Hepatic Artery Thrombosis Research Articles

Negative dynamics of the hepatic artery resistive index as a predictor of early arterial thrombosis after deceased donor liver transplantation

Aim. The study aim was to assess the negative dynamics of the hepatic artery resistive index as a reliable predictor of early thrombosis in liver transplant recipients from a postmortem donor, to determine risk factors and to identify a group of patients with an increased risk of this complication.Material and methods. From July 2018 to August 2021, 92 orthotopic liver transplants from a deceased donor were performed at the Surgical Clinic of the City Clinical Hospital n.a. S.P. Botkin. All liver grafts were taken from donors with brain death. Control Doppler ultrasound examination of hepatic blood flow in all patients was performed on days 1, 3, 5, 7, if necessary, daily. The hepatic arteries resistive index was considered normal at values from 0.55-0.79, high at 0.8-0.89, extremely high above 0.9. Depending on the resistive index value on the 1st postoperative day and its further dynamics, we divided the patients into 3 groups. In each group, we analyzed the incidence of hepatic artery thrombosis and assessed the impact of various risk factors on the resistive index elevation on the 1st day after surgery and on its growth during dynamic observation in the early postoperative period.Results. Of 92 liver transplants, in three cases, we recorded hepatic artery thrombosis (3.2%), which was not associated with technical difficulties of arterial reconstruction. No mortality was recorded in all three cases. In patients with a normal or high resistive index on the 1st day, without its increase during dynamic observation, the incidence of arterial thrombosis was 0%. In patients with a normal or high resistive index on the 1st day, and its increase during dynamic observation, as well as in patients with an extremely high resistive index on the 1st day, the incidence of arterial thrombosis was 18.1% and 11.1%, respectively. The risk factors of thrombosis were the age of the recipient over 50 years old in an extremely high resistive index on the 1st postoperative day (p=0.024), and the age of the donor over 50 years old in the growth of the resistive index during follow-up (p=0.04).Conclusion. The lack of positive dynamics in the hepatic artery resistive index reduction may be an additional predictor of arterial thrombosis after liver transplantation. This fact makes it possible to identify a high-risk group of arterial thrombosis, to take additional preventive measures in these patients and to improve the immediate results of treatment in this group of patients.

A Long Graft Artery is a Safe and Reproducible Procedure for Arterial Reconstruction In Liver Transplantation

Although a short and nonredundant anastomosis is most often performed in liver transplantation, there is no strong evidence in the literature about the ideal arterial reconstruction. We describe here the "long-artery" technique that enables a wide side-to-end anastomosis and preserves arterial length. We present the results between 2011 and 2019 of the "long-artery" technique performed in our center. Patients with a split liver transplantation or aortohepatic conduits were not included. This technique uses the whole arterial axis of the graft. A side-to-end anastomosis is performed between the common and/or proper hepatic artery of the recipient, and the celiac trunk with an aortic patch of the graft, while the gastroduodenal artery of the recipient is preserved. An omental flap is positioned under the graft artery to prevent kinking. Eight hundred thirty-two transplant patients were included in the analysis. Early hepatic artery thrombosis was diagnosed in 22 (2.6%) patients and occurred within the first 10 days after the procedure. A thrombectomy was performed in 7 patients, which was successful in 4 patients, and 18 patients were retransplanted. Seven patients (0.8%) developed a late hepatic artery thrombosis, including 2 patients who were retransplanted. The "long-artery" technique is a safe and efficient technique for arterial reconstruction in liver transplantation and does not seem to increase the rate of early hepatic artery thrombosis.

Multimodality Imaging after Liver Transplant: Top 10 Important Complications.

