Biomarkers and heterogeneous fibroblast phenotype associated with incisional hernia.

Development of incisional hernia (IH) is multifactorial but inflammation and abdominal wall ECM (extracellular matrix) disorganization are key pathological events. We investigated if the differential expression of fibroblast biomarkers reflects the cellular milieu and the dysregulated ECM in IH tissues. Expression of fibroblast biomarkers, including connective tissue growth factor, alpha-smooth muscle actin (α-SMA), CD34 (cluster of differentiation 34), cadherin-11 and fibroblast specific protein 1 (FSP1), was examined by histology and immunofluorescence in the hernial-fascial ring/neck tissue (HRT) and hernia sack tissue (HST) harvested from the patients undergoing hernia surgery and compared with normal fascia (FT) and peritoneum (PT) harvested from brain-dead healthy subjects undergoing organ procurement for transplantation. The H&E staining revealed alterations in tissue architecture, fibroblast morphology, and ECM organization in the IH tissues compared to control. The biomarker for undifferentiated fibroblasts, CD34, was significantly higher in HST and decreased in HRT than the respective FT and PT controls. Also, the findings revealed an increased level of CTGF (connective tissue growth factor) with decrease in α-SMA in both HRT and HST compared to the controls. In addition, an increased level of FSP1 (fibroblast specific protein 1) and cadherin-11 in HRT with decreased level in HST were observed relative to the respective controls (FT and PT). Hence, these findings support the heterogeneity of fibroblast population at the laparotomy site that could contribute to the development of IH. Understanding the mechanisms causing the phenotype switch of these fibroblasts would open novel strategies to prevent the development of IH following laparotomy.

The European Hernia Society classification applied to the rare cases of parastomal hernia after ileal conduit urinary diversion: a retrospective cohort of 96 patients.

INTRODUCTION: To determine the incidence and classification of parastomal hernia (PH) following ileal conduit urinary diversion and to identify risk factors for PH development. METHODS: We performed a retrospective review of our cystectomy database which includes benign and malignant cases from 2011-2016. Patients with an abdominal CT at 24 ± 2 months post-operation were included. PH were classified according to the European Hernia Society (EHS) system. Regression analyses were performed on variables associated with parastomal hernia. RESULTS: A total of 96 patients were included in the study. The incidence of PH on CT is 20.2% at one year and 28.1% at two years. Using the EHS classification, the majority of PH was small (≤ 5 cm), but up to 50% were associated with a concomitant incisional hernia. On multivariable analysis, (C-index = 0.71), obesity was associated with a higher risk of PH (OR = 2.8, 95% CI 1.06-7.42, p = 0.04), whereas prior tobacco use was associated with a lower risk of PH at 2 years (OR = 0.23, 95% CI 0.09-0.63, p < 0.01). CONCLUSIONS: Hernia after ileal conduit is common with radiographic rates approaching 30% at two years, with obesity being an independent risk factor. The relationship between prior tobacco use and a lower hernia rate may be limited to this study but presents an opportunity for future investigation. No difference in PH rates were observed between open and minimally invasive surgery and between intracorporeal and extracorporeal conduits.

Pooled data analysis of primary ventral (PVH) and incisional hernia (IH) repair is no more acceptable: results of a systematic review and metanalysis of current literature.

PURPOSE: Primary (PVHs) and incisional (IHs) ventral hernias represent a common indication for surgery. Nevertheless, most of the papers presented in literature analyze both types of defect together, thus potentially introducing a bias in the results of interpretation. The purpose of this systematic review and meta-analysis is to highlight the differences between these two entities. METHODS: Methods MEDLINE, Scopus, and Web of Science databases were reviewed to identify studies evaluating the outcomes of both open and laparoscopic repair with mesh of PVHs vs IHs. Search was restricted to English language literature. Risk of bias was assessed with MINORS score. Primary outcome was recurrence, and secondary outcomes were baseline characteristics and intraoperative and postoperative data. Fixed effects model was used unless significant heterogeneity, assessed with the Higgins I square (I2), was encountered. RESULTS: The search resulted in 783 hits, after screening; 11 retrospective trials were selected including 38,727 patients. Mean MINORS of included trials was 15.2 (range 5-21). The estimated pooled proportion difference for recurrence was - 0.09 (- 0.11; - 0.07) between the two groups in favor of the PVH group. On metanalysis, PVHs were smaller in area and diameters, affected younger and less comorbid patients, and were more frequently singular; the operative time and length of stay was quicker. Other complications did not differ significantly. CONCLUSION: Our paper supports the hypothesis that PVH and IH are different conditions with the latter being more challenging to treat. Accordingly, EHS classifications should be adopted systematically as well as pooling data analysis should be no longer performed in clinical trials.

Prospective evaluation of poly-4-hydroxybutyrate mesh in CDC class I/high-risk ventral and incisional hernia repair: 18-month follow-up.

BACKGROUND: Long-term resorbable mesh represents a promising technology for complex ventral and incisional hernia repair (VIHR). Preclinical studies indicate that poly-4-hydroxybutyrate (P4HB) resorbable mesh supports strength restoration of the abdominal wall. This study evaluated outcomes of high-risk subjects undergoing VIHR with P4HB mesh. METHODS: This was a prospective, multi-institutional study of subjects undergoing retrorectus or onlay VIHR. Inclusion criteria were CDC Class I, defect 10-350 cm2, ≤ 3 prior repairs, and ≥ 1 high-risk criteria (obesity (BMI: 30-40 kg/m2), active smoker, COPD, diabetes, immunosuppression, coronary artery disease, chronic corticosteroid use, hypoalbuminemia, advanced age, and renal insufficiency). Physical exam and/or quality of life surveys were performed at regular intervals through 18 months (to date) with longer-term, 36-month follow-up ongoing. RESULTS: One hundred and twenty-one subjects (46M, 75F) with an age of 54.7 ± 12.0 years and BMI of 32.2 ± 4.5 kg/m2 (mean ± SD), underwent VIHR. Comorbidities included the following: obesity (n = 95, 78.5%), hypertension (n = 72, 59.5%), cardiovascular disease (n = 42, 34.7%), diabetes (n = 40, 33.1%), COPD (n = 34, 28.1%), malignancy (n = 30, 24.8%), active smoker (n = 28, 23.1%), immunosuppression (n = 10, 8.3%), chronic corticosteroid use (n = 6, 5.0%), advanced age (n = 6, 5.0%), hypoalbuminemia (n = 3, 2.5%), and renal insufficiency (n = 1, 0.8%). Hernia types included the following: primary ventral (n = 17, 14%), primary incisional (n = 54, 45%), recurrent ventral (n = 15, 12%), and recurrent incisional hernia (n = 35, 29%). Defect and mesh size were 115.7 ± 80.6 and 580.9 ± 216.1 cm2 (mean ± SD), respectively. Repair types included the following: retrorectus (n = 43, 36%), retrorectus with additional myofascial release (n = 45, 37%), onlay (n = 24, 20%), and onlay with additional myofascial release (n = 8, 7%). 95 (79%) subjects completed 18-month follow-up to date. Postoperative wound infection, seroma requiring intervention, and hernia recurrence occurred in 11 (9%), 7 (6%), and 11 (9%) subjects, respectively. CONCLUSIONS: High-risk VIHR with P4HB mesh demonstrated positive outcomes and low incidence of hernia recurrence at 18 months. Longer-term 36-month follow-up is ongoing.