Effect of three training programs on surgical performance in single-port laparoscopic surgery.

OBJECTIVE: The aim of this study was to evaluate the effect of three training methodologies on the acquisition of psychomotor skills for laparoendoscopic single-site surgery (LESS), using straight and articulating instruments. METHODS: A prospective study was conducted with subjects randomly divided into three groups, who performed a specific training for 12 days using three laparoscopic tasks in a laparoscopic simulator. Group-A trained in conventional laparoscopy setting using straight instruments and in LESS setting using both straight and articulating instruments. Group-B trained in LESS setting using straight and articulating instruments, whereas Group-C trained in LESS setting using articulating instruments. Participants' performance was recorded with a video-tracking system and evaluated with 12 motion analysis parameters (MAPs). RESULTS: All groups obtained significant differences in their performance in most of the MAPs. Group-C showed an improvement in nine MAPs, with a high level of technical competence. Group-A presented a marked improvement in bimanual dexterity skills. CONCLUSIONS: Training in LESS surgery using articulating laparoscopic instruments improves the quality of skills and allows smoother learning curves.

OBJETIVO: Evaluar el efecto de tres métodos de entrenamiento en la adquisición de habilidades psicomotrices para la cirugía laparoendoscópica por puerto único (LESS, laparoendoscopic single-site surgery) utilizando instrumental recto y articulado. MÉTODO: Se realizó un estudio prospectivo con sujetos divididos aleatoriamente en tres grupos, quienes realizaron un entrenamiento específico durante 12 días utilizando tres tareas laparoscópicas en un simulador laparoscópico. El grupo A entrenó en el entorno laparoscópico convencional con instrumentos rectos, y en el entorno LESS con instrumentos rectos y articulados. El grupo B entrenó en el entorno LESS con instrumentos rectos y articulados. El Grupo C entrenó en el entorno LESS con instrumentos articulados. El desempeño de los participantes se registró con un sistema de seguimiento en video y fue evaluado con 12 parámetros de análisis de movimiento (MAP, motion analysis parameters). RESULTADOS: Todos los grupos obtuvieron diferencias significativas en su desempeño para la mayoría de los MAP. El grupo C mostró una mejora en nueve MAP, con un alto nivel de competencia técnica. El grupo A mostró una marcada mejora en la habilidad de destreza bimanual. CONCLUSIONES: El entrenamiento en cirugía LESS con instrumentos articulados mejora la calidad de las habilidades adquiridas y permite curvas de aprendizaje más suaves.

An implantable magnetic drive mechanism for non-invasive arteriovenous conduit blood flow control.

OBJECTIVE: Hemodialysis patients usually receive an arteriovenous fistula (AVF) in the arm as vascular access conduit to allow dialysis 2-3 times a week. This AVF introduces the high flow necessary for dialysis, but over time the ever-present supraphysiological flow is the leading cause of complications. This study aims to develop an implantable device able to non-invasively remove the high flow outside dialysis sessions. METHODS: The developed prototype features a magnetic ring allowing external coupling and torque transmission to non-invasively control an AVF valve. Mock-up devices were implanted into arm and sheep cadavers to test sizes and locations. The transmission torque, output force, and valve closure are measured for different representative skin thicknesses. RESULTS: The prototype was placed successfully into arm and sheep cadavers. In the prototype, a maximum output force of 78.9±4.2 N, 46.7±1.9 N, 25.6±0.7 N, 13.5±0.6 N and 6.3±0.4 N could be achieved non-invasively through skin thicknesses of 1-5 mm respectively. The fistula was fully collapsible in every measurement through skin thickness up to the required 4 mm. CONCLUSION: The prototype satisfies the design requirements. It is fully implantable and allows closure and control of an AVF through non-invasive torque transmission. In vivo studies are pivotal in assessing functionality and understanding systemic effects. SIGNIFICANCE: A method is introduced to transfer large amounts of energy to a medical implant for actuation of a mechanical valve trough a closed surface. This system allows non-invasive control of an AVF to reduce complications related to the permanent high flow in conventional AVFs.

Development of Silk Fibroin Scaffolds for Vascular Repair.

