Imperial College London

Dr George Garas

Faculty of MedicineDepartment of Surgery & Cancer

Honorary Clinical Research Fellow
 
 
 
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Contact

 

g.garas

 
 
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Location

 

Queen Elizabeth the Queen Mother Wing (QEQM)St Mary's Campus

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Summary

 

Publications

Citation

BibTex format

@article{Garas:2017:10.1245/s10434-017-6210-y,
author = {Garas, G and Markar, SR and Malietzis, G and Ashrafian, H and Hanna, GB and Zacharakis, E and Jiao, LR and Argiris, A and Darzi, A and Athanasiou, T},
doi = {10.1245/s10434-017-6210-y},
journal = {Annals of Surgical Oncology},
pages = {221--230},
title = {Induced Bias Due to Crossover Within Randomized Controlled Trials in Surgical Oncology: A Meta-regression Analysis of Minimally Invasive versus Open Surgery for the Treatment of Gastrointestinal Cancer.},
url = {http://dx.doi.org/10.1245/s10434-017-6210-y},
volume = {25},
year = {2017}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - BACKGROUND: Randomized controlled trials (RCTs) inform clinical practice and have provided the evidence base for introducing minimally invasive surgery (MIS) in surgical oncology. Crossover (unplanned intraoperative conversion of MIS to open surgery) may affect clinical outcomes and the effect size generated from RCTs with homogenization of randomized groups. OBJECTIVES: Our aims were to identify modifiable factors associated with crossover and assess the impact of crossover on clinical endpoints. METHODS: A systematic review was performed to identify all RCTs comparing MIS with open surgery for gastrointestinal cancer (1990-2017). Meta-regression analysis was performed to analyze factors associated with crossover and the influence of crossover on endpoints, including 30-day mortality, anastomotic leak rate, and early complications. RESULTS: Forty RCTs were included, reporting on 11,625 patients from 320 centers. Crossover was shown to affect one in eight patients (mean 12.6%, range 0-45%) and increased with American Society of Anesthesiologists score (β = + 0.895; p = 0.050). Pretrial surgeon volume (β = - 2.344; p = 0.037), composite RCT quality score (β = - 7.594; p = 0.014), and site of tumor (β = - 12.031; p = 0.021, favoring lower over upper gastrointestinal tumors) showed an inverse relationship with crossover. Importantly, multivariate weighted linear regression revealed a statistically significant positive correlation between crossover and 30-day mortality (β = + 0.125; p = 0.033), anastomotic leak rate (β = + 0.550; p = 0.004), and early complications (β = + 1.255; p = 0.001), based on intention-to-treat analysis. CONCLUSIONS: Crossover in trials was associated with an increase in 30-day mortality, anastomotic leak rate, and early complications within the MIS group based on intention-
AU - Garas,G
AU - Markar,SR
AU - Malietzis,G
AU - Ashrafian,H
AU - Hanna,GB
AU - Zacharakis,E
AU - Jiao,LR
AU - Argiris,A
AU - Darzi,A
AU - Athanasiou,T
DO - 10.1245/s10434-017-6210-y
EP - 230
PY - 2017///
SN - 1068-9265
SP - 221
TI - Induced Bias Due to Crossover Within Randomized Controlled Trials in Surgical Oncology: A Meta-regression Analysis of Minimally Invasive versus Open Surgery for the Treatment of Gastrointestinal Cancer.
T2 - Annals of Surgical Oncology
UR - http://dx.doi.org/10.1245/s10434-017-6210-y
UR - http://hdl.handle.net/10044/1/54541
VL - 25
ER -