Effects of surgical flow disruptions on surgeons' resources: a pilot study.

BACKGROUND: Minimally invasive surgery requires surgeons to allocate more attention and efforts than open surgery. A surgeon's pool of resource is affected by the multiple occurrences of interruptions and distractions in the operating room. Surgical flow disruption has been addressed from a quantitative perspective. However, little is known on its impact on the surgeons' physiological resources. METHODS: Three physiological markers, heat flux (HF), energy expenditure in metabolic equivalent of tasks and galvanic skin response were recorded using body sensor monitoring during the 21 surgical operations. The three markers, respectively, represent: stress, energy mobilization and task engagement. A total of 8 surgeons with different levels of expertise (expert vs. novice) were observed performing 21 surgical procedures categorized as short versus long. Factors of distractions were time-stamped, and triangulated with physiological markers. Two cases illustrate the impact of surgical flow disruptions on the surgeons. RESULTS: The results indicate that expert surgeons' mental schemata are better organized than novices. Additionally, the physiological markers indicate that novice surgeons display a higher HF at the start (tendency p = .059) and at the end of procedures (p = .001) when compared to experts. However, during longer procedures, expert surgeons have higher HF at the start (p = .041) and at the end (p = .026), than at the start and end of a short procedure. CONCLUSION: Data collected during this pilot study showed that interruptions and disruptions affect novice and expert surgeons differently. Surgical flow disruption appears to be taxing on the surgeons' mental, emotional and physiological resources; as a function of the length and nature of the disruptions. Several training curricula have incorporated the use of virtual reality programs to train surgeons to cope with the new technology and equipment. We recommend integrating interruptions and distractions in virtual reality training programs as these impact the surgeons' pool of resources.

Identification of technical errors and hazard zones in sleeve gastrectomy using OCHRA : "OCHRA for sleeve gastrectomy".

BACKGROUND: The sleeve gastrectomy is an example of minimally invasive surgery. It is important to determine the critical steps of the procedure in order to reduce complications and increase safety and efficiency. OBJECTIVE: The aim of this study was to detect the key elements of the sleeve gastrectomy and find the potential hazard zones of the procedure. SETTING: Bariatric department of a large teaching hospital in the Netherlands. METHODS: A prospective clinical observation study was performed including 60 sleeve gastrectomy procedures. An expert panel determined the key steps, and two experts assessed the procedures systematically for technical errors according to the principles of Observational Clinical Human Reliability Assessment (OCHRA). RESULTS: A total of 213 technical errors have been made, and the majority were made during mobilization of the greater curvature and during stapling of the stomach. In 44.6 %, errors had consequences and 96 additional actions were performed. There was a significant correlation between errors during opening of the lesser sac and postoperative complications, and between repositioning of the stapler and postoperative complications. CONCLUSIONS: In this study, the 13 key steps of the SG were defined, and OCHRA was considered a valuable assessment tool for surgical performance and potential hazard zones. Most consequential errors are made during dissection of the greater curvature and during stapling of the stomach. Errors during the start of mobilization of the greater curvature and repositioning of the stapler lead to longer duration of the procedure and are associated with a higher risk of postoperative complications.

Grasping soft tissue by means of vacuum technique.

INTRODUCTION: A notable characteristic of bariatric surgery is the frequent manipulation of the bowel. The bowel is large, delicate, flexible, and has a natural lubricant on the tissue surface. Therefore the bowel is difficult to grasp and manipulate. Vacuum technique is commonly used in industry for all types of grasping and manipulation. Two types of nozzles that differed slightly in geometry (NT1 and NT2), were reviewed in an experimental set up for pull tests on pig bowels. MATERIALS AND METHODS: An experimental set-up was used to conduct a series of pull tests on pig bowel tissue. The basic principle of the measurements was a Newton's force balance; F(Pmax)=Δp×A. Student t-tests, two-way ANOVA and Wilcoxon signed rank tests were conducted for the statistical analysis of NT1 and NT2 with regard to the maximum pull force (F(Pmax)). RESULTS: Concerning NT1 the Newton's force balance could not be confirmed. Concerning NT2 the Newton's force balance could partly be confirmed. For both nozzle types the effect of Δp on F(Pmax) was significant. F(Pmax) increases linear in proportion as Δp increases. This relation between F(Pmax) and Δp was confirmed by the Newton's force balance. DISCUSSION: The results confirm that vacuum technique can be used as a grasp technique for soft organs, particularly the bowels. By means of a clever design of the nozzle a firm grip can be obtained on the bowel segments. Therefore vacuum technique should be studied for further development of instruments, graspers and retractors, to be used in the abdominal area.

