Konstantinos Zapsalis

Dr. Konstantinos Zapsalis


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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1 February 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
SSSavvas Symeonidis
Savvas Symeonidis
IMIoannis Mantzoros
Ioannis Mantzoros
EAElissavet Anestiadou
Elissavet Anestiadou
OIOrestis Ioannidis
Orestis Ioannidis
PCPanagiotis Christidis
Panagiotis Christidis
SAStamatis Angelopoulos
Stamatis Angelopoulos
Background: Intraoperative biliary anatomy recognition is crucial for safety during laparoscopic cholecystectomy, since iatrogenic bile duct injuries represent a fatal complication, occurring in up to 0.9% of patients. Indocyanine green fluorescence cholangiography (ICG-FC) is a safe and cost-effective procedure for achieving a critical view of safety and recognizing early biliary injuries. The aim of this study is to compare the perioperative outcomes, usefulness and safety of standard intraoperative cholangiography (IOC) with ICG-FC with intravenous ICG. Methods: Between 1 June 2021 and 31 December 2022, 160 patients undergoing elective LC were randomized into two equal groups: Group A (standard IOC) and group B (ICG-FC with intravenous ICG). Results: No significant difference was found between the two groups regarding demographics, surgery indication or surgery duration. No significant difference was found regarding the visualization of critical biliary structures. However, the surgeon satisfaction and cholangiography duration presented significant differences in favor of ICG-FC. Regarding the inflammatory response, a significant difference between the two groups was found only in postoperative WBC levels. Hepatic and renal function test results were not significantly different between the two groups on the first postoperative day, except for direct bilirubin. No statistically significant difference was noted regarding 30-day postoperative complications, while none of the complications noted included bile duct injury events. Conclusions: ICG-FC presents equivalent results to IOC regarding extrahepatic biliary visualization and postoperative complications. However, more studies need to be performed in order to standardize the optimal dose, timing and mode of administration.

20 June 2025 in World Journal of Experimental Medicine
Verified
Journal Article
Open access
KZKonstantinos Zapsalis
Konstantinos Zapsalis
OIOrestis Ioannidis
Orestis Ioannidis
CXChristos Xylas
Christos Xylas
KSKonstantinos Siozos
Konstantinos Siozos
GGGeorgios Gemousakakis
Georgios Gemousakakis
SAStamatios Angelopoulos
Stamatios Angelopoulos
BACKGROUND Incisional hernias are a common complication of previous surgeries and remain a persistent issue in clinical practice, posing a significant burden on healthcare systems despite advances in education and technology. Surgical techniques, primarily involving the use of mesh to cover the abdominal wall gap, are widely used as a standard intervention strategy. AIM To examine the regeneration of the aponeurosis defect in the anterior abdominal wall in rats using regenerative mimetic factors of the extracellular matrix [ReGeneraTing Agent (RGTA)], adipose tissue micrografts (ATM), and platelet rich plasma (PRP) as regenerative agents. METHODS Regenerative agents such as RGTA, ATM, and PRP are gaining popularity. ATM involves autologous adipose tissue cells with mesenchymal stem cell markers and a high percentage of stromal vascular fraction cells. RGTAs are heparan sulfate (HS) mimetics that replace degraded HSs in damaged tissue, enhancing the quality and speed of repair. PRP is a concentrated plasma preparation containing seven fundamental proteins responsible for tissue production. An acellular dermal matrix is a biological implant free of cellular or antigenic components, making it an excellent material for reconstructive surgery. Polyglactin is a synthetic, absorbable mesh that loses 50% of its strength after fourteen days, providing initial support for new tissue regeneration before being completely absorbed. RESULTS Rats will undergo a laparotomy with a precise 2 cm by 2 cm excision of the anterior abdominal wall fascia below the umbilicus. They will be divided into sixteen groups, each receiving different combinations of regenerative factor injections into the denervated area in both non-contaminated and contaminated environments. A collagen-elastin matrix will be used to join the aponeurosis edges, with an absorbable polyglactin mesh anchored over it. Samples will be taken for macroscopic, histological, and immunohistochemical evaluation of tissue regeneration. CONCLUSION Our study aims to demonstrate how these factors promote cell proliferation and healing of the denervated anterior abdominal wall, potentially reducing the frequency and complications of incisional hernias. This approach could offer a more economical and efficient treatment option compared to current costly methods.

