Comparative anatomy of the ovine and human pelvis for laparoscopic sacrocolpopexy: evaluating the effectiveness of the ovine model.

INTRODUCTION AND HYPOTHESIS: Laparoscopic sacrocolpopexy (LSC) is a functional reconstructive surgery used to treat pelvic organ prolapse (POP) in middle-aged women. Although LSC is widely used, its implementation is hindered by perceived technical difficulties and surgical learning curves. Surgeons require adequate experience with LSC prior to performing the procedure on patients to improve their quality of life. This study is aimed at demonstrating the effectiveness of the ovine model (OM) for training and research in LSC, while also comparing anatomical differences between ovine and human models during the procedure. METHODS: The animal model and training were provided by the Jesús Usón Minimally Invasive Surgery Centre. Urologists and gynecologists with experience in LSC participated in a course and their findings were recorded and documented. RESULTS: Differences in patient positioning, trocar placement, and reperitonealization were identified between the ovine and human models. Hysterectomy is always performed in the ovine model, whereas it is not mandatory in humans. There are also differences in the dissection of the levator ani muscle and attachment point of the posterior mesh to the uterus between the two models. Despite differences in some areas, the ovine pelvic structure and vagina are similar in size to those of humans. CONCLUSIONS: The ovine model is a valuable tool for surgeons in their learning curve for LSC, allowing for safe and effective practice prior to performing the procedure on patients. The use of the OM can help to improve the quality of life for women affected by pelvic organ prolapse.

In Vitro and In Vivo Response of Zinc-Containing Mesoporous Bioactive Glasses in a Sheep Animal Model.

Zinc-enriched mesoporous bioactive glasses (MBGs) are bioceramics with potential antibacterial and osteogenic properties. However, few assays have been performed to study these properties in animal models. In this study, MBGs enriched with up to 5% ZnO were synthesized, physicochemically characterized, and evaluated for their osteogenic activity both in vitro and in vivo. The ZnO MBGs showed excellent textural properties despite ZnO incorporation. However, the release of Zn2+ ions inhibited the mineralization process when immersed in simulated body fluid. In vitro assays showed significantly higher values of viability and expression of early markers of cell differentiation and angiogenesis in a ZnO-content-dependent manner. The next step was to study the osteogenic potential in a sheep bone defect model. Despite their excellent textural properties and cellular response in vitro, the ZnO MBGs were not able to integrate into the bone tissue, which can be explained in terms of inhibition of the mineralization process caused by Zn2+ ions. This work highlights the need to develop nanostructured materials for bone regeneration that can mineralize to interact with bone tissue and induce the processes of implant acceptance, cell colonization by osteogenic cells, and regeneration of lost bone tissue.

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.

Assessment of Laparoscopic Skills in Veterinarians Using a Canine Laparoscopic Simulator.

The aim of the present study was to assess the content and construct validity of the Canine Laparoscopic Simulator (CLS). Forty-two veterinarians were assigned to experienced (n=12), control (n=15), and training (n=15) groups, which were assessed while performing four laparoscopic tasks on the CLS. The initial and final assessments of all tasks were performed blindly by two experienced surgeons using the Global Operative Assessment of Laparoscopic Skills (GOALS) and a task-specific checklist. At the end of the study, the subjects completed an anonymous survey. The experienced group performed all of the tasks faster, with higher GOALS and checklist scores than the training and control groups (p≤.001). In the second assessment, the training group reduced the time needed to complete all of the tasks and obtained significantly higher GOALS and checklist scores than the control group. The participants perceived the CLS and its training program to be positive or very positive. The CLS and its training program demonstrated content and construct validity, supporting the suitability of the simulator for training and teaching and its ability to distinguish the degree of experience in laparoscopic surgery among veterinarians. In addition, face validity showed that the veterinarians fully accepted the CLS's usefulness for learning basic laparoscopic skills.

Validation of a model of intensive training in digestive laparoscopic surgery.

