Aristotelis Perrakis

Prof. Dr. Aristotelis Perrakis

Department of General, Visceral, Vascular and Transplant Surgery, University Hospital Magdeburg, Leipzigerstr 44, 39120 Magdeburg, Germany
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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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11 July 2022 in Cancers
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MRMirhasan Rahimli
Mirhasan Rahimli
Aristotelis PerrakisAristotelis Perrakis
Aristotelis Perrakis
MAMihailo Andric
Mihailo Andric
JSJessica Stockheim
Jessica Stockheim
MFMareike Franz
Mareike Franz
Roland S. CronerRoland S. Croner
Roland S. Croner
Background: Robotic procedures are an integral part of modern liver surgery. However, the advantages of a robotic approach in comparison to the conventional laparoscopic approach are the subject of controversial debate. The aim of this systematic review and meta-analysis is to compare robotic and laparoscopic liver resection with particular attention to the resection margin status in malignant cases. Methods: A systematic literature search was performed using PubMed and Cochrane Library in accordance with the PRISMA guidelines. Only studies comparing robotic and laparoscopic liver resections were considered for this meta-analysis. Furthermore, the rate of the positive resection margin or R0 rate in malignant cases had to be clearly identifiable. We used fixed or random effects models according to heterogeneity. Results: Fourteen studies with a total number of 1530 cases were included in qualitative and quantitative synthesis. Malignancies were identified in 71.1% (n = 1088) of these cases. These included hepatocellular carcinoma, cholangiocarcinoma, colorectal liver metastases and other malignancies of the liver. Positive resection margins were noted in 24 cases (5.3%) in the robotic group and in 54 cases (8.6%) in the laparoscopic group (OR = 0.71; 95% CI (0.42–1.18); p = 0.18). Tumor size was significantly larger in the robotic group (MD = 6.92; 95% CI (2.93–10.91); p = 0.0007). The operation time was significantly longer in the robotic procedure (MD = 28.12; 95% CI (3.66–52.57); p = 0.02). There were no significant differences between the robotic and laparoscopic approaches regarding the intra-operative blood loss, length of hospital stay, overall and severe complications and conversion rate. Conclusion: Our meta-analysis showed no significant difference between the robotic and laparoscopic procedures regarding the resection margin status. Tumor size was significantly larger in the robotic group. However, randomized controlled trials with long-term follow-up are needed to demonstrate the benefits of robotics in liver surgery.

12 November 2021 in Journal of Clinical Medicine
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Aristotelis PerrakisAristotelis Perrakis
Aristotelis Perrakis
MRMirhasan Rahimli
Mirhasan Rahimli
Andrew A. GumbsAndrew A. Gumbs
Andrew A. Gumbs
VNVictor Negrini
Victor Negrini
MAMihailo Andric
Mihailo Andric
Roland S. CronerRoland S. Croner
Roland S. Croner
Background: The implementation of robotics in liver surgery offers several advantages compared to conventional open and laparoscopic techniques. One major advantage is the enhanced degree of freedom at the tip of the robotic tools compared to laparoscopic instruments. This enables excellent vessel control during inflow and outflow dissection of the liver. Parenchymal transection remains the most challenging part during robotic liver resection because currently available robotic instruments for parenchymal transection have several limitations and there is no standardized technique as of yet. We established a new strategy and share our experience. Methods: We present a novel technique for the transection of liver parenchyma during robotic surgery, using three devices (3D) simultaneously: monopolar scissors and bipolar Maryland forceps of the robot and laparoscopic-guided waterjet. We collected the perioperative data of twenty-eight patients who underwent this procedure for minor and major liver resections between February 2019 and December 2020 from the Magdeburg Registry of minimally invasive liver surgery (MD-MILS). Results: Twenty-eight patients underwent robotic-assisted 3D parenchyma dissection within the investigation period. Twelve cases of major and sixteen cases of minor hepatectomy for malignant and non-malignant cases were performed. Operative time for major liver resections (≥ 3 liver segments) was 381.7 (SD 80.6) min vs. 252.0 (70.4) min for minor resections (p < 0.01). Intraoperative measured blood loss was 495.8 (SD 508.8) ml for major and 256.3 (170.2) ml for minor liver resections (p = 0.090). The mean postoperative stay was 13.3 (SD 11.1) days for all cases. Liver surgery-related morbidity was 10.7%, no mortalities occurred. We achieved an R0 resection in all malignant cases. Conclusions: The 3D technique for parenchyma dissection in robotic liver surgery is a safe and feasible procedure. This novel method offers an advanced locally controlled preparation of intrahepatic vessels and bile ducts. The combination of precise extrahepatic vessel handling with the 3D technique of parenchyma dissection is a fundamental step forward to the standardization of robotic liver surgery for teaching purposing and the wider adoption of robotic hepatectomy into routine patient care.

