Excellent outcomes in combined liver-kidney transplantation: Impact of kidney donor profile index and delayed kidney transplantation

Simultaneous liver-kidney transplantation: future perspective

BACKGROUND

The aims of this narrative review were (i) to describe the current indications of SLKT, (ii) to report evolution of SLKT activity, (iii) to report the outcomes of SLKT, (iv) to explain the immune-protective effect of liver transplant on kidney transplant, (v) to explain the interest of delay kidney transplantation, using hypothermic machine perfusion (HMP), (vi) to report kidney after liver transplantation (KALT) indications and (vii) to describe the value of the increase in the use of extended criteria donors (ECD) and particular controlled donation after circulatory death (cDCD) transplant, thanks to the development of new organ preservation strategies.

METHOD

Electronic databases were screened using the keywords "Simultaneous", "Combined", "kidney transplantation" and "liver transplantation". The methodological and clinical heterogeneity of the included studies meant that meta-analysis was inappropriate.

RESULTS

 A total of 1,917 publications were identified in the literature search. Two reviewers screened all study abstracts independently and 1,107 of these were excluded. Thus, a total of 79 full text articles were assessed for eligibility. Of these, 21 were excluded. In total, 58 studies were included in this systematic review.

CONCLUSIONS

 Simultaneous liver-kidney transplantation has made a significant contribution for patients with dual-organ disease. The optimization of indication and selection of SLKT patients will reduce futile transplantation. Moreover, increasing the use of transplants from extended criteria donors, in particular cDCD, should be encouraged, thanks to the development of new modalities of organ preservation.

Outcomes of Combined Liver-Kidney Transplantation - Single Center Experience

BACKGROUND

There is continuous growth of combined liver-kidney transplantation (CLKTx) numbers with remarkable outcomes, especially among patient with liver cirrhosis and end-stage renal disease. The aim was to present a single center experience.

METHODS

Twenty patients (9 males) with a mean age of 48 (range: 20-62) years underwent CLKTx from 2005 to 2022. Indications were polycystic liver and kidney diseases (ADPKD) in 12 cases, cirrhosis due to hepatitis (4 patients), and 1 case of amyloidosis, alcoholic liver disease, nonalcoholic steatosis, and congenital hepatic fibrosis with concomitant glomerulonephritis. After hepatectomy, half of the patients had orthotopic liver transplantation with piggy-back technique, and the other had conventional technique. All but 1 recipient had biliary end-to-end anastomosis. 3 patients had preemptive kidney graft transplantation. 4 underwent simultaneous right-side nephrectomy due to volume of the right kidney. Kidney was transplanted from the separate incision after abdominal closure with typical anastomoses. Tacrolimus, mycophenolate mofetile, basiliximab, and steroids were applied for all recipients.

RESULTS

Mean follow-up was 57.7 ± 54 months. No primary non-function of the grafts occurred. Delayed kidney graft function (DGF) occurred in 8 patients. Three-month, 1-year, and 5-year cumulative survival rates were: 90%, 80%, and 72% respectively. None of the patients required retransplantation, and 1 recipient returned to hemodialysis 19 months after transplantation. Preemptive kidney transplantation and simultaneous right-side nephrectomy were not significant for DGF and recipient survival. No deaths within the first year occurred in piggy-back technique.

CONCLUSIONS

CLKTx is safe and effective in the treatment of both liver and kidney failure.

Simultaneous split liver/kidney transplantation: A national and single center experience report

BACKGROUND

End-stage liver disease (ESLD) and end-stage renal disease (ESRD) are prevalent diseases for which the definitive treatment is transplantation. With limited organ supply, strategies to maximize organ availability has led to increasing rates of split liver transplantations for ESLD patients. Therefore, simultaneous split liver and kidney transplantations (SSLK) for patients with ESLD and ESRD could represent a treatment option for comorbid patients. However, current practice and outcomes after SSLK are unknown.

METHODS

We aim to report national trends and our experience with patients undergoing SSLK. We performed a retrospective review of the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research file from January 2011-April 2022. Descriptive analysis of preoperative characteristics, postoperative outcomes and actuarial graft and patient survivals are reported.

