Internal Versus External Drainage With a Pancreatic Duct Stent For Pancreaticojejunostomy During Pancreaticoduodenectomy for Patients at High Risk for Pancreatic Fistula: A Comparative Study

BACKGROUND

The aim of this study was to determine whether internal or external drainage with a pancreatic duct stent is the optimal pancreaticojejunostomy method to prevent pancreatic fistula (PF) after pancreaticoduodenectomy (PD) for subgroups of patients at high risk for PF.

MATERIALS AND METHODS

A total of 495 patients who underwent PD were reviewed. Univariate and multivariate analyses were used to identify risk factors for PF after PD. We further compared the incidence of PF and outcomes between the internal and external drainage groups for subgroups of patients at high risk for PF.

RESULTS

There was no difference in the incidence of complications according to the Clavien-Dindo classification or the rate of PF after PD in both groups (P = 0.961 and P = 0.505, respectively). The incidence of mortality was 3.8% in the internal drainage group and 3.9% in the external drainage group (P = 0.980). Univariate and multivariate analyses identified male gender (odds ratio [OR] = 2.93; 95% confidence interval [CI], 1.78-4.83; P = 0.000), pancreatic duct diameter (<3 mm) (OR = 2.58; 95% CI, 1.57-4.23; P = 0.000), and soft pancreatic texture (OR = 2.92; 95% CI, 1.71-4.98; P = 0.000) as independent risk factors for PF after PD. No differences in the incidence of PF for the subgroups of patients with one, two, or three risk factors were observed between the internal and external drainage groups (P = 0.334, P = 1.000, and P = 0.936, respectively). No differences in total complications, delayed gastric emptying, postpancreatectomy hemorrhage, biliary fistula, infection complications, reoperation, perioperative mortality, or postoperative hospital stay were noted. In addition, liquid loss and tube-related complications occurred in the external drainage group.

CONCLUSIONS

Internal drainage is the optimal method to prevent PF after PD for subgroups of patients at high risk for PF because the surgical procedure is simple and prevents liquid loss and tube-related complications associated with external drainage. However, no differences in the incidence of PF and other complications after PD were observed between the two approaches.

Long-term curative effects of combined hepatocholangioplasty with choledochostomy through an isolated jejunum passage on hepatolithiasis complicated by stricture

BACKGROUND

Hepatocholangioplasty combined with choledochostomy was designed through an isolated jejunum passage in 1988. This study was undertaken to evaluate its long-term curative effects in 163 patients.

METHODS

The 163 patients with hepatolithiasis complicated by stricture were treated with this procedure from 1988 to 2003.

RESULTS

Among these patients, 19 patients with postoperative hepatolithiasis complicated by acute cholangitis were treated successfully with percutaneous paracentesis drainage through the isolated jejunum passage and without operation, 36 patients had postoperative residual or recurrent stones (35 patients had stones removed through the stoma and one underwent relaparotomy because of stenosis of the common bile duct along with stone in canceration). The clearance rate of stones after the isolated jejunum passage was 97%; 35 patients (21%) complicated with stricture due to hepatolith were treated with combined hepatocholangioplasty and choledochostomy. Follow-up for 1 to 15 years showed no recurrent stricture of the biliary tract. The operation also successfully prevented reflux cholangitis and other serious complications after Roux-en-Y cholangio-jejunostomy.

CONCLUSION

Hepatocholangioplasty combined with choledochostomy through an isolated jejunum passage may significantly improve the long-term curative effects of hepatolithiasis with stricture.

