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.

Variation in Susceptibility to Downy Mildew Infection in Spanish Minority Vine Varieties.

Downy mildew is one of the most destructive diseases affecting grapevines (Vitis vinifera L.). Caused by the oomycete Plasmopara viticola (Berk. and Curt.) Berl. and de Toni, it can appear anywhere where vines are cultivated. It is habitually controlled by the application of phytosanitary agents (copper-based or systemic) at different stages of the vine growth cycle. This, however, is costly, can lead to reduced yields, has a considerable environmental impact, and its overuse close to harvest can cause fermentation problems. All grapevines are susceptible to this disease, although the degree of susceptibility differs between varieties. Market demands and European legislation on viticulture and the use of phytosanitary agents (art. 14 of Directive 128/2009/EC) now make it important to know the sensitivity of all available varieties, including minority varieties. Such knowledge allows for a more appropriate use of phytosanitary agents, fosters the commercial use of these varieties and thus increases the offer of wines associated with different terroirs, and helps identify material for use in crop improvement programmes via crossing or genetic transformation, etc. Over 2020-2021, the susceptibility to P. viticola of 63 minority vine varieties from different regions of Spain was examined in the laboratory using the leaf disc technique. Some 87% of these varieties were highly susceptible and 11% moderately susceptible; just 2% showed low susceptibility. The least susceptible of all was the variety Morate (Madrid, IMIDRA). Those showing intermediate susceptibility included the varieties Sanguina (Castilla la Mancha, IVICAM), Planta Mula (Comunidad Valenciana, ITVE), Rayada Melonera (Madrid, IMIDRA), Zamarrica (Galicia, EVEGA), Cariñena Roja (Cataluña, INCAVI), Mandrègue (Aragón, DGA) and Bastardo Blanco (Extremadura, CICYTEX). The highly susceptible varieties could be differentiated into three subgroups depending on sporulation severity and density.

Transarterial prostatic embolization: initial experience in a canine model.

OBJECTIVE: The purpose of this study was to prospectively evaluate pathologic responses to transarterial prostatic embolization and its technical safety in a canine model. MATERIALS AND METHODS: Ten adult male beagle dogs were surgically castrated and given hormonal therapy for 4 months to induce prostatic hyperplasia. After three months of hormonal therapy, the dogs were randomly assigned to a transarterial prostatic embolization group (n = 7) or a control group (n = 3). Dogs in the transarterial prostatic embolization group were subjected to embolization with microspheres 300-500 µm in diameter. Four months after the study was begun, all dogs were sacrificed for pathologic study. Transrectal ultrasound and MRI were performed to evaluate pathologic responses. The data on prostate size acquired with transrectal ultrasound were processed for statistical analysis by paired Student t test. RESULTS: The canine prostatic hyperplasia model was successfully established in 10 dogs. The increase in mean prostate size being as great as 572% after 3 months of hormonal therapy. An intraprostatic cavity was detected 1 month after transarterial prostatic embolization in all seven dogs. Four dogs had significant shrinkage of the prostate, and the other three had an increase in prostate size. Imaging examinations and necropsy revealed a huge cavity occupying almost the entire prostate in the three dogs with increased prostate size. No complications associated with transarterial prostatic embolization were encountered. CONCLUSION: Transarterial prostatic embolization is a safe procedure that can induce prostatic infarction and ablate the prostate. The findings suggest the procedure has potential clinical applications in the care of patients with benign prostatic hyperplasia.

Biological response of laser macrostructured and oxidized titanium alloy: an in vitro and in vivo study.