Patients who have undergone liver transplant are now regularly seen in day-to-day radiology practice. All surgical techniques for liver transplant require arterial, portal venous, hepatic venous and caval, and biliary anastomoses. This review is focused on the 10 "not to be missed" complications of liver transplant that affect the health and life of the graft and graft recipient. Arterial complications are the most common and devastating. Early hepatic artery thrombosis may be catastrophic because the biliary tree is solely dependent on the hepatic artery after transplant and collateral vessels have not yet formed. In contrast, delayed hepatic artery thrombosis may be more insidious as collateral arteries develop. US findings of delayed hepatic artery thrombosis may be similar to those of hepatic artery stenosis and celiac artery stenosis. Splenic artery steal syndrome is an increasingly recognized cause of graft ischemia. Venous complications are much less common. Hepatic venous and caval complications are notable for their increased incidence in living-donor and pediatric transplants. Biliary complications often result from arterial ischemia. Biliary cast syndrome is a notable example in which ischemic biliary mucosa sloughs into and obstructs the duct lumens. Neoplasms also may occur within the hepatic graft and may be due to recurrent malignancy, posttransplant lymphoproliferative disorder, or metastases. US is the initial imaging modality of choice, particularly in the acute postoperative setting. Further evaluation with contrast-enhanced US, CT, or MRI; catheter angiography; endoscopic retrograde cholangiopancreatography; and/or nuclear medicine studies is performed as needed. An invited commentary by Bhargava is available online. Online supplemental material is available for this article. ©RSNA, 2022.

An Incidental Finding of Spontaneous Hepatic Artery Thrombosis in a Healthy Patient

Hepatic artery thrombosis (HAT) outside the setting of liver transplantation is exceedingly rare. Few cases of HAT leading to hepatic infarction have been reported, and management strategies have varied from symptom control to anticoagulation and antiplatelet therapy. Cases of spontaneous HAT without hepatic dysfunction, however, have not been previously reported. We report the case of an incidentally found spontaneous HAT without signs of hepatic dysfunction or injury in an otherwise healthy 45-year-old woman. Treatment consisted of therapeutic anticoagulation and antiplatelet therapy. Resolution of the HAT was confirmed by follow-up ultrasound imaging, and the patient remained free of HAT at 12-month follow-up magnetic resonance imaging.

Surgical Outcomes of Domino Liver Transplantation Using Grafts From Living Donors With Familial Amyloid Polyneuropathy.

Domino liver transplantation (DLT) using grafts from donors with familial amyloid polyneuropathy is an acceptable procedure for expanding the donor pool. The vascular and biliary reconstructions in living donor DLT (LDDLT) are technically demanding, and data on the short-term and long-term surgical outcomes of domino donors and recipients in LDDLT are limited. In this study, we identified 25 domino recipients from our liver transplantation program (1999-2018), analyzed the vascular and biliary reconstructions performed, and evaluated the surgical outcomes, including graft survival. Piggyback technique was adopted in all 25 domino donors. The only surgical complication in domino donors was hepatic vein (HV) stenosis with an incidence rate of 4%. In 22 domino recipients, right HV and middle/left HV were reconstructed separately. A total of 10 recipients had 2 arteries anastomosed, and 18 underwent duct-to-duct biliary anastomosis. HV stenosis and biliary stricture had incidence rates of 8% and 24%, respectively, in the recipients, but none of them developed hepatic artery thrombosis. The 1-year and 5-year graft survival rates were 100% each in the domino donors, and 84.0% and 67.3% in the domino recipients, respectively. In conclusion, LDDLT has acceptable outcomes without increasing the operative risk in donors despite the demanding surgical technique involved.

Recurrent HCC: First indication for liver resections in liver transplantation recipients - 39 years of experience at an international reference center

Background: Liver resections (LR) in liver transplantation recipients (LTR) are extremely rare. The reason for LR in LTR include: management of hepatic artery thrombosis (HAT), ischemic biliary lesions (IBL), liver abscess, liver trauma and recurrence of malignancies (specially hepatocellular carcinoma-HCC). Even though re-transplantation is the treatment of choice for complications like HAT or IBL; organ shortage, increasing time in waiting lists, and the decreased survival after re-transplantation, have encouraged graft-saving procedures.

Application of continuous renal replacement therapy in infants with acute kidney injury after liver transplantation

