Optimal changes in portal hemodynamics induced by splenectomy during living donor liver transplantation

Association of gut microbiota with portal vein pressure in patients with liver cirrhosis undergoing living donor liver transplantation

Background and Aim

Many recent studies have shown a relationship between various systemic diseases and the gut microbiota (GM), with the gut-liver axis receiving particular attention. In contrast, no report has comprehensively shown the effects of GM on the pathophysiology of patients undergoing living donor liver transplantation (LDLT).

Method

We enrolled 16 recipients who underwent LDLT for liver cirrhosis, and 17 donors constituted the reference group. We examined the differences in GM between recipients and donors. We also examined the relationships between GM, short-chain fatty acids, and portal vein pressure (PVP) in recipients.

Results

There was no significant difference in alpha-diversity between the recipients and donors, but there was variation in beta-diversity among the recipients. The abundance of the phylum Bacteroidetes was significantly higher in recipients than in donors (P = 0.016), and it was positively correlated with PVP (r = 0.511, P = 0.043). Propionic acid, which is a component of short-chain fatty acids, was positively correlated with PVP (r = 0.544, P = 0.0295), the phylum Bacteroidetes (r = 0.677, P = 0.004), and total bilirubin concentration (r = 0.501, P = 0.048). Propionic acid was negatively correlated with serum albumin concentration (r = -0.482, P = 0.043).

Conclusion

Our findings suggest relationships between fecal Bacteroidetes levels, propionic acid concentrations, and PVP in patients with liver cirrhosis undergoing LDLT.

Preventing Small-for-size Syndrome in Living Donor Liver Transplantation: Guidelines From the ILTS-iLDLT-LTSI Consensus Conference

Small-for-size syndrome (SFSS) is a well-recognized complication following liver transplantation (LT), with up to 20% developing this following living donor LT (LDLT). Preventing SFSS involves consideration of factors before the surgical procedure, including donor and recipient selection, and factors during the surgical procedure, including adequate outflow reconstruction, graft portal inflow modulation, and management of portosystemic shunts. International Liver Transplantation Society, International Living Donor Liver Transplantation Group, and Liver Transplant Society of India Consensus Conference was convened in January 2023 to develop recommendations for the prediction and management of SFSS in LDLT. The format of the conference was based on the Grading of Recommendations, Assessment, Development, and Evaluation system. International experts in this field were allocated to 4 working groups (diagnosis, prevention, anesthesia, and critical care considerations, and management of established SFSS). The working groups prepared evidence-based recommendations to answer-specific questions considering the currently available literature. The working group members, independent panel, and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and evidence-based recommendations provided by working group 2 that can be implemented to prevent SFSS in LDLT patients.

Technical challenges in LDLT - Overcoming small for size syndrome and venous outflow reconstruction

Living Donor Liver Transplantation (LDLT) emerged as an alternative treatment option for patients with end-stage liver disease waiting for an organ from a deceased donor. In addition to allowing for a faster access to transplantation, LDLT provides improved recipient outcomes when compared to deceased donor LT. However, it represents a more complex and demanding procedure for the transplant surgeon. In addition to a comprehensive preoperative donor assessment and stringent technical considerations during the donor hepatectomy to ensure upmost donor safety, the recipient procedure also comes with intrinsic challenges during LDLT. A proper approach during both procedures will result in favorable donor and recipient's outcomes. Hence, it is critical for the transplant surgeon to know how to overcome such technical challenges and avoid deleterious complications. One of the most feared complications following LDLT is small-for-size syndrome (SFSS). Although, surgical advances and deeper understanding of the pathophysiology behind SFSS has allowed for a safer implementation of LDLT, there is currently no consensus on the best strategy to prevent or manage this complication. Therefore, we aim to review current practices in technically challenging situations during LDLT, with a particular focus on management of small grafts and venous outflow reconstructions, as they possess one of the biggest technical challenges faced during LDLT.

Volume and flow modulation strategies to mitigate post-hepatectomy liver failure

INTRODUCTION

Post hepatectomy liver failure is the most common cause of death following major hepatic resections with a perioperative mortality rate between 40% to 60%. Various strategies have been devised to increase the volume and function of future liver remnant (FLR). This study aims to review the strategies used for volume and flow modulation to reduce the incidence of post hepatectomy liver failure.

METHOD

An electronic search was performed of the MEDLINE, EMBASE and PubMed databases from 2000 to 2022 using the following search strategy "Post hepatectomy liver failure", "flow modulation", "small for size flow syndrome", "portal vein embolization", "dual vein embolization", "ALPPS" and "staged hepatectomy" to identify all articles published relating to this topic.

RESULTS

Volume and flow modulation strategies have evolved over time to maximize the volume and function of FLR to mitigate the risk of PHLF. Portal vein with or without hepatic vein embolization/ligation, ALPPS, and staged hepatectomy have resulted in significant hypertrophy and kinetic growth of FLR. Similarly, techniques including portal flow diversion, splenic artery ligation, splenectomy and pharmacological agents like somatostatin and terlipressin are employed to reduce the risk of small for size flow syndrome SFSF syndrome by decreasing portal venous flow and increasing hepatic artery flow at the same time.

