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Peter S. Amenta, Muhammad S. Ali, Aaron S. Dumont, L. Fernando Gonzalez, Stavropoula I. Tjoumakaris, David Hasan, Robert H. Rosenwasser and Pascal Jabbour

Intravenous and intraarterial recombinant tissue plasminogen activator remains underutilized in the treatment of acute ischemic stroke, largely due to strict adherence to the concept of the therapeutic time window for administration. Recent efforts to expand the number of patients eligible for thrombolysis have been mirrored by an evolution in endovascular recanalization technology and techniques. As a result, there is a growing need to establish efficient and reliable means by which to select candidates for endovascular intervention beyond the traditional criteria of time from symptom onset. Perfusion imaging techniques, particularly CT perfusion used in combination with CT angiography, represent an increasingly recognized means by which to identify those patients who stand to benefit most from endovascular recanalization. Additionally, CT perfusion and CT angiography appear to provide sufficient data by which to exclude patients in whom there is little chance of neurological recovery or a substantial risk of postprocedure symptomatic intracranial hemorrhage. The authors review the current literature as it pertains to the limitations of time-based selection of patients for intervention, the increasing utilization of endovascular therapy, and the development of a CT perfusion-based selection of acute stroke patients for endovascular recanalization. Future endeavors must prospectively evaluate the utility and safety of CT perfusion-based selection of candidates for endovascular intervention.

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Nohra Chalouhi, Pascal Jabbour, Robert M. Starke, Stavropoula I. Tjoumakaris, L. Fernando Gonzalez, Samantha Witte, Robert H. Rosenwasser and Aaron S. Dumont

Object

Surgical clipping of posterior inferior cerebellar artery (PICA) aneurysms can be challenging and carries a potentially significant risk of morbidity and mortality. Experience with endovascular therapy has been limited to a few studies. The authors assess the feasibility, safety, and efficacy of endovascular therapy in the largest series of proximal and distal PICA aneurysms to date.

Methods

A total of 76 patients, 54 with proximal and 22 with distal PICA aneurysms, underwent endovascular treatment at Jefferson Hospital for Neuroscience between 2001 and 2011.

Results

Endovascular treatment was successful in 52 patients (96.3%) with proximal aneurysms and 19 patients (86.4%) with distal aneurysms. Treatment consisted of selective aneurysm coiling in 60 patients (84.5%) (including 4 with stent assistance and 4 with balloon assistance) and parent vessel trapping in 11 patients (15.5%). Specifically, a deconstructive procedure was necessary in 9.6% of proximal aneurysms (5 of 52) and 31.6% of distal aneurysms (6 of 19). There were 9 overall procedural complications (12.7%), 6 infarcts (8.5%; 4 occurring after deliberate occlusion of the PICA), and 3 intraprocedural ruptures (4.2%). The rate of procedure-related permanent morbidity was 2.8%. Complete aneurysm occlusion was achieved in 63.4% of patients (45 of 71). One patient (1.4%) treated with selective aneurysm coiling suffered a rehemorrhage on postoperative Day 15. The mean angiographic follow-up time was 17.2 months. Recurrence and re-treatment rates were, respectively, 20% and 17.1% for proximal aneurysms compared with 30.8% and 23.1% for distal aneurysms. Favorable outcomes (moderate, mild, or no disability) at follow-up were seen in 93% of patients with unruptured aneurysms and in 78.7% of those with ruptured aneurysms.

Conclusions

Endovascular therapy is a feasible, safe, and effective treatment in patients with proximal and distal PICA aneurysms, providing excellent patient outcomes and adequate protection against rehemorrhage. The long-term incidence of aneurysm recanalization appears to be high, especially in distal aneurysms, and requires careful angiographic follow-up.

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L. Fernando Gonzalez, Neil R. Crawford, Robert H. Chamberlain, Luis E. Perez Garza, Mark C. Preul, Volker K. H. Sonntag and Curtis A. Dickman

Object. The authors compared the biomechanical stability resulting from the use of a new technique for occipitoatlantal motion segment fixation with an established method and assessed the additional stability provided by combining the two techniques.

