bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of the Dialysis Access Consortium (DAC) Aggrenox prevention of access stenosis trial
Authors: Dixon Bradley S , Beck Gerald J , Dember Laura M , Depner Thomas A , Gassman Jennifer J , Greene Tom , Himmelfar Jonathan , Hunsicker Lawrence G , Kaufman James S , Lawson Jeffrey H , Meyers Catherine M , Middleton John P , Radeva Milena , Schwab Steve J , Whiting James F , Feldman Harold I 
Published: October 2005

Background Surgically created arteriovenous (AV) grafts are the most common type of hemodialysis vascular access in the United States, but fail frequently due to the development of venous stenosis. The Dialysis Access Consortium (DAC) Aggrenox Prevention of Access Stenosis Trial tests the hypothesis that Aggrenox (containing dipyridamole and aspirin) can prevent stenosis and prolong survival of arteriovenous grafts. Methods This is a multicenter, randomized, double-blind, placebo-controlled trial that will enroll 1056 subjects over four years with one-half year follow-up. Subjects undergoing placement of a new AV graft for hemodialysis are randomized to treatment with Aggrenox or placebo immediately following access surgery. The primary outcome is primary unassisted patency defined as the time from access placement until thrombosis or an access procedure carried out to maintain or restore patency. The major secondary outcome is cumulative access patency. Monthly access flow monitoring is incorporated in the study design to enhance detection of a hemodynamically significant access stenosis before it leads to thrombosis. Results This paper describes the key issues in trial design, broadly including: 1) ethical issues surrounding the study of a clinical procedure that, although common, is no longer the clinical intervention of choice; 2) acceptable risk (bleeding) from the primary intervention; 3) inclusion of subjects already receiving a portion of the study intervention; 4) inclusion of subjects with incident rather than prevalent qualifying clinical conditions; 5) timing of the study intervention to balance safety and efficacy concerns; and 6) the selection of primary and secondary study endpoints. Conclusions This is the first, large, multicenter trial evaluating a pharmacologic approach to prevent AV graft stenosis and failure, an important and costly problem in this patient population. Numerous design issues were addressed in implementing the trial and these will form a roadmap for future trials in this area.
Design of the Dialysis Access Consortium (DAC) clopidogrel prevention of early AV fistula thrombosis trial
Authors: Dember Laura M , Kaufman James S , Beck Gerald J , Dixon Bradley S , Gassman Jennifer J , Greene Tom , Himmelfarb Jonathan , Hunsicker Lawrence G , Kusek John W , Lawson Jeffrey H , Middleton John P , Radeva Milena , Schwab Steve J , Whiting James F , Feldman Harold I 
Published: October 2005

Background The Dialysis Access Consortium (DAC) was developed to investigate interventions to improve hemodialysis vascular access outcomes. The autogenous arteriovenous fistula created by direct connection of native artery to vein is the recommended vascular access for hemodialysis. However, it fails frequently due to clotting after surgery. Purpose The DAC Early AV Fistula Thrombosis Trial tests the hypothesis that clopidogrel can prevent early fistula failure and increase the number of fistulas that ultimately become usable for hemodialysis access. This is one of two initial and concurrent trials being performed by the DAC. The companion trial investigates pharmacologic approaches to prevent venous stenosis leading to AV graft failure. Methods This is a multicenter, randomized, double-blind, placebo-controlled trial that will enroll 1284 patients over four years. Patients undergoing creation of a new native arteriovenous (AV) fistula are randomized to treatment with clopidogrel or placebo for six weeks following fistula creation surgery. The primary outcome is fistula patency at six weeks. The major secondary outcome is fistula suitability for dialysis. Results This paper examines key aspects of this study that have broad relevance to trial design including: 1) the selection of an intermediate event as the primary outcome, 2) timing of the intervention to balance efficacy and safety concerns, 3) ethical considerations arising from required modifications of concomitant drug therapy, and 4) choosing an efficacy or effectiveness evaluation of the intervention. Conclusions This is the first, large, multicenter trial evaluating a pharmacologic approach to prevent early AV fistula failure and promote more usable fistulas for hemodialysis. The methodologic challenges identified and addressed during the development of this trial should help to inform the design of future vascular access trials, and are relevant to clinical trials addressing a wide range of questions.
Situated Action: A Symbolic Interpretation
Authors: Vera Alonso H. , Simon Herbert A. 
Published: October 2005

