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Ciaran J. Powers and Allan H. Friedman

✓The authors present a brief and selective history of surgery for peripheral nerve tumors to illustrate how the current understanding of the nature of disease influences the choice of surgical intervention. There was very little understanding of the anatomy and function of peripheral nerves in ancient times; consequently, surgical treatments for peripheral nerve tumors were based on the writings of authorities. The confusion between traumatic neuromas and genuine nerve sheath tumors coupled with the belief that manipulation of a peripheral nerve might be lethal to the patient stifled the development of surgical techniques for the management of nerve tumors in the 18th and 19th centuries. It was not until the 20th century, with an increased understanding of the microscopic anatomy of nerve sheath tumors, that efficacious surgical treatments for these diseases were developed. Continued advances in the understanding of the biology of these tumors will continue to impact their surgical management.

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Shahid M. Nimjee, Ciaran J. Powers and Ketan R. Bulsara

✓In this paper the authors review the literature concerning de novo cavernoma formation after radiation treatment. PubMed and MEDLINE database searches were performed. Data were compiled on all patients in whom de novo cavernomas formed after radiation treatment and whose cases were reported in the literature. The authors found reports in the literature of 76 patients in whom cavernomas formed de novo after radiation treatment. The mean age of the patients was 11.7 years, and the majority of these lesions occurred in males. The patients received a mean radiation dose of 60.45 Gy. The mean latency period before detection of the cavernoma was 8.9 years, and most of these lesions were detected incidentally. In symptomatic patients, the most common presenting symptoms were seizures. Thirty-seven of the patients had evidence of hemorrhage, and 54% of these required surgical intervention.

De novo formation of cavernomas after radiation treatment is a relatively rare phenomenon. Patients in whom these cavernomas develop need to be followed closely because there is a propensity for the lesions to hemorrhage. Surgical intervention to treat symptomatic lesions has a favorable outcome.

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Ciaran J. Powers, Timothy George and Herbert E. Fuchs

✓Ventriculoperitoneal (VP) shunt failure is a common problem encountered by pediatric neurosurgeons. The majority of such failures are due to obstruction of the device. Conditions in which intraabdominal pressure is chronically elevated, such as pregnancy, have been associated with shunt failure. Chronic constipation may also result in abnormally elevated intraabdominal pressure and may be an underrecognized cause of distal VP shunt failure. The authors describe the cases of two children who presented with clinical and imaging evidence of VP shunt failure and who were also severely constipated. Treatment of their constipation resulted in both clinical and imaging-documented resolution of their shunt failure.

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Ciaran J. Powers, Vinod K. Podichetty and Robert E. Isaacs

✓ Pedicle screw (PS) instrumentation provides an exceptionally rigid construct to promote fusion in cases of spinal trauma and degenerative disease. Although the safety of traditional open techniques for PS placement has been well documented, there are no large series in the literature in which the safety of percutaneously placed PSs has been examined. Because the advantages of minimally invasive spine surgery are becoming more widely recognized, especially in regard to the lessening of morbidity caused by pain and blood loss, there will be a greater demand for spine surgeons to place PSs percutaneously. During a 2-year period, the authors placed 287 PSs percutaneously with the aid of intraoperative fluoroscopy. Only one of these screws was later found to have breached the spinal canal, yielding a breach rate of 0.35% for percutaneously placed PSs (one of 287).

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Urinary tract infection

Ciaran J. Powers and E. Antonio Chiocca

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Ciaran J. Powers, Catherine C. Pizzi, Thomas J. Cummings and Allan H. Friedman

✓ The authors report on an unusual case of a primary intracranial myxoma in a 39-year-old woman. The patient presented with headache and generalized seizure. Magnetic resonance imaging revealed a large right frontal tumor resembling a parasagittal meningioma. A gross-total resection was performed, and histological review confirmed the lesion as a myxoma. Results of additional workup revealed the absence of a primary myxoma elsewhere. This case represents the third published report of a primary intracranial myxoma and the second report of a supratentorial myxoma.

