Fatigue of Narrow Dental Implants: Influence of the Hardening Method.

The use of narrow titanium dental implants (NDI) for small ridges, reduced interdental space, or missing lateral incisors can be a viable option when compared to the conventional wider dental implants. Furthermore, in many cases, standard diameter implant placement may not be possible without grafting procedures, which increases the healing time, cost, and morbidity. The aim of this study was to analyze the mechanical viability of the current narrow implants and how narrow implants can be improved. Different commercially available implants (n = 150) were tested to determine maximum strength, strain to fracture, microhardness, residual stress, and fatigue obtaining the stress-number of cycles to fracture (SN) curve. Fractography was studied by scanning electron microscopy. The results showed that when the titanium was hardened by the addition of 15% of Zr or 12% cold worked, the fatigue limit was higher than the commercially pure grade 4 Ti without hardening treatment. Grade 4 titanium without hardening treatment in narrow dental implants can present fractures by fatigue. These narrow implants are subjected to high mechanical stresses and the mechanical properties of titanium do not meet the minimal requirements, which lead to frequent fractures. New hardening treatments allow for the mechanical limitations of conventional narrow implants to be overcome in dynamic conditions. These hardening treatments allow for the design of narrow dental implants with enhanced fatigue life and long-term behavior.

Learning curves of basic laparoscopic psychomotor skills in SINERGIA VR simulator.

PURPOSE: Surgical simulators are currently essential within any laparoscopic training program because they provide a low-stakes, reproducible and reliable environment to acquire basic skills. The purpose of this study is to determine the training learning curve based on different metrics corresponding to five tasks included in SINERGIA laparoscopic virtual reality simulator. METHODS: Thirty medical students without surgical experience participated in the study. Five tasks of SINERGIA were included: Coordination, Navigation, Navigation and touch, Accurate grasping and Coordinated pulling. Each participant was trained in SINERGIA. This training consisted of eight sessions (R1-R8) of the five mentioned tasks and was carried out in two consecutive days with four sessions per day. A statistical analysis was made, and the results of R1, R4 and R8 were pair-wise compared with Wilcoxon signed-rank test. Significance is considered at P value <0.005. RESULTS: In total, 84.38% of the metrics provided by SINERGIA and included in this study show significant differences when comparing R1 and R8. Metrics are mostly improved in the first session of training (75.00% when R1 and R4 are compared vs. 37.50% when R4 and R8 are compared). In tasks Coordination and Navigation and touch, all metrics are improved. On the other hand, Navigation just improves 60% of the analyzed metrics. Most learning curves show an improvement with better results in the fulfillment of the different tasks. CONCLUSIONS: Learning curves of metrics that assess the basic psychomotor laparoscopic skills acquired in SINERGIA virtual reality simulator show a faster learning rate during the first part of the training. Nevertheless, eight repetitions of the tasks are not enough to acquire all psychomotor skills that can be trained in SINERGIA. Therefore, and based on these results together with previous works, SINERGIA could be used as training tool with a properly designed training program.

Decomposition and analysis of laparoscopic suturing task using tool-motion analysis (TMA): improving the objective assessment.

PURPOSE: The laparoscopic suturing task is a complex procedure that requires objective assessment of surgical skills. Analysis of laparoscopic suturing task components was performed to improve current objective assessment tools. METHODS: Twelve subjects participated in this study as three groups of four surgeons (novices, intermediates and experts). A box-trainer and organic tissue were used to perform the experiment while tool movements were recorded with the augmented reality haptic system. All subjects were right-handed and developed a surgeon's knot. The laparoscopic suturing procedure was decomposed into four subtasks. Different objective metrics were applied during tool-motion analysis (TMA). Statistical analysis was performed, and results from three groups were compared using the Jonckheere-Terpstra test, considering significant differences when P ≤ 0.05. RESULTS: Several first, second and fourth subtask metrics had significant differences between the three groups. Subtasks 1 and 2 had more significant differences in metrics than subtask 4. Almost all metrics showed superior task executions accomplished by experts (lower time, total path length and number of movements) compared with intermediates and novices. CONCLUSION: The most important subtasks during suture learning process are needle puncture and first knot. The TMA could be a useful objective assessment tool to discriminate surgical experience and could be used in the future to measure and certify surgical proficiency.

Validation of SINERGIA as training tool: a randomized study to test the transfer of acquired basic psychomotor skills to LapMentor.