CONCLUSION

The current review outlines the various strategies of volume and flow modulation that can be used in isolation or combination in the management of patients at risk of PHLF.

Current evidence on posthepatectomy liver failure: comprehensive review

INTRODUCTION

Despite important advances in many areas of hepatobiliary surgical practice during the past decades, posthepatectomy liver failure (PHLF) still represents an important clinical challenge for the hepatobiliary surgeon. The aim of this review is to present the current body of evidence regarding different aspects of PHLF.

METHODS

A literature review was conducted to identify relevant articles for each topic of PHLF covered in this review. The literature search was performed using Medical Subject Heading terms on PubMed for articles on PHLF in English until May 2022.

RESULTS

Uniform reporting on PHLF is lacking due to the use of various definitions in the literature. There is no consensus on optimal preoperative assessment before major hepatectomy to avoid PHLF, although many try to estimate future liver remnant function. Once PHLF occurs, there is still no effective treatment, except liver transplantation, where the reported experience is limited.

DISCUSSION

Strict adherence to one definition is advised when reporting data on PHLF. The use of the International Study Group of Liver Surgery criteria of PHLF is recommended. There is still no widespread established method for future liver remnant function assessment. Liver transplantation is currently the only effective way to treat severe, intractable PHLF, but for many indications, this treatment is not available in most countries.

Does modification of portal pressure and flow enhance recovery of the recipient after living donor liver transplantation? A systematic review of literature and expert panel recommendations

BACKGROUND

Portal inflow modulation (PIM) aimed at reducing portal hyperperfusion is commonly used in living donor liver transplantation (LDLT) to reduce the risk of small-for-size syndrome (SFSS). Many different techniques, both pharmacological and surgical have been used for this purpose. There is, however, little consensus on the best method of PIM, its exact role in preventing SFSS and on early post-LDLT recovery.

OBJECTIVES

To identify whether modifications of portal pressures and flows enhance recovery after LDLT and to provide international expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel.

PROSPERO ID

CRD42021260997.

RESULTS

Five hundred and ninety four articles were identified through databases' search. Of the 24 included for a final review by the working group (WG), there were five randomized control trials, four prospective studies and 15 retrospective series. Six outcome measures which were likely to influence early recovery after LDLT, especially in small-for-size grafts (SFSG) were shortlisted. These included acute kidney injury, SFSS, morbidity including sepsis, length of ICU and hospital stay, morbidity of the PIM technique and overall mortality. The WG noted that PIM in this subset of LDLT recipients had a beneficial effect on all the outcomes measures.

CONCLUSIONS

Considering all decision domains, the panel recommends pre- and intraoperative actual graft weight validation, portal pressure/flow measurements, and a comprehensive donor evaluation for the determination of potentially small-for-size/ small-for-flow grafts as mandatory. (Quality of Evidence: Moderate | Grade of Recommendation: Strong) Pharmacological PIM helps improve early renal function in LDLT recipients. (Quality of Evidence: High | Grade of Recommendation: Strong) In selected patients with SFSG, PIM helps reduce SFSS/EAD and sepsis. (Quality of Evidence: Moderate | Grade of Recommendation: Strong) PIM in the form of splenectomy has increased morbidity compared to splenic artery ligation (SAL). (Quality of Evidence: Low | Grade of Recommendation: Strong) In LDLT recipients with SFSG, PIM may help reduce morbidity/mortality. (Quality of Evidence: Low | Grade of Recommendation: Strong) In LDLT recipients with SFSG, modification of portal pressures and flows enhances recovery after LDLT. (Quality of Evidence: Moderate | Grade of Recommendation: Strong).

Successful Simultaneous Subtotal Splenectomy During Left Lobe Auxiliary Liver Transplantation for Portal Inflow Modulation and Severe Hypersplenism Correction: A Case Report

Adult-to-adult living donor liver transplantation with small partial liver grafts often requires intraoperative portal inflow modulation to prevent portal hyperperfusion and subsequent small-for-size syndrome (SFSS). However, there are concerns about the specific morbidity of these modulation techniques. This study aims to lower post-perfusion portal venous pressure and correct severe hypersplenism in a patient with end-stage liver cirrhosis by simultaneous subtotal splenectomy during auxiliary partial orthotopic liver transplantation (APOLT). A 29-year-old man was diagnosed with cryptogenic cirrhosis and severe portal hypertension suffered recurrent acute variceal bleeding, severe thrombocytopenia, and massive ascites before admission to our hospital. After the recipient's left liver was resected, we performed APOLT using his 51-year-old father's left lobe graft with a graft-to-recipient weight ratio of 0.55%. Intraoperatively, simultaneous subtotal splenectomy was performed to lower graft post-perfusion portal vein pressure below 15 mmHg and correct severe hypersplenism-related pancytopenia. The recipient's postoperative hospital course was uneventful with no occurrence of SFSS and procedure-related complications. Platelet and leukocyte counts remained in the normal ranges postoperatively. The living donor was discharged 6 days after the operation and recovered well-with no complications. After a follow-up period of 35.3 months, both the recipient and donor live with good liver function and overall condition. This is the first case report of simultaneous subtotal splenectomy during APOLT using small-for-size living-donated left liver lobes, which is demonstrated to be a viable procedure for modulating portal inflow and correcting severe hypersplenism in selected adult patients with end-stage liver cirrhosis. APOLT using a small-for-size liver graft may be a safe and feasible treatment option for selected adult patients with end-stage liver cirrhosis.

