Cauda Equina and Filum Terminale Arteriovenous Fistulas: Anatomic and Radiographic Features.

Intradural AVF below the conus medullaris may develop either on the filum terminale or the cauda equina (lumbosacral and coccygeal radicular nerves). Although not a few filum terminale AVFs are found in the literature, only 3 detailed cauda equina AVFs have been reported. Here, we analyze the angiographic and MR imaging findings of our cauda equina and filum terminale AVF cases, supplemented with literature research to characterize the radiologic features of the 2 entities. On angiography, filum terminale AVFs were invariably supplied by the extension of the anterior spinal artery accompanied by a closely paralleling filum terminale vein. Cauda equina AVFs were fed by either a radicular or a spinal artery or both arteries, often with a characteristic wavy radicular-perimedullary draining vein. On thin-section axial MR imaging, the filum terminale AVF draining vein joined the spinal cord at the conus medullaris apex, but that of the cauda equina AVF joined above the conus medullaris apex.

Swine hybrid aneurysm model for endovascular surgery training.

The aim of this study was to develop a technically simple swine aneurysm-training model by inserting a silicone aneurysm circuit in the cervical vessels. A silicone aneurysm circuit was created by designing multiple aneurysms in size and configuration on a silicone vessel. Five swine underwent surgical implantation of this circuit in the cervical vessels: one end in the common carotid artery and the other in the external jugular vein. Using this model, an aneurysm coiling procedure was simulated under fluoroscopic guidance, roadmapping and digital subtraction angiography. Creating an aneurysm model for training purposes by this method was technically simple and enabled the formation of a wide variety of aneurysms in a single procedure. The quality of the model was uniform and the model was reproducible. Coiling training using this model resembled a realistic clinical situation. The swine hybrid aneurysm-training model was advantageous from the standpoint of technical simplicity in the creation and variety of aneurysms it provided. The swine hybrid aneurysm model may be an additional option for aneurysm coiling training.

Protective effect of neurotropin against lipopolysaccharide-induced hypotension and lethality linked to suppression of inducible nitric oxide synthase induction.

Neurotropin is a non-protein extract from the dermis of rabbits inoculated with vaccinia virus and has been clinically used as an analgesic in Japan. We present in the current report evidence for its potential therapeutic value against endotoxin shock. Administration of this compound prior to lipopolysaccharide (LPS) challenge resulted in a reversal of a decrease of the mean arterial pressure in rats and also amelioration of lethality in mice. Anti-inducible nitric oxide synthase (iNOS) Western blotting of tissue extracts from LPS-treated mice revealed almost complete suppression of iNOS induction by Neurotropin. The findings in vivo were reproduced in in vitro experiments in which cultured human umbilical vascular endothelial cells were challenged with LPS. Simultaneous treatment of the cells with Neurotropin resulted in complete suppression of iNOS induction and significant reduction of cell death. These results suggested a therapeutic value of Neurotropin in the treatment of endotoxin shock that was linked, at least in part, to suppression of iNOS induction and reduced cell damage in vascular endothelial cells.

Hypereosinophilic syndrome with generalized myasthenia gravis.

A patient with hypereosinophilic syndrome simultaneously had generalized myasthenia gravis. Ultrastructural and functional studies demonstrated an increase of the activated hypodense eosinophils. The eosinophilic cationic protein level in plasma and whole blood paralleled the severity of congestive heart failure. A high level of interleukin-5 was detected in both serum and in conditioned medium of T cells by interleukin-2 stimulation before therapy. The findings indicate that both diseases may be associated with a common T-cell abnormality.

Disappearance of neutrophil fluctuations in a child with cyclic neutropenia by combination therapy of granulocyte colony-stimulating factor and high-dose immunoglobulin.