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Wenjie ShiWenjie Shi
Wenjie Shi
CLChen Li
Chen Li
TWThomas Wartmann
Thomas Wartmann
CKChristoph Kahlert
Christoph Kahlert
RDRenfei Du
Renfei Du
Ulf Dietrich KahlertUlf Dietrich Kahlert
Ulf Dietrich Kahlert
Background: Transient receptor potential channels (TRPs) have been demonstrated to take on functions in pancreatic adenocarcinoma (PAAD) biology. However, little data are available that validate the potential of TRP in a clinical translational setting. Methods: A TRPs-related gene signature was constructed based on the Cox regression using a TCGA-PAAD cohort and receiver operating characteristic (ROC) was used to evaluate the predictive ability of this model. Core genes of the signature were screened by a protein-to-protein interaction (PPI) network, and expression validated by two independent datasets. The mutation analysis and gene set enrichment analysis (GSEA) were conducted. Virtual interventions screening was performed to discover substance candidates for the identified target genes. Results: A four TRPs-related gene signature, which contained MCOLN1, PKD1, TRPC3, and TRPC7, was developed and the area under the curve (AUC) was 0.758. Kaplan–Meier analysis revealed that patients with elevated signature score classify as a high-risk group featuring significantly shorter recurrence free survival (RFS) time, compared to the low-risk patients (p < 0.001). The gene prediction model also had a good predictive capability for predicting shortened overall survival (OS) and disease-specific survival (DSS) (AUC = 0.680 and AUC = 0.739, respectively). GSEA enrichment revealed the core genes of the signature, TRPC3 and TRPC7, were involved in several cancer-related pathways. TRPC3 mRNA is elevated in cancer tissue compared to control tissue and augmented in tumors with lymph node invasion compared to tumors without signs of lymph node invasion. Virtual substance screening of FDA approved compounds indicates that four small molecular compounds might be potentially selective not only for TRPC3 protein but also as a potential binding partner to TRPC7 protein. Conclusions: Our computational pipeline constructed a four TRP-related gene signature that enables us to predict clinical prognostic value of hitherto unrecognized biomarkers for PAAD. Sensory ion channels TRPC3 and TRPC7 could be the potential therapeutic targets in pancreatic cancer and TRPC3 might be involved in dysregulating mitochondrial functions during PAAD genesis.

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CECornelius Engelmann
Cornelius Engelmann
MSMartina Sterneck
Martina Sterneck
KWKarl Heinz Weiss
Karl Heinz Weiss
STSilke Templin
Silke Templin
SZSteffen Zopf
Steffen Zopf
Frank TackeFrank Tacke
Frank Tacke
Human cytomegalovirus (CMV) remains a major cause of mortality and morbidity in human liver transplant recipients. Anti-CMV therapeutics can be used to prevent or treat CMV in liver transplant recipients, but their toxicity needs to be balanced against the benefits. The choice of prevention strategy (prophylaxis or preemptive treatment) depends on the donor/recipient sero-status but may vary between institutions. We conducted a series of consultations and roundtable discussions with German liver transplant center representatives. Based on 20 out of 22 centers, we herein summarize the current approaches to CMV prevention and treatment in the context of liver transplantation in Germany. In 90% of centers, transient prophylaxis with ganciclovir or valganciclovir was standard of care in high-risk (donor CMV positive, recipient CMV naive) settings, while preemptive therapy (based on CMV viremia detected during (bi) weekly PCR testing for circulating CMV-DNA) was preferred in moderate- and low-risk settings. Duration of prophylaxis or intense surveillance was 3–6 months. In the case of CMV infection, immunosuppression was adapted. In most centers, antiviral treatment was initiated based on PCR results (median threshold value of 1000 copies/mL) with or without symptoms. Therefore, German transplant centers report similar approaches to the prevention and management of CMV infection in liver transplantation.

