Early Allograft Dysfunction After Live Donor Liver Transplantation: It's Time to Redefine?

BACKGROUND

An ideal definition of early allograft dysfunction (EAD) after live donor liver transplantation (LDLT) remains elusive. The aim of the present study was to compare the diagnostic accuracies of existing EAD definitions, identify the predictors of early graft loss due to EAD, and formulate a new definition, estimating EAD-related mortality in LDLT recipients.

METHODS

Consecutive adult patients undergoing elective LDLT were analyzed. Patients with technical (vascular, biliary) complications and biopsy-proven rejections were excluded.

RESULTS

There were 19 deaths due to EAD of a total of 304 patients. On applying the existing definitions of EAD, we revealed their limitations of being either too broad with low specificity or too restrictive with low sensitivity in patients with LDLT. A new definition of EAD-LDLT (total bilirubin >10 mg/dL, international normalized ratio [INR] > 1.6 and serum urea >100 mg/dL, for five consecutive days after day 7) was derived after doing a multivariate analysis. In receiver operator characteristics analysis, an AUC for EAD-LDLT was 0.86. The calibration and internal cross-validation of the new model confirmed its predictability.

CONCLUSION

The new model of EAD-LDLT, based on total bilirubin >10 mg/dL, INR >1.6 and serum urea >100 mg/dL, for five consecutive days after day 7, has a better predictive value for mortality due to EAD in LDLT recipients.

Is Portal Venous Pressure or Porto-systemic Gradient Really A Harbinger of Poor Outcomes After Living Donor Liver Transplantation?

BACKGROUND

Portal hyperperfusion as a cause of small for size syndrome (SFSS) after living donor liver transplantation (LDLT) remains controversial. Portal venous pressure (PVP) is often measured indirectly and may be confounded by central venous pressure (CVP).

METHODS

In 42 adult cirrhotics undergoing elective LDLT, PVP was measured by direct canulation of portal vein and porto systemic gradient (PSG) was obtained after subtracting CVP from PVP. None underwent portal inflow modulation. SFSS was looked in 27 patients after excluding 15 with technical complications.

RESULTS

Clinical features of SFSS found in 6 patients, 5 with graft recipient weight ratio (GRWR) > 0.8% and PVP < 20 mm of Hg. One with GRWR < 0.8% could truly be labeled as SFSS. Incidence of SFSS was not higher in patients with elevated PVP > 20 mm of Hg (14.3% vs 0%, P = 0.259) or PSG > 13 mm of Hg (33.3% vs 0%, P = 0.111). Intensive care unit (ICU) stay was longer in patients with elevated PVP (14.55 vs 9.13 days, P = 0.007) and PSG (16.8 vs 9.72 days, P = 0.009). There was no difference in graft functions, post-operative complications and mortality in first month post-LDLT.

CONCLUSION

Elevated PVP or PSG increased morbidity but neither predicted SFSS nor affected survival.

Succinct guide to liver transplantation for medical students

Literature on liver transplantation for use in medical education is limited and as yet unsatisfactory. The aim of this article is to help medical students gain enough insight into the reality of being a liver transplant recipient. This is crucial so in the future they can feel confident in approaching these patients with adequate knowledge and confidence. The knowledge-tree based learning core topics are designed for a 2-h class including indication/contraindication in the real-world setting, model for end stage liver disease scoring and organ allocation policy, liver transplantation for hepatic malignancy, transplantation surgery, immunosuppression strategy in practical consideration, and management of viral hepatitis. The rationales of each topic are discussed comprehensively for better understanding by medical students. Recipient candidates may have reversible contraindications that halt the surgery temporarily and therefore, it warrants re-evaluation before transplant. Organ allocation policy is primarily based on disease severity instead of waiting time. Transplant surgery usually involves resection of the whole liver, in situ implantation with reconstruction of the hepatic vein, the portal vein, the hepatic artery and the biliary duct in sequence. The primary goal of artificial immunosuppression is to prevent graft rejection, and the secondary one is to reduce its complication or side effects. Life-long oral nucleoside/nucleotide analogues against hepatitis virus B is needed while short course of direct acting agents against hepatitis viral C is enough to eradicate the virus. Basic understanding of the underlying rationales will help students prepare for advanced learning and cope with the recipients confidently in the future.

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Recipient candidates may have reversible contraindications that halt the surgery temporarily and therefore, it warrants re-evaluation before transplant.

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Organ allocation policy is primarily based on disease severity instead of the waiting time period.

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Hepatocellular carcinoma can be cured by liver transplantation if certain criteria met to predict low risk of extrahepatic dissemination before transplant.

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Transplant surgery usually involves resection of the whole liver, in situ implantation with reconstruction of the hepatic vein, the portal vein, the hepatic artery and the biliary duct in sequence.

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The primary goal of artificial immunosuppression is to prevent graft rejection, and the secondary one is to reduce its complication or side effects.

Challenges and Outcome of Left-lobe Liver Transplants in Adult Living Donor Liver Transplants

Adult-to-adult living donor liver transplant (LDLT) frequently depend on using the right-lobes of the donor for obtaining adequate graft-to-recipient weight ratio (GRWR) of over 0.8% in the recipient. However, left-lobes remain an important option in adults, since the morbidity in the donor is considerably less with left donor hepatectomy when compared with right side liver resection. Further benefits of left-lobes in LDLT include more predictable anatomy of the left hepatic duct and left portal vein, which are usually long and single resulting in easier anastomosis in the recipient. Likewise, left-lobe grafts are easier to implant with an excellent venous outflow through the combined orifice of left and middle hepatic vein, as opposed to the complex hepatic vein reconstruction required in right-lobe grafts. However, left hepatic artery is often multiple unlike the right hepatic artery. The holy grail of left-lobe transplants is avoidance of small for size syndrome (SFSS) in the recipients. The strategies for overcoming SFSS currently depend on circumventing portal hyperperfusion in the graft. Measurement of portal pressure and modulating it if high, by splenic artery ligation, splenectomy, or hemiportocaval shunts are proving successful in avoiding SFSS. The future aim in adult LDLT should be to use the left-lobe as much as possible for the benefit of the donor at the same time avoiding SFSS even at very low GRWR for the benefit of the recipient.