Cervical radiculopathy secondary to compression from congenital anomalous vertebral arteries (VAs) is a known entity. Patients present with a variety of symptoms ranging from upper-extremity numbness to true occipital neuralgia. Treatment options for extracranial tortuous VAs include conservative management or some form of surgical microvascular decompression (MVD). The authors report on a patient with a congenital anomalous VA loop causing cervical nerve root compression. Successful MVD was conducted with relief of the patient's symptoms. A novel sling technique was used for mobilization of the VA. To the authors' knowledge, this is the first MVD described utilizing this technique.
Adesh Tandon, Sid Chandela, David Langer and Chandranath Sen
Sid Chandela, Juan Alzate, Chandranath Sen, Joon Song, Yasunari Nimi, Alejandro Berenstein and David Langer
✓Endovascular and cerebral bypass therapies are rarely used in children. The authors describe the treatment of a partially coiled giant distal vertebral artery (VA)–posterior inferior cerebellar artery (PICA) aneurysm in a child. They performed a side-to-side PICA–PICA anastomosis followed by endovascular VA aneurysm deconstruction with PICA preservation.
A healthy 11-year-old boy developed progressive holocephalic headaches over the course of 2 months. Magnetic resonance imaging and magnetic resonance angiography revealed a large right PICA aneurysm causing brainstem compression. In November 2005, 2 Neuroform stents and Guglielmi detachable coils and Matrix were placed in the aneurysm at an outside institution. In 2006, angiography demonstrated aneurysm enlargement from which the PICA originated, coil compaction, and increased mass effect. The patient underwent a PICA–PICA bypass with intraoperative flow measurements followed by endovascular embolization of the aneurysm and parent VA. An angiogram obtained after the procedure demonstrated filling of the right PICA medullary branch through the bypass and obliteration of the aneurysm. The patient remained neurologically intact.
Giant aneurysms of the posterior circulation are rare but do occur in children. With the aid of combined surgical and endovascular strategies the authors were able to safely eliminate the aneurysm from circulation with good outcome. Cerebral bypass and endovascular deconstructive therapies can be used safely in children but should be reserved for cases in which direct treatment carries significant risk. Careful surgical and endovascular planning with intraoperative flow assessment is essential for good outcome.
Andrea Szelényi, David Langer, Karl Kothbauer, Adauri Bueno de Camargo, Eugene S. Flamm and Vedran Deletis
The authors in this study evaluated muscle motor evoked potentials (MMEPs) elicited by transcranial electrical stimulation (TES) and direct cortical stimulation as a means of monitoring during cerebral aneurysm surgery. The analysis focused on the value and frequencies of any intraoperative changes and their correlation to the postoperative motor status.
One hundred nineteen patients undergoing surgery for 148 cerebral aneurysms were included in the study. Muscle motor evoked potentials were elicited by a train of five constant-current anodal stimuli with an individual pulse duration of 0.5 msec and a stimulation rate of 2 Hz. Stimulation intensity was up to 240 mA for TES and up to 33 mA for direct cortical stimulation. The MMEPs were continuously recorded from the abductor pollicis brevis and tibialis anterior muscles bilaterally and from the biceps brachii and extensor digitorum communis muscles contralateral to the surgical side. The motor status was evaluated immediately after surgery and 7 days later.
In 97% of the patients MMEPs were recordable for continuous neurophysiological monitoring of the vascular territory of interest throughout the surgery. In 14 patients significant intraoperative MMEP changes occurred, resulting in a transient motor deficit in one patient and a permanent motor deficit in six. The permanent loss of MMEPs in three patients was followed by a permanent severe motor deficit in one patient and severe clinical deterioration in the other two.
Data in this study demonstrated that MMEPs are a useful means of intraoperative neurophysiological monitoring of motor pathway integrity and predicting postoperative motor status. The intraoperative loss of MMEPs reliably predicts both severe and permanent postoperative motor deficits.
Elad I. Levy, Adnan H. Siddiqui, L. Nelson Hopkins, David J. Langer and Christopher S. Ogilvy
Navraj S. Heran, Joon K. Song, Mark J. Kupersmith, Yasunari Niimi, Katsunari Namba, David J. Langer and Alejandro Berenstein
The optimal therapy for ophthalmic segment aneurysms with anterior optic pathway compression (AOPC) is undecided. Surgical results have been described, but the results of endovascular coil therapy have not been well documented.
The authors retrospectively reviewed data obtained in all patients who harbored unruptured ophthalmic segment aneurysms with AOPC who underwent endovascular coil therapy at their institution. They analyzed baseline and outcome visual function, aneurysm features, extent of aneurysm closure, internal carotid artery (ICA) occlusion, additional interventions, and neurological outcome.
