This document supplementary information for “Suture characteristics after exposure to amniotic fluid from an in vitro model of fetal surgery.” This is an R Markdown document published on Rpubs.org, and provides access to key coding used during analyses as well as tables not available in the manuscript.
There was not sufficient room in the paper to include details on the performance of all sutures. We include supplementary tables here describing those. Table 2, below, describe baseline information for all the sutures we tested, including controls.
| Table 2. Suture Characteristics | |||
| Suture | Manufacturer | Lot number | Expiration date |
|---|---|---|---|
| Barbed glycomer 631 (V-Loc) | Medtronic (Minneapolis, MN) | A2G0150VY | 2025-06-30 |
| A2D0091VY | 2024-03-31 | ||
| A2E0787VY | 2025-04-30 | ||
| A2G0350VFY | 2025-06-30 | ||
| A2H0407VY | 2025-07-31 | ||
| A1D0091VY | 2024-03-31 | ||
| Braided ethylene terephthalate (Ethibond) | Ethicon (Blue Ash, OH) | PH6730 | 2024-05-30 |
| QBMRPA | 2025-01-31 | ||
| Braided ethylene terephthalate (Ethibond) | Ethicon (Blue Ash, OH) | PEM665 | 2024-04-30 |
| Braided polyglactin 910 (Vicryl) | Ethicon (Blue Ash, OH) | RH2ALQ | 2026-06-30 |
| SC2AXM | 2027-02-28 | ||
| SC2APX | 2027-02-28 | ||
| SE2ATD | 2027-04-30 | ||
| PJ9696 | 2024-07-31 | ||
| RL2APT | 2026-09-30 | ||
| QCMDDT | 2025-02-28 | ||
| QL2AHD | 2025-09-30 | ||
| SB2APU | 2027-01-31 | ||
| SA2ASC | 2026-12-31 | ||
| Monofilament poliglecaprone 25 (Monocryl) | Ethicon (Blue Ash, OH) | RKMAXC | 2023-08-31 |
| REMMQL | 2023-04-30 | ||
| RHMCKD | 2030-06-30 | ||
| SDMPPP | 2024-01-31 | ||
| Monofilament poliglecaprone 25 (Monocryl) | Ethicon (Blue Ash, OH) | SCMRPE | 2024-02-29 |
| Monofilament poly-4-hydroxybutyrate (Monomax) | B. Braun (Bethlehem, PA) | 120082 | 2023-02-18 |
| Monofilament polydioxanone (PDS) | Ethicon (Blue Ash, OH) | QMMBJX | 2022-10-31 |
| SBMLUX | 2024-01-31 | ||
| SBMMDJ | 2024-01-31 | ||
| RGMJDS | 2023-05-31 | ||
| SMBLUX | 2024-01-31 | ||
Braided polyester sutures such as ethylene terephthalate and polyglactin 910 are the strongest sutures available. They have more surface area than monofilaments and have more drag as they move through tissue, and this friction also increases the likelihood of the suture abrading and cutting itself in knot-tying. Glycomer 631, which is composed of glycolide, dioxanone, and trimethylene carbonate, is a barbed polyester wound closure system, designed to avoid the need for laparoscopic or intracorporeal knot-tying. It has high strength which is progressively lost over 110 days, with 25% of load-carrying capacity lost in two weeks and 60% lost at three weeks. Poliglecaprone 25 is a rapidly-dissolving monofilament which loses 40% of its strength at 1 week and 60% at 2 weeks, and 0% at 119 days. Poly-4-hydroxybutyrate (PHB) is a biopolymer produced by microorganisms and utilized in sutures for its biodegradability. As a suture, PHB has comparative strength to permanent polypropylene monofilaments and can be stretched to almost ten times its length before fracture and degrades gradually over 12-18 months. Polydioxanone (PDS) is a strong, long-lasting synthetic monofilament which loses 30% of its tensile strength at 2 weeks, 50% at 4 weeks, and 75% at 6 weeks until it is finally absorbed at 180 days.1 Polyglactin 910 is incorporated into short-acting braided suture which loses 25% of its tensile strength at 2 weeks and 50% at 3 weeks, completely dissolving by 90 days.
