No abstract

Oncogenesis after cyst excision for choledochal cyst and suitable surgical procedures for this operation are discussed. The clinical data of 23 patients with cancer of the biliary tree after excision of choledochal cyst reported in the English-language and Japanese literature were reviewed, and data for 1353 Japanese patients with choledochal cyst and/or pancreaticobiliary malunion were analyzed. In the 23 patients reported in the literature, age at cyst excision ranged from 1 to 55 years (average, 23.0 +/- 13.7 years), and cancers were detected at age 18-60 years (average, 32.1 +/- 12.2 years), with intervals between cyst excision and cancer detection of 1-19 years (average, 9.0 +/- 5.5 years). Sites of cancer development were: intrahepatic, six; anastomotic, eight; hepatic side residual cyst, three; and the intrapancreatic duct, six. In the Japanese patients with choledochal cyst and/or pancreaticobiliary malunion, the incidence of cancer associated with primary choledochal cyst and/or pancreaticobiliary malunion was 16.2% (219/1353). The incidence of cancer development after cyst excision in this population, of whom 1291/1353 underwent surgery, was assumed to be 0. 7%. Nearly half of the 23 patients in the literature had undergone inadequate cyst excision. Oncogenesis of cancers after cyst excision is possibly different from that of choledochal cysts.

Congenital biliary cysts occur not only in the choledochus but also everywhere in the biliary tree, and are frequently accompanied by pancreatobiliary malunion. Alonso-Lej and colleagues first classified choledochal cysts into three types, in 1959. Due to the recognition of intrahepatic involvement, we refined their classification into six types, in 1977, and this has become the reference. However, this classification does not include the concept of pancreatobiliary malunion and has caused some confusion, especially in regard to types Ic and IVA. Type Ic, showing fusiform dilatation, has a pancreatobiliary malunion and often extends continuously to the intrahepatic duct. Type IVA, with intrahepatic involvement, shows primary ductal stricture, especially around the hepatic hilum and umbilicus. The incidence of the stricture is considerably greater than was previously assumed, and upstream intrahepatic ducts often join the dilated duct, with distinct caliber change. Intrahepatic dilatation may develop primarily, due to the stricture, combined with weakness of the duct wall. This stricture can be corrected by portal dissection in the liver to obtain a large anastomosis. In patients with intrahepatic involvement, we should carefully find the stricture by suitable cholangiograms, or by intraoperative cholangioscopy. Detecting the ductal stricture is obviously important, rather than classifying the cyst as type Ic or IVA.

The incidence of carcinoma arising in the wall of the congenital bile duct cysts is much higher than previously assumed. The authors report 4 such cases of primary and secondary carcinomas and review their clinical features through the similar 59 cases in the literature. Of the 63 cases, the average age was much younger, at least several decades, compared with cases of extra-hepatic carcinoma without bile duct cysts. The female-male ratio was 2.5:1. Racial preponderance was also observed, namely, the majority were Japanese. Additionally, many patients previously received various internal drainage procedures, especially choledochocystoduodenostomy. As the treatment, primary excision of the extrahepatic bile duct cyst seems to give the best results because it can avoid ascending cholangitis and prevent development of carcinoma. However, carcinoma still can arise in the intrahepatic bile duct cyst, which cannot be removed at the present time.

No abstract

The structure of high-temperature liquids is an important topic for understanding the fragility of liquids. Here we report the structure of a high-temperature non-glass-forming oxide liquid, ZrO2, at an atomistic and electronic level. The Bhatia–Thornton number–number structure factor of ZrO2 does not show a first sharp diffraction peak. The atomic structure comprises ZrO5, ZrO6 and ZrO7 polyhedra with a significant contribution of edge sharing of oxygen in addition to corner sharing. The variety of large oxygen coordination and polyhedral connections with short Zr–O bond lifetimes, induced by the relatively large ionic radius of zirconium, disturbs the evolution of intermediate-range ordering, which leads to a reduced electronic band gap and increased delocalization in the ionic Zr–O bonding. The details of the chemical bonding explain the extremely low viscosity of the liquid and the absence of a first sharp diffraction peak, and indicate that liquid ZrO2 is an extremely fragile liquid.

Ru(Cp*)Cl(PPh3)2 (Cp* ) pentamethylcyclopentadienyl; PPh3 ) triphenylphosphine) has been found to be a versatile catalyst that is applicable to living radical polymerization of methyl methacrylate (MMA), methyl acrylate (MA), and styrene (St) with Al(Oi-Pr)3 as an additive. The numberaverage molecular weights (Mn) of the obtained polymers increased in proportion to monomer conversion, and the molecular weight distributions were very narrow (Mw/Mn < 1.1). Effective initiators were all alkyl halides (R-X), where X ) Cl for MMA; Cl and Br for St; and Cl, Br, and I for MA. Ru(Cp*)Cl(PCy3) (Cy ) cyclohexyl) also proved an effective catalyst for living radical polymerization of MMA, faster than that with Ru(Cp*)Cl(PPh3)2, to produce polymers with narrow molecular weight distributions (Mw/Mn < 1.2).

A reoperation after excisional procedure was carried out in seven cases due to early or late postoperative complications. Of the 12 patients with early complications, four underwent relaparotomy due to anastomotic leakage and bleeding. Late complications were seen in nine patients with recurrent cholangitis caused by an anastomotic stricture, and three patients with intrahepatic involvement required a reoperation several years after the initial surgery. Recurrent cholangitis after biliary reconstruction mainly occurs due to an anastomotic stricture of the hepaticoenterostomy. There was no significant difference in the results between hepaticoduodenostomy and hepaticojejunostomy over a long follow-up period. A wide anastomotic stoma that permits free drainage of bile into the intestine is imperative to the prevention of cholangitis, and can be created by an incision extending along the lateral wall of both the hepatic ducts with a hepaticoenterostomy at the hilum. This procedure is obviously necessary in all patients with or without intrahepatic involvement. Carcinoma of the intrahepatic ducts and the retained distal choledochus have rarely developed in patients undergoing cyst excision followed by biliary reconstruction. Complete excision of the whole extrahepatic bile duct could prevent carcinoma arising in the distal choledochus, although it could not prevent carcinoma arising from the intrahepatic ducts. However, patients with carcinoma of the intrahepatic duct were reported to have had symptoms of biliary stricture for a long time since the cyst excision. Bile stagnation in the intrahepatic ducts is possibly responsible for the development of carcinoma. A wide anastomosis resulting in free drainage of bile appears to be essential to the prevention of carcinoma arising in the intrahepatic ducts after cyst excision.