'Burn and Push' technique: A novel robotic liver parenchymal transection technique

BACKGROUND

Liver parenchymal transection during robotic liver resection (RLR) remains a significant challenge due to the limited range of specialised instruments. This study introduces our 'Burn and Push' technique as a novel approach to address these challenges.

METHODS

A retrospective analysis was conducted on 20 patients who underwent RLR using the 'Burn and Push' technique at Virginia Commonwealth University Health System from November 2021 to August 2023. The study evaluated peri- and post-operative outcomes.

RESULTS

The median operation time was 241.5 min (range, 90-620 min), and the median blood loss was 100 mL (range, 10-600 mL). Major complications occurred in one case, with no instances of postoperative bleeding, bile leak, or liver failure.

CONCLUSIONS

The 'Burn and Push' technique is a viable and efficient alternative for liver parenchymal transection in RLR. Further research with larger sample sizes and consideration of the learning curve is necessary to validate these findings.

Liver transplantation for post-COVID-19 cholangiopathy: A case series

BACKGROUND

Post-COVID-19 cholangiopathy is an emerging cholestatic liver disease observed in patients recovering from severe COVID-19 infection. Its prognosis is poor, necessitating liver transplantation in some cases. This study aimed to investigate the outcomes of liver transplantation for post-COVID-19 cholangiopathy.

METHODS

Seven patients who underwent liver transplantation for post-COVID-19 cholangiopathy at three institutions between 2020 and 2022 were included in this retrospective multi-center case series.

RESULTS

At the time of initial COVID-19 infection, all patients developed acute respiratory distress syndrome, and six patients (86%) required ICU admission. Median time intervals from the initial COVID-19 diagnosis to the diagnosis of post-COVID-19 cholangiopathy and liver transplantation were 4 and 12 months, respectively. Four patients underwent living donor liver transplantation, and three patients underwent deceased donor liver transplantation. The median MELD score was 22 (range, 10-38). No significant intraoperative complications were observed. The median ICU and hospital stays were 2.5 and 12.5 days, respectively. One patient died due to respiratory failure 5 months after liver transplantation. Currently, the patient and graft survival rate is 86% at a median follow-up of 11 months.

CONCLUSIONS

Liver transplantation is a viable option for patients with post-COVID-19 cholangiopathy with acceptable outcome. Timely identification of this disease and appropriate management, including evaluation for liver transplantation, are essential.

Domino Liver Transplantation for Unresectable Colon Cancer Liver Metastasis From a Donor With Heterozygous Familial Hyperlipidemia: A Case Report

Liver transplantation (LT) is a potential curative treatment for unresectable colorectal cancer liver metastasis (CRLM). Familial hypercholesterolemia (FH) is an inherited condition characterized by elevated low-density lipoprotein cholesterol (LDL-C) levels. Liver transplantation is offered for selected cases, and an explanted liver can be used as a domino graft. We report the first report of domino LT for unresectable CRLM using a liver from a patient with heterozygous FH. The domino donor was a 30-year-old female with a history of heterozygous FH. She had failed medical therapies for FH, including plasmapheresis; therefore, she underwent living donor LT as a treatment for FH. The explanted liver was transplanted to the domino recipient. She has been doing well with normal LDL-C levels. The domino recipient was a 44-year-old female with a history of stage 4 sigmoid cancer with liver metastases, for which she underwent laparoscopic sigmoid colectomy and right hepatectomy. She developed unresectable lesions in the remnant left lobe, which were controlled well with chemotherapy; therefore, she underwent domino LT. She is doing well without recurrence at the 31-month follow-up. Domino LT from a donor with heterozygous FH is feasible for strictly selected patients with unresectable CRLM.

Single incision simultaneous liver kidney transplantation: Feasibility and outcomes

BACKGROUND

Traditionally, simultaneous liver kidney transplantation (SLK) has been performed using a subcostal incision for the liver allograft and a lower abdominal incision for kidney transplantation (dual incision, DI). At our institution, we performed SLK using a single subcostal incision (SI). The aim of this study was to report the outcomes of single versus dual incisions for SLK.

METHODS

A retrospective cohort study of consecutive SLK procedures performed at our center from January 2015 to April 2021 was performed. The demographic characteristics, complications, intraoperative findings, and complications after SI and DI were statistically compared.

RESULTS

A total 37 SLK were performed (19 DI and 18 SI). The age and indications for transplantation were comparable between the two groups. Patient in SI group had significantly higher MELD score (27.0 ± 1.5 vs. 31.7 ± 1.5, p = .038). The cold ischemic time of kidney transplantation (599 ± 26 min vs. 447 ± 27 min, p < .001) and the total surgical time (508 ± 21 min vs. 423 ± 22 min, p = .008) were significantly shorter in the SI group. The incidence of complications and post-transplant kidney function was comparable between the groups. A slightly higher incidence of surgical site complications was noted in the DI group without any statistically significance (p = .178).

CONCLUSIONS

Single-subcostal incision SLK is technically feasible and has comparable outcomes to dual-incision SLK. SI was associated with shorter cold ischemic time for kidney transplant, as well as shorter overall operative time.

