Strategies to prevent or reduce acute and chronic kidney injury in liver transplantation

Hospital readmission for acute kidney injury is independently associated with de novo end-stage renal disease after liver transplantation

End-stage renal disease (ESRD) after liver transplantation (LT) is associated with high morbidity and mortality. The consequences of hospitalizations for post-LT acute kidney injury (AKI) are poorly understood. Using linked Medicare claims and transplant registry data, we analyzed adult liver alone recipients not receiving pretransplant dialysis between January 1, 2007, and December 31, 2016. Covariate-adjusted Cox proportional hazards models stratified by center evaluated factors associated with AKI readmission during the first post-LT year, and whether AKI readmission was associated with de novo early (<1 y) or late (≥1 y) ESRD post-LT. The cohort included 10,559 patients and was 64.5% male, 72.5% White, 8.1% Black, and 14.0% Hispanic with median age 62 years. Overall, 2875 (27.2%) patients had ≥1 AKI hospitalization during the first year. Estimated glomerular filtration rate at LT was associated with AKI readmission (adjusted HR: 1.16 per 10 mL/min/1.73m 2 decrease; p <0.001). The adjusted HR for early ESRD in patients with ≥1 AKI readmission <90 days post-LT was 1.90 ( p <0.001). The adjusted HRs for late ESRD with 1 and ≥2 prior AKI readmissions were 1.57 and 2.80, respectively ( p <0.001). AKI readmissions in the first post-LT year impact over one-quarter of recipients. These increase the risk of subsequent ESRD, but may represent an opportunity to intervene and mitigate further renal dysfunction.

Effect of dexmedetomidine on the incidence of postoperative acute kidney injury in living donor liver transplantation recipients: a randomized controlled trial

BACKGROUND

Acute kidney injury (AKI) is one of the most common complications after living-donor liver transplantation (LDLT) that has great impact on recipient and graft outcomes. Dexmedetomidine is reported to decrease the incidence of AKI. In the current study, the authors investigated whether intraoperative dexmedetomidine infusion would reduce the AKI following LDLT.

MATERIAL AND METHODS

In total, 205 adult patients undergoing elective LDLT were randomly assigned to the dexmedetomidine group ( n =103) or the control group ( n =102). Dexmedetomidine group received continuous dexmedetomidine infusion at a rate of 0.4 mcg/kg/h after the anesthesia induction until 2 h after graft reperfusion. The primary outcome was to compare the incidence of AKI. Secondary outcomes included serial lactate levels during surgery, chronic kidney disease, major adverse cardiovascular events, early allograft dysfunction, graft failure, overall mortality, duration of mechanical ventilation, intensive care unit, and hospital length of stay. Intraoperative hemodynamic parameters were also collected.

RESULTS

Of 205 recipients, 42.4% ( n =87) developed AKI. The incidence of AKI was lower in the dexmedetomidine group (35.0%, n =36/103) compared with the control (50.0%, n =51/102) ( P =0.042). There were significantly lower lactate levels in the dexmedetomidine group after reperfusion [4.39 (3.99-4.8) vs 5.02 (4.62-5.42), P =0.031] until the end of surgery [4.23 (3.73-4.74) vs 5.35 (4.84-5.85), P =0.002]. There were no significant differences in the other secondary outcomes besides lactate. Also, intraoperative mean blood pressure, cardiac output, and systemic vascular resistance did not show any difference.

CONCLUSION

Our study suggests that intraoperative dexmedetomidine administration was associated with significantly decreased AKI incidence and lower intraoperative serum lactate levels in LDLT recipients, without untoward hemodynamic effects.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Evolving challenges with long-term care of liver transplant recipients

The number of liver transplants (LT) performed worldwide continues to rise, and LT recipients are living longer post-transplant. This has led to an increasing number of LT recipients requiring lifelong care. Optimal care post-LT requires careful attention to both the allograft and systemic issues that are more common after organ transplantation. Common causes of allograft dysfunction include rejection, biliary complications, and primary disease recurrence. While immunosuppression prevents rejection and reduces incidences of some primary disease recurrence, it has detrimental systemic effects. Most commonly, these include increased incidences of metabolic syndrome, various malignancies, and infections. Therefore, it is of utmost importance to optimize immunosuppression regimens to prevent allograft dysfunction while also decreasing the risk of systemic complications. Institutional protocols to screen for systemic disease and heightened clinical suspicion also play an important role in providing optimal long-term post-LT care. In this review, we discuss these common complications of LT as well as unique considerations when caring for LT recipients in the years after transplant.

Late-onset Chronic Kidney Disease Over 2 Decades After Pediatric Liver Transplantation: A Single-center, Retrospective Study

BACKGROUND

Although chronic kidney disease (CKD) after liver transplantation (LTx) is a common complication in adults, its long-term significance after pediatric LTx remains unclear. We examined the decades-long transition of renal function and revealed the risk factors for late-onset CKD after pediatric LTx in a single-center retrospective cohort of 117 pediatric LTx recipients who survived >5 y.

