RENAL TRANSPLANT

RENAL TRANSPLANT : 

RENAL TRANSPLANT

History : 

History First successful transplant – 1954 2 year survival rate is >90% at present

Eligible Patients : 

Eligible Patients Patient must have evidence of endstage renal failure, defined as current or impending dialysis dependency. Indications Glomerulonephritis (55%) Diabetic nephropathy (20-30%) Chronic pyelonephritis (8%) Polycystic kidney disease (5%)

Contraindications : 

Contraindications Systemic malignancy Active infection Seropositivity, i.e., HIV, Hepatitis B Noncompliant patient

Renal Allograft : 

Renal Allograft Allograft – Any tissue transplanted from one human to another. Renal allograft harvested: From living, related donor From brain dead donor (cadaveric)

Surgical Technique : 

Surgical Technique Surgical implantation into right or left iliac fossa, most often on the right. Generally, donor kidney is flipped anteroposteriorly before being placed in the iliac fossa to facilitate the vascular anastomosis and ensure correct orientation of the ureter.

Vascular Hookup : 

Vascular Hookup Due to its lower incidence of renal artery stenosis, an end renal artery – to – side external iliac artery anastomosis is preferred over end renal artery – to – end internal iliac artery. End – to – side anastomosis between the renal vein and the external iliac vein.

Slide 9: 

A – end-to-side anastomosis, allograft artery to external iliac artery B – end-to-end anastomosis, allograft artery to internal iliac artery C – Carrell’s patch from the donor aorta. Utilized for multiple renal arteries or for a small renal artery from a child.

Technical Considerations : 

Technical Considerations Superficial Anatomic detail is clearer Cortex may appear more echogenic Enlarges Adults, volume typically increases up to 30% May increase up to 200% with discrepancy of donor to recipient size Dilatation of collecting system Slight hydronephrosis is common

Rejection : 

Rejection Sonographic Manifestations Increased allograft size Increased cortical echogenicity Increased prominence of renal pyramids Focal cortical hypoechoic regions Decreased echogenicity of renal sinus Increased flow resistance in parenchymal arteries

Rejection : 

Rejection Acute Chronic

Increased Flow Resistance : 

Increased Flow Resistance Zwiebel, Pg. 469 RI ≥0.7 Renal Transplant Imaging and Intervention RI >0.9

Perigraft Fluid Collections : 

Perigraft Fluid Collections Seroma & Hematoma Abscess Urinoma Lymphocele Zwiebel, pg. 471 Table 30-3

Lymphocele : 

Lymphocele

Vascular Complications : 

Vascular Complications Arterial Stenosis Most common vascular complication, ~10% of transplant patients Early – most often a technical defect Later – generally due to intimal hyperplasia Vascular Occlusion – typically immediate, <1 week Renal artery <1% of all renal transplants Typically appears acutely Technical defect Rejection Renal vein <1% of transplant patients

Diagnostic Criteria : 

Diagnostic Criteria Normal Flow Parameters Velocity: 80 – 118 cm/s Volume flow: 346 – 422 cc/minute Abnormal Flow Parameters: stenosis >50–60% Velocity: >190 cm/s with poststenotic turbulence Velocity: ≥250 cm/s Systolic velocity ratio >3

Renal Artery Stenosis : 

Renal Artery Stenosis

Renal Artery Stenosis : 

Renal Artery Stenosis

Renal Vein ThrombosisDoppler Flow Characteristic : 

Renal Vein ThrombosisDoppler Flow Characteristic

Vascular Complications : 

Vascular Complications Arteriovenous Fistula Generally due to trauma from renal biopsy Pseudoaneurysm Generally due to trauma from renal biopsy May be at arterial or venous anastomosis

A-V Fistula : 

A-V Fistula

Pseudoaneurysm : 

Pseudoaneurysm

Pseudoaneurysm : 

Pseudoaneurysm

Sources : 

Sources Introduction to Vascular Ultrasonography, 4th Ed., Zwiebel, Chapter 30 Renal Transplant Imaging and Intervention, Zwirewich www.radiology.co.uk/srs - x/tutors/renaltx/ren1.htm