Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Nikolaos Ptohis is active.

Publication


Featured researches published by Nikolaos Ptohis.


Cases Journal | 2009

Hughes-Stovin Syndrome: a case report and review of the literature

Athanasios N. Chalazonitis; Stefanos B Lachanis; Panagiotis Mitseas; Panagiotis Argyriou; Joannie Tzovara; Petros Porfyrides; Evangelia Sotiropoulou; Nikolaos Ptohis

BackgroundHughes-Stovin syndrome is a rare entity. The aetiology of Hughes-Stovin syndrome is still unknown and the natural course of the illness is usually fatal; however it is supposed to be a clinical variant manifestation of Behçet disease.Case presentationWe report the case of an 18 years old, greek male patient with Hughes-Stovin syndrome, who initially presented with deep vein thrombosis. There were no findings consistent with Behçet disease and the haemoptysis was treated successfully with methylprednisolone. Pathogenesis, imaging investigation and treatment of this syndrome are also briefly discussed.ConclusionIn young men presenting with venous thrombosis as revealed on imaging examination, with platelet count and coagulation tests within normal and hemoptysis the eventuality of Hughes-Stovin syndrome is to be considered.


Diagnostic and interventional radiology | 2008

Percutaneous radiofrequency thermal ablation in the management of lung tumors: presentation of clinical experience on a series of 35 patients.

Loukas Thanos; Sofia Mylona; Nikolaos Ptohis; Spyridon Tsiouris; Evangelia Sotiropoulou; Anastasia Pomoni; Maria Pomoni

PURPOSE To present our results in a series of 35 patients with malignant pulmonary lesions, who underwent radiofrequency thermal ablation (RFA) during a period of 18 months. MATERIALS AND METHODS In our institution, 55 RFA sessions under computed tomography (CT) guidance were performed on 48 pulmonary malignant lesions (23 inoperable primary and 25 metastatic) in 35 patients. RESULTS Total necrosis was noted in 19 primary (82.6%) and in 19 metastatic lesions (76%). In four primary (17.4%) and in six metastatic lesions (14%), partial necrosis was achieved, and a second RFA session was performed. The 6-month spiral CT follow-up demonstrated recurrence in seven lesions (14.5%) (four primary and three metastatic), which were treated with an additional RFA session. Two of the patients who underwent the procedure died of disseminated disease after one year, accounting for a 1-year survival rate of 94.2%. Mean survival was 14.48 +/- 3.3 months. CONCLUSION RFA is an effective method for treating unresectable lung carcinoma and lung metastases.


CardioVascular and Interventional Radiology | 2009

High-Flow Renal Arteriovenous Fistula Treated with the Amplatzer Vascular Plug: Implementation of an Arterial and Venous Approach

Elias N. Brountzos; Nikolaos Ptohis; Maria Grammenou-Pomoni; Irini Panagiotou; Dimitrios Kelekis; Athanasios D. Gouliamos; Nikolaos Kelekis

We present a 28-year-old man with a large symptomatic arteriovenous fistula (AVF) treated with embolization using the Amplatzer vascular plug (AVP). Although embolization may be considered the first-line therapy in the treatment of AVFs, there is an inherent high risk of migration of the embolic agents into the venous and pulmonary circulations. This case is illustrative of the ease and safety of using this device in high-flow renal AVFs.


Journal of Medical Case Reports | 2012

Pulmonary adenocarcinoma presenting with penile metastasis: a case report

Christos Karanikas; Nikolaos Ptohis; Evgenia Mainta; Christos S Baltas; Dimitris Athanasiadis; Simos Lechareas; Nikolaos Katirtzoglou; Spyros Xynogalos

