bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of operative benefit for unruptured cerebral aneurysms: a theoretical approach
Authors: Chang Han Soo , Kirino Takaaki 
Published: June 2009

✓ The indications for surgery on unruptured asymptomatic cerebral aneurysms are still unclear. In this report, the authors use mathematical methods to attempt to quantify the benefit of surgery for unruptured aneurysms.
Theoretical survival curves for either operative or conservative treatment were obtained by solving differential equations on the survival rate of a patient harboring an unruptured aneurysm. Patients' life expectancies were calculated as areas under these curves, and operative benefit was quantified as a gain in average life expectancy. To analyze morbidity, two concepts were introduced: premorbid survival rate and average premorbid survival period, and the operative gain of average premorbid survival period was calculated under certain assumptions.
Larger operative benefit was observed in younger patients, with increasingly less benefit in the elderly. The operative gain of average life expectancy was 3.9 years for a 40-year-old patient, 2.4 years for 50, 1.3 years for 60, and 0.6 years for a 70-year-old. Quantified operative benefit is presented in a table for various patient ages, yearly rupture rates, and expected operative morbidity and mortality.
This mathematical method would be useful to both surgeons and patients in making their decisions on surgery.
Effects of subarachnoid hemorrhage on vascular responses to calcitonin gene—related peptide and its related second messengers
Authors: Sutter Bernhard , Suzuki Satoshi , Arthur Adam S. , Kassell Neal F. , Lee Kevin S. 
Published: June 2009

✓ Calcitonin gene—related peptide (CGRP) is a potent vasodilator and a primary signaling molecule in neurovascular communication. In the present study, the authors examined cerebrovascular responses to CGRP and its related second messenger systems during cerebral vasospasm induced by subarachnoid hemorrhage (SAH). Tension measurements were performed in vitro on ring strips of basilar arteries obtained from rabbits subjected to artificial SAH and from control (non-SAH) animals. In vessels from SAH animals, which were preconstricted with serotonin, the vasorelaxant response to CGRP was attenuated. Because it has been suggested that vasodilation elicited by CGRP is mediated by cyclic 3′,5′-adenosine monophosphate (cAMP) and/or cyclic 3′,5′-guanosine monophosphate (cGMP), the vascular effects of directly activating these second messenger systems were also examined. The relaxant effect of forskolin, which activates adenylate cyclase directly, was slightly enhanced after SAH. In contrast, the relaxant effect of nitroglycerin (GTN), which activates soluble guanylate cyclase directly, was unchanged after SAH.
The attenuation of CGRP-induced vasorelaxation could be the result of a modification in its ability to stimulate the production of second messengers. Experiments testing the capacity of CGRP to elevate cAMP levels showed no significant differences between vessels from non-SAH and SAH animals. Similarly, the resting levels of cAMP and the forskolin-induced elevations of cAMP did not differ between non-SAH and SAH animals. In contrast, cGMP levels were lower in resting and CGRP-treated vessels from SAH animals than in those from non-SAH animals. No significant differences in the levels of cGMP were observed between non-SAH and SAH vessels treated with GTN.
This study indicates that CGRP-induced vasodilation is attenuated during vasospasm in a rabbit model of SAH. The findings also demonstrate that vasodilatory responses mediated by cAMP and cGMP are intact, although the levels of cGMP in SAH vessels are reduced. Together, these observations suggest that an attenuation in the capacity of vessels to dilate in response to CGRP occurs during cerebral vasospasm, and this change in CGRP vasoactivity is a result of modifications prior to, or independent of, the elevation of cyclic nucleotide second messengers.
Pharmacological and morphological effects of in vitro transluminal balloon angioplasty on normal and vasospastic canine basilar arteries
Authors: Chan Patrick D. S. , Findlay J. Max , Vollrath Bozena , Cook David A. , Grace Michael , Chen Ming H. , Ashforth Robert A. 
Published: June 2009