To investigate the clinical application of continuous renal replacement therapy (CRRT) in infants with acute kidney injury (AKI) after liver transplantation. A retrospective study was conducted on infants with AKI after liver transplantation in Tianjin First Center Hospital from January 1, 2019 to June 1, 2021. Infants with AKI within 1 year after liver transplantation were divided into CRRT group and non-CRRT group according to whether CRRT was performed. The preoperative and intraoperative condition, the postoperative complications were compared, the risk factors of CRRT for AKI infants, the clinical characteristics of CRRT were analyzed, and the prognosis between CRRT group and non-CRRT group were compared. (1) A total of 512 cases of pediatric liver transplantation were performed. A total of 189 cases (36.9%) developed AKI within 1 year after surgery, including 18 cases in CRRT group and 171 cases in non-CRRT group. (2) There was no significant difference in preoperative conditions between the two groups. The duration of liver transplantation (hours: 8.8±1.5 vs. 7.5±1.3) and intraoperative blood loss [mL: 370 (220-800) vs. 310 (200-400)] in CRRT group were significantly higher than those in non-CRRT group. CRRT group had significantly higher incidence of postoperative complication [unplanned operation: 8 cases (44.4%) vs. 14 cases (8.2%), primary nonfunction: 1 case (5.6%) vs. 0 case (0%), retransplantation: 3 cases (16.7%) vs. 0 case (0%), hepatic artery thrombosis: 3 cases (16.7%) vs. 4 cases (2.3%), intestinal fistula: 2 cases (11.1%) vs. 2 cases (1.2%)] than non-CRRT group (all P < 0.05). (3) The average start time of CRRT was 10 (1-240) days. The per capita frequency of CRRT treatment was 3.3 (1.0-14.0) times. The average duration of each CRRT treatment was 10.1 (6.0-19.3) hours, the average reduction rate of serum creatinine (SCr) was 25.6% (13.5%-45.0%) after CRRT. (4) In CRRT group, 5 patients died, the 1-year and 2-year survival rates were both 72.22%. In non-CRRT group, 6 patients died, the 1-year and 2-year survival rates were 97.1% and 96.5%, respectively. There were significant differences in 1-year and 2-year survival rates between the two groups (both P < 0.01). The incidence of AKI after pediatric liver transplantation was high, and most infants treated with CRRT were associated with serious surgical complications. CRRT was a powerful means to remove inflammatory factors and maintain the stability of circulation and internal environment, which could improve the multi-organ dysfunction effectively.

North American Biliary Stricture Management Strategies in Children After Liver Transplantation: A Multicenter Analysis From the Society of Pediatric Liver Transplantation (SPLIT) Registry.

Biliary strictures affect 4%-12% of pediatric liver transplantations. Biliary strictures can contribute to graft loss if left untreated; however, there remains no consensus on the best course of treatment. Study objectives included analyses of outcomes associated with biliary stricture management strategies via percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP), or surgery. We identified pediatric liver transplantation recipients (2011-2016) with biliary strictures from the Society of Pediatric Liver Transplantation (SPLIT) registry and retrieved imaging, procedural, and operative reports from individual centers. Subanalyses were performed to specifically evaluate PTC and ERCP for "optimal biliary outcome" (OBO), defined as graft survival with stricture resolution and without recurrence or surgery. A total of 113 children with a median follow-up of 3.9years had strictures diagnosed 100days (interquartile range, 30-290) after liver transplantation; 81% were isolated anastomotic strictures. Stricture resolution was achieved in 92% within 101days, more frequently with isolated anastomotic strictures (96%). 20% of strictures recurred, more commonly in association with hepatic artery thrombosis (32%). Patient and graft survival at 1 and 3 years were 99% and 98% and 94% and 92%, respectively. In a subgroup analysis of 79 patients with extrahepatic strictures managed by PTC/ERCP, 59% achieved OBO following a median of 4 PTC, and 75% following a median of 3 ERCP (P<0.001). Among patients with OBO, those with ERCP had longer time intervals between successive procedures (41, 47, 54, 62, 71days) than for PTC (27, 31, 36, 41, 48days; P<0.001). Allograft salvage was successful across all interventions. Stricture resolution was achieved in 92%, with 20% risk of recurrence. Resolution without recurrence was highest in patients with isolated anastomotic strictures and without hepatic artery thrombosis.

Effect of magnification in pediatric liver transplantation: Asystematic review and meta-analysis.

Hepatic artery thrombosis (HAT) represents a devastating and often fatal complication of liver transplantation. Due to the small vessel caliber in pediatric patients, the use of an operating microscope has largely become the standard for hepatic artery reconstruction to reduce the rate of HAT. Recent evidence, however, suggests that loupe magnification for anastomosis may be equally effective. We aimed to determine the effect of magnification on the rate of hepatic artery thrombosis in pediatric liver transplantation. A systematic search of the literature was conducted. Thousand eighty-eight unique titles were assessed by two independent reviewers. Studies directly comparing rates of HAT from loupe magnification and operating microscope-assisted anastomoses were eligible for meta-analysis. Among primary transplants, the rate of HAT was 6.0%. Operating microscope anastomosis was associated with a 2.6% decrease in the rate of HAT compared to that of loupe magnification (4.9% and 7.4%, respectively, p<.040). When re-transplants were included, the rate of HAT was 5.8%. Operating microscope anastomosis was associated with a 1.0% decrease in the rate of HAT compared to that of loupe magnification (5.3% and 6.3%, respectively, p<.279). Meta-analysis of eligible studies demonstrated a reduction in the rate of HAT with the use of an operating microscope (p<.03). Anastomosis under an operating microscope may be associated with decreased rates of HAT in children undergoing primary liver transplantation. Further high-quality studies comparing the two techniques are needed.

