Establishing a Multidisciplinary Cavernous Carotid Injury Simulation to Train Neurosurgical, Otolaryngology, and Anesthesia Residents.

Carotid artery injuries are serious complications of endoscopic endonasal surgery. As these occur rarely, simulation training offers an avenue for technique and algorithm development in resident learners. This study develops a realistic cadaveric model for the training of crisis resource management in the setting of cavernous carotid artery injury. An expanded endonasal approach and right cavernous carotid injury is performed on a cadaveric head. The cadaver's right common carotid artery is cannulated and connected to a perfusion pump delivering pressurized simulated blood. A simulation mannequin is incorporated into the model to allow for vital sign feedback. Surgical and anesthesia resident learners are tasked with obtaining vascular control with a muscle patch technique and medical management over the course of 3 clinical scenarios with increasing complexity. Crisis management instructions for an endoscopic endonasal approach to the cavernous carotid artery and blood pressure control were provided to the learners prior to beginning the simulation. An independent reviewer evaluated the learners on communication skills, crisis management algorithms, and implementation of appropriate skill sets. After each scenario, residents were debriefed on how to improve technique based on evaluation scores in areas of situational awareness, decision-making, communications and teamwork, and leadership. After the simulation, learners provided feedback on the simulation and this data was used to improve future simulations. The benefit of this cadaveric model is ease of set-up, cost-effectiveness, and reproducibility.

Development of a Cadaveric Multiport Model of Posterior Circulation Aneurysm Clipping for Neurosurgery and Otolaryngology Residents.

Posterior circulation aneurysms are difficult to treat with the current methods of coiling and clipping. To address limitations in training, we developed a cadaveric model to train learners on endoscopic clipping of posterior circulation aneurysms. An endoscopic transclival approach (ETA) and a transorbital precaruncular approach (TOPA) to successfully access and clip aneurysms of the posterior circulation are described. The model has flexibility in that a colored silicone compound can be injected into the cadaveric vessels for the purpose of training learners on vascular anatomy. The other option is that the model could be connected to a vascular perfusion pump allowing real-time appreciation of a pulsatile or ruptured aneurysm. This cadaveric model is the first of its kind for training of endoscopic clipping of posterior circulation aneurysms. Learners will develop proficiency in endoscopic skills, appropriate dissection, and appreciation for relative anatomy while developing an algorithm that can be employed in a real operative arena. Going forward, various clinical scenarios can be developed to enhance the realism, allow learners from different specialties to work together, and emphasize the importance of teamwork and effective communication.

Combined Endoscopic Transorbital and Endonasal Repair of High Flow Orbital Apex/Middle Fossa Cerebrospinal Fluid Leak with a Nasoseptal Flap.

BACKGROUND AND IMPORTANCE: High flow orbital apex or middle fossa cerebrospinal fluid (CSF) leaks can be life threatening and complex to repair. These leaks associated with large dural defects are most commonly repaired with an open temporalis muscle patch or free flaps, but these flaps do not always stop the leak. CLINICAL PRESENTATION: A 65-year-old patient presented two years after orbital exenteration and radiation for squamous cell carcinoma. He developed multi-organism meningitis and pneumocephalus secondary to a large high-flow orbital apex/middle fossa CSF leak. To repair the leak, a combined endoscopic transorbital/endonasal approach with pedicled nasospetal flap and dermis fat graft was used. We describe the unique endoscopic technique that was used to treat the life threatening high flow orbital apex/middle fossa CSF leak. The technique allowed the use of the transposed pedicled flap, which is an alternative to the free flap in controlling CSF leak. Cisternogram post-operatively and clinical exam confirmed resolution of CSF leak. Although a critically ill patient at admission with a modified Rankin scale (MRS) of 5, he was discharged home on continued IV antibiotic therapy with a MRS of 3. Endoscopic evaluation at three months after treatment showed the effectiveness of the flap and he continued to improve clinically. CONCLUSION: This is the first case to describe a combined endoscopic transorbital and endonasal repair of high flow orbital apex/middle fossa CSF leak with a pedicled nasoseptal flap. These techniques can be utilized during initial reconstruction after orbital exenteration or as a salvage flap.

Crisis Management Simulation: Establishing a Dual Neurosurgery and Anesthesia Training Experience.

