Monday, April 25, 2011

Pediatric vs. Adult Transplants

Pediatric transplantation has been a focus of this blog, mainly because I'm especially interested in the stories and unique issues of children who need organ transplants. Many aspects of transplantation are similar between children and adults, but there are some key differences.


Kidney

Percent pediatric: 5%

Indications in adults

  • Diabetes
  • Hypertension
  • Glomerulonephritis

Indications in children

  • Renal dysplasia
  • Posterior urethral valve
  • Focal segmental glomerulosclerosis

Differences in surgical approach

In adults, a kidney transplant is placed in the pelvis and attached to the blood vessels going to the leg (usually the external iliac vessels). For children between 10 kg and 20 kg, the kidney is placed in the abdomen and attached to the main blood vessels in the body (aorta and inferior vena cava). For children under 10 kg, dialysis is generally preferred to a kidney transplant. Young children actually do better with adult kidneys rather than kidneys from other children.


Liver

Percent pediatric: 12%

Indications in adults

  • Hepatitis C infection
  • Alcoholic cirrhosis
  • Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC)

Indications in children

  • Biliary atresia
  • Metabolic diseases
  • Fulminant hepatic failure

Differences in surgical approach

Children can often receive the left lateral lobe of an adult liver, either from a deceased donor (split liver transplant) or a living donor (living donor liver transplant). The left lateral lobe is relatively easier to identify and divide than the right lateral lobe (relatively easier--both are very challenging operations!), and children were the first recipients of partial liver transplants. Children can also receive a whole organ liver transplant from another child.


Heart

Percent pediatric: 13%

Indications in adults

  • Ischemic cardiomyopathy
  • Idiopathic cardiomyopathy

Indications in children

  • Cardiomyopathy (particularly dilated cardiomyopathy)
  • Congenital heart disease (particularly hypoplastic left heart syndrome)

Differences in surgical approach

Patients receiving heart transplants for congenital heart diseases (usually children, sometimes adults) often need a longer segment of donor aorta with the transplant. The native aorta may have been part of the original problem and reconstructed as a "neoaorta" as part of the Norwood operation, so the aorta may also need replaced at the time the heart needs replaced.


Lung

Percent pediatric: 4%

Indications in adults

  • COPD (chronic obstructive pulmonary disease)
  • Cystic fibrosis
  • Idiopathic pulmonary fibrosis

Indications in children

  • Cystic fibrosis
  • Pulmonary hypertension
  • Congenital lung malformations

Differences in surgical approach

The younger and smaller a lung transplant patient is, the more likely they are to receive a double lung transplant and need cardiopulmonary (heart-lung) bypass for the operation. However, the operation is generally the same in children and adults.


Small bowel

Percent pediatric: 57%

Indications in adults

  • Mesenteric ischemia
  • Crohn's disease
  • Intestinal tumors (desmoid and carcinoid)

Indications in children

  • Gastroschisis
  • Necrotizing enterocolitis (NEC)
  • Malrotation and midgut volvulus

Differences in surgical approach

One of the challenges with intestinal transplants is that the donor usually needs to be of a smaller body size than the recipient. Since children needing intestinal transplants are small already (because of their intestinal failure and...because they're children), finding a smaller donor than the recipient can be especially challenging.

7 comments:

GH James said...

The way that you have explained about the different pediatric and adult transplants is very impressive. Good information is shared.

Yang Brand said...

Good information about organs transplantation. i am very impressive by the reading of this blog Thank you

petter said...

Great post Thanks for this entry. Waiting for next one.

Anonymous said...

Hi there - I'm wondering can an adult's heart be put into a child? I've heard that there can be a 2:1 size difference (even 3:1 in some situations http://ejcts.oxfordjournals.org/content/41/2/427.full#ref-2).
But could say a 30 year old man's heart be put into an 8 year old child's body?
Thanks for your help.

Manu Varma said...

Anon 7:25 - I really can't say what the maximum size mismatch is but, generally speaking, size mismatches are a problem, especially for children waiting for heart (or lung) transplants.

PBC mom said...

My 13-year-old daughter was diagnosed via a liver biopsy to have Primary Biliary Cirrhosis (I was tod this is extremely rare) and will need a liver transplant from a cadaver. How do they exclude a person as a candidate for a living donor transplant?

Manu Varma said...

There are many possible reasons, but in general you get less donor tissue from a living donor transplant since the donor still needs to be left relatively more "whole" That is, you can't safely take out too much tissue from the donor, but obviously for a deceased donor there's no worry. With PBC, she may need more tissue than usual to reconstruct the bile duct, and they may feel that this can't be done safely with a living donor liver. Of course, this is all my general guess and you should ask her transplant doctors exactly why...they should definitely have a reason and be able to share it with you.