Donor needs to be from the family (1^st or 2^nd degree) – mother, father, son, daughter, sister, brother, spouse, cousins, maternal & paternal Uncles, grand parents if they <60 years of age.

Donor should be blood group compatible – table below is a good guide for the same

Blood group compatibility chart

Should be a healthy individual or with controlled co-morbidities, between the age of 18–60 years, who is in sound state of mind.

Should not be overweight – Body Mass Index >30, or pregnant.

Those consuming alcohol on regular basis are not suitable; smokers should stop smoking ideally 6 weeks before surgery.

The donation should be voluntary and should not under coercion. Donor are counselled adequately before and after investigations and can voluntarily withdraw consent at any time during and after the investigations if they feel they are being coerced into doing so.

Part of the liver to be removed and regeneration:

In a person having a normal functioning liver, 75% of liver can be safely removed and only 25% of remnant liver is required for life. For the safety of the donor we strive to have a remnant of at least 30%. In an adult patient generally right lobe is taken as the graft and it constitutes nearly 60% of the liver volume, while left lobe is about 40% of whole liver volume and is generally used as graft in small size adults or in children. For children, only part of left lobe (left lateral segment) is removed as graft. Liver has a unique capacity to regenerate and hence the remnant liver in the donor grows back to normal size in 2-3 months. The same fate happens to the implanted graft liver in the recipient. This process of regeneration starts immediately after surgery and about 70-80% of the liver regeneration is complete as early as 2 weeks after surgery. Remaining regeneration occurs slowly over a period of 8-12 weeks.

Once a donor is identified, he/she is thoroughly investigated. Donor is seen by the cardiologist, pulmonologist, gynaecologist (for female donors), and anaesthesiologist before planning for surgery.

The donors are assessed in multiple steps so that if they are found to be unsuitable due to any medical conditions they are not investigated further for donation and are advised for remedial measure for their medical conditions.

Patients who require urgent liver transplant, their donors are evaluated in one step after confirming their blood group because we do not want to waste precious time before transplant. However, final decision is taken once all the reports are ready and acceptable. 

Normally the workup of the donor can take 2-3 days which may or may not require hospitalization but this can be hastened to 6-10 hours in case of patients of FHF.

Donor assessment involves three steps:

• First step – Basic screening
  1. Blood group
  2. Complete blood count to rule out any gross abnormal values in hemoglobin, total leukocyte count and platelets
  3. Viral markers for hepatitis B and hepatitis C infection.
  4. Complete liver function tests
  5. Serum creatinine for assessment of renal functions and it is required before doing a contrast CT scan (which is the next stage).
  6. Plain CT-scan of the abdomen – this gives information about the fat content in the liver by calculating the LAI (Liver Attenuation Index). Donor who is found to have fatty liver at this level would go either for biopsy or would be rejected depending on the value of liver attenuation index (LAI). Any LAI ≥6 is acceptable; those with LAI between 0 to 5 undergoes a liver biopsy to account for the fat content in the liver, if the patient does not have another donor. Liver biopsy is also done if the donor BMI is >30. Donor is asked to reduce weight, liver biopsy is done after the BMI has reduced to <30.

Donors having low LAI whose patient has stable liver disease (can wait for transplant), or if there is no one else to donate, are advised weight reduction regime. Once the LAI gets better/or if the liver biopsy shows <20% fat content are deemed acceptable for liver donation. Any fat content >20% is not acceptable.

• Second step – Triphasic CT scan of the abdomen – Once the basic screening is satisfactory, this imaging is done to look for the volume of the whole liver, volume of the part to be removed and that of the remnant liver. The right or left lobe graft is decided depending upon whether the volume of that part of the liver is at least 0.8% of the patient’s body weight. At the same time the remnant liver volume should be at least 30% of the whole volume of the liver.

Apart from giving information about the volume it also gives information about the vascular anatomy of the liver. This guides the donor surgery and also helps in planning the implantation of the liver graft into the patient.

MRCP – This is a MRI scan which is done to see the anatomy of the bile ducts. This is important before donor surgery and it gives a road map for deciding upon the site for dividing the bile duct.

