The Rist radial access system: a multicenter study of 152 patients.

BACKGROUND: Transradial access (TRA) for neurointervention is becoming increasingly popular as experience with the technique grows. Despite reasonable efficacy using femoral catheters off-label, conversion to femoral access occurs in approximately 8.6-10.3% of TRA cases, due to an inability of the catheter to track into the vessel of interest, lack of support, or radial artery spasm. METHODS: This is a multicenter, retrospective case series of patients undergoing neurointerventions using the Rist Radial Access System. We also present our institutional protocol for using the system. RESULTS: 152 patients were included in the cohort. The most common procedure was flow diversion (28.3%). The smallest radial diameter utilized was 1.9 mm, and 44.1% were performed without an intermediate catheter. A majority of cases (96.1%) were completed successfully; 3 (1.9%) required conversion to a different radial catheter, 2 (1.3%) required conversion to femoral access, and 1 (0.7%) was aborted. There was 1 (0.7%) minor access site complication and 4 (2.6%) neurological complications. CONCLUSIONS: The Rist catheter is a safe and effective tool for a wide range of complex neurointerventions, with lower conversion rates than classically reported.

A comparison of dual-lumen balloon and simple microcatheters in the embolization of DAVFs and AVMs using onyx.

Endovascular embolization of arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) has become the mainstay in treatment for these pathologies. Traditional techniques required the formation of a proximal plug of Onyx around the microcatheter prior to embolization to avoid reflux. Recently, dual-lumen balloon catheters have been introduced as a potential solution to this issue. We sought to compare our institutional experience with dual-lumen balloons to traditional microcatheters in the endovascular embolization of AVMs and DAVFs. A retrospective analysis of consecutive patients treated with Scepter between 2016 and 2020 was obtained. A control cohort treated with Marathon between 2012 and 2020 was also obtained. Variables collected included patient demographics, procedure times, pedicles treated, operative complications, obliteration rate, and retreatment rate. A total of 44 trial (30 DAVFs and 14 AVMs) and 25 control (15 DAVFs and 10 AVMs) subjects were identified. Average Scepter procedure times were 66.0 and 68.0 min for DAVFs and AVMs, respectively. Average Scepter volume of Onyx injected was 2.2 and 1.4 mL for DAVFs and AVMs, respectively. Complete angiographic occlusion Scepter rate was 86.7% and 50.0% for DAVFs and AVMs, respectively. The Scepter retreatment rate was 13.3% and 50.0% for DAVFs and AVMs, respectively. Predictors of angiographic occlusion included the number of pedicles (OR 0.54, 95%CI 0.30-0.97, p = 0.04). Predictors of retreatment included DAVF (OR 0.16, 95%CI 0.04-0.66, p = 0.01) and Marathon (OR 3.34, 95%CI 1.00-11.56, p = 0.05). Our study shows that dual-lumen balloon catheters are a viable option in the embolization of DAVFs and AVMs.

Pediatric Middle Cerebral Artery Occlusion with Dissection Following a Trampoline Trauma.

BACKGROUND: Owing to the rarity of acute ischemic stroke in the pediatric population, evidence supporting the efficacy in children of the various treatments used in adults is scanty. This included mechanical thrombectomy for acute ischemic stroke. CASE DESCRIPTION: we present the case of an 11-year-old female with acute left hemiparesis, numbness, and left facial droop occurring after tumbling on a trampoline. Computed tomography angiography revealed an 11-mm nonfilling defect in the right middle cerebral artery. She underwent thrombectomy approximately 8.5 hours after the onset of symptoms, and a Thrombolysis in Cerebral Infarction (TICI) scale score of 2b was achieved. She had an uneventful postoperative recovery. CONCLUSION: Pediatric patients likely have more reserve and collateral flow and benefit from a longer therapeutic window following acute ischemic stroke.

Onyx Embolization of Spinal Arteriovenous Fistula via Scepter Balloon.

