A review of available prosthetics for ventral hernia repair. Ann Surg. 2011;253:16-26. [PMID: 21135699 DOI: 10.1097/sla.0b013e3181f9b6e6]

Outcomes of synthetic and biologic mesh in abdominal wall reconstruction: A propensity-matched analysis in Centers for Disease Control and Prevention class 1 and 2 wounds

INTRODUCTION

The choice of biologic compared with synthetic mesh in abdominal wall reconstruction remains controversial, especially in Centers for Disease Control and Prevention class 1 and 2 wounds. This study evaluated wound complications and hernia recurrence with a 2:1 propensity-matched sample and extended follow-up.

METHODS AND PROCEDURES

A prospectively maintained abdominal wall reconstruction database was queried for patients undergoing open abdominal wall reconstruction using biologic or synthetic mesh in Centers for Disease Control and Prevention class 1 and 2 wounds. Patients receiving synthetic or biologic mesh were propensity score matched in a 2:1 fashion. Univariate, bivariate, and inferential analyses were conducted. Unless stated, data are reported as biologic compared with synthetic.

RESULTS

In total, 519 patients were compared, 173 with biologic and 346 with synthetic mesh. Defect size (215.2 ± 153.6 cm2 vs 251.5 ± 284.3 cm2), body mass index (33.6 ± 9 kg/m2 vs 34 ±17.7 kg/m2), and comorbidities were well matched (all P > .05). Although Centers for Disease Control and Prevention wound class was used in the match, it was significantly different between groups (Centers for Disease Control and Prevention 1:43.4% vs 81.2%, Centers for Disease Control and Prevention 2:56.6% vs 18.8%; P < .001). The rate of component separation (40.1% vs 44.2%; P = .397), fascial closure (97.7% vs 98.3%; P = .738), and panniculectomy (33.5% vs 29.2%; P = .315) were similar. Mesh size was also similar (816.4 ± 555.5 vs 892.2 ± 487.8 cm2; P = .112). Wound complications were equal, including wound breakdown (10.5% vs 7.5%; P = .315), wound cellulitis (5.2% vs 5.8%; P = .843), wound infection (7.5% vs 4.6%; P = .223), seroma requiring intervention (6.4% vs 7.8%; P = .597), and mesh infection (1.2% vs 0.9%; P > .999). The biologic group had an increased length of stay (6.8 ± 5.5 days vs 5.4 ± 2.3 days; P < .001) and greater hospital charges ($82,181 ± 50,356 vs $62,221 ± 26,817 USD; P < .001). Mean follow-up after biologic repair was longer (33.9 ± 36.6 months vs 23.3 ± 32.3 months; P < .001). Hernia recurrence between the biologic and synthetic groups was not significantly different (2.9% vs 1.4%; P = .313). On multivariable regression, wound complications were predictive of recurrence, and panniculectomy was predictive of wound complications.

CONCLUSION

In a 2:1 matched analysis of Centers for Disease Control and Prevention 1 and 2 wounds with nearly 3-years of follow-up, biologic and synthetic mesh had similar rates of wound complications and recurrence in abdominal wall reconstruction.

Surface treatment of artificial implants with hybrid nanolayers: results of antibacterial tests, leachates and scanning electron microscope analysis

Purpose

The aim of this study was to evaluate the antibacterial efficacy of surface-treated hernia implants modified by a hybrid nanolayer with incorporated Ag, Cu, and Zn cations using the sol-gel method.

Methods

The materials (polypropylene, polyester, and polyvinylidene difluoride) were activated by vacuum plasma treatment or UV C radiation, then modified and tested for bacterial strains of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). The AATCC 100 (2019) method for quantitative and the ISO 20645 agar plate propagation method for qualitative evaluation of microbiological efficacy were used. The gradual release of incorporated ions was monitored over time in simulated body fluids (blood plasma, peritoneal fluid) and physiological saline using an inductively coupled plasma mass spectrometer. The thickness and the homogeneity of the layers were measured for individual random samples with scanning electron microscope analysis (SEMA) and evaluated with an elemental analysis.

Results

Qualitative and quantitative microbiological tests clearly show the great suitability of vacuum plasma and UV C with sol AD30 (dilution 1:1) surface treatment of the implants. The absolute concentration of Ag, Cu, and Zn cations in leachates was very low. SEMA showed a high degree of homogeneity of the layer and only very rare nanocracks by all tested materials appear after mechanical stress.

Conclusion

This study confirms that surface treatment of meshes using the sol-gel method significantly increases the antibacterial properties. The nanolayers are sufficiently mechanically resistant and stable and pose no threat to health.

Maximizing mesh mileage: evaluating the long-term performance of a novel hybrid mesh for ventral hernia repair

PURPOSE

The objective of this study is to evaluate the safety and long-term outcomes of GORE Synecor™ in ventral hernia repair (VHR).

METHODS

This retrospective, single-center case review analyzed outcomes in patients who underwent VHR with Synecor from May 2016 to December 2022. Primary outcomes were hernia recurrence and mesh infection rates. Secondary outcomes were 30-day morbidity, 30-day mortality, 30-day readmission, re-operation, surgical-site infection (SSI) and occurrence (SSO) rates, and occurrences requiring intervention (SSOI).

RESULTS

278 patients were identified. Mean follow-up was 24.1 (0.2-87.1) months. Mean hernia defect size was 63.4 (± 77.2) cm2. Overall hernia recurrence and mesh infection rates were 5.0% and 1.4% respectively. No mesh infections required full explantation. We report the following overall rates: 13.3% 30-day morbidity, 4.7% 30-day readmission, 2.9% re-operation, 7.2% SSI, 6.1% SSO, and 2.9% SSOI. 30-day morbidity was significantly higher in non-clean (42.1% vs 11.2%, p < 0.01), onlay (OL) mesh (37.0% vs preperitoneal (PP) 16.4%, p = 0.05 vs retrorectus (RR) 15.0%, p < 0.05 vs intraperitoneal (IP) 5.2%, p < 0.001), and open cases (23.5% vs 3.1% laparoscopic vs 4.4% robotic, p < 0.01). SSI rates were significantly higher in non-clean (31.6% vs 5.4%, p < 0.001), OL mesh (29.6% vs RR 11.3%, p < 0.05 vs PP 5.5%, p < 0.01 vs IP 0.0%, p < 0.001), and open cases (15.2% vs 0% laparoscopic vs 0% robotic, p < 0.05).

CONCLUSION

Long-term performance of a novel hybrid mesh in VHR demonstrates a low recurrence rate and favorable safety profile in various defect sizes and mesh placement locations.

Quality of life measures and cost analysis of biologic versus synthetic mesh for ventral hernia repair: The Preventing Recurrence in Clean and Contaminated Hernias randomized clinical trial

BACKGROUND

Although the most durable method for ventral hernia repairs involves using mesh, whether to use biologic mesh versus synthetic mesh remains controversial. This study aimed to compare synthetic and biologic meshes with respect to patient-reported quality of life scores and costs after ventral hernia repair surgeries.

METHODS

This study is part of the Preventing Recurrence in Clean and Contaminated Hernias (PRICE) pragmatic randomized control trial conducted from March 2014 through October 2018. Patients were randomized 1:1 to undergo ventral hernia repair using either a biologic or synthetic mesh. The coprimary outcomes were 2-year changes in Visual Analog Scale, Activities Assessment Scale, Hernia-Related Quality-of-Life Survey, and Short-Form 36 Health Survey (SF-36) quality-of-life scores from repair. The secondary outcome was the overall cost per patient.

