Biomedical subjects
Publications and source records attributed to D F Jimenez.
One patient with a solitary plasmacytoma of the frontal bone was treated with complete surgical resection. To reconstruct the large calvarial defect, a split-thickness calvarial graft was harvested from the parietal area and secured in place with miniplates. Solitary plasmacytomas of the calvaria are not common. Clinical presentation, diagnostic criteria, therapeutic approaches, and prognosis are discussed.
A technique for the construction of a frontal bar and a forehead plate as a single unit is described. This technique could be used in any procedure in which a frontal bandeau is advanced and the forehead needs to be remodeled. By using microscrew fixation, the bulkiness of miniplates and wires is eliminated.
The authors review the pathophysiology of penetrating and perforating cranial wounds. Radiologic evaluation includes computed tomography and angiography. Operative technique and perioperative critical care are discussed, with special emphasis on the control of the intracranial pressure. Other problems such as fluid and electrolyte disorders and nutrition are discussed in relation to neurosurgery.
This study included 72 cases of surgically treated aneurysms, Hunt and Hess Grades 1-4, operated on within 72 hours of the ictus. All had anterior circulation aneurysms, and exposure was standard pterional approach. Once dissection had progressed to the point that the site of the aneurysm was identified, the patient was placed in burst suppression (6-8 bursts/minute), using etomidate 0.5 mg/Kg, with a constant infusion of 12 mg/min to maintain burst suppression. Sugita temporary clips were applied to the feeding vessel(s), the C1 or C4 portion of the carotid artery, the A1 segment(s) of the anterior cerebral or M1 segment of MCA. For ACOM aneurysms. Heubner was not included in the clip, and for MCA aneurysm an attempt was made to apply the clip distal to the lenticulostriates. Mean arterial pressure was elevated by 10% with neosynephrine. Once the temporary clips were applied, dissection of the neck and final clipping was accomplished, followed by removal of the temporary clips. Clip placement was inspected to assess for complete obliteration of the lesion. In 40% of cases, two or more permanent clips were required for aneurysmal obliteration. Occlusion time ranged from 3 to 63 minutes. Reperfusion at 5 minute intervals was not performed, based on the hypothesis that reperfusional injury potentiates an ischaemic insult. No vessel injury occurred as a result of temporary clip placement, as assessed by direct visual inspection at the time of surgery and angiographic picture one week following surgery. No new neurologic deficit was encountered postoperatively in any patient in the distribution of the occluded vessel.(ABSTRACT TRUNCATED AT 250 WORDS)
We present a model used to describe the effects of systemic thermal injury in cerebral permeability with the use of an open, acute pial window technique. Sprague-Dawley rats were anesthetized, and an open pial window was constructed. The area was then bathed with artificial cerebrospinal fluid with a pH adjusted to 7.4 that was heated to a constant temperature of 37 degrees C, which was allowed to circulate into a reservoir at a rate of 2 cc/min. The fluid was infused with a gas mixture of 5% carbon dioxide and 95% nitrogen. A warming blanket was placed under the animal's ventral surface, and the animal's temperature was maintained at 37 degrees C and monitored with a rectal thermal probe. Experimental animals were submerged to the xiphoid process in 100 degrees C water bath for a total of 6 seconds, which produced a 70% total body surface area third degree burn. Control animals were submerged in 37 degrees C water for 6 seconds. The animals were then injected with a constant infusion of bovine albumin coupled with fluorescein isothiocyanate. Recordings were taken every 15 minutes for 6 hours. The vascular albumin leakage was determined from the ratio of interstitium to vascular fluorescence and expressed as a percentage. The percent albumin leakage in the control group was found to be significantly different from that in the experimental group at all periods measured. The mean increase in permeability ranged from 20% at 15 minutes to 104% at 6 hours. These changes were found to be statistically significant with the use of unpaired t test at a P value of .0001. The model presented is the first to demonstrate changes in cerebral permeability after acute severe systemic thermal injury.