New technology applications: Knotless barbed suture for tracheal resection anastomosis

Biomechanical properties of the ex vivo porcine trachea: A benchmark for three-dimensional bioprinted airway replacements

PURPOSE

Combining tissue engineering and three-dimensional (3D) printing may allow for the introduction of a living functional tracheal replacement graft. However, defining the biomechanical properties of the native trachea is a key prerequisite to clinical translation. To achieve this, we set out to define the rotation, axial stretch capacity, and positive intraluminal pressure capabilities for ex vivo porcine tracheas.

STUDY DESIGN

Animal study.

MATERIALS AND METHODS

Six full-length ex vivo porcine tracheas were bisected into 5.5 cm segments. Maximal positive intraluminal pressure was measured by sealing segment ends with custom designed 3D printed caps through which a pressure transducer was introduced. Axial stretch capacity and rotation were evaluated by stretching and rotating the segments along their axis between two clamps, respectively.

RESULTS

Six segments were tested for axial lengthening and the average post-stretch length percentage was 148.92% (range 136.81-163.48%, 95% CI 153-143%). The mean amount of length gain achieved per cartilaginous ring was 7.82% (range 4.71-10.95%, 95% CI 6.3-9.35%). Four tracheal segments were tested for maximal positive intraluminal pressure, which was over 400 mmHg. Degree of rotation testing found that the tracheal segments easily transformed 180° in anterior-posterior bending, lateral bending, and axial rotational twisting.

CONCLUSIONS

We define several biomechanical properties of the ex vivo porcine trachea by reporting the rotation, axial stretch capacity, and positive intraluminal pressure capabilities. We hope that this will aid future work in the clinical translation of 3D bioprinted airway replacement grafts and ensure their compatibility with native tracheal properties.

Biomechanical properties of canine staphylectomies closed with barbed or smooth suture

OBJECTIVE

To compare the duration of closure and biomechanical properties of staphylectomies closed with absorbable bidirectional barbed suture or smooth monofilament suture in a simple continuous or interrupted pattern STUDY DESIGN: Ex vivo study SAMPLE POPULATION: Soft palates (n = 60) harvested from mesaticephalic canine cadavers METHODS: One centimeter of tissue was excised from the caudal border of each soft palate, and the oral and nasopharyngeal mucosal surfaces were apposed with 2-0 bidirectional Quill Monoderm knotless closure device barbed suture (Q), 3-0 Monocryl in a simple continuous (MC) pattern, or 3-0 Monocryl in a simple interrupted (MI) pattern (n = 20 per group). Duration of closure was compared between groups. Tissues were tested under tension to failure, and mode of failure data were collected by video capture.

RESULTS

Closure time was longer for MI closures than for Q and MC closures, with means of 259.9, 215.4, and 196.7 seconds, respectively (P < .0001). No difference was detected in yield force, force to first tissue rupture, maximum force, and energy required for yield and maximum force between groups. Energy to yield was 190.0, 167.8, and 188.95 N-mm for MI, Q, and MC closures, respectively.

CONCLUSION

Biomechanical properties of staphylectomies closed with barbed or smooth sutures did not differ in this cadaveric model.

CLINICAL SIGNIFICANCE

Barbed suture can be considered as an alternative for closure of canine staphylectomies. These results provide evidence to justify additional research to evaluate clinical outcomes in dogs undergoing staphylectomy.

Despite the Effects of Tension and Intraluminal Pressure, Which Suture Technique Is the Most Appropriate for Prevention of Air Leakage or Anastomotic Dehiscence in Tracheal Anastomoses in the Short Term? An Experimental Research on Ex Vivo Model

Purpose: We performed an experimental study comparing different suture techniques in trachea anastomoses using the ex vivo sheep model, which deals with the parameters that suture tension, air leakage, intraluminal pressure, and tension at which the anastomosis will rupture. We aimed to find an answer to “Which suture technique should be used in tracheal anastomoses?”

Methods: In all, 45 sheep tracheas were randomly divided into three groups (each n = 15) differing in suture technique for anastomoses: single stitches, mixed, and continuous suture. The anastomoses were evaluated for air leakage under normal (25 mbar) and high (70 mbar) intraluminal pressures without tension. Then, air leakage was followed under high intraluminal pressure with tensile stress. Tension levels of dehiscence were also recorded. Data were statistically evaluated.

Results: No air leakage was observed at 25 mbar intraluminal pressure. At 70 mbar pressure without tension, no statistically significant difference was found among the groups (p >0.05). However, single-stitch technique was the best in terms of air leakage tension and rupture tension levels (p <0.05).

