Does the degree of calcification of the celiac trunk and superior mesenteric artery on preoperative computerized tomography predict the risk of anastomotic leak after right colectomy? A single center retrospective study.

Anastomotic leak is a serious complication of colonic surgery. The aim of our study is to evaluate the impact of vascular calcifications of the celiac axis and superior mesenteric artery in patients undergoing elective right colectomy, and particularly their relationship to the risk of anastomotic leak. MATERIALS AND METHODS: We performed a retrospective analysis of preoperative abdominal computerized tomography (CT) scans of patients who underwent right colectomy at the Vendean Departmental Hospital (France) between January 2011 and December 2016. We established a calcification score, which was correlated to the incidence of anastomotic leak and to the patients' American Society of Anesthesiologists (ASA) score. RESULTS: The charts of 250 patients were reviewed. Twenty-three patients had a postoperative anastomotic leak. A stratified analysis revealed that the risk of developing an anastomotic leak was statistically significantly increased in patients whose calcification score was equal to or greater than 3 (P<0.05). In these patients, the risk was increased by a factor of 3.48 [odds ratio: 3.48 (1.45-8.36)]. A second stratified analysis showed that a calcification score of 2 at the level of the celiac axis takeoff was correlated with a statistically significantly increased risk of anastomotic leak (P<0.01). There was a correlation between a calcification score≥3 and an ASA score≥3. CONCLUSION: A calcification score≥3 correlates to an increased risk of anastomotic leak. The analysis of CT findings is simple, easy and reproducible. This calcification score should be confirmed by a prospective study.

Reevaluating species number, distribution and endemism of the coral genus Pocillopora Lamarck, 1816 using species delimitation methods and microsatellites.

Species delimitation methods based on genetic information, notably using single locus data, have been proposed as means of increasing the rate of biodiversity description, but can also be used to clarify complex taxonomies. In this study, we explore the species diversity within the cnidarian genus Pocillopora, widely distributed in the tropical belt of the Indo-Pacific Ocean. From 943 Pocillopora colonies sampled in the Western Indian Ocean, the Tropical Southwestern Pacific and Southeast Polynesia, representing a huge variety of morphotypes, we delineated Primary Species Hypotheses (PSH) applying the Automatic Barcode Gap Discovery method, the Poisson Tree Processes algorithm and the Generalized mixed Yule-coalescent model on two mitochondrial markers (Open Reading Frame and Dloop) and reconstructing a haploweb using one nuclear marker (Internal Transcribed Spacer 2). Then, we confronted identified PSHs to the results of clustering analyses using 13 microsatellites to determine Secondary Species Hypotheses (SSH). Based on the congruence of all methods used and adding sequences from the literature, we defined at least 18 Secondary Species Hypotheses among 14 morphotypes, confirming the high phenotypic plasticity in Pocillopora species and the presence of cryptic lineages. We also identified three new genetic lineages never found to date, which could represent three new putative species. Moreover, the biogeographical ranges of several SSHs were re-assessed in the light of genetic data, which may have direct implications in conservation policies. Indeed, the cryptic diversity within this genus should be taken into account seriously, as neglecting its importance is source of confusion in our understanding of ecosystem functioning. Next generation sequencing, combined with other parameters (i.e. microstructure, zooxanthellae identification, ecology even at a micro-scale, resistance and resilience ability to bleaching) will be the next step towards an integrative framework of Pocillopora taxonomy, which will have profound implications for ecological studies, such as studying biodiversity, response to global warming and symbiosis.

One species for one island? Unexpected diversity and weak connectivity in a widely distributed tropical hydrozoan.

Isolation by distance (IBD) is one of the main modes of differentiation in marine species, above all in species presenting low dispersal capacities. This study reports the genetic structuring in the tropical hydrozoan Lytocarpia brevirostris α (sensu Postaire et al, 2016b), a brooding species, from 13 populations in the Western Indian Ocean (WIO) and one from New Caledonia (Tropical Southwestern Pacific). At the local scale, populations rely on asexual propagation at short distance, which was not found at larger scales; identical genotypes were restricted to single populations. After the removal of repeated genotypes, all populations presented significant positive FIS values (between 0.094*** and 0.335***). Gene flow was extremely low at all spatial scales, between sites within islands (<10 km distance) and among islands (100 to>11 000 km distance), with significant pairwise FST values (between 0.012*** and 0.560***). A general pattern of IBD was found at the Indo-Pacific scale, but also within sampled ecoregions of the WIO province. Clustering analyses identified each sampled island as an independent population, whereas analysis of molecular variance indicated that population genetic differentiation was significant at small (within island) and intermediate (among islands within province) spatial scales. The high population differentiation might reflect the life cycle of this brooding hydrozoan, possibly preventing regular dispersal at distances more than a few kilometres and probably leading to high cryptic diversity, each island housing an independent evolutionary lineage.