METHODS

The estimated glomerular filtration rate (eGFR) and CKD stages were calculated using serum creatinine. Risk factor analysis for late-onset CKD was performed in 41 patients whose eGFR could be evaluated at >20 y after LTx.

RESULTS

The median age at LTx was 1.3 y, and most primary diagnoses were biliary atresia (77%). The mean pre-LTx and 1, 5, 10, 20, and >20 y post-LTx eGFRs were 180, 135, 131, 121, 106, and 95 mL/min/1.73 m 2 , respectively, with a median renal follow-up period of 15 y. The eGFR declined by 47% at >20 y after LTx ( P  < 0.001). CKD was observed in 8%, 19%, and 39% of cases at 10, 20, and >20 y after LTx, respectively. In patients receiving cyclosporine, trough levels were 1.5 times higher in those with CKD up to 10 y after LTx. The multivariate analysis showed that older age at LTx (odds ratio, 1.3 by 1 y; P  = 0.008) and episodes of repeated/refractory rejection (odds ratio, 16.2; P  = 0.002) were independent risk factors of CKD >20 y after LTx.

CONCLUSIONS

In conclusion, renal function deteriorates slowly yet steadily after pediatric LTx. Long-term careful surveillance is essential after pediatric LTx, especially in repeated/refractory rejection or long-term high trough-level use of cyclosporine cases.

Postoperative Blood Pressure Deficit and Acute Kidney Injury After Liver Transplant

OBJECTIVES

Acute kidney injury is a common cause of morbidity in liver transplant recipients. In critically ill patients who received an orthotopic liver transplant, we examined whether those with acute kidney injury had a greater deficit between pretransplant and posttransplant hemodynamic pressure-related parameters compared with those without acute kidney injury in the early postoperative period.

MATERIALS AND METHODS

We included patients who underwent an orthotopic liver transplant during the study period. We obtained premorbid and intensive care unit time-weighted average values for hemodynamic pressure-related parameters (systolic, diastolic, and mean arterial pressure; central venous pressure; mean perfusion pressure; and diastolic perfusion pressure) and calculated deficits in those values. We defined acute kidney injury progression as an increase of ≥1 Kidney Disease: Improving Global Outcomes stage.

RESULTS

We included 150 eligible transplantrecipients, with 88 (59%) having acute kidney injury progression. Acute kidney injury was associated with worse clinical outcomes. All achieved pressure-related values were similar between transplant recipients with or without acute kidney injury progression. However, those with acute kidney injury versus those without progression had greater diastolic perfusion pressure deficit at 12 hours (-8.33% vs 1.93%; P = .037) and 24 hours (-7.38% vs 5.11%; P = .002) and increased central venous pressure at 24 hours (46.13% vs 15%; P = .043) and 48 hours (40% vs 20.87%; P = .039).

CONCLUSIONS

Patients with acute kidney injury progression had a greater diastolic perfusion pressure deficit and increased central venous pressure compared with patients without progression. Such deficits might be modifiable risk factors for the prevention of acute kidney injury progression.

The Effects of sodium bicarbonate Ringer’s solution on acute kidney injury and the clinical outcomes after liver transplantation: A randomized controlled trial

Background: Acute kidney injury is the most common complication after liver transplantation. Sodium bicarbonate Ringer’s solution is a new type of crystalloid solution that has been recently used in the clinical setting. Whether sodium bicarbonate Ringer’s solution reduces the occurrence of postoperative AKI and improves the clinical outcomes of liver transplantation patients is not clear.

Objective: To compare the effects of sodium bicarbonate Ringer’s solution versus normal saline on acute kidney injury and clinical outcomes following classic orthotopic liver transplantation.

Methods: Sixty-four participants were randomly assigned to the sodium bicarbonate Ringers (BRS) group or the normal saline (NS) group. The primary outcomes were the incidence and severity of acute kidney injury after liver transplantation. The secondary outcomes included the rate of renal replacement therapy, length of mechanical ventilation, stay in the ICU, stay in the hospital after surgery and 30-day mortality. Other outcomes included the concentration of sodium, chloride, bicarbonate, anion gap, lactate concentration and changes in chloride preoperatively and postoperatively.

Result: Sixty-two patients completed the trial and were analyzed, with 31 patients in each group. There was a significantly lower rate of postoperative acute kidney injury in the BRS group (14/31, 45.2%) than in the NS group (24/31, 77.4%), with a relative risk of 0.58 (95% CI, 0.38–0.90; p = 0.009). The severity of AKI in the BRS group was lower than that in the NS group (Z = -2.932, p = 0.003). There was no significant difference observed in the secondary outcomes. For other outcomes, the concentration of preoperative sodium was lower than postoperative sodium in the NS group (137.2 vs. 140.4, p = 0.009). The concentration of preoperative chloride was lower than that of postoperative chloride in the NS group (102.9 vs. 106.2, p < 0.001). The change in the concentration of chloride in the BRS group was lower than that in the NS group (1.6 vs. 4.7, p = 0.006).

