Detecting gas upwelling hazards in coastal areas through integration of active and passive electrical and seismic methods (Fiumicino, Central Italy)

The accurate location of gas upwelling flows is still an open problem for non-invasive imaging techniques in populated areas. Gas blowouts of deep origin may represent a serious threat to human health in urban areas and should be correctly imaged with high-resolution for assessing the related hazards. In this work, we propose an integration of active (electrical resistivity tomography and high-resolution sub-bottom profiling complemented with the multibeam bathymetry) and passive (self-potential and ambient noise recordings) geophysical methods to image gas upwelling flows in the coastal area of Fiumicino (Central Italy), where the gas presence is well-documented by previous works. We demonstrate that merging seismic sub-bottom profiling and electrical resistivity tomography has enormous diagnostic potential for gas detection, since they combine the high resolution needed to correctly image the subsurface and the interfaces between different media with the high diagnostic capability of electrical methods to detect anomalies associated with the gas emissions. Passive seismic methods complement the analysis enabling an estimation of the shear-wave velocity through array measurements. Finally, the reconstruction of the natural electrical sources, inferred from the inversion of self-potential data, confirms the location of the near-surface gas upwelling flows assessed through the resistivity model. This work demonstrates that the integration of high-resolution active and passive seismic and electrical methods can be an effective choice for the accurate location of risk-prone areas by imaging the near surface gas pathways where borehole drilling is strongly limited if not forbidden

Are antifibrinolytic drugs equivalent in reducing blood loss and transfusion in cardiac surgery? A meta-analysis of randomized head-to-head trials

BACKGROUND: Aprotinin has been shown to be effective in reducing peri-operative blood loss and the need for re-operation due to continued bleeding in cardiac surgery. The lysine analogues tranexamic acid (TXA) and epsilon aminocaproic acid (EACA) are cheaper, but it is not known if they are as effective as aprotinin. METHODS: Studies were identified by searching electronic databases and bibliographies of published articles. Data from head-to-head trials were pooled using a conventional (Cochrane) meta-analytic approach and a Bayesian approach which estimated the posterior probability of TXA and EACA being equivalent to aprotinin; we used as a non-inferiority boundary a 20% increase in the rates of transfusion or re-operation because of bleeding. RESULTS: Peri-operative blood loss was significantly greater with TXA and EACA than with aprotinin: weighted mean differences were 106 mls (95% CI 37 to 227 mls) and 185 mls (95% CI 134 to 235 mls) respectively. The pooled relative risks (RR) of receiving an allogeneic red blood cell (RBC) transfusion with TXA and EACA, compared with aprotinin, were 1.08 (95% CI 0.88 to 1.32) and 1.14 (95% CI 0.84 to 1.55) respectively. The equivalent Bayesian posterior mean relative risks were 1.15 (95% Bayesian Credible Interval [BCI] 0.90 to 1.68) and 1.21 (95% BCI 0.79 to 1.82) respectively. For transfusion, using a 20% non-inferiority boundary, the posterior probabilities of TXA and EACA being non-inferior to aprotinin were 0.82 and 0.76 respectively. For re-operation the Cochrane RR for TXA vs. aprotinin was 0.98 (95% CI 0.51 to 1.88), compared with a posterior mean Bayesian RR of 0.63 (95% BCI 0.16 to 1.46). The posterior probability of TXA being non-inferior to aprotinin was 0.92, but this was sensitive to the inclusion of one small trial. CONCLUSION: The available data are conflicting regarding the equivalence of lysine analogues and aprotinin in reducing peri-operative bleeding, transfusion and the need for re-operation. Decisions are sensitive to the choice of clinical outcome and non-inferiority boundary. The data are an uncertain basis for replacing aprotinin with the cheaper lysine analogues in clinical practice. Progress has been hampered by small trials and failure to study clinically relevant outcomes

Autograft from quadrangular resection for floppy valve repair in endocarditis

We present a case of reconstruction of the anterior leaflet in mitral valve prolapse and subacute bacterial endocarditis in which the resected prolapsing segment of the posterior leaflet was used as patch material. Competence of the valve was achieved with no recurrence of infection. Quadrangular resection of the posterior leaflet supplies presumably viable patch material for valve repair, which is particularly useful in bacterial endocarditis and when pliability is required

Cyanoacrylate glue as an alternative to an additional suture line in the repair of type A aortic dissection

We describe the use of cyanoacrylate glue in conjunction with gelatin-resorcinol-formalin glue for the treatment of type A aortic dissection. Instead of placing an additional suture line 2-3 cm from the edges of the aortic stumps to create a large pocket for gluing, we have been using a cyanoacrylate adhesive for approximating the walls of the true and false lumina without the risk of tearing them. Moreover, the simplicity and quickness of the procedure enables application of the cyanoacrylate glue even deeper into the aortic arch, creating a wider area for gluing the dissected layers

33.Free right internal thoracic artery in a "horseshoe" configuration: a new technical approach for "in situ" conduit lengthening.

Severe chronic obstructive pulmonary disease with large lung volumes may prevent both the "in situ" internal thoracic arteries to reach coronary anastomoses sites. We present a method to revascularize the left antero-lateral myocardial wall using the right internal thoracic artery as a "free graft" anastomosed side to end to the "in situ" left internal thoracic artery, in a "horseshoe" fashion. The two ends of the "free graft" were anastomosed to the left anterior descending coronary artery and the second obtuse marginal branch, respectively. This method was successfully used in a 74-year-old patient with severe chronic obstructive pulmonary disease