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Dive into the research topics where Ioannis Vassiliou is active.

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Featured researches published by Ioannis Vassiliou.


Pancreas | 2009

Pancreatic leakage after pancreaticoduodenectomy: the impact of the isolated jejunal loop length and anastomotic technique of the pancreatic stump.

Georgios Fragulidis; Nikolaos Arkadopoulos; Ioannis Vassiliou; Athanasios Marinis; Theodosios Theodosopoulos; Vaia Stafyla; Maria Kyriazi; Konstantinos Karapanos; Nikolaos Dafnios; Andreas Polydorou; Dionysios Voros; Vassilios Smyrniotis

Objectives To evaluate the impact of the length of the isolated jejunal loop and the type of pancreaticojejunostomy on pancreatic leakage after pancreaticoduodenectomy. Methods One hundred thirty-two consecutive patients who underwent a pancreaticoduodenectomy were studied according to the length of the isolated jejunal loop (short loop, 20-25 cm vs long loop, 40-50 cm) and the type of pancreaticojejunostomy (invagination vs duct to mucosa). Results The use of the long isolated jejunal loop was associated with a significantly lower pancreatic leakage rate compared with the use of a short isolated jejunal loop (4.34% vs 14.2%, P < 0.05). In addition, the use of duct-to-mucosa technique was associated with significantly lower incidence of postoperative pancreatic fistula compared with the invagination technique (4.2% vs 14.5%, P < 0.05). Finally, patients with a short isolated jejunal loop compared with patients with a long loop had increased morbidity (50.7% vs 27.5%, P < 0.05) and prolonged hospital stay (16.3 ± 1.9 days vs 10.2 ± 2.3 days, P < 0.05). Overall mortality rate was 1.5%. Conclusions The use of a long isolated jejunal loop and a duct-to-mucosa pancreaticojejunostomy is associated with decreased pancreatic leakage rate after pancreaticoduodenectomy.


World Journal of Surgical Oncology | 2006

Malignant potential of intrahepatic biliary papillomatosis: a case report and review of the literature

Ioannis Vassiliou; Evi Kairi-Vassilatou; Athanasios Marinis; Theodosios Theodosopoulos; Nikolaos Arkadopoulos; Vassilios Smyrniotis

BackgroundBiliary papillomatosis (BP) is a rare disease entity with a strong malignant potential. It is characterized by multiple papillary adenomas involving both the intrahepatic and extrahepatic biliary tree. BP was considered in the past to be a disease with low malignant potential. However, a current review of the English literature revealed a high rate of malignant occurrence of approximately 41% and histological analysis along with the expression pattern of mucin core proteins (MUC) and mucin carbohydrate antigens suggests that BP is a borderline or low grade malignant neoplasm with a high malignant potential.Case presentationA 68 year-old male patient was referred to our hospital due to the presence of sudden right upper quadrant abdominal pain, nausea and dark urine. Imaging workup demonstrated dilatation of the left hepatic duct without the presence of a space-occupying lesion. A left hepatectomy and cholecystectomy were carried out and histological analysis revealed a moderately to poorly differentiated carcinoma of the left hepatic duct in the background of biliary papillomatosis. Postoperative course was uneventful. Unfortunately, two years after initial diagnosis the patient rapidly deteriorated and died from multiple pulmonary secondary deposits.ConclusionBP should not be considered to be a benign disease. The clinical behavior, the high recurrence rate and the even higher malignant transformation occurrence, as well as the presence of carcinogenetic indicators (K-ras mutation, overexpression of p53, MUC and Tn antigens) strongly support that BP is a low-grade neoplasm with high malignant potential.


Archives of Medical Science | 2013

Total thyroidectomy as the single surgical option for benign and malignant thyroid disease: a surgical challenge.

