Drs. Rivas and Varela, UT Southwestern Medical Center (image) UT Southwestern Medical Center Share Print E-Mail Caption Drs. Homero Rivas (right) and J. Esteban Varela successfully removed a gallbladder through a unique operation requiring only a single incision in the bellybutton rather than the traditional four incisions. Credit UT Southwestern Medical Center Usage Restrictions Please use credit line. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.