Design and evaluation of a smart passive dynamic arm support for robotic-assisted laparoscopic surgery.

Surgeons performing robotic-assisted laparoscopic surgery experience physical stress and overuse of shoulder muscles due to sub-optimal arm support during surgery. The objective is to present a novel design and prototype of a dynamic arm support for robotic laparoscopic surgery to evaluate its ergonomics and performance on the AdLap-VR simulation training device. The prototype was designed using the mechanical engineering design process: Technical requirements, concept creation, concept selection, 3D-design and built of the prototype. A crossover study was performed on a marble sorting task on the AdLap-VR. The first group performed four trials without the arm support, followed by four trials with the arm support, and the other group executed the sequence vice versa. The performance parameters used were time to complete (s), path length (mm), and the number of collisions. Afterward, the participants filled out a questionnaire on the ergonomic experience regarding both situations. 20 students executed 160 performed trials on the AdLap-VR Significant decreases in the subjective comfort parameters mental demand, physical demand, effort and frustration were observed as a result of introducing the novel arm support. Significant decreases in the objective performance parameters path length and the number of collisions were also observed during the tests. The newly developed dynamic arm support was found to improve comfort and enhance performance through increased stability on the robotic surgery skills simulator AdLap-VR.

Robot-assisted pelvic floor reconstructive surgery: an international Delphi study of expert users.

BACKGROUND: Robotic surgery has gained popularity for the reconstruction of pelvic floor defects. Nonetheless, there is no evidence that robot-assisted reconstructive surgery is either appropriate or superior to standard laparoscopy for the performance of pelvic floor reconstructive procedures or that it is sustainable. The aim of this project was to address the proper role of robotic pelvic floor reconstructive procedures using expert opinion. METHODS: We set up an international, multidisciplinary group of 26 experts to participate in a Delphi process on robotics as applied to pelvic floor reconstructive surgery. The group comprised urogynecologists, urologists, and colorectal surgeons with long-term experience in the performance of pelvic floor reconstructive procedures and with the use of the robot, who were identified primarily based on peer-reviewed publications. Two rounds of the Delphi process were conducted. The first included 63 statements pertaining to surgeons' characteristics, general questions, indications, surgical technique, and future-oriented questions. A second round including 20 statements was used to reassess those statements where borderline agreement was obtained during the first round. The final step consisted of a face-to-face meeting with all participants to present and discuss the results of the analysis. RESULTS: The 26 experts agreed that robotics is a suitable indication for pelvic floor reconstructive surgery because of the significant technical advantages that it confers relative to standard laparoscopy. Experts considered these advantages particularly important for the execution of complex reconstructive procedures, although the benefits can be found also during less challenging cases. The experts considered the robot safe and effective for pelvic floor reconstruction and generally thought that the additional costs are offset by the increased surgical efficacy. CONCLUSION: Robotics is a suitable choice for pelvic reconstruction, but this Delphi initiative calls for more research to objectively assess the specific settings where robotic surgery would provide the most benefit.

Validation of the portable virtual reality training system for robotic surgery (PoLaRS): a randomized controlled trial.

BACKGROUND: As global use of surgical robotic systems is steadily increasing, surgical simulation can be an excellent way for robotic surgeons to acquire and retain their skills in a safe environment. To address the need for training in less wealthy parts of the world, an affordable surgical robot simulator (PoLaRS) was designed. METHODS: The aim of this pilot study is to compare learning curve data of the PoLaRS prototype with those of Intuitive Surgical's da Vinci Skills Simulator (dVSS) and to establish face- and construct validity. Medical students were divided into two groups; the test group (n = 18) performing tasks on PoLaRS and dVSS, and the control group (n = 20) only performing tasks on the dVSS. The performance parameters were Time, Path length, and the number of collisions. Afterwards, the test group participants filled in a questionnaire regarding both systems. RESULTS: A total of 528 trials executed by 38 participants were measured and included for analyses. The test group significantly improved in Time, Path Length and Collisions during the PoLaRS test phase (P ≤ 0.028). No differences was found between the test group and the control group in the dVSS performances during the post-test phase. Learning curves showed similar shapes between both systems, and between both groups. Participants recognized the potential benefits of simulation training on the PoLaRS system. CONCLUSIONS: Robotic surgical skills improved during training with PoLaRS. This shows the potential of PoLaRS to become an affordable alternative to current surgical robot simulators. Validation with similar tasks and different expert levels is needed before implementing the training system into robotic training curricula.

