Renal transplant evaluation: multimodality imaging of post-transplant complications

Transplantation for type 1 diabetes: radiologist's primer on islet, pancreas and pancreas-kidney transplantation imaging

Whole-organ pancreas, pancreatic-kidney and islet transplantation are surgical therapeutic options for the treatment of type 1 diabetes. They can enable effective glycemic control, improve quality of life and delay/reduce the secondary complications of type 1 diabetes mellitus. Radiologists are integral members of the multidisciplinary transplantation team involved in these procedures, with multimodality imaging serving as the mainstay for early recognition and management of transplant related complications. This review highlights the transplantation procedures available for patients with type 1 Diabetes Mellitus with a focus on the imaging appearance of transplantation-related complications.

Prophylactic Peri-Nephric Drain Placement in Renal Transplant Surgery: A Systematic Review and Meta-Analysis

Renal transplantation is common worldwide, with >25,000 procedures performed in 2022. Usage of prophylactic perinephric drains is variable in renal transplantation; drains are associated with risks, and there is a lack of consensus regarding benefit of routine drain placement in these patients. This meta-analysis assessed whether prophylactic drainage reduced need for reintervention postoperatively. This systematic review and meta-analysis was carried out using the Preferred Reporting Items in Systematic Reviews and Meta-Analysis, and prospectively registered on PROSPERO. Summary statistics for outcomes of interest underwent meta-analyses to a confidence interval (CI) of 95% and are presented as Forest Plots for Odds Ratio (OR). A systematic literature search in June 2023 revealed 1,540 unique articles across four databases. Of these, four retrospective cohort studies were selected. Meta-analysis of three studies showed no significant reduction in reintervention rate with pre-emptive drain placement, OR = 0.59 (95% CI: 0.16-2.23), p = 0.44. Meta-analysis did not show a significant reduction in perinephric collections with prophylactic drain insertion OR = 0.55 (95% CI: 0.13-2.37), p = 0.42. Finally, there is not good evidence that drain placement reduces superficial wound complications or improves 12-month graft survival. Further work is needed, including well-designed, prospective studies to assess the risks and benefits of drain placement in these patients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023422685, Identifier PROSPERO CRD42021255795.

Thermoablative Treatment of De Novo Tumor in Kidney Allograft

BACKGROUND

The overall cancer risk increases in transplant patients, including in kidney allografts. This study aimed to analyze the outcome of patients with kidney allograft malignant tumors who underwent percutaneous thermal ablation.

METHODS

We included 26 renal allograft tumors, including 7 clear-cell renal cell carcinoma (RCCs), 16 papillary RCCs, 1 clear-cell papillary RCC, and 2 tubulocystic RCCs, treated in 19 ablation sessions. Outcomes of thermal ablation therapy were assessed, including technical success, adverse events, local tumor progression, development of metastases, survival after thermal ablation, and changes in renal function.

RESULTS

Success rate was achieved in all ablation sessions (primary success rate: 96%; secondary success rate: 100%). No adverse events were observed in grades 3, 4, or 5. The median follow-up period was of 34 mo (15-69 mo). Two patients died during follow-up from a cause independent of renal cancer. The median decrease in estimated glomerular filtration rate 1 y after procedure was -4 (interquartile range, -7 to 0) mL/min/1.73 m 2 . One patient returned to dialysis within the year of the procedure.

CONCLUSIONS

Percutaneous thermal ablation shows convincing results for treating malignant renal graft tumors and should be a useful treatment option. The shorter hospitalization time, the advantage of avoiding a potentially challenging dissection of the transplant, and the excellent preservation of allograft function appear encouraging to extend this indication.

Diagnostic value of contrast-enhanced ultrasound (CEUS) in kidney allografts - 12 years of experience in a tertiary referral center

BACKGROUND

B-Mode and Doppler ultrasound are standard diagnostic techniques for early postoperative monitoring and long-term follow-up of kidney transplants. In certain cases, contrast-enhanced ultrasound (CEUS) is used to clarify unclear Doppler findings.

OBJECTIVE

To investigate the diagnostic performance of CEUS in the workup of renal allograft pathologies.

METHODS

A systematic search for CEUS examinations of renal transplants conducted in our department between 2008 and 2020 was performed using the following inclusion criteria: i) patient age ≥18 years and ii) confirmation of diagnosis by biopsy and histopathology, imaging follow-up by CEUS, contrast-enhanced computed tomography (ceCT), contrast-enhanced magnetic resonance imaging (ceMRI), or angiography, or intraoperative findings. Exclusion criteria were: i) CEUS performed in the setting of a study and ii) CEUS for other indications than dedicated renal transplant examination. Statistical analysis was performed separately for subgroups with different indications (focal vs non-focal).

RESULTS

Overall, 78 patients were included in the statistical analysis, which revealed high sensitivity (92.2%, 95% -confidence interval [CI] 81.5-96.9%) and high specificity (88.9%, 95% -CI 71.9-96.1%) of CEUS.

CONCLUSIONS

The high diagnostic performance demonstrated here and the superficial location of kidney allografts advocate the additional use of CEUS in the follow-up of renal transplant recipients.