Incidence and Risk Factors for Long-Term Mesh Explantation Due to Infection in More than 100,000 Hernia Operation Patients

Hernia Mesh Complications: Management of Mesh Infections and Enteroprosthetic Fistula

The potential consequences of mesh infection mandate careful consideration of surgical approach, mesh selection, and preoperative patient optimization when planning for ventral hernia repair. Intraperitoneal mesh, microporous or laminar mesh, and multifilament mesh typically require explantation, whereas macroporous, monofilament mesh in an extraperitoneal position is often salvageable. Delayed presentation of mesh infection should raise the suspicion for enteroprosthetic fistula when intraperitoneal mesh is present. When mesh excision is necessary, the surgeon must carefully consider both the risk of recurrent infection as well as hernia recurrence when deciding on single-stage definitive reconstruction versus primary closure with delayed reconstruction.

Predictors for surgical site infection in patients undergoing therapeutic or prophylactic intra-abdominal onlay mesh (IPOM) implantation in clean and contaminated surgical fields

BACKGROUND

Prophylactic intra-abdominal onlay mesh (IPOM) implantation has been shown to reduce the rate of fascial dehiscence and incisional hernia. However, surgical site infection (SSI) in presence of an IPOM remains a concern. The aim of this study was to assess predictors for SSI following IPOM placement in hernia and non-hernia abdominal surgery in clean and contaminated surgical fields.

METHODS

Observational study including patients undergoing IPOM placement at a Swiss tertiary care hospital 2007-2016. IPOM implantation was performed in hernia and non-hernia elective and emergency abdominal surgery, including contaminated and infected surgical fields. The incidence of SSI was prospectively assessed by Swissnoso according to CDC criteria. The effect of disease- and procedure-related factors on SSI was assessed in multivariable regression analysis, adjusting for patient-related factors.

RESULTS

A total of 1072 IPOM implantations were performed. Laparoscopy was performed in 415 patients (38.7%), laparotomy in 657 patients (61.3%). SSI occurred in 172 patients (16.0%). Superficial, deep, and organ space SSI were found in 77 (7.2%), 26 (2.4%), and 69 (6.4%) patients, respectively. Multivariable analysis revealed emergency hospitalization (OR 1.787, p = 0.006), previous laparotomy (1.745, p = 0.029), duration of operation (OR 1.193, p < 0.001), laparotomy (OR 6.167, p < 0.001), bariatric (OR 4.641, p < 0.001), colorectal (OR 1.941, p = 0.001), and emergency (OR 2.510, p < 0.001) surgery, wound class ≥ 3 (OR 3.878, p < 0.001), and non-polypropylene mesh (OR 1.818, p = 0.003) as independent predictors for SSI. Hernia surgery was independently associated with a lower risk for SSI (OR 0.165, p < 0.001).

CONCLUSION

This study revealed emergency hospitalization, previous laparotomy, duration of operation, laparotomy, as well as bariatric, colorectal, and emergency surgery, abdominal contamination or infection, and usage of non-polypropylene mesh as independent predictors for SSI. In contrast, hernia surgery was associated with a lower risk for SSI. The knowledge of these predictors will help to balance benefits of IPOM implantation against the risk for SSI.

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.

Reoperation Through a Prosthetic-Reinforced Abdominal Wall and Its Association With Postoperative Outcomes and Longitudinal Health Care Utilization

Importance

Prosthetic reinforcement of critically sized incisional hernias is necessary to decrease hernia recurrence, but long-term prosthetic-mesh footprint may increase complication risk during subsequent abdominal operations.

Objective

To investigate the association of prior incisional hernia repair with mesh (IHRWM) with postoperative outcomes and health care utilization after common abdominal operations.

Design, Setting, and Participants

This was a population-based, retrospective cohort study of patients undergoing inpatient abdominal surgical procedures during the period of January 2009 to December 2016, with at least 1 year of follow-up within 5 geographically diverse statewide inpatient/ambulatory databases (Florida, Iowa, Nebraska, New York, Utah). History of an abdominal operation was ascertained within the 3-year period preceding the index operation. Patients admitted to the hospital with a history of an abdominal operation (ie, bariatric, cholecystectomy, small- or large-bowel resection, prostatectomy, gynecologic) were identified using the International Classification of Diseases, Ninth Revision and Tenth Revision, Clinical Modification procedure codes. Patients with prior IHRWM were propensity score matched (1:1) to controls both with and without a history of an abdominal surgical procedure based on clinical and operative characteristics. Data analysis was conducted from March 1 to November 27, 2021.

Main Outcomes and Measures

The primary outcome was a composite of adverse postoperative outcomes (surgical and nonsurgical). Secondary outcomes included health care utilization determined by length of hospital stay, hospital charges, and 1-year readmissions. Logistic and Cox regression determined the association of prior IHRWM with the outcomes of interest. Additional subanalyses matched and compared patients with prior IHR without mesh (IHRWOM) to those with a history of an abdominal operation.

