Alice Miranda

Transesophageal pulmonary lobectomy with single transthoracic port assistance: study with survival assessment in a porcine model

BACKGROUND AND STUDY AIMS Thoracoscopic pulmonary lobectomy is being performed in an increasing number of patients. The aims of the current study were to assess natural orifice transluminal endoscopic surgery (NOTES) as an alternative to transthoracic endoscopic surgery, and to test the feasibility of peroral transesophageal right upper pulmonary lobectomy with the assistance of a single transthoracic trocar. METHODS In 10 acute and 4 survival pigs, right upper pulmonary lobectomy was performed using a forward-viewing double-channel gastroscope and an operative thoracoscope with a 5-mm working channel inserted through a single transthoracic 12-mm) port. Time, safety, and feasibility of the following steps were recorded in all animals: esophagotomy, hilar dissection, individual ligation of the hilum elements, pulmonary lobectomy, and specimen retrieval. In the survival experiments, esophagotomy was closed using a reticulated laparoscopy suture device and an esophageal stent was placed. These animals were kept alive and monitored for 2 weeks. RESULTS Esophagotomy was performed safely in all animals (mean procedure duration 5.4 ± 1.7 minutes). Dissection of the right upper lobe hilum elements (bronchus, arteries, and veins) was carried out without adverse events. Individual ligation of the hilum elements was performed in all but two cases (time for dissection and ligation 44.2 ± 14.8 minutes). Lobectomy and specimen retrieval were completed in all animals (9.5 ± 3.1 minutes). Esophagotomy closure and stent placement were carried out in 20.0 ± 2.8 minutes in the survival animals. These animals fed normally and gained weight postoperatively without signs of disease. Endoscopic examination before necropsy revealed a pseudo-diverticulum in one animal, and wound dehiscence with confined collection/recess in the remaining animals. CONCLUSIONS Transesophageal right upper pulmonary lobectomy using single transthoracic trocar assistance is feasible and may represent a step towards scar-free pulmonary lobectomy.

TRANSTHORACIC SINGLE PORT WITH PERORAL ASSISTANCE: AN ANIMAL EXPERIMENT TO ASSESS A LESS INVASIVE TECHNIQUE FOR HUMAN ESOPHAGEAL ATRESIA REPAIR

Thoracoscopic repair of esophageal atresia has becoming the gold standard in many centers because it allows a better cosmetic result and avoids the musculoskeletal sequelae of a thoracotomy. Natural orifice translumenal endocopic surgery (NOTES) is a new surgical paradigm, and its human application has already been started in some procedures. In the present study, we explore the feasibility of performing an esophagoesophageal anastomosis using a single transthoracic single port combined with a peroral access in a rabbit model to simulate repair of esophageal atresia by hybrid NOTES in a human newborn. Adult male rabbits (Oryctolagus cuniculus, n=28) were used to perform the surgical protocol. We used a transthoracic telescope with a 3-mm working channel and a flexible endoscope with a 2.2-mm working channel by peroral access. We performed total esophagotomy with peroral scissors followed by an esophagoesophageal anastomosis achieved with a rigid transthoracic scope helped by the peroral operator. Extracorporeal transthoracic knots were performed to complete the anastomosis. The anastomoses were examined in loco and ex loco, after animal sacrifice. We successfully accomplished a complete esophageal anastomosis in all rabbits using a combination of transthoracic and peroral 3-mm instruments. This study provides important insights for a possible translation of hybrid NOTES to human newborns with esophageal atresia. Forward studies to accomplish their feasibility in human newborns will still be necessary.

Left atrial appendage ligation with single transthoracic port assistance: a study of survival assessment in a porcine model (with videos)

BACKGROUND Left atrial appendage (LAA) exclusion is a well-known procedure for the prevention of stroke in high-risk patients with atrial fibrillation and contraindication to long-term oral anticoagulant therapy. OBJECTIVE To evaluate a natural orifice transluminal endoscopic surgery (NOTES) approach for LAA ligation. DESIGN In 4 acute and 6 survival pigs, we performed LAA by using a forward-viewing, single-channel gastroscope and an operative thoracoscope with a 3-mm working channel (introduced through an 8-mm single transthoracic port). SETTING Animal laboratory. INTERVENTIONS The gastroscope was introduced in the thoracic cavity through an esophageal submucosal tunnel. An end loop introduced through the gastroscope was used to legate the LAA. In the survival experiments, the esophageal mucosa was closed using hemoclips. MAIN OUTCOME MEASUREMENTS The time, safety, and feasibility of the procedure were recorded. In the survival experiments, endoscopy and postmortem examination were performed on postoperative day 14. RESULTS Creation of a submucosal tunnel and esophagotomy were safely performed in all animals without incidents. The mean time for esophagotomy was 17.0 ± 6.3 minutes. Pericardial dissection and LAA ligation were performed in all animals but 1. The mean time for LAA ligation was 34.4 ± 19.1 minutes. No adverse events occurred during the survival period. Endoscopy showed complete esophageal closure. Postmortem examination revealed pleural adhesions on the site of pericardial dissection, and the LAA was fibrotic with the endoloop in place. LIMITATIONS Animal study. CONCLUSIONS LAA ligation with single transthoracic trocar assistance is feasible and may be an alternative to anticoagulant therapy or to permanent intracardiac implants in patients with atrial fibrillation.