✓ Despite growing clinical use of transluminal balloon angioplasty (TBA) to treat cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH), the precise mechanism of action of balloon dilation on the cerebral arterial wall is unknown. In this experiment the authors examined the pharmacological and morphological changes in 10 normal and 12 vasospastic canine basilar arteries followingin vitrosilicone microballoon TBA. For the SAH group in which the double-hemorrhage model was used, vasospasm was confirmed by angiography and the animals were killed on Day 7 after the first SAH.In vitroTBA was performed on basilar arteries from normal and SAH dogs immediately after sacrifice and removal of the brain. The procedure was performed while the arteries were maintained in oxygenated Krebs buffer. In the pharmacological studies, potassium chloride, prostaglandin F2α, serotonin, and noradrenaline were used as vasoconstrictors, and bradykinin and calcium ionophore A23187 were used to produce an endothelium-dependent dilation. In both normal and vasospastic groups, the pharmacological responses of dilated segments of basilar arteries were compared to those of nondilated segments of the same arteries.Vessels from all groups were examined using scanning electron microscopy (EM) and transmission EM. Scanning EM was used to study the intact vessel wall, the smooth-muscle cell layer obtained after digestion with hydrochloric acid, and the extracellular matrix obtained after digestion with bleach. Cross-sections of the vessel wall were examined using transmission EM.The most striking finding was that immediately afterin vitroTBA of both normal and vasospastic canine basilar arteries, there was a significant reduction (p < 0.05) of responses to both vasoconstrictors and vasorelaxants. As revealed by scanning EM and transmission EM, both normal and vasospastic vessels dilated with TBA showed flattening and patchy denudation of the endothelium, and straightening and occasional rupturing of the internal elastic lamina. In addition, vasospastic vessels dilated with TBA showed decreased surface rippling and mild stretching and straightening of smooth-muscle cells, and mild thinning of the tunica media. There was no gross vascular disruption or obvious change in the extracellular matrix of the vessel walls of either normal or vasospastic arteries after TBA. These results suggest that functional impairment of vasoreactivity in the vessel wall as a result of mechanical stretching of the smooth-muscle layer plays a more important role than structural alteration, at least in the immediate dilation produced in vasospastic arteries byTBA.
Chronic tonsillar herniation in Crouzon's and Apert's syndromes: the role of premature synostosis of the lambdoid suture
Authors: Cinalli Giuseppe , Renier Dominique , Sebag Guy , Sainte-Rose Christian , Arnaud Eric , Pierre-Kahn Alain 
Published: June 2009

✓ The incidence of chronic tonsillar herniation (CTH) was evaluated with magnetic resonance imaging in 44 patients with Crouzon's syndrome and 51 with Apert's syndrome; the incidence was 72.7% in Crouzon's syndrome and 1.9% in Apert's syndrome. All the patients with Crouzon's syndrome and progressive hydrocephalus had CTH, but of 32 individuals with Crouzon's syndrome and CTH, only 15 had progressive hydrocephalus. Five patients with Apert's syndrome were treated for progressive hydrocephalus; none had CTH.
The patterns of suture closure in these two groups of patients were studied, and significant differences in coronal, sagittal, and lambdoid sutures were found between patients with Crouzon's and Apert's syndromes. In Crouzon's syndrome, significant differences in the pattern of lambdoid suture closure were found between the groups with and without CTH; in the group with CTH, the lambdoid closure appeared earlier. The authors propose that the high incidence of individuals with CTH who have Crouzon's syndrome is related to the premature synostosis of the lambdoid suture in the first 24 months of age.
Long-term outcome of hypothalamic/chiasmatic astrocytomas in children treated with conservative surgery
Authors: Sutton Leslie N. , Molloy Patricia T. , Sernyak Heidi , Goldwein Joel , Phillips Peter L. , Rorke Lucy B. , Moshang Thomas , Lange Beverly , Packer Roger J. 
Published: June 2009

