Hierarchically structured carbon and silica by chemical foaming

Foamed organic/silica hybrid materials are synthesized via cationic polymerization of organic carbonates with twin monomers. They are converted into hierarchically structured carbon and silica.

Normothermic Ex Vivo Kidney Perfusion Following Static Cold Storage-Brief, Intermediate, or Prolonged Perfusion for Optimal Renal Graft Reconditioning?

Normothermic ex vivo kidney perfusion (NEVKP) demonstrated superior results compared to hypothermic storage in donation after circulatory death (DCD) kidney transplantation. It is unknown whether an optimal perfusion time exists following hypothermic storage to allow for the recovery of renal grafts from cold ischemic injury. In a porcine model of DCD kidney autotransplantation, the impact of initial static cold storage (SCS) (8 h) followed by various periods of NEVKP recovery was investigated: group A, 8 hSCS only (control); group B, 8 hSCS + 1 hNEVKP (brief NEVKP); group C, 8 hSCS + 8 hNEVKP (intermediate NEVKP); and group D, 8 hSCS + 16 hNEVKP (prolonged NEVKP). All grafts were preserved and transplanted successfully. One animal in group D was sacrificed and excluded by postoperative day 3 due to hind limb paralysis, but demonstrated good renal function. Postoperative graft assessment during 8 days' follow-up demonstrated lowest levels of peak serum creatinine for intermediate (C) and prolonged (D) NEVKP (p = 0.027). Histological assessment on day 8 demonstrated a significant difference in tubular injury (p = 0.001), with highest values for group B. These results suggest that longer periods of NEVKP following SCS are feasible and safe for postponing surgical transplant procedure and superior to brief NEVKP, reducing the damage caused during cold ischemic storage of renal grafts.

Management of neglected ACL avulsion fractures: a case series and systematic review

INTRODUCTION

Neglected tibial eminence avulsion fractures of the anterior cruciate ligament (ACL) are uncommonly seen in modern times, but are fairly common due to a missed diagnosis/mismanagement in developing countries.

OBJECTIVES

To determine the outcomes after open reduction and internal fixation of late presenting ACL avulsion fractures, and to review the literature for similar cases, in an attempt to evaluate the ideal surgical management in this unique scenario.

STUDY DESIGN

Retrospective observational study and systematic review MATERIALS: The study included 10 male and 2 female cases (mean age 29.9 years). Patients were assessed for the pre-operative knee range-of-motion (ROM), flexion deformity and stability; functional assessment was conducted using the Lysholm scale, both pre and post-operatively. Open reduction and internal fixation with two partially threaded screws (via a mini anterior approach) was performed in all 12 cases. All patients were clinically followed up for a minimum duration of 12 months. We searched PubMed, Embase and Cochrane databases from the period of inception to January 15, 2017 for similar case series/reports involving management of chronic/neglected ACL avulsion fractures and systematically reviewed these studies following standard PRISMA guidelines.

RESULTS

The median duration of presentation after injury was 12 months (range 3 to 312 months; mean 45.3 months). The mean follow-up duration was 24.1 months (range 12-48 months). All patients achieved normal knee extension except one patient who had a residual 5° flexion contracture. On physical examination, Lachman and pivot-shift tests were negative in all but 1 patient. No case required ACL reconstruction, and the fractures united radiologically within 12 weeks; all patients regained former activity levels.

DISCUSSION

Eleven published studies, mainly case reports, reported on the management of chronic/neglected ACL avulsion fractures. Arthroscopic suture/wire fixation, arthroscopic debridement of avulsed fragment and open reduction, internal fixation (ORIF) with screws are the described techniques for this uncommon entity. However, anatomic reduction of ACL avulsion fractures is difficult arthroscopically as crater depth assessment and repositioning of the avulsed fragment become a problem; the avulsed fragment may also hypertrophy, and some contractures in ACL may develop. A mini-open procedure does not add to the morbidity, overcomes reduction obstacles and allows easy fixation with screws, and can be done even in centers that do not have arthroscopic experience. The key point is accurate reduction and rigid fixation, ensuring no impingement on full extension CONCLUSIONS: Mini-open fixation allows accurate, anatomic reduction and stable fixation with screws, and should be the preferred method of fixation for late presenting ACL avulsion fractures; embedding the fragment deep into the crater or size reduction are key to preventing extension deficits.

Continuous Normothermic Ex Vivo Kidney Perfusion Is Superior to Brief Normothermic Perfusion Following Static Cold Storage in Donation After Circulatory Death Pig Kidney Transplantation

Hypothermic preservation is known to cause renal graft injury, especially in donation after circulatory death (DCD) kidney transplantation. We investigated the impact of cold storage (SCS) versus short periods of normothermic ex vivo kidney perfusion (NEVKP) after SCS versus prolonged, continuous NEVKP with near avoidance of SCS on kidney function after transplantation. Following 30 min of warm ischemia, kidneys were removed from 30-kg Yorkshire pigs and preserved for 16 h with (A) 16 h SCS, (B) 15 h SCS + 1 h NEVKP, (C) 8 h SCS + 8 h NEVKP, and (D) 16 h NEVKP. After contralateral kidney resection, grafts were autotransplanted and pigs followed up for 8 days. Perfusate injury markers such as aspartate aminotransferase and lactate dehydrogenase remained low; lactate decreased significantly until end of perfusion in groups C and D (p < 0.001 and p = 0.002). Grafts in group D demonstrated significantly lower serum creatinine peak when compared to all other groups (p < 0.001) and 24-h creatinine clearance at day 3 after surgery was significantly higher (63.4 ± 19.0 mL/min) versus all other groups (p < 0.001). Histological assessment on day 8 demonstrated fewer apoptotic cells in group D (p = 0.008). In conclusion, prolonged, continuous NEVKP provides superior short-term outcomes following DCD kidney transplantation versus SCS or short additional NEVKP following SCS.