Ischemic colitis:Clinical practice in diagnosis and treatment

Ischemic colitis is the most common form of ischemic injury of the gastrointestinal tract and can present either as an occlusive or a non-occlusive form. It accounts for 1 in 1000 hospitalizations but its incidence is underesti- mated because it often has a mild and transient nature. The etiology of ischemic colitis is multifactorial and the clinical presentation variable. The diagnosis is based on a combination of clinical suspicion, radiographic, endo- scopic and histological findings. Therapy and outcome depends on the severity of the disease. Most cases of the non-gangrenous form are transient and resolve spontaneously without complications. On the other hand, high morbidity and mortality and urgent operative intervention are the hallmarks of gangrenous ischemic colitis.

Thrombosis and inflammatory bowel disease-the role of genetic risk factors

Thromboembolism is a significant cause of morbidity and mortality in patients with inflammatory bowel disease （IBD）. Recent data suggest thromboembolism as a disease-specific extraintestinal manifestation of IBD, which is developed as the result of multiple interactions between acquired and genetic risk factors. There is evidence indicating an imbalance of procoagulant, anticoagulant and fibrinolitic factors predisposing in thrombosis in patients with IBD. The genetic factors that have been suggested to interfere in the thrombotic manifestations of IBD include factor V Leiden, factor Ⅱ （prothrombin, G20210A）, methylenetetrahydrofolate reductase gene mutation （MTHFR, 6777T, plasminogen activator inhibitor type 1 （PAI-1） gene mutation and factor X Ⅲ （val34leu）. In this article we review the current data and future prospects on the role of genetic risk factors in the development of thromboembolism in TBD.

Multipotent role of platelets in inflammatory bowel diseases:A clinical approach

There is evidence that inflammatory bowel diseases (IBD) combine both inflammation and coagulation in their pathogenesis and clinical manifestations. Although platelets (PLT) are well known for their role in hemostasis, there are a rising number of studies supporting their considerable role as inflammatory amplifiers in chronic inflammatory conditions. IBD are associated with several alterations of PLT, including number, shape, and function, and these abnormalities are mainly attributed to the highly activated state of circulating PLT in IBD patients. When PLT activate, they increase in size, release a great variety of bio-active inflammatory and procoagulant molecules/particles, and express a variety of inflammatory receptors. These inflammatory products may represent a part of the missing link between coagulation and inflammation, and can be considered as possible IBD pathogenesis instigators. In clinical practice, thrombocytosis is associated both with disease activity and iron deficiency anemia. Controlling inflammation and iron replacement in anemic patients usually leads to a normalization of PLT count. The aim of this review is to update the role of PLT in IBD and present recent data revealing the possible therapeutic implications of anti-PLT agents in future IBD remedies.

Stimulating erythropoiesis in inflammatory bowel disease associated anemia

Anemia is a frequent complication in patients with inflammatory bowel disease (IBD), and is associated with decreased quality of life and increased rate of hospitalization. The primary therapeutic targets of IBD- associated anemia are iron deficiency and anemia of chronic disease. An important prognostic parameter of the success or failure of therapy is the outcome of the underlying disease. Iron deficiency should be appropriately managed with iron supplementation. However, the use of oral iron therapy is limited by several problems, the most important being gastrointestinal side effects leading occasionally to disease relapse and poor iron absorption. Intravenous iron preparations are more reliable, with iron sucrose demonstrating the best efficacy and tolerability. Treatment with erythropoietin or darbepoetin has been proven to be effective in patients with anemia, who fail to respond to intravenous iron. Patients with ongoing inflammation have anemia of chronic disease and may require combination therapy comprising of intravenous iron sucrose and erythropoietin. After initiating treatment, careful monitoring of hemoglobin levels and iron parameters is needed in order to avoid recurrence of anemia. In conclusion, anemia in the setting of IBD should be aggressively diagnosed, investigated, and treated. Future studies should define the optimal dose and schedule of intravenous iron supplementation and appropriate erythropoietin therapy in these patients.

Is there a role for Tc-99m (V) DMSA scintigraphy in ischemic colitis?

