Inadequate awareness of adherence to ARRIVE guidelines, regarding reporting quality of hernia models repaired with meshes: a systematic review.

PURPOSE: Research papers involving animal studies often display poor reporting standards, leading to lower study reproducibility. We aim to determine the difference in reporting animal studies regarding abdominal wall hernia repair with mesh placement, before and after the publication of ARRIVE-2010 (Animal Research: Reporting of In Vivo Experiments) guidelines. Furthermore, we aim to present the most up-to-date reporting quality using the updated ARRIVE-2020 as criteria. METHODS: All animal studies concerning hernia repair with meshes were systematically searched. Articles published in the 5 years leading up to the ARRIVE-2010 (pre-ARRIVE) and articles within the last 5 years until the updated ARRIVE 2.0 (post-ARRIVE) were compared for overall species and specific species separately. Articles published last year were evaluated for presenting fully reported (sub)items. RESULTS: The number of fully reported (sub)items per article was on average significantly higher for pre-ARRIVE than post-ARRIVE for overall species (mean (SD) = 14.0 (2.8) vs. 12.6 (2.5), P < 0.001). The same applies to rabbit (mean (SD) = 14.8 (2.6) vs. 12.6 (2.6), P = 0.001) and pig studies (mean (SD) = 14.5 (2.7) vs. 11.6 (2.6), P = 0.004), with no significance in rat studies (mean (SD) = 13.6 (2.9) vs. 12.9 (2.3), P = 0.076). Significance was found in several (sub)items between pre-ARRIVE and post-ARRIVE (n = 7, 3, 8, and 3 for overall species, rat, rabbit, and pig studies, respectively). CONCLUSION: General reporting quality of animal experiments has been improved markedly by ARRIVE guidelines. However, more improvements are required considering the arrival of ARRIVE 2.0 guidelines.

A systematic review of seroma formation following drain-free mastectomy.

BACKGROUND: Seroma is a common complication after mastectomy. The aim of this review is to elucidate whether closed suction drainage can safely be omitted in patients undergoing mastectomy when assessing seroma formation and its complications. The second aim is to assess the influence of flap fixation on seroma related complications, as there is existing evidence showing that combining mastectomy with flap fixation may make the use of drainage systems obsolete. SEARCH & SELECTION: A review of the literature was performed and articles that compared mastectomy with drainage and mastectomy without drainage were selected. Due to the small number of eligible studies, no selection based on whether flap fixation was performed was possible. If outcome was described in terms of seroma formation or seroma related complications, papers were eligible for inclusion. Studies older than 20 years, animal studies, studies not written in English and studies with male patients were excluded. RESULTS: A total of eight articles were eligible for inclusion. Four prospective studies and four retrospective studies were included. In four studies, flap fixation was performed. Frequency of seroma formation as well as seroma that required intervention was reported. The included studies demonstrated that omitting closed suction drainage does not lead to a higher incidence of seroma formation in patients undergoing mastectomy. CONCLUSION: Despite substantial heterogeneity, there is evidence that drainage can safely be omitted without exacerbating seroma formation and its complications. A well-powered, randomized controlled trial evaluating the effect of drainage omission on seroma formation, with or without flap fixation, is needed.

META Score: An International Consensus Scoring System on Mesh-Tissue Adhesions.

BACKGROUND: Currently, the lack of consensus on postoperative mesh-tissue adhesion scoring leads to incomparable scientific results. The aim of this study was to develop an adhesion score recognized by experts in the field of hernia surgery. METHODS: Authors of three or more previously published articles on both mesh-tissue adhesion scores and postoperative adhesions were marked as experts. They were queried on seven items using a modified Delphi method. The items concerned the utility of adhesion scoring models, the appropriateness of macroscopic and microscopic variables, the range and use of composite scores or subscores, adhesion-related complications and follow-up length. This study comprised two questionnaire-based rounds and one consensus meeting. RESULTS: The first round was completed by 23 experts (82%), the second round by 18 experts (64%). Of those 18 experts, ten were able to participate in the final consensus meeting and all approved the final proposal. From a total of 158 items, consensus was reached on 90 items. The amount of mesh surface covered with adhesions, tenacity and thickness of adhesions and organ involvement was concluded to be a minimal set of variables to be communicated separately in each future study on mesh adhesions. CONCLUSION: The MEsh Tissue Adhesion scoring system is the first consensus-based scoring system with a wide backing of renowned experts and can be used to assess mesh-related adhesions. By including this minimal set of variables in future research interstudy comparability and objectivity can be increased and eventually linked to clinically relevant outcomes.

Functional Compromise Cohort Study (FCCS): Sarcopenia is a Strong Predictor of Mortality in the Intensive Care Unit.

