Mussismilia braziliensis White Plague Disease Is Characterized by an Affected Coral Immune System and Dysbiosis.

Infectious diseases are one of the major drivers of coral reef decline worldwide. White plague-like disease (WPL) is a widespread disease with a complex etiology that infects several coral species, including the Brazilian endemic species Mussismilia braziliensis. Gene expression profiles of healthy and WPL-affected M. braziliensis were analyzed in winter and summer seasons. The de novo assembly of the M. braziliensis transcriptome from healthy and white plague samples produced a reference transcriptome containing 119,088 transcripts. WPL-diseased samples were characterized by repression of immune system and cellular defense processes. Autophagy and cellular adhesion transcripts were also repressed in WPL samples, suggesting exhaustion of the coral host defenses. Seasonal variation leads to plasticity in transcription with upregulation of intracellular signal transduction, apoptosis regulation, and oocyte development in the summer. Analysis of the active bacterial rRNA indicated that Pantoea bacteria were more abundant in WPL corals, while Tistlia, Fulvivirga, and Gammaproteobacteria Ga0077536 were more abundant in healthy samples. Cyanobacteria proliferation was also observed in WPL, mostly in the winter. These results indicate a scenario of dysbiosis in WPL-affected M. braziliensis, with the loss of potentially symbiotic bacteria and proliferation of opportunistic microbes after the start of the infection process.

Ecogenomics and metabolic potential of the South Atlantic Ocean microbiome.

The unique combination of depth, salinity, and water masses make the South Atlantic Ocean an ecosystem of special relevance within the global ocean. Yet, the microbiome of this ecosystem has received less attention than other regions of the global Ocean. This has hampered our understanding of the diversity and metabolic potential of the microorganisms that dwell in this habitat. To fill this knowledge gap, we analyzed a collection of 31 metagenomes from the Atlantic Ocean that spanned the epipelagic, mesopelagic and bathypelagic zones (surface to 4000 m). Read-centric and gene-centric analysis revealed the unique taxonomic and functional composition of metagenomes from each depth zone, which was driven by differences in physical and chemical parameters. In parallel, a total of 40 metagenome-assembled genomes were obtained, which recovered one third of the total community. Phylogenomic reconstruction revealed that many of these genomes are derived from poorly characterized taxa of Bacteria and Archaea. Genomes derived from heterotrophic bacteria of the aphotic zone displayed a large apparatus of genes suited for the utilization of recalcitrant organic compounds such as cellulose, chitin and alkanes. In addition, we found genomic evidence suggesting that mixotrophic bacteria from the bathypelagic zone could perform carbon fixation through the Calvin-Benson-Bassham cycle, fueled by sulfur oxidation. Finally, we found that the viral communities shifted throughout the water column regarding their targeted hosts and virus-to-microbe ratio, in response to shifts in the composition and functioning their microbial counterparts. Our findings shed light on the microbial and viral drivers of important biogeochemical processes that take place in the South Atlantic Ocean.

Modelling the influence of environmental parameters over marine planktonic microbial communities using artificial neural networks.

Guanabara Bay is a tropical estuarine ecosystem that receives massive anthropogenic impacts from the metropolitan region of Rio de Janeiro. This ecosystem suffers from an ongoing eutrophication process that has been shown to promote the emergence of potentially pathogenic bacteria, giving rise to public health concerns. Although previous studies have investigated how environmental parameters influence the microbial community of Guanabara Bay, they often have been limited to small spatial and temporal gradients and have not been integrated into predictive mathematical models. Our objective was to fill this knowledge gap by building models that could predict how temperature, salinity, phosphorus, nitrogen and transparency work together to regulate the abundance of bacteria, chlorophyll and Vibrio (a potential human pathogen) in Guanabara Bay. To that end, we built artificial neural networks to model the associations between these variables. These networks were carefully validated to ensure that they could provide accurate predictions without biases or overfitting. The estimated models displayed high predictive capacity (Pearson correlation coefficients ≥0.67 and root mean square error ≤ 0.55). Our findings showed that temperature and salinity were often the most important factors regulating the abundance of bacteria, chlorophyll and Vibrio (absolute importance ≥5) and that each of these has a unique level of dependence on nitrogen and phosphorus for their growth. These models allowed us to estimate the Guanabara Bay microbiome's response to changes in environmental conditions, which allowed us to propose strategies for the management and remediation of Guanabara Bay.

