Biomedical subjects

Yonson Ku

Publications and source records attributed to Yonson Ku.

33 records · Page 2Linked to original sources

PubMed2002

Selection of pancreaticojejunostomy techniques according to pancreatic texture and duct size.

HYPOTHESIS: Selection of proper pancreaticojejunostomy techniques according to pancreatic texture and the main duct size reduces the pancreatic fistula rate. DESIGN AND PATIENTS: Data from 50 consecutive patients undergoing pancreatoduodenectomy with 3 different anastomotic techniques prospectively used according to pancreatic texture and the main duct size were analyzed. Duct-invagination anastomosis was selected for pancreata with a small duct (n = 34 [29 with a soft texture and 5 with a hard texture]). Stitches between the stump parenchyma and the jejunal seromuscular layer were added to this anastomosis procedure only for the hard pancreata. Pancreata with a large duct were reconstructed with a conventional duct-to-mucosa anastomosis (n = 16). SETTING: A university hospital department of digestive surgery. RESULTS: The morbidity was 40% (20 of 50 patients) in this series. Four patients (8%) with a soft pancreas and a small duct developed a pancreatic stump leak after duct-invagination anastomosis, but all of them were removed without sequelae. No pancreatic anastomotic leak was seen in this series, which resulted in no mortality, no remnant pancreatectomy, and only 1 relaparotomy in the consecutive 50 patients. CONCLUSION: The proper selection of pancreatic reconstruction techniques according to our criteria may reduce the pancreatic fistula rate, eliminate risky pancreatic anastomotic leaks, and result in excellent outcomes for those undergoing pancreatoduodenectomy.

Anastomosis, Surgical↗

PubMed2002

Carcinosarcoma of the gallbladder with chondroid differentiation.

Carcinosarcoma of the gallbladder is an uncommon neoplasm. We herein report the case of a patient with carcinosarcoma of the gallbladder with chondroid differentiation, treated by cholecystectomy with liver segmentectomy and lymph node dissection for a tumor which occupied the entire gallbladder and spread to the liver. Histologically, the tumor contained two distinct components: a mixture of both well and poorly differentiated tubular adenocarcinoma and sarcomatoid tissue with chondroid differentiation. From a review of the literature, it was seen that carcinosarcomas of the gallbladder could be divided into two groups: one group with apparent sarcomatous differentiation, such as chondroid, osteoid, and rhabdomyosarcomatous differentiation, and the other group, of carcinosarcomas with a sarcomatous portion composed of anaplastic spindle cells. Each group had a poor prognosis in spite of surgical resection of tumors. Our patient died of peritoneal dissemination 7 months after surgery.

Aged↗

PubMed2002

Isolated hepatic perfusion chemotherapy for unresectable malignant hepatic tumors.

Treatment failure with conventional approaches, including systemic and regional chemotherapy, for refractory advanced primary or metastatic hepatic cancers has evoked periodic waves of enthusiasm for isolated hepatic perfusion (IHP) over the past 50 years. With technical refinements of the procedure and the introduction of a novel biochemical regimen combining tumor necrosis factor and melphalan, several hepatobiliary-oncological centers initiated clinical trials of IHP in the 1990s. In parallel, a percutaneous technique of IHP has been developed in this era as a minimally invasive, simple form of IHP, and phase I and II studies have been done in some specialized centers. This study attempts to review past and current techniques of IHP, and to outline their possible role in the treatment of unresectable hepatic tumors, with special reference to hepatocellular carcinoma and colorectal hepatic metastases.

Antineoplastic Agents↗

PubMed2002

Successful 24-h preservation of canine small bowel using the cavitary two-layer (University of Wisconsin solution/perfluorochemical) cold storage method.

We previously developed the two-layer cold storage method (TLM), which allows sufficient oxygen delivery to the canine pancreas during preservation, and successfully achieved 96-h preservation. In this study, we applied a modified TLM (cavitary TLM) to small bowel preservation in a canine heterotopic transplant model. Using simple storage in University of Wisconsin solution (UWM, group 1, n = 12) or cavitary TLM (group 2, n = 8), 40 cm segments of the jejunum were preserved for 24 h at 4 degrees C. The nonpreservation group served as the control (group 3, n = 8). The grafts were implanted heterotopically as a Thiry-Vella loop. Eleven of 12 dogs in group 1 died within 3 days post-transplant as a result of graft intraluminal hemorrhage, while all dogs in groups 2 and 3 survived until day 7. Histological analyses showed almost normal structures of the graft mucosa in groups 2 and 3 at day 7. Results from maltose and acetaminophen absorption tests in group 2 were comparable to those in group 3. Only one survivor in group 1 showed distinct graft mucosal damage, confirmed by histological and functional analyses. In our transplant model, the canine small bowel was successfully preserved by cavitary TLM for at least 24 h, while this preservation time was beyond the limit with UWM.

