Modeling realistic synaptic inputs of CA1 hippocampal pyramidal neurons and interneurons via Adaptive Generalized Leaky Integrate-and-Fire models.

Computational models of brain regions are crucial for understanding neuronal network dynamics and the emergence of cognitive functions. However, current supercomputing limitations hinder the implementation of large networks with millions of morphological and biophysical accurate neurons. Consequently, research has focused on simplified spiking neuron models, ranging from the computationally fast Leaky Integrate and Fire (LIF) linear models to more sophisticated non-linear implementations like Adaptive Exponential (AdEX) and Izhikevic models, through Generalized Leaky Integrate and Fire (GLIF) approaches. However, in almost all cases, these models are tuned (and can be validated) only under constant current injections and they may not, in general, also reproduce experimental findings under variable currents. This study introduces an Adaptive GLIF (A-GLIF) approach that addresses this limitation by incorporating a new set of update rules. The extended A-GLIF model successfully reproduces both constant and variable current inputs, and it was validated against the results obtained using a biophysical accurate model neuron. This enhancement provides researchers with a tool to optimize spiking neuron models using classic experimental traces under constant current injections, reliably predicting responses to synaptic inputs, which can be confidently used for large-scale network implementations.

INSIGHTS ON AROMATASE IMMUNOHISTOCHEMISTRY: VARIATIONS BETWEEN INTRINSIC MOLECULAR SUBTYPES OF BREAST CANCERS.

CONTEXT: Aromatase is a key enzyme in local estrogen production by androgen conversion, especially in women post-menopause. There have been controversies concerning aromatase localization in breast carcinomas and its association with current histopathological variables. MATERIAL AND METHODS: Using polyclonal antibody immunohistochemistry we assessed (by intensity and percentage scores) the immunolocalization of aromatase in 70 tissue samples, and described particularities within the molecular subtypes of breast cancer. RESULTS: Aromatase was found in all tissue compartments: tumor (95.7%), stroma (58.6%) and adipose tissue (94.3%). Aromatase expression in tumor cells correlated inversely with tumor grading (p=-0.361, p=0.027), and positively with estrogen receptor status (ER, p=0.143, p<0.001). Dividing the study group by intrinsic subtypes, a strongly inversely association between tumor aromatase and grading (p=-0.486, p<0.001), and between stromal aromatase and Ki67-index (p=-0.448, p=0.048) was observed in luminal A breast cancer. Tumor aromatase and ER percentage scores had stronger correlations in luminal B HER2 negative (p=0.632, p=0.002), and positive (p=0.324, p=0.026) tumors. In contrast, in triple negative tumors, a positive association stromal aromatase and Ki67 index (p=-0.359, p=0.007) was observed. CONCLUSION: Local aromatase was linked to better tumor differentiation and proliferation in luminal breast subtypes, and not in triple negative cases, suggesting a potential prognostic role of aromatase in breast carcinomas.

Pancreaticoduodenectomy In Patients With Hepatic Artery, Anatomic Variants: Tailoring, Perioperative Care and Surgical Outcomes.

Introduction: Pancreaticoduodenectomy (PD) is the procedure of choice in patients with tumors of pancreatic head or periampullary region. Hepatic artery anatomic variants (HAav) are frequently encountered during PD. Aim: To evaluate the incidence of HAav in a series of PDs and their consequence on technical tailoring and outcome. Material and Methods: Forty-five patients with HAav were identified in a consecutive series of 140 PDs for periampullary and pancreatic head tumors performed between January 1, 2007 and December 31, 2015. The groups with or without HAav were compared in terms of operative approach, complications and survival. Results: All patients underwent Whipple procedure, with right posterior approach for those having HAav. HAav was spared without damage in 41 cases. Four patients in whom the HAav were either sacrificed (2) or damaged (2) required arterial reconstruction. Conclusions: HAav are frequently encountered during PD. Its safeguarding is mandatory but in malignancy it can be damaged or sacrificed, hence arterial reconstruction is required. HAav have no negative impact on surgical morbidity and outcome.

Rectal impalement injury: from cruelty to salvage endeavour.

