Significance of measured intraoperative portal vein flows after thrombendvenectomy in deceased donor liver transplantations with portal vein thrombosis

Therapeutic anticoagulation after liver transplantation is not useful among patients with pre-transplant Yerdel-grade I/II portal vein thrombosis: A two-center retrospective study

BACKGROUND

Portal vein thrombosis (PVT) is no longer a contraindication for liver transplantation (LT). While therapeutic anticoagulation (tAC) is recommended during the waiting period, there is no evidence for its usefulness in the prevention of PVT recurrence after LT.

OBJECTIVES

The aim of our study was to evaluate the role of tAC post-LT in the prevention of PVT recurrence.

PATIENTS/METHODS

All adult LTs performed in two high-volume centers between 2003 and 2018 were retrospectively analysed. Only patients with PVT classified as Yerdel grade I or II and with standard portal reconstruction were included. PVT recurrence and tAC-associated morbidity within 1 year were compared between patients receiving tAC or not.

RESULTS

During the study period, of 2612 LTs performed, 235 (9%) patients with PVT were included; 113 patients (48.1%) received post-LT tAC (tAC group) while 122 (51.9%) did not (non-tAC group). The incidence of bleeding events was significantly higher in the tAC group (26 [23%] vs. 5 [4.1%], P < .01) and the initial hospitalization duration was longer (21 vs. 17.5 days, P < .01). Within the first year, PVT recurrence was observed for 9 (3.8%) patients without any difference between the tAC and non-tAC groups (6 [5.1%] vs. 3 [2.5%], P = .39). The only identified risk factor for PVT recurrence was the recipients' age (odds ratio= 0.94, P = .03). Graft (P = .11) and patient (P = .44) survival were similar between the two groups.

CONCLUSION

Therapeutic anticoagulation is not necessary in the prevention of grade I/II PVT recurrence and is associated with higher morbidity and longer hospital stay.

The Impact of Portal Vein Thrombosis on Liver Transplant Outcomes: Does Grade or Flow Rate Matter?

BACKGROUND

Portal vein thrombosis (PVT) makes the technical aspect of liver transplantation challenging and also affects outcomes. Our aim was to study impact of PVT grade and postreperfusion portal flow on posttransplant outcomes.

METHODS

Patients who underwent transplantation with PVT between January 2007 and May 2017 were selected (n = 126). Data on grade of PVT and portal vein flow were collected. Patients were classified into 2 groups; low grade (Yerdel Grade I, n = 73) and high grade (Yerdel Grade II or III, n = 53). Using portal flow rate, patients were divided into high flow (≥1000 mL/min, n = 95) and low flow (<1000 mL/min, n = 31). Additional analyses of flow by graft weight and complications were performed.

RESULTS

Postoperatively, incidence of biliary strictures were significantly greater in high-grade PVT compared with low grade (P = 0.02). Incidence of postoperative portal vein thrombosis was higher in low flow after reperfusion compared with high flow (P = 0.02), as was bile leak (P = 0.02). On identifying factors associated with graft loss, moderate to severe ascites preoperatively, high PVT grade and bile leak were associated with worse graft survival. Subanalysis performed combining grade and flow showed that low grade, high flow had the highest graft survival while high grade, low flow had the lowest (P = 0.006). High-grade PVT with low flow also appeared to be an independent risk factor for biliary complications (P = 0.01).

CONCLUSIONS

In conclusion, biliary complications, especially strictures are more common in high-grade PVT and graft survival is worse in high-grade PVT and low portal flow.

Does graft hemodynamics affect the risk of hepatocellular carcinoma recurrence after liver transplantation?

Although experimental studies have reported that hepatic ischemia-reperfusion injury promotes tumor growth and metastases, the impact of graft hemodynamics on the recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is unclear. To investigate the association between graft hemodynamics and HCC recurrence after LT, we conducted a retrospective analysis of 279 patients who underwent LT for HCC. Graft hemodynamics including portal vein flow (PVF), hepatic artery flow (HAF), and total hepatic flow (THF) was analyzed as a predictor of HCC recurrence, using competing risk regression analyses. The cutoff values of PVF, HAF, and THF were set at the lower quartile of distribution. A cumulative recurrence curve demonstrated that low THF (<1511 mL/min, P = .005) was significantly associated with increased recurrence, whereas neither low PVF (<1230 mL/min, P = .150) nor low HAF (<164 mL/min, P = .110) was significant. On multivariate analysis, outside Milan criteria (sub-hazard ratio [SHR] = 3.742; P < .001), microvascular invasion (SHR = 3.698; P < .001), and low THF (SHR = 2.359; P = .010) were independently associated with increased HCC recurrence. In conclusion, our findings suggest that graft hemodynamics may play an important role in HCC recurrence after LT.