Visuo-spatial ability in colonoscopy simulator training.

Visuo-spatial ability is associated with a quality of performance in a variety of surgical and medical skills. However, visuo-spatial ability is typically assessed using Visualization tests only, which led to an incomplete understanding of the involvement of visuo-spatial ability in these skills. To remedy this situation, the current study investigated the role of a broad range of visuo-spatial factors in colonoscopy simulator training. Fifteen medical trainees (no clinical experience in colonoscopy) participated in two psycho-metric test sessions to assess four visuo-spatial ability factors. Next, participants trained flexible endoscope manipulation, and navigation to the cecum on the GI Mentor II simulator, for four sessions within 1 week. Visualization, and to a lesser degree Spatial relations were the only visuo-spatial ability factors to correlate with colonoscopy simulator performance. Visualization additionally covaried with learning rate for time on task on both simulator tasks. High Visualization ability indicated faster exercise completion. Similar to other endoscopic procedures, performance in colonoscopy is positively associated with Visualization, a visuo-spatial ability factor characterized by the ability to mentally manipulate complex visuo-spatial stimuli. The complexity of the visuo-spatial mental transformations required to successfully perform colonoscopy is likely responsible for the challenging nature of this technique, and should inform training- and assessment design. Long term training studies, as well as studies investigating the nature of visuo-spatial complexity in this domain are needed to better understand the role of visuo-spatial ability in colonoscopy, and other endoscopic techniques.

Vacuum grasping as a manipulation technique for minimally invasive surgery.

BACKGROUND: Laparoscopic surgery requires specially designed instruments. Bowel tissue damage is considered one of the most serious forms of lesion, specifically perforation of the bowel. METHODS: An experimental setting was used to manipulate healthy pig bowel tissue via two vacuum instruments. During the experiments, two simple manipulations were performed for both prototypes by two experienced surgeons. Each manipulation was repeated 20 times for each prototype at a vacuum level of 60 kPa and 20 times for each prototype at a vacuum level of 20 kPa. All the manipulations were macroscopically assessed by two experienced surgeons in terms of damage to the bowel. RESULTS: In 160 observations, 63 ecchymoses were observed. All 63 ecchymoses were classified as not relevant and negligible. No serosa or seromuscular damages and no perforations were observed. CONCLUSION: Vacuum instruments such as the tested prototypes have the potential to be used as grasper instruments in minimally invasive surgery.

Meaningful assessment method for laparoscopic suturing training in augmented reality.

BACKGROUND: To be an effective training tool, a laparoscopic simulator has to provide metrics that are meaningful and informative to the trainee. Time, path length and smoothness are often used parameters, but are not very informative on the quality of the performance. This study aims to validate a newly developed assessment method for laparoscopic suturing on the ProMIS augmented reality simulator, and compares it with scores of objective observers. METHODS: Twenty-four participants practised their suturing skills on the augmented reality suturing module: experienced participants (n = 10), >50 clinical laparoscopic suturing experience; and novice participants (n = 14), without laparoscopic experience. The performances were recorded and assessed by two unrelated observers and compared with the assessment scores. The assessment score was a calculation of time spent in the correct area and quality (strength) of the knot. To test the accuracy of the individual assessment parameters, we compared these with each other. RESULTS: The experienced participants had significantly higher performance scores than the novice participants in the beginner-level mode (mean 95.73 vs. 60.89, standard deviation 2.63 vs. 17.09, p < 0.001, independent t-test). The performance scores of the assessment method (n = 43) correlated significantly with the scorings of the objective observers (Spearman's rho 0.672; p < 0.001). The parameter time spent in correct area had a calculated significant correlation with the strength of the knot (n = 229, Spearman's rho 0.257, p < 0.001), but this was clinically irrelevant. CONCLUSION: This assessment method is a valid tool for objectively assessing laparoscopic suturing skills. Although assessment parameters can correlate, to provide informative feedback it is important to combine meaningful measurements in the assessment of suturing skills.