PURPOSE: Laparoscopic surgery is commonly used in many surgical procedures but requires a learning process to develop the necessary skills. Virtual reality simulators play an essential role within the training curricula. This paper aims to determine whether training in SINERGIA VR simulator allows novice surgeons to improve their basic psychomotor laparoscopic skills. METHODS: Forty-two people participated in this study, including 28 unexperience medical students and 14 expert surgeons who developed previously more than 100 laparoscopic procedures. Medical students made a pre-training test in LapMentor II; then, they trained in SINERGIA and they finally accomplished a post-training test in LapMentor II. Experts just made one trial in LapMentor II. A statistical analysis was carried out and results of pre- and post-training tests of novices were compared with Wilcoxon signed-rank test. Pre- and post-training tests of novices were also compared with results of experts with Mann-Whitney U test. RESULTS: Most metrics provided by LapMentor II and included in this study show significant differences when comparing pre- and post-training tests of novices. Analysis of pre-training test of novices and experts results show significant differences in all analyzed metrics for all studied tasks. On the other hand, LapMentor was not able to distinguish between experts and novices after training in SINERGIA for any metric in the camera manipulation task and for some metrics of the other tasks. CONCLUSIONS: Training in SINERGIA VR simulator allows improvement of basic psychomotor laparoscpic skills and transferring them to another virtual simulator. Therefore, it could be used in laparoscopic surgery training programs.

Anatomical changes due to pneumoperitoneum analyzed by MRI: an experimental study in pigs.

PURPOSE: Different effects on cardiovascular and respiratory systems and liver are associated with pneumoperitoneum. This study aimed to determine the morphological changes in the abdominal anatomy as a result of increased intra-abdominal pressure due to pneumoperitoneum using MRI. METHODS: Ten healthy female pigs were used in this study. MRI studies of the abdomen in supine position were made before the creation of pneumoperitoneum and 1 h after increasing the pressure to 14 mmHg. Changes in area, volume, and longitudinal and transverse length of the liver were measured. The diameters of the lumen of the abdominal aorta, the inferior vena cava and portal vein were observed in three positions along the abdominal cavity. The position of the diaphragm after the induction of pneumoperitoneum was also analyzed. RESULTS: After induction of pneumoperitoneum, volume and transverse length of the liver was significantly increased, while peak area was decreased. Stenosis in the aortic lumen was observed (P < 0.05). Longitudinal and transverse diameters of the portal lumen were reduced, but significant differences were only found in the longitudinal diameter. Alterations in the diameter of the inferior vena cava lumen were obtained in three analyzed positions, but differences were significant only in two of them. A mean cranial displacement of the diaphragm equal to 25 mm was also observed. CONCLUSION: Increasing abdominal pressure up to laparoscopic pressure (14 mmHg) provokes morphological changes in the liver, vascular structures and diaphragm. These changes could be related to functional alterations that different organs experience after the induction of pneumoperitoneum.

Empleo del modelo animal en la formación enendoscopia diagnóstica y terapéutica de la vía biliar / Animal model training in diagnostic and therapeutic biliary tract endoscopy teaching

Objetivo. Mostrar nuestra experiencia en la formación en endoscopia terapéutica de la vía biliar en modelo animal. Materiales y métodos. Esta actividad formativa tiene una duración de 13 horas y comienza iniciando al alumno en las diferencias anatómicas de las especies que se emplean, la porcina y la canina, con respecto a la anatomía humana. Las prácticas consisten en habituar al endoscopista a la visión lateral del duodenoscopio; se realizan en un modelo porcino debido a que es más sencillo atravesar el esfínter pilórico, aunque no suele ser muy adecuado para la canulación de la papila duodenal. Tras superar la primera fase se utiliza el modelo canino, que permite adquirir las habilidades y destrezas propias de esta técnica. La evaluación de los resultados se realiza mediante una encuesta anónima. Resultados. El 76% de los alumnos confirma que ha avanzado mucho con este entrenamiento, un 18% regular y un 6% poco. El 75% considera que, tras realizar esta actividad de formación, se encontraría capacitado para llevar a cabo la técnica en su hospital. El 94% de los alumnos recomendaría esta actividad a sus compañeros. Conclusiones. El empleo del modelo animal en la formación en colangio pancreatografía retrógada endoscópica (CPRE)permite la adquisición de habilidades básicas necesarias para la práctica, ya que posibilita la repetición de las maniobras y la tutela continuada. Consideramos que con esta metodología mixta se podría acortar la curva de aprendizaje de la CPRE y disminuiría la iatrogenia en las primeras fases (AU)

