Postoperative pulmonary vascular growth in patients with congenital diaphragmatic hernia.

BACKGROUND: Postoperative pulmonary growth in congenital diaphragmatic hernias (CDH) remains unclear. We investigated postoperative pulmonary vascular growth using serial lung perfusion scintigraphy in patients with CDH. METHODS: Neonates with left CDH who underwent surgery and postoperative lung perfusion scintigraphy at our institution between 2001 and 2020 were included. Patient demographics, clinical courses, and lung scintigraphy data were retrospectively analyzed by reviewing medical records. RESULTS: Twenty-one patients with CDH were included. Of these, 10 underwent serial lung scintigraphy. The ipsilateral perfusion rate and median age on the 1st and serial lung scintigraphy were 32% (34 days) and 33% (3.6 years), respectively. Gestational age at prenatal diagnosis (p = 0.02), alveolar-arterial oxygen difference (A-aDO2) at birth (p = 0.007), and preoperative nitric oxide (NO) use (p = 0.014) significantly correlated with the 1st lung scintigraphy. No other variables, including operative approach, were significantly correlated with the 1st or serial scintigraphy findings. All patients improved lung perfusion with serial studies [Difference: + 7.0 (4.3-13.25) %, p = 0.001, paired t-test]. This improvement was not significantly correlated with preoperative A-aDO2 (p = 0.96), NO use (p = 0.28), or liver up (p = 0.90). The difference was significantly larger in patients who underwent thoracoscopic repair than in those who underwent open abdominal repair [+ 10.6 (5.0-17.1) % vs. + 4.25 (1.2-7.9) %, p = 0.042]. CONCLUSION: Our study indicated a postoperative improvement in ipsilateral lung vascular growth, which is possibly enhanced by a minimally invasive approach, in patients with CDH.

The importance of designing a protector for a preterm and low birth weight infant with ectopia cordis.

Ectopia cordis is a rare condition with expected low survival rate based on past studies. We encountered a case of a preterm and low birth weight infant with ectopia cordis. When the infant cried, the prolapse of the heart, liver, and intestinal tract worsened. A pressure-applying protector was used to protect the organs and reduce the prolapse. Upon application, the infant's tachypnea and desaturation worsened. Fluoroscopic examination suggested that the pressure from the prolapsed regions was impeding pulmonary expansion and negatively affecting circulation. It is essential to carefully design a protector that accommodates the infant's growth.

A case of Hirschsprung's disease with segmental dilatation of the colon.

BACKGROUND: Segmental dilatation of the colon (SDC) is a rare disease that is characterized by an abrupt segment of dilated colon between regions of normal-sized colon. We herein report a case of SDC associated with Hirschsprung's disease (HD). CASE PRESENTATION: The patient developed abdominal distension soon after birth, and enema examination showed localized intestinal dilatation from the descending colon to the sigmoid colon with significant caliber changes on both the oral and anal sides of the dilated colon. The findings of the rectal mucosal biopsy were consistent with HD. We considered this case to be a combination of HD and SDC and performed laparoscopic-assisted Soave pull-through with resection of the dilated colon when the patient was 7 months old. Resected specimens showed steep caliber changes on the oral and anal sides of the dilated colon. In the pathological examination, no ganglion cells were found in the submucosa on the anal side of the dilated colon. Based on the above findings, we finally made the diagnosis of HD with SDC. CONCLUSION: In HD with a characteristic dilated colon, the possibility of SDC should be considered.

Design and validation of looping assistance methods in robotic-assisted neonatal surgical suturing in a chest model.

BACKGROUND: Neonate patients have a reduced thoracic cavity, making thoracoscopic procedures even more challenging than their adult counterparts. METHODS: We evaluated five control strategies for robot-assisted thoracoscopic surgical looping in simulations and experiments with a physical robotic system in a neonate surgical phantom. The strategies are composed of state-of-the-art constrained optimization and a novel looping force feedback term. RESULTS: All control strategies allowed users to successfully perform looping. A user study in simulation showed that the proposed strategy was superior in terms of Physical demand p < 0.05 $\left(p< 0.05\right)$ and task duration p < 0.05 $\left(p< 0.05\right)$ . The cumulative sum analysis of inexperienced users shows that the proposed looping force feedback can speed up the learning. Results with surgeons did not show a significant difference among control strategies. CONCLUSIONS: Assistive strategies in looping show promise and further work is needed to extend these benefits to other subtasks in robot-aided surgical suturing.