Utilization of a Reduced Graft from a Severely Traumatized Liver: A Case Report and Strategy to Increase Availability of Livers for Transplant

Background: Trauma victims with liver lacerations in the hilum are typically excluded from liver donation. We report a case of a successful liver transplant from a deceased donor with a grade 4 hilar liver laceration. Case Presentation: We used a liver with a high-grade laceration from a 28-year-old brain-dead traffic accident victim. The liver had grade IV lacerations in the right and caudate lobes. In situ split liver technique was applied to control the lacerations after an intraoperative cholangiogram revealed favourable anatomy. The left hemi-liver graft was procured, retaining the entire vena cava and the full length of the main hepatic vasculature. The recipient was a 62-year-old female patient with end-stage liver disease, with a Model for End-Stage Liver Disease-Sodium score of 19. The left lobe graft was transplanted using the standard piggy-back technique. The patient was discharged on postoperative day 7 after an uneventful recovery. At two-month follow-up, she continues to do well, with normal hepatic function and unremarkable imaging studies. Conclusion: This is the first reported case of a successful liver transplant of a severely lacerated liver made possible by the application of split liver techniques. In situ splitting of a severely traumatized liver could permit the utilization of a reduced graft for small recipients.

Development, management, and resolution of biliary complications after living and deceased donor liver transplantation: a report from the adult-to-adult living donor liver transplantation cohort study consortium

Adult recipients of living donor liver transplantation (LDLT) have a higher incidence of biliary complications than recipients of deceased donor liver transplantation (DDLT). Our objective was to define the intensity of the interventions and the time to resolution after the diagnosis of biliary complications after liver transplantation. We analyzed the management and resolution of posttransplant biliary complications and investigated the comparative effectiveness of interventions in LDLT and DDLT recipients. For the analysis of biliary complications (leaks or strictures), we used a retrospective cohort of patients who underwent liver transplantation at 8 centers between 1998 and 2006 (median follow-up from onset=4.7 years). The numbers, procedure types, and times to resolution were compared for LDLT and DDLT recipients. Posttransplant biliary complications occurred in 47 of the 189 DDLT recipients (25%) and in 141 of the 356 LDLT recipients (40%). Biliary leaks constituted 38% of the post-DDLT biliary complications (n=18) and 65% of the post-LDLT biliary complications (n=91). The median times to first biliary complications were similar for DDLT and LDLT (11 versus 14 days for leaks, P=0.63; 69 versus 107 days for strictures, P=0.34). Overall, 1225 diagnostic and therapeutic procedures, including reoperation and retransplantation, were performed (6.5±5.4 per recipient; 5.5±3.6 for DDLT versus 6.8±5.8 for LDLT, P=0.52). The median number of months to the resolution of a biliary complication (i.e., a tube-, stent-, and drain-free status) did not significantly differ between the DDLT and LDLT groups for leaks (2.3 versus 1.3 months, P=0.29) or strictures (4.9 versus 2.3 months, P=0.61). Although the incidence of biliary complications is higher after LDLT versus DDLT, the treatment requirements and the time to resolution after the development of a biliary complication are similar for LDLT and DDLT recipients.

Substitution of tenofovir/emtricitabine for Hepatitis B immune globulin prevents recurrence of Hepatitis B after liver transplantation

BACKGROUND

Hepatitis B immune globulin (HBIg) with or without nucleos(t)ide analogue (NA) inhibitors has been shown to prevent recurrence of hepatitis B virus (HBV) following orthotopic liver transplantation (OLT). However, the use of HBIg has many disadvantages.

AIMS

The present study was performed to determine if converting patients from HBIg ± NA to combination NA therapy could prevent recurrence of HBV.

METHODS

Twenty-one recipients without evidence of HBV recurrence on HBIg ± NA for ≥ 6 months were enrolled. Patients received their last injection of HBIg at the time they initiated tenofovir disoproxil fumarate/emtricitabine (TDF/FTC; Truvada(®) ) and were followed up for 31.1 ± 9.0 [range 15-47] months.

RESULTS

After 1 year, 3 patients (14%) had detectable HBsAg, one of whom was non-compliant. Two of 3 with recurrence cleared HBsAg by last follow-up on TDF/FTC; the non-compliant patient became HBV DNA-undetectable with re-institution of TDF/FTC. TDF/FTC saved $12,469/year over our standard-of-care, monthly intramuscular HBIg/lamivudine. There was no evidence of a general adverse effect of TDF/FTC on renal function. However, 3 patients developed reversible acute renal failure; on renal biopsy, 1 had possible TDF/FTC-induced acute tubular necrosis.

CONCLUSIONS

Substitution of TDF/FTC for HBIg prevented recurrence of HBV DNA in 100% (20/20) of patients who were compliant with the medication and led to substantial cost savings over HBIg-containing regimens.

Living donor liver transplantation for neonatal hemochromatosis using non-anatomically resected segments II and III: a case report

INTRODUCTION

Neonatal hemochromatosis is the most common cause of liver failure and liver transplantation in the newborn. The size of the infant determines the liver volume that can be transplanted safely without incurring complications arising from a large graft. Transplantation of monosegments II or III is a standard method for the newborns with liver failure.

CASE PRESENTATION

A three-week old African-American male neonate was diagnosed with acute liver failure secondary to neonatal hemochromatosis. Living-related liver transplantation was considered after the failure of intensive medical therapy. Intra-operatively a non-anatomical resection and transplantation of segments II and III was performed successfully. The boy is growing normally two years after the transplantation.

CONCLUSION

Non-anatomical resection and transplantation of liver segments II and III is preferred to the transplantation of anatomically resected monosegements, especially when the left lobe is thin and flat. It allows the use of a reduced-size donor liver with intact hilar structures and outflow veins. In an emergency, living-related liver transplantation should be offered to infants with liver failure secondary to neonatal hemochromatosis who fail to respond to medical treatment.

