# Sinusoidal Obstruction Syndrome Post-allogeneic Transplantation: A Complex Multisystem Challenge

## TL;DR

A patient with leukemia developed severe sinusoidal obstruction syndrome after a stem cell transplant, highlighting the complex challenges in diagnosis and treatment.

## Contribution

This case study emphasizes the need for early intervention and multidisciplinary care in managing severe post-transplant sinusoidal obstruction syndrome.

## Key findings

- Defibrotide treatment led to reduced bilirubin levels but was interrupted due to complications.
- Hepatorenal syndrome and respiratory failure developed despite critical care interventions.
- The case underscores the importance of tailored risk-benefit assessments and early management of SOS.

## Abstract

We present the case of a 41-year-old female with chronic myeloid leukemia (CML) in blast crisis who underwent haploidentical allogeneic stem cell transplantation. Her post-transplant course was complicated by neutropenic sepsis and mucositis, followed by the development of sinusoidal obstruction syndrome (SOS) on post-transplant day (POD) 10, evidenced by rising hyperbilirubinemia (peak 22.2 mg/dL) and significant weight gain primarily due to fluid retention. Imaging confirmed hepatosplenomegaly and portal vein dilation, leading to the SOS diagnosis.

Defibrotide was initiated on POD 16, leading to a progressive decline in bilirubin levels (from 22.2 mg/dL to 2.4 mg/dL by POD 22), suggesting a therapeutic response. However, thrombocytopenia and gastrointestinal hemorrhage necessitated dose interruptions. Supportive care included fluid management, albumin infusions, and diuresis, but hepatorenal syndrome developed, requiring continuous renal replacement therapy (CRRT). On POD 27, she developed acute hypoxic respiratory failure, requiring a high-flow nasal cannula and later vasopressor support for worsening hemodynamic instability. Despite intensified critical care measures, including broad-spectrum antimicrobials and transfusion support, her condition deteriorated, leading to progressive multiorgan failure and transition to comfort care on POD 34.

This case highlights the diagnostic and therapeutic challenges of severe post-transplant SOS, emphasizing the need for early intervention, a tailored risk-benefit assessment of defibrotide, and multidisciplinary critical care strategies for high-risk patients.