INTRODUCTION: Our objective was to assess a laparoscopic training model for general surgery residents. METHODS: Twelve general surgery residents carried out a training program, consisting of a theoretical session (one hour) and a hands-on session on simulator (7 h) and on animal model (13 h). For the first and last repetitions of simulator tasks and the Nissen fundoplication technique, time and scores from the global rating scale objective structured assessment of technical skills (OSATS) were registered. Before and after the course, participants performed 4 tasks on the virtual reality simulator LAPMentor™: 1) hand-eye coordination, 2) hand-hand coordination, 3) transference of objects and 4) cholecystectomy task, registering time and movement metrics. Moreover, the residents completed a questionnaire related to the training components on a 5-point rating scale. RESULTS: The last repetition of the tasks and the Nissen fundoplication technique were performed faster and with a higher OSATS score. After the course, the participants performed all LAPMentor™ tasks faster, increasing the speed of movements in all tasks. Number of movements decreased in tasks 2, 3 and 4; as well as path length in tasks 2 and 4. Training components were positively rated by residents, being the suture task the aspect best rated (4.90 ± 0.32). CONCLUSIONS: This training model in digestive laparoscopic surgery has demonstrated to be valid for the improvement of basic and advanced skills of general surgery residents. Intracorporeal suturing and the animal model were the best rated training elements.

Multidisciplinary characterization of the long-bone cortex growth patterns through sheep's ontogeny.

Bone researches have studied extant and extinct taxa extensively trying to disclose a complete view of the complex structural and chemical transformations that model and remodel the macro and microstructure of bone during growth. However, to approach bone growth variations is not an easy task, and many aspects related with histological transformations during ontogeny remain unresolved. In the present study, we conduct a holistic approach using different techniques (polarized microscopy, Raman spectroscopy and X-ray diffraction) to examine the histomorphological and histochemical variations in the cortical bone of sheep specimens from intrauterine to adult stages, using environmentally controlled specimens from the same species. Our results suggest that during sheep bone development, the most important morphological (shape and size) and chemical transformations in the cortical bone occur during the first weeks of life; synchronized but dissimilar variations are established in the forelimb and hind limb cortical bone; and the patterns of bone tissue maturation in both extremities are differentiated in the adult stage. All of these results indicate that standardized histological models are useful not only for evaluating many aspects of normal bone growth but also to understand other important influences on the bones, such as pathologies that remain unknown.

Hemostatic sponge effect on adhesion prevention in a porcine model.

BACKGROUND: In this work, we aimed to assess the preventive effect of an absorbable hemostatic collagen sponge (HCS) on the reduction of postsurgical gynecological adhesions in a porcine model. MATERIALS AND METHODS: Forty female pigs were subjected to a right uterine horn myotomy and left uterine horn deserosation. They were randomly divided into two groups, HCS application and control, which were rearranged into laparotomy and laparoscopy groups. Resulting adhesions were macroscopically and microscopically semiquantitatively analyzed after a 5 mo follow-up. RESULTS: The incidence of adhesion-free animals did not significantly differ between groups, although it increased when the HCS was placed in both laparotomy (from 10%-12.5%) and laparoscopy groups (from 20%-50%). On the contrary, a significant reduction was observed in adhesion severity when the HCS was applied in the laparotomy groups (P < 0.01). Regarding microscopic study, hemostatic sponge application significantly reduced the inflammation score in the laparoscopic approach (P < 0.01). Fibrosis, unlike inflammation, differs between both approaches. In the laparoscopic group, fibrosis was reduced with application of the HCS, whereas in the laparotomy group greater fibrosis was observed within the HCS group. CONCLUSIONS: HCS has shown to be safe for gynecological use. Although number and extent of adhesions did not decrease with HCS, inflammation and adhesions' severity were reduced in the laparoscopic and laparotomy approaches, respectively.

Performance analysis on physical simulator of four different instrument setups in laparo-endoscopic single-site (LESS) surgery.

