Origami Crane Training Improves Laparoscopic Surgical Skills for Gynecological Surgery.

Mastering bimanual dexterity and hand–eye coordination is essential in laparoscopic surgery. Novice surgeons should master these techniques with dry box training;[ 1 2 3 ] experienced surgeons in facilities with low surgical volumes may require continued training. Origami is a Japanese paper craft culture in which paper is folded into various shapes, such as animals. Origami crane training is challenging because paper cranes are folded using only two laparoscopic forceps in a dry box. This study aimed to demonstrate whether origami crane training could be effective in improving laparoscopic skills for a surgeon certified in laparoscopic surgery with insufficient surgical volumes.

A total of 1000 origami cranes were folded over 44 months. The initial training time was 35 min. The fastest training time was 6 min 38 s (crane no. 686). The learning curve showed gradual improvement [ Figure 2 ]. Crane no. 1–38 were folded while observing the video monitor. Crane No. 39–168 were folded under direct vision because the accuracy did not improve. Crane no. 169–200 were folded both under direct vision and with a video monitor. Crane no. 201 and above were folded by observing only the video monitor. Time trials were randomly performed after trial crane no. 169. Learning curve in origami crane training. •: Observation of monitor. ▲: Direct vision. Dotted line: Boundary between the first-half group and second-half group The cumulative number of origami cranes folded per month is shown in Figure 3 . The average number of origami cranes folded per month was 22.7 (standard deviation = 11.3). The pace of training became continuous after the time trial stabilized. The accuracy of the completed cranes also noticeably improved [ Figure 4 ]. Monthly cumulative number of folded origami cranes. Dotted line: Boundary between the first-half group and second-half group Completed origami cranes. (a) Before training, (b) After training The average time for vaginal cuff suturing in 80 cases of TLH was found to be 778.3 ± 166.7 s, with an average error count of 0.91 ± 1.17. No complications associated with vaginal cuff suturing were observed in any of the cases. A comparison between the first-half ( n = 40) and second-half ( n = 40) groups revealed significant improvements in both the duration (840.5 ± 188.0 s vs. 716.0 ± 115.6 s, P = 0.001) and number of errors (1.17 ± 1.46 vs. 0.65 ± 0.66, P = 0.042) [ Table 1 ]. The total number of errors was small, although a decreasing trend was observed for the following errors: (i) inserting or passing the needle inadequately and (ii) repeating the same manipulation. Comparison of first-half and second-half groups of vaginal cuff suturing in total laparoscopic hysterectomies *Comparison of first-half and second-half groups. Data are reported as the mean±SD. SD: Standard deviation

Origami crane training has the potential to enhance laparoscopic surgical skills and maintain a high level of motivation among surgeons. Furthermore, the cultural practice of “Senbazuru,” which involves folding and sending one thousand paper cranes, is rooted in Japanese tradition and serves as a prayer for the recovery of ill or injured family and friends. We suggest that engaging in this practice fosters a sincere and dedicated mindset among surgeons. Conceptualization: Hiroshi Kuroda, Kenro Chikazawa. Data curation: Hiroshi Kuroda. Formal analysis: Hiroshi Kuroda, Kenro Chikazawa, Investigation: Hiroshi Kuroda, Kenro Chikazawa, Kako Kuroiwa, Risa Otomo, Ranka Aritake, Shinichi Iwasaki, Akitoshi Hasegawa. Methodology: Hiroshi Kuroda, Kenro Chikazawa. Project administration: Hiroshi Kuroda, Kenro Chikazawa, Akitoshi Hasegawa. Resources: Hiroshi Kuroda, Kenro Chikazawa, Kako Kuroiwa, Risa Otomo, Ranka Aritake, Shinichi Iwasaki, Akitoshi Hasegawa. Supervision: Akitoshi Hasegawa. Validation: Hiroshi Kuroda. Visualization: Hiroshi Kuroda. Roles/Writing - Original draft: Hiroshi Kuroda, Kenro Chikazawa. Writing - Review and editing: Hiroshi Kuroda, Kenro Chikazawa, Akitoshi Hasegawa. All authors have read and agreed to the final version of the manuscript. The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request. There are no conflicts of interest.

