Incisional hernia: challenge of re-operations after mesh repair

Complete Versus Partial Excision of an Infected Mesh Following Abdominal Wall Hernia Repair: A Systematic Review and Meta-analysis

BACKGROUND

To evaluate comparative outcomes of complete and partial excision of infected mesh following abdominal wall hernia repair.

METHODS

A systematic search of electronic databases, including MEDLINE, EMBASE, CINAHL, and CENTRAL, and bibliographic reference lists with application of a combination of free text and controlled vocabulary search adapted to thesaurus headings, search operators and limits was conducted. Surgical site infection chronic sinus formation, recurrent hernia, and need for reoperation were the evaluated outcome measures.

RESULTS

Six comparative observational studies were identified, reporting a total of 317 patients of whom 193 underwent complete mesh excision and the remaining 123 patients underwent partial mesh excision for an infected mesh following abdominal wall hernia repair. The complete mesh excision was associated with significantly lower rates of SSIs (OR: .36; 95% CI, .16-.81, P = .01), chronic sinus formation (OR: .11; 95% CI, .02-.71, P = .02), and reoperation (OR: .10; 95% CI, .03-.33, P = .0001) compared to the partial mesh excision. There was no significant difference in hernia recurrence rate (OR: 3.96.16, 95% CI .62-25.44, P = .15) between two groups. The between-study heterogeneity was moderate in all the analyses.

CONCLUSIONS

Complete mesh excision may be associated with lower SSI, chronic sinus formation and need for reoperation when compared to the partial mesh excision in an infected mesh event. However, the available evidence has failed to report the outcomes with respect to the main confounding factors which, together with other important outcomes such as fistula formation, should be considered by future high quality research.

Non-closure of the Free Peritoneal Flap During Laparoscopic Hernia Repair of Lower Abdominal Marginal Hernia: A Retrospective Analysis

Background: During lower abdominal marginal hernia repair, the peritoneal flap is routinely freed to facilitate mesh placement and closed to conclude the procedure. This procedure is generally called trans-abdominal partial extra-peritoneal (TAPE). However, the necessity of closing the free peritoneal flap is still controversial. This study aimed to investigate the safety and feasibility of leaving the free peritoneal flap in-situ. Methods: A retrospective review was conducted on 68 patients (16 male, 52 female) who underwent laparoscopic hernia repair between June 2014 and March 2021. Patients were diagnosed as the lower abdominal hernia and all required freeing the peritoneal flap during the operation. Patients were divided into 2 groups: one group was TAPE group with the closed free peritoneal flap, another group left the free peritoneal flap unclosed. Analyses were performed to compare both intraoperative parameters and postoperative complications. Results: There were no significant differences in demographic, comorbidity, hernia characteristics and ASA classification. The intra-operative bleeding volume, visceral injury, hospital stay, urinary retention, visual analog scale (VAS) score, dysuria, intestinal obstruction, surgical site infection, mesh infection, recurrence rate and hospital stay were similar among the two groups. Mean operative time of the flap closing procedure was higher than for patients with the free peritoneal flap left in-situ (p = 0.002). Comparisons of postoperative complications showed flap closure resulted in a higher incidence of seroma formation (p = 0.005). Conclusion: Providing a barrier-coated mesh is used during laparoscopic lower abdominal marginal hernia repair, it is safe to leave the free peritoneal flap in-situ and this approach may prevent the occurrence of seromas.

Prosthetic meshes for hernia repair: State of art, classification, biomaterials, antimicrobial approaches, and fabrication methods

Worldwide, hernia repair represents one of the most frequent surgical procedures encompassing a global market valued at several billion dollars. This type of surgery usually requires the implantation of a mesh that needs the appropriate chemical, physical and biological properties for the type of repair. This review thus presents a description of the types of hernias, current hernia repair methods, and the state of the art of prosthetic meshes for hernia repair providing the most important meshes used in clinical practice by surgeons working in this area classified according to their biological or chemical nature, morphology and whether bioabsorbable or not. We emphasise the importance of surgical site infection in herniatology, how to deal with this microbial problem, and we go further into the future research lines on the production of advanced antimicrobial meshes to improve hernia repair and prevent microbial infections, including multidrug-resistant strains. A great deal of progress has been made in this biomedical field in the last decade. However, we are still far from an ideal antimicrobial mesh that can also provide excellent integration to the abdominal wall, mechanical performance, low visceral adhesion and minimal inflammatory or foreign body reactions, among many other problems.

