Does closure of the direct hernia defect in laparoscopic inguinal herniotomy reduce the risk of recurrence and seroma formation?: a systematic review and meta-analysis.

PURPOSE: Recurrence is a known complication to inguinal herniotomy with an incidence of 10 to 15 percent (Hernia Surge Group in Hernia 22:165, 2018). Previous studies have shown that direct hernia or large defects are risk factors for postoperative seroma formation (Morito et al. in Surg Endosc https://doi.org/10.1007/s00464-021-08814-2 , 2021). These types of defects are often closed during open herniotomy (Rosenberg et al. in Dan Med Bull 58: C4243, 2011). This is not routine during laparoscopic surgery. A recent study has indicated that closure of the medial defect during laparoscopy may reduce recurrence and seroma formation. As a result, we performed the present systematic review to evaluate the efficacy of this add on to the standard procedure. METHODS: An extensive search was carried out in PubMed and Embase. All studies involving adults undergoing laparoscopic direct hernioplasty were enrolled and screened with predefined inclusion criteria, to be part of a systematic review with data synthesis and meta-analysis. RESULTS: The search identified 108 publications of which four met the inclusion criteria. Two studies (Ng et al. in Hernia 24:1093-1098, 2020; Usmani et al. in Hernia 24:167-171, 2020) showed reduced risk of recurrence. The remaining studies (Zhu et al. in Surg Laparosc Endosc Percutan Tech 29:18-21, 2019; Li and Zhang in Surg Endosc 32:1082-1086, 2018) reported no recurrence in any of the patients included. Two articles (Usmani et al. in Hernia 24:167-171, 2020; Zhu et al. in Surg Laparosc Endosc Percutan Tech 29:18-21, 2019) showed a decrease in risk of postoperative seroma, one showed a significant increase (Ng et al. in Hernia 24:1093-1098, 2020). None of the included studies showed an increase in the risk of postoperative pain or postoperative complications. CONCLUSION: This review suggests that closure versus non-closure of the medial hernia defect in laparoscopic inguinal hernioplasty reduces the risk of recurrence and seroma formation without an increase in postoperative pain or complications. Further randomized controlled trials are needed for further evaluation.

Polypropelene-mesh properties and type of anchoring do not influence strength of parietal ingrowth.

PURPOSE: In laparoscopic ventral hernia repair, parietal ingrowth of the mesh is of crucial importance. Until significant ingrowth occurs integrity of the repair depends solely on mesh overlap and anchoring device. Relatively few studies have addressed the effect of mesh properties and anchoring device on long-term parietal ingrowth. METHODS: In 20 sheep, using laparoscopy, we inserted two different polypropylene-based meshes, Physiomesh™ and Ventralight™ ST, anchored with Protack™, SecureStrap™, or Glubran™. After 6 and 12 months, 10 sheep at each time point were euthanized, and we harvested the meshes with corresponding fascia. Mesh with fascia was attached on an Alwetron™ materials testing machine and pulled apart obtaining the peel-off energy (kilojoule (kJ)). RESULTS: The strength of parietal ingrowth at 6 months was 5.99 ± 0.54 kJ (mean ± SEM), 4.94 ± 0.54 kJ and 7.35 ± 0.55 kJ when anchored with Protack™, Glubran™, or SecureStrap™, respectively. At 6 months, the strength of parietal ingrowth of SecureStrap™ was significantly higher than Glubran™ (p = 0.04). No significant difference was seen between any other combinations. Parietal ingrowth at 12 months was 7.05 ± 0.56 kJ, 7.55 ± 0.54 kJ, and 5.73 ± 0.54 kJ when anchored with Protack™, Glubran™, and SecureStrap™, respectively. No significant difference in strength of parietal ingrowth was seen between the three types of anchoring, (p = 1.00, p = 1.00, and p = 0.29). CONCLUSIONS: At 12 months, the strength of parietal ingrowth was the same for all comparisons. The two polypropylene meshes showed equal strength of parietal ingrowth independent of mesh properties and anchoring devices used.

Mesh shrinkage depends on mesh properties and anchoring device: an experimental long-term study in sheep.

