The Penn Transplant Institute (PTI) is performing living donor liver transplantation (LDLT) to provide a better path to transplantation for patients with end-stage liver disease, and the potential for improved outcomes.
Living donor liver transplantation (LDLT) is possible because of the unique segmental anatomy of the liver and the long recognized capacity of the liver to regenerate following tissue loss, a characteristic that permits healthy individuals to donate a portion of the organ to another person. Although deceased-donor livers remain the principal source of liver transplantation, the proportion of liver transplants involving living donors is increasing steadily. In 2021, according to the Organ Procurement and Transplantation Network (OPTN), more than 6% of all liver transplants in the United States involved living donors, with 569 living-donor liver transplants performed at 78 participating centers. In that year, 10% of liver transplants at the Penn Transplant Institute involved a living donor.
The PTI has one of the busiest LDLT programs in the nation and is the largest and most experienced program in the Philadelphia region. Since the first LDLT took place at the Institute in 1995 (an adult to child procedure), more than 175 adult to adult LDLTs have been performed at Penn Medicine, Figure 1). LDLT recipients at the PTI have the best survival rates and among the lowest complication rates in the nation at 1, 3, and 5 years post-LDLT transplant.(Figure 2).
About Liver Transplantation: the Waiting List, MELD, and Organ Allocation
Figure 2: Post-LDLT survival at the Penn Transplant Institute at 1, 3, and 5 years vs. UNOS region 2, northeast centers and other national transplant centers.
Today, more than 12,000 people are on the liver transplant waiting list in the United States. Patients are organized on the liver transplant waitlist according to sickest first, as determined by the the Model for End Stage Liver Disease (MELD) score.
The MELD score ranges from 6 to 40 and is calculated from patients' serum creatinine (or dialysis status), bilirubin, sodium, and International Normalized Ratio (INR -a measure of clotting factors) and is highly predictive of mortality risk on the waiting list.
Patients with the highest MELD scores (i.e., 35 and above) may receive a liver within days or weeks. Those with lower MELD scores may stay on the waiting list for months or even sometimes years before undergoing liver transplant. Beyond the MELD score, a number of factors can influence time on the waiting list, such as the patient's blood type or anatomical factors. As individuals approach eligibility for an organ, they are evaluated for livers as they become available. Persons who do not match the available organ are then bypassed from the list of potential recipients. Whatever their score, all patients on the waiting list remain at risk for acute decompensation and the multi-organ complications of liver disease progression over time.
MELD Score Threshold Diversity at the Penn Transplant Institute
Figure 3: At the Penn Transplant Institute, the MELD score for 89% of patients having DDLT is between 20 and 40. By contrast, the MELD score for most patients having LDLT at the PTI is <15.
Because there is no upper or lower threshold for MELD score at the PTI, the Penn LDLT program does not exclude patients with higher MELD scores for LDLT. In addition, there is no minimum MELD score to be considered for LDLT at PTI. In fact, the option of LDLT plays a key role in offering access to liver transplantation for patients with lower MELD scores. Most deceased donor livers are transplanted in patients with higher MELD scores, usually over 25, but more than 40% of LDLT recipients at the PTI have a mean MELD score of 15 or less, providing a pathway to transplantation for these patients that would otherwise not be possible (Figure 3).
LDLT Donorship at the PTI
The PTI makes every effort to assist individuals who demonstrate a willingness to donate organs to the liver transplantation program. There are strict protocols in place to meet regulatory requirements and to ensure safety of the donor. A great deal of testing is needed and an abundance of education is provided to the potential donor so they understand the risks of the procedure and to ensure donor appropriateness and understanding.
Qualifications: To qualify as a living liver donor at the PTI, individuals must be physically fit and in good health with no significant medical problems or surgical history. They should be between 21 and 50 years of age (slightly younger or older donors will be considered on a case-by-case basis). Factors such as sex and race or ethnicity are not considered in determining a successful match. In addition, PTI has a non-directed (i.e., altruistic) liver donor program. Thus, potential donors do not need to have a pre-existing relationship with the intended recipient to donate.