Prosthetic mesh hernioplasty versus primary repair in incarcerated and strangulated groin and abdominal wall hernias with or without organ resection. Retrospective study

PURPOSE

The use of synthetic materials in emergency surgery for abdominal wall hernia in a potentially infected operating field has long been debated. In the present study, we evaluated the outcome of mesh prostheses in the management of incarcerated and strangulated abdominal wall hernias with or without organ resection.

METHODS

Between March 2012 and January 2020, medical records of 301 patients who underwent emergency surgery for incarcerated and strangulated abdominal wall hernias were retrospectively evaluated. The interventions were exclusively realized by two surgical teams, one of which used polypropylene mesh prostheses (group I), whereas the second team performed primary hernia repair (group II). The outcome of patients was observed for a mean follow-up period of 18.2 months. Categorical data were analyzed with the χ2 test or likelihood ratio. Logistic regression was used for adjustments in multivariate analysis. Statistical analyses were realized with SPSS, version 18. P values < 0.05 were considered statistically significant. For multiple comparisons between types of hernia, the significance level was set to P < 0.0083 according to Bonferroni adjustment.

RESULTS

Of the 301 patients, 190 were men (63.1%), and 111 were women (36.9%). The mean age was 59,98 years (range 17-92). Overall, 226 (75.1%) patients were treated with synthetic mesh replacement. One hundred two organ resections (34%) were performed involving the omentum, small intestine, colon, and appendix. No significant difference was identified in terms of postoperative complications, between the two groups both in patients who underwent organ resection and in patients who did not.

CONCLUSION

Synthetic materials may safely be used in the emergency management of incarcerated and strangulated groin and abdominal wall hernias in patients with or without organ resection, although they cannot formally be recommended due to the limited number of cases of the present study.

Retroprosthetic Seroma After Laparoscopic Ventral Hernia Repair Is Related to Mesh Used?

Purpose: Retroprosthetic seroma (RS) is defined as a fluid collection located between the abdominal viscera and the intraperitoneal mesh implanted during surgery. Aim of this study is to report the incidence and clinical impact of RS based on the type of mesh implanted during laparoscopic ventral hernia repair (LVHR). Materials and Methods: Patients who underwent LVHR were allocated in group A if expanded polytetrafluoroethylene (ePTFE) mesh was used during surgery and in group B if other types of mesh were used. Patients were evaluated on postoperative day (POD) 1 and 7 with physical examination and 1 month after surgery by physical examination and with an abdominal computed tomography scan, respectively. Results: Sixty patients were included. Of these 41 patients (68.3%) were included in group A and 19 patients (31.7%) in group B. Signs of RS were not observed in any patient on POD 7. One month after surgery, RS was observed in 13 patients (21.6%). One patient (7.7%) with RS experienced great discomfort and mesh detachment, and underwent a second surgical treatment. All RSs were observed in group A, and the difference with group B was statistically significant (P = .005). Conclusions: The use of ePTFE mesh is related to the development of RS. The treatment of choice without clinical symptoms should be conservative. Randomized control trial and prospective studies with a larger sample size and control group are required to confirm these data, although this study shows a high evidence of the relation of RS and the type of mesh.

Comparison of biological and alloplastic meshes in ventral incisional hernia repair

PURPOSE

The aim of our retrospective analysis was to compare the results of incisional hernia repair by porcine small intestinal submucosa-derived (SIS) meshes with those obtained by alloplastic polypropylene-based (PP) meshes in comparable surgical indications by matched-pair design. We hypothesized that in incisional hernia, SIS mesh repair is associated with fewer recurrences and SSO than PP mesh repair in incisional hernias.

