Imperial College London

DrConstantinosSimillis

Faculty of MedicineDepartment of Surgery & Cancer

Honorary Clinical Senior Lecturer
 
 
 
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constantinos.simillis99

 
 
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Location

 

West Middlesex HospitalWest Middlesex Hospital

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Summary

 

Publications

Publication Type
Year
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95 results found

Jones NK, Tom B, Simillis C, Bennet J, Gourgiotis S, Griffin J, Blaza H, Nasser S, Baker S, Gouliouris Tet al., 2024, Impact of penicillin allergy labels on surgical site infections in a large UK cohort of gastrointestinal surgery patients., JAC Antimicrob Resist, Vol: 6

OBJECTIVES: Studies in the USA, Canada and France have reported higher surgical site infection (SSI) risk in patients with a penicillin allergy label (PAL). Here, we investigate the association between PALs and SSI in the UK, a country with distinct epidemiology of infecting pathogens and range of antimicrobial regimens in routine use. METHODS: Electronic health records and national SSI surveillance data were collated for a retrospective cohort of gastrointestinal surgery patients at Cambridge University Hospitals NHS Foundation Trust from 1 January 2015 to 31 December 2021. Univariable and multivariable logistic regression were used to examine the effects of PALs and the use of non-β-lactam-based prophylaxis on likelihood of SSI, 30 day post-operative mortality, 7 day post-operative acute kidney injury and 60 day post-operative infection/colonization with antimicrobial-resistant bacteria or Clostridioides difficile. RESULTS: Our data comprised 3644 patients and 4085 operations; 461 were undertaken in the presence of PALs (11.3%). SSI was detected after 435/4085 (10.7%) operations. Neither the presence of PALs, nor the use of non-β-lactam-based prophylaxis were found to be associated with SSI: adjusted OR (aOR) 0.90 (95% CI 0.65-1.25) and 1.20 (0.88-1.62), respectively. PALs were independently associated with increased odds of newly identified MRSA infection/colonization in the 60 days after surgery: aOR 2.71 (95% CI 1.13-6.49). Negative association was observed for newly identified infection/colonization with third-generation cephalosporin-resistant Gram-negative bacteria: aOR 0.38 (95% CI 0.16-0.89). CONCLUSIONS: No evidence was found for an association between PALs and the likelihood of SSI in this large UK cohort, suggesting significant international variation in the impact of PALs on surgical patients.

Journal article

Siriwardena AK, Serrablo A, Fretland ÅA, Wigmore SJ, Ramia-Angel JM, Malik HZ, Stättner S, Søreide K, Zmora O, Meijerink M, Kartalis N, Lesurtel M, Verhoef K, Balakrishnan A, Gruenberger T, Jonas E, Devar J, Jamdar S, Jones R, Hilal MA, Andersson B, Boudjema K, Mullamitha S, Stassen L, Dasari BVM, Frampton AE, Aldrighetti L, Pellino G, Buchwald P, Gürses B, Wasserberg N, Gruenberger B, Spiers HVM, Jarnagin W, Vauthey J-N, Kokudo N, Tejpar S, Valdivieso A, Adam Ret al., 2023, Multisocietal European consensus on the terminology, diagnosis, and management of patients with synchronous colorectal cancer and liver metastases: an E-AHPBA consensus in partnership with ESSO, ESCP, ESGAR, and CIRSE., Br J Surg, Vol: 110, Pages: 1161-1170