Donor Post-Transplant Experience at the PTI
Donors typically spend 5 to 7 days in the hospital and are active by the time of discharge. They are able to increase their activity and strength over the first few weeks. Laboratory tests and follow up imaging is done on a regular basis and reviewed carefully by the team. The typical recovery period is 6 to 12 weeks. Donors may frequently return to work earlier if they are able to work remotely from home. Typically, within a few months of surgery, the liver will have regrown to nearly its original volume. Donors continue to be followed for their lifetime.
PTI Accommodations and Programs
Penn Medicine offers accommodations and other considerations for living donors in the liver transplantation program. Among these are a Distance Donor Protocol, which offers aid to donors who live more than 100 miles from Philadelphia to minimize time and costs when traveling to Philadelphia for education and testing. The Penn Medicine Clyde F. Barker Transplant House offers affordable accommodations, which helps ease the economic and emotional burdens that accompany organ transplant for patients, living donors, and their families. Qualifying prospective donors also have access to the National Living Donor Assistance Center (NLDAC) which gives financial aid to eligible living donors for their travel costs.
Donor Mentoring Program - For prospective donors, the Penn Donor Mentoring Program puts donors in touch with prior donors, matching them with previous donors who have similar life circumstances. These mentors provide encouragement and help new donor candidates navigate their experience.
For more information about living donorship and the LDLT program, please visit the LDLT FAQ page.
The Living Donor Liver Transplantation Coordinator, and primary contact for the Program, is Linda Wood, BSN, RN, who can be reached at 215-615-0564 or linda.wood@uphs.upenn.edu.
Case Study
In 2017, Deborah C., a 48-year-old woman, was diagnosed with primary sclerosing cholangitis, a chronic autoimmune liver disease that slowly damages the bile ducts, and was told that she would eventually need a liver transplant.
Later that year, Deborah had a series of procedures to evaluate for suspected cholangiocarcinoma (bile duct cancer) at the site of a bile duct stricture.
Living liver donor Kim S. and recipient Deborah C. one year after Kim donated a portion of her liver to Deborah, whose liver had been destroyed by primary sclerosing cholangitis, a chronic inflammatory disease of the bile ducts.
Ultimately, these investigations were unable to make a definitive determination of malignancy, but because cholangiocarcinoma could not be ruled out, Deborah subsequently had a right hepatectomy. Fortunately, the duct stricture turned out to be benign, and for the next three years, her clinical course was relatively stable. During this time, Deborah and her hepatologist agreed that given her low MELD score, her best option for a transplant when needed would be an LDLT, though living donor transplant was not an option where she was receiving care.
Shortly after being hospitalized for a severe episode of bacterial cholangitis, Deborah scheduled a consultation with a hepatologist at the Hospital of the University of Pennsylvania to discuss transferring her care to Penn Medicine's LDLT program.
Over the next few months, Deborah's bacterial cholangitis recurred three times, resulting each time in hospitalization and mounting debility. Despite progressive liver disease, persistent jaundice, fatigue and pruritus, her MELD score never exceeded 20, far below the average score to undergo a DDLT. At this point, Deborah began actively seeking a living donor.
But her case was not straightforward. Because of her previous liver resection surgery and the amount of scar tissue that remained, she required a large portion of liver from the left lobe of a living donor, not the more commonly transplanted right lobe.
After the first person to offer was ruled out because her left lobe was too small, Kim, a nurse practitioner and close friend who had been attending Deborah since her first illness, offered to be her living liver donor. On consultation, Kim's left lobe was deemed large enough to donate, providing Deborah with the transplant she needed.
The surgery went smoothly, and in the weeks that followed, Deborah's health, appearance and sense of well-being began a dramatic improvement. Within three weeks, her bilirubin returned to normal, her pruritus resolved, and she regained her energy.
While she previously could not get through the workday without feeling extreme fatigue, within 6 weeks of transplant she had more energy than she had in years. Her donor, Kim, had an uneventful recovery and returned to work four weeks after her surgery.
At three months, Deborah and Kim had their follow-up MRIs. Both their liver grafts had undergone appropriate regeneration, and both women had nearly full-size livers. As evidence of their continuing health and friendship, Kim and Deborah ran a half marathon together within a year of their shared surgery.