Conclusion: The most reliable and advantageous is single-stitch technique for a tracheal anastomosis in short-term results. Further studies are needed to analyze longer ventilation periods in terms of other serious complications as ischemic dehiscence and stenosis.

Comparison of two different barbed suture materials for end-to-end jejuno-jejunal anastomosis in pigs

BACKGROUND

Hand-sewn intestinal anastomoses are a fundamental procedure in both open and laparoscopic intestinal surgery. Self-retaining barbed suture devices have been tested for a variety of surgical applications. With the exception of clinical reports and various experimental studies on enterotomy, little has been published so far on the use of barbed suture for end-to-end intestinal anastomoses. The aim of the study was to compare two different barbed suture materials for end-to-end jejuno-jejunal anastomosis in pigs. End-to-end jejuno-jejunal anastomosis were performed with unidirectional barbed (A group), bidirectional barbed (B group) or normal (C group) sutures in each animal. A comparison was then made between the groups based on adhesions scoring, suturing time, bursting pressure and histopathology.

RESULTS

Mean construction times in the A group (518 ± 40 s) and in the B group (487 ± 45 s) were significantly lower than in the C group (587 ± 63 s) but were not different between A and B group (P = 0.10). Mean bursting pressures were significantly higher in the intact intestine (197 ± 13 mmHg) than in any other group (group A 150 ± 16 mmHg, group B 145 ± 22 mmHg, group C 145 ± 24 mmHg). Among anastomotic techniques, the bursting pressures were not significantly different. Histologically no difference could be detected in the grade of inflammation, collagen deposition and neovascularization at the anastomotic sites.

CONCLUSIONS

Barbed sutures can be effectively used for handsewn end-to-end jejunojejunal anastomosis in pigs. They are comparable to normal suture but could provide a shorter surgical time.

Feasibility of a novel laparoscopic technique with unidirectional knotless barbed sutures for the primary closure of duodenal ulcer perforation

BACKGROUND

Laparoscopic primary repair is one of the main procedures used for perforated gastric ulcers, and this technique requires reproducible and secure suturing. The aim of this study was to investigate the safety and efficacy of a novel continuous suture method with barbed sutures during laparoscopic repair for perforated peptic ulcers.

PATIENTS AND METHODS

Clinical data from 116 consecutive patients undergoing laparoscopic repair for perforated peptic ulcers were collected between November 2009 and October 2015. Continuous suturing with 15-cm-long unidirectional absorbable barbed sutures was used for laparoscopic repair in the study group, termed group V (n = 51). Patients who underwent laparoscopic repair with conventional interrupted sutures were defined as group C (n = 65). The complication and operative data were compared between groups.

RESULTS

Although there was no difference between group V and group C in the overall complication rate (15.7% vs. 24.6%; p = 0.259), the complication rate related to suturing was lower (3.9% vs. 15.4%; p = 0.04) in group V. Group V showed rates of 0% for leakage, 2% for intra-abdominal fluid collection, and 2% for stricture; the corresponding rates in group C were 3.1, 7.7, and 4.6%, respectively. Regarding operative data, the total operation time (V vs. C, 87.7 min vs. 131.2 min), total suture time (7.1 min vs. 25.3 min), and suture time per stitch (1.2 min vs. 6.2 min) were significantly shorter in group V than in group C (p < 0.001).

CONCLUSION

The use of a continuous suture technique with unidirectional barbed sutures is as safe as the conventional suture technique and allows easier and faster suturing in the repair of perforated peptic ulcers.

Robot-assisted bronchoplasty using continuous barbed sutures

We describe in this article our bronchoplastic robot-assisted techniques. This consists of using continuous barbed sutures. Our aim is to show the feasibility and the interest of using robotics and this kind of suture material for complex bronchial procedures. We report four cases in France and the UK, two wedge bronchoplasties and two sleeve bronchoplasties for central pulmonary tumors.

Effectiveness of a barbed suture in the repair of bile duct injury during laparoscopic cholecystectomy: Report of two cases

INTRODUCTION

Bile duct injury during laparoscopic cholecystectomy occurs in rare cases. We report two cases using barbed suture for repair in bile duct injury during laparoscopic cholecystectomies.

PRESENTATION OF CASES

The first patient was a 73-year-old woman who underwent elective laparoscopic cholecystectomy for cholecystolithiasis. When the gallbladder was dissected from the bed, bile spillage was observed and an injured small bile duct was detected. The bile duct could not be managed using a titanium clip. The second patient was an 83-year-old woman who underwent emergent laparoscopic cholecystectomy for gallbladder torsion. After the gallbladder was dissected from the bed, bile spillage was observed. In both cases, a running suture, of absorbable monofilament 3-0 barbed suture, was used to laparoscopically repair the injuries.

