Low-dose aspirin confers protection against acute cellular allograft rejection after primary liver transplantation

Comparing the efficacy and safety of thromboprophylaxis with enoxaparin versus normal saline after liver transplantation: randomized clinical trial

BACKGROUND

Venous thrombosis represents a significant complication after deceased-donor liver transplantation, yet there are currently no established protocols for thromboprophylaxis after deceased-donor liver transplantation. The aim of this study was to evaluate the efficacy and safety of prophylactic anticoagulation in patients undergoing deceased-donor liver transplantation.

METHODS

A dual-centre RCT of patients assigned to receive either enoxaparin or normal saline after liver transplantation was conducted. The primary efficacy outcome was the incidence of venous thrombosis (portal vein thrombosis and deep vein thrombosis) and the primary safety outcome was the incidence of major bleeding.

RESULTS

A total of 462 patients were recruited. In the intention-to-treat analysis, 89 patients (19.3%) experienced venous thrombosis and 141 patients (30.5%) experienced major bleeding within 90 days after transplantation. No significant differences were observed in the incidence of venous thrombosis, portal vein thrombosis, or deep vein thrombosis between the two groups in the intention-to-treat cohort. The anticoagulant group demonstrated a markedly elevated incidence of major bleeding (35.5% versus 25.5%, P = 0.020). Subgroup analysis revealed that anticoagulation was associated with a lower risk of deep vein thrombosis in hepatocellular carcinoma patients (HR 0.44 (95% c.i. 0.23 to 0.86), P = 0.016), without a significantly higher risk of major bleeding.

CONCLUSION

Use of prophylactic anticoagulation with enoxaparin is associated with a significantly higher incidence of major bleeding in patients undergoing deceased-donor liver transplantation, rather than a lower likelihood of venous thrombosis.

REGISTRATION NUMBER

ChiCTR2000032441 (www.chictr.org.cn).

Antiplatelet Prophylaxis Reduces the Risk of Early Hepatic Artery Thrombosis Following Liver Transplantation in High-Risk Patients

The prevention of hepatic artery thrombosis (HAT) is pivotal for graft survival immediately after liver transplantation (LT). This study aimed to identify risk factors (RF) for early HAT (eHAT) and assess the benefit of antiplatelet prophylaxis (AP). This retrospective single-center study included 836 adult patients who underwent LT between 2007 and 2022. AP was administered for 3 months in N = 127 patients for surgical reasons. In total, 836 patients underwent LT, of whom 5.5% developed eHAT. In multivariable analysis, arterial anastomotic redo (aHR = 4.33), arterial reconstruction (aHR = 3.72) and cryptogenic liver cirrhosis (aHR = 4.25) were independent RFs for eHAT and AP appeared to be protective (aHR = 0.18). Indeed, in patients with at least one RF who received AP (RF+AP+, n = 94), the eHAT rate was significantly lower (3.2% vs. 21.3%, p < 0.001) than in those with RF who did not receive AP (RF+AP-, n = 89). The effect was even more pronounced when focusing on surgical RF alone (i.e., redo and/or reconstruction) with an additional improvement in 1 year graft survival of 85.3% vs. 70.4%, p = 0.02. AP did not pose an increased risk of bleeding. In conclusion, the main RFs for eHAT include arterial anastomotic redo, arterial reconstruction and cryptogenic liver cirrhosis as LT indications. Our results suggest that AP may protect against eHAT development in these high-risk patients.

Acetylsalicylic acid use and development of cardiac allograft vasculopathy: A national prospective study using highly automated 3-D optical coherence tomography analysis

BACKGROUND

There is conflicting evidence on the role of acetylsalicylic acid (ASA) use in the development of cardiac allograft vasculopathy (CAV).

METHODS

A nationwide prospective two-center study investigated changes in the coronary artery vasculature by highly automated 3-D optical coherence tomography (OCT) analysis at 1 month and 12 months after heart transplant (HTx). The influence of ASA use on coronary artery microvascular changes was analyzed in the overall study cohort and after propensity score matching for selected clinical CAV risk factors.

RESULTS

In total, 175 patients (mean age 52 ± 12 years, 79% male) were recruited. During the 1-year follow-up, both intimal and media thickness progressed, with ASA having no effect on its progression. However, detailed OCT analysis revealed that ASA use was associated with a lower increase in lipid plaque (LP) burden (p = .013), while it did not affect the other observed pathologies. Propensity score matching of 120 patients (60 patient pairs) showed similar results, with ASA use associated with lower progression of LPs (p = .002), while having no impact on layered fibrotic plaque (p = .224), calcification (p = .231), macrophage infiltration (p = .197), or the absolute coronary artery risk score (p = .277). According to Kaplan-Meier analysis, ASA use was not associated with a significant difference in survival (p = .699) CONCLUSION: This study showed a benefit of early ASA use after HTx on LP progression. However, ASA use did not have any impact on the progression of other OCT-observed pathologies or long-term survival.