Aim. To show our experience in training in therapeutic endoscopy of the biliary tract in animal model. Materials and methods. This training activity has duration of 13 hours and starts initiating the trainee in anatomical differences with regard to human anatomy that occur between species that are used, the swine and canine. The practices consist of endoscopist to habituate the lateral view of duodenoscope, performing on pig model because it is easier to pass through the pyloricsphincter, although this is not very suitable for cannulation of the duodenal papilla. After passing the first stage, we used the canine model to acquire the skills and abilities specific to this technique. The performance evaluation is done through an anonymous survey. Results. 76% of students confirmed that they have made good progress with this training, 18% regular and 6% that shortly. 75% believed that after making this training would be found competent to carry out the technique in their hospitals. About 94% of students would recommend this activity. Conclusions. The use of animal model in training in endoscopic retrograde cholangiopancreatography (ERCP)permits the acquisition of basic skills needed for practice, a sit enables the repetition of the maneuvers and continuing care. We believe that this mixed methodology could shorten the learning curve for ERCP and reduce iatrogenic in the early stages (AU)

Effects of premedication with tiletamine/zolazepam/medetomidine during general anesthesia using sevoflurane/fentanyl in swine undergoing pancreas transplantation.

OBJECTIVE: To assess cardiac and hemodynamic responses and body temperature during long-term general anesthesia using sevoflurane/fentanyl after premedication with a tiletamine/zolazepam/medetomidine combination in swine undergoing experimental pancreas transplantation. MATERIALS AND METHODS: Twelve Landrace female pigs of means weight 46.4 +/- 5.1 kg were premedicated by intramuscular administration of tiletamine/zolazepam (3.5 mg/kg), medetomidine (0.03 mg/kg), and atropine (0.02 mg/kg), before anesthesia with 0.75 minimum alveolar concentration sevoflurane and continuous intravenous fentanyl infusion (5.7 +/- 0.7 microg/kg/h). Assessment of heart rate, arterial blood pressure, and temperature in pigs undergoing allogenic pancreas transplant surgery were registered at the start of anesthesia (T0), as well as at 60 (T60), 120 (T120), and 180 (T180) minutes after T0, and finally at the end of anesthesia (T anesthesia end), when we switched off the sevoflurane vaporizer. Analysis of variance was used to determine differences between times with P < .05 considered significant. Results are given as mean values +/- standard deviations. RESULTS: Arterial blood pressure significantly decreased from T120 to the end of anesthesia, while a significantly decreased heart rate was only evident at T60. Body temperature decreased significantly from T60 to the end of anesthesia. These decreases, however, lacked clinical relevance; all parameters were within normal range. No major anesthetic complications were observed in this study. CONCLUSIONS: The administration of a tiletamine/zolazepam/medetomidine combination as premedication in swine subjected to pancreas transplantation allowed for a safe reduction of sevoflurane/fentanyl requirements during long-term general anesthesia. Despite arterial blood pressure and body temperature evidencing a decrease during anesthetic maintenance, all parameters remained within normal range values.

[Usefulness of renal resistive index in the diagnosis and evolution of the obstructive uropathy. Experimental study]. / Utilidad del indice de resistencia renal en la valoración y evolución de la uropatía obstructiva. Estudio experimental.

OBJECTIVE: The study was focused on determining the effectiveness and reliability of using the renal resistance index as a method of diagnosing and monitoring the evolution of obstructive uropathy treatment. For this purpose, we conducted an experimental study on a homogenous group of animals that all had the same level of obstruction. MATERIAL AND METHODS: 15 healthy female pigs were used. The experiment was divided into three phases: phase I consisted of a study prior to unilateral pyeloureteral junction obstruction, performing retrograde ureteropyelography, renal B-mode ultrasound and duplex-Doppler (of both kidneys) at a level of the arcuate arteries. Then, the obstruction was performed on the animals. Phase II commenced by diagnosing the lesion, 6 weeks after the previous phase, by means of the aforementioned diagnostic methods. Finally, the endourological treatment was completed. Animals were monitored (Phase III) 15 weeks after the endopyelotomy, using the same methods as in the study, by assessing the urinary tract (fluoroscopy) and both kidneys by determining the renal resistance index and ratio. RESULTS: All the animals in the study showed signs of urinary obstruction on radiology and renal ultrasound 6 weeks after ureteral ligature. After treatment and follow-up, all animals showed signs of having recovered from the obstructive uropathy. Values of deltaRI during the 3 phases are detailed below. Fase I deltaIR = 0.01, Fase II deltaIR = 0.11, Fase III deltaIR = 0.02. CONCLUSION: RI determination using duplex-Doppler is effective for distinguishing obstructive dilatation using non-invasive techniques. However, this parameter provides very slight differences and it can also be influenced by too many direct and indirect factors (observational, patient age, anaesthesia, haemodynamic parameters, etc.), to supplant the classic diagnostic methods.