IntroductionPenile metastases are an extremely rare occurrence, and most primary malignancies are located in the urinary bladder, prostate, rectum, and rectosigmoid. Although very few cases of penile metastases have been reported, those of lung cancer as the primary tumor are very rare. Among the latter, squamous cell carcinomas constitute the majority, whereas adenocarcinomas are almost exceptions. To the best of our knowledge, only two cases have been reported.Case presentationWe report the case of a 59-year-old Greek man who presented with persistent cough and chest pain that had started one month prior to a medical appointment. A physical examination, complete laboratory work-up, computed tomography scanning (of the chest, brain, and abdomen), pelvic magnetic resonance imaging, penile ultrasonography, bone scanning, and histological analyses were conducted. Afterward, a lung adenocarcinoma metastatic to the bones, brain, adrenals, lymph nodes, and penis was diagnosed. The primary lesion was a mass of 4cm in diameter in the apical segment of the lower lobe of the right lung. The patient was treated with bone and brain radiotherapy and various cycles of first- and second-line chemotherapy, and partial response was achieved five months after the initial appointment.ConclusionsAlthough these metastatic sites are well known to occur from a primary pulmonary malignancy, penile metastasis is extremely rare. Its identification requires prompt awareness by the physician despite the dismal prognosis. Furthermore, since the penis usually is omitted from the physical examination and lung cancer is the leading cause of cancer-related deaths, more penile metastases may be detected in the future, making early detection and appropriate management of great importance.


Vascular and Endovascular Surgery | 2011

Retrograde Transpopliteal Approach of Iliofemoral Lesions

Elias Brountzos; Konstantinos G. Moulakakis; Efthimios D. Avgerinos; Ilias Dalainas; Triantafillos G. Giannakopoulos; John D. Kakisis; Nikolaos Ptohis; Ourania Preza; Christos D. Liapis

Purpose: Aim of this study is to present our initial experience with the use of the retrograde popliteal artery access in patients with certain anatomic lesions. Methods: Between September 2008 and September 2010, 24 patients underwent a transpopliteal retrograde subintimal recanalization. Instead of its usage when antegrade recanalization failed, the “facedown” technique was preferred as a first choice in patients with common femoral artery stenosis or occlusion, proximal lesions of the superficial femoral artery (SFA) with no stump, severe obesity, tandem iliac, and SFA lesions. Results: Technical success was achieved in 91.7% of patients.The complication rate was 12.5%. The primary patency at 6, 12, and 18 months was 86.4%, 65.8%, and 65.8%, respectively. Conclusions: The retrograde popliteal artery approach can be considered as the primary SFA recanalization strategy in carefully selected patients, with competitive immediate and midterm results.


Cases Journal | 2009

Renal artery rupture following cutting balloon angioplasty for fibromuscular dysplasia: a case report

Elias N. Brountzos; Nikolaos Ptohis; Helen Triantafyllidi; Irene Panagiotou; Themistoklis N. Spyridopoulos; Evangelos Misiakos; Alexios Kelekis

IntroductionAngioplasty with the use of cutting balloons has been suggested by some case reports and small series for the treatment of renal artery stenoses that are resistant to conventional balloon catheters. Based on this limited experience, the use of this technology has been suggested as safe. Herein, we report a renal artery rupture following angioplasty with a cutting balloon. The complication was salvaged with a stent graft.Case presentationA 30-year-old white female patient with resistant hypertension caused by a severe renal artery stenosis attributed to fibromuscular dysplasia, was submitted to conventional balloon angioplasty without success. Dilatation of the lesion with a cutting balloon resulted in arterial rupture, with concomitant retroperitoneal hematoma.ConclusionCutting balloon angioplasty of renal artery lesions resistant to conventional balloon angioplasty should not be considered as safe as previously thought. When proceeding with such a procedure, a stent graft should be available for immediate use.


Molecular Imaging | 2011

Increased Breast Density Correlates with the Proliferation- Seeking Radiotracer 99m Tc(V)-DMSA Uptake in Florid Epithelial Hyperplasia and in Mixed Ductal Carcinoma In Situ with Invasive Ductal Carcinoma but Not in Pure Invasive Ductal Carcinoma or in Mild Epithelial Hyperplasia

Vassilios Papantoniou; Pipitsa Valsamaki; Evangelia Sotiropoulou; Angeliki Tsaroucha; Spyridon Tsiouris; Maria Sotiropoulou; Spyridon Marinopoulos; Evangelia Kounadi; Theodore Karianos; Athina Fothiadaki; Aikaterini Archontaki; Konstantinos Syrgiannis; Nikolaos Ptohis; Nikolaos Makris; Georgios Limouris; Aris Antsaklis