BACKGROUND: Contemporary management of patients with synchronous colorectal cancer and liver metastases is complex. The aim of this project was to provide a practical framework for care of patients with synchronous colorectal cancer and liver metastases, with a focus on terminology, diagnosis, and management. METHODS: This project was a multiorganizational, multidisciplinary consensus. The consensus group produced statements which focused on terminology, diagnosis, and management. Statements were refined during an online Delphi process, and those with 70 per cent agreement or above were reviewed at a final meeting. Iterations of the report were shared by electronic mail to arrive at a final agreed document comprising 12 key statements. RESULTS: Synchronous liver metastases are those detected at the time of presentation of the primary tumour. The term 'early metachronous metastases' applies to those absent at presentation but detected within 12 months of diagnosis of the primary tumour, the term 'late metachronous metastases' applies to those detected after 12 months. 'Disappearing metastases' applies to lesions that are no longer detectable on MRI after systemic chemotherapy. Guidance was provided on the recommended composition of tumour boards, and clinical assessment in emergency and elective settings. The consensus focused on treatment pathways, including systemic chemotherapy, synchronous surgery, and the staged approach with either colorectal or liver-directed surgery as first step. Management of pulmonary metastases and the role of minimally invasive surgery was discussed. CONCLUSION: The recommendations of this contemporary consensus provide information of practical value to clinicians managing patients with synchronous colorectal cancer and liver metastases.

Journal article

Simillis C, Charalambides M, Mavrou A, Afxentiou T, Powar MP, Wheeler J, Davies RJ, Fearnhead NSet al., 2023, Operative blood loss adversely affects short and long-term outcomes after colorectal cancer surgery: results of a systematic review and meta-analysis, TECHNIQUES IN COLOPROCTOLOGY, Vol: 27, Pages: 189-208, ISSN: 1123-6337

Journal article

Simillis C, Khatri A, Dai N, Afxentiou T, Jephcott C, Smith S, Jadon R, Papamichael D, Khan J, Powar MP, Fearnhead NS, Wheeler J, Davies Jet al., 2023, A systematic review and network meta-analysis of randomised controlled trials comparing neoadjuvant treatment strategies for stage II and III rectal cancer, CRITICAL REVIEWS IN ONCOLOGY HEMATOLOGY, Vol: 183, ISSN: 1040-8428

Journal article

Mantikas KT, Moser N, Gulli C, Cunningham D, Georgiou P, Simillis C, Kalofonou Met al., 2023, Detection of the Colorectal Cancer TP53 p.R248W Mutation on a Lab-on-Chip ISFET Platform

This paper describes a method of detection for the TP53 mutation that leads to the p.R248W substitution, commonly found in colorectal cancer cases. This is achieved through the design and implementation of a pH-sensitive and mutation specific Loop-mediated isothermal amplification (pH-LAMP) method and the experimental validation using a Lab-on-Chip (LoC) platform, with an integrated array of Ion-Sensitive Field Effect Transistors (ISFETs) that can detect pH changes. Synthetic TP53 DNA was detected in pH-LAMP reactions, on both a qPCR platform and the LoC, using primers that are specific to each allele (wild-type or mutant). Assays successfully detected the target mutation within 20minutes, demonstrating the potential of the method for multi-target testing. This technology, when coupled with a sample preparation method, could allow for a Point-of-Care genetic testing platform for colorectal cancer to be realised, aiding patient stratification and treatment decisions.

Conference paper

Ashcroft J, Noorani A, Simillis C, 2023, An Unusual Presentation of an Appendiceal Adenocarcinoma, GASTROENTEROLOGY, Vol: 164, Pages: 24-26, ISSN: 0016-5085

Journal article

Anyomih TTK, Jennings T, Mehta A, O'Neill JR, Panagiotopoulou I, Gourgiotis S, Tweedle E, Bennett J, Davies RJ, Simillis Cet al., 2023, Systematic review and meta-analysis comparing perioperative outcomes of emergency appendectomy performed by trainee vs trained surgeon, AMERICAN JOURNAL OF SURGERY, Vol: 225, Pages: 168-179, ISSN: 0002-9610

Journal article

Rooney S, Meyer J, Afzal Z, Ashcroft J, Cheow H, DePaepe K, Powar M, Simillis C, Wheeler J, Davies J, Joshi Het al., 2022, The Role of Preoperative Imaging in the Detection of Lateral Lymph Node Metastases in Rectal Cancer: A Systematic Review and Diagnostic Test Meta-analysis, DISEASES OF THE COLON & RECTUM, Vol: 65, Pages: 1436-1446, ISSN: 0012-3706