PURPOSE: To assess both the in vitro and in vivo biological response of a laser modified surface in an integrated manner. A combined innovative approach applies lasers to macrostructure as well as to oxidize the surface of titanium alloy implants. MATERIALS AND METHODS: A Nd:YAG marking and ArF excimer lasers were used for macrostructuring and UV-oxidizing the surface of Ti6Al4V discs, respectively. Human fetal osteoblastic cell culture and a sheep tibia model were used to assess the cell response and the osseogeneration capability of as-machined, laser macrostructured and laser macrostructured and oxidized surfaces. RESULTS: In vitro: Laser macrostructuration alone did not promote cell response. Cellular proliferation was enhanced by the additional UV laser oxidation. In vivo: A greater significant percentage of bone-implant contact was obtained for both laser treated surfaces compared to machine-turned control samples, three months after implantation, in spite of the low cellular response for macrostructured samples. The use of sheep model for six months appears to be less adequate for a comparison because of the high level of bone integration in all samples. In spite of the often reported positive effect of titanium oxidation on the triggering of faster osseointegration, in this experiment the additional UV laser oxidation did not lead to a significant in vivo improvement. CONCLUSIONS: Laser macrostructuration of titanium alloy surfaces appears to promote bone apposition and may therefore constitute a promising surface modification strategy. In animal models, the natural process of titanium surface oxidation, because of physiologic fluids, alters properties observed in vitro with cells.

Video-based assistance system for training in minimally invasive surgery.

In this paper, the development of an assisting system for laparoscopic surgical training is presented. With this system, we expect to facilitate the training process at the first stages of training in laparoscopic surgery and to contribute to an objective evaluation of surgical skills. To achieve this, we propose the insertion of multimedia contents and outlines of work adapted to the level of experience of trainees and the detection of the movements of the laparoscopic instrument into the monitored image. A module to track the instrument is implemented focusing on the tip of the laparoscopic tool. This tracking method does not need the presence of artificial marks or special colours to distinguish the instruments. Similarly, the system has another method based on visual tracking to localize support multimedia content in a stable position of the field of vision. Therefore, this position of the support content is adapted to the movements of the camera or the working area. Experimental results are presented to show the feasibility of the proposed system for assisting in laparoscopic surgical training.

Ureteral double-J wire stent effectiveness after endopyelotomy: an animal model study.

OBJECTIVES: The aim of this experimental study was to assess the possibility of decreasing the size of the ureteral stents used after an endopyelotomy. To this end, an experimental study was performed which compared a ureteral double-J wire stent versus a standard 7F ureteral stent after endopyelotomy. METHODS: Twenty healthy female pigs were randomly divided into 2 groups: group I (double pigtail ureteral stent 7F) and group II (lumenless ureteral double-J wire stent, Zebrastent™, 0.035 inches in diameter). Percutaneous, endoluminal ultrasonographic and fluoroscopic studies were analyzed during the 3 different phases of the study. The first phase included premodel documentation of normal urinary tracts and laparoscopic ureteropelvic junction (UPJ) obstruction induction. During the second phase, 6 weeks later, diagnosis and endopyelotomy were carried out. Sixteen weeks after the obstruction treatment, follow-up imaging studies and postmortem evaluations of all animals were performed. RESULTS: After the sonographic and fluoroscopic assessments, we determined the success rate for each group: 80% for group I and 90% for group II. No significant statistical differences were evident in the evolution of the diameter of the UPJ between groups. Better healing of the UPJ and a lower level of retroperitoneal repercussions were seen in group II. CONCLUSIONS: The ureteral double-J wire stent (Zebrastent) has been shown to be highly effective after endopyelotomy. This means that it is possible to reduce the size of ureteral stents after endopyelotomy with the advantages that this entails. Double-J ureteral stents probably act as a scaffold rather than a mold.

Preliminary results with a training program for thoracoscopic atrial fibrillation therapy.

BACKGROUND: Novel devices have been designed for the treatment of atrial fibrillation (AF) using minimally invasive approaches. This study aimed to determine the usefulness of a sheep model for training in cardiac surgical ablation using a minimally invasive approach in an experimental hands-on training course. METHODS: After initial training using a laparoscopic pelvic trainer, 15 sheep were subjected to surgery by six thoracic surgeons attending a hands-on thoracoscopic course. Dissection to the posterior wall of the pulmonary veins was followed by insertion of a microwave device around both the caudal cava vein and the pulmonary veins. The complications were recorded, and the effectiveness of the surgery was evaluated by complete deployment of the microwave device. The animals were killed after completion of the procedure. RESULTS: Isolation of the cava vein and the pulmonary veins and placement of the microwave probe were performed successfully for 10 animals using a complete thoracoscopic approach. Two animals died during the procedure. The main complications of the procedure were hemorrhage and difficulty isolating the blood vessels using a minimally invasive procedure. After the training period, the thoracoscopic surgical maneuvers were accurate and reliable. CONCLUSION: The technical feasibility of performing safe and efficient thoracoscopic placement of a microwave device in a sheep model was demonstrated in this study, suggesting that the results of this study are a useful contribution to the development of an animal model for surgical training and experimental cardiac surgeries.

