Effect of Selective Inflow Occlusion on Hemodynamic Conditions during Laparoscopic Left HemihepatectomyEffect of Selective Inflow Occlusion on Hemodynamic Conditions during Laparoscopic Left Hemihepatectomy

Background/Aims: Selective inflow occlusion instead of portal triad clamping was used during laparoscopic left hemihepatectomy in our institution. This study observed its hemodynamic effects during operation. Methodology: Hemodynamic parameters including heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), cardiac index (CI), systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR) were collected at 6 time points: after induction, after insufflation with CO2, after patient in reverse Trendelenburg position, after left branch of hepatic artery was occluded, after left branch of portal vein was occluded and after desufflation with patient supine. Results: No severe perioperative cardiopulmonary complications were observed. Occlusion of left branch of hepatic artery brought no significant hemodynamic change. Occlusion of left branch of portal vein increased CVP and CI and decreased SVR. CO2 inflation caused HR, MAP and SVR to increase. The change to reverse Trendelenburg position caused CVP and PAP to decrease. When placed in the supine position with deflation, MAP, CVP, PAP, PCWP and CI went to a higher than base level. HR and SVR returned to base level. Conclusions: Using selective inflow occlusion in laparoscopic left hemihepatectomy caused few hemodynamic changes before and after occlusion in patients without cardiopulmonary diseases. However, the change of position and inflation or deflation caused significant changes.     

Novel application of four-dimensional sonography with B-flow imaging and spatiotemporal image correlation in the assessment of fetal congenital heart defects

Aims: To evaluate the role of four‐dimensional (4D) ultrasound with B‐flow imaging and spatiotemporal image correlation (STIC) in the evaluation of normal fetal heart and congenital heart disease during pregnancy. Methods: Volume data sets of the fetal heart were acquired with automated transverse and longitudinal sweeps of the anterior chest wall. We studied 31 normal fetuses and 28 fetuses with congenital heart disease (6 with double‐outlet right ventricle, 5 with complete transposition of great arteries, 8 with tetralogy of Fallot, 3 with right aortic arch, 2 with persistent left superior vena cava, 3 with truncus arteriosus communis, and 1 with interruption of aortic arch) at gestation ages ranging from 18 to 39 weeks using transabdominal 4D B‐flow sonography with STIC (4D BF‐STIC). Results: Four‐dimensional BF‐STIC demonstrated dynamic angiographic features in both normal and abnormal fetal hearts. Four‐dimensional BF‐STIC images could not be obtained in two normal fetuses at 18.9 and 35.6 weeks because of the high fetal heart rate and inappropriate fetal position. Of the other 29 fetuses all extracardiac vessels such as aorta, pulmonary artery, ductus arteriosus, inferior vena cava, and ductus venosus could be detected on reconstructed images. In seven normal cases, a 4D image was recorded to allow simultaneous visualization of all four pulmonary veins. In the 28 fetuses with cardiac anomalies, 4D sonography with B‐flow imaging and STIC detected the “digital casts” of the outflow tracts, great arteries, and veins draining into the heart. These results demonstrate spatial relationship among these structures which provide important anatomical information. Conclusion: Four‐dimensional BF‐STIC provides a means of real time three‐dimensional evaluation of fetal extracardiac hemodynamics in the second and third trimesters. This novel technique assists in the evaluation of fetal cardiac hemodynamics and may play an important role in future fetal cardiac research and in the identification of anatomical features of different congenital cardiac anomalies. (Echocardiography 2012;29:614‐619)     

Anomalous expression of chloride transporters in the sclerosed hippocampus of mesial temporal lobe epilepsy patients

The Na+-K+-Cl-cotransporter 1 and K+-Cl-cotransporter 2 regulate the levels of intracellular chloride in hippocampal cells.Impaired chloride transport by these proteins is thought to be involved in the pathophysiological mechanisms of mesial temporal lobe epilepsy.Imbalance in the relative expression of these two proteins can lead to a collapse of Cl-homeostasis,resulting in a loss of gamma-aminobutyric acid-ergic inhibition and even epileptiform discharges.In this study,we investigated the expression of Na+-K+-Cl-cotransporter 1 and K+-Cl-cotransporter 2 in the sclerosed hippocampus of patients with mesial temporal lobe epilepsy,using western blot analysis and immunohistochemistry.Compared with the histologically normal hippocampus,the sclerosed hippocampus showed increased Na+-K+-Cl-cotransporter 1 expression and decreased K+-Cl-cotransporter 2 expression,especially in CA2 and the dentate gyrus.The change was more prominent for the Na+-K+-Cl-cotransporter 1 than for the K+-Cl-cotransporter 2.These experimental findings indicate that the balance between intracellular and extracellular chloride may be disturbed in hippocampal sclerosis,contributing to the hyperexcitability underlying epileptic seizures.Changes in Na+-K+-Cl-cotransporter 1 expression seems to be the main contributor.Our study may shed new light on possible therapies for patients with mesial temporal lobe epilepsy with hippocampal sclerosis.     

Extracts from rabbit skin inflamed by the vaccinia virus attenuate bupivacaine-induced spinal neurotoxicity in pregnant rats

Extracts from rabbit skin inflamed by the vaccinia virus can relieve pain and promote repair of nerve injury. The present study intraperitoneally injected extracts from rabbit skin inflamed by the vaccinia virus for 3 and 4 days prior to and following intrathecal injection of bupivacaine into pregnant rats. The pain threshold test after bupivacaine injection showed that the maximum possible effect of tail-flick latency peaked 1 day after intrathecal injection of bupivacaine in the extract-pretreatment group, and gradually decreased, while the maximum possible effect in the bupivacaine group continued to increase after intrathecal injection of bupivacaine. Histological observation showed that after 4 days of intrathecal injection of bupivacaine, the number of shrunken, vacuolated, apoptotic and caspase-9-positive cells in the dorsal root ganglion in the extract-pretreatment group was significantly reduced compared with the bupivacaine group. These findings indicate that extracts from rabbit skin inflamed by the vaccinia virus can attenuate neurotoxicity induced by intrathecal injection of bupivacaine in pregnant rats, possibly by inhibiting caspase-9 protein expression and suppressing nerve cell apoptosis.     