RESULTS

National review of the UNOS transplant registry from 2011-2021 of adult patients undergoing initial transplantation via SSLK demonstrates that this procedure remains uncommon, with only 76 such cases captured in that time. Nevertheless, survival rates at 1, 3, and 5 years remains robust, at 94%, 92%, and 90% for patients overall, 90%, 88%, 88%, for the liver graft, and 93%, 91%, 88% for the kidney graft, respectively. Review of a single center experience with three such patients from 2019-2021 has shown a safe, enduring transplant option with no graft complications seen.

CONCLUSIONS

SSLK is both safe and a feasible option to optimize organ supply while allowing recipients to receive quality liver and kidney grafts and should be considered more often by transplant centers going forward.

Osmotic response during kidney perfusion with cryoprotectant in isotonic or hypotonic vehicle solution

Organ cryopreservation would revolutionize transplantation by overcoming the shelf-life limitations of conventional organ storage. To prepare an organ for cryopreservation, it is first perfused with cryoprotectants (CPAs). These chemicals can enable vitrification during cooling, preventing ice damage. However, CPAs can also cause toxicity and osmotic damage. It is a major challenge to find the optimal balance between protecting the cells from ice and avoiding CPA-induced damage. In this study, we examined the organ perfusion process to shed light on phenomena relevant to cryopreservation protocol design, including changes in organ size and vascular resistance. In particular, we compared perfusion of kidneys (porcine and human) with CPA in either hypotonic or isotonic vehicle solution. Our results demonstrate that CPA perfusion causes kidney mass changes consistent with the shrink-swell response observed in cells. This response was observed when the kidneys were relatively fresh, but disappeared after prolonged warm and/or cold ischemia. Perfusion with CPA in a hypotonic vehicle solution led to a significant increase in vascular resistance, suggesting reduced capillary diameter due to cell swelling. This could be reversed by switching to perfusion with CPA in isotonic vehicle solution. Hypotonic vehicle solution did not cause notable osmotic damage, as evidenced by low levels of lactate dehydrogenase (LDH) in the effluent, and it did not have a statistically significant effect on the delivery of CPA into the kidney, as assessed by computed tomography (CT). Overall, our results show that CPA vehicle solution tonicity affects organ size and vascular resistance, which may have important implications for cryopreservation protocol design.

Simultaneous Heart-kidney Transplant With Planned Delayed Implantation of the Kidney Graft After Ex Vivo Perfusion

BACKGROUND

Simultaneous heart-kidney transplant (SHK) is an established option for patients with severe heart failure and chronic kidney disease. Recent studies in simultaneous liver-kidney transplantation demonstrate favorable outcomes achieved by delaying implantation of the kidney for over 24 h. This report describes a case series of consecutive patients listed for SHK who had planned delayed implantation of the kidney graft.

METHODS

This case series represents a retrospective analysis of SHK patients extracted from the transplant database at a single center.

RESULTS

There were 7 patients who underwent SHK during the study period. In all cases, kidney grafts were maintained on hypothermic ex vivo pulsatile perfusion for delayed implantation (mean cold ischemia 53 h [range, 31-69]). The first 5 patients had 100% 1-y heart and kidney graft survival with good function. Patient 6 was unstable on extracorporeal membrane oxygenation post-heart transplant. The kidney was implanted at 69 h, and the patient died soon thereafter. Patient 7 was also unstable on extracorporeal membrane oxygenation after heart transplant. The decision was made to implant the kidney into a backup kidney recipient. The heart transplant recipient subsequently died several days later, whereas the kidney was successfully transplanted in the alternate candidate.

CONCLUSIONS

This case series highlights the potential utility of delayed kidney implantation in SHK patients. SHK with delayed renal transplant may provide an improved physiologic environment for renal transplant, which may result in improved early renal graft function. Delayed kidney transplant also provides the opportunity to transplant the kidney graft into an alternate candidate.