Benign prostatic hyperplasia: transcatheter arterial embolization as potential treatment--preliminary study in pigs.

PURPOSE: To prospectively evaluate the technical feasibility and safety of transcatheter arterial embolization (TAE) of the prostate in healthy pigs. MATERIALS AND METHODS: The study was approved by the institutional ethics committee for animal research. Sixteen large white male pigs were randomly assigned to the embolization group (n = 8) or control group (n = 8). Selective angiography was performed in all animals after general anesthesia was induced. In the embolization group, microspheres 500-700 microm in diameter were used to occlude the prostatic branches. Three months later, the animals' sexual function while breeding with female pigs was subjectively evaluated by using a three-point scale. At necropsy, the prostates were removed for size measurement and histopathologic examination. Paired Student t and Wilcoxon rank sum tests were used for statistical analysis. RESULTS: TAE was technically successful in all animals, without associated complications. The mean prostate volume after embolization was significantly (P < .001) reduced compared with the mean prostate volume for the group control. No significant difference (P = .328) in sexual function was noted between the two groups. Histologic examination revealed that the microspheres had occluded the arterioles of the prostate, with disappearance of the nearby partially normal gland structure and atrophy of the residual gland tissue. CONCLUSION: TAE of the prostate can induce shrinkage of the prostate without compromising the sexual desire and erectile function of animals. This finding suggests that TAE has potential as an alternative treatment for symptomatic benign prostatic hyperplasia in humans.

Reliability and validity of endoluminal sonography in a porcine model of ureteropelvic junction obstruction.

PURPOSE: The objective of this study was to evaluate the usefulness and reliability of endoluminal ultrasonography in ureteropelvic junction (UPJ) obstruction and to describe the changes in sonographic appearance that take place during obstruction and after treatment. MATERIALS AND METHODS: Twelve large healthy white female pigs were randomly divided into two groups: Group 1 (laparoscopic pyeloplasty) and group 2 (cutting balloon endopyelotomy). Percutaneous and endoluminal ultrasonographic and fluoroscopic studies were analyzed during the three phases of the study. The first phase included premodel documentation of a normal urinary tract and laparoscopic UPJ obstruction. During the second phase 6 weeks later, diagnosis and endourologic treatment were performed. Fifteen weeks after obstruction management, follow-up imaging studies and postmortem evaluation of all animals were performed. RESULTS: At the end of the study, group 1 had a lesser degree of fibrosis in the muscle-adventitia layers and periureteral repercussion, as well as a better peristaltic recovery. The animal study shows a positive correlation among the results of the pathologic and the endoluminal ultrasonographic studies in UPJ obstruction. CONCLUSIONS: Endoluminal ultrasonography provides excellent information regarding ureteral and periureteral anatomy. Among the two techniques evaluated in the study, laparoscopic pyeloplasty caused the lesser reaction at the reconstructed area. Fibrous replacement at the muscle-adventitia layers and periureteral area may be useful as indicators of the better therapeutic technique as well as for the assessment of post-therapeutic ureteral evolution and recurrences.

Maxillary sinus-floor elevation: an animal model.