BACKGROUND: Functional compromise in elderly patients is considered to be a significant contributing factor in increased postoperative morbidity and mortality. It is described as a state of reduced physiologic reserves including, e.g., sarcopenia, cachexia, malnutrition and frailty with increased susceptibility to adverse health outcomes. Aim of this study was to investigate the association of sarcopenia with mortality in ICU patients. METHODS: A retrospective analysis of a total of 687 patients admitted to the ICU from January 2013 until December 2014 was performed. Indirect measurements of functional compromise in these patients were conducted. Sarcopenia was assessed using the L3 muscle index by using Osirix© on computed tomography scans. Groningen Frailty Indicator (GFI) and Short Nutritional Assessment Questionnaire (SNAQ) scores were extracted from the digital patient filing system and were used to assess frailty and nutritional status. These factors were analyzed using logistic regression analysis as predictor for in-hospital mortality and 6-month mortality, which was the primary endpoint along with other secondary outcome measures. RESULTS: Age was an independent predictor of in-hospital mortality, OR 1.043 (95% CI 1.030-1.057, p < 0.001). Analysis of sarcopenia showed OR 2.361 (95% CI 1.138-4.895, p = 0.021), for GFI OR 1.012 (95% CI 0.919-1.113, p = 0.811) and for SNAQ OR 1.262 (95% CI 1.091-1.460, p = 0.002). CONCLUSION: This study shows a promising role for the sarcopenia score as a predictor of mortality on the ICU, based upon CT imaging at L3 level and SNAQ score. Further research is necessary to test this in larger cohorts and to develop a possible instrument to predict mortality in the intensive care unit.

Effects of supercritical carbon dioxide sterilization on polysaccharidic membranes for surgical applications.

Sterilization methods such as ɣ-irradiation, steam sterilization and ethylene oxide gas treatment can have negative effects on molecular structure and properties of polysaccharide-based biomaterials. In this perspective, the use of supercritical carbon dioxide (scCO2) has been proposed as an alternative method for biomaterial sterilization. In this work, chemical, mechanical and biological properties of polysaccharidic membranes for surgical applications were investigated after sterilization by scCO2. Four sets of sterilizing conditions were considered and SEC analyses were performed in order to identify the one with lower impact on the polysaccharidic matrix of membranes (alginate). Mechanical tests showed that the resistance of membranes was slightly affected after sterilization. Biological analyses proved the biocompatibility of the sterilized membranes both in vitro and in a preliminary in vivo test. Overall, this study points out that this sterilization technique can be successfully employed to achieve an effective and safe sterilization of polysaccharidic membranes for surgical use.

Functional mucous layer and healing of proximal colonic anastomoses in an experimental model.

BACKGROUND: Anastomotic leakage (AL) is the most dreaded complication after colorectal surgery, causing high morbidity and mortality. Mucus is a first line of defence against external factors in the gastrointestinal tract. In this study, the structural mucus protein Muc2 was depleted in genetically engineered mice and the effect on healing of colonic anastomoses studied in an experimental model. METHODS: Mice of different Muc2 genotypes were used in a proximal colonic AL model. Tissues were scored histologically for inflammation, bacterial translocation was determined by quantitative PCR of bacterial 16S ribosomal DNA, and epithelial cell damage was determined by assessing serum levels of intestinal fatty acid-binding protein. RESULTS: Of 22 Muc2-deficient (Muc2-/- ) mice, 20 developed AL, compared with seven of 22 control animals (P < 0·001). Control mice showed normal healing, whereas Muc2-/- mice had more inflammation with less collagen deposition and neoangiogenesis. A tendency towards higher bacterial translocation was seen in mesenteric lymph nodes and spleen in Muc2-/- mice. Intestinal fatty acid-binding protein levels were significantly higher in Muc2-/- mice compared with controls (P = 0·011). CONCLUSION: A functional mucous layer facilitates the healing of colonic anastomoses. Clinical relevance Colorectal anastomotic leakage remains the most dreaded complication after colorectal surgery. It is known that the aetiology of anastomotic leakage is multifactorial, and a role is suggested for the interaction between intraluminal content and mucosa. In this murine model of proximal colonic anastomotic leakage, the authors investigated the mucous layer at the intestinal mucosa, as the first line of defence, and found that a normal, functioning mucous layer is essential in the healing process of colonic anastomoses. Further research on anastomotic healing should focus on positively influencing the mucous layer to promote better postoperative recovery.

Comparison of three different application routes of butyrate to improve colonic anastomotic strength in rats.