Intraoperative Increase of Portal Venous Pressure is an Immediate Predictor of Posthepatectomy Liver Failure After Major Hepatectomy: A Prospective Study

OBJECTIVES

The aim of this study was to assess intraoperative changes of hepatic macrohemodynamics and their association with ascites and posthepatectomy liver failure (PHLF) after major hepatectomy.

SUMMARY OF BACKGROUND DATA

Large-scale ascites and PHLF remain clinical challenges after major hepatectomy. No study has concomitantly evaluated arterial and venous liver macrohemodynamics in patients undergoing liver resection.

METHODS

Portal venous pressure (PVP), portal venous flow (PVF), and hepatic arterial flow (HAF) were measured intraoperatively pre- and postresection in 67 consecutive patients with major hepatectomy (ie, resection of ≥3 liver segments). A group of 30 patients with minor hepatectomy served as controls. Liver macrohemodynamics and their intraoperative changes (ie, Δ) were analyzed as predictive biomarkers of ascites and PHLF using Fisher exact, t test, or Wilcoxon rank sum test for univariate and logistic regression for multivariate analyses.

RESULTS

Major hepatectomy increased PVP by 26.9% (P = 0.001), markedly decreased HAF by 40.7% (P < 0.001), and slightly decreased PVF by 13.4% (P = 0.011). Minor resections had little effects on hepatic macrohemodynamics. There was no significant association of liver macrohemodynamics with ascites. While middle hepatic vein resection caused higher postresection PVP after right hepatectomy (P = 0.04), the Pringle maneuver was associated with a significant PVF (P = 0.03) and HAF reduction (P = 0.03). Uni- and multivariate analysis revealed an intraoperative PVP increase as an independent predictor of PHLF (P = 0.025).

CONCLUSION

Intraoperative PVP kinetics serve as independent predictive biomarker of PHLF after major hepatectomy. These data highlight the importance to assess intraoperative dynamics rather than the pre- and postresection PVP values.

Living donor liver transplantation in small-for-size setting

Small-for-Size Syndrome (SFSS) is one of the most feared complication of adult split liver and living donor liver transplantation. SFSS stems from a disproportionate/excessive portal vein flow relative to the volume of the implanted liver graft, and is currently one of the major practical limits to partial liver grafts' transplantation. In the last few decades many graft inflow modulation (GIM) techniques have been proposed to curtail the portal vein flow, allowing for successful transplantation of small partial liver grafts. Graft inflow modulation techniques span from Splenic Artery Ligation (SAL), to Splenectomy, Porto-Systemic Shunts and the lately proposed Splenic Devascularization. A patient tailored approach balancing the risk of SFSS with GIM specific morbidity, is more important than identifying the ideal GIM technique. Here we summarize the most recently published data to provide general indications in the challenging preoperative choice of a GIM techniques.

Post-transplant inflow modulation for early allograft dysfunction after living donor liver transplantation

Background

To treat small-for-size syndrome (SFSS) after living donor liver transplantation (LDLT), many procedures were described for portal flow modulation before, during, or after transplantation. The selection of the procedure as well as the best timing remains controversial.

Case presentation

A 43-year-old female with end-stage liver disease underwent LDLT with extended left with caudate lobe graft from her donor who was her 41-year-old brother (graft volume/standard liver volume (GV/SLV), 35.7%; graft to recipient weight ratio (GRWR), 0.67%). During the surgery, splenectomy could not be performed owing to severe peri-splenic adhesions to avoid the ruined bleedings. The splenic artery ligation was not also completely done because it was dorsal to the pancreas and difficult to be approached. Finally, adequate portal vein (PV) inflow was confirmed after portal venous thrombectomy. As having post-transplant optional procedures that are accessible for PV flow modulation, any other procedures for PV modulation during LDLT were not done until the postoperative assessment of the graft function and PV flow for possible postoperative modulation of the portal flow accordingly. Postoperative PV flow kept as high as 30 cm/s. By the end of the 1st week, there was a progressive deterioration of the total bilirubin profile (peak as 19.4 mg/dL) and ascitic fluid amount exceeded 1000 mL/day. Therefore, splenic artery embolization was done effectively and safely on the 10th postoperative day (POD) to reverse early allograft dysfunction as PV flow significantly decreased to keep within 20 cm/s and serum total bilirubin levels gradually declined with decreased amounts of ascites below 500 mL on POD 11 and thereafter. The patient was discharged on POD 28 with good condition.

Conclusions

SFSS can be prevented or reversed by the portal inflow modulation, even by post-transplant procedure. This case emphasizes that keeping accessible angiographic treatment options for PV modulation, such as splenic artery embolization, after LDLT is quite feasible.

