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Featured researches published by Michio Kanai.


Annals of Surgery | 2000

Management of Hilar Cholangiocarcinoma: Comparison of an American and a Japanese Experience

Jane I. Tsao; Yuji Nimura; Junichi Kamiya; Naokazu Hayakawa; Satoshi Kondo; Masato Nagino; Masahiko Miyachi; Michio Kanai; Katsuhiko Uesaka; Koji Oda; Ricardo L. Rossi; John W. Braasch; John M. Dugan

ObjectiveTo compare the experience and outcome in the management of hilar cholangiocarcinoma at one American and one Japanese medical center. Summary Background DataControversies surround the issues of extent of resection for hilar cholangiocarcinoma and whether the histopathology of such cancers are similar between patients treated in America and in Japan. MethodsRecords were reviewed of 100 patients treated between 1980 and 1995 at the Lahey Clinic in the United States, and of 155 patients treated between 1977 and 1995 at Nagoya University Hospital in Japan. Selected pathologic slides of resected cancers were exchanged between the two institutions and reviewed for diagnostic concordance. ResultsIn the Lahey cohort, there were 25 resections, 53 cases of surgical exploration with biliary bypass or intubation, and 22 cases of percutaneous transhepatic biliary drainage or endoscopic biliary drainage without surgery. In the Nagoya cohort, the respective figures were 122, 10, and 23. The overall 5-year survival rate of all patients treated (surgical and nonsurgical) during the study periods was 7% in the Lahey cohort and 16% in the Nagoya cohort. The overall 10-year survival rates were 0% and 12%, respectively. In patients who underwent resection with negative margins, the 5- and 10-year survival rates were 43% and 0% for the Lahey cohort and 25% and 18% for the Nagoya cohort. The surgical death rate for patients undergoing resection was 4% for Lahey patients and 8% for Nagoya patients. Of the patients who underwent resection, en bloc caudate lobectomy was performed in 8% of the Lahey patients and 89% of the Nagoya patients. Histopathologic examination of resected cancers showed that the Nagoya patients had a higher stage of disease than the Lahey patients. ConclusionsIn both Lahey and Nagoya patients, survival was most favorable when resection of hilar cholangiocarcinoma was accomplished with margin-negative resections. Combined bile duct and liver resection with caudate lobectomy contributed to a higher margin-negative resection rate in the Nagoya cohort.


Annals of Surgery | 1998

The pattern of infiltration at the proximal border of hilar bile duct carcinoma. A histologic analysis of 62 resected cases

Eiji Sakamoto; Yuji Nimura; Naokazu Hayakawa; Junichi Kamiya; Satoshi Kondo; Masato Nagino; Michio Kanai; Masahiko Miyachi; Katsuhiko Uesaka

OBJECTIVE To clarify the importance of different patterns of infiltration at the proximal border of hilar bile duct carcinomas. SUMMARY BACKGROUND DATA There are few detailed pathologic studies on the proximal resection margins in patients with hilar bile duct carcinoma. METHODS Serial sections of 62 specimens of resected hilar bile duct carcinoma were examined histologically to determine the involved layers and routes of invasion at the proximal border. The degree of cancer extension was determined, and the relation between the length of the tumor-free resection margin and postoperative anastomotic recurrences was analyzed. RESULTS Mucosal extension was predominant in papillary and nodular tumors, but submucosal extension was predominant in diffusely infiltrating and nodular-infiltrating tumors. Submucosal extension usually consisted of direct or lymphatic invasion. The mean length of submucosal extension was 6.0 mm. Superficial spread of cancer, defined as mucosal extension of more than 20 mm from the main lesion, was seen in 8 specimens. No patient had an anastomotic recurrence when the tumor-free resection margin was greater than 5 mm. CONCLUSIONS The pattern of infiltration at the proximal border of resected hilar bile duct carcinomas is closely related to the gross tumor type. The length of submucosal extension is usually less than 10 mm. Superficial spread of cancer is seen in more than 10% of cases. A tumor-free proximal resection margin of 5 mm appears to be adequate in hilar bile duct carcinoma.


