Absorbable versus nonabsorbable sutures

There are many options for wound repair. It is no secret that the face is a common location for lacerations in children. Because children, especially toddlers and preschoolers, are inclined to be scared by intimidating ED physicians many parents inquire about dissolvable sutures, so that their child will not have to be held down twice (once for placement and once for removal). Therefore, the goal of this post is to review the use of absorbable versus nonabsorbable sutures in children.

Materials

Plain gut

• Absorbable
• Tensile strength: Up to 8-9 days
• Natural treated product. Can also come from sheep.

Fast absorbing plain gut

• Absorbable
• Tensile strength: 5-7 days
• Heat treated so that it dissolves faster. Great for facial lacerations in which removal will be difficult. 6-0 is very thin and breaks easily, so 5-0 could be used on faces too.

Chromic gut

• Absorbable
• Tensile strength: 10-14 days
• Monofilament
• Good for intraoral and hand/finger wounds

Vicryl

• Absorbable
• Tensile strength: 21 days
• Braided
• Complete absorption takes up to 90 days – therefore only applicable for deep/dermal sutures. Consider in nailbed lacerations.

Vicryl Rapide

• Absorbable
• Tensile strength: 10 days
• Begins to fall off/out in 7 days
• May be good for closing lacerations under a cast, also could be used in a similar fashion to fast absorbing plain gut

Ethilon

• Non absorbable
• Monofilament
• Nylon
• Low reactivity and great tensile strength. The filament has “memory” which means that it will coil back into the loop shape it had in packaging. Thus, you’ll need at least 4 knots for it to hold.

Prolene

• Non absorbable
• Monofilament
• Ploypropylene plastic
• Low reactivity and high tensile strength. It is slick, and thus you need 4-5 knots to secure it. It comes in blue, which is pretty, and easier to see. It can also be more expensive that Ethilon.
• Great option for a variety of wounds e.g. 6-0 for faces.

Silk

• Multifilament
• Lowest tensile strength of nonabsorbable sutures
• Spider-Man likes it

Absorbable vs Nonabsorbable: The evidence

In the past it was felt that the cosmetic results of non-absorbable sutures were superior. Studies in the last decade would suggest otherwise. Karounis et al performed a RCT on patients under the age of 18 with fresh lacerations (<12 hours). They excluded wounds that could be glued, animal/human bites, grossly  contaminated wounds, puncture/crush wounds, wounds crossing joints, lacerations of tendon/nerve/cartilage, collagen vascular disease, immunodeficiency, diabetes mellitus, bleeding disorder, and scalp lacerations. Patients were randomized to absorbable plain gut or nylon, and then repaired by a Pediatric Emergency Medicine attending or Fellow. 10 days later a nurse evaluated the wound using a 6 point Wound Evaluation Score that had been previously validated. The wound score had the following components:

• Presence of step-off
• Contour irregularities
• Margin separation
• Edge inversion
• Extensive distortion
• Overall cosmetic appearance

6/6 was the best possible score. A single blinded plastic surgeon then saw each patient 4-5 months later and rated the wound according to a visual analog scale of cosmesis (also pre-validated) and the wound evaluation score. Ultimately they noted the following:

• There was no difference between groups in the wound evaluation score, infection rate or dehiscience at the 10 day follow up. RR 0.73, 95% CI = 0.45 to 1.17
• Only two thirds made it to the 4-5 month visit. The WES again saw no difference, RR 0.88, 85% CI = 0.62 to 1.26
• At the 4-5 month follow up 36% of the absorbable group had a 6/6 versus 28% of the nonabsorbable group. This result was not statistically significant.

Luck et al also performed a non-inferiority RCT 4 years later. this time only on pediatric facial lacerations. Ultimately 47 patients were recruited, and after being randomized had follow up at 5-7 days and 3 months. As opposed to the previous study, Luck and colleagues had each wound assessed by 3 separate raters using a visual analog scale. A difference of 15mm on the VAS was the threshold for significance. Parents also rated the wounds. The authors ultimately concluded that nonabsorbable sutures were not inferior to nylon for pediatric facial wounds in terms of appearance. Specifically, they noted the following:

• The mean VAS by the raters for the catgut group was 92.3 (95% confidence interval [CI], 89.1-95.4) vs 93.7 (95% CI, 91.4-96.0) for nylon group was – absolute difference of mean values 1.4 (95% CI, -5.31 to 8.15). This was obviously <15mm.
• The mean parental VAS score for the gut was 86.3 (95% CI, 78.4-94.1) and for nylon was 91.2 (95% CI, 86.9-95.4). This difference was 4.9 (95% CI, 2.41-7.41).
• There was also no significant differences in the rates of infection, wound dehiscence, keloid formation, and parental satisfaction.

In Conclusion

You might be saying to yourself at this point that the case is closed. Well, not so fast. The first study used plain gut which could take up to a month to completely dissolve. As noted earlier this material maintains tensile strength for at least 8 to 9 days otherwise. Fast absorbing plain gut is the most appropriate option, given that the strength is maintained for only 5-7 days. It can take 2x that to completely dissolve. It is also tougher to work with, and the evidence isn’t there yet. So we probably shouldn’t tell parents that that don’t need to follow-up if we use fast absorbing plain gut. Though tensile strength is no longer maintained the sutures will still be present and thus anything still in the skin of the face at 7 days should come out. I have also noted that it can be hard to fully evert wounds that are under a tension with fast absorbing plain gut. This should also be considered with facial wounds that are a bit gaping. Ultimately you would do well to become facile with multiple different suture materials.

More reading

Closing the Gap: Advanced Wound Closure for the Emergency Professional Academic Life in Emergency Medicine: Paucis Verbis card: Sutures