Living Donor Liver Transplantation Alone Is Not Inferior to Combined Kidney Liver Transplant for Cirrhotic Patients With Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is common in patients with chronic liver disease (CLD) as is acute kidney injury (AKI). The differentiation between CKD vs AKI is often difficult and sometimes the both may coexist. A combined kidney-liver transplant (CKLT) may result in a kidney transplant in patients whose renal function is likely to recover or at least who have stable renal function post-transplant. We retrospectively enrolled 2742 patients who underwent living donor liver transplant at our center from 2007 to 2019.

METHODS

This audit was carried out in liver transplant recipients with CKD 3 to 5 who underwent either liver transplant alone (LTA) or CKLT to look at outcomes and long-term evolution of renal function. Forty-seven patients met the medical eligibility criteria for CKLT. Of the 47 patients, 25 underwent LTA and the rest 22 underwent CKLT. The diagnosis of CKD was made according to the Kidney Disease: Improving Global Outcomes classification.

RESULTS

Preoperative renal function parameters were comparable between the 2 groups. However, CKLT patients had significantly lower glomerular filtration rates (P = .007) and higher proteinuria (P = .01). Postoperatively, renal function, and comorbidities were comparable between the 2 groups. Survival was similar at 1, 3, and 12 months, respectively (log-rank; P = .84, = .81, and = .96, respectively). At the end of the study period, 57% of patients who survived in LTA groups had stabilized renal function (Creatinine = 1.8 ± 0.6 mg/dL).

CONCLUSIONS

Liver transplant alone is not inferior to CKLT in living donor situations. Renal dysfunction is stabilized in the long term whereas long-term dialysis may be carried out in others. Living donor liver transplantation alone is not inferior to CKLT for cirrhotic patients with CKD.

Modified Mercedes Single Incision for Combined Liver Kidney Transplant: A Case Series Report

BACKGROUND

The traditional approach in combined liver-kidney transplantation involves 2 separate and sequential incisions. We describe a modification of the standard Mercedes incision that allows a single-incision operation while providing and maintaining adequate exposure to enable safe dual-allograft transplantation.

METHODS

Modification of the standard Mercedes incision includes bilateral, subcostal, muscle splitting incision 4 fingerbreadths below the rib edge with a midline, cephalad incision and inferior ± medial ipsilateral extension on the side of intended iliac fossa laterality for renovascular and ureteroneocystostomy anastomosis.

RESULTS

Five consecutive patients (3 women/2 men; mean age, 49 years; median body mass index, 29.8 kg/m²) underwent combined liver-kidney transplantation for end-stage liver disease and progressive hepatorenal syndrome via a modified Mercedes single-incision approach (at a median Model for End-stage Liver Disease of 37) without an additional kidney transplant incision, extraperitoneal exposure, or addition of wound retractors. Two out of the 5 patients experienced postoperative wound complications, including 1 with delayed wound healing and 1 with superficial dehiscence. All patients have normal dual-allograft function at or beyond 6 months posttransplantation.

CONCLUSIONS

The modified Mercedes single-incision technique is safe and feasible. Lowering the subcostal incisions with unilateral, inferomedial extension allows adequate visualization of the lower abdominopelvic area without compromising exposure of the upper abdomen for both renal and liver allograft implantation. Further studies are needed to prove the theoretical benefits of this technique.

Predictors of Kidney Delayed Graft Function and Its Prognostic Impact following Combined Liver-Kidney Transplantation: A Recent Single-Center Experience

