A Mechanical Explanation for the Development of Enteroatmospheric Fistulas in Open Abdomen

Hyperdry Human Amniotic Membrane as a Protective Dressing for Open Wounds With Exposed Bowel in Mice

INTRODUCTION

An enteroatmospheric fistula forms when the exposed bowel is perforated with chronic enteric fistula formation. Currently, there is no established preventative method for this condition. Hyperdry (HD) amniotic membrane (AM) can promote early granulation tissue formation on the exposed viscera and is suitable for dressing intractable wounds as it possesses anti-inflammatory, antibacterial, and immunomodulatory properties. This study investigated whether HD-AM promotes early formation of blood vessel-containing granulation tissue for enteroatmospheric fistula treatment.

METHODS

An experimental animal model of an open wound with exposed bowel was developed. A 15 × 20 mm wound was prepared on the abdomen of Institute of Cancer Research mice, and the HD-AM was placed. The mice were assigned to one of the following groups: HD-AM group, in which the stromal layer of the HD-AM was placed in contact with the exposed bowel; HD-AM UD group, in which the epithelial layer of the HD-AM was placed in contact with the exposed bowel; and the HD-AM (-) or control group, in which the HD-AM was not used.

RESULTS

On postoperative days 7 and 14, granulation tissue thickness significantly increased in the HD-AM and HD-AM UD groups compared with that in the HD-AM (-) group. Macrophages accumulated in the HD-AM epithelium only in the HD-AM group. During HD-AM contact, a subset of invading macrophages switched from M1 to M2 phenotype.

CONCLUSIONS

HD-AM is a practical wound dressing with its scaffolding function, regulation of TGF β-1 and C-X-C motif chemokine 5 (CXCL-5), and ability to induce M1-to-M2 macrophage conversion.

Regenerative medicine for digestive fistulae therapy: Benefits, challenges and promises of stem/stromal cells and emergent perspectives via their extracellular vesicles

Despite current management strategies, digestive fistulae remain extremely debilitating complications associated with significant morbidity and mortality, generating a need to develop innovative therapies in these indications. A number of clinical trials and experimental studies have thus investigated the potential of stem/stromal cells (SCs) or SC-derived extracellular vesicles (EVs) administration for post-surgical and Crohn's-associated fistulae. This review summarizes the physiopathology and current standards-of-care for digestive fistulae, along with relevant evidence from animal and clinical studies regarding SC or EV treatment for post-surgical digestive fistulae. Additionally, existing preclinical models of fistulizing Crohn's disease and results of SC therapy trials in this indication will be presented. The optimal formulation and administration protocol of SC therapy products for gastrointestinal fistula treatment and the challenges for a widespread use of darvadstrocel (Alofisel) in clinical practice will be discussed. Finally, the potential advantages of EV therapy and the obstacles towards their clinical translation will be introduced.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Open abdomen with vacuum-assisted wound closure and mesh-mediated fascial traction in patients with complicated diffuse secondary peritonitis: A single-center 8-year experience

BACKGROUND

Open abdomen (OA) treatment in patients with peritonitis is increasing worldwide. Various temporary abdominal closure devices are being used. This study included patients with complicated diffuse secondary peritonitis, OA, and vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM). The aim of this study was to describe mortality and major morbidity in terms of delayed primary fascial closure and enteroatmospheric fistula rates.

METHODS

This was a single-academic-center retrospective study of consecutive patients with diffuse peritonitis, OA, and VAWCM between years 2008 and 2016. Descriptive and univariate analyses were performed.

RESULTS

Forty-one patients were identified and analyzed. Median age was 59 years, preoperative septic shock was diagnosed in 54% (n = 22), and 59% (n = 24) had a postoperative peritonitis. Mortality was 29% (n = 12), and 76% (n = 31) of patients were admitted in the intensive care unit. The median duration of OA was 7 days with a median of two dressing changes. Delayed primary fascial closure rate among survivors was 92% (n = 33), and enteroatmospheric fistulas developed in 7% (n = 3). In a subgroup analysis, patients with OA in the primary laparotomy for peritonitis (n = 27) were compared with patients with OA in the subsequent laparotomies (n = 14). There were no significant differences between groups.

CONCLUSIONS

The VAWCM technique in patients with complicated secondary diffuse peritonitis and OA yields excellent results in terms of delayed primary fascial closure rate and a low number of enteroatmospheric fistulas. It seems to be safe to close the abdomen at the index laparotomy, if possible, even if there is a risk of a need of OA later.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.