| BackgroundBiliary lithiasis,including gallbladder stones, common bile duct stones, intrahepatic bile duct stones and so on. With the people's lifestyle changes and the arrival of aging society, constitute spectrum of biliary calculus disease are changing, in which the incidence of cholelithiasis showed an upward trend year by year. For cholelithiasis,since the late 80's of 20th century, laparoscopic cholecystectomy,as the representative of minimally invasive surgical techniques, have become the development trend of new century, and bring the treatment of cholelithiasis from the open cholecystectomy era of surgery into the era of laparoscopic surgery. However, Laparoscopic cholecystectomy is still not without incident today, according to statistics,its bile duct injury rate is still about 0.2%-0.3%. As the acceptance of laparoscopic cholecystectomy is on an increasing number, strengthening the training of laparoscopic cholecystectomy is still very important to the training of surgeons.Although there have been a variety of domestic and foreign commercial virtual laparoscopic surgical training machines, but most of them is still at the basic training level, and difficult to achieve individual and thus could not significantly reduce the complications of laparoscopic cholecystectomy occurred. At the same time, for the surgical treatment of bile duct stones, there have been two different trends recently. On the one hand, most of the common bile duct stones and some of the intrahepatic bile duct stones have been able to achieve minimally invasive laparoscopic treatment,On the other hand, due to people's understanding of pathological changes of intrahepatic bile duct stones were more and more detailed, open surgery of intrahepatic bile duct stones tended to be a joint model of a variety of surgical method in order to achieve the purpose of "remove the lesion, taking every stones, corrected narrow, unobstructed drainage and prevent recurrence". Thus,how to further enhance the safety of laparoscopic surgery and how to choose a reasonable and effective surgical method for biliary lithiasis have become the two major practical problems for surgeons.However, The essence of these two major issues remained how to achieve a individualized surgical treatment for specific patients with biliary lithiasis.In 2003, our research group performed 3-dimensional reconstruction and simulation surgery based on data collected from CT scanning of a digitalized virtual female Chinese No.1 liver perfusion specimen. Later, our study was extended to 3-dimensional reconstruction and visible simulation surgery of the liver, pancreas, gallbladder, spleen, and vascular system based on 64-slice helical CT scanning data. At present, we were able to perform individualized Visible Simulation Surgery of hepatobiliary diseases, including liver cancer and pancreatic cancer etc. This current study addressed the utilization of visible simulation surgery and the "individual-oriented" thinking on the two areas of minimally invasive and laparotomy surgery for biliary lithiasis.ObjectivesThis study aims:1) to establish individual-based virtual simulation laparoscopic surgery system based on the virtual simulation technology, and explore the application value of the system by using of force feedback devices and virtual laparoscopic surgical instruments to complete the virtual laparoscopic cholecystectomy,laparoscopic bile duct incision and liver resection, etc.2) bring the virtual simulation technology into the laparotomy treatment for complex hepatolithiasis, and to explore its clinical application value at the options of reasonable surgical method choice and re-biliary-tract surgery.Methods1 Study of individual laparoscopic surgery virtual visualization System for gallbladder stone disease1.1 The object of study:the patient, female,43 years old, recurrent upper abdominal pain for more than 10 years, diagnosed as "gallstones and chronic cholecystitis."1.2 Equipment:the software included ACDSee9 Message-Center (ACD System Ltd), MI-3DVS (self-developed), Free-Form Modeling System (Sens-Able Technologies, Inc.USA). The hardware included PHANTOM (PHANTOM Desktop), Main computer:memory 2G; Xeon 5130 processor 2.0G*2.1.3 Development of laparoscopic simulation surgical instrumentsOn the basis of previous studies, simulation surgical instruments were developed through three steps, such as geometry modeling, movement modeling and physical modeling. The laparoscopic simulation surgical instruments included laparoscopic surgery TORCAR, electro-coagulation hook, organization pliers, titanium clamp, scissors, cholangioscopy, ultrasonic knife,etc. Virtual laparoscopic basic surgical operation was carried out using force feed-back devices of Phantom with particle-spring-damper force feedback model in Free-Form Modeling System.1.4 CT scanning and data collection of biliary lithiasisThe patients were scanned from the top of diaphragm to the lower edge of liver in supine position. The CT scanner settings involved 250mAs,120KV, and thickness of 5mm, interval of 5mm,0.984 pitch, and rotation speed of 0.5S/cycle. Scanning was delayed 20 to 25S after arterial phase,50 to 55S after venous phase. Then data were transferred to Mxview working station. Data of plain scan, arterial