title: A comparative study of survival after minimally invasive and open oesophagectomy.
abstract: BACKGROUND
  Oesophageal cancer is increasing in incidence worldwide. Minimally invasive techniques have been used to perform oesophagectomy, but concerns regarding these techniques remain. Since its description by Cuschieri in 1992, the use of minimally invasive oesophagectomy (MIO) has increased, but still only used in a minority of resections in the UK in 2009. In particular, there has been reluctance to use minimally invasive (thoracoscopic and laparoscopic) techniques in more advanced cancers for fears regarding the adequacy of the oncological resection. In order to identify any factors that could affect survival, we undertook a retrospective analysis on all patients who underwent surgery in our department over an 8-year period.
  
  
  METHODS
  A retrospective data analysis was undertaken on all patients who underwent oesophagectomy in a tertiary upper gastrointestinal surgery unit, from 2005 to 2012 inclusive. Data were collected from the departmental database and case note review, with follow-up and survival data to time of data collection. The survival data were analysed using univariate and multivariate Cox proportional hazard regression models to determine which variables affected survival. Variables examined included age, tumour position, tumour stage (T0, 1, 2 vs T3, 4), nodal stage (N0 vs N1), tumour histology, completeness of resection (R0 vs R1), use of neoadjuvant chemotherapy and operative technique (thoracoscopic/laparoscopic (MIO) vs laparoscopic abdomen/open chest (Lap assisted) vs Open.
  
  
  RESULTS
  334 patients underwent oesophagectomy between 2005 and 2012. Male to female ratio was 3.75:1, with a mean age of 64 years (range 36-87). There were 83 open oesophagectomies, 187 laparoscopically assisted oesophagectomies and 64 minimally invasive oesophagectomies. Following univariate regression analysis the following factors were found to be correlated to survival: use of neoadjuvant chemotherapy (Hazard Ratio 2.889, 95 % CI 1.737-4.806), T stage 3 or 4 (3.749, 2.475-5.72), Node positive (5.225, 3.561-7.665), R1 resection (2.182, 1.425-3.341), type of operation (MIO compared to open oesophagectomy) (0.293, 0.158-0.541). There was no significant relationship between age, tumour position or tumour histology and length of survival. When these factors were entered into a multivariate model, the independently significant factors correlated to survival were found to be T stage 3 or 4 (HR 1.969, 1.248-3.105), Node positive (3.833, 2.548-5.766) and type of operation (MIO compared to open) (0.5186, 0.277-0.972).
  
  
  CONCLUSIONS
  Multiple small studies have found reduced pulmonary complication rates and duration of hospital stay when using a minimally invasive approach compared to open. Concerns in the literature over long-term outcomes, however, have led to limited utilisation of this method, especially in advanced disease. The data from this large study show significantly better survival following operations performed using minimally invasive techniques compared to open, however, we have not adjusted for some known or unknown confounding factors. International and national RCTs, however, will provide more information in due course.
authors.affiliation: Oesophagogastric Unit, University Hospitals Bristol, Upper Maudlin Street, Bristol, BS2 8HW, UK, oliburdall@doctors.net.uk.
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Burdall
authors.forename: Alexander P
authors.initials: AP
authors.lastname: Boddy
authors.forename: James
authors.initials: J
authors.lastname: Fullick
authors.forename: Jane
authors.initials: J
authors.lastname: Blazeby
authors.forename: Richard
authors.initials: R
authors.lastname: Krysztopik
authors.forename: Christopher
authors.initials: C
authors.lastname: Streets
authors.forename: Andrew
authors.initials: A
authors.lastname: Hollowood
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Barham
authors.forename: Dan
authors.initials: D
authors.lastname: Titcomb
mesh_terms: D000328:Adult; D000368:Aged; D004938:Esophageal Neoplasms / Q000401:mortality* / Q000601:surgery; D016629:Esophagectomy / Q000379:methods / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D010535:Laparoscopy / Q000401:mortality*; D007902:Length of Stay / Q000639:trends; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013908:Thoracotomy / Q000401:mortality*; D006113:United Kingdom / Q000453:epidemiology