Tensile strength testing for resorbable mesh fixation systems in laparoscopic ventral hernia repair

Collateral damage of wandering ProTacks

CASE

A 75-year-old man presented with mixed obstructive and storage lower urinary tract symptoms (LUTS). He had undergone transurethral resection of the prostate (TURP) 5 years and laparoscopic inguinal hernia repair 20 years ago. He had a stone adherent to the bladder wall and an occlusive prostate.

OUTCOME

He underwent a re-do TURP and stone removal. Stone removal revealed an underlying metal coil straddling the bladder wall, which had served as a nidus for stone formation. The metal ring was a ProTack staple from previous hernia surgery, which had detached and wandered into the bladder. At follow-up after 12 weeks, the patient was asymptomatic, and his urine was sterile. Therefore, he chose to be treated conservatively for the ProTack and was started on periodic follow-up and cystoscopic surveillance. Shortly after review, he developed intestinal obstruction, which resolved spontaneously and was thought to be secondary to adhesions from other tacks that had migrated into the peritoneal cavity.

CONCLUSION

We have reported a case of a ProTack from a previous hernia repair migrating into the bladder and also causing intestinal obstruction. The case is very rare because of the combination of complications. Clinicians should beware of delayed complications and damage to other organs due to metallic hernia staples.

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.

Laparoscopic closure of the vaginal rings in the standing horse using a tacked intraperitoneal slitted mesh (TISM) technique

BACKGROUND

Indirect inguinal herniation (IIH) is a potentially life-threatening condition in stallions. The ideal preventive measure for breeding stallions ensures a minimally invasive closure of the vaginal ring that avoids recurrence of IIH while preserving both testicles.

OBJECTIVES

To describe a minimally invasive laparoscopic tacked intra-peritoneal slitted mesh (TISM) technique in the standing horse to close the vaginal rings and to evaluate its efficacy in preventing recurrence of IIH in stallions.

STUDY DESIGN

Retrospective case series.

METHODS

Medical records of 17 stallions with a history of IIH were reviewed retrospectively. The surgical procedure was performed on the standing horse through a flank approach using four laparoscopic portals. The vaginal ring was covered with a commercial mesh. The mesh was partially cut to create a slitted mesh with two flaps: the dorsal flap was passed under the spermatic cord and ductus deferens and the ventral flap above. The mesh was secured in place with laparoscopic tacks. Long-term follow-up was obtained by a structured telephone interview of the owners.

RESULTS

A total of 32 laparoscopic vaginal rings closures were successfully performed in 17 horses. No major intra- or postoperative complications occurred. None of the horse suffered from re-occurrence. Nine of the 13 active breeding stallions were breeding again with similar semen quality as before treatment, 4/13 will resume their breeding activity during the next breeding season. None of the horses were castrated and none of the owners reported abnormal size or shape of the testicles. In three stallions, post-operative pain and activity limitations were noted that gradually resolved after 6 months.

MAIN LIMITATIONS

The lack of large numbers to compare the results of different mesh and tack combinations, the lack of follow-up veterinary examinations and the limited number of laparoscopic rechecks.

CONCLUSION

The TISM technique is an effective minimally invasive technique to surgically reduce the size of the vaginal ring and thereby prevent recurrence of IIH.

Atraumatic laparoscopic intraperitoneal mesh fixation using a new laparoscopic device: an animal experimental study

PURPOSE

Laparoscopic ventral and incisional hernia repair (LVIHR) has become a common procedure because of its feasibility and safety, but it is not free of complications. Acute and chronic post-operative pain and bleeding caused by traumatic fixation of the mesh are frequently prolonging the hospital stay. The aim of this study was to analyze the behavior of n-butyl-cyanoacrylate (GLUBRAN^® 2) as only mesh fixation METHODS: Ten female pigs were involved in the study and were divided into two groups of five (A and B). Animals in each group underwent a laparoscopic procedure in which two meshes were placed intraperitoneally and fixed with the same synthetic glue only. Animals in group A were sacrificed after 3 weeks, and those in group B were sacrificed after 12 weeks. We studied the morphological, biomechanical, and histological characteristics of the intraperitoneal mesh-tissue interface RESULTS: No disruption, migration or folding was observed in any of the pigs. In group A, the mean tensile strength was 1.4 N/cm (± 0.2) while in group B, the mean tensile strength was 2.5 N/cm (± 0.8). Histological analyses, in areas where mesh was fixed using the glue, showed a chronic lymphocytic inflammatory reaction with a granulomatous component and a marked desmoplastic reaction made up of immature collagen and numerous fibroblasts acquiring myofibroblastic characteristics. In some areas corresponding to fixation, the desmoplastic reaction originated from mature lamellar bone tissue with osteocytes and osteoblasts.