venous phase, portal vein phase were stored in Mxview working station. Its format was transferred from DICOM to BMP.1.5 CT image segmentation and 3-dimension reconstruction1.5.1 Segmentation of liver,biliary system and abdominal vascular system imageData of hepatic tissue, bile duct system and abdominal vascular system were processed by a self-developed Medical Image Processing System. This Medical Image Processing System uses a self-adaptive region growing algorithm to segment previous tissues' images consecutively and obtained data in Stereo Lithography format. In which segmentation of biliary system and the stone image required accurate as far as possible. In common conditions, the segmentation of gallbladder and the stone image were more satisfied, because the density of gallbladder bile quite different with the surrounding tissue. But when the gallbladder filled by stones, atrophic gallbladder,stone incarcerated within gallbladder neck and cystic duct,especially gallbladder neck and cystic duct structure was small, or hepatic portal bile duct was non-expanded, image segmentation became more difficult, In such cases,image segmentations to different stage of CT data were carried out, and by complement each other, get a complete system and biliary stones STL data.1.5.2 Abdomen and abdominal wall tissue segmentation Standard Template Library data of the abdominal wall tissue including skin, ribs, sternum, spine aorta were obtained by a 3-dimensional dynamic region growing method.1.5.3 3-dimensional reconstruction of liver, bile duct systems,vascularsystem,abdominal wall,etc.Data of liver, bile duct systems,vascular system,abdominal wall in Standard Template Library format were introduced to the Freeform Modelling system to be smoothed and noise was eliminated. Then images of the liver and bile duct systems were reconstructed,Then the system configured them into a set of three-dimensional reconstruction organs model according to their real space location of the organization automatically,and we can zoom, rotate, transparency the different components of the model to observe the structure or details.1.6 Laparoscopic surgery scenario building and laparoscopic surgery virtual simulationLaparoscopic surgery position is different from laparotomy, set the position of abdominal wall and abdominal viscera three-dimensional reconstruction model is similar to the actual position of laparoscopic cholecystectomy.Set the viewing angle of laparoscopic surgery to 30-degree using Freeform Modeling System Image Rotation-Move tool. Furthermore, laparoscopic surgery display screen is simulated by Freeform Modeling System software work window. Through the window zoom in/out, pan around analog cameras advance and retreat, glance, and rotation functions.Then use the PHANTOM force feedback devices and self-developmented laparoscopic surgical instruments for the virtual simulation of laparoscopic cholecystectomy.Compared with laparotomy, the scope of activities of laparoscopic surgical instruments was limited by TORCAR location, range of peritoneal cavity, organizational structure and other constraints, the virtual simulation of surgery was also required to adapt to these requirements, But sometimes in order to show an important organizational structures or major surgical procedures, abdominal wall or other structure can be transparent, or even temporatedly hidden.2 study of individual laparoscopic surgery virtual visualization system for patient with intrahepatic and extrahepatic stones2.1 The object of study:the patient, male,45 years old, found stones in common bile duct three years ago, and recurrent abdominal pain for more than a year, CT NOTE:left lateral lobe of liver bile duct stones, common bile duct stones, bile ducts expansion"2.2 Original 64-slice CT scan data collection, image segmentation and three-dimensional reconstruction This step was in agreement with "1.4."。2.3 Laparoscopic instrument design and development This step was in agreement with "1.3"2.4 Laparoscopic surgery scenario building and laparoscopic surgery virtual simulation This step was in agreement with "1.6", by using virtual laparoscopic instruments simulate, the major surgical procedures of laparoscopic common bile duct incision and hepatic left lateral lobectomy were simulated.3 Applications of three-dimensionnal reconstruction and virtual simulation technique to intrahepatic caculi3.1 The object of study:to collect 64-slice spiral CT data of four cases from 22 cases of bile duct stones patients in our hospital from October 2008 to October 2009: Example 1:XX patient, ID:161510,female,53 years old, recurrent abdominal pain for 10 years. CT NOTE:left hepatic bile duct stone. Example 2:XX patient, ID:115350,female,45 years old, bile duct stones found three years ago, CT NOTE: intrahepatic bile duct stones, bile duct expansion, gas in intrahepatic bile duct. Example 3:XX patients, ID:110230,female,45 years old, recurrent abdominal pain for more than one year. CT NOTE:a significant expansion of bile duct, left/right intrahepatic bile duct and common bile duct stones. Example 4:XX patients, 1316271,female,52 years old, for upper abdominal pain recurring more than 10 years admitted to hospital, CT Tip:left and right hepatic bile duct contained