Auxiliary partial orthotopic liver transplantation as a rescue for small-for-size grafts harvested from living donors

Auxilliary Liver Transplantation According to the RAPID Procedure in Noncirrhotic Patients: Technical Aspects and Early Outcomes

OBJECTIVE

To present technical details and short-term experiences of liver transplantation as a 2-stage procedure using small for size grafts in a multicenter cohort study.

BACKGROUND

Two-stage liver transplantation using small for size grafts should be a feasible procedure with lower morbidity and mortality rates. Retrospective cohort study between 2015 and 2022 with multicenter experience. Twenty-three resection and partial liver transplantation with delayed total hepatectomy procedures for noncirrhotic indications were performed in 6 European centers (20 with grafts from living donors and 3 after deceased donation). Procedure's feasibility, graft volumetric changes, morbidity, and mortality of donor and recipient were explored.

RESULTS

There was a low donor morbidity (4.3%) in our cohort. Hypertrophy of the graft was rapid (mean graft volume increases 107% between both stages) and offered the opportunity for remnant hepatectomy after a median of 14 days. In all cases, portomesenteric flow was routed to the graft by right remnant portal vein ligation. Portal vein inflow modulation to alleviate transient harmful portal hypertension was not needed in any case. Early postoperative mortality (4.3%) of the recipients were low. Ten patients suffered from complications ≥IIIb according to the Clavien-Dindo classification.

CONCLUSIONS

Two-stage liver transplantation is a feasible option for noncirrhotic patients allowing the safe use of small for size grafts and could possibly be extended with caution to liver diseases with portal hypertension and cirrhosis. The resection and partial liver transplantation with delayed total hepatectomy technique might be a viable option for expanding the donor pool given the current organ shortage especially for low-model of end stage liver disease patients.

Successful Simultaneous Subtotal Splenectomy During Left Lobe Auxiliary Liver Transplantation for Portal Inflow Modulation and Severe Hypersplenism Correction: A Case Report

Adult-to-adult living donor liver transplantation with small partial liver grafts often requires intraoperative portal inflow modulation to prevent portal hyperperfusion and subsequent small-for-size syndrome (SFSS). However, there are concerns about the specific morbidity of these modulation techniques. This study aims to lower post-perfusion portal venous pressure and correct severe hypersplenism in a patient with end-stage liver cirrhosis by simultaneous subtotal splenectomy during auxiliary partial orthotopic liver transplantation (APOLT). A 29-year-old man was diagnosed with cryptogenic cirrhosis and severe portal hypertension suffered recurrent acute variceal bleeding, severe thrombocytopenia, and massive ascites before admission to our hospital. After the recipient's left liver was resected, we performed APOLT using his 51-year-old father's left lobe graft with a graft-to-recipient weight ratio of 0.55%. Intraoperatively, simultaneous subtotal splenectomy was performed to lower graft post-perfusion portal vein pressure below 15 mmHg and correct severe hypersplenism-related pancytopenia. The recipient's postoperative hospital course was uneventful with no occurrence of SFSS and procedure-related complications. Platelet and leukocyte counts remained in the normal ranges postoperatively. The living donor was discharged 6 days after the operation and recovered well-with no complications. After a follow-up period of 35.3 months, both the recipient and donor live with good liver function and overall condition. This is the first case report of simultaneous subtotal splenectomy during APOLT using small-for-size living-donated left liver lobes, which is demonstrated to be a viable procedure for modulating portal inflow and correcting severe hypersplenism in selected adult patients with end-stage liver cirrhosis. APOLT using a small-for-size liver graft may be a safe and feasible treatment option for selected adult patients with end-stage liver cirrhosis.

Auxiliary Liver Graft Can Be Protected From HBV Infection in HBsAg Positive Blood Circulation

Auxiliary grafts have a high risk of Hepatitis B virus (HBV) infection in patients with chronic HBV-related diseases. Hepatitis B virus-related auxiliary partial orthotopic liver transplantation (APOLT) cases were reviewed to show the results of current methods to block native-to-graft HBV transmission. Three patients received APOLT for HBV-related liver cirrhosis and a recurrent upper gastrointestinal hemorrhage between April 2015 and January 2017 by the liver transplant team of Beijing Friendship Hospital affiliated with Capital Medical University. All three patients were positive for HBV surface antigen (HBsAg) and had a negative HBV DNA test result before transplantation. After auxiliary transplantations, HBsAg was found to be positive in two patients and negative in one patient. To avoid graft infection of HBV, entecavir-based therapy was employed and the remnant native livers of the recipients were removed 51-878 days after liver transplantation. Then, serum conversions of HBsAg were found in all three cases. For the first time, this case series shows the possibility of blocking the transmission of HBV from a native liver to a graft in auxiliary transplantation by entecavir-based therapy. Among the cases, a left lobe graft was successfully implanted as a replacement of the right lobe of the recipient, which is also discussed.