BACKGROUND: Spinal arteriovenous fistulas (AVFs) are a rare entity that can have devastating neurologic outcomes. Currently, these lesions are treated via open microsurgical resection or transarterial embolization with good success. However, some patients cannot be treated with a minimally invasive endovascular technique secondary to difficulty catheterizing their vascular anatomy. Our aim is to present a case of balloon-assisted Onyx embolization of a spinal AVF. CASE DESCRIPTION: We present the case of a 59-year-old male with progressive lower back pain with lower-extremity weakness. We performed a spinal angiogram where an AVF was identified with very torturous anatomy. The patient was originally treated with open microsurgical resection; however, ≈6 weeks later the fistula and symptoms returned. At that time, we were able to treat the lesion with the Scepter-C balloon. CONCLUSIONS: We present a challenging case in which normal embolization microcatheters were unable to navigate difficult anatomy, but we were able to gain access and obliterate the fistula by using a balloon catheter.

Bilateral Mechanical Thrombectomies for Simultaneous MCA Occlusions.

BACKGROUND: Bilateral hemispheric dysfunction is devastating to consciousness. We present a unique case of a patient who developed bilateral middle cerebral artery infarcts with significant neurological improvement post bilateral thrombolysis in cerebral infarction (TICI) 3 thrombectomies. CASE DESCRIPTION: The patient is a 64-year-old woman who presented 3 hours after her husband was awakened and found her with left hemiplegia. She had a history of atrial fibrillation and had her apixaban held for 5 days before the coronary angiogram that she received the day before arrival. Upon presentation, she was antigravity on the right side and withdrawing on the left side. Computed tomography angiogram showed a right M1 occlusion and an left M2 occlusion. Computed tomography perfusion revealed a mismatch with large penumbra, and she was taken for mechanical thrombectomy. Mechanical thrombectomy was performed using a combination of stent retriever and aspiration catheter with a TICI 3 revascularization. By the following morning, the patient was full strength on the right and antigravity on the left with a left facial droop. The patient recovered her speech and was fully oriented before leaving for rehabilitation on postoperative day 3. CONCLUSIONS: The transient hypercoagulable state that was created with the withdrawal of apixaban likely increased our patient's risk of stroke. The literature supports continuing oral anticoagulants for endovascular procedures. The devastating consequences of thromboembolic events, whether stroke or pulmonary embolism, can be catastrophic, but luckily, mechanical thrombectomy provides the means to minimize the morbidity and mortality from bilateral infarctions.

A Morphometric Analysis for the Feasibility of Percutaneous Translacerum Access of the Internal Carotid Artery Based on Computed Tomography Angiography.

BACKGROUND: The increasing frequency of elderly patients with severe tortuous anatomy, especially when combined with fibromuscular dysplasia, can make intracranial canalization severely difficult or impossible. Computed tomography angiography was used to determine the feasibility of accessing the internal carotid artery (ICA) via a percutaneous translacerum approach. METHODS: Twenty consecutive stroke activations with CT angiography were reconstructed in three-dimensional models to take measurements to assess if currently available technologies could safely provide access. We assessed the diameter of the foramen lacerum and ICA. Entry points and angulations were measured based on trajectory. Our trajectory was based on anatomic observations that provided a safe corridor from the angle of the jaw to the foramen lacerum. RESULTS: Based on the 40 carotid arteries from 20 patients, 77.5% had a large enough foramen lacerum to provide access to the ICA. Although there were no traversals of the pharynx, we noted a 20% traversal of the eustachian tube and 5% traversal of a small maxillary artery branch. There was no large-vessel traversal by the trajectory. All patients with bilateral stenotic foramen lacerum were African-American women; 44% of African-American women had bilateral stenotic foramen lacerum. The diameter of the ICA and foramen lacerum would not be prohibitive of sheath placement in patients without stenosis with adequate canalized length of sheath necessary for stability. CONCLUSIONS: Access of the ICA via the foramen lacerum can be safely performed with currently available technologies.

Dural arteriovenous fistula associated with a glomus jugulare tumour presenting with only pulsatile tinnitus.

