Tensile Comparison of Polydioxanone, Polyglyconate, and Barbed Glycolide-Trimethylene Carbonate Suture in Canine Cadaveric Tensor Fascia Lata

Strength of small-bites abdominal wall closure using different suturing methods and materials in an experimental animal model

PURPOSE

Using small instead of large bites for laparotomy closure results in lower incidence of incisional hernia, but no consensus exists on which suture material to use. This study aimed to compare five different closure strategies in a standardized experimental setting.

METHODS

Fifty porcine abdominal walls were arranged into 5 groups: (A) running 2/0 polydioxanone; (B) interlocking 2/0 polydioxanone; (C) running size 0 barbed polydioxanone; (D) running size 0 barbed glycolic acid and trimethylene carbonate; (E) running size 0 suturable polypropylene mesh. The small-bites technique was used for linea alba closure in all. The abdominal walls were divided into a supra- and infra-umbilical half, resulting in 20 specimens per group that were pulled apart in a tensile testing machine. Maximum tensile force and types of suture failure were registered.

RESULTS

The highest tensile force was measured when using barbed polydioxanone (334.8 N ± 157.0), but differences did not reach statistical significance. Infra-umbilical abdominal walls endured a significantly higher maximum tensile force compared to supra-umbilical (397 N vs 271 N, p < 0.001). Barbed glycolic acid and trimethylene carbonate failed significantly more often (25% vs 0%, p = 0.008).

CONCLUSION

Based on tensile force, both interlocking and running suture techniques using polydioxanone, and running sutures using barbed polydioxanone or suturable mesh, seem to be suitable for abdominal wall closure. Tensile strength was significantly higher in infra-umbilical abdominal walls compared to supra-umbilical. Barbed glycolic acid and trimethylene carbonate should probably be discouraged for fascial closure, because of increased risk of suture failure.

Stapled fascial suture: ex vivo modeling and clinical implications

BACKGROUND

Recently, in the field of abdominal wall repair surgery, some minimally invasive procedures introduced the use of staplers to provide a retromuscular prosthetic repair. However, to the knowledge of the authors, there are little data in the literature about the outcomes of stapled sutures adoption for midline reconstruction. This study aims to investigate the biomechanics of stapled sutures, simple (stapled), or oversewn (hybrid), in comparison with handsewn suture. From the results obtained, we tried to draw indications for their use in a clinical context.

METHODS

Human cadaver fascia lata specimens, sutured (handsewn, stapled, or hybrid) or not, underwent tensile tests. The data on strength (maximal stress), ultimate strain (deformability), Young's modulus (rigidity), and dissipated specific energy (ability to absorb mechanical energy up to the breaking point) were recorded for each type of specimens and analyzed.

RESULTS

Stapled and hybrid suture showed a significantly higher strength (handsewn 0.83 MPa, stapled 2.10 MPa, hybrid 2.68 MPa) and a trend toward a lower ultimate strain as compared to manual sutures (handsewn 344%, stapled 249%, hybrid 280%). Stapled and hybrid sutures had fourfold higher Young's modulus as compared to handsewn sutures (handsewn 1.779 MPa, stapled 7.374 MPa, hybrid 6.964 MPa). Handsewn and hybrid sutures showed significantly higher dissipated specific energy (handsewn 0.99 mJ-mm3, stapled 0.73 mJ-mm3, hybrid 1.35 mJ-mm3).

CONCLUSION

Stapled sutures can resist high loads, but are less deformable and rigid than handsewn suture. This suggests a safer employment in case of small defects or diastasis (< W1 in accord to EHS classification), where the presumed tissutal displacement is minimal. Oversewing a stapled suture improves its efficiency, becoming crucial in case of larger defects (> W1 in accord to EHS classification) where the expected tissutal displacement is maximal. Hybrid sutures seem to be a good compromise.

Evaluation of barbed suture for celiorrhaphy and subcutaneous closure in bitches with pyometra submitted to ovariohysterectomy

Purpose

To evaluate the use of barbed sutures over the surgical time, the leukogram, the tissue thickness in which the sutures were employed (ultrasonography), the costs, and the possible complications in bitches with pyometra submitted to ovariohysterectomy (OH).

Methods

Convectional 2.0 polyglyconate suture was used in the control group (CG n = 10) and 2.0 barbed polyglyconate suture in the barbed group (BG n = 10) to perform celiorrhaphy (simple continuous pattern) and subcutaneous closure (continuous intradermal pattern). Data were assessed using paired (leukogram between 24 and 48 h within the same group) and unpaired (leukogram, surgical time, tissue thickness, and costs) Student’s t-test. The Fisher exact test was used to assess the occurrence of seroma between groups (p < 0.05). Results are shown as mean ± standard error of mean.