World Journal of Surgery | 2001

Complications of Hepatectomy for Hilar Cholangiocarcinoma

Masato Nagino; Junichi Kamiya; Katsuhiko Uesaka; Tsuyoshi Sano; Hideo Yamamoto; Naokazu Hayakawa; Michio Kanai; Yuji Nimura

Abstract. We retrospectively reviewed postoperative complications in 105 patients with hilar cholangiocarcinoma who underwent hepatectomy at Nagoya University Hospital from January 1990 through March 1999. Of the 105 subjects, 97 (92.4%) underwent resection of two or more Healeys segments of the liver. Combined portal vein resection was performed in 33 (31.4%) patients and pancreatoduodenectomy in 10 (9.5%). Twenty (19.0%) patients had no postoperative complications, another 39 (37.1%) patients had minor complication(s) only, and the remaining 46 (43.8%) developed major complication(s). The morbidity rate reached as high as 81.0%. Major complications required relaparotomy in 11 (10.5%) patients. Of the 46 patients with major complication(s) 36 recovered; the remaining 10 patients died of liver failure with other organ failure(s) or of intraabdominal bleeding 12, 14, 18, 21, 57, 75, 75, 87, 93, or 134 days after surgery. Thus the 30-day mortality was 3.8% and the overall mortality 9.5%. Pleural effusion was the most frequent complication found in 66 (62.9%) patients, followed by wound sepsis in 39 (37.1%), and then liver failure in 29 (27.6%). Liver failure developed in 16.7% of 48 patients with less than 50% liver resection and in 36.8% of 57 patients with 50% or more resection (P < 0.05). Other organ failures, including renal, respiratory, gastrointestinal, and hematologic failures, developed as a sign of multiple organ failure following liver failure in most patients or preceding liver failure in a few patients. None of the six patients with four or more organ failures survived. Hepatectomy for hilar cholangiocarcinoma is risky owing to impaired hepatic functional reserve in jaundiced patients and the technical difficulty associated with hepatobiliary resection. Our goal is to reduce mortality to less than 5% while keeping a high resectability rate (above 80%).


Surgery | 1996

Preoperative intrahepatic segmental cholangitis in patients with advanced carcinoma involving the hepatic hilus.

Michio Kanai; Yuji Nimura; Junichi Kamiya; Satoshi Kondo; Masato Nagino; Masahiko Miyachi; Yasutomo Goto

BACKGROUND Major hepatic resection for biliary tract carcinoma continues to be a risky operation. In this study we examined the influence of preoperative intrahepatic segmental cholangitis on posthepatectomy mortality. METHODS We analyzed retrospectively the clinical features of 118 patients who underwent liver resection including more than two segments for biliary tract carcinoma involving the hepatic hilus. RESULTS Intrahepatic segmental cholangitis was encountered before operation in 22 cases. The morbidity and mortality rates for these patients were significantly higher than those of patients without preoperative cholangitis. Selective percutaneous transhepatic biliary drainage was performed before operation in 11 patients for segmental cholangitis. The morbidity rate of patients after hepatectomy was significantly lower than that of patients treated without percutaneous transhepatic biliary drainage. CONCLUSIONS The presence of preoperative intrahepatic segmental cholangitis is a major prognostic factor in the outcome of major hepatic resection for biliary carcinoma. Selective percutaneous transhepatic biliary drainage for preoperative intrahepatic segmental cholangitis plays an important role in reducing complications after major hepatic resection.


International Journal of Gastrointestinal Cancer | 1997

Distal Pancreatectomy with En Bloc Resection of the Celiac Artery for Carcinoma of the Body and Tail of the Pancreas

Toshihiko Mayumi; Yuji Nimura; Junichi Kamiya; Satoshi Kondo; Masato Nagino; Michio Kanai; Masahiko Miyachi; Katsura Hamaguchi; Naokazu Hayakawa

SummaryConclusionCombined resection of the celiac artery with a distal pancreatectomy (DP) increases the resectability and improves the overal prognosis of patients with locally advanced ductal cancer of the body and tail of the pancreas.BackgroundCarcinoma of the body and tail of the pancreas is often unresectable because of invasion to adjacent organs. We evaluated a DP including anen bloc resection of the celiac artery (“extended”), for pancreatic cancer that had invaded the common hepatic and/or celiac arteries.MethodsSix cases of an “extended” DP were compared with 19 cases of a “standard” DP for pancreatic ductal carcinoma in terms of clinical and pathologic findings, perioperative course, and long-term outcome. We also compared the survival rate of these two groups with a third group consisting of 22 patients with unresectable pancreatic ductal carcinoma.ResultsThe mean operative time, postoperative serum aspartate aminotransferase concentration, and length of hospital stay did not significantly differ between the “extended” and “standard” DP groups. The cumulative 1- and 3-yr accumulated survival rates for the “extended,” “standard,” and unresectable groups were 40.0, 33.3, and 5.4, and 20.0, 16.6, and 0%, respectively. Statistically significant differences (p<0.01) existed between the “extended” and unresected groups.