Silk fibroin (SF) is a biocompatible natural protein with excellent mechanical characteristics. SF-based biomaterials can be structured using a number of techniques, allowing the tuning of materials for specific biomedical applications. In this study, SF films, porous membranes, and electrospun membranes were produced using solvent-casting, salt-leaching, and electrospinning methodologies, respectively. SF-based materials were subjected to physicochemical and biological characterizations to determine their suitability for tissue regeneration applications. Mechanical analysis showed stress-strain curves of brittle materials in films and porous membranes, while electrospun membranes featured stress-strain curves typical of ductile materials. All samples showed similar chemical composition, melting transition, hydrophobic behavior, and low cytotoxicity levels, regardless of their architecture. Finally, all of the SF-based materials promote the proliferation of human umbilical vein endothelial cells (HUVECs). These findings demonstrate the different relationship between HUVEC behavior and the SF sample's topography, which can be taken advantage of for the design of vascular implants.

Development and evaluation of different electroactive poly(vinylidene fluoride) architectures for endothelial cell culture.

Tissue engineering (TE) aims to develop structures that improve or even replace the biological functions of tissues and organs. Mechanical properties, physical-chemical characteristics, biocompatibility, and biological performance of the materials are essential factors for their applicability in TE. Poly(vinylidene fluoride) (PVDF) is a thermoplastic polymer that exhibits good mechanical properties, high biocompatibility and excellent thermal properties. However, PVDF structuring, and the corresponding processing methods used for its preparation are known to significantly influence these characteristics. In this study, doctor blade, salt-leaching, and electrospinning processing methods were used to produce PVDF-based structures in the form of films, porous membranes, and fiber scaffolds, respectively. These PVDF scaffolds were subjected to a variety of characterizations and analyses, including physicochemical analysis, contact angle measurement, cytotoxicity assessment and cell proliferation. All prepared PVDF scaffolds are characterized by a mechanical response typical of ductile materials. PVDF films displayed mostly vibration modes for the a-phase, while the remaining PVDF samples were characterized by a higher content of electroactive ß-phase due the low temperature solvent evaporation during processing. No significant variations have been observed between the different PVDF membranes with respect to the melting transition. In addition, all analysed PVDF samples present a hydrophobic behavior. On the other hand, cytotoxicity assays confirm that cell viability is maintained independently of the architecture and processing method. Finally, all the PVDF samples promote human umbilical vein endothelial cells (HUVECs) proliferation, being higher on the PVDF film and electrospun randomly-oriented membranes. These findings demonstrated the importance of PVDF topography on HUVEC behavior, which can be used for the design of vascular implants.

Use of a new device for gasless endosurgery in a laparoscopic diaphragmatic hernia repair ex vivo canine model: A pre-clinical study.

OBJECTIVES: To test the feasibility of a new device for gasless laparoscopy in providing working space for diaphragmatic hernia repair in an ex vivo canine model as a pre-clinical study. STUDY DESIGN: Technical feasibility study. ANIMAL: Eight beagles and two greyhound cadavers (not client-owned). METHODS: The new device was used for abdominal traction in gasless laparoscopic reconstruction of diaphragmatic hernias produced in dog cadavers. It consists of three main parts (vertical and horizontal rods, a three-piece structure, and a 3D-printed unit that incorporates slots for haemostatic forceps). Composite hernias (two incisions of about 4 cm) were closed by an intra-corporeal suture [suture group (GS), n = 5] or by a central suture and a polypropylene mesh [mesh group (GM), n = 5]. Surgical steps were T1 (primary port access up to third port placement), T2 (defect development), and T3 (diaphragmatic reconstruction). Total surgical time (TT) was also recorded. RESULTS: The defect was successfully developed and reconstructed in all cadavers. To close the defect, 7.0 ± 0.7 crossed mattress sutures were required in the GS, and 15.2 ± 1.9 hernia staples and one intra-corporal suture were used in the GM. T3 was longer (p = 0.0076) in GS (50.00 ± 16.46 min) than in GM (23.24 ± 5.25 min). TT was 87.22 ± 19.23 min in GS and 66.45 ± 6.38 min in GM (p = 0.0547). CONCLUSIONS: Gasless laparoscopic diaphragmatic hernia repair using the developed device is feasible in the canine cadaver model. Both suture and mesh graft techniques for experimental diaphragmatic herniorrhaphy can be performed using this new device in this pre-clinical model. CLINICAL SIGNIFICANCE: This new device for gasless laparoscopy allows diaphragmatic herniorrhaphy by intra-corporeal suture or mesh implantation in ex vivo canine model. The device demonstrates potential for future use in clinical cases.

