Robotic surgery for inguinal and ventral hernia repair: a systematic review and meta-analysis.

BACKGROUND: This systematic review and meta-analysis assessed the effectiveness of robotic surgery compared to laparoscopy or open surgery for inguinal (IHR) and ventral (VHR) hernia repair. METHODS: PubMed and EMBASE were searched up to July 2022. Meta-analyses were performed for postoperative complications, surgical site infections (SSI), seroma/hematoma, hernia recurrence, operating time (OT), intraoperative blood loss, intraoperative bowel injury, conversion to open surgery, length of stay (LOS), mortality, reoperation rate, readmission rate, use of opioids, time to return to work and time to return to normal activities. RESULTS: Overall, 64 studies were selected and 58 were used for pooled data analyses: 35 studies (227 242 patients) deal with IHR and 32 (158 384 patients) with VHR. Robotic IHR was associated with lower hernia recurrence (OR 0.54; 95%CI 0.29, 0.99; I2: 0%) compared to laparoscopic IHR, and lower use of opioids compared to open IHR (OR 0.46; 95%CI 0.25, 0.84; I2: 55.8%). Robotic VHR was associated with lower bowel injuries (OR 0.59; 95%CI 0.42, 0.85; I2: 0%) and less conversions to open surgery (OR 0.51; 95%CI 0.43, 0.60; I2: 0%) compared to laparoscopy. Compared to open surgery, robotic VHR was associated with lower postoperative complications (OR 0.61; 95%CI 0.39, 0.96; I2: 68%), less SSI (OR 0.47; 95%CI 0.31, 0.72; I2: 0%), less intraoperative blood loss (- 95 mL), shorter LOS (- 3.4 day), and less hospital readmissions (OR 0.66; 95%CI 0.44, 0.99; I2: 24.7%). However, both robotic IHR and VHR were associated with significantly longer OT compared to laparoscopy and open surgery. CONCLUSION: These results support robotic surgery as a safe, effective, and viable alternative for IHR and VHR as it can brings several intraoperative and postoperative advantages over laparoscopy and open surgery.

Evaluation of diagnostic laparoscopy for penetrating abdominal injuries: About 131 anterior abdominal stab wound.

BACKGROUND: The management of hemodynamically stable patients with anterior abdominal stab wounds (AASW) is debated. Mini-invasive techniques using laparoscopy and non-operative management (NOM) have reduced the rate of nontherapeutic laparotomies after AASW leading to unnecessary morbidity. The aim of this study was to determine with a systematic diagnostic laparoscopy of peritoneal penetration (PP), patients who do not require abdominal exploration in the management of stable patient with an AASW. METHODS: All patients with AASW were retrospectively recorded from 2006 to 2018. Criteria of inclusion were AASW patients who underwent a systematic diagnostic laparoscopy. Criteria of exclusion were patients with an evisceration, impaling, clinical peritonitis, and hemodynamic instability. If no PP was detected, laparoscopy was terminated. If defects of peritoneum were found, a laparotomy was performed looking for diagnosis and treatment of intra-abdominal injuries. RESULTS: On 131 AASW patients, 35 underwent immediate emergency laparotomy, 96 underwent diagnostic laparoscopy, 47 were positive (PP) and had an intra-abdominal exploration by laparotomy, 32 (68.1%) had intra-abdominal injuries which required treatment. All patients with an intra-abdominal injury had a positive diagnostic laparoscopy. For the 49 patients with a negative laparoscopy, the mean hospital stay was 1.6 days with ambulatory care for some patients. No patient presented a delayed injury. Non-therapeutic laparotomy rate was 15.6%. For patients who did not have an intra-abdominal injury the morbidity rate was low (3%). CONCLUSION: Our study shows that diagnostic laparoscopy was safe, with a low duration of hospitalization, a possible ambulatory care and had an excellent ability to screen the patients who did not need a abdominal exploration. This management can avoid many unnecessary laparotomies with an acceptable rate of negative laparotomy, without any delayed diagnosis of intra-abdominal injuries and with a low morbidity rate.

Anatomy of the nasal latero-lateral cartilage articulation: a micro-MRI study in human specimens.

