Barrel surgery is a term that can refer to different surgical procedures depending on the context. Here are some examples:

• Double Barrel Ostomy: This is a surgical procedure where the surgeon removes problem areas in the bowel and brings the two ends of the bowel to openings made in the wall of the belly. They stitch the edges of the bowel to the skin to create two stomas. One stoma drains waste and the other drains mucus. A bag may be placed over both stomas to collect the waste and mucus.

• Double Barrel Colostomy: This is a type of colostomy surgery where the colon is divided into two ends that form separate stomas. Stool exits from one of the stomas, while mucus made by the colon exits from the other.

• Barrel Stave Osteotomy: This is a surgical procedure used to correct an abnormal head shape. It involves removing a portion of the fused sagittal suture and making cuts through the bone either side to re-shape these sections. Once the skull bones are in place and the surgeon is happy with the result, they will be fixed in place using strong stitches that dissolve very gradually over the next few months while the bone heals.

• Double Barrel Lymphaticovenous Anastomosis: This is a microsurgical procedure used to treat lymphedema. It involves creating two anastomoses between a lymphatic vessel and a vein, using a "double barrel" technique developed to deal with size mismatch between the two types of vessels. The technique has been shown to be safe and effective in dealing with this problem.

In summary, barrel surgery can refer to different surgical procedures depending on the context, but it generally involves dividing a structure into two parts and creating two openings or stomas.