Systematic Review of Tissue-Engineered Vascular Grafts.

Pathologies related to the cardiovascular system are the leading causes of death worldwide. One of the main treatments is conventional surgery with autologous transplants. Although donor grafts are often unavailable, tissue-engineered vascular grafts (TEVGs) show promise for clinical treatments. A systematic review of the recent scientific literature was performed using PubMed (Medline) and Web of Science databases to provide an overview of the state-of-the-art in TEVG development. The use of TEVG in human patients remains quite restricted owing to the presence of vascular stenosis, existence of thrombi, and poor graft patency. A total of 92 original articles involving human patients and animal models were analyzed. A meta-analysis of the influence of the vascular graft diameter on the occurrence of thrombosis and graft patency was performed for the different models analyzed. Although there is no ideal animal model for TEVG research, the murine model is the most extensively used. Hybrid grafting, electrospinning, and cell seeding are currently the most promising technologies. The results showed that there is a tendency for thrombosis and non-patency in small-diameter grafts. TEVGs are under constant development, and research is oriented towards the search for safe devices.

Block-matching-based registration to evaluate ultrasound visibility of percutaneous needles in liver-mimicking phantoms.

PURPOSE: To present a novel methodical approach to compare visibility of percutaneous needles in ultrasound images. METHODS: A motor-driven rotation platform was used to gradually change the needle angle while capturing image data. Data analysis was automated using block-matching-based registration, with a tracking and refinement step. Every 25 frames, a Hough transform was used to improve needle alignments after large rotations. The method was demonstrated by comparing three commercial needles (14G radiofrequency ablation, RFA; 18G Trocar; 22G Chiba) and six prototype needles with different sizes, materials, and surface conditions (polished, sand-blasted, and kerfed), within polyvinyl alcohol phantom tissue and ex vivo bovine liver models. For each needle and angle, a contrast-to-noise ratio (CNR) was determined to quantify visibility. CNR values are presented as a function of needle type and insertion angle. In addition, the normalized area under the (CNR-angle) curve was used as a summary metric to compare needles. RESULTS: In phantom tissue, the first kerfed needle design had the largest normalized area of visibility and the polished 1 mm diameter stainless steel needle the smallest (0.704 ± 0.199 vs. 0.154 ± 0.027, p < 0.01). In the ex vivo model, the second kerfed needle design had the largest normalized area of visibility, and the sand-blasted stainless steel needle the smallest (0.470 ± 0.190 vs. 0.127 ± 0.047, p < 0.001). As expected, the analysis showed needle visibility peaks at orthogonal insertion angles. For acute or obtuse angles, needle visibility was similar or reduced. Overall, the variability in needle visibility was considerably higher in livers. CONCLUSION: The best overall visibility was found with kerfed needles and the commercial RFA needle. The presented methodical approach to quantify ultrasound visibility allows comparisons of (echogenic) needles, as well as other technological innovations aiming to improve ultrasound visibility of percutaneous needles, such as coatings, material treatments, and beam steering approaches.

Comparative Study of the Influence of Three-Dimensional Versus Two-Dimensional Urological Laparoscopy on Surgeons' Surgical Performance and Ergonomics: A Systematic Review and Meta-Analysis.