Adult living donor versus deceased donor liver transplantation: a 10-year prospective single center experience

It has been 4 years since the first, long-term (> 3 years) prospective comparison of adult-to-adult living donor liver transplantation (A2ALLTx) to adult deceased donor liver transplantation (ADDLTx) was reported. In this follow up, prospective, IRB approved, 10-year comparison of A2ALLTx to ADDLTx we expand on our initial observations. This data includes: age, gender, ethnicity, primary liver disease, waiting time, pretransplant CTP/MELD score, cold ischemia time (CIT), perioperative mortality, acute and chronic rejection, graft and patient survival, charges and post-transplant complications. In 10 years, 465 ADDLTx (81.3%) and 107 A2ALLTx (18.7%) were performed at VCUHS. Hepatitis C virus (HCV) was the most common reason for transplantation in both groups (54.5% vs. 48.2%). Data regarding overall patient and graft survival and retransplantation rates were similar. Comparison of patient/graft survivals, retransplantation rates in patients with and without HCV were not statistically different. A2ALLTx patients had less acute rejection (9.6% vs. 21.7%) and more biliary complications (27.1% vs. 17.6%). In conclusion, A2ALLTx is as durable a liver replacement technique as the ADDLTx. Patients with A2ALLTx were younger, had lower MELD scores, less acute rejection and similar histological HCV recurrence. Biliary complications were more common in A2ALLTx but were not associated with increased graft loss compared to ADDLTx.

Effect of hyponatraemia on outcomes following orthotopic liver transplantation

BACKGROUND

Hyponatraemia increases risk of adverse outcomes following orthotopic liver transplantation (OLT), but it is unclear whether improvement of pretransplant hyponatraemia ameliorates post-transplant complications.

AIMS

To assess impact of pretransplant hyponatraemia on post-transplant outcomes.

METHODS

We performed a retrospective analysis of 213 patients with cirrhosis who underwent liver transplantation. Patients with serum sodium <or=130 mEq/L immediately before transplantation ('hyponatraemia at OLT'; n=34) were compared with those who had experienced hyponatraemia but subsequently improved to a serum sodium >130 mEq/L at transplantation ('resolved hyponatraemia'; n=56) and to those without history of hyponatraemia before transplantation ('never hyponatraemic'; n=123). Primary endpoint was survival at 180 days post-OLT. Secondary outcomes included time until discharge alive, complications during hospitalization, length of time ventilated and length of post-transplant intensive care unit stay.

RESULTS

There was no survival difference at 180 days post-OLT between groups. After transplantation, patients with either hyponatraemia at OLT or resolved hyponatraemia had longer time until discharge alive and had higher rates of delirium, acute renal failure, acute cellular rejection and infection than those who were never hyponatraemic. As compared with patients with hyponatraemia at OLT, those with resolved hyponatraemia were more likely to be discharged alive within 3 weeks, but other outcomes, including survival, did not differ significantly.

CONCLUSIONS

We conclude that hyponatraemia at any time before liver transplantation is associated with adverse post-transplant outcome, even when hyponatraemia has resolved.

Incidence of prolonged length of stay after orthotopic liver transplantation and its influence on outcomes

Orthotopic liver transplantation (OLT) is the only effective treatment for end-stage liver disease. Although most patients do well and are discharged promptly, some require prolonged length of stay (PLOS). The prevalence of PLOS, associated factors, and their impact on survival are not well defined. We reviewed our adult OLT database for patients who survived > 30 days. PLOS was defined as hospitalization > 30 days following OLT. Of 521 OLT recipients, 68 (13%) had PLOS with a median duration of 50 days versus only 10 days for patients discharged within 30 days. Significant differences in pre-OLT variables between patients with and without PLOS included the mean wait list time (P = 0.001), hospitalization at the time of OLT (P = 0.001), and prior OLT (P = 0.041). Factors independently associated with PLOS included intensive care unit status at the time of OLT [odds ratio (OR), 4; 95% confidence interval (CI), 1.6-10.4], OLT prior to Model for End-Stage Liver Disease implementation (OR, 2.27; 95% CI, 1.04-5.26), in-hospital post-OLT bacterial infection (OR, 9.34; 95% CI, 4.65-18.86), gastrointestinal bleeding (OR, 4.34; 95% CI, 1.4-14.08), renal failure (OR, 10.86; 95% CI, 5.07-23.25), and allograft rejection (OR, 3.7; 95% CI, 1.23-11.11). One-year graft survival and patient survival were significantly less in those with PLOS (for both, P < 0.0001). Among PLOS patients, factors independently associated with increased 1-year mortality were donor age (OR, 1.07; 95% CI, 1.009-1.13), primary diagnosis of hepatitis C virus (OR, 6.89; 95% CI, 1.40-34.48), in-hospital post-OLT bacterial infection (OR, 13.3; 95% CI, 2.11-83.33), and cardiac complications (OR, 20.4; 95% CI, 1.51-250; c-statistic for the model, 0.85). In conclusion, PLOS following OLT is associated with a significant decrease in survival despite a marked increase in cost and resource utilization. Efforts to modify those factors that contribute to PLOS may reduce this event, improve survival, and reduce OLT-associated costs.

Surveillance for hepatocellular carcinoma in patients with cirrhosis improves outcome

OBJECTIVE

Liver transplantation has become an effective treatment for cirrhotic patients with early-stage hepatocellular carcinoma. We hypothesized that the quality of surveillance for hepatocellular carcinoma influences prognosis by affecting access to liver transplantation.