Acetaminophen↗

PubMed2002

Effect of portal vein embolization on function of the nonembolized lobes of the liver: Evaluation by first-pass hepatic lidocaine extraction in dogs.

BACKGROUND: Portal vein embolization (PVE) of hepatic lobes planned for resection is known to increase the margin of safety in extended hepatic resection. We examined whether volume gain could directly translate into functional gain in the nonembolized hepatic lobes after PVE, using a unique pharmacologic model of hepatic venous isolation and charcoal hemoperfusion. METHODS: Lidocaine hydrochloride (8 mg/kg) was infused over 10 minutes in the portal vein of beagles with hepatic venous isolation and charcoal hemoperfusion, which prevented hepatic recirculation of the drug, and the lidocaine first-pass hepatic extraction ratio (Lid-HER) was determined to assess the selective lobar function of the liver. First, the correlation between Lid-HER and hepatic parenchymal weight of the lidocaine perfusion area was studied. Second, PVE was performed of the left portal branch, and Lid-HER of the nonembolized lobes was determined 1 hour or 2 weeks after PVE. RESULTS: Hepatic venous isolation and charcoal hemoperfusion reduced (>95%) the postfilter and systemic lidocaine concentrations compared with prefilter concentrations. In the first study, a significant correlation was demonstrated between Lid-HER and hepatic parenchymal weight (P =.0023, r(2) = 0.992). In the second study, both weight ratio of the nonembolized lobes relative to the whole liver and Lid-HER of the nonembolized lobes showed significant increases 2 weeks after PVE of 1.7- and 1.9-fold, respectively. CONCLUSIONS: Hepatic-weight increase paralleled functional increase, as determined by Lid-HER, in the nonembolized hepatic lobes 2 weeks after PVE. Thus, volume change directly translated into functional change in future remnant noncirrhotic liver after PVE.

Alanine Transaminase↗

PubMed2002

Correlation between secondary structure of an amino-terminal portion of the nonstructural protein 3 (NS3) of hepatitis C virus and development of hepatocellular carcinoma.

Correlation between sequence variation of hepatitis C virus (HCV) and development of hepatocellular carcinoma (HCC) has not yet been demonstrated. In the present study, we analyzed sequence diversity of the NS3 protein of HCV and its possible correlation with HCC. On the basis of secondary structure of an amino-terminal portion of NS3, HCV subtype lb (HCV-1b) isolates were classified into two groups, A and B. Group A isolates were found in 4 (11%) of 36 patients with HCC, and 22 (63%) of 35 patients without HCC. On the other hand, group B isolates were found in 32 (89%) of 36 patients with HCC, and 12 (34%) of 35 patients without HCC. The distribution patterns of those groups were significantly different between patients with and without HCC (P< 0.001). HCV isolates of group B were found in both tumor and adjacent non-tumor tissues obtained from patients with HCC, suggesting that the emergence of group B isolates was not a result of, but rather a possible causative factor for development of HCC. Taken together, our present results suggest that HCV-lb strains of group B are highly associated with HCC and that the secondary structure analysis of NS3 would be useful to predict high risk for development of HCC in HCV-lb-infected patients.

Amino Acid Motifs↗

PubMed2002

Comparative sequence analysis of the core protein and its frameshift product, the F protein, of hepatitis C virus subtype 1b strains obtained from patients with and without hepatocellular carcinoma.