Massive penetrating trauma by rectal impalement is a very rare form of injury, complicated and potentially lethal. It is even rarer for such injury to result in pelvic, abdominal and thoracic internal damages. We report the case of a 62 year-old man who was admitted in emergency after an aggression with a sharp wooden stake inserted forcibly into his rectum. Clinical examination revealed the blunt extremity of the stake outside the anus and the prominent sharp end reaching his right supraclavicular fossa. Radiographic examination showed the stake extending from the rectum to the right side of the neck.Surgery disclosed penetration through the rectum, retroperitoneum,large bowel mesentery, liver, diaphragm, right lung and right 2nd rib. The patient survived following management by a multidisciplinary surgical team. As similar reported cases are scarce, knowledge of the management of the few cases that have been successfully treated is likely to prepare the emergency teams to act rationally and efficiently in such exceptionally grave circumstances.

Esophagectomy in esophageal cancer - is there an optimal approach?

INTRODUCTION: Esophageal cancer is a public health problem,with increasing incidence and postoperative morbidity over the past recent years. Although a number of new surgical techniques, including minimally invasive surgery, have been developed, mortality and morbidity have remained elevated.The element that seems to influence the early postoperative morbidity and mortality is the method of approach. MATERIAL AND METHODS: retrospective observational study which is carried out in the period 2003-2012 including esophageal neoplasm patients operated in the First Surgical Clinic -Hospital "Sf. Spiridon", Iasi. 140 patients were included, of which only 33 have received surgery with curative aim. SURGICAL TECHNIQUE: we consider 2 techniques in our study:transhiatal (TH) technique (without opening the chest)followed by esophagoplasty with cervical anastomosis and transthoracic esophagectomy (TT) with intrathoracic or cervical anastomosis. RESULTS: We performed 57.58 % (n = 19) of interventions by TT versus 42.42% (n = 14) by TH. The overall rate of postoperative morbidity rate was 78.8% (n = 26). Overall early postoperative mortality rate was 15.5% (n = 5) caused by pleuropulmonary sepsis (2 cases), lung emboli (1 case) and sepsis caused by anastomotic leak (2 cases). CONCLUSION: TT and TH esophagectomy have precise indications in esophageal surgery for malignancies, the mortality and morbidity rate being strongly influenced by the surgical approach.

Radiofrequency ablation device assisted liver resection for hepatocellular carcinoma.

UNLABELLED: The present study aim was to evaluate radiofrequency (RF)-assisted liver resection for hepatocellular carcinoma (HCC). PATIENTS AND METHODS: 35 consecutive patients were enrolled in this study. A Habib®4X RF ablation device (RFAD) was used for liver resection. The patients were divided into two groups: in group A (45.7%; n=16) liver resection was performed using the RFD, whereas in group B (54.3%; n=19), liver resection was performed without RFD. The data were analysed for statistical significance. RESULTS: The study population had a male female ratio of 25 10 and a mean age of 62.6 ± 11.6 years old. The mean overall tumor volume was 161.8 ± 35.5 mL and there were no differences in tumor volume between groups. The operative time and intraoperative blood loss were lower in group A,but without statistical significance [132.5 ± 61.5 vs 167.9 ± 46.3 mins, (P=0.061) and 459 ± 342 vs 716 ± 648 mL (P = 0.135)]. No differences were reported between the two groups in operative accidents (P = 0.508) and postoperative morbidity (P=0.782); a higher rate of late postoperative complications was found in group A (56.3% vs. 16.7%, P = 0.016). The overall postoperative mortality rate was 2.8%. Local recurrence was noted in 32.4%. The three-year cumulative survival rate was 60%. CONCLUSIONS: RFAD allows liver resection with low postoperative mortality and morbidity rates; RFD tends to decrease the operative time and blood loss.

Transarticular approach and retrograde plate osteosynthesis (TARPO) using implants with angular stability -- a series of 17 cases of complex distal femoral fractures type C3/AO.

AIM: The aim of this retrospective study was to evaluate the outcome of distal femoral fractures type C3 AO, using TARPO technique and plates with angular stability. MATERIAL AND METHODS: The study included 17 fractures type C3 AO, with 4 open fractures: 1 type I, 1 type II, and 2 type IIIA with bone loss Gustilo. All patients were operated by TARPO technique using Less Invasive Stabilization System-LISS (4 cases), Locked Compression Plates-LCP (8 cases) and plates with polyaxial stability (5 cases). The excellent stability of the construct allowed fast knee rehabilitation. The follow-up period included at least 12 months. RESULTS: 15 fractures healed within a mean time of 12.6 weeks,while 2 cases with open fractures and bone loss required secondary bone grafting. We recorded no infection or implant failures. The outcome using Neer scale was excellent in 9 cases and satisfactory in 7 cases (1 patient with discontinued follow-up). CONCLUSIONS: This demanding TARPO technique has the advantage of a faster rate of union and improved exposure of the knee joint. The locked plates provide a unique alternative in distal femoral fractures type C3 AO, as well as in osteoporotic and open fractures.