BACKGROUND: Over the past decades, minimally invasive surgery has undergone continuous development due to the demand for scarless results, with laparo-endoscopic single-site (LESS) surgery constituting one of today's most favored alternatives. In this study, we aim to assess the relative technical difficulty and performance benefits of dynamic articulating and pre-bent instruments, either combined with conventional laparoscopic tools or not, during the completion of two basic tasks hands-on simulator. METHODS: A total of 20 surgeons were included and performed two basic simulator tasks-coordination and cutting-carried out using four different combinations of LESS-designed and straight conventional laparoscopy instruments. Assessment took place before and after the completion of a 14-week training program. Performance data were objectively analyzed over video recordings with an adapted global rating scale (a-GRS) for performance evaluation, combined with a registry of total trial completion time. RESULTS: In the coordination task, the worst performance scores (p < 0.001) and longest completion times (p < 0.001 on first assessment and p < 0.01 on last assessment) were obtained with the two dynamic articulating tip instruments. On the cut trials, no significant differences between the different setups were found in a-GRS scores. The two dynamic articulating tip instruments also constituted the most time-demanding setup on both assessment trials (p < 0.05). The use of two dynamic articulating tip instruments showed significant improvement with training in all measured parameters except for performance in the cut task, in which the increase in a-GRS score was not significant. CONCLUSIONS: We conclude that the least adequate instrument set for initiation in LESS surgery is the one that combines two dynamic articulating tip instruments, as this has consistently obtained the worst results in all trials. Further data on more complex tasks and on a complete learning and skills-acquisition program must be obtained to confirm these findings.

Validation of a realistic simulator for veterinary gastrointestinal endoscopy training.

This article reports on the face, content, and construct validity of a new realistic composite simulator (Simuldog) used to provide training in canine gastrointestinal flexible endoscopy. The basic endoscopic procedures performed on the simulator were esophagogastroduodenoscopy (EGD), gastric biopsy (GB), and gastric foreign body removal (FBR). Construct validity was assessed by comparing the performance of novices (final-year veterinary students and recent graduates without endoscopic experience, n=30) versus experienced subjects (doctors in veterinary medicine who had performed more than 50 clinical upper gastrointestinal endoscopic procedures as a surgeon, n=15). Tasks were scored based on completion time, and specific rating scales were developed to assess performance. Internal consistency and inter-rater agreement were assessed. Face and content validity were determined using a 5-point Likert-type scale questionnaire. The novices needed considerably more time than the experts to perform EGD, GB, and FBR, and their performance scores were significantly lower (p<.010). Inter-rater agreement and the internal validity of the rating scales were good. Face validity was excellent, and both groups agreed that the endoscopy scenarios were very realistic. The experts highly valued the usefulness of Simuldog for veterinary training and as a tool for assessing endoscopic skills. Simuldog is the first validated model specifically developed to be used as a training tool for endoscopy techniques in small animals.

Relevance of motion-related assessment metrics in laparoscopic surgery.

INTRODUCTION: Motion metrics have become an important source of information when addressing the assessment of surgical expertise. However, their direct relationship with the different surgical skills has not been fully explored. The purpose of this study is to investigate the relevance of motion-related metrics in the evaluation processes of basic psychomotor laparoscopic skills and their correlation with the different abilities sought to measure. METHODS: A framework for task definition and metric analysis is proposed. An explorative survey was first conducted with a board of experts to identify metrics to assess basic psychomotor skills. Based on the output of that survey, 3 novel tasks for surgical assessment were designed. Face and construct validation was performed, with focus on motion-related metrics. Tasks were performed by 42 participants (16 novices, 22 residents, and 4 experts). Movements of the laparoscopic instruments were registered with the TrEndo tracking system and analyzed. RESULTS: Time, path length, and depth showed construct validity for all 3 tasks. Motion smoothness and idle time also showed validity for tasks involving bimanual coordination and tasks requiring a more tactical approach, respectively. Additionally, motion smoothness and average speed showed a high internal consistency, proving them to be the most task-independent of all the metrics analyzed. CONCLUSION: Motion metrics are complementary and valid for assessing basic psychomotor skills, and their relevance depends on the skill being evaluated. A larger clinical implementation, combined with quality performance information, will give more insight on the relevance of the results shown in this study.

[Validity studies in laparoscopic simulation. Methodology and design considerations.] / Validación en simulación laparoscópica. Consideraciones metodológicas y de diseño.