The congeries of theoretical views collectively referred to as “situated action” (SA) claim that humans and their interactions with the world cannot be understood using symbol‐system models and methodology, but only by observing them within real‐world contexts or building nonsymbolic models of them. SA claims also that rapid, real‐time interaction with a dynamically changing environment is not amenable to symbolic interpretation of the sort espoused by the cognitive science of recent decades. Planning and representation, central to symbolic theories, are claimed to be irrelevant in everyday human activity.We will contest these claims, as well as their proponents' characterizations of the symbol‐system viewpoint. We will show that a number of existing symbolic systems perform well in temporally demanding tasks embedded in complex environments, whereas the systems usually regarded as exemplifying SA are thoroughly symbolic (and representational), and, to the extent that they are limited in these respects, have doubtful prospects for extension to complex tasks. As our title suggests, we propose that the goals set forth by the proponents of SA can be attained only within the framework of symbolic systems. The main body of empirical evidence supporting our view resides in the numerous symbol systems constructed in the past 35 years that have successfully simulated broad areas of human cognition.
Microsurgical Anatomy and Quantitative Analysis of the Transtemporal-Transchoroidal Fissure Approach to the Ambient Cistern
Authors: Siwanuwatn Rungsak , Deshmukh Pushpa , Zabramski Joseph M. , Preul Mark C. , Spetzler Robert F. 
Published: October 2005

Abstract

OBJECTIVE:
Surgical approaches to ambient cistern lesions are complex. We investigated the microanatomy of the transtemporal-transchoroidal fissure approach to the ambient cistern with emphasis on exposure of the posterior cerebral artery.

METHODS:
Dissections were performed bilaterally in five silicone-injected cadaveric heads. Critical anatomic distances, specifically with reference to the P2 segment of posterior cerebral artery in relation to the inferior choroidal point and P2–P3 junction, were measured with digital calipers. Other landmarks (temporal lobe tip, points from the temporal base to the choroidal fissure) were included for quantitative analysis.

RESULTS:
The transtemporal-transchoroidal fissure approach provided adequate exposure of the ambient cistern, minimized temporal lobe retraction, and allowed assessment of regional microanatomy. The mean distance from the temporal base to the choroidal fissure measured 18.09 mm (range, 16.9–21.9 mm). The distances from the choroidal fissure to P2 varied at the coronal plane of the inferior choroidal point (mean, 6.96 mm; range, 3.6–12.0 mm) and the P2–P3 junction (mean, 6.02 mm; range, 4.3–6.9 mm), respectively.

CONCLUSION:
The transtemporal-transchoroidal fissure approach provides a corridor to the ambient cistern and P2–P3 junction while minimizing temporal lobe retraction and avoiding interruption of temporal lobe venous drainage. Because of widely variable vascular anatomy, access to posterior cerebral artery lesions using this approach requires preoperative imaging to identify the specific location of the P2–P3 junction.
Olfactory Groove Meningiomas from Neurosurgical and Ear, Nose, and Throat Perspectives: Approaches, Techniques, and Outcomes
Authors: Spektor Sergey , Valarezo Javier , Fliss Dan M. , Gil Ziv , Cohen Jose , Goldman Jose , Umansky Felix 
Published: October 2005

Abstract

OBJECTIVE:
To review the surgical approaches, techniques, outcomes, and recurrence rates in a series of 80 olfactory groove meningioma (OGM) patients operated on between 1990 and 2003.

METHODS:
Eighty patients underwent 81 OGM surgeries. Tumor diameter varied from 2 to 9 cm (average, 4.6 cm). In 35 surgeries (43.2%), the tumor was removed through bifrontal craniotomy; nine operations (11.1%) were performed through a unilateral subfrontal approach; 18 surgeries (22.2%) were performed through a pterional approach; seven surgeries (8.6%) were carried out using a fronto-orbital craniotomy; and 12 procedures (14.8%) were accomplished via a subcranial approach. Nine patients (11.3%) had undergone surgery previously and had recurrent tumor.

RESULTS:
Total removal was obtained in 72 patients (90.0%); subtotal removal was achieved in 8 patients (10.0%). Two patients, one with total and one with subtotal removal, had atypical (World Health Organization Grade II) meningiomas, whereas 78 patients had World Health Organization Grade I tumors. There was no operative mortality and no new permanent focal neurological deficit besides anosmia. Twenty-five patients (31.3%) experienced surgery-related complications. There were no recurrences in 75 patients (93.8%) 6 to 164 months (mean, 70.8 mo) after surgery. Three patients (3.8%) were lost to follow-up. In two patients (2.5%) with subtotal removal, the residual evidenced growth on computed tomography and/or magnetic resonance imaging 1 year after surgery. One of them had an atypical meningioma. The second, a multiple meningiomata patient, was operated on twice in this series.

