Bailliere's clinical gastroenterology最新文献

Percutaneous biliary drainage is the most common aetiology of haemobilia. Bile duct fistulae can also arise from the hepatic or portal vein, most commonly as a result of trauma. Percutaneous methods for treating haemobilia from all these sources are discussed in detail.

Disordered motility of the biliary tract may be associated with the aetiology of common biliary tract conditions, such as gallstones. In this instance, treatment of the gallstone disease alleviates symptoms in the majority of patients. However, in up to 10% of patients, biliary motility disorders may present in the absence of gallstones or in patients after cholecystectomy. Gallbladder dyskinesia results in biliary-type pain. This abnormality may be objectively identified using the radionuclide gallbladder ejection fraction. The majority of patients with an abnormal test are improved or cured following cholecystectomy. Sphincter of Oddi dysfunction presents with either recurrent biliary-type pain or recurrent pancreatitis. Manometry of the sphincter of Oddi objectively identifies patients with manometric stenosis. The majority of these patients are improved or cured following division of the sphincter of Oddi.

Primary sclerosing cholangitis (PSC) is a chronic, progressive cholestatic liver disease whose aetiopathogenesis is unknown. PSC is frequently associated with inflammatory bowel disease, in particular chronic ulcerative colitis, is most commonly observed in young males and is clinically characterized by fatigue, pruritus and jaundice. The diagnosis is supported by a cholestatic biochemical profile and histological abnormalities, and confirmed by visualization of an abnormal biliary tree. The natural history of the disease is currently being evaluated but is generally recognized to be slowly progressive, leading to complications of chronic cholestasis, portal hypertension and biliary cirrhosis. There is no specific medical treatment, and orthotopic liver transplantation remains the only definitive treatment for patients with end-stage PSC. A more rational approach to medical therapy will ensue upon a better understanding of the aetiopathogenesis of this disease.

The use of oral rehydration solution (ORS) with early refeeding forms the basis of therapy for dehydration secondary to diarrhoea. ORS has produced such positive results in dehydrated patients that no further scientific demonstration is needed to confirm its efficacy. This review presents several issues that remain unsettled or controversial. They include the following.

• 1.

  1. The mechanism of water handling by the intestine is discussed; this is more complex than initially thought, at the epithelial, cellular and molecular level.

• 2.

  2. The composition of ORS which has been successfully adapted for the most frequent conditions, except for severely malnourished children, is described.

• 3.

  3. In contrast to the strong scientific basis and obvious efficacy in rehydration of ORS, its consequences for growth, nutrition and mortality are difficult to demonstrate, unless adequate long-term nutritional support is also provided in addition to ORS.

• 4.

  4. Finally, discrepancies between the recommendations and the practice of oral rehydration therapy are now well documented. Analysis of the causes of these discrepancies may participate in improving public health campaigns.

Pathological processes and disease entities in the upper gastrointestinal (GI) tract, specifically those of the oesophagus and the stomach in infancy, have received a disproportionately small amount of attention until recently when appreciation of their pathophysiology and concordant importance in terms of symptomatology has been highlighted. This is probably a phenomenon secondary to improved diagnostic yield from the recent technical advances in areas such as infant endoscopy and a shift in opinion regarding the pathophysiological origin of ubiquitous symptoms of infancy such as feeding disorders, colic and irritability.

In addition, the apparently complex interactions of various aetiological factors such as pH-independent gastro-oesophageal reflux (GOR), cow's milk protein intolerance (CMPI), Helicobacter pylori gastritis and upper GI motor disorders have in the past 1–2 years become underlined in terms of aetiopathogenesis and have radically changed thinking regarding diagnosis and therapy of infants with apparent upper-GI-associated symptoms.

The contribution to comprehension of infant upper GI disorders of inflammatory paradigms and ontogeny of the upper GI tract is also a recent area worthy of mention. The recent advances in all of these areas and their contribution to the understanding, and subsequent diagnosis and therapy, of upper GI symptoms and their explanation by way of aetiopathogenesis will be explored in this chapter.

The aim of therapy in Crohn's disease in childhood is to induce and to maintain a remission of disease activity so that normal growth and development of the child may occur. Enteral nutrition may now be recommended as the first-line treatment for most children with Crohn's disease. However, the evidence for remission is better for children with Crohn's disease of the small intestine rather than of the large intestine. There is evidence that amino acid feeds (elemental), whole protein (polymeric) and. protein hydrolysate feeds (semi-elemental) may all be successful. Such a therapeutic approach can lead to healing of the mucosa and down-regulation of inflammation. However, in some cases surgery is required, particularly in children with growth failure and delayed puberty. Drug therapy also continues to have a role in therapy especially with severe colonic disease.

