Pancreas allograft rejection: correlation of transduodenal core biopsy with Doppler resistive index.

Abstract

Neither the absolute level of the RI nor the relative increase was correlated with acute rejection proved at biopsy. Changes in RIs after pancreas transplantation were a poor indicator of acute rejection, but the absolute value of the RI was elevated in cases of chronic rejection.

Pancreas Transplants: Experience with 232 Percutaneous US-guided Biopsy Procedures in 88 Patients

“…In a study of 78 US-guided cystoscopic pancreas allograft biopsies, Nelson et al (8) were unable to show correlation of the resistive index with evidence of acute mild or moderate rejection, which was present at 38 of the biopsies (positive predictive value, 47%; negative predictive value, 43%). However, the mean resistive index was significantly higher in patients with chronic rejection (0.72) than in patients without rejection (0.65), patients with acute mild rejection (0.64), and patients with acute moderate rejection (0.63).…”

“…Grayscale imaging is moderately specific but is not sensitive in depicting abnormalities suggestive of rejection (6). Considerable interest has been expressed in Doppler US imaging, although the role of the resistive index has been validated only in cases of severe acute or chronic rejection (7,8).…”

Pancreatic Transplants: Noninvasive Evaluation with Secretin-augmented MR Pancreatography and MR Perfusion Measurements—Preliminary Results

“…Despite advances in both surgical technique and postoperative management, acute rejection episodes occur in up to 60% of transplanted grafts (2). The following methods are unreliable in the detection of acute rejection: clinical and biochemical analysis, which includes blood levels of pancreatic enzymes; ultrasonography (US), with a sensitivity of 18%-58% and a specificity of 73%-100% (3)(4)(5); and computed tomography (6,7).…”

Contrast-Enhanced Ultrasonography in Pancreas Transplantation

“…In our opinion, this result is not surprising because, in contrast to the kidney, the pancreas lacks a strong capsule, so swelling from rejection does not necessarily lead to increased parenchymal pressure and elevated vascular resistance. This result is substantiated by the largest study with consequent allograft biopsies by Nelson et al (8), who demonstrated that neither the absolute RI nor the relative increase in RI was correlated with acute rejection. The increase in the RI after pancreas transplantation was a poor predictor of acute rejection; however, the absolute value of the RI was elevated in chronic rejection, which agrees with the presence of a higher pressure in the capillary bed of a fibrotic pancreas undergoing chronic rejection.…”