RESULTS

Among the 165 patients included in the study, 82 were randomized to biologic meshes and 83 to synthetic meshes. There were no significant differences in the performance between the 2 mesh types with regard to quality-of-life measures using a mixed model approach. This result was consistent even when performing subgroup analysis based on wound contamination. However, nonparametric tests comparing the differences in quality-of-life measures from preoperative to 24-month postoperative timepoints revealed that the synthetic mesh group showed a greater reduction in disability than biologic mesh for the SF-36 (median [interquartile range] of 20 [5-30] vs 6 [1-20], P = .025). This difference was due to reductions in the physical role limitations (62 [0-100] vs 0 [0-50], P = .018) and the pain (38 [12-50] vs 12 [0-25], P = .012) domains of the SF-36. Overall cost per patient was greater for biologic meshes (mean [95% confidence interval] of $80,420 [$66,485-$94,355] vs $61,036 [$48,946-$73,125], P = .038), regardless of insurance type.

CONCLUSION

In this randomized clinical trial, there were no differences in changes in quality-of-life scores at the 2-year timepoint except for the SF-36, where the synthetic mesh may be associated with less pain and physical role limitations than the biologic mesh. Overall costs per patient were less for synthetic than biologic mesh.

Ventral hernia repair using bioresorbable poly-4-hydroxybutyrate mesh in clean and contaminated surgical fields: a systematic review and meta-analysis

PURPOSE

Use of biologic or synthetic mesh in hernia repair shifts is based on evolving evidence. Poly-4-hydroxybutyrate (P4HB) biosynthetic mesh is a potential alternative to biologic and synthetic mesh in ventral hernia repair (VHR). This meta-analysis assesses the efficacy of P4HB mesh in clean and contaminated surgical settings.

METHODS

Two authors searched literature on PubMed, reviewing titles and abstracts of all articles to determine inclusion eligibility. Post-operative data were compared via transformation method to convert the proportion of patients with the outcome of interest into a suitable quantity for random-effects synthesis using STATA software.

RESULTS

Initial search yielded 287 citations. Six studies were included and categorized on whether hernia repairs were conducted in clean (CDC class I) or contaminated cases (CDC class II-IV). The pooled proportion of surgical site infection (SSI), surgical site occurrence (SSO), hernia recurrence, total surgical complications, and reoperation were calculated in 391 clean and 81 contaminated cases. For clean vs. contaminated cases, the following pooled proportions were noted: SSI (2% (CI 0-7%) vs 9% (CI 0-025) (p = 0.03), SSO: 14% (CI 5-25%) vs 35% (CI 22-50%) (p = 0.006), hernia recurrence (8% (CI 1-19%) vs 4% (CI 0-12%) (p = 0.769); surgical complications (17% (CI 6-32%) vs 50% (CI 27-72%) (p = 0.009). Reoperation data were available in 298 clean cases across four studies: 5% (CI 0-15%).

CONCLUSIONS

P4HB biosynthetic mesh may be more effective than previously thought, particularly in clean wounds. P4HB may also be superior to biologic mesh when compared to clinical trial data. Further research is necessary for more direct comparison.

Outcomes of Surgical Repair of Incisional Hernia in Patients With Severe and Morbid Obesity: A Comparative Study

Introduction Incisional hernia (IH) is a common complication after open and minimal access abdominal surgery. The current practice guidelines recommend weight reduction to achieve a body mass index (BMI) < 35 kg/m2 before surgical repair of ventral hernias. However, this could be challenging to achieve, especially in emergency presentations. This study aims to assess the safety of surgical repair of IH in patients with BMI ≥35 kg/m2. Methods A retrospective comparative study has been conducted to include all patients who had surgical repair of IH on an elective and emergency basis in a UK District General Hospital. The patients were divided into two groups. Group I BMI < 35 kg/m2 and Group II with BMI ≥35 kg/m2. A comparison was made between the two groups according to demographics, comorbidities, hernia characteristics, operative data, and outcomes. Results The study included 239 patients, 181 in Group I and 58 in Group II. Morbid obesity was associated with male patients, and they were younger than Group I, p= 0.001 and 0.013, respectively. 13.8% of Group I had DM compared to 29.3% in Group II, p= 0.007. There were no significant differences in hernia characteristics or mode of surgery between the two groups. However, Group II had more overall and wound-related complications, p= <0.001 each. There were no significant differences in 30-day and 90-day mortality, recurrence rate, or 90-day readmissions. Conclusions Surgical repair of IH in patients with severe and morbid obesity is associated with more overall and wound-related complications.

How I do it: using a hammock mesh in the reconstruction of inguinal ligament during a wide en-bloc resection of a groin mesenchymal tumor

PURPOSE

In case of soft tissue sarcomas (STS), an en-bloc resection with safe margins is recommended. To ensure safe removal without tumor rupture, STS of the groin area, retroperitoneal or pelvic mesenchymal tumors may require incision or resection of the inguinal ligament. Solid reconstruction is mandatory to prevent early and late postoperative femoral hernias. We present here a new technique of inguinal ligament reconstruction.

METHODS

Between September 2020 and September 2022, patients undergoing incision and/or resection of inguinal ligaments during a wide en-bloc resection of STS of the groin area in the Department of General Surgery in Strasbourg were included. All patients had an inguinal ligament reconstruction with biosynthetic slowly resorbable mesh shaped as a hammock, pre- or intraperitoneally, associated or not with loco-regional pedicled muscular flaps.

RESULTS

A total of 7 hammock mesh reconstructions were performed. One or several flaps were necessary in 57% of cases (4 patients): either for inguinal ligament reconstruction only (n = 1), for recovering of femoral vessels (n = 1), and for both ligament reconstruction and defect covering (n = 2). The major morbidity rate was 14.3% (n = 1), related to a thigh surgical site infection due to sartorius flap infarction. After a median follow-up of 17.8 months (range 7-31), there was neither early nor late occurrence of post-operative femoral hernia.

CONCLUSIONS

This is a new surgical tool for inguinal ligament reconstruction with the implementation of a biosynthetic slowly resorbable mesh shaped as a hammock, which should be compared to other techniques.

Outcomes of Abdominal Wall Reconstruction with a Bovine versus a Porcine Acellular Dermal Matrix: A Propensity Score-Matched Analysis

BACKGROUND

Abdominal wall reconstruction (AWR) is one of the most commonly performed procedures, yet large comparative studies comparing outcomes of AWR using bovine acellular dermal matrix (BADM) and porcine acellular dermal matrix (PADM) are lacking.

METHODS

In this retrospective cohort study of patients who underwent AWR from March of 2005 to June of 2019, the primary comparative outcome measure was hernia recurrence with BADM versus PADM. The secondary outcome was the incidence of surgical-site occurrence (SSO) and surgical-site infection. A propensity score matching approach was applied to compare the clinical outcomes between the two study groups.

RESULTS

The authors identified 725 patients who underwent AWR using BADM (50.5%) or PADM (49.5%). Their mean ± SD age was 59.8 ± 11.5 years, mean body mass index was 31.4 ± 6.7 kg/m 2 , and mean follow-up time was 42 ± 29 months. With propensity score matching, 219 matched pairs were identified. Hernia recurrence rates in BADM (11.4%) and PADM (13.7%) groups did not differ significantly ( P = 0.793). SSO (26.5% versus 29.2%; P = 0.518) and SSI (13.2% versus 11%; P = 0.456) rates did not differ significantly in the PADM and BADM groups, respectively. Conditional logistic regression model and marginal Cox proportional hazards regression model determined that type of acellular dermal matrix was not significantly associated with SSOs (adjusted OR, 1.11; 95% CI, 0.74 to 1.70; P = 0.589) or hernia recurrence (adjusted hazard ratio, 0.85; 95% CI, 0.50 to 1.42; P = 0.52).