Is Portal Inflow Modulation Always Necessary for Successful Utilization of Small Volume Living Donor Liver Grafts?

Although the well-accepted lower limit of the graft-to-recipient weight ratio (GRWR) for successful living donor liver transplantation (LDLT) remains 0.80%, many believe grafts with lower GRWR may suffice with portal inflow modulation (PIM), resulting in equally good recipient outcomes. This study was done to evaluate the outcomes of LDLT with small-for-size grafts (GRWR <0.80%). Of 1321 consecutive adult LDLTs from January 2012 to December 2017, 287 (21.7%) had GRWR <0.80%. PIM was performed (hemiportocaval shunt [HPCS], n = 109; splenic artery ligation [SAL], n = 14) in 42.9% patients. No PIM was done if portal pressure (PP) in the dissection phase was <16 mm Hg. Mean age of the cohort was 49.3 ± 9.1 years. Median Model for End-Stage Liver Disease score was 14, and the lowest GRWR was 0.54%. A total of 72 recipients had a GRWR <0.70%, of whom 58 underwent HPCS (1 of whom underwent HPCS + SAL) and 14 underwent no PIM, whereas 215 had GRWR between 0.70% and 0.79%, of whom 51 and 14 underwent HPCS and SAL, respectively. During the same period, 1034 had GRWR ≥0.80% and did not undergo PIM. Small-for-size syndrome developed in 2.8% patients. Three patients needed shunt closure at 1 and 4 weeks and 60 months. The 1-year patient survival rates were comparable. In conclusion, with PIM protocol that optimizes postperfusion PP, low-GRWR grafts can be used for appropriately selected LDLT recipients with acceptable outcomes.

Impact of imbalanced graft-to-spleen volume ratio on outcomes following living donor liver transplantation in an era when simultaneous splenectomy is not typically indicated

The impact of an imbalanced graft-to-spleen volume ratio (GSVR) on posttransplant outcomes other than postreperfusion portal hypertension remains unknown. The importance of GSVR might vary according to whether simultaneous splenectomy (SPX) is performed. This retrospective study divided 349 living donor liver transplantation (LDLT) recipients from 2006 to 2017 into 2 groups: low GSVR (≤0.70 g/mL) and normal GSVR (>0.70 g/mL). The cutoff value of GSVR was set based on the first quartile of the distributed data. Graft survival and associations with various clinical factors were investigated between the groups according to whether SPX was performed. Low GSVR did not affect outcomes when SPX was performed. In contrast, it was associated with an increased incidence of early graft loss (EGL) and poor graft survival by presenting posttransplant thrombocytopenia, cholestasis, coagulopathy, and massive ascites when the spleen was preserved. Among patients with a preserved spleen, the multivariable analysis results revealed that older donor age and low GSVR were independent risk factors for graft loss. In conclusion, low GSVR was an independent predictor of graft loss after LDLT when the spleen was preserved. Preserved spleen with extremely low GSVR may be related to persistent hypersplenism, impaired graft function, and consequent EGL.

Portal flow modulation in living donor liver transplantation: review with a focus on splenectomy

Small-for-size graft (SFSG) syndrome after living donor liver transplantation (LDLT) is the dysfunction of a small graft, characterized by coagulopathy, cholestasis, ascites, and encephalopathy. It is a serious complication of LDLT and usually triggered by excessive portal flow transmitted to the allograft in the postperfusion setting, resulting in sinusoidal congestion and hemorrhage. Portal overflow injures the liver directly through nutrient excess, endothelial activation, and sinusoidal shear stress, and indirectly through arterial vasoconstriction. These conditions may be attenuated with portal flow modulation. Attempts have been made to control excessive portal flow to the SFSG, including simultaneous splenectomy, splenic artery ligation, hemi-portocaval shunt, and pharmacological manipulation, with positive outcomes. Currently, a donor liver is considered a SFSG when the graft-to-recipient weight ratio is less than 0.8 or the ratio of the graft volume to the standard liver volume is less than 40%. A strategy for transplanting SFSG safely into recipients and avoiding extensive surgery in the living donor could effectively address the donor shortage. We review the literature and assess our current knowledge of and strategies for portal flow modulation in LDLT.

Efficiency of acoustic radiation force impulse imaging for the staging of graft fibrosis after liver transplantation

AIM

Liver biopsy is the gold standard for assessing liver fibrosis (LF) after liver transplantation (LT), but its invasiveness limits its utility. This study aimed to evaluate the usefulness of liver stiffness measurement (LSM) using acoustic radiation force impulse (ARFI) imaging to assess LF after LT.

METHODS

Between September 2013 and January 2017, 278 patients who underwent liver biopsy after LT in Kyoto University Hospital (Kyoto, Japan) were prospectively enrolled. Liver stiffness measurement was carried out using ARFI imaging; its value was expressed as shear wave velocity (Vs) [m/s]. The LF was evaluated according to METAVIR score (F0-F4). The diagnostic performance of Vs for F2≤ and F3≤ was assessed and compared with that of laboratory tests using receiver operating characteristic (ROC) analysis.