METHODS

Twenty-four matched pairs (SIS vs. PP mesh repair between 1 January 2005 and 31 December 2013) were identified by matching criteria: gender, age, comorbidities, body mass index, EHS hernia classification, mesh implantation technique, CDC wound classification, and source of contamination/primary surgery leading to incisional hernia. Minimal follow-up time was 24 months. Means and standard deviations were compared by paired t test; categorial data were compared by McNemar's test. Poisson's distribution and negative binominal distribution were employed to detect significant correlation.

RESULTS

There were no statistically significant differences between both groups in the pre- and perioperative factors and the follow-up times. There were significantly more wound complications (19 vs. 12, p = 0.041), longer hospital stay (22.0 ± 6.3 vs. 12.0 ± 3.1 days, p = 0.010), and significantly more recurrent hernias (25 vs. 12.5%, p = 0.004) after SIS mesh repair. Both the Poisson's distribution and the negative binominal distribution unveiled significantly more complication points (3-6 vs. 1-2) per month after SIS mesh repair.

CONCLUSION

There is no advantage of SIS meshes compared to PP meshes in incisional hernia repair with different degrees of wound contamination in this matched-pair analysis. Further prospective and randomized trials or at least registry studies such as the EHS register with standardized and defined conditions are warranted.

Adhesions to Mesh after Ventral Hernia Mesh Repair Are Detected by MRI but Are Not a Cause of Long Term Chronic Abdominal Pain

Aim. The aim of the present study was to perform MRI in patients after ventral hernia mesh repair, in order to evaluate MRI's ability to detect intra-abdominal adhesions. Materials and Methods. Single-center long term follow-up study of 155 patients operated for ventral hernia with laparoscopic (LVHR) or open mesh repair (OVHR), including analyzing medical records, clinical investigation with patient-reported pain (VAS-scale), and MRI. MRI was performed in 124 patients: 114 patients (74%) after follow-up, and 10 patients referred for late complaints after ventral mesh repair. To verify the MRI-diagnosis of adhesions, laparoscopy was performed after MRI in a cohort of 20 patients. Results. MRI detected adhesions between bowel and abdominal wall/mesh in 60% of the patients and mesh shrinkage in 20-50%. Adhesions were demonstrated to all types of meshes after both LVHR and OVHR with a sensitivity of 70%, specificity of 75%, positive predictive value of 78%, and negative predictive value of 67%. Independent predictors for formation of adhesions were mesh area as determined by MRI and Charlson index. The presence of adhesions was not associated with more pain. Conclusion. MRI can detect adhesions between bowel and abdominal wall in a fair reliable way. Adhesions are formed both after open and laparoscopic hernia mesh repair and are not associated with chronic pain.

Abdominal reoperation and mesh explantation following open ventral hernia repair with mesh

BACKGROUND

This study sought to identify the incidence, indications, and predictors of abdominal reoperation and mesh explantation following open ventral hernia repair with mesh (OVHR).

METHODS

A retrospective cohort study of all patients at a single institution who underwent an OVHR from 2000 to 2010 was performed. Patients who required subsequent abdominal reoperation or mesh explantation were compared with those who did not. Reasons for reoperation were recorded. The 2 groups were compared using univariate and multivariate analysis (MVA).

RESULTS

A total of 407 patients were followed for a median (range) of 57 (1 to 143) months. Subsequent abdominal reoperation was required in 69 (17%) patients. The most common reasons for reoperation were recurrence and surgical site infection. Only the number of prior abdominal surgeries was associated with abdominal reoperation on MVA. Twenty-eight patients (6.9%) underwent subsequent mesh explantation. Only the Ventral Hernia Working Group grade was associated with mesh explantation on MVA.

CONCLUSIONS

Abdominal reoperation and mesh explantation following OVHR are common. Overwhelmingly, surgical complications are themost common causes for reoperation and mesh explantation.