Proposal of fifteen new species of Parasynechococcus based on genomic, physiological and ecological features.

Members of the recently proposed genus Parasynechococcus (Cyanobacteria) are extremely abundant throughout the global ocean and contribute significantly to global primary productivity. However, the taxonomy of these organisms remains poorly characterized. The aim of this study was to propose a new taxonomic framework for Parasynechococcus based on a genomic taxonomy approach that incorporates genomic, physiological and ecological data. Through in silico DNA-DNA hybridization, average amino acid identity, dinucleotide signatures and phylogenetic reconstruction, a total of 15 species of Parasynechococcus could be delineated. Each species was then described on the basis of their gene content, light and nutrient utilization strategies, geographical distribution patterns throughout the oceans and response to environmental parameters.

Swallowable fluorometric capsule for wireless triage of gastrointestinal bleeding.

Real-time detection of gastrointestinal bleeding remains a major challenge because there does not yet exist a minimally invasive technology that can both i) monitor for blood from an active hemorrhage and ii) uniquely distinguish it from blood left over from an inactive hemorrhage. Such a device would be an important tool for clinical triage. One promising solution, which we have proposed previously, is to inject a fluorescent dye into the blood stream and to use it as a distinctive marker of active bleeding by monitoring leakage into the gastrointestinal tract with a wireless fluorometer. This paper reports, for the first time to our knowledge, the development of a swallowable, wireless capsule with a built-in fluorometer capable of detecting fluorescein in blood, and intended for monitoring gastrointestinal bleeding in the stomach. The embedded, compact fluorometer uses pinholes to define a microliter sensing volume and to eliminate bulky optical components. The proof-of-concept capsule integrates optics, low-noise analog sensing electronics, a microcontroller, battery, and low power Zigbee radio, all into a cylindrical package measuring 11 mm × 27 mm and weighing 10 g. Bench-top experiments demonstrate wireless fluorometry with a limit-of-detection of 20 nM aqueous fluorescein. This device represents a major step towards a technology that would enable simple, rapid detection of active gastrointestinal bleeding, a capability that would save precious time and resources and, ultimately, reduce complications in patients.

Evaluation of an endoscopic suturing device for transoral outlet reduction in patients with weight regain following Roux-en-Y gastric bypass.

BACKGROUND AND STUDY AIMS: A dilated gastrojejunal anastomosis (GJA) is thought to be associated with weight regain in patients with Roux-en-Y gastric bypass (RYGB). Due to a high rate of perioperative morbidity, surgical revision is not generally performed. The aim of this study was to assess the technical feasibility, safety, and early outcomes of a procedure using a commercially available endoscopic suturing device to reduce the diameter of the GJA. PATIENTS AND METHODS: This was a retrospective analysis of 25 consecutive patients who underwent transoral outlet reduction (TORe) for dilated GJA and weight regain. An endoscopic suturing device was used to place sutures at the margin of the GJA in order to reduce its aperture. On chart review, clinical data were available at 3, 6, and 12 months. RESULTS: Patients had regained a mean of 24 kg from their weight loss nadir and had a mean body mass index of 43 kg/m2 at the time of endoscopic revision. Average anastomosis diameter was 26.4 mm. Technical success was achieved in all patients (100 %) with a mean reduction in anastomosis diameter to 6 mm (range 3 - 10 mm), representing a 77.3 % reduction. The mean weight loss in successful cases was 11.5 kg, 11.7 kg, and 10.8 kg at 3, 6, and 12 months, respectively. There were no major complications. CONCLUSION: This case series demonstrated the technical feasibility, safety, and efficacy of performing gastrojejunostomy reduction using a commercially available endoscopic suturing device. This technique may represent an effective and minimally invasive option for the management of weight regain in patients with RYGB.