RESULTS

The median Vs values increased according to the progression of LF (F0, 1.18 (0.78-1.92); F1, 1.35 (0.72-3.54); F2, 1.55 (1.05-3.37); F3, 1.84 (1.41-2.97)). The Vs had the highest area under the ROC curve (AUROC) for the prediction of both F2 ≤ and F3 ≤ fibrosis (F2, 0.77; and F3, 0.85). With the cut-off value of Vs >1.31, sensitivity, specificity, positive predictive value, and negative predictive value were 89.4%, 53.3%, 37.3%, and 94.2% in predicting F2≤, respectively. Shear wave velocity diagnosed LF better than any laboratory tests regardless of the type of primary disease.

CONCLUSIONS

Acoustic radiation force impulse helps to assess graft LF after LT. The high sensitivity suggested that ARFI might reduce the frequency of liver biopsies by detecting patients who are unlikely to have significant fibrosis after LT. (Unique trial no. UMIN R000028296.).

Splenic devascularization can replace splenectomy during adult living donor liver transplantation - a historical cohort study

Simultaneous splenectomy (SSPX) in adult living donor liver transplantation (ALDLT) has definitely beneficial roles such as portal flow modulation in small-for-size graft and correction of hypersplenism-related pancytopenia, and so on, but disastrous complications after SSPX often occur. For the first time, we devised unique and innovative splenic devascularization (SDV) procedure to alleviated untoward effects of SSPX but to maintain its benefits for the indicated patients. From April 2013 to December 2014, 520 recipients underwent ALDLT, and the SSPX and SDV were simultaneously performed in 62 (11.9%) and 61 (11.7%) patients, respectively. The most common indication was hypersplenism-related pancytopenia (n = 101), small-for-size graft (n = 14), hepatitis C virus (HCV) (n = 7), and splenic artery aneurysm (n = 1). Postoperative small-for-size graft syndrome (SFSS) was absent in both SSPX and SDV, and preoperative pancytopenia was improved in both groups since postoperative 1 week, although SSPX was more substantial than SDV. Preoperative splenic volume (706.2 ± 282.9 ml) after SDV significantly decreased to 425.5 ± 204.4 ml on 1 month, respectively. In contrast to SDV, SSPX resulted in longer operation time and higher incidence of postoperative complications including mortality. In conclusion, SDV can replace SSPX during ALDLT without hampering its beneficial roles seriously, but get rid of splenectomy-related lethal complication.

Is Portal Venous Pressure Modulation Still Indicated for All Recipients in Living Donor Liver Transplantation?

There is a consensus that portal venous pressure (PVP) modulation prevents portal hypertension (PHT) and consequent complications after adult-to-adult living donor liver transplantation (ALDLT). However, PVP-modulation strategies need to be updated based on the most recent findings. We examined our 10-year experience of PVP modulation and reevaluated whether it was necessary for all recipients or for selected recipients in ALDLT. In this retrospective study, 319 patients who underwent ALDLT from 2007 to 2016 were divided into 3 groups according to the necessity and results of PVP modulation: not indicated (n = 189), indicated and succeeded (n = 92), and indicated but failed (n = 38). Graft survival and associations with various clinical factors were investigated. PVP modulation was performed mainly by splenectomy to lower final PVP to ≤15 mm Hg. Successful PVP modulation improved prognosis to be equivalent to that of patients who did not need modulation, whereas failed modulation was associated with increased incidence of small-for-size syndrome (SFSS; P = 0.003) and early graft loss (EGL; P = 0.006). Among patients with failed modulation, donor age ≥ 45 years (hazard ratio [HR], 3.67; P = 0.02) and ABO incompatibility (HR, 3.90; P = 0.01) were independent risk factors for graft loss. Survival analysis showed that PVP > 15 mm Hg was related to poor prognosis in grafts from either ABO-incompatible or older donor age ≥ 45 years (P < 0.001), but it did not negatively affect grafts from ABO-compatible/identical and young donor age < 45 years (P = 0.27). In conclusion, intentional PVP modulation is not necessarily required in all recipients. Although grafts from both ABO-compatible/identical and young donors can tolerate PHT, lowering PVP to ≤15 mm Hg is a key to preventing SFSS and consequent EGL with grafts from either ABO-incompatible or older donors.

Evaluation the efficacy and safety of simultaneous splenectomy in liver transplantation patients: A meta-analysis

BACKGROUND

Simultaneous splenectomy during liver transplantation (LT) is debated. The present meta-analysis assessed the efficacy and safety of splenectomy on the outcome of LT patients.

METHODS

We searched PubMed, Embase, and Wanfang databases for relevant studies published until the date of July 15, 2017. Quality assessment of the included studies was performed using a modified Newcastle-Ottawa Scale judgment. The data were analyzed using RevMan5.3 software.