Criteria for definition of a complex abdominal wall hernia

PURPOSE

A clear definition of "complex (abdominal wall) hernia" is missing, though the term is often used. Practically all "complex hernia" literature is retrospective and lacks proper description of the population. There is need for clarification and classification to improve patient care and allow comparison of different surgical approaches. The aim of this study was to reach consensus on criteria used to define a patient with "complex" hernia.

METHODS

Three consensus meetings were convened by surgeons with expertise in complex abdominal wall hernias, aimed at laying down criteria that can be used to define "complex hernia" patients, and to divide patients in severity classes. To aid discussion, literature review was performed to identify hernia classification systems, and to find evidence for patient and hernia variables that influence treatment and/or prognosis.

RESULTS

Consensus was reached on 22 patient and hernia variables for "complex" hernia criteria inclusion which were grouped under four categories: "Size and location", "Contamination/soft tissue condition", "Patient history/risk factors", and "Clinical scenario". These variables were further divided in three patient severity classes ('Minor', 'Moderate', and 'Major') to provide guidance for peri-operative planning and measures, the risk of a complicated post-operative course, and the extent of financial costs associated with treatment of these hernia patients.

CONCLUSION

Common criteria that can be used in defining and describing "complex" (abdominal wall) hernia patients have been identified and divided under four categories and three severity classes. Next step would be to create and validate treatment algorithms to guide the choice of surgical technique including mesh type for the various complex hernias.

In vivo MRI visualization of mesh shrinkage using surgical implants loaded with superparamagnetic iron oxides

BACKGROUND

Prosthetic mesh implants are widely used in hernia surgery. To show long-term mesh-related complications such as shrinkage or adhesions, a precise visualization of meshes and their vicinity in vivo is important. By supplementing mesh fibers with ferro particles, magnetic resonance imaging (MRI) can help to delineate the mesh itself. This study aimed to demonstrate and quantify time-dependent mesh shrinkage in vivo by MRI.

METHODS

Polyvinylidenfluoride (PVDF) meshes with incorporated superparamagnetic iron oxides (SPIOs) were implanted as an abdominal wall replacement in 30 rats. On days 1, 7, 14, or 21, MRI was performed using a gradient echo sequence with repetition time (TR)/echo time (TE) of 50/4.6 and a flip angle of 20°. The length, width, and area of the device were measured on axial, coronal, and sagittal images, and geometric deformations were assessed by surgical explantation.

RESULTS

In all cases, the meshes were visualized and their area estimated by measuring the length and width of the mesh. The MRI presented a mean area shrinkage in vivo of 13% on day 7, 23% on day 14, and 23% on day 21. Postmortem measurements differed statistically from MRI, with a mean area shrinkage of 23% on day 7, 28% on day 14, and 30% on day 21. Ex vivo measurements of shrinkage showed in vivo measurements to be overestimated approximately 8%. Delineation of the mesh helped to show folding or adhesions close to the intestine.

CONCLUSION

Loading of surgical meshes with SPIOs allows their precise visualization during MRI and guarantees an accurate in vivo assessment of their shrinkage. The authors' observation clearly indicates that shrinkage in vivo is remarkably less than that shown by illustrated explantation measurements. The use of MRI with such meshes could be a reliable technique for checking on proper operation of implanted meshes and showing related complications, obviating the need for exploratory open surgical revision.

Repair of large abdominal incisional hernia by reconstructing the midline and use of an onlay of biological material

BACKGROUND

The aim of this study was to determine the feasibility and efficacy of repairing large abdominal incisional hernias by reconstructing the midline using bilateral abdominis rectus muscle sheath (ARS) relaxing incisions and a biological material onlay.

METHODS

Between January 2002 and December 2008, 71 patients underwent repair of large incisional hernias at 2 community hospitals. After replacement of hernia sac contents into the peritoneal cavity, a relaxing incision was made in the ARS bilaterally. Then, the midline was closed primarily. The biological material was used as an onlay and sutured to the lateral edges of the relaxed ARS. Main outcome measures were postoperative complications and hernia recurrence.