Suturing training in Augmented Reality: gaining proficiency in suturing skills faster.

BACKGROUND: Providing informative feedback and setting goals tends to motivate trainees to practice more extensively. Augmented Reality simulators retain the benefit of realistic haptic feedback and additionally generate objective assessment and informative feedback during the training. This study researched the performance curve of the adapted suturing module on the ProMIS Augmented Reality simulator. METHODS: Eighteen novice participants were pretrained on the MIST-VR to become acquainted with laparoscopy. Subsequently, they practiced 16 knots on the suturing module, of which the assessment scores were recorded to evaluate the gain in laparoscopic suturing skills. The scoring of the assessment method was calculated from the "time spent in the correct area" during the knot tying and the quality of the knot. Both the baseline knot and the knot at the top of the performance curve were assessed by two independent objective observers, by means of a standardized evaluation form, to objectify the gain in suturing skills. RESULTS: There was a statistically significant difference between the scores of the second knot (mean 72.59, standard deviation (SD) 16.28) and the top of the performance curve (mean 95.82, SD 3.05; p < 0.001, paired t-test). The scoring of the objective observers also differed significantly (mean 11.83 and 22.11, respectively; SD 3.37 and 3.89, respectively; p < 0.001) (interobserver reliability Cronbach's alpha = 0.96). The median amount of repetitions to reach the top of the performance curve was eight, which also showed significant differences between both the assessment score (mean 88.14, SD 13.53, p < 0.001) and scoring of the objective observers of the second knot (mean 20.51, SD 4.14; p < 0.001). CONCLUSIONS: This adapted suturing module on the ProMIS Augmented Reality laparoscopic simulator is a potent tool for gaining laparoscopic suturing skills.

Face validity study of the ProMIS augmented reality laparoscopic suturing simulator.

To prevent unnecessary mistakes and avoidable complications in laparoscopic surgery, there has to be proper training. A safe way to train surgeons for laparoscopy is simulation. This study addresses the face validity of ProMIS, an Augmented Reality laparoscopic simulator, as a tool for training suturing skills in laparoscopic surgery. A two-paged, 12-item structured questionnaire, using a five-point-Likert scale, was presented to 50 surgeons/surgical interns. The participants were allotted to two groups: an "expert" (>50 procedures; N=23) and a referent group (<50 procedures; N=27). Non-parametric statistics were used to determine statistical differences. General consensus existed in both expert and referent groups, delineating ProMIS as a useful tool in teaching suturing skills surgeons/surgical interns (mean + or - st dev, resp, score 4.91 + or - 0.42 and 4.93 + or - 0.38) with regard to realism, tactile feedback, and suturing techniques. Significant differences in opinion regarding the ergonomics and design of ProMIS between the expert and referent groups existed. The ProMIS Augmented Reality laparoscopic simulator is regarded as a useful tool in laparoscopic training in both expert and referent groups. Although significant differences in opinion existed with regards to ergonomics and design of ProMIS, they were present between experts and novices.

Haptics in minimally invasive surgery--a review.

This article gives an overview of research performed in the field of haptic information feedback during minimally invasive surgery (MIS). Literature has been consulted from 1985 to present. The studies show that currently, haptic information feedback is rare, but promising, in MIS. Surgeons benefit from additional feedback about force information. When it comes to grasping forces and perceiving slip, little is known about the advantages additional haptic information can give to prevent tissue trauma during manipulation. Improvement of haptic perception through augmented haptic information feedback in MIS might be promising.

Acquiring basic endoscopy skills by training on the GI Mentor II.