AIM: To evaluate the role of pentavalent Tc-99m dimercaptosuccinic acid [Tc-99m (V) DMSA] in the diagnosis of ischemic colitis. METHODS: Fourteen patients with endoscopically and histologically confirmed ischemic colitis were included in the study. Tc-99m (V) DMSA scintigraphy was performed within 2 d after colonoscopy. Images were considered positive when an area of increased activity was observed in the region of interest and negative when no abnormal tracer uptake was detected. RESULTS: In 3 out of the 14 patients, Tc-99m (V) DMSA images showed moderate activity in the bowel. The scintigraphic results corresponded with the endoscopic findings. In the other 11 patients, no abnormal tracer uptake was detected in the abdomen. CONCLUSION: Besides the limited number of patients, Tc-99m (V) DMSA could not be considered as a useful imaging modality for the evaluation of ischemic colitis.

Recent advances in the management of distal ulcerative colitis

The most frequent localization of ulcerative colitis(UC) is the distal colon.In treating patients with active distal UC,efficacy and targeting of the drug to the distal colon are key priorities.Oral and rectal 5-aminosalicylic acid(5-ASA) preparations represent the first line therapy of mild-to-moderate distal UC for both induction and maintenance treatment.It has been reported that many UC patients are not adherent to therapy and that noncompliant patients had a 5-fold risk of experiencing a relapse.These findings led to the introduction of oncedaily oral regimens of 5-ASA as better therapeutic options in clinical practice due to improved adherence.New formulations of mesalazine,including the multimatrix delivery system,and mesalazine granules,which allow once-daily administration,have been developed.They have been demonstrated to be efficacious in inducing and maintaining remission in mild-to-moderate distal UC in large clinical trials.However,existing data for distal UC are rather insufficient to make a comparison between new and classical 5-ASA formulations.It seems that the new formulations are at least as effective as classical oral 5-ASA formulations.Other treatment options,in the case that 5-ASA therapy is not effective,include systemic corticosteroids,thiopurines(azathioprine or 6-mercaptopurine),cyclosporine,infliximab and surgery.The combination of a prompt diagnostic work-up,a correct therapeutic approach and an appropriate follow-up schedule is important in the management of patients with distal UC.This approach can shorten the duration of symptoms,induce a prolonged remission,improve patient's quality of life,and optimize the use of health resources.

Role of scintigraphy in inflammatory bowel disease

The diagnosis of inflammatory bowel disease(IBD) depends on direct endoscopic visualization of the colonic and ileal mucosa and the histological study of the obtained samples.Radiological and scintigraphic methods are mainly used as an adjunct to endoscopy.In this review,we focus on the diagnostic potential of nuclear medicine procedures.The value of all radiotracers is described with special reference to those with greater experience and more satisfactory results.Tc-99m hexamethylpropylene amine oxime white blood cells remain a widely acceptable scintigraphic method for the diagnosis of IBD,as well as for the evaluation of disease extension and severity.Recently,pentavalent Tc-99m dimercaptosuccinic acid has been recommended as an accurate variant and a complementary technique to endoscopy for the follow-up and assessment of disease activity.Positron emission tomography alone or with computed tomography using fluorine-18 fluorodeoxyglucose appears to be a promising method of measuring inflammation in IBD patients.

Spectrum of non-inflammatory bowel disease and non-infectious colitis

A variety of inflammatory diseases of the colon, which can be differentiated from inflammatory bowel disease (IBD) and infectious colitis by their clinical, endoscopic and histological characteristics, are reported as non- IBD and non-infectious colitis. These diseases include microscopic colitis, ischemic colitis, segmental colitis associated with diverticula, radiation colitis, diversion colitis, eosinophilic colitis and Behcet's colitis. The etiopathogenesis of most of these diseases remains obscure and the epidemiological data are rather limited. These conditions are often troublesome for the patient and are associated with diagnostic difficulties for the physician. In many cases the treatment is empirical and there is a need for future research using randomized controlled trials.

Solid extraintestinal malignancies in patients with inflammatory bowel disease

Malignancies constitute the second cause of death in patients with inflammatory bowel diseases(IBD),after cardiovascular diseases.Although it has been postulated that IBD patients are at greater risk of colorectal cancer compared to the general population,lately there has been evidence supporting that this risk is diminishing over time as a result of better surveillance,while the incidence of extraintestinal cancers(EICs)is increasing.This could be attributed either to systemic inflammation caused by IBD or to long-lasting immunosuppression due to IBD treatments.It seems that the overall risk of EICs is higher for Crohn’s disease patients and it is mainly driven by skin cancers,and liver-biliary cancers in patients with IBD and primary sclerosing cholangitis.The aims of this review were first to evaluate the prevalence,characteristics,and risk factors of EICs in patients with IBD and second to raise awareness regarding a proper surveillance program resulting in early diagnosis,better prognosis and survival,especially in the era of new IBD treatments that are on the way.