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Dive into the research topics where George Sakellaropoulos is active.

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Featured researches published by George Sakellaropoulos.


Obesity Surgery | 2002

Comparison of Nutritional Deficiencies after Roux- en-Y Gastric Bypass and after Biliopancreatic Diversion with Roux-en-Y Gastric Bypass

George Skroubis; George Sakellaropoulos; Konstantinos Pouggouras; Nancy Mead; George Nikiforidis; Fotis Kalfarentzos

Background: Patients undergoing either Roux-en-Y gastric bypass (RYGBP) or biliopancreatic diversion (BPD) with RYGBP are at risk of developing metabolic sequelae secondary to malabsorption.We compared the differences in nutritional complications between these two bariatric operations. Methods: A retrospective analysis of a prospective database was done. From June 1994 to December 2001, 243 morbidly obese patients underwent various bariatric procedures at our institution. Of these patients, 79 (BMI 45.6 ± SD=4.9) who underwent RYGBP (gastric pouch 15 ± 5ml, biliopancreatic limb 60-80 cm, alimentary limb 80-100 cm and common limb the remainder of the small intestine), and 95 super obese (BMI 57.2 ± 6.1) who underwent a BPD (gastric pouch 15 ± 5ml, biliopancreatic limb 150-200 cm, common limb 100 cm and alimentary limb the remainder of the small intestine), were selected and studied for the incidence of micronutrient deficiencies and level of serum albumin at yearly intervals postoperatively. A variety of nutritional parameters including Hb, Fe, ferritin, folic acid, vitamin B12 and serum albumin were measured preoperatively and compared postoperatively at 1, 3, 6, 12, 18 and 24 months, and yearly thereafter. Results: Nutritional parameters were compared preoperatively and at similar periods postoperatively. No statistically significant (P <0.05) difference in the occurrence of deficiency was observed between the groups for any of the nutritional parameters studied, except for ferritin, which showed a significant difference at the 2-year follow-up (37.7% low ferritin levels after RYGBP vs. 15.2% after BPD, P =0.0294). All of these deficiencies were mild, without clinical symptomatology and were easily corrected with additional supplementation of the deficient micronutrient, with no need for hospitalization. Regarding serum albumin, there was only one patient with a level below 3 g/dl in the RYGBP group and two in the BPD group.These three patients were hospitalized and received total parenteral nutrition for 3 weeks, without further complications. Conclusion:There was no significant difference in the incidence of deficiency of the nutritional parameters studied, except for ferritin, following RYGBP vs. BPD with RYGBP.The most common deficiencies encountered were of iron and vitamin B12. The incidence of hypoalbuminemia was negligible in both groups, with mean values above 4 g/dl.


European Journal of Radiology | 2004

CT angiography with three-dimensional techniques for the early diagnosis of intracranial aneurysms. Comparison with intra-arterial DSA and the surgical findings

Maria T. Karamessini; George C. Kagadis; Theodore Petsas; Dimitrios Karnabatidis; Dimitrios Konstantinou; George Sakellaropoulos; George Nikiforidis; Dimitrios Siablis

INTRODUCTION Cerebral CT angiography (CTA) is an established method applied to both the detection and treatment planning of intracranial aneurysms. The aim of our study was to compare CTA and digital subtraction angiography (DSA) findings with the surgical results mainly in patients with acute SAH and to evaluate the clinical usefulness of CTA. MATERIALS AND METHODS During the last 2 years, 82 consecutive patients were admitted under clinical symptoms and signs suggestive of harboring an intracranial aneurysm. CT angiography performed immediately afterwards the plain CT, while DSA was performed within the first 48 h of admission. All aneurysms detected were confirmed during surgery or endovascular embolization. Repeat DSA was performed in all patients having both the initial CTA and the DSA 15 days after the onset of symptoms negative. CT angiograms and conventional angiographies were studied by a consensus of two radiologists for each technique, who performed aneurysm detection, morphological features characterization and evaluation of the technique. RESULTS Surgical or/and endovascular treatment was performed in 45 patients and 53 aneurysms were confirmed. Using 3D-CT angiography, we detected 47 aneurysms in 42 patients. Conventional angiography depicted 43 aneurysms in 39 patients. The sensitivity of CTA for the detection of all aneurysms versus surgery was 88.7%, the specificity 100%, the positive predictive value (PPV) 100%, the negative predictive value (NPV) 80.7% and the accuracy 92.3%. Accordingly, the sensitivity of DSA was 87.8%, the specificity 98%, the PPV 97.7%, the NPV 89.1% and the accuracy 92.9%. Considering aneurysms > or =3 mm, CTA showed a sensitivity ranging from 93.3 to 100%, equal to that of DSA. CONCLUSION Cerebral CT angiography has an equal sensitivity to DSA in the detection of intracranial aneurysms >3 mm. It has also 100% detection rate in AcoA and MCA bifurcation aneurysms, while some locations, like posterior communicating artery aneurysms, remain problematic. The delineating features of each aneurysm are better depicted with CTA due to 3D visualization. The use of digital subtraction angiography as a diagnostic tool can be limited in equivocal cases.


