I had open gallbladder surgery (big scar!), a complete hysterectomy and two years later hernia surgery so I delayed investigating WLS because I thought I would have too much scar tissue. My surgeon asked if mesh was used on the hernia, but when he examined me, he said where he needs to go in is all "virgin" territory and he did not expect any of those surgeries to present a problem. So, I would agree, it will depend on where your hernia is.
Wish I had gone sooner now! My surgeon's office is submitting my application to insurance this week. Hope it works for you!