Combined liver−kidney transplantation (CLKT) improves patient survival among liver transplant recipients with renal dysfunction. However, kidney delayed graft function (kDGF) still represents a common and challenging complication that can negatively impact clinical outcomes. This retrospective study analyzed the incidence, potential risk factors, and prognostic impact of kDGF development following CLKT in a recently transplanted cohort. Specifically, 115 consecutive CLKT recipients who were transplanted at our center between January 2015 and February 2021 were studied. All transplanted kidneys received hypothermic pulsatile machine perfusion (HPMP) prior to transplant. The primary outcome was kDGF development. Secondary outcomes included the combined incidence and severity of developing postoperative complications; development of postoperative infections; biopsy-proven acute rejection (BPAR); renal function at 1, 3, 6, and 12 months post-transplant; and death-censored graft and patient survival. kDGF was observed in 37.4% (43/115) of patients. Multivariable analysis of kDGF revealed the following independent predictors: preoperative dialysis (p = 0.0003), lower recipient BMI (p = 0.006), older donor age (p = 0.003), utilization of DCD donors (p = 0.007), and longer delay of kidney transplantation after liver transplantation (p = 0.0003). With a median follow-up of 36.7 months post-transplant, kDGF was associated with a significantly increased risk of developing more severe postoperative complication(s) (p < 0.000001), poorer renal function (particularly at 1 month post-transplant, p < 0.000001), and worse death-censored graft (p = 0.00004) and patient survival (p = 0.0002). kDGF may be responsible for remarkable negative effects on immediate and potentially longer-term clinical outcomes after CLKT. Understanding the important risk factors for kDGF development in CLKT may better guide recipient and donor selection(s) and improve clinical decisions in this increasing group of transplant recipients.

Donor-recipient body size mismatch has no impact on outcomes after deceased donor whole liver transplantation: Role of donor liver size measurement

The role of donor-recipient body size mismatch (DRSM) on outcomes after whole liver transplantation (LT) is not clearly defined. At our center, in presence of considerable DRSM, objective assessment of the donor liver by a radiology or intraoperative evaluation by procuring surgeon was incorporated. To evaluate the impact of DRSM on graft outcomes with this approach, adult deceased donor whole liver transplants between July 2001 and December 2017 at our center were studied. DRSM was considered when the donor-recipient body surface area (BSA) ratio (DR-BSAr) was either <0.69 or >1.25. There were 54 (3.2%) transplants with DR-BSAr <0.69 and 61 (3.6%) with DR-BSAr >1.25. One-year graft survival was 85% vs. 89% vs. 89%; (p = .64) for transplants with DR-BSArs of <0.69, 0.69-1.25, and >1.25, respectively. Early allograft dysfunction (EAD) (28% vs. 27% vs. 37%; p = .07), post-transplant coagulopathy, bilirubinemia, and renal function were also comparable. In conclusion, with the actual measurement of the donor liver and recipient abdominal cavity, significant DRSM did not have a negative impact on early and long-term outcomes. Routine measurement of donor liver size by radiology may be incorporated in liver allocation to improve utilization.

Early Kidney Allograft Failure After Simultaneous Liver-kidney Transplantation: Evidence for Utilization of the Safety Net?

BACKGROUND

With the implementation of the "Safety Net," we aimed to determine the impact of simultaneous liver-kidney transplantation (SLKT), as compared to kidney transplant after liver transplant (KALT), on kidney allograft failure (KF).

METHODS

An analysis of the UNOS database for all adult patients who received either an SLKT or KALT from 2002 to 2017. The outcomes were 90-day KF and 1-year KF (as reported to UNOS, at 90- and 365-day postkidney transplant, respectively). We compared the following groups of patients: SLKT <25 (SLKT with final model for end-stage liver disease [MELD] <25), SLKT25/35 (MELD ≥25/<35), and SLKT35 (MELD ≥35) to KALT.

RESULTS

Of the 6276 patients, there were 1481 KALT, 1579 SLKT <25, 1832 SLKT25/35, and 1384 SLKT ≥35. The proportion of patients with 90-day and 1-year KF increased significantly among the KALT, SLKT <25, SLKT25/35, and SLKT ≥35 groups (P < 0.001; test for trend): 90-day KF: 3.3% versus 5.5% versus 7.3% versus 9.3% and 1-year KF: 5.1% versus 9.4% versus 12.3% versus 14.7%. After adjustment and compared with KALT, beginning at an MELD ≥25 those undergoing SLKT had significantly higher risk of 90-day and 1-year KF: 90-day KF: SLKT25/35: hazard ratio, 1.6(1.0-2.3); SLKT ≥35: 2.1(1.3-3.3); 1-year KF: SLKT25/35: hazard ratio, 1.7(1.2-2.4); SLKT ≥35: 2.1(1.5-3.0).

