Perfusion Defects Detected After Liver Transplantation on Multidetector Computerized Tomography: Short- and Long-Term Follow-up

Background

Perfusion defects are sometimes found during the follow-up computerized tomography (CT) after liver transplantation (OLT). This study sought to determine the short- and long-term outcomes of perfusion defects observed after OLT with the use of multidetector CT.

Methods

From February 4, 2004, to December 8, 2011, a total 46 LTs were performed in our hospital owing to end-stage liver cirrhosis (n = 43), liver cirrhosis with hepatocellular carcinoma (HCC; n = 1), combined HCC with cholangiocellular carcinoma (CCC; n = 1), or hepatic failure from acute hepatitis A (n = 1). The transplanted livers were procured from cadaveric (n = 24) or living related donors (n = 22). The average age of the recipient was 53.3 ± 10.4 years. The male-female ratio was 30:16. Postoperative multidetector CT was performed with a dynamic sequence in 203 examinations and with a portal phase in 46 examinations. The contrast media was Radisense. The rate of injection of 120 mL was 3 mL/s with a power injector; the iodine concentration was 300 or 370 mg/dL. Follow-up ranged from 3 months 3 days to 7 years 363 days. We classified perfusion defects as chronic segmental or subsegmental benign ischemia, transient focal perfusion defects, benign subcapsular ischemia, or fatal whole liver perfusion defects.

Results

There were 3 cases of chronic segmental or subsegmental benign ischemia, 8 focal transient perfusion defects, 1 benign subcapsular ischemia, and 4 fatal whole liver perfusion defects. Except the fatal cases, all other perfusion defects occurred in the courses of benign conditions without resection or reoperation.

Conclusions

Most perfusion defects were benign and uneventful, requiring no treatment, with the exception of fatal whole liver perfusion defects, which resulted in death after detection.     

Does Procurement Technique Affect Posttransplant Graft Function in Deceased Donor Liver Transplantation?

Introduction

Various techniques have been described deceased donor liver transplantation (DDLT) procurement. One is a technique whereby almost total dissection is done in the porta hepatis and perihepatic detachment is carried out before cross-clamping the donor aorta. In another approach, after the donor aorta is cross-clamped, rapid and minimal en bloc dissection is performed with minimal manipulation. We evaluated early posttransplant graft function among liver procurement techniques.

Method

Between January 2008 and August 2012, we performed 45 consecutive adult DDLTs. One patient was excluded from this analysis due to early death from sepsis after transplantation. The 44 included patients were divided into two cohorts according to the procurement technique: A warm dissection (n = 23; 52%) and a cold dissection group (n = 21; 48%). We compared early posttransplant graft function using the aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T-bil), and prothrombin time (PT) values of the two groups from the first to seventh postoperative day.

Result

The AST values in the warm group were significantly greater than those in the cold group on postoperative days 3 and 5. In addition, the ALT values in the warm group were greater than those in the cold group on postoperative days 4, 5, and 6. Moreover, the T-bil values in the warm group were greater than those in the cold group on postoperative days 2, 3, 4, 5, 6, and 7. However, there were no differences in PT values.

Conclusion

During liver procurement for DDLT, rapid en bloc procurement with minimal manipulation after clamping the donor aorta achieved better early graft function posttransplantation.     

A Comparative Reliability and Performance Study of Different Stent Designs in Terms of Mechanical Properties: Foreshortening,Recoil, Radial Force,and Flexibility

