development-cadaveric-multiport-model-posterior-circulation-aneurysm

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 ...

Patients with aneurysmal subarachnoid hemorrhage (SAH) are at high risk for delayed cerebral ischemia (DCI) and stroke. Epoxyeicosatrienoic acids (EETs) play an important role in cerebral blood flow regulation and neuroprotection after brain injury. Polymorphisms in the gene for the enzyme soluble epoxide hydrolase (sEH), which inactivates EETs, are associated with ischemic stroke risk and neuronal survival after ischemia. This prospective observational study of patients with SAH compares vital and neurologic outcomes based on functional polymorphisms of sEH.

Genetic variation in soluble epoxide hydrolase: association with outcome after aneurysmal subarachnoid hemorrhage.

Patients recovering from aneurysmal subarachnoid hemorrhage (SAH) are at risk for developing delayed cerebral ischemia (DCI). Experimental and human studies implicate the vasoconstrictor P450 eicosanoid 20-hydroxyeicosatetraenoic acid (20-HETE) in the pathogenesis of DCI. To date, no studies have evaluated the role of vasodilator epoxyeicosatrienoic acids (EETs) in DCI.

Protective role of p450 epoxyeicosanoids in subarachnoid hemorrhage.

Deep vein thrombosis (DVT) is a common complication of aneurysmal subarachnoid hemorrhage (aSAH). The time period of greatest risk for developing DVT after aSAH is not currently known. aSAH induces a prothrombotic state, which may contribute to DVT formation. Using repeated ultrasound screening, the hypothesis that patients would be at greatest risk for developing DVT in the subacute post-rupture period was tested.

Timing of deep vein thrombosis formation after aneurysmal subarachnoid hemorrhage.

Objective To analyze whether cavernous sinus sampling (CSS) and dynamic magnetic resonance imaging (dMRI) are consistent with intraoperative findings in Cushing disease (CD) patients. Design Retrospective outcomes study. Setting Oregon Health & Science University; 2006 and 2013. Participants A total of 37 CD patients with preoperative dMRI and CSS to confirm central adrenocorticotropic hormone (ACTH) hypersecretion. Patients were 78% female; mean age was 41 years (at diagnosis), and all had a minimum of 6 months of follow-up. Main Outcome Measures Correlations among patient characteristics, dMRI measurements, CSS results, and intraoperative findings. Results All CSS indicated presence of CD. Eight of 37 patients had no identifiable tumor on dMRI. Three of 37 patients had no tumor at surgery. dMRI tumor size was inversely correlated with age (rs = - 0.4; p = 0.01) and directly correlated to intraoperative lateralization (rs = 0.3; p < 0.05). Preoperative dMRI was directly correlated to intraoperative lateralization (rs = 0.5; p < 0.002). CSS lateralization showed no correlation with intraoperative findings (rs = 0.145; p = 0.40) or lateralization observed on preoperative dMRI (rs = 0.17; p = 0.29). Postoperative remission rate was 68%. Conclusion dMRI localization was most consistent with intraoperative findings; CSS results were less reliable. Results suggest that small ACTH-secreting tumors continue to pose a challenge to reliable preoperative localization. 

Preoperative Lateralization Modalities for Cushing Disease: Is Dynamic Magnetic Resonance Imaging or Cavernous Sinus Sampling More Predictive of Intraoperative Findings?

Background and Purpose Aneurysmal bone cysts (ABCs) rarely involve the cranium and have seldom been reported in pregnancy. Clinical Presentation We describe a case of a 28-year-old woman who presented at 37 weeks of gestation with 3 months of gradually worsening vision, 10 months of proptosis, and restricted ocular motility on the left. Brain imaging revealed a multicystic enhancing mass measuring 5.9 × 5.3 × 3.7 cm, centered on the cribriform plate on the left, extending into the anterior cranial fossa superiorly as well as the left nasal cavity, maxillary, sphenoid, and frontal sinuses. Her clinical course is described in detail; 3-month postoperative imaging demonstrated no residual mass. Conclusion A literature review revealed five previous cases of ABCs associated with pregnancy. We report a rare case of a giant ABC of fibrous dysplasia involving the paranasal sinuses and anterior cranial fossa. We postulate on the possible influence of pregnancy on the clinical course. 

Giant Aneurysmal Bone Cyst of the Anterior Cranial Fossa and Paranasal Sinuses Presenting in Pregnancy: Case Report and Literature Review.

