| Affiliation: | 1. Section of Gastrointestinal, Tumor and Endocrine Surgery, Department of Surgery, University of Colorado Anschutz Medical Campus, , Aurora, Colorado;2. Section of Gastrointestinal Surgery, Department of Surgery, University of Alabama at Birmingham, , Birmingham, Alabama;3. Colorado Health Outcomes Program, University of Colorado Anschutz Medical Campus, , Aurora, Colorado;4. Section of General Surgery, Department of Surgery, University of California at San Francisco, , San Francisco, California |