CONCLUSIONS

As compared to KALT recipients, SLKT recipients with an MELD ≥25 had significantly higher risk of early KF. Given the now well-established "Safety Net," KALT may serve as an opportunity to improve kidney outcomes in patients with an MELD ≥25.

Delayed kidney transplantation in combined liver-kidney transplantation

PURPOSE OF REVIEW

To review the impact of delayed kidney transplantation approach in combined (simultaneous) liver-kidney transplantation (CLKT).

RECENT FINDINGS

CLKT offers a life-saving procedure for patients with both end-stage liver disease and chronic kidney disease or prolonged acute kidney injury. It is the most common multiorgan transplant procedure in the US accounting for 9-10% of all liver transplants performed. The number of CLKT has also been increasing in other countries with a better understanding of hepato-renal syndrome. US is the only country which implemented a national allocation policy for CLKT in 2017. Due to the different physiological needs of liver and kidney allografts immediately after transplantation, delayed kidney transplantation approach in CLKT has been introduced for the first time by the Indiana Group, naming it as 'the Indiana Approach'. Over the years, many other groups in the US and in Europe published better outcomes in CLKT using the delayed kidney transplantation approach with the support of hypothermic machine perfusion.

SUMMARY

Several groups have shown that delayed kidney transplantation in CLKT is a safe procedure with better outcomes in graft(s) and patient survival.

Delayed Graft Function in Simultaneous Liver Kidney Transplantation

BACKGROUND

Delayed graft function (DGF) is associated with inferior posttransplant outcomes in kidney transplantation. Given these adverse outcomes, we sought to determine the incidence, unique risk factors, and posttransplant outcomes for simultaneous liver kidney (SLK) transplant recipients developing DGF.

METHODS

We studied 6214 adult SLK recipients from March 2002 to February 2017 using the Scientific Registry of Transplant Recipients. We determined associations between risk factors and DGF using Poisson multivariate regression and between DGF and graft failure and mortality using Cox proportional hazard analysis.

RESULTS

The overall rate of DGF was 21.8%. Risk factors for DGF in the hepatitis C virus (HCV)-negative recipient population included pretransplant dialysis (adjusted incident rate ratio [aIRR] 3.26, P = 0.004), donor body mass index (aIRR 1.25 per 5 kg/m, P = 0.01), and transplantation with a donation after circulatory death (aIRR 5.38, P = 0.001) or imported donor organ (regional share aIRR 1.69, P = 0.03; national share aIRR 4.82, P < 0.001). DGF was associated with a 2.6-fold increase in kidney graft failure (adjusted hazard ratio [aHR] 2.63, P < 0.001), 1.6-fold increase in liver graft failure (aHR 1.62, P < 0.001), and 1.6-fold increase in mortality (aHR 1.62, P < 0.001).

CONCLUSIONS

In HCV-negative SLK recipients, recipient pretransplant dialysis and components of kidney graft quality comprise significant risk factors for DGF. Regardless of HCV status, DGF is associated with inferior posttransplant outcomes. Understanding these risk factors during clinical decision-making may improve prevention of DGF and may represent an opportunity to improve posttransplant outcomes.

Impact of Recipient Age in Combined Liver-Kidney Transplantation: Caution Is Needed for Patients ≥70 Years

Elderly recipients (≥70 y) account for 2.6% of all liver transplants (LTs) in the United States and have similar outcomes as younger recipients. Although the rate of elderly recipients in combined liver-kidney transplant (CLKT) is similar, limited data are available on how elderly recipients perform after CLKT.

METHODS

We have previously shown excellent outcomes in CLKT using delayed kidney transplant (Indiana) Approach (mean kidney cold ischemia time = 53 ± 14 h). Between 2007 and 2018, 98 CLKTs were performed using the Indiana Approach at Indiana University (IU) and the data were retrospectively analyzed. Recipients were subgrouped based on their age: 18-45 (n = 16), 46-59 (n = 34), 60-69 (n = 40), and ≥70 years (n = 8).