Methods. Specimens were loaded using nonconstraining pure moments while recording the three-dimensional angular movement at occiput (Oc)—C1 and C1–2. Specimens were tested intact and after destabilization and fixation as follows: 1) Oc—C1 transarticular screws plus C1–2 transarticular screws; 2) occipitocervical transarticular (OCTA) plate in which C1–2 transarticular screws attach to a loop from Oc to C-2; and (3) OCTA plate plus Oc—C1 transarticular screws.

Occipitoatlantal transarticular screws reduced motion to well within the normal range. The OCTA loop and transarticular screws allowed a very small neutral zone, elastic zone, and range of motion during lateral bending and axial rotation. The transarticular screws, however, were less effective than the OCTA loop in resisting flexion and extension.

Conclusions. Biomechanically, Oc—C1 transarticular screws performed well enough to be considered as an alternative for Oc—C1 fixation, especially when instability at C1–2 is minimal. Techniques for augmenting these screws posteriorly by using a wired bone graft buttress, as is currently undertaken with C1–2 transarticular screws, may be needed for optimal performance.

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Iman Feiz-Erfan, Patrick P. Han, Robert F. Spetzler, Giuseppe Lanzino, Mauro A. T. Ferreira, L. Fernando Gonzalez and Randall W. Porter

Object

Squamous cell carcinoma (SCC) of the head and neck may involve the carotid artery (CA) in the neck or skull base. Whether tumor resection should be associated with sacrifice of the CA is debatable.

Methods

Records obtained in five consecutive patients (three men, and two women; mean age 58 years, range 47–69 years) treated for recurrent or progressive SCC involving the internal carotid artery (ICA) at the skull base were reviewed retrospectively. The ICA was sacrificed, an extracranial–intracranial (EC–IC) bypass was performed using a saphenous vein graft, and the tumor and involved ICA segment were resected.

Gross-total resection of the SCC was achieved in four cases. One patient died of an acute postoperative stroke due to bypass occlusion and did not undergo tumor resection. No other permanent ischemic or neurological deficits were noted. The other four patients died of tumor progression (survival range 2–40 months, mean 14 months). One patient survived for more than 2 years (2-year overall survival rate 20%). Histological tumor invasion of the CA wall was verified in one of the three evaluated specimens.

Conclusions

A high rate of morbidity and mortality is associated with cases in which skull base CA sacrifice and an EC–IC bypass are performed. Not all resected arteries are shown to have malignant infiltration on histological examination. Better preoperative imaging criteria are needed to define malignant infiltration of the ICA at the skull base. Chemotherapy and radiotherapy without aggressive tumor resection may be an option for these patients.

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Nicholas C. Bambakidis, L. Fernando Gonzalez, Sepideh Amin-Hanjani, Vivek R. Deshmukh, Randall W. Porter, Philip C. Daspit and Robert F. Spetzler

Combined approaches to the skull base provide maximal exposure of the complex and eloquent anatomical structures contained within the posterior fossa. Common to these combined exposures are variable degrees of petrous bone removal. Understanding the advantages of each approach is critical when attempting to balance increases in operative exposure against the risk of potential complications. Despite their risks, aggressive combined exposures to the posterior fossa enable the greatest degree of visualization of the anatomy. Consequently, surgeons can approach lesions with maximal margins of safety, which cannot otherwise be realized. To minimize morbidity in all cases, the approach chosen must be applied individually, depending on the lesion and the patient's characteristics.

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Ulises García-González, Daniel D. Cavalcanti, Abhishek Agrawal, L. Fernando Gonzalez, Robert C. Wallace, Robert F. Spetzler and Mark C. Preul

Object

There are few systematic investigations of the dissected surgical anatomy of the diploic venous system (DVS) in the neuroanatomical literature. The authors describe the DVS relative to different common neurosurgical approaches. Knowledge of this system can help avoid potential sources of unacceptable bleeding and may impact healing of the cranium.

