Endoscopic Biopsy for Intra- and Paraventricular Tumors: Rates of Complications, Mortality, and Tumor Cell Dissemination

Background and Study Aim Intra- and paraventricular tumors are frequently associated with cerebrospinal fluid (CSF) pathway obstruction. Thus the aim of an endoscopic approach is to restore patency of the CSF pathways and to obtain a tumor biopsy. Because endoscopic tumor biopsy may increase tumor cell dissemination, this study sought to evaluate this risk. Patients, Materials, and Methods Forty-four patients who underwent endoscopic biopsies for ventricular or paraventricular tumors between 1993 and 2011 were included in the study. Charts and images were reviewed retrospectively to evaluate rates of adverse events, mortality, and tumor cell dissemination. Adverse events, mortality, and tumor cell dissemination were evaluated. Results Postoperative clinical condition improved in 63.0% of patients, remained stable in 30.4%, and worsened in 6.6%. One patient (2.2%) had a postoperative thalamic stroke leading to hemiparesis and hemineglect. No procedure-related deaths occurred. Postoperative tumor cell dissemination was observed in 14.3% of patients available for follow-up. Conclusions For patients presenting with occlusive hydrocephalus due to tumors in or adjacent to the ventricular system, endoscopic CSF diversion is the procedure of first choice. Tumor biopsy in the current study did not affect safety or efficacy.

Conceptual framework for the design, implementation and validation of psychomotor skills’ assessment systems in minimally invasive surgery

