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BACKGROUND: Various reports have now established that postoperative endoscopy to examine and intervene in the process of anastomotic healing is both feasible and safe. Here we present our preliminary experience with serial postoperative endoscopy to determine its feasibility, patient acceptance and the ability to obtain and the utility of perianastomotic material for molecular analysis. METHODS: Patients undergoing LAR with ileostomy for rectal cancer were recruited for study to undergo routine serial endoscopic surveillance (SES) at three time points during the course of LAR: intraoperatively, before discharge (postoperative day 3–7) and at follow-up (postoperative day 10–28). At each endoscopy, images were captured, anastomotic tissues were lavaged and lavage fluid was retrieved. Fluid samples were analyzed using proteomics, zymography, ELISA and bacteria via 16S rRNA gene amplicon sequencing and culture of collagenolytic strains. RESULTS: SES is feasible and acceptable to this limited set of patients following LAR. Biologic analysis of perianastomotic fluids was able to detect the presence of proteins, microbiota and inflammatory mediators previously identified at anastomotic sites in animals with pathologic healing. CONCLUSION: SES can be implemented in patients undergoing LAR with a high degree of patient compliance and capture of biologic information and imaging. Application of this approach has the potential to uncover, for the first time, the natural history of normal versus pathologic anastomotic healing in patients undergoing anastomotic surgery.

BACKGROUND: Bacteria that produce collagen digesting enzymes (collagenolytic bacteria) have been shown to play a critical and previously unappreciated role in anastomotic leak pathogenesis by breaking down host tissue extracellular matrix proteins. Detection of these bacteria is labor intensive and no screening method currently exists. OBJECTIVES: In this report we evaluate a rapid screening method developed to detect the presence of these collagenolytic bacteria in clinical samples such as drain fluid, anastomotic tissue, or feces. DESIGN: We compared a new method of detecting collagenolytic bacterial species with a previously used technique using samples from a murine experimental model and then demonstrated the utility of this screening method in samples from patients with anastomotic complications. SETTING: All laboratory work and prior murine experiments were performed in Dr. Alverdy’s laboratory at the University of Chicago under IRB approved protocols. MAIN OUTCOME MEASURES: Whether this analysis can influence patient management and outcomes will require further study. PATIENTS: Samples from patients with challenging wound complications were provided by participating clinicians with verbal patient consent. Given the small number of patients this was determined to be IRB exempt. RESULTS: This screening method detects numerous strains of bacteria with collagenolytic properties, including the collagenolytic species that have previously been implicated in anastomotic leak. Once collagenolytic strains are identified, they can be speciated and tested for antibiotic resistance using standard laboratory techniques. LIMITATIONS: This study is limited by the small number of patient samples tested. CONCLUSION: Here we demonstrate the potential applicability of this assay to evaluate rare and complex anastomotic complications that often require analysis beyond standard culture and sensitivity assays. Future applications of this method may allow development of strategies to prevent anastomotic leak related to collagenolytic bacteria. See Video Abstract at http://links.lww.com/DCR/Axxx.

To determine whether intestinal colonization with methicillin-resistant Staphylococcus aureus (MRSA) can be the source of surgical site infections (SSIs).We hypothesized that gut-derived MRSA may cause SSIs via mechanisms in which circulating immune cells scavenge MRSA from the gut, home to surgical wounds, and cause infection (Trojan Horse Hypothesis).MRSA gut colonization was achieved by disrupting the microbiota with antibiotics, imposing a period of starvation and introducing MRSA via gavage. Next, mice were subjected to a surgical injury (30% hepatectomy) and rectus muscle injury and ischemia before skin closure. All wounds were cultured before skin closure. To control for postoperative wound contamination, reiterative experiments were performed in mice in which the closed wound was painted with live MRSA for 2 consecutive postoperative days. To rule out extracellular bacteremia as a cause of wound infection, MRSA was injected intravenously in mice subjected to rectus muscle ischemia and injury.All wound cultures were negative before skin closure, ruling out intraoperative contamination. Out of 40 mice, 4 (10%) developed visible abscesses. Nine mice (22.5%) had MRSA positive cultures of the rectus muscle without visible abscesses. No SSIs were observed in mice injected intravenously with MRSA. Wounds painted with MRSA after closure did not develop infections. Circulating neutrophils from mice captured by flow cytometry demonstrated MRSA in their cytoplasm.Immune cells as Trojan horses carrying gut-derived MRSA may be a plausible mechanism of SSIs in the absence of direct contamination.