The devil is in the detail: current management of perioperative surgical complications after liver transplantation

PURPOSE OF REVIEW

Despite advances in the field, perioperative morbidity is common after liver transplantation. This review examines the current literature to provide up-to-date management of common surgical complications associated with liver transplantation.

RECENT FINDINGS

Research focuses on problems with anastomoses of the vena cava, portal vein, hepatic artery, and bile ducts. Interventional endoscopic and radiological techniques are used more frequently to avoid reoperation.

SUMMARY

Advances in the management of perioperative surgical complications have focused on minimally invasive measures that successfully treat technical problems with implantation of liver allografts from both living and deceased donors.

Novel classification of non-malignant portal vein thrombosis: A guide to surgical decision-making during liver transplantation

Non-tumoral portal vein thrombosis (PVT) is present at liver transplantation in 5% to 26% of cirrhotic patients, and the prevalence of complex PVT as defined here (grade 4 Yerdel, and grade 3,4 Jamieson and Charco) has been reported in 0% to 2.2%. Adequate portal inflow is mandatory to ensure graft and patient survival after liver transplantation. With time, the proposed classifications of non-tumoral chronic PVT have evolved from being anatomy-based, to also incorporating functional parameters. However, none of the currently proposed classifications are directed towards decision-making, regarding the choice of inflow to the graft during transplantation and the outcomes thereof. The present scoping review i) addresses the limits of the currently available classifications in terms of surgical decisiveness, ii) clarifies the concept of physiological or non-physiological portal inflow reconstruction, and subsequently, iii) proposes a new classification of non-tumoral PVT in candidates for liver transplantation; to help tailor the surgical strategy to an individual patient, in order to provide portal inflow to the graft together with control of prehepatic portal hypertension whenever feasible.

Portal vein thrombosis in patients with liver cirrhosis and its impact on early and long-term outcomes after liver transplantation

AIM

Portal vein thrombosis (PVT) is a common complication amongst patients with liver cirrhosis. The PVT risk factors and its impact on post liver transplant outcome has not been well defined, yet. This study aimed to investigate PVT prevalence, its risk factors and influence on early and long-term outcomes after liver transplantation.

METHODS

Adult (>18 years) patients with liver cirrhosis undergoing liver transplantation between March 2013 to March 2015 were included. Presence or absence of PVT was recorded at transplant. PVT risk factors in patients with liver cirrhosis and its impact on early and long-term outcomes were analysed.

RESULTS

Portal vein thrombosis was diagnosed in 174 patients (17.3%). Large oesophageal varices (grade II and III vs grade I) (OR: 2.5; 95% CI: 1.46-4.26; P = 0.001), diabetes mellitus before transplantation (OR: 2.03; 95% CI: 1.13-3.64; P = 0.017) and cryptogenic-NASH (OR: 1.36; 95% CI: 1.08-1.72; P = 0.008) as a cause of underlying liver disease were the independent risk factors for PVT. PVT (OR: 2.05; 95% CI: 1.10-3.81; P = 0.023) was an independent predictor of early (within 90 days) posttransplant mortality, but did not influence long-term survival.

CONCLUSION

Portal vein thrombosis prevalence is high in pretransplant period. NASH related cirrhosis and diabetes mellitus might be risk factors for PVT. More intense screening of these patients for PVT is warranted.

Intraoperative Portal Vein Flow > 123 mL/min Per 100 g Predicts a Better Survival of Patients After Liver Transplantation

OBJECTIVE

To assess the importance of intraoperative portal vein flow measurement during liver transplantation in relation to postoperative complications and graft and patient survival.