Real-time computed tomography-based augmented reality for natural orifice transluminal endoscopic surgery navigation.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) is technically challenging owing to endoscopic short-sighted visualization, excessive scope flexibility and lack of adequate instrumentation. Augmented reality may overcome these difficulties. This study tested whether an image registration system for NOTES procedures (IR-NOTES) can facilitate navigation. METHODS: In three human cadavers 15 intra-abdominal organs were targeted endoscopically with and without IR-NOTES via both transgastric and transcolonic routes, by three endoscopists with different levels of expertise. Ease of navigation was evaluated objectively by kinematic analysis, and navigation complexity was determined by creating an organ access complexity score based on the same data. RESULTS: Without IR-NOTES, 21 (11·7 per cent) of 180 targets were not reached (expert endoscopist 3, advanced 7, intermediate 11), compared with one (1 per cent) of 90 with IR-NOTES (intermediate endoscopist) (P = 0·002). Endoscope movements were significantly less complex in eight of the 15 listed organs when using IR-NOTES. The most complex areas to access were the pelvis and left upper quadrant, independently of the access route. The most difficult organs to access were the spleen (5 failed attempts; 3 of 7 kinematic variables significantly improved) and rectum (4 failed attempts; 5 of 7 kinematic variables significantly improved). The time needed to access the rectum through a transgastric approach was 206·3 s without and 54·9 s with IR-NOTES (P = 0·027). CONCLUSION: The IR-NOTES system enhanced both navigation efficacy and ease of intra-abdominal NOTES exploration for operators of all levels. The system rendered some organs accessible to non-expert operators, thereby reducing one impediment to NOTES procedures.

Marginal ulceration after Roux-en-Y gastric bypass surgery: characteristics, risk factors, treatment, and outcomes.

BACKGROUND AND STUDY AIMS: Marginal ulcers are one of the most common complications after gastric bypass. Reported incidence varies widely (0.6-16 %) and pathogenesis is unclear. The aim of the present study was to describe characteristics, risk factors, management, and outcomes of endoscopically documented ulcers. PATIENTS AND METHODS: Data from all patients diagnosed with marginal ulcers at endoscopy between 2003 and 2010 were retrospectively reviewed. RESULTS: A total of 103 patients with marginal ulcers presented with pain (63 %) and/or bleeding (24 %), a median of 22 months after surgery. Ulcers were located on the anastomosis (50 %) or the jejunum (40 %); sutures were visible in 35 %, and gastrogastric fistulae in 8 %. The mean pouch length was 5.6 cm. Diabetes (odds ratio [OR] 2.5; P = 0.03), smoking (OR 2.5; P = 0.02), and gastric pouch length (OR 1.2; P = 0.02) were significantly associated with marginal ulcer formation on univariate analysis; diabetes was significantly associated on multivariate analysis (OR 5.6; P = 0.003). The risk of developing a marginal ulcer decreased with time (OR 0.8; P < 0.01) and was not associated with the use of nonsteroidal anti-inflammatory drugs. At first endoscopic follow-up, 67 % of ulcers had healed. Recurrence occurred in four patients and nine patients required surgical revision. CONCLUSIONS: The vast majority of marginal ulcers had a favorable outcome after medical treatment. However, 9 % of patients eventually required surgical revision. Therefore, endoscopic follow-up is essential. Diabetes, smoking, and long gastric pouches were significant risk factors for marginal ulcer formation, suggesting increased acid exposure and mucosal ischemia are both involved in marginal ulcer pathogenesis. Management of these factors may prove effective in managing marginal ulcers, and tailoring postoperative proton pump inhibitor therapy to patients with multiple risk factors could be effective.

The Synthesium Brachycladiidae Odhner, 1905 (Digenea) association with hosts based on nuclear and mitochondrial genes.

Synthesium pontoporiae, exclusive parasite of the endangered dolphin, Pontoporia blainvillei, is endemic and restricted to the South Atlantic and belongs to the Brachycladiidae family Odhner, 1905. The study of this family has been limited by the difficulty of accessing the parasites from their marine mammal hosts and as a consequence there is a paucity of genetic information available. Herein we present a genetic analysis using 18S rDNA sequences of S. pontoporiae and S. tursionis and the ND3 mtDNA sequence of S. pontoporiae. The genetic analysis of 18S rDNA sequences of brachycladiids and acanthocolpids determined two major clusters associated with their definitive hosts, marine mammals and fishes, respectively. Considering the tree topology of brachycladiids ND3 mtDNA gene, two clusters were defined, one with the Synthesium species. This work contributes with fundamental genetic information on S. pontoporiae, and suggests a Brachycladiidae genetic evolution related to their hosts.