Examination of the effectiveness of bedside nasojejunal tube placement using a portable imaging device with a flat panel detector.

Transporting pediatric patients with severe cardiovascular complications to the fluoroscopy room can be difficult. Therefore, we started using a portable imaging device with a flat panel detector (FPD) for nasojejunal tube (NJT) placement. The purpose of this study was to investigate the differences in length of time of NJT placement and dosage of radiation exposure using a portable imaging device with FPD versus fluoroscopy. Pediatric patients who underwent NJT placement between April 2016 and December 2018 were identified retrospectively from the clinical records. The age, sex, body weight, and height of each child at the time of the procedure as well as the procedure time, outcomes of the procedure, and dosage of radiation exposure was compared between the two groups. In 76 cases of NJT placement (41 patients), there was no significant difference in the success rate of NJT placement between the FPD (90%) and fluoroscopy groups (95%). However, the NJT placement time was significantly longer in the FPD group than in the fluoroscopy group (488 s vs 291 s). According to our calculations, the radiation dosage was lower in the FPD group than in the fluoroscopy group (136 µGy per procedure vs 2819 µGy per procedure). These results suggest that NJT placement using a portable imaging device with an FPD can be an effective method for children who are difficult to transport with an equal success rate and lower dosage of radiation exposure compared with conventional fluoroscopy.

Face and construct validity assessment of training models for intestinal anastomosis in low-birth-weight infants.

PURPOSE: It is difficult to perform intestinal anastomosis in low-birth-weight infants because the intestinal diameter is small and the discrepancy in diameter of the proximal and distal intestines is often large, but there has been no optimal-sized training model. Therefore, we developed a new intestinal anastomosis training model that imitated the size of the intestine in low-birth-weight infants, and evaluated its face and construct validity. METHODS: Two intestinal models were developed with crossMedical, Inc. using a hydrophilic acrylic material (wet model) or a polyurethane soft resin (dry model). The inner diameter of the simulated intestinal tract was 15 mm on the oral end and 6 mm on the anal end. Thirteen pediatric surgeons performed anastomosis and responded to the questionnaire. RESULTS: In the questionnaire, the wet model had significantly higher scores than the dry model in "appearance", "softness" and "usefulness for training". In the anastomotic results of the wet model, the anastomosis leak pressure was significantly correlated with the number of intestinal anastomotic experiences in low-birth-weight infants (correlation coefficient = 0.64, P = 0.035). CONCLUSIONS: The wet-type intestinal anastomosis model showed good face validity. Its leak pressure had a significant correlation with clinical experience; thus, construct validity was demonstrated.

Optimal Viewing Direction of the Oblique Laparoscope in Single-Incision Laparoscopic Percutaneous Extraperitoneal Closure for Inguinal Hernia.

Background: It is difficult for novice surgeons to manipulate the oblique laparoscope in single-incision laparoscopic percutaneous extraperitoneal closure (SILPEC) for inguinal hernia because of collisions between the instruments. To standardize manipulation of the laparoscope, we studied the viewing direction of the oblique laparoscope, and assessed the optimal manipulation of the laparoscope to avoid collisions. Methods: A retrospective chart review was performed on patients who underwent SILPEC between April 2016 and April 2017. The viewing direction of the 30° oblique laparoscope was measured according to the location of the field stop pointer. Patients were divided into three groups according to the viewing direction at the beginning of the procedure: the inside viewing direction was from -90° to -11°, upward viewing direction was from -10° to 10°, and outside viewing direction was from 11° to 90°. The length of the procedure, viewing direction at the end, and the percentage of cases in which there was a change in viewing direction during the procedure were compared. Results: Ninety-eight cases of SILPEC were performed during the study period. The percentage of patients with a change in category of viewing direction in the inside, upward, and outside groups was 35%, 21%, and 11%, respectively, showing a significant difference among the three groups. Conclusions: Setting the initial viewing direction to the outside can reduce correction of the viewing direction during SILPEC. Because the intersection angle between the outside-viewing laparoscope and forceps is close to a right angle, this might reduce collisions.

Discovery of Candidate Stool Biomarker Proteins for Biliary Atresia Using Proteome Analysis by Data-Independent Acquisition Mass Spectrometry.