We present the second known case of a dural arteriovenous fistula (DAVF) associated with a glomus jugulare tumour in a 66-year-old man and the first with a presenting symptom of pulsatile tinnitus. The tumour occluded the left internal jugular vein at the bulb. Our patient opted for monitoring, but the tinnitus progressed and became debilitating, prompting him to proceed with embolisation of the tumour. Angiography revealed a DAVF of the left transverse sinus with retrograde flow. Embolisation of 80% of the tumour did not relieve symptoms. The patient returned for embolisation of the DAVF. Occlusion of the DAVF achieved symptomatic relief. A quandary develops during a procedure when the surgeon discovers that another intervention could satisfy the patient, while the patient is under anaesthesia. The higher flow in the DAVF likely causes the tinnitus in those with a patent sigmoid sinus, and embolisation of the DAVF alone could achieve relief.

One-piece Orbitozygomatic Craniotomy for Resection of Rathke's Cleft Cyst: Operative Video.

Objective The video stars orbitozygomatic resection of Rathke's cleft cyst with suprasellar extension in a 37-year-old male patient presenting with severe headaches and bitemporal hemianopia. Clinical and radiological characteristics along with surgical technique (positioning, bony opening, surgical dissection and debulking, closure), histopathology, and postoperative course are described. Methods Preoperative MRI demonstrated a noncontrast-enhancing cystic lesion in the sella with suprasellar extension causing compression of both optic nerves. A one-piece orbitozygomatic craniotomy was performed. The tumor was encountered in the interoptic space. First, the cyst was decompressed and fluid appearing like motor oil was aspirated. Both optic nerves were decompressed and dissected free from the cyst wall. Intraoperatively, the most challenging aspect was separating the tumor from surrounding vascular structures, including bilateral A1 arteries and the left carotid bifurcation. A combination of sharp and blunt dissection was utilized to free the tumor from adhesions to critical neurovascular structures. Once freed, the suprasellar aspect of the tumor was mobilized into the operative cavity and debulked. Finally, the sellar component of the tumor was removed all the way down to the sellar floor. Postoperative MRI demonstrated decompressed bilateral optic nerves with an intact pituitary stalk with preservation of normal pituitary gland. Histopathology identified pathognomonic features consistent with diagnosis of Rathke's cleft cyst, including flattened ciliated epithelium and presence of Rathke's cleft remnants. Results Postoperatively, bilateral improvement in vision was noted with transient diabetes insipidus. Patient was discharged home on postoperative day 4. Conclusion A one-piece orbitozygomatic craniotomy is an effective and safe strategy for resection of Rathke's cleft cysts with suprasellar extension. The link to the video can be found at: https://youtu.be/-Yqtcd2gLSs .

Early intervention in cauda equina syndrome associated with better outcomes: a myth or reality? Insights from the Nationwide Inpatient Sample database (2005-2011).