PURPOSE: To study the anatomy of the latero-lateral joint (LLJ) between the upper lateral (ULC) and lower lateral (LLC) crus of the nasal cartilages, usually described as a scroll articulation. METHODOLOGY: Six nasal pyramids were taken in monobloc from fresh cadavers and imaged on micro-MRI with 0.4 mm slice thickness. Images were jointly interpreted by two head and neck radiologists and one surgeon. The junction between the ULC and LLC, the presence of ligaments and of sesamoid or accessory cartilages were assessed. RESULTS: Eight LLJs could be analyzed, with four types of junctions: hook-shaped cephalic border of the LLC turned towards the nasal fossa and linear caudal border of the ULC (n = 3), hook-shaped caudal border of the ULC and linear cephalic border of the LLC lateral crus (n = 1), hook-shaped border of both cartilaginous edges with clinging (n = 1) (scroll articulation) or without clinging (n = 3). No ligament or sesamoid cartilage was found, but posterior accessory cartilages were seen in 75% of the cases. CONCLUSION: The classical scroll articulation of the LLJ has been observed in only 1/8 cases on micro-MRI images. The anatomy of the LLJ could explain the surgical difficulty in raising the tip of the nose in some patients and not in others.

Sarcopenia in Children With End-Stage Liver Disease on the Transplant Waiting List.

Sarcopenia predicts morbidity and mortality in adults with end-stage liver disease (ESLD) and is determined by total psoas muscle area (tPMA) measurement from computed tomography (CT) imaging. Recently developed pediatric age- and sex-specific tPMA growth curves provide the opportunity to ascertain prevalence and impact of sarcopenia in children awaiting liver transplantation (LT). This retrospective single-center study evaluated sarcopenia in children between 1 and 16 years with ESLD and a clinically indicated abdominal CT less than 3 months before first isolated LT. Sarcopenia was defined as tPMA z score less than -2 measured at the intervertebral L4-5 level. Patient demographic, biochemical, and outcome data were recorded. tPMA was compared with other measures of nutritional status using univariate and multivariate logistic analyses. Outcome measures included 1-year morbidity events and mortality after LT. CT images from 25 (64% female) children with median age of 5.50 (interquartile range [IQR], 3.75-11.33) years were reviewed. Ten children (40%) had a tPMA z score less than -2. Sarcopenia was associated with lower z scores for weight (odds ratio [OR], 0.38; P = 0.02), height (OR, 0.32; P = 0.03), and nutritional support before LT (OR, 12.93; P = 0.01). Sarcopenic children had a longer duration of pediatric intensive care unit (PICU) stay (3.50 [IQR, 3.00-6.00] versus 2.00 [IQR, 2.00-3.50] days; P = 0.03). Sarcopenia was prevalent in 40% of children with ESLD awaiting LT, and lower tPMA z score was associated with deficient anthropometrics and need for nutritional support before LT. Post-LT PICU duration was increased in children with sarcopenia, reflecting adverse outcomes associated with muscle loss. Further studies are needed to elucidate the underlying mechanisms of sarcopenia in children with ESLD.

The relationship between R&D, the absorptive capacity of knowledge, human resource flexibility and innovation: Mediator effects on industrial firms.

This paper analyzes data from 1666 Spanish industrial firms to test how some human resource (HR) flexibility dimensions mediate the relationship between research and development (R&D) efforts and the absorptive capacity of knowledge (AC). The results show that external R&D experts and core employee training partially mediate the relationship between R&D effort and AC, whereas temporary employment does not mediate that relationship. These findings seem to suggest that HR flexibility dimensions that are more knowledge-intensive are more influential on the development of absorptive capabilities. Another finding is that the mediator effects of HR and AC are positively related to innovation performance, suggesting that firms may combine them more effectively with R&D efforts to enhance innovation.

Easing anxiety in preparation for pediatric magnetic resonance imaging: a pilot study using animal-assisted therapy.

