Catgut Sutures: Definition and Recommendations
Catgut sutures are natural, absorbable suture materials derived from purified collagen from the intestines of animals (typically sheep or cattle), but they are generally not recommended for modern surgical use due to their higher tissue reactivity, infection risk, and availability of superior synthetic alternatives.
What Are Catgut Sutures?
- Catgut sutures are monofilament absorbable sutures made from purified collagen derived from animal intestines 1
- They come in two main varieties: plain catgut and chromic catgut (treated with chromium salts to slow absorption) 2, 3
- Catgut sutures are absorbed through proteolytic enzymatic degradation, unlike synthetic absorbable sutures which undergo hydrolysis 1
Disadvantages of Catgut Sutures
- Catgut sutures induce more intense tissue inflammatory reactions compared to modern synthetic absorbable sutures 2, 4
- They are associated with persistence of local infection even in chronic implantation, as evidenced by large numbers of neutrophils at wound sites 2
- Catgut sutures are associated with more pain and higher risk of requiring resuturing compared to synthetic alternatives 5
- They demonstrate inferior tensile strength compared to synthetic alternatives like Maxon (polyglyconate) and Vicryl (polyglactin) during critical wound healing periods 4
Current Recommendations
- Slowly absorbable synthetic sutures are recommended over catgut for closure of emergency laparotomy with high-quality evidence (CoE: A-High) 6
- Synthetic absorbable sutures like monofilament poliglecaprone (Monocryl) and polyglyconate (Maxon) are preferred over catgut due to their lower tissue reactivity 5
- Triclosan-coated sutures significantly reduce surgical site infection prevalence compared to non-coated sutures, including catgut (GoR 1B) 6
- For optimal wound closure, the "small bite" technique (5mm from wound edge, 5mm between stitches) is recommended over larger bites to prevent incisional hernia 6
Limited Applications
- Despite general recommendations against catgut, a 2002 study found that buried subcuticular catgut sutures in clean surgical wounds showed acceptable results with only 4.3% infection/dehiscence rate 1
- However, this limited finding is outweighed by multiple studies and guidelines showing superior outcomes with synthetic alternatives 6, 4
Alternative Suture Materials
- Monofilament sutures are generally recommended as they cause less bacterial seeding and may reduce infection risk 7, 5
- Slowly absorbable synthetic sutures like polyglyconate (Maxon) and poliglecaprone (Monocryl) demonstrate lower degrees of chronic inflammation compared to catgut 4, 8
- Polydioxanone (PDS) shows lower degrees of inflammation and foreign body reaction with no stone formation in urological applications, making it preferable to catgut 8
Key Considerations for Suture Selection
- A suture-to-wound length ratio of 4:1 or higher reduces the risk of incisional hernia and wound complications 6
- The "small bite" technique (approximately 5mm from wound edges and 5mm between stitches) is recommended for closure of midline laparotomy 6
- Monofilament sutures generally cause less tissue reaction than multifilament sutures 2, 3