New England Medical Center Posterior Circulation Stroke Registry: I. Methods, Data Base, Distribution of Brain Lesions, Stroke Mechanisms, and Outcomes

Among 407 New England Medical Center Posterior Circulation Registry (NEMC-PCR) patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs before strokes, and 16% had only posterior circulation TIAs. Embolism was the commonest stroke mechanism accounting for 40% of cases (24% cardiac origin, 14% arterial origin, 2% had potential cardiac and arterial sources). In 32%, large artery occlusive lesions caused hemodynamic brain infarction. Stroke mechanisms in the posterior and anterior circulation are very similar. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes), while the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Infarcts that included the distal territory were twice as common as those that included the proximal or middle territories. Most distal territory infarcts were attributable to embolism. Thirty day mortality was low (3.6%). Embolic stroke mechanism, distal territory location, and basilar artery occlusive disease conveyed the worst prognosis.     

Digital and conventional chest images: observer performance with Film Digital Radiography System

The Film Digital Radiography System (FilmDRS) is a device with a laser optical film digitizer, 2,000 X 2,000 X 12-bit memory, and a 1,000-line video display. To evaluate the adequacy of this device for general radiography of the chest, four readers independently analyzed both radiographs and the corresponding video display of the digitized chest images of 150 patients, consisting of 100 images of abnormalities and 50 normal images. The overall results indicate equal sensitivity for the two systems. The FilmDRS, with interactive windowing, proved superior in the detection of hilar and mediastinal disease. X-ray film was superior in allowing detection of hyperlucent states. There was equivalent sensitivity for other disease categories. Superior specificity was achieved with conventional radiographs.     

Laparoscopic visual field

Background: In order for robotic devices to be introduced successfully into surgical practice, the development of transparent surgeon/machine interfaces is critical. Methods: This study evaluated the standard foot pedal for the AESOP robot compared to a voice control interface. Speed, accuracy, learning curves, durability of learning at 2 weeks, and operator-interface failures were analyzed in an ex vivo model. Results: Foot control was faster and had less operator-interface failures. Voice control was more accurate as measured by ``pass points.' The foot control learning curve reached a plateau at the third trial, while the voice control did not fully plateau. Durability of learning favored the foot control but was not significantly different. Conclusions: Currently, the voice control is more accurate and has the advantage of not requiring the surgeon to look away from the operative field. However, it is slower and may require more attention as an interface. As voice recognition software continues to advance, speed and transparency are anticipated to improve. Received: 24 October 1997/Accepted: 2 February 1998     

Laparoscopic nephroureterectomy: initial clinical case report.

Using a 12-mm GIA laparoscopic stapling device, a method of organ entrapment, and a recently developed high-speed electrical tissue morcellator, laparoscopic nephroureterectomy was accomplished in an 82-year-old male with a low-grade transitional cell cancer of the renal pelvis.     

New England Medical Center Posterior Circulation Stroke Registry II. Vascular Lesions

Among 407 New England Medical Center Posterior Circulation Registry (NEMC-PCR) patients, the extracranial (ECVA) and intracranial vertebral arteries (ICVA) were the commonest sites of severe occlusive disease followed by the basilar artery (BA). Severe occlusive lesions were found in >1 large artery in 148 patients; 134 had unilateral or bilateral severe disease at one arterial location. Single arterial site occlusive disease occurred most often in the ECVA (52 patients, 15 bilateral) followed by the ICVA (40 patients, 12 bilateral) and the BA (46 patients). Involvement of the ICVAs and the BA was very common and some patients also had ECVA lesions. Hypertension, smoking, and coronary and peripheral vascular disease were most prevalent in patients with extracranial disease while diabetes and hyperlipidemia were more common when occlusive lesions were only intracranial. Intra-arterial embolism was the most common mechanism of brain infarction in patients with ECVA and ICVA occlusive disease. ICVA occlusive lesions infrequently caused infarction limited to the proximal territory (medulla and posterior inferior cerebellum). BA lesions most often caused infarcts limited to the middle posterior circulation territory (pons and anterior inferior cerebellum). Posterior cerebral artery occlusive lesions were predominantly embolic. Penetrating artery disease caused mostly pontine and thalamic infarcts. Prognosis was poorest in patients with BA disease. The best prognosis surprisingly was in patients who had multiple arterial occlusive lesions; they often had position-sensitive transient ischemic attacks during months or years.     

Telerobotische Chirurgie zwischen Baltimore und München

Die rasante Entwicklung der Laparoskopie in der Urologie erfordert die Ausbildung von Spezialisten, um den hohen Standard der Patientenversorgung zu gew?hrleisten.     

Flexible, actively deflectable fiberoptic ureteronephroscopy

We performed 76 flexible, actively deflectable ureteronephroscopic procedures in 68 patients. Of the patients 61 were examined transurethrally, 3 via an ileal loop, 2 percutaneously and 2 via ureterostomy. Indications for flexible, actively deflectable ureteronephroscopy included urolithiasis in 28 patients, upper tract filling defect in 25, lateralizing hematuria in 8, retrograde endopyelotomy in 2, post-endopyelotomy evaluation in 6, surveillance for transitional cell carcinoma in 4 and other reasons in 3. The area of interest was accessed successfully in 96% of the patients. In 57 instances an attempt was made to inspect all calices and was successful in two-thirds of the patients. However, greater than 75% of the collecting system was accessed in all but 2 of these 57 patients. Over-all, diagnostic and/or therapeutic maneuvers were successful in 84% of the patients. Flexible, actively deflectable ureteronephroscopy provides the urologist with a minimally invasive means to evaluate and treat pathological conditions of the upper urinary tract.