Intestinal and Multivisceral Transplantation: Complications

Endovascular Treatment of a Multi-visceral Aortic Conduit Blowout With Parallel Stent Grafts and Coils

Multi-visceral transplantation (MVT) is a complex surgical procedure involving the transplantation of multiple abdominal organs as a single unit, typically used as bailout treatment of patients with devastating abdominal pathologies. Due to the complexity of the procedure, major and even life-threatening complications can happen. Vascular complications, including anastomotic breakdowns or pseudoaneurysms due to infections, can be universally lethal. Open surgical repair is often not an option due to the hostile operative field. We report a case of endovascular salvage of multi-visceral aortic conduit blowout utilizing parallel stent grafts and coils without sacrifice of the transplanted viscera. This combination can successfully control bleeding and maintain graft perfusion in this rare but devastating complication.

Plasticity of intragraft alloreactive T cell clones in human gut correlates with transplant outcomes

The site of transition between tissue-resident memory (TRM) and circulating phenotypes of T cells is unknown. We integrated clonotype, alloreactivity, and gene expression profiles of graft-repopulating recipient T cells in the intestinal mucosa at the single-cell level after human intestinal transplantation. Host-versus-graft (HvG)-reactive T cells were mainly distributed to TRM, effector T (Teff)/TRM, and T follicular helper compartments. RNA velocity analysis demonstrated a trajectory from TRM to Teff/TRM clusters in association with rejection. By integrating pre- and post-transplantation (Tx) mixed lymphocyte reaction-determined alloreactive repertoires, we observed that pre-existing HvG-reactive T cells that demonstrated tolerance in the circulation were dominated by TRM profiles in quiescent allografts. Putative de novo HvG-reactive clones showed a transcriptional profile skewed to cytotoxic effectors in rejecting grafts. Inferred protein regulon network analysis revealed upstream regulators that accounted for the effector and tolerant T cell states. We demonstrate Teff/TRM interchangeability for individual T cell clones with known (allo)recognition in the human gut, providing novel insight into TRM biology.