NOTES spin-off for the therapeutic gastroenterologist: natural orifice surgery.

Natural orifice transluminal endoscopic surgery (NOTES) has ushered in a new era in flexible endoscopy. Over the past decade, modest advances have been made in addressing the fundamental challenges of NOTES surgery including transluminal access and closure techniques, and advancement of NOTES-specific technology. Despite these encouraging initial efforts significant obstacles to widespread acceptance of NOTES as a surgical option persist. Moreover, due to the well-documented safety and efficacy of laparoscopic techniques, the question remains as to the best candidate NOTES procedure. Presently, interest has shifted from true NOTES to hybrid procedures and single incision laparoscopic surgery, due to the lure of more immediate success. Additionally, there is also a growing awareness of the potential applications of natural orifice surgery techniques to the present field of therapeutic endoscopy. Research into transluminal access and closure has born several techniques and devices that are now being explored in endoscopic procedures such as full-thickness resection, endoscopic myotomy, direct endoscopic pancreatic necrosectomy and bariatric endoscopy. Such NOTES "spin-off" procedures are expanding the armamentarium of today's therapeutic endoscopists, and a growing body of literature suggests that they will play a significant role in the evolution of therapeutic endoscopy in the future.

Image Registered Gastroscopic Ultrasound (IRGUS) in human subjects: a pilot study to assess feasibility.

BACKGROUND AND STUDY AIMS: Endoscopic ultrasound (EUS) is a complex procedure due to the subtleties of ultrasound interpretation, the small field of observation, and the uncertainty of probe position and orientation. Animal studies demonstrated that Image Registered Gastroscopic Ultrasound (IRGUS) is feasible and may be superior to conventional EUS in efficiency and image interpretation. This study explores whether these attributes of IRGUS will be evident in human subjects, with the aim of assessing the feasibility, effectiveness, and efficiency of IRGUS in patients with suspected pancreatic lesions. PATIENTS AND METHODS: This was a prospective feasibility study at a tertiary care academic medical center in human patients with pancreatic lesions on computed tomography (CT) scan. Patients who were scheduled to undergo conventional EUS were randomly chosen to undergo their procedure with IRGUS. Main outcome measures included feasibility, ease of use, system function, validated task load (TLX) assessment instrument, and IRGUS experience questionnaire. RESULTS: Five patients underwent IRGUS without complication. Localization of pancreatic lesions was accomplished efficiently and accurately (TLX temporal demand 3.7 %; TLX effort 8.6 %). Image synchronization and registration was accomplished in real time without procedure delay. The mean assessment score for endoscopist experience with IRGUS was positive (66.6 ± 29.4). Real-time display of CT images in the EUS plane and echoendoscope orientation were the most beneficial characteristics. CONCLUSIONS: IRGUS appears feasible and safe in human subjects, and efficient and accurate at identification of probe position and image interpretation. IRGUS has the potential to broaden the adoption of EUS techniques and shorten EUS learning curves. Clinical studies comparing IRGUS with conventional EUS are ongoing.

The role of a computed tomography-based image registered navigation system for natural orifice transluminal endoscopic surgery: a comparative study in a porcine model.