28 September 2021 in Journal of Clinical Medicine
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Nikolaos VassosNikolaos Vassos
Nikolaos Vassos
Aristotelis PerrakisAristotelis Perrakis
Aristotelis Perrakis
WHWerner Hohenberger
Werner Hohenberger
Roland S. CronerRoland S. Croner
Roland S. Croner
Background: Duodenal gastrointestinal stromal tumors (GIST) are a rare subset of GIST. Their surgical management in this anatomically complex region consists of varied approaches, and the administration of imatinib mesylate (IM) has not been clarified. Methods: We retrospectively reviewed patients with duodenal GIST treated during a 10-year-period. We analysed the clinicopathological characteristics and survival factors and evaluated the perioperative and long-term outcomes based on the extent of resection ((ocal-resection (LR) versus pancreaticoduodenectomy (PD)) and the IM-administration. The median follow-up period was 60 months (range, 12–140). Results: A total of thirteen patients (M:F = 7:6) with median age of 64 years (range, 42–77) underwent resection of duodenal GIST. Median tumor size was 5.2 cm (range, 1.5–13.3). Eight patients (61.5%) underwent LR and five patients (38.5%) PD. R0-resection was achieved in 92.5%. Neoadjuvant IM-therapy was administered in five patients leading to tumor downsizing and in 40% to less-extended resection. The PD group consisted of larger tumors with higher mitotic count, mostly located in D2 (p = 0.031). The PD group had longer operative time (p = 0.026), longer hospital stay (p = 0.016), and higher rate of postoperative complications (p = 0.128). The actuarial 1-, 3-, and 5-year overall survival were 92.5%, 84%, and 73.5%, respectively, whereas the disease-free survival rates at 1, 3, and 5 years were 91.5%, 83%, and 72%, respectively. A tendency towards increased risk of disease recurrence was demonstrated for patients with tumor >5 cm and high-risk potential. There was not statistic survival benefit for one or the other surgical approach. Conclusion: The type of resection depends on duodenal site of origin and tumor size. LR can be the treatment of choice for duodenal GIST whenever technically feasible. Recurrence of duodenal GIST is dependent on tumor biology rather than surgical approach. Administration of IM in neaodjuvant setting should be considered in cases with high-risk GIST scheduled for PD since it might facilitate less-extended resection.

16 October 2020 in Surgery Today
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Aristotelis PerrakisAristotelis Perrakis
Aristotelis Perrakis
DKDagmar Knüttel
Dagmar Knüttel
MRMirhasan Rahimli
Mirhasan Rahimli
MAMihailo Andric
Mihailo Andric
RCRoland S. Croner
Roland S. Croner
NVNikolaos Vassos
Nikolaos Vassos
Purpose: Incisional hernia (IH) is not uncommon after liver transplantation (LT). We investigated the long-term outcome of mesh-based hernia repair using an inlay-onlay technique. Methods: Our analysis was based on a prospective collected database of all LT recipients from our hospital over a period of 15 years. We analyzed clinical data including the period between LT and hernia development, the size and localization of the hernia, the length of in-hospital stay, immunosuppression, and postoperative morbidity, as well as follow-up data. The median follow-up period was 120 (range 12–200) months. Results: Among a total of 220 patients who underwent a collective 239 LTs, 29 (13%) were found to have an IH after a median period of 27.5 months (range 3–96 months). There were 12 (41%) men and 17 (59%) women, with a median age of 51 years. The median size of the IH was 13 cm (range 2–30 cm) and the median in-hospital stay was 6 days. Mild postoperative complications developed in seven patients, including two onlay mesh infections. One patient (3.4%) suffered recurrence. Conclusion: Mesh-based hernia repair using the inlay/onlay technique represents an effective and safe method for patients with an IH after LT, without additional risk from continuous immunosuppression.