Acute airway obstruction in a patient with achalasia.

Megaesophagus resulting from achalasia is a rare but serious cause of acute airway obstruction. We treated achalasia in a 52-year-old woman with acute respiratory distress and stridor. Chest X-ray and endoscopy showed a marked dilatation of the cervical esophagus with a large amount of undigested food. Emergency suction of the food through a nasogastric tube led to decompression of the esophagus and the immediate relief of respiratory symptoms. These findings suggest a dysfunction of the upper esophageal sphincter as a possible mechanism. As this exceptional complication of achalasia is fatal, a wider appreciation is required.

The effect of CyberDome, a novel 3-dimensional dome-shaped display system, on laparoscopic procedures.

BACKGROUND: Laparoscopic surgeons require extended experience of cases to overcome the lack of depth perception on a two-dimensional (2D) display. Although a three-dimensional (3D) display was reported to be useful over two decades ago, 3D systems have not been widely used. Recently, we developed a novel 3D dome-shaped display (3DD) system, CyberDome. STUDY DESIGN: In the present study, a total of 23 students volunteered. We evaluated the effects of the 3DD system on depth perception and laparoscopic procedures in comparison with the 2D, a conventional 3D (3DP) or the 2D high definition (HD) systems using seven tasks. RESULTS: The 3DD system significantly improved depth perception and laparoscopic performance compared with the 2D system in six new tasks. We further found that the 3DD system shortened the execution time and reduced the number of errors during suturing and knot tying. The 3DD system also provided more depth perception than the 3DP and 2D HD systems. CONCLUSIONS: The novel 3DD system is a promising tool for providing depth perception with high resolution to laparoscopic surgeons.

The frontal cortex is activated during learning of endoscopic procedures.

BACKGROUND: To date, several training and evaluation systems for endoscopic surgery have been developed, such as virtual-reality simulators and box trainers. However, despite current advances in these objective assessments, no functional brain studies during learning of endoscopic surgical skills have been carried out. In the present study, we investigated cortical activation using near-infrared spectroscopy (NIRS) during endoscopic surgical tasks. STUDY DESIGN: A total of 21 right-handed subjects, comprising 4 surgical experts, 4 trainees, and 13 novices, participated in the study. Suturing and knot-tying tasks were performed in a box trainer. Cortical activation was assessed in all subjects by task-related changes in hemoglobin (Hb) oxygenation using NIRS. RESULTS: In surgical experts and novices with no experience of endoscopic surgical training, we found no changes in oxy-Hb, deoxy-Hb or total-Hb levels in any of the frontal channels. In surgical trainees and one novice with experience of endoscopic surgical training, we found significant increases in oxy-Hb and total-Hb levels in most of the frontal channels. There were significant differences in oxy-Hb and total-Hb levels in CH-19 between surgical experts and trainees (p = 0.02 for both), and between surgical trainees and novices with no experience of endoscopic surgical training (p = 0.008 for both). Furthermore, additional training increased oxy-Hb levels in the frontal cortex of novices with no experience of endoscopic surgical training but had no such effect on surgical experts. CONCLUSIONS: The present data suggest that NIRS is a feasible tool for assessing brain activation during endoscopic surgical tasks, and may have a large impact on the future development of teaching, training, and assessment methods for endoscopic surgical skills.