DISCUSSION

Laparoscopic repair of a bile duct injury is technically challenging, especially in the gallbladder bed where suturing is very difficult because of the tangential approach and the risk of additional liver laceration. Barbed sutures have the benefit of being knotless, thus, performing a running suture is not difficult, even in laparoscopic procedures. Further, absorbable and monofilament threads are generally better suited for biliary surgery, compared with non-absorbable and braided sutures, because of the potential association of the other types of materials with bile duct stone and stricture formation.

CONCLUSION

We believe that the V-Loc™ device is an effective and appropriate option for bile duct injuries that occur during laparoscopic cholecystectomies, particularly around the gallbladder bed, and it is especially useful for surgeons unfamiliar with intracorporeal knot tying.

Effect of n-butyl-2-cyanoacrylate on the tensile strength and pressure resistance of tracheal anastomoses ex vivo

OBJECTIVES

To investigate the effects of n-butyl-2-cyanoacrylate on tracheal anastomoses in terms of increased tension and intraluminal pressure ex vivo.

STUDY DESIGN

Ex vivo experimental study.

SETTING

Tertiary referral center (Department of Otolaryngology).

SUBJECTS AND METHODS

Thirty sheep tracheas were used. Four cartilage rings were resected from the tracheas that were 20 cm in length. End-to-end anastomoses were performed by using Vicryl only (group 1), Vicryl and n-butyl-2-cyanoacrylate (group 2), and n-butyl-2-cyanoacrylate only (group 3). The amount of force to break off the anastomosis and the amount of intraluminal pressure to arouse air leakage through the anastomosis were measured.

RESULTS

The mean force required to break off was 171.9 ± 29.7 N in group 1, 164.8 ± 26 N in group 2, and 13.52 ± 2 N in group 3. The mean force required to break off in group 3 was significantly lower than those in groups 1 and 2 (P = .008 and P = .008, respectively). The mean pressure required to cause air leakage was 49.6 ± 9.1 mm Hg in group 1, 113 ± 14.4 mm Hg in group 2, and 15 ± 4.2 mm Hg in group 3. Group 2 was found to be more resistant to intraluminal pressure than groups 1 and 3 (P = .008 and P = .008, respectively).

CONCLUSION

n-Butyl-2-cyanoacrylate had no significant effect on tensile strength. However, its application on the suture line provided extra pressure resistance ex vivo. We believe that further studies need to be conducted to investigate its long-term effects and histological impact on tracheal anastomoses in vivo.

Biomechanical changes from long-term freezer storage and cellular reduction of tracheal scaffoldings

OBJECTIVES/HYPOTHESIS

To determine structural biomechanical changes in tracheal scaffolds resulting from cellular reduction and storage at -80(o) C.

STUDY DESIGN

Laboratory-based study.

METHODS

Forty-four rabbit tracheal segments were separated into four treatment groups: untreated (group A, control), cellular-reduced (group B), storage at -80(o) C followed by cellular reduction (group C), and cellular-reduced followed by storage at -80(o) C (group D). Tracheal segments were subjected to uniaxial tension (n = 21) or compression (n = 23) using a universal testing machine to determine sutured tensile yield load and radial compressive strengths at 50% lumen occlusion. Mean differences among groups for tension and compression were compared by analysis of variance with post-hoc Tukey-Kramer test.

RESULTS

The untreated trachea (group A) demonstrated mean yield strength of 5.93 (± 1.65) N and compressive strength of 2.10 (± 0.51) N. Following treatment/storage, the tensile yield strength was not impaired (group B = 6.79 [± 1.58] N, C = 6.21 [± 1.40] N, D = 6.26 [± 1.18]; P > 0.10 each). Following cellular reduction, there was a significant reduction in compressive strength (group B = 0.44 N [± 0.13], P < 0.0001), but no further reduction due to storage (group C = 0.39 N [± 0.10]; P = 0.97 compared to group B).

CONCLUSION

The data suggest cellular reduction leads to loss of compressive strength. Freezing at -80°C (either before, or subsequent to cellular reduction) may be a viable storage method for tracheal grafts.