Objective: The objective of this study is to compare the use of three-dimensional (3D) vision systems with traditional two-dimensional systems in laparoscopic urological surgery, analyzing the benefits, limitations, and impact of introducing this medical technology with regard to surgical performance and the surgeon's ergonomics. Methods: A systematic review with a structured bibliographic search was conducted in the electronic libraries (PubMed and EMBASE) until August 2019 and with no language restrictions. Studies on 3D visualization technology in laparoscopic urologic surgery, randomized controlled trials, and observational comparative studies were included. Relevant data were extracted and analyzed. Results: A total of 25 articles were obtained, of which 4 were clinical studies with patients, 2 studies were carried out in experimental animal models, and the remaining 19 were conducted in simulated environments. Regarding the European training program in basic laparoscopic urological skills, the results showed no significant differences in execution time using either imaging system. Three-dimensional vision led to a significant reduction in surgery time in pyeloplasty and radical nephrectomy. In addition, there was a reported decrease in blood loss in adrenalectomy, nephron-sparing nephrectomy, radical nephrectomy, simple nephrectomy, and pyeloplasty using 3D vision. Regarding ergonomics, the studies generally described no differences in side effects (headache, nausea, eye strain) when comparing the two types of visualization systems. Surgeons reported reduced workloads and stress with 3D vision than with traditional laparoscopy. Conclusions: Three-dimensional laparoscopic systems essentially advance surgical performance in less-experienced laparoscopic surgeons. Three-dimensional laparoscopy leads to improvements in surgery time, which is important for specific surgical procedures involving intracorporeal ligatures and sutures. The results achieved on the surgeons' ergonomics showed better depth perception and decreased stress and workloads during 3D vision with no differences in potential side effects.

Identification of intra-abdominal lymphatics in canine carcasses by laparoscopic fluorescence lymphography with intradermal and intrapopliteal ICG administration.

OBJECTIVE: To evaluate the feasibility of laparoscopic fluorescence lymphography (LFL) using indocyanine green (ICG) via intradermal (ID) or intrapopliteal (IPP) administration in an ex vivo canine model. METHODS: Six thawed adult male dog carcasses were placed in the Trendelenburg position after placing three surgical ports in triangulation. ICG (0.5 mg/ml; 0.05 mg/kg) was administered to five of the carcasses (one carcass was a pilot) via ID in the left torso and IPP (right position, by surgical access) to stain the lymphatic pathway and medial iliac lymph node (MILN). Fluorescence quality, staining time, structures stained, and lymph node histopathology were assessed. Thoracic duct staining was also evaluated. RESULTS: ID administration showed staining of parts of the lymphatic pathway of the iliosacral lymph center in all cases using a single dose of ICG, with left MILN visualization in four carcasses. IPP administration showed staining of the right MILN in all cases, using a single dose in four carcasses. ICG reached the thoracic duct in one case. The two administration routes showed similar results in terms of required ICG volume, staining time, and visualization quality, although IPP was more effective in staining the MILN. CONCLUSIONS: This study confirms the feasibility of staining the iliosacral lymph center (mainly the MILNs) by LFL in thawed dog carcasses via ID or IPP administration of ICG. However, the IPP route showed greater effectiveness in staining the MILN.

European association for endoscopic surgery (EAES) consensus statement on single-incision endoscopic surgery.

BACKGROUND: Laparoscopic surgery changed the management of numerous surgical conditions. It was associated with many advantages over open surgery, such as decreased postoperative pain, faster recovery, shorter hospital stay and excellent cosmesis. Since two decades single-incision endoscopic surgery (SIES) was introduced to the surgical community. SIES could possibly result in even better postoperative outcomes than multi-port laparoscopic surgery, especially concerning cosmetic outcomes and pain. However, the single-incision surgical procedure is associated with quite some challenges. METHODS: An expert panel of surgeons has been selected and invited to participate in the preparation of the material for a consensus meeting on the topic SIES, which was held during the EAES congress in Frankfurt, June 16, 2017. The material presented during the consensus meeting was based on evidence identified through a systematic search of literature according to a pre-specified protocol. Three main topics with respect to SIES have been identified by the panel: (1) General, (2) Organ specific, (3) New development. Within each of these topics, subcategories have been defined. Evidence was graded according to the Oxford 2011 Levels of Evidence. Recommendations were made according to the GRADE criteria. RESULTS: In general, there is a lack of high level evidence and a lack of long-term follow-up in the field of single-incision endoscopic surgery. In selected patients, the single-incision approach seems to be safe and effective in terms of perioperative morbidity. Satisfaction with cosmesis has been established to be the main advantage of the single-incision approach. Less pain after single-incision approach compared to conventional laparoscopy seems to be considered an advantage, although it has not been consistently demonstrated across studies. CONCLUSIONS: Considering the increased direct costs (devices, instruments and operating time) of the SIES procedure and the prolonged learning curve, wider acceptance of the procedure should be supported only after demonstration of clear benefits.