OBJECTIVES: To describe a roadmap of the most representative milestones and considerations in the validation of surgical simulators, especially those of laparoscopic surgery. And additionally, help determine when in this process a simulator can be considered as validated. METHODS: A non-systematic review was carried out searching terms like simulation, validation, training, assessment, skills and learning curve, as well as providing the experience accumulated by our center. RESULTS: An ideal classical validation process should consist of the following steps: fidelity, verification/calibration/ reliability, subjective and objective strategies. Baseline tests of fidelity and verification/calibration/ technological reliability are not always detailed in the simulation literature. A simulator can be considered validated if, at least, satisfactorily completed any of the two main objective strategies, that is, constructive and/or criterion validity. CONCLUSIONS: The methodologies to validate simulators as useful and reliable for the improvement of psychomotor/ technical skills are widely analyzed, although there is a variety of approaches depending on the scientific reference consulted, not being implemented equally in all works. This apparent arbitrariness should be considered in advance because it can lead the researcher to misunderstandings, especially when the simulator will be regarded as valid.

OBJETIVOS: Describir una hoja de ruta de los hitos y consideraciones más representativos en la validación de simuladores quirúrgicos, especialmente los de cirugía laparoscópica. Y adicionalmente contribuir a determinar en qué momento de este proceso puede considerarse un simulador como validado.MÉTODOS: Se realizó una revisión no sistemática con los términos simulación, validación, formación, entrenamiento, evaluación, habilidades y curva de aprendizaje, además de aportar la experiencia acumulada por nuestro centro. RESULTADOS: Un proceso ideal clásico de validación debería constar de los siguientes pasos: Fidelidad, Verificación/ Calibración/Fiabilidad, estrategias subjetivas y objetivas. Las pruebas de inicio tanto de Fidelidad como de Verificación/Calibración/Fiabilidad tecnológica no siempre están descritas de manera explícita en los trabajos de validación de simuladores. Un simulador puede considerarse validado si al menos ha completado satisfactoriamente una validación de cualquiera de los dos grandes bloques de tipo objetivo, es decir, constructiva y/o de criterio. CONCLUSIONES: Los métodos que permiten validar simuladores como útiles y fiables para la mejora de habilidades de tipo psicomotor/técnico están ampliamente documentados aunque existe cierta variedad de enfoques en función de la referencia científica que se consulte, no aplicándose por igual en todos los trabajos. Esta aparente arbitrariedad debería ser conocida de antemano porque puede llevar al investigador a ciertos equívocos, especialmente a la hora de afirmar cuándo el simulador se considera plenamente validado.

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.

Validation of a structured intensive laparoscopic course for basic and advanced gynecologic skills training.

OBJECTIVE: To describe and validate a gynecologic laparoscopic-surgery training model. METHODS: The present prospective observational study was conducted at the Minimally Invasive Surgery Centre Jesús Usón, Cáceres, Spain, between January 2011 and June 2013. Novice gynecologists attended a 3-day course including simulation and animal training. Participants' were assessed before and after training using a virtual reality simulator; during training, gynecologists were timed and assessed using an Objective and Structured Assessment of Technical Skills score. The virtual reality simulator-assessed skills were eye-hand coordination, hand-hand coordination, and transference of objects. Participants were asked to rate various elements of the training program using a five-point scale. RESULTS: The study enrolled 21 gynecologists. Participants performed all tasks faster (P<0.001), using fewer movements (P<0.05 for left and right instruments), after receiving training. During participants' final animal and simulator training sessions, completion times were reduced (P<0.001) and assessment scores (P<0.001) increased for all techniques and tasks. Participants considered suturing to be the most useful aspect of the basic-skills training (4.95±0.22); animal training received a higher rating than simulator training for practicing new techniques (4.81±0.40 vs 4.05±0.86) and maintaining skills (4.76±0.54 vs 3.95±0.97). CONCLUSION: Combining proficiency-based physical simulation and animal training models under expert guidance is an efficient model for improving basic and advanced laparoscopic skills. Suturing and animal models were the preferred training components.

Evaluation in a Dog Model of Three Antimicrobial Glassy Coatings: Prevention of Bone Loss around Implants and Microbial Assessments.

