Laparoscopic mechanical fixation devices: does firing angle matter?

Safety and efficacy of absorbable and non-absorbable fixation systems for intraperitoneal mesh fixation: an experimental study in swine

PURPOSE

Choice of the best possible fixation system in terms of safety and effectiveness for intraperitoneal mesh placement in hernia surgery remains controversial. The aim of the present study was to compare the performance of four fixation systems in a swine model of intraperitoneal mesh fixation.

METHODS

Fourteen Landrace swine were utilized in the study. The experiment included two stages. Initially, four pieces of mesh (Ventralight ™ ST) sizing 10 × 5 cm were placed and fixed intraperitoneally to reinforce 4 small full thickness abdominal wall defects created with diathermy. These defects were repaired primarily with absorbable suture before mesh implantation. Each mesh was anchored with a different tack device between Absorbatack™, Protack™, Capsure™, or Optifix™. The second stage took place after 60 days and included euthanasia, laparoscopy, and laparotomy via U-shaped incision to obtain the measurements for the outcome parameters. The primary endpoint of the study was to compare the peel strength of the compound tack/mesh from the abdominal wall. Secondary parameters were the extent and quality of visceral adhesions to the mesh, the degree of mesh shrinkage and the histological response around the tacks.

RESULTS

Thirteen out of 14 animals survived the experiment and 10 were included in the final analysis. Capsure™ tacks had higher peel strength when compared to Absorbatack™ (p = 0.028); Protack™ (p = 0.043); and Optifix™ (p = 0.009). No significant differences were noted regarding the extent of visceral adhesions (Friedman's test p value 0.854), the adhesion quality (Friedman's test p value 0.506), or the mesh shrinkage (Friedman's test p value = 0.827). Four out of the ten animals developed no adhesions at all 2 months after implantation.

CONCLUSION

Capsure™ fixation system provided higher peel strength that the other tested devices in our swine model of intraperitoneal mesh fixation. Our findings generate the hypothesis that this type of fixation may be superior in a clinical setting. Clinical trials with long-term follow-up are required to assess the safety and efficacy of mesh fixation systems in hernia surgery.

Absorbable Mg surgical tack: Proof of concept &in situ fixation strength

A prototype magnesium (Mg) surgical tack is tested comparatively against commercially available tacks made of titanium (ProTack^tm, Medtronic) and PLGA (AbsorbaTack^tm, Medtronic). The pull-out force is measured in situ in a lap-shear pull-out test, using porcine abdominal muscle tissue as a model. The Mg tack had a pull-out force comparable to those of the commercially available tacks. The majority of the Mg tacks also had a more ductile failure mode (i.e. the tacks deformed prior to failure), compared to the commercial tacks which pulled directly from the tissue with no deformation. The Mg tacks deformed as they were removed from the tissue, causing less damage to the tissue in the process. This is the first reported use of a Mg alloy in this application, and the proof of concept indicates that this is an area that deserves further interest and study.

Postoperative Pain After Laparoscopic Repair of Primary Umbilical Hernia: Titanium Tacks Versus Absorbable Tacks: A Prospective Comparative Cohort Analysis of 80 Patients With a Long-term Follow-up

We investigated if a novel fixation device with absorbable tacks (Securestrap) causes less early and chronic postoperative pain after laparoscopic repair with a double-crown mesh fixation of ventral abdominal wall hernia when compared with the standard fixation device with nonabsorbable titanium tacks (Protack). The primary outcome measure was early postoperative pain at 2, 6, and 12 weeks postoperatively. The secondary outcome measure was chronic postoperative pain measured ≥18 months after surgery. Pain levels were assessed using a visual analog scale ranging from 0 (no pain) to 100 mm (excruciating pain). Early postoperative pain was significantly lower in group 2 (absorbable tacks) at 6 (2 vs. 5; P=0.008) and 12 weeks (1 vs. 2; P=0.008) but not at follow-up (6 vs. 11; P=0.21). Given the very low visual analog scale scores in both groups, the clinical significance of these finding remains open to discussion.

Use of Nonabsorbable Spiral Tacks for Mesh Reinforcement in Thoracoscopic Repair of Congenital Diaphragmatic Hernia

Thoracoscopic prosthetic repair of congenital diaphragmatic hernia (CDH) is a well-established and safe technique in experienced hands but the patching procedure is technically demanding and time consuming. To address the challenges associated with this process (confined working space and restricted time), the aim of this article is to assess the potential improvements in feasibility, efficacy, and safety of patch fixation by using nonabsorbable helicoidal tacks in neonates and infants for the repair of large CDH by thoracoscopy. The new technique has all the advantages of minimal invasive surgery in very young children combined with the advantages of reduced operating time and increased simplicity, and may be a good option in cases of recurrence.

Current Status and Challenges of Laparoscopy in Ventral Hernia Repair

Laparoscopic repair of ventral hernias gained strong popularity in the late nineties with some of the early enthusiasm lost later in time. We review the current status and challenges of laparoscopy in ventral hernia repair and best practices in this area. We specifically looked at patient and hernia defect factors, technical considerations that have contributed to the successes, and some of the failures of laparoscopic ventral hernia repair (LVHR). Patients best suited for a laparoscopic repair are those who are obese and diabetic with a total defect size not to exceed 10 cm in width or a "Swiss cheese" defect. Overlap of mesh to healthy fascia of at least 5 cm in every direction, with closure of the defect, is essential to prevent recurrence or bulging over time. Complications specifically related to surgical site occurrence favor the laparoscopic approach. Recurrence rates, satisfaction, and health-related quality of life results are similar to open repairs, but long-term data are lacking. There is still conflicting data regarding ways of fixating the mesh. The science of prosthetic material appropriate for intraperitoneal placement continues to evolve. The field continues to be plagued by single author, single institution, and small nonrandomized observational studies with short-term follow-up. The recent development of large prospective databases might allow for pragmatic and point-of-care studies with long-term follow-up. We conclude that LVHR has evolved since its inception, has overcome many challenges, but still needs better long-term studies to evaluate evolving practices.

