Orestis Lyros

Dr. Orestis Lyros

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2018 in Journal of Gastric Cancer
Verified
Journal Article
Open access
Ines GockelInes Gockel
Ines Gockel
Boris Jansen-WinkelnBoris Jansen-Winkeln
Boris Jansen-Winkeln
LHLinda Haase
Linda Haase
PRPhilipp Rhode
Philipp Rhode
MMMatthias Mehdorn
Matthias Mehdorn
René ThiemeRené Thieme
René Thieme
Gockel I, et al. J Gastric Cancer. 2018 Aug;18:e37. https://doi.org/10.5230/jgc.2018.18.e37

14 March 2019 in Obesity Surgery
Verified
Journal Article
Closed access
PDF file
OLOrestis Lyros
Orestis Lyros
YMYusef Moulla
Yusef Moulla
MMMatthias Mehdorn
Matthias Mehdorn
KSKatrin Schierle
Katrin Schierle
RSRobert Sucher
Robert Sucher
ADArne Dietrich
Arne Dietrich

30 July 2019 in Oncotarget
Verified
Journal Article
Open access
SPSebastian Prill
Sebastian Prill
JRJakob Rebstock
Jakob Rebstock
ATAnja Tennemann
Anja Tennemann
JKJustus Körfer
Justus Körfer
RSRasmus Sönnichsen
Rasmus Sönnichsen
SKSonja Kallendrusch
Sonja Kallendrusch
Purpose: Presence of tumor-associated macrophages (TAM) and high levels of ferritin and lipocalin 2 (Lcn2) in the tumor microenvironment are associated with poor prognosis in many types of cancer. Here we investigate whether iron deprivation influences TAM phenotype and chemotherapy resistance in tumor slice cultures (TSC) of gastric cancer. Results: TAM remained morphologically and functionally stable for four DIV. DFO treatment for 72 h decreased ferritin expression in TAM and in the tumor stroma but did not alter Lcn2 expression. TAM phenotype was altered after 72 h of cisplatin or DFO treatment compared with control conditions. Single DFO treatment and combined treatment with cytotoxic drugs significantly increased tumor cell apoptosis in TSC of gastric cancer. Methods: TSC were manufactured by cutting tissue of gastric cancer resection specimens in 350 μm thick slices and cultivating them under standard conditions on a filter membrane, at an air-liquid interface. After 24 h ex vivo, TSC were treated with irinotecan (100 nM) or cisplatin (10 μM) alone and in combination with deferoxamine (DFO; 10 μM, 100 μM), respectively, for 72 h. After four days in vitro (DIV) the TSC were fixated with paraformaldehyde, paraffin embedded and analyzed by immunohistochemistry for apoptosis (cPARP), proliferation (Ki67), TAM (CD68, CD163), ferritin, and Lcn2 expression. Conclusions: TAM are well preserved and can be studied in TSC of gastric cancer. Iron deprivation significantly increased tumor cell apoptosis.

8 August 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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George TriantafyllouGeorge Triantafyllou
George Triantafyllou
OLOrestis Lyros
Orestis Lyros
NANikolaos Arkadopoulos
Nikolaos Arkadopoulos
PKPanagiotis Kokoropoulos
Panagiotis Kokoropoulos
FDFotis Demetriou
Fotis Demetriou
Maria PiagkouMaria Piagkou
Maria Piagkou
The pancreas exhibits a uniquely intricate vascular architecture characterized by frequent and clinically significant morphological variations. These variations—impacting both arterial supply and venous drainage—are critical determinants in surgical planning, radiologic interpretation, and interventional outcomes. This comprehensive review examines the full spectrum of pancreatic vascular anatomy, with particular emphasis on embryological development, imaging manifestations, and surgical relevance. Key arterial structures, including the superior and inferior pancreaticoduodenal arteries (SPDAs and IPDAs) and the dorsal pancreatic artery (DPA)—are explored in detail alongside accessory branches. On the venous side, focus is placed on the gastrocolic trunk (GCT) of Henle, the uncinate and centro-inferior pancreatic veins, and the dorsal pancreatic vein (DPV). The review highlights that arterial aberrations, such as a DPA originating from the superior mesenteric artery (SMA), or duplicated patterns of the IPDA, as well as venous anomalies such as variant drainage of the GCT or the centro-inferior pancreatic vein, have substantial implications during pancreaticoduodenectomy, distal pancreatectomy, and transplantation procedures. With advances in multidetector computed tomography (MDCT), magnetic resonance angiography (MRA), and three-dimensional (3D) modeling, high-risk vascular variants can now be accurately mapped preoperatively, facilitating safer and more effective minimally invasive and robotic-assisted surgeries. In conclusion, the recognition and understanding of pancreatic vascular variations are imperative for optimal surgical and interventional management. This review underscores the importance of multidisciplinary collaboration among surgeons, radiologists, and anatomists, which will allow them to integrate detailed anatomical knowledge into clinical workflows, ultimately improving patient outcomes in pancreatic procedures.

