Two kidney-transplant women with therapy-resistant hypertension: diagnostic error of a renal artery stenosis

Color duplex sonography in severe transplant renal artery stenosis: a comparison of end-to-end and end-to-side arterial anastomoses

OBJECTIVE

The aim of this study was to investigate differences in Doppler parameters between severe transplant renal artery stenosis (TRAS, arterial lumen reduction >80%) with end-to-end (EE) arterial anastomosis and that with end-to-side (ES) arterial anastomosis.

METHODS

We retrospectively reviewed color duplex sonography (CDUS) and digital subtraction angiography (DSA) images in 38 patients with severe TRAS (19 cases with EE and 19 cases with ES) between January 1, 2000, and December 31, 2006. Doppler parameters were analyzed, including peak systolic velocity (PSV) in the iliac artery, PSV at the arterial anastomosis, PSV in the transplant renal artery, PSV ratio of the stenotic artery/artery proximal to the stenosis, and acceleration time (AT) in the artery distal to the stenosis (in the intrarenal artery). All 38 cases with severe TRAS were initially diagnosed with CDUS and confirmed by DSA.

RESULTS

There were significant differences in PSV in the stenotic artery (P<.01), PSV in the iliac artery (P<.001), and PSV ratios of stenotic artery/artery proximal to the stenosis (P<.001) between arterial anastomosis of EE and that of ES. There was no statistically significant difference in AT in the intrarenal artery between the two types of anastomosis (P>.05).

CONCLUSION

Significantly different PSVs in the stenotic artery, the iliac artery, and the PSV ratio between EE and ES arterial anastomoses should be considered in the interpretation of CDUS when screening for severe TRAS. Different criteria of CDUS need to be established depending on the type of arterial anastomosis in order to improve the accuracy in diagnosing severe TRAS.

Intrarenal color duplex ultrasonography: a window to vascular complications of renal transplants

OBJECTIVE

We analyze and discuss the importance of intrarenal color duplex ultrasonography (CDUS) in the diagnosis and differential diagnosis of vascular complications in renal transplants.

METHODS

We retrospectively reviewed results of CDUS, especially intrarenal CDUS, in 102 consecutive inpatients with vascular complications of renal transplants from January 1, 2000, to December 31, 2006. Correlations between CDUS and magnetic resonance angiography, digital subtraction angiography, surgical findings, and clinical diagnoses were studied.

RESULTS

Abnormal findings on intrarenal CDUS clearly represent vascular complications primarily located at the main renal vessels and intrarenal vessels. In our study, there were 5 cases of false-negative intrarenal arteriovenous fistulas, 1 case of false-positive transplant renal vein thrombosis, and 2 cases of false-negative transplant renal artery stenosis. The accuracy of detecting vascular complications of renal transplants with CDUS was 92% (94/102).

CONCLUSIONS

Intrarenal CDUS is a noninvasive, accurate diagnostic tool that can be administrated portably and is easily repeatable, thereby making it not only a highly valuable imaging technique but also the method of choice in screening and diagnosing vascular complications of renal transplants.