Journal of Endourology | 2010

Comparative assessment of laparoscopic single-site surgery instruments to conventional laparoscopic in laboratory setting.

Jens-Uwe Stolzenburg; Panagiotis Kallidonis; Min-A Oh; Nabi Ghulam; Minh Do; Tim Haefner; Anja Dietel; Holger Till; George Sakellaropoulos; Evangelos Liatsikos

INTRODUCTION Laparoendoscopic single-site surgery (LESS) represents the latest innovation in laparoscopic surgery. We compare in dry and animal laboratory the efficacy of recently introduced pre-bent instruments with conventional laparoscopic and flexible instruments in terms of time requirement, maneuverability, and ease of handling. MATERIALS AND METHODS Participants of varying laparoscopic experience were included in the study and divided in groups according to their experience. The participants performed predetermined tasks in dry laboratory using all sets of instruments. An experienced laparoscopic surgeon performed 24 nephrectomies in 12 pigs using all sets of instruments. Single port was used for all instrument sets except for the conventional instruments, which were inserted through three ports. The time required for the performance of dry laboratory tasks and the porcine nephrectomies was recorded. Errors in the performance of dry laboratory tasks of each instrument type were also recorded. RESULTS Pre-bent instruments had a significant advantage over flexible instruments in terms of time requirement to accomplish tasks and procedures as well as maneuverability. Flexible instruments were more time consuming in comparison to the conventional laparoscopic instruments during the performance of the tasks. There were no significant differences in the time required for the accomplishment of dry laboratory tasks or steps of nephrectomy using conventional instruments through appropriate number of ports in comparison to pre-bent instruments through single port. DISCUSSION Pre-bent instruments were less time consuming and with better maneuverability in comparison to flexible instruments in experimental single-port access surgery. Further clinical investigations would elucidate the efficacy of pre-bent instruments.


Urology | 2010

A Comparison of Outcomes for Interfascial and Intrafascial Nerve-sparing Radical Prostatectomy

Jens-Uwe Stolzenburg; Panagiotis Kallidonis; Do Minh; Anja Dietel; Tim Häfner; Robert Rabenalt; George Sakellaropoulos; Roman Ganzer; Uwe Paasch; Lars Christian Horn; Evangelos Liatsikos

OBJECTIVE To compare the outcome of intrafascial nerve-sparing endoscopic extraperitoneal radical prostatectomy (nsEERPE) with interfascial (standard) nsEERPE. METHODS Four-hundred patients underwent nsEERPE; 200 patients underwent bilateral intrafascial nsEERPE (group A) and 200 bilateral standard nsEERPE (group B). Tumor stages of T1 and T2a, prostate-specific antigen level <10 ng/mL, maximal Gleason score 3+4 (not 4+3) and preoperative potency were considered as candidates for nsEERPE. Patients were randomized to the aforementioned groups. Perioperative data, and functional and oncological outcome were reviewed. Patients not requiring any pads or requiring 1 pad for safety were defined as continent. Patients responding positively to sexual encounter profile diary question numbers 2, 3, and 5 were considered as potent. RESULTS Perioperative data were similar between groups. At 3 months, 74% of group A and and 63% of group B were continent. At 6 months, the respective figures were 87.9% and 76.2%, respectively (A, B). At 12 months, 93.2% of group A and 90.7% of group B were continent. Potency rates of group A were 93.5% (<55 years), 83.3% (55-65 years), and 60% (>65 years) at 12 months. The respective figures for Group B were 77.1%, 50%, and 40%. Positive surgical margins were detected in 9% and 9.5% of groups A and B, respectively. CONCLUSIONS Intrafascial nsEERPE provides significantly better potency in patients <55 years of age at 12 months and in patients 55-65 years of age at 6 and 12 months, with probably limited effect on the oncological outcome. Significantly improved continence was observed at 3 and 6 months in favor of intrafascial nsEEPRE.


Liver International | 2007

Neuropsychological function in Greek patients with chronic hepatitis C

Katerina Karaivazoglou; Konstantinos Assimakopoulos; Konstantinos Thomopoulos; George J. Theocharis; Lambros Messinis; George Sakellaropoulos; Chryssoula Labropoulou-Karatza

Background: Research has shown that hepatitis C virus (HCV) infection is associated with subclinical neuropsychological deficits in the absence of hepatic encephalopathy.


