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Dive into the research topics where Nikolaos Dafnios is active.

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Featured researches published by Nikolaos Dafnios.


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 | 2009

A rare coexistence of adrenal cavernous hemangioma with extramedullar hemopoietic tissue: a case report and brief review of the literature

Nikolaos Arkadopoulos; Maria Kyriazi; Anneza Yiallourou; Vaia Stafyla; Theodosopoulos T; Nikolaos Dafnios; Vassilis Smyrniotis; Agathi Kondi-Pafiti

BackgroundCavernous hemangiomas of the adrenal gland are rare, benign, non-functioning neoplastic tumors. To our knowledge, 55 cases have been reported in the literature to date.Case presentationWe report the first case of a large, non-functioning adrenal cavernous hemangioma that was incidentally found during the preoperative staging workup of a 75 year old woman with left breast adenocarcinoma. Imaging with US, CT scan and MRI showed a heterogeneous 8 cm mass with non-specific radiological features that was located on the left adrenal gland. The mass was surgically excised and pathology revealed an adrenal hemangioma with areas of extramedullar hemopoiesis.ConclusionAlthough adrenal hemangiomas are rare and their preoperative diagnosis is difficult, they should always be included in the differential diagnosis of adrenal neoplasms.


Cases Journal | 2009

Mixed acinar-endocrine carcinoma of the pancreas: a case report and review of the literature

Maria Kyriazi; Nikolaos Arkadopoulos; Vaia Stafyla; Anneza Yiallourou; Nikolaos Dafnios; Theodosios Theodosopoulos; Evi Kairi-Vassilatou; Vassilios Smyrniotis

Introduction: Pancreatic tumors usually display either a ductal, an acinar or an endocrine differentiation. Mixed exocrine and endocrine pancreatic tumors are extremely rare. There have been a few reports of the rare entity of mixed acinar-endocrine carcinoma of the pancreas, where the endocrine cells represent more than 30% of the tumor. We herein describe a case of such a pancreatic tumor in an asymptomatic patient. Case presentation: A 74-year-old male patient with no evident clinical symptoms was referred for surgical resection of a large mass located on the pancreatic head, which was confirmed by an abdominal U/S, CT and MRI. FNA of the mass under endoscopic ultrasound guidance showed the cytology specimen to comprise of cells with morphological and immunohistochemical characteristics of endocrine pancreatic neoplasms. The patient underwent a modified Whipple’s procedure and his post-operative course was uneventful. Pathological examination of the tumor revealed a mixed acinar-endocrine carcinoma of the pancreas. Conclusion: Mixed tumors of the pancreas are extremely rare and their clinical features and pathogenesis remain unclear. The endocrine component seems to influence their prognosis favorably. Therefore, aggressive surgical therapy remains the only well established line of treatment for these tumors. Further accumulation of clinical cases will help clarify the clinical course and the optimal therapy for these unusual tumors.


World Journal of Surgical Oncology | 2006

Aggressive treatment of metastatic squamous cell carcinoma of the rectum to the liver: a case report and a brief review of the literature

Theodosios Theodosopoulos; Athanasios Marinis; Nikolaos Dafnios; John Vassiliou; Lazaros Samanides; Eleni E. Carvounis; Vassilios Smyrniotis

BackgroundRectal squamous cell carcinoma (SCC) is a rare tumor. The incidence of this malignancy has been reported to be 0.25 to 1 per 1000 colorectal carcinomas. From a review of the English literature 55 cases of SCC of the rectum have been published. In this study we report a rectal metastatic SCC to the liver, discussing the efficacy of aggressive adjuvant and neo-adjuvant therapies on survival and prognosis.Case presentationA 39-year-old female patient with a pure SCC of the rectum diagnosed endoscopically is presented. The patient underwent initially neoadjuvant chemo-radiotherapy and then abdominoperineal resection with concomitant bilateral oophorectomy and hysterectomy, followed by adjuvant chemo-radiotherapy. Five months after the initial operation liver metastasis was demonstrated and a liver resection was carried out, followed by adjuvant chemotherapy. Eighteen months after the initial operation the patient is alive.ConclusionAlthough prognosis of rectal SCC is worse than that of adenocarcinoma, an aggressive therapeutic approach with surgery as the primary treatment, followed by combined neo- and adjuvant chemo-radiotherapy, may be necessary in order to improve survival and prognosis.


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.


BMC Research Notes | 2010

Safety and effectiveness of outpatient laparoscopic cholecystectomy in a teaching hospital: a prospective study of 110 consecutive patients.

Athanasios Marinis; Emmanouil Stamatakis; Athanasia Tsaroucha; Nikolaos Dafnios; Georgios Anastasopoulos; Georgios Polymeneas; Theodosios Theodosopoulos

BackgroundThe aim of this study was to evaluate the safety and efficacy of outpatient laparoscopic cholecystectomy (OLC) in a day surgery unit in a teaching hospital. OLC was offered to patients with symptomatic cholelithiasis who met the following established inclusion criteria: ASA (American Society of Anesthesiology) physical status classification class I and II; age: 18 - 70 years; body mass index (BMI) < 30 kg/m2; patient acceptance and cooperation (informed consent); presence of a responsible adult to accompany the patient to his residency; patient residency in Athens. The primary study end-point was to evaluate success rates (patient discharge on the day of surgery), postoperative outcome (complications, re-admissions, morbidity and mortality) and patient satisfaction. A secondary endpoint was to evaluate its safe performance under appropriate supervision by higher surgical trainees (HSTs).Findings110 consecutive patients, predominantly female (71%) and ASA I (89%) with a mean age 40.6 ± 8.1 years underwent an OLC. Surgery was performed by a HST in 90 patients (81.8%). A mean postoperative pain score 3.3 (range 0-6) occurred in the majority of patients and no patient presented postoperative nausea or vomiting. Discharge on the day of surgery occurred in 95 cases (86%), while an overnight admission was required for 15 patients (14%). Re-admission following hospital discharge was necessary for 2 patients (1.8%) on day 2, due to persistent pain in the umbilical trocar site. The overall rate of major (trocar site bleeding) and minor morbidity was 15.5% (17 patients). At 1 week follow-up, 94 patients (85%) were satisfied with their experience undergoing OLC, with no difference between grades of operating surgeons.ConclusionsThis study confirmed that OLC is clinical effective and can be performed safely in a teaching hospital by supervised HSTs.