Diagnosis and treatment of splenic artery steal syndrome after liver transplantation

AbstractIntroductionSplenic artery steal syndrome is a phenomenon which cause graft ischaemia and dysfunction after liver transplantation.Case PresentationA 31 year old women underwent living donor liver transplantation (LDLT) with a diagnosis of cryptogenic liver cirrhosis. In postoperative follow‐up liver enzymes were elevated. Dynamic computed tomography and digital subtraction angiography revealed splenic artery steal syndrome. Splenic artery ligation was performed for treatment.DiscussionThe diagnosis of splenic artery steal syndrome is made by the presence of slowed hepatic artery flow compared to the splenic artery without hepatic artery thrombosis or stenosis on digital subtraction angiography.ConclusionAlthough interventional radiological procedures are the first‐line treatment method, surgical treatment methods (splenectomy, splenic artery ligation) are successful in increasing hepatic artery flow.

Whole liver transplantation in children under 10 kg: How to minimize the high risks of a still challenging procedure.

Whole liver transplantation in infants <10kg is a rare procedure with moderate outcomes (67%-79% graft survival at 1year) and high rates of vascular complications (hepatic artery thrombosis 5-26%). Retrospective single-center analysis of whole liver transplantation in infants <10kg and systematic review of the literature focused on survival rates and surgical complications. Between January 2005 and December 2020, 175liver transplantations in 173 children were performed at our center. A total of 92 (53%) children weighed less than 10kg; 19 (21%) of them underwent WLT and constitute the study population. Median age of the recipients was 10months (21days-24months) and median body weight 6.5 (3.1-9.8) kg. Median age of the donors was 5 (1-84) months and median body weight 6.1 (4-21) kg. Median donor-to-recipient body weight ratio was 1.2 (range: 0.6-4.5). Postoperatively, neither hepatic artery nor portal vein thrombosis occurred. A biliary complication occurred in 4 cases: 1 bile leak (early), 3 anastomotic stenoses (1 delayed and 2late), and 1 non-anastomotic stenosis (late). Patient survival rate at 1, 5, and 10years was 100%, 92%, and 92%, respectively. Overall, death-censored graft survival after 1, 5, and 10 was 100%. Our results are excellent in terms of complications and graft and patient survival. This involves not only high-end surgical performance but also close interdisciplinary perioperative cooperation based on strong standard operating procedures and mainly focused on fluid management, hemostasiology, and strict monitoring of vessel patency.

Vascular Reconstruction and Outcomes of Adult-to-Adult Right Lobe Living Donor Liver Transplantations: A Single Center Experience in Viet Nam

Introduction: Outflow and inflow reconstruction of the liver graft is a key to successful results of living donor liver transplantation (LDLT) using right lobe graft. Methods: We prospectively analyzed the data on all right lobe LT adult patients, consecutively performed from January 2019 to December 2020 in Central Military Hospital 108. When the remnant and total liver volume ratio (RLV/ TFLV) less than 35%, we used modified right lobe (MRL) graft. In the case using extended right lobe (ERL) graft (RLV/ TFLVgreater than 35%), we conjoined MHV and RHV. Reconstruction of the portal vein (PV) was done by end-to-end anastomosis by using continuous sutures. Reconstruction of the hepatic artery was done by end-to-end anastomosis by using continuous sutures and surgical loupes. Results: A total of 52 cases of adult-to-adult LDLT using right lobe graft were collected. For hepatic vein reconstruction, there were 10 cases using MRL and 42 cases of ERL. The intervention rate for outflow stenosis was 0/52 case (0%) of a mean follow- up of 11.4±6.5 months (range, 1-28 months). PV stenosis were detected in 2 patients (3,8%) whom were successfully treated with stent placement. No hepatic artery thrombosis and hepatic artery stenosis were found after LDLTs. Conclusion: The single orifice hepatic vein reconstruction in LDLT using right lobe graft is a simple and feasible surgical technique and it can prevent effectively RHV stenosis. PV stent placement was technically and clinically effective technique in managing PV stenosis after LDLT.