Conclusion: Sodium bicarbonate Ringer’s solution reduced the incidence and severity of acute kidney injury after classic orthotopic liver transplantation.

Acute kidney injury within 100 days post allogeneic hematopoietic cell transplantation is associated with increased risk of post-transplant complications and poor transplant outcomes

Allogeneic hematopoietic cell transplantation (HCT) offers cure for some patients with hematological diseases but is associated with significant risk of morbidity and mortality. We investigated the incidence of AKI and its impact on transplant outcomes among 408 patients transplanted at Princess Margaret Hospital Cancer Centre, Toronto, Canada. The overall incidence of AKI at 100 days was 64.2%. Compared to those with no AKI, patients who developed AKI had inferior 2-y overall survival (OS), 44.7% vs. 62.4% (P = 0.0004), higher 2-y transplant related mortality (TRM) 36.8% vs. 18.7% (P = 0.0003), lower 2-y graft-vs-host disease (GVHD)- and relapse-free survival (GRFS), 21.0% vs. 39.8% (P = 0.0002), and higher 100-day grade 3-4 acute GVHD (aGVHD), 12.4% vs. 6.3% (P = 0.01). There was no difference in 2-y incidence of relapse between the AKI and non-AKI groups, 24.2% vs. 24.3% (P = 0.84), 100-day grade 2-4 aGVHD, 27.7% vs. 25.7 (P = 0.41) or 2-y moderate-severe chronic GVHD, 24.0% vs. 21.6% (P = 0.79). Patients who develop AKI within 100 days of HCT have inferior OS and GRFS with higher rates of TRM and grade 3-4 aGVHD. These results highlight the importance of close monitoring of renal function, multidisciplinary collaboration, and implementation of protective strategies throughout HCT to optimize transplant and kidney outcomes.

Kidney disease in children with heart or liver transplant

Over the past few decades, there has been increasing recognition of kidney disease in children with non-kidney solid organ transplantation. The risk of kidney disease in children undergoing heart or liver transplantation is higher than the general population as the underlying disease and its associated management may directly impair kidney function. Both heart and liver failures contribute to hypoperfusion and kidney ischemia before patients reach the point of transplant. The transplant surgery itself can often be complicated by acute kidney injury (AKI), which may be further exacerbated by a complicated postoperative course. In the short- and long-term post-transplant period, these children are at risk of acute illness, exposed to nephrotoxic medications, and susceptible to rare but severe infections and immunologic insults that may contribute to AKI and chronic kidney disease (CKD). In some, CKD can progress to kidney failure with replacement therapy (KFRT). CKD and KFRT are associated with increased morbidity and mortality in this patient population. Therefore, it is critical to monitor for and recognize the risk factors for kidney injury in this population and mitigate these risks. In this paper, the authors provide an overview of kidney disease pertaining to heart and liver transplantation in children with guidance on monitoring, diagnosis, prevention, and management.

Intraoperative Oxygen Delivery and Acute Kidney Injury after Liver Transplantation

Although intraoperative hemodynamic variables were reported to be associated with acute kidney injury (AKI) after liver transplantation, the time-dependent association between intraoperative oxygen delivery and AKI has not yet been evaluated. We reviewed 676 cases of liver transplantation. Oxygen delivery index (DO2I) was calculated at least ten times during surgery. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. The area under the curve (AUC) was calculated as below a DO2I of 300 (AUC < 300), 400 and 500 mL/min/m2 threshold. Also, the cumulative time below a DO2I of 300 (Time < 300), 400, and 500 mL/min/m2 were calculated. Multivariable logistic regression analysis was performed to evaluate whether AUC < 300 or time < 300 was independently associated with the risk of AKI. As a sensitivity analysis, propensity score matching analysis was performed between the two intraoperative mean DO2I groups using a cutoff of 500 ml/min/m2, and the incidence of AKI was compared between the groups. Multivariable analysis showed that AUC < 300 or time < 300 was an independent predictor of AKI (AUC < 300: odds ratio [OR] = 1.10, 95% confidence interval [CI] 1.06-1.13, time < 300: OR = 1.10, 95% CI 1.08-1.14). Propensity score matching yielded 192 pairs of low and high mean DO2I groups. The incidence of overall and stage 2 or 3 AKI was significantly higher in the lower DO2I group compared to the higher group (overall AKI: lower group, n = 64 (33.3%) vs. higher group, n = 106 (55.2%), P < 0.001). In conclusion, there was a significant time-dependent association between the intraoperative poor oxygen delivery <300 mL/min/m2 and the risk of AKI after liver transplantation. The intraoperative optimization of oxygen delivery may mitigate the risk of AKI.

