According to a new Facebook post by Sandra Araya, wife of SLAYER bassist/vocalist Tom Araya, Tom "was suffering from vertigo due to extreme dehydration and lack of rest," causing the cancelation of the band's appearance at the Sydney, Australia stop of the Soundwave festival on Sunday, February 27. She adds, "Our doctor is in the process of getting the results on the test that were ran (major time zone difference and being the weekend has held up those results). Hopefully there will be nothing more to add after the results are returned."The Sydney appearance on Sunday, February 27 would have marked SLAYER's second show on the annual festival tour. Araya underwent back surgery in early 2010 which forced the band off the road for a period of several months. He stated about the procedure in an interview, "I apparently had compressed discs on my neck which caused bone spurs. The compressed discs were causing compression on my nerves that was affecting my left side, and basically that was it. I was in Australia, and that's when I... I mean it was severe pain. I had had a case of pain here and there, but this was non-stop. It got to a point where by the time I got to Japan, I hooked up with a doctor, and was able to make an appointment. As soon as I got home, I went and saw him. I had three discs that were compressed, and they removed them, and put a plate in." Regarding what the surgery itself entailed, Araya said, "It entailed them cutting a small little hole in my throat, moving everything to one side, clearing out cartilage in between the discs, putting bone spacers in there, and putting the plate in. That's a two-to-two-and-a-half-hour procedure. Yeah, it was pretty serious. You could say I'm a true metalhead now, I guess (laughs)." SLAYER is currently on the road without founding guitarist Jeff Hanneman, who underwent emergency surgery on his right arm in January after contracting a serious infection, possibly caused by a spider bite. He is now recuperating at home and is expected to make a full recovery. He will return to the SLAYER lineup as soon as he has fully recovered. Hanneman's temporary replacement for the Soundwave festival is Gary Holt from veteran San Francisco Bay Area thrashers EXODUS.