BACKGROUND CONTEXT: Evidence-based consensus on timing to surgical decompression following symptom onset in patients with cauda equina syndrome (CES) is limited or widely debated. PURPOSE: This study aimed to investigate whether timing to intervention in the management of patients with CES has an impact on outcomes. STUDY DESIGN/SETTING: This is a retrospective cohort study. PATIENT SAMPLE: The patient sample included 4,066 adult patients with CES registered in the Nationwide Inpatient Sample database (2005-2011) and undergoing elective decompression surgery. OUTCOME MEASURES: The outcome measures are inpatient mortality, unfavorable discharge (discharge to rehabilitation), prolonged length of stay (LOS>75th percentile), and high hospital charges in patients undergoing decompression for CES. METHODS: The patients were stratified into three categories based on timing to surgical intervention: (1) within 24 hours (n=1,846, 45.6%); (2) between 24 and 48 hours (n=1,080, 26.6%), and (3) beyond 48 hours (n=1,130, 27.8%). Multivariable logistic regression fitted with generalized estimating equations using the sandwich variance-covariance matrix estimator to account for the clustering of similar outcomes within hospitals was used to examine the association of timing to surgical intervention categories with binary primary end points. For metric end points (charges), we used the ordinary least squares model to test the effect of timing to intervention. RESULTS: The mean age of the cohort was 50.19±17.55 years and 41% were female. In comparison to patients operated within 24 hours, increased likelihood of inpatient mortality (odds ratio [OR]: 3.61, 95% confidence interval [CI]: 1.32-9.85, p=.012), unfavorable discharge (OR: 2.23, 95% CI: 1.87-2.66, p<.001), prolonged postsurgical LOS (OR: 1.76, 95% CI: 1.44-2.14, p<.001), and high hospital charges (OR:1.92, 95% CI: 1.81-2.05, p<.001) were observed in patients operated on over 48 hours since admission. Likewise, patients with incomplete CES with intervention beyond 48 hours had higher odds for unfavorable discharge (OR: 2.51, 95% CI: 1.99-3.17, p<.001), prolonged postsurgical LOS (OR: 1.73, 95% CI: 1.35-2.20, p<.001), and high hospital charges (OR: 1.94, 95% CI: 1.79-2.10, p<.001). Likewise, patients with complete CES with interventions beyond 48 hours had higher odds for unfavorable discharge (OR: 1.86, 95% CI: 1.41-2.45, p<.001), prolonged postsurgical LOS (OR: 2.06, 95% CI: 1.53-2.77, p<.001), and high hospital charges (OR: 1.39, 95% CI: 1.15-1.68, p<.001). CONCLUSIONS: Early intervention in CES, regardless of the subtype (complete or incomplete), has higher likelihood of improved inpatient outcomes. The odds of getting better were higher, however, with incomplete CES. The timing of intervention did not seem to matter in traumatic CES as compared with degenerative etiology. Prospective randomized controlled trials may further help elucidate the impact of early intervention on outcomes in patients with CES.

Impact of associated injuries in conjunction with fracture of the axis vertebra on inpatient outcomes and postoperative complications: a Nationwide Inpatient Sample analysis from 2002 to 2011.

BACKGROUND CONTEXT: There are limited data available on the impact of associated spinal (other spinal injuries [OSIs]) and extra-spinal injuries (ESIs) occurring in conjunction with fractures of the axis vertebra (C2) on clinical outcomes. PURPOSE: This study aimed to compare outcomes in patients with isolated C2 fractures versus patients with associated injuries in conjunction with C2 fractures. STUDY DESIGN/SETTING: A retrospective cohort study. PATIENT SAMPLE: A total of 30,472 adult patients with C2 fractures (International Classification of Diseases, Ninth Revision, Clinical Modification code 805.02) registered in the Nationwide Inpatient Sample (NIS) database (2002-2011) comprised the patient sample. OUTCOME MEASURES: Inpatient mortality, unfavorable discharge, prolonged length of stay (LOS) and high-end hospital charges in the non-operative and operative cohorts, and postoperative complications (deep venous thrombosis [DVT]; acute renal failure [ARF]; respiratory complications and wound infections) for the operative cohort were the outcome measures. METHODS: Patients were stratified into four categories based on injury type: (1) isolated C2 fracture (n=10,135; 33.3%); (2) C2 fracture+OSI (8.7%); (3) C2 fracture+ESI (37.2%); and (4) C2 fracture+OSI+ESI (20.8%). Multivariable logistic regression fitted with generalized estimating equations using the sandwich variance-covariance matrix estimator to account for clustering of similar outcomes within hospitals was used to examine the association of primary endpoints for each of the associated injury categories with reference to isolated C2 fractures. RESULTS: Mean age of the cohort was 66.27±21.67 years and 52% were female. Of the cohort, 52% underwent surgical intervention for C2 fracture. In a pooled regression analysis involving the operative cohort, the risks for inpatient mortality (odds ratio [OR]: 3.77; 95% confidence interval [CI]: 3.02-4.70; p<.001), unfavorable discharge (OR: 1.83; 95% CI: 1.66-2.01; p<.001), prolonged LOS (OR: 1.33; 95% CI: 1.18-1.50; p<.001), high hospital charges (OR: 1.49; 95% CI: 1.31-2.69; p<.001), DVT (OR: 2.08; 95% CI: 1.61-2.68; p<.001), and ARF (OR: 1.46; 95% CI: 1.16-1.83; p=.001) were significantly higher in patients with additional injuries when compared with patients with C2 fractures alone. Likewise, increased chances of inpatient mortality (OR: 1.40; 95% CI: 1.21-1.62; p<.001), unfavorable discharge (OR: 1.24; 95% CI: 1.15-1.34; p<.001) and high hospital charges (OR: 1.31; 95% CI: 1.21-1.43; p<.001) were observed in a pooled analysis of patients with concomitant associated injuries in the non-operative cohort. CONCLUSIONS: Associated injuries occurring concomitantly with C2 fractures adversely influence postoperative outcomes. In comparison to isolated C2 fractures, patients with associated injuries tend to have a greater propensity for higher health-care resource use because of more complicated and longer hospital inpatient stay.

