Tomoyoshi Okamoto

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.

Efficient and cancer-selective gene transfer to hepatocellular carcinoma in a rat using adenovirus vector with iodized oil esters.

Gene therapy for cancer requires efficient, selective gene transfer to cancer cells. In gene therapy for hepatocellular carcinoma (HCC), gene transfer is efficient for small tumors, but not for large tumors. The delivery of anticancer agents and of iodized oil esters as embolic agents through tumor-feeding arteries is known as transarterial embolization. We speculate that genes may be efficiently and selectively transferred for HCC using iodized oil esters because these esters may remain together with a genetic vector within HCC selectively. Hence, we have studied the effect of iodized oil esters on adenovirus vector–mediated gene transfer for HCC in vivo. A rat model of HCC induced with diethylnitrosamine and phenobarbital was injected with either AxCALacZ, which expresses the β-galactosidase of Escherichia coli , or AxCALacZ and iodized oil esters into the hepatic artery. Histological comparisons revealed that the β-galactosidase expression in the rats with HCC injected with AxCALacZ and iodized oil esters was greater ( P <.0001) in small tumors ( P =.0046) and large tumors ( P =.0023), and more selective ( P =.0229) than in only AxCALacZ-injected rats. These results suggest that iodized oil esters are injected into hepatic artery together with adenovirus vector, and that genes may be efficiently and cancer-selectively transferred to HCC. Cancer Gene Therapy (2001) 8, 713–718

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.

Internal hernia through a peritoneal defect in the pouch of Douglas: Report of a case.

INTRODUCTION Internal hernia is a rare entity which can cause intestinal obstruction. The most common type of internal hernia is the paraduodenal hernia which accounts for 53% of cases, and the internal hernia within the pelvis account for 7%. Perineal hernia, which is classified as pelvic hernia, usually occurs due to weakening of the pelvic floor musculature and thus, should be distinguished from the internal hernia caused by peritoneal defects in the pelvic cavity. PRESENTATION OF CASE We present a case of 28-year-old female who presented intestinal obstruction. Conservative therapies failed and she required emergency laparotomy. The operative findings revealed a peritoneal defect of 2cm in diameter in the pouch of Douglas, through which the ileum was incarcerated and strangulated. The incarcerated bowel was reduced, and the intestinal color quickly returned to normal. Therefore a primary closure of the peritoneal defect was performed and the postoperative course was uneventful. DISCUSSION A PubMed search for the case of internal hernia through a defect in the pouch of Douglas revealed only three, making this an extremely rare condition. CONCLUSION Because of rarity of this hernia, the etiology is unknown. However, our patient is a young female with no history of pregnancy, abdominal surgery, or trauma, therefore the cause of the peritoneal defect is considered congenital.

Does preoperative pancreatic duct stenting prevent pancreatic fistula after surgery? A cohort study

BACKGROUND/OBJECTIVE Postoperative pancreatic fistula remains a major complication after pancreatic surgeries. To prevent pancreatic fistula, one of the employed management strategies is pancreatic duct stenting. The purpose of this study was to evaluate the efficacy and safety of preoperative pancreatic stenting to prevent pancreatic fistula after surgery. METHODS Subjects comprised 18 consecutive patients who underwent pancreatic surgeries. Patients were divided into 2 groups: stenting group (n=7); and non-stenting group (n=11). Complications after stent placement were analyzed. Compared parameters between groups included background, incidence and grading of pancreatic fistula as judged by international study group of pancreatic fistula (ISGPF) criteria, duration until drain removal, and mean maximum level of drain amylase. RESULTS Two patients displayed mild pancreatitis with high serum amylase levels after stenting. No significant differences in background or any other compared parameters to assess drainage effect were identified between stenting and non-stenting groups. Complications related to placement of the stent tube occurred in 4 patients with tube occlusion or cholestasis. CONCLUSIONS Although drainage effect in the stenting group was compared with that in the non-stenting group, no obvious effect was obtained. This procedure seems to require further investigation on indications for postoperative drainage to decrease the incidence of pancreatic fistula.