Journal of Cardiac Surgery | 2008

Antegrade Versus Retrograde Cerebral Perfusion in Relation to Postoperative Complications Following Aortic Arch Surgery for Acute Aortic Dissection Type A

Efstratios Apostolakis; Efstratios Koletsis; Panagiotis Dedeilias; John N. Kokotsakis; George Sakellaropoulos; Argini Psevdi; Konstantin Bolos; Dimitrios Dougenis

Abstract  Background: Aortic arch surgery is impossible without the temporary interruption of brain perfusion and therefore is associated with high incidence of neurologic injury. The deep hypothermic circulatory arrest (HCA), in combination with antegrade or retrograde cerebral perfusion (RCP), is a well‐established method of brain protection in aortic arch surgery. In this retrospective study, we compare the two methods of brain perfusion. Materials and Methods: From 1998 to 2006, 48 consecutive patients were urgently operated for acute type A aortic dissection and underwent arch replacement under deep hypothermic circulatory arrest (DHCA). All distal anastomoses were performed with open aorta, and the arch was replaced totally in 15 cases and partially in the remaining 33 cases. Our patient cohort is divided into those protected with antegrade cerebral perfusion (ACP) (group A, n = 23) and those protected with RCP (group B, n = 25). Results: No significant difference was found between groups A and B with respect to cardiopulmonary bypass‐time, brain‐ischemia time, cerebral‐perfusion time, permanent neurologic dysfunction, and mortality. The incidence of temporary neurologic dysfunction was 16.0% for group A and 43.50% for group B (p = 0.04). The mean extubation time was 3.39 ± 1.40 days for group A and 4.96 ± 1.83 days for group B (p = 0.0018). The mean ICU‐stay was 4.4 ± 2.3 days for group A and 6.9 ± 2.84 days for group B (p = 0.0017). The hospital‐stay was 14.38 ± 4.06 days for group A and 19.65 ± 6.91 days for group B (p = 0.0026). Conclusion: The antegrade perfusion seems to be related with significantly lower incidence of temporary neurological complications, earlier extubation, shorter ICU‐stay, and hospitalization, and hence lower total cost.


Interactive Cardiovascular and Thoracic Surgery | 2009

Low incidence of bronchopleural fistula after pneumonectomy for lung cancer.

Nikolaos D. Panagopoulos; Efstratios Apostolakis; Efstratios Koletsis; Christos Prokakis; Panagiotis Hountis; George Sakellaropoulos; Ion Bellenis; Dimitrios Dougenis

Bronchopleural fistula (BPF) after pneumonectomy for NSCLC remains a highly morbid complication. We examined possible factors including the surgical techniques associated with BPF development. From 221 pneumonectomies for NSCLC, bronchial stump closure was mechanically performed in 192 patients and manually in the remaining 29. In all right-sided pneumonectomies mechanical closure was performed with associated stump coverage. In 114/130 left-sided procedures where mechanical closure was selected, bronchial stump remained uncovered. In the remaining 16 left-sided cases where manual stump closure was selectively performed, the stump was covered utilizing various tissues. Risk factors were classified into preoperative, intra-operative and postoperative. Five patients (2.3%) developed BPF. Univariate analysis revealed peri-operative transfusion, respiratory infection at the time of presentation, neoadjuvant therapy, right-sided pneumonectomy, manual type of bronchial closure, days of postoperative hospitalization and mechanical ventilation as significant risk factors for BPF development. Multivariate analysis followed revealing preoperative respiratory infection and right pneumonectomy as the only independent risk factors. In our series, a selected stump coverage policy showed a low incidence of BPF development. Mechanical stapling was superior to manual closure, although not as an independent factor. Early recognition of possible risk factors associated with fistula development is of paramount importance.


International Journal of Hematology | 2004

Markers of endothelial and in vivo platelet activation in patients with essential thrombocythemia and polycythemia vera

Marina Karakantza; Nikolaos Giannakoulas; Panagiotis Zikos; George Sakellaropoulos; Alexandra Kouraklis; Anthi Aktypi; Ioannis C. Metallinos; Eleni Theodori; N. Zoumbos; Alice Maniatisa