Clinical Outcomes of Adult Living Donor Liver Transplantation in High MELD Recipients: A Systematic Review and Meta-Analysis

Introduction: There is a clear survival advantage of living donor liver transplantation (LDLT) over waiting for deceased donor liver transplantation (DDLT) for patients with low Model for End-Stage Liver Disease (MELD) score. Results from several centers suggest that the outcomes following LDLT in patients with high-MELD(HM) and low-MELD(LM) are comparable. The aim of study was to verify this observation by performing a meta-analysis of available literature to determine patient survival and graft survival and postoperative outcomes. Methods: Following PROSPERO registration CRD-42021261501, a systematic database search was conducted for literature published between 1990-2021. Ten studies with 2,183 LDLT recipients were identified (N=490 HM group and N=1,693 LM group) and meta-analysis was performed using RevMan 5.3 and STATA/SE-16. Results: Patients in the HM group had comparable mortality at 1, 3 and 5 years post-transplant compared to patients LM group (5-year Hazard Ratio(HR)1.19; 95%CI 0.79-1.79; P-value 0.40). Graft survival was also comparable (5-year HR1.08; 95%CI 0.72-1.63; P-value 0.71.) No statistically significant difference was observed in terms of major morbidity, hepatic artery thrombosis, biliary complications, intraabdominal bleeding, wound infection and rejection. However, HM group had statistically significant higher risk for pulmonary infection, abdominal fluid collection and prolonged ICU stay(Figure 1, Table 1). Conclusions: HM patients submitted to LDLT had overall comparable survival, graft survival and major morbidity rate compared to LM group despite higher risk for pulmonary infection, abdominal fluid collection and prolonged ICU stay.Tabled 1FP13-4Table1 Post transplant outcomesA. OutcomesOdds ratio95%CIP-valueI2 (%)Major morbidity1.530.92-2.540.10$41%Hepatic artery thrombosis1.180.52-2.670.70$0%Biliary complications1.060.72-1.570.75$14%Wound infections1.460.51-4.240.48$0%Intraabdominal bleeding1.870.98-3.540.06$0%Pulmonary infections2.071.05-4.080.04**40%Abdominal fluid collections2.261.21-4.240.01**0%B. OutcomesMean difference95%CIP-valueI2 (%)Length of ICU stay1.140.43-1.840.00∗∗29%Strength: I2 --Mild to moderate heterogeneity, $: non-significant difference or comparable outcomes, *: significant difference Open table in a new tab Strength: I2 --Mild to moderate heterogeneity, $: non-significant difference or comparable outcomes, *: significant difference

Impact and Consequences of Recipient Gastroduodenal Artery (GDA) Ligation Prior to Hepatic Artery (HA) Anastomosis during Orthotopic Liver Transplantation (OLT)

Introduction: In Orthotopic Liver Transplantation, the recipient GDA is often ligated for the HA anastomosis. It is done either to gain mobility, length on recipient HA or in support of the hypothesis that it would prevent “Steal syndrome” protecting the anastomosis. The aim of study is to evaluate its impact on prevention of HA thrombosis (HAT) and consequences of such ligation.

Biliary Complications Following Donation after Brainstem Death Liver Transplantation

Introduction: Biliary complications are increasingly seen after liver transplantation. Different modalities are used to overcome these complications. In this study, we investigated the occurrence of biliary complications following donation after brainstem death (DBD) liver transplant and their management. Methods: A retrospective review of patients who underwent DBD orthotopic liver transplant (OLT) from October 2014 to October 2020. The primary outcome was biliary stricture and the secondary outcome was return to theatre. Results: A total of 366 patients underwent DBD whole OLT during the study period. There were 229 (62.6%) males and 137 (37.4%) females. Recipients median age was 55 years (range 16-73) and donors median age was 50.5 years (range 11-89). Mean cold ischaemic time was 581 ± 218.7 minutes. Duct to duct anastomosis was performed in 240 (65.6%) patients, and 126 (34.4%) patients underwent Roux-en-Y hepaticojejunostomy (RYHJ). Eighteen (4.9%) patients experienced bile leak, 39 (10.7%) patients experienced anastomotic biliary stricture (ABS) and 18 (4.9%) patients had ischaemic cholangiopathy. Hepatic artery thrombosis occurred in 27 (7.4%) patients, 29 (7.9%) patients had early allograft dysfunction and six (1.6%) patients experienced primary non function. ABS was treated with RYHJ in 23 (6.3%) patients, Endoscopic Retrograde Cholangiopancreatography (ERCP) in nine (2.5%) patients, conservative management in eight (2.2%) patients and retransplant in one (0.3%) patient. Overall, 84 (22.9%) patients returned to theatre and 27 (7.4%) patients underwent retransplant. Conclusion: Biliary complications following DBD liver transplant is a frequent occurrence and careful monitoring and planning is required to improve patients’ outcomes.