Utilidad del índice de resistencia renal en la valoración y evolución de la uropatía obstructiva. Estudio experimental / Usefulness of renal resistive index in the diagnosis and evolution of the obstructive uropathy. Experimental study

Objetivo: El planteamiento del estudio va enfocado a determinar la efectividad y fiabilidad de la medición del índice de resistencia renal (IR) para el diagnóstico y evolución tras el tratamiento de la uropatía obstructiva. Para ello realizamos un estudio experimental con un grupo homogéneo y con un grado de obstrucción uniforme. Material y métodos: Se emplean 15 animales de la especie porcina, todas hembras sanas. El planteamiento experimental está vertebrado en tres fases; la primera consiste en el estudio previo a la obstrucción de la unión pieloureteral unilateral mediante ureteropielografía retrógrada, nefrosonografía en modo B y dúplex-Doppler (ambos riñones) al nivel de las arterias arciformes. Posteriormente se procede a la creación del modelo animal de obstrucción. La Fase II comienza con el diagnóstico de la lesión 6 semanas después de la anterior fase, mediante los medios diagnósticos citados. Finalmente se completa el tratamiento endourológico. El seguimiento de los animales (Fase III) se realiza transcurridas 15 semanas tras la endopielotomía, valorando al igual que durante el estudio, la vía urinaria (fluoroscopia) y la afectación en ambos riñones mediante la determinación del índice de resistencia renal y su ratio. Resultados: Todos los animales del estudio mostraron signos radiológicos y nefrosonográficos de obstrucción urinaria tras 6 semanas de la ligadura ureteral. Tras el tratamiento y seguimiento todos los animales mostraron signos de recuperación de la uropatía obstructiva. Los valores del DeltaIR a lo largo de las 3 fases se detallan a continuación. Fase I DeltaIR = 0.01, Fase II DeltaIR = 0.11, Fase III DeltaIR = 0.02. Conclusiones: La valoración del IR mediante dúplex-Doppler es efectiva para la diferenciación de la dilatación obstructiva mediante técnicas no invasivas. Pero este parámetro aporta unas diferencias muy leves y además puede verse afectado por demasiados factores de modo directo o indirecto (observador, edad del paciente, anestesia, parámetros hemodinámicos, etc.), como para relegar los métodos de diagnóstico clásicos

Objective: The study was focused on determining the effectiveness and reliability of using the renal resistance index as a method of diagnosing and monitoring the evolution of obstructive uropathy treatment. For this purpose, we conducted an experimental study on a homogenous group of animals that all had the same level of obstruction. Material and methods: 15 healthy female pigs were used. The experiment was divided into three phases: phase I consisted of a study prior to unilateral pyeloureteral junction obstruction, performing retrograde ureteropyelography, renal Bmode ultrasound and duplex-Doppler (of both kidneys) at a level of the arcuate arteries. Then, the obstruction was performed on the animals. Phase II commenced by diagnosing the lesion, 6 weeks after the previous phase, by means of the aforementioned diagnostic methods. Finally, the endourological treatment was completed. Animals were monitored (Phase III) 15 weeks after the endopyelotomy, using the same methods as in the study, by assessing the urinary tract (fluoroscopy) and both kidneys by determining the renal resistance index and ratio. Results: All the animals in the study showed signs of urinary obstruction on radiology and renal ultrasound 6 weeks after ureteral ligature. After treatment and follow-up, all animals showed signs of having recovered from the obstructive uropathy. Values of DeltaRI during the 3 phases are detailed below. Fase I DeltaIR = 0.01, Fase II DeltaIR = 0.11, Fase III DeltaIR = 0.02. Conclusion: RI determination using duplex-Doppler is effective for distinguishing obstructive dilatation using non-invasive techniques. However, this parameter provides very slight differences and it can also be influenced by too many direct and indirect factors (observational, patient age, anaesthesia, haemodynamic parameters, etc.), to supplant the classic diagnostic methods

[Animal models in urological laparoscopic training]. / Modelos experimentales en la cirugía laparoscópica urológica.