A Methodical Quantification of Needle Visibility and Echogenicity in Ultrasound Images.

During ultrasound-guided percutaneous interventions, needle localization can be a challenge. To increase needle visibility, enhancements of both the imaging methods and the needle surface properties have been investigated. However, a methodical approach to compare potential solutions is currently unavailable. The work described here involves automated image acquisition, analysis and reporting techniques to collect large amounts of data efficiently, delineate relevant factors and communicate effects. Data processing included filtering, line fitting and image intensity analysis steps. Foreground and background image samples were used to compute a contrast-to-noise ratio or a signal ratio. The approach was evaluated in a comparative study of commercially available and custom-made needles. Varied parameters included needle material, diameter and surface roughness. The shafts with kerfed patterns and the trocar and chiba tips performed best. The approach enabled an intuitive polar depiction of needle visibility in ultrasound images for a large range of insertion angles.

The use of 3D laparoscopic imaging systems in surgery: EAES consensus development conference 2018.

BACKGROUND: The use of 3D laparoscopic systems is expanding. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference with the aim of creating evidence-based statements and recommendations for the surgical community. METHODS: Systematic reviews of the PubMed and Embase libraries were performed to identify evidence on potential benefits of 3D on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by an international surgical and engineering expert panel which were presented and voted at the EAES annual congress, London, May 2018. RESULTS: 9967 abstracts were screened with 138 articles included. 18 statements and two recommendations were generated and approved. 3D significantly shortened operative time (mean difference 11 min (8% [95% CI 20.29-1.72], I2 96%)). A significant reduction in complications was observed when 3D systems were used (RR 0.75, [95 CI% 0.60-0.94], I2 0%) particularly for cases involving laparoscopic suturing (RR 0.57 [95% CI 0.35-0.90], I2 0%). In 69 box trainer or simulator studies, 64% concluded trainees were significant faster and 62% performed fewer errors when using 3D. CONCLUSION: We recommend the use of 3D vision in laparoscopy to reduce the operative time (grade of recommendation: low). Future robust clinical research is required to specifically investigate the potential benefit of 3D laparoscopy system on complication rates (grade of recommendation: high).

Assessment of Postural Ergonomics and Surgical Performance in Laparoendoscopic Single-Site Surgery Using a Handheld Robotic Device.

PURPOSE: New laparoscopic devices are being continuously developed to overcome some of the technical and ergonomic limitations of laparoendoscopic single-site (LESS) surgery. This study aims to assess the surgeon's surgical performance and ergonomics during the use of a handheld, robotic-driven, articulating laparoscopic instrument during LESS surgery. METHODS: Seven right-handed experienced surgeons took part in this study. A set of basic suturing tasks and digestive and urological procedures in a porcine model were performed. Surgeons used both a conventional laparoscopic needle holder and a robotic device. The learning curve, execution time, and precision using the surgical needle were assessed. The surgeon's posture was analyzed using a motion tracking system and a data glove. RESULTS: After the training period, execution time on the intracorporeal suturing was significantly shorter using the conventional needle holder. The precision was higher using the conventional instrument in the horizontal plane, but the number of attempts to position the needle was lower using the robotic device (1.625 ± 0.250 vs 1.188 ± 0.375 attempts). The extension of the elbow (134.681 ± 14.35° vs 120.631 ± 13.134°) and the flexion of the shoulder (26.122 ± 7.411° vs 18.475 ± 14.166°) were significantly lower using the robotic instrument. The wrist posture using the robotic device was ergonomically acceptable during both surgical procedures. CONCLUSIONS: Results show a positive learning curve in ergonomics and surgical performance using the robotic instrument during LESS surgery. This instrument improves the surgeon's body posture and the needle positioning errors. The use of the robotic instrument is feasible and safe during LESS partial nephrectomy and sigmoidectomy procedures.

Interpretation of motion analysis of laparoscopic instruments based on principal component analysis in box trainer settings.

