Development and assessment of an ex-vivo bench model aimed at laparoscopic ureteric reconstructive techniques

INTRODUCTION/BACKGROUND

Reconstructive and ablative urologic techniques require special technical mastery, especially the intracorporeal suturing.

OBJECTIVE

To report the subjective evaluation of a versatile ex-vivo model aimed to practice laparoscopic ureteric reconstructive techniques (LURT) on box-trainer.

STUDY DESIGN

The model is a continuous portion of porcine urinary bladder ("dilated pelvis"), the vesico-ureteral joint ("stenosis") and healthy ureter. All 127 participants (n = 119 urologists and n = 8 paediatric surgeons) performed on the model laparoscopic Anderson-Hynes dismembered pyeloplasty, and then, in the animal model, different LURT procedures (ureteroneocystostomy, ureteric reimplantation and/or dismembered pyeloplasty). The model was subjectively evaluated (face and content validity), through a 12 items questionnaire, based on a Likert scale (1-5 points) and a global question (1-10 points).

RESULTS

The total mean rating for 11/12 items was very high (>4points). Only one was rated under 3 points. The overall total mean rating from 1 to 10 points was very high (9.19 ± 0.82 points). In 10/12 items, expert's feedback (content validity) prevailed over non-experts (face validity).

DISCUSSION/CONCLUSION

The model was highly accepted for the practice of LURT techniques. Additionally, it is cost-effective, easy to assemble, ethically considerate, and realistic.

The assessment of surgical skills as a complement to the training method. Revision

CONTEXT AND OBJECTIVE

The acquisition and improvement of surgical skills constitute a fundamental element in the training of any practitioner. At present, however, the assessment of these skills is a scarcely developed area of research. The aim of this study was to analyse the peculiarities of the various assessment systems and establish the minimum criteria that a skills and knowledge assessment system should meet as a method for assessing surgical skills in urological surgery.

ACQUISITION OF EVIDENCE

Scientific literature review aimed at the various currently available assessment systems for skills and competencies (technical and nontechnical), with a special focus on the systematic reviews and prospective studies.

SUMMARY OF THE EVIDENCE

After conducting the review, we found that the various assessment systems for surgical competence have, in our opinion, a number of shortcomings. There is a certain degree of subjectivity in the assessment of surgeons by the evaluators. The assessment of nontechnical competencies is not formally recorded. There is no description of a follow-up assessment or any basic parameters associated with healthcare quality. There is no registration of associated competencies associated with the various surgical techniques. There is also no ranking of these competencies and the specific peculiarities for their application.

CONCLUSIONS

We believe that the development of a new assessment system for surgical competencies (technical and nontechnical) aimed at assessing urologists in the various surgical techniques is necessary. To this end, our team has worked on developing the Evaluation System for Surgical Competencies on Laparoscopy, which is based on the definition, ranking and assessment of competencies demonstrated by surgeons.

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.

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.

[Diagnosis and follow up with endoluminal ultrasound in the endourologic treatment of experimental ureteral stenosis]

OBJECTIVES

The objective of this study is to determine the utility and reliability of endoluminal sonography transducer in the diagnosis and follow up after the treatment of partial ureteral obstruction.

MATERIAL AND METHODS

Ten healthy Large White female pigs, weighing 35-40 Kg, were induced a partial ureteral obstruction by laparoscopic approach. All the studied animals underwent the same three-phase procedure; inducement (phase 1), diagnosis (phase 2) and treatment of experimental strictures (phase 3), as well as, a month follow up. In all the stages of the study endoluminal sonography was used to diagnose the stricture and to assess the treatment, as well as, to measure the internal ureter diameter.

RESULTS

The endoluminal ultrasonography was able to assess, in all the cases, the affectation of all the ureteral layers. All the animals develop a ureteral stricture after a four weeks ligature and, except in one animal, they progress favourably after the treatment using the balloon rupture technique of the stricture ureter. The means of the ureteral diameter are: phase 1 (0.46 +/- 0.10 cm), phase 2 (0.30 +/- 0.17 cm), phase 3 (0.47 +/- 0.13 cm).

CONCLUSIONS

The use of the IVUS in the diagnosis of ureteral strictures results safe and useful, as well as, its application in the election and in the assessment of the treatment.