Perioperative Low-Dose Aspirin Management for Planned Clipping Surgery: When, How Long, and With What Precautions?

BACKGROUND AND OBJECTIVE: Perioperative low-dose aspirin (ASA) management for open craniotomy surgery lacked information. We analyze to establish the perioperative ASA strategy to minimize both hemorrhagic and thromboembolic complications. METHODS: The investigators designed a multicenter retrospective study, which included patients scheduled to have clipping surgery for unruptured intracranial aneurysm. The incidence and risk factors were analyzed for postoperative hemorrhagic complications and major cardio- and cerebrovascular events (MACCEs) within 1 month postoperation. RESULTS: This study included 503 long-term ASA users of 3654 patients at three tertiary centers. The incidence of hemorrhagic complications and MACCEs was 7.4% (37/503) and 8.8% (44/503), respectively. Older age (>70 years, odds ratio [OR]: 2.928, 95% CI [1.337-6.416]), multiple aneurysms operation (OR: 2.201, 95% CI [1.017-4.765]), large aneurysm (>10 mm, OR: 4.483, 95% CI [1.485-13.533]), and ASA continuation (OR: 2.604, 95% CI [1.222-5.545]) were independent risk factors for postoperative hemorrhagic complications. Intracranial hemorrhage was the only type of hemorrhagic complication that increased in the ASA continuation group (10.6% vs 2.9%, P = .001). Between the ASA continuation and discontinuation groups, the overall incidence of MACCEs was not significantly different (log-rank P = .8). In the subgroup analysis, ASA discontinuation significantly increased the risk of MACCEs in the secondary prevention group (adjusted hazard ratio: 2.580, 95% CI [1.015-6.580]). CONCLUSION: ASA continuation increased the risk of postoperative intracranial hemorrhage. Simultaneously, ASA discontinuation was the major risk factor for postoperative MACCEs in the high-risk group. Without evidence of intracranial hemorrhage, early ASA resumption was indicated (a total cessation duration <7-10 days) in the secondary prevention group.

Pedicled frontal periosteal rescue flap via eyebrow incision for skull base reconstruction (SevEN-002).

PURPOSE: Cerebrospinal fluid (CSF) leakage is one of the major complications after endoscopic endonasal surgery. The reconstructive nasoseptal flap is widely used to repair CSF leakage. However, it could not be utilized in all cases; thus, there was a need for an alternative. We developed a pericranial rescue flap that could cover both sellar and anterior skull base defects via the endonasal approach. A modified surgical technique that did not violate the frontal sinus and cause cosmetic problems was designed using the pericranial rescue flap. METHODS: We performed 12 cadaveric dissections to investigate the applicability of the lateral pericranial rescue flap. An incision was made, extending from the middle to the lateral part of the eyebrow. The pericranium layer was dissected away from the galea layer, from the supraorbital region towards the frontoparietal region. With endoscopic assistance, the periosteal flap was raised, the flap base was the pericranium layer at the eyebrow incision. After a burr-hole was made in the supraorbital bone, the pericranial flap was inserted via the intradural or extradural pathway. RESULTS: The mean size of the pericranial flap was 11.5 cm × 3.2 cm. It was large enough to cross the midline and cover the dural defects of the anterior skull base, including the sellar region. CONCLUSION: We demonstrated a modified endoscopic technique to repair the anterior skull base defects. This minimally invasive pericranial flap may resolve neurosurgical complications, such as CSF leakage.

Virtual dissection of the real brain: integration of photographic 3D models into virtual reality and its effect on neurosurgical resident education.