The management of patients with intestinal failure has benefited from progress in parenteral nutrition (PN), especially home-based PN. Intestinal transplantation is therefore possible and is now, in some conditions, the logical therapeutic option. Since 1985, more than 180 small-bowel grafts have been done, involving the isolated small bowel with or without the colon (38%), the liver-small bowel (46%) or several organs (16%). Two-thirds of recipients were under 20 years of age, and indications were short-bowel syndrome (64%), severe intractable diarrhoea (13%), abdominal cancer (13%) or chronic intestinal pseudo-obstruction syndrome (8%). Of the patients, 51% survived > 2 years after the graft. Patient and graft survival depends on the type of immunosuppression, i.e. cyclosporine or FK506. The results must be interpreted carefully as they represent the first experience in numerous centres using different immunosuppressive protocols, without any randomization. The results from the largest of these centres reflect the current situation more closely.

Functional grafts lead to gastrointestinal autonomy (weaning of PN) while maintaining satisfactory nutritional status and normal growth in childhood. Intestinal transplantation is theoretically indicated for all patients permanently or dependent for a long time on PN. However, as PN is generally well tolerated, even for long periods, each indication for transplantation must be carefully weighed up in terms of the iatrogenic risk and quality of life. When PN has reached its limits, especially in those associated with vascular, infectious, hepatic or metabolic complications, intestinal transplantation must be undertaken. Transplantation of the small bowel alone remains the first option, as combined liver-small bowel grafting is only indicated in the case of life-threatening progressive cirrhogenic liver disease.

The intractable diarrhoeas of infancy present very major problems of clinical management. However, the conceptual importance of these conditions lies in the information that they may provide about normal small-intestinal function in humans: among such infants will be found the human equivalents of the ‘knock-out’ mice, in which targeted gene disruption allows sometimes unexpected insight into the regulation of intestinal function. The challenge posed by the intractable diarrhoeal syndromes, of working backwards from an apparently common phenotype to probably multiple genotypes, is, however, immense. Very few of these conditions have been described at the genetic level, although the molecular basis of pathogenesis has been better explored in recent years.

The two major groups of intractable diarrhoea are due to (1) primary epithelial abnormalities (which usually present within the first few days of life) and (2) immunologically mediated (which generally present after the first few weeks). The high prevalence of autoimmune enteropathy among infantile autoimmune disease, in contrast to adult autoimmunity, is intriguing and may reflect constitutive abnormality of extrathymic lymphocyte maturation. The use of potent immunosuppressive drugs and increasing expertise with parenteral nutrition are improving the outlook of these previously fatal conditions.

Viewed globally, however, the pressing problem is to treat effectively the millions of infants who die from severe persistent diarrhoea and wasting, which would certainly not be considered intractable in wealthy countries.

Coeliac disease is the life-long intolerance to dietary gluten, usually characterized by severe damage to the small-intestinal mucosa. The widespread use of sensitive diagnostic tools, such as the serum anti-gliadin and the anti-endomysial antibodies, has shown not only that coeliac disease is one of the commonest disorders in Western countries but also that this condition is characterized by a higher degree of clinical variability than previously thought (typical, atypical and silent forms). The existence of a latent-potential coeliac disease and even a gluten-sensitive disease with immunological activation of an otherwise normal small-intestinal mucosa has recently been postulated. An increased prevalence of coeliac disease in a number of other disorders has also been reported in both children and adults. The reasons for such a wide clinical heterogeneity are still poorly understood but are likely to depend on both genetic and environmental factors. Further investigations are required to evaluate the impact of undiagnosed, clinically milder forms of coeliac disease on the well-being of the population.

Damage to the developing central nervous system may result in significant dysfunction in the gastrointestinal tract and is reflected in impairment in oral-motor function, rumination, gastro-oesophageal reflux, with or without aspiration, delayed gastric emptying and constipation. These problems can all potentially contribute to feeding difficulty in disabled children. Early recognition of an infant with neurological impairment that is compromising the normal feeding process is crucial. Detailed assessment of the nature of the feeding difficulties will help to predict the anticipated future nutritional needs and will allow decisions to be made about the appropriateness of input from different professionals (speech therapy, dietitians, gastroenterologists). Only when such information has been carefully assembled will rational and directed medical and surgical therapy be possible. Nutritional rehabilitation of disabled children can be associated with increased mortality and morbidity secondary to gastro-oesophageal reflux, retching, dumping syndrome or aspiration. It may also entail an increased work for care givers and increase costs of care. It is therefore necessary to document the impact of such rehabilitation on growth and quality of life for both patient and care giver.