Munenori Uemura

Skills assessment using a virtual reality simulator, LapSim™, after training to develop fundamental skills for endoscopic surgery

Abstract Education and training to maintain medical safety are very important within clinical settings. We have established a training center for endoscopic surgery and we regularly hold a unique training course, which focuses on the development of fundamental skills. One hundred and ninety-four surgeons who participated in our training course were divided into four groups according to their experience in performing laparoscopic procedures. Group 1: 0–19 laparoscopic procedures (n=44). Group 2: 20–49 laparoscopic procedures (n=53). Group 3: 50–99 laparoscopic procedures (n=46). Group 4: more than 100 laparoscopic procedures (n=55). All subjects underwent evaluation for “Lifting & Grasping” using a virtual reality (VR) simulator, LapSim™, before and after the training course. The mean efficiency score, time to completion and tissue damage after training were significantly improved after the training as compared with before training. Before training, subjects with greater experience had better scores. However, the only significant difference in the score was between the low experience group and greatest experience group. After training, the score increased in all groups compared with that before training, and there was no significant difference between groups. This study demonstrates the feasibility of using a VR simulator to assess fundamental skills for endoscopic surgery after training. We found that the scores for the task were associated with the level of experience of the surgeons.

Development of a robotic system with six-degrees-of-freedom robotic tool manipulators for single-port surgery.

Current robotic systems have limitations for single‐port surgery (SPS) because the instruments are large, the arms collide and the field of vision requires manual readjustment. We have developed an SPS robotic system that manipulates the vision field.

Comparison of transtibial and transportal techniques in drilling femoral tunnels during anterior cruciate ligament reconstruction using 3D-CAD models

Purpose The purpose of this study was to assess the differences in bone tunnel apertures between the trans-accessory medial portal (trans-AMP) technique and the transtibial (TT) technique in double-bundle anterior cruciate ligament reconstruction. The extent of ovalization and the frequency of overlap of the two tunnel apertures were compared. Methods The simulation of femoral tunnel drilling with the TT and the trans-AMP techniques was performed using three-dimensional computer aided design models from two volunteers. The incidence angle of drilling against the intercondylar wall, the femoral tunnel position, the ovalization, and the overlap were analyzed. The aperture and location of the tunnels were also examined in real anterior cruciate ligament reconstruction cases (n=36). Results The surgical simulation showed that a lower drill incident angle induced by the TT technique made the apertures of two tunnels more ovalized, located anteromedial tunnels in a shallower position to prevent posterior wall blow out, and led to a higher frequency of tunnel overlap. The trans-AMP group had tunnel places within the footprint and had less ovalization and overlap. The results of analysis for tunnels in the clinical cases were consistent with results from the surgical simulation. Conclusion In the TT technique, the shallow anteromedial tunnel location and more ovalized tunnel aperture can lead to a higher frequency of tunnel overlap. Compared with the TT technique, the trans-AMP technique was more useful in preparing femoral tunnels anatomically and avoiding tunnel ovalization and overlapping in double-bundle anterior cruciate ligament reconstruction.

An augmented reality navigation system for pediatric oncologic surgery based on preoperative CT and MRI images.

PURPOSE In pediatric endoscopic surgery, a limited view and lack of tactile sensation restrict the surgeons abilities. Moreover, in pediatric oncology, it is sometimes difficult to detect and resect tumors due to the adhesion and degeneration of tumors treated with multimodality therapies. We developed an augmented reality (AR) navigation system based on preoperative CT and MRI imaging for use in endoscopic surgery for pediatric tumors. METHODS The patients preoperatively underwent either CT or MRI with body surface markers. We used an optical tracking system to register the reconstructed 3D images obtained from the CT and MRI data and body surface markers during surgery. AR visualization was superimposed with the 3D images projected onto captured live images. Six patients underwent surgery using this system. RESULTS The median age of the patients was 3.5 years. Two of the six patients underwent laparoscopic surgery, two patients underwent thoracoscopic surgery, and two patients underwent laparotomy using this system. The indications for surgery were local recurrence of a Wilms tumor in one case, metastasis of rhabdomyosarcoma in one case, undifferentiated sarcoma in one case, bronchogenic cysts in two cases, and hepatoblastoma in one case. The average tumor size was 22.0±14.2 mm. Four patients were treated with chemotherapy, three patients were treated with radiotherapy before surgery, and four patients underwent reoperation. All six tumors were detected using the AR navigation system and successfully resected without any complications. CONCLUSIONS The AR navigation system is very useful for detecting the tumor location during pediatric surgery, especially for endoscopic surgery.

