A randomized control trial to evaluate the importance of pre-training basic laparoscopic psychomotor skills upon the learning curve of laparoscopic intra-corporeal knot tying

Abstract

Background: Training of basic laparoscopic psychomotor skills improves the acquisition of more advanced laparoscopic tasks, such as laparoscopic intra-corporeal knot tying (LICK). This randomized controlled trial was designed to evaluate whether pre-training of basic skills, as laparoscopic camera navigation (LCN), hand-eye coordination (HEC), and bimanual coordination (BMC), and the combination of the three of them, has any beneficial effect upon the learning curve of LICK. The study was carried out in a private center in Asunción, Paraguay, by 80 medical students without any experience in surgery. Four laparoscopic tasks were performed in the ENCILAP model (LCN, HEC, BMC, and LICK). Participants were allocated to 5 groups (G1-G5). The study was structured in 5 phases. In phase 1, they underwent a base-line test (T₁) for all tasks (1 repetition of each task in consecutive order). In phase 2, participants underwent different training programs (30 consecutive repetitions) for basic tasks according to the group they belong to (G1: none; G2: LCN; G3: HEC; G4: BMC; and G5: LCN, HEC, and BMC). In phase 3, they were tested again (T₂) in the same manner than at T₁. In phase 4, they underwent a standardized training program for LICK (30 consecutive repetitions). In phase 5, they were tested again (T₃) in the same manner than at T₁ and T₂. At each repetition, scoring was based on the time taken for task completion system.

Results: The scores were plotted and non-linear regression models were used to fit the learning curves to one- and two-phase exponential decay models for each participant (individual curves) and for each group (group curves). The LICK group learning curves fitted better to the two-phase exponential decay model. From these curves, the starting points (Y0), the point after HEC training/before LICK training (Y1), the Plateau, and the rate constants (K) were calculated. All groups, except for G4, started from a similar point (Y0). At Y1, G5 scored already better than the others (G1 p = .004; G2 p = .04; G3 p < .0001; G4 NS). Although all groups reached a similar Plateau, G5 has a quicker learning than the others, demonstrated by a higher K (G1 p < 0.0001; G2 p < 0.0001; G3 p < 0.0001; and G4 p < 0.0001).

Conclusions: Our data confirms that training improves laparoscopic skills and demonstrates that pre-training of all basic skills (i.e., LCN, HEC, and BMC) shortens the LICK learning curve.

Keywords: ENCILAP model; Education; Intra-corporeal knot tying; LASTT model; Laparoscopy; Psychomotor skills; Training; Training box.

Fig. 1

The ENCILAP model

Fig. 2

The Szabo trainer box

Fig. 3

Flow chart. LPS laparoscopic psychomotor skills, LCN laparoscopic camera navigation, HEC hand-eye coordination, BMC bimanual coordination, LICK laparoscopic intra-corporeal knot tying

Fig. 4

Laparoscopic intra-corporeal knot tying (LICK). Individual learning curves. Each participant performed 33 consecutive repetitions (R0–R32) of LICK. The scores were plotted, and individual learning curves were observed. Most of them fitted to the one-phase exponential decay model, whereas some of them to the two-phase exponential decay model and some did not fit at all to any model

Fig. 5

Laparoscopic intra-corporeal knot tying (LICK). Group learning curves. Participants of all groups performed 33 consecutive repetitions (R0–R32) of LICK. Phase 1 (P1): 1 repetition (T ₁). Phase 2 (P2): no repetitions (training of basic tasks). Phase 3 (P3): 1 repetition (T ₂). Phase 4 (P4): 30 repetitions (LICK training). Phase 5 (P5): 1 repetition (T ₃). The scores were plotted, and group learning curves were fitted to a one-phase exponential decay model