METHODS

A total of 269 patients with cirrhosis and hepatocellular carcinoma were retrospectively categorized into 3 groups according to quality of surveillance: standard-of-care (n=172) (group 1); substandard surveillance (n=48) (group 2); and absence of surveillance in patients not recognized to be cirrhotic (n=59) (group 3).

RESULTS

Three-year survival in the 60 patients who underwent liver transplantation was 81% versus 12% for patients who did not undergo transplantation (P<.001). The percentages of patients who underwent transplantation according to tumor stage at diagnosis (T1, T2, T3, and T4) were 58%, 35%, 10%, and 1%, respectively. Hepatocellular carcinoma was diagnosed at stages 1 and 2 in 70% of patients in group 1, 37% of patients in group 2, and only 18% of patients in group 3 (P <.001). Liver transplantation was performed in 32% of patients in group 1, 13% of patients in group 2, and 7% of patients in group 3 (P<.001). Three-year survival from cancer diagnosis in patients in group 3 (12%) was significantly worse than in patients in group 1 (39%) or group 2 (27%) (each P<.05). Eighty percent of patients in group 3 had subtle abnormalities of cirrhosis on routine laboratory tests.

CONCLUSION

The quality of surveillance has a direct impact on hepatocellular carcinoma stage at diagnosis, access to liver transplantation, and survival.

Hepatitis C virus infection and kidney transplantation: predictors of patient and graft survival

BACKGROUND

The effect of hepatitis C virus (HCV) infection on patients undergoing kidney transplantation (KTx) is uncertain. This study aimed to evaluate the outcomes of our HCV+/end-stage renal disease (ESRD) patient population based on the therapeutic option including KTx or continuation in dialysis.

METHODS

KTx performed at Virginia Commonwealth University Hospital between January 2000 and December 2004 were tracked prospectively. Forty-three out of a total of 394 KTx patients included in the analysis were HCV+. A group of 52 contemporaneous HCV+/ESRD patients listed, but never transplanted, was also analyzed. HCV-negative transplanted patients were used as the control group.

RESULTS

Patient survival posttransplantation was 81.4% and 68.5% at 1 and 3 years in the HCV+ group, and 97.1% and 92.9% at 1 and 3 years in the HCV- group, respectively (P=0.001). Graft survival was 81.2% and 64.1% at 1 and 3 years in the HCV+ group, and 93.2% and 84.1% at 1 and 3 years posttransplantation in the HCV- group (P=0.01). Univariate analysis identified Knodell score as a predictor of mortality in HCV+ patients (P=0.04). Cox proportional hazards multivariate analysis identified deceased donor (P=0.02), previous kidney transplant (P=0.007), pretransplant diabetes (P=0.05), and Knodell Score (P=0.012) as predictors of patient mortality. Patient survival was superior in HCV+ patients undergoing KTx versus remaining on dialysis.

CONCLUSIONS

Patients with ESRD/HCV+ benefit from KTx without achieving the excellent survival of HCV-/ESRD patients. Liver biopsy is a useful tool to identify advanced liver disease at pretransplantation time.

Multimodality therapy and liver transplantation in patients with cirrhosis and hepatocellular carcinoma: 6 years, single-center experience

The treatment of patients with cirrhosis and hepatocellular carcinoma (HCC) has improved dramatically over the past 10 years. We conducted a 6-year prospective study, using multimodality ablation therapy (MMT) combined with liver transplantation (LTx) for patients with cirrhosis and unresectable HCC. Subjects were classified as: group 1 (n = 35), intention to treat with MMT + LTx; group 2 (n = 16), contemporaneous LTx with "incidental" HCC on explants; group 3 (n = 94), MMT alone; and group 4 (n = 19), palliative care alone. MMT included trans-arterial chemo-embolization (54.4%), trans-arterial chemo-infusion (28.6%), and radio frequency ablation (17%). Group 1, with a mean wait time of 11.6 months pre-MELD era and 5.4 months post-MELD era, had a mean of 2.4 +/- 1.2 MMTs and achieved 1- 3-, and 5-year patient survivals of 100, 100, and 76%, respectively, which was not different from group 2 (incidental HCC), namely 93, 93, and 93%, respectively; or to a contemporaneous non-HCC LTx group: namely 84.3, 78.7, and 73.9%, respectively. Despite careful pretransplant HCC staging, 22.8% (8 of 35) group 1 subjects were understaged. Those subjects in group 1 with true T1-2 stage HCC achieved 100% cancer-free survival at 5 years. Only three cases of HCC recurrence occurred in our series, all of whom were understaged. Our data suggest that pretransplant MMT followed by timely LTx provides excellent disease-free survival at 5 years for patients with true T1-2 stage HCC and cirrhosis. Pretransplant HCC understaging contributes to posttransplant HCC recurrence after LTx.

Salvage Procedure for Unexpected Portal Vein Thrombosis in Living Donor Liver Transplantation

Portal vein thrombosis (PVT) is considered a relative contraindication to living donor liver transplantation (LDLTx) due to technical difficulty and ethical considerations. So far, there have been a few reported cases of LDLTx with PVT, most of which were treated by thrombectomy with or without a venous conduit. We report a case of LDLTx in an unexpected recipient with grade 4 diffuse PVT, which was successfully managed using a variceal left gastric vein and a deceased donor iliac vein conduit to create a "de novo portal vein" for splanchnic inflow to the right lobe. The patient experienced an uneventful postoperative course with normal blood flow in the de novo portal vein at 1-year follow up. This report demonstrated that a variceal collateral vein can be used as appropriate alternative inflow for the right lobe in LDLTx cases in which an unexpected PVT is encountered.