The rectal remnant after total colectomy for colitis - intra-operative,post-operative and longer-term considerations.

OBJECTIVES: Acute severe colitis requires surgery in around 30% of the cases. Total colectomy with ileostomy is the standard procedure with distinct advantages to a laparoscopic approach. Less agreement exists regarding the formation or configuration of the retained rectal stump and its short-term and long-term management. In this review, aspects of management of the rectal remnant, including perioperative considerations, potential complications, medical treatment, surveillance and implications for proctectomy and reconstructive surgery are explored. METHODS: A thorough literature review exploring the PubMed and EMBASE databases was undertaken to clarify the evidence base surrounding areas of controversy in the surgical approach to acute severe colitis. In particular, focus was given to evidence surrounding management of the rectal remnant. RESULTS: There is a paucity of high quality evidence for optimal management of the rectal stump following colectomy, and randomised trials are lacking. Establishment of laparoscopic colectomy has been associated with distinct advantages as well as the emergence of unique considerations, including those specific to rectal remnant management. CONCLUSIONS: Early surgical involvement and a multidisciplinary approach to the management of acute severe colitis are advocated. Laparoscopic subtotal colectomy and ileostomy should be the operation of choice, with division of the rectum at the pelvic brim leaving a closed intraperitoneal remnant. If the rectum is severely inflamed, a mucus fistula may be useful, and an indwelling rectal catheter is probably advantageous to reduce the complications associated with stump dehiscence. Patients electing not to proceed to proctectomy should undergo surveillance for dysplasia of the rectum.

Transanal total mesorectal excision for rectal cancer: the journey towards a new technique and its current status.

INTRODUCTION: The surgical approach to total mesorectal excision (TME) for rectal cancer has undergone a substantial evolution with the adoption of more minimally invasive procedures. Transanal TME (taTME) is the latest advanced technique pioneered to tackle difficult pelvic dissections. Areas covered: The evolution of TME surgery from open to laparoscopic, robotic and transanal techniques was explored in this review. The outcomes to date on the latest approach, taTME, are reviewed and the future direction of rectal cancer surgery proposed. A literature search was performed using Embase, Medline, Web of Science and Cochrane databases for articles published between January 2005 to May 2016 using the keywords 'transanal', 'TME', 'laparoscopy', 'robotics', 'minimally invasive', 'outcomes' and 'training'. Expert commentary: Surgical experience in taTME is growing and randomised controlled trials have been planned and initiated worldwide. However, the learning curve for this procedure remains to be established and a structured training programme is necessary to ensure safe introduction and dissemination of the technique in the clinical setting. Further innovation including stereotactic navigation and more specialised transanal equipment are currently being explored and are likely to enhance the technique further.

Transanal total mesorectal excision: Myths and reality.

Transanal total mesorectal excision (TaTME) is a new and promising approach for the treatment of rectal cancer. Whilst the experience is still limited, there are growing evidences that this approach might overcome the limits of standard low anterior resection. TaTME might help to decrease the conversion rate especially in difficult patients, and to improve the pathological results, while preserving the urogenital function. Evaluation of data from large registries and randomized studies should help to draw firmer conclusions. Beyond these technical considerations, the next challenge seems to be clearly the safe introduction of this approach, motivating the development of dedicated courses.

Intestinal stem cells and intestinal homeostasis in health and in inflammation: A review.

BACKGROUND: The human intestine is a complex group of organs, highly specialized in processing food and providing nutrients to the body. It is under constant threat from microbials and toxins and has therefore developed a number of protective mechanisms. One important mechanism is the constant shedding of epithelial cells into the lumen; another is the production and maintenance of a double-layered mucous boundary in which there is continuous sampling of the luminal microbiota and a persistent presence of antimicrobial enzymes. However, the gut needs commensal bacteria to effectively break down food into absorbable nutrients, which necessitates constant communication between the luminal bacteria and the intestinal immune cells in homeostasis. Disruption of homeostasis, for whatever reason, will give rise to (chronic) inflammation. DISCUSSION: Both medical and surgical management of this disruption is discussed.

Dynamic Article: Permanent Sacral Nerve Stimulation Under Local Anesthesia: Feasibility, Best Practice, and Patient Satisfaction.