The core protein of hepatitis C virus (HCV) has been implicated in hepatocarcinogenesis. In order to determine whether there is a correlation between mutations of the core protein and the development of hepatocellular carcinoma (HCC), the core protein-coding sequence of the viral genome of HCV subtype 1b (HCV-1b) obtained from patients with and without HCC was analyzed. We found that 12 (40.0%) of 30 HCV-1b isolates from patients with HCC but none of 29 isolates from patients without HCC had a point mutation(s) in an N-terminal region of 20 residues. Similarly, 10 (33.3%) of 30 isolates from patients with HCC had mutations in a limited region between residues 141 and 160, whereas only 2 (6.9%) of 29 isolates from patients without HCC did. The differences between the two groups were statistically significant. The mutations were found in isolates from both cancerous and adjacent noncancerous tissues of patients with HCC, suggesting that the mutations were present before the development of HCC. The other regions of the core protein of some isolates also had mutations, but no significant difference was observed between isolates from patients with HCC and those from patients without HCC. The F protein, a frameshift product that is still hypothetical for HCV-1b strains, showed more sequence diversity than the core protein among the isolates analyzed, but there were no significant differences in the mutation rates or positions between isolates from patients with HCC and isolates from patients without HCC, except for a short N-terminal sequence of approximately 11 residues that is shared with the core protein.

Amino Acid Sequence↗

PubMed2002

Prognostic significance of S100A4 expression in gallbladder cancer.

The calcium-binding protein S100A4 has been characterized as a metastasis-inducing molecule, and regulates cell motility and invasiveness of cancer cells. In order to clarify the significance of the expression of S100A4 as a prognostic factor in gallbladder cancer, S100A4 expression in resected gallbladder cancers were examined using an immunohistochemical staining technique. The relationship between S100A4 expression and clinicopathological factors including prognosis were evaluated. Twenty-five of 60 cases (42%) demonstrated positive staining for S100A4. There was no statistically significant association between S100A4 and histological grade, T, N, M factor, presence of stone, or stage. Kaplan-Meier method showed the 5-year survival rate of the group staining positive for S100A4 (31.5%) to be statistically poorer than that of the group staining negative for S100A4 (78.2%). Also in T2 cases, the 5-year survival rate of the group staining positive for S100A4 (57.1%) was statistically poorer than that of the group staining negative for S100A4 (83.3%). On univariate analysis, positive staining for S100A4 was a significant prognostic factor, and the hazard ratio was 4.05. On multivariate analysis, positive staining for S100A4 is also a significant predictor of prognosis second to T factor. These results indicate that positive staining for S100A4 is useful in assessing the prognosis of patients with gallbladder cancer as well as TNM factors.

Aged↗

PubMed2001

New pancreatic duct-invagination anastomosis using ultrasonic dissection for nonfibrotic pancreas with a nondilated duct.

Nonfibrotic pancreases with a nondilated duct are susceptible to pancreatic fistula or leakage following pancreaticoduodenectomy. We developed a novel pancreatic duct-invagination anastomosis using an ultrasonic dissector and applied this technique to 14 consecutive pancreaticoduodenectomies and 1 segmental pancreatectomy for otherwise normal pancreases. With the aid of an ultrasonic dissector, even branch pancreatic ducts were skeletonized, ligated securely, and divided during pancreatic transection. Moreover, the main duct was exposed (> 1 cm) easily by ultrasonic dissection and a small-caliber pancreatic tube was inserted into the duct on the stump. Subsequently, pancreatic duct invagination could be easily done through a 10 G intravenous catheter passed through the gastrointestinal tract. The main duct was anchored to the adjacent serosa, but any pancreatic parenchymal sutures, possibly leading to internal laceration and/or parenchymal ischemia particularly in soft nonfibrotic pancreases, were avoidable during the procedures. All the anastomoses were done within 10 minutes. Only 1 patient (6.7%)developed pancreatic fistula, which resolved spontaneously in 21 days postoperatively. Neither anastomotic leakage nor remnant pancreatitis was seen in this series. Although a prospective, randomized study is needed, this technique may contribute to reduced morbidity after pancreaticoduodenectomy for a nonfibrotic pancreas with a nondilated main duct.

Aged↗

PubMedDate not supplied

Risk factors influencing pancreatic leakage and the mortality after pancreaticoduodenectomy in a medium-volume hospital.

