Living donor liver transplantation (LDLT) is an unavoidable procedure due to the shortage of deceased donors. Since the first successful living donor liver transplant [1,2], many reports have shown excellent outcomes, but the safety of the donors after donation is still one of the main issues in LDLT [3-11]. Serious complications including mortality [12-14] have been reported to these days. Moreover, there is an arguing that low-volume centers cannot perform liver transplant with acceptable outcome. Our institution started a liver transplant program since June 28, 2006 and did liver transplantation 11 liver transplantations a year maximally, and one liver transplantation a year minimally during the study period. Therefore, we are going to evaluate the overall safety of living donors in our center.

This study was approved by the Institutional Review Board of Konkuk University Medical Center (IRB File No. KUMC 2023-08-061). Because this study was conducted retrospectively, the need for obtaining informed consent was waived.

Before starting the liver transplantation program, we educated surgical residents, nurses who were related with the liver transplantation (work at the operating room, at the surgical intensive care unit, and at the surgical ward) more than 10 hours each. The lectures were done by professors who wound involve in the liver transplantation program such as gastroenterologists, a radiologist, an interventionist, an infectious disease doctor, a pathologist, and also including me. We also send them to the experienced hospitals, nearby our center, as observers for several days. We checked perioperative orders with related Departments and determined the primary attending in each Department for perioperative risk evaluation and management. At last, we simulated every procedure just before the first liver transplantation in our center even with the staffs who work at the support team such as hospital accounting, admission and discharge, hospital insurance, etc.

Among the 54 liver transplantations, which is total number in our institution from June 2006, 29 living donors of adult LDLTs, which were performed from June 2006 to December 2015 (last living donor liver transplant in our institution), were analyzed. All living donors are related to recipients. All donor hepatectomy was done with open laparotomy. The first 11 living donors of liver transplants (Group 1) were performed with the help of an outside experienced team and the other 18 living donors of liver transplants (Group 2) were performed in our center independently. They were all right lobe donors and were strictly selected based on remnant liver volume and steatosis. They were checked with laboratory tests and abdominal computed tomography (CT) at one month, at six months and at twelve months after donation. We performed independent Student’s t-test to determine the significance of differences between two groups using Exel 2023 (Microsoft, Redmond, WA, USA). Statistical significance was accepted for p values less than 0.05.

The mean age of donors was 27.8 years (16–52 years). Male donors were 21, and female donors were 8. All donors were immediate family. Characteristics of donors of two groups were summarized in Table 1. There were no statistical differences between two groups in age, body mass index, residual liver volume, and graft volume/recipient weight ratio. There was no operative mortality and no re-operation. The mean operation time was 5 hours and 38.3 minutes (4 hours 10 minutes to 7 hours 45 minutes). The mean amount of bleeding was 541.4 mL (200–1,200 mL). The mean hospital stay was 12.9 days (9–27 days). There was no intraoperative blood transfusion. There was one major complication which was biliary stricture and it was improved with endoscopic retrograde biliary drainage (ERBD). There were three minor complications which were mild depression with poor diet, wound infection, and postoperative blood transfusion. Group 2 was compared with Group 1 and summarized in Table 2, and only the operation time in Group 2 was statistically longer than Group 1. All donors were checked with laboratory tests and abdominal CT at one month, at six months, and at one year after operation and all showed no abnormal laboratory tests and all showed well regenerated liver and no diagnostic abnormality except one with plastic stent of ERBD at one month. This patient was managed with balloon dilatation and plastic stent insertion for 3 months and recovered well without any problems since November 2011.

Table 1 . Charateristics of donors.

	Group 1 (n=11)	Group 2 (n=18)	p-value
Sex (male:female)	9:2	12:6
Age (yr)	28.6±11.6	27.2±9.3	0.727
Body mass index (kg/m2)	22.6±3.2	23.3±3.0	0.529
Residual liver volume (%)	39.4±4.9	38.4±3.1	0.513
Graft volume/recipient weight ratio	1.26±0.16	1.29±0.33	0.748

Values are presented as mean±standard deviation..