BACKGROUND: Motion analysis parameters (MAPs) have been extensively validated for assessment of minimally invasive surgical skills. However, there are discrepancies on how specific MAPs, tasks, and skills match with each other, reflecting that motion analysis cannot be generalized independently of the learning outcomes of a task. Additionally, there is a lack of knowledge on the meaning of motion analysis in terms of surgical skills, making difficult the provision of meaningful, didactic feedback. In this study, new higher significance MAPs (HSMAPs) are proposed, validated, and discussed for the assessment of technical skills in box trainers, based on principal component analysis (PCA). METHODS: Motion analysis data were collected from 25 volunteers performing three box trainer tasks (peg grasping/PG, pattern cutting/PC, knot suturing/KS) using the EVA tracking system. PCA was applied on 10 MAPs for each task and hand. Principal components were trimmed to those accounting for an explained variance > 80% to define the HSMAPs. Individual contributions of MAPs to HSMAPs were obtained by loading analysis and varimax rotation. Construct validity of the new HSMAPs was carried out at two levels of experience based on number of surgeries. RESULTS: Three new HSMAPs per hand were defined for PG and PC tasks, and two per hand for KS task. PG presented validity for HSMAPs related to insecurity and economy of space. PC showed validity for HSMAPs related to cutting efficacy, peripheral unawareness, and confidence. Finally, KS presented validity for HSMAPs related with economy of space and knotting security. CONCLUSIONS: PCA-defined HSMAPs can be used for technical skills' assessment. Construct validation and expert knowledge can be combined to infer how competences are acquired in box trainer tasks. These findings can be exploited to provide residents with meaningful feedback on performance. Future works will compare the new HSMAPs with valid scoring systems such as GOALS.

Anthropomorphic liver phantom with flow for multimodal image-guided liver therapy research and training.

PURPOSE: The objective of this study was to develop a multimodal, permanent liver phantom displaying functional vasculature and common pathologies, for teaching, training and equipment development in laparoscopic ultrasound and navigation. METHODS: Molten wax was injected simultaneously into the portal and hepatic veins of a human liver. Upon solidification of the wax, the surrounding liver tissue was dissolved, leaving a cast of the vessels. A connection was established between the two vascular trees by manually manipulating the wax. The cast was placed, along with different multimodal tumor models, in a liver shaped mold, which was subsequently filled with a polymer. After curing, the wax was melted and flushed out of the model, thereby establishing a system of interconnected channels, replicating the major vasculature of the original liver. Thus, a liquid can be circulated through the model in a way that closely mimics the natural blood flow. RESULTS: Both the tumor models, i.e., the metastatic tumors, hepatocellular carcinoma and benign cyst, and the vessels inside the liver model, were clearly visualized by all the three imaging modalities: CT, MR and ultrasound. Doppler ultrasound images of the vessels proved the blood flow functionality of the phantom. CONCLUSION: By a two-step casting procedure, we produced a multimodal liver phantom, with open vascular channels, and tumor models, that is the next best thing to practicing imaging and guidance procedures in animals or humans. The technique is in principle applicable to any organ of the body.

Initial experience using a robotic-driven laparoscopic needle holder with ergonomic handle: assessment of surgeons' task performance and ergonomics.

PURPOSE: The objective of this study is to assess the surgeons' performance and ergonomics during the use of a robotic-driven needle holder in laparoscopic suturing tasks. METHODS: Six right-handed laparoscopic surgeons with different levels of experience took part in this study. Participants performed a set of three different intracorporeal suturing tasks organized in ten trials during a period of five weeks. Surgeons used both conventional (Conv) and robotic (Rob) laparoscopic needle holders. Precision using the surgical needle, quality of the intracorporeal suturing performance, execution time and leakage pressure for the urethrovesical anastomosis, as well as the ergonomics of the surgeon's hand posture, were analyzed during the first, fifth and last trials. RESULTS: No statistically significant differences in precision and quality of suturing performance were obtained between both groups of instruments. Surgeons required more time using the robotic instrument than using the conventional needle holder to perform the urethrovesical anastomosis, but execution time was significantly reduced after training ([Formula: see text] 0.05). There were no differences in leakage pressure for the anastomoses carried out by both instruments. After training, novice surgeons significantly improved the ergonomics of the wrist ([Formula: see text] 0.05) and index finger (Conv: 36.381[Formula: see text], Rob: 30.389[Formula: see text]; p = 0.024) when using the robotic instrument compared to the conventional needle holder. CONCLUSIONS: Results have shown that, although both instruments offer similar technical performance, the robotic-driven instrument results in better ergonomics for the surgeon's hand posture compared to the use of a conventional laparoscopic needle holder in intracorporeal suturing.