14 December 2025 in Medical Sciences
Verified
Journal Article
Open access
PDF file
SPStyliani Parpoudi
Styliani Parpoudi
IMIoannis Mantzoros
Ioannis Mantzoros
OIOrestis Ioannidis
Orestis Ioannidis
KZKonstantinos Zapsalis
Konstantinos Zapsalis
TGThomai Gamali
Thomai Gamali
SAStamatis Angelopoulos
Stamatis Angelopoulos
Background/Objectives: The safety of intraperitoneal mesh placement in contaminated fields remains controversial because of the increased risk of inflammation and adhesion formation. N-acetyl-L-cysteine (NAC) has antioxidant, pro-fibrinolytic and antibiofilm actions that could attenuate this response. The aim of this study is to determine whether NAC reduces mesh-related inflammation in a septic model created by intraperitoneal Escherichia coli (E.coli) inoculation. The primary comparison was prospectively defined between E. coli–inoculated animals treated with NAC (D) and those without NAC (B). Groups without E. coli (A,C,E) are presented for context and were compared previously. Methods: In this randomized, double-blind experimental model (five groups, n = 20 per group), all rats underwent midline laparotomy with intraperitoneal placement of a composite mesh, followed by standardized ciprofloxacin administration. The septic groups received intraperitoneal E. coli, while the NAC-treated groups additionally received intraperitoneal NAC (150 mg/kg). Serum levels of IL-1α, IL-6, and TNF-α were measured on postoperative days 7, 14, and 21. On day 21, adhesions were graded using the Modified Diamond system, histology (inflammatory infiltration, fibrosis, neovascularization) was scored, and mesh cultures were obtained. Cytokine data were analyzed with repeated-measures ANOVA, while categorical or ordinal outcomes were assessed using χ2 or Fisher’s exact tests with Bonferroni-adjusted pairwise comparisons. Results: E. coli inoculation significantly increased adhesion burden and worsened histologic scores compared with controls (both p < 0.001). NAC administration in the septic model significantly reduced adhesions and improved all histologic domains relative to E. coli alone (all p ≤ 0.003), with values comparable to controls (non-significant across domains). For cytokines, there was a significant overall group effect for IL-1α, IL-6, and TNF-α (all p < 0.001), without a main effect of time or time × group interaction. Pairwise contrasts showed lower IL-1α (p = 0.024), IL-6 (p < 0.001), and TNF-α (p < 0.001) levels in group D versus B, and lower IL-6 and TNF-α in group D versus A (both p < 0.001). Mesh culture positivity rate was higher in group B than A (p < 0.001) and showed a non-significant reduction in group D versus B (p = 0.10). No perioperative deaths occurred. Conclusions: NAC attenuated septic, mesh-associated inflammation—normalizing adhesions and histology and reducing IL-6 and TNF-α— supporting its role as a host-directed adjunct alongside antibiotics. Further translational studies are warranted to define the optimal dose, timing, and clinical indications.

31 August 2025 in Bioengineering
Verified
Journal Article
Open access
PDF file
KZKonstantinos Zapsalis
Konstantinos Zapsalis
OIOrestis Ioannidis
Orestis Ioannidis
EAElissavet Anestiadou
Elissavet Anestiadou
MPMaria Pantelidou
Maria Pantelidou
KSKostas Siozos
Kostas Siozos
SAStamatis Angelopoulos
Stamatis Angelopoulos
Adipose tissue micrografts (ATM) and dermis micrografts (DMG) have emerged as promising autologous therapies in regenerative wound care, leveraging mechanically disaggregated cell–matrix constructs to modulate the wound microenvironment and promote tissue repair. This scoping review systematically analyzed clinical studies investigating ATMs and DMGs in acute and chronic wounds. Eight studies, comprising randomized controlled trials, observational studies, and case series, were identified, involving diverse wound types such as burns, ulcers, surgical dehiscence, and posttraumatic defects. All interventions utilized mechanical disaggregation (Rigenera® system) to produce micrografts, which were applied via perilesional injection, scaffold-assisted delivery, or topical administration. Outcomes consistently demonstrated accelerated re-epithelialization, enhanced angiogenesis, improved scar remodeling, and low complication rates. In select studies, micrografts were combined with platelet-rich fibrin or stromal vascular fraction, suggesting potential synergistic effects. While one randomized trial showed superior healing outcomes with DMGs over collagen scaffolds, others yielded mixed results, likely reflecting heterogeneity in methodology and outcome measures. Overall, the available clinical evidence supports the safety, feasibility, and biological activity of micrograft-based therapies. However, larger, standardized, and mechanistically driven studies are required to validate their efficacy and define optimal protocols across wound etiologies.