Journal article

Yeow M, Soh S, Wong J, Koh FH, Syn N, Fearnhead NS, Wheeler J, Davies RJ, Chong CS, Simillis Cet al., 2022, Transanal tube <i>versus</i> defunctioning stoma after low anterior resection for rectal cancer: network meta-analysis of randomized controlled trials, BRITISH JOURNAL OF SURGERY, Vol: 109, Pages: 900-903, ISSN: 0007-1323

Journal article

Simillis C, Taylor B, Ahmad A, Lal N, Afxentiou T, Powar MP, Smyth EC, Fearnhead NS, Wheeler J, Davies RJet al., 2022, A systematic review and meta-analysis assessing the impact of body mass index on long-term survival outcomes after surgery for colorectal cancer, EUROPEAN JOURNAL OF CANCER, Vol: 172, Pages: 237-251, ISSN: 0959-8049

Journal article

Anyomih TTK, Jennings T, Mehta A, O'Neill JR, Panagiotopoulou I, Gourgiotis S, Tweedle E, Bennett J, Davies RJ, Simillis Cet al., 2022, Systematic review and meta-analysis comparing perioperative outcomes of pediatric emergency appendicectomy performed by trainee vs trained surgeon, PEDIATRIC SURGERY INTERNATIONAL, Vol: 38, Pages: 1187-1196, ISSN: 0179-0358

Journal article

Kontovounisios C, 2022, Locally recurrent rectal cancer according to a standardized MRI classification system: a systematic review of the literature, Journal of Clinical Medicine, Vol: 11, ISSN: 2077-0383

(1) Background: Classification of Locally recurrent rectal cancer (LRRC) is not currently stand-ardized. The aim of this review was to evaluate pelvic LRRC according to the Beyond TME (BTME) classification system and to consider commonly associated primary tumour characteristics. (2) Methods: A systematic review of the literature prior to April 2020 was performed through elec-tronic searches of the Science Citation Index Expanded, EMBASE, MEDLINE and CENTRAL da-tabases. The primary outcome was to assess location and frequency of previously classified pelvic LRRC and translate this information into the BTME system. Secondary outcomes were assessing primary tumour characteristics. (3) Results: A total of 58 eligible studies classified 4558 sites of LRRC, most commonly found in the central compartment (18%), following anterior resection (44%), in patients with an ‘advanced’ primary tumour (63%) and following neoadjuvant radio-therapy (29%). Most patients also classified had a low rectal primary tumour. Lymph node status of the primary tumour leading to LRRC was comparable, with 52% node positive versus 48% node negative tumours. (4) Conclusion: This review evaluates the largest number of LRRCs to date using a single classification system. It has also highlighted the need for standardized reporting in order to optimise perioperative treatment planning.

Journal article

Charalambides M, Afxentiou T, Pellino G, Powar MP, Fearnhead NS, Davies RJ, Wheeler J, Simillis Cet al., 2022, A systematic review and network meta-analysis comparing energy devices used in colorectal surgery, TECHNIQUES IN COLOPROCTOLOGY, Vol: 26, Pages: 413-423, ISSN: 1123-6337

Journal article

Pellino G, Fuschillo G, Simillis C, Selvaggi L, Signoriello G, Vinci D, Kontovounisios C, Selvaggi F, Sciaudone Get al., 2022, Abdominal versus perineal approach for external rectal prolapse: systematic review with meta-analysis, BJS Open, Vol: 6, ISSN: 2474-9842

