Controlled donation after circulatory death lung transplantation: Results of the French protocol including in situ abdominal normothermic regional perfusion and ex vivo lung perfusion.

BACKGROUND: The French national protocol for controlled donation after circulatory determination of death (cDCD) includes normothermic regional perfusion (NRP) in case of abdominal organ procurement and additional ex-vivo lung perfusion (EVLP) before considering lung transplantation (LT). METHODS: We made a retrospective study of a prospective registry that included all donors considered for cDCD LT from the beginning of the program in May 2016 to November 2021. RESULTS: One hundred grafts from 14 donor hospitals were accepted by 6 LT centers. The median duration of the agonal phase was 20 minutes [2-166]. The median duration from circulatory arrest to pulmonary flush was 62 minutes [20-90]. Ten lung grafts were not retrieved due to prolonged agonal phases (n = 3), failure of NRP insertion (n = 5), or poor in situ evaluation (n = 2). The remaining 90 lung grafts were all evaluated on EVLP, with a conversion rate of 84% and a cDCD transplantation rate of 76%. The median total preservation time was 707 minutes [543-1038]. Seventy-one bilateral LTs and 5 single LTs were performed for chronic obstructive pulmonary disease (n = 29), pulmonary fibrosis (n = 21), cystic fibrosis (n = 15), pulmonary hypertension (n = 8), graft-versus-host disease (n = 2), and adenosquamous carcinoma (n = 1). The rate of PGD3 was 9% (n = 5). The 1-year survival rate was 93.4%. CONCLUSION: After initial acceptance, cDCD lung grafts led to LT in 76% of cases, with outcomes similar to those already reported in the literature. The relative impacts of NRP and EVLP on the outcome following cDCD LT should be assessed prospectively in the context of comparative studies.

Investigating ultrasound-induced acoustic softening in aluminum and its alloys.

Ultrasonic vibration has been observed to lower the flow stress necessary to initiate plastic deformation, a phenomenon known as "acoustic softening". This unique effect of ultrasound has been extensively applied in welding, machining, forming of metals, and ultrasonic additive manufacturing to lower the yield stress necessary to initiate plastic deformation, it nevertheless lacks fundamental investigation. Some prior studies showed experimental errors due to the design of experimental setups and the associated testing methods that have been introduced, leading to questions about their observations and conclusions. Therefore, an experimental setup described in this paper is designed to minimize the constraints identified from the setups in prior studies. Three types of aluminum are studied: Al 1100-O a commercially pure aluminum, Al 6061-O an aluminum alloy without precipitate strengthening, and Al 6061-T6 a precipitate-strengthened aluminum alloy. The acoustic softening and residual effect are compared based on the similarities and differences in microstructures of the three types of aluminum. In both acoustic softening and residual effect, linear relations are obtained between stress change and ultrasound intensities. The slope defined by the linear relations, i.e. the acoustic softening factor, depends on the microstructure of the specific material. The underlying mechanism of acoustic softening is associated with the activation of dislocations by ultrasonic energy and subsequently their interactions with other dislocations and precipitates, whereas the residual effects are attributed to the permanent changes in dislocation density due to dislocation annihilation, dynamic annealing, and dislocation-precipitate interaction.

An in vivo evaluation of the auto apical reverse function of the Root ZX II.

AIM: To evaluate in vivo the accuracy of the Root ZX II (J. Morita) apex locator in controlling the apical extent of rotary instrumentation when using the Auto Apical Reverse (AAR) set at the levels 0.5, 1.0 and 1.5. METHODOLOGY: Thirty single-rooted premolar teeth scheduled for extraction were divided into three groups (n = 10), according to the AAR setting 0.5, 1.0 and 1.5. The root canals were prepared using ProTaper (Dentsply Maillefer). After rotary instrumentation, the last file used (F3) was manually introduced into the extent of the root canal preparation and fixed before tooth extraction. The apical third of the root was dissected until exposure of the file. The distance from the file tip to the major apical foramen was obtained. RESULTS: Measurements within the range -1.0 to 0.0 mm were obtained in 30% of the teeth with AAR 0.5, 50% with AAR 1.0 and in 0% with AAR 1.5. The proportions test revealed a significant difference between the AAR settings 1.0 and 1.5 (P = 0.0188). Overinstrumentation occurred in 70% of the teeth with AAR 0.5 and in 40% with AAR 1.0. The measurements short of the acceptable range occurred in 10% of the teeth with setting AAR 1.0 and in 100% of the cases with AAR 1.5. A significant difference was found when comparing the percentage of teeth in which the file tip was short and beyond the established range between groups, except when comparing AAR 0.5 and AAR 1.0. CONCLUSION: The AAR function of the Root ZX II was not an accurate method for controlling the apical extent of rotary instrumentation in vivo. The setting 0.5 presented overinstrumentation in most of the canals, the setting 1.5 was short in all cases, and the setting 1.0 provided an adequate working length in only 50% of the teeth.

Fixation of first metatarsal basal osteotomy using Acutrak screw.

BACKGROUND: The purpose of this study is to determine clinical and radiological outcome following the internal fixation of first metatarsal basal osteotomy using Acutrak screw. METHODS: Between May 1999 and December 2003, 37 feet undergoing basal closing wedge osteotomy were stabilised using Acutrak screw. The minimum follow-up period was 18 months. The position and fate of the screw, complications, hallux valgus, intermetatarsal and metatarsal declination angles, and time for bony union were assessed postoperatively and at the final follow-up. RESULTS: Seventy-nine percent of the corrected feet had achieved excellent or good AOFAS score, 13% fair, and 8% poor score. The average preoperative intermetatarsal, hallux valgus and first metatarsal declination angles were 17.3 degrees (12-20 degrees), 38 degrees (17-53 degrees) and 22.5 degrees (16-30 degrees), respectively. These were reduced to 10.3 degrees (0-16 degrees), 14.6 degrees (9-26 degrees) and 20.4 degrees (16-26 degrees) following surgery and 11.2 degrees (0-18 degrees), 16.0 degrees (12-22 degrees) and 20.1 degrees (16-23 degrees), respectively, at the final follow-up. Clinical and radiological union has been achieved in all cases. CONCLUSION: Our technique provides stable fixation with minimal loss of position at the osteotomy site.