CONCLUSIONS

Both BADMs and PADMs provide durable, long-term outcomes. The hernia recurrence and postoperative surgical complication rates were not significantly different between BADM and PADM.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Biologic versus synthetic mesh in open ventral hernia repair: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Ventral hernia repair is one of the most common operations performed worldwide, and using mesh is standard of care to decrease recurrence. Biologic meshes are increasingly used to minimize complications associated with synthetic mesh, but with significantly higher cost and unclear efficacy. Until recently, most of the evidence supporting the use of biologic meshes was from retrospective cohorts with high heterogeneity and risk of bias. We aimed to report a meta-analysis of randomized controlled trials comparing the outcomes of synthetic and biologic mesh in elective open ventral hernia repair.

METHODS

A literature search of PubMed, Embase, and Cochrane Library databases was performed to identify randomized controlled trials comparing biologic and synthetic mesh in elective open ventral hernia repairs. The postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Statistical analysis was performed using RevMan 5.4. Heterogeneity was assessed with I2 statistics.

RESULTS

A total of 1,090 studies were screened, and 22 were fully reviewed. Four randomized controlled trials and 632 patients were included in the meta-analysis. Fifty-eight percent of patients had contaminated wounds (Wound Classification II-IV). Hernia recurrence (odds ratio 2.75; 95% confidence interval 1.76-4.31; P < .00001; I2 = 0%) and surgical site infections (odds ratio 1.53; 95% confidence interval 1.02-2.29; P = .04; I2 = 0%) were significantly more common in patients with biologic mesh. The rates of seroma, hematoma, and mesh removal were similar in both groups.

CONCLUSION

As compared to synthetic mesh, biologic meshes resulted in increased hernia recurrences and surgical site infections. Current evidence supports macroporous, uncoated synthetic mesh as the implant of choice for elective open ventral hernia repair, and its use should be considered even in contaminated cases.

Biological prosthesis, platelet enriched plasma and bone marrow stem cells in complicated incisional hernia reconstruction in emergency surgery: a prospective case control study

Numerous innovations have been aided by abdominal wall surgical repair. Abdominal wall surgery was drastically altered by synthetic materials. Tissue engineering was unquestionably first applied to biomaterials. The purpose of the present study is to compare different repeating approaches with rising tissue engineering complexity in repairing complex incisional hernia in emergency setting. Patients with complicated incisional hernia were prospectively included in the study and divided into 4 groups: DR (Direct Repair) group underwent direct reconstruction of the abdominal wall, BR (Biological mesh Repair) group underwent reconstruction of the abdominal wall with biological mesh (retro-muscular), BPR [Biological mesh and Platelet Enriched Plasma (PEP), gel] group underwent reconstruction of the abdominal wall with Biological mesh (retro-muscular) and PEP, BPSR (biological mesh, PEP gel and Bone Marrow Stem Cells) group underwent reconstruction of the abdominal wall with biological mesh (retromuscular), PEP and Bone Marrow Stem cells (BMSc). Forty patients were enrolled. Patients in the DR group experienced a higher rate of severe complication (p<0.05). Recurrence rates were 60% for DR patients, 20% for BM patients and 10% for the BM+PEP group (p<0.05). Median follow-up period was 64.6, 55.7 and 55.8 months (p<0.05). 7- and 30-days abdominal wall thickness is progressively increased by different techniques: BP, BP+PEP and BP+PEP+BMSc (p<0.05). No mortality was registered. Tissue engineering techniques in abdominal wall reconstruction showed promising results. They seem to reduce the recurrence rate without increasing complication one in complicated incisional abdominal wall hernia. Although many aspects are yet to be determined and standardized, it seems extremely important to continue research and experimentation in this field.

Thoracoscopic mesh implantation as a definitive treatment approach for peritoneal dialysis-associated hydrothorax

Pleuroperitoneal leakage with the formation of hydrothorax is a rare complication of peritoneal dialysis, usually necessitating termination of peritoneal dialysis. We hypothesized that implantation of a polypropylene mesh on the diaphragm using video-assisted thoracoscopic surgery might induce permanent closure of pleuroperitoneal leakage. We report a case series of n = 12 peritoneal dialysis patients with pleuroperitoneal leakage and right-sided hydrothorax who underwent video-assisted thoracoscopy with mesh implantation from 2011 to 2020. Pleuroperitoneal leakage had been confirmed before surgery by intraperitoneal administration of toluidine blue, contrast-enhanced computer tomography or glucose determination from the pleural effusion. Median time from the start of peritoneal dialysis to manifestation of pleuroperitoneal leakage was 52 days. Video-assisted thoracoscopic surgery revealed multiple penetration points in the tendinous part of the diaphragm in all patients, which appeared as blebs. These were closed by covering the whole diaphragm with a polypropylene mesh. In all patients, peritoneal dialysis was paused for three months and bridged by hemodialysis. After restarting peritoneal dialysis and a median follow-up time of 1.9 years, none of the patients experienced a recurrence of pleuroperitoneal leakage. This case series demonstrates that pleuroperitoneal leakage in peritoneal dialysis patients can be permanently closed using thoracoscopic mesh implantation and allows peritoneal dialysis to be continued as renal replacement therapy.

Graphical abstract

Outcomes of biologic versus synthetic mesh in CDC class 3 and 4 open abdominal wall reconstruction

INTRODUCTION

Abdominal wall reconstruction (AWR) in a contaminated field is associated with an increased risk of wound complications, infection, and reoperation. The best method of repair and mesh choice in these operations have generated marked controversy. Our aim was to compare outcomes of patients who underwent AWR with biologic versus synthetic mesh in CDC class 3 and 4 wounds.

METHODS

A prospective, single-institution database was queried for AWR using biologic or synthetic mesh in CDC Class 3 and 4 wounds. Hernia recurrence and complications were measured. Multivariable logistic regression was performed to identify factors predicting both.

RESULTS

In total, 386 patients with contaminated wounds underwent AWR, 335 with biologic and 51 with synthetic mesh. Groups were similar in age, sex, BMI, and rate of diabetes. Biologic mesh patients had larger hernia defects (298 ± 233cm² vs. 208 ± 155cm²; p = 0.004) and a higher rate of recurrent hernias (72.2% vs 47.1%; p < 0.001), comorbidities(5.8 ± 2.7 vs. 4.2 ± 2.4, p < 0.01), and a nearly fivefold increase in Class 4 wounds (47.8% vs. 9.8%, p < 0.001), while fascial closure trended to being less common (90.7% vs 96.1%; p = 0.078). Hernia recurrence was comparable between biologic and synthetic mesh (10.4% vs. 17.6%, p = 0.132). Wound complication rates were similar (36.1% vs. 33.3%, p = 0.699), but synthetic mesh had higher rates of mesh infection (1.2% vs 11.8%; p < 0.001) and infection-related resection (0% vs 7.8%, p < 0.001), with 66% of those synthetic mesh infections requiring excision. On logistic regression, wound complications (OR 5.96 [CI 1.60-22.17]; p = 0.008) and bridging mesh (OR 13.10 [CI 2.71-63.42];p = 0.030) predicted of hernia recurrence (p < 0.05), while synthetic mesh (OR 18.6 [CI 2.35-260.4] p = 0.012) and wound complications (OR 20.6 [CI 3.15-417.7] p = 0.008) predicted mesh infection.

CONCLUSIONS

Wound complications in AWR with CDC class 3 and 4 wounds significantly increased mesh infection and hernia recurrence; failure to achieve fascial closure also increased hernia recurrence. Use of synthetic versus biologic mesh increased the mesh infection rate by 18.6 times.

Giant Incisional Hernia Repair Using Open Intraperitoneal Dual Mesh

Aim

Giant incisional herniae are larger than 15 cm and are typically treated with an open approach. Our aim was to highlight the outcomes of treating giant incisional hernia using open intraperitoneal dual mesh.

Methods

Between January 2015 and December 2021, 25 patients with giant incisional hernias, where fascial defects were 15-30 cm, were evaluated retrospectively. Intraperitoneal dual mesh was used in all patients. The patients were evaluated in terms of age, gender, body mass index (BMI), previous abdominal surgeries, defect diameter, anesthesia method, length of hospital stay, drain application, complications, and recurrence.