BackgroundExternal rectal prolapse (ERP) is a debilitating condition in which surgery plays an important role. The aim of this study was to evaluate the outcomes of abdominal approaches (AA) and perineal approaches (PA) to ERP.MethodsThis was a PRISMA-compliant systematic review with meta-analysis. Studies published between 1990 and 2021 were retrieved. The primary endpoint was recurrence at the last available follow-up. Secondary endpoints included factors associated with recurrence and function. All studies were assessed for bias using the Newcastle–Ottawa Scale and Cochrane tool.ResultsFifteen studies involving 1611 patients (AA = 817; PA = 794) treated for ERP were included, three of which were randomized controlled trials (RCTs; 114 patients (AA = 54; PA = 60)). Duration of follow-up ranged from 12 to 82 months. Recurrence in non-randomized studies was 7.7 per cent in AA versus 20.1 per cent in PA (odds ratio (OR) 0.29, 95 per cent confidence interval (c.i.) 0.17 to 0.50; P < 0.001, I2 = 45 per cent). In RCTs, there was no significant difference (9.8 per cent versus 16.3 per cent, AA versus PA (OR 0.82, 95 per cent c.i. 0.29 to 2.37; P = 0.72, I2 = 0.0 per cent)). Age at surgery and duration of follow-up were risk factors for recurrence. Following AA, the recurrence rates were 10.1 per cent and 6.2 per cent in patients aged 65 years and older and less than 65 years of age, respectively (effect size [e.s.] 7.7, 95 per cent c.i. 4.5 to 11.5). Following PA, rates were 27 per cent and 16.3 per cent (e.s. 20.1, 95 per cent c.i. 13 to 28.2). Extending follow-up to at least 40 months increased the likelihood of recurrence. The median duration of hospital stay was 4.9 days after PA versus 7.2 days after AA. Overall, incontinence was less likely after AA (OR 0.32), but constipation occurred more frequently (OR 1.68). Most studies were retrospective, a

Journal article

Charalambides M, Mavrou A, Jennings T, Powar MP, Wheeler J, Davies RJ, Fearnhead NS, Simillis Cet al., 2022, A systematic review of the literature assessing operative blood loss and postoperative outcomes after colorectal surgery, INTERNATIONAL JOURNAL OF COLORECTAL DISEASE, Vol: 37, Pages: 47-69, ISSN: 0179-1958

Journal article

Bhojwani D, Gourgiotis S, Simillis C, 2021, Volvulus of the Appendix, GASTROENTEROLOGY, Vol: 161, Pages: 1809-1810, ISSN: 0016-5085

Journal article

Aseem R, Naseem T, Simillis C, Pawa N, Jason Set al., 2021, General Surgical Registrar in the Emergency Department: Developing and Evaluating a New Surgical Role, Publisher: OXFORD UNIV PRESS, ISSN: 0007-1323

Conference paper

Aseem R, Simillis C, Smith J, Arora S, Pawa Net al., 2021, Developing as Future Leaders: A Systematic Review of Quality Improvement Training in Junior Doctors, Publisher: OXFORD UNIV PRESS, Pages: 123-123, ISSN: 0007-1323

Conference paper

Ashcroft J, Singh AA, Ramachandran B, Habeeb A, Hudson V, Meyer J, Simillis C, Davies RJet al., 2021, Comparative Effectiveness of Interventions to Reduce Ileus After Colorectal Surgery: A Network Meta-Analysis, Publisher: OXFORD UNIV PRESS, ISSN: 0007-1323

Conference paper

Ashcroft J, Singh AA, Ramachandran B, Habeeb A, Hudson V, Meyer J, Simillis C, Davies RJet al., 2021, Reducing ileus after colorectal surgery: A network meta-analysis of therapeutic interventions, CLINICAL NUTRITION, Vol: 40, Pages: 4772-4782, ISSN: 0261-5614

Journal article

Kontovounisios C, 2021, Systematic review of classification systems for locally recurrent rectal cancer, BJS Open, Vol: 5, Pages: 1-14, ISSN: 2474-9842

