Hemodynamic consequences of spontaneous splenorenal shunts in deceased donor liver transplantation

Hemodynamic alterations with large spontaneous splenorenal shunt ligation during adult deceased donor liver transplantation

Background

A large spontaneous splenorenal shunt (SRS) will greatly impact portal inflow to the graft during liver transplantation (LT). Direct ligation of a large SRS is an uncommon surgical procedure and the hemodynamic consequences of this procedure are unknown.

Methods

In this retrospective study, we described our technique for direct ligation of a large SRS and the consequent hemodynamic changes during LT. 3-Dimensional computed tomography and Doppler ultrasonography were used to evaluate SRS and portal vein blood flow volume (PFV).

Results

A total of 22 recipients had large SRS including 13 with PFV <85 ml/min/100 g (ligation group) and 9 with PFV ≥85 ml/min/100 g (no ligation group). The diameter of SRS was significantly larger in the ligation group than in the non-ligation group (22.92 ± 4.18 vs. 16.24 ± 3.60 mm; p = 0.0009). In all ligation patients, the SRS was easily identified and isolated, it was located just below the distal pancreas and beside the inferior mesenteric vein. PV flow increased significantly from 68.74 ± 8.77 to 116.80 ± 16.50 ml/min/100 g (p < 0.0001) after ligation; this was followed by a reduction in peak systolic velocity of the hepatic artery from 58.17 ± 14.87 to 46.67 ± 13.28 cm/s (p = 0.0013).

Conclusions

Direct ligation of large SRS was an effective and safe surgical procedure to overcome the problem of portal hypoperfusion during LT.

Management of spontaneous portosystemic shunts at the time of liver transplantation: treatment or observation? Results of a systematic review

BACKGROUND

Optimal treatment of spontaneous portosystemic shunts (SPSS) during liver transplantation (LT) remains debated. We systematically reviewed the literature on definitions, treatment and outcomes of patients presenting SPSS undergoing LT.

METHODS

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we used PubMed to retrieve all studies dealing with SPSS and LT between January 1987 and January 2020. The primary endpoints were definitions and outcomes according to the management of SPSS (treatment vs observation).

RESULTS

Thirteen studies detailing the management of 962 SPSS were retrieved. Hemodynamically significant SPSS were defined as those having diameter ≥ 10 mm in 41% (n = 395) of patients. SPSS were splenorenal (42%), cavo-gastric (15.2%), umbilical (7.4%), mesenterico-caval (n = 31; 3.2%), mesenterico-renal (0.1%) and unreported (31.9%), respectively. At the time of LT 372 shunts (38.7%) were treated while 590 were observed (61.3%). During a follow-up time ranging from 4 months to 5 years, the reported overall survival (OS) at 1 year was not significantly different except for one study. Portal vein anastomosis complications (i.e. reduced flow, stenosis or thrombosis) were similarly reported in observed [n = 26 (4%)] and ligated SPSS [n = 10 (2%)] (p = 0.22) but the rate of relaparotomy was significantly higher in observed SPPS (16 vs 2; p = 0.01) to rescue post LT portal vein thrombosis (n = 6) and reduced portal flow and graft dysfunction (n = 10).

CONCLUSIONS

There was a heterogeneous management of SPSS during LT in the literature. Ligation of SPPS did not reduce vascular complications neither improved survival. A randomized prospective study might contribute to identify best management of SPSS at time of LT.

Spontaneous portosystemic shunt embolization in liver transplant recipients with recurrent hepatic encephalopathy

INTRODUCTION AND OBJECTIVES

Spontaneous portosystemic shunts (SPSS) are a common cause of recurrent hepatic encephalopathy (HE). Shunt occlusion is an effective and safe procedure when performed in patients with cirrhosis and preserved liver function. We aimed to describe our experience with SPSS embolization after liver transplantation (LT).

PATIENTS

We identified five patients who underwent SPSS embolization after LT. Clinical, biochemical and technical procedure data were collected.

RESULTS

At presentation, all patients had developed graft cirrhosis and HE after LT. Median Model for End-stage Liver Disease (MELD) at embolization was 9 (range 7-12), median Child-Pugh was 8 (range 7-9). Splenorenal and mesocaval shunt were the most frequent types of SPSS found. Three patients have been completely free of HE. Of the two patients who had HE recurrence after embolization, one patient had two episodes of HE which was controlled well with medications. The other patient required three embolizations because of recurrent HE. Median follow-up was 4.4 years (range 1.0-5.0) and MELD score at last follow up was 13 (range 10-18) and median Child-Pugh score B, 7 points (range 5-12).

CONCLUSIONS

SPSS can be considered as a cause of HE after LT. SPSS embolization is feasible and safe in LT recipients.

Augmentation Patch V-venoplasty to Correct Atretic Changes of the Portal Vein During Adult Liver Transplantation

The development of large spontaneous portosystemic shunts (PSS) is a common finding in liver cirrhosis. The diversion of the portal flow through PSS directly into the caval system causes progressive liver atrophy and atretic changes of the portal vein. During both living and deceased donor liver transplantation (LT), persistence of large PSS has been associated to portal flow steal phenomena causing decreased patients and graft survival. Atretic changes of the portal vein and large PSS often coexist potentially representing a technical challenge during portal vein reconstruction. We herein describe (with a didactical video) an easy augmentation patch V-venoplasty used in the presence of atretic changes of the portal vein LT.

