Michihiro Hayashi - Academia.edu (original) (raw)

Papers by Michihiro Hayashi

Journal of Surgical Oncology

Background and Objectives Hepatitis C virus (HCV) infection plays an important role in the develo... more Background and Objectives Hepatitis C virus (HCV) infection plays an important role in the development of not only hepatocellular carcinoma (HCC) but also intrahepatic cholangiocarcinoma (ICC). The aim of this study was to identify the specific characteristics of HCV-related ICC.Methods Of 90 patients who underwent curative resection for mass-forming ICC, 33 patients had chronic HCV infection. We examined the relationship between HCV infection and the clinicopathologic findings and surgical outcomes.ResultsThe incidence of simultaneous HCC was significantly higher in patients infected with HCV (30.3%) than in those without HCV infection (5.3%). Four patients were diagnosed with metachronous HCC after resection for HCV-related ICC. Patients with HCV infection had a significantly shorter overall survival time than patients without HCV infection, although there was no difference in ICC tumor-free survival rates between the two groups. Five HCC-related deaths occurred in patients with H...

Langenbeck's archives of surgery / Deutsche Gesellschaft für Chirurgie, 2014

The purpose of this study was to clarify the clinicopathological features of extrahepatic hepatoc... more The purpose of this study was to clarify the clinicopathological features of extrahepatic hepatocellular carcinoma (HCC) recurrence after hepatectomy in order to schedule optimal treatment strategies for better long-term outcomes. A cohort of 206 patients who had undergone curative hepatectomy for HCC was analysed; 133 patients had developed relapse. Among them, 101 patients had intrahepatic recurrence only (IHR), and 32 patients had extrahepatic recurrence (EHR). Clinicopathological and survival data were compared between the two groups. The overall survival rate after hepatectomy was better in the IHR than in the EHR group (p<0.0001). The recurrence-free interval after hepatectomy was significantly shorter in the EHR than in the IHR group (258 vs. 487 days, p<0.0043). Patients in the EHR group were more likely to have a high PIVKA II, a large tumour, and microscopic portal vein invasion when compared with patients in the IHR group. Microscopic portal vein invasion was the mo...

Surgical endoscopy, 2015

Laparoscopic hepatectomy (Lap-Hx) has been increasingly performed for patients with liver tumors ... more Laparoscopic hepatectomy (Lap-Hx) has been increasingly performed for patients with liver tumors as surgical techniques and devices have progressed. However, the long-term outcomes of Lap-Hx for malignant liver tumors are not oncologically guaranteed. This study compared the short- and long-term outcomes between Lap-Hx and open hepatectomy (Open-Hx) for malignant liver tumors by matched-pair analysis. The indications for Lap-Hx at our department are a tumor size of <5 cm and fewer than two lesions without macroscopic vascular invasion or the need for biliary reconstruction. In total, 135 patients underwent Lap-Hx for malignant liver tumors through December 2013. We compared the short- and long-term outcomes between Lap-Hx and Open-Hx in patients who met the above-mentioned indications. With respect to short-term outcomes, the operation time, blood loss, postoperative hospital stay, white blood cell count, and C-reactive protein level after Lap-Hx were significantly better than th...

Surgical laparoscopy, endoscopy & percutaneous techniques, 2013

Control of bleeding is important in parenchymal transection during laparoscopic liver resection. ... more Control of bleeding is important in parenchymal transection during laparoscopic liver resection. We suggest a new technique using Endo intestinal clips for the intestinal tract to achieve easy, safe hepatoduodenal ligament clamping during laparoscopic liver resection. In this study, 10 consecutive patients underwent pure laparoscopic liver resection. Pringle's maneuver was performed using Endo intestinal clips directly on the hepatoduodenal ligament. Laparoscopic Pringle's maneuver using Endo intestinal clips is very easy and safe. In this series, Pringle's maneuver was used a mean of 3.4 times (range, 1 to 5) in each case. Mean operative time was 271.0 minutes (range, 105 to 415 min) and mean volume of intraoperative blood loss was 119.5 mL (range, 10 to 320 mL). No intraoperative or postoperative morbidity or mortality was encountered. Pringle's maneuver using Endo intestinal clips can be performed easily and safely during laparoscopic liver resection.

