Transplant Surgery Flashcards
Organ or tissue transplanted from one individual to another of the same species
Allograft
Organ or tissue transplanted from one point to another of the same individuals body
Autograft
Graft placed in a site different from that where the organ is normally located e.g. kidney transplant
Heterotopic Graft
What is Human Leukocyte Antigens (HLA)?
Immediate graft destruction (minutes to hours)
- Cause?
- Characteristics?
- Therapy?
Hyperacute Rejection
- Caused by ABO or preformed anti-HLA antibodies (from previous blood transfusion/transplant/pregnancy).
- Characterized by interstitial haemorrhage and intravascular thrombosis.
- The only therapeutic option is to remove the allograft immediately
Graft destruction weeks to months (<6)
- Cause?
- Characteristics?
- Therapy?
Acute Rejection
- Antibody-mediated, cell-mediated or BOTH
- Characterised by mononuclear cells (Cytotoxic T-Cells, B-Cells, natural killer (NK) cells) infiltration of the graft
- Reversible usually with additional immunosuppressives
Graft rejection after first six months as late as years after transplant
Chronic Rejection
- Most common cause of graft failure. Cause not fully understood though alloantibodies major cause
- Results in intimal thickening and fibrosis of graft vessels as well as graft atrophy
- Functional deterioration of the graft over months/years resulting in complete graft failure
Early Causes of Allograft Dysfunction
Primary non-function – irreversible ischaemic damage
Delayed function – reversible ischaemic injury
Hyperacute/Acute rejection
Arterial or venous thrombosis of graft vessels
Drug toxicity
Infection
Mechanical obstruction e.g. ureter/bile duct
Late Causes of Allograft Dysfunction
Chronic rejection
Arterial Stenosis
Recurrence of original disease in graft
Mechanical Obstruction
MOA of Immunosuppression
Examples
Immunosuppressive agents work to prevent rejection by acting at different stages during T-Cell activation
Most regimens include steroids, a calcineurin inhibitor (tacrolimus), and an anti-proliferative agent (azathioprine)
Side Effects of Immunosuppression
Indications for Liver Transplant
- Paracetamol overdose
- Alcoholic liver dx [6/12 abstinence b4 consideration]
- Hepatocellular carcinoma
- HCV
Complications of Liver Transplant
Rejection
Opportunistic infection
SCC of Skin
Contraindications for Liver Transplant
Predicted life expectancy <5 years
Chronic current systemic infection [sepsis]
Continued abuse of alcohol or drugs
Active malignancy
Indications for Cardiac Transplant
Recurrent life-threatening left ventricular arrhythmias despite an implantable cardiac defibrillator, antiarrhythmic therapy, or catheter-based ablation.
End-stage congenital HF with no evidence of pulmonary hypertension.
Refractory angina without potential medical or surgical therapeutic options.
Cardiogenic shock requiring continuous intravenous inotropic therapy.
Refractory cardiogenic shock requiring intra-aortic balloon pump counterpulsation or left ventricular
assist device (LVAD).
Contraindications of Cardiac Transplant
Prognosis Following Heart Transplant
Median survival is 11 years
Primary causes of death:
- Graft Failure
- Opportunistic Infection
- Allograft Rejection
- Allograft Vasculopathy
What is the Left Ventricular Assist Device (LVAD)?
When is it used?
Implantable long-term mechanical circulatory support device that is used in patients with advanced heart failure.
Indications for Lung Transplant
Advanced chronic obstructive pulmonary disease (COPD)
Interstitial lung disease (ILD)
Cystic fibrosis (CF)
Emphysema due to alpha-1 antitrypsin deficiency
Pulmonary arterial hypertension (PAH)
Absolute Contraindications to Lung Transplant
Active Mycobacterium tuberculosis infection
Malignancy in the last two years
Significant dysfunction of other vital organs
Un-correctable bleeding disorder
BMI ≥35 kg/m2
Active tobacco smoking / drug or alcohol dependency
Unresolved psychosocial problems or noncompliance with medical therapy
Prognosis Following Lung Transplant
Median survival for all adult lung transplant recipients is 6.5 years.
Double lung transplant has a higher median survival compared to single lung transplant (7.6 versus, 4.7 years, respectively) however it is felt that this is largely due to the typically younger recipients receiving a double lung transplant.
Indications for Kidney Transplant
Treatment of choice for those with end-stage kidney disease (ESKD. Successful kidney transplant reduces mortality risk and improves quality of life in the majority of patients in comparison to maintenance dialysis. Transplant is also more cost-effective than dialysis.
Surgical Technique of Kidney Transplant
Complications of Kidney Transplant
Acute tubular necrosis
Arterial/Venous thrombosis
Urinary leak/obstruction
Calcineurin inhibitor toxicity
Hyperacute rejection
Later:
- Acute/chronic rejection
- Ureteric obstruction (lymphocele, ureteric stricture)
- Recurrent disease
- UTI
Indications for Pancreas Transplant
Whole-organ pancreas transplantation represents the only therapeutic option for long-term insulin independence
95% of all pancreas transplants are performed in conjunction with a kidney transplant - simultaneous pancreas and kidney transplant (SPK)
Most patients who are evaluated for a pancreas transplant in conjunction with kidney transplantation are type 1 diabetics with concomitant nephropathy
Assessment for SPK Transplant
Simultaneous pancreas and kidney transplant (SPK)
Complications of Pancreas Transplant?
Vascular thrombosis of graft (5%)
Graft pancreatitis
Wound infection (10%)
Duodenal anastomotic leaks
Bladder anastomosis complications
Acute rejection occurs (10-20%) - can occur in isolation or effect both pancreas + Kidney