OBJECTIVE: Virtual reality (VR) is increasingly being used for education and surgical simulation in neurosurgery. So far, the 3D sources for VR simulation have been derived from medical images, which lack real color. The authors made photographic 3D models from dissected cadavers and integrated them into the VR platform. This study aimed to introduce a method of developing a photograph-integrated VR and to evaluate the educational effect of these models. METHODS: A silicone-injected cadaver head was prepared. A CT scan of the specimen was taken, and the soft tissue and skull were segmented to 3D objects. The cadaver was dissected layer by layer, and each layer was 3D scanned by a photogrammetric method. The objects were imported to a free VR application and layered. Using the head-mounted display and controllers, the various neurosurgical approaches were demonstrated to neurosurgical residents. After performing hands-on virtual surgery with photographic 3D models, a feedback survey was collected from 31 participants. RESULTS: Photographic 3D models were seamlessly integrated into the VR platform. Various skull base approaches were successfully performed with photograph-integrated VR. During virtual dissection, the landmark anatomical structures were identified based on their color and shape. Respondents rated a higher score for photographic 3D models than for conventional 3D models (4.3 ± 0.8 vs 3.2 ± 1.1, respectively; p = 0.001). They responded that performing virtual surgery with photographic 3D models would help to improve their surgical skills and to develop and study new surgical approaches. CONCLUSIONS: The authors introduced photographic 3D models to the virtual surgery platform for the first time. Integrating photographs with the 3D model and layering technique enhanced the educational effect of the 3D models. In the future, as computer technology advances, more realistic simulations will be possible.

Coil-Protected Technique for Liquid Embolization in Neurovascular Malformations.

OBJECTIVE: To evaluate the safety and efficacy of the coil-protected technique for liquid embolization in neurovascular malformations. MATERIALS AND METHODS: Twenty-two patients who underwent coil-protected liquid embolization for symptomatic cranial (n = 13) and spinal (n = 9) arteriovenous fistula (AVF) or arteriovenous malformations (AVMs) were identified. A total of 36 target feeder vessels were embolized with N-butyl cyanoacrylate and/or Onyx (Medtronic). This technique was used to promote delivery of a sufficient amount of liquid embolic agent into the target shunt or nidus in cases where tortuous feeding arteries preclude a microcatheter wedging techniqu and/or to prevent reflux of the liquid embolic agent in cases with a short safety margin. The procedure was considered technically successful if the target lesion was sufficiently filled with liquid embolic agent without unintentional reflux. Angiographic and clinical outcomes were retrospectively evaluated. RESULTS: Technical success was achieved for all 36 target feeders. Post-embolization angiographies revealed complete occlusion in 16 patients and near-complete and partial occlusion in three patients each. There were no treatment-related complications. Of the six patients who showed near-complete or partial occlusion, five received additional treatments: two received stereotactic radiosurgery for cerebral AVM, two underwent surgical removal of cerebral AVM, and one underwent additional embolization by direct puncture for a mandibular AVM. Finally, all patients showed complete (n = 19) or near-complete (n = 3) occlusion of the target AVF or AVM on follow-up angiographies. The presenting neurological symptoms improved completely in 15 patients (68.2%) and partially in seven patients (31.8%). CONCLUSION: The coil-protected technique is a safe and effective method for liquid embolization, especially in patients with various neurovascular shunts or malformations who could not be successfully treated with conventional techniques.

Long-Term Results of Gamma Knife Radiosurgery for Intracranial Meningioma.

BACKGROUND: The predominant treatment modality for meningioma is surgical resection. However, gamma knife radiosurgery is also an important treatment modality for meningioma that is small or cannot be completely removed because of its location. In this study, we evaluated the effectiveness and long-term results of radiosurgical treatment for meningioma in our institution. METHODS: We studied 628 patients (130 men and 498 women) who underwent gamma knife radiosurgery for intracranial meningioma, which is radiologically diagnosed, from Jan 2008 to Nov 2012. We included patients with single lesion meningioma, and followed up after 6 months with imaging, and then at 24 months with a clinical examination. Patients with high-grade meningioma or multiple meningiomas were excluded. We analyzed each of the factors associated with progression free survival. The median patient's age was 56.8 years. Maximal dosage was 27.8 Gy and marginal dosage was 13.9 Gy. RESULTS: The overall tumor control rate was 95%. Twenty-eight patients (4.4%) showed evidence of tumor recurrence. Ninety-eight patients (15%) developed peritumoral edema (PTE) after gamma-knife surgery; two of them (2%) underwent surgical resections due to PTE. Nine patients had craniotomy and tumor removal after gamma knife surgery. CONCLUSION: Gamma knife surgery for intracranial meningioma has proven to be a safe and effective treatment tool with successful long-term outcomes. Gamma knife radiosurgery can be especially effective in cases of remnant meningioma after surgical resection or where PTE is not present.