The effect of CyberDome, a novel 3-dimensional dome-shaped display system, on laparoscopic procedures

BackgroundLaparoscopic surgeons require extended experience of cases to overcome the lack of depth perception on a two-dimensional (2D) display. Although a three-dimensional (3D) display was reported to be useful over two decades ago, 3D systems have not been widely used. Recently, we developed a novel 3D dome-shaped display (3DD) system, CyberDome.Study designIn the present study, a total of 23 students volunteered. We evaluated the effects of the 3DD system on depth perception and laparoscopic procedures in comparison with the 2D, a conventional 3D (3DP) or the 2D high definition (HD) systems using seven tasks.ResultsThe 3DD system significantly improved depth perception and laparoscopic performance compared with the 2D system in six new tasks. We further found that the 3DD system shortened the execution time and reduced the number of errors during suturing and knot tying. The 3DD system also provided more depth perception than the 3DP and 2D HD systems.ConclusionsThe novel 3DD system is a promising tool for providing depth perception with high resolution to laparoscopic surgeons.

Three-dimensional high-definition neuroendoscopic surgery: A controlled comparative laboratory study with two-dimensional endoscopy and clinical application

BACKGROUND The purpose of this research was to investigate the usefulness of three-dimensional (3D) endoscopy compared with two-dimensional (2D) endoscopy in neuroendoscopic surgeries in a comparative study and to test the clinical applications. METHODS Forty-three examinees were divided into three groups according to their endoscopic experience: novice, beginner, or expert. Examinees performed three separate tasks using 3D and 2D endoscopy. A recently developed 3D high-definition (HD) neuroendoscope, 4.7 mm in diameter (Shinko Optical Co., Ltd., Tokyo, Japan) was used. In one of the three tasks, we developed a full-sized skull model of acrylic-based plastic using a 3D printer and a patients thin slice computed tomography data, and evaluated the execution time and total path length of the tip of the pointer using an optical tracking system. Sixteen patients underwent endoscopic transnasal transsphenoidal pituitary surgery using both 3D and 2D endoscopy. RESULTS Horizontal motion was evaluated using task 1, and anteroposterior motion was evaluated with task 3. Execution time and total path length in task 3 using the 3D system in both novice and beginner groups were significantly shorter than with the 2D system (p < 0.05), although no significant difference between 2D and 3D systems in task 1 was seen. In both the novice and beginner groups, the 3D system was better for depth perception than horizontal motion. No difference was seen in the expert group in this regard. The 3D HD endoscope was used for the pituitary surgery and was found very useful to identify the spatial relationship of carotid arteries and bony structures. CONCLUSIONS The use of a 3D neuroendoscope improved depth perception and task performance. Our results suggest that 3D endoscopes could shorten the learning curve of young neurosurgeons and play an important role in both general surgery and neurosurgery.

Intercondylar Roof Impingement After Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension

Background: Although an anatomically placed graft in anterior cruciate ligament (ACL) reconstruction is reported to have a low risk of roof impingement, which may cause deterioration of the graft or an extension deficit, the incidence of roof impingement by these grafts has not been evaluated in hyperextensible knees. Purpose: To evaluate the incidence of roof impingement by the native ACL in hyperextensible knees and to examine the risk of roof impingement by anatomic placement of the ACL graft in hyperextensible knees. Study Design: Controlled laboratory study. Methods: Twelve patients were selected for a hyperextensible knee group (group A), defined as having hyperextension of the knee of greater than 10°. Twelve patients were recruited to a normal extension knee group (group B) with normal extension of the knee of less than 5° of hyperextension. Magnetic resonance imaging (MRI) scans of the knee positioned in 30° of flexion and full extension were acquired from all patients. The shape of the native ACL at full extension was compared between the groups. A 3-dimensional (3D) bone model was created from the acquired 2D MRI scans. A virtual anatomic double-bundle ACL reconstruction in each patient and a virtual anatomic single-bundle reconstruction in the patients in group A were performed using the 3D MRI bone models. The volume of the overlap between the graft and roof was calculated to evaluate graft impingement in each instance. Results: The MRI scans showed posterior bowing of the native ACL in the group A knees. The simulated double-bundle ACL reconstruction showed that the overlapped volume was significantly greater in patients in group A than in patients in group B (P < .05). However, the overlap of the simulated single-bundle ACL reconstruction was significantly less than for the double-bundle ACL reconstruction (P < .05). Conclusion: To reduce the risk of roof impingement by the graft, single-bundle ACL reconstruction with the graft placed at the center of the footprint might be the better method for patients with a hyperextensible knee than an anatomic double-bundle ACL reconstruction. Clinical Relevance: It is recommended that surgeons cautiously consider roof impingement after anatomic double-bundle ACL reconstruction in patients with a hyperextensible knee.