Las técnicas de cirugía de mínima invasión (CMI) se están consolidando hoy en día como alternativa a la cirugía tradicional, debido a sus numerosos beneficios para los pacientes. Este cambio de paradigma implica que los cirujanos deben aprender una serie de habilidades distintas de aquellas requeridas en cirugía abierta. El entrenamiento y evaluación de estas habilidades se ha convertido en una de las mayores preocupaciones en los programas de formación de cirujanos, debido en gran parte a la presión de una sociedad que exige cirujanos bien preparados y una reducción en el número de errores médicos. Por tanto, se está prestando especial atención a la definición de nuevos programas que permitan el entrenamiento y la evaluación de las habilidades psicomotoras en entornos seguros antes de que los nuevos cirujanos puedan operar sobre pacientes reales. Para tal fin, hospitales y centros de formación están gradualmente incorporando instalaciones de entrenamiento donde los residentes puedan practicar y aprender sin riesgos. Es cada vez más común que estos laboratorios dispongan de simuladores virtuales o simuladores físicos capaces de registrar los movimientos del instrumental de cada residente. Estos simuladores ofrecen una gran variedad de tareas de entrenamiento y evaluación, así como la posibilidad de obtener información objetiva de los ejercicios. Los diferentes estudios de validación llevados a cabo dan muestra de su utilidad; pese a todo, los niveles de evidencia presentados son en muchas ocasiones insuficientes. Lo que es más importante, no existe un consenso claro a la hora de definir qué métricas son más útiles para caracterizar la pericia quirúrgica. El objetivo de esta tesis doctoral es diseñar y validar un marco de trabajo conceptual para la definición y validación de entornos para la evaluación de habilidades en CMI, en base a un modelo en tres fases: pedagógica (tareas y métricas a emplear), tecnológica (tecnologías de adquisición de métricas) y analítica (interpretación de la competencia en base a las métricas). Para tal fin, se describe la implementación práctica de un entorno basado en (1) un sistema de seguimiento de instrumental fundamentado en el análisis del vídeo laparoscópico; y (2) la determinación de la pericia en base a métricas de movimiento del instrumental. Para la fase pedagógica se diseñó e implementó un conjunto de tareas para la evaluación de habilidades psicomotoras básicas, así como una serie de métricas de movimiento. La validación de construcción llevada a cabo sobre ellas mostró buenos resultados para tiempo, camino recorrido, profundidad, velocidad media, aceleración media, economía de área y economía de volumen. Adicionalmente, los resultados obtenidos en la validación de apariencia fueron en general positivos en todos los grupos considerados (noveles, residentes, expertos). Para la fase tecnológica, se introdujo el EVA Tracking System, una solución para el seguimiento del instrumental quirúrgico basado en el análisis del vídeo endoscópico. La precisión del sistema se evaluó a 16,33ppRMS para el seguimiento 2D de la herramienta en la imagen; y a 13mmRMS para el seguimiento espacial de la misma. La validación de construcción con una de las tareas de evaluación mostró buenos resultados para tiempo, camino recorrido, profundidad, velocidad media, aceleración media, economía de área y economía de volumen. La validación concurrente con el TrEndo® Tracking System por su parte presentó valores altos de correlación para 8 de las 9 métricas analizadas. Finalmente, para la fase analítica se comparó el comportamiento de tres clasificadores supervisados a la hora de determinar automáticamente la pericia quirúrgica en base a la información de movimiento del instrumental, basados en aproximaciones lineales (análisis lineal discriminante, LDA), no lineales (máquinas de soporte vectorial, SVM) y difusas (sistemas adaptativos de inferencia neurodifusa, ANFIS). Los resultados muestran que en media SVM presenta un comportamiento ligeramente superior: 78,2% frente a los 71% y 71,7% obtenidos por ANFIS y LDA respectivamente. Sin embargo las diferencias estadísticas medidas entre los tres no fueron demostradas significativas. En general, esta tesis doctoral corrobora las hipótesis de investigación postuladas relativas a la definición de sistemas de evaluación de habilidades para cirugía de mínima invasión, a la utilidad del análisis de vídeo como fuente de información y a la importancia de la información de movimiento de instrumental a la hora de caracterizar la pericia quirúrgica. Basándose en estos cimientos, se han de abrir nuevos campos de investigación que contribuyan a la definición de programas de formación estructurados y objetivos, que puedan garantizar la acreditación de cirujanos sobradamente preparados y promocionen la seguridad del paciente en el quirófano. Abstract Minimally invasive surgery (MIS) techniques have become a standard in many surgical sub-specialties, due to their many benefits for patients. However, this shift in paradigm implies that surgeons must acquire a complete different set of skills than those normally attributed to open surgery. Training and assessment of these skills has become a major concern in surgical learning programmes, especially considering the social demand for better-prepared professionals and for the decrease of medical errors. Therefore, much effort is being put in the definition of structured MIS learning programmes, where practice with real patients in the operating room (OR) can be delayed until the resident can attest for a minimum level of psychomotor competence. To this end, skills’ laboratory settings are being introduced in hospitals and training centres where residents may practice and be assessed on their psychomotor skills. Technological advances in the field of tracking technologies and virtual reality (VR) have enabled the creation of new learning systems such as VR simulators or enhanced box trainers. These systems offer a wide range of tasks, as well as the capability of registering objective data on the trainees’ performance. Validation studies give proof of their usefulness; however, levels of evidence reported are in many cases low. More importantly, there is still no clear consensus on topics such as the optimal metrics that must be used to assess competence, the validity of VR simulation, the portability of tracking technologies into real surgeries (for advanced assessment) or the degree to which the skills measured and obtained in laboratory environments transfer to the OR. The purpose of this PhD is to design and validate a conceptual framework for the definition and validation of MIS assessment environments based on a three-pillared model defining three main stages: pedagogical (tasks and metrics to employ), technological (metric acquisition technologies) and analytical (interpretation of competence based on metrics). To this end, a practical implementation of the framework is presented, focused on (1) a video-based tracking system and (2) the determination of surgical competence based on the laparoscopic instruments’ motionrelated data. The pedagogical stage’s results led to the design and implementation of a set of basic tasks for MIS psychomotor skills’ assessment, as well as the definition of motion analysis parameters (MAPs) to measure performance on said tasks. Validation yielded good construct results for parameters such as time, path length, depth, average speed, average acceleration, economy of area and economy of volume. Additionally, face validation results showed positive acceptance on behalf of the experts, residents and novices. For the technological stage the EVA Tracking System is introduced. EVA provides a solution for tracking laparoscopic instruments from the analysis of the monoscopic video image. Accuracy tests for the system are presented, which yielded an average RMSE of 16.33pp for 2D tracking of the instrument on the image and of 13mm for 3D spatial tracking. A validation experiment was conducted using one of the tasks and the most relevant MAPs. Construct validation showed significant differences for time, path length, depth, average speed, average acceleration, economy of area and economy of volume; especially between novices and residents/experts. More importantly, concurrent validation with the TrEndo® Tracking System presented high correlation values (>0.7) for 8 of the 9 MAPs proposed. Finally, the analytical stage allowed comparing the performance of three different supervised classification strategies in the determination of surgical competence based on motion-related information. The three classifiers were based on linear (linear discriminant analysis, LDA), non-linear (support vector machines, SVM) and fuzzy (adaptive neuro fuzzy inference systems, ANFIS) approaches. Results for SVM show slightly better performance than the other two classifiers: on average, accuracy for LDA, SVM and ANFIS was of 71.7%, 78.2% and 71% respectively. However, when confronted, no statistical significance was found between any of the three. Overall, this PhD corroborates the investigated research hypotheses regarding the definition of MIS assessment systems, the use of endoscopic video analysis as the main source of information and the relevance of motion analysis in the determination of surgical competence. New research fields in the training and assessment of MIS surgeons can be proposed based on these foundations, in order to contribute to the definition of structured and objective learning programmes that guarantee the accreditation of well-prepared professionals and the promotion of patient safety in the OR.