We present the experience of the Minimally Invasive Surgery Centre (MISC) in the development of a modular training model in laparoscopic surgery. The experience analysis includes the description of the training objectives, the learning process of simple and advance laparoscopic urologic techniques, as well as some current and future considerations before applying the laparoscopic techniques. This learning program pretends to optimize the knowledge of the surgeon and the clinical practice of these surgical techniques. The phases of the learning process have been classified in four levels, which include different modules and models and whose application will depend on the experience and surgical skills. This pyramidal training system permits the student to advance step by step through each level depending on her surgical skills. We have presented our experience in twelve courses about laparoscopic urology and four courses of laparoscopic radical prostatectomy, in which more than 300 urologists have assisted. Furthermore, some Spanish Urology Units have been developing special experimental training programs on laparoscopic radical prostatectomy, partial nephrectomy or laparoscopic dismembered pyeloplasty with Anderson-Hynes technique. It has been previously described that laparoscopic modular learning constitutes a very useful concept to avoid problems related to an incomplete and incorrect learning process. Also it seems clear that the laparoscopic training reduces the learning curve in laparoscopic urologic techniques.

Modelo de formación en cirugía laparoscópica ginecológica / Teaching model of gynaecological laparoscopic surgery

En este capítulo se describe un modelo experimentalde enseñanza de cirugía laparoscópicaginecológica en cuatro niveles distintos

A experimental model of teaching gynaecologicallaparoscopic surgery in four different levelsis developed in this chapter

Modelos experimentales en la cirugía laparoscópica urológica / Animal moels in urological laparoscopic training

Presentamos la experiencia del Centro de Cirugía de Mínima Invasión (CCMI) en el desarrollo de un modelo de entrenamiento secuencial para la formación en cirugía laparoscópica urológica dotado con diferentes niveles de experiencia. Este análisis incluye la descripción de los objetivos de formación, el proceso de enseñanza de las técnicas urológicas sencillas y avanzadas y algunas consideraciones actuales y futuras antes de aplicar con éxito las técnicas laparoscópicas. El resultado final del programa de aprendizaje pretende optimizar la formación del cirujano y la práctica clínica de estas técnicas quirúrgicas. Las etapas del aprendizaje han sido clasificadas en cuatro niveles, diferenciándose a su vez una serie de módulos y modelos para el aprendizaje cuya aplicación dependerá de la experiencia y destreza del cirujano. Basado en este sistema piramidal de entrenamiento hemos establecido un programa de aprendizaje donde el alumno avanza paso a paso a través de cada nivel dependiendo de su nivel de habilidad. Presentamos nuestra experiencia en doce cursos de formación en laparoscopia urológica y cuatro cursos de formación en prostatectomía radical laparoscópica, habiendo asistido más de 300 urólogos a dichas actividades. Por otra parte, destacamos la puesta en marcha conjunta con algunos Servicios de Urología españoles de programas especiales de aprendizaje experimental de técnicas más complejas, como la prostatectomía radical laparoscópica, nefrectomía parcial o pieloplastia desmembrada de Anderson-Hynes. Como ya hemos advertido en otros trabajos, y como aseveran otros grupos, el aprendizaje laparoscópico por niveles constituye un concepto muy útil para evitar problemas derivados de un aprendizaje quirúrgico incompleto e incorrecto, al tiempo que permite reducir la curva de aprendizaje de las técnicas quirúrgicas urológicas haciendo posible implantar técnicas de cierta complejidad técnica en la práctica quirúrgica habitual en la especialidad de Urología

We present the experience of the Minimally Invasive Surgery Centre (MISC) in the development of a modular training model in laparoscopic surgery. The experience analysis includes the description of the training objectives, the learning process of simple and advance laparoscopic urologic techniques, as well as some current and future considerations before applying the laparoscopic techniques. This learning program pretends to optimize the knowledge of the surgeon and the clinical practice of these surgical techniques. The phases of the learning process have been classified in four levels, which include different modules and models and whose application will depend on the experience and surgical skills. This pyramidal training system permits the student to advance step by step through each level depending on her surgical skills. We have presented our experience in twelve courses about laparoscopic urology and four courses of laparoscopic radical prostatectomy, in which more than 300 urologists have assisted. Furthermore, some Spanish Urology Units have been developing special experimental training programs on laparoscopic radical prostatectomy, partial nephrectomy or laparoscopic dismembered pyeloplasty with Anderson-Hynes technique. It has been previously described that laparoscopic modular learning constitutes a very useful concept to avoid problems related to an incomplete and incorrect learning process. Also it seems clear that the laparoscopic training reduces the learning curve in laparoscopic urologic techniques

Relationship of bispectral index values, haemodynamic changes and recovery times during sevoflurane or propofol anaesthesia in rabbits.

