Shinji Onda

Clinical application of navigation surgery using augmented reality in the abdominal field

This article presents general principles and recent advancements in the clinical application of augmented reality-based navigation surgery (AR based NS) for abdominal procedures and includes a description of our clinical trial and subsequent outcomes. Moreover, current problems and future aspects are discussed. The development of AR-based NS in the abdomen is delayed compared with another field because of the problem of intraoperative organ deformations or the existence of established modalities. Although there are a few reports on the clinical use of AR-based NS for digestive surgery, sophisticated technologies in urology have often been reported. However, the rapid widespread use of video- or robot assisted surgeries requires this technology. We have worked to develop a system of AR-based NS for hepatobiliary and pancreatic surgery. Then we developed a short rigid scope that enables surgeons to obtain 3D view. We recently focused on pancreatic surgery, because intraoperative organ shifting is minimal. The position of each organ in overlaid image almost corresponded with that of the actual organ with about 5 mm of mean registration errors. Intraoperative information generated from this system provided us with useful navigation. However, AR-based NS has several problems to overcome such as organ deformity, evaluation of utility, portability or cost.

Utility of augmented reality system in hepatobiliary surgery

Background/purposeThe aim of this study was to evaluate the utility of an image display system for augmented reality in hepatobiliary surgery under laparotomy.MethodsAn overlay display of organs, vessels, or tumor was obtained using a video see-through system as a display system developed at our institute. Registration between visceral organs and the surface-rendering image reconstructed by preoperative computed tomography (CT) was carried out with an optical location sensor. Using this system, we performed laparotomy for a patient with benign biliary stricture, a patient with gallbladder carcinoma, and a patient with hepatocellular carcinoma.ResultsThe operative procedures performed consisted of choledochojejunostomy, right hepatectomy, and microwave coagulation therapy. All the operations were carried out safely using images of the site of tumor, preserved organs, and resection aspect overlaid onto the operation field images observed on the monitors. The position of each organ in the overlaid image closely corresponded with that of the actual organ. Intraoperative information generated from this system provided us with useful navigation. However, several problems such as registration error and lack of depth knowledge were noted.ConclusionThe image display system appeared to be useful in performing hepatobiliary surgery under laparotomy. Further improvement of the system with individualized function for each operation will be essential, with feedback from clinical trials in the future.

Identification of inferior pancreaticoduodenal artery during pancreaticoduodenectomy using augmented reality-based navigation system

In pancreaticoduodenectomy (PD), early ligation of the inferior pancreaticoduodenal artery (IPDA) before efferent veins has been advocated to decrease blood loss by congestion of the pancreatic head to be resected. In this study, we herein report the utility of early identification of the IPDA using an augmented reality (AR)‐based navigation system (NS).

Short rigid scope and stereo‐scope designed specifically for open abdominal navigation surgery: clinical application for hepatobiliary and pancreatic surgery

BackgroundWe have reported the utility of an image display system using augmented reality (AR) technology in hepatobiliary surgery under laparotomy. Among several procedures, we herein report a system using a novel short rigid scope and stereo-scope, both designed specifically for open abdominal navigation surgery, and their clinical application for hepatobiliary and pancreatic surgery.MethodsThe 3D reconstructed images were obtained from preoperative computed tomography data. In our specialized operating room, after paired-point matching registration, the reconstructed images are overlaid onto the operative field images captured by the short rigid scopes. The scopes, which are compact and sterilizable, can be used in the operative field. The stereo-scope provides depth information. Eight patients underwent operations using this system, including hepatectomy in two, distal pancreatectomy in three, and pancreaticoduodenectomy in three patients. The stereo-scope was used in five patients.ResultsAll eight operations were performed safely using the novel short rigid scopes, and stereo images were acquired in all five patients for whom the stereo-scope was used. The scopes were user friendly, and the intraoperative time requirement for our system was reduced compared with the conventional method.ConclusionsThe novel short rigid scope and stereo-scope seem to be suitable for clinical use in open abdominal navigation surgery. In hepatobiliary and pancreatic surgery, our novel system may improve the safety, accuracy and efficiency of operations.

Navigation Surgery Using an Augmented Reality for Pancreatectomy

Aim: The aim of this study was to evaluate the utility of navigation surgery using augmented reality technology (AR-based NS) for pancreatectomy. Methods: The 3D reconstructed images from CT were created by segmentation. The initial registration was performed by using the optical location sensor. The reconstructed images were superimposed onto the real organs in the monitor display. Of the 19 patients who had undergone hepatobiliary and pancreatic surgery using AR-based NS, the accuracy, visualization ability, and utility of our system were assessed in five cases with pancreatectomy. Results: The position of each organ in the surface-rendering image corresponded almost to that of the actual organ. Reference to the display image allowed for safe dissection while preserving the adjacent vessels or organs. The locations of the lesions and resection line on the targeted organ were overlaid on the operating field. The initial mean registration error was improved to approximately 5 mm by our refinements. However, several problems such as registration accuracy, portability and cost still remain. Conclusion: AR-based NS contributed to accurate and effective surgical resection in pancreatectomy. The pancreas appears to be a suitable organ for further investigations. This technology is promising to improve surgical quality, training, and education.

