5-Hydroxytryptamine (5-HT, serotonin) is a neurotransmitter in both the central nervous system and peripheral structures, acting also as a hormone in platelets. Although its concentration in the gut covers >90% of all organism resources, serotonin is mainly known as a neurotransmitter that takes part in the pathology of mental diseases. Serotonin modulates not only CNS neurons, but also pain transmission and platelet aggregation. In the periphery, 5-HT influences muscle motility in the gut, bronchi, uterus, and vessels directly and through neurons. Serotonin synthesis starts from hydroxylation of orally delivered tryptophan, followed by decarboxylation. Serotonin acts via numerous types of receptors and clinically plays a role in several neural, mental, and other chronic disorders, such as migraine, carcinoid syndrome, and some dysfunctions of the alimentary system. 5-HT acts as a paracrine hormone and growth factor. 5-HT receptors in both the brain and gut are targets for drugs modifying serotonin neurotransmission. The aim of the present article is to review the 5-HT receptors in the gastrointestinal (GI) tract to determine the role of serotonin in GI physiology and pathology, including known GI diseases and the role of serotonin in GI pharmacotherapy.

Background: Surgical management of severe pancreatic fistula after pancreatoduodenectomy remains challenging, and carries high mortality. The aim of this retrospective study was to compare different surgical techniques used at relaparotomy for pancreatic fistula after pancreatoduodenectomy, and to identify factors predictive of failure to rescue.Methods: A total of 43 patients after pancreatoduodenectomy developed a pancreatic fistula requiring relaparotomy. The perioperative data and outcomes were reviewed retrospectively.Results: Completion pancreatectomy, simple drainage of the pancreatic anastomosis and external wirsungostomy were performed in 17, 16, and 10 cases, respectively. The mortality rate for completion pancreatectomy was 47.1%, compared with 56.3% for simple drainage (p = 0.598) and 50.0% for external wirsungostomy (p = 0.883). Simple drainage was associated with a higher rate of further relaparotomies (56.3%) in comparison with completion pancreatectomy (23.5%, p = 0.055) and external wirsungostomy (0%, p = 0.003). A rescue resection of the pancreatic remnant after failed simple drainage resulted invariably in death. On multivariate analysis, the factors predictive of mortality after relaparotomy for pancreatic fistula were organ failure on the day of reoperation (p = 0.001) and need of further surgical reintervention (p = 0.007). Conclusion: Timely reintervention and appropriate surgical technique are essential for reducing mortality after reoperation for pancreatic fistula after pancreatoduodenectomy.

BackgroundSmall bowel tumours are rare and comprise less than 2 % of all primary gastrointestinal neoplasms. Among these tumours, a leiomyosarcoma belonging to soft tissue sarcomas is extremely rare and accounts for about 1 % of malignant mesenchymal lesions in the gastrointestinal tract. Due to its aggressive nature and slow growth, it is often diagnosed at the late stage when curative treatment is impossible. Authors report a first case of leiomyosarcoma with chronic recurrent ileocaecal intussusception and literature review to analyse diagnosis and treatment features of the ileum mesenchymal tumours.Case presentationWe present a case of an 87-year-old Caucasian man suffering from cramp-like abdominal pain for months. Due to lack of clinical signs and unspecific complaints, a diagnosis was delayed. Despite a detailed in-hospital examination, a proper diagnosis was established as late as during an operation. The patient was treated by surgery with good results. An uncommon laparoscopic resection of the small bowel with a tumour was performed. A histopathological investigation confirmed a very rare mesenchymal lesion of the distal ileum. The patient is under control with no recurrence for 1 year of the follow-up period.ConclusionsReported case indicates that a usually asymptomatic tumour can cause uncommon chronic recurrent ileus signs. CT and MRI scans are investigation of choice in such cases, but they are sometimes inconclusive. It might be worth highlighting the good results of laparoscopic leiomyosarcoma lesion resection with a very good outcome.

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract, but they represent less than 3% of all gastrointestinal tract malignancies. This is a detailed case study of a 52-year-old male patient treated for very uncommon histological subtype of gastric GIST with atypical clinical presentation, asymptomatic progress and late diagnosis. The resected tumour, giant in diameters, was confirmed to represent the most rare histopathologic subtype of GISTs - sarcomatoid epithelioid GIST. We report this case and review the literature with a special focus on pathomorphological evaluation, biological aggressiveness and prognostic factors. To our knowledge this is the first report of giant GIST of very uncommon sarcomatoid epithelioid subtype. It is concluded that clinicians should pay attention to the fact that initial diagnosis may be delayed due to mildly asymptomatic and non-specific clinical presentation. Asymptomatic tumours diagnosed at a late stage, which is often the case, can be large on presentation. Prognosis for patients diagnosed with GIST depend on tumour size, mitotic rate, histopathologic subtype and tumour location. That is why early diagnosis and R0 resection, which is usually feasible and safe even in giant gastric sarcomatoid epithelioid subtype of GISTs, are the key factors for further treatment and good prognosis.

Background Definitive surgical repair of persistent fistulas of the small intestine remains a surgical challenge with a high rate of re-fistulation and mortality. The aim of this study was to evaluate the type and incidence of complications after definitive surgical repair, and to identify factors predictive of severe postoperative complications or fistula recurrence. Material/Methods This was a retrospective study of 42 patients who underwent elective surgical repair of a persistent fistula of the small intestine. The analysis included preoperative and intraoperative parameters. Results The healing rate after definitive surgery was 71.4%. Postoperative complications developed in 88.1% of patients. The mortality rate was 7.2%. Fistula recurrence was recognized in 21.4% of cases. Overall, 93 complications occurred in 37 patients. The most common complications were septic (48.0%). Hemorrhagic and digestive tract-related complications accounted for 19.0% and 15.0% of all complications, respectively. Severe complications (Clavien-Dindo grade III–V) made up 28.0% of all complications. In univariate analysis, multiple fistulas (p=0.03), higher C-reactive protein level (p=0.01), and longer time interval from admission to definitive surgery (p=0.01) were associated with an increased risk of severe complications or fistula recurrence. In multivariate analysis, only multiple fistulas were an independent risk factor for severe complications or fistula recurrence (OR=8.2, p=0.04). Conclusions Fistula complexity determines the risk of severe postoperative complications or fistula recurrence after definitive surgical repair of the persistent small intestine fistulas. Inflammatory parameters should be normalized before definitive surgery.