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）胃肠道的患病节段时，通过仔细地将剩余末端缝合或缝合在一起以创建称为“吻合”的可行且密封良好的连接来重建其连续性。吻合口构建后最具破坏性和致残性的并发症是“渗漏”，其中吻合口组织无法愈合、分离，并且肠内容物逃逸到腹膜中，导致败血症、腹膜炎甚至死亡。几十年来，吻合口漏率没有变化，涉及食管和直肠的最高风险病例的吻合口漏率仍为10%。我们已经获得了令人信服的证据，肠道微生物是吻合口漏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以产生高度的胶原酶，其能够表达“组织破坏表型”，导致吻合口不愈合、分离和渗漏。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MMP 9切割成其活性形式，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IV抗生素方案不能消除这些有害的微生物，而将局部抗生素（DTA）直接应用于吻合组织通过抑制胶原酶和防止MMP 9裂解成其活性形式来完全保护吻合口漏。我们已经在人类中产生了初步数据，这些数据强烈表明，当患者正常的固有微生物群不再能够抑制这些再生病原体的组织损伤作用时，携带表达“泄漏表型”的病原体的患者风险最大。在本计划提案中，我们将开展一项试验来直接检验这一假设。我们将计划一项试验，其中接受低位科洛-直肠切除术（称为低位前切除术（LAR）和转向保护性造口（回肠造口术））的患者在术后3个不同的时间间隔接受乙状结肠镜检查（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16 s rRNA测序和表型测定（包括胶原酶和MMP 9切割活性）与微生物群的组成和功能变化相关。在SES-DTA试验中，患者将随机接受直接局部抗生素（DTA）与安慰剂的应用，并在21天内（术后第2-3、7-10和14-21天）的3次SES发作时跟踪吻合口愈合。该计划提案汇集了独特的合格研究人员，他们是肠道微生物组研究，吻合口漏结直肠手术的发病机制，对接受结直肠手术患者的多中心试验以及生物统计学和生物信息学的所有方面的领先权威。该试验将是第一个直接检查吻合口组织愈合情况并将愈合与微生物组成和功能相关联的试验。它将通过提供一种临床路径来预测和预防结肠直肠手术的实践 吻合口漏

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.