Jesús Usón

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.

An animal model of abdominal aortic aneurysm created with peritoneal patch: technique and initial results.

AbstractThe purpose of this study was to develop an abdominal aortic aneurysm model that more closely resembles the morphology of human aneurysms with potential for further growth of the sac. An infrarenal abdominal aortic aneurysm (AAA) model was created with a double-layered peritoneal patch in 27 domestic swine. The patch, measuring in average from 6 to 12 cm in length and from 2 to 3 cm in width, was sutured to the edge of an aortotomy. Pre- and postsurgical digital subtraction aortograms (DSA) were obtained to document the appearance and dimensions of the aneurysm. All animals were followed with DSA for up to 5 months. Laparoscopic examination enhanced by the use of laparoscopic ultrasound was also carried out in 2 animals to assess the aneurysm at 30 and 60 days following surgery. Histological examination was performed on 4 animals. All the animals that underwent the surgical creation of the AAA survived the surgical procedure. Postsurgical DSA demonstrated the presence of the AAA in all animals, defined as more than 50% increase in diameter. The aneurysmal mean diameter increased from the baseline of 10.27 ± 1.24 to 16.69 ± 2.29 mm immediately after surgery, to 27.6 ± 6.59 mm at 14 days, 32.45 ± 8.76 mm at 30 days (p < 0.01), and subsequently decreased to 25.98 ± 3.75 mm at 60 days. A total of 15 animals died of aneurysmal rupture that occurred more frequently in the long aneurysms (≥6 cm in length) than the short aneurysms (<6 cm in length) during the first 2 weeks after surgery (p < 0.05). No rupture occurred beyond 16 days after surgery. Four animals survived and underwent 60-day angiographic follow-up. Laparoscopic follow-up showed strong pulses, a reddish external appearance and undetectable suture lines on the aneurysmal wall. On pathology, the patches were well incorporated into the aortic wall, the luminal wall appeared almost completely endothelialized, and cellular and matrix proliferation were noted in the aneurysmal wall. A reproducible technique for the creation of an infrarenal AAA model was developed using a peritoneal patch in swine. The aneurysm model proved to have potential for further growth of the sac and a tendency to rupture. Because of the growth potential, this might be a better model than those with a noncompliant aneurysmal wall for the preclinical evaluation of stent-graft devices.

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

Abstract 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.

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.

Ergonomic Assessment of Hand Movements in Laparoscopic Surgery Using the CyberGlove

The main objective of this chapter is the automation of the ergonomic assessment of the wrist’s positions, through biomechanics analysis techniques, specifically using the rapid upper limb assessment (RULA). So, this allows establishing new use and design guidelines of the laparoscopic instruments, in order to reduce the influence of risk factors in the wrist area, which are associated with forced positions during the development of laparoscopic activities.

Adult hydrocele and spermatocele.

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Effectiveness of three-dimensional fluoroscopy in percutaneous nephrostomy: an animal model study.

OBJECTIVES To present, in an experimental study, an assessment of innovative digital fluoroscopy systems with three-dimensional (3D) reconstruction for use in endourologic applications. METHODS The experiment was performed in a pig model. We used 5 pigs. An obstructive uropathy model was created in the right kidney to dilate the urinary tract for group 1. Group 2 consisted of the nondilated left kidney. After selecting the tract on the 3D image, the lower caliceal group was punctured in the 2 kidneys under fluoroscopic control, to assess the efficiency of the 3D reconstruction when selecting the renal calix to be punctured. RESULTS The 3D reconstruction system allowed us to obtain reconstruct the pelvis in three dimensions, isolated as the pelvis and renal parenchyma, as well as the adjacent bony relationships. In this study, the success rate was 100% for locating the selected renal calix. CONCLUSIONS With this 3D reconstruction system, we were able to obtain a series of images that allowed for the study of the volume of the kidney, perfectly determining its renal calix distribution in the operating room. This enabled us to determine the precise delineation of the target calix. We, therefore, consider this new urologic application of fluoroscopy very useful in surgical planning for antegrade access of the upper urinary tract.

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

BackgroundNovel 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.MethodsAfter 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.ResultsIsolation 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.ConclusionThe 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.

Evaluation of the duration of ureteral stenting following endopyelotomy: Animal study

Background: The purpose of the present paper was to evaluate whether it is possible to reduce the duration of ureteral stenting following endopyelotomy, and thus reduce side‐effects.

Angiographic study and therapeutic embolization of soft-tissue fibrosarcoma in a dog: case report and literature.

A case of soft-tissue fibrosarcoma with pulmonary metastases in a dog is reported. Although three attempts of fine-needle aspiration (FNA) biopsy failed to provide definitive tumor diagnosis, results of angiography strongly indicated a soft-tissue sarcoma. Transcatheter arterial embolization (TAE) using particles of gelatin sponge was performed following selective angiography. The mass was decreased in size on reevaluation 2 weeks after embolization. The dog was euthanized on the request of the owners due to overall failing health. Necropsy and pathological study confirmed the diagnosis of soft-tissue fibrosarcoma with pulmonary metastases. In a review of the literature, angiographic findings of soft-tissue sarcoma in the dog of this report were similar to those in human beings, suggesting a potential role for angiography in the differential diagnosis of suspect soft-tissue fibrosarcomas and for guiding FNA or surgical biopsy. Previous reports have also shown therapeutic embolization to be an effective treatment both in experimental animal study and in clinical practice in the human; therefore, TAE could be an effective adjunctive treatment of soft-tissue fibrosarcoma in the dog.