Adult living donor versus deceased donor liver transplantation: a 6-year single center experience

No long-term (>3 years) prospective comparison of adult-to-adult living donor liver transplantation (A2ALLTx) to adult deceased donor liver transplantation (ADDLTx) has been reported. This is a prospective, IRB approved, 6-year comparison of A2ALLTx to ADDLTx. Data include: age, gender, ethnicity, primary liver disease, waiting time, pretransplant CTP/MELD score, cold ischemia time (CIT), perioperative mortality, acute and chronic rejection, graft and patient survival, charges and post-transplant complications. In 6 years, 202 ADDLTx (74.5%) and 69 A2ALLTx (25.5%) were performed at VCUHS. Hepatitis C virus (HCV) was the most common reason for transplantation in both groups (48.1% vs. 42%). Data regarding overall patient and graft survival, monetary charges and retransplantation rates were similar. Comparison of patient/graft survivals, retransplantation rates in patients with and without HCV were not statistically different. A2ALLTx patients had less acute rejection (11.5% vs. 23.9%) and more biliary complications (26.1% vs. 11.4%). Overall, A2ALLTx is as durable a liver replacement technique as the ADDLTx. Patients with A2ALLTx were younger, had lower MELD scores, less acute rejection and similar histological HCV recurrence. Biliary complications were more common in A2ALLTx but were not associated with increased graft loss compared to ADDLTx.

Non-resective ablation therapy for hepatocellular carcinoma: effectiveness measured by intention-to-treat and dropout from liver transplant waiting list

BACKGROUND

Orthotopic liver transplantation (OLT) for patients with small hepatocellular carcinoma (HCC) is widely accepted, and the usefulness of local ablation techniques as a bridge for liver transplantation is still under investigation.

METHODS

From December 1997 to February 2003, patients with cirrhosis and T0-T1-T2-T3 stage HCC received multi-modality ablative therapy (MMT) for the treatment of their HCC and were evaluated for OLT; listed, and transplanted when an allograft became available. MMT included radiofrequency ablation (RFA), and/or Trans-Arterial Chemo-Embolization (TACE), and alcohol (EtOH) ablation, followed by Trans-Arterial Chemo-Infusion (TACI), with repeated treatments based on follow up hepatic magnetic resonance imaging (MRI) during the waiting period for OLT.

RESULTS

A total of 135 HCC patients were seen at our center within this time frame. The intention-to-treat group included 33 (24.4%) patients with T0, T1, T2, T3 HCC and cirrhosis. There were 31 men and two women. The mean age was 53.6 +/- 7.2 yr. All patients received MMT with a mean of 2.90 +/- 1.5 procedures per patient. Tumor-node-metastasis (TNM) stages at time of listing were: T0 in one patient, T1 in nine patients, T2 in 17 patients, and T3 in six patients. Twenty-eight (85%) patients have received OLT. Five (12.19%) patients were listed and removed (dropout) from the transplant waiting list after waiting 5, 5, 5, 8, and 14 months respectively. The waiting time of the HCC listed group was 9.1 +/- 14.8 months with a mean follow up of 32 months. OLT patient survival and cancer-free survival are 92.9% and 95.24%, respectively; the overall survival of intention-to-treat group was 79% at 32 months follow up. Predictors of dropout included an alpha-fetoprotein (AFP, >400 ng/mL) and T3 HCC stage.

CONCLUSION

Aggressive ablation therapy with a short transplant waiting time optimizes the use of OLT for curative intent in selective cirrhotic HCC patients.

Massive hepatic artery atherosclerosis of an otherwise suitable donor liver: a case report

Most of the few reports about hepatic artery disease found in the literature describe hepatic artery aneurysms or hepatic artery calcifications. Atherosclerosis of the hepatic artery is not commonly evaluated during deceased donor liver procurement. Herein we present a case of a stable 47-year-old Caucasian female donor whose liver function tests were within normal limits and a liver biopsy showed less than 5% steatosis. The liver when received at our center appeared grossly unremarkable. Back-table evaluation showed a complete occlusion of the trunk of the proper hepatic artery. The pathology report revealed hepatic occlusion due to arterial atherosclerosis. Transplantation was canceled, and the liver was used for isolated hepatocyte perfusion, revealing < 25% hepatocyte viability. Hepatic artery atherosclerosis and patency need to be evaluated at the time of procurement to prevent recipient morbidity due to anesthetic induction, or initiation of a recipient abdominal incision prior to declining the liver graft for this rare finding.

Effects of interferon treatment on liver histology and allograft rejection in patients with recurrent hepatitis C following liver transplantation

Recurrent hepatitis C after liver transplantation remains a significant cause of graft loss and retransplantation. Although treatment of recurrent hepatitis C with interferon-based regimens has become widely accepted as safe and can lead to sustained virologic clearance of hepatitis C virus (HCV) RNA, long-term histologic improvement and the risk of precipitating graft rejection remain controversial. The present study is a retrospective evaluation of the clinical and histological consequences of treating recurrent hepatitis C with interferon-based therapy in a selected group of liver transplant recipients. Twenty-three liver transplant recipients with recurrent hepatitis C and histologic evidence of progressive fibrosis completed at least 6 months of interferon, 83% of whom received pegylated-interferon alpha-2b; only 4 tolerated ribavirin. Overall, 11 patients (48%) had undetectable HCV RNA at the end of 6 months of treatment. Of these patients, 3 remained HCV RNA-negative on maintenance interferon monotherapy for 33 months, and the other 8 (35%) completed treatment and remained HCV RNA-undetectable 24 weeks after discontinuation of interferon. Overall necroinflammatory activity in liver biopsies obtained 2 years after HCV RNA became undetectable decreased significantly (7.73 +/- 2.37 vs. 5.64 +/- 2.94 units before and after treatment, respectively; P =.016). However, 5 of these 11 patients had no histologic improvement in follow-up liver histology. Liver biopsies in the 12 nonresponders demonstrated disease progression. Of the 23 patients treated with interferon, 8 (35%) had evidence of acute or chronic rejection on posttreatment liver biopsy, most of whom had no previous history of rejection (P <.01 for comparison of pretreatment and posttreatment prevalence of histologic rejection), and 2 experienced graft loss from chronic rejection, requiring retransplantation. In conclusion, interferon treatment of recurrent hepatitis C does not consistently improve histologic disease after virologic response, and it may increase the risk of allograft rejection.

