There have been several innovations to prevent gastric leaks, such as oversewing the staple line, or utilizing synthetic and biologic materials, however, none of these are supported by prospective randomized human studies [Citation1]. A recent study, “Effect of acellular amniotic membrane matrix patch on healing of cut surface after sleeve gastrectomy in rats,” looked at overall recovery and the incidence of leaks after an amniotic membrane patch was placed on a healing cut surface after sleeve gastrectomy (SG) [Citation2]. The authors measured differences in levels of polymorphonuclear leukocytes (PMNs), granulation formation and vascularization, distributions of edema, type of mucosal epithelium and fibroblastic proliferation among other biological markers of wound healing. Rats that underwent SG with primary gastrorrhaphy with an acellular amniotic membrane patch (AAMMP) tested against rats that underwent the same procedures but without an AAMMP (control). They also examined a second experimental group of rats after SG with incomplete primary gastrorrhaphy and covered with AAMMP. This study is novel because it assesses the application of the AAMMP in a rat model as a method to prevent leaks and to improve healing with additional growth factors. One of their main findings was that cut surface leakage was more common in control group (without AAMMP) compared to the experimental groups (with AAMMP), and that the AAMMP effectively sealed 90% of incomplete primary gastrorrhaphy areas in the second experimental group. Furthermore, the level of granulation tissue, vascularization, and fibroblastic proliferation were higher in the experimental group, and the levels of edema and type of mucosal epithelium were higher in the control group. The authors concluded that the utilization of AAMMP resulted in improved healing. In addition, the AAMMP allowed for safe healing in areas with incomplete suturing [Citation2].
Although leak etiology varies, it can be divided into two broad categories: ischemic and mechanical-tissular [Citation1, Citation3]. The authors in this study purposefully created a mechanical-tissular leak [Citation2]. While the effects of the AAMMP on ischemic leaks are not reviewed in this study, the results seen here are an important step in continuing to improve and define the standard of care with the goal of lowering morbidity and mortality.
One potential limitation of this paper is the unclear specification of how the size of the defect (the incomplete primary gastrorrhaphy) directly relates to clinical outcome. In future studies, it would be prudent to analyze at what size a defect must be to be considered clinically significant. Perhaps the size of the defect in this study was too small to have any effect on the outcomes measured. If not, then what are the minimum and maximum defect sizes to benefit from AAMMP application? If future studies continue to show that the usage of AAMMP improves and prevents gastric leakage, its implementation into patient care, and subsequent standardization is technically feasible and requires a minimal extension of operation time. Additionally, a more detailed description of categories for necrosis, edema, and other characteristics would be helpful as well as more distinct boundaries between the levels of each characteristic.
The usage of the amniotic membrane has also been shown to be beneficial in other specialties by reducing inflammation, decreasing healing time, and even strengthening tissue (such as colonic anastomoses) [Citation4–6]. The addition of the amniotic membrane has been thought to act like a scaffold for fibroblast proliferation, thus, promoting wound healing [Citation4–6].
Other preventative treatment methods, such as the usage of fibrosealants, have shown positive outcomes in a porcine model [Citation7]. It is important to note, however, that the mechanism of action for fibrosealants differs from that of the AAMMP. Fibrosealants create a fibrin matrix “by mimicking the least step of the normal physiological coagulation cascade” [Citation7]. Further studies of the application of AAMMP, and possibly the combination of AAMMP and fibrosealant, are needed to analyze the additional benefits associated with its usage. Multiple meta-analyses and several systematic reviews have been published regarding efforts to prevent gastric leakage (e.g. reinforcement of the staple line, application of fibrosealants); however, a gold standard has yet to be established [Citation1, Citation7].
As the authors expressed in their discussion, further investigation into the application of AAMMP as a leak preventative should be made in animal studies with hopes for eventual human applications. If proven to be successful as a preventative tool, it would be prudent to add a cost-effective element to future studies. This article should pave the way for continued study and application of AAMMPs, not only on different and more difficult anastomoses, but also with a much larger research population to draw significant conclusions. Finally, it would be compelling to see a study regarding AAMMP application that documents the different stages of healing, measures bursting pressures and hydroxiproline levels, as well as the aforementioned cost-effective analysis.
DECLARATION OF INTEREST
The authors confirm that they have no competing interests to declare.
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