High biomass yield increases in a primary effluent wastewater phytofiltration are associated to altered leaf morphology and stomatal size in Salix miyabeana.

Municipal wastewater treatment using willow 'phyto'-filtration has the potential for reduced environmental impact compared to conventional treatment practices. However, the physiological adaptations underpinning tolerance to high wastewater irrigation in willow are unknown. A one-hectare phytofiltration plantation established using the Salix miyabeana cultivar 'SX67' in Saint-Roch-de-l'Achigan, Quebec, Canada, tested the impact of unirrigated, potable water or two loads of primary effluent wastewater 19 and 30 ML ha-1 yr-1. A nitrogen load of 817 kg N ha-1 from wastewater did not increase soil pore water nitrogen concentrations beyond Quebec drinking water standards. The willow phytofiltration phenotype had increased leaf area (+106-142%) and leaf nitrogen (+94%) which were accompanied by significant increases in chlorophyll a + b content. Wastewater irrigated trees had higher stomatal sizes and a higher stomatal pore index, despite lower stomatal density, resulting in increased stomatal conductance (+42-78%). These developmental responses led to substantial increases in biomass yields of 56-207% and potable water controls revealed the nitrogen load to be necessary for the high productivity of 28-40 t ha-1 yr-1 in wastewater irrigated trees. Collectively, this study suggests phytofiltration plantations could treat primary effluent municipal wastewater at volumes of at least 19 million litres per hectare and benefit from increased yields of sustainable biomass over a two-year coppice cycle. Added-value cultivation practices, such as phytofiltration, have the potential to mitigate negative local and global environmental impact of wastewater treatment while providing valuable services and sustainable bioproducts.

Fenestrated endovascular grafting: the French multicentre experience.

PURPOSE: This study aims to evaluate the medium-term outcomes following aortic aneurysm repair using fenestrated endografts performed in 16 French academic centres. MATERIALS AND METHODS: A retrospective analysis of prospectively collected data was carried out. This study included all patients treated with fenestrated endografts in France between May 2004 and January 2009. Patients were judged to be at high risk for open surgical repair. Fenestrated endografts were designed using computed tomography (CT) reconstructions performed on three-dimensional (3D) workstations. All patients were evaluated with CT, duplex ultrasound and plain film radiograph at discharge, 6, 12, 18 and 24 months, and annually thereafter. RESULTS: A total of 134 patients (129 males) were treated over the study period. Median age and aneurysm size were 73 years (range 48-91 years) and 56 mm (range 45-91 mm), respectively. A total of 403 visceral vessels were perfused through a fabric fenestration, including 265 renal arteries. One early conversion to open surgery was required. Completion angiography and discharge CT scan showed that 398/403 (99%) and 389/394 (99%) respective target vessels were patent. The 30-day mortality rate was 2% (3/134). Pre-discharge imaging identified 16 (12%) endoleaks: three type I, 12 type II and one type III. After the procedure, transient or permanent dialysis was required in four (3%) and two (1%) patients, respectively. The median duration of follow-up was 15 months (range 2-53 months). No aneurysms ruptured or required open conversion during the follow-up period. Twelve of 131 patients (9%) died during follow-up (actuarial survival at 12 and 24 months: 93% and 86%, respectively). Median time from procedure to death was 15 months. None of these deaths were aneurysm related. Aneurysm sac size decreased by more than 5 mm in 52%, 65.6% and 75% of patients at 1, 2 and 3 years, respectively. Three (4%) patients had sac enlargement within the first year, associated with a persistent endoleak. During follow-up, four renal artery occlusions were detected. A total of 12 procedure-related re-interventions were performed in 12 patients during follow-up, including six to correct endoleaks, and five to correct threatened visceral vessels. CONCLUSIONS: The use of endovascular prostheses with graft material incorporating the visceral arteries is safe and effective in preventing rupture in the medium term. A predictable high mortality rate was depicted during follow-up in this high-risk cohort. Meticulous follow-up to assess sac behaviour and visceral ostia is critical to ensure optimal results.