Results

Eleven of the patients were male and 14 were female. The mean age was 62±13.5 years (29-82 years). The average BMI was 32 kg/m2 (20-52 kg/m2). The mean size of the fascial defect was 22±5.5 cm (15-30). The mean operation time was 90 minutes (70-130 minutes). Six patients had type I and II complications according to the Clavien-Dindo classification, specifically superficial skin infections, skin erosion, subcutaneous bleeding, and temporary ileus due to intestinal adhesion. During the average follow-up period of 36 months (6-70 months), no major complications were observed related to the recurrence and use of dual mesh.

Conclusion

In the treatment of giant incisional hernia, open intraperitoneal dual mesh application should be kept in mind as an effective treatment option with low complication and recurrence rates.

Xenogeneic Mesh Provides Safe and Durable Long-Term Outcomes in Abdominal Wall Reconstruction of High-Risk Centers for Disease Control and Prevention Class III and IV Defects

OBJECTIVE

Evaluate long-term outcomes of abdominal wall reconstruction (AWR) using xenogeneic mesh in patients with Centers for Disease Control and Prevention (CDC) class III/IV defects. We hypothesized that AWR with xenogeneic mesh results in acceptable outcomes.

BACKGROUND

Optimal mesh selection in AWR of CDC class III/IV defects is controversial. Outcomes using xenogeneic mesh are lacking.

METHODS

We conducted a retrospective cohort study of patients who underwent AWR using xenogeneic mesh in CDC class III/IV defects from March 2005 to June 2019. Primary outcome was hernia recurrence (HR). Secondary outcomes were surgical site occurrence (SSO) and surgical site infection (SSI).

RESULTS

Of consecutive 725 AWRs, we identified 101 patients who met study criteria. Sixty-eight patients had class III defects, while 33 had class IV defects. Patients had a mean age of 61.3 ± 11.1 years, mean body mass index of 31.8 ± 7.3 kg/m2, and mean follow-up time of 41.9 ± 26.3 months. Patients had HR rate of 21%, SSO rate of 49%, and SSI rate of 24. Class IV defects were predictive of SSOs (odds ratio [OR], 2.88; 95% confidence interval [CI], 1.11-7.42; P = 0.029) but not HR (hazard ratio, 1.60; 95% CI, 0.59-4.34; P = 0.355) or SSIs (OR, 2.62; 95% CI, 0.85-8.10; P = 0.094).

CONCLUSIONS

Patients with class IV defects have a higher risk of SSOs, but not HR or SSIs, compared with patients with class III defects. Despite the high level of defect contamination, AWR with xenogeneic mesh demonstrated acceptable HR, SSO, and SSI rates. Therefore, safe and durable long-term outcomes are achievable in single-stage AWR using xenogeneic mesh for CDC class III/IV defects.

BMI: does it predict the need for component separation?

PURPOSE

Patient optimization and selecting the proper technique to repair large incisional hernias is a multifaceted challenge. Body mass index (BMI) is a modifiable variable that may infer higher intra-abdominal pressures and, thus, predict the need for component separation (CS) at the time of surgery, but no data exist to support this. This paper assesses if the ratio of anterior-posterior (AP): transverse (TRSV) abdominal diameter, from pre-operative CT imaging, indicates a larger proportion of intra-abdominal fat and correlates with a hernia defect requiring a component separation for successful tension-free closure.

METHODS

Ninety patients were identified who underwent either an open hernia repair with mesh by primary closure (N = 53) or who required a component separation at the time of surgery (N = 37). Pre-operative CT images were used to measure hernia defect width, AP abdominal diameter, and TRSV abdominal diameter. Quantitative data, nominal data, and logistic regression was used to determine predictors associated with surgical group categorization.

RESULTS

The average hernia defect widths for primary closure and CS were 7.7 ± 3.6 cm (mean ± SD) and 9.8 ± 4.5, respectively (p = 0.015). The average BMI for primary closure was 33.9 ± 7.2 and 33.8 ± 4.9 for those requiring CS (p = 0.924). The AP:TRSV diameter ratios for primary closure and CS were 0.41 ± 0.08 and 0.49 ± 0.10, respectively (p < 0.001). In a multivariate analysis including both defect width and AP:TRSV diameter ratio, only AP:TRSV diameter ratio predicted the need for a CS (p = 0.001) while BMI did not (p = 0.92).

CONCLUSION

Intraabdominal fat distribution measured by AP:TRSV abdominal diameter ratio correlates with successful tension-free fascial closure during incisional hernia repair, while BMI does not.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

Incisional hernia repair by synthetic mesh prosthesis in patients with inflammatory bowel disease: a comparative analysis

Background

Patients with inflammatory bowel disease (IBD) have a high-life time risk undergoing abdominal surgery and are prone to develop incisional hernias (IH) in the postoperative course. Therefore, we investigated the role of IBD as perioperative risk factor in open ventral hernia repair (OVHR) as well as the impact of IBD on hernia recurrence during postoperative follow-up.

Methods

The postoperative course of 223 patients (Non-IBD (n = 199) and IBD (n = 34)) who underwent OVHR were compared by means of extensive group comparisons and binary logistic regressions. Hernia recurrence was investigated in the IBD group according to the Kaplan–Meier method and risk factors for recurrence determined by Cox regressions.

Results

General complications (≥ Clavien-Dindo I) occurred in 30.9% (72/233) and major complications (≥ Clavien-Dindo IIIb) in 7.7% (18/233) of the overall cohort with IBD being the single independent risk-factor for major complications (OR = 4.2, p = 0.007). Further, IBD patients displayed a recurrence rate of 26.5% (9/34) after a median follow-up of 36 months. Multivariable analysis revealed higher rates of recurrence in patients with ulcerative colitis (UC, 8/15, HR = 11.7) compared to patients with Crohn’s disease (CD, 1/19, HR = 1.0, p = 0.021).

Conclusion

IBD is a significant risk factor for major postoperative morbidity after OVHR. In addition, individuals with IBD show high rates of hernia recurrence over time with UC patients being more prone to recurrence than patients with CD.

The Effect of Adipose-Derived Stromal Vascular Fraction Cells to Abdominal Wall Fascia Defects in Rats: An Experimental Study

OBJECTIVE

Various synthetic and biological meshes have been developed to reduce recurrence and complications in ventral incisional hernia repairs. Adipose tissue is a rich reserve for mesenchymal stromal cells. In the present study we aimed to examine the effects of adipose-derived mesenchymal stromal cells (AD-MSCs) on abdominal incisional hernia repairs in rats.

MATERIALS AND METHODS

The study involved 32 male Wistar-Albino rats, weighing 200-250 g, which were divided into three groups. In Group 1 (control group) only an incisional hernia model was created. In Group 2, the incisional hernia model was created and 1 ml stromal vascular fraction (SVF), obtained from inguinal lipectomy material and containing mesenchymal stromal cells, was injected into the edges of the defect in the same session. In Group 3, only the incisional hernia model was created in the first stage and after 14 days, 1 ml of SVF was injected into the edges of the defect. Skin incisions of rats in Group 1 and 2 were opened on postoperative day 28 while in group 3 were opened on day 42. Peritoneal formation in abdominal wall defect was evaluated macroscopically and histopathologically.

RESULTS

Peritoneal formation was significantly superior in Groups 2 and 3 than in Group 1 (p: 0.031). In histopathological evaluation, the structural distortion and polymorphonuclear leukocyte (PMNL) levels were significantly higher in Group 1 than in Group 3 (p: 0.048 and p: 0.046, respectively). Granulation, capillary density, fibrosis and collagen organization were higher in Group 2 and 3, however this difference was not statistically significant (p > 0.05).