PURPOSE: The choice of mesh and anchoring device in laparoscopic ventral hernia repair is controversial. Clinically important long-term properties of mesh and anchoring device such as mesh shrinkage have been sparsely investigated. Furthermore, the effect of various anchoring devices on mesh properties has never been examined. METHODS: In 20 sheep, using laparoscopy, we inserted three PhysiomeshTM (large pore, lightweight) and three VentralightTMST (small pore, mediumweight), anchored with ProTackTM, SecurestrapTM or GlubranTM, respectively. After 6 and 12 months, 10 sheep at each time-point, we euthanized the animals, harvested the meshes with fascia, and measured the exact size and area of the mesh, expressing mesh shrinkage as a percentage of the initial area. RESULTS: The shrinkage of PhysiomeshTM was 35.7 %, 23.8 % and 17.7 % when anchored with ProtackTM, GlubranTM or SecurestrapTM, respectively. Shrinkage with ProtackTM was significantly higher than with either GlubranTM or SecurestrapTM, respectively (p<0.01 and p<0.01). The shrinkage of VentralightTMST was 19.3 %, 22.2 % and 19.6 % when anchored with ProtackTM, GlubranTM and SecurestrapTM, respectively (p>0.05 for all pairwise comparisons). Overall shrinkage of PhysiomeshTM anchored with ProtackTM was significantly higher for all comparisons (p<0.01). CONCLUSION: Our results suggest that mesh shrinkage in sheep takes place within 6 months after implantation. A significant interaction between mesh and type of anchoring indicates that shrinkage may depend on both mesh properties and anchoring device. The results of the current study imply that the combined effect of mesh and anchoring device should be evaluated in future studies.

Shrinkage of intraperitoneal onlay mesh in sheep: coated polyester mesh versus covered polypropylene mesh.

BACKGROUND: Currently, the laparoscopic placement of intraperitoneal mesh constitutes an acceptable option in the management of ventral hernia. To date, relatively little has been published on the consequences of intra-abdominal placement of a mesh with respect to the decrease of mesh size (shrinkage). METHODS: In each of 16 sheep, four meshes (dimensions 10 × 10 cm), two based on polyester and two on polypropylene, were placed laparoscopically on intact peritoneum and fixed with either non-absorbable or absorbable tacks. After 3, 6, 12, and 18 months, four animals, respectively, underwent a new laparoscopy with the harvesting of mesh and fascia. Quantitative measurement of the mesh size was performed and expressed as percentage shrinkage. Random core biopsies of mesh and adjacent tissue were obtained and histologically examined. RESULTS: There was a significant difference of the two meshes with respect to shrinkage at all time points. The coated polyester-based mesh was exposed to more shrinkage compared to the polypropylene mesh covered with anti-adhesive material. Random biopsies at 3 months showed an increased foreign body reaction to the coated polyester mesh. CONCLUSIONS: This study is the first long-term experimental study on mesh shrinkage after the laparoscopic placement of mesh. The polyester-based mesh induced a more intense foreign body reaction and was exposed to significantly more shrinkage than the covered polypropylene mesh.

Functional cine MRI and transabdominal ultrasonography for the assessment of adhesions to implanted synthetic mesh 5-7 years after laparoscopic ventral hernia repair.

BACKGROUND: Laparoscopic ventral hernia repair (LVHR) has gained worldwide acceptance, due to its minimally invasive character, feasibility and low rate of complications. Animal experiments have shown marked adhesions to the intraperitoneal mesh (IPM), the clinical consequences being unclear. This study aimed to describe the extension of adhesions to the mesh, 5-7 years after LVHR, using two validated non-invasive radiologic methods. METHODS: Real-time transabdominal ultrasonography (TAU) and cine magnetic resonance imaging (MRI) was applied to 30 patients with prior LVHR and implantation of IPM (Intramesh W3, Cousin Biotech, France). The visceral slide was measured in nine predefined abdominal segments. Values

Intraperitoneal onlay mesh: an experimental study of adhesion formation in a sheep model.

PURPOSE: Current hernia literature shows that the use of mesh in ventral hernia repair reduces the risk of recurrence significantly. In laparoscopic repair, the mesh is placed intraperitoneally. Accordingly, the close contact between mesh and viscera involves a risk of adhesion formation. In this experimental study, we examined the degree of de novo adhesion formation over time to currently available meshes. METHODS: Sixteen sheep each received laparoscopic placement of four (10 x 10 cm) meshes on intact peritoneum. Two different mesh materials (coated vs. non-coated) and two different fixation devices (absorbable/non-absorbable) were investigated. (Parietex Composite, DynaMesh IPOM, ProTack and AbsorbaTack). After 3, 6, 12 and 18 months, four animals, respectively, underwent a new laparoscopy to determine the extent of adhesions to the mesh. RESULTS: Parietex Composite significantly reduced the formation of intraabdominal adhesions compared to DynaMesh IPOM. The mean extent of adhesions increases over time without reaching a steady state within the first 12 months after laparoscopic placement. CONCLUSIONS: This is the first long-term (18 months) experimental study on adhesion formation in sheep after laparoscopic placement of mesh and may serve as a template for future studies on meshes before marketing.