Results

The time spent to perform the celiorrhaphy (195.30 ± 17.37 s vs. 204 ± 16.00 s), subcutaneous closure (174.0 ± 15.86 s vs. 198.0 ± 15.62 s), and the total surgical time (24.30 ± 1.44 min vs. 23.00 ± 1.30 min) did not differ between BG and CG, respectively (p > 0.05). Leukogram at 48 h post-surgery did not differ between groups (p = 0.20). No differences were observed in the subcutaneous and the abdominal wall thickness (cm) assessed by ultrasonography at 48 h in BG (0.31 ± 0.04, 0.80 ± 0.05) and CG (0.34 ± 0.03, 0.72 ± 0.06), respectively. Similarly, 15 days post-surgery the same structures did not differ between BG (0.26 ± 0.02, 0.74 ± 0.08) and CG (0.26 ± 0.03, 0.64 ± 0.05) (p > 0.05). In one bitch from each group, a mild seroma was observed on one side of the surgical wound 48 h after surgery (p = 1.00). The procedures in which barbed sutures were used had an average additional cost of R$ 200.00 ± 11.66 (p < 0.0001).

Conclusions

Barbed suture has proven to be efficient and safe for abdominal and subcutaneous closure. However, considering its current high cost in addition thatthe surgical time of bitches with pyometra undergone OH was not reduced, no advantages were observed with theuse of barbed sutures for this type of surgery.

Cadaveric Evaluation of Load to Failure in Canine Gingiva Apposed With Varied Suture Patterns Using Poliglecaprone 25

The purpose of the study was to determine the effect of suture pattern and repair length on the load to failure in an ex vivo canine gingival model. Healthy mandibular gingiva and mucosa were harvested from fresh cadavers euthanized for purposes unrelated to the study. Samples were randomly assigned by length and pattern. Lingual and buccal free gingival margins were apposed using a simple interrupted (SI), cruciate (XT), simple continuous (SC), or unidirectional knotless continuous barbed suture (SF) closure technique with USP 4-0 poliglecaprone 25^{i, ii} applied over 2 lengths (3 cm and 6 cm). A custom template was used to ensure uniform suture bite application. Surgical time was recorded. Using a soft tissue mechanical testing frame, samples were tensioned to failure. Testing was video recorded and reviewed in conjunction with the tension trace data for tension at initial failure (T_fail) and maximum tension sustained (T_max). Two factor ANOVA by length and pattern was performed followed by individual one way T-tests. Statistically significant findings were XT-SC-SF patterns were quicker to perform than SI. SF was more likely to fail by suture breakage than tissue tearing, and SF withstood less tension at the 3 cm length than SI-XT-SC. No significant difference was detected in T_max or T_fail between SI and SC or XT. The study demonstrates that SC and XT are comparable to SI in tension resistance and faster to perform suggesting that SC and XT could replace SI for extraction site closure although further in vivo testing is required.

Optimal Suture Bite Size for Closure of Feline Linea Alba-A Cadaveric Study

Objective: This study aimed to determine the most appropriate suture bite and stitch interval (SBSI) size for closing feline linea alba.

Study design: Randomized ex vivo mechanical testing.

Sample population: Ventral abdominal walls from 35 male feline cadavers were harvested and separated into 125 segments.

Methods: Segments were incised along midline then sutured back together using 3-0 polydioxanone using one of the following SBSI: 3, 5, 7.5, or 10 mm whereby the distance represents the distance both between the suture bites, and from the bite to incision line. The location of segments as well as the weight of the cadaver were recorded. A single linear distraction mechanical breaking test was performed. Statistical analyses (logistic and linear regression) were performed to determine which factors were associated with visual and mechanical failure, as well as load at failure or maximum displacement.

Results: SBSI was significantly associated with load at failure or maximum displacement (p < 0.001). In particular, 5 mm SBSI had the highest load at failure amongst all the bite sizes (LSmeans = 27.55N, 95% Confidence Interval (CI): 23.65–31.44); this was significantly higher than 7.5 mm (LSmeans = 19.15N, 95% CI: 15.26–23.05, p = 0.016) and 10 mm (LSmeans = 16.55N, 95%CI:12.39–20.70, p = 0.0012) but not significantly higher than 3 mm (LSmeans = 23.78N, 95% CI: 19.69–27.86, p = 0.2). Increased SBSI increased the odds of visual failure (p < 0.001) whereas increased weight of the cadaver reduced the odds of visual failure (OR = 0.52, 95%CI: 0.30–0.88, p = 0.016).

Conclusion: The 5 mm SBSI had the highest load at failure and was not significantly different from the 3 mm SBSI when apposing feline linea alba using 3-0 polydioxanone.

Clinical significance: Using 5 mm SBSI is the preferred bite size compared to 7.5 or 10 mm SBSI when apposing feline linea alba with 3-0 polydioxanone.

Polymer sutures for simultaneous wound healing and drug delivery - A review

Drug delivery using suitable polymeric devices has gathered momentum in the recent years due to their remarkable properties. The versatility of polymeric materials makes them reliable candidates for site targeted drug release. Among them biodegradable sutures has received considerable attention because they offer great promises in the realm of drug delivery. Sutures have been found to be an effective strategy for the delivery of antibacterial agents or anti-inflammatory drugs to the surgical site. Recent developments yielded sutures with improved mechanical properties, but designing sutures with all the desirable properties is still under investigation. This review is an attempt to analyze the recent developments pertaining to biologically active sutures emphasizing their potential as drug delivery vehicle.