CONCLUSIONS

Adipose-derived stromal vascular fraction cells obtained from inguinal lipectomy material in rats positively affect the repair of abdominal incisional hernias by increasing peritoneal formation, and reducing structural distortion and PMNL infiltration.

Biologic mesh is non-inferior to synthetic mesh in CDC class 1 & 2 open abdominal wall reconstruction

BACKGROUND

Biologic mesh has historically been used in contaminated abdominal wall reconstructions (AWRs). No study has compared outcomes of biologic and synthetic in clean and clean-contaminated hernia ventral hernia repair.

METHODS

A prospective AWR database identified patients undergoing open, preperitoneal AWR with biologic mesh in CDC class 1 and 2 wounds. Using propensity score matching, a matched cohort of patients with synthetic mesh was created. The objective was to assess recurrence rates and postoperative complications.

RESULTS

Fifty-eight patients were matched in each group. Patient in the biologic group had higher rates of immunosuppression, history of transplantation, and inflammatory bowel disease (p ≤ 0.05). Operative variables were comparable for biologic vs synthetic, including defect size (230.5 ± 135.4 vs 268.7 ± 194.5 cm², p = 0.62), but the synthetic mesh group had larger meshes placed (575.6 ± 247.0 vs 898.8 ± 246.0 cm² p < 0.0001). Wound infections (15.5% vs 8.9%, p = 0.28) were equivalent, and recurrence rates (1.7% vs 3.4%, p = 1.00) were similar on follow up (19.3 ± 23.3 vs 23.3 ± 29.7 months, p = 0.56).

CONCLUSIONS

In matched, lower risk, complex AWR patients with large hernia defects, biologic and synthetic meshes have equal outcomes.

Giant omphalocele: Delayed closure using the San Martin technique following epithelialization of the membrane

AIM

The management of patients with congenital anterior abdominal wall defects remains challenging, particularly in cases of giant omphalocele. In 1948, San Martín described a surgical technique for the repair of large midline incisional hernias in adults without the need for a mesh. The purpose of this report is to describe our experience with this technique for the delayed closure of giant omphaloceles.

METHODS

We retrospectively reviewed the outcomes of all patients with giant omphalocele managed with the San Martin technique between September 2013 and March 2019. Data collected included birth weight, gestational age, associated malformations, neonatal hospital stay, age at the time of the abdominal wall closure, days on mechanical ventilation (MV) after the closure, time to initiation of enteral feedings, intra- and postoperative complications, and postoperative hospital stay.

RESULTS

A total of 8 patients were included in the study. The median birth weight was 3.190 (2.150 to 3.400) grams. The median gestational age was 35 (32 to 38) weeks. The median age at surgery was 6 (5 to 13) years. The median postoperative days on MV was 3 (3 to 11) days. Enteral feeding were initiated postoperatively at a median of 4 (2 to 4) days. There was one intraoperative complication (minor vascular injury). There were no short-term or long-term complications directly related to the surgical technique. The median postoperative hospital stay was 10 (6 to 16) days. The follow-up was 18 months to 8 years.

CONCLUSION

We believe that the San Martín technique is a valid alternative for the delayed closure of giant omphaloceles.

LEVEL OF EVIDENCE

According to the Journal of Pediatric Surgery this research corresponds to type of study level IV for case series with no comparison group.

Prevention of incisional hernia at the site of stoma closure with different reinforcing mesh types: a systematic review and meta-analysis

PURPOSE

To evaluate safety and efficacy of a mesh reinforcement following stoma reversal to prevent stoma site incisional hernia (SSIH) and differences across the prostheses used.

METHODS

A systematic search of PubMed/MEDLINE, EMBASE, SCOPUS and Cochrane databases was conducted to identify comparative studies until September 2020. A meta-analysis of postoperative outcomes and a network meta-analysis for a multiple comparison of the prostheses with each other were performed.

RESULTS

Seven studies were included in the analysis (78.4% ileostomy and 21.6% colostomy) with a total of 1716 patients with (n = 684) or without (n = 1032) mesh. Mesh placement was associated with lower risk of SSIH (7.8%vs18.1%, OR0.266,95% CI 0.123-0.577, p < 0.001) than no mesh procedures but also with a longer operative time (SMD 0.941, 95% CI 0.462-1.421, p < 0.001). There was no statistically significant difference in terms of Surgical Site infection (11.5% vs 11.1%, OR 1.074, 95% CI 0.78-1.48, p = 0.66), seroma formation (4.4% vs 7.1%, OR 1.052, 95% CI 0.64-1.73, p = 0.84), anastomotic leakage (3.7% vs 2.7%, OR 1.598, 95% CI 0.846-3.019, p = 0.149) and length of stay (SMD - 0.579,95% CI - 1.261 to 0.102, p = 0.096) between mesh and no mesh groups. Use of prosthesis was associated with a significant lower need for a reoperation than no mesh group (8.1% vs 12.1%, OR 0.332, 95% CI 0.119-0.930, p = 0.036). Incidence of seroma is lower with biologic than polypropylene meshes but they showed a trend towards poor results compared with polypropylene or biosynthetic meshes.

CONCLUSION

Despite longer operative time, mesh prophylactic reinforcement at the site of stoma seems a safe and effective procedure with lower incidence of SSIH, need for reoperation and comparable short-term outcomes than standard closure technique. A significant superiority of a specific mesh type was not identified.

Experimental Study Comparing Structural Changes Induced by Biologic Versus Synthetic Mesh Implants in Nephropexy

Background: The study suggests that the use of the extracellular bovine-derived peritoneum matrix as a new biological implant opens up new prospects for nephropexy. Materials and Methods: Experimental nephropexy was performed in 64 white shorthaired adult rats, divided for 2 groups: extracellular bovine-derived peritoneum matrix, UltraPro mesh. Implants were 1,5*1,5cm per one animal. Observation periods were 7, 21, 30 and 180 days. The tissue was stain with H&E, Van Gieson’s with pikro-fuchin. Cellular infiltrate was evaluated by counting granulocytes, mononuclear cells, and foreign-body giant cells on five high-magnification images for each stained section (×400). Results: The use of the extracellular bovine-derived peritoneum matrix induced less intense and less prolonged chronic inflammatory response, as well as intense production of new collagen fibers more similar to the native connective tissue in terms of their histologic structure. The UltraPro mesh induced moderately persistent chronic inflammatory response throughout the 6- month study period. Conclusion: Histologic evaluation demonstrates high biocompatibility of both the extracellular bovine-derived peritoneum matrix, and the UltraPro mesh implants.The results of using  new biological material are not worse than synthetic mesh. The data obtained justify further research of the extracellular bovine-derived peritoneum matrix as a plastic material for nephropexy.

Ventral hernia repair with synthetic mesh in a contaminated field: a systematic review and meta-analysis

PURPOSE

The use of mesh in ventral hernia repair becomes especially challenging when associated with a contaminated field. Permanent synthetic mesh use in this setting is currently debated and this discussion is yet to be resolved clinically or in the literature. We aim to systematically assess postoperative outcomes of non-absorbable synthetic mesh (NASM) used in ventral hernia repair in the setting of contamination.

METHODS

A literature search of PubMed, Embase, Scopus, Cinahl, and Cochrane Library identified all articles from 2000-2020 that examined the use of NASM for ventral hernia repair in a contaminated field. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Qualitative analysis was completed for all included studies using a modified Newcastle-Ottawa scale.

RESULTS

Of 630 distinct publications and 104 requiring full review, this study included 17 articles published between 2007 and 2020. Meta-analysis demonstrated absorbable mesh was associated with more HR (OR 1.89, 1.15-3.12, p = 0.008), SSO (OR 1.43, 0.96-2.11, p = 0.087), SSI (OR 2.84, 1.85-4.35, p < 0.001), and unplanned reoperation (OR 1.99, 1.19-3.32, p = 0.009) compared to NASM.

