A new approach for evaluating the resectability of pancreatic and periampullary neoplasms.

OBJECTIVE: To establish a new standard for assessing the resectability of pancreatic and periampullary tumors by the Medical Image Three-Dimensional Visualization System (MI-3DVS). METHODS: Eighty cases of pancreatic and periampullary tumors were examined. The 64-slice multidetector CT (64-MDCT) images and patient data were processed by MI-3DVS. The main elements examined by MI-3DVS included tumor shape, size, and location; distribution of related vessels; luminal morphology of large vessels; distribution and morphology of the small peripancreatic veins; morphology, degree of dilation, and obstructive sites of bile and pancreatic ducts. Based on vascular characteristics of MI-3DVS findings, the cases were classified into five types. Type I and II were resectable, type III were potentially resectable or resectable with combined vascular resection and reconstruction, and type IV and V were unresectable. The outcome was then compared with corresponding CT angiography (CTA) analysis and actual surgical observations. RESULTS: Among the 80 cases, MI-3DVS indicated that 60 were resectable and the remaining 20 were not. In contrast, CTA indicated 50 resectable cases and 30 unresectable cases. For 57 cases of pancreatic ductal carcinomas and all 80 cases periampullary tumors, MI-3DVS assessment yielded a positive predictive value of 100%, negative predictive value of 100%, a sensitivity of 100%, a specificity of 100%, and an accuracy of 100%. While CTA generated corresponding values of 96%, 60%, 80%, 90%, 82.5%. The overall differences between the two methods were significant (P < 0.05). CONCLUSION: The new classification system is able to reliably assess the resectability of pancreatic and periampullary tumors.

Three-dimensional reconstruction of the uterine vascular supply through vascular casting and thin slice computed tomography scanning.

It was the objective of this study to construct a model of the uterine vascular supply through vascular casting and thin slice computed tomography scanning. This will provide a teaching aide for the understanding of uterine artery embolization (UAE) procedures, as well as normal uterine and ovarian arterial anatomy. Using 20% chlorinated poly vinyl chloride, we infused and cast a set of a normal uterus, vagina and bilateral adnexa through the uterine artery and ovarian artery. After thin slice CT scanning, we obtained the three-dimensional (3D) reconstruction by maximum intensity projection (MIP) and surface-shaded display (SSD), and then observed its figure and characteristics. A model of the uterine vascular supply can be successfully reconstructed by vascular casting and thin slice CT scanning. The 3D reconstruction offers a clear view of the course of the uterine artery and its blood supply distribution. It has two major branches: The intramuscular uterine branch and the cervicovaginal branch (1). Blood supply is generally unilateral, with communicating branches between the two sides and possible anastomoses between the arterial blood supply of the uterus and the ovaries. The major blood supply of the cervix comes from the cervicovaginal branch of the uterine artery, while the vaginal arterial supply derives directly from the internal iliac artery. The CT technique allows real-time 360 degrees rotation and changes in model for in-depth study of the vascular network and its adjacent tissues. It is possible to construct an in vitro uterine arterial network by vascular casting and CT scanning, which can provide unique insight into the female genitourinary system arterial network. Based on this, we can create reconstructions as well as models for different diseases such as leiomyomata, adenomyosis, and endometrial cancer. These models will provide morphological evidence to the interventional therapy and UAE teaching in Obstetrics and Gynecology.

Biomechanical effect of vertebroplasty on the adjacent intervertebral levels using a three-dimensional finite element analysis.

OBJECTIVE: To investigate the biomechanical effect of different volume, distribution and leakage to adjacent disc of bone cement on the adjacent vertebral body by three-dimensional osteoporosis finite element model of lumbar. METHODS: L(4)-L(5) motion segment data of the cadaver of an old man who had no abnormal findings on roentgenograms were obtained from computed tomography (CT) scans. Three-dimensional model of L(4)-L(5) was established with Mimics software, and finite element model of L(4)-L(5) functional spinal unit (FSU) was established by Ansys 7.0 software. The effect of different loading conditions and distribution of bone cement after vertebroplasty on the adjacent vertebral body was investigated. RESULTS: This study presented a validated finite element model of L(4)-L(5) FSU with a simulated vertebroplasty augmentation to predict stresses and strains of adjacent untreated vertebral bodies. The findings from this FSU study suggested the endplate and disc stress of the adjacent vertebral body was not influenced by filling volume of bone cement but unipedicle injection and leakage to the disc of bone cement could concentrate the stress of adjacent endplate. CONCLUSIONS: Asymmetric distributions and leakage of cement into intervertebral disc can improve the stress of endplate in adjacent vertebral body. These results suggest that optimal biomechanical configuration should have symmetric placement and avoid leakage of cement in operation.

Effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation.

AIM: To study effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation. METHODS: Two of Wistar rats were chosen randomly for normal liver pathology control and ten of SD rats chosen randomly for liver function control as blank group (no operation). The rest of Wistar and SD rats were divided into four groups: control group (only liver transplantation), Dex group (donors receiving intraperitoneal injection of dexamethasone), SpC group (recipients receiving infusion of spleen cells of donors), Dex-SpC group (recipients receiving infusion of apoptotic spleen cells of donors), with each group except blank group, containing 10 SD rats and 10 Wistar rats, respectively. Wistar rats received liver transplantation from SD rats, in the meantime they received infusion of spleen cells of donors, which were induced by an intraperitoneal injection of dexamethasone (3 mg/(d.kg).b.w) for three days before liver transplantation. The serum alanine transaminase (ALT), total bilirubin (T bili), liver pathological changes and survival time were analysed. Statistical analysis was carried out using SPSS 10.0 for Windows. Differences of the parametric data of ALT in means were examined by one-way ANOVA. Differences of ALT between two groups were examined by LSD. Differences of the nonparametric data of T bili in means and scores of pathology classification for acute rejection were examined by Kruskal-Willis H test. The correlations between ALT and T bili were analysed by Bivariate. Kaplan-Meier curves were used to demonstrate survival distribution. The log-rank test was used to compare the survival data. RESULTS: There were significant differences in ALT of the five groups (F = 23.164 P = 0.000), and ALT in Dex-SpC group was significantly higher than that in blank control, control, Dex, and SpC groups (P = 0.000), and ALT in SpC group was significantly higher than that in blank control (P = 0.000), control (P = 0.004), and Dex groups (P = 0.02). Results of nonparametric analysis of T bili showed that there were differences in T bili of the five groups (chi(2) = 33.265 P = 0.000). T bili in Dex-SpC group was significantly higher than that in blank control, control, Dex, and SpC groups. T bili in SpC group was higher than that in blank control, control, and Dex groups. There were significant differences in scores of pathology classification for acute rejection in each of the groups (chi(2) = 25.933,P = 0.000). The pathologically more serious acute rejection was found in Dex-SPC group than in other groups. No sign of acute rejection was observed in the blank control group. Slight acute rejection was observed in the control group. Slight-moderate acute rejection was observed in the Dex group. Moderate-acute rejection was observed in the SpC group. Severe-acute rejection was observed in the Dex-SpC group. The survival time in Dex-SpC group was shorter than in other groups (statistic = 11.13, P = 0.011). ALT and T bili were positively correlated (r = 0.747, P = 0.000, two-tailed). CONCLUSION: In order to reduce quantity of blood loss from rats after liver transplantation, only one of ALT or T bili is needed for liver function measurement of rats. Simultaneous injection of apoptotic spleen cells from donors induced by dexamethasone to liver transplantation rats aggravates acute rejection. One important mechanism of aggravation of acute rejection may be that apoptotic cells are not removed in time and that dead cells including apoptotic cells release inflammatory factors.

[Studies on the hepatic three-dimensional reconstruction and virtual surgery using the hepatic images of the digitized virtual Chinese human female number 1 database].

OBJECTIVE: To study digitized virtual hepatic three-dimensional reconstruction and virtual hepatic surgery. METHODS: The whole series of hepatic images taken from the database of digitized Virtual Chinese Human Female Number 1 (VCH-F1) was employed to reconstruct a three-dimensional (3D) liver. First, studied some algorithms for registration of human liver tissue images, and then, segmented the regions of liver, vein, bile duct, and gallbladder from the images. Based on them, the 3D visualization human liver model was reconstructed. Finally, a 3D visualization demo system of liver was developed based on personal computer and Windows operation system. RESULTS: This demo system of liver provided a graphics user interface to rotate, scale the 3D liver to observe the 3D hepatic structure, and a virtual liver simulation system of resection with primary function. CONCLUSIONS: The study may be beneficial to the future research on digitized virtual hepatic and virtual hepatic surgery, and the 3D visualization demo system of liver may be beneficial to the research on the hepatic structure.

