Why is it possible –

1. The liver has tremendous reserve and up to 75% can be removed from the donor without any adverse effect to the donor.
2. Functionally the transplanted liver starts working immediately and by the end of 3^rd week post transplant have a normal function biochemically. For the donor there is minimal change in liver function parameters biochemically but are inconsequential and this also reverts back to normal after 2-3 days.
3. The liver has an ability to grow, both by increasing the size as well as the number of cells, so that it reverts back to nearly 90% of its desired size for both the donor and the recipient within 6 weeks.

Why we need LDLT? (in Nutshell)

• Critical shortage of organs ( Donation rates approx 0.6 PPM)*
• Huge gap between demand and supply (patients waiting for liver 40k-50k.  Liver transplant 1700-1800/yr  ( approx estimates*).
• Long wait times ( sick pts/HCC/ high MELD can’t wait)
• High drop out rates or wait list mortality.
• Size mismatch (kids and small patients, of course split is an option)
• Saves extra life by giving away organs from pool ( helps pt without LDLT option)

* Organ retrieval and banking organzation-AIIMS

Principle of Living donor liver transplant

Double Equipoise:  “Balances between   donor risk and recipient benefit”

• Donor Mortality rates  1%- 0.3%
• Recipient survival rates  > 90%
• Ability to regenerate!
• All the rules of DDLT may not be applicable ( private property)

Living donor liver transplant: Who can become a living donor? (Requirements)

• Donor close relative of recipient
• Between 18-55 yrs (up to 60yrs in other Asian nations)
• Blood group matching only ( NO HLA or Rhesus matching required)
• Mentally and medically (No DM, uncontrolled HTN, malignancy etc) fit to donate.
• Good BMI ( not obese or overweight)
• No coercion or financial benefits

Living donor liver transplant versus deceased (cadaveric) liver transplant

Liver transplantation (LT) is the best treatment for patients with end-stage liver disease (cirrhosis). Living donor LT (LDLT) has developed as an alternative to deceased donor LT (DDLT) in order to overcome the critical shortage of deceased organ donations, particularly in India (Asia). The retrospective A2ALL cohort study concluded that graft survival did not differ significantly for recipients of LDLT compared with DDLT once centres have sufficient experience with LDLT. LDLT can shorten the waiting time and lower the dropout rate (hepatocellular cancer). One meta‐analyses revealed comparable patient survival rates and no significant differences in the recurrence rates between LDLT and DDLT recipients. Another meta‐analysis provided evidence of lower disease‐free survival (DFS) after LDLT compared with DDLT for HCC. In 2014, meta-analysis concluded that biliary complications, vascular complications, and retransplantation occur more frequently in LDLT recipients because of its technical complexity, but the biliary complication rate appears to decrease dramatically as a centre gains greater LDLT experience. Recent retrospective review revealed superior survival rates in LDLT compared to DDLT. The study also concluded comparable biliary/vascular complications and early reoperation rate in both the groups. Hospital cost were also 30% lower in LDLT group. Various preoperative optimisations including nutritional treatment can also be planned for both the donor and recipient in LDLT. Unfavourable characteristic associated with LDLT includes donor risk. Donor morbidity is not uncommon and the donor mortality rate is around 0.1–0.3%. Hence the principle of double equipoise in LDLT, which balances the donor risk and recipient benefits.   LDLT means recipient receive partial graft  (65%-70% of the whole liver) , hence it may not meet the metabolic demands of a very huge or a very sick patient. However liver has the ability to regenerate to meet the metabolic demands of the given recipient. Since the organs in LDLT scenario are private property, rules of listing applicable for DDLT recipients doesn’t apply. Hence the waiting period is not only minimised it helps optimisation of recipients too which translates into improved outcomes.  DDLT on the other hand has certain set of rules (listing criteria) to be followed for example the HCC recipient needs to be within predefined criteria ( MILAN criteria), minimum required MELD criteria and certain types decompensation ( hepatic encephalopathy, hepato-pulmonary syndrome etc). Quality of organs cannot be controlled in DDLT scenario, however in LDLT that is a viable option.  Overall from the available experience and evidence it can be safely concluded that both the options are equally good and share its own set of problem. However from patient perspective early transplant can improve outcomes and reduce the cost of treatment.