Neurosurgery value and quality in the context of the Affordable Care Act: a policy perspective.

Neurosurgeons provide direct individualized care to patients. However, the majority of regulations affecting the relative value of patient-related care are drafted by policy experts whose focus is typically system- and population-based. A central, prospectively gathered, national outcomes-related database serves as neurosurgery's best opportunity to bring patient-centered outcomes to the policy arena. In this study the authors analyze the impact of the Affordable Care Act (ACA) on the determination of quality and value in neurosurgery care through the scope, language, and terminology of policy experts. The methods by which the ACA came into law and the subsequent quality implications this legislation has for neurosurgery will be discussed. The necessity of neurosurgical patient-oriented clinical registries will be discussed in the context of imminent and dramatic reforms related to medical cost containment. In the policy debate moving forward, the strength of neurosurgery's argument will rest on data, unity, and proactiveness. The National Neurosurgery Quality and Outcomes Database (N(2)QOD) allows neurosurgeons to generate objective data on specialty-specific value and quality determinations; it allows neurosurgeons to bring the patient-physician interaction to the policy debate.

Placement of C1 Pedicle Screws Using Minimal Exposure: Radiographic, Clinical, and Literature Validation.

BACKGROUND: Traditional C1-2 fixation involves placement of C1 lateral mass screws. Evolving techniques have led to the placement of C1 pedicle screws to avoid exposure of the C1-C2 joint capsule. Our minimal dissection technique utilizes anatomical landmarks with isolated exposure of C2 and the inferior posterior arch of C1. We evaluate this procedure clinically and radiographically through a technical report. METHODS: Consecutive cases of cranial-vertebral junction surgery were reviewed for one fellowship trained spinal surgeon from 2008-2014. Information regarding sex, age, indication for surgery, private or public hospital, intra-operative complications, post-operative neurological deterioration, death, and failure of fusion was extracted. Measurement of pre-operative axial and sagittal CT scans were performed for C1 pedicle width and C1 posterior arch height respectively. RESULTS: 64 patients underwent posterior cranio-vertebral junction fixation surgery. 40 of these patients underwent occipital-cervical fusion procedures. 7/9 (77.8%) C1 instrumentation cases were from trauma with the remaining two (22.2%) from oncologic lesions. The average blood loss among isolated C1-C2 fixation was 160cc. 1/9 patients (11.1%) suffered pedicle breech requiring sub-laminar wiring at the C1 level. On radiographic measurement, the average height of the C1 posterior arch was noted at 4.3mm (range 3.8mm to 5.7mm). The average width of the C1 pedicle measured at 5.3mm (range 2.8 to 8.7mm). The patient with C1 pedicle screw failure had a pedicle width of 2.78mm on pre-operative axial CT imaging. CONCLUSION: Our study directly adds to the literature with level four evidence supporting a minimal dissection of C1 arch in the placement of C1 pedicle screws with both radiographic and clinical validation. CLINICAL RELEVANCE: Justification of this technique avoids C2 nerve root manipulation or sacrifice, reduces bleeding associated with the venous plexus, and leaves the third segment of the vertebral artery unexplored. Pre-operative review of imaging is critical in the placement of C1-C2 instrumentation.

Woodrow Wilson's hidden stroke of 1919: the impact of patient-physician confidentiality on United States foreign policy.