✓ The feasibility of radical surgery for astrocytomas of the optic chiasm/hypothalamus has been reported by several groups. Such surgery carries significant risks, however, including permanent damage to the pituitary gland, optic apparatus, hypothalamic structures, and carotid arteries. The benefits of radical surgery, both in terms of efficacy and toxicity, should, therefore, be evaluated against standard therapy, as is usually done for new chemotherapeutic protocols.
To this end, a retrospective review was performed of 33 patients treated at Children's Hospital of Philadelphia between 1976 and 1991 who met criteria that would have made them eligible for radical surgery in many centers today, but were treated with either no surgery or conservative surgery (< 50% resection) or biopsy followed by adjuvant therapy with local radiation therapy (29 patients) and/or chemotherapy with actinomycin-D and vincristine (18 patients). The review encompassed all children with a globular enhancing mass of at least 2 cm in the hypothalamic/chiasmatic region, no evidence of optic nerve involvement or involvement of the optic radiations by computerized tomography or magnetic resonance imaging, and follow up of at least 3 years. All but one patient had tissue confirmation of a low-grade or pilocytic astrocytoma. Thirteen of the patients were 2 years of age or younger at diagnosis.
Five individuals died: three of tumor progression, one of acute shunt malfunction, and one of intercurrent infection. The remaining 28 were alive at last follow up, a mean of 10.9 years from diagnosis. Twenty-three surviving patients have functional vision in at least one eye, 12 require no endocrine replacement, and 16 are in or have completed schooling with regular academic requirements.
If radical surgery is to become standard care for children with low-grade astrocytomas of the hypothalamic/chiasmatic region, long-term survival and functional outcome will have to equal or surpass those of historical controls who were treated conservatively.
Reoperation for recurrent metastatic brain tumors
Authors: Bindal Rajesh K. , Sawaya Raymond , Leavens Milam E. , Hess Kenneth R. , Taylor Sarah H. 
Published: June 2009

✓ Results of reoperation in 48 patients who developed recurrent brain metastases between January 1984 and April 1993 are presented. Median time from first craniotomy to diagnosis of recurrence (time to recurrence) was 6.7 months. Median Karnofsky performance scale (KPS) score prior to reoperation was 80. Recurrence was local in 30 patients, distant in 16 patients, and both local and distant in two patients. Median survival time after reoperation was 11.5 months. There were no operative mortalities. Multivariate analysis revealed that presence of systemic disease (p = 0.008), KPS scores less than or equal to 70 (p = 0.008), time to recurrence of less than 4 months (p = 0.008), age greater than or equal to 40 years (p = 0.51), and primary tumor type of breast or melanoma (p = 0.028) negatively affected patient survival time. These five factors were used to develop a grading system (Grades I–IV). Patients categorized in Grade I had a 5-year survival rate of 57%, whereas the median survival time of patients in Grades II, III, and IV was 13.4, 6.8, and 3.4 months, respectively (p < 0.0001).
Overall, 26 patients developed a second recurrence after reoperation. Seventeen patients underwent a second reoperation, whereas nine did not. Patients undergoing a second reoperation survived a median of 8.6 additional months versus 2.8 months for those who did not (p < 0.0001).
This study concludes that reoperation for recurrent brain metastasis can prolong survival and improve quality of life. A second reoperation can also increase survival. Five factors influence survival: status of systemic disease, KPS score, time to recurrence, age, and type of primary tumor. The grading system using these five factors correlates with survival time. Reoperation should be approached with caution in Grade IV patients because of their poor prognosis.
Application of frameless stereotaxy to pedicle screw fixation of the spine
Authors: Kalfas Iain H. , Kormos Donald W. , Murphy Michael A. , McKenzie Rick L. , Barnett Gene H. , Bell Gordon R. , Steiner Charles P. , Trimble Mary Beth , Weisenberger Joseph P. 
Published: June 2009