CONCLUSION

The use of NASM for ventral hernia repair in a contaminated field may be a safe alternative to absorbable mesh, as evidenced by lower rates of postoperative complications. This review counters the current clinical paradigm, and additional prospective randomized controlled trials are warranted.

Biologic Mesh in Surgery: A Comprehensive Review and Meta-Analysis of Selected Outcomes in 51 Studies and 6079 Patients

BACKGROUND

In recent decades, biologic mesh (BM) has become an important adjunct to surgical practice. Recent evidence-based clinical applications of BM include but are not limited to: reconstruction of abdominal wall defects; breast reconstruction; face, head and neck surgery; periodontal surgery; other hernia repairs (diaphragmatic, hiatal/paraesophageal, inguinal and perineal); hand surgery; and shoulder arthroplasty. Prior systematic reviews of BM in complex abdominal wall hernia repair had several shortcomings that our comprehensive review seeks to address, including exclusion of laparoscopic repair, assessment of risk of bias, use of an acceptable meta-analytic method and review of risk factors identified in multivariable regression analyses.

MATERIALS AND METHODS

We sought articles of BM for open ventral hernia repair reporting on early complications, late complications or recurrences and included minimum of 50. We used the quality in prognostic studies risk of bias assessment tool. Random effects meta-analysis was applied.

RESULTS

This comprehensive review selected 62 articles from 51 studies that included 6,079 patients. Meta-analytic pooling found that early complications are present in about 50%, surgical site occurrences (SSOs) in 37%, surgical site infections (SSIs) in 18%, reoperation in 7%, readmission in 20% and mortality in 3%. Meta-analytic estimates of late outcomes included overall complications (42%), SSOs (40%) and SSIs (22%). Specific SSOs included seroma (14%), hematoma (4%), abscess (10%), necrosis (5%), dehiscence (8%) and fistula formation (5%). Reoperation occurred in about 17%, mesh explantation in 9% and recurrence in 36%.

CONCLUSION

Estimates of nearly all outcomes from individual studies were highly heterogeneous and sensitivity analyses and meta-regressions generally failed to explain this heterogeneity. Recurrence is the only outcome for which there are consistent findings for risk factors. Bridge placement of BM is associated with higher risk of recurrence. Prior hernia repair, history of reintervention and history of mesh removal were also risk factors for increased recurrence.

Human Primary Dermal Fibroblasts Interacting with 3-Dimensional Matrices for Surgical Application Show Specific Growth and Gene Expression Programs

Several types of 3-dimensional (3D) biological matrices are employed for clinical and surgical applications, but few indications are available to guide surgeons in the choice among these materials. Here we compare the in vitro growth of human primary fibroblasts on different biological matrices commonly used for clinical and surgical applications and the activation of specific molecular pathways over 30 days of growth. Morphological analyses by Scanning Electron Microscopy and proliferation curves showed that fibroblasts have different ability to attach and proliferate on the different biological matrices. They activated similar gene expression programs, reducing the expression of collagen genes and myofibroblast differentiation markers compared to fibroblasts grown in 2D. However, differences among 3D matrices were observed in the expression of specific metalloproteinases and interleukin-6. Indeed, cell proliferation and expression of matrix degrading enzymes occur in the initial steps of interaction between fibroblast and the investigated meshes, whereas collagen and interleukin-6 expression appear to start later. The data reported here highlight features of fibroblasts grown on different 3D biological matrices and warrant further studies to understand how these findings may be used to help the clinicians choose the correct material for specific applications.

Outcomes of Poly-4-hydroxybutyrate Mesh in Ventral Hernia Repair: A Systematic Review and Pooled Analysis

Within the past decade, poly-4-hydroxybutyrate (P4HB) biosynthetic mesh has been introduced as a potential alternative to traditional biologic and synthetic mesh in ventral hernia repair (VHR). The aim of this study was to systematically assess clinical outcomes with the P4HB in VHR.

Methods

A literature search identified all articles published in 2000 involving the use of P4HB in VHR. Descriptive statistics were used to synthesize collective data points, including postoperative outcomes. A pooled analysis of postoperative outcomes was performed using chi-square test and Fisher exact test.

Results

Across 7 studies, the P4HB was used in 453 patients. The mean rate of surgical site infection (SSI) was 6.8% (31/453), reoperation 10.7% (30/281), and recurrence 9.1% (41/453). At an average follow-up of 26.8 months, the incidence of recurrence was 10.4% (28/270). Onlay was significantly associated with increased recurrence (14.2% versus 4.4%, P = 0.001). Among sublay placements, there was no difference in recurrence in clean (Center for Disease Control [CDC] 1) or contaminated (CDC >1) wounds (2.7% versus 6.1%, P = 0.585), but contaminated wounds were associated with increased SSI (2.7% versus 15.2%, P = 0.028). Ventral Hernia Working Group grade 2 and 3 did not have different incidences of recurrence (8.0% versus 5.1%, P = 0.526) nor SSI (5.1% versus 14.6%, P = 0.265).

Conclusions

Overall, clinical outcomes of the P4HB mesh in VHR are acceptable. The P4HB mesh serves as a reliable alternative to traditional synthetic and biologic mesh across a range of defect characteristics and patient health conditions. Further research is needed to better understand the conditions in which it may provide a clinical benefit over traditional mesh types.

Poly-4-hydroxybutyrate (Phasix™) mesh onlay in complex abdominal wall repair

BACKGROUND

Poly-4-hydroxybutyric acid (P4HB, Phasix™) is a biosynthetic polymer that degrades by hydrolysis that can be woven into a mesh for use in soft tissue reinforcement. Herein, we describe our initial experience performing complex abdominal wall repair (CAWR) utilizing component separation and P4HB mesh as onlay reinforcement.

METHODS

All patients undergoing CAWR between June 2014 and May 2017 were followed prospectively for postoperative outcomes. Only those patients who underwent components separation with primary repair of the fascial edges followed by onlay of P4HB mesh were included in this study.

RESULTS

105 patients (52 male, 53 female; mean age 59.2 years, range 22-84) met inclusion criteria. Mean BMI was 29.1 (range 16-48); 52% patients had prior attempted hernia repair, most with multiple medical comorbidities (71% of patients with ASA 3 or greater). 30% of cases were not clean at the time of repair (CDC class 2 or greater). Median follow-up was 36 months (range 9-63). Eighteen patients (17%) developed a hernia recurrence ranging from 2 to 36 months postoperatively. Five (5%) patients developed a localized superficial infection treated with antibiotics, three (2.8%) required re-operation for non-healing wounds, and six (6%) patients developed seroma.

CONCLUSIONS

These data demonstrate a relatively low rate of hernia recurrence, seroma, and other common complications of CAWR in a highly morbid patient population. Importantly, the rate of mesh infection was low and no patients required complete mesh removal, even when placed into a contaminated or infected surgical field.

Differential recurrence after laparoscopic incisional hernia repair: importance of a nationwide registry-based mesh surveillance

BACKGROUND

Identification of suboptimal mesh products is essential to improve the outcome after hernia surgery. This study investigated whether a national clinical database combined with administrative registries may serve as a tool for postmarketing evaluation of mesh products for hernia surgery.

METHODS

This was a propensity score-matched case-control cohort study comparing outcomes in patients undergoing laparoscopic incisional hernia repair with either one particular mesh or any other synthetic mesh. Data on patients registered in the Danish Ventral Hernia Database between 2010 and 2016 were combined with administrative data from the Danish National Patient Registry. The primary outcome was operation for recurrence. Secondary outcomes were 30-day readmission, 30-day reoperation for complications (excluding hernia recurrence), and mortality after 30 and 90 days.

RESULTS

In total, 740 patients who underwent repair with one particular mesh were matched with 1479 patients who received any other synthetic mesh. The rate of repair for hernia recurrence was significantly higher in the particular mesh group than in the reference group: 12·8 versus 6·3 per cent respectively (hazard ratio 2·09, 95 per cent c.i. 1·57 to 2·79; P < 0·001). Use of the particular mesh increased the risk of readmission (odds ratio (OR) 1·53, 1·16 to 2·01; P = 0·002) and reoperation for a complication (OR 1·60, 1·03 to 2·47, P = 0·030). No difference in mortality was found.

CONCLUSION

Clinical registries with prospectively collected data can provide long-term surveillance of commercial mesh. Laparoscopic incisional hernia repair with one particular mesh was associated with an increased rate of short-term complications and double the risk of repair for recurrence.

Guidelines for treatment of umbilical and epigastric hernias from the European Hernia Society and Americas Hernia Society

BACKGROUND

Umbilical and epigastric hernia repairs are frequently performed surgical procedures with an expected low complication rate. Nevertheless, the optimal method of repair with best short- and long-term outcomes remains debatable. The aim was to develop guidelines for the treatment of umbilical and epigastric hernias.

METHODS

The guideline group consisted of surgeons from Europe and North America including members from the European Hernia Society and the Americas Hernia Society. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach, the Scottish Intercollegiate Guidelines Network (SIGN) critical appraisal checklists, and the Appraisal of Guidelines for Research and Evaluation (AGREE) instrument were used. A systematic literature search was done on 1 May 2018, and updated on 1 February 2019.

RESULTS

Literature reporting specifically on umbilical and epigastric hernias was limited in quantity and quality, resulting in a majority of the recommendations being graded as weak, based on low-quality evidence. The main recommendation was to use mesh for repair of umbilical and epigastric hernias to reduce the recurrence rate. Most umbilical and epigastric hernias may be repaired by an open approach with a preperitoneal flat mesh. A laparoscopic approach may be considered if the hernia defect is large, or if the patient has an increased risk of wound morbidity.

CONCLUSION

This is the first European and American guideline on the treatment of umbilical and epigastric hernias. It is recommended that symptomatic umbilical and epigastric hernias are repaired by an open approach with a preperitoneal flat mesh.

The in vivo biocompatibility of titanized polypropylene lightweight mesh is superior to that of conventional polypropylene mesh

OBJECTIVE

To evaluate the histological response to and changes in the biomechanical properties of titanized polypropylene lightweight mesh and conventional polypropylene mesh at 1 and 12 weeks following implantation in the sheep vagina.

METHODS

We compared a titanized polypropylene lightweight mesh (TiLOOP Mesh) to a conventional polypropylene mesh (Gynemesh PS) in a sheep vagina model. Explants were harvested after 1 and 12 weeks (n = 6/mesh type/time point) for histological observation. After 12 weeks, mesh-tissue complex specimens were biomechanically assessed by a uniaxial tension system.

RESULTS

One week after implantation, there was no significant difference in the inflammatory response between the two groups. Twelve weeks after implantation, the TiLOOP light mesh elicited a lower inflammatory response than was observed for the Gynemesh PS (1.44 ± 0.61 vs 2.05 ± 0.80, P = .015). Twelve weeks after implantation, the collagen I/III ratio was lower in the TiLOOP light mesh group than in the Gynemesh PS group (9.41 ± 5.06 vs 15.21 ± 8.21, P = .019). The messenger RNA expression levels of the inflammatory factors interleukin 10 and tumor necrosis factor α were lower in the TiLOOP Mesh group than in the Gynemesh PS group at both 1 and 12 weeks (P < .05). There were no significant differences in any of the evaluated biomechanical characteristics between the two meshes (P > .05).

CONCLUSION

Although the titanized polypropylene lightweight mesh induces slightly less tissue reactivity and has better in vivo biocompatibility, further studies should be conducted including the complications and the success rate of pelvic organ prolapse in patients before recommending it in pelvic floor reconstruction.

Abdominal skin tensile strength in aesthetic and massive weight loss patients and its role in ventral hernia repair

Background

Clarifying the biomechanics of abdominal skin could lead to different uses for this tissue such as the ventral repair of hernias in patients with excess skin and incisional hernias. The objective of this study was to compare the maximum tensile strength of abdominal skin to commercial meshes and to verify whether or not it varies between aesthetic patients and massive weight-loss patients.

Methods

Experimental cross-sectional study. Skin samples sized 32 × 20 mm were taken from 15 abdominoplasties and 10 panniculectomies. The skin specimens were analyzed in vertical and horizontal tensile strength tests. Results were compared between the two groups including their traction directions. Commercial meshes were also tested. The results were analyzed using the Generalized Estimating Equation.

Results

The maximum tensile strength supported vertically by abdominal dermis was 403.5 ± 27.4 N in the abdominoplasty group and 425.9 ± 33.9 N in the panniculectomy group. Horizontally, the values were 596.5 ± 32.2 N and 612.5 ± 43.9 N respectively. The strengths between traction directions were significantly different (p < 0.001). There were no differences between the groups with regard to the maximum tensile strength (p = 0.472). Tested commercial meshes had the following values: polypropylene 104.6 N, low-weight polypropylene 54.4 N, polytetrafluorethylene (PTFE) 82.2 N, and hydrated porcine small-intestinal submucosa 60.0 N.

Conclusion

In our study, the tensile strength of the tested human abdominal dermis samples, both aesthetic and post-bariatric, was superior to the commercial meshes. Therefore, in selected cases, abdominal dermis could be an alternative tool in abdominal reconstruction during panniculectomies with concomitant hernia repair.

Electronic supplementary material

The online version of this article (10.1186/s12893-019-0523-7) contains supplementary material, which is available to authorized users.

Non-Cross-Linked Collagen Mesh Performs Best in a Physiologic, Noncontaminated Rat Model

BACKGROUND

In laparoscopic incisional hernia repair, direct contact between the prosthesis and abdominal viscera is inevitable and may lead to adhesions. Despite the large variety of mesh prosthesis, little is known about their in vivo behavior. Biological meshes are considered to have many advantages, but due to their price they are rarely used. A rat model was used to assess biological and conventional synthetic meshes on their in vivo characteristics.

DESIGN

One-hundred twenty male Wistar rats were randomized into five groups of 24 rats. A mesh was implanted intraperitoneally and fixated with nonresorbable sutures. The following five meshes were implanted: Parietene (polypropylene), Permacol (cross-linked porcine acellular dermal matrix), Strattice (non-cross-linked porcine acellular dermal matrix), XCM Biologic (non-cross-linked porcine acellular dermal matrix), and Omyra Mesh (condensed polytetrafluoroethylene). The rats were sacrificed after 30, 90, or 180 days. Incorporation, shrinkage, adhesions, abscess formation, and histology were assessed for all meshes.

RESULTS

All animals thrived postoperatively. After 180 days, Permacol, Parietene, and Omyra Mesh had a significantly better incorporation than Strattice ( P = .001, P = .019, and P = .037 respectively). After 180 days, Strattice had significantly fewer adhesions on the surface of the mesh than Parietene ( P < .001), Omyra Mesh ( P = .011), and Permacol ( P = .027). After 30 days, Permacol had significantly stronger adhesions than Strattice ( P = .030). However, this difference was not significant anymore after 180 days. After 180 days, there was significantly less shrinkage in Permacol than in Strattice ( P = .001) and Omyra Mesh ( P = .050).

CONCLUSION

Based on incorporation, adhesions, mesh shrinkage, and histologic parameters, Strattice performed best in this experimental rat model.

Experimental study of a new original mesh developed for pelvic floor reconstructive surgery

INTRODUCTION AND HYPOTHESIS

Most synthetic meshes used in transvaginal surgery are made of polypropylene, which has a stable performance, but does not easily degrade in vivo. However, mesh-related complications are difficult to address and have raised serious concerns. A new biomaterial mesh with good tissue integration and few mesh-related complications is needed. To evaluate the effect of a new bacterial cellulose (BC) mesh on pelvic floor reconstruction following implantation in the vagina of sheep after 1 and 12 weeks.