BACKGROUND/AIMS: This study was designed to evaluate risk factors influencing pancreatic leakage and pancreatic leakage-related mortality in a medium-volume hospital. METHODOLOGY: We retrospectively reviewed the clinical records of 107 patients who underwent pancreaticoduodenectomy at the Kobe University Hospital. Fourteen predictive factors for pancreatic leakage and the pancreatic leakage-related mortality were evaluated using univariate and multivariate logistic regression models. RESULTS: In univariate analysis, the degree of pancreatic fibrosis, type of resection (PD/PPPD), anastomosis techniques (invagination or duct-to-mucosa anastomosis), anastomosis sites (jejunum/stomach), and the presence of congestion in anastomosis sites significantly influenced pancreatic leakage, and the degree of pancreatic fibrosis influenced pancreatic leakage-related mortality. Multivariate logistic regression analysis revealed that congestion in anastomosis sites was the strongest parameter for pancreatic leakage. Univariate analysis of the patients with normal/mild fibrosing pancreas revealed that pancreatic leakage was influenced by type of resection, anastomosis techniques, anastomosis sites, congestion in anastomosis sites and the management of pancreas parenchyma. CONCLUSIONS: In a medium-volume hospital, reconstruction after pancreaticoduodenectomy should be performed with careful attention to pancreas and anastomosis sites. In the patients with normal/mild fibrosing pancreas, duct-to-mucosa anastomosis without suturing the pancreas parenchyma may be a useful technique for reconstruction.

Adult↗

PubMedDate not supplied

Suppressive effects of tea polyphenol and conformational changes with receptor for advanced glycation end products (RAGE) expression in human hepatoma cells.

BACKGROUND/AIMS: It is reported that polyphenol is associated with low risk of hepatoma and that RAGE (receptor for advanced glycation end products) is important for cancer invasion. METHODOLOGY: Effects of teapolyphenol, EGCG (epigallocatechin-3-gallate) were studied. Proliferation of on human hepatoma cells, HLF, was measured with the use of WST-1 colorimetric assay. Cell invasion was analyzed by the Matrigel invasion assay. Morphology and immunohistological staining of expression of RAGE were also performed. RESULTS: Proliferation was inhibited with the addition of EGCG in a dose-dependent manner. EGCG (200 mumol/L) produced a profound growth suppression of HLF cells (24.5%). Cell invasion was also inhibited with preincubation of 100 mumol/L of EGCG (10.2%). In addition to the antitumor effects, neurite-like conformational changes of HLF cells were observed. Addition of EGCG (100 mumol/L) showed the expression of RAGE on cell surface in accordance to the morphological changes. CONCLUSIONS: The pathway associated to cell movement might be activated with RAGE expression. Although EGCG inhibits the growth and invasion, the cells which expressed RAGE seem to survive. Thus, the enrollment of RAGE should be analyzed to clarify the mechanisms of cancer resistance.

Antineoplastic Agents, Phytogenic↗

PubMedDate not supplied

Predicting factors for survival of patients with unresectable pancreatic cancer: a management guideline.

BACKGROUND/AIMS: When pancreatic cancer cannot be resected, palliative procedures including gastroenteric bypass and biliary bypass may be selected. However, since predicting survival is difficult, indication of these procedures remains unclear. This study was designed to elucidate the prognostic factors of patients with unresectable pancreatic cancer in order to improve their quality of life. METHODOLOGY: We treated 187 consecutive patients with unresectable pancreatic cancer at the Kobe University Hospital. Fifteen prognostic variables for survival were analyzed (sex, age, the degree of pain, diet, presence of jaundice, main site of the tumor, tumor size, major vessel invasion, liver metastasis, peritoneal dissemination, distal metastasis and operative procedures) in surgically treated patients (n = 125). All patients were followed until death. Cox's proportional hazard model and logistic regression models were used to determine the factors influencing the survival of patients with unresectable pancreatic cancer. RESULTS: Cox's proportional hazard model revealed that duodenal invasion (p = 0.001) and liver metastasis (p < 0.0001) significantly influenced the survival of the patients with unresectable pancreatic cancer. In multivariate logistic regression analysis, liver metastasis (p = 0.009) and peritoneal dissemination (p = 0.004) were significant factors on the six-month survival after palliative operation. CONCLUSIONS: Liver metastasis and peritoneal dissemination were negative predictive factors for the six-month survival of patients with unresectable pancreatic cancer. Palliative bypass surgery is recommended for patients expected to survive long-term (more than six-months).

Adolescent↗

PubMedDate not supplied

Factors influencing hepaticojejunostomy leak following pancreaticoduodenal resection; importance of anastomotic leak test.

