Stereoscopic display using rapid varifocal mirror oscillations.

A dynamic volumetric display technique is described in which a vibrating membrane mirror is used in conjunction with an appropriate two-dimensional pattern generator. The mirror can be driven electrostatically or by a loudspeaker and causes the virtual image of the pattern surface to sweep out a volume of image space. The two-dimensional pattern is a repetitively time-varying one and can be generated by stroboscopic optical projection, by a computer, or other means. The volumetric figures which were generated include a simulated air traffic control situation display and a mathematical surface.

Splenic preservation following splenic trauma.

Increased awareness of the problem of overwhelming post-splenectomy sepsis has aroused interest in methods of splenic preservation in patients with abdominal trauma. In the past 6 years, we have treated 272 patients for splenic trauma at our institution, 41 of whom underwent splenic preservation. Mortality rates in those undergoing splenectomy vs. preservation were 23.4% and 4.9%, respectively, severe head injuries constituting cause of death in the latter. Overall morbidity in the two groups was not significantly different (40.7% vs. 39%). Pulmonary complications were predominant in both groups (splenectomy, 27.7%; splenic preservation, 23.1%) with atelectasis more common in the latter. Three subphrenic abscesses occurred in the splenectomy group, none in the repair group. Sepsis was twice as frequent in the splenectomy group (8.7% vs. 4.9%). Mode of injury was slightly more severe in the splenectomy group with these patients sustaining mor chest, spine, associated intra-abdominal, and vascular injuries, thus accounting for the high mortality. Average operative time was not increased by addition of repair (2 hr 54 min vs. 2 hr 33 min). Only on repair required return to the operating room, because of a missed hilar laceration at the original laparotomy, emphasizing the importance of care in technique. Postoperative scans in selected patients showed good functional activity. We conclude that splenic preservation is a technically safe procedure in patients exhibiting hemodynamic stability.

Injuries associated with splenic trauma.

Renewed interest in conservative nonoperative management of splenic trauma in children led us to review our experience with this injury in 258 patients over the past 5 1/2 years. Blunt trauma was the predominant type of injury, occurring in 241 patients: 80% of these patients had associated extra-abdominal injuries, predominantly involving the head, chest, and extremities; 59% of patients with penetrating trauma had concomitant extra-abdominal injuries, mainly of the thorax. Serious concomitant intra-abdominal injuries requiring operative therapy were found in 36.5 and 94%, respectively, of patients sustaining splenic injury from blunt and penetrating trauma. Children under the age of 16 years exhibited a similar incidence (32.6 and 100%), respectively). Renal, hepatic, diaphragmatic, intestinal, mesenteric, and vascular injuries were most frequent. The pitfall of conservative nonoperative management lies in missing these concomitant serious intra-abdominal injuries. Diagnostic peritoneal lavage is most useful in defining the patients who should undergo exploratory laparotomy, therefore reducing morbidity and mortality secondary to neglected injuries.