Biliary atresia (BA) is a destructive inflammatory obliterative cholangiopathy of the neonate that affects various parts of the bile duct. If early diagnosis followed by Kasai portoenterostomy is not performed, progressive liver cirrhosis frequently leads to liver transplantation in the early stage of life. Therefore, prompt diagnosis is necessary for the rescue of BA patients. However, the prompt diagnosis of BA remains challenging because specific and reliable biomarkers for BA are currently unavailable. In this study, we discovered potential biomarkers for BA using deep proteome analysis by data-independent acquisition mass spectrometry (DIA-MS). Four patients with BA and three patients with neonatal cholestasis of other etiologies (non-BA) were recruited for stool proteome analysis. Among the 2110 host-derived proteins detected in their stools, 49 proteins were significantly higher in patients with BA and 54 proteins were significantly lower. These varying stool protein levels in infants with BA can provide potential biomarkers for BA. As demonstrated in this study, the deep proteome analysis of stools has great potential not only in detecting new stool biomarkers for BA but also in elucidating the pathophysiology of BA and other pediatric diseases, especially in the field of pediatric gastroenterology.

A large superior mesenteric artery aneurysm and ileal obstruction: a rare presentation of polyarteritis nodosa in an infant.

Polyarteritis nodosa (PAN) is a rare form of vasculitis that occurs in childhood and affects small- and medium-sized arteries. Large aneurysms due to PAN can induce fatal complications like rupturing or occlusion of the affected arteries. Here, we report a case of a 4-month-old girl with PAN complicated by a large superior mesenteric artery aneurysm and ileal obstruction. We controlled her blood pressure to prevent the artery from rupturing. A combination of prednisolone, intravenous cyclophosphamide, and plasma exchange reduced the inflammation. She developed mechanical ileus due to ileum stricture and underwent bowel resection. Histopathological examinations revealed reparative arteritis around the healed ulcer. Her postoperative course was uneventful without further dilatation of the aneurysm. This case highlights the importance of intensive immunosuppressive therapy and appropriate blood pressure control in pediatric patients with PAN complicated by large aneurysms. Mechanical ileus can develop and may require surgical management even after remission of vasculitis.

Development of a Skill Evaluation System for the Camera Assistant Using an Infant-Sized Laparoscopic Box Trainer.

AIMS: Our aims were to develop a training system for camera assistants (CA), and evaluate participants' performance as CA. METHODS: A questionnaire on essential requirements to be a good CA was administered to experts in pediatric endoscopic surgery. An infant-sized box trainer with several markers and lines inside was developed. Participants performed marker capturing and line-tracing tasks using a 5-mm 30° scope. A postexperimental questionnaire on the developed system was administered. The task completion time was measured. RESULTS: The 5-point evaluation scale was used for each item in the questionnaire survey of experts. The abilities to maintain a horizontal line (mean score: 4.5) and to center the target in a specified rectangle on the monitor (4.5) as well as having a full understanding of the operative procedure (4.3) were ranked as highly important. Fifty-two participants, including 5 surgical residents, were enrolled in the evaluation experiment. The completion time of capturing the markers was significantly longer in the resident group than in the nonresident group (244 versus 124 seconds, P = .04), but that of tracing the lines was not significantly different between the groups. The postexperimental questionnaire showed that the participants felt that the line-tracing tasks (3.7) were more difficult than marker-capturing tasks (2.9). CONCLUSIONS: Being proficient in manipulating a camera and having adequate knowledge of operative procedures are essential requirements to be a good CA. The ability was different between the resident and nonresident groups even in a simple task such as marker capturing.

Evaluation of Surgical Devices Using an Artificial Pediatric Thoracic Model: A Comparison Between Robot-Assisted Thoracoscopic Suturing Versus Conventional Video-Assisted Thoracoscopic Suturing.

BACKGROUND: Pediatric robot-assisted surgery is increasingly being performed, but it is difficult to perform this procedure in infants. A pediatric thoracoscopic model of a 1-year-old patient was developed in our previous study, and this model was used to evaluate the use of a surgical robot for infant surgery. METHODS: Eight pediatric surgeons performed an intracorporeal suturing and knot-tying task using the da Vinci Xi Robotic Surgical System. The task completion time, number of needle manipulations, and force applied during suturing of the robot-assisted thoracoscopic surgery (RATS) group were compared with those of the video-assisted thoracoscopic surgery (VATS) group whose data had been collected from the same 8 surgeons in our previous study. RESULTS: The RATS group showed a significantly shorter completion time than the VATS group in the knot-tying phase (P = .016) and in the total phase (P = .0078). The RATS group showed a significantly smaller number of manipulations than the VATS group in the total phase (P = .039). The RATS group showed a significantly smaller pushing force index than the VATS group in the suturing phase (P = .031), knot-tying phase (P = .031), and in the total phase (P = .031). A seventh rib in the model was dislocated in all RATS group cases. CONCLUSIONS: The da Vinci Surgical System might be useful in infants because of fast movement and small pushing force. However, the robotic 8 mm instruments were too large for use in the thoracic cavity of the 1-year-old infant.