BACKGROUND: Children undergoing magnetic resonance imaging (MRI) can experience negative emotions both before and during their scan, causing them to move and often necessitating the use of procedural sedation. Several strategies to improve patient compliance have been attempted. OBJECTIVE: This study was designed to evaluate the effectiveness of a non-pharmacological intervention to reduce anxiety in pediatric patients preparing for MRI using animal-assisted therapy. MATERIALS AND METHODS: An animal intervention pilot study was performed in patients who agreed in advance to interact with a dog. Patients and caregivers filled out questionnaires, including questions designed to capture changes in patient emotion before and after the intervention. MRI diagnostic quality was compared to age- and gender-matched control groups with and without general anesthesia. RESULTS: The intervention in 21 patients comparing pre- and post-scan surveys demonstrated a statistically significant improvement in patient anxiety levels (P<0.01). Diagnostic MRI scans were achieved in 19/21 (90%), with no significant difference in exam quality or times compared against control groups. The majority of caregivers and staff members agreed strongly that patients benefited from the therapy dog's presence. CONCLUSION: The use of animal-assisted therapy in a pilot group in our MRI division resulted in a beneficial effect on patients' emotional status, easing anxiety in preparation for scheduled scans, without impacting MRI quality or duration. Further randomized studies will be needed to demonstrate its significance in reducing sedation rates in children undergoing MRI.

A guide for effective anatomical vascularization studies: useful ex vivo methods for both CT and MRI imaging before dissection.

The objective of this study was to develop a simple and useful injection protocol for imaging cadaveric vascularization and dissection. Mixtures of contrast agent and cast product should provide adequate contrast for two types of ex vivo imaging (MRI and CT) and should harden to allow gross dissection of the injected structures. We tested the most popular contrast agents and cast products, and selected the optimal mixture composition based on their availability and ease of use. All mixtures were first tested in vitro to adjust dilution parameters of each contrast agent and to fine-tune MR imaging acquisition sequences. Mixtures were then injected in 24 pig livers and one human pancreas for MR and computed tomography (CT) imaging before anatomical dissection. Colorized latex, gadobutrol and barite mixture met the above objective. Mixtures composed of copper sulfate (CuSO4 ) gadoxetic acid (for MRI) and iodine (for CT) gave an inhomogeneous signal or extravasation of the contrast agent. Agar did not harden sufficiently for gross dissection but appears useful for CT and magnetic resonance imaging (MRI) studies without dissection. Silicone was very hard to inject but achieved the goals of the study. Resin is particularly difficult to use but could replace latex as an alternative for corrosion instead of dissection. This injection protocol allows CT and MRI images to be obtained of cadaveric vascularization and anatomical casts in the same anatomic specimen. Post-imaging processing software allow easy 3D reconstruction of complex anatomical structures using this technique. Applications are numerous, e.g. surgical training, teaching methods, postmortem anatomic studies, pathologic studies, and forensic diagnoses.

A radio-anatomical correlation study of the cisterna chyli.

Surgical laparoscopic procedures in the retroperitoneal and supramesocolic spaces are increasingly frequent. There is a high risk of iatrogenic intraoperative injury of the retroperitoneal lymphatic structures during these procedures. A precise understanding of the anatomy of the thoracic duct (TD) and the cisterna chyli (CC) is essential for safe surgical procedures in this area. However, routine imaging procedures rarely and often incorrectly visualize the CC. The objective of this study was to evaluate the feasibility of a retrograde injection of the TD to fill the CC with a contrast agent in 16 human cadavers. Both magnetic resonance lymphography (MRI) and computed tomography (CT) studies could be performed on the same anatomical specimen, using a contrast medium which hardened, allowing gross dissection. MRI and CT detectability were evaluated, and imaging results were compared with the anatomical dissection. The CC of 12/16 cadavers were successfully injected, and four were unsuccessful due to technical difficulties, showing the effectiveness of the method. This technique can improve understanding of the anatomy of the TD and CC and provides an original option to study the complex anatomy of these structures by correlating precise cadaveric dissections with cross-sectional imaging.

Unraveling Pancreatic Segmentation.

BACKGROUND: Limited pancreatic resections are increasingly performed, but the rate of postoperative fistula is higher than after classical resections. Pancreatic segmentation, anatomically and radiologically identifiable, may theoretically help the surgeon removing selected anatomical portions with their own segmental pancreatic duct and thus might decrease the postoperative fistula rate. We aimed at systematically and comprehensively reviewing the previously proposed pancreatic segmentations and discuss their relevance and limitations. METHODS: PubMed database was searched for articles investigating pancreatic segmentation, including human or animal anatomy, and cadaveric or surgical studies. RESULTS: Overall, 47/99 articles were selected and grouped into 4 main hypotheses of pancreatic segmentation methodology: anatomic, vascular, embryologic and lymphatic. The head, body and tail segments are gross description without distinct borders. The arterial territories defined vascular segments and isolate an isthmic paucivascular area. The embryological theory relied on the fusion plans of the embryological buds. The lymphatic drainage pathways defined the lymphatic segmentation. These theories had differences, but converged toward separating the head and body/tail parts, and the anterior from posterior and inferior parts of the pancreatic head. The rate of postoperative fistula was not decreased when surgical resection was performed following any of these segmentation theories; hence, none of them appeared relevant enough to guide pancreatic transections. CONCLUSION: Current pancreatic segmentation theories do not enable defining anatomical-surgical pancreatic segments. Other approaches should be explored, in particular focusing on pancreatic ducts, through pancreatic ducts reconstructions and embryologic 3D modelization.