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David Dornbos III, Constantine L. Karras, Nicole Wenger, Blake Priddy, Patrick Youssef, Shahid M. Nimjee and Ciarán J. Powers


The utilization of the Pipeline embolization device (PED) has increased significantly since its inception and original approval for use in large, broad-necked aneurysms of the internal carotid artery. While microsurgical clipping and advances in endovascular techniques have improved overall efficacy in achieving complete occlusion, recurrences still occur, and the best modality for retreatment remains controversial. Despite its efficacy in this setting, the role of PED utilization in the setting of recurrent aneurysms has not yet been well defined. This study was designed to assess the safety and efficacy of PED in the recurrence of previously treated aneurysms.


The authors reviewed a total of 13 cases in which patients underwent secondary placement of a PED for aneurysm recurrence following prior treatment with another modality. The PEDs were used to treat aneurysm recurrence or residual following endovascular coiling in 7 cases, flow diversion in 2, and microsurgical clipping in 4. The mean time between initial treatment and retreatment with a PED was 28.1 months, 12 months, and 88.7 months, respectively. Clinical outcomes, including complications and modified Rankin Scale (mRS) scores, and angiographic evidence of complete occlusion were tabulated for each treatment group.


All PEDs were successfully placed without periprocedural complications. The rate of complete occlusion was 80% at 6 months after PED placement and 100% at 12 months in these patients who underwent PED placement following failed endovascular coiling; there were no adverse clinical sequelae at a mean follow-up of 26.1 months. In the 2 cases in which PEDs were placed for treatment of residual aneurysms following prior flow diversion, 1 patient demonstrated asymptomatic vessel occlusion at 6 months, and the other exhibited complete aneurysm occlusion at 12 months. In patients with aneurysm recurrence following prior microsurgical clipping, the rate of complete occlusion was 100% at 6 and 12 months, with no adverse sequelae noted at a mean clinical follow-up of 27.7 months.


The treatment of recurrent aneurysms with the PED following previous endovascular coiling, flow diversion, or microsurgical clipping is associated with a high rate of complete occlusion and minimal morbidity.

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Shahid M. Nimjee, Ciaran J. Powers, Roger E. McLendon, Gerald A. Grant and Herbert E. Fuchs

Cerebrospinal fluid overproduction resulting in communicating hydrocephalus is observed in patients who have choroid plexus papilloma or choroid plexus carcinoma. Less often, patients with these conditions have diffuse villous hyperplasia. Prior studies report CSF production greater than 3 L per day in these patients. These patients are treated with CSF shunting or by either unilateral choroid plexectomy or staged bilateral choroid plexectomy. The authors present a patient who had a number of congenital anomalies and a karyotype that revealed balanced translocations, 5 to 7 and 9 to 11. She presented with hydrocephalus and had CSF production of 5 L per day, greater output than ever previously reported. She was treated with a single-stage bilateral choroid plexectomy. Histopathological analysis revealed a bilateral choroid plexus papilloma. Postoperatively, the patient responded well clinically and showed radiographic improvement of her hydrocephalus. Bilateral choroid plexus papilloma has been reported in the literature as a cause for neonatal and congenital hydrocephalus. It can result in high CSF output and can be successfully treated with a single-stage bilateral choroid plexectomy. Further studies are ongoing to identify genes involved in embryogenesis of the choroid plexus.

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Ciaran J. Powers, Ali R. Zomorodi, Gavin W. Britz, David S. Enterline, Michael J. Miller and Tony P. Smith


Inadvertent catheterization of brachiocephalic arteries (carotid artery, subclavian artery, or vertebral artery) during attempted placement of a central venous catheter can have potentially disastrous complications. While removal of the catheter in the operating room is almost always an option, there are circumstances in which a less invasive approach may be more appropriate. The authors present their experience using endovascular techniques for removal of inadvertently placed central venous catheters to elucidate potential options for successful nonsurgical management.


The authors reviewed their database of interventional procedures that occurred between January 1, 2000, and February 1, 2009. All cases referred for management of suspected brachiocephalic arterial catheterization or arterial injury after attempted placement of a central venous catheter were included. Medical records and radiological imaging were reviewed to determine patient demographics, clinical situation, methods for removal, as well as clinical and imaging follow-up.


