Population Covered By The Guidance
This pathway provides guidance on the imaging of adult patients with acute renal transplant dysfunction following surgery.
Date reviewed: January 2012
Date Published: January 2012
- A Doppler ultrasound is indicated in all patients with allograft dysfunction
- Sonography is useful in diagnosing thrombosis of the renal artery or vein, urinary obstruction, urine leaks and for biopsy
- Nuclear scintigraphy can give information regarding the function of a transplanted kidney
- Renal biopsy is useful in transplanted kidneys deemed to have adequate blood flow but poor function looking for acute rejection
- Arterial obstruction demonstrated on ultrasound, can further be managed with renal angiography
References are graded from Level I to V according to the Oxford Centre for Evidence-Based Medicine, Levels of Evidence. Download the document
- O'Neill WC, Baumgarten DA. Ultrasonography in renal transplantation. Am J Kidney Dis. 2002;39(4):663-78. (Review article)
- Tublin ME, Dodd GD III. Sonography of renal transplantation. Radiol Clin North Am. 1995;33:447-59. (Review article)
- Gottlieb Th, Voci SL, Cholewinski SP, et al. Sonography: a useful tool to detect the mechanical causes of renal transplant dysfunction. J Clin Ultrasound. 1999;27:325-33. (Level II/III evidence)
- Kelcz F, Pozniak MA, Pirsch JD, et al. Pyramidal appearance and resistive index: insensitive and nonspecific sonographic indicators of renal transplant rejection. AJR Am J Roentgenol. 1990;155:531-5. (Level II evidence). View the reference
- Turetschek K, Nasel C, Wunderbaldinger P, et al. Power Doppler versus color Doppler imaging in renal allograft evaluation. J Ultrasound Med. 1996;15:517-22. (Level II evidence). View the reference
- Claudon M, Lefevre F, Hestin D, et al. Power Doppler imaging: evaluation of vascular complications after renal transplantation. AJR Am J Roentgenol. 1999;173:41-6. (Review article)
- Grenier N, Douws C, Morel D, et al. Detection of vascular complications in renal allografts with color Doppler flow imaging. Radiology. 1991;178:217-23. (Level III evidence)
- Taylor KJW, Morse SS, Rigsby CM, et al. Vascular complications in renal allografts: detection with duplex Doppler US. Radiology. 1987:162:31-8. (Level III evidence)
- Sidhu MK, Gambhir S, Jeffery RB Jr, et al. Power Doppler imaging of acute renal transplant rejection. J Clin Ultrasound. 1999;27:171-5. (Level III evidence)
- Woolfson RG, Neild GH. The true clinical significance of renography in nephro-urology. Eur J Nucl Med. 1997;24(5):557-70. (Review article)
- Cofan F, Gilabert R, Oppenheimer F et al Duplex-Doppler ultrasound and MAG-3 scintigraphy in the evaluation of acute tubular necrosis after kidney transplantation Transplant Proc. 1997;29:1376-7. (Level II evidence). View the reference
- Wilczek HE. Percutaneous needle biopsy of the renal allograft. Transplantation. 1990;50:790-7. (Level III evidence)
Further Reading
- Baxter GM. Ultrasound of renal transplantation. Clin Radiol. 2001;56:802-18. (Pictorial review)
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| SYMBOL | RRL | EFFECTIVE DOSE RANGE |
|---|---|---|
| None | 0 | |
| Minimal | < 1 millisieverts | |
| Low | 1-5 mSv | |
| Medium | 5-10 mSv | |
| High | >10 mSv |
Disclaimer
Status Of Recommendations Each pathway is designed to assist clinicians in situations when faced with a large array of possible diagnostic tests and examinations. However, it is recognised that diagnostic practice may differ from a particular pathway depending on local availability of equipment and expertise, as well as the experience of individual clinicians. Therefore each pathway is neither a rigid set of rules, nor a substitute for clinical assessment, and individual patient circumstances should always be considered.
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Acute Renal Transplant Dysfunction
Acute Renal Transplant Dysfunction
There are many causes of delayed graft function following allograft transplantation
- Renal failure immediately following allograft transplantation is called ‘Delayed Graft Function’ (DGF). This refers to oliguria or the requirement of dialysis in the immediate post-operative period
- The major causes of DGF are
- Acute tubular necrosis (ATN)
- Acute antibody mediated rejection
- Rejection superimposed on ischemic ATN
- Urinary tract obstruction
- Vascular occlusion
- Atheroemboli
- Segmental cortical infarction
- The role of imaging modalities is to help in the differentiation between these causes of DGF. Doppler ultrasound and nuclear medicine scintigraphy are useful initial investigations
Doppler Ultrasound
Doppler Ultrasound
Indicated in almost all patients with allograft dysfunction or urinary tract abnormalities
- Indicated in almost all patients with allograft dysfunction or urinary tract abnormalities ,
- Sensitivity approaching 100% in diagnosing urinary tract obstruction, a common cause of acute allograft failure
- US findings in acute renal transplant dysfunction include swelling, enlarged pyramids, decreased cortico-medullary differentiation and Doppler changes such as increased resistive index. However these findings are non-specific and can be seen in acute tubular necrosis and cyclosporin toxicity ,
- In the immediate postoperative period, sonography is useful in diagnosing surgical causes of DGF such as thrombosis of the renal artery or vein, extrinsic or intrinsic causes of urinary tract obstruction and urine leaks ,
- Colour and power Doppler provide useful information regarding blood flow to the kidney and vascular complications in renal allografts ,
- In occlusion of the main renal artery by thrombus, Doppler US demonstrates a lack of arterial flow distal to the occlusion and absence of venous flow ,,,
- Renal vein thrombosis presents with marked elevated resistive index and reversal of arterial flow in diastole together with absent venous signals ,
- Useful for
- Guiding percutaneous biopsy
- Diagnosing fluid collections in patients with graft pain or ipsilateral leg oedema
- Measurement of residual bladder volume
- Identification of ureteral stents
- Limitations - lacks specificity (false positives for urinary tract obstruction may result if collecting system of kidney is not examined when bladder is empty, since full bladder may cause dilatation of transplant collecting system)
Radionuclide Imaging (Renogram)
Radionuclide Imaging (Renogram)
Allows assessment of graft perfusion, function and excretion. The most common finding is normal perfusion with increased retention and little excretion indicating acute tubular necrosis
- Allows assessment of graft perfusion, function and excretion. The most common finding is normal perfusion with increased retention and little excretion indicating acute tubular necrosis. The grade of ATN on nuclear scintigraphy is correlated with graft survival
- Class I ATN – delayed transit time but with excretion
- Class II ATN – no excretion phase
- Class III ATN – low uptake and flat curve of tracer
- In acute antibody mediated rejection there is absent perfusion and function
- Useful in the diagnosis of obstruction and cortical scar formation in the renal transplant but its contribution to the diagnosis of parenchymal dysfunction remains unproven
Renal Angiogram
Renal Angiogram
Useful in confirming and possibly treating stenoses in patients with positive US or those with inadequate or equivocal US when clinical suspicion is strong
- Useful in confirming and possibly treating stenoses in patients with positive US or those with inadequate or equivocal US when clinical suspicion is strong ,,
Renal Biopsy
Renal Biopsy
"Gold Standard" in the diagnosis of acute renal transplant rejection
- "Gold Standard" in the diagnosis of acute renal transplant rejection ,,
- Disadvantages - invasive procedure with a risk of complications