 Endoscopic skull base approaches are being used to address complicated neurovascular pathology. These approaches are safest when proximal vascular control of the cavernous carotid artery (CavCA) can be obtained.  We present a cadaver-based anatomic simulation study showing the feasibility of clip placement for the CavCA as it courses through the cavernous sinus. The arterial vessels were injected with red microfil (Flow Tech, Carver, Massachusetts) to enhance visibility. The endoscope was directed through a precaruncular transorbital approach and instrumentation was managed through an endonasal transsphenoidal approach.  The dual approach minimized the "coning down" and instrument "sword fighting" that occurs as the rod lens endoscope and instruments are used laterally and posterior toward the clivus and brainstem. The precaruncular transorbital approach improved visualization of the clip application and improved the functional working area. The transorbital port allowed better appreciation of the distal clip tines, and the laterally positioned cranial nerves.  The advantages may be most realized in the setting of endoscopic endonasal resection of highly vascular lesions and/or bleeding from a ruptured aneurysm being clipped. Simulated training provides an excellent opportunity to enhance skill sets and increase familiarity with anatomical visualization before entering the operative arena.

Dual Endoscopic Endonasal Transsphenoidal and Precaruncular Transorbital Approaches for Clipping of the Cavernous Carotid Artery: A Cadaveric Simulation.

  Simulation training offers a useful opportunity to appreciate vascular anatomy and develop the technical expertise required to clip intracranial aneurysms of the posterior circulation.   In cadavers, a comparison was made between the endoscopic transclival approach (ETA) alone and a combined multiportal approach using the ETA and a transorbital precaruncular approach (TOPA) to evaluate degrees of freedom, angles of visualization, and ergonomics of aneurysm clip application to the posterior circulation depending on basilar apex position relative to the posterior clinoids.   ETA alone provided improved access to the posterior circulation when the basilar apex was high riding compared with the posterior clinoids. ETA + TOPA provided a significantly improved functional working area for instruments and visualization of the posterior circulation for a midlevel basilar apex. A single-shaft clip applier provided improved visualization and space for instruments. Proximal and distal vascular control and feasibility of aneurysmal clipping were demonstrated.   TOPA is a medial orbital approach to the central skull base; a transorbital neuroendoscopic surgery approach. This anatomical simulation provides surgical teams an alternative to the ETA approach alone to address posterior circulation aneurysms, and a means to preoperatively prepare for intraoperative anatomical and surgical instrumentation challenges.

Endoscopic Endonasal Transclival Approach versus Dual Transorbital Port Technique for Clip Application to the Posterior Circulation: A Cadaveric Anatomical and Cerebral Circulation Simulation Study.

  Anterior and posterior clinoidectomies have been proposed to augment exposure of the basilar apex. A sequential quantitative benefit analysis offered by these maneuvers has not been reported.   Fourteen datasets from eight cadaveric specimens were analyzed. A modified orbitozygomatic frontotemporal craniotomy was performed. The extent of proximal control of the basilar artery was determined through the exposed opticocarotid and carotidoculomotor triangles before and after clinoidectomies and mobilization of the third nerve at the porous oculomotarius.   Removal of the anterior and posterior clinoids significantly improved proximal basilar artery access (   < 0.012) and increased the opticocarotid triangle and carotidoculomotor triangle areas (   < 0.017). Surgical freedom increased inferosuperiorally in the opticocarotid triangle following anterior clinoidectomy (   < 0.047) and in carotidoculomotor triangle following posterior clinoidectomy (   < 0.047). Mobilization of the third nerve increased surgical freedom in the mediolateral projection of the carotidoculomotor triangle (   < 0.047).   Anterior and posterior clinoidectomies significantly improved the area of exposure of the opticocarotid triangle, carotidoculomotor triangle, and the exposed length of the basilar artery available for proximal control. This improvement is extremely important for large or giant aneurysms of the upper basilar artery or aneurysms hidden by the posterior clinoid.

Quantitative Anterior and Posterior Clinoidectomy Analysis and Mobilization of the Oculomotor Nerve during Surgical Exposure of the Basilar Apex Using Frameless Stereotaxis.

Cerebrospinal fluid rhinorrhea from a lateral skull base defect refractory to spontaneous healing and/or conservative management is most commonly managed via open surgery. Approach for repair is dictated by location of the defect, which may require surgical exploration. The final common pathway is the eustachian tube (ET). Endoscopic ET obliteration via endonasal and lateral approaches is under development. Whereas ET anatomy has been studied, surgical landmarks have not been previously described or quantified. We aimed to define surgical parameters of specific utility to endoscopic ET obliteration.