CONCLUSION

Laparoscopic mesh fixation with only the synthetic comonomer glue GLUBRAN^® 2 is feasible, effective, and safe in intraperitoneal incisional/ventral hernia repair in this animal model.

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.

Mesh fixation using novel bio-adhesive coating compared to tack fixation for IPOM hernia repair: in vivo evaluation in a porcine model

BACKGROUND

Mesh fixation in hernia repair is currently based on penetrating sutures or anchors, with proven early and late complications such as pain, adhesions, erosions, and anchor migration. In an attempt to reduce these complications, a bio-adhesive-based self-fixation system was developed. The purpose of this study was to assess the performance and safety of this novel self-adhesive mesh (LifeMesh™) by comparing it with standard tack fixation.

METHODS

A full-thickness abdominal wall defect was created bilaterally in 24 pigs. The defects were measured 14 days later, and laparoscopic intraperitoneal onlay mesh (IPOM) repairs were performed. In each animal, both LifeMesh and a titanium tack-fixed control, either uncoated polypropylene mesh (PP) or composite mesh (Symbotex™), were used. After 28 and 90 days, we performed macroscopic evaluation and analyzed the fixation strength, shrinkage, adhesion scores, and histopathology in all samples.

RESULTS

Measurements at both time points revealed that LifeMesh had fully conformed to the abdominal wall, and that its fixation strength was superior to that of the tack-fixated Symbotex and comparable to that of the tack-fixated PP. Shrinkage in all groups was similar. Adhesion scores with LifeMesh were lower than with PP and comparable with Symbotex at both time points. Histology demonstrated similar tissue responses in LifeMesh and Symbotex. Lack of necrosis, mineralization, or exuberant inflammatory reaction in all three groups pointed to their good progressive integration of the mesh to the abdominal wall. By 28 days the bio-adhesive layer in LifeMesh was substantially degraded, allowing a gradual tissue ingrowth that became the main fixation mode of this mesh to the abdominal wall.

CONCLUSIONS

The excellent incorporation of LifeMesh to the abdominal wall and its superior fixation strength, together with its low adhesion score, suggest that LifeMesh may become a preferred alternative for abdominal wall repair.

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.

Evolution and advances in laparoscopic ventral and incisional hernia repair

Primary ventral hernias and ventral incisional hernias have been a challenge for surgeons throughout the ages. In the current era, incisional hernias have increased in prevalence due to the very high number of laparotomies performed in the 20^th century. Even though minimally invasive surgery and hernia repair have evolved rapidly, general surgeons have yet to develop the ideal, standardized method that adequately decreases common postoperative complications, such as wound failure, hernia recurrence and pain. The evolution of laparoscopy and ventral hernia repair will be reviewed, from the rectoscopy of the 4^th century to the advent of laparoscopy, from suture repair to the evolution of mesh reinforcement. The nuances of minimally invasive ventral and incisional hernia repair will be summarized, from preoperative considerations to variations in intraoperative practice. New techniques have become increasingly popular, such as primary defect closure, retrorectus mesh placement, and concomitant component separation. The advent of robotics has made some of these repairs more feasible, but only time and well-designed clinical studies will tell if this will be a durable modality for ventral and incisional hernia repair.

Titanium versus absorbable tacks comparative study (TACS): a multicenter, non-inferiority prospective evaluation during laparoscopic repair of ventral and incisional hernia: study protocol for randomized controlled trial

BACKGROUND

Laparoscopic repair of ventral and incisional hernias has gained popularity since many studies have reported encouraging results in terms of outcomee and recurrence. Choice of mesh and fixation methods are considered crucial issues in preventing recurrences and complications. Lightweight meshes are considered the first choice due to their biomechanical properties and the ability to integrate into the abdominal wall. Titanium helicoidal tacks still represent the "gold standard" for mesh fixation, even if they have been suggested to be involved in the genesis of post-operative pain and complications. Recently, absorbable tacks have been introduced, under the hypothesis that there will be no need to maintain a permanent fixation device after mesh integration. Nevertheless, there is no evidence that absorbable tacks may guarantee the same results as titanium tacks in terms of strength of fixation and recurrence rates. The primary end point of the present trial is to test the hypothesis that absorbable tacks are non-inferior to titanium tacks in laparoscopic incisional and ventral hernia repair (LIVHR) by lightweight polypropylene mesh, in terms of recurrence rates at 3-year follow-up. Surgical complications, post-operative stay, comfort and pain are secondary end points to be assessed.