CONCLUSION:
A variety of surgical approaches are used for OGM resection. An approach tailored to the tumor's size, location, and extension, combined with modern microsurgical cranial base techniques, allows full OGM removal with minimal permanent morbidity, excellent neurological outcome, and very low recurrence rates.
Artificial Pedicle Screw Reconstruction of the Cervical Spine after Lateral Paramedian Transpedicular Approach for Lesions of the Ventral Cervical Spinal Canal
Authors: Acosta Frank L. , Ames Christopher P. 
Published: October 2005

Abstract

OBJECTIVE:
We describe in detail the anatomic and surgical principles of a lateral cervical paramedian transpedicular approach, a novel technique that provides access to the ventral cervical spinal canal. We also describe single-stage posterior column reconstruction of the cervical spine in which traditional cervical lateral mass screws are used simultaneously to reconstruct the cervical pedicle and to allow for three-column stabilization in a continuous posterior screw-rod construct after this approach.

METHODS:
This technique is a modification of traditional thoracic posterolateral extracavitary approaches and has been used by our group for the resection of intradural and extradural spinal lesions, as we illustrate.

RESULTS:
This approach is particularly useful in cases where significant pathological characteristics of the trachea or esophagus preclude an anterior approach to the cervical spine and in cases in which multiple levels are involved.

CONCLUSION:
Cervical spinal stability is enhanced, because all cervical levels are incorporated into the final screw-rod construct.
Anterolateral Approach to the V2 Segment of the Vertebral Artery
Authors: Bruneau Michaël , Cornelius Jan Frederick , George Bernard 
Published: October 2005

Abstract

OBJECTIVE:
We describe our surgical technique of exposure and control of the second segment of the vertebral artery (VA V2 segment). Our basic principle is that working in the VA vicinity is more confident under visual control.

METHODS:
The VA V2 segment extends classically in and between the transverse processes from C6 to C2. This segment can be exposed through an anterolateral approach, passing medially to the sternocleidomastoid muscle and laterally to the internal jugular vein. Except in case of anatomic variation, the VA V2 segment is protected by the transverse processes bone, even if a pathological process displaces the VA along its course between them. The safest technique to expose the VA V2 segment then is to reach first the transverse process by cutting the longus colli muscle. Afterward, dividing intertransversary muscles permits exposure of and safely controls the VA by following its course. If required, the VA V2 segment can even be freed by opening the transverse process as far as the dissection is performed in the subperiosteal plane. In fact, the VA V2 segment is surrounded by a venous plexus and a periosteal sheath. This sheath gives a plane out of which the dissection is safe, avoiding troublesome venous bleeding or VA damage.

RESULTS:
This technique is very efficient for degenerative disorders, hour glass tumors, and vascular surgeries.

CONCLUSION:
Exposure and control of the VA V2 segment is safe if anatomy and variations are perfectly known, and if a rigorous step-by-step surgical technique is followed.
Three-dimensional Relationships of The Optic Radiation
Authors: Rubino Pablo Augusto , Rhoton Albert L. , Tong Xiaoguang , de Oliveira Evandro 
Published: October 2005

Abstract

OBJECTIVE:
This study examined the relationship of the optic radiation to the landmarks important in temporal lobe surgery.

METHODS:
The optic radiation was dissected by applying Klingler's fiber dissection technique to 20 formalin-fixed human hemispheres. The dissections were performed with the operating microscope and imaged in three-dimensional photographs. Several measures quantified the relationship of the radiation to reliable surgical landmarks.

RESULTS:
In all specimens, the anterior loop of the radiation extended to the anterior tip of the roof of the temporal horn. The anterior edge of the optic radiation was located an average of 25 mm (range, 22–30 mm) behind the temporal pole. The optic radiation extended an average of 5 mm (range, 3–6 mm) anterior to the hippocampus head and 22 mm (range, 20–25 mm) anterior to the anterior edge of the lateral geniculate body. The optic radiation also extended an average of 2 mm (range, 1–3 mm) anterior to the tip of the temporal horn. The relationships of the optic radiation to important surgical landmarks are discussed.

