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.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophins group which plays a crucial role in brain development and neurogenesis. In the hypothalamus it is described as playing a role in energy metabolism and feeding behaviour. The hippocampal concentration of BDNF is believed to play an important role in learning and memory, it has a protective role in neurodegeneration and stress responses. BDNF is also known to take part in many other processes, e.g. angiogenesis, proliferation, cell migration and apoptosis. With its receptor TrkB, neurotrophins are important agents that playa role in neural diseases, as well as in cardiovascular and metabolic disorders, such as diabetes mellitus or acute coronary syndrome. Over the last few years, BDNF interaction with TrkB has also been found to be involved in cancer development, including brain, breast, urinary and gastrointestinal cancer. TrkB expression itself has been described as an aggressive neural tumour. BDNF/TrkB signalling takes part in promoting tumour growth and metastasis. The presented review focuses on gastrointestinal cancer and presents the current literature concerning influence of BDNF and TrkB receptor in cancer progression. Special attention is also paid to data confirming the possible role of BDNF/TrkB interaction in chemotherapy resistance. This might present the opportunity to assess the BDNF and TrkB pathway as a possible novel target for anticancer therapies.

Purpose: The aim of the study was to determine of carcinoembryonal antigen and matrix metalloproteinase 2 peritoneal washes and serum concentration in patients suffering from colorectal cancer concerning tumor staging and 5-year survival rate in these patients. Methods: 80 patients who underwent curative surgery for colorectal cancer were included into the study. Preoperative serum and intraoperative peritoneal washes CEA and MMP-2 concentrations were measured. Results: Concerning tumor penetration CEA-s and CEA-p concentration was higher in subsequent stages from T2 to T4. Both CEA-s and CEA-p concentration was lower in T2 comparing to T3 and T4. Significant difference of CEA-s and CEA-p was noted between T2 and T4 stages. MMP2-s concentration was higher in T3 comparing to T2, the highest MMP2-p concentration was in T4, with no statistical significance. Concerning nodular status significant difference of CEA-s was noted between N0 and N1. For CEA-p significance was found between N0 and N2 as between N1 and N2. MMP2-s concentration was the highest in N1, MMP2-p concentration was the highest in T4, with no statistical significance. 5-year survival rate for all patients was 63,53%. There were significant differences in CEA-s and CEA-p concentration between patients with negative and positive 5-year survival. Conclusion: Intraoperative peritoneal washes concentration of CEA may potentially serve as an important factor for more precise colorectal cancer staging. CEA-p and CEA-s concentration correlates with survival rate in patients suffering from colorectal cancer and can be useful as an additional prognostic factor. Usefulness of MMP2 measurement still requires further studies.

Background Brain derived neurotrophic factor (BDNF) is a neurotrophin involved in neural and metabolic diseases, but it is also one of the crucial factors in cancer development and metastases. In the current study, we investigated serum BDNF concentrations in patients that underwent surgical treatment for colorectal cancer or pancreatic cancer. Methods Serum BDNF concentrations were measured with standard enzyme-linked immunosorbent assays, before and on the third day after the operation, in 50 consecutive patients with colorectal cancer and 25 patients with pancreatic cancer (tumours in the head of pancreas). We compared pre- and postoperative BDNF levels, according to the subsequent TNM stage, histologic stage, lymph node involvement, neuro- or angio-invasion, and resection range. Results In the pancreatic cancer group, BDNF concentrations fell significantly postoperatively (p = 0.011). In patients that underwent resections, BDNF concentrations fell (p = 0.0098), but not in patients that did not undergo resections (i.e., laparotomy alone). There were significant pre- and postoperative differences in BDNF levels among patients with (p = 0.021) and without (p = 0.034) distant metastases. Significant reductions in BDNF were observed postoperatively in patients with small tumours (i.e., below the median size; p = 0.023), in patients with negative angio- or lymphatic invasion (p = 0.028, p = 0.011, respectively), and in patients with lymph node ratios above 0.17 (p = 0.043). In the colon cancer group, the serum BDNF concentrations significantly fell postoperatively in the entire group (p = 0.0076) and in subgroups of patients with or without resections (p = 0.034, p = 0.0179, respectively). Significant before-after differences were found in subgroups with angioinvasions (p = 0.050) and in those without neuroinvasions (p = 0.049). Considering the TNM stages, the postoperative BDNF concentration fell in groups with (p = 0.0218) and without (p = 0.034) distant metastases and in patients with tumours below the median size (p = 0.018). Conclusion Our results suggested that BDNF might play an important role in gastrointestinal cancer development. BDNF levels were correlated with tumour volume, and with neuro-, angio- and lymphatic invasions. In pancreatic cancer, BDNF concentrations varied according to the surgical procedure and they fell significantly after tumour resections. Thus, BDNF may serve as a potential marker of complete resections in underdiagnosed patients. However, this hypothesis requires further investigation. In contrast, no differences according to the procedure was made in patients with colon cancer.