Imaging of intestinal transplantation

Intestinal and Multivisceral Transplantation: Complications

Advancements in immunosuppression protocols, surgical techniques, and postoperative care in the last few decades have improved outcomes of intestinal transplant patients. Normal immediate postoperative imaging appearance can simulate pathology. Intestinal transplant recipients are prone for several postoperative complications due to the complex surgical technique, which involves multiple anastomoses, and immunogenic nature of the allograft intestine. Imaging plays a crucial role in detection of several major complications including infectious, immunologic, vascular, gastrointestinal, pancreaticobiliary, genitourinary, and neoplastic complications. The awareness of the posttransplant anatomy and normal imaging appearances helps radiologists anticipate and accurately detect posttransplant complications.

Intestinal transplantation: an update

PURPOSE OF REVIEW

The role of intestinal transplant has expanded in recent years and is no longer only considered for patients with no other options remaining. 5 year survival in high-volume centres is over 80% for certain graft types. The aim of this review is to update the audience on the current state of intestinal transplant, with a focus on recent medical and surgical advances.

RECENT FINDINGS

There has been a greater understanding of the interplay and balance of host and graft immune responses, which may facilitate individualized immunosuppression. Some centres are now performing 'no-stoma' transplants, with preliminary data showing no adverse effects from this strategy and other surgical advances have lessened the physiological insult of the transplant operation. Earlier referrals are encouraged by transplant centres, such that vascular access or liver disease has not progressed too much to increase the technical and physiological challenge of the procedure.

SUMMARY

Clinicians should consider intestinal transplant as a viable option for patients with intestinal failure, benign unresectable abdominal tumours or acute abdominal catastrophes.

Graft assessment for acute rejection after intestinal transplantation: current status and future perspective

Intestinal transplantation has since its inception evolved as a lifesaving treatment option for patients with irreversible intestinal failure who can no longer be sustained on parenteral nutrition. Improvement in short-term survival after transplantation has also justified the expansion of treatment indications. Unfortunately, success is somewhat limited by a plateau observed in long-term survival. The reason for this sub-optimal long-term result experienced in this cohort may in part be attributed to the intestinal graft with the lymphoid content it carries inflicting the host with multiple complications where acute cellular rejection is one of the most common causes for graft loss. Graft monitoring is for this reason of paramount importance and detection of rejection at an early stage essential to enable early instigation of treatment and successful reversal of the pathology. Due to the challenges in diagnosing acute rejection with a noninvasive marker we are still limited to a surveillance protocol using endoscopy and biopsies for the diagnosis of rejection. The purpose of our paper is to review the adequacy of different methods in monitoring the graft for acute rejection using biomarkers, endoscopy and imaging. In conclusion, the evidence base continues to support the use of histology for the diagnosis of acute rejection. The role of biomarkers are still debatable, although markers such as calprotectin might be beneficial in excluding an ongoing process.