BACKGROUND: Achieving proficiency in flexible endoscopy requires a great amount of practice. Virtual reality (VR) simulators could provide an effective alternative for clinical training. This study aimed to gain insight into the proficiency curve for basic endoscope navigation skills with training on the GI Mentor II. METHODS: For this study, 30 novice endoscopists performed four preset training sessions. In each session, they performed one EndoBubble task and managed multiple VR colonoscopy cases (two in first session and three in subsequent sessions). Virtual reality colonoscopy I-3 was repeatedly performed as the last VR colonoscopy in each session. The assignment for the VR colonoscopies was to visualize the cecum as quickly as possible without causing patient discomfort. Five expert endoscopists also performed the training sessions. Additionally, the performance of the novices was compared with the performance of 20 experienced and 40 expert endoscopists. RESULTS: The novices progressed significantly, particularly in the time required to accomplish the tasks (p < 0.05, Friedman's analysis of variance [ANOVA], p < 0.05, Wilcoxon signed ranks). The experts did not improve significantly, except in the percentage of time the patient was in excessive pain. For all the runs, the performance of the novices differed significantly from that of both the experienced and the expert endoscopists (p < 0.05, Mann-Whitney U). The performance of the novices in the latter runs differed less from those of both the experienced and the expert endoscopists. CONCLUSIONS: The study findings demonstrate that training in both VR colonoscopy and EndoBubble tasks on the GI Mentor II improves the basic endoscope navigation skills of novice endoscopists significantly.

Reviewing the structural features of autologous platelet-leukocyte gel and suggestions for use in surgery.

The therapeutic use of autologously prepared platelet-leukocyte gel (PLG) is a relatively new technology which might stimulate and accelerate soft-tissue and bone healing. The effectiveness of this procedure lies in the exogenous delivery of a wide range of platelet growth factors, intentionally released from autologously prepared PLG. The rationale to employ this technique is to mimic physiological wound healing and reparative tissue processes. Despite an increase in clinical PLG applications, the structures and kinetics of this biological material have not been completely examined. Electron microscopic imaging was performed to evaluate platelet-leukocyte gel structures. Furthermore, directions for PLG application are presented, based on results from published articles in various surgical disciplines. In conclusion, PLG can be useful in a wide range of clinical applications to enhance healing following surgical procedures, since exogenous applied PLG releases instantly platelet growth factors, in the presence of leukocytic cells.

The use of autologous platelet-leukocyte gels to enhance the healing process in surgery, a review.

BACKGROUND: The therapeutic use of autologously prepared, platelet-leukocyte-enriched gel (PLG) is a relatively new technology for the stimulation and acceleration of soft tissue and bone healing. The effectiveness of this procedure lies in the delivery of a wide range of platelet growth factors mimicking the physiologic wound healing and reparative tissue processes. Despite an increase in PLG applications, the structures and kinetics of this autogenously derived biologic material have not been observed. METHODS: A review of the most recent literature was performed to evaluate the use of PLG in various surgical disciplines. RESULTS: The review showed that the application of PLG has been extended to various surgical disciplines including orthopedics, cardiac surgery, plastic and maxillofacial surgery, and recently also endoscopic surgery. CONCLUSION: This review demonstrates the usefulness of PLG in a wide range of clinical applications for improvement of healing after surgical procedures.

Laparoscopic cholecystectomy under segmental thoracic spinal anaesthesia: a feasibility study.

BACKGROUND: Laparoscopic surgery is normally performed under general anaesthesia, but regional techniques have been found beneficial, usually in the management of patients with major medical problems. Encouraged by such experience, we performed a feasibility study of segmental spinal anaesthesia in healthy patients. METHODS: Twenty ASA I or II patients undergoing elective laparoscopic cholecystectomy received a segmental (T10 injection) spinal anaesthetic using 1 ml of bupivacaine 5 mg ml-1 mixed with 0.5 ml of sufentanil 5 microg ml-1. Other drugs were only given (systemically) to manage patient anxiety, pain, nausea, hypotension, or pruritus during or after surgery. The patients were reviewed 3 days postoperatively by telephone. RESULTS: The spinal anaesthetic was performed easily in all patients, although one complained of paraesthesiae which responded to slight needle withdrawal. The block was effective for surgery in all 20 patients, six experiencing some discomfort which was readily treated with small doses of fentanyl, but none requiring conversion to general anaesthesia. Two patients required midazolam for anxiety and two ephedrine for hypotension. Recovery was uneventful and without sequelae, only three patients (all for surgical reasons) not being discharged home on the day of operation. CONCLUSIONS: This preliminary study has shown that segmental spinal anaesthesia can be used successfully and effectively for laparoscopic surgery in healthy patients. However, the use of an anaesthetic technique involving needle insertion into the vertebral canal above the level of termination of the spinal cord requires great caution and should be restricted in application until much larger numbers of patients have been studied.

Segmental spinal anaesthesia for cholecystectomy in a patient with severe lung disease.