Results

Of the 914 105 patients undergoing common abdominal surgical procedures (81 123 bariatric [8.9%], 284 450 small- or large-bowel resection [31.1%], 223 768 cholecystectomy [24.5%], 33 183 prostatectomy [3.6%], and 291 581 gynecologic [31.9%]), all 3517 patients (age group: 46-55 years, 1547 [44.0%]; 2396 majority sex [68.1%]) with prior IHRWM were matched to patients without a history of abdominal surgical procedures. After matching, prior IHRWM was associated with increased overall complications (odds ratio [OR], 1.43; 95% CI, 1.27-1.60), surgical complications (OR, 1.51; 95% CI, 1.34-1.70), length of hospital stay (mean increase of 1.03 days; 95% CI, 0.56-1.49 days; P < .001), index admission charges (predicted mean difference of $11 896.10; 95% CI, $6096.80-$17 695.40; P < .001), and 1-year unplanned readmissions (hazard ratio, 1.14; 95% CI, 1.05-1.25; P = .002). This trend persisted even when comparing matched patients with prior IHRWM to patients with a history of abdominal surgical procedures, and the treatment outcome disappeared when comparing patients with prior IHRWOM to those without a previous abdominal operation.

Conclusions and Relevance

Reoperation through a previously prosthetic-reinforced abdominal wall was associated with increased surgical complications and health care utilization. This risk appeared to be independent of a history of abdominal surgical procedures and was magnified by the presence of a prosthetic-mesh footprint in the abdominal wall.

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.

Infección temprana de la malla quirúrgica en herniorrafia incisional. Incidencia, factores de riesgo y desenlaces en más de 60.000 pacientes

Introducción. La infección de la malla en cirugía de reparación de hernias de pared abdominal es un desenlace pobre, asociado a un incremento en el riesgo de complicaciones. El objetivo del presente estudio fue analizar la incidencia, los factores asociados y desenlaces en pacientes llevados a herniorrafia incisional con malla con posterior diagnóstico de infección temprana. Métodos. Estudio de cohorte retrospectiva. Se utilizaron los datos de egresos hospitalarios de la National Inpatient Sample (NIS) de los Estados Unidos de América para identificar a todos los pacientes adultos llevados a herniorrafia incisional durante los años 2010 a 2015. Se utilizaron modelos de regresión logística bivariada y multivariada para evaluar los factores de riesgo en infección temprana de la malla, y finalmente, modelos de regresión logística y lineal, según el tipo de variable dependiente, de tipo stepwise forward para evaluar la asociación entre el diagnóstico de infección de malla y los desenlaces adversos. Resultados. En total se incluyeron 63.925 pacientes. La incidencia de infección temprana de la malla fue de 0,59 %, encontrando como factores asociados: comorbilidades (obesidad, desnutrición proteico calórica, anemia carencial y depresión), factores clínico-quirúrgicos (adherencias peritoneales, resección intestinal, cirugía laparoscópica y complicaciones no infecciosas de la herida) y administrativos o asistenciales. Conclusiones. La infección temprana, aunque infrecuente, se asocia con un aumento significativo en el riesgo de complicaciones. La optimización prequirúrgica con base en los factores de riesgo para este desenlace nefasto es un elemento clave para la reducción de la incidencia y mitigación del impacto de la infección en los pacientes con herniorrafía incisional con malla.

Risks and Prevention of Surgical Site Infection After Hernia Mesh Repair and the Predictive Utility of ACS-NSQIP

AIM

The aim of this paper was to provide a narrative review of surgical site infection after hernia surgery and the influence of perioperative preventative interventions.

METHODS

The review was based on current national and international guidelines and a literature search.

RESULTS

Mesh infection is a highly morbid complication after hernia surgery, and is associated with hospital re-admission, increased health care costs, re-operation, hernia recurrence, impaired quality of life and plaintiff litigation. The American College of Surgeons National Surgical Quality Improvement Program is a particularly useful resource for the study and evidence-based practise of abdominal wall hernia repair.

DISCUSSION

The three major modifiable patient comorbidities significantly associated with postoperative surgical site infection in hernia surgery are obesity, tobacco smoking and diabetes mellitus. Preoperative optimization includes weight loss, cessation of smoking, and control of diabetes. Intraoperative interventions relate, in particular, to the control of fomite mediated transmission in the operating theatre and prevention of mesh contamination with S. aureus CFUs. Risk management strategies should also target the niche ecological conditions which enable bacterial survival and subsequent biofilm formation on an implanted mesh. Outcomes of mesh infection after hernia surgery are closely related to mesh type and porosity, patient smoking status, presence of MRSA, bacterial adhesion and biofilm production. The use of suction drains and the timing of drain removal are controversial and discussed in detail. Finally, the utility of the ACS-NSQIP Surgical Risk Calculator in predicting complications and outcomes in individual patients and the importance of quality improvement initiatives in surgical units are emphasized.

