Clinics in Colon and Rectal Surgery最新文献

Inflammatory bowel diseases (IBDs) result from dysregulated immune responses to environmental and microbial triggers in genetically susceptible hosts. Many clinical observations and animal studies support the role of the microbiome in the pathogenesis of IBD. Restoration of the fecal stream leads to postoperative Crohn's recurrence, while diversion can treat active inflammation. Antibiotics can be effective in prevention of postoperative Crohn's recurrence and in pouch inflammation. Several gene mutations associated with Crohn's risk lead to functional changes in microbial sensing and handling. However, the evidence linking the microbiome to the IBD is largely correlative, given the difficulty in studying the microbiome before disease occurs. Attempts to modify the microbial triggers of inflammation have had modest success to date. Exclusive enteral nutrition can treat Crohn's inflammation though no whole food diet to date has been shown to treat inflammation. Manipulation of the microbiome through fecal microbiota transplant and probiotics have had limited success. Further focus on early changes in the microbiome and functional consequences of microbial changes through the study of metabolomics are needed to help advance the field.

Perioperative hyperglycemia is a risk factor in surgical patients. Complications, including infection and mortality, are associated with hyperglycemia in both diabetic and nondiabetic patients. Stress hyperglycemia results in a state of insulin resistance. Insulin administration has been shown to reduce the complications associated with hyperglycemia. Glycemic targets provide goals for individualized treatment of hyperglycemia in surgical patients in the preoperative, intraoperative, and postoperative periods.

Successful outcomes after colorectal surgery result not only from technique in the operating room, but also from optimization of the patient prior to surgery. This article will discuss the role of preoperative assessment and optimization in the colorectal surgery patient. Through discussion of the various clinical models, readers will understand the range of options available for optimization. This study will also present information on how to design a preoperative clinic and the barriers to success.

Despite advances in antisepsis techniques, surgical site infection remains the most common and most costly reason for hospital readmission after surgery. Wound infections are conventionally thought to be directly caused by wound contamination. However, despite strict adherence to surgical site infection prevention techniques and bundles, these infections continue to occur at high rates. The contaminant theory of surgical site infection fails to predict and explain most postoperative infections and still remains unproven. In this article we provide evidence that the process of surgical site infection development is far more complex than what can be explained by simple bacterial contamination and hosts' ability to clear the contaminating pathogen. We show a link between the intestinal microbiome and distant surgical site infections, even in the absence of intestinal barrier breach. We discuss the Trojan-horse mechanisms by which surgical wounds may become seeded by pathogens from within one's own body and the contingencies that need to be met for an infection to develop.

The role of the microbiome in influencing the development and course of human disease is increasingly understood and appreciated. In diverticular disease, the microbiome presents an intriguing potential link between the disease and its long-established risk factors, dietary fiber and industrialization. However, current data have yet to demonstrate a clear link between specific alterations in the microbiome and diverticular disease. The largest study of diverticulosis is negative and studies of diverticulitis are small and heterogeneous. Although multiple disease-specific hurdles exist, the early state of the current research and the many un- or underexplored clinical phenotypes present a significant opportunity for investigators to improve our knowledge of this common and incompletely understood disease.

Anastomotic leak, defined by the International Study Group of Rectal Cancer as "a communication between the intra- and extraluminal compartments owing to a defect of the integrity of the intestinal wall at the anastomosis," is one of the most devastating complications in colorectal surgery. Much work has been done to identify causes of leak; however, despite advances in surgical technique, the prevalence of anastomotic leak has remained at around 11%. The potential causative role of bacteria in the etiopathology of anastomotic leak was established in the 1950s. More recently, alterations in the colonic microbiome have been shown to affect rates of anastomotic leak. Multiple perioperative factors that alter the homeostasis of the gut microbiota community structure and function have been linked to anastomotic leak after colorectal surgery. Here, we discuss the role of diet, radiation, bowel preparation, medications including nonsteroidal anti-inflammatory drugs, morphine, and antibiotics, and specific microbial pathways that have been implicated in anastomotic leak via their effects on the microbiome.

The widespread adoption of minimally invasive colorectal surgery has led to improved patient recovery and outcomes. Specimen extraction sites remain a major source of pain and potential postoperative morbidity. Careful selection of the extraction site incision may allow surgeons to decrease postoperative pain, infectious complications, or rates of hernia formation. Options include midline, paramedian, transverse, Pfannenstiel, and natural orifice sites. Patient, disease, and surgeon-related factors should all be considered when choosing a site. This article will review different options for specimen extraction sites.

A surgeon must possess the knowledge and technical skill to obtain length following a left-sided colorectal resection to perform a tension free anastomosis. The distal target organ - either rectum or anus - is fixed in location, and therefore requires surgeons to acquire mastery of proximal mobilization of the colonic conduit. Generally, splenic flexure mobilization (SFM) provides adequate length. Surgeons benefit from clearer understanding of the multiple steps involved in SFM as a result of improved visualization and demonstration of the relevant anatomy - adjacent organs and the attachments, embryologic planes, and mesenteric structures. Much may be attributed to laparoscopic and robotic platforms which provided improved exposure and as a result, development or refinement of novel approaches for SFM with potential advantages. Complete mobilization draws upon the sum or combination of the varied approaches to accomplish the goal. However, in the situation where extended resection is necessary or in the case of re-operative surgery sacrificing either more proximal or distal large intestine often occurs, the transverse colon or even the ascending colon represents the proximal conduit for anastomosis. This challenging situation requires familiarity with special maneuvers to achieve colorectal or coloanal anastomosis using these more proximal conduits. In such instances, operative techniques such as either ileal mesenteric window with retroileal anastomosis or de-rotation of the right colon (Deloyer's procedure) enable the intestinal surgeon to construct such anastomoses and thereby avoid stoma creation or loss of additional large intestine.

Ileal pouch-anal anastomosis is a popular way of reconstruction the gastrointestinal tract after total proctocolectomy for ulcerative colitis. The pouch-anal anastomosis is usually stapled, which requires the preservation of a small amount of upper anal canal and lower rectum. This includes the anal transition zone (ATZ), a surprisingly small and irregular ring of tissue at and just above the dentate line. The ATZ and rectal cuff is prone to inflammation and neoplasia, particularly in patients who had a colon cancer or dysplasia at the time their large bowel was removed. This high-risk group needs ATZ/rectal cuff surveillance before and after the surgery. Those without colorectal dysplasia preoperatively are at low risk of developing ATZ/rectal cuff dysplasia postoperatively and follow-up can be more relaxed. Treatment of ATZ dysplasia is difficult and may mean mucosectomy, pouch advancement, pouch removal, or a redo pelvic pouch.