Calcineurin inhibitor-induced chronic nephrotoxicity in liver transplant patients is reversible using rapamycin as the primary immunosuppressive agent

The purpose of this study was to determine whether calcineurin inhibitor (CNI)-induced chronic nephrotoxicity in liver transplant patients is reversible by replacement of the CNI with rapamycin as the primary immunosuppressive agent. CNIs, while providing potent immunosuppression for liver transplant patients, exhibit nephrotoxicity as a major side-effect. Whereas acute CNI-induced nephrotoxicity is reversible by withdrawal of the CNI, chronic nephrotoxicity due to CNIs is a progressive process thought to be irreversible. Eight liver transplant patients with CNI-induced chronic nephrotoxicity were converted to rapamycin as the primary immunosuppressive agent. The CNI was either discontinued (four patients) or the dosage lowered to maintain a subtherapeutic level (four patients). Renal function as assessed by serum creatinine was measured before and after conversion to rapamycin. Two patients progressed to dialysis dependence following conversion to rapamycin. These two patients had been on CNIs for a mean of 112 months (range 93-131 months) prior to conversion to rapamycin. Five patients experienced improvement in renal function. These patients had been on calcineurin inhibitors for a mean of 60 months (range 42-75 months) prior to conversion. One patient with chronic nephrolithiasis as a contributing factor to his renal dysfunction has progressed to dialysis dependence despite conversion to rapamycin following exposure to a CNI for 24 months. In the five patients with improved renal function, serum creatinine levels decreased significantly (2.4 +/- 0.3 mg/dL to 1.5 +/- 0.1 mg/dL, p < 0.05) by a mean of 7.2 months (range 5-10 months) after conversion from CNI to rapamycin-based immunosuppression. Liver function remained stable after conversion to rapamycin. CNI-induced chronic nephrotoxicity can be reversed upon withdrawal of the CNI. Rapamycin is an effective replacement agent as primary immunosuppressive therapy following withdrawal of CNIs in liver transplant patients with CNI-induced chronic nephrotoxicity.

Humoral responses to pig-to-baboon cardiac transplantation: implications for the pathogenesis and treatment of acute vascular rejection and for accommodation

Organs transplanted between phylogenetically-disparate species, such as from the pig into the primate, are subject to hyperacute and acute vascular rejection. Hyperacute rejection of a porcine organ by a primate is thought to be initiated by the binding of xenoreactive natural antibodies to Galalpha1-3Gal expressed on the endothelial lining of blood vessels in the xenograft. The factor(s) which initiates acute vascular rejection is uncertain; however, there is some evidence implicating xenoreactive antibodies. The nature of the humoral response which might contribute to acute vascular rejection of a porcine organ was investigated in baboons which received a porcine cardiac xenograft plus immunosuppression with methylprednisolone, azathioprine, and cyclosporine. Following rejection and surgical removal of the xenografts, the serum concentration of xenoreactive antibodies increased in untreated animals but in immunosuppressed animals was similar to the concentration in preimmune serum. The antibodies in the sensitized recipients were specific for Galalpha1-3Gal (70-95%) and other determinants (5-30%). However, cross-blocking studies showed that, following xenotransplantation, the immunosuppressed baboons had no detectable IgM or IgG directed against "new" endothelial antigens. These results indicate that antibodies made by immunosuppressed individuals in response to xenotransplantation are much like xenoreactive natural antibodies and suggest that acute vascular rejection might in some cases be addressed by therapeutic strategies aimed at those antibodies.

The humoral immune response in humans following cross-perfusion of porcine organs

A major question in xenotransplantation is the nature of the humoral response that would occur following the transplantation of a xenogeneic organ into an immunosuppressed recipient as such a response could mediate delayed types of injury to the graft. To begin to address this issue we characterized the changes in the properties of xenoreactive antibodies occurring in patients exposed to porcine organs under conditions simulating transplantation. In two patients whose blood had been cross-perfused through porcine livers as a treatment for hepatic failure, the titer of xenoreactive IgM increased by four-fold and the titer of xenoreactive IgG increased by sixty-fold within ten days after perfusion procedures. The xenoreactive IgM and IgG antibodies were specific for Gal alpha 1-3Gal based on binding to porcine endothelial cells and bovine thyroglobulin, which express this determinant, and on the decrease in binding following treatment of porcine endothelial cells or bovine thyroglobulin with alpha-galactosidase. The sequential addition to endothelial cells of amounts of serum known to saturate antibody-binding sites obtained before and ten days after perfusion of porcine organs revealed no increase in binding of IgM above the level observed with serum obtained before perfusion, suggesting that new determinants were not identified. Moreover, the functional avidity of binding to porcine endothelial cells of IgM in serum obtained before and ten days after perfusion of porcine organs was unchanged. Even at later times, the presence of newly elicited antibodies against porcine aortic endothelial cell targets was not detected. Thus, exposure to porcine antigens in a vascularized organ results in increases in the levels of xenoreactive IgM and IgG antibodies--however, these antibodies exhibit properties similar to natural antibodies.