Renal damage after liver transplantation

Background: Patients following liver transplantation are at risk to develop acute kidney injury (AKI). The aim of our study was to assess risk factors for the development of AKI and the impact of AKI on the outcome of patients after liver transplantation (OLT).

Patients and methods: In this retrospective study, we analyzed 149 patients undergoing OLT from 1/2004 to 12/2007. AKI was defined according to the KDIGO definition representing the AKIN and the RIFLE classification, and according to the need for renal replacement therapy (RRT).

Results: According to the AKIN criteria alone 14 patients, according to the RIFLE criteria alone no patient and according to both definitions 30 patients developed AKI. RRT was required in 54 patients experiencing AKI, whereas 51 patients did not develop AKI. Pre OLT serum creatinine (SCr) significantly predicted the development of AKI requiring RRT, but not AKI without RRT requirement. Survival rate was significantly inferior after 28 days, one or three years in patients with AKI requiring RRT (70.4, 46.4, 44.4% vs. 100, 92.2, 90.2%, P < 0.001). There was no difference in survival between patients experiencing AKI according to the RIFLE or AKIN criteria without RRT requirement and patients without AKI.

Conclusion: Pre OLT renal dysfunction assessed by SCr was the most important risk factor predicting severe forms of AKI, but not milder forms of AKI. AKI requiring RRT had a detrimental impact on patients’ survival, whereas milder forms of AKI were not associated with a worse outcome.

Chronic kidney disease in liver transplantation: Evaluation of kidney function

Chronic kidney disease is one of the main comorbidities affecting liver transplant recipients. Most of those patients have some degree of acute or chronic kidney dysfunction at the time of transplantation, moreover they can also develop de novo chronic kidney disease once transplanted. An important increase in the incidence of chronic kidney disease in the «MELD era» has been observed. This phenomenon has partially been attributed to the weight that kidney function carries for organ allocation. In addition, the generalized use of calcineurin inhibitors has also been a contributing factor. It is of the utmost importance for us to be familiar with the current methods for evaluating kidney function before and after a liver transplantation. The two main biomarkers available today for that purpose are serum creatinine and cystatin C. Several equations have been derived from those biomarkers and have been tested in that context with mixed results, due to their biologic variability and the lack of standardization in their measurement. The gold standard continues to be the direct determination of the glomerular filtration rate through different methods; however, that is only done for research purposes. It is also essential to know the current classification of acute kidney injury and chronic kidney disease in order to make early diagnosis. The present review focuses on the recognition, diagnosis, and classification of chronic kidney disease and acute kidney injury in liver transplantation recipients.

Tailored Predictive Formulas for Glomerular Filtration Rate for Early Detection of Deteriorating Renal Function After Pediatric Living-Donor Liver Transplant

OBJECTIVES

In pediatric patients, renal dysfunction after living-donor liver transplant is a major issue that is difficult to evaluate. Recently, predictive equations for Japanese children have been introduced.

MATERIALS AND METHODS

We conducted a retrospective study by prospectively collecting data on 26 patients under 16 years old who underwent living-donor liver transplant between June 2004 and March 2015. Serum creatinine and cystatin C levels were measured. Paired t tests and Bland-Altman plots were used to compare the following formulas for estimated glomerular filtration rate: the Schwartz formula and 3 formulas that were matched with Japanese children (polynomial, simple, and cystatin C formulas).

RESULTS

Average estimated glomerular filtrations rates (in mL/min/1.73 m2) were 143.46, 122.90, 121.58, and 123.31 using the Schwartz, polynomial, simple, and cystatin C formulas, respectively. The estimated glomerular filtrations rate for biliary atresia was 141.53 ± 31.37 versus 109.95 ± 19.52 for other diseases, with significant differences only noted with the cystatin C formula. The formulas tailored for Japanese children showed significantly lower estimated glomerular filtrations rates than those obtained using the Schwartz formula (P < .01).

CONCLUSIONS

The use of formulas for measuring estimated glomerular filtrations rates that are based on race may allow early detection of deteriorating renal function.