Animal facility videoendoscopic intubation station: tips and tricks from mice to rabbits

Endotracheal intubation of laboratory animals is a common procedure shared by several research fields for different purposes, such as mechanical ventilation of anaesthetized animals, instillation of cytotoxic nanoparticles, infectious agents or tumour cells for induction of disease models, and even for diagnostic and therapeutic purposes. These different research purposes, achieved in different animal models, require technical expertise and equipment that suits every research need from animal facilities. In this short report we propose a videoendoscopic intubation station that could be shared among the most common laboratory animals, namely the mouse, rat, guinea pig and rabbit, from neonates to adult animals. This report aims to contribute to the reduction of animals excluded from experiments due to false paths during direct and blind intubations and to the refinement of procedures by replacing surgical approaches such as tracheotomy.

Inflammatory response and long-term behavioral assessment after neonatal CO2-pneumothorax: study in a rodent model

BACKGROUND Carbon-dioxide (CO2)-pneumothorax during minimally invasive surgery induces well-known metabolic changes. However, little is known about its impact on the central nervous system. The aim of this work is to evaluate the acute impact of CO2-pneumothorax over central cytokine response and its long-term effect on animal behavior. METHODS This is an experimental study where neonatal Sprague-Dawley rats are submitted to CO2-pneumothorax. Peripheral and central cytokine response was evaluated 24h after insufflation, and peripheral immune cell phenotyping was evaluated 24h and 4weeks post-insufflation. Progenitor cell survival was evaluated in the hippocampal dentate gyrus, and the behavioral analysis was performed in adulthood to test cognition, anxious-like, and depressive-like behavior. RESULTS Significantly increased IL-10 levels were observed in the cerebrospinal-fluid (CSF) of animals submitted to CO2-pneumothorax, while no differences were found in serum. Regarding pro-inflammatory cytokines, no differences were observed in the periphery or centrally. CO2-pneumothorax event did not alter the survival of newborn cells in the hippocampal dentate gyrus, and no impact on long-term behavior was observed. CONCLUSIONS Neonatal animals submitted to CO2-pneumothorax present acutely increased CSF IL-10 levels. The CO2-pneumothorax seems to result in no significant outcome over neurodevelopment as no functional behavioral alterations were observed in adulthood.

Resection of Sentinel Lymph Nodes by an Extraperitoneal Minilaparoscopic Approach Using Indocyanine Green for Uterine Malignancies: A Preclinical Comparative Study.

Background. The sentinel lymph node (SLN) concept might minimize surgical aggressiveness in cervical and endometrial malignancies. The aim of the study was to test the feasibility and reliability of minilaparoscopic extraperitoneal SLN excision after indocyanine green (ICG) cervical injection using a high-definition near infrared (NIR) imaging system in an in vivo porcine model. The same procedure was performed using conventional laparoscopic instruments and both outcomes were compared. Methods. Twenty-four animals were equally and randomly divided into a minilaparoscopic group (group A) and a 5-mm conventional laparoscopic group (group B). A high-definition NIR imaging system and a 30° ICG endoscope were used. First, ICG (0.5 mL) was injected in the paracervical region. The SLN coloring time was recorded. An extraperitoneal approach to the SLN was executed with the same CO2 retropneumoperitoneum pressures (10 mm Hg). In both groups, the times for SLN localization and excision, as well as complications, were registered. Finally, a laparotomy was then done to evaluate whether any stained SLN still remained. The same surgical team performed all experiments. Results. SLNs were identified and extraperitoneally excised in all animals without major complications. The SLN localization varied between animals from external iliac to preaortic regions. The surgical times were shorter with minilaparoscopy (39.3 ± 13 minutes) than with conventional 5-mm instruments (51.3 ± 14.17 minutes; P = .042). In group B, one stained SLN remained and was only detected by laparotomy. Conclusions. We confirmed the feasibility and reliability of extraperitoneal minilaparoscopic approach for identification, dissection, and excision of SLN using an NIR imaging system and ICG.

MP45-09 EFFECTS OF CASTRATION AND TESTOSTERONE REPLACEMENT OVER SEROTONIN (PROSTATIC AND PLASMATIC): A MICE IN VIVO STUDY.

Here, we hypothesized that modulating the plasmatic levels of 5-HT through a tryptophan-rich diet we could inhibit prostatic growth. METHODS: C57BL6 adult male mice were divided in 2 groups, Group 1: fed with a normal diet and Group 2: fed with, for a 3-month period. After the sacrifice of the mice, the prostate was dissected and weighted. By ELISA, prostatic 5-HT concentration was determined and by Western Blot, AR expression was evaluated in both groups. RESULTS: We observed that mice fed with a tryptophan-rich diet for 3 months present a significant reduction in the prostatic weight comparatively to mice fed with normal diet (fig1). Intra-prostatic 5-HT concentration was significantly increased in mice fed with a tryptophanrich diet (fig2). Furthermore, we demonstrated that the expression of AR in prostatic tissue from mice who underwent tryptophan supplementation was inferior to the AR expression in the normal diet group (fig3). CONCLUSIONS: Modulating diet through tryptophan enrichment, with the consequent increase in prostatic serotonin, decreases prostate size and down-regulates AR. These results suggests that a tryptophan rich diet could be potential used to prevent or treat BPH.

