The present invention is a method and apparatus for performing peritoneal distension. The method includes providing a support structure on a surgical table, wherein the support structure includes a substantially vertical post and an arm assembly. A distal end of the arm assembly is positioned over a patient on the surgical table while the vertical post remains stationary. A peritoneal distension instrument extending from the arm assembly is coupled to a peritoneal structure of the patient. The peritoneum of the patient is distended by vertically raising the arm assembly while the post remains stationary relative to the surgical table. The apparatus is a surgical instrument support structure including a substantially vertical post having a gear rack disposed generally along the post's axis and an arm assembly movably coupled along the gear rack extending from the gear rack for holding a surgical instrument. The arm assembly includes a circular gear rotatably coupled to the arm assembly in engagement with the gear rack and a mechanism for rotating the circular gear, whereby rotation of the circular gear raises and lowers the arm assembly relative to the vertical post.