Tolvaptan for Fluid Management in Living Donor Liver Transplant Recipients

BACKGROUND Tolvaptan, an antagonist of the vasopressin V2 receptor is a novel oral diuretic that promotes water excretion selectively. We have used furosemide as a primary diuretic and added human atrial natriuretic peptide (hANP) if necessary for fluid management postoperatively in living-donor liver transplantation (LDLT) recipients. Recently we introduced tolvaptan and used both tolvaptan and furosemide as primary diuretics. MATERIAL AND METHODS Clinical outcomes were compared between LDLT recipients whose postoperative fluid management was performed before (control group, n=10) and after (tolvaptan group, n=16) introduction of tolvaptan. RESULTS Preoperative and intraoperative demographic data did not differ significantly between the groups except for the period of post-surgical follow-up and total ischemic time. Urine volume was 1,242±692, 2,240±1307, and 2,268±1262 mL on postoperative day 1, 3, and 7, respectively, in the tolvaptan group. These volumes did not significantly differ from those in control group (1,027±462, 1,788±909, and 2,057±1216 mL on day 1, 3, and 7 postoperatively, respectively). Body weight gain and fluid volume from abdominal drainage tubes postoperatively did not differ significantly between groups. The time from hANP initiation to discontinuation and the time to removal of central vein catheters were significantly reduced in tolvaptan-treated patients. No severe side effects directly related to tolvaptan were observed. The survival rate at month 6 was 90.0% in control patients versus 93.8% in tolvaptan-treated patients. CONCLUSIONS The outcomes of this investigation indicate that tolvaptan in combination with furosemide provides an adequate diuretic for fluid management subsequent to LDLT without causing adverse effects.

Renal Outcomes in Patients With IgA Nephropathy Undergoing Liver Transplant: A Retrospective Cohort Study

Background

End-stage liver disease (ESLD) is the most common cause of secondary immunoglobulin A nephropathy (IgAN). Multiple mechanisms have been proposed to explain the association between liver disease and IgAN. Although some mechanisms are expected to reverse in patients after liver transplant, the long-term renal prognosis is unclear for these patients.

Methods

This observational retrospective cohort study examined the renal outcomes of 14 patients who had IgAN with end-stage liver disease and subsequently underwent either liver transplant alone or combined liver and kidney transplant at a single tertiary care center.

Results

Of the 7 patients who underwent liver transplant alone, hematuria persisted in 2, 4 had progressive loss of kidney function with worsening proteinuria in 3 but only 1 reached end-stage renal disease 5 years posttransplant. Among 7 combined liver and kidney transplant recipients, 1 had histologic and 1 had histologic and clinical recurrence of IgAN without kidney allograft loss.

Conclusions

IgAN in patients with advanced liver disease does not necessarily resolve after liver transplant but has overall favorable renal outcomes.

Effect of Early Everolimus-Facilitated Reduction of Tacrolimus on Efficacy and Renal Function in De Novo Liver Transplant Recipients: 24-Month Results for the North American Subpopulation

Background

A recent randomized phase III study of 719 de novo liver transplant recipients showed that early everolimus plus reduced-dose tacrolimus (EVR + rTAC) led to significantly better kidney function than standard TAC (TAC-C), without compromising efficacy. In that study, patients from North America (n = 211) had increased risk factors for posttransplant renal insufficiency at study start, relative to patients from Europe and rest of world (eg, worse renal function, more diabetes, older age).

Methods

A post hoc analysis was performed to assess whether these regional disparities affected study outcomes in North American patients.

Results

In this subpopulation, estimated glomerular filtration rates at randomization were higher in TAC-C over EVR + rTAC (76.4 vs 69.3 mL/min per 1.73 m²). Mean changes in estimated glomerular filtration rate values (mL/min per 1.73 m²) favored EVR + rTAC over TAC-C at months 12 (+3.7 vs −4.5; P = 0.032), 24 (+2.7 vs −6.6; P = 0.042), and 36 (+4.3 vs −8.1; P = 0.059). The composite efficacy endpoint of treated biopsy-proven acute rejection, graft loss, or death was 10.9%, 14.1%, and 14.1% for EVR + rTAC and 13.1%, 17.2%, and 19.3% for TAC-C at months 12, 24, and 36, respectively.

Conclusions

Although the North American cohort had more comorbidities, results were consistent with the overall population for efficacy and renal function.

In order to reduce nephrotoxicity in liver transplantation, several strategies are being explored including early everolimus-facilitated tacrolimus dose reduction, which in a recent multicenter study led to better kidney function versus standard TAC without compromising efficacy. In this North American cohort sub-analysis, results are similar despite higher baseline comorbidities.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.

Three-year Outcomes in De Novo Liver Transplant Patients Receiving Everolimus With Reduced Tacrolimus: Follow-Up Results From a Randomized, Multicenter Study

BACKGROUND

Data are lacking regarding the long-term effect of preemptive conversion to everolimus from calcineurin inhibitors early after liver transplantation to avoid renal deterioration.

METHODS

In a prospective, multicenter, open-label study, de novo liver transplant patients were randomized at day 30 to (i) everolimus + reduced exposure tacrolimus (EVR + Reduced TAC), (ii) everolimus + tacrolimus elimination (TAC Elimination), or (iii) standard exposure tacrolimus (TAC Control).

