Treatment of choice for end stage renal disease Imaging to establish baseline and diagnosis of potential complications Review common surgical

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2 Treatment of choice for end stage renal disease Imaging to establish baseline and diagnosis of potential complications Review common surgical techniques Review normal appearance Discuss US diagnosis of medical, urological and vascular complications

3 Extraperitoneal RT or LT iliac fossa End to side anastomosis to EIA and EIV Carrell Patch: renal artery and part of the aorta harvested, aorta attaches to EIA Uretero neocystostomy Kobayashi et al. Radiographics 2007

4 Extraperitoneal RT or LT iliac fossa End to side anastomosis to EIA and EIV End to end anastomosis to IIA Uretero neocystostomy Kobayashi et al. Radiographics 2007

5 Gray scale Echotexture Fluid collection, hydronephrosis Color and power Doppler Perfusion Intra renal spectral Doppler Intra renal resistance to flow PSV in main RA and Iliac artery Detect stenoses or occlusions Doppler main RV Detect stenoses or occlusions

6 RI=PSV EDS/PSV Nl: 0.5 to 0.8

7 Power versus color

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9 Day 0 to 7 post op Acute tubular necrosis ATN Hyperacute rejection Renal vein thrombosis (surgical complication) Renal artery occlusion Peritransplant hematoma Graft infection Nixon and al Radiographics 2013;33:1227

10 1 week to 1 month post op Acute rejection Urinary tract obstruction Renal vein thrombosis (post rejection) Urinoma Post biopsy complications Nixon and al Radiographics 2013;33:1227

11 Over 1 month post op Acute rejection Chronic rejection Calcineurin inhibitor toxicity Ureteral obstruction Lymphocele Renal artery stenosis Post biopsy complications Post transplant lymphoproliferative disorder Nixon and al Radiographics 2013;33:1227

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13 Delayed graft function Need for dialysis within 1 week after TX Non specific imaging findings Increase impedance to flow in capillary bed Elevated RI >=0.8 Enlarged TX with loss of cortico-medullay differentiation Timing is everything Biopsy may be needed for specific diagnosis

14 Acute tubular necrosis

15 Within 1 week post op: Acute tubular necrosis After post op week 1 Acute rejection ATN Calcineurin inhibitors Polyoma virus Severe hydronephrosis Pyelonephritis

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17 Small collections common early post op Hematoma (immediate complication) Urinoma Seroma Lymphocele (late complication) Overlapping appearance: aspiration for final diagnosis if needed May compress TX vessels or ureter

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20 Hypoechoic mass with thick echogenic rim May mimic renal tumor

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23 Critical finding Perinephric hematoma

24 Emergent surgical evacuation of hematoma, large urine output

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27 Critical finding Reversal of flow in Tx arteries Can we find the renal vein?

28 Diagnosis: thrombosed transplant vein Emergent surgery: transplant nephrectomy

29 Catastrophic complication seen in 0.5-4% cases Lack of collateral venous circulation More common in LT iliac fossa TX Surgical complication, diagnosis within hours post op: potential thrombectomy Delayed thrombosis caused by vasculitis secondary to severe acute rejection :transplant nephrectomy Severe venous kink can mimic thrombosis

30 Immediate notification of the transplant team Ominous sign requiring urgent management especially in the immediate post op period Present in 1.2% of studies in 1 series of 5,089 US Look for the renal vein Lockhart & al. AJR 2008;190: 650

31 Timing is everything Early post op period hours Renal vein thrombosis hematoma with Page kidney ATN Hyper acute rejection Within 1 month post op ATN Acute rejection Renal vein thrombosis Delayed occurrence Poor prognostic sign unless there is a treatable surgical lesion: 33-35% graft loss

32 Biopsy: severe acute rejection

33 Post operative edema Kink Stenosis

34 Renal artery thrombosis (< 1% of TX) Catastrophic complication results in loss of the graft Usually immediate post op period

35 Critical finding

36 Right TX nephrectomy: no arterial flow necrotic TX

37 Thrombosis of polar branch Thrombosis of accessory artery

38 Reported in 1 to 16% of cases Worsening renal function and hypertension Bruit over TX Stenosis can be at the anastomosis or distal Color Doppler to identify area of aliasing Doppler spectrum for diagnosis PSV in MRA > cm/s PSV RA/PSV Iliac A > cm/s Polak & al Transplant Proc 2006;38: 131

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42 Renal artery stenosis Kink in the renal artery Size mismatch between small donor artery and larger recipient artery

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44 Urine leak Usually in early post op period (within 4 to 6 weeks) Non specific fluid collection Contrast CT with delayed images or nuclear medicine imaging Urinary obstruction Ischemic urinary stricture Urothelium thickening Non specific finding

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47 Arteriovenous fistulae Iatrogenic: biopsy needle pierces arterial and venous wall Most are asymptomatic and resolve spontaneously Seen 1 week after biopsy in up to 50% pts, uncommonly significant clinically Hematoma Look for active extravasation Pseudo aneurysm alone or with arteriovenous fistula

48 Asymptomatic patient

49 Hematuria after renal Tx biopsy

50 Arteriovenous fistula

51 Post biopsy hematoma with active extravasation

52 Pseudoaneurysm

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55 BX: drug toxicity Post biopsy AVF

56 Results from immunosuppression Renal TX: <1% pts affected B lymphocyte proliferation Epstein Barr virus mediated Soft tissue masses usually extranodal GI tract, CNS, TX itself Diagnosis: biopsy Management Modulation of immunosuppression Chemotherapy if aggressive PTLD

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58 Ultrasound with Doppler plays a critical role in management of patients with renal transplant. Timing is everything Baseline US Know surgical anatomy, talk to the transplant surgeon