Application of augmented reality navigation in laparoscopic and robot-assisted liver surgery / 中华外科杂志

In recent years, laparoscopic surgery and robotic surgery have been widely used, and various intraoperative image navigation systems have also developed rapidly. However, the liver itself has a complex vessel and duct system, which increase the difficulty of liver surgery. The augmented reality image navigation system combines the three-dimensional reconstructed image of the liver with the real liver anatomy, which presents the specific relationship between the tumor location and the surrounding vessels for the surgeon. Compared with other intraoperative image navigation methods, augmented reality has its unique advantages. This paper provides an overview of current advances in registration technology in augmented reality image navigation system, and focuses on its applications in liver surgery, including laparoscopic surgery and robotic surgery. Finally, the technological problems and difficulties still faced at present are summarized, and future directions worth studying in this field are proposed.

Clinical experiences of surgical manipulations for hepatic masses in difficult sites / 中国医学科学院学报

<p><b>OBJECTIVE</b>To summarize the surgical experiences, risks, complications, and managements for hepatic masses in difficult sites.</p><p><b>METHODS</b>Totally 47 patients were divided into three groups based on the liver tumor sites: primary porta hepatis group, secondary porta hepatis group, and caudate lobe group. All patients underwent different portion of hepatectomy.</p><p><b>RESULTS</b>The surgery duration was (289.6 +/- 62.2) ml-nutes, intra-operative blood loss was (602.3 +/- 256.4) ml, and intra-operative blood transfusion was (524.0 +/- 325.9) ml. Incidence of surgical complications in each group was 61.5%, 26.9%, and 25%, respectively. Serious complications observed were biliary leakage (27.7%), bleeding (6.4%), and post-operative liver failure (2.1%). Three perioperative deaths were reported: two patients died of bleeding, and one patient died from liver failure.</p><p><b>CONCLUSIONS</b>Dissection of the liver and exposure of major blood vessels and biliary ducts are of critical importance in the surgeries for hepatic masses in difficult sites, and post-operative complications may be remarkably reduced through delicate manipulations of the small intra-hepatic vessels and biliary ducts during resection. A thorough pre-operative evaluation plays a key role in predicting the feasibility and risks of the surgery. Damage to the major blood vessels adjacent to the tumor, in addition to bleeding, may result in in-flow or outflow obstruction and cause necrosis of the corresponding hepatic lobe. Compared with damage to the primary portal area, vascular damage to the secondary porta is generally associated with higher fatality.</p>

Preoperative evaluation of liver function using 99mTc-diethyl iminodiacetic acid based on single photon emission computed tomography / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a three-dimentional liver function evaluation system using 99mTc-diethyl iminodiacetic acid (99mTc-EHIDA) scintigraphy based on single photon emission computed tomography (SPECT).</p><p><b>METHODS</b>Totally 16 patients with liver lesions were divided into cirrhosis group and non-cirrhosis group. SPECT was performed 2 days before operation and 5 days after operation. Serum liver functions were examined on the same day of scintigraphy. SPECT images of areas of interest of heart and liver were aquired. Time of the peak of EHIDA density in liver (Tpeak), five-minutes heart liver index (HLI5), blood clearance index (HH15), receptor index (LHL15), and the predictive values were calculated.</p><p><b>RESULTS</b>Tpeak was not significantly different between two groups, while HLI5, HH15, and LHL15 were significantly different (P = 0.033, P = 0.001, and P = 0.005). HLI, and LHL15 were significantly correlated with preoperative total protein and prealbumin levels (P = 0.003, P = 0.015, P = 0.022, P = 0.038) and post-operative prealbumin (P = 0.037, P = 0.042). The predictive values of HLI5 and LHL15 correlated well with postoperative HLI5 and LHL15 (r = 0.675, P = 0.016; r = 0.629, P = 0.028).</p><p><b>CONCLUSION</b>The three-dimentional liver function evaluation system using 99mTc-EHIDA based on liver SPECT may facilitate the further studies of risks of liver surgery.</p>

Early recurrence after the resection of hepatocellular carcinoma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To observe the precise time of the recurrence after resection of hepatocellular carcinoma (HCC) and to further explore the risk factors associated with postoperative recurrence.</p><p><b>METHODS</b>Totally 94 patients who had undergone resection of HCC were divided into three groups based on the time of recurrence, which was indicated by the digital subtraction angiography (DSA) examination: recurrence between 1 to 6 months, recurrence between 7 to 12 months, and tumor-free after 12 months. Patients with intra-hepatic recurrence were treated with transcatheter arterial chemoembolization and confirmed by CT scans after embolization, contrast-enhanced ultrasound, or magnetic resonance imaging.</p><p><b>RESULTS</b>The recurrence rates of 6 months and 1 year were 30.9% and 36.2%, respectively. No statistically significant difference between 6-month and 1-year recurrence rates was observed. Nine (26.5%) patients with recurrence and five (8.3%) patients free of tumor had previously presented as multifocal HCC, which showed a statistical significance (P = 0.032). The diagnostic accuracy of DSA was 87.2%, which was eventually confirmed by the other investigations.</p><p><b>CONCLUSIONS</b>Most recurrences occure within the first six months postoperatively and multifocal carcinogenesis is one of the risk factors associated with early recurrence after liver resection for advanced HCC. DSA is an important surveillance for early detection of intra-hepatic recurrence after surgery; meanwhile, it also provides information for early management to control the disease progression and for future active therapies.</p>

The effect of vascular endothelia growth factor encapsulated in nanoparticles on chronic limb ischemia / 中华外科杂志

<p><b>OBJECTIVE</b>To experimentally investigate direct intramuscular gene transfer of nanoparticles encoding vascular endothelial growth factor for the treatment of peripheral artery disease.</p><p><b>METHODS</b>The human VEGF(165) cDNA was cloned into the eukaryotic expression vector PIRES2 under the control of cytomegalovirus promoter/enhancer. The recombinant gene was transferred into a rabbit model of chronic hindlimb ischemia by naked plasmid and nanoparticle respectively. Ischemia was induced in the hindlimb of New Zealand White rabbits by ligation of the distal external iliac artery and complete excision of the femoral artery and all its branches. At day 7 postoperation animals received VEGF(165) plasmid (10 intramuscular) or nanoparticle-VEGF(165) (8 intramuscular). With RT-PCR, immunohistochemistry analysis, and angiography, the expression and biological effects of VEGF(165) gene in experimental animals were investigated.</p><p><b>RESULTS</b>Two weeks after initiation of therapy, angiography showed that the transfer of VEGF(165) gene stimulated the formation of focal neovessels and established collateral circulation. The adductor muscle of ischemic limbs was histologically examined at day 14. Capillary density was increased among VEGF(165)-transfected rabbits, especially Nano-VEGF(165)-treated animals (Naked VEGF(165) plasmid = 50.18 per mm(2), Nano-VEGF(165) = 81.22 per mm(2), Control = 29.54 per mm(2), P < 0.05). RT-PCR showed that the transcription and expression of VEGF(165) gene in experimental group were significantly higher than those of control groups.</p><p><b>CONCLUSIONS</b>Intramuscular administration of VEGF(165) induces collateral artery augmentation in the rabbit model of chronic limb ischemia. Nanoparticle can act as a vector to transfect specific gene and it will benefit gene transfer.</p>