Influence of crossdrafts on the performance of a biological safety cabinet.
A biological safety cabinet was tested to determine the effect of crossdrafts (such as those created by normal laboratory activity or ventilation) upon the ability of the cabinet to protect both experiments and investigators. A simple crossdraft, controllable from 50 to 200 feet per min (fpm; 15.24 to 60.96 m/min), was created across the face of the unit. Modifications of standardized procedures involving controlled bacterial aerosol challenges provided stringent test conditions. Results indicated that, as the crossflow velocities exceeded 100 fpm, the ability of the cabinet to protect either experiments or investigators decreased logarithmically with increasing crossdraft speed. Because 100 fpm is an airspeed easily achieved by some air conditioning and heating vents (open windows and doorways may create velocities far in excess of 200 fpm), the proper placement of a biological safety cabinet within the laboratory--away from such disruptive air currents--is essential to satisfactory cabinet performance. (+info)
National Child Passenger Safety Week--February 14-20, 1999.
In 1997, 1791 U.S. children aged <15 years were killed and 282,000 were injured while riding in motor vehicles. National Child Passenger Safety Week, February 14-20, 1999, will highlight safety recommendations for children aged >4 years and weighing >40 lbs who have outgrown their child safety seats. (+info)
3D angiography. Clinical interest. First applications in interventional neuroradiology.
3D angiography is a true technical revolution that allows improvement in the quality and safety of diagnostic and endovascular treatment procedures. 3D angiography images are obtained by reconstruction of a rotational angiography acquisition done on a C-arm (GE Medical Systems) spinning at 40 degrees per second. The carotid or vertebral selective injection of a total of 15 ml of non-ionic contrast media at 3 ml/sec over 5 seconds allows the selection of the "arterial phase". Four hundred sixty 3D angiographic studies were performed from December 1996 to September 1998 on 260 patients and have been analyzed in MIP (Maximum Intensity Projection) and SSD (Shaded Surface Display) views. The exploration of intracranial aneurysms is simplified and only requires, for each vascular axis, a biplane PA and Lateral run followed by a single rotational angiography run. The 3D angiography image is available on the workstation's screen (Advantage Workstation 3.1, GE Medical Systems) in less than 10 minutes after the acquisition of the rotational run. It therefore allows one to analyze, during the intervention, the aneurysm's angioarchitecture, in particular the neck, and select the best therapeutic technique. When endovascular treatment is the best indication, 3D angiography allows one to define the optimal angle of view and accurately select the microcoils dimensions. 3D angiography replaces the multiple oblique views that used to be required to analyze the complex aneurysms and therefore allows a reduction of the total contrast medium quantity, the patient X-ray dose and the length of the intervention time which is a safety factor. Also, in particular for complex cases, it brings additional elements complementing the results of standard 2D DSA and rotational angiograms. In the cervical vascular pathology, 3D angiography allows for a better assessment of the stenosis level and of dissection lesions. Our current research activities focus on the matching without stereotactic frame between 3D X-ray angiography and volumetric MR acquisition, which should allow us to improve the treatment of intracerebral arterio-venous malformations (AVMs). (+info)
Penetrating sledding injuries to the lower torso--2 case reports.
Sledding accidents are frequent and vary in severity. Penetrating sledding injuries are uncommon but may be devastating. Snow-racers--sleds with both steering and braking devices--may be associated with an increased rate of injury. The authors present 2 cases of lower-torso penetrating trauma associated with the use of snow-racers. Both cases involved penetration--of the perineum in one case and the inguinal area in the other--by wooden sticks. Both patients recovered fully after prompt surgical intervention. The authors suggest that the absence of a protective panel at the front of the snow-racer may result in the sledder's lower torso being more exposed to objects encountered while sledding. The injuries reported raise concerns about the safety of modern sleds and the possibility that design changes are needed. (+info)
Surgical transluminal iliac angioplasty with selective stenting: long-term results assessed by means of duplex scanning.