BACKGROUND AND STUDY AIMS: Most natural orifice transluminal endoscopic surgery (NOTES) procedures have been performed in animal models through the anterior stomach wall, but this approach does not provide efficient access to all anatomic areas of interest. Moreover, injury of the adjacent structures has been reported when using a blind access. The aim of the current study was to assess the utility of a CT-based (CT: computed tomography) image registered navigation system in identifying safe gastrointestinal access sites for NOTES and identifying intraperitoneal structures. METHODS: A total of 30 access procedures were performed in 30 pigs: anterior gastric wall (n = 10), posterior gastric wall (n = 10), and anterior rectal wall (n = 10). Of these, 15 procedures used image registered guidance (IR-NOTES) and 15 procedures used a blind access (NOTES only). Timed abdominal exploration was performed with identification of 11 organs. The location of the endoscopic tip was tracked using an electromagnetic tracking system and was recorded for each case. Necropsy was performed immediately after the procedure. The primary outcome was the rate of complications; secondary outcome variables were number of organs identified and kinematic measurements. RESULTS: A total of 30 animals weighting a mean (± SD) of 30.2 ± 6.8 kg were included in the study. The incision point was correctly placed in 11 out of 15 animals in each group (73.3 %). The mean peritoneoscopy time and the number of properly identified organs were equivalent in the two groups. There were eight minor complications (26.7 %), two (13.3 %) in the IR-NOTES group and six (40.0 %) in the NOTES only group ( P = n. s.). Characteristics of the endoscope tip path showed a statistically significant improvement in trajectory smoothness of motion for all organs in the IR-NOTES group. CONCLUSION: The image registered system appears to be feasible in NOTES procedures and results from this study suggest that image registered guidance might be useful for supporting navigation with an increased smoothness of motion.

Changes in vegetation in northern Alaska under scenarios of climate change, 2003-2100: implications for climate feedbacks.

Assessing potential future changes in arctic and boreal plant species productivity, ecosystem composition, and canopy complexity is essential for understanding environmental responses under expected altered climate forcing. We examined potential changes in the dominant plant functional types (PFTs) of the sedge tundra, shrub tundra, and boreal forest ecosystems in ecotonal northern Alaska, USA, for the years 2003-2100. We compared energy feedbacks associated with increases in biomass to energy feedbacks associated with changes in the duration of the snow-free season. We based our simulations on nine input climate scenarios from the Intergovernmental Panel on Climate Change (IPCC) and a new version of the Terrestrial Ecosystem Model (TEM) that incorporates biogeochemistry, vegetation dynamics for multiple PFTs (e.g., trees, shrubs, grasses, sedges, mosses), multiple vegetation pools, and soil thermal regimes. We found mean increases in net primary productivity (NPP) in all PFTs. Most notably, birch (Betula spp.) in the shrub tundra showed increases that were at least three times larger than any other PFT. Increases in NPP were positively related to increases in growing-season length in the sedge tundra, but PFTs in boreal forest and shrub tundra showed a significant response to changes in light availability as well as growing-season length. Significant NPP responses to changes in vegetation uptake of nitrogen by PFT indicated that some PFTs were better competitors for nitrogen than other PFTs. While NPP increased, heterotrophic respiration (RH) also increased, resulting in decreases or no change in net ecosystem carbon uptake. Greater aboveground biomass from increased NPP produced a decrease in summer albedo, greater regional heat absorption (0.34 +/- 0.23 W x m(-2) x 10 yr(-1) [mean +/- SD]), and a positive feedback to climate warming. However, the decrease in albedo due to a shorter snow season (-5.1 +/- 1.6 d/10 yr) resulted in much greater regional heat absorption (3.3 +/- 1.24 W x m(-2) x 10 yr(-1)) than that associated with increases in vegetation. Through quantifying feedbacks associated with changes in vegetation and those associated with changes in the snow season length, we can reach a more integrated understanding of the manner in which climate change may impact interactions between high-latitude ecosystems and the climate system.

Genomic diversity of vibrios associated with the Brazilian coral Mussismilia hispida and its sympatric zoanthids (Palythoa caribaeorum, Palythoa variabilis and Zoanthus solanderi).