RESULTS

A total of 16 studies consisting of 2198 patients (892 patients received splenectomy during LT [SPLT group] and 1306 patients received LT only [LT group]) were included in the present meta-analysis. Efficacy analysis revealed that pooled hazard ratio for overall survival (OS) between 2 groups was not significantly different (hazard ratio = 1.03; 95% confidence interval [CI]: 0.71-1.50). SPLT group had less postoperative rejection (odds ratio [OR] = 0.63, 95% CI: 0.50-0.79) and small for size syndrome (OR = 0.23, 95% CI: 0.07-0.79). SPLT group had significantly lower preoperative platelet (mean difference [MD] = -17.23, 95% CI: -19.54, -14.91), but significantly higher postoperative platelet (MD = 170.45, 95% CI: 108.33-232.56). Conversely, SPLT group had significant higher preoperative portal pressure (MD = 1.54, 95% CI: 0.75-2.33) and significant lower postoperative portal pressure (MD = -1.17, 95% CI: -2.24, -0.11). Safety analysis revealed that SPLT group had significantly longer operation time (MD = 56.66, 95% CI: 35.96-77.35), more intraoperative blood loss (MD = 1.08, 95% CI: 0.25-1.91), and more intraoperative red blood cell (RBC) transfusion (MD = 3.77, 95% CI: 3.22-4.33). Furthermore, SPLT group had significantly higher incidence of postoperative hemorrhage (OR = 3.07, 95% CI: 1.92-4.91), postoperative thrombosis (OR = 3.63, 95% CI: 1.06-12.45), and perioperative infection (OR = 2.62, 95% CI: 1.76-3.90). In addition, perioperative mortality was significantly higher in the SPLT group (OR = 3.14, 95% CI: 1.31-7.52). Postoperative hospital stay did not differ significantly between 2 groups (OR = -1.75, 95% CI: -3.66-0.16).

CONCLUSIONS

Splenectomy benefits LT patients in increasing platelet count. However, splenectomy is a morbid procedure as splenectomy increases operation time, intraoperative blood loss, intraoperative RBC transfusion, and postoperative complications. Splenectomy does not improve OS but increase perioperative mortality. Therefore, splenectomy should be performed only in selective patients.

Liver graft-to-spleen volume ratio as a useful predictive factor of the early graft function in children and young adults transplanted for biliary atresia: a retrospective study

A graft volume/standard liver volume ratio (GV/SLV) > 35% or graft/recipient weight ratio (GRWR) > 0.8% has been considered as a standard criteria of graft selection. Even if the graft size meets these selection criteria, small-for-size syndrome can still occur depending on the portal venous flow (PVF). The aim of this study was to identify other factors contributing to portal hyperperfusion and the post-transplant course, focusing on the graft volume-to-spleen volume ratio (GV/SV). Thirty-seven BA patients who underwent living donor liver transplantation were reviewed retrospectively. First, we evaluated the preoperative factors contributing to portal hyperperfusion. Second, we evaluated the factors contributing to post-transplant complications, such as thrombocytopenia, hyperbilirubinemia, and coagulopathy. The GV/SLV was >35% in all cases; however, portal hyperperfusion (≥250 ml/min/100 g graft) was found in 12 recipients (35.3%). Furthermore, although the GRWR was >0.8% in over 90% of cases, portal hyperperfusion was found in 10 recipients (32.3%). In contrast, the GV/SV showed a significant correlation with the PVF after reperfusion. If the GV/SV was <0.88, about 80% of recipients developed portal hyperperfusion. Furthermore, the GV/SV also showed a significant correlation with post-transplant persistent thrombocytopenia and hyperbilirubinemia. The GV/SV < 0.88 predicts portal hyperperfusion, post-transplant persistent thrombocytopenia, and hyperbilirubinemia.

Short- and Long-term Outcomes of De Novo Liver Transplant Patients Treated With Once-Daily Prolonged-Release Tacrolimus

BACKGROUND

Tacrolimus is the key immunosuppressive drug for liver transplantation. Once-daily prolonged-release tacrolimus (TAC-PR) exhibits good drug adherence but has difficulty controlling the trough level in the early phase of liver transplantation. The aim of this study was to compare the feasibility and efficacy of immediately starting oral TAC-PR versus traditional twice-daily tacrolimus (TAC-BID) in de novo liver transplantation recipients.

METHODS

The study included 28 patients treated with conventional TAC-BID and 60 patients treated with TAC-PR (median follow-up 70.5 months). Short-term and long-term outcomes were compared.

RESULTS

Patient characteristics were similar except for the incidence of hepatocellular carcinoma and type of graft. Dose adjustment was more frequently required for TAC-PR than TAC-BID (73.3% vs 42.9%, P = 0.006), but trough levels of TAC during the first 3 months after liver transplantation were controlled well in both groups. The rate of acute cellular rejection and long-term renal function were similar in both groups. In both groups, renal function worsened during the first 6 months after transplantation and remained stable until the end of the follow-up period. The 1-year, 3-year, and 5-year survival rates were 96.4%, 85.7%, and 85.7% for TAC-BID and 96.7%, 94.8%, and 94.8% for TAC-PR, respectively. The overall survival curve for TAC-PR was not inferior to that of TAC-BID.

CONCLUSIONS

The TAC-PR protocol was feasible and effective with strict adjustment.