RESULTS

Median defect size was 195 cm(2) (range, 150-420 cm(2)), median surgical time was 125 minutes, and median hospital stay was 6 days. There were no deaths and no wound infections. Wound seroma, the most frequent postoperative complication, occurred in 51 (72%) of the 71 patients. There was 1 (1.4%) recurrence.

CONCLUSIONS

In these 71 patients, our technique for repair of large abdominal incisional hernias was safe and effective.

Biocompatibility of prosthetic meshes in abdominal surgery

Surgical meshes today represent a group of implants mainly used for hernia repair. Modern hernia surgery is no longer imaginable without the application of these special biomaterials leading to millions of implantations each year worldwide. Because clinical trials are insufficient to evaluate the distinct effects of modified mesh materials in regard to tissue biocompatibility and functionality, a basic understanding of the physicochemical properties of mesh materials, as well as the underlying cause for hernia formation, is essential for a rational selection of the most appropriate device. The most important properties of meshes were found to be the type of filament, tensile strength, and experimental data, which indicate that particularly the mesh's porosity is of outstanding importance.

A randomised, multi-centre, prospective, double blind pilot-study to evaluate safety and efficacy of the non-absorbable Optilene Mesh Elastic versus the partly absorbable Ultrapro Mesh for incisional hernia repair

Background

Randomised controlled trials with a long term follow-up (3 to 10 years) have demonstrated that mesh repair is superior to suture closure of incisional hernia with lower recurrence rates (5 to 20% versus 20 to 63%). Yet, the ideal size and material of the mesh are not defined. So far, there are few prospective studies that evaluate the influence of the mesh texture on patient's satisfaction, recurrence and complication rate. The aim of this study is to evaluate, if a non-absorbable mesh (Optilene^® Mesh Elastic) will result in better health outcomes compared to a partly absorbable mesh (Ultrapro^® Mesh).

Methods/Design

In this prospective, randomised, double blind study, eighty patients with incisional hernia after a midline laparotomy will be included. Primary objective of this study is to investigate differences in the physical functioning score from the SF-36 questionnaire 21 days after mesh insertion. Secondary objectives include the evaluation of the patients' daily activity, pain, wound complication and other surgical complications (hematomas, seromas), and safety within six months after intervention.

Discussion

This study investigates mainly from the patient perspective differences between meshes for treatment of incisional hernias. Whether partly absorbable meshes improve quality of life better than non-absorbable meshes is unclear and therefore, this trial will generate further evidence for a better treatment of patients.

Trial registration

NCT00646334

Laparoscopic repair of incisional hernias located on the abdominal borders: a retrospective critical review

BACKGROUND

The aim of this study was to assess feasibility and results of laparoscopic approach to repair incisional hernias of the abdominal borders, the weakest points of abdominal wall.

METHODS

Since 2002 through 2008 a total of 39 patients with fascial defects of the abdominal borders underwent laparoscopic repair. The defects were suprapubic (n=18), subxiphoidal (n=15), and lateral sided (n=6). The body mass index was >oe=30 Kg/m2 in 19 patients. The parietal defects was measured both externally and from within the peritoneal cavity and 56% of meshes were fixed only by tacks, especially in suprapubic site.

RESULTS

The mean operating time was 161.8+/-25 minutes. There was 1 intraoperative complication, an intestinal injury repaired laparoscopically. Conversion was needed in 1 patient for massive adhesions. Postoperative early surgical complications were 7 (1 seroma). Morbidity in obese and nonobese patients showed no statistically relevant difference (P>0.05). There was no postoperative death. Mean hospital stay was 5.1+/-3 days. The mean follow-up was 37 months and recurrence was observed in 3 cases.

CONCLUSIONS

The onlay laparoscopic approach for repair of incisional hernias of the abdominal borders can warrant good results. Obesity is not a contraindication to laparoscopic repair. Anyway, further experiences are necessary to confirm these results.