World War I catapulted the United States from traditional isolationism to international involvement in a major European conflict. Woodrow Wilson envisaged a permanent American imprint on democracy in world affairs through participation in the League of Nations. Amid these defining events, Wilson suffered a major ischemic stroke on October 2, 1919, which left him incapacitated. What was probably his fourth and most devastating stroke was diagnosed and treated by his friend and personal physician, Admiral Cary Grayson. Grayson, who had tremendous personal and professional loyalty to Wilson, kept the severity of the stroke hidden from Congress, the American people, and even the president himself. During a cabinet briefing, Grayson formally refused to sign a document of disability and was reluctant to address the subject of presidential succession. Wilson was essentially incapacitated and hemiplegic, yet he remained an active president and all messages were relayed directly through his wife, Edith. Patient-physician confidentiality superseded national security amid the backdrop of friendship and political power on the eve of a pivotal juncture in the history of American foreign policy. It was in part because of the absence of Woodrow Wilson's vocal and unwavering support that the United States did not join the League of Nations and distanced itself from the international stage. The League of Nations would later prove powerless without American support and was unable to thwart the rise and advance of Adolf Hitler. Only after World War II did the United States assume its global leadership role and realize Wilson's visionary, yet contentious, groundwork for a Pax Americana. The authors describe Woodrow Wilson's stroke, the historical implications of his health decline, and its impact on United States foreign policy.

Treatment of vertebrobasilar fusiform aneurysms with Pipeline embolization device.

OBJECT: Treatment of complex intracranial aneurysms with Pipeline embolization device (PED) (ev3/Covidien Vascular Therapies) has gained recent popularity. One application of PEDs that is not well described in the literature is the utility and long-term safety in treatment of vertebrobasilar fusiform (VBF) aneurysms. Despite the advancements in endovascular therapy, VBF aneurysms continue to challenging pathology. The authors provide long-term follow-up of VBF aneurysms treated with PEDs. METHODS: We retrospectively reviewed four patients that were treated at Louisiana State University Health Sciences Center in Shreveport with PEDs for VBFs from 2012 to 2014. Each patient was discussed in a multidisciplinary setting between neurosurgeons and neurointerventionalists. Each patient underwent platelet function tests to ensure responsiveness to anti-platelet agents and was treated by one neurointerventionalist (HC). All patients were placed on aspirin and Plavix and were confirmed for therapeutic response prior to discharge. RESULTS: Follow-up ranged from 12 to 25 months, with a mean of 14.25 months. Two cases presented with a recurrence after the initial treatment, both of which required subsequent treatment. Of the four patients treated, one patient developed hemiparesis and three died. CONCLUSION: Despite reports describing successful treatment of VBF aneurysms with PEDs, delayed complications after obliteration and remodeling can occur. We describe our institutional experience of VBFs treated with PEDs. Treatment of holobasilar fusiform aneurysms may carry a worse prognosis after treatment. Further long-term follow-up will provide a better understanding of this pathology.

Unilateral Acute Closed-Angle Glaucoma After Elective Lumbar Surgery Reveals Multiple Intracranial Aneurysms. A Case Report and Discussion on Workup of Differential Diagnoses.

The purpose of our paper is to present a case of a rare complication of posterior lumbar surgery. Our patient presented for elective lumbar decompression, which was complicated by durotomy. She then developed sudden headache and right eye pain once upright on postoperative day 2. Then on postoperative day 3, she developed a dilated nonreactive pupil with extraocular movements intact. A computed tomography scan of the head was negative for subarachnoid hemorrhage. Magnetic resonance angiography showed a possible right posterior communicating artery aneurysm. She was transferred to a tertiary center with a severe headache and a nonreactive pupil, raising concern for evolving third nerve palsy due to aneurysm. A cerebral angiogram was performed and showed multiple aneurysms. Aneurysm location did not explain the patient's symptoms, and ophthalmology was consulted. Elevated intraocular pressure was noted, and the patient was diagnosed with acute angle-closure glaucoma (AACG). Our patient was medically treated and subsequently underwent laser peripheral iridotomy. She has had improved vision and pupillary function at 1 month follow-up. The diagnosis is complicated by a durotomy, which led to cascade in the differential diagnosis to rule out intracranial pathology. Her age and home medications, which had sympathomimetic effects, placed her at increased risk, but lying prone in the dark under the drapes was likely the lead causative factor. In conclusion, a postoperative posterior spine patient with eye pain and changes in vision and pupils should be evaluated with AACG in mind due to the devastating consequences if left untreated or treatment is delayed.