Effectiveness of an Integrated Video Recording and Replaying System in Robotic Surgical Training.

OBJECTIVE: This study evaluated the effectiveness of using a video recording and replaying system in robotic surgical training. SUMMARY BACKGROUND DATA: Robotic surgical videos are reviewed to accelerate the acquisition of robotic surgical skills. However, few professional recording and replaying systems have been used during robotic surgical training. The effectiveness of these professional video systems should be investigated and validated. METHODS: A randomized study was conducted to analyze the performance of 60 participants, who were unfamiliar with surgical robotics, in a robotic simulator. Participants were enrolled in 2 groups to perform 2 exercises on a Mimic dV-Trainer. One group was trained with the new protocol based on a recording and replaying system (controller of events on simulator and robot) and the other group was trained with the conventional method. The overall scores were automatically evaluated by the simulator. The number of additional requests for reviewing the videos or watching the trainer's demonstration and the learning curves based on the overall scores were compared between the 2 groups. RESULTS: The group trained with controller of events on simulator and robot presented a significantly improved learning curve in both exercises (P < 0.001) with more additional requests (P < 0.001) in comparison with the group trained with the conventional method. CONCLUSIONS: In robotic skills training, the use of a recording and replay system is beneficial and more efficient than the conventional training method.

Quantitative Analysis of Subtalar Joint Motion With 4D CT: Proof of Concept With Cadaveric and Healthy Subject Evaluation.

OBJECTIVE: The purpose of this study was to show the application of quantitative 4D CT for subtalar joint evaluation in healthy volunteers and cadavers. MATERIALS AND METHODS: Fifteen healthy volunteers with no history of subtalar joint trauma and three cadavers were prospectively evaluated with dynamic CT. The subtalar joint was evaluated during a pronosupination cycle. All acquisitions (cadavers and healthy volunteers) were performed using intermittent sequential mode with a 320-MDCT scanner. Angles and distances between the talus and the calcaneus were measured semiautomatically. Measurement variation was described in healthy volunteers and in cadavers, the latter before and after resection of the cervical and interosseous ligaments. The mean effective dose was below 0.1 mSv. RESULTS: In cadavers, mean increases in joint amplitude over 19% and of 22% were seen after partial ligament sectioning and after full ligament sectioning, respectively. The interobserver variability of the measurement ratios was considered to be excellent for three of the measurements made (ICC > 0.87) and moderate for the fourth (ICC = 0.57). The normal range of joint motion in healthy volunteers is described, with joint amplitudes varying from 6.4% to 22.8%. CONCLUSION: Quantitative dynamic CT of the subtalar joint can provide a detailed analysis of joint motion, supporting its potential role in the evaluation of subtalar instability.

"Alarm-corrected" ergonomic armrest use could improve learning curves of novices on robotic simulator.

BACKGROUND: In robotic surgery, the professional ergonomic habit of using an armrest reduces operator fatigue and increases the precision of motion. We designed and validated a pressure surveillance system (PSS) based on force sensors to investigate armrest use. The objective was to evaluate whether adding an alarm to the PSS system could shorten ergonomic training and improve performance. STUDY DESIGN: Twenty robot and simulator-naïve participants were recruited and randomized in two groups (A and B). The PSS was installed on a robotic simulator, the dV-Trainer, to detect contact with the armrest. The Group A members completed three tasks on the dV-Trainer without the alarm, making 15 attempts at each task. The Group B members practiced the first two tasks with the alarm and then completed the final tasks without the alarm. The simulator provided an overall score reflecting the trainees' performance. We used the new concept of an "armrest load" score to describe the ergonomic habit of using the armrest. RESULTS: Group B had a significantly higher performance score (p < 0.001) and armrest load score (p < 0.001) than Group A from the fifth attempt of the first task to the end of the experiment. CONCLUSIONS: Based on the conditioned reflex effect, the alarm associated with the PSS rectified ergonomic errors and accelerated professional ergonomic habit acquisition. The combination of the PSS and alarm is effective in significantly shortening the learning curve in the robotic training process.