CONCLUSION:
The optic radiation reached the anterior tip of the temporal horn. Resections that extend through the roof of the temporal horn more than 3 cm behind the temporal pole cross the anterior loop of the optic radiation.
Technical Improvements and Results of Open-door Expansive Laminoplasty with Hydroxyapatite Implants for Cervical Myelopathy
Authors: Kihara Shun-ichi , Umebayashi Takeshi , Hoshimaru Minoru 
Published: October 2005

Abstract

OBJECTIVE:
A new, modified technique of cervical open-door laminoplasty with hydroxyapatite implants was developed to enlarge the spinal canal in stable fashion yet preserve the architecture of the cervical spine and surrounding tissues. To assess the efficacy of this technique, a retrospective review of neurological and radiological outcomes after cervical laminoplasty was conducted.

METHODS:
Clinical charts and cervical x-rays of 151 patients with cervical stenotic myelopathy were reviewed. Patients were treated with the cervical laminoplasty between May 2001 and January 2002. The patient group comprised 69 women and 82 men ranging in age from 30 to 86 years (mean, 63 yr). Neurological outcomes were evaluated according to the Japanese Orthopaedic Association grade. To assess alignment and mobility of the cervical spine, the C2–C7 angle was used.

RESULTS:
The average Japanese Orthopaedic Association grade was 8.1 ± 2.5 before surgery and 15.2 ± 1.5 at 1 year after surgery (P &lt; 0.01). No neurological complications were observed. The average C2–C7 angle at the neutral position increased from 8.3 ± 11.7 degrees before surgery to 14.9 ± 11.6 degrees at 1 year after surgery (P &lt; 0.01). The range of motion between C2 and C7 was 36.9 ± 12.5 degrees and 29.1 ± 10.8 degrees before and 1 year after surgery, respectively.

CONCLUSION:
A new modified technique of cervical open-door laminoplasty described herein offers some solutions to the problems associated with conventional techniques of cervical laminoplasty.
Craniofacial Resection for Cranial Base Malignancies Involving the Infratemporal Fossa
Authors: Bilsky Mark H. , Bentz Brandon , Vitaz Todd , Shah Jatin , Kraus Dennis 
Published: October 2005

Abstract

OBJECTIVE:
Cranial base malignancies involving the infratemporal fossa have been considered unresectable. Advanced operative techniques have made tumor resection feasible in an en bloc fashion with negative histological margins, but there are limited data regarding outcome analysis in patients who have undergone resection of malignant tumors in this area.

METHODS:
At Memorial Sloan-Kettering Cancer Center, 25 patients underwent anterolateral cranial base resections for tumors that involved the infratemporal fossa during a 7-year period. The most common tumors were sarcoma (n = 9), squamous cell carcinoma (n = 6), and adenoid cystic carcinoma (n = 3). The median size of the tumors was 6 cm, and 12 tumors involved the anterior cranial base and/or orbit.
Tumor resections were divided into three types. Twelve patients underwent Type 1 dissection for tumors involving only the infratemporal fossa and maxillary sinus; 2 patients underwent Type 2 dissections involving the infratemporal fossa and anterior cranial base; and 11 patients underwent Type 3 dissection, which included the infratemporal fossa, anterior cranial base, and orbit. All patients required free flap reconstruction, 22 of which were rectus abdominis free flaps.

RESULTS:
Complications occurred in seven patients, including a single mortality resulting from a myocardial infarction. The 2-, 3-, and 5-year survival rates were 69, 63, and 56%, respectively. The relapse-free survival rates were 47% at 2 and 3 years and 41% at 5 years. Recurrences were local in nine patients and distant in four patients.

CONCLUSION:
Despite the extensive nature of many infratemporal fossa tumors, they can be resected with acceptable morbidity. Survival rates approach those of anterior cranial base malignancies without infratemporal fossa involvement.
Transcallosal Transchoroidal Approach to Tumors of the Third Ventricle
Authors: Kasowski Hahnah J. , Nahed Brian V. , Piepmeier Joseph M. 
Published: October 2005

Abstract
ALTHOUGH THE LITERATURE is rich with descriptions of the approach to the third ventricle, surgeons remain cautiously reserved. In this report, we demonstrate that the transcallosal approach can be easily performed provided that preoperative planning is adequate. Familiarity with the course of major cortical and deep draining veins grants the surgeon a wide exposure of the posterior third ventricle. We discuss the indications, surgical technique, and pitfalls to this approach while providing an accompanying video mirroring our discussion.
Neuroendoscopic Aspiration of Hematocephalus Totalis: Technical Note
Authors: Longatti PierLuigi , Fiorindi Alessandro , Martinuzzi Andrea 
Published: October 2005

Abstract

OBJECTIVE AND IMPORTANCE:
Massive intraventricular hemorrhage requires aggressive and rapid management to decrease intracranial hypertension. The amount of intraventricular blood is a strong prognostic predictor, and its fast removal is a priority. Neuroendoscopy may offer some advantages over more traditional surgical approaches. We describe here the technical details and clinical outcomes of the neuroendoscopic management of massive tetraventricular hemorrhage in 25 consecutive patients, highlighting the potential pitfalls and the advantages of the technique.