Journal of Hepato-biliary-pancreatic Surgery | 1995

Hilar cholangiocarcinoma—surgical anatomy and curative resection

Yuji Nimura; Naokazu Hayakawa; Junichi Kamiya; Satoshi Kondo; Masato Nagino; Michio Kanai

We have studied the surgical anatomy of the intrahepatic bile duct, hepatic hilus, and caudate lobe based on intraoperative findings and selective cholangiography of surgical patients and resected specimens, and have established the cholangiographic anatomy of the intrahepatic subsegmental bile duct. Thorough knowledge of the three-dimensional anatomy of the subsegmental bile duct, hepatic hilus, and caudate lobe is indispensable for curative surgery of hilar cholangiocarcinoma. We designed and actually performed 15 kinds of hepatic segmentectomies with caudate lobectomy and extrahepatic bile buct resection in 100 consecutive patients, with curative resection being possible in 82 patients. Postoperative survival after curative resection of hilar cholangiocarcinoma was better than expected, and the 5-year survival rates for all 82 patients with curative resection and for 55 patients with curative surgery without portal vein resection were 31% and 43%, respectively. Hepatic segmentectomy with caudate lobectomy and extrahepatic bile duct resection should be designed not only in accordance with the preoperative diagnosis of tumor extension into the intrahepatic bile ducts but also so that curative surgery for advanced hilar cholangiocarcinoma can be performed.


Langenbeck's Archives of Surgery | 2002

Mode of tumor spread and surgical strategy in gallbladder carcinoma.

Satoshi Kondo; Yuji Nimura; Junichi Kamiya; Masato Nagino; Michio Kanai; Katsuhiko Uesaka; Naokazu Hayakawa

Abstract Background and aims. The mode and degree of tumor spread in gallbladder carcinoma is poorly documented. The present study classifies the patterns of dissemination of this tumor with a focus on surgical strategy. Patients and methods. Surgical specimens from 112 patients who underwent curative resection were reviewed. There were stage I, II, III, and IV in 9, 11, 14, and 78 patients, respectively. Results. Six types of spread were identified. In the hepatic bed type (n=20) a large mass in the fundus and body penetrated into the liver through the gallbladder bed with or without contiguous spread to the gastrointestinal tract. The extent of hepatectomy was individualized from wedge resection to extended right hepatectomy based on the clinical findings. In the hepatic hilum type (n=26) a relatively small tumor in the neck infiltrated the hepatic hilum causing obstructive jaundice. Extended right hepatectomy plus bile duct resection with or without portal vein resection was necessary for curative resection because the tumor had extended into the right portal pedicle, and postoperative hepatic failure was common. In the bed and hilum type (n=18) a huge mass occupying the entire gallbladder involved both the gallbladder bed and the hepatic hilum. Extended right hepatectomy with combined resection of contiguous spread was necessary for curative resection. In the lymph node type (n=15) enlarged metastatic lymph nodes were the most prominent feature, and the primary tumor remains limited to the gallbladder in most cases. Extended lymphadenectomy with combined individualized resection was performed. In the cystic duct type (n=9) a small mass arising from the cystic duct involved the common bile duct. This type presented at an earlier stage than the first four types. In the localized type (n=24) tumor spread is localized to the gallbladder and presented at the earliest stage of any type. Simple cholecystectomy with or without wedge hepatic resection and regional lymphadenectomy resulted in a satisfactory outcome. Prognosis depends on the stage rather than on the mode of tumor spread. Even in the advanced types favorable results may be obtained in selected patients undergoing radical resection for M0 tumors without portal vein invasion. Success also was achieved in the rare patients with para-aortic lymph node metastases that were not infiltrative. Conclusions. These six types of gallbladder cancer can be diagnosed preoperatively by clinical and radiological examination. This information should assist the surgeon in the choice of operation and predict outcome.


Langenbeck's Archives of Surgery | 2002

Bacteremia after hepatectomy: an analysis of a single-center, 10-year experience with 407 patients

Hidetaka Shigeta; Masato Nagino; Junichi Kamiya; Katsuhiko Uesaka; Tsuyoshi Sano; Hideo Yamamoto; Naokazu Hayakawa; Michio Kanai; Yuji Nimura