Palmar tilt changes due to distal radius fractures and radiocarpal instability: a biomechanical study.

OBJECTIVE: To investigate the impact of dorsally angulated malunited distal radius fractures on the stability of the radiocarpal joint. METHODS: Eight fresh upper limb specimens from 4 human cadavers were obtained, in which radial osteotomy was performed to prepare models of Frykman I distal radius fracture. Pressure-sensitive film was applied to study the changes in the contact area distribution and the pressure load across the radiocarpal joint in response to palmar tilt variation, and the lateral radiograph of the wrist was taken at the end of pressure loading. RESULTS: When the dorsal tilt exceeded 10 degrees, the radioscaphoid and radiolunate articular contact areas were markedly decreased (P<0.01) and shifted to the dorsal aspect of the radiocarpal joint, where the pressure load was significantly increased (P<0.01). A dorsal radiocarpal subluxation was liable to occur on the sagittal plane when the dorsal tilt exceeded 40 degrees. CONCLUSION: A dorsal tilt over 10 degrees is the most primary cause of radiocarpal instability after a dorsal deformity due to distal radius fractures.

Three-dimensional reconstruction of the peripancreatic vascular system based on computed tomographic angiography images and its clinical application in the surgical management of pancreatic tumors.

OBJECTIVE: This study aimed to investigate the clinical significance of 3-dimensional (3D) reconstruction of peripancreatic vessels for patients with suspected pancreatic cancer (PC). METHODS: A total of 89 patients with PC were included; 60 patients randomly underwent computed tomographic angiography. Based on the findings of 3D reconstruction of peripancreatic vessels, the appropriate method for individualized tumor resection was determined. These patients were compared with 29 conventionally treated patients with PC. RESULTS: The rate of visualization was 100% for great vessels around the pancreas. The detection rates for anterior superior pancreaticoduodenal artery, posterior superior pancreaticoduodenal artery, anterior inferior pancreaticoduodenal artery, posterior inferior pancreaticoduodenal artery, dorsal pancreatic artery, superior marginal arterial branch of the pancreatic head, anterior superior pancreaticoduodenal vein, posterior superior pancreaticoduodenal vein, anterior inferior pancreaticoduodenal vein, and posterior inferior pancreaticoduodenal vein were 86.6%, 85.0%, 76.6%, 71.6%, 91.6%, 53.3%, 61.6%, 55.0%, 43.3%, and 51.6%, respectively. Forty-three patients who had undergone 3D reconstruction underwent surgery. Of the 29 conventionally treated patients, 19 underwent surgery. The operative time, blood loss, length of hospital stay, and complication incidence of the 43 patients were superior to that of the 19 patients. CONCLUSIONS: A peripancreatic vascular reconstruction can reveal the vascular anatomy, variations of peripancreatic vascular, and tumor-induced vascular changes; the application of the simulation surgery platform could reduce surgical trauma and decrease operative time.

Biomechanical analysis of the impact of fibular osteotomies at tibiotalar joint: A cadaveric study.

BACKGROUND: Osteotomy of the fibula is a common orthopedic procedure performed for various indications, including harvesting fibula for grafting purposes. The effect of fibular osteotomy and need for tibiofibular syndesmotic fixation fusion at different levels on tibiotalar joint is matter of debate. We performed a biomechanical analysis of the impact of fibular osteotomies at different levels and whether the fixation of distal tibiofibular joint mitigates instability caused by the osteotomy. MATERIALS AND METHODS: Six lower limb specimens from fresh adult cadavers were used to prepare leg-foot models. The specimens were assigned to six status according to the level of osteotomy and whether fixation of distal tibiofibular joint was performed or not. Each specimen was then loaded axially to 700 N by the material testing machine, and the tibiotalar joint contact area and peak pressure were measured using an electronic pressure sensor. RESULTS: The contact area and the pressure of tibiotalar joint showed significant changes when compared to the normal specimen. All osteotomy specimens had a decreased tibiotalar contact area and an increased peak pressure. This positively correlated with proximity of level of osteotomy to the lateral malleolus. CONCLUSIONS: Through this study, we found that fibular osteotomy had an adverse effect in terms of decreasing the contact surface of tibiotalar joint that led to increased peak pressure in the joint. However, bone fusion and screw fixation of the distal tibiofibular joint reduced these adverse effects.