stones, expanded common bile duct exists stones.3.2 Apparatus and equipments were similar to the "1.2"3.3 64-slice spiral CT original scan data acquisition, image segmentation,3D reconstruction were similar to the "1.4"3.4 Visible simulation surgery for intrahepatic calculiThe Free-Form Modelling System was used to reconstruct 3-dimensional models of viscera according to their real spatial position. The stereo model and its components could be amplified, deleted, rotated, and hyalinized to clarify the anatomical character of tissue structures, calculi distribution, bile duct stricture and deformity, vascular arrangement, and parenchymal lesions from omni-direction, multi-angle, and different levels. Then, according to the Chinese Guideline of Hepatobiliary Calculi Diagnosis and Treatment, we classified the disease and determined the optimal operation planning. Finally, simulated operations were performed in the Free-Form Modelling System by a force feed-back instrument (PHANTOM). The simulated operation helped us to predict the difficulties that may be encountered in the real operation process and what precautions to take.4 Applications of three-dimensionnal reconstruction and virtual simulation technique to reoperational patients of intrahepatic caculi4.1 The object of study:to analysis 3 cases underwent biliary reoperatons: Example 1:XX patients, ID1145376,female,45 years old, upper abdominal pain recurrence for more than 10 years, accepted"bile duct exploration" (the specific surgical method unknown) five years ago, CT Tip:left intrahepatic bile duct stones, a hilar low-density lesion unknown nature existed. Example 2:XX patients, ID:1195132,female,56 years old, recurrent upper abdominal pain for more than 10 years, and underwent biliary tract surgery two times (both common bile duct exploration and T-tube drainage), CT Tip:stones filld in left, right hepatic bile duct and common bile duct. Example 3:XX patients, ID:1293786,female,46 years old, recurrent upper abdominal pain for more than eight years, there were two times history of biliary tract surgery (common bile duct exploration and T-tube drainage), CT Tip:expansion of intra-and extrahepatic bile duct, intrahepatic stones were scattered, large common bile duct stones.4.2. Apparatus and equipment were in agreement with the "1.2"4.3 original 64-slice spiral CT scan data acquisition, image segmentation,3D reconstruction were in agreement with the "1.4"4.4. virtual surgery for reoperations of Intrahepatic bile duct stones this part was similar to "3.4"Results1 Study of individual laparoscopic surgery virtual visualization System for gallbladder stone disease1.1 Design and development of laparoscopic surgical instrumentsThe virtual laparoscopic instruments in this study could complete some simple laparoscopic operation procedure by a force feed-back instrument (PHANTOM), the feedback powerful feelings and findings of the simulation of surgical procedures were consistent with the clinical process.1.2 Abdominal organs and abdominal wall tissue image segmentation and three-dimensional reconstruction1.2.1 Liver and peripheral vascular system image segmentationThe hepatobiliary tract model was segmented with the Medical Image Process System, after smoothing with the Free-Form Modelling System, and its structure become clearer and all of the structures including the bile duct, hepatic artery, hepatic vein, portal vein, and calculi were reconstructed in 3-dimensions successfully.1.2.2 Biliary system and the stone image segmentation and three-dimensional reconstructionThe biliary system model can more truly reflect the relationship between gallbladder,common bile duct and the left/right hepatic bile duct Three-dimensional model of biliary system, abdominal organs and vascular models with integrated, the structures of triangle gallbladder, liver duodenum ligament and right hepatic door could be seen clearly, their structural characteristics were very important for laparoscopic surgery. 1.2.3 Abdominal wall image segmentation and three-dimensional reconstructionThe thoraco-abdominal wall model were clear, strong stereo and had skin texture appearance, and the structures which had significant value for laparoscopic surgery such as the navel, bilateral costal arch, xiphoid angle could be seen clearly. When the transparency of abdominal wall model was set to 0, the abdominal organs and abdominal vascular structure could be fully displayed. In order to observe the details from different ranges, such as zooming in, zooming, and rotation operations could be taken.1.3 The establishment of laparoscopic surgery scenarioSet the position of abdominal wall and abdominal viscera three-dimensional reconstruction model similar to the actual position of laparoscopic cholecystectomy, and set the viewing angle of laparoscopic surgery to 30-degree using FreeForm Modeling System Image Rotation-Move tool. Then use the PHANTOM force feedback devices and self-developmented laparoscopic surgical instruments to simulate laparoscopic basic procedures. Sometimes, in order to show an important organizational structures or major surgical procedures, abdominal wall or other structure could be transparent, or even temporarily hidden.1.4 Laparoscopic visualization of basic laparoscopic surgical