EVA: Laparoscopic instrument tracking based on endoscopic video analysis for psychomotor skills assessment

INTRODUCTION: The EVA (Endoscopic Video Analysis) tracking system a new tracking system for extracting motions of laparoscopic instruments based on non-obtrusive video tracking was developed. The feasibility of using EVA in laparoscopic settings has been tested in a box trainer setup. METHODS: EVA makes use of an algorithm that employs information of the laparoscopic instrument's shaft edges in the image, the instrument's insertion point, and the camera's optical centre to track the 3D position of the instrument tip. A validation study of EVA comprised a comparison of the measurements achieved with EVA and the TrEndo tracking system. To this end, 42 participants (16 novices, 22 residents, and 4 experts) were asked to perform a peg transfer task in a box trainer. Ten motion-based metrics were used to assess their performance. RESULTS: Construct validation of the EVA has been obtained for seven motion-based metrics. Concurrent validation revealed that there is a strong correlation between the results obtained by EVA and the TrEndo for metrics such as path length (p=0,97), average speed (p=0,94) or economy of volume (p=0,85), proving the viability of EVA. CONCLUSIONS: EVA has been successfully used in the training setup showing potential of endoscopic video analysis to assess laparoscopic psychomotor skills. The results encourage further implementation of video tracking in training setups and in image guided surgery.

EVA: Endoscopic Video Analysis of the surgical scene for the assessment of MIS psychomotor skills

The present work covers the first validation efforts of the EVA Tracking System for the assessment of minimally invasive surgery (MIS) psychomotor skills. Instrument movements were recorded for 42 surgeons (4 expert, 22 residents, 16 novice medical students) and analyzed for a box trainer peg transfer task. Construct validation was established for 7/9 motion analysis parameters (MAPs). Concurrent validation was determined for 8/9 MAPs against the TrEndo Tracking System. Finally, automatic determination of surgical proficiency based on the MAPs was sought by 3 different approaches to supervised classification (LDA, SVM, ANFIS), with accuracy results of 61.9%, 83.3% and 80.9% respectively. Results not only reflect on the validation of EVA for skills? assessment, but also on the relevance of motion analysis of instruments in the determination of surgical competence.

Changing the paradigm: endoscopic video analysis and information extraction for safer surgeries

Background: Minimally invasive surgery creates two technological opportunities: (1) the development of better training and objective evaluation environments, and (2) the creation of image guided surgical systems.

Fetal endoscopic telesurgery using an Internet protocol connection: clinical and technical challenges

Until recently, fetoscopic laser surgery to seal the placental anastomoses that cause severe twin-to-twin transfusion syndrome has been available in only a few centres worldwide. The technique typically takes a long time to learn. We have used a dedicated Internet Protocol (IP) connection for tele-education to assist the introduction of fetoscopic laser surgery to Australia. During the implementation of the international telemedicine link, there were multiple clinical and technical problems, which were eventually overcome. The quality of images and of video-sequences was comparable to that supported by an ISDN connection. Pictures of live surgery performed by an expert in Florida, USA, were transmitted and viewed by a novice team in Brisbane, Australia. The Australian team has performed 19 fetoscopic laser operations to date. Preliminary results are comparable to those from centres that have performed over 100 procedures.