| Table 3. Suture Tensile Properties | |||||||
| Suture | Cross-sectional area (mm3) | Fluid exposure (hours) | Suture pull type | Failure load (N) | Failure strain | Failure stress (MPa) | Initial Modulus (MPa) |
|---|---|---|---|---|---|---|---|
| Barbed glycomer 631 (V-Loc) | 0.04 | Control | Straight pull | 25.50 | 0.13 | 622.70 | 3521.7 |
| Braided ethylene terephthalate (Ethibond) | 0.02 | Control | Straight pull | 35.31 | 0.17 | 2188.04 | 5774.0 |
| Braided polyglactin 910 (Vicryl) | 0.02 | Control | Straight pull | 41.68 | 0.22 | 2524.06 | 10485.0 |
| Monofilament poliglecaprone 25 (Monocryl) | 0.03 | Control | Straight pull | 39.23 | 0.59 | 1408.16 | 3294.4 |
| Monofilament poly-4-hydroxybutyrate (Monomax) | 0.02 | Control | Straight pull | 28.93 | 1.15 | 1226.04 | 1173.2 |
| Monofilament polydioxanone (PDS) | 0.02 | Control | Straight pull | 27.46 | 0.59 | 1163.70 | 4540.5 |
Table 4 is in the paper, but the subsequent tables in this document lay out details missing in that table, which had to be shortened for readability. Below are extensive mean characteristics of sutures exposed to NTD AF for 24 hours. There are few changes from control behavior, even for sutures of short lifespans.
| Table 5. Suture Tensile Properties after 24-hour Exposure to NTD AF | |||||||||||
| Suture | pull | Failure load (N) | SD (N) | Failure strain | SD | Failure stress (MPa) | SD (MPa) | Mean Initial Modulus (MPa) | SD (MPa) | Cross-sectional area (mm3) | SD (mm3) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Monofilament polydioxanone (PDS) | |||||||||||
| Knot pull | 22.56 | 4.16 | 0.44 | 0.05 | 905.48 | 190.50 | 1887.05 | 98.36 | 0.02 | 0.00 | |
| Straight pull | 32.12 | 9.36 | 0.66 | 0.31 | 1310.23 | 381.91 | 1799.75 | 132.72 | 0.02 | 0.00 | |
| Monofilament poly-4-hydroxybutyrate (Monomax) | |||||||||||
| Knot pull | 21.09 | 0.69 | 0.63 | 0.04 | 951.25 | 110.98 | 815.16 | 223.42 | 0.02 | 0.00 | |
| Straight pull | 36.53 | 3.12 | 0.51 | 0.34 | 1758.78 | 170.54 | 1985.75 | 1216.44 | 0.02 | 0.00 | |
| Monofilament poliglecaprone 25 (Monocryl) | |||||||||||
| Knot pull | 32.12 | 3.12 | 0.58 | 0.09 | 1143.55 | 125.28 | 1450.59 | 933.26 | 0.03 | 0.00 | |
| Straight pull | 42.91 | 11.44 | 0.67 | 0.20 | 1529.26 | 426.17 | 2093.39 | 2077.77 | 0.03 | 0.00 | |
| Braided polyglactin 910 (Vicryl) | |||||||||||
| Knot pull | 29.67 | 0.35 | 0.20 | 0.01 | 2506.07 | 1189.61 | 11339.10 | 7167.09 | 0.01 | 0.01 | |
| Straight pull | 30.40 | 4.16 | 0.32 | 0.26 | 1810.19 | 362.45 | 6316.65 | 4605.32 | 0.02 | 0.00 | |
| Braided ethylene terephthalate (Ethibond) | |||||||||||
| Knot pull | 27.95 | 0.69 | 0.16 | 0.02 | 1910.84 | 930.34 | 8893.55 | 4359.24 | 0.02 | 0.01 | |
| Straight pull | 37.27 | 8.32 | 0.17 | 0.02 | 2028.44 | 913.34 | 13045.00 | 117.38 | 0.02 | 0.00 | |
| Barbed glycomer 631 (V-Loc) | |||||||||||
| Straight pull | 17.41 | 6.59 | 0.46 | 0.19 | 439.31 | 199.63 | 434.88 | 340.56 | 0.04 | 0.00 | |
When sutures were allowed to continue to incubate in warmed NTD AF on 1.2 N of tension for 4 weeks, the following measurements were seen. Details of each suture’s performance and t tests comparing mean suture performance to the control tests are listed in the paper.