Allograft inflow - concern in liver transplantation after intraoperative radiotherapy for cholangiocarcinoma.

UNLABELLED: Patients who underwent local radiotherapy during surgical resection for cholangiocarcinoma are at increased risk of developing extensive thrombosis of splanchnic vessels and secondary biliary cirrhosis on the remnant liver; hence they become liver transplantation candidates. In these recipients, adequate graft inflow cannot be provided by conventional liver transplantation procedures. Cavoportal hemitransposition and renoportal anastomosis alongside complex arterial reconstructions are innovative techniques to restore allograft inflow in such cases. We report two cases of hilar cholangiocarcinoma formerly treated by left hepatectomy-Whipple en Bloc and intraoperative radiotherapy that developed late secondary biliary cirrhosis requiring liver transplantation. During transplant procedure, concern has been raised by the previous radiation-induced peritoneal injury with extended splanchnicthrombosis. Cavoportal hemitransposition and renoportal anastomosis were performed respectively, beside arterial graft reconstructions. Patients survived 57 and 18 days respectively, after transplantation. Cavoportal hemitransposition and renoportal anastomosis likewise complex arterial reconstructions are life-saving procedures to secure allograft inflow in the setting of radiation-induced extensive splanchnic thrombosis. However,this condition adversely affects patient and graft survival owing to high rates of early vascular and biliary complications, so these patients are not good liver transplantation candidates. ABBREVIATIONS: CCA - cholangiocarcinoma, CPHT - cavoportal hemitrans position, Ct - celiac trunk, DSVT - diffusesplanchnic vein thrombosis, HA - hepatic artery, IVC - inferior vena cava, LRV - left renal vein, LT - liver transplantation, PV- portal vein, PVT - portal vein thrombosis, RISC -radiation induced sclerosing cholangitis, RISC-BC - radiationinduced sclerosing with biliary cirrhosis, RPA - renoportal anastomosis.

Emergency pancreaticoduodenectomy for bleeding pancreatic pseudoaneurysm in patient with common mesentery and replaced right hepatic artery.

Pancreaticoduodenectomy is infrequently performed in emergency, so much the less in lack of traumatic evidence.A rare vascular complication of the pancreatic pseudocyst,the pseudoaneurysm, presents as a pulsating malformation which may lead to life-threatening bleeding if left untreated.Its optimal treatment remains controversial. Most authors agree that angioembolization is the first step to stabilize the patient's condition, with further surgery if such be the case.We herein report an unusual case of pancreatic head pseudocyst complicated with a bleeding pseudoaneurysm arising from the inferior pancreaticoduodenal artery, in a patient with multiple comorbid conditions, common mesentery,hepatic artery variant and hemodynamic instability. An emergency early retropancreatic approach pancreaticoduodenectomy was performed with uneventful immediate and long-term outcome. We highlight that emergency surgery allowed both rapid control over the bleeding with hemostasis and removal of the pseudocyst. This is particularly relevant in high-risk patients in whom selective angioembolization is no more of choice.

Atypical hepatic resection technique for hepatocellular carcinoma using radiofrequency Habib™ 4X Device.

INTRODUCTION: The number of liver resections significantly increased worldwide in the last 20 years. In many hepatic tumours, liver resection remains the best therapeutic option. A difficult intraoperative goal is to obtain a safe haemostasis on the transection plane. Technological innovation in recent decades allowed the development of different tools that allow better control of bleeding, faster and easier haemostasis. METHODS: We prospectively reviewed the patients diagnosed with hepatocellular carcinoma who underwent an atypical liver resection using a radio frequency (RF) ablation. SURGICAL TECHNIQUE: We used a Habib™ 4X bipolar, handheld, disposable RF ablation device. The technique is similar to parenchymal approach, but after the operative ultrasound exam to confirm the tumour and resection plane and liver mobilisation, we perform a plane of coagulative necrosis around the tumour using Habib™ 4X. The parenchyme is then sectioned using the scalpel. RESULTS: 19 patients with hepatocellular carcinoma were included in this study. The mean operative blood loss volume was 170±90.7 ml. The mean operation time was 118±58 min. The postoperative morbidity rate was 32% (n=6) and the reintervention rate was 5.3% (n=1). We encountered no postoperative deaths. The overall mean postoperative stay was 11.6±5.1 days. CONCLUSION: Bipolar radiofrequency device Habib™ 4X allows a shorter operative time with minimal blood loss and low rate of morbidity and mortality.