Selective approach for transperitoneal and extraperitoneal endoscopic nephrectomy in children

Purpose: From the experience of a large combined series of transperitoneal. (TP) and retroperitoneal (RP) endoscopic complete and partial nephroureterectornies in children, we present a logical selective endoscopic approach to benign renal pathology. Materials and Methods: During a 5-year period 122 complete nephrectomies and nephroureterectomies (bilateral 2, invisible ectopic 8) and 63 partial nephroureterectomies for duplex (52 upper, 8 lower) or singleton polar disease (xanthogranulomatous pyelonephritis 1, cyst 2) were performed. Of the partial nephrectomies, ureterectomy, bladder repair and lower moiety reimplantation were performed in 8. Patient age ranged from 2.7 months to 14 years (mean 2.9 years). Preoperative weight ranged from 2.7 to 98 kg (mean 12.3). The position of the renal remnant, the presence or absence of a refluxing ureter and the need for ureterectomy were the major determining factors affecting choice of endoscopic approach. Results: A total of 179 (96.7%) procedures were successfully completed endoscopically. The 6 open conversions (3.2%) occurred early in our experience. The operating time reflected the complexity of the excision and lower urinary reconstruction (lateral and posterior RP 25 to 145 minutes [mean 921) TP with ureterocelectomy and bladder neck repair 105 to 355 minutes [mean 153]. Hospital stay for RP and simple TP was 1.5 days (mean 1 to 4) and for complicated TP 2 to 8 days (mean 3.5). Conclusions: We suggest a posterior retroperitoneal approach with isolated renal excision without extended ureterectomy. The lateral retroperitoneal approach allows complete ureterectomy as well as better exposure to horseshoe and pelvic kidneys and, therefore, avoids exposure to intraperitoneal. structures. Finally, the transperitoneal approach is recommended when complete moiety excision with lower urinary reconstruction is anticipated.

A prospective assessment of SRS-24 scores after endoscopic anterior instrumentation for scoliosis

Study Design. Prospective clinical case series. Objective. To evaluate the clinical outcome of anterior endoscopic instrumention for scoliosis using the SRS-24 questionnaire and to examine how these scores change over a 2-year follow-up period. Summary of Background Data. Anterior endoscopic instrumentation correction has several advantages compared with open procedures. However, the clinical results of this technique using a validated outcome measure have rarely been reported in the literature. Methods. A total of 83 consecutive patients underwent endoscopic anterior instrumentation performed at a single unit. Patients completed the SRS-24 questionnaire before surgery and at 3, 6, 12, and 24 months after surgery. The SRS-24 scores were compared between each of the follow-up intervals. Results. The pain, general self-image, and function from back condition domains improved after surgery (P < 0.05). Activity level significantly improved between 3 and 6 months, and both function domains improved between 6 and 12 months (P < 0.05). None of the domains increased significantly after 1 year. Conclusions. Endoscopic anterior instrumentation for scoliosis significantly improved pain, self-image, and function. The greatest improvement in function occurred between 6 and 12 months after surgery. The SRS-24 scores at 1 year from surgery may provide a good indicator of patient outcome in the long-term.

Electropermanent magnetic anchoring for surgery and endoscopy

The use of magnets for anchoring of instrumentation in minimally invasive surgery and endoscopy has become of increased interest in recent years. Permanent magnets have significant advantages over electromagnets for these applications; larger anchoring and retraction force for comparable size and volume without the need for any external power supply. However, permanent magnets represent a potential hazard in the operating field where inadvertent attraction to surgical instrumentation is often undesirable. The current work proposes an interesting hybrid approach which marries the high forces of permanent magnets with the control of electromagnetic technology including the ability to turn the magnet OFF when necessary. This is achieved through the use of an electropermanent magnet, which is designed for surgical retraction across the abdominal and gastric walls. Our electropermanent magnet, which is hand-held and does not require continuous power, is designed with a center lumen which may be used for trocar or needle insertion. The device in this application has been demonstrated successfully in the porcine model where coupling between an intraluminal ring magnet and our electropermanent magnet facilitated guided insertion of an 18 Fr Tuohy needle for guidewire placement. Subsequent investigations have demonstrated the ability to control the coupling distance of the system alleviating shortcomings with current methods of magnetic coupling due to variation in transabdominal wall thicknesses. With further refinement, the magnet may find application in the anchoring of endoscopic and surgical instrumentation for minimally invasive interventions in the gastrointestinal tract.