Preliminary Study of Video-Based Pediatric Endoscopic Surgical Skill Assessment Using a Neonatal Esophageal Atresia/Tracheoesophageal Fistula Model.

PURPOSE: Thoracoscopic esophageal atresia/tracheoesophageal fistula (EA/TEF) repair in neonates is technically difficult because of the small working space and fragility of tissues. This study aimed to show the construct validity of the neonatal EA/TEF simulator by video-based assessment of endoscopic suturing skill. MATERIALS AND METHODS: A rapid-prototyped neonatal chest model with an artificial esophagus model similar to the actual neonatal esophagus was developed. Forty pediatric surgeons performed an endoscopic intracorporeal suturing task and a knot-tying task using the model, and a questionnaire survey was administered. Each task was video recorded and assessed using two skill assessment methods (the 29-point checklist method and the error assessment sheet method). The task completion time and the number of manipulations were measured. RESULTS: With regard to experience in performing thoracoscopic TEF repair, the experienced surgeons (ESs, ≥3 EA/TEF repair experiences, n = 6) were significantly superior to the inexperienced surgeons (ISs, <3 experiences, n = 34) in all metrics. Upon comparison by the pediatric Endoscopic Surgical Skill Qualification (ESSQ) status, there were no significant differences in all metrics between the ESSQ-qualified (n = 15) and nonqualified (n = 25) surgeons. The qualified ESs (n = 6) were significantly superior to the qualified ISs (n = 9) in all metrics. CONCLUSION: Video-based endoscopic surgical skill assessment using the neonatal EA/TEF simulator could differentiate ESs from ISs. The construct validity of the simulator was demonstrated, and the simulator would be useful especially for practicing thoracoscopic EA/TEF procedures.

More than one-third of successfully nonoperatively treated patients with complicated appendicitis experienced recurrent appendicitis: Is interval appendectomy necessary?

BACKGROUND: Although nonoperative treatment (non-OPT) for complicated appendicitis is performed widely, the long-term outcomes and merits of interval appendectomy (IA) need to be evaluated. METHODS: Between April 2007 and December 2013, all appendicitis patients with well-circumscribed abscess or phlegmon were required to select either laparoscopic surgery (OPT) or non-OPT with optional IA on admission. Optional IA was planned at ≥3months after non-OPT. For non-OPT, intravenous injection of antibiotics was continued until the serum C-reactive protein concentration decreased to <0.5mg/dL, with occasional drainage of abscesses. RESULTS: Thirty-three patients chose OPT, and 55 chose non-OPT. Among non-OPT patients, 16 selected IA. The success rate of non-OPT was 98.2%. Recurrence occurred in 13 (34.2%) of the 38 non-IA group patients. Although the non-IA group patients frequently had perforated appendicitis at recurrence, they visited the hospital earlier than at the initial appendicitis and had less inflammation. Readmission rate or complications in patients undergoing IA were not different compared with those of the patients in the non-IA group, who had recurrence at ≥3months, or with those of patients in the OPT group. CONCLUSION: Although many patients experienced recurrent appendicitis after successful nonoperative treatment, IA may not be necessary after non-OPT. LEVEL OF EVIDENCE: Prospective comparative study, level II.

Pediatric Thoracoscopic Surgical Simulation Using a Rapid-Prototyped Chest Model and Motion Sensors Can Better Identify Skilled Surgeons Than a Conventional Box Trainer.

