Recovery of portal blood flow after percutaneous transhepatic biliary drainage in patients with obstructive jaundice

Pharmacokinetic Study of Nalbuphine in Surgical Patients Undergoing General Anesthesia with Varying Degrees of Liver Dysfunction

Purpose

This study aimed to characterize the pharmacokinetics of nalbuphine in patients undergoing general anesthesia with varying degrees of liver dysfunction.

Patients and Methods

Twenty-four patients were enrolled and divided into three cohorts based on liver function: normal liver function (n = 13), mild liver dysfunction (n = 5), and moderate/severe liver dysfunction (n = 6). During the induction of anesthesia, they received 15 mg of nalbuphine intravenously. Venous blood samples were collected from each patient. The plasma concentration of nalbuphine was determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The pharmacokinetic parameters of nalbuphine were calculated by non-compartmental analysis (NCA) using Phoenix WinNonlin software.

Results

Compared with the normal liver function group, the plasma elimination half-life (T_1/2) of nalbuphine was increased by approximately 33% in the moderate/severe liver dysfunction group (2.66 h vs 3.54 h, P<0.05), and the volume of distribution (V_d) increased by approximately 85% (100.08 L vs 184.95 L, P<0.05). Multivariate analysis revealed that weight and platelet were associated with clearance (CL); total bilirubin as an independent factor was associated with T_1/2, and weight associated with area under the curve (AUC_(0→∞)) independently.

Conclusion

The T_1/2, mean residence time, and V_d of nalbuphine in patients with moderate/severe liver dysfunction were prolonged or increased significantly compared with those in the normal liver function group. These data suggest that it may need to be used with caution when nalbuphine is administered to patients with moderate or severe liver dysfunction.

Obstructive Jaundice doesn't Change the Population Pharmacokinetics of Etomidate in Patients who Underwent Bile Duct Surgery

BACKGROUND

Etomidate is commonly used in the induction of anesthesia. We have previously confirmed that etomidate requirements are significantly reduced in patients with obstructive jaundice and that etomidate anesthesia during endoscopic retrograde cholangiopancreatography (ERCP) results in more stable hemodynamics when compared with propofol. The aim of the present study is to investigate whether obstructive jaundice affects the pharmacokinetics of etomidate in patients who underwent bile duct surgery.

METHODS

18 patients with obstructive jaundice and 12 non-jaundiced patients scheduled for bile duct surgery were enrolled in the study. Etomidate 0.333 mg/kg was administered by IV bolus for anesthetic induction. Arterial blood samples were drawn before, during, and up to 300 minutes after the bolus. Plasma etomidate concentrations were determined using a validated high-performance liquid chromatography-tandem mass spectrometry assay. A population nonlinear mixed-effects modeling approach was used to characterize etomidate pharmacokinetics. The covariates of age, gender, height, weight, body surface area (BSA), body mass index (BMI), lean body mass (LBM), total bilirubin (TBL), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), creatinine (CR), blood urea nitrogen (BUN) were tested for significant effects on parameters using a multiple forward selection approach. Covariate effects were judged based on changes in the objective function value (OFV).

RESULTS

A three-compartment disposition model adequately described the pharmacokinetics of etomidate. The model was further improved when height was a covariate of total clearance [Cl1=1.30+0.0232(HT-162), ΔOFV=-7.33; P<0.01)]. The introduction of any other covariates, including bilirubin and total bile acids, did not improve the model significantly (P>0.01). For the height of 162cm, the final pharmacokinetic parameter values were as follows: V1=1.42 (95% CI, 1.01-1.83, L), V2=5.52 (95% CI, 4.07-6.97, L), V3=63.9 (95% CI, 41.95-85.85, L), Cl1= 1.30 (95% CI, 1.19-1.41, L/min), Cl2= 1.21 (95%CI, 0.95-1.47, L/min), and Cl3=0.584 (95%CI, 0.95-1.21, L/min), respectively.

CONCLUSION

A 3-compartment open model might best describe the concentration profile of etomidate after bolus infusion for anesthesia induction. The pharmacokinetics of etomidate were not changed by the presence of obstructive jaundice.