Recurrence rate after absorbable tack fixation of mesh in laparoscopic incisional hernia repair

Background

The mesh fixation technique in laparoscopic incisional hernia repair may influence the rates of hernia recurrence and chronic pain. This study investigated the long-term risk of recurrence and chronic pain in patients undergoing laparoscopic incisional hernia repair with either absorbable or non-absorbable tacks for mesh fixation.

Methods

This was a nationwide consecutive cohort study based on data collected prospectively concerning perioperative information and clinical follow-up. Patients undergoing primary, elective, laparoscopic incisional hernia repair with absorbable or non-absorbable tack fixation during a 4-year interval were included. Follow-up was by a structured questionnaire regarding recurrence and chronic pain, supplemented by clinical examination, and CT when indicated. Recurrence was defined as either reoperation for recurrence or clinical/radiological recurrence.

Results

Of 1037 eligible patients, 84·9 per cent responded to the questionnaire, and 816 were included for analysis. The median observation time for the cohort was 40 (range 0–72) months. The cumulative recurrence-free survival rate was 71·5 and 82·0 per cent after absorbable and non-absorbable tack fixation respectively (P = 0·007). In multivariable analysis, the use of absorbable tacks was an independent risk factor for recurrence (hazard ratio 1·53, 95 per cent c.i. 1·11 to 2·09; P = 0·008). The rate of moderate or severe chronic pain was 15·3 and 16·1 per cent after absorbable and non-absorbable tack fixation respectively (P = 0·765).

Conclusion

Absorbable tack fixation of the mesh was associated with a higher risk of recurrence than non-absorbable tacks for laparoscopic mesh repair of incisional hernia, but did not influence chronic pain.

Biomechanical evaluation of three fixation modalities for preperitoneal inguinal hernia repair: a 24-hour postoperative study in pigs

PURPOSE

Tacks and sutures ensure a strong fixation of meshes, but they can be associated with pain and discomfort. Less invasive methods are now available. Three fixation modalities were compared: the ProGrip™ laparoscopic self-fixating mesh; the fibrin glue Tisseel™ with Bard™ Soft Mesh; and the SorbaFix™ absorbable fixation system with Bard™ Soft Mesh.

MATERIALS AND METHODS

Meshes (6 cm ×6 cm) were implanted in the preperitoneal space of swine. Samples were explanted 24 hours after surgery. Centered defects were created, and samples (either ten or eleven per fixation type) were loaded in a pressure chamber. For each sample, the pressure, the mesh displacement through the defect, and the measurements of the contact area were recorded.

RESULTS

At all pressures tested, the ProGrip™ laparoscopic self-fixating mesh both exhibited a significantly lower displacement through the defect and retained a significantly higher percentage of its initial contact area than either the Bard™ Soft Mesh with Tisseel™ system or the Bard™ Soft Mesh with SorbaFix™ absorbable fixation system. Dislocations occurred with the Bard™ Soft Mesh with Tisseel™ system and with the Bard™ Soft Mesh with SorbaFix™ absorbable fixation system at physiological pressure (,225 mmHg). No dislocation was recorded for the ProGrip™ laparoscopic self-fixating mesh.

CONCLUSION

At 24 hours after implantation, the mechanical fixation of the ProGrip™ laparoscopic self-fixating mesh was found to be significantly better than the fixation of the Tisseel™ system or the SorbaFix™ absorbable fixation system.

Evaluation of absorbable mesh fixation devices at various deployment angles

BACKGROUND

Hernia repair failure may occur due to suboptimal mesh fixation by mechanical constructs before mesh integration. Construct design and acute penetration angle may alter mesh-tissue fixation strength. We compared acute fixation strengths of absorbable fixation devices at various deployment angles, directions of loading, and construct orientations.

METHODS

Porcine abdominal walls were sectioned. Constructs were deployed at 30°, 45°, 60°, and 90° angles to fix mesh to the tissue specimens. Lap-shear testing was performed in upward, downward, and lateral directions in relation to the abdominal wall cranial-caudal axis to evaluate fixation. Absorbatack™ (AT), SorbaFix™ (SF), and SecureStrap™ in vertical (SSV) and horizontal (SSH) orientations in relation to the abdominal wall cranial-caudal axis were tested. Ten tests were performed for each combination of device, angle, and loading direction. Failure types and strength data were recorded. ANOVA with Tukey-Kramer adjustments for multiple comparisons and χ (2) tests were performed as appropriate (p < 0.05 considered significant).

RESULTS

At 30°, SSH and SSV had greater fixation strengths (12.95, 12.98 N, respectively) than SF (5.70 N; p = 0.0057, p = 0.0053, respectively). At 45°, mean fixation strength of SSH was significantly greater than SF (18.14, 11.40 N; p = 0.0002). No differences in strength were identified at 60° or 90°. No differences in strength were noted between SSV and SSH with different directions of loading. No differences were noted between SS and AT at any angle. Immediate failure was associated with SF (p < 0.0001) and the 30° tacking angle (p < 0.01).

CONCLUSIONS

Mesh-tissue fixation was stronger at acute deployment angles with SS compared to SF constructs. The 30° angle and the SF device were associated with increased immediate failures. Varying construct and loading direction did not generate statistically significant differences in the fixation strength of absorbable fixation devices in this study.