PURPOSE: We previously developed a pediatric thoracoscopic surgical simulator and showed its construct validity. In this study, the same skill assessment experiments were conducted in an additional 31 surgeons and the results of 53 surgeons in total were analyzed. METHODS: A suture pad with force sensors was placed in a rapid-prototyped pediatric chest model of a 1-year-old patient. Participants completed the endoscopic intracorporeal suturing and knot-tying task, both in the pediatric chest model setup and in a box trainer setup. The task was evaluated using eight metrics: the 29-point checklist score, error score, number of manipulations, task completion time, force index, width of the pad's slit after suturing, and right and left tool paths. RESULTS: The 53 participants included skilled surgeons certified by the Endoscopic Surgical Skill Qualification (ESSQ) system (n = 8) and unskilled surgeons without the certification (n = 45). The skilled surgeons showed significantly better performance than the unskilled surgeons in six metrics in the pediatric chest model setup. In contrast, no significant differences between the two groups were observed in the box trainer setup. Upon comparison between the setups, the unskilled surgeons showed worse results in six metrics in the pediatric chest model than in the box trainer, whereas the skilled surgeons showed equivalent performance in both setups. CONCLUSIONS: Our pediatric thoracoscopic surgical simulator was superior to the conventional box trainer for identifying skilled surgeons. The skilled surgeons showed excellent performance even in the intricate pediatric chest model, providing quantified targets for young pediatric surgeons' training.

A multi-degree-of-freedom needle driver with a short tip and small shaft for pediatric laparoscopic surgery: in vivo assessment of multi-directional suturing on the vertical plane of the liver in rabbits.

BACKGROUND: Laparoscopic Kasai portoenterostomy has been performed in infants with biliary atresia at several institutions, but laparoscopic anastomosis requiring multi-directional suturing on a vertical plane of the liver remains a challenge. To assist multi-directional suturing, we developed a multi-degree-of-freedom (DOF) needle driver whose tip length was 15 mm and shaft diameter was 3.5 mm. The tip of the multi-DOF needle driver has three DOFs for grasp, flection and rotation. The aim of this study was to evaluate the performance of the multi-DOF needle driver in two kinds of in vivo experiments. METHODS: Surgeons were asked to perform four-directional laparoscopic suturing on a vertical plane of the liver in six rabbits using the multi-DOF needle driver or a conventional needle driver. The needle grasping time, the needle handling time, the number of needle insertions, the number of liver lacerations, the suturing width and depth, and the area of necrotic tissues were analyzed and compared. Additionally, one surgeon was asked to perform laparoscopic hepato-jejunostomy in four rabbits to assess the feasibility of Kasai portoenterostomy using the multi-DOF needle driver. RESULTS: The suturing depth using the multi-DOF needle driver was significantly larger than that using the conventional needle driver in both the right and downward suturing directions. No statistically significant differences were found in other metrics. Liver lacerations were observed only when suturing was performed using the conventional needle driver. The experimental laparoscopic hepato-jejunostomy using the multi-DOF needle driver was successful. CONCLUSIONS: Using the multi-DOF needle driver, uniform multi-directional suturing on a vertical plane of the liver could be performed. The short distal tip of the multi-DOF needle driver demonstrated its advantages in multi-directional suturing in a small body cavity. The multi-DOF needle driver may be able to be used to perform complex tasks in laparoscopic Kasai portoenterostomy.

Long-term outcomes of operative versus nonoperative treatment for uncomplicated appendicitis.

PURPOSE: Although nonoperative treatment for uncomplicated appendicitis is now an accepted approach, there are few reports in children. The aim of this study was to compare long-term outcomes between operative and nonoperative treatment in children. METHODS: Between April 2007 and December 2013, all uncomplicated appendicitis patients were asked to select either operative (laparoscopic surgery) or nonoperative treatment on admission. For nonoperative treatment, intravenous injection of antibiotics was continued until serum C-reactive protein concentration decreased to below 0.5mg/dL. A questionnaire survey on satisfaction with treatment was added afterwards and performed more than 1year after treatment. RESULTS: Eighty-six patients chose operative treatment, and 78 chose nonoperative treatment. The success rate of nonoperative treatment was 98.7%. There was no difference in the length of hospital stay between the two groups. Ileus occurred in two operatively-treated patients, while recurrence of appendicitis occurred in 22 nonoperatively-treated patients (28.6 %) after an average of 4.3years of follow-up. The overall nonoperative treatment failure including both early failure and recurrence occurred more frequently among those with appendicoliths than without appendicoliths. Satisfaction levels were higher for operative treatment. CONCLUSIONS: Although the success rate of nonoperative treatment was very high, a considerable number of patients experienced recurrence.

Laparoscopic partial gastrectomy of a huge gastric duplication cyst in an infant.

Gastric duplication cyst is a rare anomaly, and most cases are recognized during childhood. Recently, several pediatric cases with small gastric duplication cysts treated by laparoscopic resection have been reported. Here, we describe an infant in whom we successfully performed laparoscopic partial gastrectomy for the treatment of a huge gastric duplication cyst. To the best of our knowledge, this is the largest gastric duplication cyst treated by laparoscopic surgery among infants. We introduce our procedure and some tips.