RESULTS

Randomization to TAC Elimination was terminated prematurely due to a higher rate of treated biopsy-proven acute rejection (tBPAR) during TAC withdrawal. Of 370 patients who completed the 24-month core study on-treatment, 282 (76.2%) entered an additional 12-month extension phase. The composite efficacy failure endpoint (tBPAR, graft loss or death) occurred in 11.5% of EVR+Reduced TAC patients versus 14.6% TAC Controls from randomization to month 36 (difference, -3.2%; 95% confidence interval, -10.5% to 4.2%; P = 0.334). Treated BPAR occurred in 4.8% versus 9.2% of patients (P = 0.076). From randomization to month 36, mean (SD) estimated glomerular filtration rate decreased by 7.0 (31.3) mL/min per 1.73 m in the EVR+Reduced TAC group, and 15.5 (22.7) mL/min per 1.73 m in the TAC Control group (P = 0.005). Rates of adverse events, serious adverse events, and discontinuation due to adverse events were similar in both groups during the extension.

CONCLUSIONS

A clinically relevant renal benefit after introduction of everolimus with reduced-exposure tacrolimus at 1 month after liver transplantation was maintained to 3 years in patients who continued everolimus therapy to the end of the core study, with comparable efficacy and no late safety concerns.

Hypoalbuminemia Within Two Postoperative Days Is an Independent Risk Factor for Acute Kidney Injury Following Living Donor Liver Transplantation: A Propensity Score Analysis of 998 Consecutive Patients

OBJECTIVE

Acute kidney injury is a known major complication of liver transplantation. Previous reports have shown that hypoalbuminemia is associated with an increased risk of acute kidney injury. However, little is known about the relationship between the early postoperative albumin level and acute kidney injury after living donor liver transplantation. The aim of this study was to identify the influence of the postoperative albumin level on acute kidney injury prevalence after living donor liver transplantation.

DESIGN

A retrospective analysis.

SETTING

A tertiary care university hospital.

PATIENTS

Nine hundred and ninety-eighty patients underwent living donor liver transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We divided the enrolled patients into two groups: group 1 included patients whose postoperative albumin level was less than 3.0 g/dL (n = 522), and group 2 included patients with an albumin level greater than or equal to 3.0 g/dL (n = 476). The prevalence of acute kidney injury, major adverse cardiac events, hospital stay, ICU stay, 30-day mortality, and overall mortality was analyzed using inverse probability of treatment weighting and propensity-score matching (n = 249 pairs) analysis. The prevalence of acute kidney injury was higher in group 1 defined by both Acute Kidney Injury Network (after adjusting for inverse probability of treatment weighting [n = 364; 69.7%] and propensity-score matching [n = 152; 61.0%]) and Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (after adjusting for inverse probability of treatment weighting [n = 419; 80.3%] and propensity-score matching [n = 190; 76.3%]). The overall mortality was higher in group 1 after adjusting for inverse probability of treatment weighting (n = 61; 11.7%) and propensity-score matching (n = 23; 9.2%). The hospital (p < 0.001) and ICU (p = 0.006) stays were significantly prolonged in group 1. Acute kidney injury was associated with ICU stay by the Acute Kidney Injury Network criteria (p = 0.034), and overall mortality was correlated with acute kidney injury by the Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (p = 0.014).

CONCLUSIONS

Early postoperative hypoalbuminemia is an independent risk factor for acute kidney injury, and postoperative acute kidney injury is related to postoperative ICU stay and overall mortality after living donor liver transplantation.

Evaluation of renal functions in pediatric liver transplantation

AKI is an important complication after LT. As our LT series contains a quite high number of children with ALF unlike published studies, we aimed to determine pre-LT and long-term renal functions in children both with ALF and with CLD. Demographic and disease-related data of 134 transplanted children were evaluated retrospectively. Pre-LT and follow-up GFR and pediatric RIFLE scores were determined. Mean pre-LT GFR was not dependent on the disease presentation or severity of chronic disease. While there was an initial decline until first week of post-LT in CLD children, an increase was observed in ALF. Neither mean GFR nor the pRIFLE on follow-up was different with respect to the type of LT or disease presentation. Mean GFR at first and sixth months were lower in children on cyclosporine compared to tacrolimus (p = 0.001 and p = 0.002, respectively). In conclusion, GFR-time curve was different in children with or without ALF. Type of LT, and severity of the CLD were not risk factors for CKD in any time, but younger age at LT, CLD, and cyclosporine usage were at sixth months of follow-up.