Evaluation of safety of concomitant splenectomy in living donor liver transplantation: a retrospective study

In Asian countries, concomitant splenectomy in living donor liver transplantation (LDLT) is indicated to modulate the portal vein pressure in the small-sized graft to protect against small for size syndrome. While concomitant splenectomy in deceased donor liver transplantation is almost contraindicated based on Western Reports of increased mortality and morbidity rate due to septic complications, there are few studies about that in LDLT. So, we retrospectively investigated the clinical outcome of adult LDLT at Kyoto University Hospital from July 2010 to July 2016. We divided the patients (n = 164) into those with concomitant splenectomy (n = 88) and those without (n = 76). The splenectomy group showed significantly increased operative time and intraoperative blood loss (P = 0.008, P = 0.0007, respectively), and significantly higher rate of postoperative splenic vein thrombosis and cytomegalovirus infection (P = 0.03, P = 0.016, respectively). However, there were no significant differences between the two groups regarding the incidence of postoperative hemorrhage (P = 0.06), post-transplant bacteremia (P = 0.38), infection-related mortality rates (P = 0.8), acute rejection (P = 0.87), and patient and graft survival (P = 0.66, P = 0.67 respectively); finally, model for end-stage liver disease score above 30 was an independent predictor for infection-related mortality post-transplant (HR = 5.99, 95% CI = 2.15-16.67, P = 0.001). In conclusion, concomitant splenectomy in LDLT can be safely performed when indicated.

Modulation of hepatic perfusion did not improve recovery from hepatic outflow obstruction

Background

Focal hepatic venous outflow obstruction frequently occurs after extended liver resection and leads to a portal hypertension, arterial hypoperfusion and parenchymal necrosis.

In this study, we investigated the pharmacological modulation of liver perfusion and hepatic damage in a surgical model of hepatic outflow obstruction after extended liver resection by administration of 5 different drugs in comparison to an operative intervention, splenectomy.

Methods

Male inbred Lewis rats (Lew/Crl) were subjected to right median hepatic vein ligation + 70% partial hepatectomy. Treatment consisted of a splenectomy or the application of saline, carvedilol or isosorbide-5-mononitrate (ISMN) (5 mg · kg⁻¹ respectively 7,2 mg · kg⁻¹ per gavage 12 h⁻¹). The splenectomy was performed during operation. The effect of the treatments on hepatic hemodynamics were measured in non-operated animals, immediately after operation (n = 4/group) and 24 h after operation (n = 5/group). Assessment of hepatic damage (liver enzymes, histology) and liver cell proliferation (BrdU-immunohistochemistry) was performed 24 h after operation. Furthermore sildenafil (10 μg · kg⁻¹ i.p. 12h⁻¹), terlipressin (0.05 mg · kg⁻¹ i.v. 12 h⁻¹) and octreotide (10 μg · kg⁻¹ s.c. 12 h⁻¹) were investigated regarding their effect on hepatic hemodynamics and hepatic damage 24 h after operation (n = 4/group).

Results

Carvedilol and ISMN significantly decreased the portal pressure in normal non-operated rats from 11,1 ± 1,1 mmHg (normal rats) to 8,4 ± 0,3 mmHg (carvedilol) respectively 7,4 ± 1,8 mmHg (ISMN). ISMN substantially reduced surgery-induced portal hypertension from 15,4 ± 4,4 mmHg to 9,6 ± 2,3 mmHg. Only splenectomy reduced the portal flow immediately after operation by approximately 25%. No treatment had an immediate effect on the hepatic arterial perfusion. In all treatment groups, portal flow increased by approximately 3-fold within 24 h after operation, whereas hepatic arterial flow decreased substantially. Neither treatment reduced hepatic damage as assessed 24 h after operation. The distribution of proliferating cells appeared very similar in all drug treated groups and the splenectomy group.

Conclusion

Transient relative reduction of portal pressure did not result in a reduction of hepatic damage. This might be explained by the development of portal hyperperfusion which was accompanied by arterial hypoperfusion.

Electronic supplementary material

The online version of this article (doi:10.1186/s40360-017-0155-4) contains supplementary material, which is available to authorized users.

Graft inflow modulation in adult-to-adult living donor liver transplantation: A systematic review

INTRODUCTION

Small-for-size syndrome (SFSS) has an incidence between 0 and 43% in small-for-size graft (SFSG) adult living donor liver transplantation (LDLT). Portal hypertension following reperfusion and the hyperdynamic splanchnic state are reported as the major triggering factors of SFSS. Intra- and postoperative strategies to prevent or to reduce its onset are still under debate. We analyzed graft inflow modulation (GIM) during adult LDLT considering the indications, efficacy of the available techniques, changes in hemodynamics and outcomes.

MATERIALS AND METHODS

A systematic literature search was performed using PubMed, EMBASE, Scopus and the Cochrane Library Central. Treatment outcomes including in-hospital mortality and morbidity, re-transplantation rate, 1-, 3-, and 5-year patient overall survival and 1-, 3-, and 5-year graft survival rates, hepatic artery and portal vein flows and pressures before and after inflow modulation were analyzed.