Influence of surgical intervention on neurodevelopmental outcome in infants with focal intestinal perforation.

BACKGROUND: Intestinal perforation is known to correlate with neurodevelopmental outcome in very low-birthweight (VLBW) infants, and its two major causes are necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP). Infants with FIP are reported to have better neurodevelopmental outcome than infants with NEC, but outcome has not been compared with that in infants without diseases that require surgery. The aim of this study was to compare neurodevelopmental outcomes between FIP survivors and infants without diseases that require surgery. METHODS: Records of VLBW infants with FIP and infants without surgical diseases were retrospectively analyzed. Neurodevelopmental outcome was compared between eight infants with FIP and 24 case-matched control infants without surgical diseases using the Kyoto Scale of Psychological Development. Control group members were individually matched with FIP survivors for sex, gestational age, birthweight, and intraventricular hemorrhage (IVH) grade. Those with an episode of sepsis or severe IVH (grade 3-4) that occurred irrespective of FIP were excluded. RESULTS: Three FIP survivors and 12 infants without surgical diseases were classified as neurodevelopmentally normal (37.5% vs 50%, P = 0.69) at a corrected age of 18 months-3 years. All neurodevelopmentally normal FIP survivors were born at a gestational age ≥ 26 weeks. CONCLUSION: Excluding the influence of sepsis or severe IVH, no significant difference was found in neurodevelopmental outcome between FIP survivors and infants without surgical diseases. None of the FIP infants born before 26 weeks of gestation, however, had normal neurodevelopment, suggesting that longer gestation might be needed to overcome the stress associated with FIP.

Quantitative pediatric surgical skill assessment using a rapid-prototyped chest model.

INTRODUCTION: Though minimally invasive pediatric surgery has become more widespread, pediatric-specific surgical skills have not been quantitatively assessed. MATERIAL AND METHODS: As a first step toward the quantification of pediatric-specific surgical skills, a pediatric chest model comprising a three-dimensional rapid-prototyped pediatric ribcage with accurate anatomical dimensions, a suturing skin model with force-sensing capability, and forceps with motion-tracking sensors were developed. A skill assessment experiment was conducted by recruiting 16 inexperienced pediatric surgeons and 14 experienced pediatric surgeons to perform an endoscopic intracorporeal suturing and knot-tying task in both the pediatric chest model setup and the conventional box trainer setup. RESULTS: The instrument motion measurement was successful in only 20 surgeons due to sensor failure. The task completion time, total path length of instruments, and applied force were compared between the inexperienced and experienced surgeons as well as between the box trainer and chest model setups. The experienced surgeons demonstrated better performance in all parameters for both setups, and the pediatric chest model was more challenging due to the pediatric features replicated by the model. CONCLUSION: The pediatric chest model was valid for pediatric skill assessment, and further analysis of the collected data will be conducted to further investigate pediatric-specific skills.

Video-based skill assessment of endoscopic suturing in a pediatric chest model and a box trainer.

PURPOSE: Pediatric endoscopic surgery requires special surgical skills because of the small working space and tissue fragility. This article presents a video-based skill assessment method for endoscopic suturing using a pediatric chest model. MATERIALS AND METHODS: A commercial suture pad was placed in a rapid-prototyped pediatric chest model of a 1-year-old patient to simulate the thoracoscopic repair of esophageal atresia type C. Twenty-eight pediatric surgeons (9 experts, 9 intermediates, and 10 trainees) performed an endoscopic intracorporeal suturing and knot-tying task both in the pediatric chest model and in a box trainer. The tasks were video-recorded and rated by two blinded observers using the 29-point checklist method and a suturing errors score sheet method. The task completion time and the number of needle manipulations were measured. RESULTS: The expert group showed better performance than the intermediate and trainee groups in the pediatric chest model, and the differences were larger than those in the box trainer. Significant differences between the expert and the trainee groups were observed in the items related to safety such as the skills for keeping the needle in view at all times. Significant differences between the expert and intermediate groups were observed in the items related to task quality and efficiency such as the smoothness of knot tying and the number of needle manipulations. CONCLUSIONS: Video-based skill assessment of endoscopic suturing using the pediatric chest model and a box trainer distinguished pediatric endoscopic surgeons according to their clinical experience, and pediatric-specific skills were identified.