• Third step – advanced work-up – Once the liver is found to be fat free and of adequate volume, the remaining investigations are guided towards ruling out any overt abnormalities in other systems and also for fitness before a major surgical procedure.
  1. Psychiatric clearance is obtained for all donors before transplantation; this is especially to rule out donation under any sort of coercion, also to confirm that the donor is in sound state of mind.
  2. Chest physician clearance is given after the chest X-ray and pulmonary function test are done.
  3. Cardiology clearance is given once the ECG, echocardiography and stress echocardiography (wherever indicated) is done.
  4. Gynaecology clearance is for female donors, ultrasound of the pelvis, pap smear and mammography/ultrasound of the breast is performed and clearance is obtained.
  5. Anaesthesia clearance is obtained as for any major surgical procedure.
• Authorisation Committee clearance is obtained and formalities mentioned in the appropriate section are to be fulfilled.

Donor Surgery (Operative procedure)

Donor is admitted one day prior to the day of transplantation. Routine blood tests are done (haemogram, liver and renal functions) before the day of surgery.

On the day of surgery, the donor and patient, both are wheeled in two different operation rooms simultaneously.  Both the surgeries start simultaneously (except in patients with hepatocellular carcinoma, where recipient is opened up first to rule out any extra-hepatic spread of tumor before starting the donor surgery).  The part of liver which is planned to be taken as graft is carefully removed, safeguarding the remnant liver in the donor.

Gall bladder is routinely removed at the time of donor hepatectomy surgery irrespective of the type of graft planned- right, left, left lateral or posterior segment graft. This is because the gall bladder blood supply might get compromised and also because the cystic duct is utilized for intra-operative cholangiogram which aids in the transection of the bile duct and thereby reduces/avoids biliary complications in both the donor and the recipient. It is important to note that the gall bladder is just a storage organ for bile, which is actually formed in the liver; hence removal of the gall bladder does not in any way harm the donor. Once the recipient is ready to receive the graft only then the proposed graft is removed and sent for benching in a basin containing ice. After the procedure, wound is closed in the donor carefully (cosmetic sutures which are absorbable-does not require removal) and a tube drain is kept at times to drain any collected fluid. This is generally removed in 3-4 days. The operation generally lasts for 6-8 hours. We also are performing donor surgery with the assistance of laparoscopy. The advantage is smaller incision and less pain, otherwise everything remains the same.

Benching

The graft after resection is flushed with cold preservative solution to remove all the blood. Benching also involves clearing and preparing the vessels and bile ducts for implantation in the patient.

.Postoperative care

Generally blood transfusion is not required in this procedure. Donor is extubated (removed from the mechanical ventilator) after surgery in the operation theatre. He/she is shifted to the Intensive care unit for overnight observation. After surgery, donor has a tube in the nose to keep the stomach empty and avoid vomiting immediately after recovery from anaesthesia. This is usually removed on the first postoperative day. Urinary catheters are there for convenience in the initial 2-3 postoperative days, following which as the donor starts ambulating, the catheter is removed. Donor would also have some intravenous lines for giving fluids and medications; these are progressively removed over a period of 4-5 days. For pain relief, epidural analgesia (catheter in the back)/ intravenous analgesia/ local wound block is used, which can be supplemented if required with additional dosage and in combination.

Generally donor is shifted to the ward on the first postoperative day. Diet is started gradually from the first day following surgery and is progressed to normal diet by the 2^nd or 3^rd day. Most of the medications are stopped by 3-4 days. Operatively placed tube drain is removed by 3^rd or 4^th day depending upon the amount and kind of drainage. By 5^th or 6^th postoperative day, if everything is progressing as expected donor is discharged. Liver functions return to normal by 5-6 days following surgery.

At discharge, pain killers, vitamins are prescribed. These are stopped in 3-4 weeks. Operative wound would require dressings for 7-10 days. Donor should avoid strenuous activity and lifting heavy weights for 3-months following surgery. However he/she could resume daily activities and jobs which do not require physical exertion. This surgery leaves a scar across the upper part of abdomen.

Complications

They are minor and can occur in 10-15% of patients in the form of some fluid collection in the abdomen or chest. Like any other surgery there is a chance of bleeding, bile leak, wound infection, which would require attention in some. This would require extra days of stay in the hospital, antibiotics or aspirations under image guidance. Risk to life in this procedure is about ≤ 0.05% for right lobe donation and ≤ 0.02% for left lobe donation.