Adjuvant Hepatic Arterial Infusion Pump Chemotherapy after Resection of Colorectal Liver Metastases; Surgical Complications, Toxicity, and Survival in a Prospective Study in the Netherlands

Background: Hepatic arterial infusion pump (HAIP) chemotherapy remains a promising treatment for patients with colorectal liver metastases (CRLM). The aim of this study was to investigate surgical complications, toxicity, and survival outcomes of patients who received adjuvant HAIP chemotherapy for CRLM. Methods: A single arm phase II study was performed in four centers. Patients with resectable CRLM without extrahepatic disease were eligible. An infusion pump was implanted after complete local treatment of CRLM followed by a maximum of 6 cycles of HAIP chemotherapy with floxuridine. Outcomes were 90 days pump-related major complications (Clavien Dindo grade ≥III), intra-arterial chemotherapy-related severe toxicity (CTCAE grade ≥III), and overall survival (OS). Results: Twenty-nine patients were included. Four patients (11.8%) had pump-related major complications, all requiring pump replacement; one for pump dysfunction, two for pump dislocation, and one for pump pocket infection. All patients started with HAIP chemotherapy. The median number of cycles was 5 (IQR 4-6), and the median cumulative dosage was 72% (IQR 55-85%). Ten patients (34%) required intra-arterial steroid treatment for biliary toxicity. Seven patients (24%) developed severe toxicity; five patients required stent-placement (three for biliary sclerosis/hyperbilirubinemia, two for persistent increase in liver enzymes without hyperbilirubinemia), one patient developed hepatic artery thrombosis, one patient required endoscopic extraction of an intrahepatic gallstone. Two-year OS was 93% (95%CI: 85-100%). Conclusion: Adjuvant HAIP chemotherapy for CRLM may result in major complications and severe toxicity; 1 in 7 patients required pump replacement and 1 in 6 patients required stent-placement for biliary sclerosis. Two-year OS was 93%.Tabled 1Patient and surgical characteristicsMedian [IQR] / n (%)Age at resection (years)57 [50-64]Clinical Risk Score (Fong score)2 [1-3]Preoperative systemic CTx9 (30)Major hepatectomy6 (21)Synchronous resection with primary CRC3 (10)Open ablation (with or without resection)11 (45)Surgery time (min)247 [204-300]Blood loss (mL)455 [187-762]Postoperative hospital stay (days)8 (6-9) Open table in a new tab

Hepatic Artery Thrombosis After Orthotopic Liver Transplant: Experience in the Last 10 Years

Hepatic artery thrombosis (HAT) is the second cause of graft failure, after primary disfunction. It has a significant morbidity, with a retransplant and mortality rate in early hepatic artery thrombosis of 50%. The incidence of this event goes from 2% to 9% in the adult population. The objective is to assess the incidence of HAT in a third-level hospital. The study design is an observational retrospective study, collecting data of the transplant recipient from 2010 to 2020. Incidence of HAT was 5.33% (39/732). A statistical difference was found with the blood intraoperative administration (P=.002) and with the presence of anatomic abnormalities in the hepatic artery between the HAT and the non-HAT group. We did not find any statistical difference with portal thrombosis (P=.73) between the groups. HAT is a fatal complication after an orthotopic liver transplant, which can lead to graft loss and even recipient death. For these reasons, we should early identify risk factors associated with this event early and try to minimize them to avoid the devastating consequences.

Persistent biliary hypoxia and lack of regeneration are key mechanisms in the pathogenesis of posttransplant nonanastomotic strictures.