Detrimental impact of early biopsy-proven rejection in liver transplantation

Existing literature offers conflicting conclusions about whether early acute cellular rejection influences long-term outcomes in liver transplantation. We retrospectively collected donor and recipient data on all adult, first-time liver transplants performed at a single center between 2008 and 2020. We divided this population into two cohorts based on the presence of early biopsy-proven acute cellular rejection (EBPR) within the first 90 days post-transplant and compared outcomes between the groups. There were 896 liver transplants that met inclusion criteria with 112 cases (12.5%) of EBPR. Recipients who developed EBPR had higher biochemical Model for End-Stage Liver Disease scores (28 vs. 24, p < .01), but other donor and recipient characteristics were similar. Recipients with EBPR had similar overall survival compared to patients without EBPR (p = .09) but had decreased graft survival (p < .05). EBPR was also associated with decreased time to first episode of late (> 90 days post-transplant) rejection (p < .0001) and increased vulnerability to bacterial and viral infection (p < .05). In subgroup analysis of recipients with autoimmune indications for liver transplantation, EBPR had a more pronounced association with patient death (hazard ratio [HR] 3.9, p < .05) and graft loss (HR 4.0, p < .01). EBPR after liver transplant is associated with inferior graft survival, increased susceptibility to late rejections, and increased vulnerability to infection.

Determinants of early surgical complications after pediatric liver transplantation: A single center/single surgeon experience over 20 years

BACKGROUND

The risk of early surgical complications of liver transplantation (LT) is higher in children when compared with adults. The aims of the present retrospective study from a single center cohort/single surgeon were to identify the predictive factors for surgical complications after pediatric LT.

METHODS

All children receiving a first LT from October 1990 to October 2010 in our center were included.

RESULTS

Included 151 children (boys 55.0%), with a mean age of 4.8 ± 4.8 years, and a mean weight of 17.9 ± 14.4 kg. Thirty-seven patients were transplanted within the first year, and 59 patients had a body weight below 10 kg. The main initial liver disease was biliary atresia (49.0%). Living donor LT was performed in 39 cases (25.8%), cadaveric whole liver LT in 50 cases (33.1%), and cadaveric partial liver LT in 62 cases (41.1%). Early surgical complications included reoperation (37.8%), vascular complications (8.6%), i.e. arterial (3.3%) or portal thrombosis/stenosis (7.3%) within the first month, and biliary complications in the first 90 days occurred in 22.5% of the cases. The main indications for surgical revision were abdominal bleeding, treatment of a biliary complication, and bowel perforation. Multivariate analysis disclosed that only graft type (split and moreover from a living donor) was significantly and independently associated with the occurrence of biliary complication, and that indication for LT, period, graft type, and operative time were significantly and independently associated with the necessity of surgical revision.

CONCLUSION

Our results emphasize that surgical complications are frequent and strongly depend on patient/graft characteristics.

Importance of Anatomical Variation of the Hepatic Artery for Complicated Liver and Pancreatic Surgeries: A Review Emphasizing Origin and Branching

Knowledge of anatomical variations of the hepatic artery from its origin to intrahepatic segmentation is of utmost importance for planning upper abdominal surgeries including liver transplantation, pancreatoduodenectomy, and biliary reconstruction. The origin and branching pattern of the hepatic artery was thoroughly described by the classification of Michels and Hiatt. Some rare variations of the hepatic artery were classified by Kobayashi and Koops. By the use of the multidetector computed tomography (MDCT) technique, the branching pattern of the hepatic artery can be visualized quite accurately. Unawareness of these arterial variations may lead to intraoperative injuries such as necrosis, abscess, and failure of the liver and pancreas. The origin and course of the aberrant hepatic arteries are crucial in the surgical planning of carcinoma of the head of the pancreas and hepatobiliary surgeries. In liver transplant surgeries, to minimize intraoperative bleeding complications and postoperative thrombosis, exact anatomy of the branching of the hepatic artery, its variations and intrahepatic course is of utmost importance. This review discusses variations in the anatomy of the hepatic artery from its origin to branching by the use of advanced imaging techniques and its effect on the liver, pancreatic, biliary and gastric surgeries.