Current surgical dogma dictates that tissue ischemia and hypoxia are major contributing factors in anastomotic leak despite scant evidence. The aim of this study was to determine if tissue hypoxia is a feature of anastomotic leakage in rats following colon resection and segmental devascularization. Rats were randomly assigned to undergo sham operation, segmental colon devascularization alone, colectomy alone, or segmental devascularization plus colectomy. Tissue hypoxia present at the colon anastomosis site across the various treatment groups was determined at sacrifice on postoperative day 6. Pimonidazole HCl was injected 30 min prior to sacrifice. Anastomotic tissues were examined and scored for healing versus leakage using an anastomotic healing score (AHS). Collagen content, hypoxia, enteric smooth muscle and periendothelial stromal patterning, and apoptosis were evaluated histologically. No differences in tissue hypoxia were noted in the 16% of anastomotic tissues with poor healing compared to the remaining 84% of rats whose anastomoses healed well. No significant changes were found in cell death in the submucosa of any group. Consistent with previous findings, poor healing was associated with lower collagen content. Submucosal thickness correlated with increased arteriole diameter (R 2 = 0.25, p

The anastomotic healing complications of postoperative leak and stricture continue to plague surgeons despite many broadly targeted interventions. Evaluation of preventive measure efficacy is difficult due to inconsistent definitions and reporting of these complications. Few interventions have been shown to impact rates of leakage or stricture. However, new evidence is emerging that the intestinal microbiota can play an important role in the development of anastomotic complications. A more holistic approach to understanding the mechanisms of anastomotic complications is needed in order to develop tailored interventions to reduce their frequency. Such an approach may require a more complete definition of the role of the microbiota in anastomotic healing.

BACKGROUND: Despite ever more powerful antibiotics, newer surgical techniques, and enhanced recovery programs, anastomotic leaks remain a clear and present danger to patients. Previous work from our laboratory suggests that anastomotic leakage may be caused by Enterococcus faecalis strains that express a high collagenase phenotype (i.e., collagenolytic). Yet the mechanisms by which the practice of surgery shifts or selects for collagenolytic phenotypes to colonize anastomotic tissues remain unknown. METHODS: Here, we hypothesized that morphine, an analgesic agent universally used in gastrointestinal surgery, promotes tissue colonization with collagenolytic E. faecalis and causes anastomotic leak. To test this, rats were administered morphine in a chronic release form as would occur during routine surgery or vehicle. Rats were observed for 6 days and then underwent exploratory laparotomy for anastomotic inspection and tissue harvest for microbial analysis. These results provide further rationale to enhanced recovery after surgery (i.e., ERAS) programs that suggest limiting or avoiding the use of opioids in gastrointestinal surgery. RESULTS: Results demonstrated that compared to placebo-treated rats, morphine-treated rats demonstrated markedly impaired anastomotic healing and gross leaks that correlated with the presence of high collagenase-producing E. faecalis adherent to anastomotic tissues. To determine the direct role of morphine on this response, various isolates of E. faecalis from the rats were exposed to morphine and their collagenase activity and adherence capacity determined in vitro. Morphine increased both the adhesiveness and collagenase production of four strains of E. faecalis harvested from anastomotic tissues, two that were low collagenase producers at baseline, and two that were high collagenase producers at baseline. CONCLUSION: These results provide further rationale to enhanced recovery after surgery (i.e., ERAS) programs that suggest limiting or avoiding the use of opioids in gastrointestinal surgery.

We have recently demonstrated that collagenolytic Enterococcus faecalis plays a key and causative role in the pathogenesis of anastomotic leak, an uncommon but potentially lethal complication characterized by disruption of the intestinal wound following segmental removal of the colon (resection) and its reconnection (anastomosis). Here we hypothesized that comparative genetic analysis of E. faecalis isolates present at the anastomotic wound site before and after surgery would shed insight into the mechanisms by which collagenolytic strains are selected for and predominate at sites of anastomotic disruption. Whole genome optical mapping of four pairs of isolates from rat colonic tissue obtained following surgical resection (herein named "pre-op" isolates) and then 6 days later from the anastomotic site (herein named "post-op" isolates) demonstrated that the isolates with higher collagenolytic activity formed a distinct cluster. In order to perform analysis at a deeper level, a single pair of E. faecalis isolates (16A pre-op and 16A post-op) was selected for whole genome sequencing and assembled using a hybrid assembly algorithm. Comparative genomics demonstrated absence of multiple gene clusters, notably a pathogenicity island in the post-op isolate. No differences were found in the fsr-gelE-sprE genes (EF1817-1822) responsible for regulation and production of collagenolytic activity. Analysis of unique genes among the 16A pre-op and post-op isolates revealed the predominance of transporter systems-related genes in the pre-op isolate and phage-related and hydrolytic enzyme-encoding genes in the post-op isolate. Despite genetic differences observed between pre-op and post-op isolates, the precise genetic determinants responsible for their differential expression of collagenolytic activity remains unknown.