Ioannis Vassiliou; Aliki Tympa; Nikolaos Arkadopoulos; Fotios Nikolakopoulos; Thalia Petropoulou; Vassilios Smyrniotis

Introduction Total thyroidectomy has been the treatment of choice for patients with malignant thyroid disease. However, the efficacy and safety of this procedure for patients with benign disease is still a matter of debate. The aim of this study is to show that total thyroidectomy can be safely performed for both malignant and benign disease. Material and methods A retrospective study on 216 patients was conducted. Once an indication for surgery was established, our single surgical treatment was total thyroidectomy. Age, sex, nature of thyroid disease, final pathology and postoperative complications were recorded. Results For both benign and malignant disease, total thyroidectomy resulted in no permanent laryngeal nerve injury and no permanent hypoparathyroidism. Temporary laryngeal nerve palsy occurred in 0.9% and 3% of patients with benign and malignant disease respectively (p = 0.245). Six percent of patients with benign and 10.0% of patients with malignant thyroid disease suffered temporary hypoparathyroidism (p = 0.280). Immediate reoperation for postoperative hemorrhage was performed in 1.7% of patients with benign disease and in 1.0% of patients with malignancy with an uneventful outcome (p = 0.650). Conclusions When performed by surgeons experienced in endocrine surgery, total thyroidectomy may be considered as the treatment of choice for both malignant and benign thyroid disease requiring surgical treatment. Total thyroidectomy virtually eliminates the requirement of completion thyroidectomy for incidentally diagnosed thyroid carcinoma and significantly reduces the rate of reoperation for recurrent disease, as it provides an immediate and permanent cure for all benign thyroid diseases, with a low incidence of postoperative complications.


Hpb Surgery | 2012

Anesthetic Considerations in Hepatectomies under Hepatic Vascular Control

Aliki Tympa; Kassiani Theodoraki; Athanassia Tsaroucha; Nikolaos Arkadopoulos; Ioannis Vassiliou; Vassilios Smyrniotis

Background. Hazards of liver surgery have been attenuated by the evolution in methods of hepatic vascular control and the anesthetic management. In this paper, the anesthetic considerations during hepatic vascular occlusion techniques were reviewed. Methods. A Medline literature search using the terms “anesthetic,” “anesthesia,” “liver,” “hepatectomy,” “inflow,” “outflow occlusion,” “Pringle,” “hemodynamic,” “air embolism,” “blood loss,” “transfusion,” “ischemia-reperfusion,” “preconditioning,” was performed. Results. Task-orientated anesthetic management, according to the performed method of hepatic vascular occlusion, ameliorates the surgical outcome and improves the morbidity and mortality rates, following liver surgery. Conclusions. Hepatic vascular occlusion techniques share common anesthetic considerations in terms of preoperative assessment, monitoring, induction, and maintenance of anesthesia. On the other hand, the hemodynamic management, the prevention of vascular air embolism, blood transfusion, and liver injury are plausible when the anesthetic plan is scheduled according to the method of hepatic vascular occlusion performed.


World Journal of Surgical Oncology | 2010

The combined effect of erythropoietin and granulocyte macrophage colony stimulating factor on liver regeneration after major hepatectomy in rats

Ioannis Vassiliou; Evangelos Lolis; Constantinos Nastos; Aliki Tympa; Theodosios Theodosopoulos; Nikolaos Dafnios; George Fragulidis; Matrona Frangou; Kondi-Pafiti A; Vassilios Smyrniotis