BACKGROUNDClassification of pelvic local recurrence (LR) after surgery for primary rectal cancer is not currently standardised and optimal imaging is required to categorise anatomical site and plan treatment in patients with LR. The aim of this review was to evaluate the systems used to classify locally recurrent rectal cancer (LRRC) and the relevant published outcomes.METHODSA systematic review of the literature prior to April 2020 was performed through electronic searches of the Science Citation Index Expanded, EMBASE, MEDLINE and CENTRAL databases. The primary outcome was to review the classifications currently in use; the secondary outcome was the extraction of relevant information provided by these classification systems including prognosis, anatomy and prediction of R0 after surgery. RESULTSA total 21 out of 58 eligible studies, classifying LR in 2,086 patients were reviewed. Studies used at least one of the following eight classification systems proposed by Institutions or Institutional Groups (Mayo Clinic, Memorial Sloan-Kettering -original and modified-, Royal Marsden and Leeds) or authors (Yamada, Hruby and Kusters). Negative survival outcomes were associated with increased pelvic fixity, associated symptoms of LR, lateral compared with central LR and three or more pelvic compartment involvement. A total of seven studies used MRI with specifically defined anatomical compartments to classify LR.CONCLUSION This review highlights the various imaging systems in use to classify LRRC and some of the prognostic indicators for survival and oncological clearance based on these systems. Implementation of an agreed classification system to consistently document pelvic LR should provide more detailed information on anatomical site of recurrence, burden of disease and standards for comparative outcome assessment. This would optimise treatment planning, operative procedures and research into LR. An MRI classification system with its inherent anatomic precision is id

Journal article

Meyer J, Simillis C, Joshi H, Xanthis A, Ashcroft J, Buchs N, Ris F, Davies RJet al., 2021, Does the Choice of Extraction Site During Minimally Invasive Colorectal Surgery Change the Incidence of Incisional Hernia? Protocol for a Systematic Review and Network Meta-Analysis, INTERNATIONAL JOURNAL OF SURGERY PROTOCOLS, Vol: 25, Pages: 216-219, ISSN: 2468-3574

Journal article

Simillis C, Singh HKSI, Afxentiou T, Mills S, Warren OJ, Smith JJ, Riddle P, Adamina M, Cunningham D, Tekkis PPet al., 2020, Postoperative chemotherapy improves survival in patients with resected high-risk Stage II colorectal cancer: results of a systematic review and meta-analysis, COLORECTAL DISEASE, Vol: 22, Pages: 1231-1244, ISSN: 1462-8910

Journal article

Baird DLH, Kontovounisios C, Simillis C, Pellino G, Rasheed S, Tekkis PPet al., 2020, Factors associated with metachronous metastases and survival in locally advanced and recurrent rectal cancer, BJS Open, Vol: 4, Pages: 1172-1179, ISSN: 2474-9842

BackgroundBetter understanding of the impact of metachronous metastases in locally advanced and recurrent rectal cancer may improve decision‐making. The aim of this study was to investigate factors influencing metachronous metastasis and its impact on survival in patients who have a beyond total mesorectal excision (bTME) operation.MethodsThis was a retrospective study of consecutive patients who had bTME surgery for locally advanced and recurrent rectal cancer at a tertiary referral centre between January 2006 and December 2016. The primary outcome was overall survival. Cox proportional hazards regression analyses were performed. The influence of metachronous metastases on survival was investigated.ResultsOf 220 included patients, 171 were treated for locally advanced primary tumours and 49 for recurrent rectal cancer. Some 90·0 per cent had a complete resection with negative margins. Median follow‐up was 26·0 (range 1·5–119·6) months. The 5‐year overall survival rate was 71·1 per cent. Local recurrence and metachronous metastasis rates were 11·8 and 22·2 per cent respectively. Patients with metachronous metastases had a worse overall survival than patients without metastases (median 52·9 months versus estimated mean 109·4 months respectively; hazard ratio (HR) 6·73, 95 per cent c.i. 3·23 to 14·00). Advancing pT category (HR 2·01, 1·35 to 2·98), pN category (HR 2·43, 1·65 to 3·59), vascular invasion (HR 2·20, 1·22 to 3·97) and increasing numbers of positive lymph nodes (HR 1·19, 1·07 to 1·16) increased the risk of metachronous metastasis. Nine of 17 patients (53 per cent) with curatively treated synchronous metastases at presentation developed metachronous metastases, compared with 40 of 203 (19·7 per cent) without synchronous metastases (P = 0·002). Corresponding me