Neurodevelopment impact of CO2-pneumoperitoneum in neonates: experimental study in a rat model

BACKGROUND Laparoscopy is becoming more common in neonates. However, concerns remain about the impact of the carbon-dioxide (CO2)-insufflation over the neonatal brain. We aim to evaluate the peripheral (serum) and central (cerebrospinal fluid [CSF]) cytokine response after neonatal CO2-pneumoperitoneum and its impact over neurodevelopmental milestones acquisition and long-term behavioral outcomes. MATERIALS AND METHODS Rats were subjected to a systematic assessment of neurodevelopmental milestones between postnatal day 1 (PND 1) and PND 21. At PND 10, neonatal rats were anesthetized, mechanically ventilated, and exposed to different pressures and times of abdominal CO2-insufflation. Immediately after pneumoperitoneum, corticosterone was analyzed in serum. Twenty-four hours after intervention, serum and CSF were collected to assess inflammatory response (interleukin [IL]-10, IL-1β, tumor necrosis factor [TNF]-α, and interferon [IFN]-γ). In adulthood, animals from each group were submitted to several tests to assess different behavioral domains (locomotion, anxiety, mood, and cognition). RESULTS The antiinflammatory cytokine IL-10 was significantly increased in CSF in CO2-insufflated groups, with no other significant changes in the other biomarkers. Acquisition of neurodevelopmental milestones was maintained in all studied groups. No significant differences were observed in adult behavior in the different CO2-insufflation conditions. CONCLUSIONS Neonatal CO2-pneumoperitoneum does not seem to have any negative impact on neurodevelopment or induce behavioral alterations in adulthood. Minimally invasive surgery results in a central antiinflammatory profile, and further studies on the functional consequences of these phenomena are needed.

MP17-14 DEPLETION OF PERIPHERAL SEROTONIN SYNTHESIS INDUCES BENIGN PROSTATIC GROWTH IN MICE: MORE EVIDENCE FOR THE NEW “NEUROENDOCRINE THEORY” IN BPH ETIOLOGY

up-regulated collagen 1 and aSMA protein expression in response to IL-4 or IL-13 treatment. These effects were ablated through co-treatment with IL-4 and IL-13 receptors antibodies. Low concentrations of IL-4 and IL-13 significantly up-regulated N1 and primary prostate cell proliferation. Prostate fibroblasts treated with IL-4 or IL-13 significantly and almost equivalently up-regulated IL-13 protein expression, suggesting the establishment of an autocrine IL-13 expression loop. Treatment with IL-4 alone up-regulated IL-4, but not IL-13, protein expression. Neither IL-4 nor IL-13 affected TGFbeta expression levels. CONCLUSIONS: The results of these studies show that IL-4 and IL-13 promote myofibroblast phenoconversion and collagen accumulation, and thus support a role for IL-4/IL-13 promotion of prostatic fibrosis associated with LUTD. A major new discovery reported here is that Th2 cytokines, particularly IL-13, can establish autocrine expression loops in prostate fibroblasts that may promote continual myofibroblast phenoconversion in the lower urinary tract. These findings support the investigation of small molecules or antibodies that target Th2 IL-4/IL13 activities for the prevention or treatment of lower urinary tract fibrosis.

Serotonin regulates prostate growth through androgen receptor modulation

Aging and testosterone almost inexorably cause benign prostatic hyperplasia (BPH) in Human males. However, etiology of BPH is largely unknown. Serotonin (5-HT) is produced by neuroendocrine prostatic cells and presents in high concentration in normal prostatic transition zone, but its function in prostate physiology is unknown. Previous evidence demonstrated that neuroendocrine cells and 5-HT are decreased in BPH compared to normal prostate. Here, we show that 5-HT is a strong negative regulator of prostate growth. In vitro, 5-HT inhibits rat prostate branching through down-regulation of androgen receptor (AR). This 5-HT’s inhibitory mechanism is also present in human cells of normal prostate and BPH, namely in cell lines expressing AR when treated with testosterone. In both models, 5-HT’s inhibitory mechanism was replicated by specific agonists of 5-Htr1a and 5-Htr1b. Since peripheral 5-HT production is specifically regulated by tryptophan hydroxylase 1(Tph1), we showed that Tph1 knockout mice present higher prostate mass and up-regulation of AR when compared to wild-type, whereas 5-HT treatment restored the prostate weight and AR levels. As 5-HT is decreased in BPH, we present here evidence that links 5-HT depletion to BPH etiology through modulation of AR. Serotoninergic prostate pathway should be explored as a new therapeutic target for BPH.