Clinical progress of auxiliary liver transplantation

After half a century of development, auxiliary liver transplantation (ALT) technology gradually matured and major indications of ALT have been gradually expanded. This review summarized the history of ALT and introduced indications for ALT which including metabolic liver disease, fulminant hepatic failure, highly sensitized kidney transplantation, prevention of hepatic resection of small hepatic syndrome, etc.; at the same time, the hot issues related to ALT were discussed, including the regulation of hepatic portal blood flow of transplanted liver and residual liver, how to treat the graft liver and remaining liver on second stage. Additionally, the expansion of indications for ALT which included the implementation of ALT for patients with liver cancer and ALT for patients with liver cirrhosis was discussed. It was believed that ALT can greatly alleviate the contradiction of insufficient source of graft liver.

Small-for-size syndrome in liver transplantation: Definition, pathophysiology and management

BACKGROUND

Since the first success in an adult patient, living donor liver transplantation (LDLT) has become an universally used procedure. Small-for-size syndrome (SFSS) is a well-known complication after partial LT, especially in cases of adult-to-adult LDLT. The definition of SFSS slightly varies among transplant physicians. The use of a partial liver graft has risks of SFSS development. Persistent portal vein (PV) hypertension and PV hyper-perfusion after LT were identified as the main factors. Hence, various approaches were explored to modulate PV flow and decrease PV pressure in order to alleviate this syndrome. Herein, the definition, clinical symptoms, pathophysiology, basic research, as well as preventive and treatment strategies for SFSS are reviewed based on an extensive review of the literature and on our own experiences.

DATA SOURCES

The articles were collected through PubMed using search terms "liver transplantation", "living donor liver transplantation", "living liver donation", "partial graft", "small-for-size graft", "small-for-size syndrome", "graft volume", "remnant liver", "standard liver volume", "graft to recipient body weight ratio", "sarcopenia", "porcine", "swine", and "rat". English publications published before March 31, 2020 were included in this review.

RESULTS

Many transplant surgeons performed PV flow modulation, including portocaval shunt, splenic artery ligation and splenectomy. With these techniques, patient outcome has been improved even when using a "small" graft. Other factors, such as preoperative recipients' nutritional and skeletal muscle status, graft congestion, and donor factors, were also identified as risk factors which all have been addressed using various strategies.

CONCLUSIONS

The surgical approach controlling PV flow and pressure could help to prevent SFSS especially in severely ill recipients. In the absence of efficacious medications to resolve SFSS, conservative treatments, including aggressive fluid balance correction for massive ascites, anti-microbiological therapy to prevent or control sepsis and intensive nutritional therapy, are all required if SFSS could not be prevented.

Longterm outcomes of auxiliary partial orthotopic liver transplantation in preadolescent children with fulminant hepatic failure

By preserving part of the native liver, auxiliary partial orthotopic liver transplantation (APOLT) provides the advantage of potential immunosuppression (ISP) withdrawal if the native liver recovers but has had limited acceptance, especially in the United States, due to technical complications and low rates of native liver regeneration. No previous study has evaluated APOLT specifically for preadolescent children with fulminant hepatic failure (FHF). This population might benefit especially based on greater capacity for liver regeneration. Data from 13 preadolescent children who underwent APOLT were compared to 13 matched controls who underwent orthotopic liver transplantation (OLT) for FHF from 1996 to 2013. There were no significant differences in patient demographics or survival between the 2 groups. However, all surviving OLT recipients (10/13) remain on ISP, while all but 1 surviving APOLT recipient (12/13) showed native liver regeneration, and the first 10 recipients (76.9%) are currently off ISP with 2 additional patients currently weaning. In our experience, APOLT produced excellent survival and high rates of native liver regeneration in preadolescent children with FHF. This represents the largest series to date to report such outcomes. Liberating these children from lifelong ISP without the downside of increased surgical morbidity makes APOLT an attractive alternative. In conclusion, we therefore propose that, with the availability of technical expertise and with the technical modifications above, APOLT for FHF should be strongly considered for preteenage children with FHF.

Establishment of a new pig model for auxiliary partial orthotopic liver transplantation

AIM: To establish a new pig model for auxiliary partial orthotopic liver transplantation (APOLT).

METHODS: The liver of the donor was removed from its body. The left lobe of the liver was resected in vivo and the right lobe was used as a graft. After the left lateral lobe of the recipient was resected, end-to-side anastomoses of suprahepatic inferior vena cava and portal vein were performed between the donor and recipient livers, respectively. End-to-end anastomoses were made between hepatic artery of graft and splenic artery of the host. Outside drainage was placed in donor common bile duct.

RESULTS: Models of APOLT were established in 5 pigs with a success rate of 80%. Color ultrasound examination showed an increase of blood flow of graft on 5^th d compared to the first day after operation. When animals were killed on the 5^th d after operation, thrombosis of hepatic vein (HV) and portal vein (PV) were not found. Histopathological examination of liver samples revealed evidence of damage with mild steatosis and sporadic necrotic hepatocytes and focal hepatic lobules structure disorganized in graft. Infiltration of inflammatory cells was mild in portal or central vein area. Hematologic laboratory values and blood chemical findings revealed that compared with group A (before transplantation), mean arterial pressure (MAP), central venous pressure (CVP), buffer base (BB), standard bicarbonate (SB) and K⁺ in group B (after portal vein was clamped) decreased (P<0.01). After reperfusion of the graft, MAP, CVP and K+ restored gradually.