RESULTS

From 563 articles, 12 studies dated between 2003 and 2014 fulfilled the selection criteria and were therefore included in the study. These comprised a total of 449 adult patients who underwent inflow modulation during adult-to-adult LDLT. Types of GIM described were splenic artery ligation, splenectomy, meso-caval shunt, spleno-renal shunt, portocaval shunt, and splenic artery embolization. Mortality and morbidity ranged between 0 and 33% and 17% and 70%, respectively. Re-transplantation rates ranged between 0% and 25%. GIM was associated with good survival for both graft and recipients, reaching an 84% actuarial rate at 5 years. Through the use of GIM, irrespective of the technique, a statistically significant reduction of PVF and PVP was obtained.

CONCLUSIONS

GIM is a safe and efficient technique to avoid or limit portal hyperperfusion, especially in cases of SFSG, decreasing overall morbidity and improving outcomes.

Relationship between immune function recovery and infectious complications in patients following living donor liver transplantation

AIM

The ImmuKnow (IK) assay enables the evaluation of peripheral blood CD4(+) adenosine triphosphate activity to facilitate an objective assessment of the cellular immune function in immunosuppressed patients. However, it is unclear whether the IK assay is utilized during the acute postoperative periods following living donor liver transplantation (LDLT).

METHODS

The IK values of 43 LDLT recipients were measured during the month following LDLT to evaluate the relationship between the measured IK values and infectious events.

RESULTS

The IK values after LDLT were significantly increased compared with the IK values before LDLT ( P < 0.01). During the month following transplantation, the rate of bacterial infection in the recipients with IK values of more than 225 ng/mL was significantly lower than that in the recipients with IK values of 225 ng/mL or less ( 42.1% vs 91.7%, respectively; P < 0.01). The rate of severe infections among the recipients who maintained IK values of more than 150 ng/mL was significantly lower than that among the recipients with IK values of 150 ng/mL or less during the month following transplantation ( 3.7% vs 56.3%, respectively; P < 0.01).

CONCLUSION

The immune system of LDLT recipients dramatically improved following transplantation. The IK values of LDLT recipients were associated with the incidence of infectious events during the perioperative period after LDLT. Monitoring IK values was useful during both the acute and long-term postoperative periods.

Feasible usage of ABO incompatible grafts in living donor liver transplantation

BACKGROUND

The use of ABO incompatible (ABOi) graft in living donor liver transplantation (LDLT) has not been an established procedure worldwide.

METHODS

Four hundred and eight adult LDLTs, using ABOi (n=19) and non-ABOi (n=389) grafts, were performed as a single center experience.

RESULTS

In ABOi-LDLT group (n=19), median isoagglutinin titer before plasma exchange (PE) at LDLT and after LDLT (max) was ×256, ×32 and ×32, respectively. Rituximab was given at 21.8±6.1 days before LDLT and PE was performed 3.7±1.6 times. Although ABOi-LDLTs had increased rate of splenectomy (89.4% vs. 44.7%, P<0.001) and lower portal venous pressure (PVP) at the end of surgery (13.8±1.1 vs. 16.9±0.2 mmHg, P=0.003), other operative factors including graft ischemic time, operative time and blood loss were not different between the groups. Although ABOi-LDLTs had increased incidence of cytomegalovirus infection (52.6% vs. 22.9%, P=0.007), other post-transplant complications including bacterial sepsis and acute rejection were not different between the groups. The 5-year graft survival rate was 87.9% in ABOi-LDLTs and 80.3% in non-ABOi-LDLTs (P=0.373).

CONCLUSIONS

ABOi-LDLT could be safely performed, especially under rituximab-based protocol.

Modulation of splanchnic circulation: Role in perioperative management of liver transplant patients

Splanchnic circulation is the primary mechanism that regulates volumes of circulating blood and systemic blood pressure in patients with cirrhosis accompanied by portal hypertension. Recently, interest has been expressed in modulating splanchnic circulation in patients with liver cirrhosis, because this capability might produce beneficial effects in cirrhotic patients undergoing a liver transplant. Pharmacologic modulation of splanchnic circulation by use of vasoconstrictors might minimize venous congestion, replenish central blood flow, and thus optimize management of blood volume during a liver transplant operation. Moreover, splanchnic modulation minimizes any high portal blood flow that may occur following liver resection and the subsequent liver transplant. This effect is significant, because high portal flow impairs liver regeneration, and thus adversely affects the postoperative recovery of a transplant patient. An increase in portal blood flow can be minimized by either surgical methods (e.g., splenic artery ligation, splenectomy or portocaval shunting) or administration of splanchnic vasoconstrictor drugs such as Vasopressin or terlipressin. Finally, modulation of splanchnic circulation can help maintain perioperative renal function. Splanchnic vasoconstrictors such as terlipressin may help protect against acute kidney injury in patients undergoing liver transplantation by reducing portal pressure and the severity of a hyperdynamic state. These effects are especially important in patients who receive a too small for size graft. Terlipressin selectively stimulates V1 receptors, and thus causes arteriolar vasoconstriction in the splanchnic region, with a consequent shift of blood from splanchnic to systemic circulation. As a result, terlipressin enhances renal perfusion by increasing both effective blood volume and mean arterial pressure.