The Kidney in Pediatric Liver Disease

There is an intricate relationship between the liver and the kidney, with renal physiology and function intimately involved in many primary disorders of pediatric liver disease. The hemodynamic changes of progressive cirrhosis affect and are directly affected by changes in renal blood flow and renal handling of sodium and free water excretion. Resulting complications of worsening ascites, hyponatremia, and acute kidney injury frequently complicate the care of children with advanced liver disease and contribute significant morbidity and mortality. While liver transplantation may restore hemodynamic stability, nearly 40% of pediatric liver transplant recipients develop chronic kidney disease post-transplant and approximately 25% are left with clinical hypertension. This review seeks to provide a basic understanding of this relationship to enable the provision of optimal care to children with liver disease.

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

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 14^th, 21^st and 28^th 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://clinicaltrials.gov/ct2/show/NCT01707810

Underestimation of chronic renal dysfunction after liver transplantation: ICEBERG study

AIM: To compare prevalence of chronic renal dysfunction (CRD) according to serum creatinine (sCr) vs estimated glomerular filtration rate (eGFR) among maintenance liver transplant patients.

METHODS: The ICEBERG study was an observational, retrospective, cross-sectional, and multicenter study. Consecutive adult patients (aged 18 years or older) with liver transplantation (LT) performed at least two years previously were recruited. Multi-organ transplant recipients were excluded. Chronic renal dysfunction was defined according to sCr based criteria in routine clinical practice (≥ 2 mg/dL) and eGFR using MDRD-4 equation (< 60 mL/min per 1.73 m²). Agreement between sCr definition and eGFR assessment was evaluated using the Kappa index. Cox regression analysis was applied to identify predictive factors for developing CRD after LT.

RESULTS: A total of 402 patients were analyzed (71.6% males). Mean ± SD age at transplant was 52.4 ± 9.8 years. Alcoholic cirrhosis without hepatocellular carcinoma was the most common reason for LT (32.8%). Mean time since LT was 6.9 ± 3.9 years. Based on sCr assessment, 35.3% of patients (95%CI: 30.6-40.0) had CRD; 50.2% (95%CI: 45.3-55.1) according to eGFR. In 32.2% of cases, sCr assessment had underestimated CRD. Multivariate analysis showed the following factors associated with developing CRD: eGFR < 60 mL/min per 1.73 m² at three months post-transplant [hazard ratio (HR) = 4.76; 95%CI: 2.78-8.33; P < 0.0001]; calcineurin inhibitor use (HR = 2.31; 95%CI: 1.05-5.07; P = 0.0371); male gender (HR = 1.98; 95%CI: 1.09-3.60; P = 0.0260); and ≥ 10 years post-transplantation (HR = 1.95; 95%CI: 1.08-3.54; P = 0.0279).

CONCLUSION: Seven years after LT, CRD affected half our patients, which was underestimated by sCr. An eGFR < 60 mL/min per 1.73 m² three months post-LT was predictive of subsequent CRD.

Intraoperative terlipressin therapy reduces the incidence of postoperative acute kidney injury after living donor liver transplantation

OBJECTIVE

To evaluate the effect of intraoperative infusion with terlipressin on the incidence of acute kidney injury (AKI) after living donor liver transplantation (LDLT).

DESIGN

Retrospective case-controlled study.

SETTING

Government hospital.

PARTICIPANTS

The medical records of 303 patients who underwent LDLT were reviewed retrospectively.

INTERVENTIONS

Patients were divided into 2 groups on the basis of intraoperative administration of terlipressin. The primary outcome was AKI, as defined by the Acute Kidney Injury Network criteria. Secondary outcomes included the requirement for postoperative dialysis and in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

The incidence of AKI was 38% (n = 115); AKI occurred in 24 (24.2%) patients who received terlipressin versus 91 (44.6%) in the control group (p = 0.001). The incidence of postoperative dialysis was 9.2% (n = 28). Postoperative dialysis was needed by 8 patients (8.1%) in the terlipressin group versus 20 patients (9.8%) in the control group (p = 0.62). Multivariate logistic regression analysis indicated that terlipressin protected against AKI (odds ratio [OR], 0.4; 95% confidence interval [CI], 0.2-0.8; p = 0.013) but not the need for dialysis (OR, 0.7; 95% CI, 0.2-2.2; p = 0.53) or the in-hospital mortality (OR, 1.1; 95% CI, 0.5-2.3; p = 0.7). Adjustment, using the propensity score, did not alter the association between the use of terlipressin and AKI reduction (OR, 0.46; 95% CI, 0.22-0.89; p = 0.03).

CONCLUSION

These results suggested that intraoperative terlipressin therapy is associated with significant reductions in the risk of AKI in LDLT patients.

Intravenous fenoldopam for early acute kidney injury after liver transplantation

PURPOSE

Acute kidney injury remains a serious complication after orthotopic liver transplantation. To date, several 'renal-protective' agents have been explored in this setting but with conflicting and disappointing results. Therefore, our aim is to evaluate the effects of fenoldopam in liver transplant patients with an established renal injury.

