Methodist Advanced (MAD) Skills Drills : Modification of a Box Trainer to Enable ‘Off Axis’ Training in Advanced Laparoscopic Surgery

Rohan A Joseph, MD, Brian J Dunkin, MD, Barbara L Bass, MD, Patrick R Reardon, MD. Methodist Institute for Technology, Innovation and Education (MITIE), Deaprtment of Surgery, The Methodist Hospital, Houston -TX

Introduction: Standard laparoscopic surgery utilizes a triangulated configuration of the instruments with respect to the camera. This on-axis configuration is seldom encountered in advanced laparoscopic surgery (ALS) where off axis configurations of the instruments makes the task challenging due to the ergonomic and spatial challenges introduced. The on axis configuration of current validated training platforms is thus inadequate to meet these challenges. Training to proficiency in a box trainer modified for this purpose may enhance intra-operative performance. This ongoing study seeks to develop and validate a box trainer expressly suited for this purpose.

Methods: A standard box trainer (Simulab Corp) was modified to allow off axis configuration of the instruments with respect to the camera. The simulated abdominal wall has eight stations labeled 1-8 along an imaginary circle with each station being at 45° increments to the neutral position (station 1). Thus station 2 is 45° from and station 3 is 90° from station 1 and so on. A color CCD camera with variable focal length and zoom was mounted behind station 1. A series of LED lights mounted horizontally on a rigid bar provided ambient lighting. To establish a baseline for performance, 8 expert surgeons who are fellowship trained in minimally invasive surgery and are certified in the fundamentals of laparoscopy (FLS) were invited to participate. Each subject performed 3 validated drills: running string (UT Southwestern, Dallas), PEG transfer and intra-corporeal suturing (FLS) under proctor supervision. All subjects performed each of the three tasks as they moved from station 1-8 by rotating the box clockwise. Subjects were scored with respect to time and accuracy. The scoring system has been extensively described previously. A score of zero was administered if the subject was unable to complete the task. A cut off time of 300 seconds was applied to the running string drill and 600 seconds to the other two tasks. All performances were digitally recorded. Results are expressed as mean ± SD.


Task 1 Running String

Time (sec)53±10.458±16.272±14.2144±54.5201±79.8206±67.4102±19.258±10.6
Score (/300)247±10.4242±16.2228±14.2156±54.5139±51.9110±58.2198±19.2242±10.6

Task 2 PEG Transfer

Time (sec)76±22.192±24.1120±24.4226±92.2463±171.2377±135.6166±39.7101±18.2
Score (/ 600)524±22.1508±24.1480±24.4381±89.2220±142258±99.3434±43.1496±22

Task 3 Intra corporeal Suture

Time (sec)151±92.4144±97.9221±113.1391±195.7455±186552±90.9238±122.1134±49.5
Score (/ 600)449±91.8454±97.8377±116.7242±194.2331±78.1166±95.5358±121.2464±50.9

Conclusions: The MAD skills drills challenge even the best surgeons as reflected in higher times and lower scores at stations 4, 5 & 6. These drills demonstrate potential for off- axis training in ALS. Further work will establish construct and concurrent validity.

Session: SS16
Program Number: S096

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