Effect of intraperitoneal administration of sterile human cerebrospinal fluid in rats.

INTRODUCTION: Distal ventriculoperitoneal shunt failure can be attributed to unabsorbed cerebrospinal fluid (CSF) from peritoneum. The objective of the experiment was to determine peritoneal reaction in rats after intraperitoneal administration of human CSF and evolution of local inflammatory response. MATERIALS AND METHODS: Wistar rats were used divided into four groups: three groups in which intraperitoneal injection of 3 mL, 2 mL and 0.5 mL of sterile human CSF was done and a control group. After sacrificing the animals, at 24, 48 or 72 hours, macro- and microscopic examination of the peritoneal cavity and peritoneal fluid analysis were performed. The experiment was done in compliance with legislation regarding animal research. RESULTS: Administration of high dose CSF (3 mL) led to death of all specimens. The dose of 0.5 mL of sterile CSF intraperitoneally administered was compatible with survival. Peritoneal response varied from necrotic-purulent reaction, with maximum intensity in group 1, and milder in group 2, to minimum inflammation in small foci and polymorphic cells in group 3. Inflammation only partially resolved in some specimens from group 3 after 72 hours, which incriminates the role of unabsorbed peritoneal CSF in pathogenesis of abdominal complications of ventriculoperitoneal shunts. CONCLUSIONS: Intraperitoneal administration of sterile human CSF caused inflammatory response of varying degrees and with multiple locations. High doses of CSF led to death of specimens. At 24 hours, the peritoneal response ranging from congestion to purulent reaction was acute, intense and diffuse but after 72 hours, the inflammatory response was mild, focal and limited.

Early retropancreatic lamina dissection during pancreaticoduodenectomy: how, when and why?

UNLABELLED: Pancreaticoduodenectomy is the procedure of choice for tumors of the pancreatic head and periampullary region. During pancreaticoduodenectomy, early neck division may be inadequate in case of hepatic artery anatomic variants, suspected involvement of the superior mesenteric vessels or intraductal papillary mucinous neoplasms. MATERIAL AND METHODS: We describe our early approach to the superior mesenteric vessels during pancreaticoduodenectomy, by retroportal lamina dissection before pancreatic transection. RESULTS: We used this approach in 41 patients. There were 28 patients with abnormal hepatic artery, which was spared in 26 cases. Hepatic artery reconstruction was required in 2 cases. Nine patients with intraductal papillary mucinous neoplasms underwent 6 pancreaticoduodenectomies extented to the body and 3 total pancreaticoduodenectomies. Four patients with adenocarcinoma involving the portomesenteric vein required pancreaticoduodenectomy with venous resection and reconstruction. CONCLUSIONS: Early retropancreatic lamina dissection is useful way to tailor a pancreaticoduodenectomy which is recommended in selective indications.

Laparoscopic approach to ovarian dermoid cysts.

INTRODUCTION: Ovarian dermoid cysts (mature cystic teratomas) are a benign type of germ cell tumours and the most common ovarian neoplasms in women of fertile age. The aim of this study was to analyze the safety of the laparoscopic approach in ovarian dermoid cysts. METHODS: We performed a prospective study between 2006 and ' 2010 including 38 mature cystic teratomas treated either laparoscopically or by open access. All preoperative and postoperative data were included in an MS Access database and statistically analysed with SPSS v. 17 for Windows. RESULTS: The study group was divided into 2 subgroups according to the approach: laparoscopic (25 cases - 2 conversions) and classic (13 cases). The mean age of the patients was 40.34 years (range 19-74): 36.92 years for laparoscopic group and significantly higher 46.21 years for open approach group. Twelve cases were admitted as emergencies either because of complications (torsion or rupture of the teratoma) (11 cases) or associated with acute appendicitis (one case). The latter did not influence the decision for open or laparoscopic approach. Only 29 out of 38 cases had preoperative measurement of CA 125. CA 19-9 was performed in 27 cases and elevated levels were found in 21 cases (78%). Cysts over 10 cm presented higher values of CA 19-9. The mean cysts diameter was 11.29 cm (range 2-27 cm): 13.93 cm mean cyst diameter for open approach vs 9.75 cm for laparoscopic approach. The specimen removal required aspiration of the content for cysts bigger the 10 cm in laparoscopic approach. Mean hospital stay was 4.05 days (range 2-6 days) for the laparoscopic group, significantly lower when compared with the open approach group: 6.96 days (range 5-16 days). CONCLUSIONS: Laparoscopic management of ovarian dermoid tumours is a safe and efficient procedure. It does not increase complications rate in comparison with the open approach, offering a shorter hospital stay, a quick recovery and very important, it allows a conservative treatment, especially in premenopausal women who want to be pregnant.