OBJECTIVES: To find an animal model for modified Caldwell-Luc procedure training. The animal model should have (1) a proper cortical thickness in the lateral wall; (2) a similar morphology and resistance of the Schneiderian membrane in humans; and, finally, (3) an oral approach. MATERIALS AND METHODS: Twelve fresh heads (four Merino sheep, four Murciano-Granadina goats and four Large-White pigs). Two skulls from each of these species were also used. Several three-dimensional imagings from the skulls of each species were acquired using a C-arm. Two fresh heads of each species were used to perform the modified Caldwell-Luc procedure. Two fresh heads of each species were firstly frozen at -30 degrees C for 48 h and then sawed in blocks containing only the target region of the maxillary sinus. RESULTS: The average thickness was 2.03 mm in goat and sheep and 2.80 in pig. Releasing and elevation of the Schneiderian membrane from the sinus floor were easy in the three species. The approach of the maxillary sinus in sheep, goat and pig from the buccal vestibule required a previous surgical enlargement of the buccal vestibule. CONCLUSIONS: In conclusion, the cortical bone thickness and Schneider membrane characteristics in Merina sheep and Murciano-Granadina goat allow a perfect training for the modified Caldwell-Luc procedure. However, the approach from the oral cavity needs, in these species, a previous enlargement of the buccal vestibule. The excessive thickness of the cortical bone restricts the use of pigs for this technique.

Endotracheal stenting therapy in dogs with tracheal collapse.

Tracheal collapse in dogs is a common respiratory disorder, typically presenting with a history of chronic cough, increasing respiratory difficulties, and episodes of dyspnoea. Medical treatment is the therapy of choice and surgical repair is considered when patients do not respond well. Minimally invasive endotracheal stenting is a promising new therapy under investigation, but there remain significant challenges to overcome potential complications. The purpose of this article is to provide a comparative overview of intra-luminal stenting of the trachea in human and veterinary medicine. The currently available stents and their potential clinical application to the veterinary patient will be discussed.

Technical feasibility of totally natural orifice cholecystectomy in a swine model.

The goal of this study was to evaluate the feasibility of totally NOTES performing a cholecystectomy without laparoscopic assistance. A gastroscope was used through a transvaginal access in five acute female pigs. An incision of 2 cm was created in the vagina and pneumoperitoneum was obtained with a Veress needle. The gallbladder was located in the abdominal cavity using endoscopic transillumination for spatial orientation. After the abdominal suspension of the gallbladder the cholecystectomy was completed with the NOTES technique in four animals without complications. In one animal we had technical problems and the procedure was stopped. The mean operative time was 110 minutes. The transvaginal approach provides complete abdominal exploration and both the cystic duct and artery were identified, clipped, and transected. After dissection the gallbladder was removed through the vagina. Our results showed that completely transvaginal NOTES cholecystectomy is a feasible technique performed only with a flexible endoscope.

Levothyroxine therapy and imatinib.

Levothyroxine requirements in patients with hypothyroidism are usually stable. Consequently, thyroid function is usually monitored once or twice yearly. Occasionally, the dose of levothyroxine can be changed by pharmacological reactions. We report the case of a 59-year-old woman who was under levothyroxine therapy for hypothyroidism secondary to subtotal thyroidectomy, with clinical and biochemical euthyroidism, who required an increased dose of levothyroxine after starting imatinib therapy. The patient was diagnosed with chronic myeloid leukemia and imatinib therapy was started. Subsequently, we observed clinical and biochemical hypothyroidism, requiring an increase in levothyroxine dose. Some cases of hypothyroidism after initiation of imatinib therapy in patients with levothyroxine replacement therapy have recently been published. Our case provides further evidence of a reaction between the two drugs. Therefore, we discuss the most likely physiopathological mechanisms contributing to imatinib-induced hypothyroidism in patients under levothyroxine replacement therapy.

SINERGIA laparoscopic virtual reality simulator: didactic design and technical development.

VR laparoscopic simulators have demonstrated its validity in recent studies, and research should be directed towards a high training effectiveness and efficacy. In this direction, an insight into simulators' didactic design and technical development is provided, by describing the methodology followed in the building of the SINERGIA simulator. It departs from a clear analysis of training needs driven by a surgical training curriculum. Existing solutions and validation studies are an important reference for the definition of specifications, which are described with a suitable use of simulation technologies. Five new didactic exercises are proposed to train some of the basic laparoscopic skills. Simulator construction has required existing algorithms and the development of a particle-based biomechanical model, called PARSYS, and a collision handling solution based in a multi-point strategy. The resulting VR laparoscopic simulator includes new exercises and enhanced simulation technologies, and is finding a very good acceptance among surgeons.