Effects of calcium entry blocker (nicardipine) tocolysis in rhesus macaques: fetal plasma concentrations and cardiorespiratory changes

Tocolytic doses of nicardipine, a dihydropyridine calcium entry blocker, were administered to chronically catheterized rhesus monkeys between days 128 and 132 of gestation. During periods of spontaneous uterine contractility, a 500 micrograms nicardipine bolus was injected intravenously, and this was followed by continuous infusion (6 micrograms/kg/min) to the mother for 1 hour. Uterine activity (amniotic fluid pressure) and maternal heart rate and blood pressure were monitored continuously. Paired maternal and fetal blood samples were drawn at frequent intervals to monitor pH, PO2, PCO2, and plasma nicardipine concentrations. Peak maternal nicardipine concentrations ranged from 175 to 865 ng/ml while peak fetal levels ranged from 7 to 35 ng/ml. Fetal heart rate and blood pressure were unaffected. However, fetuses became acidotic (pH 7.26 +/- 0.01 versus 7.33 +/- 0.01) and hypoxemic (PO2 16.0 +/- 3.2 versus 24.5 +/- 2.0 mm Hg) after maternal nicardipine treatment (p less than 0.01). Despite the fact that maternal nicardipine treatment exerted a significant tocolytic effect, the undesirable fetal side effects are of concern and deserve further investigation.

Ketorolac tromethamine absorption, distribution, metabolism, excretion, and pharmacokinetics in animals and humans

Ketorolac tromethamine (KT), a potent non-narcotic analgesic, with cyclooxygenase inhibitory activity, was administered (14C-labeled and unlabeled) intravenously (iv), orally (po), and intramuscularly (im) in solution to humans, cynomolgus monkeys, rabbits, rats, and mice. KT was absorbed rapidly (Tmax less than 1.0 hr) and efficiently (greater than 87%) following po and im doses in all species. The plasma half-life of ketorolac (K) ranged from 1.1 hr (rabbits) to 6.0 hr (humans). The protein binding of K ranged from 72.0% (mouse) to 99.2% (humans). Linear pharmacokinetics of K was observed in the mouse after single oral doses of KT ranging from 0.25 to 16 mg/kg. Radioactivity was excreted predominantly into urine, ranging from 78.9% (mouse) to 102% (monkey) following iv doses. The dose was excreted into urine primarily as K conjugates, K, and p-hydroxy-K in humans. The monkey was similar to humans with respect to kinetics, but did not form the p-hydroxy metabolite. The rabbit was unusual in that it exhibited substantial presystemic metabolism (50%). The rat excreted a much higher percentage of radioactivity into the feces and formed an additional unidentified metabolite. The most comparable species with respect to humans metabolically was the mouse. The metabolism and excretion of K was similar following iv, po, and im doses within each species studied.

Capillary column gas chromatographic method using electron-capture detection for the simultaneous determination of nicardipine and its pyridine metabolite II in plasma

A rapid, specific and direct method based on capillary column gas chromatography with electron-capture detection is described for the simultaneous determination of nicardipine, a new calcium antagonist, and its pyridine metabolite II in human plasma. In this method, the nicardipine, its pyridine metabolite II and internal standard are extracted from the plasma and then partially purified by acid-base partitioning prior to the final injection onto the capillary column gas chromatograph for quantification by means of an electron-capture detector. The quantification limit of the method is 1 ng/ml of plasma for both nicardipine and its pyridine metabolite II. The coefficients of variation for nicardipine and the pyridine metabolite II at concentrations of 1-50 ng/ml are less than 7% and less than 9% (n = 4), respectively. The method has been validated against a previously developed high-performance liquid chromatographic method (sensitivity 5 ng/ml).

A high-performance liquid chromatographic method for the simultaneous determination of nicardipine and its pyridine metabolite II in plasma

A rapid and specific method in which reverse-phase high-performance liquid chromatography (HPLC) with UV detection was used for the simultaneous determination of nicardipine and its pyridine metabolite II in human plasma is described. Nicardipine, its pyridine metabolite II, and the internal standard were extracted from plasma and partially purified by acid-base partitioning. Final purification and quantitation were achieved by HPLC by using a reverse-phase column and a UV detector (254 nm). The extraction efficiencies for nicardipine and its pyridine metabolite II from 1 mL of plasma were 77.4 and 81.1%, respectively. The sensitivity of the assay was 5 ng/mL for both nicardipine and its pyridine metabolite II, and the linear concentration range of the assay was 5-150 ng/mL for both compounds. The low coefficients of variation (less than or equal to 5%) for samples spiked with nicardipine and its pyridine metabolite II in this concentration range demonstrate good reliability and reproducibility of the assay. The HPLC procedure has been validated by comparison with a GC-electron-capture detection (ECD) procedure, which gives the combined concentration of nicardipine-its pyridine metabolite II (total) and with an HPLC/GC-ECD procedure, which gives the concentration of its pyridine metabolite II. All three methods, which were developed in our laboratory, were used to analyze nicardipine and its pyridine metabolite II in specimens of plasma from subjects treated with nicardipine hydrochloride. Good correlations were found for concentrations of nicardipine, its pyridine metabolite II, and nicardipine plus the metabolite determined by these three procedures. The HPLC procedure is suitable for use in pharmacokinetic studies following administration of nicardipine hydrochloride to humans.