operationIn the laparoscopic virtual environment,using PHANToM manipulate the "electrocoagulation hook", "titanium clamp", "scissors", "grasping forceps" and other virtual laparoscopic insruments to complete the main process of laparoscopic cholecystectomy.including:gallbladder triangle revealed, cystic duct and cystic artery occlusion and cut off, separation of the gallbladder bed, remove the gallbladder specimens,ect. The whole simulation process was similar to the actual surgical procedure.2 study of individual laparoscopic surgery virtual visualization system for patient with intrahepatic and extrahepatic stones2.1 64-slice spiral CT acquisition, image segmentation and three-dimensional reconstructionThe result was Similar to the result "1.2"2.2 Design and development of laparoscopic surgical instrumentsThe result was similar to the result "1.3"2.3 Laparoscopic surgery visualization process for hepatolithiasis2.3.1 Surgery position settings:In the laparoscopic virtual environment, the position of abdominal wall and abdominal viscera three-dimensional reconstruction model was similar to the actual position of laparoscopic cholecystectomy.2.3.2 Set the location of the TORCARS:First, the establishment of 1.0cm TORCAR for observation at the Cullen hole, placed in camera shot. Then set the location of disposes hole (1.0cmTORCAR) and two auxiliary holes (0.5cmTORCAR) under xiphoid and left/right ribs.2.3.3 Main process of laparoscopic surgery for hepatolithiasis in the laparoscopic virtual environmentIncluding:Cholecystectomy steps, Common bile duct incision and take Stones, Choledochoscopic exploration and take stones from common bile duct, Laparoscopic hepatic left lateral lobectomy steps, Common bile duct T tube and peritoneal drainage tube placement ect. The whole simulation process was similar to the actual surgical procedure.3 Applications of three-dimensionnal reconstruction and virtual simulation technique to intrahepatic caculi3.1 64-slice spiral CT acquisition, image segmentation and three-dimensional reconstructionThe result was Similar to the result "1.2",and the 3-dimensional model could be amplified, rotated, and hyalinized to clarify the anatomical character of tissue structure with omni-directional, multi-angle, and multi-level views. After we localized the intrahepatic calculi and determined the calculi shape, deformity or stricture of the bile tract system, the distribution of the intrahepatic vessel system, and parenchyma lesions, an optimal surgical option was chosen.3.2. Virtual reality of surgical procedures and actual surgical conditions.Case1:3-dimensional reconstruction revealed that the stones were localized in the bile duct of left lateral lobe, and no stones were present in the caudate lobe. This case was defined as typeⅡb+E of hepatobiliolithiasis and a left lateral lobectomy, cholecystetomy, choledochotomy, and T-tube drainage was recommended. the program was proofed feasible and safe by virtual simulation technology, but to protect the deputy right hepatic duct and liver vein were very important, there are certain risks in these surgical steps. The patient recovered uneventfully after operation.Case 2:This case was defined as typeⅡb+Eb hepatobiliary lithiasis according 3-D reconstruction and CT film, we could see that the junction of the bilateral hepatic duct was narrowed, the opening of the right posterior bile duct was narrowed, and the bile duct of the right and left caudate lobe entered the right hepatic bile duct ect. We choose to perform 1st and 2nd grade choledochoplasty and choledochojejunostomy. Because first hepatic hilum was high, quadrate lobectomy was essential to expose hepatic hilum. Because air in the intrahepatic bile duct suggested sphincter of Oddi dysfunction, cholecystectomy, choledochotomy, and common bile duct exploration were necessary. the program was proofed feasible and safe by virtual simulation technology. At present the patient has not yet accepted operation.Case 3:3-dimensional reconstruction revealed that stones were found in left/right intrahepatic bile duct and extrahepatic bile duct. The intrahepatic bile duct was markedly dilated and the hilar bile duct did not appear to be narrowed, This case was defined as typeⅢa+Ea hepatobiliary lithiasis. The best surgical option was cholecystectomy, choledocholithotomy of the common bile duct, and hepatic hilum and choledochojejunostomy. And the Patient underwent surgery, intraoperative situation is similar to the virtual surgical findings, the patient recovered uneventfully after operation.Case 4:3-dimensional reconstruction revealed that stones were found in left/right intrahepatic bile duct and extrahepatic bile duct. and the stones of right intrahepatic bile duct in this case were secondary stones.This case was defined as typeⅡa+Ea hepatobiliary lithiasis, The best surgical option was cholecystectomy, choledocholithotomy of the common bile duct, and left lateral lobectomy, intraoperative situation is similar to the virtual surgical findings, the patient recovered uneventfully after operation.4,Applications of three-dimensionnal reconstruction and virtual simulation technique to reoperational patients of intrahepatic caculi4.1 64-slice spiral CT acquisition, image segmentation and three-dimensional