AIMS: A taxonomic survey of the vibrios associated with the Brazilian endemic coral Mussismilia hispida and the sympatric zoanthids (i.e. Palythoa caribaeorum, Palythoa variabilis and Zoanthus solanderi). METHODS AND RESULTS: Mucus of 54 cnidarian specimens collected in three different places at São Sebastião in two consecutive years (i.e. 2005 and 2006) was used for taxonomic characterization of the cnidarian microbiota. Ninety-eight of the 151 vibrio isolates fell within the vibrio core group according to partial 16S rDNA sequences. We performed the sequencing of recA and pyrH genes of all vibrio isolates. The most abundant taxa belonged to the vibrio core group (Vibrio harveyi, Vibrio rotiferianus, Vibrio campbellii and Vibrio alginolyticus), Vibrio mediterranei (=Vibrio shillonii) and Vibrio chagasii. With the exception of V. chagasii which was found only in the mucus of M. hispida, the other species appeared in different hosts with no evidence for the presence of host-specific clones or species. Using rep-PCR analysis, we observed a high genomic heterogeneity within the vibrios. Each vibrio isolate generated a different rep-PCR fingerprint pattern. There was a complete agreement between the grouping based on rep-PCR and concatenated sequences of pyrH, recA and 16S rDNA, but the pyrH gene has the highest discriminatory power for vibrio species identification. CONCLUSION: The vibrio core group is dominant in the mucus of these cnidarians. There is a tremendous diversity of vibrio lineages within the coral mucus. pyrH gene sequences permit a clear-cut identification of vibrios. SIGNIFICANCE AND IMPACT OF THE STUDY: The taxonomic resolution provided by pyrH (but not recA) appears to be enough for identifying species of vibrios and for disclosing putative new taxa. The vibrio core group appears to be dominant in the mucus of the Brazilian cnidarians. The overrepresentation of these vibrios may reflect as yet unknown ecological functions in the coral holobiont.

Magnetic retraction in natural-orifice transluminal endoscopic surgery (NOTES): addressing the problem of traction and countertraction.

BACKGROUND AND STUDY AIMS: Because of their reliance on the flexible endoscope, most current procedures in natural-orifice transluminal endoscopic surgery (NOTES) suffer from the inability to vigorously grasp and move tissue or to retract organs. We aimed to assess the use of internal and external magnets that might allow the vigorous multiaxial traction/countertraction required in more complicated NOTES procedures. METHODS: Ex vivo and in vivo porcine model. Study components were: (1) Evaluation of force-distance relationship of this magnetic retraction system using a digital tensiometer. (2) Application of this magnetic retraction system to two procedures in the porcine model: (a) Liver retraction during transcolonic cholecystectomy in five nonsurvival pigs. Procedure time was recorded and compared to historical controls. (b) Mesh positioning for implantation into the anterior abdominal wall for ventral hernia repair in three survival pigs. RESULTS: Over a distance of 5 cm to 0.25 cm, the magnetic force of our system increased from 3 to 90 gramforce (29.42 to 882.60 mN.) In vivo, the magnet system provided robust liver retraction, shortening the procedure time of NOTES cholecystectomy from a historical mean of 68 minutes (range 42 - 90 minutes; n = 5) to 49.6 minutes (range 33 - 61 minutes; n = 3). The magnetic system also greatly enhanced mesh positioning and stability, and these animals survived for 2 weeks without complications. CONCLUSIONS: Our basic system provided critical liver retraction during NOTES cholecystectomy and was also instrumental in moving and stabilizing mesh for implantation during NOTES ventral hernia repair. Magnets can potentially provide the vigorous traction and countertraction required to advance NOTES procedures.

Transluminal closure for NOTES: an ex vivo study comparing leak pressures of various gastrotomy and colotomy closure modalities.

BACKGROUND AND STUDY AIMS: Transluminal closure is fundamental to the safe introduction of natural orifice transluminal endoscopic surgery (NOTES) into humans. Suture, staples, and clips have been used. We aimed to evaluate the acute strength of various gastrotomy and colotomy closure techniques in an ex vivo porcine model by assessing air leak pressures. PATIENTS AND METHODS: The following closure modalities were assessed with at least five samples per arm: conventional open/laparoscopic suturing techniques including full-thickness interrupted sutures, double-layer sutures, and purse-string sutures, as well as endoscopic clips and endoscopic staples. Historical values for transgastric closures with hand-sewn interrupted sutures, endoscopic clips, and a prototype endoscopic suture device were used from our laboratory's prior study. RESULTS: Using Kruskal-Wallis analysis, the overall comparisons were significant ( P = 0.0038 for gastrotomy closure; P = 0.0018 for colotomy closure). Post hoc paired comparisons revealed that the difference between all closure arms versus negative control were significant. Significance could not be established among the various closure arms. However, trends suggested hand-sewn double-layer sutures, endoscopic staples, and both hand-sewn and endoscopically-placed purse-string sutures produced the strongest closures. Furthermore, endoscopic clips appeared sufficient for colotomy closure when ideally placed. CONCLUSIONS: Suture (both hand-sewn and endoscopically deployed) appears to produce the strongest closures in both stomach and colon, with the important caveats that (1) a continuous through-thickness suture track be avoided, such as in the full-thickness closure, or (2) suture holes be buried, such as in the purse-string configuration. When suture tracks are full-thickness, they can serve as leak sites. Staples and clips can produce comparable closures, but only under ideal conditions.