Systematic review and meta-analysis of risk factors for Mesh infection following Abdominal Wall Hernia Repair Surgery

BACKGROUND

Surgical Mesh Infection (SMI) after Abdominal Wall Hernia Repair (AWHR) represents a catastrophic complication. We performed a systematic review and meta-analysis to analyze the risk factors for SMI in the context of AWHR.

METHODS

PubMed, Embase, Scielo, and LILACS were searched without language or time restrictions from inception until June 2021. Articles evaluating the association between demographic, clinical, laboratory and surgical characteristics with SMI in AWHR were included.

RESULTS

23 studies were evaluated, comprising a total of 118,790 patients (98% males; mean age 56.5 years) with a mesh infection pooled prevalence of 4%. Significant risk factors for SMI were type 2 diabetes mellitus, obesity, smoking history, steroids use, ASA III/IV, laparotomy vs laparoscopy, emergency surgery, duration of surgery and onlay mesh position vs sublay. The quality of evidence was regarded as very low-moderate.

CONCLUSION

Several factors, highlighting sociodemographic characteristics, comorbidities, and the clinical scenario, may increase the risk of developing mesh infections in AWHR. The recognition and mitigation of these may significantly reduce mesh infection rates in this context.

Risk of Hernia Mesh Explantation following Early Versus Late Onset Skin and Soft Tissue Infection

To estimate the relative risk of explantation in patients with skin and soft tissue infection onset within 90 days of hernia surgery, compared with days 91-365 and after 1 year.

BACKGROUND

Infectious complications occurring after hernia repair with synthetic mesh require prolonged treatment, and eventual mesh explantation. Little is known whether early versus late onset infection is associated with differential risk of mesh removal, and whether treatment with long-term antibiotics or debridement are associated with mesh salvage.

METHODS

This was a retrospective observational cohort study. We obtained data on all inguinal, umbilical, and ventral hernia repairs with implanted synthetic mesh performed in Veterans Affairs hospitals during 2008-2015. Participants without a 5-year infection after hernia surgery were excluded. Logistic regression estimated the association of mesh explantation with exposure to mesh-related infection during postoperative days 0-90, versus days 91-365 versus after 1 year. Additional covariates included any subsequent abdominal operation, antibiotic administration, and incision and drainage (I&D) or debridement procedures.

RESULTS

One thousand eight hundred eighty-five patients underwent index hernia repair and developed a skin and soft tissue infection within 5 years. Infection onset during days 91-365 was associated with increased explantation risk (OR, 1.62; 95% CI, 1.04-2.48), as was increased antibiotic use (OR, 1.04; 95% CI, 1.03-1.05) and surgical treatments (OR, 3.74; 95% CI, 3.02-4.67). Subsequent abdominal operation was associated with lower explantation risk (OR, 0.46; 95% CI, 0.33-0.61).

CONCLUSIONS

Early infections may be more suitable for conservative management. Later-onset infections have lower probability of mesh salvage and should be considered for earlier explantation to save the patients prolonged courses of antibiotics and surgical interventions.

Re-Infection after Explantation of Infected Hernia Mesh: Are the Same Micro-Organisms Involved?

Background: It is unclear if a history of mesh explantation for infection is predictive of future microbiology after subsequent hernia operations. We investigated how often the same causative organism is cultured in the initial explantation and subsequent repairs. Patients and Methods: We obtained data on patients undergoing ventral/incisional, umbilical, and inguinal hernia repairs from the Veterans Affairs Surgical Quality Improvement Program during 2008-2015. Manual review was performed for all patients with an administrative code indicative of mesh explantation and those with explantation for infection were retained. We then obtained data on cultured organisms from the mesh site at the time of index explantation and at any re-repair or subsequent explantation during a follow-up period ending in December 2020. Results: We identified 332 patients undergoing mesh explantation because of infection (64.8% ventral, 18.7% umbilical, 16.6% inguinal). Mean age was 60.3 years (standard deviation [SD], 9.7) and 93.9% were male. The same organism was cultured at re-infection in 23 of 59 (39%) cases. Gram-positive micro-organisms were the most prevalent in 20 of 23 (87%). Among the gram-positive, Staphylococcus aureus was the most common pathogen and was cultured in 18 of 20 (90%) cases, of which 14 of 18 (77.8%) were methicillin-susceptible Staphylococcus aureus (MSSA) and 4 of 18 (22.2%) were methicillin-resistant Staphylococcus aureus (MRSA). Three of 23 (13%) gram-negative organisms were the same at both re-infection and index explantation consisting of Escherichia coli in 2 of 3 (66.7%), and Pseudomonas aeruginosa in one of three (33.3%). Conclusions: Identification of organisms at time of prosthetic infection is helpful not only in treating the initial infection, but also in prevention of infection with the same organisms after subsequent repairs. Same organism re-infection should not be underestimated, particularly when Staphylococcus aureus is isolated.