INTRODUCTION: Despite extensive research, anastomotic leakage (AL) remains one of the most dreaded complications after colorectal surgery. Since butyrate enemas are known to enhance anastomotic healing, several administration routes have been explored in this study. METHODS: Three intraluminal approaches involving butyrate were investigated: (1) butyrin-elucidating patch, (2) a single injection of hyaluronan-butyrate (HA-But) prior to construction of the proximal anastomosis and (3) rectal hyaluronan-butyrate (HA-But) enemas designed for distal anastomoses. The main outcome was AL and secondary outcomes were bursting pressure, histological analysis of the anastomosis, zymography to detect MMP activity and qPCR for gene expression of MMP2, MMP9, MUC2 and TFF3. RESULTS: Neither the patches nor the injections led to a reduction of AL in experiments 1 and 2. In experiment 3, a significant reduction of AL was accomplished with the (HA-But) enema compared to the control group together with a higher bursting pressure. Histological analysis detected only an increased inflammation in experiment 2 in the hyaluronan injection group compared to the control group. No other differences were found regarding wound healing. Zymography identified a decreased proenzyme of MMP9 when HA-But was administered as a rectal enema. qPCR did not show any significant differences between groups in any experiment. CONCLUSION: Butyrate enemas are effective in the enhancement of colonic anastomosis. Enhanced butyrate-based approaches designed to reduce AL in animal models for both proximal and distal anastomoses were not more effective than were butyrate enemas alone. Further research should focus on how exogenous butyrate can improve anastomotic healing after gastrointestinal surgery.

Enhanced bioadhesivity of dopamine-functionalized polysaccharidic membranes for general surgery applications.

UNLABELLED: An emerging strategy to improve adhesiveness of biomaterials in wet conditions takes inspiration from the adhesive features of marine mussel, which reside in the chemical reactivity of catechols. In this work, a catechol-bearing molecule (dopamine) was chemically grafted onto alginate to develop a polysaccharide-based membrane with improved adhesive properties. The dopamine-modified alginates were characterized by NMR, UV spectroscopy and in vitro biocompatibility. Mechanical tests and in vitro adhesion studies pointed out the effects of the grafted dopamine within the membranes. The release of HA from these resorbable membranes was shown to stimulate fibroblasts activities (in vitro). Finally, a preliminary in vivo test was performed to evaluate the adhesiveness of the membrane on porcine intestine (serosa). Overall, this functionalized membrane was shown to be biocompatible and to possess considerable adhesive properties owing to the presence of dopamine residues grafted on the alginate backbone. STATEMENT OF SIGNIFICANCE: This article describes the development of a mussels-inspired strategy for the development of an adhesive polysaccharide-based membrane for wound healing applications. Bioadhesion was achieved by grafting dopamine moieties on the structural component on the membrane (alginate): this novel biomaterial showed improved adhesiveness to the intestinal tissue, which was demonstrated by both in vitro and in vivo studies. Overall, this study points out how this nature-inspired strategy may be successfully exploited for the development of novel engineered biomaterials with enhanced bioadhesion, thus opening for novel applications in the field of general surgery.

Long-term evaluation of adhesion formation and foreign body response to three new meshes.

INTRODUCTION: Mesh-related adhesions are a significant clinical problem following intraperitoneal mesh placement. In this study, we evaluated adhesion formation to three relatively new meshes for intraperitoneal use. METHODS: Three new meshes for intraperitoneal use (Omyra(®) mesh, Physiomesh(®), and Hi-Tex Endo-IP(®)) were implanted intraperitoneally in rats and compared with a polypropylene control mesh (Parietene(®)) after 7 or 90 days. Adhesion formation, incorporation (tensile strength), shrinkage, and foreign body reaction were scored. RESULTS: Hi-Tex Endo-IP and Physiomesh(®) showed significantly less adhesion formation when compared to Parietene at both time points (p < 0.05). Shrinkage was highest in Omyra mesh after 90 days, which was significantly more compared to Parietene(®) (p < 0.001). Physiomesh(®) only showed a significant reduction in craniocaudal mesh length, compared to Parietene and Hi-Tex Endo-IP (p < 0.05). After 90 days, Hi-Tex Endo-IP(®) showed significantly higher and Physiomesh(®) significantly lower incorporation strengths compared to all other groups (p < 0.05). Microscopic evaluation revealed massive foreign body reaction to Hi-Tex Endo-IP(®), leading to an extensive and thick collagenous scar adherent to the abdominal wall. Fractioning of the Physiomesh(®) coating over time led to an increase in interfilamentary granuloma formation, leading to scar plate formation, but with only minimal to no abdominal wall adherence. Both Parietene(®) and Omyra(®) showed a mild foreign body response. CONCLUSION: Although clear distinctions can be made between meshes and some meshes excel, none of the meshes are superior in all aspects required for effective and safe incisional hernia repair.