Study of laparoscopic forces perception for defining simulation fidelity.

One of the most controversial dilemmas in virtual reality laparoscopic simulators design is the incorporation of force feedback (FF). This issue is approached with an experimental design in which surgeons assess the resistance against pulling of four different tissues, which are characterized with the acquisition of interaction forces. Comparing subjective assessments with objective force parameters we aim to determine the fidelity boundary beyond which no more realism is necessary in simulation. Interaction pulling forces of four tissues have been characterized, which can constitute a basis for requirements of a FF algorithm. Results have also led to the hypothesis that surgeons are able to differentiate tissues and perceive somesthesic information although resulting interaction forces are of the same magnitude than interferences like trocar friction.

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.

Ataxia and focal dystonia in Kallmann syndrome.

A case of Kallmann syndrome (KS) associated with rare neurological manifestations is presented. Cerebellar ataxia probably caused by a small posterior fossa and a focal dystonia affecting the left lower limb expand the spectrum of neurological manifestations occurring in KS. Further studies are needed to better understand these manifestations.

Treatment of experimental ureteral strictures by endourological ureterotomy and implantation of stents in the porcine animal model.

The objective of this study is to evaluate the dilation of the ureter using endoureterotomy and an expanding-sheath double pigtail ureteral stent in the treatment of experimentally induced ureteral strictures in the porcine animal model. This is a new treatment in the ureteral strictures resolution in Veterinary Urology, although it is not a common affection, it usually appears as a consequence of ureteritis and in the iatrogenic female genital surgery. The experimental study is design in three phases: induction of experimental stricture, diagnosis and treatment of the stricture and follow-up. We have used 10 healthy Large White female pigs. The internal ureteral diameter was measured prior to laparoscopic ligature stricture induction using retrograde ureteropyelography (RUPG). Experimental stricture was diagnosed 4 weeks after intervention, using RUPG and ultrasound, and treated by endoureterotomy and subsequent placement of a double pigtail ureteral stent, which was removed 6 weeks later. The study finished 4 weeks later with measurement of ureteral diameters using RPUG and ultrasound evaluation. Except in one case, all ureters displayed permanent dilation of the strictured area for 10 weeks after treatment (6 weeks with ureteral stent and 4 more weeks without stent). Finally, this technique proved to be effective in cases of short-length and short-living ureteral strictures, and represents a viable alternative to conventional surgery in animals.

Evaluation in an animal model of a hybrid covered metallic ureteral stent: a new design.

OBJECTIVE: To evaluate a new design for a hybrid, dynamic, metallic ureteral stent that might avoid the formation of urothelial hyperplasia after ureteral metallic stenting in an experimental study. MATERIALS AND METHODS: A total of 30 healthy female pigs were included in the present study, and an experimental obstructive uropathy in the right lumbar ureter was created in each pig. Obstruction was confirmed using percutaneous ultrasonography and retrograde ureteral pyelography and endoluminal ultrasonography 6 weeks after obstructive uropathy model creation. Then, the pigs were randomly distributed into 2 groups. Group 1 underwent standard metallic ureteral self-expanding internally covered stent deployment. Group 2 received a new hybrid metallic ureteral self-expanding internally covered stent. The follow-up period was 6 months. RESULTS: The hybrid metallic ureteral self-expanding internally covered stent group had a lower rate of urothelial hyperplasia (21% vs 70%), reduced stent migration (6.6% vs 33.3%), and a greater success rate after 6 months of follow-up (86.6% vs 47%) compared with the standard metallic ureteral self-expanding internally covered stent deployment group, with statically significant differences between the 2 groups. CONCLUSION: Our experimental results have indicated that the use of the hybrid metallic ureteral self-expanding internally covered stent in ureteral strictures is feasible, safe, and effective and reduces the formation of urothelial hyperplasia without secondary interventions to maintain ureteral patency.