Faculty Bibliography

OBJECTIVE:Centers offering adult living donor liver transplantation (LDLT) mostly use right lobe grafts due to fears of providing recipients with insufficient hepatic volume, and the technical challenges presented by using left lobe grafts (LLGs). LLGs therefore represent approximately 5% of adult LDLTs performed in the United States. Here we present the largest North American experience with the use of LLG for adult LDLT. METHODS:Analysis of a prospectively maintained database of LDLTs performed from 1998 to 2015 at our institution. RESULTS:A total of 214 adult LDLTs were studied. Fifty-six patients (26%) received LLG. LLG recipients were more likely to be women, had significantly lower BMI, graft weight, and graft-weight-recipient-weight ratios (P < 0.05 for all). There were no significant differences in vascular or biliary complication between the groups. No significant differences existed in patient or graft survival at 1, 3, and 5 years (P = 0.747 and P = 0.398 respectively). Despite significantly increased risk of small-for-size syndrome in LLG, there was no increased risk of retransplant within 90-days or perioperative mortality in LLG recipients (P = 0.308 and P = 0.932 respectively). Graft type did not predict patient or graft outcomes on regression analysis (P = 0.857 and 0.399 respectively). CONCLUSIONS:Despite smaller graft sizes, outcomes of adult LDLT using LLG are comparable to right lobe grafts transplants. Left lobes can provide an important resource in an era of severe organ shortages, and these data should serve to allay the concerns of the transplant community in the United States.

Homozygous familial hypercholesterolemia (HoFH) is a rare, inherited, life-threatening, metabolic disorder of low-density lipoprotein (LDL) receptor function characterized by elevated serum LDL cholesterol (LDL-C) and rapidly progressive atherosclerotic cardiovascular disease (ACVD). Since LDL receptors are predominantly found on hepatocytes, orthotopic liver transplantation (OLT) has emerged as a viable intervention for HoFH because LDL receptor activity is restored. This study assessed the effects of OLT on ACVD and ACVD risk factors in pediatric patients with HoFH. We analyzed lipids, lipoproteins, body mass index, glucose, blood pressure, and cardiovascular imaging in 8 pediatric patients who underwent OLT for HoFH. Total serum cholesterol, LDL-C, lipoprotein (a), and apolipoprotein B/apolipoprotein A1 ratio decreased to normal values in all subjects (p values <0.001) at 1 month after OLT and were maintained for the length of follow-up (2 to 6 years). There were few complications related to surgery or immunosuppressive therapy. Two patients developed mild hypertension. In the first 4 subjects monitored for 4 to 6 years after OLT, coronary artery disease did not develop or progress except in 1 minor artery in 1 subject and actually regressed in 2 subjects with >50% stenosis. However, aortic valve stenosis progressed in 2 of 4 subjects. In conclusion, OLT is an effective therapeutic option for patients with HoFH with coronary artery disease and persistently elevated serum LDL-C despite maximum medical therapy. Aortic valvular disease may progress. Long-term data are needed to evaluate the true risk-benefit ratio of this surgical approach.

By preserving part of the native liver, auxiliary partial orthotopic liver transplantation (APOLT) provides the advantage of potential immunosuppression (ISP) withdrawal if the native liver recovers but has had limited acceptance, especially in the United States, due to technical complications and low rates of native liver regeneration. No previous study has evaluated APOLT specifically for preadolescent children with fulminant hepatic failure (FHF). This population might benefit especially based on greater capacity for liver regeneration. Data from 13 preadolescent children who underwent APOLT were compared to 13 matched controls who underwent orthotopic liver transplantation (OLT) for FHF from 1996 to 2013. There were no significant differences in patient demographics or survival between the 2 groups. However, all surviving OLT recipients (10/13) remain on ISP, while all but 1 surviving APOLT recipient (12/13) showed native liver regeneration, and the first 10 recipients (76.9%) are currently off ISP with 2 additional patients currently weaning. In our experience, APOLT produced excellent survival and high rates of native liver regeneration in preadolescent children with FHF. This represents the largest series to date to report such outcomes. Liberating these children from lifelong ISP without the downside of increased surgical morbidity makes APOLT an attractive alternative. In conclusion, we therefore propose that, with the availability of technical expertise and with the technical modifications above, APOLT for FHF should be strongly considered for preteenage children with FHF.

It is unclear how the immune response in early life becomes appropriately stimulated to provide protection while also avoiding excessive activation as a result of diverse new antigens. T cells are integral to adaptive immunity; mouse studies indicate that tissue localization of T cell subsets is important for both protective immunity and immunoregulation. In humans, however, the early development and function of T cells in tissues remain unexplored. We present here an analysis of lymphoid and mucosal tissue T cells derived from pediatric organ donors in the first two years of life, as compared to adult organ donors, revealing early compartmentalization of T cell differentiation and regulation. Whereas adult tissues contain a predominance of memory T cells, in pediatric blood and tissues the main subset consists of naive recent thymic emigrants, with effector memory T cells (T(EM)) found only in the lungs and small intestine. Additionally, regulatory T (T(reg)) cells comprise a high proportion (30-40%) of CD4(+) T cells in pediatric tissues but are present at much lower frequencies (1-10%) in adult tissues. Pediatric tissue T(reg) cells suppress endogenous T cell activation, and early T cell functionality is confined to the mucosal sites that have the lowest T(reg):T(EM) cell ratios, which suggests control in situ of immune responses in early life.