Histopathologically Proven Autoimmune Pancreatitis Mimicking Neuroendocrine Tumor or Pancreatic Cancer

Autoimmune pancreatitis (AIP) can be difficult to distinguish from pancreatic cancer. We report a case of histopathologically proven AIP mimicking neuroendocrine tumor (NET) or pancreatic cancer in a 53-year-old man. He was referred to our hospital for further evaluation of a pancreatic mass detected on ultrasonography at a medical check-up. Abdominal ultrasonography showed a 15-mm hypoechoic mass located in the pancreatic body. Computed tomography revealed a tumor without any contrast enhancement, and magnetic resonance imaging demonstrated the mass to be hyperintense on diffusion-weighted image. Endoscopic retrograde cholangiopancreatography revealed slight dilatation of a branch of the pancreatic duct without stricture of the main pancreatic duct. The common bile duct seemed intact. Under suspicion of a non-functioning NET or malignant neoplasm, laparotomy was performed. At laparotomy, an elastic firm and well-circumscribed mass was found suggestive of a non-functioning NET, thus enucleation was performed. Histopathologically, the lesion corresponded to AIP.

Pancreatic Follicular Lymphoma Presenting as Acute Pancreatitis: Report of a Case

Pancreatic B-cell lymphoma is rare; it accounts for 0.2% to 2.0% of extranodal non-Hodgkin lymphoma, and constitutes less than 0.5% of all pancreatic malignancies. Most histologic types of the pancreatic lymphoma are diffuse large B-cell lymphoma, and follicular lymphoma is quite rare. We report here a case of pancreatic follicular lymphoma that was initially detected by acute pancreatitis. This is the first reported case of pancreatic follicular lymphoma presenting with acute pancreatitis. A 71-year-old woman had epigastric and left upper quadrant abdominal pain. Computed tomography (CT) revealed features of acute pancreatitis. After standard therapy for pancreatitis, enhanced CT showed a pancreatic tumor (50 × 35 mm) in the body of the pancreas with gradual enhancement. Endoscopic retrograde cholangiopancreatography and magnetic resonance cholangiopancreatography showed a complete interruption of the pancreatic duct in the body, with mild dilation of the duct in the tail of the pancreas. Endoscopic ultrasonography revealed hypervascularity of the pancreatic tumor. The patient underwent distal pancreatectomy to remove the cause of pancreatitis and to disclose the diagnosis. Histologic examination revealed follicular lymphoma of pancreas. Despite recent improvement in clinical strategies, differential diagnosis between pancreatic lymphoma and pancreatic cancer is still difficult without histologic information. Pancreatic lymphoma should be considered as a differential diagnosis in a patient who initially presents with acute pancreatitis.

Novel navigation system by augmented reality technology using a tablet PC for hepatobiliary and pancreatic surgery

We previously developed an image‐guided navigation system (IG‐NS) using augmented reality technology for hepatobiliary and pancreatic (HBP) surgery. This system superimposed a 3D model onto a stereoscope‐captured surgical field (i.e., the scope method). Unfortunately, this method requires an expensive stereoscope, surgeons have to shift their eyesight away from the surgical field, and the method has poor controllability. Therefore, an IG‐NS using a tablet PC (i.e., the tablet method) was developed. The aim of the current study is to evaluate the efficiency of this novel method.

Simultaneous Resection for Synchronous Double Primary Cancers of the Pancreas and the Liver

Simultaneous resection of synchronous hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC) is extremely rare. Case 1 is a 64-year-old woman, who had undergone anterior resection for rectal cancer 3 years earlier was pointed out to have a cystic tumor in the pancreatic tail and a solitary tumor in the liver. CT revealed a hypovascular tumor in the pancreatic tail and a liver tumor with early enhancement. With a diagnosis of simultaneous HCC and PDAC, she underwent laparotomy, in which intraoperative frozen section examination of the liver was compatible with HCC. Therefore, she underwent hepatic resection as well as distal pancreatectomy and splenectomy. The patient received adjuvant chemotherapy with S-1 and remains well with no evidence of tumor recurrence as of 28 months after resection. Case 2 is a 73-year-old man with sustained viral response to antiviral treatment for hepatitis C virus, who was pointed out to have a tumor in the pancreatic head and a solitary tumor in the liver. Gadoxetic acid-enhanced MRI exhibited enhancement compatible with HCC. With a diagnosis of concomitant HCC and PDAC, surgery was performed. Intraoperative frozen section examination was compatible with HCC, for which a pancreaticoduodenectomy was performed. The patient received adjuvant chemotherapy with S-1 and remains well with no evidence of tumor recurrence as of 16 months after resection. In conclusion, we describe 2 cases of hepato-pancreatectomy for synchronous double primary cancers of the pancreas and the liver, where exclusion of the liver tumor as a metastatic lesion from the pancreatic cancer is important.

Renal Infarction during Anticoagulant Therapy after Living Donor Liver Transplantation

Introduction: Liver transplant recipients are at risk for complications of vascular thrombosis. The reconstructed hepatic artery and portal vein thrombosis potentially result in hepatic failure and graft loss. Renal infarction is a rare clinical condition, but in severe cases, it may lead to renal failure. We herein report a case of renal infarction after living donor liver transplantation (LDLT) during anticoagulant therapy. Case Presentation: A 60-year-old woman with end-stage liver disease due to primary biliary cholangitis underwent LDLT with splenectomy. Postoperatively, tacrolimus, mycophenolate mofetil, and steroid were used for initial immunosuppression therapy. On postoperative day (POD) 5, enhanced computed tomography (CT) revealed splenic vein thrombosis, and anticoagulant therapy with heparin followed by warfarin was given. Follow-up enhanced CT on POD 20 incidentally demonstrated right renal infarction. The patient’s renal function was unchanged and the arterial flow was good, and the splenic vein thrombosis resolved. At 4 months postoperatively, warfarin was discontinued, but she developed recurrent splenic vein thrombosis 11 months later, and warfarin was resumed. As of 40 months after transplantation, she discontinued warfarin and remains well without recurrence of splenic vein thrombosis or renal infarction. Conclusion: Renal infarction is a rare complication of LDLT. In this case, renal infarction was incidentally diagnosed during anticoagulant therapy and was successfully treated.