BackgroundThe liver presents a remarkable capacity for regeneration after hepatectomy but the exact mechanisms and mediators involved are not yet fully clarified. Erythropoietin (EPO) and Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) have been shown to promote liver regeneration after major hepatectomy.Aim of this experimental study is to compare the impact of exogenous administration of EPO, GM-CSF, as well as their combination on the promotion of liver regeneration after major hepatectomy.MethodsWistar rats were submitted to 70% major hepatectomy. The animals were assigned to 4 experimental groups: a control group (n = 21) that received normal saline, an EPO group (n = 21), that received EPO 500 IU/kg, a GM-CSF group (n = 21) that received 20 mcg/kg of GM-CSF and a EPO+GMCSF group (n = 21) which received a combination of the above. Seven animals of each group were killed on the 1st, 3rd and 7th postoperative day and their remnant liver was removed to evaluate liver regeneration by immunochemistry for PCNA and Ki 67.ResultsOur data suggest that EPO and GM-CSF increases liver regeneration following major hepatectomy when administered perioperatively. EPO has a more significant effect than GM-CSF (p < 0.01). When administering both, the effect of EPO seems to fade as EPO and GM-CSF treated rats have decreased regeneration compared to EPO administration alone (p < 0.01).ConclusionEPO, GM-CSF and their combination enhance liver regeneration after hepatectomy in rats when administered perioperatively. However their combination has a weaker effect on liver regeneration compared to EPO alone. Further investigation is needed to assess the exact mechanisms that mediate this finding.


The Cardiology | 2008

Gastrointestinal Emergencies in Cardiac Surgery

Ioannis Vassiliou; Emmanouel Papadakis; Nikolaos Arkadopoulos; Kassiani Theodoraki; Athanasios Marinis; Theodosios Theodosopoulos; George Palatianos; Vassilios Smyrniotis

Objectives: The aim of this study is to retrospectively analyze risk factors, diagnosis and management of gastrointestinal (GI) complications following cardiac operations. Methods: Patients who developed GI complications after a cardiac operation were studied. Anesthesia protocols, techniques of cardiac surgery, potential risk factors, complications and medical and surgical interventions were reviewed and analyzed. Results: Out of 3,724 consecutive patients undergoing heart operations during an 8-year period, 33 patients developed GI complications. Eleven patients developed ischemic colitis, 8 cholecystitis, 6 GI bleeding, 4 liver failures, 3 pancreatitis and 1 esophageal hernia. Patients with GI complications had a lower mean ejection fraction compared to patients not developing these complications (45.1 vs. 49.7%, p < 0.01). Also, patients undergoing an urgent cardiac operation were significantly more likely (3.49 times more likely) to develop GI complications postoperatively. Of the 33 affected patients, 18 were treated conservatively and 15 underwent an emergency exploratory laparotomy. Overall mortality was 12% (4 patients). Conclusions: Intestinal ischemia and cholecystitis appear to be the most frequent GI complications associated with cardiac surgery. Risk factors include a low ejection fraction and an urgent cardiac operation. Early recognition and treatment of these complications may reduce mortality.


World Journal of Surgical Oncology | 2010

Gastric glomus tumor: A case report

Ioannis Vassiliou; Aliki Tympa; Theodosios Theodosopoulos; Nikolaos Dafnios; Georgios Fragulidis; Andreas Koureas; Evi Kairi

Gastric glomus tumors are rare mesenchymal tumors of the gastrointestinal tract. We describe a 72-year-old patient who presented with episodes of melena and was subsequently investigated for a tumor of the antrum of the stomach. Surgical resection revealed a 2 × 2 × 1.7 cm well circumscribed submucosal tumor, extending into the muscularis propria. The histopathologic examination of the specimen demonstrated a glomus tumor of the stomach. We discuss the preoperative investigation, the diagnostic problems and the surgical treatment of the patient with this rare submucosal lesion.


World Journal of Gastrointestinal Surgery | 2010

An ongoing dispute in the management of severe pancreatic fistula: Pancreatospleenectomy or not?

Dionysios Dellaportas; Aliki Tympa; Constantinos Nastos; Vasiliki Psychogiou; Andreas Karakatsanis; Andreas Polydorou; George Fragulidis; Ioannis Vassiliou; Vassilios Smyrniotis