METHODS/DESIGN

Two hundred and twenty patients with ventral hernia will be randomized into 2 groups: Group A (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by titanium tacks; Group B (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by absorbable tacks.

DISCUSSION

A few retrospective studies have reported similar results when comparing absorbable versus non-absorbable tacks in terms of intraoperative and early post-operative outcomes. These studies have the pitfalls to be retrospective evaluation of small series of patients, and the reported results still need to be validated by larger series and prospective studies. The aim of the present trial is to investigate and test the non-inferiority of absorbable versus non-absorbable tacks in terms of hernia recurrence rates, in order to assess whether the use of absorbable tacks may achieve the same results as non-absorbable tacks in mid-term and long-term settings.

TRIAL REGISTRATION NUMBER

NCT02076984: 5 June 2014 (ClinicalTrials.gov).

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.

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.

Laparoscopic ventral hernia repair: is there an optimal mesh fixation technique? A systematic review

PURPOSE

The purpose of this study is to distinguish the optimal mesh fixation technique used in laparoscopic ventral hernia repair (LVHR). A particular fixation technique of the mesh to the abdominal wall is required, which should be strong enough to prevent migration of the mesh and, at the same time, keep injury to the abdominal wall minimal to prevent postoperative discomfort and pain.

METHODS

An extensive literature search was performed in the PubMed database from its onset until November 2012. All series of at least 30 patients operated by laparoscopy for a ventral hernia, with the use of a standardized surgical technique well-defined in the “Methods” section, and with a follow-up of at least 12 months were included. The series were categorized according to the technique of mesh fixation described: “tacks and sutures,” “tacks only,” and “sutures only.” For each treatment group, the recurrence rate was adjusted to the number of patients treated and the 95 % confidence interval was calculated. No overlap between two intervals was defined as a significant difference in recurrence rate.

RESULTS

A total of 25 series were included for statistical evaluation. Thirteen trials used both tacks and sutures, ten used only tacks, and two used only sutures. Overall recurrence rate was 2.7 % (95 % CI [1.9–3.4 %]).

CONCLUSION

None of the currently available mesh fixation techniques used for LVHR was found to be superior in preventing hernia recurrence as well as in reducing abdominal wall pain. The pain reported was remarkably high with all different fixation devices. Further research to develop solid and atraumatic fixation devices is warranted.

Laparoscopic mechanical fixation devices: does firing angle matter?

BACKGROUND

A variety of permanent and absorbable tacks are available for mesh fixation during laparoscopic hernia repairs. Although manufacturers recommend deploying tacks perpendicular to the tissue, achieving this can sometimes be challenging. This study aimed to analyze comparatively the effects of angled deployment among commonly used tacks.

METHODS

A piece of composite mesh was fixed to the peritoneal surface of a pig with a single tack fired at either a perpendicular (90°) or acute (30°) angle. A lap-shear test was performed to determine fixation strength. Two permanent tacks (a titanium spiral tack: Protack [PT]; and a hollow screw fastener: PermaFix [PF]) and three absorbable tackers (a solid screw: Absorbatack [AT]; a hollow screw fastener: SorbaFix [SF]; and a strap: SecurStrap [SS]) were challenged. A total of 16 samples were performed for each device at each angle. A nonabsorbable transfascial suture was used as a control condition.

RESULTS

Transabdominal sutures had the maximum acute tensile strength (ATS) (29.9 ± 5.5 N). Protack at both 90° and 30° performed significantly better than absorbable tacks (p < 0.01). No significant difference was found among absorbable tacks at 90°. When the same construct was compared at different angles, SS and SF performance was not affected (p = 0.07 and 0.2, respectively). In contrast, PT and AT had significantly reduced fixation strength (p = 0.003 and 0.004, respectively). However, PT fired at an acute angle had fixation equal to that of absorbable tacks fired perpendicularly.

CONCLUSION

Transabdominal sutures performed better than tacks in the acute setting. No absorbable fixation device demonstrated superior efficacy within its class. Spiral titanium tacks provided better fixation than absorbable tacks at both perpendicular and acute angles. Moreover, titanium spiral tacks deployed at 30° performed equal to or better than absorbable tacks fired perpendicularly to the tissue. It appears that spiral titanium tacks should be strongly considered for cases in which perpendicular tack deployment cannot be achieved.