Long-term outcomes after stent insertion in patients with early and late hepatic vein outflow obstruction after living donor liver transplantation

Metallic Stents for Hepatic Venous Outflow Obstruction After Living-Donor Liver Transplantation and their Therapeutic Effects

BACKGROUND

Living-donor liver transplantation (LDLT) is established as a standard therapy for end-stage liver disease; however, vessel reconstruction is more demanding due to the short length and small size of the available structures compared with deceased-donor whole liver transplantation. Interventional radiology (IR) has become the first-line treatment for vascular complications after LDLT. Hepatic venous outflow obstruction (HVOO) is a life-threatening complication after LDLT. The aim of this study of 592 adult-to-adult LDLT cases was to investigate the safety and efficacy of stent implantation for HVOO after LDLT.

METHODS

Records of patients who developed HVOO requiring any treatment were collected with special reference to the metallic stent implantation. There were 232 left-side grafts and 360 right-side grafts. Sixteen cases developed HVOO after LDLT with an incidence rate of 2.7%, 5 with a left liver graft (2%), and 11 with a right-side graft (3%). The IR was attempted for 14 cases; among those, 8 cases were treated by stent implantation.

RESULTS

The technical success rate of the initial stent implantation was 100%. The pressure gradient at the stenotic site significantly improved from 12.2 (range, 10.9-20.4 cm H2O) to 3.9 cm H2O (range, 1.4-8.2 cm H2O; P = .03). The volume of the congested graft liver decreased significantly from 1448 (range, 788-2170 mL) to 1265 mL (range, 748-1665 mL; P = .01), and the serum albumin level improved significantly from 3.3 (range, 1.7-3.7 g/dL) to 3.7 g/dL (range, 2.9-4.1 g/dL; P = .02). No procedure-related complication was noted, and the long-term stent patency was 100%.

CONCLUSION

Metallic stent implantation for stenotic venous anastomosis after LDLT is a safe and effective treatment.

Endovascular Treatment of Venous Outflow and Portal Venous Complications After Liver Transplantation

Liver transplantation continues to rapidly evolve, and in 2020, 8906 orthotopic liver transplants were performed in the United States. As a technically complex surgery with multiple vascular anastomoses, stenosis and thrombosis of the venous anastomoses are among the recognized vascular complications. While rare, venous complications may be challenging to manage and can threaten the graft and the patient. In the last 20 years, endovascular approaches have been increasingly utilized to treat post-transplant venous complications. Herein, the evaluation and interventional treatment of post-transplant venous outflow complications, portal vein stenosis, portal vein thrombosis, and recurrent portal hypertension with transjugular intrahepatic portosystemic shunt (TIPS) are reviewed.

A case of hepatic venous outflow obstruction caused by migration of the remnant liver into the subphrenic space after extended posterior sectionectomy of the liver

INTRODUCTION

Hepatic venous outflow obstruction (HVOO) is a rare complication of hepatectomy. We report a case of HVOO caused by remnant liver migration into the subphrenic space after hepatectomy, which was successfully managed by repositioning of the remnant liver.

PRESENTATION OF CASE

A 55-year-old Japanese man was diagnosed with a liver tumor on ultrasound. Contrast-enhanced CT revealed early enhancement in the arterial phase, followed by a washout in the late phase. Preoperative diagnosis was hepatocellular carcinoma, and hand-assisted laparoscopic extended posterior sectionectomy was performed. On postoperative day 1, middle hepatic vein (MHV) flow was not detected on ultrasound, and the portal flow was hepatofugal. CT during arterial portography revealed absence of the portal flow to the medial and anterior sections, and remnant liver migration into the subphrenic space. Therefore, we suspected that HVOO was caused by the remnant liver migration and performed redo laparotomy to reposition the remnant liver with suturing of the falciform ligament to the anterior abdominal wall. Postoperatively, contrast-enhanced CT demonstrated that the remnant liver remained in the anatomical position, and the medial and anterior sections were well enhanced.

DISCUSSION

HVOO might occur irrespective of whether the left triangular ligament is preserved. We believe that it is necessary to fix the remnant liver to the abdominal wall in cases with poor venous blood flow confirmed by intraoperative ultrasound. If kinking of the hepatic vein persists, stent insertion should be performed.

CONCLUSION

HVOO after hepatectomy is rare but potentially fatal, and prevention and countermeasures should be discussed.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Tolerogenic Role of Myeloid Suppressor Cells in Organ Transplantation

Myeloid-derived suppressor cells (MDSC) are a heterogeneous population of immature cells of myeloid origin with a specific immune inhibitory function that negatively regulates the adaptive immune response. Since MDSC participate in the promotion of tolerance in the context of organ transplantation, therapeutic strategies that regulate the induction and development of MDSC have been the center of scientist attention. Here we review literature regarding induction of MDSC with demonstrated suppressive function among different types of allografts and their mechanism of action. While manipulation of MDSC represents a potential therapeutic approach for the promotion of donor specific tolerance in solid organ transplantation, further characterization of their specific phenotype, which distinguishes MDSC from non-suppressive myeloid cells, and detailed evaluation of the inhibitory mechanism that determines their suppressive function, is necessary for the realistic application of MDSC as biomarkers in health and disease and their potential use as immune cell therapy in organ transplantation.