Group 1, living donor liver transplantations with help; Group 2, living donor liver transplantations without help..

Table 2 . Outcomes of donors.

	Group 1 (n=11)	Group 2 (n=18)	p-value
Operation time (min)
Mean±SD	323±44	383±49.5	0.026
Median	320	350
Estimated blood loss (mL)	454.5±186.4	594.4±356.0	0.240
Graft/recipient body weight ratio
Mean±SD	1.12±0.13	1.12±0.28	0.957
Postoperative complications (n)
Bleeding	0	0
Biliary stricture	0	1
Wound infection	1	0
Reoperation	0	0
Transfusion	0	1
Postoperative hospital stay
Mean±SD (day)	13.9±5.6	12.2±2.7	0.283

Group 1, living donor liver transplantations with help; Group 2, living donor liver transplantations without help; SD, standard deviation..

The donor and the recipient surgical procedures in adult LDLT are more complex than for whole-liver deceased donor transplantation [3]. And more, the procedure of donor is very complicated because the portion of the liver to be removed should be handled with extreme care, and because superior concerns should be paid for the safety of donors who are not diseased patients. For the safety, we evaluated the safety of donors in LDLT in our center.

We prepared our transplantation team including resident, anesthesiologists, and nurses for the liver transplantation. We send them to a large volume liver transplant center for several weeks and we did first 11 LDLT with the help of two surgeons, one for the donor and another for the recipient, in our center. The results are shown in Table 2. The operative time was the only meaningful difference and one reported that prolonged operative time was found to be an independent risk factor for complications by multivariate analysis [15]. But in our cases, the difference might be from the fact that one in Group 1 didn’t need middle hepatic vein reconstruction, which made operation time short, and that one in the Group 2 had two portal vein, one hepatic artery which branched early, and two bile duct made operation time longer and one in the Group 2 had a bleeding event.

In donors undergoing right hemihepatectomy showed some serious complications resulting from hepatic parenchymal loss [4-7]. Therefore, we strictly selected donors based on remnant liver volume and steatosis. We refused donors whose remnant liver volume less than 30%. For example, one donor candidate showed remnant liver volume 29%, we asked another radiologist to do the volumetry again and it also turned out to be 29% of remnant liver volume. We refused him as a donor strictly. Preoperative biopsy for the donor who showed fatty liver in the preoperative CT and refused who showed more than 30% of macrosteatosis. In our series, estimated mean remnant volume was 39.0%, and we had no problems with small remnant volume.

One of the most important complications after donor procedure is biliary injury [8-11]. Even the precise biliary anatomy and meticulous hilar dissection, we experienced one biliary complication in Group 2. We thought the biliary tree would have no problem at the time of resection but the elevation of serum total bilirubin and abdominal CT made us to do an intervention. This patient was managed with balloon dilatation 4 weeks later after the operation and plastic stent inserted and kept for 3 months and removed then. She recovered well with no problem since November 2011.

We experienced three minor complications which were mild depression with poor diet, wound infection, and postoperative blood transfusion. The one who showed mild depression recovered well with the short help of a psychiatrist during the admission period and needed no more help after discharge. The one who had wound infection were managed with daily dressing and wound repair. And the last one who had a postoperative blood transfusion was well recovered without any complication. If I could have noticed before transfusion, I might have stopped transfusion, but I was with recipient in operating room at that time. Usually residents ask me to transfuse or not when it is about liver donor, because I educated them to do so. Her preoperative hemoglobin was 12.2 g/dL and dropped to 8.8 g/dL after surgery, but vital signs were tolerable postoperatively such as blood pressure were 101–105/52–63 mmHg and pulse rates were between 84 and 95 per minutes. And discharge color of drain was not bloody but serosanguinous and hour urine amount was between 80 and 150 mL. But a first-year resident did transfusion.

We have had an acceptable outcome in donor safety in a low-volume transplant center. Thorough preparation and the sincere assistance of an experienced liver transplantation team at beginning and a new well-prepared transplant team could guarantee a favorable safety of donors even in a low-volume transplant center.

There was no funding related to this study.

All authors have no conflicts of interest to declare.