Endoscopic incision for the treatment of refractory esophageal anastomotic strictures: outcomes of 13 cases with a minimum follow-up of 12 months

Background and aim: Endoscopic incision is an alternative method for refractory esophageal strictures; however, little is known about its long-term efficacy. The aim of the study is to assess the long-term outcomes of endoscopic incision for treating refractory esophageal anastomotic strictures. Methods: Between September 2011 and September 2014, 13 patients with refractory esophageal anastomotic strictures were treated with endoscopic incision. Their clinical data were retrospectively collected to evaluate the efficacy and safety of the technique. Results: All the 13 patients underwent the procedure successfully with median operation duration of 15 minutes. A total of 27 sessions were necessary to maintain lumen patency until September 2015, and 7 patients needed retreatment. The symptoms relieved in all the cases, and the median dysphagia score decreased from 4 to 1 during a median follow-up of 24 months. The median diameter of stricture was enlarged from 4 mm to 12 mm. As a short-term effect, dysphagia symptoms improved in 100% (13/13), 84.6% (11/13) and 76.9% (10/13) of the patients one, three and six months after a single treatment. As long-term effect, the dysphagia improved in 61.5% (8/13), 63.6% (7/11) and 60% (6/10) of the patients 12, 18 and 24 months after a single treatment. Conclusions: The efficacy of endoscopic incision is favorable in the short term. However, retreatment is needed to maintain the long-term lumen patency for parts of the patients.

Endoscopic band ligation without resection in selected patients for small and superficial upper gastrointestinal tract lesions

Background and aim: The aim of this study was to evaluate the efficacy of endoscopic band ligation (EBL) in carefully selected patients who would benefit from this method of resection. Methods: Patients with early upper gastrointestinal and small (< 15 mm) lesions treated with EBL (Duette® Multi-Band Mucosectomy) were prospectively recruited and retrospectively analyzed between 2010 and 2015. All cases were discussed in a multidisciplinary cancer committee and it was concluded that, owing to patient conditions, surgery was not possible and that not conducting histology would not change the clinical management. A first endoscopic control with biopsies was planned at 4-8 weeks. If there was no persistence of the lesion, new controls were programmed at 6 and 12 months. Results: The group (n = 12) included 5 esophagus lesions (adenosquamous carcinoma, n = 1; carcinoma squamous, n = 2; adenocarcinoma, n = 2); 4 gastric lesions (high grade dysplasia, n = 1; adenocarcinoma, n = 2; neuroendocrine tumor [NET], n = 1), and 3 duodenal lesions (NETs) (n = 3). The mean tumor diameter was 9.6 ± 2.8 mm (range 4-15). Only one minor adverse event was described. At first follow-up (4-8 weeks), there was 91.6% and 75% of endoscopic and histological remission, respectively. At 6-month follow-up there was 70% of both endoscopic remission and negative biopsies. And at 12 months, there was 100% and 75% of endoscopic and histological remission, respectively. Persisting lesions were T1 cancers. The median follow-up was 30.6 months. Conclusion: EBL without resection is an easy and safe technique that should be considered in patients with multiple morbidities and small superficial UGI lesions.