Ex vivo biomechanical comparison of V-LOC 180® absorbable wound closure device and standard polyglyconate suture for diaphragmatic herniorrhaphy in a canine model

OBJECTIVE

To compare 2-0 polyglyconate barbed suture (V-LOC™ 180 Absorbable Wound Closure Device, Covidien, Mansfield, MA) to standard 2-0 monofilament absorbable polyglyconate suture (Maxon™, Covidien) for maximum load to failure and failure mode when used to appose standardized defects in canine diaphragm muscle.

STUDY DESIGN

Randomized, cadaveric ex vivo mechanical testing.

SAMPLE POPULATION

Canine cadaveric hemi-diaphragmatic specimens (n = 32 pairs).

METHODS

Thirty-two cadaveric diaphragm specimens were collected and divided to obtain 64 muscle specimens (9 cm × 4 cm). Paired specimens were bisected in the midpoint of their 9 cm length in the direction of the muscle fibers and apposed using either 2-0 polyglyconate or 2-0 barbed polyglyconate (V-LOC™ 180 Absorbable Wound Closure Device) in a simple continuous pattern. Increasing tension was applied perpendicular to the suture line until specimen failure. Failure mode and maximum load to failure were recorded for each specimen.

RESULTS

Mean ± SD failure load of simulated herniorrhaphies performed with barbed polyglyconate suture (54.5 ± 10.27 N) was not significantly different than repair with polyglyconate (56.9 ± 10.87 N). Failure mode for both construct types was suture tear out rather than suture failure.

CONCLUSIONS

Clinical application of 2-0 barbed polyglyconate suture can be considered as an alternative to the use of 2-0 polyglyconate for diaphragmatic herniorrhaphy.

Defining the biomechanical properties of the rabbit trachea

OBJECTIVES/HYPOTHESIS

Surgical advancements rely heavily on validated animal models. The New Zealand White (NZW) rabbit is a widely used model for airway research, including regenerative medicine applications. Currently, the biomechanical properties of the normal rabbit trachea are not known. Our objective was to define these properties to assist in the standardization and understanding of future airway research using this model.

STUDY DESIGN

Laboratory-based study.

METHODS

Fresh tracheas from four adult NZW rabbits were dissected into 20 segments. To examine the biomechanical properties, segments were subjected to uniaxial tension (n = 9) and compression (n = 11) testing. Yield and maximum load (tension) and force at 50% displacement (compression) were recorded, and differences between segments were examined using analysis of covariance.

RESULTS

Normative data for native rabbit trachea show mean maximum load = 6.44 newtons (N), yield load = 5.93 N, and compressive strength = 2.10 N. In addition to establishing the baseline measurements, statistically significant differences in tensile measures based on location along the trachea and diameter were identified. Proximal segments had significantly higher maximum load (P = .0029) and yield load (P = .0062) than distal segments. Association between diameter and both maximum load (P = .0139) and yield load (P = .0082) was observed.

CONCLUSIONS

The adult NZW rabbit trachea is intrinsically less able to withstand tensile and compressive forces, compared to other airway models such as sheep or cadaveric human. Establishment of normative values will enable future research into changes in tracheal biomechanical properties during regenerative medicine manipulation and processing.

The application of the V-Loc closure device for gastrointestinal sutures: a preliminary study

BACKGROUND

Leakage is one of the major complications in gastrointestinal surgery. This preliminary study compared a new barbed absorbable thread for gastrointestinal sutures with monofil suture material in a cadaver model.

METHODS

In this study, mechanical experiments were performed in 20 recently deceased individuals. Incisions were made in the small intestine, colon, and stomach, and then sutures were created with the V-Loc closure device and monofil suture material. Intestinal bursting pressure was measured by inserting a balloon and slowly filling it with air until there was a dehiscence, or wall or suture rupture.

RESULTS

The bursting pressures differed significantly between the two sutures in the small intestine, showing the advantage of the V-Loc closure device, which had a mean bursting pressure of 116.2 mmHg compared with 110 mmHg for the monofil suture (p = 0.003). The mean bursting pressure did not differ significantly between the two sutures in the colon and the stomach. The mean bursting pressures for the V-Loc closure device were 141.3 mmHg (stomach) and 137.2 mmHg (colon) compared with the monofil suture material bursting pressures of 133 mmHg (stomach) and 134.8 mmHg (colon).

CONCLUSIONS

Because the bursting strength of the sutures created with monofil suture material differs significantly from that of the V-Loc closure device, the V-Loc suture material should be used for gastrointestinal sutures. Although the two sutures did not differ significantly in the colon or the stomach, the V-Loc closure device should be used for these as well because its advantages may overrule those of the monofil suture. No knot tying is required, and the operating time can be shorter. Especially for laparoscopic surgery, the V-Loc closure device is recommended.