reconstructionThe result were Similar to the result "3.1".4.2 Virtual reality of surgical procedures and actual surgical conditions.The 3-D models could be amplified, rotated, and hyalinized to clarify the anatomical character of tissue structure with omni-directional, multi-angle, and multi-level views. After we localized the intrahepatic calculi and determined the calculi shape, deformity or stricture of the bile tract system, the distribution of the intrahepatic vessel system, and parenchyma lesions, the reasons of bile duct stones recurrence was analysised, and then a reasonable surgical method was determinded according to the reasons. Finally,virtual above-mentioned surgical procedures were taken and to guide the actual surgical procedure.case 1:Three-dimensional reconstruction results:stones were found in the left hepatic lobe, and the left intrahepatic bile duct was in cystic dilatation state, the opening of left hepatic duct was narrow, no stones within common bile duct low-density lesion nearby hilar bile duct maybe the bowel anastomosised with the bile duct, etc.This case was defined as typeⅡb of hepatobiliolithiasis according to results of 3-D,the reasons of stone recurrence were left intrahepatic duct stricture and inappropriate choledochojejunostomy.The rational surgical method as follows:left lateral lobectomy, bile-intestinal anastomosis demolition and reconstruction. In Virtual surgery, we found that we could cut and shaped the bile duct stricture from the bile duct stump,and then took exploration from this way, found the opening of biliary-enteric anastomosis is very smooth,and none stones in the common bile duct,thus the step of bile-intestinal anastomosis demolition and reconstruction was canselled, the patient recovered uneventfully after operation.case 2:Three-dimensional reconstruction showed that:The stones were found in the left lobe and extrahepatic bile duct, intrahepatic bile duct system was dilatation, and bile duct variation existed in the left hepatic lobe.3-D model also showed that left hepatic lobe of liver was atrophied, and left portal vein and left hepatic vein were occlusioned and so on.According to the 3-D results,this case was defined as typeⅡa+E of hepatobiliolithiasis, the reasons of stones recurrence were malformations of intrahepatic bile ducts and vascular which were not corrected in the first operation. A reasonable surgical method as follows:left lateral lobectomy of the liver,bile duct plastic,bile-intestinal anastomosis. Actual surgery confirmed the malformations of intrahepatic bile ducts and vascular and achieve surgical planning, the patient recovered uneventfully after operation.case 3:Three-dimensional reconstruction results:stones existed in the left, right hepatic duct and common bile duct, intrahepatic and extrahepatic bile ducts were expanded, intrahepatic bile duct system had no stenosises. According to the 3-D results,this case was defined as typeⅡa+E of hepatobiliolithiasis, the reasons of Stones recurrence were cholestasis in intrahepatic and common bile duct. A reasonable surgical method as follows:left lateral lobectomy of the liver, right posterior hepatic lobectomy, common bile duct incision,side-side biliary-enteric anastomosis, the actual surgery completed the scheduled surgical planning successfully, and the patient recovered uneventfully after operation.Conclusions1. The individual laparoscopic virtual visualization system was able to establish a realistic scenario of laparoscopic surgery, complete successfully the major surgical procedures of laparoscopic cholecystectomy, laparoscopic bile duct exploration and left hepatic lobectomy. The self-developed virtual laparoscopic surgical instruments have vivid image, can increase the visual effect of surgical simulation. The "individual" features of this system can help practitioners to avoid the mind-set from the common laparoscopic surgery training system,to overcome the gap between training and actual operation, and thus to reduce the complications in actual laparoscopic surgery. Meanwhile, individual virtual simulation of laparoscopic surgery system is also an open system.2. Individual laparoscopic virtual visualization system is also at an early stage, it needs to continue to absorb the latest computer virtual reality technology in order to gradually improve its functions.3. Three-dimensional reconstruction and virtual simulation technology have very important application value for hepatolithiasis laparotomy surgery and those patients underwent re-operation of this disseas also benefit from these technologies. Compared to general imaging technologies, three-dimensional reconstruction and virtual simulation technology have more advantages in the following areas such as showing stones' distribution accurately, displaying bile duct stenosises overall, discovering bile duct and/or vascular variations, analysis the reasons of stone recurrence specificly, providing accurate clinical classification and reasonable operation program,etc. Meanwhile simulation surgical procedures can also assess the feasibility and safety of the selected operation programs, provide guidance to actual surgical operations and thus improve the clinical efficacy of hepatolithiasis furthermore.
|
PDF Full Text Request