The microorganisms that inhabit hospitals may influence patient recovery and outcome, although the complexity and diversity of these bacterial communities can confound our ability to focus on potential pathogens in isolation. To develop a community-level understanding of how microorganisms colonize and move through the hospital environment, we characterized the bacterial dynamics among hospital surfaces, patients, and staff over the course of 1 year as a new hospital became operational. The bacteria in patient rooms, particularly on bedrails, consistently resembled the skin microbiota of the patient occupying the room. Bacterial communities on patients and room surfaces became increasingly similar over the course of a patient's stay. Temporal correlations in community structure demonstrated that patients initially acquired room-associated taxa that predated their stay but that their own microbial signatures began to influence the room community structure over time. The α- and β-diversity of patient skin samples were only weakly or nonsignificantly associated with clinical factors such as chemotherapy, antibiotic usage, and surgical recovery, and no factor except for ambulatory status affected microbial similarity between the microbiotas of a patient and their room. Metagenomic analyses revealed that genes conferring antimicrobial resistance were consistently more abundant on room surfaces than on the skin of the patients inhabiting those rooms. In addition, persistent unique genotypes of Staphylococcus and Propionibacterium were identified. Dynamic Bayesian network analysis suggested that hospital staff were more likely to be a source of bacteria on the skin of patients than the reverse but that there were no universal patterns of transmission across patient rooms.

Surgery involving the gastrointestinal tract continues to prove challenging because of the persistence of unpredictable complications such as anastomotic leakage and life-threatening infections. Removal of diseased intestinal segments results in substantial catabolic stress and might require complex reconstructive surgery to maintain the functional continuity of the intestinal tract. As gastrointestinal surgery necessarily involves a breach of an epithelial barrier colonized by microorganisms, preoperative intestinal antisepsis is used to reduce infection-related complications. The current approach to intestinal antisepsis varies widely across institutions and countries with little understanding of its mechanism of action, effect on the gut microbiota and overall efficacy. Many of the current approaches to intestinal antisepsis before gastrointestinal surgery run counter to emerging concepts of intestinal microbiota contributing to immune function and recovery from injury. Here, we review evidence outlining the role of gut microbiota in recovery from gastrointestinal surgery, particularly in the development of infections and anastomotic leak. To make surgery safer and further reduce complications, a molecular, genetic and functional understanding of the response of the gastrointestinal tract to alterations in its microbiota is needed. Methods can then be developed to preserve the health-promoting functions of the microbiota while at the same time suppressing their harmful effects.

Introduction Residents learn technical and communication skills during training and practice both concurrently during awake surgical procedures. Patients have expressed mixed views on resident involvement in their surgical care, making this context challenging for residents to navigate. We sought to qualitatively explore resident perspectives on teaching during awake surgical procedures. Methods Residents in Urology, Obstetrics and Gynecology, and General Surgery who had been exposed to 10 or more awake surgical procedures were recruited for recorded focus groups at the University of Chicago. Recordings were transcribed, coded, and reviewed by 3 researchers using the constant comparative method until thematic saturation was reached. Results Twenty-five residents participated in 5 focus groups. Residents identified positive educational techniques during awake surgery including preprocedural communication, explaining teaching and the resident role, whispering/nonverbal communication, involving the patient in education, and confident educator. Residents described challenges and failures in education, including hesitating to ask questions, hesitating to correct a learner, whispering/nonverbal communication, and taking over. In discussing informed consent during awake procedures, some residents described that the consent process should or did change during awake procedures, for example, to include more information about the resident role. Conclusions Residents participating in awake surgical procedures offer new insights on successful techniques for teaching during awake surgery, emphasizing that good communication in the procedure room starts beforehand. They also identify challenges with teaching in this context, often related to a lack of open and clear communication.

As we have seen throughout this monograph, microbes play a key role in both human health, disease, response to surgery and pharmacologic intervention. Advancing the understanding of these complex relationships is in its infancy. Technological advances in analysis, large data management and interpretation of data are rapidly evolving to address disease states which have eluded investigator and clinicians. What has been learned so far, however is both exciting and humbling.

Background Surgeons are increasingly performing procedures on awake patients. Communication during such procedures is complex and underexplored in the literature. Methods Surgeons were recruited from the faculty of 2 hospitals to participate in an interview regarding their approaches to communication during awake procedures. Three researchers used the constant comparative method to transcribe, code, and review interviews until saturation was reached. Results Twenty-three surgeons described the advantages and disadvantages of awake procedures, their communication with the awake patient, their interactions with staff and with trainees, the environment of awake procedures, and how communication in this context is taught and learned. Conclusions Surgeons recognized communication during awake procedures as important and reported varied strategies for ensuring patient comfort in this context. However, they also acknowledged challenges with multiparty communication during awake procedures, especially in balancing commitments to teaching with their duty to comfort the patient.