CONCLUSION: Significant decrease of congestion in portal vein and shortened blocking time were obtained because of the application of in vitro veno-venous bypass during complete vascular clamping. This new procedure, with such advantages as simple vessel processing, quality anastomosis, less postoperative hemorrhage and higher success rate, effectively prevents ischemia reperfusion injury of the host liver and deserves to be spread.

Living-donor liver transplantation: present status and future perspective

About 15 years have passed since the first liver transplant from a living donor (living donor liver transplantation: LDLT), and the status of the procedure has since been established as a standard cure for end-stage liver disease in Japan where liver transplantation (LTx) from deceased donors has not yet been accepted. However, the following problems are surfacing with the increase in the number of LDLTs between adults: graft size mismatching, an ABO blood-type incompatible transplantation, the expansion of LDLT indication to hepatocellular carcinoma (HCC), the relapse of hepatitis C after LDLT, marginal donors, and the freedom from immunosuppressive treatment. In this article we outline the present conditions of these problems and the future view of the LDLT.

Adult living donor liver transplantation: current status

Living donor liver transplantation was developed in response to a shortage of full-size grafts for children. The progression from reduced-size cadaveric grafts to use of living donors occurred subsequent to expansion of liver anatomy knowledge and practical use of hepatic segments. A major benefit of pediatric live donor liver transplantation is the grafting of children without using livers from the cadaver donor pool. A major drawback of the procedure relates to the need to perform surgery and assign risk to an otherwise healthy individual. The ethical challenge has been discussed in detail and, although not ideal, the procedure "passes muster" on grounds of informed consent and the good of helping another human being. Formidable success appears to have been attained with the adult-to-adult procedure thus far; however, the transplant community still awaits center-specific and compiled data to determine whether the procedure truly reduces adult waiting list times for liver transplant recipients with minimal donor risk.

Postoperative flow cytometry crossmatch in living donor liver transplantation: clinical significance of humoral immunity in acute rejection

BACKGROUND

The role of humoral immunity in acute rejection in solid organ transplantation remains controversial, although it is known that the presence of antidonor antibodies may precipitate graft rejection. We investigated the clinical relevance of antidonor humoral immunity for living donor liver transplantation (LDLT) by means of flow cytometry crossmatch (FCXM).

METHODS

T cell FCXM using fresh donor peripheral lymphocytes was performed before and up to 1 month after LDLT in 58 patients. Ten patients received ABO-incompatible grafts. IgM and IgG antidonor antibodies were analyzed in relation to clinical acute rejection as defined by liver function tests with or without histological evidence.

RESULTS

Pretransplantation FCXM was positive for five patients (8.6%), resulting in two cases of positive posttransplantation FCXM and two rejection episodes. Twelve patients (20.7%) showed positive posttransplantation FCXM. The incidence of acute rejection within 1 month was 100% in FCXM-positive patients and 17.4% in FCXM-negative patients (P<0.001). Thirteen (76.5%) of 17 rejection episodes in ABO-compatible cases were associated with concomitant antidonor IgM antibody. IgG antibody was also identified in six of these episodes. Antidonor antibodies disappeared after rejection treatments in all cases, but with some delay in clinical improvement. On the other hand, no antidonor antibodies were detected in any of the four rejection episodes in ABO-incompatible cases.

CONCLUSIONS

Early acute rejection in LDLT is significantly associated with antidonor T cell antibody formation in ABO-compatible cases. This suggests a definite role for donor-specific humoral immunity in acute rejection. Rejection episodes without antidonor antibodies may suggest graft injury by pure cellular immunity, or possibly the presence of humoral immunity triggered by antigens not present on donor T cells.

Auxiliary partial orthotopic liver transplantation from living donors: significance of portal blood flow

BACKGROUND

Auxiliary liver transplantation has several advantages over standard orthotopic liver transplantation. However, functional competition has been reported even in auxiliary partial orthotopic liver transplantation (APOLT). We evaluated herein the interaction in APOLT between the native liver and the graft in terms of portal blood flow and regeneration. The need for diversion of the portal blood flow to the graft was also assessed.

METHODS

A total of 15 patients received APOLT from living donors. Portal blood flow to the native liver was preserved in 6 patients, and the portal vein to the native liver was preemptively transected at the time of transplantation in 9 patients.

RESULTS

Of the patients with preservation of the portal blood flow to the native liver, two showed inadequate graft portal blood flow just after operation, and in the other three patients the graft portal blood flow decreased or the graft atrophied after deterioration of the graft function. In the patients with preemptive transection of the portal vein to the native liver, optimal graft portal blood flow was obtained, and the native liver, supplied only by arterial inflow, supported a small-for-size graft until the graft regenerated. The damage to the native liver was minimal.

CONCLUSIONS

Functional competition may occur in APOLT with preservation of the portal blood flow to the native liver, whereas preemptive transection of the native liver portal vein is a safe procedure and effectively prevents the portal steal phenomenon.