Methods

Using a high-speed drill with a 2-mm bit, the authors removed the outer layer of the compact bone in the skull to expose the DVS in 12 formalin-fixed cadaver heads. Pterional, supraorbital, and modified orbitozygomatic craniotomies were performed to delineate the relationship of the DVS.

Results

The draining point of the frontal diploic vein (FDV) was located near the supraorbital notch. The draining point of the anterior temporal diploic vein (ATDV) was located in all pterional areas; the draining point of the posterior temporal diploic vein (PTDV) was located in all asterional areas. The PTDV was the dominant diploic vessel in all sides. The FDV and ATDV could be damaged during supraorbital, modified orbitozygomatic, and pterional craniotomies. The anterior DVS connected with the sphenoparietal and superior sagittal sinus (SSS). The posterior DVS connected with the transverse and sigmoid sinuses and was the dominant diploic vessel in all 24 sides. Of all the major diploic vessels, the location and pattern of distribution of the FDV were the most constant. The parietal bone contained the most diploic vessels. No diploic veins were found in the area delimited by the temporal squama.

Conclusions

The pterional, orbitozygomatic, and supraorbital approaches place the FDV and ATDV at risk. The major anterior diploic system connects the SSS with the sphenoparietal sinus. The posterior diploic system connects the SSS with the transverse and sigmoid sinuses.

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Nohra Chalouhi, Aaron S. Dumont, Stavropoula Tjoumakaris, L. Fernando Gonzalez, Jurij R. Bilyk, Ciro Randazzo, David Hasan, Richard T. Dalyai, Robert Rosenwasser and Pascal Jabbour

Object

Endovascular therapy is the primary treatment option for carotid-cavernous fistulas (CCFs). Operative cannulation of the superior ophthalmic vein (SOV) provides a reasonable alternative route to the cavernous sinus when all transvenous and transarterial approaches have been unsuccessful. The role of the liquid embolic agent Onyx in the management of CCFs has not been well documented, especially when using an SOV approach. The purpose of this study is to assess the safety and efficacy of Onyx embolization of CCFs through a surgical cannulation of the SOV.

Methods

The authors retrospectively reviewed all patients with CCFs who were treated with Onyx through an SOV approach between April 2009 and April 2011. Traditional endovascular approaches had failed in all patients.

Results

A total of 10 patients were identified, 1 with a Type A CCF, 5 with a Type B CCF, and 4 with a Type D CCF. All fistulas were embolized in 1 session. Onyx was the sole embolic agent used in 7 cases and was combined with coils in 3 other cases. Complete obliteration was achieved in 8 patients and a significant reduction in fistulous flow was achieved in 2 patients, which later progressed to near-complete occlusion on angiographic follow-up. All patients experienced a complete clinical recovery with excellent cosmetic results and were free from recurrence at their latest clinical follow-up evaluations.

Conclusions

Onyx embolization is an excellent therapy for CCFs in general, and through an SOV approach in particular. Direct operative cannulation of the SOV followed by Onyx embolization may be the best treatment option in patients with CCFs when all other endovascular approaches have been exhausted.

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Nohra Chalouhi, Cory D. Bovenzi, Vismay Thakkar, Jeremy Dressler, Pascal Jabbour, Robert M. Starke, Sonia Teufack, L. Fernando Gonzalez, Richard Dalyai, Aaron S. Dumont, Robert Rosenwasser and Stavropoula Tjoumakaris

Object

Aneurysm recurrence after coil therapy remains a major shortcoming in the endovascular management of cerebral aneurysms. The need for long-term imaging follow-up was recently investigated. This study assessed the diagnostic yield of long-term digital subtraction angiography (DSA) follow-up and determined predictors of delayed aneurysm recurrence and retreatment.

Methods

Inclusion criteria were as follows: 1) available short-term and long-term (> 36 months) follow-up DSA images, and 2) no or only minor aneurysm recurrence (not requiring further intervention, i.e., < 20%) documented on short-term follow-up DSA images.

