Serial Endoscopic Surveillance (SES) and Direct Topical Antibiotics (DTA) to prev

描述（由申请人提供）：当外科医生切除（切除）胃肠道病变部分时，通过小心地将剩余末端缝合或钉接在一起，以创建可行且密封良好的连接（称为“吻合”），重新建立其连续性。吻合口构造后最具破坏性和致残性的并发症是“渗漏”，即吻合口组织不能愈合、分离，肠内容物逸入腹膜，导致败血症、腹膜炎甚至死亡。吻合口漏率几十年来没有改变，在涉及食道和直肠的高危病例中仍保持在10%。我们已经获得了令人信服的证据，证明肠道微生物是吻合口瘘发病机制背后的驱动力。我们的工作表明，某些肠道微生物在体内被激活，产生高度的胶原酶，这种胶原酶能够表达一种“组织破坏表型”，导致吻合口不愈合、分离和泄漏。我们发现肠道微生物在体内转化，在恢复过程中表达高胶原酶，可以将肠道MMP9裂解为活性形式，并分解愈合所需的胶原蛋白。重要的是，我们的数据表明，目前使用的静脉注射抗生素方案并不能消除这些有害微生物，而直接将局部抗生素（DTA）应用于吻合组织，通过抑制胶原酶和防止MMP9裂解成活性形式，完全防止吻合口泄漏。我们在人类中产生的初步数据强烈表明，当携带表达“泄漏表型”的病原体的患者的正常本地微生物群不再能够约束这些变本加的病原体对组织的破坏作用时，他们的风险最大。在这个规划提案中，我们将开发一个试验来直接检验这个假设。我们将计划进行一项试验，在该试验中，接受低位结肠直肠切除术的患者，称为低前切除术（LAR）并转移保护性造口（回肠造口），在手术后的3个不同的时间间隔，通过乙状结肠镜进行连续内镜检查（SES），并进行图像采集和微生物分析。吻合口愈合的图像将通过16s rRNA测序和表型分析（包括胶原酶和MMP9裂解活性）与微生物群的组成和功能变化相关联。在SES-DTA试验中，患者将被随机分配使用直接局部抗生素（DTA）和安慰剂，并在21天（术后2-3、7-10和14-21天）的3次SES发作时追踪吻合口愈合情况。该计划提案汇集了具有独特资质的研究人员，他们是肠道微生物组研究、结直肠手术吻合口漏发病机制、结直肠手术患者多中心试验以及生物统计学和生物信息学各方面的权威人士，以实施该试验。这项试验将首次直接检测吻合口组织的愈合情况，并将愈合与微生物组成和功能联系起来。它将通过提供预测和预防的临床途径来改变结肠直肠手术的实践

DESCRIPTION (provided by applicant): When surgeons remove (resect) a diseased segment of the gastrointestinal tract, its continuity is reestablished by carefully suturing or stapling th remaining ends together to create a viable and well- sealed connection referred to as an "anastomosis." The most devastating and disability complication following anastomotic construction is a "leak" where anastomotic tissues fail to heal, separate, and intestinal contents escape into the peritoneum causing sepsis, peritonitis and even death. Anastomotic leak rates have not changed in decades and remain at 10% for the highest risk cases involving the esophagus and rectum. We have generated compelling evidence that intestinal microbes are the driving force behind the pathogenesis of anastomotic leak. Our work demonstrates that certain intestinal microbes become activated in vivo to produce a high degree of collagenase that is capable of expressing a "tissue destroying phenotype" leading to anastomotic non- healing, separation, and leak. We show that intestinal microbes become transformed in vivo to express high collagenase over the course of recovery that can cleave intestinal MMP9 to its active form and breakdown the collagen needed for healing. Importantly our data demonstrate that currently used IV antibiotic regimens do not eliminate these offending microbes whereas direct application of topical antibiotics (DTA) to anastomotic tissues completely protects against anastomotic leak by suppressing collagenase and preventing MMP9 cleavage to its active form. We have generated preliminary data in humans that strongly suggests that patients harboring pathogens expressing the "leak phenotype" are most at risk when their normal indigenous microbiota can no longer constrain the tissue damaging effects of these renegade pathogens. In this planning proposal we will develop a trial to directly test this hypothesis. We will plan a tril in which patients undergoing a low colo- rectal resection, termed a low anterior resection (LAR) with a diverting protective stoma (ileostomy), are subjected to serial endoscopic examination (SES) by sigmoidoscopy with image capture and microbial analysis at 3 separate intervals following surgery. Images of anastomotic healing will be correlated to compositional and functional changes in the microbiota via 16s rRNA sequencing and phenotype assay including collagenase and MMP9 cleavage activity. In the SES-DTA trial, patients will be randomized to application of direct topical antibiotics (DTA) versus placebo and anastomotic healing tracked at 3 SES episodes over the course of 21 days (postoperative days 2-3, 7-10, and 14-21). This planning proposal has assembled uniquely qualified investigators who are leading authorities on intestinal microbiome research, the pathogenesis of anastomotic leak colorectal surgery, multi-centered trials on patients undergoing colorectal surgery, and all facets of biostastistics and bioinformatics to operationalize the trial. This trial will be the first of its kind to directly exmine anastomotic tissues as they heal and correlate healing to microbial composition and function. It will change the practice of colo-rectal surgery by providing a clinical path to predict and prevent anastomotic leak.