Variation in the level of xenoantigen expression in porcine organs

Hyperacute rejection of vascularized porcine to primate xenografts is initiated by the binding of xenoreactive natural antibodies to donor endothelium. We tested the hypothesis that the level of xenoantigen expression varies in the population of potential porcine donors and may determine the amount of binding of xenoreactive natural antibodies to a porcine organ perfused by xenogeneic blood. Two hundred ninety pigs were studied using an inhibition ELISA that quantitated the xenoantigen level on porcine platelets. Based on this assay, the levels of xenoantigen expression in the population adhered to a normal distribution. Kidneys from pigs found to express high antigen levels and kidneys from pigs found to express low antigen levels were perfused with baboon blood using an extracorporeal circuit. In multiple experiments, a significant difference was observed in the amount of xenoreactive natural antibody adsorbed by high antigen versus low antigen organs. Normalizing for the weight of the perfused organs and for levels of natural antibody in individual baboons, high antigen organs adsorbed 3.6 +/- 1.3 U of xenoreactive natural antibody/g and low antigen organs adsorbed -0.8 +/- 1.0 U of xenoreactive natural antibody/g (P < 0.002). Immunopathology of tissues from the perfused organs demonstrated more deposition of IgM and C4 in high than in low xenoantigen organs. The quantitative relationship between binding of xenoreactive natural antibodies to platelets and to whole organs suggests that platelets are a valid representation of endothelial cell antigen expression in vivo. Despite the probable importance of Gal alpha(1-3)Gal as an epitope recognized by xenoreactive natural antibodies, differences in the binding to platelets or to organs of the GS-I-B4 lectin that recognizes that sugar had no correlation with the differences in binding of IgM to these tissues. Variation in expression of xenoantigen may be exploited to selectively breed donors for xenotransplantation that are less susceptible to attack by xenoreactive natural antibodies.

Cardiac xenografts between primate species provide evidence for the importance of the alpha-galactosyl determinant in hyperacute rejection

Transplants performed between phylogenetically disparate species are subject to hyperacute rejection initiated by binding of xenoreactive natural Abs to endothelium in the donor organ. Binding of these Abs activates complement, leading to tissue injury and destruction of the graft. Human xenoreactive natural Abs recognize Gal alpha 1-3Gal beta 1-4GlcNAc (galactose alpha 1-3galactose beta 1-4-N-acetylglucosame); however, the relative importance of this Ag in graft rejection has not been proved. The present study was conducted to test the potential importance of alpha-galactosyl (alpha-Gal) determinants in the pathogenesis of hyperacute rejection. To this end, hearts (n = 3) from New World monkeys (Saimiri scureus, squirrel monkey), which can synthesize Gal alpha 1-3Gal, were transplanted heterotopically into Old World monkeys (Papio species, baboon), which do not synthesize Gal alpha 1-3Gal determinants and which have circulating anti-alpha Gal Abs. The xenografts were rejected in 51 to 56 min (mean +/- SD = 53.3 +/- 2.5), results similar to those observed in porcine grafts transplanted into baboons. Histologic analysis of the hearts revealed thrombosis and intraparenchymal hemorrhage and immune deposits consisting of IgM, Clq, C3, C4, C5b, and the membrane attack complex, but not properdin or factor B of the recipient deposited on graft endothelium. Sera obtained from baboons after perfusion of squirrel monkey kidneys revealed depletion of alpha-Gal-specific Abs and anti-pig endothelial cell Abs. These findings provide strong evidence that the Abs that accumulate in New World monkey organs during perfusion with baboon blood are the same Abs that would accumulate in a porcine organ transplanted into a primate and suggest that hyperacute rejection is not necessarily a reflection of phylogenetic distance but that the expression of terminal alpha-Gal residues provides an adequate target to initiate that process.

Cardiac xenografts between primate species provide evidence for the importance of the alpha-galactosyl determinant in hyperacute rejection

Transplants performed between phylogenetically disparate species are subject to hyperacute rejection initiated by binding of xenoreactive natural Abs to endothelium in the donor organ. Binding of these Abs activates complement, leading to tissue injury and destruction of the graft. Human xenoreactive natural Abs recognize Gal alpha 1-3Gal beta 1-4GlcNAc (galactose alpha 1-3galactose beta 1-4-N-acetylglucosame); however, the relative importance of this Ag in graft rejection has not been proved. The present study was conducted to test the potential importance of alpha-galactosyl (alpha-Gal) determinants in the pathogenesis of hyperacute rejection. To this end, hearts (n = 3) from New World monkeys (Saimiri scureus, squirrel monkey), which can synthesize Gal alpha 1-3Gal, were transplanted heterotopically into Old World monkeys (Papio species, baboon), which do not synthesize Gal alpha 1-3Gal determinants and which have circulating anti-alpha Gal Abs. The xenografts were rejected in 51 to 56 min (mean +/- SD = 53.3 +/- 2.5), results similar to those observed in porcine grafts transplanted into baboons. Histologic analysis of the hearts revealed thrombosis and intraparenchymal hemorrhage and immune deposits consisting of IgM, Clq, C3, C4, C5b, and the membrane attack complex, but not properdin or factor B of the recipient deposited on graft endothelium. Sera obtained from baboons after perfusion of squirrel monkey kidneys revealed depletion of alpha-Gal-specific Abs and anti-pig endothelial cell Abs. These findings provide strong evidence that the Abs that accumulate in New World monkey organs during perfusion with baboon blood are the same Abs that would accumulate in a porcine organ transplanted into a primate and suggest that hyperacute rejection is not necessarily a reflection of phylogenetic distance but that the expression of terminal alpha-Gal residues provides an adequate target to initiate that process.