BACKGROUND: The increasing incidence of fecal incontinence and the use of sacral neuromodulation have an increasing impact on health care providers and health care costs. OBJECTIVE: The purpose of this study was to investigate the technical and clinical success rates, complications, and patient satisfaction of the implantation of permanent sacral nerve stimulation under local anesthesia. DESIGN: A cohort analysis of consecutive patients with sacral nerve stimulation for fecal incontinence over a period of 1 year was performed. SETTINGS: This study was conducted at a specialized pelvic floor unit in a tertiary care center. PATIENTS: Sixty-one patients were available for the assessment after 1-year follow-up. MAIN OUTCOME MEASURES: Technical success, procedural time, and complications were noted. Clinical outcome (including Fecal Incontinence Severity Index, Fecal Incontinence Quality of Life scale, and Gastrointestinal Quality of Life Index were collected prospectively before and after treatment. RESULTS: All procedures were successfully completed under local anesthesia, with a median total procedural time of 50 minutes (range, 26-72 minutes). All patients were discharged on the day of their procedure. Postoperative complications occurred in 3 patients (4.9%). At 3 months follow-up, the median Fecal Incontinence Severity Index score was reduced from 37 to 27 (p = 0.001). Both the Fecal Incontinence Quality of Life scale and the Gastrointestinal Quality of Life Index had improved from 63 to 82 (p < 0.001) and 72 to 90 (p = 0.012). At a mean follow-up of 13 months, both the Fecal Incontinence Quality of Life scale and the Gastrointestinal Quality of Life Index improved further to 90 (p < 0.001) and 94 (p < 0.001). All patients would recommend the procedure under local anesthesia to other patients. No patients experienced leg pain during follow-up. LIMITATIONS: This study involved a relatively small group of patients, and patient satisfaction was only recorded for the last 22 patients. No exact cost calculations were made. CONCLUSIONS: Permanent sacral nerve stimulation implantation under local anesthesia has high technical and clinical success rates. It is safe, well tolerated by patients, and has obvious logistical and financial benefits.

Colonization and transmission of meticillin-susceptible and meticillin-resistant Staphylococcus aureus in a murine nasal colonization model.

Nasal colonization by Staphylococcus aureus is an important risk factor for the development of a nosocomial infection. Acquisition of nasal colonization by S. aureus increases mortality in hospitalized patients, but little is known about the transmission dynamics of S. aureus. To study S. aureus transmission, colonization and colonization persistence, we developed a murine transmission model. In 20 cages, 2 out of 10 mice were nasally inoculated (at 5×10(8) c.f.u. per mouse) with either meticillin-susceptible S. aureus (MSSA) (10 cages) or meticillin-resistant S. aureus (MRSA) (10 cages). On days 5, 15, 25 and 40, all mice in a cage were swabbed or sacrificed and nasal colonization and c.f.u. were determined in all 10 mice by nasal dissection or by nasal swab. Spread and subsequent stable colonization by both MSSA and MRSA from colonized to uncolonized mice within a cage was seen. At day 5, an increased number of colonized mice were observed in the MSSA group compared to the MRSA group (P = 0.003). On day 40, the mean number of c.f.u. per mouse was higher for MRSA than for MSSA (P = 0.06). Faecal-oral transmission was shown to be a possibly important transmission route in this model. These results suggest a more rapid spread of MSSA compared to MRSA. However, MRSA shows a more stable nasal colonization after a longer period of time.

Methicillin resistance transfer from Staphylocccus epidermidis to methicillin-susceptible Staphylococcus aureus in a patient during antibiotic therapy.

BACKGROUND: The mecA gene, encoding methicillin resistance in staphylococci, is located on a mobile genetic element called Staphylococcal Cassette Chromosome mec (SCCmec). Horizontal, interspecies transfer of this element could be an important factor in the dissemination of methicillin-resistant S. aureus (MRSA). Previously, we reported the isolation of a closely related methicillin-susceptible Staphylococcus aureus (MSSA), MRSA and potential SCCmec donor Staphylococcus epidermidis isolate from the same patient. Based on fingerprint techniques we hypothesized that the S. epidermidis had transferred SCCmec to the MSSA to become MRSA. The aim of this study was to show that these isolates form an isogenic pair and that interspecies horizontal SCCmec transfer occurred. METHODOLOGY/RESULTS: Whole genome sequencing of both isolates was performed and for the MSSA gaps were closed by conventional sequencing. The SCCmec of the S. epidermidis was also sequenced by conventional methods. The results show no difference in nucleotide sequence between the two isolates except for the presence of SCCmec in the MRSA. The SCCmec of the S. epidermidis and the MRSA are identical except for a single nucleotide in the ccrB gene, which results in a valine to alanine substitution. The main difference with the closely related EMRSA-16 is the presence of SaPI2 encoding toxic shock syndrome toxin and exfoliative toxin A in the MSSA-MRSA pair. No transfer of SCCmec from the S. epidermidis to the MSSA could be demonstrated in vitro. CONCLUSION: The MSSA and MRSA form an isogenic pair except for SCCmec. This strongly supports our hypothesis that the MRSA was derived from the MSSA by interspecies horizontal transfer of SCCmec from S. epidermidis O7.1.