In this study, we found that training using origami crane techniques could enhance a gynecological surgeon’s laparoscopic surgical skills. Our research is the first to provide evidence of the effectiveness of origami crane training in improving intraoperative laparoscopic performance. The study design encompassed several notable features: continuous evaluation through time trials, video monitoring, direct observation, and assessment based on vaginal cuff suturing. Origami crane training, also known as box training, was initially documented in a Japanese publication in 2020,[ 5 ] and two English language papers have been published on this training method.[ 6 7 ] However, no study has been conducted to assess its effectiveness in improving laparoscopic surgery performance. Our results demonstrated a significant improvement in intraoperative laparoscopic performance through this training approach. Of note, this training may be challenging due to the manipulation and folding of a delicate 7.5 cm × 7.5 cm paper using only two forceps, demanding precise bimanual dexterity and depth perception. Furthermore, the paper is prone to tearing if not smoothly and gently handled. Consequently, it could take a novice up to 2 h to fold a single crane.[ 7 ] Novice surgeons should continue off-the-job training using a dry box or virtual simulator to optimize the safety and efficiency in which surgeries are performed in the operating room.[ 2 5 8 9 ] Further, there is an association between the surgical volume and outcomes.[ 10 ] However, questions remain regarding how many cases are needed for gynecological surgeons to reach and maintain a plateau in surgical performance and whether surgeons require further off-the-job training if their surgical volume is not sufficient. These questions are controversial. Terzi et al .[ 11 ] reported that a plateau in the learning curve for TLH was reached after the first 75 cases, while Schützendübel et al .[ 12 ] reported that a plateau in time was not reached after performing more than 100 TLHs. The plateaus for each surgeon differ between individuals and may be related to surgical volume. Surgical volume in gynecologic surgery is important and reportedly correlates with operative time and complication rates.[ 13 14 ] Vree et al . reported that high-volume surgeons (>51 cases/year) performed hysterectomy with shorter operative times and less blood loss than surgeons with lower surgical volumes.[ 14 ] However, low surgical volume in facilities in rural areas is not rare,[ 15 ] and there is the same problem in Japanese educational hospitals due to a lack of centralization. Surgeons in such facilities must maintain or improve their skills while facing low surgical volume and also coaching residents; continuous dry box training may address this problem. Therefore, this study focused on a laparoscopy-qualified surgeon who performed weekly surgery and this challenging training method. This study’s training protocol involved continuous evaluation through a time trial conducted in a dry box. A video demonstrating the training process is available ( https://www.youtube.com/watch?v=E5ZmuGFi-18 ), Utilizing a time trial in a controlled environment offers distinct advantages, including clearly defined goals, reduced errors, and the promotion of efficient performance, leading to enhanced learning.[ 16 ] In addition, it helps maintain motivation during long-term training.[ 9 ] However, highlighting that time trials often emphasize speed over accuracy is important, which could potentially result in unsafe surgical practices. To address this concern, time trials were randomly omitted after crane no. 170, allowing for more accurate training without time-related pressures. Furthermore, the inclusion of training sessions conducted under direct vision is crucial. Tokunaga et al .[ 17 ] reported that training under direct vision yields superior outcomes regarding improved bimanual dexterity compared to video monitoring alone. In the present study, training under direct vision was implemented between cranes no. 39 and 168, aiming to foster stable and precise manipulation techniques. This study assessed intraoperative laparoscopic performance by evaluating vaginal cuff suturing during TLHs. In gynecologic laparoscopic surgery, there is currently no standardized method available for evaluating the impact of off-the-job training on surgical performance. This lack of standardization may be attributed to the significant variations in size and adhesion of gynecological tumors, particularly in cases of endometriosis. Therefore, we determined that vaginal cuff suturing, which exhibits minimal case-by-case variation, was the most suitable parameter for evaluation. Moreover, this technique demands both accuracy and swiftness and is associated with the occurrence of vaginal cuff dehiscence, with reported incidence rates ranging between 0.41% and 1.27% in patients undergoing TLH procedures.[ 18 19 20 ] Origami crane training holds potential benefits not only for gynecologists but also for other laparoscopic surgeons, such as general surgeons and urologists, as well as for medical students and residents. This training method encompasses essential skills for laparoscopic surgery, including bimanual dexterity, hand-eye coordination, depth perception, and delicate tissue handling. These skills align with the components evaluated in the Global Operative Assessment of Laparoscopic Skills.[ 21 ] This training may have improved surgical accuracy and precision, thereby reducing suturing errors. Importantly, this training approach is simple and cost-effective; only a dry box and paper are required, enabling training to be conducted at any facility by anyone interested. Our study findings suggest that dry box training may be effective in maintaining or improving the skills of surgeons with limited surgical volume. This study demonstrated how one surgeon’s experience with origami crane training contributed to his surgical performance and encouraged high motivation even after time trials had plateaued. This study had several limitations. First, it employed a retrospective design and involved a single participant, which limits the generalizability of the findings. In addition, latent bias cannot be ruled out because the study was not blinded. Because there was no control group in this study, we cannot rule out the possibility that the improvements with vaginal cuff suturing were due to additional surgical experience and not the result of origami crane training alone. However, origami crane training may be one of the factors that contributed to the surgical improvements. Second, the evaluation of this training should not solely rely on time trials but also include an assessment of accuracy on completion, however, this aspect was not addressed in the present study. Therefore, future studies should be conducted with several surgeons or residents, a control group for comparison, and an evaluation of the accuracy of the origami cranes.