Development of a smart surgical robot with bended forceps for infant congenital esophageal atresia surgery

Minimally invasive surgery (MIS) is commonly used in pediatric operations. This method greatly benefits patients because of the reduced surgical trauma. To perform such surgery smoothly, doctors must be highly skilled. To reduce operating difficulties, a great deal of research on surgical systems have been carried out. However, in some cases, smaller workspaces limit the application of MIS. For example, the workspace of infant congenital esophageal atresia (ICEA) surgery is only around 30×30×30 mm. Until now, most ICEA surgeries have been manually performed with traditional instruments. This paper presents a smart surgical robot (SSR) for ICEA surgery. The robot is composed of two slave arms, each consisting of a positioning manipulator and a surgical tool manipulator. The positioning manipulator uses a selective compliance assembly robot arm (SCARA) and a screw-pair mechanism to achieve translational movement in 3D space, and the surgical tool manipulator uses a “double screw drive + universal joint” structure to allow an omni directional bending motion. During surgery, the surgeon first creates the workspace manually to explore the target esophagus. The SSR system is then applied to perform operation. The configuration of the SSR means it can perform tissue manipulation under endoscopic view in a small workspace. Experimental results show that the endoscopic view permits the SSR system to be operated intuitively and accurately in the target workspace.

In vivo experiments of a surgical robot with vision field control for single port endoscopic surgery

Recently, robotics systems are focused to assist in Single Port Endoscopic Surgery (SPS). However, the existing system required a manual operation of vision and viewpoint, hindering the surgical task. We proposed a surgical endoscopic robot for SPS with dynamic vision control, the endoscopic view being manipulated by a master controller. The prototype robot consists of a manipulator for vision control, and dual tool tissue manipulators (gripping: 5DOFs, cautery: 3DOFs) can be attached at the tip of sheath manipulator. In particular, this paper focuses on an in vivo experiment. We showed that vision control in the stomach and a cautery task by a cautery tool could be effectively achieved.

An Endoscopic Surgical Skill Validation System for Pediatric Surgeons Using a Model of Congenital Diaphragmatic Hernia Repair

PURPOSE We developed a system to objectively verify the endoscopic surgical skills of pediatric surgeons. MATERIALS AND METHODS We developed a thoracoscopic model of congenital diaphragmatic hernia mimicking a newborns size. The examinees were divided into Experts (n = 10) and Trainees (n = 19), and each group performed two tasks (Task 1, reduction of a herniated intestine from the thoracic space to the abdomen; Task 2, perform three suture ligatures of a diaphragm defect using intracorporeal knot-tying). The end points were the time required to complete Task 1, time score calculated using the residual time from the time limit for Task 2, number of complete full-thickness sutures, maximum air-pressure tolerance, degree of diaphragm deformation, and the residual defect areas after suturing. We also evaluated the total path length and velocity of the forceps tips using a three-dimensional position measurement instrument. RESULTS The Experts had significantly superior results for the time for Task 1, time score, number of complete full-thickness sutures, maximum air-pressure tolerance, and degree of diaphragm deformation in Task 2 (all P < .05). We found that the total path length and average velocities for the left forceps were inferior to those of the right forceps in both tasks in the Trainees (both P < .05, respectively), whereas the Expert group showed no significant laterality in these tasks. CONCLUSIONS Our model could validate the quality of endoscopic surgical skills and could differentiate between Expert and Trainee pediatric surgeons. The Experts could use their forceps equally well to perform tasks even in a small working space.