Functional outcomes in symptomatic versus asymptomatic patients undergoing incisional hernia repair: Replacing one problem with another? A prospective cohort study in 1312 patients

Background: Incisional hernias can be associated with pain or discomfort. Surgical repair especially mesh reinforcement, may likewise induce pain. The primary objective was to assess the incidence of pain after hernia repair in patients with and without pre-operative pain or discomfort. The secondary objectives were to determine the preferred mesh type, mesh location and surgical technique in minimizing postoperative pain or discomfort. Materials and methods: A registry-based prospective cohort study was performed, including patients undergoing incisional hernia repair between September 2011 and May 2019. Patients with a minimum follow-up of 3–6 months were included. The incidence of hernia related pain and discomfort was recorded perioperatively. Results: A total of 1312 patients were included. Pre-operatively, 1091 (83%) patients reported pain or discomfort. After hernia repair, 961 (73%) patients did not report pain or discomfort (mean follow-up = 11.1 months). Of the pre-operative asymptomatic patients (n = 221), 44 (20%, moderate or severe pain: n = 14, 32%) reported pain or discomfort after mean follow-up of 10.5 months. Of those patients initially reporting pain or discomfort (n = 1091), 307 (28%, moderate or severe pain: n = 80, 26%) still reported pain or discomfort after a mean follow-up of 11.3 months postoperatively. Conclusion: In symptomatic incisional hernia patients, hernia related complaints may be resolved in the majority of cases undergoing surgical repair. In asymptomatic incisional hernia patients, pain or discomfort may be induced in a considerable number of patients due to surgical repair and one should be aware if this postoperative complication

Ageing of polyvinylidene fluoride hollow fiber membranes in sodium hypochlorite solutions

International audienceIn order to study the effect of cleaning operations on polyvinylidene fluoride (PVDF) hollow fiber membrane stability, ageing of two PVDF based membranes (one is additive free, the other contains hydrophilic additives) in contact with sodium hypochlorite solutions with various pH values has been studied. The aim of this experimental study was to identify the degradation mechanisms and to gain a better understanding of the effect of the (macro)molecular structure changes on the mechanical and functional properties of the membranes. In both membranes, double bond formation, chain scission and crosslinking are observed and all these processes (except crosslinking) are faster in acidified solutions than in natural NaOCl solutions (pH 11.5). It can be deduced that if ionic processes such as dehydrofluorination occur, radical processes resulting from the presence of hypochlorous acid and perhaps its coexistence with the ClO− ion, predominate in acidified solutions. The presence of non-fluorinated aliphatic or cycloaliphatic additives, which are highly reactive with bleach, accelerates chain scission at the expense of crosslinking. In the chosen conditions (135 days in 4000 ppm bleach solutions at 40 °C), PVDF chains are degraded but not enough to induce polymer embrittlement. While in the additive free membrane no significant change of the use properties has been observed, the polymeric additives of the other membrane are completely destroyed, leading to a decrease of the membrane hydrophilicity, but their destruction improves the membrane selectivity by a decrease of the average porosity

Artificial intelligence solution to classify pulmonary nodules on CT

International audienceThe purpose of this study was to create an algorithm to detect and classify pulmonary nodules in two categories based on their volume greater than 100 mm3 or not, using machine learning and deep learning techniques