| Table 6. Suture Tensile Properties after 4-week Exposure to NTD AF | |||||||||||
| Suture | pull | Failure load (N) | SD (N) | Failure strain | SD | Failure stress (MPa) | SD (MPa) | Mean Initial Modulus (MPa) | SD (MPa) | Cross-sectional area (mm3) | SD (mm3) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Monofilament polydioxanone (PDS) | |||||||||||
| Knot pull | 26.48 | 1.39 | 0.83 | 0.02 | 1168.57 | 68.41 | 846.28 | 550.44 | 0.02 | 0.00 | |
| Straight pull | 27.95 | 10.40 | 0.57 | 0.19 | 1140.20 | 424.34 | 1581.30 | 1643.32 | 0.02 | 0.00 | |
| Monofilament poly-4-hydroxybutyrate (Monomax) | |||||||||||
| Knot pull | 23.54 | 0.00 | 0.43 | 0.15 | 1123.33 | 0.00 | 2126.10 | 1390.31 | 0.02 | 0.00 | |
| Straight pull | 32.85 | 7.63 | 0.51 | 0.06 | 1567.98 | 364.06 | 3070.90 | 1621.96 | 0.02 | 0.00 | |
| Monofilament poliglecaprone 25 (Monocryl) | |||||||||||
| Knot pull | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.03 | 0.00 | |
| Straight pull | 0.24 | 0.34 | 0.03 | 0.04 | 8.62 | 12.20 | 220.03 | 311.16 | 0.03 | 0.00 | |
| Braided polyglactin 910 (Vicryl) | |||||||||||
| Knot pull | 4.66 | 1.04 | 0.05 | 0.01 | 274.17 | 43.92 | 1518.20 | 1.84 | 0.02 | 0.00 | |
| Straight pull | 4.90 | 1.39 | 0.13 | 0.05 | 293.33 | 100.90 | 6411.30 | 6001.50 | 0.02 | 0.00 | |
| Braided ethylene terephthalate (Ethibond) | |||||||||||
| Knot pull | 26.72 | 3.81 | 0.29 | 0.06 | 1392.64 | 136.39 | 2500.15 | 1415.56 | 0.02 | 0.00 | |
| Straight pull | 26.97 | 4.85 | 0.23 | 0.10 | 1460.55 | 599.05 | 6678.45 | 2662.33 | 0.02 | 0.00 | |
| Barbed glycomer 631 (V-Loc) | |||||||||||
| Straight pull | 16.67 | 4.16 | 0.25 | 0.04 | 409.94 | 68.95 | 716.44 | 411.20 | 0.04 | 0.00 | |
Below are extensive mean characteristics of sutures exposed to TTTS AF for 24 hours. There are few changes from control behavior, even for sutures of short lifespans, and not much difference from NTD AF incubation for 24 hours.
| Table 7. Suture Tensile Properties after 24-hour Exposure to TTTS AF | |||||||||||
| Suture | pull | Failure load (N) | SD (N) | Failure strain | SD | Failure stress (MPa) | SD (MPa) | Mean Initial Modulus (MPa) | SD (MPa) | Cross-sectional area (mm3) | SD (mm3) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Monofilament polydioxanone (PDS) | |||||||||||
| Knot pull | 23.21 | 3.44 | 0.54 | 0.36 | 951.41 | 180.85 | 1901.82 | 1117.35 | 0.02 | 0.00 | |
| Straight pull | 27.13 | 4.42 | 0.43 | 0.11 | 1152.17 | 209.09 | 2981.00 | 725.37 | 0.02 | 0.00 | |
| Monofilament poly-4-hydroxybutyrate (Monomax) | |||||||||||
| Knot pull | 34.32 | 0.98 | 1.06 | 0.44 | 1555.60 | 89.38 | 1658.83 | 398.57 | 0.02 | 0.00 | |
| Straight pull | 24.52 | 5.46 | 0.52 | 0.33 | 1121.55 | 157.46 | 4167.37 | 4658.89 | 0.02 | 0.00 | |
| Monofilament poliglecaprone 25 (Monocryl) | |||||||||||