A total of 13 patients, ranging in age from 31 to 88 years old, were referred to interventional radiology for management of suspected inadvertent arterial catheterization of the brachiocephalic arteries. Angiography confirmed arterial catheterization in 9 patients. Three patients were referred after developing uncontrolled hemorrhage or expanding hematomas following attempted catheterization. One patient who had an arterial waveform after placement of an internal jugular catheter was found to have early venous filling from a dialysis fistula requiring no intervention. Ten patients were treated in the interventional suite using angiographically monitored manual pressure (1 patient), balloon tamponade (3 patients), use of a percutaneous closure device (1 patient), stent grafting (4 patients), or embolization of the injured vessel alone (1 patient). One patient was taken to the operating room for removal of the inadvertently placed catheter due to vessel thrombosis. No procedural complications were encountered, and no patient required sacrifice of a major brachiocephalic vessel.


Angiographic evaluation of patients who underwent inadvertent catheterization of brachiocephalic arteries or their branches allowed successful endovascular treatment or excluded the need for intervention in 12 (92%) of 13 patients. The choice and use of specific endovascular techniques should be dictated by patient factors and the vessel inadvertently catheterized.

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Benjamin L. Brown, Demetrius Lopes, David A. Miller, Rabih G. Tawk, Leonardo B. C. Brasiliense, Andrew Ringer, Eric Sauvageau, Ciarán J. Powers, Adam Arthur, Daniel Hoit, Kenneth Snyder, Adnan Siddiqui, Elad Levy, L. Nelson Hopkins, Hugo Cuellar, Rafael Rodriguez-Mercado, Erol Veznedaroglu, Mandy Binning, J Mocco, Pedro Aguilar-Salinas, Alan Boulos, Junichi Yamamoto and Ricardo A. Hanel


The authors sought to determine whether flow diversion with the Pipeline Embolization Device (PED) can approximate microsurgical decompression in restoring function after cranial neuropathy following carotid artery aneurysms.


This multiinstitutional retrospective study involved 45 patients treated with PED across the United States. All patients included presented between November 2009 and October 2013 with cranial neuropathy (cranial nerves [CNs] II, III, IV, and VI) due to intracranial aneurysm. Outcome analysis included clinical and procedural variables at the time of treatment as well as at the latest clinical and radiographic follow-up.


Twenty-six aneurysms (57.8%) were located in the cavernous segment, while 6 (13.3%) were in the clinoid segment, and 13 (28.9%) were in the ophthalmic segment of the internal carotid artery. The average aneurysm size was 18.6 mm (range 4–35 mm), and the average number of flow diverters placed per patient was 1.2. Thirty-eight patients had available information regarding duration of cranial neuropathy prior to treatment. Eleven patients (28.9%) were treated within 1 month of symptom onset, while 27 (71.1%) were treated after 1 month of symptoms. The overall rate of cranial neuropathy improvement for all patients was 66.7%. The CN deficits resolved in 19 patients (42.2%), improved in 11 (24.4%), were unchanged in 14 (31.1%), and worsened in 1 (2.2%). Overtime, the rate of cranial neuropathy improvement was 33.3% (15/45), 68.8% (22/32), and 81.0% (17/21) at less than 6, 6, and 12 months, respectively. At last follow-up, 60% of patients in the isolated CN II group had improvement, while in the CN III, IV, or VI group, 85.7% had improved. Moreover, 100% (11/11) of patients experienced improvement if they were treated within 1 month of symptom onset, whereas 44.4% (12/27) experienced improvement if they treated after 1 month of symptom onset; 70.4% (19/27) of those with partial deficits improved compared with 30% (3/10) of those with complete deficits.


Cranial neuropathy caused by cerebral aneurysm responds similarly when the aneurysm is treated with the PED compared with open surgery and coil embolization. Lower morbidity and higher occlusion rates obtained with the PED may suggest it as treatment of choice for some of these lesions. Time to treatment is an important consideration regardless of treatment modality.