Occasionally patients awaiting heart or lung transplant because of terminal disease require other types of surgery, but present significant challenges to the anaesthetist because of impaired organ function. Regional anaesthesia may have much to offer such patients and we here report one who underwent successfully a laparoscopic cholecystectomy under segmental subarachnoid (spinal) anaesthesia performed at the low thoracic level. The anatomical and physiological consequences of such a technique are discussed.

Intraoperative ultrasonography in open and laparoscopic abdominal surgery: an overview.

This article reviews the current state of intraoperative ultrasonography in open surgery (IOUS) and laparoscopic surgery (LUS). The review is based on extensive study of data published (Pubmed search) and on 25 years of personal experience with intraoperative ultrasonography. The main application areas of IOUS and LUS and its use during liver, biliary tract, and pancreatic surgery are discussed. The benefits and limitations as well as future expectations with regard to the existing and emerging applications also are discussed. New developments in ultrasound technology and the increasing experience of surgeons in ultrasonography secure the future for IOUS and LUS.

Determination of face validity for the Simbionix LAP mentor virtual reality training module.

This study determines the expert and referent face validity of LAP Mentor, the first procedural virtual-reality (VR) trainer. After a hands-on introduction to the simulator a questionnaire was administered to 49 participants (21 expert laparoscopists and 28 novices). There was a consensus on LAP Mentor being a valid training model for basic skills training and the procedural training of laparoscopic cholecystectomies. As 88% of respondents saw training on this simulator as effective and 96% experienced this training as fun it will likely be accepted in the surgical curriculum by both experts and trainees. Further validation of the system is required to determine whether its performance concurs with these favourable expectations.

Consensus guidelines for validation of virtual reality surgical simulators.

The Work Group for Evaluation and Implementation of Simulators and Skills Training Programmes is a newly formed subgroup of the European Association of Endoscopic Surgeons (EAES). This work group undertook a review of validation evidence for surgical simulators and the resulting consensus is presented in this article. Using clinical guidelines criteria, the evidence for validation for 6 different simulators was rated and subsequently translated to a level of recommendation for each system. The simulators could be divided into 2 basic types; systems for laparoscopic general surgery and flexible gastrointestinal endoscopy. Selection of simulators for inclusion in this consensus was based on their availability and relatively widespread usage as of July 2004. While level 2 recommendations were achieved for a few systems, it was clear that there was an overall lack of published validation studies with rigorous experimental methodology. Since the consensus meeting, there have been a number of new articles, system upgrades and new devices available. The work group intends to update these consensus guidelines on a regular basis, with the resulting article available on the EAES website (http://www.eaes-eur.org).

Tunga penetrans. A case report and review of the literature.

Tungiasis is an infection caused by infestation of Tunga Penetrans into the epidermis. Although, at the moment, presentation of this condition seems rare in Europe and Northern America, tungiasis is highly endemic in other parts of the world. We describe a case of Tunga Penetrans infection in the foot of a 22-year old Dutch female returning from Kenya, and present a review of the literature. Now that intercontinental travel is increasing, physicians in other parts of the world will be expected to recognize and treat this exotic infection. Knowledge of human tungiasis is mandatory in order to recognize the symptoms, achieve correct diagnosis and ensure adequate medical treatment to our patients.

Consensus guidelines for validation of virtual reality surgical simulators.

The Work Group for Evaluation and Implementation of Simulators and Skills Training Programmes is a newly formed sub-group of the European Association of Endoscopic Surgeons (EAES). This work group undertook a review of validation evidence for surgical simulators and the resulting consensus is presented in this article. Using clinical guidelines criteria, the evidence for validation for six different simulators was rated and subsequently translated to a level of recommendation for each system. The simulators could be divided into two basic types; systems for laparoscopic general surgery and flexible gastrointestinal endoscopy. Selection of simulators for inclusion in this consensus was based on their availability and relatively widespread usage as of July 2004. Whilst level 2 recommendations were achieved for a few systems, it was clear that there was an overall lack of published validation studies with rigorous experimental methodology. Since the consensus meeting, there have been a number of new articles, system upgrades and new devices available. The work group intends to update these consensus guidelines on a regular basis, with the resulting article available on the EAES website (http://www.eaes-eur.org ).