Oncological benefit of preoperative endoscopic biliary drainage in patients with hilar cholangiocarcinoma

Due to advances in endoscopic equipment and techniques, preoperative endoscopic biliary drainage (EBD) has been developed to serve as an alternative to percutaneous transhepatic biliary drainage (PTBD). This study sought to clarify the benefit of EBD in comparison to PTBD in patients who underwent radical resections of hilar cholangiocarcinoma. One hundred and forty-one patients underwent radical surgery for hilar cholangiocarcinoma between 2000 and 2008 were retrospectively divided into two groups based on the type of preoperative biliary drainage, PTBD (n = 67) or EBD (n = 74). We investigated if the different biliary drainage methods affected postoperative survival and mode of recurrence after median observation period of 82 months. The survival rate for patients who underwent EBD was significantly higher than those who had PTBD (P = 0.004). Multivariate analysis revealed that PTBD was one of the independent factors predictive of poor survival (hazard ratio: 2.075, P = 0.003). Patients with PTBD more frequently developed peritoneal seeding in comparison to those who underwent EBD (P = 0.0003). PTBD was the only independent factor predictive of peritoneal seeding. In conclusion, EBD might confer an improved prognosis over PTBD due to prevention of peritoneal seeding, and is recommended as the initial procedure for preoperative biliary drainage in patients with hilar cholangiocarcinoma.

Simultaneous biliary drainage and portal vein embolization before extended hepatectomy for hilar cholangiocarcinoma: preliminary experience

BACKGROUND

Patients with resectable hilar cholangiocarcinoma often present obstructive jaundice and a small future remnant liver (FRL) ratio. A sequential approach comprising preoperative biliary drainage followed by portal vein embolization (PVE) is usually performed but leads to long preoperative management (6-12 weeks) before patients can undergo resection. To simplify and shorten this phase of liver preparation, we developed a new preoperative approach that involves percutaneous biliary drainage and PVE during the same procedure. We report the outcomes of this combined procedure.

METHODS

During 1 year, four patients underwent simultaneous biliary drainage and PVE followed 1 month later by surgical resection of hilar cholangiocarcinoma. Liver volumes were assessed by CT before, and 1, and 3 months after the combined procedure. Serum liver enzymes were assessed before and 1 month after the combined procedure.

RESULTS

The combined procedure was feasible in all cases, with no related complications. After the combined procedure, transaminases remained stable or decreased, whereas gamma-glutamyl-transpeptidase, alkaline phosphatase, and bilirubin decreased. During the first month, the left lobe volume increased by +27.9 % (range 19-40.9 %). The FRL ratio increased from 24.9 to 33.2 %. All patients underwent R0 liver resection with a favorable postoperative outcome. The remnant liver volume increased by +132 % (range 78-245 %) between 1 and 3 months.

CONCLUSIONS

Simultaneous percutaneous biliary drainage and PVE is feasible. This all-in-one preoperative approach greatly decreases waiting time until surgical resection. These encouraging results warrant further investigation to confirm the safety and to evaluate the reduction in the dropout rate for liver resection in this tumor with poor prognosis.

Doppler estimation of portal blood flow after percutaneous transhepatic portal vein embolization

OBJECTIVE

To elucidate changes in portal blood flow (PBF) after percutaneous transhepatic portal vein embolization and their possible association with hypertrophy of the nonembolized hepatic segments.

SUMMARY BACKGROUND DATA

The increase in PBF of the nonembolized hepatic segments after embolization is presumed to trigger hypertrophy of these segments. However, changes in PBF after embolization have not been investigated, and their extent remains unknown.

METHODS

The authors prospectively measured PBF velocity, using color Doppler ultrasound, in 21 patients without cirrhosis who underwent embolization of the right portal vein or the right portal vein plus the left medial portal branch. Liver hypertrophy was assessed with a volumetric study using computed tomography.

RESULTS

The PBF velocity significantly increased, from 11.1+/-3.6 cm/sec before embolization to 20.1+/-7 cm/sec 1 day after embolization. Subsequently, the velocity gradually decreased, but it remained significantly elevated until postembolization day 14. The volume of the nonembolized segments significantly increased from 370+/-141 cm3 to 488+/- 145 cm3. The hypertrophy rate (cm3/day) of the nonembolized segments after embolization correlated closely with the extent of increase in the PBF velocity, expressed as the velocity on day 1 divided by the velocity before embolization. The hypertrophy rate had a significant correlation with the absolute value of the PBF velocity on day 1, but its correlation coefficient was low. No significant correlations were observed between the hypertrophy rate and other clinical variables.

CONCLUSIONS

The hypertrophy rate of nonembolized hepatic segments after embolization is predictable from the extent of the increase in the PBF velocity. This can be estimated easily and noninvasively with Doppler ultrasound 1 day after embolization.