Prospective Randomized Trial Comparing Hepatic Venous Outflow and Renal Function after Conventional versus Piggyback Liver Transplantation

Abstract

Background: This randomized prospective clinical trial compared the hepatic venous outflow drainage and renal function after conventional with venovenous bypass (n = 15) or piggyback (n = 17) liver transplantation.

Methods: Free hepatic vein pressure (FHVP) and central venous pressure (CVP) measurements were performed after graft reperfusion. Postoperative serum creatinine (Cr) was measured daily on the first week and on the 14th, 21st and 28th postoperative days (PO). The prevalence of acute renal failure (ARF) up to the 28th PO was analyzed by RIFLE-AKIN criteria. A Generalized Estimating Equation (GEE) approach was used for comparison of longitudinal measurements of renal function.

Results: FHVP-CVP gradient > 3 mm Hg was observed in 26.7% (4/15) of the patients in the conventional group and in 17.6% (3/17) in the piggyback group (p = 0.68). Median FHVP-CVP gradient was 2 mm Hg (0-8 mmHg) vs. 3 mm Hg (0-7 mm Hg) in conventional and piggyback groups, respectively (p = 0.73). There is no statistically significant difference between the conventional (1/15) and the piggyback (2/17) groups regarding massive ascites development (p = 1.00). GEE estimated marginal mean for Cr was significantly higher in conventional than in piggyback group (2.14 ± 0.26 vs. 1.47 ± 0.15 mg/dL; p = 0.02). The conventional method presented a higher prevalence of severe ARF during the first 28 PO days (OR = 3.207; 95% CI, 1.010 to 10.179; p = 0.048).

Conclusion: Patients submitted to liver transplantation using conventional or piggyback methods present similar results regarding venous outflow drainage of the graft. Conventional with venovenous bypass technique significantly increases the harm of postoperative renal dysfunction.

Trial registration: ClinicalTrials.gov https://ichgcp.net/clinical-trials-registry/NCT01707810.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1. Chart showing the flow of patients during the stages of eligibility, assessment, enrollment and allocation.

Fig 2. Gradient between the free hepatic vein pressure and the central venous pressure (FHVP-CVP).

Large symbols represent mean FHVP-CVP gradient values and bars represent standard deviation. Small symbols represent individual FHVP-CVP gradient values. Median FHVP-CPV gradients are similar in conventional and piggyback techniques (p = 0.74). In the piggyback group, four variants of hepatic venous outflow reconstruction were used: anastomosis to the cuff of the middle and left hepatic veins (grey square); to the right and middle hepatic veins (grey diamond); to the right, middle and left hepatic veins (black diamond); and side-to-side anastomosis between graft’s and recipient’s vena cava (black square). ANOVA comparison showed a significant difference between these 4 reconstructions (p = 0.04).

Fig 3. Mean serum creatinine (Cr) values from the preoperative period till the 28th postoperative day.

Bars represent standard error. The estimated marginal mean for Cr was significantly higher in conventional than in piggyback group (2.14 ± 0.26 vs. 1.47 ± 0.15 mg/dL; p = 0.02).

Fig 4. Prevalence of acute renal failure (ARF) till the 28th postoperative day according to RIFLE-AKIN staging.

Class N = no renal impairment; Class R = risk; Class I = injury; Class F = failure. The conventional method presented a significantly higher prevalence of severe ARF (Class I + F) during the first 28 postoperative days (OR = 3.207; 95% CI, 1.010 to 10.179; p = 0.048).

Fig 5. Patient’s postoperative Kaplan-Meir survival curves in conventional and piggyback groups (p = 0.32).