We investigated endothelial and in vivo platelet activation in a cohort of 52 patients with essential thrombocythemia (ET) and polycythemia vera (PV) before and after cytoreductive treatment, 22 healthy controls, and 17 patients with acute cerebrovascular ischemia (ACVI) and normal platelet counts.We measured platelet expression of CD62P and CD63 antigens and levels of soluble vascular cell adhesion molecule 1 (sVCAM-1).We found increased in vivo platelet activation in all patients with ET and PV, both before and after cytoreductive treatment, compared with controls. In patients with arterial thrombosis, platelet expression of CD62P, and in patients with erythromelalgia, expression of both markers was higher compared with expression in patients without thrombotic complications. In patients with ET and PV before and after treatment, sVCAM-1 expression was increased compared with expression in controls but also compared with expression in patients with ACVI and normal platelet counts. In patients with arterial thrombosis and erythromelalgia, in vivo platelet activation correlated with the level of sVCAM-1. Our findings indicated that in vivo platelet activation reflects intrinsic platelet defects in patients with ET and PV, persists after cytoreductive treatment, and results in endothelial damage, probably through release of angiogenic factors and/or activation of white blood cells.


Thyroid | 2013

Improved Levothyroxine Pharmacokinetics After Bariatric Surgery

Margarita I. Gkotsina; Marina Michalaki; Irene Mamali; Georgios Markantes; George Sakellaropoulos; Fotios Kalfarentzos; Apostolos G. Vagenakis; Kostas B. Markou

BACKGROUND The absorption of levothyroxine (LT4) is affected by many factors. Bariatric surgery is recommended in severely obese patients. The aim of this study was to determine the consequences of bariatric surgery on LT4 pharmacokinetic parameters, and to identify the regions of the gastrointestinal tract where LT4 is absorbed in patients with severe obesity before and after surgery. METHODS We studied 32 severely obese nonhypothyroid patients who underwent sleeve gastrectomy (SG; n=10), Roux-en-Y gastric bypass (RYGBP; n=7), or biliopancreatic diversion with long limbs (BPD-LL; n=15). Before surgery, from 8:00 a.m., blood samples were collected before and every 30 minutes after the oral administration of a solution of 600 μg of LT4. The same procedure was repeated 35 days after surgery. We estimated the pharmacokinetic parameters of LT4 before and after surgery, including the area under the curve (AUC), the peak thyroxine concentration (Cmax), and the time to peak thyroxine concentration (Tmax). RESULTS Following surgery, in the SG group, the mean AUC was higher than it was before surgery (18.97±6.01 vs. 25.048±6.47 [μg/dL]·h; p<0.01), whereas the values of Cmax and Tmax were similar to those before surgery. In the RYGBP group, mean AUC, Cmax, and Tmax were similar before and after surgery. In the BPD-LL group, mean AUC and Cmax were higher after surgery than before (14.18±5.64 vs. 25.51±9.1 [μg/dL]·h, p<0.001; 5.62±1.34 vs. 8.16±2.57 μg/dL, p<0.001, respectively), whereas Tmax was similar. CONCLUSIONS The pharmacokinetic parameters of LT4 absorption are improved following SG and BPD-LL types of bariatric procedures. We conclude that the stomach, the duodenum, and the upper part of the jejunum are not sites for LT4 absorption, because in the above-mentioned bariatric procedures these are bypassed or removed.


Urologia Internationalis | 2010

Effect of bladder neck preservation during endoscopic extraperitoneal radical prostatectomy on urinary continence.

Jens-Uwe Stolzenburg; Panagiotis Kallidonis; James Hicks; Minh Do; Anja Dietel; George Sakellaropoulos; Abdulrahman Al-Aown; Evangelos Liatsikos

Objective: The current study investigates the effect of bladder neck (BN) preservation on postoperative continence and positive surgical margins (+SMs). Patients and Methods: 150 patients (group 1) who underwent BN-sparing endoscopic extraperitoneal radical prostatectomy (EERPE) and 90 patients treated with EERPE and BN resection (group 2) were retrospectively evaluated. Results: Both groups were similar for age, prostate-specific antigen and prostate size. There was no significant difference in operative time, mean blood loss or transfusion rate. Mean catheterization time was similar. The overall +SM rates were very similar at 10.7% for group 1 and 10.0% for group 2 (group 1, pT2 = 5.1% and pT3 = 30.3%; group 2, pT2 = 2.9% and pT3 = 33.3%). One of 16 patients in group 1 and 1 of 9 in group 2 had a +SM at BN. Statistically significant differences in continence were observed 24 h after catheter removal and 3 months postoperatively between both groups. Conclusion: BN preservation proved to have an impact on postoperative early continence of patients undergoing EERPE. Continence of patients who underwent BN preservation was improved after catheter removal and at the 3-month follow-up in comparison to those without BN preservation, but +SMs were not affected by the BN-sparing surgery.

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D. Cavouras

Technological Educational Institute of Athens

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Spiros Kostopoulos

Technological Educational Institute of Athens

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Dimitris Glotsos

Technological Educational Institute of Athens

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