Transformation of arachidonate into 6-oxoprostaglandin F1 alpha, thromboxane B2 and prostaglandin E2 by sheep lung microsomal fraction

In the presence of haemoglobin and isoproterenol, the microsomal fraction of sheep lung catalysed the conversion of arachidonate predominantly into thromboxane B2 and to a lesser extent into 6-oxoprostaglandin F1alpha. Very little prostaglandin E2 and prostaglandin F2alpha were formed. If reduced glutathione was added in combination with haemoglobin and isoproterenol, the synthesis of prostaglandin E2 was favoured over that of thromboxane B2 and 6-oxoprostaglandin F1alpha. The identities of these products were confirmed by t.l.c. and by combined g.l.c.-mass spectrometry. These results indicate that microsomal fraction of sheep lung possesses active prostaglandin synthase, prostacyclin synthase and thromboxane synthase activities.

Hydroxylated metabolies of R,S-1-(tetrahydro-2-furanyl)-5-fluorouracil (Ftorafur) in rats and rabbits

Two hydroxylated metabolies (M1 and M2) have been isolated from rabbit urine after administration of Ftorafur (FT). The structures of 3'-OH-FT and 4'-OH-FT were assigned to M1 and M2, respectively. A reverse-phase high performance liquid chromatography assay was developed for jeasuring FT, M1, M2, and 5-fluorouracil (FU) plasma levels. M1, M2, and FU were present in rabbit and rat plasma in greatly varying concentrations after FT administration. Pharmacokinetic studies suggest that FU formation proceeds via metabolic intermediate(s) and that the extent of FT activation is variable. A horse liver thymidine phosphorylase ,reparation capable of catalyzing the conversion of beta-ribo-2'-deoxy-5-fluorouracil to FU was inactive against FT and M1. However, 20% of M2 was converted to FU by this enzume, which suggests that the urinary metabolite M2 consisted of a mixture of enantiomers with 20% present in the natural beta-D configuration. The stereochemistry of M1 remains unknown. Hydroxylation of FT to beta-D-4'-OH-FT and subsequent cleavage to FU by thymidine phosphorylase represents one possible activation mechanism of FT to FU. ,owever, lack of correlation between plasma levels of M2 and FU indicates that this mode of metabolic activation may account for only part of the overall activation of FT in vivo.

Determination of ftorafur and 5-fluorouracil levels in plasma and urine

A gas chromatographic method was developed for ftorafur (Ft) detection in plasma and urine with a sensitivity of 1 mug/ml. Specific determination of its metabolite 5-fluorouracil (FU) with a sensitivity of 1 ng/ml was achieved by column chromatographic separation from Ft and subsequent gas chromatography-mass spectrometry of bis-silyl-FU in the selected ion mode (GC-MS-SIM) using bis-15N-FU as internal standard. Intravenous injections of 2-14C-Ft and 2',5'-14C-Ft were given to rats and rabbits respectively, and plasma and urine were analyzed for Ft, and 14C activity. Unchanged Ft accounted for most of the 14C activity in plasma, while FU concentrations were below 0.15% and 0.4% relative to Ft concentrations in the rabbit and the rat, respectively. 30-60% of the urinary 14C activity was unchanged Ft and less than 0.2% FU. The significance or low FU levels is discussed in view of the hypothesis that Ft acts as a transport form of its metabolite FU.