A specialized needle with an orifice in the back curve (back hole) of the epidural needle for separate spinal needle passage has been made available. A: The tip of the epidural needle is shown in the epidural space. A spinal needle is shown passing through the lumen of the epidural needle and entering the subarachnoid space. B: After the spinal anesthesia has been accomplished, the spinal needle is withdrawn and an epidural catheter is advanced into the epidural space. Source: Chapter 16. Combined Spinal–Epidural Anesthesia, NYSORA Textbook of Regional Anesthesia and Acute Pain Management Citation: Hadzic A. NYSORA Textbook of Regional Anesthesia and Acute Pain Management; 2007 Available at: http://accessanesthesiology.mhmedical.com/DownloadImage.aspx?image=/data/books/hadz/hadz_c016f011a.jpg&sec=39830139&BookID=413&ChapterSecID=39828163&imagename= Accessed: October 20, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved