Long-term outcomes after contaminated complex abdominal wall reconstruction

Double-Layer Asymmetric Porous Mesh with Dynamic Mechanical Support Properties Enables Efficient Single-Stage Repair of Contaminated Abdominal Wall Defect

Contamination tolerance and long-term mechanical support are the two critical properties of meshes for contaminated abdominal wall defect repair. However, biological meshes with excellent pollution tolerance fail to provide bio-adaptive long-term mechanical support due to their rapid degradation. Here, a novel double-layer asymmetric porous mesh (SIS/PVA-EXO) is designed by simple and efficient in situ freeze-thaw of sticky polyvinyl alcohol (PVA) solution on the loosely porous surface of small intestinal submucosal decellularized matrix (SIS), which can successfully repair the contaminated abdominal wall defect with bio-adaptive dynamic mechanical support through only single-stage surgery. The exosome-loaded degradable loosely porous SIS layer accelerates the tissue healing; meanwhile, the exosome-loaded densely porous PVA layer can maintain long-term mechanical support without any abdominal adhesion. In addition, the tensile strength and strain at break of SIS/PVA-EXO mesh change gradually from 0.37 MPa and 210% to 0.10 MPa and 385% with the degradation of SIS layer. This unique performance can dynamically adapt to the variable mechanical demands during different periods of contaminated abdominal wall reconstruction. As a result, this SIS/PVA-EXO mesh shows an attractive prospect in the treatment of contaminated abdominal wall defect without recurrence by integrating local immune regulation, tissue remodeling, and dynamic mechanical supporting.

Five-Year Follow-Up of a Slowly Resorbable Biosynthetic P4HB Mesh (Phasix) in VHWG Grade 3 Incisional Hernia Repair

Objective

To assess the 5-year recurrence rate of incisional hernia repair in Ventral Hernia Working Group (VHWG) 3 hernia with a slowly resorbable mesh.

Summary Background Data

Incisional hernia recurs frequently after initial repair. In potentially contaminated hernia, recurrences rise to 40%. Recently, the biosynthetic Phasix mesh has been developed that is resorbed in 12-18 months. Resorbable meshes might be a solution for incisional hernia repair to decrease short- and long-term (mesh) complications. However, long-term outcomes after resorption are scarce.

Methods

Patients with VHWG grade 3 incisional midline hernia, who participated in the Phasix trial (Clinilcaltrials.gov: NCT02720042) were included by means of physical examination and computed tomography (CT). Primary outcome was hernia recurrence; secondary outcomes comprised of long-term mesh complications, reoperations, and abdominal wall pain [visual analogue score (VAS): 0-10].

Results

In total, 61/84 (72.6%) patients were seen. Median follow-up time was 60.0 [interquartile range (IQR): 55-64] months. CT scan was made in 39 patients (68.4%). A recurrence rate of 15.9% (95% confidence interval: 6.9-24.8) was calculated after 5 years. Four new recurrences (6.6%) were found between 2 and 5 years. Two were asymptomatic. In total, 13/84 recurrences were found. No long-term mesh complications and/or interventions occurred. VAS scores were 0 (IQR: 0-2).

Conclusions

Hernia repair with Phasix mesh in high-risk patients (VHWG 3, body mass index >28) demonstrated a recurrence rate of 15.9%, low pain scores, no mesh-related complications or reoperations for chronic pain between the 2- and 5-year follow-up. Four new recurrences occurred, 2 were asymptomatic. The poly-4-hydroxybutyrate mesh is a safe mesh for hernia repair in VHWG 3 patients, which avoids long-term mesh complications like pain and mesh infection.

Poly-4-hydroxybutyrate Mesh for Ventral Hernia Repairs: A Single-Surgeon Experience

Background

Poly-4-hydroxybutyrate (P4HB) (Phasix) biosynthetic mesh was recently introduced as an alternative to synthetic and biologic meshes for ventral hernia repair (VHR). However, outcomes data are limited. This study aims to analyze outcomes of VHR with P4HB mesh and identify predictors of postoperative outcomes.

Methods

We performed a retrospective study of adults who underwent open VHR with P4HB by the senior author from 2014 to 2020 with >12 months' follow-up. Subgroup comparisons and multivariate logistic regression were performed.

Results

Inclusion criteria were met by 169 patients with a median of 15 months of follow-up. Overall, 21.9% had surgical site occurrences, 17.8% required reoperation, and 4.7% had recurrences. Patients with prior VHR (47.9%) experienced similar outcomes to those without. Patients with prior mesh infection (18.3%) had higher rates of postoperative mesh infection (6.5% vs 0.7%; P = .029) but did not have higher rates of reoperation. Retrorectus repairs (45.5%) had similar outcomes to onlay repairs (54.5%). Recurrence risk was increased by hypertension (odds ratio [OR] = 13.64; P = .046), immunosuppression (OR = 42.57; P = .004), and history of prior VHR (OR = 20.20; P = .014).

Conclusions

This study aimed to analyze outcomes of VHR augmented with P4HB mesh through retrospective review. VHR with P4HB mesh produces acceptable recurrence rates with favorable complication risks compared with biologic and synthetic meshes. Predictors of recurrence include a history of prior hernia repair, hypertension, and immunosuppression. A history of prior mesh infection seems to place patients at risk for developing subsequent infection but did not increase need for reoperation.

Gastrointestinal procedures and anastomoses can be safely performed during complex abdominal wall reconstruction

INTRODUCTION

The literature regarding combined abdominal wall reconstruction and gastrointestinal surgery is limited and largely suggests staged procedures due to a reported increased incidence of surgical site infections (SSIs), hernia recurrence and anastomotic leak, but this exposes patients to the risks of two substantial procedures. This study evaluates the outcomes of single-stage GI surgery with complex abdominal wall reconstructions (CAWR) by a single surgeon.

METHODS

Analysis of 10 years of a prospectively maintained single surgeon CAWR database compared those who had CAWR-alone with those having concomitant gastrointestinal surgery (CAWR-GI) such as stoma reversal or bowel resection but excluding cholecystectomy, gynaecological surgery and adhesiolysis alone. Groups were compared using the paired t test (continuous data) and Fisher's exact test (nominal data).

RESULTS

Overall, 62 elective cases (42 CAWR-alone vs. 20 CAWR-GI) were analysed. Baseline demographics (age, BMI, co-morbidities, smoking status and hernia size) showed no differences; CAWR-GI mean operating time was significantly longer compared to the CAWR-alone group (5.4 h vs. 4.1 h) with an increased incidence of post-operative ileus in the intestinal group (40% vs. 11.9%, p < 0.05). Post-operative complications were common (chest infection (32.3%) and SSI (41.9%)), but similar between groups. There were no anastomotic leaks, and the hernia recurrence rate at almost 4 years median follow-up was 10% in both groups.

CONCLUSION

Performing simultaneous intestinal surgery during complex abdominal wall repair can be performed safely without increasing the risk of hernia recurrence, mesh infections or anastomotic leak. A careful choice of mesh implant is required.

Biological abdominal wall expansion in pediatric liver recipients after transplantation with large-for-size organs

BACKGROUND

After pediatric split liver transplantation, intra-abdominal loss of domain due to large-for-size left lateral grafts is a frequent problem for fascial closure and potentially leads to reduced liver perfusion and abdominal compartment syndrome. Therefore, delayed fascial closure with the use of temporary silastic meshes and reoperation or alternative fascial bridging procedures are necessary.

METHODS

Between March 2019 and October 2021, biologic meshes were used for abdominal wall expansion in 6 cases of pediatric split liver transplantation. These cases were analyzed retrospectively.

RESULTS

One male and 5 female children with median age of 6 months (range: 0-57 months) and weight of 6 kg (range: 3.5-22 kg) received a large-for-size left lateral graft. Graft-to-recipient weight ratio (GRWR) was 4.8% (range: 1.5%-8.5%) in median. Biologic mesh implantation for abdominal wall expansion was done in median 7 days (range: 3-11 days) after transplantation when signs of abdominal compartment syndrome with portal vein thrombosis in 3 and of the liver artery in 1 case occurred. In 2 cases, bovine acellular collagen matrix and 4 cases ovine reinforced tissue matrix was used. Median follow-up was 12.5 months (range: 4-28 months) and showed good liver perfusion by sonography and normal corporal development without signs of ventral hernia. One patient died because of fulminant graft rejection and emergency re-transplantation 11 months after the initial transplantation.

CONCLUSIONS

Biologic meshes can be used as safe method for abdominal wall expansion to achieve fascial closure in large-for-size liver transplant recipients. Usage for primary fascial closure can be considered in selected patients.

Ventral hernia repair in high-risk patients and contaminated fields using a single mesh: proportional meta-analysis

PURPOSE

The use of mesh is a common practice in ventral hernia repair (VHR). Lack of consensus on which prosthetic material works better in different settings remains. This meta-analysis aims to summarize the available evidence on hernia recurrence and complications after repair with synthetic, biologic, or biosynthetic/bioabsorbable meshes in hernias grade 2-3 of the Ventral Hernia Working Group modified classification.

METHODS

A literature search was conducted in January 2021 using Web of Science (WoS), Scopus, and MEDLINE (via PubMed) databases. Randomized Controlled Trials (RCTs) and observational studies with adult patients undergoing VHR with either synthetic, biologic, or biosynthetic/bioabsorbable mesh were included. Outcomes were hernia recurrence, Surgical Site Occurrence (SSO), Surgical Site Infection (SSI), 30 days re-intervention, and infected mesh removal. Random-effects meta-analyses of pooled proportions were performed. Quality of the studies was assessed, and heterogeneity was explored through sensitivity analyses.

RESULTS

25 articles were eligible for inclusion. Mean age ranged from 47 to 64 years and participants' follow-up ranged from 1 to 36 months. Biosynthetic/bioabsorbable mesh reported a 9% (95% CI 2-19%) rate of hernia recurrence, lower than synthetic and biologic meshes. Biosynthetic/bioabsorbable mesh repair also showed a lower incidence of SSI, with a 14% (95% CI 6-24%) rate, and there was no evidence of infected mesh removal. Rates of seroma were similar for the different materials.

CONCLUSIONS

This meta-analysis did not show meaningful differences among materials. However, the best proportions towards lower recurrence and complication rates after grade 2-3 VHR were after using biosynthetic/slowly absorbable mesh reinforcement. These results should be taken with caution, as head-to-head comparative studies between biosynthetic and synthetic/biologic meshes are lacking. Although, biosynthetic/bioabsorbable materials could be considered an alternative to synthetic and biologic mesh reinforcement in these settings.

Semiresorbable biologic hybrid meshes for ventral abdominal hernia repair in potentially contaminated settings: lower risk of recurrence

In case of potential contamination, implantation of synthetic meshes in hernia and abdominal wall surgery is problematic due to a higher risk of mesh infection. As an alternative, a variety of different biologic meshes have been used. However, relevant data comparing outcome after implantation of these meshes are lacking. Between January 2012 and October 2021, biologic meshes were used for reconstruction of the abdominal wall in 71 patients with preoperative or intraoperative abdominal contamination. In this retrospective study, semiresorbable biologic hybrid meshes (BHM) and completely resorbable meshes (CRM) were compared and analyzed using a Castor EDC database. In 28 patients, semiresorbable biologic hybrid meshes were used; in 43 patients, completely resorbable meshes were used. Both groups showed no difference in age, gender, BMI, operation duration, hernia size and Charlson comorbidity index. The risk degree of surgical-site occurrences was graded according to the Ventral Hernia Working Group (VHWG) classification, and the median value was 3 (range 2-4) in the BHM group and 3 (range 2-4) in the CRM group. Hernia recurrence within 24 months after hernia repair was significantly lower in the BHM group (3.6% vs. 28.9%; p = 0.03), while postoperative complication rate, with respect to seromas in need of therapy (61.4% vs. 55.5%, p = 0.43) and operative revision (28.6% vs. 16.3%, p = 0.22) was not different in either group. Biologic hybrid meshes can be used safely in case of possible contamination. BHM seems to reduce the risk of hernia recurrence compared to completely resorbable biologic meshes, but this has to be investigated further.

Comparison of outcomes of ventral hernia repair using different meshes: a systematic review and network meta-analysis

PURPOSE

We conducted a network meta-analysis to evaluate potential differences in patient outcomes when different meshes, especially biological meshes, were used for ventral hernia repair.

METHODS

PubMed, Embase, Cochrane Library, and Clinical Trials.gov databases were searched for studies comparing biological meshes with biological or synthetic meshes for ventral hernia repair. The outcomes were hernia recurrence rate, surgical site infection, and seroma. We performed a two-step network meta-analysis to investigate the outcomes of several biological meshes: non-cross-linked human acellular dermal matrix (NCHADM), non-cross-linked porcine ADM (NCPADM), non-cross-linked bovine ADM (NCBADM), cross-linked porcine ADM (CPADM), and porcine small intestinal submucosa (PSIS).

RESULTS

From 6304 publications, 23 studies involving 2603 patients were finally included. We found no differences between meshes in recurrence at 1-year follow-up and in surgical site infection rate. NCBADM was associated with the lowest recurrence rate and the lowest surgical site infection rate. NCHADM implantation was associated with the lowest rate of seroma. PSIS was associated with a higher risk of seroma than NCHADM (pooled risk ratio 3.89, 95% confidence interval 1.13-13.39) and NCPADM (RR 3.42, 95% CI 1.29-9.06).

CONCLUSIONS

Our network meta-analysis found no differences in recurrence rate or surgical site infection among different biological meshes. The incidence of postoperative seroma was higher with PSIS than with acellular dermal matrices. We observed large heterogeneity in the studies of ventral hernia repair using biological meshes, and, therefore, well-designed randomized clinical trials are needed.

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.

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.

Bovine versus porcine acellular dermal matrix for abdominal wall herniorrhaphy or bridging

BACKGROUND

The management of complicated ventral hernias (CVH), namely ventral hernias in actively or recently infected/contaminated operative fields, and open abdomens in which the native fascia cannot be primarily reapproximated, pose a surgical challenge. Fetal Bovine and Porcine Acellular Dermal Matrix (BADM and PADM) biologic meshes are being increasingly used in these scenarios. A comparison, however, of clinically relevant outcomes between the two is lacking. With this investigation, we aim to review and compare clinically relevant outcomes in patients that underwent abdominal wall herniorrhaphy with either BADM or PADM at a tertiary urban academic institution over a 5-year period.

METHODS

Patients who had a BADM or PADM implanted during CVH over a 5-year period at a tertiary urban academic hospital were identified. Baseline clinical and hernia characteristics, as well as postoperative outcomes were compared after a retrospective chart review. Phone interviews were also conducted to assess for recurrence, followed by in-person visits as indicated. Cox Proportional Hazard regression was fitted to identify risk factors for recurrence.

RESULTS

Of the 140 patients who underwent biologic mesh implantation for CVH, 109 were for ventral hernia repair and 31 for open abdomen bridging. Mean age was 52.7 ± 14.2 and males constituted 57.9% of our sample, while 25.1% had undergone > 5 prior abdominal operations. Thirty percent were active smokers, and another 30% required emergency surgery. Only immunosuppression was a risk factor for recurrence [HR 13.3 (1.04-169.2), p = 0.047] on Cox Proportional Hazard regression, while mesh selection had no effect.

CONCLUSIONS

Both BADM and PADM meshes perform well in CVH, with satisfactory recurrence rates, only slightly higher compared to traditional synthetic mesh repairs.

"Delayed-Immediate" Hernia Repairs in Infected Wounds: Clinical and Economic Outcomes

BACKGROUND

Wound class in hernia repairs impacts surgical technique and outcomes. Hernia recurrence and complications are high when dirty wounds are treated in one stage. We hypothesize patients who undergo intentionally staged repairs are less likely to have adverse outcomes and associated costs.

METHODS

Patients were identified by retrospective chart review. Patient characteristics and outcome variables were collected. An economic analysis of cost variables was performed using medical records and published meta-analyses.

RESULTS

There were 8 patients in the staged repairs group and 10 patients in the control group. Length of stay was 14.9 days (±8.8), and 8.7 days (±6.4), respectively. Rate of hernia recurrence within 1 year was 14.3% and 37.5%. Rate of mesh infection at 30 days was 0% and 10%. Compared to controls, delayed-immediate repairs had a nearly 2-fold index surgical cost.

DISCUSSION

Although there is an increased cost associated with delayed-immediate repairs, this cost may be offset by the decreased infection, seroma, dehiscence, enterocutaneous fistula formation, and hernia recurrence rate that necessitates future interventions. Further data collection is required to determine if clinical and economic benefit is seen long-term.

Nationwide increase in component separation without concomitant rise in readmissions: A nationwide readmissions database analysis

BACKGROUND

The use of component separation technique (CST) in complex abdominal wall reconstruction (AWR) increases the rate of primary musculofascial closure but can be associated with increased wound complications, which may require readmission. This study examines 3-year trends in readmissions for patients undergoing AWR with or without CST.

METHODS

The Nationwide Readmissions Database was queried for patients undergoing elective AWR from 2016-2018. CST, demographic characteristics, and 90-day complications and readmissions were determined. CST versus non-CST readmissions were compared, including matched subgroups. Standard statistics and logistic regression were used.

RESULTS

Over the 3-year period, 94,784 patients underwent AWR. There was an annual increase in the prevalence of CST: 4.0% in 2016; 6.1% in 2017; 6.7% in 2018 (P < .01), which is a 67.5% upsurge during that time. Most cases (82.3%) occurred at urban teaching hospitals, which had more comorbid patients (P < .01). The yearly 90-day readmission rate did not change: 16.0%, 18.2%, and 16.9% (P = .26). Readmissions were higher for CST patients than non-CST patients (17.1% vs 15.7%), but not in the matched subgroup (17.0% vs 16.4%; P = .41). Most commonly, readmissions were for infection (28.3%); 14.3% of readmitted patients underwent reoperation. Smoking, morbid obesity, diabetes, chronic lung disease, urban-teaching hospital status, and increased length of stay increased the chance of readmission (all P < .05).

CONCLUSION

From 2016 to 2018, the use of CST increased 67.5% nationwide without an increase in readmissions. As we look toward clinical targets to reduce risk of readmission, modifiable health conditions, such as smoking, morbid obesity, and diabetes should be targeted during the prehabilitation process.

Bowel obstruction secondary to gallstone ileus within an inguinoscrotal hernia: a rare diagnosis in an elderly patient

Gallstone ileus and obstructed inguinal hernias are respectively, rare and common causes of small bowel obstruction. There are no published cases of these pathologies occurring simultaneously. Here, we describe a unique case of an elderly male patient presenting with a small bowel obstruction caused by these combined pathologies. Following an acute presentation with obstructive symptoms, a CT scan demonstrated small bowel obstruction due to a large gallstone lodged in the neck of an inguinoscrotal hernia with associated pneumobilia. The case may have been managed conservatively if it was not for the presence of the gallstone. Previous imaging had incidentally demonstrated gallstones in the gallbladder and a large uncomplicated right inguinoscrotal hernia. It is presumed that a cholecystoduodenal fistula formed and a gallstone then migrated downstream to lodge within the neck of the inguinoscrotal hernia. This case underscores the concept that even in the presence of an “obvious” cause of small bowel obstruction, such as an irreducible, large inguinoscrotal hernia, we must always maintain a healthy clinical skepticism and an open mind to other unexpected aetiologies, which may account for the clinical presentation that might impact subsequent management.

Outcomes of mid-term and long-term degradable biosynthetic meshes in single-stage open complex abdominal wall reconstruction

OBJECTIVE

To assess clinical outcomes in patients that underwent open single-stage complex abdominal wall reconstruction (CAWR) with biosynthetic mesh.

METHODS

Retrospective observational study of two prospectively registered series of consecutive patients undergoing CAWR with either long-term degradable (LTD) Phasix^™ or mid-term degradable (MTD) BIO-A^® biosynthetic mesh in a single institution between June 2016 and December 2019.

RESULTS

From 169 patients with CAWR, 70 consecutive patients were identified who underwent CAWR with either LTD or MTD biosynthetic mesh. More than 85% of patients had an incisional hernia that could be classified as moderately complex to major complex due to a previous wound infection (67%), one or more complicating comorbidities (87.1%), one or more complicating hernia characteristics (75.7%) or contaminated or dirty defects (37.1%). Concomitant component separation was performed in 43 of 70 patients (61.4%). Overall surgical site infection (SSI) rate in these CAWR patients was 45.7%. Seventeen of 70 patients (24.3%) had computed tomography (CT) - and culture-confirmed SSI in direct contact of mesh, suspicious of mesh infection. Mesh removal for persistent local infection occurred in 10% (7 of 70) after a median of 229 days since surgery. Salvage rate of mesh after direct contact with infection was 58.8%. All removed meshes were in the LTD group. Seven patients (10%) had a recurrence; four patients in the LTD group (10%) had a recurrence at a median follow-up of 35 months and three patients in the MTD group (10%) at a median follow-up of 11 months. Three of the seven recurrences occurred in patients with SSI in persistent and direct contact with mesh.

CONCLUSIONS

Comorbid patients undergoing open complex abdominal wall reconstruction are at high risk of postoperative wound complications regardless of which type of biosynthetic mesh is used. When in persistent and direct contact with infection, long-term biodegradable biosynthetic meshes may need to be removed, whereas mid-term biodegradable biosynthetic meshes can be salvaged.

Long-Term Clinical Outcomes of an Antibiotic-Coated Non-Cross-linked Porcine Acellular Dermal Graft for Abdominal Wall Reconstruction for High-Risk and Contaminated Wounds

BACKGROUND

Abdominal wall reconstruction in high-risk and contaminated cases remains a challenging surgical dilemma. We report long-term clinical outcomes for a rifampin-/minocycline-coated acellular dermal graft (XenMatrix™ AB) in complex abdominal wall reconstruction for patients with a prior open abdomen or contaminated wounds.

METHODS

Patients undergoing abdominal wall reconstruction at our institution at high risk for surgical site occurrence and reconstructed with XenMatrix™ AB with intent-to-treat between 2014 and 2017 were included. Demographics, operative characteristics, and outcomes were collected. The primary outcome was hernia recurrence. The secondary outcomes included length of stay, surgical site occurrence, readmission, morbidity, and mortality.

RESULTS

Twenty-two patients underwent abdominal wall reconstruction using XenMatrix™ AB during the study period. Two patients died while inpatient from progression of their comorbid diseases and were excluded. Sixty percent of patients had an open abdomen at the time of repair. All patients were from modified Ventral Hernia Working Group class 2 or 3. There were a total of four 30-day infectious complications including superficial cellulitis/fat necrosis (15%) and one intraperitoneal abscess (5%). No patients required reoperation or graft excision. Median clinical follow-up was 38.2 months with a mean of 35.2 +/- 18.5 months. Two asymptomatic recurrences and one symptomatic recurrence were noted during this period with one planning for elective repair of an eventration. Follow-up was extended by phone interview which identified no additional recurrences at a median of 45.5 and mean of 50.5 +/-12.7 months.

CONCLUSION

We present long-term outcomes for patients with high-risk and contaminated wounds who underwent abdominal wall reconstruction reinforced with XenMatrix™ AB to achieve early, permanent abdominal closure. Acceptable outcomes were noted.

Long-Term Outcomes in Complex Abdominal Wall Reconstruction Repaired With Absorbable Biologic Polymer Scaffold (Poly-4-Hydroxybutyrate)

Introduction

After promising early outcomes in the use of absorbable biologic mesh for complex abdominal wall reconstruction, significant criticism has been raised over the longevity of these repairs after its 2-year resorption profile.

Methods

This is the long-term (5-year) follow-up analysis of our initial experience with the absorbable polymer scaffold poly-4-hydroxybutyrate (P4HB) mesh compared with a consecutive contiguous group treated with porcine cadaveric mesh for complex abdominal wall reconstructions. Our clinical analysis was performed using Stata 14.2 and Excel 16.16.23.

Results

After a 5-year follow-up period, the P4HB group (n = 31) experienced lower rates of reherniation (12.9% vs 38.1%; P = 0.017) compared with the porcine cadaveric mesh group (n = 42). The median interval in months to recurrent herniation was similar between groups (24.3 vs 20.8; P = 0.700). Multivariate logistic regression analysis on long-term outcomes identified smoking (P = 0.004), African American race (P = 0.004), and the use of cadaveric grafts (P = 0.003) as risks for complication while smoking (P = 0.034) and the use of cadaveric grafts (P = 0.014) were identified as risks for recurrence. The long-term cost analysis showed that P4HB had a $10,595 per case costs savings over porcine cadaveric mesh.

Conclusions

Our study identified the superior outcomes in clinical performance and a value-based benefit of absorbable biologic P4HB scaffold persisted after the 2-year resorption timeframe. Data analysis also confirmed the use of porcine cadaveric grafts independently contributed to the incidence of complications and recurrences.

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.

The application possibility of acellular dermal matrix decorated with nano-silver in the reconstruction of contaminated abdominal wall

Acellular dermal matrix (ADM) is a biomaterial, which commonly used for repair of tissue defects; however, infection is the main factor underlying the failure of treatments involving ADM. To enhance the anti-infection ability of ADM, we constructed a new form of ADM that was decorated with nano-silver ('NS-ADM'). The introduction of nano-silver did not destroy the decellularized structure of ADM, and no significant difference was detected with regards to the maximum tensile force when compared between NS-ADM and ADM (P = 0.351). NS-ADM was not cytotoxic to cell growth when the concentration of nano-silver solution ≤ 25 ppm and exhibited strong antibacterial activity in vitro. Besides, when rats were inoculated with 10⁴ CFU/mL, there were significantly lower bacterial counts in the NS-ADM group than in the ADM group when assessed seven days after surgery (P = 0.047); no significant differences were detected on days 14 and 28. Although there were no significant differences in bacterial counts on days 7, 14, or 21 between the two groups (rats were inoculated with 10⁶ CFU/mL), the number of rats showing reduced bacterial counts or clearing was higher in the NS-ADM group than in the ADM group. Rats that were inoculated with 10⁸ CFU/mL showed repair failure. Overall, NS-ADM is a promising antibacterial biomaterial for repairing contaminated soft-tissue defects, in which antibacterial properties are superior to ADM. The antibacterial activity of NS-ADM was limited for severe infections, and further in vivo studies are needed to evaluate its efficacy and biosafety.

Surgical Site Infection: The Scourge of Abdominal Wall Reconstruction

Background: Surgical site infection (SSI) is a well-recognized and potentially catastrophic complication of abdominal wall reconstruction (AWR). The authors present a review of the literature surrounding SSI in AWR, exploring prevention and treatment strategies as well as risk factors. Methods: A comprehensive review of the current literature was undertaken. Evidence was reviewed and summarized with particular focus on prevention and treatment strategies available to hernia surgeons. Results: Patient risk factors for SSI are well described in the literature and include obesity, smoking, and other comorbidities. Contaminated hernias and cases involving enterocutaneous fistulae are also at higher risk of SSI. Surgical decisions such as type of mesh, plane of mesh placement, and fascial release may all contribute to SSI risk. To treat established mesh infection, conservative management with antibiotic agents and negative pressure therapy is a reasonable option in some cases. Removal of prosthesis appears to provide favorable results, however, repeat surgery can be problematic Conclusions: Surgical site infection remains an important pathology in the world of AWR. Surgeons have a wealth of tools in their arsenal to prevent and treat SSI and should be aware of the emerging evidence in the fast-moving specialty of hernia surgery. Complex cases should be handled by surgeons and centers with expertise in treating such patients.

Should simultaneous stoma closure and incisional hernia repair be avoided?

PURPOSE

Patients scheduled for stoma closure may also have an incisional hernia. Studies have reported acceptable outcomes after contaminated ventral hernia repair, but whether stoma closure and incisional hernia repair should be performed as a combined procedure is unknown. This study examined combined stoma closure and incisional hernia repair compared with incisional hernia repair only.

METHODS

This was a nationwide propensity-score matched study. Patients who underwent elective incisional hernia repair from 2007-2017 were identified in the Danish Hernia Database. All patients who underwent concurrent stoma closure were matched 1:3 with patients who underwent incisional hernia repair only. The primary outcome was reoperation for hernia recurrence, whereas secondary outcomes included anastomotic leakage, length of hospital stay, and 30-day reoperation and readmission rates.

RESULTS

In total, 516 patients were included. The risk of reoperation for recurrence was increased after concurrent stoma closure compared with incisional hernia repair only (hazard ratio 1.69, 95% confidence interval 1.01-2.82, p = 0.044). Seven (5.4%) patients who underwent incisional hernia repair concurrent to stoma closure were reoperated for anastomotic leakage. Length of hospital stay and reoperation rates within 30 days were increased after concurrent stoma closure compared with incisional hernia repair only (median 8 versus 3 days, p < 0.001 and 29.5% versus 18.6%, p = 0.013), whereas there was no difference in 30-day readmission rates (p = 0.251).

CONCLUSIONS

Stoma closure and incisional hernia repair should be performed as a dual-stage procedure to decrease the risk of hernia recurrence.