Journal of Surgical Simulation 2016; 3: 43 - 48

Published: 31 December 2016


Original article

Single-incision laparoscopic surgery operative performance by experienced surgeons: a randomized trial comparing articulating versus standard straight instruments

Georgios Pafitanis, Damjan Veljanoski and Bijendra Patel
Corresponding author: Georgios Pafitanis, The Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, UK. Email:


Background: Single-incision laparoscopic surgery (SILS) is the latest innovation in minimally invasive surgery. Advantages of SILS over conventional laparoscopic surgery include faster patient recovery, reduced peri-operative pain and further improvement in cosmesis. The challenges of SILS are attributed to the coaxial arrangement of the instruments, which requires certain technical skills and manual dexterity different to that of conventional laparoscopic surgery. Technical difficulties due to the loss of triangulation require further investigation to allow this novel technique to be refined. The aim of our study is to compare the operative performance by experienced surgeons using standard straight versus articulating instruments on a simulated SILS box trainer.

Methods: Consultant laparoscopic surgeons performed two basic laparoscopic tasks, according to the Fundamentals of Laparoscopic Surgery (FLS) course: peg transfer and pattern cutting, using two types of instruments in a randomized order. The influence of the instrumentation on the surgeon’s performance was measured by calculating time taken, errors and instrument clashes. These parameters reflected the effectiveness of the instrument on the surgeon’s laparoscopic skills (hand-eye coordination, depth perception, dexterity and complementary bimanual skills). The difference in performance reflects the effect of instrumentation on the surgeon’s laparoscopic skill. Statistical analysis was carried out using an independent-sample t-test. Two parameters were generated in order to avoid multiple comparisons: overall precision (OP) and overall performance time (OPT). All results were presented the as mean ± standard error of the mean with the P value.

Results: Ten consultant laparoscopic surgeons from four different specialties were recruited. The average experience in conventional laparoscopic surgery was 11.8 ± 5.2 years. The OPT with articulating instruments was 282 ± 11 s and 275 ± 12 s with standard straight instruments. The difference in operating time between the groups was not statistically significant (P = 0.856). The OP with the articulating instruments was 4.2 ± 0.4 and 9.8 ± 0.7 with the standard straight instruments. The articulating instruments demonstrated a statistically significant decrease in both errors and instrument clashes (P = 0.03).

Conclusions: The use of an articulating instrument proved to be superior to standard straight instruments in SILS. The increased triangulation improved precision and reduced errors. Novel articulating instruments demonstrate different characteristics, the benefits of which should be established before their application in clinical SILS practice.


SILS; simulation; articulating; instruments; performance