| Knot pull | 23.05 | 2.08 | 0.33 | 0.05 | 834.24 | 64.86 | 1491.45 | 458.56 | 0.03 | 0.00 | |
| Straight pull | 38.25 | 13.62 | 0.44 | 0.16 | 1366.38 | 494.14 | 1941.53 | 636.40 | 0.03 | 0.00 | |
| Braided polyglactin 910 (Vicryl) | |||||||||||
| Knot pull | 27.13 | 3.00 | 0.23 | 0.10 | 2331.15 | 882.92 | 13171.87 | 10849.41 | 0.01 | 0.00 | |
| Straight pull | 27.79 | 5.66 | 0.30 | 0.15 | 1810.49 | 519.61 | 5701.67 | 5518.39 | 0.02 | 0.01 | |
| Braided ethylene terephthalate (Ethibond) | |||||||||||
| Knot pull | 27.46 | 1.96 | 0.26 | 0.16 | 2343.34 | 753.59 | 10650.07 | 4852.53 | 0.01 | 0.00 | |
| Straight pull | 30.73 | 8.79 | 0.22 | 0.04 | 2262.19 | 1224.18 | 10717.30 | 8221.72 | 0.02 | 0.00 | |
| Barbed glycomer 631 (V-Loc) | |||||||||||
| Straight pull | 32.03 | 12.34 | 0.31 | 0.10 | 771.77 | 269.77 | 1196.11 | 716.31 | 0.04 | 0.00 | |
When sutures are incubated for 4 weeks in TTTS AF on 1.2 N of tension, they behave differently from controls, and some also behave differently from sutures exposed to NTD AF for 4 weeks on the same amount of tension. See the paper for full details of all comparisons.
| Table 8. Suture Tensile Properties after 4-week Exposure to TTTS AF | |||||||||||
| Suture | pull | Failure load (N) | SD (N) | Failure strain | SD | Failure stress (MPa) | SD (MPa) | Mean Initial Modulus (MPa) | SD (MPa) | Cross-sectional area (mm3) | SD (mm3) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Monofilament polydioxanone (PDS) | |||||||||||
| Knot pull | 26.81 | 9.87 | 1.01 | 0.46 | 1150.08 | 469.43 | 778.37 | 197.19 | 0.02 | 0.00 | |
| Straight pull | 33.67 | 5.58 | 0.87 | 0.09 | 1422.14 | 183.93 | 690.38 | 485.70 | 0.02 | 0.00 | |
| Monofilament poly-4-hydroxybutyrate (Monomax) | |||||||||||
| Knot pull | 24.19 | 4.63 | 0.38 | 0.07 | 1110.61 | 142.16 | 2571.57 | 1367.35 | 0.02 | 0.00 | |
| Straight pull | 34.81 | 7.22 | 0.52 | 0.17 | 1603.85 | 298.14 | 3165.93 | 527.92 | 0.02 | 0.00 | |
| Monofilament poliglecaprone 25 (Monocryl) | |||||||||||
| Knot pull | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.03 | 0.00 | |
| Straight pull | 0.83 | 0.48 | 0.03 | 0.01 | 29.72 | 17.25 | 858.57 | 644.24 | 0.03 | 0.00 | |
| Braided polyglactin 910 (Vicryl) | |||||||||||
| Knot pull | 0.60 | 0.33 | 0.02 | 0.01 | 35.42 | 12.11 | 594.98 | 237.83 | 0.02 | 0.01 | |
| Straight pull | 0.75 | 0.64 | 0.04 | 0.06 | 50.19 | 38.98 | 437.93 | 464.62 | 0.02 | 0.01 | |
| Braided ethylene terephthalate (Ethibond) | |||||||||||
| Knot pull | 35.31 | 6.43 | 0.18 | 0.05 | 2418.70 | 384.14 | 12415.20 | 4491.68 | 0.02 | 0.00 | |
| Straight pull | 43.15 | 12.29 | 0.21 | 0.02 | 3080.57 | 1307.91 | 7743.93 | 7487.80 | 0.02 | 0.00 | |
| Barbed glycomer 631 (V-Loc) | |||||||||||
| Straight pull | 12.91 | 5.20 | 0.17 | 0.03 | 316.14 | 131.99 | 1292.50 | 749.51 | 0.04 | 0.00 | |