Medicine (Abingdon, England : UK ed.)最新文献

Technological advancements have shaped the landscape of modern gastroenterology thanks to the accessibility of the gastrointestinal tract to endoscopic interventions. Over the last decade increasing research efforts have been dedicated to integrating artificial intelligence into endoscopy to allow the early detection of premalignant and early malignant lesions. Meanwhile, progress has been made in minimally invasive cell collection devices to reduce the burden of endoscopy in the context of preventive medicine. In the context of therapeutic interventions, there has been significant advancement in endoscopic techniques for the resection of early-stage cancer and the palliation of advanced malignancies. In the field of benign disease, novel techniques have been introduced to expand the endoscopic therapeutic portfolio for conditions such as gastro-oesophageal reflux disease, type 2 diabetes and obesity. This review addresses novel gastrointestinal procedures that have been developed or gained substantial evidence in the last 5 years, which are likely to impact clinical practice in the future.

Inherited gastrointestinal (GI) cancer syndromes account for 5–10% of cancers of the GI tract. Surveillance is tailored to prevent cancer or enable its early detection. Lynch syndrome accounts for 3% of colorectal cancers (CRCs). It is caused by a germline pathogenic variant that affects one of four mismatch repair genes: MLH1, MSH2, MSH6 or PMS2. Individuals with a variant affecting MLH1 have the highest risk of developing CRC. Familial adenomatous polyposis (FAP) is an autosomal dominant syndrome caused by a truncating mutation of the APC gene. It is characterized by the development of adenomas in the colon and upper GI tract. Almost 100% of patients who have not undergone a colectomy develop CRC, and 5% of FAP patients develop duodenal cancer. MUTYH-associated polyposis is an autosomal recessive cancer syndrome with a similar phenotype and surveillance strategy to FAP. Peutz–Jeghers syndrome is an autosomal dominant condition characterized by hamartomas of the GI tract; these patients are at increased risk of cancer of the GI tract, breast and pancreas. Juvenile polyposis syndrome is associated with the development of GI tract hamartomas and an associated increased risk of cancer of the colon and stomach.

Colonic diverticula are formed by mucosal outpouching from the colonic wall. Their presence increases with increasing age, with most, white patients, being situated in the left colon. The aetiology of these outpouchings is not fully understood but dietary, lifestyle and genetic factors have all been implicated. Most patients with diverticula are asymptomatic (diverticulosis); however, approximately 20% develop symptoms such as intermittent abdominal pain and change in bowel habit and are said to have symptomatic diverticular disease. Acute diverticulitis is characterized by acute inflammation within these pockets, with associated constitutional symptoms. Other complications include perforation, abscess, fistulae, strictures and bleeding, albeit in relatively few people. Stratifying patients using high-quality computed tomography is important as it allows a more tailored approach to treatment. Managing chronic symptoms in symptomatic diverticulosis requires identifying those with irritable bowel syndrome, who might respond differently, from those with symptoms after acute diverticulitis. A high-fibre diet, cyclical antibiotics and anti-inflammatory treatments have been proposed, but no treatments have yet been shown to benefit unselected patients with symptomatic diverticular disease. Planned surgical resection in symptomatic patients must be undertaken on a case-by-case basis. In those with complicated disease tailored treatment based on age, co-morbidity and functional status is the main stay of management.

The most common form of pancreatic cancer is pancreatic ductal adenocarcinoma. The long-term outcome of pancreatic cancer is extremely poor: overall median survival from diagnosis is 3–6 months without treatment, increasing to around 23 months with resectional surgery and adjuvant treatment. Pancreatic cancer is usually diagnosed late and has a biological phenotype characterized by resistance to all cancer treatment modalities and early metastasis. Jaundice is the most common presenting symptom. Endoscopic stent placement is preferable to transhepatic stenting. The average patency of metal biliary stents is about twice that of plastic stents, which last about 4 months. Curative surgery is rare. Pancreatoduodenectomy is the most appropriate resectional procedure for tumours of the pancreatic head. Surgery should be confined to specialist centres to reduce morbidity and mortality and increase resection rates. Adjuvant treatment is recommended for patients undergoing resection with curative intent. Efforts should be made to obtain a tissue diagnosis in patients selected for palliation. In the event of gastric outlet obstruction, endoscopic duodenal stenting should be used in addition to palliative endoscopic biliary stenting. If chemotherapy is used for palliation, the combination chemotherapy regimen of FOLFIRINOX (leucovorin (folinic acid), 5-fluorouracil, irinotecan, oxaliplatin) is currently the treatment of choice.