Use of natural user interfaces for image navigation during laparoscopic surgery: initial experience.

BACKGROUND: Surgical environments require special aseptic conditions for direct interaction with the preoperative images. We aim to test the feasibility of using a set of gesture control sensors combined with voice control to interact in a sterile manner with preoperative information and an integrated operating room (OR) during laparoscopic surgery. MATERIAL AND METHODS: Two hepatectomies and two partial nephrectomies were performed by three experienced surgeons in a porcine model. The Kinect, Leap Motion, and MYO armband in combination with voice control were used as natural user interfaces (NUIs). After surgery, surgeons completed a questionnaire about their experience. RESULTS: Surgeons required <10 min training with each NUI. They stated that NUIs improved the access to preoperative patient information and kept them more focused on the surgical site. The Kinect system was reported as the most physically demanding NUI and the MYO armband in combination with voice commands as the most intuitive and accurate. The need to release one of the laparoscopic instruments in order to use the NUIs was identified as the main limitation. CONCLUSIONS: The presented NUIs are feasible to directly interact in a more intuitive and sterile manner with the preoperative images and the integrated OR functionalities during laparoscopic surgery.

Objective assessment based on motion-related metrics and technical performance in laparoscopic suturing.

PURPOSE: The aim of this study is to present the construct and concurrent validity of a motion-tracking method of laparoscopic instruments based on an optical pose tracker and determine its feasibility as an objective assessment tool of psychomotor skills during laparoscopic suturing. METHODS: A group of novice ([Formula: see text] laparoscopic procedures), intermediate (11-100 laparoscopic procedures) and experienced ([Formula: see text] laparoscopic procedures) surgeons performed three intracorporeal sutures on an ex vivo porcine stomach. Motion analysis metrics were recorded using the proposed tracking method, which employs an optical pose tracker to determine the laparoscopic instruments' position. Construct validation was measured for all 10 metrics across the three groups and between pairs of groups. Concurrent validation was measured against a previously validated suturing checklist. Checklists were completed by two independent surgeons over blinded video recordings of the task. RESULTS: Eighteen novices, 15 intermediates and 11 experienced surgeons took part in this study. Execution time and path length travelled by the laparoscopic dissector presented construct validity. Experienced surgeons required significantly less time ([Formula: see text]), travelled less distance using both laparoscopic instruments ([Formula: see text]) and made more efficient use of the work space ([Formula: see text]) compared with novice and intermediate surgeons. Concurrent validation showed strong correlation between both the execution time and path length and the checklist score ([Formula: see text] and [Formula: see text], [Formula: see text]). CONCLUSIONS: The suturing performance was successfully assessed by the motion analysis method. Construct and concurrent validity of the motion-based assessment method has been demonstrated for the execution time and path length metrics. This study demonstrates the efficacy of the presented method for objective evaluation of psychomotor skills in laparoscopic suturing. However, this method does not take into account the quality of the suture. Thus, future works will focus on developing new methods combining motion analysis and qualitative outcome evaluation to provide a complete performance assessment to trainees.

Muscle activity and hand motion in veterinarians performing laparoscopic training tasks with a box trainer.

