Background: Training of surgical residents based on the traditional Halstedian model is becoming increasingly scrutinized. The emergence of competency-based training has put pressure on training programs to provide high-fidelity simulation sessions that compliment residents’ training in the operating room. Here we present a novel combination of perfused cadaveric avian wing model in conjunction with live rats for neurosurgical resident training. Methods: The brachial artery of cadaveric duck wing was cannulated and connected to a roller pump. The duck wings remain perfused while residents performed microvascular anastomoses of the brachial and ulnar arteries. This took place prior to live rat modules. Results: The duck wing brachial artery diameter measured 1.5-2.0 mm, similar to the proximal middle cerebral artery in humans. The ulnar artery diameter measured 1.0-1.5 mm, similar to the cortical vessels. 8 interrupted stitches were placed during anastomosis using a 10-0 Nylon suture. Residents who performed the duck wing module felt more comfortable when they moved onto the live rat model with a shallower learning curve. Conclusions: The perfused cadaveric avian wing model provides intermediate to high fidelity simulation that complements the live rat model well. The number of rats needed for neurosurgical simulation training could be reduced via the use of avian wings.

Background: Premature occlusion of draining veins during surgical resection of arteriovenous malformations (AVM’s) can lead to disastrous consequences. Interestingly, some authors have recently demonstrated effective endovascular trans-venous Onyx embolization of select AVM’s. Methods: Case report Results: A 71year old female presented to the hospital with sudden onset right sided weakness and sensory change. Investigations revealed right fronto-parietal ICH secondary to a parasagittal Rolandic AVM with arterial supply from ACA and MCA branches. Drainage occurs via a single large cortical vein to the superior sagittal sinus. Partial intraarterial embolization was initially performed. Surgical resection of the remaining nidus was deemed high risk. A craniotomy was performed and the large cortical draining vein was cannulated with a 4Fr micro-puncture system under direct visualization. A DMSO compatible micro-catheter was navigated retrograde close to the nidus. The draining vein was occluded using a surgical clip, and Onyx was immediately injected. Retrograde complete embolization of the AVM was observed. A total of 3ml of Onyx was injected, and the catheter was left in-situ. Patient was discharge 2 weeks later with minimal defi cits. Conclusions: Open trans-venous embolization is a viable option for select AVM’s with a single draining vein and are not favorable candidates for trans-arterial embolization, surgery or radiation.

Background: The infratemporal fossa is an anatomically complex region. Lesions that arise in the infratemporal fossa are uncommon; however, their surgical resection remain challenging. Here we present a modified preauricular subtemporal approach initially described by Obwegeser et al. used in four patients with large skull base lesions. Methods: Retrospective case series of 4 patients Results: Four patients with various lesions of the infratemporal fossa (aneurysmal bone cyst, giant cell tumor of the bone, recurrent melanoma and recurrent clival chordoma) underwent surgical resection using the modified Obwegeser approach. A multidisciplinary team cared for patients consisting of maxillofacial surgery, otolaryngology and neurosurgery. After either nasotracheal intubation or tracheostomy, the patient’s jaw was temporarily wired shut. A curvilinear incision was fashioned and the root of zygoma was exposed (masseter attached) and osteotomized followed by inferior mobilization. The mandibular condyle is osteomized next and TMJ disarticulated with temporalis muscle still attached and reflected superiorly. Surgical resection of tumor then proceeded centered around the region bridging the temporal and infratemporal fossae. Reconstruction was carried out using plates and screws. Conclusions: The modified Obwegeser approach can provide safe and direct access to certain infratemporal fossa lesions with good cosmesis and functional outcome for patients without substantially increasing OR time.

Background: Premature occlusion of draining veins during surgical resection of arteriovenous malformations (AVM’s) can lead to disastrous consequences. Interestingly, some authors have recently demonstrated effective endovascular trans-venous Onyx embolization of select AVM’s. Methods: Case report Results: A 71-year old female presented to the hospital with sudden onset right sided weakness and sensory change. Investigations revealed right fronto-parietal ICH secondary to a parasagittal Rolandic AVM with arterial supply from ACA and MCA branches. Drainage occurs via a single large cortical vein to the superior sagittal sinus. Partial intra-arterial embolization was initially performed. Surgical resection of the remaining nidus was deemed high risk. A craniotomy was performed and the large cortical draining vein was cannulated with a 4Fr micro-puncture system under direct visualization. A DMSO compatible micro-catheter was navigated retrograde close to the nidus. The draining vein was occluded using a surgical clip, and Onyx was immediately injected. Retrograde complete embolization of the AVM was observed. A total of 3ml of Onyx was injected, and the catheter was left in-situ. Patient was discharge 2 weeks later with minimal deficits. Conclusions: Open trans-venous embolization is a viable option for select AVM’s with a single draining vein and are not favorable candidates for trans-arterial embolization, surgery or radiation.

Background: Brain arteriovenous malformations (AVM’s) are abnormal connections between arteries and veins. Endovascular glue embolization with N-butyl cyanoacrylate (NBCA) is an accepted form of treatment, with most complications related to timing of polymerization. Current literature reports a wide range of polymerization times with large discrepancies between in-vivo and in-vitro results. Methods: Polymerization time was measured for mixtures of lipiodol/NBCA of 50/50, 60/40, 70/30. The influence of pH, temperature and presence of biological catalysts on polymerization rate was investigated in-vivo using submerged droplet tests. PVA-C, silicone and endothelium surfaces were compared and contact angles were measured to assess physical interaction with NBCA. High-speed video of glue injection through a microcatheter was captured to characterize coaxial flow. Results: Polymerization rate increases with pH and temperature. A hydrophilic substrate such as PVA-C provides surface properties that are most similar to endothelium. Endothelium provides a catalytic surface that increases the rate of polymerization. Blood products further increase the polymerization rate with RBC’s providing almost instantaneous polymerization of NBCA upon contact. Characterization of coaxial flow shows dripping to jetting transition with significant wall effect. Conclusions: We have successfully deconstructed and characterized the dynamic behavior of NBCA embolization. A refined understanding of NBCA behavior could help reduce embolization-related complications.