24 May 2025 in Surgical and Radiologic Anatomy
Verified
Journal Article
Open access
PDF file
George TriantafyllouGeorge Triantafyllou
George Triantafyllou
NBNektarios Belimezakis
Nektarios Belimezakis
OLOrestis Lyros
Orestis Lyros
NANikolaos Arkadopoulos
Nikolaos Arkadopoulos
FDFotis Demetriou
Fotis Demetriou
Maria PiagkouMaria Piagkou
Maria Piagkou
Purpose: This evidence-based systematic review with meta-analysis aims to synthesize the inferior mesenteric artery (IMA) variants including their origin level, branching patterns, and morphometric characteristics. Materials and methods: The study adhered to the latest guidelines. Four online databases were used for the systematic review, and studies that reported the prevalence of IMA variants were considered eligible for inclusion. A statistical meta-analysis was conducted using R programming software with a random-effects model to calculate the pooled prevalence of the variants. Results: Twenty-three (23) studies were included in this analysis. The IMA typically originated at the 3rd lumbar vertebra (L3) level, occurring in 70.16% of cases. The most common branching pattern of the IMA was bifurcated, indicating a pooled prevalence of 63.89%. This predominant pattern involved the IMA bifurcating into the left colic artery (LCA) and a common trunk for both the superior rectal artery (SRA) and the sigmoid artery (SA), with a pooled prevalence of 46.09%. The IMA trifurcation and tetrafurcation had pooled prevalences of 27.35% and 11.62%, respectively. The diameter of the IMA had a pooled mean of 41.41 mm, and the distance from the IMA’s origin to the LCA had a pooled mean of 40.67 mm. Conclusions: This review of existing literature delineates the IMA levels of origin, branching patterns, and morphometric characteristics. A comprehensive understanding of the surgical anatomy of this vessel is imperative during colorectal cancer procedures. Consequently, surgeons operating in this anatomical region must possess an in-depth knowledge of typical and variant anatomical structures.

15 November 2025 in Diagnostics
Verified
Journal Article
Open access
PDF file
George TriantafyllouGeorge Triantafyllou
George Triantafyllou
OLOrestis Lyros
Orestis Lyros
DIMITRIOS SCHIZASDIMITRIOS SCHIZAS
DIMITRIOS SCHIZAS
NANikolaos Arkadopoulos
Nikolaos Arkadopoulos
FDFotis Demetriou
Fotis Demetriou
Maria PiagkouMaria Piagkou
Maria Piagkou
The vascular anatomy of the stomach is both complex and highly variable, with direct implications for oncologic, bariatric, esophageal, and interventional procedures. This comprehensive review combines anatomical, radiological, and surgical evidence on arterial and venous variations in the stomach. The left gastric artery, traditionally the first branch of the coeliac trunk, often shows variants such as a direct aortic origin or association with an abnormal left hepatic artery. The right gastric artery most frequently arises from the proper hepatic artery, but its origin can vary significantly. The gastroepiploic arteries exhibit diversity in their origin, size, and connection patterns, with occasional duplication or absence. Additional vessels, including the posterior gastric artery and the short gastric arteries, also contribute to variations in arterial supply. Venous drainage largely follows the arterial pattern. The left and right gastric veins and the gastroepiploic venous arcade are major routes, while variants of the left gastric vein and the gastrocolic trunk (Henle’s trunk) contribute to complexity through different convergence patterns. These vascular variations have significant clinical implications, as they impact the safety of D2 lymphadenectomy, the risk of ischemic complications during laparoscopic sleeve gastrectomy, the success of gastric conduit formation in esophagectomy, and the effectiveness of transarterial embolization for upper gastrointestinal bleeding. Preoperative vascular mapping with multidetector computed tomography angiography and 3D reconstruction reliably defines individual anatomy, allowing for customized surgical planning and reducing operative risks. Recognizing both common and rare gastric vascular variants is essential for safe and effective surgical and endovascular management of gastric disease.