Human complement regulatory proteins protect swine-to-primate cardiac xenografts from humoral injury

The susceptibility of xenografts to hyperacute rejection is postulated to reflect in part failure of complement regulatory proteins (CRPs) to control activation of heterologous complement on graft endothelium. To test this concept, transgenic swine expressing the human CRP decay accelerating factor and CD59 were developed using a novel expression system involving transfer of the proteins from erythrocytes to endothelial cells. Hearts from transgenic swine transplanted into baboons had markedly less vascular injury and functioned for prolonged periods compared to hearts from nontransgenic swine. These results indicate that expression of human CRPs in xenogeneic organs may contribute to successful xenografting and suggest that intercellular protein transfer might be a useful approach for expression of heterologous proteins in endothelial cells.

Graft-versus-host reaction-induced immune modulation. I. Donor-recipient genetic disparity and the differential expression of Lyt-2, L3T4, and Ly-6 during acute reactions in the host thymus

To investigate the effects of graft-vs-host reactions (GvHR) on cells in a central lymphoid compartment, GvHR were induced across class I/II or class II only major histocompatibility complex differences utilizing the parent into nonirradiated F1 hybrid (P----F1) model. Thymocytes were subsequently examined during the acute stage of GvHR for the expression of Lyt-2, L3T4, and Ly-6 cell surface molecules. Class I/II "suppressive" GvHR resulted in a dramatic decrease (greater than 85%) in total thymocyte numbers by 2 wk after parental cell injection. Although a dramatic decrease in the percentages of Lyt-2 (85%----30%) and L3T4 (95%----50%) expression was observed, the percentage of thymocytes expressing Ly-6 was markedly increased compared to uninjected controls (5%----greater than 80%). This increased percentage was not due solely to a selective loss of Ly-6 negative cells from the thymus, since the actual number of Ly-6 positive cells was greater in GvHR mice than in controls. Class II GvHR during the same time interval resulted in a less dramatic decrease (20 to 60%) in total thymocyte numbers. In addition, the effect on the percentages of Lyt-2 (85%----approximately 70%) and L3T4 (95%----approximately 85) expression was subtle and transient. However, intrathymic Ly-6 expression was again clearly enhanced (5%----20 to 30%). Class I/II "proliferative" or "stimulatory" GvHR differ from "suppressive" reactions in that they are characterized by stimulatory pathologic symptoms and the appearance of autoimmune abnormalities. Such GvHR were found to result in minimal alteration of total thymocyte numbers. Similarly, the percentage expression of Lyt-2 and L3T4 was marginally affected. However, the percentage of Ly-6 expression was increased from 5%----20 to 30% and thus these intrathymic lymphocyte profiles more closely resemble those of class II as compared to class I/II "suppressive" GvHR. The present findings therefore demonstrate that major histocompatibility complex differences alone do not necessarily determine the effects of GvHR on recipient thymocytes and that Ly-6 is a useful marker for the early detection of GvHR-associated immunologic events.

Graft-versus-host reaction-induced immune modulation. I. Donor-recipient genetic disparity and the differential expression of Lyt-2, L3T4, and Ly-6 during acute reactions in the host thymus

To investigate the effects of graft-vs-host reactions (GvHR) on cells in a central lymphoid compartment, GvHR were induced across class I/II or class II only major histocompatibility complex differences utilizing the parent into nonirradiated F1 hybrid (P----F1) model. Thymocytes were subsequently examined during the acute stage of GvHR for the expression of Lyt-2, L3T4, and Ly-6 cell surface molecules. Class I/II "suppressive" GvHR resulted in a dramatic decrease (greater than 85%) in total thymocyte numbers by 2 wk after parental cell injection. Although a dramatic decrease in the percentages of Lyt-2 (85%----30%) and L3T4 (95%----50%) expression was observed, the percentage of thymocytes expressing Ly-6 was markedly increased compared to uninjected controls (5%----greater than 80%). This increased percentage was not due solely to a selective loss of Ly-6 negative cells from the thymus, since the actual number of Ly-6 positive cells was greater in GvHR mice than in controls. Class II GvHR during the same time interval resulted in a less dramatic decrease (20 to 60%) in total thymocyte numbers. In addition, the effect on the percentages of Lyt-2 (85%----approximately 70%) and L3T4 (95%----approximately 85) expression was subtle and transient. However, intrathymic Ly-6 expression was again clearly enhanced (5%----20 to 30%). Class I/II "proliferative" or "stimulatory" GvHR differ from "suppressive" reactions in that they are characterized by stimulatory pathologic symptoms and the appearance of autoimmune abnormalities. Such GvHR were found to result in minimal alteration of total thymocyte numbers. Similarly, the percentage expression of Lyt-2 and L3T4 was marginally affected. However, the percentage of Ly-6 expression was increased from 5%----20 to 30% and thus these intrathymic lymphocyte profiles more closely resemble those of class II as compared to class I/II "suppressive" GvHR. The present findings therefore demonstrate that major histocompatibility complex differences alone do not necessarily determine the effects of GvHR on recipient thymocytes and that Ly-6 is a useful marker for the early detection of GvHR-associated immunologic events.