Organ and tissue transplantation

CHAPTER 21 Organ and tissue transplantation



Transplantation has developed from an experimental procedure over 50 years ago, to an established therapeutic option for most types of end-stage organ failure. For kidney, heart and liver transplantation, a 1-year graft survival in excess of 85% can be expected.




Organ and tissue donors


Organs and tissues may be obtained from:





Deceased donors



Donation after brain death (DBD)



General criteria


(→ Table 21.1)


TABLE 21.1 General criteria for deceased donors













Brainstem dead with intact circulation
Cause of death:




Exclusions:
Absolute

Relative









As the organ shortage became more severe, it was realized that ideal requirements for selection of organ donors were not feasible. Selection criteria for solid organ donors have therefore recently been relaxed. Organs that long ago would not have been considered for transplantation, are currently being used, bringing in a new class of organ donor termed the ‘expanded criteria donor; ECD’ formerly known as ‘marginal’ donor. ECD is any brain-dead donor aged >60 years or a donor aged >50 with two of the following conditions: a history of hypertension; a terminal serum creatinine level >150 μmol/L, or death resulting from a cerebrovascular accident. Selection of liver and heart and heart/lung donors depends on size match with the recipient. Also, no attempt is made to match other than on blood group compatibility with these organs. HLA typing and cross-matching are not currently undertaken.





Brainstem death


This is covered in Chapter 18, as this is the province of doctors independent of the transplant team.



Living donors




Organ donation and transplantation is governed by the Human Tissue Act 2004, which supercedes the Human Organ Transplant Act 1989. The Human Tissue Authority (HTA) was established in 2005 to implement the provisions of the Act, which came into force in 2006.


Categories of living donation established under the Act are:








Work-up for a living donor


For a genetically related donor, there are three potential histocompatibility matches:





The following sequence is undertaken:











If all of the above are satisfactory, the patient undergoes an angiography (usually CT angiography and urography) to assess the renal vasculature and to check for any abnormality in the excretory system. It is ideal that at least one kidney should have a single artery to anastomose to the recipient’s artery (either end-to-end) to the recipient’s internal iliac artery (or end-to-side) to the recipient’s external iliac artery. Although kidneys with multiple arteries can be used in deceased donor transplantation as they can be removed with a Carrel patch of aorta, clearly this is not the case with a living donor. However, with living donors it is possible to use kidneys with multiple arteries, e.g. two equal sized arteries may be anastomosed in a double-barrelled fashion before being anastomosed to the recipient’s arteries; or a small polar artery may be anastomosed to the side of the main renal artery.


If angiography and urography are normal, the donor recipient pair will be referred to the independent assessor who will send a report to the clinician responsible for the donor and a copy to the HTA indicating that the transplant may go ahead.


Jun 14, 2017 | Posted by in GENERAL SURGERY | Comments Off on Organ and tissue transplantation

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