The aim of this manuscript is to review controversies in managing severe pancreatic fistula after pancreatic surgery. Significant progress in surgical technique and perioperative care has reduced the mortality rate of pancreatic surgery. However, leakage of the pancreatic stump still accounts for the majority of surgical complications after pancreatic resection. Various strategies have been employed in order to manage pancreatic fistula. Nonetheless high grade pancreatic fistula evokes controversy in relation to the choice of treatment. A Medline search was performed, with regard to conservative treatment options versus completion pancreatectomy for the management of pancreatic fistula grade C. Pancreatic fistula rates remain unchanged with an incidence ranging from 5%-20% and this is considered as the most important cause of postoperative death. Many authors claim that completion pancreatectomy has probably lost its role in favour of interventional radiology procedures, while others believe that completion pancreatectomy continues to have a place in the management of patients with severe clinical deterioration after pancreatic fistula who do not respond to non-surgical interventions. There is no agreement on the best clinical management of severe pancreatic fistula after pancreatic surgery. Completion pancreatectomy is reserved for patients not improving with conventional measures.


Oxidative Medicine and Cellular Longevity | 2016

Beyond Preconditioning: Postconditioning as an Alternative Technique in the Prevention of Liver Ischemia-Reperfusion Injury

Kassiani Theodoraki; Iosifina Karmaniolou; Aliki Tympa; Marios-Konstantinos Tasoulis; Constantinos Nastos; Ioannis Vassiliou; Nikolaos Arkadopoulos; Vassilios Smyrniotis

Liver ischemia/reperfusion injury may significantly compromise hepatic postoperative function. Various hepatoprotective methods have been improvised, aiming at attenuating IR injury. With ischemic preconditioning (IPC), the liver is conditioned with a brief ischemic period followed by reperfusion, prior to sustained ischemia. Ischemic postconditioning (IPostC), consisting of intermittent sequential interruptions of blood flow in the early phase of reperfusion, seems to be a more feasible alternative than IPC, since the onset of reperfusion is more predictable. Regarding the potential mechanisms involved, it has been postulated that the slow intermittent oxygenation through controlled reperfusion decreases the burst production of oxygen free radicals, increases antioxidant activity, suppresses neutrophil accumulation, and modulates the apoptotic cascade. Additionally, favorable effects on mitochondrial ultrastructure and function, and upregulation of the cytoprotective properties of nitric oxide, leading to preservation of sinusoidal structure and maintenance of blood flow through the hepatic circulation could also underlie the protection afforded by postconditioning. Clinical studies are required to show whether biochemical and histological improvements afforded by the reperfusion/reocclusion cycles of postconditioning during early reperfusion can be translated to a substantial clinical benefit in liver resection and transplantation settings or to highlight more aspects of its molecular mechanisms.


European Journal of Gastroenterology & Hepatology | 2013

The role of variations within microRNA in inflammatory bowel disease.

Ioannis Papaconstantinou; Konstantinos Stamatis; Charalambos Tzathas; Ioannis Vassiliou; Georgios Giokas; Maria Gazouli

MicroRNAs (miRNAs) are small noncoding RNAs that are implicated in gene expression regulation at both a transcriptional and at a translational level. Single-nucleotide polymorphisms may occur in miRNA biogenesis pathway genes, primary miRNA, pre-miRNA, or a mature miRNA sequence. Such polymorphisms may be functional with respect to biogenesis and actions of mature miRNA. These single-nucleotide polymorphisms may have a potential to affect the efficiency of miRNA binding to the target sites or can create or disrupt binding sites. The resulting gene dysregulation may involve changes in phenotype and may eventually prove critical for the susceptibility to inflammatory bowel disease and its onset. In this review, we summarize their importance as candidate inflammatory bowel disease biomarkers.

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Vassilios Smyrniotis

National and Kapodistrian University of Athens

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Nikolaos Arkadopoulos

National and Kapodistrian University of Athens

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Theodosios Theodosopoulos

National and Kapodistrian University of Athens

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Nikolaos Dafnios

National and Kapodistrian University of Athens

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Aliki Tympa

National and Kapodistrian University of Athens

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Athanasios Marinis

National and Kapodistrian University of Athens

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Georgios Fragulidis

National and Kapodistrian University of Athens

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Andreas Polydorou

National and Kapodistrian University of Athens

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Anneza Yiallourou

National and Kapodistrian University of Athens

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