Effect of ketamine administration, alone and in combination with E-6837, on climbing behavior.

Some types of schizophrenia have been associated with repetitive movements lacking specific purpose, also known as stereotyped behavior. Dopamine agonists (D2) and noncompetitive N-methyl-D-aspartate receptor antagonists (e.g. ketamine) have been administered in rodent models to induce stereotyped behavior that resembles some motor symptoms of schizophrenia. Recently, a relationship has been found between 5-HT6 receptors (5-HT6Rs) and dopaminergic activity. The present study evaluates the effect of ketamine (5 and 10 mg/kg), alone and in combination with the 5-HT6R agonist E-6837, on the climbing behavior of male mice. Ketamine was administered with an acute (1 day) and subchronic (5 day) scheme. Later, these doses and schemes were combined with an acute scheme of E-6837 (5 and 10 mg/kg). With both the acute and the subchronic schemes, ketamine increased climbing behavior at a dose of 10 mg/kg, and this effect was reversed by E-6837 (at 5 and 10 mg/kg). The present results suggest that there is an interaction between N-methyl-D-aspartate and 5-HT6 receptors in the regulation of climbing behavior. Further research is necessary to provide more evidence on this interaction.

Face, content, construct, and concurrent validity of a novel robotic surgery patient-side simulator: the Xperience™ Team Trainer.

OBJECTIVES: To determine the face, content, construct, and concurrent validity of the Xperience™ Team Trainer (XTT) as an assessment tool of robotic surgical bed-assistance skills. METHODS: Subjects were recruited during a robotic surgery curriculum. They were divided into three groups: the group RA with robotic bed-assistance experience, the group LS with laparoscopic surgical experience, and the control group without bed-assistance or laparoscopic experience. The subjects first performed two standard FLS exercises on a laparoscopic simulator for the assessment of basic laparoscopic skills. After that, they performed three virtual reality exercises on XTT, and then performed similar exercises on physical models on a da Vinci(®) box trainer. RESULTS: Twenty-eight persons volunteered for and completed the tasks. Most expert subjects agreed on the realism of XTT and the three exercises, and also their interest for teamwork and bed-assistant training. The group RA and the group LS demonstrated a similar level of basic laparoscopic skills. Both groups performed better than the control group on the XTT exercises (p < 0.05). The performance superiority of the group RA over LS was observed but not statistically significant. Correlation of performance was determined between the tests on XTT and on da Vinci(®) box trainer. CONCLUSIONS: The introduction of XTT facilitates the training of bedside assistants and emphasizes the importance of teamwork, which may change the paradigm of robotic surgery training in the near future. As an assessment tool of bed-assistance skills, XTT proves face, content, and concurrent validity. However, these results should be qualified considering the potential limitations of this exploratory study with a relatively small sample size. The training modules remain to be developed, and more complex and discriminative exercises are expected. Other studies will be needed to further determine construct validity in the future.

Robotic surgery simulation validity and usability comparative analysis.

BACKGROUND: The introduction of simulation into minimally invasive robotic surgery is relatively recent and has seen rapid advancement; therefore, a need exists to develop training curriculums and identify systems that will be most effective at training surgical skills. Several simulators have been introduced to support these aims-the daVinci skills simulator, Mimic dV-Trainer, Surgical Simulated Systems' RoSS, and Simbionix Robotix Mentor. While multiple studies have been conducted to demonstrate the validity of these systems, studies comparing the perceived value of these devices as tools for education and skills are lacking. METHODS: Subjects who qualified as medical students or physicians (n = 105) were assigned a specific order to use each of the three simulators. After completing a demographic questionnaire, participants performed one exercise on the three simulators and completed a second questionnaire regarding their experience with the device. After using all systems, they completed a final questionnaire, which detailed their comparative preferences. The subject's performance metrics were also collected from each simulator. RESULTS: The data confirmed the face, content, and construct validity for the dV-trainer and skills simulator. Similar validities could not be confirmed for the RoSS. >80 % of the time, participants chose the skills simulator in terms of physical comfort, ergonomics, and overall choice. However, only 55 % thought the skills simulator was worth the cost of the equipment. The dV-Trainer had the highest cost preference scores with 71 % of respondents feeling it was worth the investment. CONCLUSIONS: Usability can affect the consistency and commitment of users of robotic surgical simulators. In a previous study, these simulators were objectively reviewed and compared in terms of their system capabilities. Collectively, this work will offer end-users and potential buyers a comparison of the perceived value and preferences of robotic simulators.