Impact of mesh positioning on foreign body reaction and collagenous ingrowth in a rabbit model of open incisional hernia repair

BACKGROUND

Incisional hernia remains as one of the most common surgical complications. Different mesh techniques are used in 75-80% of hernia repair. The aim of this study was to evaluate the dependence of mesh positioning and the type of mesh implanted on foreign body reaction and collagenous ingrowth.

MATERIALS AND METHODS

In 24 male Chinchilla rabbits, an incisional hernia repair was performed with mesh reinforcement either by sublay (n = 12) or by onlay technique (n = 12). In each group, two different types of mesh prosthesis were investigated: polypropylene (PP, Prolene) and polypropylene-polyglecaprone 25 composite (PP-PG, UltraPro). On postoperative day 60, the inflammatory and connective tissue formation was characterised by measuring the diameter of inner cellular infiltrate and outer fibrous capsule of the foreign body granuloma, and by verifying the collagen type I/III ratio. Furthermore, the expression of matrix metalloproteinase-2 (MMP-2) was analysed.

RESULTS

Microscopic investigation of the mesh/host-tissue interface showed typical formation of foreign body granuloma. The diameters of the inner part of the foreign body granuloma representing the amount of inflammatory cell infiltrate were significantly increased in the PP mesh compared to the PP-PG mesh, both in the sublay group (PP 13.1 +/- 1.21 microm vs. PP-PG 11.7 +/- 0.34 microm; P = 0.026) and in the onlay group (PP 13.1 +/- 1.24 microm vs. PP-PG 11.2 +/- 0.55 microm; P = 0.009). The diameter of the fibrous capsule as the outer ring of the granuloma was significantly increased when investigating the PP mesh in sublay position (29.5 +/- 1.12 microm) compared to the PP mesh in onlay position (27.9 +/- 0.73 microm) (P = 0.026). Investigating the quality of perifilamentary collagen deposition expressed as collagen type I/III ratio, the sublay group showed significantly elevated values compared to the onlay group (PP sublay 3.1 +/- 0.18 vs. PP onlay 2.4 +/- 0.41; P = 0.004) (PP-PG sublay 3.5 +/- 0.34 vs. PP-PG onlay 2.6 +/- 0.13; P = 0.002). The analysis of MMP-2 expression revealed no significant differences.

CONCLUSION

The beneficial results of mesh reinforcement in the sublay technique might be due to a superior quality of postoperative connective tissue formation. Mesh incorporation, irrespective of positioning, is favourable in low-weight, large, porous mesh material represented by a reduced inflammatory part of the foreign body granuloma.

A computerized tomography scan method for calculating the hernia sac and abdominal cavity volume in complex large incisional hernia with loss of domain

Preoperative progressive pneumoperitoneum (PPP) is a safe and effective procedure in the treatment of large incisional hernia (size > 10 cm in width or length) with loss of domain (LIHLD). There is no consensus in the literature on the amount of gas that must be insufflated in a PPP program or even how long it should be maintained. We describe a technique for calculating the hernia sac volume (HSV) and abdominal cavity volume (ACV) based on abdominal computerized tomography (ACT) scanning that eliminates the need for subjective criteria for inclusion in a PPP program and shows the amount of gas that must be insufflated into the abdominal cavity in the PPP program. Our technique is indicated for all patients with large or recurrent incisional hernias evaluated by a senior surgeon with suspected LIHLD. We reviewed our experience from 2001 to 2008 of 23 consecutive hernia surgical procedures of LIHLD undergoing preoperative evaluation with CT scanning and PPP. An ACT was required in all patients with suspected LIHLD in order to determine HSV and ACV. The PPP was performed only if the volume ratio HSV/ACV (VR = HSV/ACV) was >or=25% (VR >or= 25%). We have performed this procedure on 23 patients, with a mean age of 55.6 years (range 31-83). There were 16 women and 7 men with an average age of 55.6 years (range 31-83), and a mean BMI of 38.5 kg/m(2) (range 23-55.2). Almost all patients (21 of 23 patients-91.30%) were overweight; 43.5% (10 patients) were severely obese (obese class III). The mean calculated volumes for ACV and HSV were 9,410 ml (range 6,060-19,230 ml) and 4,500 ml (range 1,850-6,600 ml), respectively. The PPP is performed by permanent catheter placed in a minor surgical procedure. The total amount of CO(2) insufflated ranged from 2,000 to 7,000 ml (mean 4,000 ml). Patients required a mean of 10 PPP sessions (range 4-18) to achieve the desired volume of gas (that is the same volume that was calculated for the hernia sac). Since PPP sessions were performed once a day, 4-18 days were needed for preoperative preparation with PPP. The mean VR was 36% (ranged from 26 to 73%). We conclude that ACT provides objective data for volume calculation of both hernia sac and abdominal cavity and also for estimation of the volume of gas that should be insufflated into the abdominal cavity in PPP.