OBJECTIVE: To evaluate muscle activity and hand motion in veterinarians performing a standard set of laparoscopic training tasks. SAMPLE: 12 veterinarians with experience performing laparoscopic procedures. PROCEDURES: Participants were asked to perform peg transfer, coordination, precision cutting, and suturing tasks in a laparoscopic box trainer. Activity of the right biceps brachii, triceps brachii, forearm flexor, forearm extensor, and trapezius muscles was analyzed by means of surface electromyography. Right hand movements and wrist angle data were registered through the use of a data glove, and risk levels for the wrist joint were determined by use of a modified rapid upper limb assessment (RULA) method. One-way repeated-measures ANOVA with a Bonferroni post hoc test was performed to compare values between tasks. RESULTS: Activity in the biceps muscle did not differ significantly among the 4 tasks. Activity in the triceps, forearm flexor, and forearm extensor muscles was significantly higher during precision cutting than during the coordination task. Activity in the trapezius muscle was highest during the suturing task and did not differ significantly among the other 3 tasks. The RULA score was unacceptable (score, 3) for the coordination, peg transfer, and precision cutting tasks but was acceptable (score, 2) for the suturing task. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the ergonomics of laparoscopic training depended on the tasks performed and the design of the instruments used. Precision cutting and suturing tasks were associated with the highest muscle activity. Acceptable wrist position, as determined with the RULA method, was found with the suturing task, which was performed with an axial-handled instrument.

Utilidad de un sistema de seguimiento óptico de instrumental en cirugía laparoscópica para evaluación de destrezas motoras / Usefulness of an optical tracking system in laparoscopic surgery for motor skills assessment

INTRODUCCIÓN: En este trabajo se estudia la utilidad de un sistema de evaluación de destrezas quirúrgicas basado en el análisis de los movimientos del instrumental laparoscópico. MÉTODO: El sistema consta de un simulador físico laparoscópico y un sistema de seguimiento y evaluación de habilidades técnicas quirúrgicas. En el estudio han participado 6 cirujanos con experiencia intermedia (entre 1 y 50 intervenciones laparoscópicas) y 5 cirujanos expertos (más de 50 intervenciones laparoscópicas), todos ellos con la mano derecha como dominante. Cada sujeto realizó 3 repeticiones de una tarea de corte con la mano derecha en tejido sintético, una disección de la serosa gástrica y una sutura en la disección realizada. Para cada ejercicio se analizaron los parámetros de tiempo, distancia recorrida, velocidad, aceleración y suavidad de movimientos para los instrumentos de ambas manos. RESULTADOS: En la tarea de corte, los cirujanos expertos muestran menor aceleración (p = 0,014) y mayor suavidad en los movimientos (p = 0,023) en el uso de la tijera. Respecto a la actividad de disección, los cirujanos expertos requieren menos tiempo (p = 0,006) y recorren menos distancia con ambos instrumentos (p = 0,006 para disector y p = 0,01 para tijera). En la tarea de sutura, los cirujanos expertos presentan menor tiempo de ejecución que los cirujanos de nivel intermedio (p = 0,037) y recorren menos distancia con el disector (p = 0,041). CONCLUSIONES: El sistema de evaluación se mostró útil en las tareas de corte, disección y sutura, y constituye un progreso en el desarrollo de sistemas avanzados de entrenamiento y evaluación de destrezas quirúrgicas laparoscópicas

INTRODUCTION: The objective of this study is to assess the usefulness of an evaluation system of surgical skills based on motion analysis of laparoscopic instruments. METHOD: This system consists of a physical laparoscopic simulator and a tracking and assessment system of technical skills in laparoscopy. Six surgeons with intermediate experience (between 1 and 50 laparoscopic surgeries) and 5 experienced surgeons (more than 50 laparoscopic surgeries) took part in this study. All participants were right-handed. The subjects performed 3 repetitions of a cutting task on synthetic tissue with the right hand, dissection of a gastric serous layer, and a suturing task in the dissection previously done. Objective metrics such as time, path length, speed of movements, acceleration and motion smoothness were analyzed for the instruments of each hand. RESULTS: In the cutting task, experienced surgeons show less acceleration (P=.014) and a smoother motion (P=.023) using the scissors. Regarding the dissection activity, experienced surgeons need less time (P=.006) and less length with both instruments (P=.006 for dissector and P=.01 for scissors). In the suturing task, experienced surgeons require less time (P=.037) and distance traveled (P=.041) by the dissector. CONCLUSIONS: This study shows the usefulness of the evaluation system for the cutting, dissecting, and suturing tasks. It represents a significant step in the development of advanced systems for training and assessment of surgical skills in laparoscopic surgery