New surgical procedures taking advantage of the regenerative abilities of the liver are being introduced as potential curative therapies to these patients either to provide auxiliary support while the native liver recovers or undergoes hypertrophy. For patients with hepatocellular carcinoma outside of the Milan criteria or bilobar colorectal metastases liver transplantation is not an option. Fulminant hepatic failure can be treated but requires life-long immunosuppression. These complex surgical procedures require high quality and directed imaging.

OBJECTIVE:The aim of the study was to compare the short-term donor outcomes of laparoscopic left lateral sectionectomy (LLLS) for adult to child living donor liver transplantation (A-C LDLT) and laparoscopic donor nephrectomy (LDN). BACKGROUND:Although laparoscopy has become the standard approach in kidney donors, its use remains limited and controversial in LLS for A-C LDLT due to the lack of conclusive assessment of procedure-related morbidity. METHODS:From 2001 to 2014, 124 healthy donors undergoing laparoscopic LLLS for A-C LDLT at 5 tertiary referral centers in Europe, North America, and Asia, and 300 healthy donors undergoing LDN at 2 tertiary centers in Europe were retrospectively analyzed. The outcomes of LLLS were compared with those of LDN including the use of the comprehensive complication index (CCI). RESULTS:Although liver donors experienced significantly less overall (16.9% vs 31.7%, P = 0.002) and grade 1 to 2 (12.1% vs 24.7%, P = 0.004) complications than kidney donors, the rates of major complication (≥ grade 3) were similar between the 2 groups. In both groups, donors experiencing postoperative complications had similar CCI (19.3 vs 21.9 for liver and kidney donors, respectively, P = 0.29). After propensity score analysis allowing for matching donors on age, sex, and body mass index, the postoperative outcomes remained comparable between the 2 groups. CONCLUSION/CONCLUSIONS:Laparoscopic LLS for A-C LDLT yields at least similar short-term donor outcomes as LDN. These results provide the first validation for a laparoscopic donor hepatectomy and suggest that the laparoscopic approach should be considered a new standard practice for retrieval of left lateral section liver grafts as it is for kidney donation.

Living donor liver transplantation has failed to become a major means of transplantation in the United States, where <5% of the transplants are performed with living donors. At least 30% to 50% of the complications of donor hepatectomy appear to be related to abdominal wall trauma, including hernia, bowel obstruction, and chronic abdominal discomfort. We analyzed our experience with laparoscopically procured donor hepatectomy. We compared 22 full laparoscopic donor hepatectomies to 20 open/hybrid hepatectomies over an 11-year period. Donor and recipient demographics, complications, and graft and recipient outcomes were analyzed. All 22 laparoscopically procured liver allografts were transplanted successfully. The laparoscopically procured grafts took longer to procure (7 hours 58 minutes versus 6 hours 38 minutes; P < 0.001). The laparoscopically procured cases had lower blood loss (177.3 versus 3753 cc; P < 0.001), a shorter length of stay, and significantly reduced days off work (P = .01). The 1-year graft survival was not different (90% in the laparoscopic group and 85% in the open group; P = 0.70). The 1-year patient survival was not different (95% in the laparoscopic group and 85% in the open group; P = 0.32). There was a trend toward lower wound issues in the laparoscopic group, but this did not reach significance (the hybrid/open group had a 15% hernia rate versus 5% for the laparoscopic group). In experienced living donor centers, laparoscopic liver donation appears to be feasible for all pediatric recipients and some adult recipients. Outcomes for the recipients of laparoscopically procured grafts do not appear significantly different from outcomes with hybrid/open techniques.

BACKGROUND:Regulatory T cells (Treg) are being explored for their tolerance-inducing capabilities. Freezing and banking Treg for future use makes this strategy more clinically applicable. We aimed to devise an improved method of expanding and cryopreserving Treg to maximize yield, purity, and function for use in xenotransplantation. METHODS:cells were isolated by flow cytometric sorting and expanded for 26 days in culture with IL-2, anti-CD3 antibody, artificial APCs transfected with human CD58, CD32, and CD80, and rapamycin with weekly restimulations. Expanded Treg were frozen for 2 months then thawed and cultured for 48 hours in medium plus 1) no additives, 2) IL-2, 3) anti-CD3 antibody, 4) IL-2 + anti-CD3 antibody, and 5) IL-2 + anti-CD3 antibody + L cells. Phenotype and suppression were assessed after expansion, immediately after thawing, and after culturing. RESULTS:We expanded purified baboon Treg more than 10,000-fold. Expanded Treg exhibited excellent suppression in functional assays. Cryopreservation decreased suppressive function without changing phenotype, but increasing amounts of reactivation after thawing produced significantly better viability and suppressive function with a trend towards greater Treg purity. CONCLUSIONS:infusion should be possible.