.01). The anteroposterior diameter was an average of 8.1 vs 15.78 mm, and the laterolateral diameter was an average of 18.77 vs 44.54 mm (p < 0.01). The neurovascular contents of this area were exposed up to the insular segment of the middle cerebral artery. The surgical freedom analysis revealed a possible increased lateral maneuverability of instruments inserted in the contralateral nostril compared with a midline target (average 384.11 vs 235.31 mm2; p < 0.05).
Bone removal from the medial aspect of the lesser sphenoid wing, including the anterior clinoid process, may increase the exposure and surgical freedom of the extended endoscopic endonasal transtuberculum transplanum approach over the lateral segment of the anterior skull base. Although this study represents a preliminary anatomical investigation, it could be useful to refine the indications and limitations of the endoscopic endonasal corridor for the surgical management of skull base lesions involving the lateral portion of the planum sphenoidale.