Georgios Vrakas

Dr. Georgios Vrakas

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

View All Publications
13 April 2019 in Transplant International
Verified
Journal Article
Open access
PDF file
AWAnnemarie Weißenbacher
Annemarie Weißenbacher
GVGeorgios Vrakas
Georgios Vrakas
DNDavid Nasralla
David Nasralla
CCCarlo D. L. Ceresa
Carlo D. L. Ceresa
Organ preservation and re‐conditioning using machine perfusion technologies continue to generate promising results in terms of viability assessment, organ utilisation and improved initial graft function. Here, we summarise the latest findings and study the results of ex‐vivo/ex‐situ hypothermic (HMP) and normothermic machine perfusion (NMP) in the area of abdominal organ transplantation (kidney, liver, pancreas and intestine). We also consider the potential role of normothermic regional perfusion (NRP) to re‐condition DCD organs before retrieval. The findings from clinical studies reported to date suggest that machine perfusion will offer real benefits when compared with conventional cold preservation. Several randomized trials are expected to report their findings within the next two years which may shed light on the relative merits of different perfusion methods and could indicate which perfusion parameters may be most useful to predict organ quality and viability. Further work is needed to identify composite endpoints that are relevant for transplanted organs that have undergone machine preservation. Multi‐centre trials to compare and analyse the combinations of NRP followed by HMP and/or NMP, either directly after organ retrieval using transportable devices or when back‐to‐base, are needed. The potential applications of machine preservation technology beyond the field of solid organ transplantation are also considered.

29 December 2015 in American Journal of Transplantation
Verified
Journal Article
Open access
PDF file
UGU. A. Gerlach
U. A. Gerlach
GVGeorgios Vrakas
Georgios Vrakas
BSB. Sawitzki
B. Sawitzki
RMR. Macedo
R. Macedo
SRS. Reddy
S. Reddy
AVA. Vaidya
A. Vaidya
Abdominal wall transplantation (AWTX) has revolutionized difficult abdominal closure after intestinal transplantation (ITX). More important, the skin of the transplanted abdominal wall (AW) may serve as an immunological tool for differential diagnosis of bowel dysfunction after transplant. Between August 2008 and October 2014, 29 small bowel transplantations were performed in 28 patients (16 male, 12 female; aged 41 ± 13 years). Two groups were identified: the solid organ transplant (SOT) group (n = 15; 12 ITX and 3 modified multivisceral transplantation [MMVTX]) and the SOT‐AWTX group (n = 14; 12 ITX and 2 MMVTX), with the latter including one ITX‐AWTX retransplantation. Two doses of alemtuzumab were used for induction (30 mg, 6 and 24 h after reperfusion), and tacrolimus (trough levels 8–12 ng/mL) was used for maintenance immunosuppression. Patient survival was similar in both groups (67% vs. 61%); however, the SOT‐AWTX group showed faster posttransplant recovery, better intestinal graft survival (79% vs. 60%), a lower intestinal rejection rate (7% vs. 27%) and a lower rate of misdiagnoses in which viral infection was mistaken and treated as rejection (14% vs. 33%). The skin component of the AW may serve as an immune modulator and sentinel marker for immunological activity in the host. This can be a vital tool for timely prevention of intestinal graft rejection and, more important, avoidance of overimmunosuppression in cases of bowel dysfunction not related to graft rejection.

1 November 2013 in Journal of Vascular Surgery
Verified
Journal Article
Closed access
GVGeorgios Vrakas
Georgios Vrakas
FDFatima Defigueiredo
Fatima Defigueiredo
STSam Turner
Sam Turner
CJChris Jones
Chris Jones
JTJohn Taylor
John Taylor
FCFrancis Calder
Francis Calder

27 May 2013 in Transplantation
Verified
Journal Article
Closed access
RSRajinder Pal Singh
Rajinder Pal Singh
GVGeorgios Vrakas
Georgios Vrakas
SHSamiha Hayek
Samiha Hayek
SHSara Hayek
Sara Hayek
SASadia Anam
Sadia Anam
MDMartin W. Drage
Martin W. Drage
Background Peripancreatic fluid collections (PPFC) are a serious complication after simultaneous pancreas-kidney transplantation (SPKTx). Methods Retrospective study for all 223 SPKTx performed from December 8, 1996, to October 10, 2011, to evaluate the risk factors (RF) and impact of PPFCs on outcomes was conducted. Results Clinically significant PPFCs were seen in 36 (16%) cases, all within 3 months after transplantation. Radiologic drainage resolved 2 (6%) cases, and 34 required laparotomy (mean [SD], 4 [7]). Compared with the non-PPFC group (n=186), the PPFC group had similar patient and total kidney graft survivals but significantly lower total pancreas survival (68% vs. 85%) and greater incidence of infections (75% vs. 46%, all P<0.05) at 5 years. PPFCs were associated with early graft pancreatitis in 18 (50%), pancreatic fistula in 20 (56%, 9 with obvious duodenal stump leak) and infection in the collection in 20 (56%) cases. Comparison of PPFCs with pancreas graft loss to the PPFCs with surviving grafts showed that the incidence of pancreatic fistula was greater in the former (90% pancreas graft loss vs. 42% pancreas graft survival, P30 years to be significant (P=0.03; odds ratio, 3.4; confidence interval, 1.1–10.5) and a trend of association with donor body mass index >30 and pancreas cold ischemia time greater than 12 hr. Conclusions PPFCs are associated with significant reduction in pancreas allograft survival and impact resource use. Donor age >30 years is a significant RF for their development. PPFCs associated with pancreatic fistula carry a greater risk for pancreas graft loss.

1 May 2017 in Current Opinion in Gastroenterology
Verified
Journal Article
Closed access
PDF file
LLLarry Loo
Larry Loo
GVGeorgios Vrakas
Georgios Vrakas
SRSrikanth Reddy
Srikanth Reddy
PAPhilip Allan
Philip Allan
The purpose of this article is to review the existing literature on the current indications, surgical techniques, immunosuppressive therapy and outcomes following intestinal transplantation (ITx). Over recent years, ITx has become a more common operation with approximately 2500 procedures carried out worldwide by 2014. It is reserved for patients with intestinal failure and who have developed complications of home parenteral nutrition or who have a high risk of dying from their underlying disease. Recent advances such as the improvement in survival rates, not only for isolated small bowel transplants but also following inclusion of a liver graft in combined liver-small bowel transplant, and the utility of citrulline as a noninvasive biomarker to appreciate acute rejection herald an exciting shift in the field of ITx. With advancements in immunosuppressive drugs, induction regimens, standardization of surgical techniques and improved postoperative care, survival is increasing. In due course, it will most likely become as good as remaining on home parenteral nutrition and as such could become a viable first-line option.

1 April 2015 in Transplantation Proceedings
Verified
Journal Article
Closed access
Andrea FrillingAndrea Frilling
Andrea Frilling
HGHenk Giele
Henk Giele
GVGeorgios Vrakas
Georgios Vrakas
SRS. Reddy
S. Reddy
RMR. Macedo
R. Macedo
AVA. Vaidya
A. Vaidya