The American surgeon, 2013

Laparoscopic liver resection is currently performed in an increasing number of institutions as a ... more Laparoscopic liver resection is currently performed in an increasing number of institutions as a minimally invasive treatment. However, no randomized controlled trials have compared laparoscopic and open liver resections. Twenty-three laparoscopic and 24 open liver resections for colorectal cancer liver metastases (CRCLM) were performed, and these data for both were retrospectively compared in the short-term results. The estimated blood loss was 99 ± 207 mL in the laparoscopic group and 397 ± 381 mL in the open group (P = 0.0018); blood loss was significantly higher in the open group. There were no differences in the surgical procedure, blood loss, transfusion rate, pathological margins, postoperative complications, 30-day mortality, duration of intravenous drip, or hospital stay. On postoperative courses, the values of total bilirubin, white blood cell count, and C-reactive protein were significantly lower in the laparoscopic group. The data of the present series suggest the lesser...

Hepato-gastroenterology

Although pure laparoscopic liver resection is thought to be a useful method in terms of cosmetic ... more Although pure laparoscopic liver resection is thought to be a useful method in terms of cosmetic outcome and less invasiveness, this procedure has not yet become widespread, presumably due to its high technical demands and proficiency requirements. In order to achieve surgical safety and minimum invasiveness simultaneously, we recently implemented a small skin incision left hepatectomy technique, which is feasible in most centers not currently performing the pure laparoscopic technique. To summarize, a small skin incision of 8-10 cm is taken on the right subcostal region, and Alexis wound retractor (Applied Medical, Rancho Santa Margarita, CA, USA) is attached to appropriately expand the wound. Peanuts swabs and board-shaped spatulae are used to spread the surgical field during the procedure. The left hepatic vein, as well as the common trunk of the left-middle hepatic veins, is approached and secured by the Arantius's ligament traction method. Both manipulation of the hepatic h...

Experimental and clinical transplantation : official journal of the Middle East Society for Organ Transplantation, 2011

Late-onset hepatic failure, the least of the fulminant hepatic failures, has not occurred in pati... more Late-onset hepatic failure, the least of the fulminant hepatic failures, has not occurred in patients with hepatitis A virus-related acute liver failure. We report a rare case of hepatitis A virus-related late-onset hepatic failure treated successfully by an emergent liver transplant. A 58-year-old Japanese woman who presented with fever and general malaise was diagnosed as having jaundice and liver dysfunction by a positive serum test for anti-hepatitis A virus IgM, which ultimately led to a diagnosis of acute hepatitis A virus associated hepatitis. Despite intensive treatment, her general condition was poor, and she developed a hepatic coma 79 days from the onset of the disease. Under a diagnosis of hepatitis A virus-related late onset hepatic failure, she was given a living-donor liver transplant 82 days from the start of the disease. The resected native liver revealed submassive necrosis with marked cholestasis, compatible with late-onset hepatic failure. Today, 5 years after th...

World journal of gastrointestinal surgery, Jan 27, 2010

Since actinomycosis sometimes causes an abdominal tumor which mimics malignancy, treatment strate... more Since actinomycosis sometimes causes an abdominal tumor which mimics malignancy, treatment strategy varies from case to case. We herein report two cases which were treated with a combination of antibiotics and surgical intervention. Both patients presented with an intra-abdominal tumor lesion mimicking malignant disease after an appendectomy for acute appendicitis. Case 1 received surgical extirpation of the abdominal tumor in the liver and kidney twice since the clinical diagnosis of actinomycosis was not made. In contrast, case 2 was successfully treated by a combination of antibiotics and laparoscopic surgery following the experience of case 1. When a high probability diagnosis can be made, a laparoscopic approach is a useful and effective option to treat this condition.