BACKGROUND: Simulation training has been shown to be an effective teaching tool. Learner management of an intraoperative crisis such as a major cerebrovascular bleed requires effective teamwork, communication, and implementation of key skill sets at appropriate time points. This study establishes a first of a kind simulation experience in a neurosurgery/anesthesia resident (learners) team working together to manage an intraoperative crisis. METHODS: Using a cadaveric cavernous carotid injury perfusion model, 7 neurosurgery and 6 anesthesia learners, were trained on appropriate vascular injury management using an endonasal endoscopic technique. Learners were evaluated on communication skills, crisis management algorithms, and implementation of appropriate skill sets at the right time. A preanatomic and postanatomic examination and postsimulation survey was administered to neurosurgery learners. Anesthesia learners provided posttraining evaluation through a tailored realism and teaching survey. RESULTS: Neurosurgery learners' anatomic examination score improved from presimulation (33.89%) to postsimulation (86.11%). No significant difference between learner specialties was observed for situation awareness, decision making, communications and teamwork, or leadership evaluations. Learners reported the simulation realistic, beneficial, and highly instructive. CONCLUSIONS: Realistic, first of kind, clinical simulation scenarios were presented to a neurosurgery/anesthesia resident team who worked together to manage an intraoperative crisis. Learners were effectively trained on crisis management, the importance of communication, and how to develop algorithms for future implementation in difficult scenarios. Learners were highly satisfied with the simulation training experience and requested that it be integrated more consistently into their residency training programs.

Paramedian Forehead Flap for Repair of Refractory High-Flow Anterior Skull Base CSF Leak.

AIM: The paramedian forehead flap (PMFF) has been well described for nasal reconstruction. However, it has never been reported for use in the repair of high flow anterior skull base cerebral spinal fluid (CSF) leaks. MATERIAL AND METHODS: The patient is a 55 yo African American male cocaine abuser who initially presented with a high flow anterior skull base CSF leak, extensive pneumocephalus, and intra-cerebral and intra-ventricular abscesses with an oro-nasal-cerebral fistula. The patent initially underwent bi-frontal craniotomy, exenteration of the frontal sinus, abdominal fat graft, resection of intra-cerebral abscesses, and repair of high flow anterior skull base CSF leak with a pedicled pericranial flap (PF). 18 months after the patient's surgery he had resumed his use of cocaine and suffered necrosis of his PF. This caused his high flow CSF leak to recur. After extensive psychiatric treatment, he stopped cocaine use and was subsequently repaired with a pedicled de-epithelialized PMFF originating off the bilateral supratrochlear arteries. RESULTS: The patient has had no CSF leak for 3 years, and primary closure of the forehead was achieved with good cosmetic outcome. CONCLUSION: This case highlights the use of PMFF for the treatment of recurrent high flow anterior skull base CSF leak. It also highlights the importance of treatment of the patient's underlying medical disorder, in this case, the patient's addiction to cocaine. We provide a detailed discussion for the use of the de-epithelialized PMFF and how it can be utilized as a vascularized reconstructive technique to repair complex refractory cerebral spinal fluid leaks.

Pravastatin attenuates hypertension, oxidative stress, and angiogenic imbalance in rat model of placental ischemia-induced hypertension.

Preeclampsia is a pregnancy-specific condition characterized by an imbalance of circulating angiogenic factors and new-onset hypertension. Although current treatment options are limited, recent studies suggest that pravastatin may improve angiogenic profile and reduce blood pressure in preeclampsia. We hypothesized pravastatin would restore angiogenic balance and reduce mean arterial pressure (MAP) in rats with reduced utero-placental perfusion pressure (RUPP)-induced hypertension. Pravastatin was administered intraperitoneally (1 mg/kg per day) in RUPP (RUPP+P) and normal pregnant rats (NP+P) from day 14 to 19 of pregnancy. On day 19, MAP was measured via catheter, conceptus data were recorded, and tissues collected. MAP was increased (P<0.05) in RUPP compared with NP dams, and pravastatin ameliorated this difference. Pravastatin attenuated decreased fetal weight and plasma vascular endothelial growth factor and the RUPP-induced increased soluble fms-like tyrosine kinase-1 when compared with NP dams. Pravastatin treatment did not improve angiogenic potential in RUPP serum and decreased (P<0.05) endothelial tube formation in NP rats. RUPP rats presented with indices of oxidative stress, such as increased placental catalase activity and plasma thiobarbituric acid reactive substances along with decreased plasma total antioxidant capacity compared with NP controls, and pravastatin attenuated these effects. MAP, fetal weight, plasma vascular endothelial growth factor, and plasma soluble fms-like tyrosine kinase-1 were unchanged in NP+P compared with NP controls. The present data indicate that treatment with pravastatin attenuates oxidative stress and lowers MAP in placental ischemia-induced hypertension, but may have negative effects on circulating angiogenic potential during pregnancy. Further studies are needed to determine whether there are long-term deleterious effects on maternal or fetal health after pravastatin treatment during pregnancy-induced hypertension or preeclampsia.