One gynecologist who was certified as a laparoscopy-qualified surgeon 2 years before this study participated in the study. The participant had performed more than 300 laparoscopic surgeries, including 100 total laparoscopic hysterectomies (TLHs), before this study. The study period was 44 months, during which 1000 origami cranes were folded in a dry box. The LapaSta ® (Japan Polymer Technology Co.) was used as the training box. A video camera and monitor were installed [ Figure 1 ]. A needle holder (Ethicon Co.) and Maryland forceps (Japan Polymer Technology Co.) were used for the right and left hands, respectively. The origami paper had a standard white color on one side and various colors on the other; the dimensions were 7.5 cm × 7.5 cm. The same procedure as that for the typical origami crane was performed using forceps ( https://www.youtube.com/watch?v=8melTrGQcOg&list=LL&index=3 ). The time required for completing the origami crane test was also recorded. Set-up for dry box training A total of 189 laparoscopic surgeries were performed by the surgeon during the study, including 91 TLHs. The intraoperative performance of vaginal cuff suturing in TLH was assessed. Of the 91 cases, 80 were verified and used in this study. A total of six cases were excluded because surgical videos could not be verified. Furthermore, five cases were excluded because vaginal cuff suturing was performed by other surgeons. The follow-up period for the patients was 4 months. Complications related to vaginal cuff suturing included reoperation, postponement of hospitalization, and readmission due to vaginal cuff dehiscence, bleeding, or infection. Vaginal cuff suturing was performed using simple interrupted sutures at both apices and interrupted cruciate sutures between the two apices using VICRYL CT-1 (Ethicon Co.). The operative time and number of errors of vaginal cuff sutures were evaluated by reviewing the surgical videos. The 80 cases were divided into 40 first-half cases (first-half group) and 40 second-half cases (second-half group), and suturing times and error counts were compared. Errors were defined as (i) popping the needle grasping with the needle holder; (ii) inserting or passing the needle inadequately, requiring reinsertion; (iii) repeating the same manipulation with poor performance; (iv) loose knots; and (v) dangerous manipulation with the possibility of organ damage. All analyses were performed using R software (version 1.61) and the EZR software program (Y Kanda, Saitama, Japan).[ 4 ] Student’s t -test was used to compare the mean time of vaginal cuff suturing between the first-half and the second-half groups because the data were parametric. Student’s t -test was also used to compare the mean number of errors between the first-half and the second-half groups because the data were nonparametric. However, no difference was observed in the median of these values between the first-half and second-half groups. Statistical significance was defined as P < 0.05. This study was approved by Kawasaki Saiwai Hospital Research Ethics Committee on April 3, 2023 (No. 4-45) and conducted in accordance with the code of ethics of the Declaration of Helsinki. Consent was obtained from all patients through the opt-out method.