International surgery

In liver surgery, postoperative bile leakage occurs with a steady incidence and hampers the clini... more In liver surgery, postoperative bile leakage occurs with a steady incidence and hampers the clinical course of patients, even giving rise to mortality. Clinical parameters of 20 patients complicated with postoperative bile leakage were retrospectively compared with those of 394 patients without this complication after liver resection. On multivariate analysis, significant independent risks for postoperative bile leakage included the following: (1) high-risk operative procedure that exposes the major Glisson's sheath on the cut surface, including caudate lobectomy, central bisegmentectomy, and right anterior sectionectomy, (2) repeated hepatectomy, and (3) the presence of intraoperative bile leakage. The subgroup of patients in whom (1) leakage occurred from an injured bile duct with stenosis, or (2) leakage occurred from the divided bile duct suffered for a prolonged period. Patients at high risk require more vigilant observation and expeditious treatment perioperatively. During...

International surgery

The aim of this study was to retrospectively assess the optimal timing for removal of abdominal d... more The aim of this study was to retrospectively assess the optimal timing for removal of abdominal drainage after liver resection for hepatocellular carcinoma (HCC). A total of 148 patients were divided into 2 groups. In Group I, drains were removed according to the judgment of the surgeon. In Group II, drains were removed on postoperative day (POD) 2, except in cases of bile leakage, purulent ascites, or hemorrhage. Postoperative complications were compared between the 2 groups. Postoperative hospital stay was shorter in Group II than in Group I. Six patients required drain reinsertion for abdominal abscess and massive ascites. The risk factor for drain reinsertion was volume of drain discharge greater than 450 mL on POD 2. Early removal of the drain is desirable after surgical treatment of HCC. Moreover, it seems preferable to determine the necessity of drain removal based on assessment of the volume and nature of drain discharge on POD 2.

Transplantation, Jan 27, 1999

Although living donor liver transplantation for small pediatric patients is increasingly accepted... more Although living donor liver transplantation for small pediatric patients is increasingly accepted, its expansion to older/larger patients is still in question because of the lack of sufficient information on the impact of graft size mismatching. A total of 276 cases of living donor liver transplantation, excluding ABO-incompatible, auxiliary, or secondary transplants, were reviewed from graft size matching. Forty-three cases were highly urgent cases receiving intensive care preoperatively. Cases were categorized into five groups by graft-to-recipient weight ratio (GRWR): extra-small-for-size (XS; GRWR<0.8%, 17 elective and 4 urgent cases), small (S; 0.8< or =GRWR< 1.0%, 21 and 7), medium (M; 1.0< or =GRWR<3.0%, 119 and 19), large (L; 3.0< or =GRWR<5.0%, 67 and 10), and extra-large (XL; GRWR> or =5.0%, 9 and 3). Smaller-for-size grafts were associated not only with larger and older recipients, but also with rather older donors. Posttransplant bilirubin clearan...

World Journal of Gastrointestinal Surgery, 2012

Schwannoma is predominantly a benign neoplasm of the Schwann cells in the neural sheath of the pe... more Schwannoma is predominantly a benign neoplasm of the Schwann cells in the neural sheath of the peripheral nerves. Occurrence of schwannoma in parenchymatous organs, such as liver, is extremely rare. A 64-year-old man without neurofibromatosis was observed to have a space-occupying lesion of 23mm diameter in the liver during follow-up examination for a previously resected gastrointestinal stromal tumor (GIST) in the small intestine. He underwent lateral segmentectomy of the liver under a provisional diagnosis of hepatic metastatic recurrence of the GIST. Histological examination confirmed the diagnosis of a benign schwannoma, confirmed by characteristic pathological findings and positive immunoreactions with the neurogenic marker S-100 protein, but negative for c-kit, or CD34. The tumor was the smallest among the reported cases. When the primary hepatic schwannoma is small in size, preoperative clinical diagnosis is difficult. Therefore, this disease should be listed as differential diagnosis for liver tumor with clinically benign characteristics.