Non-invasive imaging of the crystalline structure within a human tooth

The internal crystalline structure of a human molar tooth has been non-destructively imaged in cross-section using X-ray diffraction computed tomography. Diffraction signals from high-energy X-rays which have large attenuation lengths for hard biomaterials have been collected in a transmission geometry. Coupling this with a computed tomography data acquisition and mathematically reconstructing their spatial origins, diffraction patterns from every voxel within the tooth can be obtained. Using this method we have observed the spatial variations of some key material parameters including nanocrystallite size, organic content, lattice parameters, crystallographic preferred orientation and degree of orientation. We have also made a link between the spatial variations of the unit cell lattice parameters and the chemical make-up of the tooth. In addition, we have determined how the onset of tooth decay occurs through clear amorphization of the hydroxyapatite crystal, and we have been able to map the extent of decay within the tooth. The described method has strong prospects for non-destructive probing of mineralized biomaterials.     

Bi-layer collagen/microporous electrospun nanofiber scaffold improves the osteochondral regeneration

An optimal scaffold is crucial for osteochondral regeneration. Collagen and electrospun nanofibers have been demonstrated to facilitate cartilage and bone regeneration, respectively. However, the effect of combining collagen and electrospun nanofibers on osteochondral regeneration has yet to be evaluated. Here, we report that the combination of collagen and electrospun poly-l-lactic acid nanofibers synergistically promotes osteochondral regeneration. We first fabricated bi-layer microporous scaffold with collagen and electrospun poly-l-lactic acid nanofibers (COL-nanofiber). Mesenchymal stem cells were cultured on the bi-layer scaffold and their adhesion, proliferation and differentiation were examined. Moreover, osteochondral defects were created in rabbits and implanted with COL-nanofiber scaffold. Cartilage and subchondral bone regeneration were evaluated at 6 and 12 weeks after surgery. Compared with COL scaffold, cells on COL-nanofiber scaffold exhibited more robust osteogenic differentiation, indicated by higher expression levels of OCN and runx2 genes as well as the accumulation of calcium nodules. Furthermore, implantation of COL-nanofiber scaffold seeded with cells induced more rapid subchondral bone emergence, and better cartilage formation, which led to better functional repair of osteochondral defects as manifested by histological staining, biomechanical test and micro-computed tomography data. Our study underscores the potential of using the bi-layer microporous COL-nanofiber scaffold for the treatment of deep osteochondral defects.     

Biomechanical analysis of the acetabular buttress-plate: are complex acetabular fractures in the quadrilateral area stable after treatment with anterior construct plate-1/3 tube buttress plate fixation?

OBJECTIVE:

The acetabular buttress-plate has been widely used in treating difficult cases with satisfying clinical results. However, the biomechanical properties of a postoperative acetabular fracture fixed by the buttress-plate are not clear. The purpose of this study was to evaluate the biomechanical properties of stability after the anterior tube buttress-plate fixation of complex acetabular fractures in the quadrilateral area.

METHODS:

A construct was proposed based on anterior construct plate - 1/3 tube buttress plate fixation for acetabular both-column fractures. Two groups of six formalin-preserved cadaveric pelvises were analyzed: (1) group A, the normal pelvis and (2) group B, anterior construct plate-1/3 tube buttress plate with quadrilateral area fixation. The displacements were measured, and cyclical loads were applied in both standing and sitting simulations.

RESULTS:

As the load was added, the displacements were Ap = 0.013; sitting position: p = 0.009) between groups A and B.

CONCLUSION:

The anterior construct plate - 1/3 tube buttress plate fixation provided a better stable construct for early sitting. The standing mode yielded more significant differences between the groups. Placing a 1/3 tube buttress-plate via an anterior approach is a novel method of providing quadrilateral area support in this setting.     

微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折

目的探讨切开复位微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折的手术方法及疗效。方法2010年1月~2012年1月,对我院收治的15例闭合性距骨颈粉碎性骨折患者,根据Hawkins分型：Ⅱ型11例,Ⅲ型4例。术前常规行CT三维重建明确骨折类型和粉碎程度,择期行切开复位微型接骨板内固定加自体松质骨移植术。术后定期复查X片及CT观察骨折愈合情况,并记录相关并发症,采用Hawkins评分标准评估疗效。结果本组14例获得随访,随访时间12~24m,,平均16.4m。术后外侧切口边缘部分坏死1例,经局部清创换药后治愈,无并发感染,骨折均在8~12w内获得愈合,平均愈合时间11.3w,无畸形愈合发生,距骨体部分坏死1例（Ⅲ型）,轻度创伤性关节炎3例（Ⅱ型1例,Ⅲ型2例）,末次随访时未发现内固定松动断裂。Hawkins评分：优7例（Ⅱ型）,良5例（Ⅱ型4例,Ⅲ型1例）,可2例（Ⅲ型）。结论采用切开复位微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折,术中可获得满意复位,牢靠的内固定可有效维持骨折复位,自体松质骨移植可促进骨折愈合,是治疗距骨颈粉碎性骨折的有效方法。