Journal article

Nikolaou S, Qiu S, Fiorentino F, Simillis C, Rasheed S, Tekkis P, Kontovounisios Cet al., 2020, The role of Neurotensin and its receptors in non-gastrointestinal cancers: a review, Cell Communication and Signaling, Vol: 18, ISSN: 1478-811X

BackgroundNeurotensin, originally isolated in 1973 has both endocrine and neuromodulator activity and acts through its three main receptors. Their role in promoting tumour cell proliferation, migration, DNA synthesis has been studied in a wide range of cancers. Expression of Neurotensin and its receptors has also been correlated to prognosis and prediction to treatment.Main bodyThe effects of NT are mediated through mitogen-activated protein kinases, epidermal growth factor receptors and phosphatidylinositol-3 kinases amongst others. This review is a comprehensive summary of the molecular pathways by which Neurotensin and its receptors act in cancer cells.ConclusionIdentifying the role of Neurotensin in the underlying molecular mechanisms in various cancers can give way to developing new agnostic drugs and personalizing treatment according to the genomic structure of various cancers.

Journal article

Ramage L, Qiu S, Yeap Z, Simillis C, Kontovounisios C, Tekkis P, Tan Eet al., 2019, Anorectal manometry versus patient-reported outcome measures as a predictor of maximal treatment for fecal incontinence, Annals of coloproctology, Vol: 35, Pages: 319-326, ISSN: 2287-9714

PurposeThis study aims to establish the ability of patient-reported outcome measures (PROMs) and anorectal manometry (ARM) in predicting the need for surgery in patients with fecal incontinence (FI).MethodsBetween 2008 and 2015, PROMs data, including the Birmingham Bowel and Urinary Symptoms Questionnaire (BBUSQ), Short Form 36 (SF-36), Wexner Incontinence Score and ARM results, were prospectively collected from 276 patients presenting with FI. Spearman rank was used to assess correlations between specific PROMs questions and ARM assessments of sphincter motor function. Binomial regression analyses were performed to identify factors predictive of the need for surgery. Finally, receiver operating characteristic (ROC) curve analyses were performed to establish the utility of individual ARM and PROMs variables in predicting the need for surgical intervention in patients with FI.ResultsTwo hundred twenty-eight patients (82.60%) were treated conservatively while 48 (17.39%) underwent surgery. On univariate analyses, all 4 domains of the BBUSQ, all 8 domains of the SF-36, and the Wexner Incontinence Score were significant predictors of surgery. Additionally, maximum resting pressure, 5-second squeeze endurance, threshold volume, and urge volume were significant. On ROC curve analyses, the only significant ARM measurement was the 5-second squeeze endurance. PROMs, such as the incontinence domain of the BBUSQ and five of the SF-36 domains, were identified as fair discriminators of the need for surgery.ConclusionPROMs are reliable predictors of maximal treatment in patients with FI and can be readily used in primary care to aid surgical referrals and can be applied in hospital settings as an aid to guide surgical treatment decisions.

Journal article

Simillis C, Cribb E, Gurtovaya Y, Pawa Net al., 2019, Generalised purulent peritonitis and small bowel obstruction due to a spontaneously perforated ovarian dermoid cyst, BMJ CASE REPORTS, Vol: 12

Journal article

Simillis C, Lal N, Thoukididou SN, Kontovounisios C, Smith JJ, Hompes R, Adamina M, Tekkis PPet al., 2019, Meta-analysis of randomized controlled trials of surgery for rectal cancer, European Colorectal Congress, Publisher: E M H SWISS MEDICAL PUBLISHERS LTD, Pages: 8S-8S, ISSN: 1424-7860

Conference paper

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