Vacuum-assisted closure of necrotic and infected cranial wound with loss of dura mater: A technical note.

BACKGROUND: Complex cranial wounds can be a problematic occurrence for surgeons. Vacuum-assisted closure devices have a wide variety of applications and have recently been used in neurosurgical cases involving complex cranial wounds. There is only one report regarding the use of a vacuum-assisted closure device with loss of dura mater. We report a complicated case of a necrotic cranial wound with loss of dura mater. CASE DESCRIPTION: A 68-year-old female underwent an evacuation of a subdural hematoma. Postoperatively, the patient developed a wound infection that required removal of the bone flap. The wound developed a wedge-shaped necrosis of the scalp with exposure of brain tissue due to loss of dura mater from previous surgeries. She underwent debridement and excision of the necrotic tissue with placement of a synthetic dural graft (Durepair®, Medtronic, Inc.) and placement of a wound vac. The patient underwent a latissismus dorsi muscle flap reconstruction that subsequently failed. After the wound vac was replaced, the synthetic dural graft was replaced with a fascia lata graft and an anterolateral thigh free flap reconstruction. We describe the technical nuances of this complicated case, how the obstacles were handled, and the literature that discusses the utility. CONCLUSION: We describe a case of a complex cranial wound and technical nuances on how to utilize a wound-vac with loss of dura mater.

Evaluation of interspinous process distraction device (X-STOP) in a representative patient cohort.

OBJECTIVE: To test the hypothesis that the level of clinical efficacy reported in the investigational device exemption (IDE) study of the X-STOP device that led to its approval by the U.S. Food and Drug Administration could also be achieved in patients who are representative of the population approved for treatment, irrespective of whether they met all the stringent requirements of the IDE study. METHODS: A retrospective analysis was conducted of a consecutive series of 31 patients who received the X-STOP interspinous process distraction device as treatment for neurogenic intermittent claudication. Outcome was assessed at an average of 2 years after surgery by use of the Zurich Claudication Questionnaire (ZCQ), which used the definition of clinical success used in the IDE study. RESULTS: On the basis of the ZCQ, clinically significant improvement occurred in 38% of the evaluable patients (21 patients), compared with 48.4% in the IDE study; at the sites other than those of the device's inventors, the improvement level was 37%. Four patients needed additional surgery, which was a rate comparable with that reported in the IDE study. CONCLUSIONS: The success level in the controlled IDE study that established the safety and efficacy of the X-STOP device was achieved in a representative patient cohort that did not necessarily meet all the strict requirements of the IDE plan. Nevertheless, the overall results were not good, suggesting that the ZCQ definition of success might not have captured the true outcome of surgical treatment with the X-STOP device.

Categorizing and comparing psychophysical detection strategies based on biomechanical responses to short postural perturbations.