✓ Interactive frameless stereotaxy has been successfully applied to intracranial surgery. It has contributed to the improved localization of deep-seated brain lesions and has demonstrated a potential for reducing both operative time and morbidity. However, it has not been as effectively applied to spinal surgery.
The authors describe the application of frameless stereotactic techniques to spinal surgery, specifically pedicle screw fixation of the lumbosacral spine. Preoperative axial computerized tomography (CT) images of the appropriate spinal segments are obtained and loaded onto a high-speed graphics supercomputer workstation. Intraoperatively, these images can be linked to the appropriate spinal anatomy by a sonic localization digitizer device that is interfaced with the computer workstation. This permits the surgeon to place a pointing device (sonic wand) on any exposed spinal bone landmark in the operative field and obtain multiplanar reconstructed CT images projected in near-real time on the workstation screen. The images can be manipulated to assist the surgeon in determining the proper entry point for a pedicle screw as well as defining the appropriate trajectory in the axial and sagittal planes. It can also define the correct screw length and diameter for each pedicle to be instrumented.
The authors applied this device to the insertion of 150 screws into the lumbosacral spines of 30 patients. One hundred forty-nine screws were assessed to be satisfactorily placed by postoperative CT and plain film radiography. In this report the authors discuss their use of this device in the clinical setting and review their preliminary results of frameless stereotaxy applied to spinal surgery. On the basis of their findings, the authors conclude that frameless stereotactic technology can be successfully applied to spinal surgery.
Acromegaly, diabetes insipidus, and visual loss caused by metastatic growth hormone—releasing hormone-producing malignant pancreatic endocrine tumor in the pituitary gland
Authors: Genka Shigeru , Soeda Hitoshi , Takahashi Manabu , Katakami Hideki , Sanno Naoko , Osamura Yoshiyuki , Fuchinoue Tokuro , Teramoto Akira 
Published: June 2009

✓ The case of a 52-year-old woman with acromegaly, diabetes insipidus, and visual impairment caused by a metastatic growth hormone—releasing hormone (GRH)—produced pancreatic tumor is reported. Serum growth hormone (GH) and somatomedin C levels were elevated to 14 ng/ml (normal < 5 ng/ml), and 3.20 U/ml (normal < 1.88 U/ml), respectively. Paradoxical increases were observed in GH levels after glucose tolerance and thyrotropin—releasing hormone-stimulation tests. Biopsy of a pituitary tumor observed on computerized tomography scans and magnetic resonance studies revealed a metastatic cancer. When circulating GRH levels were measured, a marked increase in plasma GRH (1145 pg/ml; normal < 4—1 pg/ml) was observed. The patient died of cachexia due to metastases.
Postmortem examination revealed that a primary tumor, a malignant endocrine lesion, was present in the pancreas, with metastatic tumors in the pituitary, lung, liver, and adrenal glands. Synthesis and production of GRH by the tumor was demonstrated by Northern blotting and immunohistochemical analysis. The pituitary gland showed hyperplastic, but not adenomatous changes. The authors stress the importance of both exploration for an ectopic source of GRH and the search for a GH-producing pituitary adenoma when unusual signs and symptoms are seen in patients with acromegaly.
Surgical outcome for intra- and extrapelvic femoral nerve lesions
Authors: Kim Daniel H. , Kline David G. 
Published: June 2009

✓ Seventy-eight traumatic neuropathies were seen in 94 patients with femoral nerve lesions; 54 of these were operated on because of persistent complete functional loss and/or pain. The most common mechanism of injury to the femoral nerve was iatrogenic due to inguinal herniorrhaphy, total hip replacement, intraabdominal vascular or gynecological operation, and, less commonly, appendectomy, lumbar sympathectomy, and laparoscopic procedures. Femoral nerve injuries also resulted from penetrating gunshot and stab wounds, laceration by glass, and stretch/contusive injuries associated with pelvic fractures. There were no signs of clinical or electrical recovery in 45 of 78 patients with traumatic nerve injuries. These and other partial injuries associated with pain were explored and evaluated by intraoperative nerve stimulation and recording of nerve action potentials (NAPs).
Despite complete loss of nerve function preoperatively, 13 patients had recordable NAPs and underwent neurolysis; each recovered function to at least a Grade 3 level. Twenty-seven patients had sural graft repairs performed with graft lengths varying from 2.5 to 14 cm. Most patients had some nerve regeneration and regained function to Grade 3 to 4 levels by 2 years postoperatively. Four of five patients with suture repairs recovered to Grade 3 or better within 2 years postoperatively. Despite a proximal pelvic level for most of these injuries and, as a result, lengthy graft repairs, recovery of some useful function was the rule rather than the exception. Tumors involved the femoral nerve in 16 patients and included eight neurofibromas, four schwannomas, one neurogenic sarcoma, two ganglion cysts, and one leiomyosarcoma. All tumors were treated surgically and most were removed successfully.
Interim report on the radiosurgical treatment of cerebral arteriovenous malformations
Authors: Yamamoto Yoshihiro , Coffey Robert J. , Nichols Douglas A. , Shaw Edward G. 
Published: June 2009