Repair of Bochdalek hernia in an adult complicated by abdominal compartment syndrome, gastropleural fistula and pleural empyema: Report of a case

INTRODUCTION Bochdaleks diaphragmatic hernia (BDH) rarely developed symptomatic in adulthood but mostly required an operation. In adult BDH cases, long-term residing of the massive intraabdominal organs in the thoracic cavity passively causes loss of domain for abdominal organs (LOD). PRESENTATION OF CASE A 63-year-old man presented at our institution complaining of sudden left upper quadrant abdominal pain. Chest radiography showed a hyperdense lesion containing bowel gas in the left pleural space. Computed tomography revealed a dilated bowel above the diaphragm and intestinal obstruction suggestive of gangrenous changes. These findings were consistent with the diagnosis of incarcerated BDH and an emergency laparotomy was performed. Operative findings revealed the hypoplastic lung, lack of hernia sac, and location of the diaphragmatic defect, which indicated that his hernia was true congenital. Organs were reduced into the abdominal cavity, and large defect of the diaphragm was repaired with combination of direct vascular closure and intraperitoneal onlay mesh reinforcement using with expanded polytetrafluoroethylene (ePTFE) mesh. On the postoperative day 1, the patient fell into the shock and was diagnosed to have abdominal compartment syndrome (ACS). Conservative therapies were administered, but resulted in gastropleural fistula and pleural empyema, which required an emergency surgery. Mesh extraction and fistulectomy were performed. DISCUSSION A PubMed search for the case of ACS after repair of the adult BDH revealed only three cases, making this very rare condition. CONCLUSION In dealing with adult BDH, possible post-repair ACS should be considered.

Hepatectomy Using the Coagulating Shears Type of Ultrasonically Activated Scalpel

Since the ultrasonically activated scalpel (UAS) incorporates multiple functions, we have used it for hepatectomies. The present study discusses the noteworthy points and problems of use, and shows initial results. Intraoperative ultrasonography is an important tool for comprehending the positional relationship between the plane of division and the main blood vessels. It allows initial adjustment of coagulation and cutting effects according to the rigidity of the liver parenchyma by means of variable ultrasound levels and exchangeable blade tips, and offers good visibility of the cut surface in deep sites as long as adequate tension on the tissue and an upper position for the blade are maintained. 30 patients underwent hepatectomies using the UAS. The amount of blood loss for lobectomy was significantly less than that for partial lobectomy in normal livers in addition to a significant difference between normal and damaged livers in each group according to the extent of resection. There were no serious complications seen in all cases during the operation. The incidence of positive bile leakage was high. It is recommended that bile leakage testing be carried out as thoroughly as possible. There were 3 postoperative bile fistulas and 1 postoperative hemorrhage. In conclusion, although a dramatic improvement in blood loss and shortened operating time could not be obtained in all procedures, the safety and usefulness were demonstrated in lobectomy. The UAS can be considered as a surgical device that can contribute to the efficiency of hepatectomy, depending on the indications selected.

Stapleless laparoscopic splenectomy using harmonic scalpel by 2-step sealing.

Laparoscopic splenectomy (LS) has been accepted as a safe and effective procedure as compared with open splenectomy. Recently, there have been a few reports on the LigaSure vessel sealing system as an alternative hemostasis to clip ligation. Here we report the experience of LS using an alternative energy device, Harmonic Scalpel laparoscopic coagulating shears (LCS). Preliminary experience of LS with LCS for a patient with idiopathic thrombocytopenic purpura (ITP) is reported. Generally, two-step sealing with LCS was used for vessels of the splenic pedicle approximately 5 mm in diameter without using the Endo-GIA stapler. Operative time was 93 minutes, and blood loss was 40 mL. The patient was discharged on the third postoperative day with no intraoperative or postoperative complications. The LS with LCS was performed safely using two-step sealing. Further experience is necessary to verify the safety of this procedure.