METHODS

In this prospective study, intravenous fenoldopam 0.1 µg/kg/min was administered to consecutive liver transplant patients with postoperative (within 7 days from surgery) stage 2 acute kidney injury (AKI) according to the Acute Kidney Injury Network classification. Actual glomerular filtration rate (GFR; calculated by the iohexol plasma clearance), serum creatinine (SCr) and cystatin C (SCyC) were used to assess the effect of the medication on the patients.

RESULTS

During the study, 295 patients underwent liver transplant. Fifty-one patients (17.6%) met the inclusion criteria and the data from 48 patients were analysed. SCr and SCyC levels decreased (p < 0.001 after 48 h; p < 0.0001 after 72 h) and GFR increased (p < 0.001 after 24 h; p < 0.0001 after 72 h). When compared to a cohort of comparable patients with AKI from our historical series, the patients in the present study showed better SCr and SCyC levels. It was not necessary to discontinue the infusion of fenoldopam in any patient because of the occurrence of adverse events potentially attributable to it.

CONCLUSION

We showed that fenoldopam was capable of improving some renal function parameters in postoperative liver transplantation patients with on-going AKI. This preliminary study now sets the stage for a multicenter, randomized, placebo-controlled trial in order to provide definite evidence.

Risk factors and management of conversions to an open approach in laparoscopic liver resection: analysis of 265 consecutive cases

BACKGROUND

As a consequence of continuous technical developments in liver surgery, laparoscopic liver resection (LLR) is increasingly performed worldwide.

METHODS

Between January 2004 and December 2011, 265 LLR were performed in 242 patients for various diseases. The experience of LLR is reported focusing on risk factors of conversion and their management.

RESULTS

The overall conversion rate was 17/265 (6.4%), equally distributed over the period of the study. Statistically significant factors for conversion were found to be LLR of the postero-superior (P-S) segments (SI, SIVa; SVII; SVIII) (12.7% converted versus 2.5% non-converted groups, P = 0.01) and a major compared with a minor hepatectomy (15.2% vs. 4.6%, P = 0.02 respectively). A R0 resection was achieved in 93.2% of cases. According to Dindo's classification, complications were recorded as grade I (n = 20); grade II (6); grade III (11) and grade IV(1) events (total morbidity rate of 14%). Univariate analysis identified a major hepatectomy and resection involving P-S segments as prognostic factors for conversion whereas multivariate analysis identified the latter as an independent risk factor [P = 0.003, odds ratio (OR) = 5.9, 95% confidence interval (CI) = 1.8-18.8].

CONCLUSIONS

LLR can be safely performed with low overall morbidity. According to this experience and irrespective of the learning curve, resections of P-S segments were identified as an independent risk factor for conversion in LLR.

Intrarenal resistance index for the assessment of acute renal injury in a rat liver transplantation model

Background

Acute kidney injury (AKI) is a common complication after liver transplantation (LT) and associated with a high mortality. The renal resistive index (RI) is used to assess early renal function impairment in critical care patients. However, limited data are available concerning changes of renal RI and the development of AKI early after reperfusion. We approached to investigate the changes of renal RI and AKI after reperfusion in a rat liver transplantation model.

Methods

Rats were randomly divided into sham group or LT group. Ten rats in each group were used for the hemodynamic study and twenty for Doppler measurements during the procedure. Ten rats were sacrificed 30 min or 2 h after the reperfusion. We harvested kidneys, serum and urine for further analysis of the renal function.

Results

The intrarenal RI increased significantly in the anhepatic stage and decreased significantly after the reperfusion in the LT group compared with sham group (P < 0.05). AKI was seen after the reperfusion in the LT group. No correlation was noted between the RI and renal function parameters 30 min after reperfusion.

Conclusions

The intrarenal RI increased significantly during the anhepatic stage, and decreased significantly early after the reperfusion. Intrarenal RI was unable to assess renal function in a rat liver transplantation model.

The kidney in pediatric liver transplantation: an updated perspective

CKD continues to detract from the success of improved survival in pediatric liver transplantation, and its presence is likely under recognized. Here we review the literature regarding the prevalence, etiology, and management of renal dysfunction in pediatric liver transplant recipients. Long-term studies suggest the prevalence of CKD to be 25-38% by 5-10 yr post-transplant. While important, sole use of serum creatinine overestimates renal function in this population. Screening for and treatment of persistent proteinuria and hypertension as well as minimization of nephrotoxic insults are the mainstays to delay or prevent CKD progression. Office-based blood pressure measures are less sensitive than ABPM, which is specifically recommended by the American Heart Association for its ability to diagnose masked hypertension in pediatric liver transplant recipients. Long-term risk of CKD is predominantly secondary to CNI toxicity. CNI minimization protocols have shown promise in slowing progression of CKD while maintaining graft function, but large-scale randomized control trials with long-term follow-up are needed.