Renal Transplant

Section: Surgical Oncology Curriculum: Curriculum, page 70

General

• Preferred treatment for many pts with end-stage renal disease
  • Provides better quality of life than dialysis
  • Releases pts from the dietary and fluid restrictions of dialysis and the physical constraints imposed by the need to dialyse
• More cost-effective and probably improves survival
• Frequently the primary cause of ESRF is unknown

Indications

(Causes of ESRF)

• Glomerulonephritis
• Diabetic nephropathy
• Hypertensive nephrosclerosis
• Renal vascular disease
• Polycystic disease
• Pyelonephritis
• Obstructive uropathy
• SLE
• Analgesic nephropathy
• Metabolic diseases
• Oxalosis, Amyloid

Pre-Transplant Evaluation

• All pts formally assessed by MDT team
  • Incl. transplant surgeon and nephrologist
• Significant number are likely considered unsuitable because of major comorbidity, esp. cardiovascular disease
• Nature of the 1° renal disease does not generally affect the decision to proceed to transplantation
• No absolute upper age limit to transplantation
  • However, older patients (over the age of 65 years) are less likely to be considered because of major comorbidity
• Cardiovascular assessment particularly important
  • Cardiovascular disease very common in dialysis population
    • Esp. those with diabetes
  • The major cause of death after transplantation
• Ensure urinary tract is functional and that there is no need for corrective urological surgery
  • Only when there is intractable renal sepsis or very large polycystic kidneys that intrude into both iliac fossae is native nephrectomy required before transplantation
• Make sure able to cope psychologically with transplantation and likely to comply with immunosuppressive therapy
• Contraindications:
  • Pre-existing malignancy (wait 3yr till after treatment)
  • Active infection

Technique of renal transplant

• Placed in the iliac fossa in the experitoneal position
  • Leaving the native kidneys in-situ
• Vascular
  • Donor Renal Vein is anastomosed end-to-side to the External Iliac Vein
  • If from deceased donor, Renal Artery will come with Carrel Patch
    • Patch of Aorta that gives rise to Renal Artery/arteries
    • Anastomosed end-to-side to the External Iliac Artery
  • If the donor renal artery lacks an aortic patch, (living donor transplant)
    • Anastomose the donor artery end-to-end to the recipient Internal Iliac Artery
  • Following completion of the venous and arterial anastomoses, the vascular clamps are removed and the kidney is allowed to reperfuse with blood
• Ureter
  • Kept reasonably short to avoid the risk of distal ischaemia
  • Direct implantation of the ureter into the dome of the bladder
  • Mucosa-to-mucosa anastomosis
  • Followed by closure of the muscular wall of the bladder over the ureter to create a short tunnel
  • JJ ureteric stent left in-situ
    • Reduce the risk of urine leak or early obstruction
  • Before closing, important to check is in satisfactory position
  • Without kinking/torsion

Technical Complications

Vascular

• Incidence of vascular complications low
• Renal Artery Thrombosis (1%)
• Renal Vein Thrombosis is more common (up to 5% of cases)
  • Aetiology often uncertain
    • Sometimes from technical error
  • Presents during the 1st week
    • Sudden pain and swelling at the site of the graft
  • Diagnosis confirmed by Doppler USS
  • Urgent surgical exploration indicated
    • In most cases, transplant nephrectomy is required
  • Can be minimised by giving low-dose heparin or aspirin prophylaxis
• Renal Artery Stenosis (up to 10%)
  • Usually presents late (often years)
  • Get increasing hypertension and decreasing renal function
  • Diagnosed by angiography
  • Best treated by angioplasty
    • If unsuccessful or not technically possible, may need open surgery and vascular reconstruction

Urological

• Urological complications ~ 5% in the early post-transplant period
  • Incidence can be reduced markedly by leaving temporary ureteric stent
• Urinary leaks
  • Result from technical errors at the ureteric anastomosis or ureteric ischaemia
  • Present with discomfort and leakage of urine from the wound
  • Usually require surgical intervention
    • Reimplantation of the ureter into the bladder
    • Or anastomosis of the transplant ureter to the ipsilateral native ureter
• Obstruction of the transplant ureter
  • May occur early or late
  • Causes:
    • Technical error
    • External pressure from a haematoma or lymphocele
    • Ischaemic stricture
  • Presents with painless deterioration of graft function
  • Diagnosed on USS
    • Hydronephrosis and ureteric dilatation
  • Initial treatment is by percutaneous antegrade nephrostomy
    • And sometimes insertion of a stent
  • Some amenable to balloon dilatation
  • Most are best treated by surgical intervention

Lymphocoele

• Usually asymptomatic
• Occasionally large enough to cause ureteric obstruction or oedema of the ipsilateral leg
• Initial treatment
  • Ultrasound-guided percutaneous drainage
• In large or recurrent lymphoceles
  • Repeated instillation of povidone-iodine into the lymphocele cavity by a percutaneous drain
• Surgical intervention may be needed to drain a persistent lymphocele into the peritoneal cavity

Renal Transplant Consent

• Complications
  • Whitebook, page 122

Causes of Graft Dysfunction

Investigation of Graft Dysfunction

• Delayed Graft Function
  • Definition: Need for dialysis post- transplantation as a result of acute tubular necrosis
• Incidence:
  • 30% of heart-beating deceased donors
  • Up to 50% of NHBD kidney transplants
  • Uncommon (< 5%) following living donor transplantation
• Oliguria may be useless indicator as recipients may produce significant urine from their native kidneys
• Delayed function minimised by:
  • Optimizing donor management before kidney procurement
  • Reducing the cold ischaemia time
• Management of Early Graft Dysfunction
  • First step - urinary catheter should be irrigated in case it is occluded by a blood clot
  • Hypovolaemia fixed and CVP monitors
  • Calcineurin inhibitors often withheld/reduced
• Investigations
  • Doppler USS of graft is single most important investigation
    • Allows exclusion of vascular thrombus and urinary obstruction as causes
  • Radionucleotide scan may give information of perfusion and excretion
  • If dysfunction still present after a few days
    • USS-guided biopsy
  • ATN usually resolves within 4 weeks
  • < 5% suffer primary non-function and never regain function

Outcome After Transplant