The aim of this study was to determine and compare the degree of hypnosis achieved during propofol or sevoflurane anaesthesia in rabbits using bispectral index (BIS), and to evaluate its usefulness as a predictor of both haemodynamic changes during anaesthesia and recovery times. Twenty adult male New Zealand White rabbits, average weight 4.4 +/- 0.4 kg, were used for this study. Animals were randomly allocated to one of two groups with 10 rabbits/group. An electroencephalographic recording was obtained from each conscious rabbit prior to drug administration. All animals received buprenorphine as a preanaesthetic medication (0.05 mg/kg, intravenous [i.v.]). Anaesthesia was induced with propofol (8 mg/kg, i.v.) in all animals; 10 rabbits were maintained with sevoflurane via inhalation (1 minimum alveolar concentration--end-tidal sevoflurane concentration of 3.7%--at a fresh gas flow rate of 3 L/min; group I), and 10 were maintained with i.v. propofol (0.6 mg/kg/min; group II). The rabbits were orotracheally intubated and spontaneous ventilation was maintained throughout the study (100% oxygen). After abdominal surgery through a ventral midline laparotomy, rabbits were allowed to recover from anaesthesia. Cardiovascular variables and BIS values were recorded at intervals throughout the procedure, as was the duration of recovery from anaesthesia. In both groups, mean BIS values were significantly decreased immediately after induction, compared with baseline values obtained during consciousness. Anaesthetic depth (evaluated by clinical observation) was similar in both groups; however, group II rabbits had significantly higher (P<0.001) BIS values from 30 s before incision until anaesthesia was discontinued. There was no significant difference in BIS recorded 1 and 5 min after incision as compared with values obtained 30 s before incision in either group. During sevoflurane or propofol administration, correlations were found between BIS values and mean arterial blood pressure (MABP), and between BIS values and heart rate (HR). Mean BIS values at discontinuation of administration of the anaesthetic agent were greater in group II (69.1 +/- 6.0) than in group I (49.3 +/- 2.2). However, recovery from anaesthesia was significantly longer in group II (38.4 +/- 7.2 min) than in group I (11.5 +/- 2.5 min). In conclusion, BIS can be used to differentiate between conscious and unconscious states during anaesthesia in rabbits. BIS values derived from an electroencephalogram at the end of anaesthesia were not useful for predicting the speed of anaesthetic recovery in sevoflurane or propofol-anaesthetized rabbits undergoing abdominal surgery. Despite the correlation found between BIS and haemodynamic parameters, its usefulness as a predictor of clinically important changes in arterial blood pressure and HR in anaesthetized rabbits was limited.

[Endourologic treatment of ureteral strictures. Experimental comparative study]. / Tratamiento endourológico de estenosis ureterales. Estudio experimental comparativo.

OBJECTIVES: To compare efficacy and efficiency of two different endourological therapies for ureteral stricture, and to evaluate pathological reactions of the ureters following both endourological techniques. MATERIAL AND METHODS: Ten pigs underwent experimental induction of ureteral stricture. Four weeks later, ureteral strictures were demonstrated by imaging techniques. Animals were divided in two groups, according to the received therapy: -Group I. (5 pigs), endoballoon rupture endoureterotomy. -Group II (5 pigs), Acucise balloon endoureterotomy. Ureteral stents were placed for 3 weeks following endoureterotomy. Animals were followed up four weeks after ureteral stents retrieval. RESULTS: In all cases, ureteral stricture was proved four weeks after model induction. In one case from each group, it was needed a second balloon dilatation to achieve complete endoureterotomy. Leading to ureteral restenosis, stent migration occurred in one animal from group I. Success was achieved in 80% of cases from group I, and 100% of cases from group II. CONCLUSIONS: Our results suggest that both endourological therapies are effective. Nevertheless, a higher efficiency was proved with Acucise endoureterotomy. Our pathological evidences do not support Davis's studies on ureteral healing following endoureterotomy.