Flexible endoscopic treatment of Zenker's diverticulum: thirteen years' experience in Spain

Introduction: Flexible endoscopic treatment is one of the alternative approaches for the management of Zenker's diverticum. The present paper shows our short-term and long-term results with flexible endoscopic cricopharyngeal myotomy/septotomy. Patients and methods: A retrospective analysis of our experience in patients with Zenker's diverticulum treated using a flexible endoscope, assisted by a flexible diverticuloscope, between 2002 and 2015. Myotomy/septotomy was performed with a needle-knife papillotome under deep sedation or general anesthesia. Results: Among the 64 patients treated, two died within 10 days of surgery from causes not directly related to the procedure, and one presented with pharyngo-esophageal perforation, which recovered with conservative management at 47 days after admission. Four additional patients were lost to short-term follow-up. Among the 57 remaining patients, 52 had complete relief of dysphagia after 6 weeks. Eleven of these had recurrent symptoms on the mid and the long term. Eight were retreated with the same flexible endoscopic technique, one with a hybrid endoscopic approach, one with classical open surgery and one refused retreatment. After a mean follow-up of 2 years and a half, 33 of 37 patients reported absent or minimal dysphagia, controllable with punctual dietary restrictions. Conclusions: Flexible endoscopic treatment for Zenker's diverticulum is effective and safe. It represents an option on an equal footing to rigid endoscopy and classical open surgery and may also be used when the latter two are technically impracticable or contraindicated.

Laparoscopic Antireflux Surgery In Patients With Extra Esophageal Symptoms Related To Asthma.

Asthma, laryngitis and chronic cough are atypical symptoms of the gastroesophageal reflux disease. To analyze the efficacy of laparoscopic surgery in the remission of extra-esophageal symptoms in patients with gastroesophageal reflux, related to asthma. Were reviewed the medical records of 400 patients with gastroesophageal reflux disease submitted to laparoscopic Nissen fundoplication from 1994 to 2006, and identified 30 patients with extra-esophageal symptoms related to asthma. The variables considered were: gender, age, gastroesophageal symptoms (heartburn, acid reflux and dysphagia), time of reflux disease, treatment with proton pump inhibitor, use of specific medications, treatment and evolution, number of attacks and degree of esophagitis. Data were subjected to statistical analysis, comparing the pre- and post-surgical findings. The comparative analysis before surgery (T1) and six months after surgery (T2) showed a significant reduction on heartburn and reflux symptoms. Apart from that, there was a significant difference between the patients with daily crises of asthma (T1 versus T2, 45.83% to 16.67%, p=0.0002) and continuous crises (T1, 41.67% versus T2, 8.33%, p=0.0002). Laparoscopic Nissen fundoplication was effective in improving symptoms that are typical of reflux disease and clinical manifestations of asthma.

[balloon Laryngoplasty For Acquired Subglottic Stenosis In Children: Predictive Factors For Success].

The treatment of subglottic stenosis in children remains a challenge for the otorhinolaryngologist, and may involve both endoscopic and open surgery. To report the experience of two tertiary facilities in the treatment of acquired subglottic stenosis in children with balloon laryngoplasty, and to identify predictive factors for success of the technique and its complications. Descriptive, prospective study of children diagnosed with acquired subglottic stenosis and submitted to balloon laryngoplasty as primary treatment. Balloon laryngoplasty was performed in 37 children with an average age of 22.5 months; 24 presented chronic subglottic stenosis and 13 acute subglottic stenosis. Success rates were 100% for acute subglottic stenosis and 32% for chronic subglottic stenosis. Success was significantly associated with acute stenosis, initial grade of stenosis, children of a smaller age, and the absence of tracheostomy. Transitory dysphagia was the only complication observed in three children. Balloon laryngoplasty may be considered the first line of treatment for acquired subglottic stenosis. In acute cases, the success rate is 100%, and although the results are less promising in chronic cases, complications are not significant and the possibility of open surgery remains without prejudice.

Avoiding Pitfalls Of Intraoperative Peripheral Endovascular Surgery With The Aid Of Osirix: Expanding The Use Of Virtual Fluoroscopy.

We have shown how the analysis of the angiotomography reconstruction through OsiriX program has assisted in endovascular perioperative programming. We presented its application in situations when an unexpected existence of metallic overlapping artifact (orthopedic osteosynthesis) compromised the adequate visualization of the arterial lesion during the procedure. Through manipulation upon OsiriX software, with assistance of preview under virtual fluoroscopy, it was possible to obtain the angles that would avoid this juxtaposition. These angles were reproduced in the C-arm, allowing visualization of the occluded segment, reducing the need for repeated image acquisitions and contrast overload, allowing the continuation of the procedure.