Hannah Blanton;
Medical University of South Carolina
Madelene Lewis;
Medical University of South Carolina
Abid Irshad;
Medical University of South Carolina
Background
Renal transplants are the most common worldwide solid organ transplant. Ultrasound is the primary imaging modality to evaluate renal transplants as well as for image-guided procedures. Renal transplant complications are often categorized into early, intermediate, and late depending on occurrence time after surgery. Complications may include iatrogenic, perinephric fluid collections, vascular complications, diminished graft function, infection, and malignancy.
Educational Goals / Teaching Points
The educational goals of this exhibit are to review the surgical technique for renal transplantation, identify which complications occur early/intermediate versus late in time course, and review the common imaging appearance of these complications.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Renal transplants may be right or left sided or both in cases of en bloc kidneys. The most common placement is the right iliac fossa. The left iliac fossa is often used for a second renal transplantation or the case of a combined kidney-pancreas transplant. Vascular anatomy may vary significantly. Typically, the donor artery is anastomosed end to side to the recipient external iliac artery and the donor renal vein is usually anastomosed to the recipient external iliac vein end to side. The transplant ureter can be anastomosed to the recipient urinary bladder often at the dome (ureteroneocystostomy) or to the recipient’s native ureter using end to side anastomosis (ureteroureterostomy). It can be helpful to categorize renal transplant complications as early, intermediate, or late depending on time since surgery. The major categories of complications include iatrogenic, perinephric fluid collections, vascular, urinary, diminished renal function, infection, and malignancies. Iatrogenic complications include allograft compartment syndrome and postbiopsy AVF and pseudoaneurysm. Perinephric fluid collections can be hematoma, urinoma, abscess, or lymphocele. Vascular complications may occur any time after transplantation including renal artery stenosis, renal artery thrombosis, renal vein thrombosis, and renal vein stenosis. Renal transplant patients can develop ureteral obstruction and have increased risk for urothliasis. Diminished renal function can be related to acute tubular necrosis, rejection, or drug toxicity. There are also infectious and neoplastic complications.
Conclusion
Ultrasound is the primary imaging modality to evaluate renal allografts as it allows for prompt and accurate diagnosis. It is helpful to consider the time frame postsurgery in the imaging evaluation of complications. Radiologists should be familiar with the anatomy and imaging findings of healthy transplants and potential complications.