BACKGROUND/AIMS: Pancreatic fistula is a common complication after pancreaticoduodenostomy. Prevention of a concomitant bile leak from hepaticojejunostomy is important because it could lead to more serious complications including intraperitoneal abscess, subsequent sepsis and massive hemorrhage by activating pancreatic fistula. This study was designed to determine perioperative risk factors of the hepaticojejunostomy leak for the purpose of decreasing this morbidity. METHODOLOGY: Clinical records of 107 consecutive pancreaticoduodenal resections were reviewed. hepaticojejunostomy anastomoses were performed using absorbable sutures in an end-to-side, single-layer and interrupted fashion. A total of 8 presumed perioperative risk factors were analyzed. They included advanced age, low serum albumin, low serum total cholesterol, impaired glucose tolerance and placement of a biliary drainage catheter as preoperative factors, and dilated common hepatic duct and undone anastomotic leak test as intraoperative factors. In addition, transanastomotic stenting techniques including retrograde transhepatic bile drainage, T-tube and transjejunal drainage were compared with respect to hepaticojejunostomy leak rates. RESULTS: Hepaticojejunostomy leak was demonstrated in 9 patients (8%). Anastomotic leak testing only achieved statistical significance (p = 0.04). It is noteworthy that no hepaticojejunostomy leak developed among 28 patients who underwent this test through a retrograde transhepatic bile drainage catheter. In addition, the frequency of bile leaks (14/107) associated with the transanastomotic stenting techniques urged the necessity of appropriate intraperitoneal drain placement. CONCLUSIONS: Careful anastomotic procedures with a subsequent anastomotic leak test most effectively prevent hepaticojejunostomy leak after pancreaticoduodenal resection.

Adult↗

PubMedDate not supplied

Genetic analysis of cancer occurring in the ileocecal valve.

The ileocecal valve consists of an upper and lower segment formed by a duplication of the wall of the small and large bowels. The origin of tumor that occurs in the ileocecal valve is often difficult to prove. The tumor in the ileocecal valve was found with endoscopic examination in a 74-year-old man. The resected specimen of the tumor was genetically studied by using PCR-SSCP (polymerase chain reaction amplification, single strand conformational polymorphism) analysis to determine the origin and direction of the tumor. PCR-SSCP analysis of p53 showed a mutation of exon 8 only in the ileum side of the tumor. This suggests that the tumor has grown towards the ileum. The cancer in the ileocecal valve is derived from the colonic part of the valve which acquired the additional genetic change of p53 mutation.

Aged↗

PubMedDate not supplied

Safety of portal vein resection using centrifugal pump-assisted venous bypass between the superior mesenteric vein and the umbilical vein.

BACKGROUND/AIMS: To achieve complete resection of pancreatic cancer, portal vein resection has been performed with increasing frequency at the time of pancreaticoduodenal resection (pancreaticoduodenectomy or total pancreatectomy). In the meantime, visceral congestion and liver ischemia are of great concern during the procedure. We investigated safety of portal vein resection using a centrifugal pump-assisted bypass between the superior mesenteric vein and the umbilical vein. METHODOLOGY: A retrospective comparison was performed in 49 consecutive patients who underwent pancreatoduodenal resection with or without portal vein resection using the bypass for pancreatic cancer. Twenty-two patients underwent portal vein resection using the bypass (group 1). The other 27 patients undergoing pancreatoduodenal resection without portal vein resection comprise the control group (group 2). RESULTS: Total operative time was 756 +/- 159 min and 526 +/- 109 min (p<0.001) and median blood loss was 2090 mL and 1200 mL in groups 1 and 2, respectively. However, the centrifugal pump-assisted bypass allowed stable bypass flow, and neither intestinal edema nor ischemic change of the liver was observed during portal vein resection and the subsequent reconstruction. Postoperatively, the peak postoperative AST, ALT and total bilirubin levels showed no significant difference and postoperative day of starting a liquid diet was similar between the groups (9.0 +/- 5.4 vs. 9.8 +/- 3.8 days, p=0.48). In addition, the rates of morbidity (55% vs. 48%) including biliary and pancreatic leak as well as mortality (9% vs. 4%) did not significantly differ between the 2 groups. CONCLUSIONS: The centrifugal pump-assisted bypass may be useful to prevent hepatic ischemia and visceral congestion during portal vein resection procedures, resulting in similar postoperative outcomes to the control after pancreaticoduodenal resection for pancreatic cancer.

Aged↗