Mitsuo Shimada, MD, Shuichi Iwahashi, MD, Yuji Morine, MD, Satoru Imura, MD, Tetsuya Ikemoto, MD, Yu Saito, MD, Masato Yoshikawa, MD, Jun Higashijima, MD. Tokushima University
Objective of the technology
We have reported a possible “One-stop shop” liver surgery simulation using one-time dynamic CT (Hepatogastroenterology 2013), furthermore, correlation between signal intensity (SI) of MRI using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) and hepatobiliary scintigraphy Tc-99m galactosyl human serum albumin (GSA) to assess regional hepatic functional reserve (J Gastroenterol 2012). Herein, we introduce a new technology of “One-stop shop” liver surgery simulation equipped with assessment of liver functional reserve.
Description of the technology and method of its application
Characteristics of this “One-stop shop” technology are as follows: (1) one-time examination, (2) no-radiation exposure, (3) demonstration of liver vasculatures including, artery, portal vein, hepatic vein and biliary tract, (4) diagnosis of tumors in the liver, (5) calculation of volume of total and each segment, and especially (6) estimation of liver functional reserve in both total liver and each segment, leading to decision making of limit of resected volume of the liver.
Dynamic MRI images using fat-suppressed T1-weighted gradient-echo images with a 3D acquisition sequence were obtained before and after intravenous administration of Gd-EOB-DTPA (0.1 mg/kg body weight). The hepatocyte-phase images obtained 20 min after the injections were used for evaluation. 3D-reconstruction of MRI imaging was done by SYNAPSE VINCENT software (Fuji Medical Systems, Japan), and 3D-reconstruction was performed with manual tracing method.
Assessment of liver functional reserve:
The SI of the eight Couinaud segments of the liver were measured using a circular ROI. The SI of the right erector spine muscle was also measured at the level of the porta hepatis. ROI acquisition was performed using a commercially available picture archiving and communication system (SYNAPSE, Fujifilm Medical, Tokyo, Japan). The standardized signal intensity for each Couinaud segment was calculated as follows: standardized SI = SI of each Couinaud segments /SI of muscle. The standardized TLFR was defined as follows:
Standardized TLFR = ∑ [k=1 to 8] (standardized SI of segment (k) × volume of segment (k)) / Body surface area (FV/m2)
Our technology using one-time EOB-MRI succeeded in clearly demonstrating hepatic vasculatures including biliary tract, diagnosis of hepatic tumors, and volumetry without any radiation exposure.
With this standardized TLFR value, the following formula of resection limit was established using 28 normal liver cases (on the assumption that 70% of the liver can be resected) and 5 unresectable cirrhotic cases (recipient of transplantation) (on the assumption that 0% of the liver can be resected).
The estimated resection limit (%) = 70% × (the standardized TLFV of patient – 962)/1,076.
Other 30 patients who underwent hepatectomy were retrospectively investigated for validation of this formula. One patient having resection volume with over the resection limit died of liver failure, however, the other 29 cases within their resection limits did not suffer from liver failure.
Our new technology of “One-stop shop” liver surgery simulation could contribute safety of liver surgery, especially laparoscopic hepatectomy, because of no radiation exposure, and accurate assessment of anatomical variations and estimation of total and regional liver functional reserve (resection limit).
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 84298
Program Number: ETP744
Presentation Session: Emerging Technology Poster
Presentation Type: Poster