The purpose of this study was to assess the relationship of mammographic breast density (BD) and cell proliferation/focal adhesion kinase activation–seeking radiotracer technetium 99m pentavalent dimercaptosuccinic acid (99mTc(V)-DMSA) uptake in women with different breast histologies, that is, mild epithelial hyperplasia (MEH), florid epithelial hyperplasia (FEH), mixed ductal carcinoma in situ with invasive ductal carcinoma (DCIS + IDC), and pure IDC. Fifty-five women with histologically confirmed mammary pathologies were submitted preoperatively to mammography and 99mTc(V)-DMSA scintimammography. The percentage and intensity of 99mTc(V)-DMSA uptake and the percentage of BD were calculated by computer-assisted methods and compared (t-test) between the breast pathologies. In breasts with increased BD, FEH and DCIS + IDC were found. On the contrary, pure IDC and MEH were identified in breasts with significantly lower BD values. In breasts with increased 99mTc(V)-DMSA area and intensity of uptake, FEH was the main lesion found compared to all other histologies. Linear regression analysis between BD and 99mTc(V)-DMSA uptake area and intensity revealed significant coefficients of correlation (r = .689, p < .001 and r = .582, p < .001, respectively). Increased BD correlates with the presence of FEH and mixed DCIS + IDC but not with pure IDC or MEH. Its close relationship to 99mTc(V)-DMSA, which also showed an affinity to FEH, indicates that stromal microenvironment may constitute a specific substrate leading to progression to different subtypes of cancerous lesions originating from different pathways.


CardioVascular and Interventional Radiology | 2008

A Complicated Postsurgical Echinococcal Cyst Treated with Radiofrequency Ablation

Loukas Thanos; Sofia Mylona; P. Brontzakis; Nikolaos Ptohis; K. Karaliotas

Surgery of hydatid cysts is often complicated with intrabiliary rupture (IBR), which if not recognized may lead to biliary fistula with rather high rates of morbidity and mortality. We report our experience with the application of radiofrequency (RF) ablation for the treatment of an operated hepatic echinococcal cyst which was complicated with biliocystic communication and cysteocutaneous fistula with bile leakage. RF ablation was performed under CT guidance into the remaining cyst through the cutaneous fistula. Since ablation of the cyst and the fistula the patient has been asymptomatic.


CardioVascular and Interventional Radiology | 2008

Percutaneous Radiofrequency Ablation of Lung Tumors in Contact with the Aorta: Dangerous and Difficult but Efficient: A Report of Two Cases

Loukas Thanos; Sofia Mylona; Nikolaos Giannoulakos; Nikolaos Ptohis; Panagiota Galani; Maria Pomoni

Percutaneous imaging-guided tumor ablation is a widely accepted method for the treatment of primary and secondary lung tumors. Although it is generally feasible and effective for local tumor control, some conditions may affect its feasibility and effectiveness. Herein the authors report their experience with two patients with lung malignancies contiguous to the aorta who were successfully treated with radiofrequency ablation, even though it initially appeared highly risky due to the possible fatal complications.


Journal of Medical Case Reports | 2010

Reduced uptake of the proliferation-seeking radiotracer technetium-99m-labelled pentavalent dimercaptosuccinic acid in a 47-year-old woman with severe breast epithelial hyperplasia taking ibuprofen: a case report

Vassilios Papantoniou; Evangelia Sotiropoulou; Pipitsa Valsamaki; Angeliki Tsaroucha; Maria Sotiropoulou; Nikolaos Ptohis; Aikaterini Stipsanelli; Konstantinos Dimitrakakis; Spyridon Marinopoulos; Spyridon Tsiouris; Aris Antsaklis

IntroductionRecent studies have reported a risk reduction in the progression of benign breast disease to breast carcinoma through COX-2 pathways.Case presentationWe present a case of severe epithelial hyperplasia in a 47-year-old woman with increased breast density submitted to scintimammography by the proliferation-imaging tracer Technetium-99m-labelled pentavalent dimercaptosuccinic acid, before and after an oral ibuprofen treatment for 4 weeks. The radiotracer uptake after ibuprofen intake was significantly reduced, both visually and by semi-quantitative analysis, based on a calculation of lesion-to-background ratios.ConclusionIn proliferating breast lesions, scintigraphically displayed reduction in Technetium-99m-labelled pentavalent dimercaptosuccinic acid uptake may indicate inhibition by ibuprofen in the pathway of malignant epithelial cell transformation.

Collaboration


Dive into the Nikolaos Ptohis's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Loukas Thanos

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Maria Pomoni

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Sofia Mylona

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Aris Antsaklis

National and Kapodistrian University of Athens

View shared research outputs
Researchain Logo
Decentralizing Knowledge