Histopathologic features of the vagus nerve after electrical stimulation in swine.

This paper describes the histological features of the vagus nerve after its stimulation with an electrostimulation system that is being developed for morbid obesity treatment. An electrostimulation system was implanted laparoscopically around the ventral vagal trunk of five Large White female pigs (49.63+/-1.94 kg.). Vagal nerve stimulation was performed by continuous constant voltage current pulses. Thoracic samples of both ventral and dorsal vagal trunks were obtained thoracoscopically one month after implantation. Animals were sacrificed one month after thoracoscopic vaguectomy. Tissue samples were then harvested from the vagal nerve at the implantation site, 1cm cranial to it, thoracic portion of ventral and dorsal vagal trunks, sub-diaphragmatic dorsal vagal trunk, left and right vagus nerves. Specimens were analysed with light microscope. The severity of the lesions was graded from 0 to 4 (0: no lesion, 1: mild, 2: moderate, 3: severe and 4: extremely severe), taking into account fibrosis, vascularization, necrosis, fiber degeneration and inflammation. Electrode implantation resulted in thickened epineurium and endoneural connective tissue. The greatest lesion score was evidenced at the leads implantation site in the ventral vagal trunk, followed by, in order of decreasing lesion severity, left vagus nerve, thoracic portion of ventral vagal trunk, subdiaphragmatic dorsal vagal trunk, thoracic portion of dorsal vagal trunk and right vagus nerve. The stimulation device used in this study caused connective tissue growth, greatest in the samples located closer to the implantation site. However, there was no sign of altered vascularization in any studied specimen.

Alveolar bone necrosis and tooth exfoliation following herpes zoster infection: a review of the literature and case report.

BACKGROUND: Herpes zoster (HZ) presents as a cutaneous vesicular eruption in the area innervated by the affected sensory nerve, usually associated with severe pain. Oral manifestations of HZ appear when the mandibular or maxillary divisions of the trigeminal nerve are affected. METHODS: This is a case report of a 63-year-old woman with HZ infection with trigeminal nerve involvement that led to a rapid loss of alveolar bone and exfoliation of two teeth. RESULTS: The initial intraoral examination showed redness of the alveolar mucosa and gingiva of the lower right quadrant with multiple well-delimited and painful erosive lesions affecting the attached gingiva around the teeth. Two weeks later, teeth number 27 (lower right canine) and 28 (lower right first premolar) had class III mobility, flow of purulent exudate from the gingival sulcus, and deep pockets (>11 mm). The radiological examination showed advanced alveolar bone loss around both teeth. The prognosis for teeth number 27 and 28 was considered hopeless, and they were extracted. Due to extensive necrosis there was no interdental alveolar bone. The case is presented with a review of clinical data from patients with trigeminal HZ infection associated with osteonecrosis or exfoliation of teeth previously reported in the literature. The mechanisms by which the HZ infection leads to the alveolar bone necrosis are discussed. CONCLUSIONS: Extensive osteonecrosis and exfoliation of teeth in the area innervated by the nerve affected by HZ has been reported after HZ infection. Clinicians should be aware of this possible outcome after a trigeminal HZ infection.

Tratamiento endourológico de estenosis ureterales. Estudio experimental comparativo / Endourologic treatment of ureteral strictures. Experimental comparative study

Objetivo: Los objetivos de este estudio son la comparación de la eficacia y la eficiencia entre dos técnicas endourológicas para el tratamiento de estenosis ureterales en modelo animal, así como la valoración histológica de la cicatrización ureteral. Material y métodos: Se emplearon 10 animales de la sp. porcina. A los que se les sometió a un modelo experimental de estenosis ureteral. Transcurridas 4 semanas se realiza el diagnóstico de la obstrucción urinaria. Dividimos a los animales en 2 grupos:-Grupo I. (5 animales), endoureterotomía con balón hasta la ruptura ureteral.-Grupo II (5 animales), tratamiento mediante Acucise®. Se disponen catéteres doble pigtail durante 3 semanas. Realizándose el seguimiento a las 4 semanas de la extracción de los mismos. Resultados: Todos los animales del estudio mostraron signos de obstrucción urinaria tras 4 semanas de la ligadura ureteral. De los 10 animales, uno de cada grupo necesitó una segunda aplicación de la técnica en la misma sesión. Encontramos en el Grupo I, la migración en sentido vesical de un catéter ureteral que provoca la restenosis. Tras la valoración de los resultados determinamos que el porcentaje de éxito es de un 80% en el grupo I y de un 100% en el II. Conclusiones: A la vista de los resultados obtenidos en nuestro estudio las dos técnicas se muestran efectivas, aunque el Acucise® se mostró más eficiente. No encontramos evidencias histológicas que avalen los estudios de cicatrización de Davis tras la endoureterotomía (AU)

