Use of a novel valve stent for transcatheter pulmonary valve replacement: An animal study

ObjectiveThe goal of this study was to evaluate valvular functionality after transcatheter pulmonary valve replacement in sheep using a novel pulmonary valve stent.MethodsFresh porcine pericardium cross-linked with 0.6% glutaraldehyde was treated with L-glutamine to eliminate glutaraldehyde toxicity and sutured onto a valve ring before mounting on a nitinol stent to construct the pulmonary valve stent. Percutaneous femoral vein transcatheter pulmonary valve replacement was performed with the newly constructed valve stent. Pulmonary valve stents were implanted in 10 healthy sheep (6 males and 4 females) weighing an average of 25.7 ± 4.1 kg. Color Doppler echocardiography, 64-row computed tomography, and direct catheter examination were used to assess valvular function.ResultsImplantation was successful in 8 sheep. Shortly after surgery, all artificial valve stents exhibited normal open and close functionality and no stenosis or insufficiency. Heart rate was slightly elevated at this time, while all other hemodynamic parameters were normal. Six-month follow-up revealed no evidence of valve stent dislocation and normal valvular and cardiac functionality. There was no evidence of stent fracture. Repeated valve stent implantation was well tolerated as indicated by good valvular functionality 2 months postdelivery.ConclusionThe novel pulmonary valve stent described herein can be delivered via percutaneous femoral vein transcatheter implantation and is highly efficacious at 6 months postdelivery. Furthermore, repeated valve stent replacement was successful

Phase Control on Surface for the Stabilization of High Energy Cathode Materials of Lithium Ion Batteries.

The development of high energy electrode materials for lithium ion batteries is challenged by their inherent instabilities, which become more aggravated as the energy densities continue to climb, accordingly causing increasing concerns on battery safety and reliability. Here, taking the high voltage cathode of LiNi0.5Mn1.5O4 as an example, we demonstrate a protocol to stabilize this cathode through a systematic phase modulating on its particle surface. We are able to transfer the spinel surface into a 30 nm shell composed of two functional phases including a rock-salt one and a layered one. The former is electrochemically inert for surface stabilization while the latter is designated to provide necessary electrochemical activity. The precise synthesis control enables us to tune the ratio of these two phases, and achieve an optimized balance between improved stability against structural degradation without sacrificing its capacity. This study highlights the critical importance of well-tailored surface phase property for the cathode stabilization of high energy lithium ion batteries

Coexistence of aneurysmal subarachnoid hemorrhage and surgically identified pituitary apoplexy: a case report and review of the literature

INTRODUCTION: A ruptured aneurysm associated with a pituitary apoplexy is rare. We present the first case report of the coexistence of a ruptured posterior communicating aneurysm with a surgically discovered pituitary apoplexy where the pituitary apoplexy had not been diagnosed by a pre-operative computerized tomography scan. CASE PRESENTATION: A 31-year-old right-handed Chinese woman began to experience severe headache, vomiting and blurred vision which continued for two days. On admission to the hospital, a brain computerized tomography scan demonstrated a small amount of increased signal in the basal cisterns; no evidence of intrasellar and suprasellar lesions was seen. The appearance of her brain suggested aneurysmal subarachnoid hemorrhage. She had nuchal rigidity and reduced vision. There was no extra-ocular palsy and no other neurological deficit. Our patient had no stigmata of Cushing’s syndrome or acromegaly. During an interview for further history, she reported normal menses and denied reduced vision. Cerebral digital subtraction angiography was subsequently performed, which revealed a 6mm left posterior communicating aneurysm. Urgent left pterional craniotomy was performed. The left ruptured posterior communicating artery aneurysm was completely dissected prior to clipping. At surgery, a suprasellar mass was discovered, the tumor bulging the diaphragma sella and projecting anteriorly under the chiasm raising suspicion of a pituitary tumor. The anterior part of the tumor capsule was opened and a necrotic tumor mixed with dark old blood was removed. The appearance suggested pituitary apoplexy. Histopathology revealed pituitary adenoma with evidence of hemorrhagic necrosis. Our patient made a good recovery. CONCLUSION: Our case report proves that pituitary apoplexy can be coexistent with the rupture of a posterior communicating aneurysm. This association should be considered when evaluating any case of aneurysm. A normal computerized tomography scan does not exclude pituitary apoplexy. Pre-operative magnetic resonance imaging interpretation is required if a pituitary apoplexy is suspected. Craniotomy allows a coexisting aneurysm and pituitary apoplexy to be simultaneously treated

Pringle manoeuvre versus selective hepatic vascular exclusion in partial hepatectomy for tumours adjacent to the hepatocaval junction: A randomized comparative study

AbstractObjectiveTo compare the efficacy of selective hepatic vascular exclusion versus Pringle manoeuvre in partial hepatectomy for tumours adjacent to the hepatocaval junction.MethodsA randomized comparative trial was carried out. The primary endpoint was intraoperative blood loss. The secondary endpoints were operation time, blood transfusion, postoperative liver function recovery, procedure-related morbidity and in-hospital mortality.Results160 patients were randomized into 2 groups: the Pringle manoeuvre group (n = 80) and the selective hepatic vascular exclusion (SHVE) group (n = 80). Intraoperative blood loss and transfusion requirements were significantly less in the SHVE group. In the SHVE group, laceration of hepatic veins happened in 18 patients. Profuse intraoperative blood loss of over 2 L happened in 2 patients but no patient suffered from air embolism because the hepatic veins were controlled. In the Pringle group, the hepatic veins were lacerated in 20 patients, with profuse blood loss of over 2 L in 7 patients and air embolism in 3 patients. The rates of postoperative bleeding, reoperation, liver failure and mortality were significantly higher and the ICU stay and hospital stay were significantly longer in the Pringle group.ConclusionsSHVE was more efficacious than Pringle manoeuvre for partial hepatectomy in patients with tumours adjacent to the hepatocaval junction