[Small bowel tumours from barium meal to capsule endoscopy and from open to laparoscopic approach]. / Tumorile intestinului subtire de la tranzitul baritat la enteroscopie, de la abordul clasic la cel laparoscopic.

INTRODUCTION: Tumors of the small bowel are rare and present with nonspecific symptoms. That causes a significant delay in diagnosis and consequently a worse outcome for the patient. METHODS: In a retro-prospective study we evaluated a series of 63 patients with small bowel tumors operated in the First Surgical Clinic Iasi, during 1992-2010: 18 duodenal tumors, 26 jejunum tumors and 19 ileum tumors. There were 18 (28.6%) cases with benign tumors and 45 (71.4%) cases with malignant tumors (41 primary tumors and 4 secondary tumors). We discuss problems related to diagnosis, treatment and prognosis of these tumors in the presence of new explorations (capsule endoscopy, enteroscopy) and minimally invasive approach. RESULTS: Duodenal tumors were malignant in 14 cases (11 adenocarcinomas, 3 malignant GIST tumors) and benign in 4 cases (adenoma, lipoma, GIST tumor, schwannoma) which led to stenosis in 5 cases, upper gastrointestinal bleeding in 3 cases. Positive diagnostic was confirmed with barium meal and endoscopy. The jejunal and ileal tumors were mostly malignant 31 cases (13 carcinomas, 10 lymphomas, 2 malignant GIST and one sarcoma) with only 14 cases of benign tumors (5 GIST). Their tendency was to present as emergencies: 17 obstructions and 5 peritonitis. Modem imagistic proved useful as diagnostic tool: capsule endoscopy, CT-scan and enteroscopy. The benign tumors benefited from local resection (5 cases) and segmental enterectomy (12 cases), while malignant tumors were managed using Whiple's procedures (10 cases), duodenal-jejunal resections (1 case), segmental enterectomy (29 cases), ileocolectomy (2 cases) and three bypasses. Laparoscopic approach was performed in 8 cases. CONCLUSIONS: The incidence of small bowel tumors remains low. For diagnosis, CT-scan, enteroscopy and capsule endoscopy are very useful; unfortunately the last method is not practicable in emergency. Surgery is the best choice plus chemotherapy for some malignant tumors. Laparoscopic approach is feasible in selected cases.

Laparoscopic adrenalectomy for large solid cortical tumours--is it appropriate?

BACKGROUND: Laparoscopic adrenalectomy, the procedure of choice for small benign adrenal tumours, is also used for large tumours. Our study aims to assess the outcome of large adrenal tumours laparoscopically resected. METHODS: All patients with laparoscopic adrenalectomy performed in between 2002 and 2009, without preoperative or intraoperative malignant characteristics, were reviewed. Clinical, biochemical and CT follow-up data were reviewed for evidence of recurrent disease. RESULTS: Fifty patients underwent laparoscopic adrenalectomies in our unit, 18 of them having solid cortical tumours > or = 7 cm without preoperative or intraoperative malignant features: 6 Cushing's syndrome tumours, 8 non-secreting tumours, 4 aldosteronomas. The mean age of the patients was 46.89 years (range 22-64 years), and the mean tumour size 7.57 cm (range 7-9.1 cm). Histology identified 10 cortical adenomas, 4 malignant tumours, and 4 indeterminate tumours. The mean - follow-up was 28.94 months (range 4-58 months). Three patients died of systemic recurrent disease (liver and lung metastases) at 12, 19 and 21 month, respectively, after operation. One patient underwent a left hepatectomy for liver metastases, 33 months postoperatively. Fourteen patients have no evidence of recurrence. CONCLUSIONS: Adrenal tumours > or = 7 cm without pre- or intraoperative evidence of malignancy are resectable laparoscopically. This approach is unlikely to worsen the long-term outcome. The mortality is related to the malignancy.