The role of suture fixation on mesh contraction after abdominal hernia repair

Mesh contraction is a threat for hernia repair. Our aim is to analyze the effects of fixation techniques on mesh contraction. Forty-eight rats with abdominal wall defects were equally divided into four groups (G): G1 (control) with no repair, G2 defects were repaired with free polypropylene mesh, and G3 and G4 defects were reinforced with prolene mesh fixed by running and interrupted sutures, respectively. The corners of the defect and prolene mesh were marked with silver clips. The contraction rate was calculated by radiological measurement of distances between corner clips and by measuring the mesh areas after harvesting abdominal wall containing the patch. Host reaction was histhopathologically and biochemically examined by inflammation score, fibroblast count, thickness of the granulation tissue, and tissue hydroxyproline level. Distances between corner clips and mesh area have decreased by 31.5% and 26.4% respectively in G2, while in G3 the decrease was 24.4% (p = .008) and 22% (p = .01), respectively. Granulation tissue thickness was highest in the group with mesh fixed by running suture. The tissue hydroxyproline levels were similar in mesh repair groups. Our study suggests that mesh contraction, which reduces mesh surface, occurs during the wound healing process. In order to decrease the contraction rate, it is important to keep the mesh in place until its incorporation into the surrounding tissue. Our results suggest that mesh contraction is minimized by suture fixation, and running fixation suture, which provides more balanced tension around the mesh, seems more beneficial for decreasing contraction rate.

Hernia recurrence after laparotomy: how to close an incised light-weight mesh?

A rising number of patients require relaparotomy after implantation of mesh materials for incisional hernia (IH) repair. No published recommendation concerning how to close the incision in a surgical mesh exists. We describe a central IH recurrence through a partly absorbable mesh positioned in the retromuscular plane 16 months after laparotomy due to a small bowel ileus. This recurrence was repaired using a heavy-weight, monofilament polypropylene mesh, again in the retromuscular position. Reducing the amount of nonabsorbable material in large pore hernia meshes leads to markedly reduced scar formation rather than the formation of a thick scar plate. Once cut and resutured, this scar may be too weak to withstand the mechanical strain, giving rise to a 'blow-out' IH recurrence, as demonstrated in our case. In these cases, re-enforcement with a nonabsorbable, small, porous polypropylene mesh in the retromuscular space is feasible and leads to the development of a mechanically stable scar.

Adhesion formation of a polyvinylidenfluoride/polypropylene mesh for intra-abdominal placement in a rodent animal model

BACKGROUND

Effective laparoscopic ventral herniorrhaphy mandates the use of an intraperitoneal mesh. Visceral adhesions and shrinkage of prosthetics may complicate repairs. The aim of this study was to compare adhesion formation, mesh shrinkage and tissue ingrowth after intra-abdominal placement of a novel two-component monofilament mesh structure made of polypropylene (PP) and polyvinylidenfluoride (PVDF) with current alternatives.