BioMed Research International | 2015

The Effect of Perioperative Ischemia and Reperfusion on Multiorgan Dysfunction following Abdominal Aortic Aneurysm Repair

Konstantina Katseni; Athanasios Chalkias; Thomas Kotsis; Nikolaos Dafnios; Vassilis Arapoglou; Georgios Kaparos; Emmanuel Logothetis; Nicoletta Iacovidou; Eleni Karvouni; Konstantinos Katsenis

Abdominal aortic aneurysms (AAAs) are relatively common and are potentially life-threatening medical problems. The aim of this review is to provide an overview of the effect of I/R injury on multiorgan failure following AAA repair. The PubMed, CINAHL, EMBASE, Medline, Cochrane Review, and Scopus databases were comprehensively searched for articles concerning the pathophysiology of I/R and its systemic effects. Cross-referencing was performed using the bibliographies from the articles obtained. Articles retrieved were restricted to those published in English. One of the most prominent characteristics of AAA open repair is the double physiological phenomenon of ischemia-reperfusion (I/R) that happens either at the time of clamping or following the aortic clamp removal. Ischemia-reperfusion injury causes significant pathophysiological disturbances to distant organs, increasing the possibility for postoperative multiorgan failure. Although tissue injury is mediated by diverse mechanisms, microvascular dysfunction seems to be the final outcome of I/R.


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 Surgical Oncology | 2009

Esophagopericardial fistula as a rare complication after total gastrectomy for cancer

Nikolaos Dafnios; Georgios Anastasopoulos; Athanasios Marinis; Andreas Polydorou; Georgios Gkiokas; Georgios Fragulidis; Panayiotis Athanasopoulos; Theodosios Theodosopoulos

BackgroundEsophagopericardial fistula is a rare but life-threatening complication of benign, malignant or traumatic esophageal disease. It is most commonly associated with benign etiology and carries a high mortality rate which increases with delay in diagnosis.Case presentationWe present a case of an esophagopericardial fistula as a rare complication in a 53-year-old male patient, 7 months after total gastrectomy for an adenocarcinoma of the esophagogastric junction.ConclusionThe prognosis of esophagopericardial fistula is poor, especially when it is associated with malignancy.


World Journal of Surgical Oncology | 2006

Association between biliary complications and technique of hilar division (extrahepatic vs. intrahepatic) in major liver resections.

Vassileios Smyrniotis; Nikolaos Arkadopoulos; Kassiani Theodoraki; Dionysios Voros; Ioannis Vassiliou; Andreas Polydorou; Nikolaos Dafnios; Evangelos Gamaletsos; Kyriaki Daniilidou; Dimitrios Kannas

BackgroundDivision of major vascular and biliary structures during major hepatectomies can be carried out either extrahepatically at the porta hepatic or intrahepatically during the parenchymal transection. In this retrospective study we test the hypothesis that the intrahepatic technique is associated with less early biliary complications.Methods150 patients who underwent major hepatectomies were retrospectively allocated into an intrahepatic group (n = 100) and an extrahepatic group (n = 50) based on the technique of hilar division. The two groups were operated by two different surgical teams, each one favoring one of the two approaches for hilar dissection. Operative data (warm ischemic time, operative time, blood loss), biliary complications, morbidity and mortality rates were analyzed.ResultsIn extrahepatic patients, operative time was longer (245 ± 50 vs 214 ± 38 min, p < 0.05) while the overall complication rate (55% vs 52%), hospital stay (13 ± 7 vs 12 ± 4 days), bile leak rate (22% vs 20%) and mortality (2% vs 2%) were similar compared to intrahepatic patients. However, most (57%) bile leaks in extrahepatic patients were grade II (leaks that required non-operative interventional treatment, while most (70%) leaks in the intrahepatic group were grade I (leaks that resolved and presented two injuries (4%) of the remaining bile ducts (p < 0.05).ConclusionIntrahepatic hilar division is as safe as extrahepatic hilar division in terms of intraoperative blood requirements, morbidity and mortality. The extrahepatic technique is associated with more severe bile leaks and biliary injuries.

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Theodosios Theodosopoulos

National and Kapodistrian University of Athens

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Athanasios Marinis

National and Kapodistrian University of Athens

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Ioannis Vassiliou

National and Kapodistrian University of Athens

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Nikolaos Arkadopoulos

National and Kapodistrian University of Athens

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Vassilios Smyrniotis

National and Kapodistrian University of Athens

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Georgios Fragulidis

National and Kapodistrian University of Athens

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Anneza Yiallourou

National and Kapodistrian University of Athens

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Dionysios Voros

National and Kapodistrian University of Athens

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Vaia Stafyla

National and Kapodistrian University of Athens

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Andreas Koureas

National and Kapodistrian University of Athens

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