We report on a patient with cyclic neutropenia who was treated by granulocyte colony-stimulating factor (G-CSF) and high-dose immunoglobulin. The serial examination revealed cyclic fluctuations in the numbers of neutrophils, monocytes, platelets in peripheral blood, and in the serum G-CSF concentration. Bone marrow examination confirmed a cyclic fluctuation of both progenitor cells (CFU-GM) and CD10-positive B cells. The therapy of G-CSF followed by high-dose immunoglobulin achieved a disappearance of neutrophil oscillations. It suggested that the combination therapy of G-CSF with high-dose immunoglobulin might be effective for cyclic neutropenia.

Knee-chest position improves pulmonary oxygenation in elderly patients undergoing lower spinal surgery with spinal anesthesia.

STUDY OBJECTIVE: To define the effect of the knee-chest position on pulmonary oxygenation in patients who underwent lower spinal operations under spinal anesthesia. DESIGN: Clinical, prospective study. SETTING: Inpatient anesthesia and orthopedic surgery clinic at a municipal hospital. PATIENTS: Fifty-six patients (30 males and 26 females) who underwent lower spinal surgery under spinal anesthesia. INTERVENTIONS: After administering hyperbaric tetracaine solution and fixing the anesthesia level in the supine position for 15 minutes, patients were turned to the knee-chest position. They breathed room air normally. MEASUREMENTS AND MAIN RESULTS: Arterial blood gas tensions were measured in the supine position 15 minutes after administration of the tetracaine solution and 15 minutes after turning patients to the knee-chest position. Patients were classified into six groups according to their age: patients in their teens and 20s, 30s, 40s, 50s, 60s, and 70s. In the supine position, the mean values of the alveolar arterial oxygen tension difference (A-aDO2) of patients in their 50s, 60s, and 70s were significantly higher than those of patients in their teens and 20s, 30s, and 40s. In the knee-chest position, these high values of A-aDO2 in the older patient groups decreased significantly, thereby eliminating any significant difference in A-aDO2 among all age groups. To determine the mechanism of the improvement of pulmonary oxygenation in the elderly patients, the effect of the knee-chest position on lung volumes was studied in eight young volunteers. CONCLUSION: A significant improvement of pulmonary oxygenation was seen in elderly patients who underwent lower spinal operation with spinal anesthesia when they were turned to the knee-chest position. The knee-chest position has a beneficial effect on pulmonary oxygenation in elderly patients who are given spinal anesthesia.

Mesenteric lymphatic vasomotion following hemorrhage and retransfusion in the rat.

The effect of hemorrhage and retransfusion on the rhythmic contraction of mesenteric lymphatic vessels was studied in 24 rats, anesthetized with pentobarbital. The rats were divided into four groups according to the amount of blood withdrawn: 0.5ml/100g body weight (BW), 1ml/100g, 2ml/100g, and 2.5ml/100g. Immediately following hemorrhage at the rate of 0.5ml/100g/min, lymphatic contraction frequencies were decreased to 67 +/- 12.5, 45 +/- 24.7, 43 +/- 33.1, and 31 +/- 17.8% of the prehemorrhage values in each of the above four groups, respectively (p less than 0.01). Twenty minutes after hemorrhage, lymphatic contraction frequencies were decreased to 70 +/- 17.2, 46 +/- 36.8, and 34 +/- 41.3% in the 0.5ml/100g, 2ml/100g, and 2.5ml/100g, respectively (p less than 0.05). Immediately following hemorrhage, the lymphatic contracted diameters were also reduced to 77 +/- 9.7 and 61 +/- 9.0% of the prehemorrhage values in the 1ml/100g and 2.5ml/100g groups, respectively (p less than 0.01). Twenty minutes after hemorrhage, all withdrawn blood was reinfused. Lymphatic contraction frequency and contracted diameter recovered after retransfusion in each group but 20 minutes after retransfusion, the lymphatic contraction frequency in the 2ml/100g group was still decreased to 42 +/- 30.3% (p less than 0.01). Lymphatic contraction frequency not only decreased proportionately with hypotension during hemorrhage but after retransfusion contraction frequency correlated directly with the mean arterial pressure 20 min after hemorrhage. These data suggest that mean arterial pressure and by inference capillary blood flow and tissue oxygenation are major factors regulating lymphatic vasomotion.