PURPOSE: The safety of iliac angioplasty and selective stenting performed in the operating room by vascular surgeons was evaluated, and the short- and long-term results were assessed by means of serial duplex scanning. METHODS: Between 1989 and 1996, 281 iliac stenotic or occlusive lesions in 235 consecutive patients with chronic limb ischemia were treated by means of percutaneous transluminal angioplasty (PTA) alone (n = 214) or PTA with stent (n = 67, 23.8%). There were 260 primary lesions and 21 restenosis after a first PTA, which were analyzed separately. Stents were implanted in selected cases, either primarily in totally occluded arteries or after suboptimum results of PTA (ie, residual stenosis or a dissection). Data were collected prospectively and analyzed retrospectively. Results were reported in an intention-to-treat basis. Clinical results and patency were evaluated by means of symptom assessment, ankle brachial pressure index, and duplex scanning at discharge and 1, 3, 6, and every 12 months after angioplasty. To identify factors that may affect outcome, 12 clinical and radiological variables, including the four categories of lesions defined by the Standards of Practice Committee of the Society of Cardiovascular and Interventional Radiology, were analyzed separately. The statistical significances of life-table analysis of patency were determined by means of the log-rank test. RESULTS: There were no postoperative deaths or amputations. Local, general, and vascular complications occurred in 2.1%, 1.3% and 4.7% of cases, respectively (total, 8.1%). The mean follow-up period was 29.6 months. The cumulative patency rates +/- SE of the 260 PTAs (including 55 PTAs plus stents) were 92.9% +/- 1.5% at 1 month, 86. 5% +/- 1.7% at 1 year, 81.2% +/- 2.3% at 2 years, 78.8% +/- 2.9% at 3 years, and 75.4% +/- 3.5% at 5 and 6 years. The two-year patency rate of 21 redo PTAs (including 11 PTAs plus stents) was 79.1% +/- 18.2%. Of 12 predictable variables studied in the first PTA group, only the category of the lesion was predictive of long-term patency. The two-year patency rate was 84% +/- 3% for 199 category 1 lesions and 69.7% +/- 6.5% for 61 category 2, 3, and 4 lesions together (P =. 02). There was no difference of patency in the stented and nonstented group. CONCLUSION: Iliac PTA alone or with the use of a stent (in cases of occlusion and/or suboptimal results of PTA) offers an excellent long-term patency rate. Categorization of lesions remains useful in predicting long-term outcome. PTA can be performed safely by vascular surgeons in the operating room and should be considered to be the primary treatment for localized iliac occlusive disease. (+info)
Carotid endarterectomy and intracranial thrombolysis: simultaneous and staged procedures in ischemic stroke.
PURPOSE: The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied. METHODS: A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale. RESULTS: Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively. CONCLUSION: Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies. (+info)
Mid-term results of endoscopic perforator vein interruption for chronic venous insufficiency: lessons learned from the North American subfascial endoscopic perforator surgery registry. The North American Study Group.
PURPOSE: The safety, feasibility, and early efficacy of subfascial endoscopic perforator surgery (SEPS) for the treatment of chronic venous insufficiency were established in a preliminary report. The long-term clinical outcome and the late complications after SEPS are as yet undetermined. METHODS: The North American Subfascial Endoscopic Perforator Surgery registry collected information on 148 SEPS procedures that were performed in 17 centers in the United States and Canada between August 1, 1993, and February 15, 1996. The data analysis in this study focused on mid-term outcome in 146 patients. RESULTS: One hundred forty-six patients (79 men and 67 women; mean age, 56 years; range, 27 to 87 years) underwent SEPS. One hundred and one patients (69%) had active ulcers (class 6), and 21 (14%) had healed ulcers (class 5). One hundred and three patients (71%) underwent concomitant venous procedures (stripping, 70; high ligation, 17; varicosity avulsion alone, 16). There were no deaths or pulmonary embolisms. One deep venous thrombosis occurred at 2 months. The follow-up periods averaged 24 months (range, 1 to 53 months). Cumulative ulcer healing at 1 year was 88% (median time to healing, 54 days). Concomitant ablation of superficial reflux and lack of deep venous obstruction predicted ulcer healing (P <.05). Clinical score improved from 8.93 to 3.98 at the last follow-up (P <. 0001). Cumulative ulcer recurrence at 1 year was 16% and at 2 years was 28% (standard error, < 10%). Post-thrombotic limbs had a higher 2-year cumulative recurrence rate (46%) than did those limbs with primary valvular incompetence (20%; P <.05). Twenty-eight of the 122 patients (23%) who had class 5 or class 6 ulcers before surgery had an active ulcer at the last follow-up examination. CONCLUSIONS: The interruption of perforators with ablation of superficial reflux is effective in decreasing the symptoms of chronic venous insufficiency and rapidly healing ulcers. Recurrence or new ulcer development, however, is still significant, particularly in post-thrombotic limbs. The reevaluation of the indications for SEPS is warranted because operations in patients without previous deep vein thrombosis are successful but operations in those patients with deep vein thrombosis are less successful. Operations on patients with deep vein occlusion have poor outcomes. (+info)
Endovascular repair of a descending thoracic aortic aneurysm: a tip for systemic pressure reduction.
A proposed technique for systemic pressure reduction during deployment of a stent graft was studied. A 67-year-old man, who had a descending thoracic aneurysm, was successfully treated with an endovascular procedure. An occluding balloon was introduced into the inferior vena cava (IVC) through the femoral vein. The balloon volume was manipulated with carbon dioxide gas to reduce the venous return, resulting in a transient and well-controlled hypotension. This IVC-occluding technique for systemic pressure reduction may be safe and convenient to minimize distal migration of stent grafts. (+info)