CLINICAL PRESENTATION:
Twenty-five patients, aged 7 to 80 years, presenting with massive ventricular hemorrhage were admitted between January 1996 and May 2004 to our neurosurgery unit after an emergency computed tomographic scan. Severity of ventricular hemorrhage was graded according to the Graeb scale; the mean Graeb score was 9.8 ± 2.9. Hemorrhages were secondary to vascular malformation in 12 cases.

INTERVENTION:
Endoscopy was performed on the first day in 17 cases, with a delay of 1 to 5 days in the remaining 8 cases. A flexible endoscope with “free-hand” technique was always preferred. The ventricular cleaning proceeded in three phases: lateral ventricle, third ventricle, and then aqueduct and fourth ventricle. In selected patients, a catheter, both for intracranial pressure monitoring and for drainage, was positioned. The procedure was successfully completed in all cases. There was no surgery-related mortality. The mean length of intensive care unit stay after the operation was 18 ± 12 days. Short-term mortality (1 mo) was 12%, whereas long-term (&gt;6 mo) mortality was 24%. Complete recovery (Glasgow Outcome Scale score, 5) was achieved in 40% of cases. A ventriculoperitoneal shunt was necessary in 12% of patients.

CONCLUSION:
Intraventricular hemorrhage, analogously to other ventricular diseases, can be treated successfully with flexible endoscopes. Obviously, the limitation of this study lies in its observational nature; however, the encouraging results reported here should prompt a randomized study to evaluate the effectiveness and efficiency of the endoscopic approach in comparison to the more established semiconservative management offered by external derivation with fibrinolytic agents.
Thalamic Stimulation as a Treatment for Primary Erythromelalgia: Technical Case Report
Authors: Delye Hans , Lagae Lieven , Vermylen Jos , Nuttin Bart 
Published: October 2005

Abstract

OBJECTIVE AND IMPORTANCE:
We report the use of bilateral thalamic stimulation in a case of primary erythromelalgia with immediate and important pain relief for 3 years.

CLINICAL PRESENTATION:
A 12-year-old boy experiencing primary erythromelalgia had a 4-year history of recurrent attacks of severe burning pain in both feet, accompanied by local reddening, swelling, and heating of the skin. The attacks were triggered by warmth and exercise. The pain was relieved only by elevation and cooling of the lower limbs, which he achieved by immersing his legs in a bucket of ice water, resulting in severe ulceration of the skin.

INTERVENTION:
Because of the gradual aggravation of the signs and symptoms and resistance of the patient's condition to several medical therapies, the patient received spinal cord stimulation. The implants were removed twice because of recurrent infection. Finally, the patient was treated with bilateral electrical stimulation of the ventral posterolateral thalamic nucleus, which resulted in important pain control until 3 years later. The patient was able to avoid water immersions, and all ulcerations disappeared.

CONCLUSION:
We conclude that thalamic stimulation was successful in this case of primary erythromelalgia.
Scaled Suction for Microneurosurgery: Technical Note
Authors: Okada Yoshikazu , Kawamata Takakazu , Chernov Mikhail F. , Hori Tomokatsu 
Published: October 2005

Abstract

OBJECTIVE:
We have developed scaled suction to facilitate the measurement of aneurysm neck width and tumor size during operations.

METHODS:
We constructed a new suction device scaled every 1 mm from the tip to 3 cm and every 5 mm from 3 to 5 cm. The scaled suction devices have been used in 50 aneurysm and brain tumor operations.

RESULTS:
The new suction device permits easy measurement of aneurysm neck width, tumor size, the extent of internal decompression of tumor, and depth from the surface of the brain to the lesion.

CONCLUSION:
Our scaled suction device is a simple and useful navigator for continuously measuring intraoperative variables such as lesion size and distance between the lesion and the surrounding vital structures.