Results

Of 209 patients included in the study, 88 (42%) presented with subarachnoid hemorrhage. On shortterm follow-up DSA images, 158 (75%) aneurysms showed no recurrence, and 51 (25%) showed minor recurrence (< 20%, not retreated). On long-term follow-up DSA images, 124 (59%) aneurysms showed no recurrence, and 85 (41%) aneurysms showed recurrence, of which 55 (26%) required retreatment. In multivariate analysis, the predictors of recurrence on long-term follow-up DSA images were as follows: 1) larger aneurysm size (p = 0.001), 2) male sex (p = 0.006), 3) conventional coil therapy (p = 0.05), 4) aneurysm location (p = 0.01), and 5) a minor recurrence on short-term follow-up DSA images (p = 0.007). Ruptured aneurysm status was not a predictive factor. The sensitivity of short-term follow-up DSA studies was only 40.0% for detecting delayed aneurysm recurrence and 45.5% for detecting delayed recurrence requiring further treatment.

Conclusions

The results of this study highlight the importance of long-term angiographic follow-up after coil therapy for ruptured and unruptured intracranial aneurysms. Predictors of delayed recurrence and retreatment include large aneurysms, recurrence on short-term follow-up DSA images (even minor), male sex, and conventional coil therapy.

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Gregory P. Lekovic, L. Fernando Gonzalez, Andrew G. Shetter, Randall W. Porter, Kris A. Smith, David Brachman and Robert F. Spetzler

Object

Increasingly, radiosurgery is used to treat pineal region tumors, either as a primary treatment or as an adjunct to conventional radiation therapy. The authors report their experience with Gamma Knife surgery (GKS) for the treatment of pineal region tumors.

Methods

The authors retrospectively reviewed the charts of all patients undergoing GKS at their institution between 1997 and 2005. Seventeen patients underwent GKS for nonmetastatic tumors of the pineal region. All patients were treated using Leksell Gamma Plan treatment planning software (versions 4.12::5.34). The mean treatment volume was 7.42 cm3 (range 1.2–32.5 cm3). Prescribed doses ranged from 12 to 18 Gy. All doses were prescribed to the 50% isodose line. Independent neuroradiologists reviewed all follow-up imaging studies for evidence of progression of disease.

Results

One patient (Case 10) died 6 days after GKS. Mean clinical and imaging follow-up in the remaining 16 cases was 31 months. Local control was established during a mean neuroimaging follow-up period of 31 months (range 1–95) in 16 patients (100%). In 2 of these 16 patients (one with an anaplastic astrocytoma, the other with a primitive neuroectodermal tumor), leptomeningeal and spinal spread of tumor developed despite control of the pineal lesions. There were no new neurological deficits attributable to GKS. Three patients died (including the one who died 6 days after GKS) during the follow-up period.

Conclusions

Excellent control of pineal region brain tumors can be obtained with GKS when it is used in conjunction with surgery, conventional radiation therapy, or both. Patient survival and quality of life can be optimized through the use of multimodal treatment, including surgery, conventional radiation therapy and/or radiosurgery, and chemotherapy, when applicable.

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Vijay Agarwal, Ali Zomorodi, Pascal Jabbour, Nohra Chalouhi, Stavropoula Tjoumakaris, Ranjith Babu, Adam Back and L. Fernando Gonzalez

We present a case of a patient with rapid loss of motor strength in his lower extremities. He became bedridden with bowel and bladder incontinence, and developed saddle anesthesia. MRI of the lumbar spine showed edema in the conus medullaris and multiple flow voids within the spinal canal. A spinal angiogram showed a dorsal Type I spinal AVF. This was treated successfully with Onyx 18 (eV3, Irvine, CA). The patient showed rapid post-procedure improvement, and at discharge from the hospital to a rehabilitation center he was fully ambulatory. At 3-year follow-up, the patient was found to ambulate without difficulty. He also had improved saddle anesthesia, and he was voiding spontaneously. There was no evidence of flow voids on repeat MRI of the lumbar spine.

The video can be found here: http://youtu.be/SDYNIGNQIW8.