Background and AimsNonanastomotic biliary strictures (NAS) are a major cause of morbidity after orthotopic liver transplantation (OLT). Although ischemic injury of peribiliary glands (PBGs) and peribiliary vascular plexus during OLT has been associated with the later development of NAS, the exact underlying mechanisms remain unclear. We hypothesized that bile ducts of patients with NAS suffer from ongoing biliary hypoxia and lack of regeneration from PBG stem/progenitor cells.Approach and ResultsForty‐two patients, requiring retransplantation for either NAS (n = 18), hepatic artery thrombosis (HAT; n = 13), or nonbiliary graft failure (controls; n = 11), were included in this study. Histomorphological analysis of perihilar bile ducts was performed to assess differences in markers of cell proliferation and differentiation in PBGs, microvascular density (MVD), and hypoxia. In addition, isolated human biliary tree stem cells (hBTSCs) were used to examine exo‐metabolomics during in vitro differentiation toward mature cholangiocytes.Bile ducts of patients with NAS or HAT had significantly reduced indices of PBG mass, cellular proliferation and differentiation (mucus production, secretin receptor expression, and primary cilia), reduced MVD, and increased PBG apoptosis and hypoxia marker expression, compared to controls. Metabolomics of hBTSCs during in vitro differentiation toward cholangiocytes revealed a switch from a glycolytic to oxidative metabolism, indicating the need for oxygen.ConclusionsNAS are characterized by a microscopic phenotype of chronic biliary hypoxia attributed to loss of microvasculature, resulting in reduced proliferation and differentiation of PBG stem/progenitor cells into mature cholangiocytes. These findings suggest that persistent biliary hypoxia is a key mechanism underlying the development of NAS after OLT.

Case Report of a Patient Treated With Acenocumarol Awaiting Orthotopic Liver Transplant: Perioperative Coagulation Management and Risk for Hepatic Artery Thrombosis

End-stage liver disease is associated with a concomitant reduction of pro- and anticoagulant factors that typically leads to rebalanced hemostasis. This rebalanced hemostasis can be easily disturbed, encountering both hemostasis-related bleeding episodes and thrombotic events. This article reports a case of a 52-year-old man diagnosed with portal vein thrombosis and treated with Acenocumarol. The patient received ortothopic liver transplant. The preprocedure international normalized ratio was 3.5. A transfusion of 2000 units of prothrombin complex concentrate was indicated by Hematology. Repeated intra- and postoperative hepatic artery thrombosis resulted in graft loss and patient retransplantation in first 24 hours. The new concept of rebalanced hemostasis in these patients forces us to change our clinical decisions in preoperative coagulation management, avoiding old practices based on the traditional model such as transfusion guided by international normalized ratio and platelet count, among others that will be analyzed in present work.

Antemortem Heparin in Organ Donation After Circulatory Death Determination: A Systematic Review of the Literature.

Donation after circulatory death determination frequently involves antemortem heparin administration to mitigate peri-arrest microvascular thrombosis. We systematically reviewed the literature to: (1) describe heparin administration practices and (2) explore the effects on transplant outcomes. We searched MEDLINE and EMBASE for studies reporting donation after circulatory death determination heparin practices including use, dosage, and timing (objective 1). To explore associations between antemortem heparin and transplant outcomes (objective 2), we (1) summarized within-study comparisons and (2) used meta-regression analyses to examine associations between proportions of donors that received heparin and transplant outcomes. We assessed risk of bias using the Newcastle Ottawa Scale and applied the GRADE methodology to determine certainty in the evidence. For objective 1, among 55 eligible studies, 48 reported heparin administration to at least some donors (range: 15.8%-100%) at variable doses (up to 1000 units/kg) and times relative to withdrawal of life-sustaining therapy. For objective 2, 7 studies that directly compared liver transplants with and without antemortem heparin reported lower rates of primary nonfunction, hepatic artery thrombosis, graft failure at 5 y, or recipient mortality (low certainty of evidence). In contrast, meta-regression analysis of 32 liver transplant studies detected no associations between the proportion of donors that received heparin and rates of early allograft dysfunction, primary nonfunction, hepatic artery thrombosis, biliary ischemia, graft failure, retransplantation, or patient survival (very low certainty of evidence). In conclusion, antemortem heparin practices vary substantially with an uncertain effect on transplant outcomes. Given the controversies surrounding antemortem heparin, clinical trials may be warranted.