This study seeks to improve the mechanical performance of stents by conducting reliability performance testing and finite element method (FEM)‐based simulations for coronary stents. Three commercially available stent designs and our own new design were tested to measure the factors affecting performance, specifically foreshortening, recoil, radial force, and flexibility. The stents used in the present experiments were 3 mm in working diameter and 18 mm of working length. The results of the experiments indicate that the foreshortening of stents A, B, C, and our new design, D, was equivalent to 2.25, 0.67, 0.46, and 0.41%, respectively. The recoil of stents A, B, C, and D was 6.00, 4.35, 3.50, and 4.36%, respectively. Parallel plate radial force measurements were A, 3.72 ± 0.28 N; B, 3.81 ± 0.32 N; C, 4.35 ± 0.18 N; and D, 4.02 ± 0.24 N. Radial forces determined by applying uniform pressure in the circumferential direction were A, 28.749 ± 0.81 N; B, 32.231 ± 1.80 N; C, 34.522 ± 3.06 N; and D, 42.183 ± 2.84 N. The maximum force of crimped stent at 2.2‐mm deflection was 1.01 ± 0.08 N, 0.82 ± 0.08 N, 0.92 ± 0.12 N, and 0.68 ± 0.07 N for each of stents A, B, C and D. The results of this study enabled us to identify several factors to enhance the performance of stents. In comparing these stents, we found that our design, stent D, which was designed by a collaborative team from seven universities, performed better than the commercial stents across all parameter of foreshortening, recoil, radial force, and flexibility.     

Association between serum thymosin β4 levels of rheumatoid arthritis patients and disease activity and response to therapy

The aim of this study was to evaluate whether thymosin β4 (Tβ4) levels are increased in the serum of rheumatoid arthritis (RA) patients, and if this increase is associated with RA disease activity and resistance to treatment. Blood samples from 40 patients with RA were collected at baseline and 6 months after starting treatment with disease-modifying antirheumatic drugs (DMARD) and/or tumor necrosis factor (TNF)-α blocker. Serum levels of Tβ4 were measured by ELISA. Tβ4 levels (mean ± standard deviation) in RA patients were significantly (approximately tenfold) higher than in healthy controls (577.4 ± 67.92 vs. 56.61 ± 5.72 ng/mL). Serum Tβ4 levels in patients with severe disease activity before therapy were slightly higher than in patients with moderate disease activity (662.4 ± 491.5 vs. 462.5 ± 305.3 ng/ml, P > 0.05). Tβ4 levels were significantly associated with disease activity according to the 28-joint Disease Activity Score. The mean Tβ4 level at baseline in the DMARD treatment group was significantly lower than in the DMARD + TNF-α blocker treatment group. Tβ4 levels were increased in the serum of patients with RA and were positively associated with disease activity. Levels of Tβ4 may also be relevant in determining or predicting resistance to RA treatment. Further studies are necessary to determine if Tβ4 is an appropriate therapeutic target for controlling inflammation associated with RA.     

Viral response at 6 months is associated with treatment outcome of adefovir add-on therapy for lamivudine-resistance

Background and Aim: Adefovir add‐on therapy is recommended for patients infected with lamivudine‐resistant hepatitis B virus (HBV). We aimed to describe the long‐term treatment outcome and predictors for good response of adefovir add‐on therapy. Methods: A total of 559 chronic hepatitis B (CHB) patients who had been treated for at least 12 months with adefovir add‐on therapy due to resistance to lamivudine were retrospectively included. Complete virologic response (CVR) was defined as serum HBV DNA < 9 IU/mL. Viral responses at 6 months were classified as PCR negativity, partial virologic response (PVR, HBV DNA < 2000 IU/mL), or inadequate virologic response (IVR, HBV DNA ≥ 2000 IU/mL). Results: The median duration of follow‐up was 31.5 months (range, 12–56). The cumulative probabilities of CVR during adefovir add‐on therapy were 58%, 70%, 78%, and 80% at 12, 24, 36, and 43 months, respectively. The cumulative rates of resistance to adefovir were 0.4%, 0.8%, and 3.1% at 12, 24, and 36 months, respectively. The only baseline factor associated with CVR (hazard ratio 0.83, 95% confidence interval 0.62–0.91, P ≤ 0.001) and resistance to adefovir (hazard ratio 1.925, 95% confidence interval 1.13–3.30, P = 0.017) was serum HBV DNA level. Comparison of the cumulative rates of CVR and resistance to adefovir according to viral response at 6 months showed significant differences among the three groups (P < 0.0001 and P = 0.0005, respectively). Conclusions: Pre‐treatment HBV DNA level and viral response at 6 months is associated with treatment outcome for adefovir‐add on therapy in lamivudine resistance.