MATERIALS AND METHODS

Forty Sprague-Dawley rats were used in this study. Mesh samples were fixed as intra-abdominal only mesh at the right lateral abdominal wall. The study groups were: PVDF+PP (polypropylene parietally and polyvinylidenfluoride viscerally), PP+Col (polypropylene with a collagenoxidized film), ePTFE (smooth surface viscerally and a textured surface parietally), and PP (a pure polypropylene mesh serving as control). The meshes were explanted after 30 days. Adhesions were scored as a percentage of explanted biomaterials' affected surface area; prosthetic shrinkage was calculated. Foreign-body reaction to mesh materials was measured by investigating the amount of inflammatory infiltrate and fibrotic tissue formation.

RESULTS

In terms of adhesion score, the pure PP mesh showed the highest values followed by the ePTFE, PVDF+PP, and PP+Col meshes. Quantitative assessment of adhesion area revealed a significantly higher value of the pure PP mesh sample (62.0 +/- 22.1%) compared with the PP+Col (26.8 +/- 12.1%) and the PVDF+PP mesh (34.6 +/- 8.2%). Percentage of shrinkage showed a significantly higher value of the ePTFE mesh (52.4 +/- 13.9%) compared with all other mesh modifications (PP+Col 19.8 +/- 13.9%, PVDF+PP 19.9 +/- 7.0%, and PP 26.8 +/- 9.5%). Inflammatory infiltrate was significantly reduced in the PVDF+PP mesh group compared with all other mesh samples.

CONCLUSION

The use of the novel two-component monofilament mesh structure made of polypropylene and polyvinylidenfluoride was found to be favorable regarding adhesion formation and mesh shrinkage compared to conventional mesh materials used for intra-abdominal placement.

New technical approach for the repair of an abdominal wall defect after a transverse rectus abdominis myocutaneous flap: a case report

Introduction

Breast reconstruction with autologous tissue transfer is now a standard operation, but abnormalities of the abdominal wall contour represent a complication which has led surgeons to invent techniques to minimize the morbidity of the donor site.

Case presentation

We report the case of a woman who had bilateral transverse rectus abdominis myocutaneous flap (TRAM-flap) breast reconstruction. The surgery led to the patient developing an enormous abdominal bulge that caused her disability in terms of abdominal wall and bowel function, pain and contour. In the absence of rectus muscle, the large defect was repaired using a combination of the abdominal wall component separation technique of Ramirez et al and additional mesh augmentation with a lightweight, large-pore polypropylene mesh (Ultrapro^®).

Conclusion

The procedure of Ramirez et al is helpful in achieving a tension-free closure of large defects in the anterior abdominal wall. The additional mesh augmentation allows reinforcement of the thinned lateral abdominal wall.

Choice of mesh for laparoscopic ventral hernia repair

BACKGROUND

Surgical treatment of ventral hernias has changed dramatically over the past decades by the introduction of laparoscopy and prosthetic biomaterials for reinforcement of the abdominal wall. There are many meshes available on the market for laparoscopic ventral hernia repair (LVHR), and new meshes are introduced regularly. Experimental and clinical documentation for safety and efficacy are, however, often not available for the clinician. The choice of mesh may therefore be difficult in clinical practice. We present a review of the current literature regarding safety measures such as adhesions, fistulas, and infections as well as the available data on pain, recurrence, mesh shrinkage, and seroma formation after LVHR.

METHODS

The literature was searched systematically using PubMed/MEDLINE and EMBASE for controlled studies, prospective descriptive series and retrospective case series.

RESULTS

The literature clearly points in the direction of very few mesh-related complications after LVHR. Experimental studies and theoretical considerations may argue for using a covered mesh, i.e., a composite mesh, or ePTFE for LVHR in humans, although it is important to stress that there are no human data at the moment to support this. Concerns about using pure polypropylene mesh in the intraperitoneal position may be re-evaluated with the experience of lightweight macropore meshes from open surgery in mind. There is a tendency towards greater shrinkage in ePTFE-based meshes but no differences seems to exist between different mesh materials in other relevant outcome parameters from clinical series.

CONCLUSIONS

The literature cannot give general recommendations for choice of mesh based on randomized controlled trials. The final choice of mesh for LVHR will therefore typically be based on surgeons' preference and cost while we await further data from randomized controlled clinical trials.