Yohsuke Yagawa

Evaluation for transvaginal and transgastric NOTES cholecystectomy in human and animal natural orifice translumenal endoscopic surgery

BACKGROUND/PURPOSE Natural orifice translumenal endoscopic surgery (NOTES) is a novel concept using an endoscope via a translumenal access for abdominal surgery. This study was designed to evaluate the feasibility and technical aspects of NOTES cholecystectomy from our experience on humans and animals. METHODS NOTES cholecystectomies were performed in 12 animal experiments, including 8 pigs (6 by transgastric and 2 by transvaginal accesses) and 4 dogs (4 transvaginal accesses), and a human female cadaver. RESULTS The entire gallbladder could be removed under direct vision in all experiments. The average time was 60 min by transgastric and 40 min by transvaginal in animals. It was 87 min for human transvaginal cholecystectomy. In all animal and human procedures, there was no major complication concerning the operation. DISCUSSION The transvaginal route may be the easiest route for abdominal NOTES. Percutaneous endoscopic gastrostomy (PEG) allowed the safe performance of a controlled gastric perforation and shortened the time. The hybrid method allowed performance of a safe procedure and shortened the time. CONCLUSIONS Transvaginal and transgastric NOTES cholecystectomy is technically feasible and safe in both humans and animals. New instrumentation needs to be developed to perform a pure NOTES cholecystectomy without transabdominal assistance.

Carbon dioxide-enhanced virtual MDCT cholangiopancreatography

Background/PurposeWe investigated the feasibility of new carbon dioxide-enhanced virtual multidetector computed tomography (MDCT) cholangiopancreatography (CMCP) for intraluminal exploration in 73 patients with hepatobiliary and pancreatic disease.MethodsCMCP was performed via a percutaneous or transpapillary drainage tube, and, synchronously, intravenous contrast material was employed for virtual angiography; three-dimensional (3D) virtual reality was incorporated using OsiriX and Fovia applications. The capability of carbon dioxide to delineate the biliary and pancreatic system was evaluated.ResultsAll CMCPs showed complete technical success; complications including pancreatitis or pain never occurred. The incidences of visible third- and fourth-order biliary branches were 100 and 86.0%. The capability of carbon dioxide to pass an obstruction through an occluded hilar bile duct malignancy was 80.0%; it provided feasible information on additional bile duct segments. The full extent of the gallbladder was depicted in 72.7% of the studies. Minimum 2-mm lesions of biliary stones or gallbladder polyps were clearly detected. The main or second-order pancreatic ducts were visible in 100 and 83.3% of the studies, respectively. Carbon dioxide enabled the replacement of mucin and pancreatic juice and facilitated the detection of cystic lesions of intraductal papillary-mucinous neoplasm (IPMN) in 75.0% of the studies. We succeeded in achieving 3D spatial recognition of vascular structures in the cholangiopancreatic region, through the fusion of CMCP and 3DCT arteriography and venography in a single image scanning, and radiation time was decreased. This combined modality proved to be feasible for planning operations and for image-guided navigated surgery in the resection of a malignancy.ConclusionsTo our knowledge, this is the first report to demonstrate the diagnostic accuracy of carbon dioxide MDCT cholangiopancreatography and the use of this modality for depicting biliary, pancreatic, and fusion blood vessels simultaneously. Carbon dioxide possesses many advantages over conventional iodinated contrast agents, and it might replace more invasive diagnostic measures in the near future.