MATERIALS AND METHODS

Retrospective review including 291 patients who had all the information and covering a period of 10 years (2007-2017). Using a receiver operating characteristic curve, a cut-off point that would have the greatest impact on the probability of being alive at 5 years was established. In relation to this value, 2 groups were formed (low and high flow) and demographic variables, intraoperative variables, postoperative complications, and graft and patient survival were compared.

RESULTS

A portal flow of 123 mL/min per100 g of liver tissue was established (area under the curve = 0.58), obtaining a low-flow (n = 129) and a high-flow group (n = 162). The 2 groups were similar in their preoperative characteristics, except for a higher proportion of preoperative ascites, a higher Model for End-Stage Liver Disease score and a lower weight of donors in the high-flow group. The arterial and portal flows were significantly higher in the high-flow group. In the postoperative period, the high-flow group presented a higher rate of ascites. The 5-year survival rate of patients was significantly higher in the high-flow group (76% vs 84%, P = .03).

CONCLUSIONS

Patients undergoing liver transplantation with an intraoperative portal vein flow measurement >123 mL/min per 100 g present a greater 5-year survival rate.

Comparison of Two Devices for Intraoperative Portal Venous Flow Measurement in Living-Donor Liver Transplantation: Transit Time Ultrasound and Conventional Doppler Ultrasound

BACKGROUND

Intraoperative portal venous flow measurement provides surgeons with instant guidance for portal flow modulation during living-donor liver transplantation (LDLT). In this study, we compared the agreement of portal flow measurement obtained by 2 devices: transit time ultrasound (TTU) and conventional Doppler ultrasound (CDU).

METHODS

Fifty-four recipients of LDLT underwent intraoperative measurement of portal flow after completion of vascular anastomosis of the implanted partial liver graft. Both TTU and CDU were used concurrently. Agreement of TTU and CDU was assessed by intraclass correlation coefficient using a model of 2-way random effects, absolute agreement, and single measurement. A Bland-Altman plot was applied to assess the variability between the 2 devices.

RESULTS

The mean, median, and range of portal venous flow was 1456, 1418, and 117 to 2776 mL/min according to TTU; and 1564, 1566, and 119 to 3216 mL/min according to CDU. The intraclass correlation coefficient of portal venous flow between TTU and CDU was 0.68 (95% confidence interval, 0.51-0.80). The Bland-Altman plots revealed an average variation of 4.8% between TTU and CDU but with a rather wide 95% confidence interval of variation ranging from -57.7% to 67.4%.

CONCLUSIONS

Intraoperative TTU and CDU showed moderate agreement in portal flow measurement. However, a relatively wide range of variation exists between TTU and CDU, indicating that data obtained from the 2 devices may not be interchangeable.

Management of portal hypertension before and after liver transplantation

Orthotopic liver transplantation (OLT) represents a curative treatment option for end-stage liver disease (ESLD). Although epidemiology of ESLD has recently changed due to the rising prevalence of nonalcoholic fatty liver disease and the decreased burden of hepatitis C virus infections due to highly effective antiviral regimens, the management of portal hypertension (PHT) remains a clinical challenge in the pre- and post-OLT setting. The measurement of the hepatic venous pressure gradient represents the most reliable but invasive tool for assessment of the severity of PHT. Although novel liver ultrasound and magnetic resonance-based elastography methods have been developed, their value to screen for liver fibrosis and PHT in transplanted patients remains to be established. Nonselective beta-blockers represent the cornerstone of medical treatment of PHT, but more studies on their effects on clinical endpoints after OLT are needed. Statins are widely used to treat hyperlipidemia, which is a common condition after OLT. Although a growing body of evidence suggests that statins decrease portal pressure and PHT-related complications in ESLD, studies on potential benefits of statins after OLT are lacking. Finally, transjugular intrahepatic portosystemic shunts (TIPS) are effective in decreasing PHT and seem to decrease mortality on the OLT waiting list. Moreover, TIPS does not have an impact on liver function nor complicate the transplant surgical procedures. TIPS may also be used after OLT, but the evidence is limited. In conclusion, whereas the management of PHT in patients with ESLD is based on strong evidence, further data on the value of noninvasive monitoring tools as well as on medical and invasive treatment options in the post-OLT setting are needed to improve management strategies in patients with recurrent PHT after liver transplantation. Liver Transplantation 24 112-121 2018 AASLD.