RESULTS

Overall, more elderly patients received LT at IU (5.2%) when compared nationally (2.6%). The rate of elderly recipients in CLKT at IU was 8.2% (versus 2% Scientific Registry of Transplant Recipient). Recipient and donor characteristics were comparable between all age groups except recipient age and duration of dialysis. Patient survival at 1 and 3 years was similar among younger age groups, whereas patient survival was significantly lower in elderly recipients at 1 (60%) and 3 years (40%) (P = 0.0077). Control analyses (replicating Scientific Registry of Transplant Recipient's survival stratification: 18-45, 46-64, ≥65 y) showed similar patient survival in all age groups.

CONCLUSIONS

Although LT can be safely performed in elderly recipients, extreme caution is needed in CLKT due to the magnitude of operation.

Combined Lung-Liver and Delayed Kidney Transplantation for Cystic Fibrosis Clinical Approach and Outcome: A Case Report

Reports on the long-term outcomes and immunosuppressive regimens of multiorgan transplant patients are limited. Here, we describe a patient with cystic fibrosis complicated by multiorgan failure who was successfully treated with combined liver lung transplant and delayed kidney transplant, resulting in excellent outcomes. Delayed kidney transplant was done to reduce the operative stress of a single procedure, giving time for adequate resuscitation and weaning from vasopressors. Our patient's postoperative course was complicated by post-transplant lymphoproliferative disease, which was successfully treated with rituximab and reduced dosages of immunosuppression.

Current status of combined liver-kidney transplantation

Combined liver-kidney transplantation is a life-saving procedure for patients with end-stage liver disease and underlying chronic kidney disease, or prolonged acute kidney injury. Due to physiologic changes secondary to portal hypertension in patients with end-stage liver disease, kidney injury is common, and combined liver-kidney transplantation accounts for 10% of all the liver transplants performed in the United States. Recently implemented policy in the United States standardizes the medical criteria for eligibility, and introduces a 'safety net' for those who are transplanted with a liver graft alone, in order to be able to receive a kidney graft later. Increasing number of combined liver-kidney transplants provides a large cohort of patients to be studied in detail for identification of factors (both donor and recipient-related) associated with better outcomes. Data regarding the safety and efficacy of delaying the kidney transplant part of the combined liver-kidney transplantation, and the immunologic benefits of the multi-organ transplantations including the liver are emerging. Here, we review the most recent analyses, and provide our opinion regarding the best practices in combined liver-kidney transplantation based on the evidence.

Rapid reduction of high-level pre-formed donor-specific antibodies after simultaneous liver-kidney transplantation: a report of two cases

Background

Kidney transplantation performed in the presence of high-titre donor-specific antibodies (DSA) may result in hyper-acute or accelerated antibody-mediated rejection and rapid allograft loss. Previous studies have shown that this risk may be mitigated with simultaneous liver-kidney transplantation (SLKT); however, the mechanisms are not well defined. Here we report the evolution of pre-formed, high-level DSAs in two highly sensitised SLKT recipients peri-operatively and describe a profound sustained depletion of all DSAs from the time of liver anastomosis with no extra desensitisation therapy required.

Case presentation

Two patients underwent SLKT and received our centre’s standard renal transplant immunosuppression with basiliximab and methylprednisolone for induction therapy and prednisolone, mycophenolate and tacrolimus for maintenance therapy. HLA antibody samples were collected pre-operatively, and immediately post-liver and post-kidney revascularisation, and then regularly in the post-transplant period. Complement Dependant Cytotoxicity (CDC) crossmatches were also performed. Both patients were highly sensitised with a PRA over 97%. One patient had a positive B- and T-cell crossmatch pre-transplant. These positive CDC crossmatches became negative and the level of pre-formed DSAs reduced profoundly and rapidly, within 3 h post-liver revascularisation. The reduction in pre-formed DSAs, regardless of subclass, was seen immediately post-liver revascularisation, before implantation of the renal allografts. No significant reduction in non-donor specific HLA-antibodies was observed. Both patients maintained good graft function with no rejection on kidney allograft protocol biopsies performed at 10-weeks post-transplant.

Conclusions

These cases support the protective immunoregulatory role of the liver in the setting of SLKT, with no extra desensitisation treatment given pre-operatively for these highly sensitised patients.