Ethanol intoxication is commonly encountered and can cause hypotension, hypoglycaemia, lactic acidosis, seizures and coma. Isopropyl alcohol and its metabolite acetone cause profound depression of the central nervous system with rapid onset. Toxic alcohols include methanol, ethylene glycol and diethylene glycol; these can cause severe metabolic acidosis, acute renal failure and, for methanol, severe visual disturbance. Toxicity is attributable to metabolites and there is a characteristic delay between ingestion and the occurrence of severe toxicity. Assessment of the extent of exposure requires laboratory confirmation of toxic alcohol concentrations, which conventionally involves specialized laboratory assays that are not always readily available. Management strategies include assessment of toxic alcohol exposure, early administration of fomepizole to prevent formation of metabolites and, in patients with established poisoning, haemodialysis to remove metabolites.

Colorectal cancer is the fourth most common cause of cancer, contributing to 11% of all cancers, and the second most common cause of cancer death worldwide. The lifetime risk is greater in developed countries compared with lesser-developed countries, with survival influenced by stage of disease, socioeconomic factors and healthcare access. Early detection through bowel screening programmes in asymptomatic populations, risk stratification of symptomatic populations and surveillance of high-risk groups aim to identify early-stage disease. Specialist surgery, despite the associated morbidity and mortality, offers the best chance of cure for non-metastatic disease. Isolated metastatic disease is increasingly resected, with good results. This article summarizes the management of colorectal cancer, with a focus on early rectal and polyp cancers, which can pose management dilemmas.

Colorectal cancer (CRC) is very common, affecting >40,000 people a year in the UK. The pathogenesis is mostly sporadic, but hereditary genes and inflammatory bowel disease are well-known causative factors. The symptoms can be very variable, are based on the location of the lesion and tend to be more obscure if they are right sided. Symptoms also overlap with benign conditions so luminal imaging, mainly colonoscopy as the gold standard, is needed. Bowel cancer screening programmes are designed to detect the earlier stages of CRC. Once the diagnosis has been made, staging is undertaken through computed tomography (CT) of the chest, abdomen and pelvis. For rectal cancers, extra characteristics are obtained through magnetic resonance imaging (MRI) of the pelvis to guide potential preoperative oncology treatment. Additional investigations, such as MRI of the liver or CT positron emission tomography, are sometimes advised through multidisciplinary team discussions to further guide treatment plans.

Gastrointestinal (GI) symptoms are common in both inflammatory and non-inflammatory connective tissue disorders and can involve any part of the GI tract from mouth to anus. Dysphagia, gastro-oesophageal reflux, nausea, vomiting, abdominal pain and changes in bowel habit are common symptoms and usually arise from GI dysmotility and altered visceral sensitivity. In scleroderma, sensorimotor dysfunction is pronounced and can result in complications such as Barrett's oesophagus, gastroparesis, small intestinal bacterial overgrowth, malabsorption and malnutrition, with an associated reduction in survival. Treatment is aimed at symptom control and prevention of complications. In hypermobile Ehlers–Danlos syndrome, symptoms are often caused by functional GI disorders such as functional dyspepsia or irritable bowel syndrome; these can also be secondary to associated co-morbidities (e.g. chronic pain, anxiety, postural tachycardia syndrome, opioid use). The patho-aetiology of these conditions appears to be more related to sensory disturbances than dysmotility, although the latter can be present particularly in patients with co-morbid postural tachycardia syndrome. A holistic approach to management must be taken to address all contributing factors, especially anxiety, diet and medication adverse effects.

Most anal diseases can be diagnosed by a careful history and examination. Management of haemorrhoids involves exclusion of more serious pathology, adequate explanation of the disorder, and dietary and defecatory advice; most do not require additional treatment. Outpatient procedures or surgical intervention can be required for more symptomatic cases. Anal fissures are initially managed with bulking laxatives and non-constipating analgesics; glyceryl trinitrate ointment is standard first-line treatment. Lateral internal sphincterotomy is indicated rarely for fissures that do not heal after pharmacological management, although it is associated with a small risk of impaired continence. Anal fistulae and abscesses represent extremes of a single disease spectrum. Perianal abscesses should be treated by prompt adequate surgical drainage. Low fistulae are treated by fistulotomy. High fistulae require more complex sphincter-preserving techniques. Patients with faecal incontinence should be investigated with anal physiological tests and endoanal ultrasonography. Conservative treatment includes dietary modification, constipating drugs, physiotherapy and biofeedback. Sacral nerve stimulation represents a new, expensive but relatively non-invasive treatment option for patients with faecal incontinence after failure of first-line conservative therapy. Patients with functional constipation should be assessed to distinguish slow transit from obstructed defecation. Laparoscopic ventral rectopexy can be appropriate for selected patients with rectal intussusception.