Acquisition and cross-transmission of Staphylococcus aureus in European intensive care units.

OBJECTIVE: To study the acquisition and cross-transmission of Staphylococcus aureus in different intensive care units (ICUs). METHODS: We performed a multicenter cohort study. Six ICUs in 6 countries participated. During a 3-month period at each ICU, all patients had nasal and perineal swab specimens obtained at ICU admission and during their stay. All S. aureus isolates that were collected were genotyped by spa typing and multilocus variable-number tandem-repeat analysis typing for cross-transmission analysis. A total of 629 patients were admitted to ICUs, and 224 of these patients were found to be colonized with S. aureus at least once during ICU stay (22% were found to be colonized with methicillin-resistant S. aureus [MRSA]). A total of 316 patients who had test results negative for S. aureus at ICU admission and had at least 1 follow-up swab sample obtained for culture were eligible for acquisition analysis. RESULTS: A total of 45 patients acquired S. aureus during ICU stay (31 acquired methicillin-susceptible S. aureus [MSSA], and 14 acquired MRSA). Several factors that were believed to affect the rate of acquisition of S. aureus were analyzed in univariate and multivariate analyses, including the amount of hand disinfectant used, colonization pressure, number of beds per nurse, antibiotic use, length of stay, and ICU setting (private room versus open ICU treatment). Greater colonization pressure and a greater number of beds per nurse correlated with a higher rate of acquisition for both MSSA and MRSA. The type of ICU setting was related to MRSA acquisition only, and the amount of hand disinfectant used was related to MSSA acquisition only. In 18 (40%) of the cases of S. aureus acquisition, cross-transmission from another patient was possible. CONCLUSIONS: Colonization pressure, the number of beds per nurse, and the treatment of all patients in private rooms correlated with the number of S. aureus acquisitions on an ICU. The amount of hand disinfectant used was correlated with the number of cases of MSSA acquisition but not with the number of cases of MRSA acquisition. The number of cases of patient-to-patient cross-transmission was comparable for MSSA and MRSA.

Cyclooxygenase-2 is a target of KRASD12, which facilitates the outgrowth of murine C26 colorectal liver metastases.

PURPOSE: Mutational activation of the KRAS oncogene and overexpression of cyclooxygenase-2 (COX-2) contribute to colorectal carcinoma (CRC) development, but the relationship between these two events is unclear. This study was designed to clarify that relationship and to assess the contribution of KRAS-dependent COX-2 to the seeding of CRC cells in the liver and to their outgrowth as liver metastases in an experimental mouse model. EXPERIMENTAL DESIGN: The effect of RNA interference-mediated KRAS knockdown on COX-2 expression and activity was tested in murine C26 CRC cells. The contribution of KRAS-dependent COX-2 to early metastatic tumor cell seeding (by intravital microscopy) and outgrowth of metastases in the liver (by bioluminescence imaging) was studied by using parecoxib, a novel and highly selective liver-activated COX-2 inhibitor. Intratumoral cell proliferation, apoptosis, and tumor-associated angiogenesis were assessed by immunohistochemistry on liver tissue sections. RESULTS: Stable knockdown of mutant KRAS(D12) in murine C26 CRC cells by RNA interference lead to a dramatic reduction of COX-2 synthesis and prostaglandin E2 production. Inhibition of host or tumor cell COX-2 activity had no effect on early metastatic cell seeding in the liver but greatly reduced intrahepatic tumor cell proliferation and the rate of liver metastasis outgrowth. COX-2 inhibition had no effect on early tumor vascularization or on tumor cell apoptosis. CONCLUSIONS: The high levels of COX-2 enzyme and prostaglandin production in C26 CRC cells are primarily caused by the presence of endogenous mutant KRAS(D12). Furthermore, COX-2 inhibition affects the tumoral rather than the vascular compartment during the early stages of C26 liver metastasis outgrowth.