Surgical Parameters for Minimally Invasive Trans-Eustachian Tube CSF Leak Repair: A Cadaveric Study and Literature Review.

Noninvasively differentiating therapy-induced pseudoprogression from recurrent disease in patients with glioblastoma is prospectively difficult due to the current lack of a biologically specific imaging metric. Ferumoxytol iron oxide nanoparticle MRI contrast characterizes innate immunity mediated neuroinflammation; therefore, we hypothesized that combined ferumoxytol and gadolinium enhanced MRI could serve as a biomarker of glioblastoma pseudoprogression.

Combined iron oxide nanoparticle ferumoxytol and gadolinium contrast enhanced MRI define glioblastoma pseudoprogression.

Gross total resection of arteriovenous malformations (AVMs) of the central nervous system confirmed by formal angiography is accepted as a cure for patients. In some cases, this may not be possible. Even though in these cases other treatment modalities such as endovascular embolization and radiotherapy can be used, long-term follow-up is lacking in the literature.

Arteriovenous Malformation Presenting as Symptomatic, Enlarging and Contrast-Enhancing Mass 12 Years After Being Treated with Embolization and Radiotherapy.

To quantitatively measure surgical degree of freedom (SDF) to the anterior communicating artery (AComA) complex via removal of the orbital rim. Comparisons of SDF quadrants were made between a supraorbital and standard frontotemporal pterional craniotomy according to the surgeons' geometric microscope compass-based views.

Quantitative measurement of the surgical freedom for anterior communicating artery complex-a comparative study between the frontotemporal pterional and supraorbital craniotomy; a laboratory study.

Article	Year
Genetic variation in soluble epoxide hydrolase: association with outcome after aneurysmal subarachnoid hemorrhage. Journal of neurosurgery\| PubMed ID: 25216066	2014
Protective role of p450 epoxyeicosanoids in subarachnoid hemorrhage. Neurocritical care\| PubMed ID: 25231529	2015
Timing of deep vein thrombosis formation after aneurysmal subarachnoid hemorrhage. Journal of neurosurgery\| PubMed ID: 26162047	2015
Preoperative Lateralization Modalities for Cushing Disease: Is Dynamic Magnetic Resonance Imaging or Cavernous Sinus Sampling More Predictive of Intraoperative Findings? Journal of neurological surgery. Part B, Skull base\| PubMed ID: 26225305	2015
Giant Aneurysmal Bone Cyst of the Anterior Cranial Fossa and Paranasal Sinuses Presenting in Pregnancy: Case Report and Literature Review. Journal of neurological surgery reports\| PubMed ID: 26623230	2015
Dual Endoscopic Endonasal Transsphenoidal and Precaruncular Transorbital Approaches for Clipping of the Cavernous Carotid Artery: A Cadaveric Simulation. Journal of neurological surgery. Part B, Skull base\| PubMed ID: 27857875	2016
Endoscopic Endonasal Transclival Approach versus Dual Transorbital Port Technique for Clip Application to the Posterior Circulation: A Cadaveric Anatomical and Cerebral Circulation Simulatio... Journal of neurological surgery. Part B, Skull base\| PubMed ID: 28593110	2017
Quantitative Anterior and Posterior Clinoidectomy Analysis and Mobilization of the Oculomotor Nerve during Surgical Exposure of the Basilar Apex Using Frameless Stereotaxis. Journal of neurological surgery. Part B, Skull base\| PubMed ID: 28725515	2017
Surgical Parameters for Minimally Invasive Trans-Eustachian Tube CSF Leak Repair: A Cadaveric Study and Literature Review. World neurosurgery\| PubMed ID: 30266704	2019
Combined iron oxide nanoparticle ferumoxytol and gadolinium contrast enhanced MRI define glioblastoma pseudoprogression. Neuro-oncology\| PubMed ID: 30277536	2019
Arteriovenous Malformation Presenting as Symptomatic, Enlarging and Contrast-Enhancing Mass 12 Years After Being Treated with Embolization and Radiotherapy. World neurosurgery\| PubMed ID: 31629146	2020
Quantitative measurement of the surgical freedom for anterior communicating artery complex-a comparative study between the frontotemporal pterional and supraorbital craniotomy; a laboratory ... Acta neurochirurgica\| PubMed ID: 31650332	2019

Aclan Dogan

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