Objectives: to compare efficacy and efficiency of two different endourological therapies for ureteral stricture, and to evaluate pathological reactions of the ureters following both endourological techniques. Material and methods: Ten pigs underwent experimental induction of ureteral stricture. Four weeks later, ureteralstrictures were demonstrated by imaging techniques. Animals were divided in two groups, according to the received therapy:-Group I. (5 pigs), endoballoon rupture endoureterotomy.-Group II (5 pigs), Acucise® balloon endoureterotomy. Ureteral stents were placed for 3 weeks following endoureterotomy. Animals were followed up four weeks after ureteral stents retrieval. Results. In all cases, ureteral stricture was proved four weeks after model induction. In one case from each group, itwas needed a second balloon dilatation to achieve complete endoureterotomy. Leading to ureteral restenosis, stent migration occurred in one animal from group I. Success was achieved in 80% of cases from group I, and 100% of cases from group II. Conclusions. Our results suggest that both endourological therapies are effective. Nevertheless, a higher efficiency was proved with Acucise® endoureterotomy. Our pathological evidences do not support Davis’s studies on ureteral healing following endoureterotomy (AU)

Interactive advanced-communication multistation system for microsurgical training.

The use of cameras in microscopes is not in itself new; however, this paper describes a new use of microscope-mounted cameras in conjunction with an audio intercom system for training in microsurgical techniques. The application of new technology may enhance traditional microsurgical training. Our objective was to compare the opinions of students attending training courses before and implementation of an interactive training system. This qualitative, descriptive study analyzed the results of end-of-course satisfaction surveys carried out among 400 students (physicians and veterinarians), 240 before and 160 after implementation of the system. Compared to the conventional system used previously at the Minimally Invasive Surgery Center and still in use elsewhere, most students felt that monitoring, training, and troubleshooting were both easier and more thorough using the multistation system. The "multistation system" allows real-time, one-to-one, tutor-student interaction, obviating the need for the tutor to move from student to student, and allowing him to monitor activity at the same working magnification as the student. As a result, the level of student satisfaction has improved.

Clips metálicos VCS: una técnica de sutura más rápida y fácil de utilizar que la sutura convencionalen reconstrucciones de vasos en crecimiento / Metallic vcs clips: a suturing technique that is quicker and easier to use than conventional suture in the reconstruction of growing vessels

Introducción. La última generación de aplicadores de clips de titanio denominados instrumentos VCS (vascular closure staples), además de evitar el daño en la íntima y la hiperplasia y favorecer la distensibilidad y el crecimiento del vaso, aportan rapidez y facilidad de manejo al cirujano, en contraposición a la técnica de sutura convencional discontinua con polipropileno. Éste puede ser el método que se elija en las reconstrucciones de elementos vasculares en crecimiento (cirugía pediátrica de aorta y trasplantes), y en el que la disminución del tiempo de clampaje sea importante. Objetivos. Comprobar si la técnica de sutura con clips metálicos VCS podría resultar ser un método más rápido para el cirujano que la técnica de sutura convencional discontinua con polipropileno, en anastomosis terminoterminales de arteria y vena. Materiales y métodos. Se utilizan 30 corderos, que se someten a los 55 días de edad a una anastomosis terminoterminal en la arteria carótida y vena yugular. Resultados. Confirmamos que los aplicadores de clips VCS son más fáciles de utilizar para el cirujano y disminuyen significativamente el tiempo que se emplea en las anastomosis terminoterminales de las arterias (clips, 4,02 ñ 0,72 min; sutura, 21,89 ñ 1,93 min) y de las venas (clips, 9,82 ñ 3,97 min; sutura, 29,31 ñ 1,90 min). Conclusiones. Los clips VCS reducen significativamente el tiempo que se emplea en realizar anastomosis terminoterminales de arterias y venas en comparación con la técnica convencional discontinua con polipropileno. (AU)