METHODS

The meshes were implanted in the submucosa of the posterior vagina wall of sheep. At 1 and 12 weeks after surgery, mesh-tissue complex (MTC) specimens were harvested for histological studies and biomechanical evaluation. At 12 weeks after surgery, MTC specimens were biomechanically assessed by a uniaxial tension "pulley system".

RESULTS

The BC mesh elicited a higher inflammatory response than Gynemesh™PS at both 1 and 12 weeks after implantation. Twelve weeks after implantation, the BC mesh resulted in less fibrosis than Gynemesh™PS. Compared with the Gynemesh™PS group, the BC mesh group had increased mRNA expression of MMP-1, MMP-2, and MMP-9 (P < 0.05), but decreased expression of the anti-inflammatory factor IL-4 (P < 0.05). Twelve weeks after implantation, the ultimate load and maximum elongation percentage of the BC mesh were significantly lower than those of Gynemesh™PS.

CONCLUSIONS

The BC mesh could not be a promising biomaterial for pelvic floor reconstructive surgery unless the production process and parameters were improved.

A novel tool to evaluate bias in literature on use of biologic mesh in abdominal wall hernia repair

PURPOSE

Biologic meshes are being increasingly used for abdominal hernia repair in high-risk patients or patients with a previous history of wound infection, due to their infection-resistant properties. Several studies have been carried out to assess whether biologic mesh is superior to synthetic mesh, as well as to establish guidelines for their use. Unfortunately, most of these studies were not rigorously designed and were vulnerable to different types of bias. The systematic reviews that have been published so far on this topic contain the same biases and limitations of the primary articles that are analyzed. The lack of a literature review on the bias on the use of biological mesh prompted us to conduct the literature search, assessment and plan this article.

METHODS

We performed a literature search in PubMed, Embase and Cochrane databases of systematic reviews on biologic mesh for ventral hernia repair. The literature review was conducted using the Population, Intervention, Comparisons, Outcomes and Design approach. We identified 40 studies that matched the stringent criteria we had set. We then created a 13-point instrument to assess for bias and applied it on the primary studies that we intended to analyze.

RESULTS

Most primary studies are case series or case reports of patients undergoing abdominal hernia repair with biologic mesh, without any comparison group, and the inclusion of cases was only specified to be consecutive in 6 out of 40 cases. In terms of assessing outcomes, in none of the 40 articles were the outcome assessors blinded to the intervention or exposure status of participants.

CONCLUSION

The instrument that we created could allow to assess the risk of bias in different kind of studies. Our assessment of the studies based on the criteria that we had set up in the instrument clearly identified that further research needs to be done due to the lack of unbiased studies regarding the use of biologic meshes for abdominal hernia repair.

Laparoscopic ventral hernia repair with intraperitoneal onlay mesh-results from a general surgical unit

BACKGROUND

Symptomatic ventral herniation is a common clinical presentation. The treatment, whether elective or as an emergency, can be difficult and a variety of surgical repairs are utilised. Intraperitoneal onlay mesh (IPOM) involves the placement of a reinforcing prosthesis, usually supported by primary closure of the defect. Intra-abdominal adhesions have been highlighted as a potential complication in utilising this form of mesh placement. Several methods of laparoscopic mesh placement outside of the peritoneal cavity are gaining prominence as potential alternatives to IPOM.

AIMS

This study reviews our experience with IPOM in the repair of ventral hernia by a single surgical team.

METHODS

A prospectively maintained electronic database of all laparoscopic ventral hernia repair (LVHR) performed within the study period was analysed and reported. Follow-up questionnaires were sent to patients to follow long-term outcomes.

RESULTS

One hundred eight patients underwent LVHR over a 7-year period. Demographics demonstrated an obese patient group (BMI 30.89 ± 4.9 kg/m²), with a variety of hernia sizes and morphologies. Hernia recurrence was found in two patients (1.8%). Twenty-nine (26.8%) patients suffered a complication, but only eight (7.4%) of those required intervention beyond pharmacotherapy. Two patients required mesh explantation.

CONCLUSIONS

IPOM for the general surgeon is a relatively safe and effective method of repairing ventral hernias, with a low recurrence rate.

Controversies and Techniques in the Repair of Abdominal Wall Hernias

Abdominal wall hernia repair is one of the most common operations done by general surgeons today. Patients with incisional hernias can be extremely challenging to manage due to a number of factors that include obesity, prior hernia repairs, previous mesh placement, loss of domain, and other variables. The approach to patients with incisional hernias has evolved considerably over the last 20 years due to both advances in mesh technology and surgical approaches. Key factors in a successful outcome include modification of risk factors prior to surgery such as smoking cessation and weight reduction, selection of mesh appropriate to the hernia type and planned location of the mesh, and broad overlap of mesh beyond the margins of the hernia defect. Newer techniques such as transabdominis release and component separation with retrorectus mesh placement and robotic approaches to abdominal wall hernia are being increasingly utilized in these patients. This article reviews these aspects of abdominal wall hernia repair with a discussion of recent results and the importance of quality improvement and monitoring of outcomes.

Biodegradable hyaluronan hydrogel coatings on acellular dermis grafts-A potential strategy to improve biologic graft durability in hernia repair application

Biologic grafts used in hernia repair undergo rapid cellular infiltration and remodeling, but their premature degradation often results in hernia recurrence. We hypothesize that a temporary barrier that prevents infiltration of acute inflammatory cells into the graft during the initial 4 weeks of implantation could mitigate graft degradation. The purpose of this study is to design tyramine-substituted hyaluronan (THA) hydrogel coatings with tunable degradation properties, as a means to develop a resorbable barrier for human acellular dermis grafts (HADM). THA plugs prepared at different cross-linking densities, by varying cross-linking agent concentration (0.0001-0.0075% H₂ O₂ ), demonstrated varying rates of in vitro degradation (25 U/mL hyaluronidase, 48 h). Based on these results, HADM grafts were coated with THA at three cross-linking densities (0.0001%, 0.00075%, and 0.003% H₂ O₂ ) and THA coating degradation was evaluated in vitro (25 U/mL hyaluronidase, 48 h) and in vivo (rat intraperitoneal implantation, 1-4 weeks). THA coatings degraded in vitro and in vivo with the lowest cross-linking density (0.0001% H₂ O₂ ), generally showing greater degradation as evidenced by significant decrease in coating cross-sectional area. However, all three coatings remained partially degraded after 4 weeks of in vivo implantation. Alternate strategies to accelerate in vivo degradation of THA coatings are required to allow investigation of the study hypothesis. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2664-2672, 2019.

Biocellulose for Incisional Hernia Repair-An Experimental Pilot Study

Ventral or incisional hernia are a common disease pattern in general surgery. Mostcommonly, a mesh repair is used for reconstruction, whereby the mesh itself might causecomplications, like infections or adhesions. Biological materials, like biocellulose, might reducethese clinical problems substantially. In this prospective rodent study, a biocellulose mesh(produced by Gluconacetobacter xylinus) was implanted either by a sublay technique or assupplementation of the abdominal wall. After an observation period of 90 days, animals weresacrificed. The adhesions after the reconstruction of the abdominal wall were moderate. Thehistologic investigations revealed that the biocellulose itself was inert, with a minimal regenerativeresponse surrounding the mesh. The explanted mesh showed a minimal shrinkage (around 15%) aswell as a minimal loss of tear-out force, which might be without clinical relevance. This is the firstin vivo study describing biocellulose as a suitable mesh for the repair of ventral hernia in twodifferent hernia models. The material seems to be a promising option for solving actual problems inmodern hernia surgery.