Transcolonic ventral wall hernia mesh fixation in a porcine model.

BACKGROUND AND STUDY AIMS: A natural orifice transluminal endoscopic surgery (NOTES) approach to ventral wall hernia repair may represent a potentially less invasive alternative to current transabdominal surgical techniques. We aimed to investigate the feasibility of using transcolonic NOTES to deliver hernia repair mesh into the peritoneal cavity, as well as the ability to manipulate composite mesh and secure it to the abdominal wall. METHODS: Five pigs weighing 20 to 25 kg were used in this feasibility study involving two acute and three survival experiments. A prototype mesh delivery system was used to transfer 1.5 - 2-cm x 2.5 - 3-cm pieces of composite hernia mesh into the peritoneal cavity. Neodymium magnets on a prototype control arm were used to help position the mesh by magnetically engaging previously placed endoscopic clips. Transfascial fixation of the mesh with 3-0 monofilament sutures was achieved using a 19-gauge hollow needle, pusher wire, and a suture tag system. RESULTS: Composite hernia mesh was successfully transferred and secured in 5/5 attempts. All three survival animals thrived for 14 days prior to elective sacrifice. At necropsy, the mesh sites were found to be well peritonealized without adhesions. Suture placement through the posterior fascia was confirmed in 10/12 sutures. Of these, four sutures were within the abdominal musculature, and two sutures were through the anterior fascia (transfascial). CONCLUSIONS: Transcolonic delivery, transcutaneous magnetic manipulation, and fixation of composite hernia mesh are technically feasible in a porcine model with animal survival. An effective suturing method that allows consistent anchoring through the anterior fascia would be preferred and may require the development of novel devices.

Dual-port distal pancreatectomy using a prototype endoscope and endoscopic stapler: a natural orifice transluminal endoscopic surgery (NOTES) survival study in a porcine model.

BACKGROUND AND STUDY AIMS: Natural orifice transluminal endoscopic surgery (NOTES) is a potentially less invasive alternative to laparoscopic surgery that may be applicable to distal pancreatectomy. We aimed to demonstrate the technical feasibility of a NOTES distal pancreatectomy in an in vivo porcine model via a combined transvaginal-transcolonic approach. MATERIAL AND METHODS: The procedure was performed in five female Yorkshire pigs weighing approximately 30 kg each. A prototype endoscope ("R-scope"), advanced into the peritoneal cavity through an anterior colotomy, and a computer-assisted linear stapler, introduced transvaginally, were used in dissection and resection of the distal pancreas. Prone positioning was used to enhance retroperitoneal exposure. Pneumodissection was used for blunt dissection. The colotomies were closed with endoloops. Necropsies were done immediately after the procedure in the first three animals, and after 2 weeks' survival in the final two animals. RESULTS: Distal pancreatectomy was successful in all five animals. Prone positioning was critically important for proper exposure of retroperitoneal and pelvic structures. Pneumodissection was effective for blunt dissection, and both the linear stapler and R-scope functioned smoothly. Transvaginal and transcolonic access provided similar intraperitoneal views, and the dual-lumen approach enhanced triangulation. Both survival animals thrived postoperatively. Necropsies revealed clean staple lines; closed transcolonic and transvaginal incisions; and absence of infection, hemorrhage, or fluid collections. CONCLUSIONS: NOTES distal pancreatectomy is technically feasible in the porcine model. The transvaginal approach provides a vantage point very similar to that of the transcolonic route and holds promise as a NOTES access site, either singly or as part of a dual-lumen approach. The endoscopic linear stapler and R-scope both advance NOTES capabilities. The novel concepts of fully prone positioning, pneumodissection, and endoloop colotomy closures are introduced. Considering anatomical differences and that healthy animals were used, transferring this technique to patients with pancreatic disease might be difficult and further modifications would likely be needed.