Surgery, 2015

The benefits of anatomic resection in patients with small (&amp;amp;amp;amp;amp;amp;amp;a... more The benefits of anatomic resection in patients with small (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5 cm), solitary hepatocellular carcinomas remain unclear. Outcomes were therefore evaluated in patients who underwent anatomic resection or nonanatomic resection of small solitary hepatocellular carcinomas. Factors affecting overall survival and disease-free survival were investigated in 330 patients who underwent curative hepatectomy for solitary (≤5 cm) hepatocellular carcinomas without macroscopic vascular invasion. In addition, a propensity score matching model with 330 patients was constructed to overcome bias, with subgroups analyzed by tumor diameter (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3 cm and 3-5 cm). ICG-R15 ≥25% was confirmed as being independently associated with poorer overall survival and disease-free survival. One-to-one matching of preoperative characteristics yielded 72 pairs of patients receiving anatomic resection and nonanatomic resection, with long-term outcomes, including overall survival and disease-free survival, being similar in these 2 groups. Subgroup analysis showed that, in patients with tumors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3 cm in diameter, short-term outcomes were better in the nonanatomic resection group than in the anatomic resection group, including significantly reduced operation time (P = .02), blood loss (P = .01), blood transfusion (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01), complications (particularly bile leakage and abdominal abscess) (P = .04), and postoperative hospital stay (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). Anatomic resection was not superior to nonanatomic resection in survival outcomes in patients with solitary small hepatocellular carcinomas without macroscopic vascular invasion. Rather, postoperative short-term outcomes were more favorable with nonanatomic resection.

Surgery, 2015

Postoperative bile leakage can be a serious complication after hepatic resection. Few studies hav... more Postoperative bile leakage can be a serious complication after hepatic resection. Few studies have analyzed patients according to the time of onset of bile leakage. We analyzed differences between patients with early- and late-onset bile leakage after hepatic resection and assessed clinical characteristics and outcomes in patients with late-onset leakage. Between 2008 and 2010, 1,009 patients underwent hepatic resection at 4 participating university hospitals and 2 community hospitals. Fifty-two patients (5.1%) with postoperative bile leakage were divided into an early-onset group (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2 weeks after surgery, n = 34) and a late-onset group (≥2 weeks after surgery, n = 18). Patient characteristics and outcomes were collected prospectively and analyzed retrospectively. The proportion of patients who underwent intra-abdominal placement of a drainage catheter was significantly less in the late-onset group than the early-onset group. All 18 patients in the late-onset group developed intra-abdominal infection, and 2 died of sepsis. The proportion of patients who underwent invasive treatment (abdominal paracentesis, endoscopic biliary drainage, or second hepatic resection) was significantly greater in the late-onset group than in the early-onset group. The time to resolution of bile leakage was significantly greater in the late-onset group than the early-onset group. Patients should be monitored carefully for bile leakage for several weeks after hepatic resection, because late-onset bile leakage can cause serious complications. Intra-abdominal infection should also be treated as soon as possible, because it may induce refractory bile leakage with serious complications.