Background and aims. Septic complications after hepatectomy remain a difficult problem. Intra-abdominal sources of postoperative infections are well described in the literature. However, no studies have examined the cause and outcome of bacteremia after hepatectomy. This study evaluated the incidence and outcome of bloodstream infections, bacteremia, after hepatectomy and determined the risk factors associated with the development of this serious complication. Patients and methods. Records were retrospectively reviewed of 407 patients who underwent an elective first hepatectomy at Nagoya University Hospital between January 1990 and December 1999. The incidence, cause, outcome, and possible risk factors for bacteremia were examined. Results. A total of 403 blood cultures were performed after hepatectomy in 188 patients (46%), and bacteremia was confirmed in 46 (11%). The incidence was significantly different between patients with obstructive jaundice and those without (24% vs. 4%). Multivariate analysis identified four significant independent variables: operative time, age, obstructive jaundice, and large-scale hepatectomy. The most common bacteria isolated were Staphylococci, followed by Enterococci, Klebsiella pneumoniae, and Enterobacter. A probable source of bacteremia was identified in 21 (46%) of the 46 patients. Patients with bacteremia had higher morbidity and mortality rates than patients without bacteremia, and the incidence of organ failure was five to ten times that of patients without bacteremia; the mortality rate was 43% (20/46). Conclusions. Postoperative bacteremia is a common complication of hepatectomy to resect biliary tract carcinoma, especially in older patients with obstructive jaundice undergoing major hepatectomy. In addition, for more than half of patients with bacteremia, no clear source of the infection is identified. Thus blood cultures are mandatory in high-risk patients who spike a fever after hepatectomy to identify the correct pathogen and its antibiotic susceptibility.


World Journal of Surgery | 2003

Factors Influencing Postoperative Hospital Mortality and Long-term Survival after Radical Resection for Stage IV Gallbladder Carcinoma

Satoshi Kondo; Yuji Nimura; Junichi Kamiya; Masato Nagino; Michio Kanai; Katsuhiko Uesaka; Norihiro Yuasa; Tsuyoshi Sano; Naokazu Hayakawa

Factors influencing postoperative hospital mortality and long-term survival after radical resection of stage IV gallbladder carcinoma remain unclear. The objective of this study was to identify characteristics of patients who are good candidates in terms of surgical risk and long-term survival for radical resection of stage IV gallbladder carcinoma. A retrospective study was made of attempted surgical cure in 72 patients with stage IV gallbladder carcinoma. There were 14 postoperative hospital deaths (19%). Eleven (19%) of the 58 patients discharged from hospital survived for more than 3 years. Multivariate analysis indicated male gender, extended right hepatic lobectomy in a cholestatic liver, and portal vein resection as independent risk factors that correlated with hospital death. Distant metastasis was the sole independent factor that related negatively with long-term survival by multivariate analysis. Subset analysis was performed with combinations of the four independent factors obtained by multivariate analyses. The hospital mortality rate and the 3-year survival rate in the 44 patients without portal vein involvement were 9% and 28%, respectively, and were 3% and 27%, for the 31 women in this group. The highest 3-year survival rate (39%) was observed in the 26 patients without distant metastasis and portal vein involvement, despite a hospital mortality rate of 12%. Better patient selection may improve the outcome of radical surgery for stage IV gallbladder carcinoma. These data may be useful in designing future trials of the surgical treatment of advanced gallbladder carcinoma.


Journal of Hepato-biliary-pancreatic Surgery | 1995

Preoperative management of hilar cholangiocarcinoma

Masato Nagino; Yuji Nimura; Junichi Kamiya; Satoshi Kondo; Michio Kanai; Masahiko Miyachi; Hideo Yamamoto; Naokazu Hayakawa

From both the therapeutic and diagnostic viewpoints, percutaneous transhepatic biliary drainage (PTBD) is crucial for the preoperative management of hilar cholangiocarcinoma. The direct anterior approach under fluoroscopic guidance is the most advantageous form of PTBD. Despite some advantages, endoscopic retrograde biliary drainage is contraindicated for preoperative biliary decompression. Pertinent multiple catheterizations using PTBD result in an accurate diagnosis of cancer extent, and produce effective relief of jaundice, as well as preventing the development of cholangitis. This, in turn, permits a rational surgical strategy and improved postoperative recovery. Preoperative staging of hilar cholangiocarcinoma is achieved by tube cholangiography through the PTBD catheter and by percutaneous transhepatic cholangioscopy. Angiography and percutaneous transhepatic portography are also recommended to diagneous extramural invasion of cancer. Prevention of posthepatectomy liver failure is the greatest challenge in the treatment of this disease. A multifactorial approach that combines several elements may provide sufficient data for determing the safe limits of surgery and for predicting posthepatectomy liver failure. Preoperative percutaneous transhepatic portal vein embolization (PTPE) is an effective method for preventing this intractable complication.

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