Laparoscopic surgical education--the experience of the first surgical unit Iasi.

The classic apprenticeship model for surgical training takes place into the operating theater under the strict coordination of a senior surgeon. During the time and especially after the introduction of minimally invasive techniques as gold standard treatment for many diseases, other methods were developed to successful fulfill the well known three stages of training: skill-based behavior, rule-based behavior and knowledge-based behavior. The skills needed for minimally invasive surgery aren't easily obtained using classical apprenticeship model due to ethical, medico-legal and economic considerations. In this way several types of simulators have been developed. Nowadays simulators are worldwide accepted for laparoscopic surgical training and provide formative feedback which allows an improvement of the performances of the young surgeons. The simulators currently used allow assimilating only skill based behavior and rule-based behavior. However, the training using animal models as well as new virtual reality simulators and augmented reality offer the possibility to achieve knowledge-based behavior. However it isn't a worldwide accepted laparoscopic training curriculum. We present our experience with different types of simulators and teaching methods used along the time in our surgical unit. We also performed a review of the literature data.

Laparoscopic retrieval of gossypibomas--short series and review of literature.

UNLABELLED: Laparoscopic removal of retained abdominal foreign bodies represents an obscure domain of minimally invasive surgery. Although not an infrequent situation in general surgical practice, there are very few papers presenting laparoscopic approache in these circumstances. An iatrogenic foreign body following surgery, is a serious complication that may lead to medico-legal problem. We present our experience and a literature review. METHODS: In the last 20 years 48 patients with abdominal foreign bodies were referred to us. Out of these four gossypibomas were managed laparoscopically. RESULTS: Retained swabs represent the most common iatrogenic abdominal foreign bodies. Removal of gossypiboma present more problems in laparoscopic environment due to encapsulation and difficulties in localisation, as retained swabs unusually display radio-opaque markings. There was one conversion due to dense adhesion to the gastric wall. Postoperative recovery was uneventful in all cases. CONCLUSIONS: Gossypibomas, among abdominal foreign bodies, represent a certain reality with significant legal implications. Prevention should prevail and all efforts should be made in such respect. Laparoscopic approach is possible in selected cases (small swabs, encapsulated, no complications).

VAMPIRE: Vessel assessment and measurement platform for images of the REtina.

We present VAMPIRE, a software application for efficient, semi-automatic quantification of retinal vessel properties with large collections of fundus camera images. VAMPIRE is also an international collaborative project of four image processing groups and five clinical centres. The system provides automatic detection of retinal landmarks (optic disc, vasculature), and quantifies key parameters used frequently in investigative studies: vessel width, vessel branching coefficients, and tortuosity. The ultimate vision is to make VAMPIRE available as a public tool, to support quantification and analysis of large collections of fundus camera images.

Treatment of gastrointestinal stromal tumors--initial experience.

BACKGROUND: Gastrointestinal Stromal Tumors (GIST) offered the first opportunity of a specific treatment in neoplasms (tyrosine-kinase inhibitors) and also a new perspective of management of other neoplasms. METHODS: We have prospectively recorded the clinical characteristics, type of surgery, pathologic findings, adjuvant treatment, and recurrence of the patients with confirmed GISTs admitted between January 2004 and December 2008. RESULTS: There were 18 patients. Location of the tumor was gastric (44.44%), duodenal (11.11%), jejunal (16.67%), right colon (5.55%) and rectal (22.22%). None of our patients had clinical, imagistic or macroscopic metastases. All the patients had R0 resections, except a patient with local excision and another with R1 anterior resection for rectal GISTs. Postoperatively, 4 patients received Imatinib therapy. The mean follow-up period is 32 months (range 8-58 months); 2 recurrences, both after rectal GISTs. The rest of patients are tumor-free and subjects of prospective follow-up. CONCLUSION: We present the first 5 years experience of a prospective study of GIST started in 2004. The complete resection and the malignant potential according to Fletcher index are the most significant prognostic factors. Imatinib treatment may improve outcome in incomplete resected or high risk GISTs.