Surgery, 1999

Portal vein reconstruction is a crucial factor affecting the outcome of a successful living-relat... more Portal vein reconstruction is a crucial factor affecting the outcome of a successful living-related liver transplantation. We describe here our experience with portal vein reconstruction in 314 cases of living-related liver transplantation with use of novel surgical modalities to enable the transplant surgeons to deal with any size mismatch between the donor's and recipient's portal veins. Portal vein reconstruction was classified into 2 major groups, anastomosis without and with a vein graft. When there was no stenosis of the recipient portal vein and the diameter was the same, the portal trunk was used for anastomosis. When the diameter mismatch was minimal, branch patch anastomosis was feasible. When the recipient portal vein was significantly stenotic and the portal vein of the graft was long enough, we removed the stenotic trunk and constructed an anastomosis between the graft portal vein and the confluence of the recipient portal vein. When the graft portal vein was short, a vein graft was interposed. The vein patch technique was preferable when the diameter of the graft vein was not large enough for the interposition technique. Anastomosis without vein graft included trunk anastomosis (n = 156), branch patch anastomosis (n = 39), and confluence anastomosis (n = 22). Anastomosis with vein graft used the interposition technique (n = 77) and vein patch technique (n = 27). The origin of the grafts was mostly from the maternal left ovarian vein (70%) or the paternal inferior mesenteric vein (27%). Complications related to portal vein reconstruction occurred in 16 (5%) patients: portal vein thrombosis in 8, stenosis in 7, and fatal rupture in 1 patient. The incidence of complications was similar for all techniques except for confluence anastomosis. Our innovative techniques should be helpful for overcoming diameter or length mismatches in portal vein reconstruction in pediatric liver transplantation.

The American surgeon, 2011

Abdominal drainage after liver resection is considered unnecessary: however, there still exist a ... more Abdominal drainage after liver resection is considered unnecessary: however, there still exist a number of cases where drain is effective to prevent serious infectious complications. We re-evaluated the necessity of drain placement after liver resection from the retrospective analysis of postoperative complications with special reference to the need for drain insertion of 140 patients undergoing hepatectomy without intraoperative abdominal drainage from 2007 through 2010. Three patients required drain reinsertion in the early postoperative period (before postoperative Day 7); all had undergone extended right hepatectomy for hepatocellular carcinoma with portal vein thrombus followed by postoperative liver failure. Risk factors for postoperative bile leakage included repeated hepatectomy, operative procedure with exposure of the major Glisson's sheath (i.e., central bisegmentectomy and anterior segmentectomy), and intraoperative bile leakage. However, because the onset of this co...

Journal of gastrointestinal cancer, 2012

Small bowel adenocarcinoma is a relatively uncommon neoplasm that accounts for approximately 0.3%... more Small bowel adenocarcinoma is a relatively uncommon neoplasm that accounts for approximately 0.3% to 2.4% of digestive cancers. In comparison with carcinomas of the other areas of the gastrointestinal tract, the prognosis for small bowel adenocarcinoma is generally worse. The prognostic factors of small bowel adenocarcinoma were analyzed retrospectively, and the significance of operative procedure, lymphadenectomy, and adjuvant chemotherapy was evaluated. From 1990 to 2009, 30 patients with small bowel adenocarcinoma who underwent surgery at Osaka Medical College Hospital were analyzed with respect to tumor extent, operation method, and prognosis. Overall 5-year survival was 52.5%, and the median survival time was 27.0 months. On univariate and multivariate analyses, the location (duodenum vs. jejunum and ileum), size (greater or less than 70 mm), and tumor, nodes, and metastasis (TNM) stage (stage 0 + I + II vs. III + IV) of the tumor were the significant prognostic factors. No dif...

Transplantation, Jan 15, 2012

Search by Subject Search using Medical Subject Headings ( MeSH), a controlled... more Search by Subject Search using Medical Subject Headings ( MeSH), a controlled vocabulary for indexing life sciences content. Note that some records do not have MeSH. These include Patents and the latest PubMed and PubMed Central records.

Journal of Surgical Oncology

Langenbeck's archives of surgery / Deutsche Gesellschaft für Chirurgie, 2014

Surgical endoscopy, 2015

Surgical laparoscopy, endoscopy & percutaneous techniques, 2013

The American surgeon, 2013

Hepato-gastroenterology

Experimental and clinical transplantation : official journal of the Middle East Society for Organ Transplantation, 2011

World journal of gastrointestinal surgery, Jan 27, 2010

International surgery

Transplantation, Jan 27, 1999

World Journal of Gastrointestinal Surgery, 2012

Surgery, 2015

Surgery, 1999

The American surgeon, 2011

Journal of gastrointestinal cancer, 2012

Transplantation, Jan 15, 2012