title: A randomized controlled study to establish the effect of articulating instruments on performance in single-incision laparoscopic surgery.
abstract: OBJECTIVE
  In single-incision laparoscopic surgery (SILS), operating through 1 incision presents ergonomic challenges. No consensus exists on whether articulating instruments (ARTs) may help. This study evaluated their effect on simulated SILS, hypothesizing that they would affect performance and workload.
  
  
  METHODS
  Surgeons were randomized to 2 straight instruments (STRs), 1 ART and 1 STR, or 2 ARTs. After baseline testing, 25 repetitions of the Fundamentals of Laparoscopic Surgery (FLS) peg-transfer (PEG) task and 5 repetitions of the short-hand for the FLS pattern-cutting task (CIRCLE) were performed. Primary outcomes were maximum FLS PEG scores, CIRCLE times and errors, and Imperial College Surgical Assessment Device hand motion analysis. National Aeronautics and Space Administration (NASA) Raw Task Load Index (RTLX) questionnaires evaluated a secondary outcome--workload.
  
  
  METHODS
  The trial took place in a simulated operating theater within the Academic Surgical Unit at St Mary's Hospital, London, UK.
  
  
  METHODS
  Eligible surgeons had completed at least 5 laparoscopic cases as a primary operator. Surgeons were stratified by laparoscopic experience into intermediate (less than 25 previous procedures as primary operator) or advanced (25 procedures or more). A total of 21 surgeons were recruited and randomized; 7 of them to each instrument combination group. All surgeons completed PEG, and 5 from each group completed CIRCLE.
  
  
  RESULTS
  Groups' baseline PEG scores were similar (p = 0.625). STR-ART achieved higher maximum PEG scores than STR or ART did (median = 236 vs 198 vs 193, respectively, p = 0.002). Fastest CIRCLE times were similar (median = 190s vs 130s vs 186s, p = 0.129) as were minimum errors (median = 1 vs 2 vs 3, p = 0.101). For PEG, Imperial College Surgical Assessment Device demonstrated similar total path lengths (median = 12.3m vs 12.3m vs 16.0m, p = 0.545) and total numbers of movements (median = 89.6 vs 86.4 vs 171, p = 0.080). Groups' NASA Raw Task Load Index scores were similar (p = 0.708).
  
  
  CONCLUSIONS
  Combining 1 STR and 1 ART improved SILS performance in the PEG task. Therefore, this may be the optimum instrument configuration for use within some clinical SILS applications.
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom.
authors.forename: Harry P
authors.initials: HP
authors.lastname: Corker
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom.
authors.forename: Pritam
authors.initials: P
authors.lastname: Singh
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom. Electronic address: m.sodergren@imperial.ac.uk.
authors.forename: Mikael H
authors.initials: MH
authors.lastname: Sodergren
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom.
authors.forename: Sathyan
authors.initials: S
authors.lastname: Balaji
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Kwasnicki
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom.
authors.forename: Ara W
authors.initials: AW
authors.lastname: Darzi
authors.affiliation: Division of Surgery, Department of Surgery and Cancer, St Mary's Hospital, Imperial College London, London, United Kingdom.
authors.forename: Paraskevas
authors.initials: P
authors.lastname: Paraskeva
mesh_terms: D000328:Adult; D004867:Equipment Design; D005260:Female; D013502:General Surgery / Q000193:education*; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation* / Q000379:methods; D008297:Male; D013647:Task Performance and Analysis; D016526:Workload
keywords: Medical Knowledge; Practiced-Based Learning and Improvement; SILS; articulating; instruments; performance