Nicholas Stylopoulos

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OBJECTIVE To examine the hypothesis that elective laparoscopic repair should be routinely performed on patients with asymptomatic or minimally symptomatic paraesophageal hernias. SUMMARY BACKGROUND DATA The management of asymptomatic paraesophageal hernias is a controversial issue. Most surgeons believe that all paraesophageal hernias should be corrected(More)
There is a large and growing gap between the need for better surgical training methodologies and the systems currently available for such training. In an effort to bridge this gap and overcome the disadvantages of the training simulators now in use, we developed the Computer-Enhanced Laparoscopic Training System (CELTS). CELTS is a computer-based system(More)
Metrics are widely employed in virtual environments and provide a yardstick for performance measurement. The current method of defining metrics for medical simulation remains more an art than a science. Herein, we report a practical scientific approach to defining metrics, specifically aimed at computer-assisted laparoscopic skills training. We also propose(More)
The resolution of type 2 diabetes after Roux-en-Y gastric bypass (RYGB) attests to the important role of the gastrointestinal tract in glucose homeostasis. Previous studies in RYGB-treated rats have shown that the Roux limb displays hyperplasia and hypertrophy. Here, we report that the Roux limb of RYGB-treated rats exhibits reprogramming of intestinal(More)
The lack of data on in-vivo material properties of soft tissues has been a significant impediment in the development of virtual reality based surgical simulators that can provide the user with realistic visual and haptic feedback. As a first step towards characterizing the mechanical behavior of organs, this work presents in-vivo force response of the liver(More)
Gastrointestinal weight-loss surgery (GIWLS) is currently the most effective treatment for severe obesity, with Roux en-Y gastric bypass (RYGB) among the best of the available surgical options. Despite its widespread clinical use, the mechanisms by which RYGB induces its profound weight loss remain largely unknown. This procedure effects weight loss by(More)
Dysphagia after laparoscopic Nissen fundoplication (LNF) is commonly attributed to edema and/or improperly constructed wraps, and in some instances the cause can be difficult to identify. We report, for the first time, the development of secondary achalasia after LNF as a cause of late-onset postoperative dysphagia. A total of 250 consecutive patients(More)
Force feedback is widely assumed to enhance performance in robotic surgery, but its benefits have not yet been systematically assessed. In this study we examine the effects of force feedback on a blunt dissection task. Subjects used a telerobotic system to expose an artery in a synthetic model while viewing the operative site with a video laparoscope.(More)
Although the prevalence of obesity has increased dramatically throughout the world during the last 25 yr, its long-term control remains poor. Currently, only gastrointestinal weight loss surgery, especially Roux-en-Y gastric bypass (RYGB), is associated with substantial and sustained weight loss and resolution or significant improvement of diabetes mellitus(More)
BACKGROUND EUS is complicated because of the subtleties of US interpretation, small fields of observation, and uncertainty of probe position and orientation. OBJECTIVE Improved EUS performance is sought by providing contextual information to support US probe positioning and identification of features in US images. Our aims were to demonstrate the(More)