The olfactory fascia: an evo-devo concept of the fibrocartilaginous nose.

PURPOSE: Evo-devo is the science that studies the link between evolution of species and embryological development. This concept helps to understand the complex anatomy of the human nose. The evo-devo theory suggests the persistence in the adult of an anatomical entity, the olfactory fascia, that unites the cartilages of the nose to the olfactory mucosa. METHODS: We dissected two fresh specimens. After resecting the superficial tissues of the nose, dissection was focused on the disarticulation of the fibrocartilaginous noses from the facial and skull base skeleton. RESULTS: Dissection shows two fibrocartilaginous sacs that were invaginated side-by-side in the midface and attached to the anterior skull base. These membranous sacs were separated in the midline by the perpendicular plate of the ethmoid. Their walls contained the alar cartilages and the lateral expansions of the septolateral cartilage, which we had to separate from the septal cartilage. The olfactory mucosa was located inside their cranial ends. CONCLUSION: The olfactory fascia is a continuous membrane uniting the nasal cartilages to the olfactory mucosa. Its origin can be found in the invagination and differentiation processes of the olfactory placodes. The fibrous portions of the olfactory fascia may be described as ligaments that unit the different components of the olfactory fascia one to the other and the fibrocartilaginous nose to the facial and skull base skeleton. The basicranial ligaments, fixing the fibrocartilaginous nose to the skull base, represent key elements in the concept of septorhinoplasty by disarticulation.

Analysis of the position of the branches of the ulnar nerve in Guyon's canal using high-resolution MRI in positions adopted by cyclists.

PURPOSE: To study variations in the anatomical relationships of the branches of the ulnar nerve in Guyon's canal relative to the hamulus of hamate (HH) in a grip encountered among cyclists. MATERIALS AND METHODS: Forty-seven wrist examinations were performed on a 3-T MRI (soft antenna, 16 channels) in propeller sequence in the plane perpendicular to the carpus in 28 healthy volunteers in three cycling positions (neutral, hyperextension and ulnar deviation). The positions and distance between the superficial (SB) and deep (DB) branches of the ulnar nerve with respect to the HH were determined on the section passing through the HH. RESULTS: The mean distances between the SB (d s) and DP (d p) and HH were 2.4 and 0.6 mm, respectively. The d s in hyperextension and ulnar deviation were 2.2 mm (P = 0.3) and 3 mm (P = 0.07), respectively. The d p in hyperextension and ulnar deviation were 0.3 mm (P = 0.02) and 0.5 mm (P = 0.15), respectively. Hyperextended, 60 % of SB and 40 % of DB were close to the HH, and 26 % of DB came directly in contact with it. In ulnar deviation, 30 % of SB and 29 % of DB approached HH, and 47 % of DB were in contact with it. CONCLUSION: This study shows that SB and DB positions of the ulnar nerve vary with respect to the HH depending on the position of the wrist, and such differences may promote Guyon's canal syndrome in cyclists.

Comparative analysis of the functionality of simulators of the da Vinci surgical robot.