✓ During the authors' initial 4-year experience with radiosurgery using the Leksell cobalt-60 gamma unit, they treated 121 patients with cerebral arteriovenous malformations (AVMs). The radiosurgical dose to the margin of the nidus was 20 Gy for lesions less than 2.0 cm in diameter (volume ≤ 4.2 cm3); 18 Gy for malformations 2.1 to 3.0 cm in diameter (volume 4.2–14.1 cm3); and 16 Gy for malformations greater than 3.0 cm (volume > 14.1 cm3). Fifty-one patients underwent follow-up angiography between 1 and 3 years after treatment, and complete obliteration of the nidus was confirmed in 38 (74.5%) of these patients. Thirty-two (74.4%) of 43 AVMs with volumes of 10 cm3 or less and six (75%) of eight larger AVMs (volume 11–30 cm3) showed complete obliteration. Analysis of the time course of AVM nidus shrinkage and obliteration showed that most of the radiosurgically induced effect had occurred by 36 months after treatment. Retrospective analysis of the dose plans for 10 AVMs that were not obliterated by 36 months after gamma knife radiosurgery at the authors' institution (eight cases) or elsewhere (two cases) revealed that six AVMs had not been covered completely by the prescribed isodose. Six (5%) of the 121 patients developed neurological deficits as a direct result of radiosurgical treatment.
The authors infer from these data that malformations up to 30 cm3 in volume (approximately 4.0 cm in average diameter) can be treated effectively with an acceptably low complication rate using a radiosurgical dose of 16 Gy to the margin of the nidus. The obliteration rate for the larger malformations that were treated with a dose of 16 to 18 Gy appears to be similar to that for smaller ones treated with 18 to 20 Gy. As more experience accrues using radiosurgery to treat AVMs, patient selection criteria and the variables associated with successful obliteration of the nidus should become more clearly defined.
Treatment of carotid-cavernous sinus fistulas using a superior ophthalmic vein approach
Authors: Miller Neil R. , Monsein Lee H. , Debrun Gerard M. , Tamargo Rafael J. , Nauta Haring J. W. 
Published: June 2009

✓ The authors describe the method and results of treatment of 12 consecutive patients with carotid-cavernous sinus fistulas (CCFs). Treatment was by embolization via a transvenous approach through the superior ophthalmic vein (SOV). The CCFs (two direct and 10 dural) had previously been treated unsuccessfully or, for mechanical reasons, could not be treated by the standard techniques of endoarterial balloon occlusion, particle or glue embolization of feeding vessels from one or both external carotid arteries, or transvenous occlusion of the fistula via the ipsilateral inferior petrosal sinus. All 12 patients were successfully treated either by advancement of a detachable balloon catheter through the ipsilateral SOV into the cavernous sinus with subsequent inflation and detachment of the balloon (11 patients) or by introduction of multiple thrombogenic coils into the fistula via the ipsilateral SOV (one patient).
All patients had complete resolution of symptoms and signs after successful occlusion of the CCF. There were no intraoperative complications; however, one patient required postoperative embolization of a residual posteriorly draining fistula via the ipsilateral external carotid artery, and another developed a persistent abducens nerve paresis that eventually required surgical correction. Ten (83.3%) of the 12 patients underwent cerebral angiography 3 to 6 months after surgery, and none showed evidence of a recurrent fistula. Similarly, none of the 12 patients developed recurrent symptoms and signs suggesting recurrence of the fistula during a follow-up period that ranged from 6 months to 10 years (mean 64 months). It is concluded that the transvenous approach to the cavernous sinus through the SOV is a safe and effective treatment of both direct and dural CCFs that are not amenable to transarterial or other transvenous approaches.