Yoshitaka Maeda

Oligonucleotide microarray for prediction of early intrahepatic recurrence of hepatocellular carcinoma after curative resection

BACKGROUND Hepatocellular carcinoma has a poor prognosis because of the high intrahepatic recurrence rate. There are technological limitations to traditional methods such as TNM staging for accurate prediction of recurrence, suggesting that new techniques are needed. METHODS We investigated mRNA expression profiles in tissue specimens from a training set, comprising 33 patients with hepatocellular carcinoma, with high-density oligonucleotide microarrays representing about 6000 genes. We used this training set in a supervised learning manner to construct a predictive system, consisting of 12 genes, with the Fisher linear classifier. We then compared the predictive performance of our system with that of a predictive system with a support vector machine (SVM-based system) on a blinded set of samples from 27 newly enrolled patients. FINDINGS Early intrahepatic recurrence within 1 year after curative surgery occurred in 12 (36%) and eight (30%) patients in the training and blinded sets, respectively. Our system correctly predicted early intrahepatic recurrence or non-recurrence in 25 (93%) of 27 samples in the blinded set and had a positive predictive value of 88% and a negative predictive value of 95%. By contrast, the SVM-based system predicted early intrahepatic recurrence or non-recurrence correctly in only 16 (60%) individuals in the blinded set, and the result yielded a positive predictive value of only 38% and a negative predictive value of 79%. INTERPRETATION Our system predicted early intrahepatic recurrence or non-recurrence for patients with hepatocellular carcinoma much more accurately than the SVM-based system, suggesting that our system could serve as a new method for characterising the metastatic potential of hepatocellular carcinoma.

Effect of Cautery with Irrigation Forceps on the Remnant Liver after Hepatectomy in Rats

Monopolar cautery with irrigation forceps (CIF) was devised for use in liver resection that does not require occlusion of inflow to the remnant liver. However, a high power output is required to divide the hepatic parenchyma which boils the irrigation water. This study was performed to investigate the effects of using CIF on the hepatic parenchyma. Histologic and biochemical examination was performed in rats which had undergone hepatectomy using the CIF, irrigating bipolar (IB), Pringle’s maneuver with blunt dissection (group P), or a sham operation. A greater cautery distance was obtained with the CIF than the IB. There was no significant difference in the remnant liver function after the 1st postoperative day in any of the groups. CIF is an effective instrument for anatomic or nonanatomic hepatic resection.

Surgical stress and transient postoperative psychiatric disturbances in aged patients studied using the Yamaguchi University Mental Disorder Scale

Psychiatric disturbances often occur in aged patients after surgery, but there is no easy or precise method of predicting their occurrence. We devised an easy mental test, the Yamaguchi University Mental Disorder Scale (YDS), based on the surgical perspective. Using both this new method and the Hasegawa mental disorder scale (HDS), we examined 106 patients who had undergone general anesthesia. HDS only was used in 70 cases, while 36 cases were examined by the newly devised YDS and were then compared with the findings obtained by HDS. On the HDS examination, factors affecting postoperative psychiatric disturbances were, in order of frequency: entering the ICU, amount of bleeding, and duration of surgery. Aged patients who experienced severe surgical stress had a higher risk of developing transient postoperative psychiatric disturbances. On the YDS examination, the relationship between surgical stress and transient postoperative psychiatric disturbances was clearly indicated, as was the case with HDS. Postoperative delirium was seen in a significant proportion of patients with low preoperative scores on YDS (P<0.05), while no significant difference was observed between the mean preoperative scores on HDS and postoperative delirium. In the preoperative evaluation using YDS, postoperative delirium was found to be predictable, and YDS is thus considered to be a more valuable tool in managing aged patients.

Treatment of cholecystoduodenal fistula by laparoscopy.

We describe a patient with cholecystoduodenal fistula treated by a laparoscopic approach. Use of a flexible videoscope, flexible retractor, and endoscopic transecting stapler allows for laparoscopic treatment of cholecystoenteric fistulae.

Surgical Treatment of Hepatocellular Carcinoma

Hepatic resection is currently performed for the treatment of hepatocellular carcinoma (HCC), which is associated with a high incidence of postoperative recurrence. The aim of this study was to clarify the prognostic factors after hepatic resection for HCC. A total of 144 patients who underwent hepatic resection for HCC were studied. Eight factors including albumin, tumor size, intrahepatic metastasis (IM), invasion into the portal vein (Vp), type of hepatectomy, operative time, blood loss, and tumor margin were analyzed with multivariate analysis using a stepwise multivariate logistic regression model to evaluate the prognostic factors after hepatic resection. The relationship between operative procedures and the type of treatment modalities was also investigated, and the outcome of treatment modalities was analyzed using the survival rate after recurrence. Multivariate analysis revealed the type of hepatectomy, Vp, and IM to be independent factors related to recurrence and prognosis. The 5-year survival rate in patients without Vp and without IM was significantly higher than in patients with Vp and with IM (P > .05). The 5-year survival rate and 5-year disease-free survival rate in patients who underwent subsegmentectomy or segmentectomy or lobectomy (anatomic resection) was significantly higher than in patients who underwent partial resection (P > .01 and P > .05). Eleven (31.4%) patients with intrahepatic recurrence after anatomic resection were treated with repeat hepatectomy but only 2 (8.3%) after nonanatomic resection. Moreover, repeat hepatectomy was significantly related to the prognosis after recurrence compared with chemolipiodolization and locoregional chemotherapy (P > .05). These results suggest that anatomic resection, which was related to a low recurrence rate as well as a greater chance of reresection, may be a useful surgical treatment for hepatocellular carcinoma.

Compensatory hepatic hypertrophy after occlusion of branches of the portal vein or bile duct

The effect on the liver of portal or bile duct branch occlusion was examined in rabbits by measuring hepatic tissue blood flow and cellular kinetics, using the bromodeoxyuridine labeling index. The portal branch bile duct branch, or both, to the main lobe and caudate lobe (80.4% of total liver weight) were ligated or embolized just above the right posterior lobe (19.6%), resulting in compensatory hypertrophy of the right posterior lobe and atrophy of the main and caudate lobes. Twenty-four days after ligation, the degree of compensatory hypertrophy in the different groups was comparable. There were significant differences in the pattern of the development of hypertrophy. Ligation of both a portal branch and the corresponding bile duct resulted in more rapid hypertrophy and atrophy than ligation of a portal branch alone. Ligation of a branch of the bile duct resulted in slow development of hypertrophy and atrophy. In the embolization group, the increase in the right posterior lobe stopped 6 days after the operation, resulting that it was about 40% thereafter. Histological findings showed that the fibrin clot had contracted and was floating in the portal branch to the main lobe. These results suggested that portal blood flow to the main lobe had resumed and was gradually increasing as the clot contracted. Portal branch ligation gave results superior to those with portal branch embolization with regard to application to preoperative procedure in extended hepatobiliary surgery.

INVESTIGATION OF 6 CASES OF MALIGNANT GASTRIC LYMPHOMA

We experienced 6 cases of malignant gastric lymphoma during the 5 years from January 1984 to December 1988. In 2 of the 6 patients gastric excision and chemotherapy regimen were performed prolonged their lives for long periods, but the remaining 4 merely underwent chemotherapy. Unexpectedly, favorable result of a long survival could be obtained for the latter cases, as well as for the fomers of the said gastric excision, except for one case which died of other illness.