Recurrent and residual shunts after patent foramen ovale closure: Results from a long-term transcranial doppler study

Objectives Assess the evolution of right-to-left shunt (RLS) after transcatheter patent foramen ovale (PFO) closure. Background Despite the high number of interventional procedures performed worldwide, limited systematic data on the long-term abolition of RLS after percutaneous closure are available. Methods All patients treated at our Institution between February 2001 and July 2009 were included in this single center, prospective study, and were asked to repeat late contrast transcranial Doppler (cTCD). Rate of complete closure, residual RLS (i.e., a shunt that persists after closure), and recurrent RLS (i.e., a shunt that reappears after a previous negative cTCD) was assessed. Results Long-term follow-up was completed in 120 patients (56% male). RLS was still detectable 4.9 \ub1 2.3 years (range 1.3-10.3) after the procedure in 55 patients; 20 (17%) had residual RLS and 35 (29%) had recurrent RLS. Multivariate analysis revealed that significant predictors of residual RLS included post-procedural shunt at transesophageal echocardiography (OR 3.07, 95%CI 0.97-9.7), use of a bigger device (35 vs 25 mm, OR 3.85, 95%CI 1.22-12.2) and length of follow-up (OR 0.75, 95%CI 0.57-0.98), while only length of follow-up (OR 0.77, 95%CI 0.62-0.95) was associated with recurrent RLS. Neurological recurrences (1 stroke, 6 transient ischemic attacks) were equally distributed between the groups. Conclusion A significant number of recurrent and residual shunts may be observed by cTCD up to 5 years after PFO closure. Management of late RLSs includes periodic re-evaluation, exclusion of device-induced complications or secondary sources of RLS, and optimization of antithrombotic treatment with or without a second intervention

Groundwater characterization from an ecological and human perspective: an interdisciplinary approach in the Functional Urban Area of Parma, Italy

In the Parma Functional Urban Area, hydro-geo-ecology was investigated through an interdisciplinary approach, with emphasis on the shallow aquifer system. The study pointed out that domestic wells and fontanili are both fed by shallow groundwater affected by PCE and nitrate contamination, upgradient of the rural area located north of Parma City. Moreover, Folsomia candida tests suggested the possibility that other types of contaminants (not analysed in this study) can affect the shallow groundwater. Nowadays, PCE concentrations in the city centre are slightly higher than the limit set by law. Moreover, PCE aerobic biodegradation can be due to the local microbial community and then an effective natural attenuation can be expected along the groundwater flow pathway. These results suggest a very low risk for human health, linked to the groundwater consumption in the rural area north of Parma City. Conversely, no forecasts can be made at present about the possible impact of low PCE concentrations on the aquatic ecosystem observed at the fontanili. Concerning nitrate contamination, the higher concentrations detected in some wells and fontanili suggest a high risk for both human health and aquatic ecosystems. In a wider context, thanks to the interdisciplinary approach that combines successfully well-established investigation methods, the present study allows a better knowledge of the hydro-geo-ecological behaviour of groundwater-dependent ecosystems. At the same time, through purpose-designed experimental investigations and simulation models, this approach could be used as a sort of guideline useful in studying such complex environmental systems