BACKGROUND: The implementation of robotic technology in minimally invasive surgery has led to the need to develop more efficient and effective training methods, as well as assessment and skill maintenance tools for surgical education. Multiple simulators and procedures are available for educational and training purposes. A need for comparative evaluations of these simulators exists to aid users in selecting an appropriate device for their purposes. METHODS: We conducted an objective review and comparison of the design and capabilities of all dedicated simulators of the da Vinci robot, the da Vinci Skill Simulator (DVSS) (Intuitive Surgical Inc., Sunnyvale, CA, USA), dV-Trainer (dVT) (Mimic Technologies Inc., Seattle, WA, USA), and Robotic Surgery Simulator (RoSS) (Simulated Surgical Skills, LLC, Williamsville, NY, USA). This provides base specifications of the hardware and software, with an emphasis on the training capabilities of each system. RESULTS: Each simulator contains a large number of training exercises, DVSS = 40, dVT = 65, and RoSS = 52 for skills development. All three offer 3D visual images but use different display technologies. The DVSS leverages the real robotic surgeon's console to provide visualization, hand controls, and foot pedals. The dVT and RoSS created simulated versions of all of these control systems. They include systems management services which allow instructors to collect, export, and analyze the scores of students using the simulators. CONCLUSIONS: This study is the first to provide comparative information of the three simulators functional capabilities with an emphasis on their educational skills. They offer unique advantages and capabilities in training robotic surgeons. Each device has been the subject of multiple validation experiments which have been published in the literature. But those do not provide specific details on the capabilities of the simulators which are necessary for an understanding sufficient to select the one best suited for an organization's needs.

Determination of the latency effects on surgical performance and the acceptable latency levels in telesurgery using the dV-Trainer(®) simulator.

BACKGROUND: The primary limitation of telesurgery is the communication latency. Accurate and detailed data are lacking to reveal the latency effects on surgical performance; furthermore, the maximum acceptable latency in telesurgery remains unclear. METHODS: Sixteen medical students performed an energy dissection exercise and a needle-driving exercise on the robotic simulator dV-Trainer(®), and latencies varying between 0 and 1,000 ms with a 100-ms interval were randomly and blindly presented. Task completion time, instrument motion, and errors were automatically recorded. The difficulty, security, precision, and fluidity of manipulation were self-scored by subjects between 0 and 4 (0 the best, 2 moderate, and 4 the worst). RESULTS: Task completion time, motion, and errors increased gradually as latency increased. An exponential regression was fit to the mean times and motions (R (2) > 0.98). Subjective scorings of the four items were similar. The mean scores were less than 1 at delays ≤200 ms, then increased from 1 to 2 at 300-700 ms, and finally approached 3 at delays above. In both exercises, latencies ≤300 ms were judged to be safe by all and 400-500 ms were accepted by 66-75 % of subjects. Less than 20 % of subjects accepted delays ≥800 ms. CONCLUSIONS: The surgical performance deteriorates in an exponential way as the latency increases. The delay impact on instrument manipulation is mild at 0-200 ms, then increases from small to large at 300-700 ms, and finally becomes very large at 800-1,000 ms. Latencies ≤200 ms are ideal for telesurgery; 300 ms is also suitable; 400-500 ms may be acceptable but are already tiring; and 600-700 ms are difficult to deal with and only acceptable for low risk and simple procedures. Surgery is quite difficult at 800-1,000 ms, telementoring would be a better choice in this case.

Reconstruction of the ulnar artery in Guyon's canal with an arterial graft: Anatomical study.

Ulnar artery thrombosis in Guyon's canal can lead to vascular insufficiency in the fingers. The recommended treatment is resection and reconstruction of the pathological area. A bypass may be necessary, which may be venous or arterial. Arterial bypasses have better long-term patency; however, they are a source of donor-site complications. We carried out an anatomical study on 11 upper limbs and 7 lower limbs from cadavers to identify a technically accessible arterial graft, of a diameter suitable for bypassing the ulnar artery in Guyon's canal and with acceptable scar sequelae (few predicted postoperative complications, discreet size and/or location of scar). Three grafts were considered: anterior interosseous artery, radial recurrent artery and descending genicular artery. The various grafts were dissected and harvested from cadaver specimens, then their lengths and diameters were measured. The diameter of the candidate grafts was compared to the diameter of the distal ulnar artery. The diameter of the descending genicular artery matched the ulnar artery better than the radial recurrent artery or the anterior interosseous artery (103% vs 44% and 67%, respectively). Mean graft length was 6.6 cm. The anatomical configuration of the descending genicular artery allowed Y-shaped bypasses to be performed. Harvesting this artery appears to cause little damage and allows bypasses up to 6 cm to be performed. Despite its smaller diameter making it necessary to perform a microvascular size adjustment, the anterior interosseous artery is a candidate graft because it is long enough (119 mm) and located near the surgical site. LEVEL OF EVIDENCE: V.