In 17 patients (16 women), age 38 to 83 years, there were 28 affected eyes. All aneurysms were greater than 10 mm in diameter. In the initial procedures 16 of 17 patients received endosaccular coils and the ICA was preserved; in one patient the aneurysm was trapped and the ICA occluded. Patients then underwent follow up for a mean of 2.90 years (range 1 month–11.2 years) after the last procedure. One patient died of subarachnoid hemorrhage (SAH) 1 month postoperatively and thus no follow-up data were available for this case. Vision worsened in six patients, stabilized in four, and improved in six. Twelve patients underwent 13 subsequent procedures, including endovascular ICA occlusion in seven, repeated coil therapy in five, and optic nerve decompression in one; vision improved in 83% of these cases after ICA occlusion. A second patient died of SAH 5 months after repeated coil treatment. At the final follow up, vision had improved in eight patients (50%), stabilized in four (25%), and worsened in four (25%). In 16 patients with follow-up studies, aneurysm closure was complete in eight (50%) and incomplete in eight (50%).
The authors found that in patients with ophthalmic segment aneurysms causing chronic AOPC, endosaccular platinum coil therapy, with ICA preservation, may not benefit vision and that additional procedures may be needed. Evaluation of their results suggests that endovascular trapping of the aneurysm and sacrifice of the ICA appear to result in good visual, clinical, and anatomical outcomes.
An emerging technology for use in the creation of intracranial–intracranial and extracranial–intracranial cerebral bypass
David J. Langer, Albert Van Der Zwan, Peter Vajkoczy, Leena Kivipelto, Tristan P. Van Doormaal and Cornelis A. F. Tulleken
Excimer laser–assisted nonocclusive anastomosis (ELANA) has been developed over the past 14 years for assistance in the creation of intracranial bypasses. The ELANA technique allows the creation of intracranial–intracranial and extracranial–intracranial bypasses without the need for temporary occlusion of the recipient artery, avoiding the inherent risk associated with occlusion time. In this review the authors discuss the technique and its indications, while reviewing the clinical results of the procedure. The technique itself is explained using cartoon drawings and intraoperative photographs. Advantages and disadvantages of the technique are also discussed.
Roberto C. Heros
David J. Langer, Joon K. Song, Yasunari Niimi, Markus Chwajol, Daniel R. Lefton, Jonathan L. Brisman, Walter Molofsky, Mark J. Kupersmith and Alejandro Berenstein
✓ In patients with vein of Galen malformations, high-flow shunting decreases cerebral perfusion. By reducing or eliminating these shunts, transarterial embolization can improve cerebral perfusion and clinical outcomes. Quantifying pre-and postembolization shunt blood flow may help determine the optimal timing and efficacy of embolization and may provide prognostic information. The authors used magnetic resonance imaging noninvasive optimal vessel analysis as a novel modality to measure volumetric blood flow through vein of Galen malformation shunts in a neonate and an infant before and after transarterial embolization.
Timothy G. White, Hussam Abou-Al-Shaar, Jung Park, Jeffrey Katz, David J. Langer and Amir R. Dehdashti
Cerebral revascularization for carotid occlusion was previously a mainstay procedure for the cerebrovascular neurosurgeon. However, the 1985 extracranial-intracranial bypass trial and subsequently the Carotid Occlusion Surgery Study (COSS) provided level 1 evidence via randomized controlled trials against bypass for symptomatic atherosclerotic carotid occlusion disease. However, in a small number of patients optimal medical therapy fails, and some patients with flow-limiting stenosis develop a perfusion-dependent neurological examination. Therefore it is necessary to further stratify patients by risk to determine who may most benefit from this intervention as well as to determine perioperative morbidity in this high-risk patient population.
A retrospective review was performed of all revascularization procedures done for symptomatic atherosclerotic cerebrovascular steno-occlusive disease. All patients undergoing revascularization after the publication of the COSS in 2011 were included. Perioperative morbidity and mortality were assessed as the primary outcome to determine safety of revascularization in this high-risk population. All patients had documented hypoperfusion on hemodynamic imaging.
At total of 35 revascularization procedures were included in this review. The most common indication was for patients with recurrent strokes, who were receiving optimal medical therapy and who suffered from cerebrovascular steno-occlusion. At 30 days only 3 perioperative ischemic events were observed, 2 of which led to no long-term neurological deficit. Immediate graft patency was good, at 94%. Long term, no further strokes or ischemic events were observed, and graft patency remained high at 95%. There were no factors associated with perioperative ischemic events in the variables that were recorded.
Cerebral revascularization may be done safely at high-volume cerebrovascular centers in high-risk patients in whom optimal medical therapy has failed. Further research must be done to develop an improved methodology of risk stratification for patients with symptomatic atherosclerotic cerebrovascular steno-occlusive disease to determine which patients may benefit from intervention. Given the high risk of recurrent stroke in certain patients, and the fact that patients fail medical therapy, surgical revascularization may provide the best method to ensure good long-term outcomes with manageable up-front risks.