A gastrointestinal anastomosis is defined as a connection between two hollow viscera or regions of an organ, with the goal of viscerosynthesis, i.e., an anatomical and physiological reconstruction.
Proper suturing technique is essential for successful surgical outcome.
There is no binding standard for fashioning a gastrointestinal anastomosis. What constitutes the right technique is decided on an individual basis.
By contrast, the requirements for an ideal anastomosis are clearly defined:
- Flawless anastomosis technique
- Good arterial and venous perfusion
- Lack of tension
- Clean surgical field
If any of these requirements is lacking, any compromise will raise the risk of suture line failure with all its consequences.
The serosal surfaces of an intestinal anastomosis adhere due to fibrin exudation, normally within the first 4- 6 hours, and will result in a gas- and fluid-proof seal. In this first phase of anastomotic healing, the mechanical strength is primarily provided by the suture material.
The small intestine with its more rapid collagen production responds much faster to damaged intestinal integrity than does the large intestine, and this may explain the higher rate of early suture line failures in colorectal surgery.
Neovascularization starts on postoperative day 4 to 5 and essentially proceeds from the submucosa, the layer of the intestinal wall carrying the vessels. In this phase of wound healing, the submucosa with its abundance of collagen anchors the suture. The suture gains purchase here during that phase.
Adequate mobilization for tension-free apposition of well-perfused ends of the intestine is an absolute requirement. Extensive skeletonization must be avoided.
In hand-sutured anastomoses the layer count specifies the number of suture layers, while the thickness tells how much of the intestinal wall is penetrated during suturing.