BACKGROUND: A fundamental unsolved problem in psychophysical detection experiments is in discriminating guesses from the correct responses. This paper proposes a coherent solution to this problem by presenting a novel classification method that compares biomechanical and psychological responses. METHODS: Subjects (13) stood on a platform that was translated anteriorly 16 mm to find psychophysical detection thresholds through a Adaptive 2-Alternative-Forced-Choice (2AFC) task repeated over 30 separate sequential trials. Anterior-posterior center-of-pressure (APCoP) changes (i.e., the biomechanical response R(B)) were analyzed to determine whether sufficient biomechanical information was available to support a subject's psychophysical selection (R(Ψ)) of interval 1 or 2 as the stimulus interval. A time-series-bitmap approach was used to identify anomalies in interval 1 (a1) and interval 2 (a2) that were present in the resultant APCoP signal. If a1 > a2 then R(B) = Interval 1. If a1 < a2, then R(B)= Interval 2. If a2-a1 < 0.1, R(B) was set to 0 (no significant difference present in the anomaly scores of interval 1 and 2). RESULTS: By considering both biomechanical (R(B)) and psychophysical (R(Ψ)) responses, each trial run could be classified as a: 1) HIT (and True Negative), if R(B) and R(Ψ) both matched the stimulus interval (SI); 2) MISS, if R(B) matched SI but the subject's reported response did not; 3) PSUEDO HIT, if the subject signalled the correct SI, but R(B) was linked to the non-SI; 4) FALSE POSITIVE, if R(B) = R(Ψ), and both associated to non-SI; and 5) GUESS, if R(B) = 0, if insufficient APCoP differences existed to distinguish SI. Ensemble averaging the data for each of the above categories amplified the anomalous behavior of the APCoP response. CONCLUSIONS: The major contributions of this novel classification scheme were to define and verify by logistic models a 'GUESS' category in these psychophysical threshold detection experiments, and to add an additional descriptor, "PSEUDO HIT". This improved classification methodology potentially could be applied to psychophysical detection experiments of other sensory modalities.

The effects of diabetes and/or peripheral neuropathy in detecting short postural perturbations in mature adults.

BACKGROUND: This study explored the effects of diabetes mellitus (DM) and peripheral neuropathy (PN) on the ability to detect near-threshold postural perturbations. METHODS: 83 subjects participated; 32 with type II DM (25 with PN and 7 without PN), 19 with PN without DM, and 32 without DM or PN. Peak acceleration thresholds for detecting anterior platform translations of 1 mm, 4 mm, and 16 mm displacements were determined. A 2(DM) × 2(PN) factorial MANCOVA with weight as a covariate was calculated to compare acceleration detection thresholds among subjects who had DM or did not and who had PN or did not. RESULTS: There was a main effect for DM but not for PN. Post hoc analysis revealed that subjects with DM required higher accelerations to detect a 1 mm and 4 mm displacement. CONCLUSION: Our findings suggest that PN may not be the only cause of impaired balance in people with DM. Clinicians should be aware that diabetes itself might negatively impact the postural control system.

Grip force, EDL contractile properties, and voluntary wheel running after postdevelopmental myostatin depletion in mice.

There is no consensus about whether making muscles abnormally large by reducing myostatin activity affects force-generating capacity or the ability to perform activities requiring muscular endurance. We therefore examined grip force, contractile properties of extensor digitorum longus (EDL) muscles, and voluntary wheel running in mice in which myostatin was depleted after normal muscle development. Cre recombinase activity was induced to knock out exon 3 of the myostatin gene in 4-mo-old mice in which this exon was flanked by loxP sequences (Mstn[f/f]). Control mice with normal myostatin genes (Mstn[w/w]) received the same Cre-activating treatment. Myostatin depletion increased the mass of all muscles that were examined (gastrocnemius, quadriceps, tibialis anterior, EDL, soleus, triceps) by approximately 20-40%. Grip force, measured multiple times 2-22 wk after myostatin knockout, was not consistently greater in the myostatin-deficient mice. EDL contractile properties were determined 7-13 mo after myostatin knockout. Twitch force tended to be greater in myostatin-deficient muscles (+24%; P=0.09), whereas tetanic force was not consistently elevated (mean +11%; P=0.36), even though EDL mass was greater than normal in all myostatin-deficient mice (mean +36%; P<0.001). The force deficit induced by eccentric contractions was approximately twofold greater in myostatin-deficient than in normal EDL muscles (31% vs. 16% after five eccentric contractions; P=0.02). Myostatin-deficient mice ran 19% less distance (P<0.01) than control mice during the 12 wk following myostatin depletion, primarily because of fewer running bouts per night rather than diminished running speed or bout duration. Reduced specific tension (ratio of force to mass) and reduced running have been observed after muscle hypertrophy was induced by other means, suggesting that they are characteristics generally associated with abnormally large muscles rather than unique effects of myostatin deficiency.