22 April 2026 in Medicina
Verified
Journal Article
Open access
PDF file
AMApostolos Makrantonakis
Apostolos Makrantonakis
IMIoannis Mantzoros
Ioannis Mantzoros
OIOrestis Ioannidis
Orestis Ioannidis
KZKonstantinos Zapsalis
Konstantinos Zapsalis
EAElissavet Anestiadou
Elissavet Anestiadou
SAStamatis Angelopoulos
Stamatis Angelopoulos
Background and Objectives: Intraperitoneal onlay mesh (IPOM) reduces ventral/incisional hernia recurrence but raises concern for adhesions and infection, particularly when the operative field is not strictly clean. We aimed to determine how contamination severity modulates the peritoneal response to intraperitoneal polypropylene mesh. Materials and Methods: In a prospective, randomized, blinded rat study, 60 male Wistar rats were allocated to three groups (n = 20/group) and evaluated at postoperative day (POD) 4 and POD 8 (n = 10/timepoint): A, clean mesh placement; B, small-bowel resection with end-to-end anastomosis without spillage (“potentially septic”); and C, mesh placement followed by intraperitoneal inoculation with Escherichia coli and Staphylococcus aureus (“controlled contamination”). The primary outcome was adhesion severity (Van der Ham scale, 0–3). Secondary outcomes included semi-quantitative histological scores (0–4) for neutrophil infiltration, fibroblast proliferation, neoangiogenesis, and collagen deposition. Prespecified non-parametric analyses were applied. Results: All animals completed follow-up; no pre-sacrifice deaths occurred. Adhesion severity showed no statistically significant differences between Groups A and B at either timepoint (mean POD4: 0.3 vs. 0.6; POD8: 0.4 vs. 0.8; p > 0.05). In contrast, Group C demonstrated markedly higher adhesion scores (mean POD4: 2.3; POD8: 2.4; both p < 0.001 vs. Groups A and B), with a substantially greater proportion of grade 2–3 adhesions. Histological parameters paralleled these findings: at both POD4 and POD8, Group C showed significantly higher neutrophil, fibroblast, neoangiogenesis, and collagen scores compared with Groups A and B (all p < 0.001). No statistically significant within-group temporal differences were observed between POD4 and POD8. Conclusions: In this experimental model, intraperitoneal polypropylene mesh demonstrated similar early biological response patterns in clean and controlled contamination settings, whereas established intra-abdominal sepsis was associated with a marked escalation of inflammation, fibroproliferation, and adhesion formation. These findings suggest that selective use of synthetic intraperitoneal mesh may be considered when contamination is controlled, while caution is warranted in frankly septic environments.

23 November 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
SBStefanos Bitsianis
Stefanos Bitsianis
IMIoannis Mantzoros
Ioannis Mantzoros
EAElissavet Anestiadou
Elissavet Anestiadou
PCPanagiotis Christidis
Panagiotis Christidis
CCChristos Chatzakis
Christos Chatzakis
SAStamatis Angelopoulos
Stamatis Angelopoulos
Cytoreductive surgery (CRS), combined with hyperthermic intraperitoneal chemotherapy, has significantly improved survival outcomes in patients with peritoneal carcinomatosis from colorectal cancer (CRC). Regorafenib is an oral agent administered in patients with refractory metastatic CRC. Our aim was to investigate the outcomes of intraperitoneal administration of regorafenib for intraperitoneal chemotherapy (IPEC) or/and CRS in a rat model of colorectal peritoneal metastases regarding immunology and peritoneal cytology. A total of 24 rats were included. Twenty-eight days after carcinogenesis induction, rats were randomized into following groups: group A: control group; group B: CRS only; group C: IPEC only; and group D: CRS + IPEC. On day 56 after carcinogenesis, euthanasia and laparotomy were performed. Serum levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) as well as peritoneal cytology were investigated. Groups B and D had statistically significant lower mean levels of IL-6 and TNF-α compared to groups A and C, but there was no significant difference between them. Both B and D groups presented a statistically significant difference regarding the rate of negative peritoneal cytology, when compared to the control group, but not to group C. In conclusion, regorafenib-based IPEC, combined with CRS, may constitute a promising tool against peritoneal carcinomatosis by altering the tumor microenvironment.