OBJECTIVES: The aim of the present study is to evaluate, in a ligature-induced peri-implantitis model, the efficacy of three antimicrobial glassy coatings in the prevention of biofilm formation, intrasulcular bacterial growth and the resulting peri-implant bone loss. METHODS: Mandibular premolars were bilaterally extracted from five beagle dogs. Four dental implants were inserted on each hemiarch. Eight weeks after, one control zirconia abutment and three with different bactericidal coatings (G1n-Ag, ZnO35, G3) were connected. After a plaque control period, bacterial accumulation was allowed and biofilm formation on abutments was observed by Scanning Electron Microscopy (SEM). Peri-implantitis was induced by cotton ligatures. Microbial samples and peri-implant crestal bone levels of all implant sites were obtained before, during and after the breakdown period. RESULTS: During experimental induce peri-implantitis: colony forming units counts from intrasulcular microbial samples at implants with G1n-Ag coated abutment remained close to the basal inoculum; G3 and ZnO35 coatings showed similar low counts; and anaerobic bacterias counts at control abutments exhibited a logarithmic increase by more than 2. Bone loss during passive breakdown period was no statistically significant. Additional bone loss occurred during ligature-induce breakdown: 0.71 (SD 0.48) at G3 coating, 0.57 (SD 0.36) at ZnO35 coating, 0.74 (SD 0.47) at G1n-Ag coating, and 1.29 (SD 0.45) at control abutments; and statistically significant differences (p<0.001) were found. The lowest bone loss at the end of the experiment was exhibited by implants dressing G3 coated abutments (mean 2.1; SD 0.42). SIGNIFICANCE: Antimicrobial glassy coatings could be a useful tool to ward off, diminish or delay peri-implantitis progression.

Development and initial assessment of a training program for laparoscopic radical prostatectomy. First module: the urethrovesical anastomosis.

PURPOSE: We present our experience in the design and development of a training program in laparoscopic radical prostatectomy (LRP), and the validation of the first steps of the program by objective measurement of the attendants' skills improvement and subjective evaluation of its contents. MATERIALS AND METHODS: Our training model on LRP has a total duration of 42 hours, divided in two modules of 21 hours each, performed 1 month apart. Data included in the present study were obtained from the first module of our course. It begins with acquisition of basic knowledge in ergonomics and instrument concepts, after which the attendants develop essential laparoscopic dexterities through the performance of hands-on physical simulator tasks. During the second and third day, urologists performed urethrovesical anastomosis also in the physical simulator. Attendants' skills improvement was measured during the first module by registering surgical times and suturing quality of the anastomosis, the latter by means of a leak test. At the end of the training program, a subjective evaluation questionnaire on the different didactic and organizational aspects was handed out to the attendants. RESULTS: By comparing first and last anastomosis, we observed a significant decrease in surgical times (minutes) (T1 40.1±4.6 vs T6 24.01±3.34; P≤0.005) and an increase in intraluminal leak pressure (mm Hg) (T1 8.27±7.33 vs T6 21.09±6.72; P≤0.005). We obtained a highly positive score on all questions concerning the different topics and techniques included in the training program (≥9 points over 10). Regarding the attendants' self-assessment of acquired abilities, 78.3% considered themselves capacitated to perform the trained procedures on patients. CONCLUSIONS: Training obtained during the first module of our training model significantly decreased performance times for ex vivo urethrovesical anastomosis, simultaneously increasing its quality. In addition, validation of the training model was also demonstrated by the highly scored evaluation resulting from the attendants' assessment.

Radiologic evaluation of bone loss at implants with biocide coated titanium abutments: a study in the dog.

The objective of the present study is to evaluate bone loss at implant abutments coated with a soda-lime glass containing silver nanoparticles subjected to experimental peri-implantitis. Five beagle dogs were used in the experiments, 3 implants were installed in each quadrant of the mandibles. Glass/n-Ag coted abutments were connected to implant platform. Cotton floss ligatures were placed in a submarginal position around the abutment necks and the animals were subject to a diet which allowed plaque accumulation, and after 15 weeks the dogs were sacrificed. Radiographs of all implant sites were obtained at the beginning and at the end of the experimentally induced peri-implantitis. The radiographic examination indicated that significant amounts of additional bone loss occurred in implants without biocide coating, considering both absolute and relative values of bone loss. Percentages of additional bone loss observed in implants dressed with a biocide coated abutment were about 3 times lower (p<0.006 distal aspect; and p<0.031 at mesial aspect) than the control ones. Within the limits of the present study it seems promising the use of soda-lime glass/nAg coatings on abutments to prevent peri-implant diseases.