Friend or Foe? Spontaneous Portosystemic Shunts in Cirrhosis-Current Understanding and Future Prospects

Portal hypertension (PHT) in cirrhosis results from increased resistance to splanchnic blood flow secondary to parenchymal and vascular changes within the liver. In an attempt to counteract the increased portal pressure, two mechanisms simultaneously occur: splanchnic vasodilatation and formation of spontaneous portosystemic shunts (SPSS). Long considered to be a compensatory mechanism to decompress the portal venous system, it is now well established that SPSS are not only inefficient in decreasing the portal pressure but also contribute to reduced hepatocyte perfusion and increased splanchnic blood flow and resistance, associated with worsening PHT. Recent studies have described a high prevalence of SPSS in cirrhosis patients, increasing with liver dysfunction, and observed an association between the presence of SPSS and worse clinical outcomes. In cirrhosis patients with preserved liver functions, the presence of SPSS independently increases the risk of hepatic encephalopathy, variceal bleeding, and ascites, and reduces transplant-free survival. Moreover, the presence of SPSS in patients undergoing transjugular intrahepatic portosystemic shunting and liver transplant has been shown to variably affect the postprocedural outcome. This article provides an overview of the current understanding of the role of SPSS in the natural history of liver cirrhosis and their status as a therapeutic target and an imaging biomarker to identify patients at higher risk of developing complications of PHT.

Impact of spontaneous splenorenal shunt on liver volume and long-term survival of liver cirrhosis

BACKGROUND AND AIM

Spontaneous splenorenal shunt (SSRS) is one of the manifestations of portal hypertension in liver cirrhosis. However, the impact of SSRS on long-term survival of cirrhotic patients remains unclear. We hypothesize that SSRS may worsen liver dysfunction and deteriorate prognosis in liver cirrhosis by decreasing hepatic perfusion.

METHODS

Patients with liver cirrhosis who were admitted to our department between December 2014 and August 2019 and underwent contrast-enhanced computed tomography or magnetic resonance imaging scans were prospectively collected. The maximum diameters of SSRS and portal vein system vessels were retrospectively measured. Liver-to-abdominal area ratio, Child-Pugh, and model for end-stage liver disease scores were calculated.

RESULTS

Overall, 122 cirrhotic patients were included. The prevalence of SSRS was 30.3% (37/122). Median diameter of SSRS was 13.5 mm. Patients with SSRS had significantly thinner diameters of right portal vein (9 mm vs 11.2 mm, P = 0.001) and main portal vein (15.3 mm vs 16.8 mm, P = 0.017) than those without SSRS. Patients with SSRS had significantly lower liver-to-abdominal area ratio score (25.39 vs 31.58, P < 0.001) and higher Child-Pugh (7 vs 6, P = 0.046) and model for end-stage liver disease (12.17 vs 9.79, P < 0.006) scores than those without SSRS. Patients with SSRS had a significantly lower cumulative survival rate than those without SSRS (P = 0.014). Cox regression analysis also showed that SSRS was a risk factor of death of cirrhotic patients (hazard ratio = 4.161, 95% confidence interval = 1.215-14.255, P = 0.023).

CONCLUSIONS

Spontaneous splenorenal shunt may narrow portal vein diameter and shrink liver volume, thereby worsening liver function and increasing mortality in liver cirrhosis.

Intervention on Spontaneous Splenorenal Shunt May Decrease the Incidence of Acute Kidney Injury After Liver Transplant

OBJECTIVES

Spontaneous splenorenal shuntis a type of portosystemic shunt that develops frequently in the setting of chronic portal hypertension. It remains controversial whether shuntinterventions during liver transplant improve transplant outcomes.

MATERIALS AND METHODS

We conducted a retrospective comparison between deceased-donor liver transplant recipients who received spontaneous splenorenal shunt intervention and those who did not at a tertiary center between 2012 and 2017. Primary outcomes of interest included intraoperative transfusion requirement, hospital length of stay, acute kidney injury posttransplant, portal vein thrombosis, thrombocytopenia, and 1-year graft and patient survival.

RESULTS

Of 268 liver transplant recipients, 50 (18.6%) had large spontaneous splenorenal shunts pretransplant, with 45 patients having available radiologic and outcome data. Nine of 45 patients (20%) received shunt intervention, including pretransplant balloonoccluded retrograde transvenous obliteration (n = 5), intraoperative ligation of the left renal vein (n = 3), and intraoperative direct shunt ligation (n = 1). Demographic data, clinical characteristics, and Model for End-Stage Liver Disease scores were not different between the intervention and the nonintervention groups. Intraoperative transfusion, length of hospitalization, portal vein thrombosis, thrombocytopenia, and 1-year graft and patient survival were also similar between the 2 groups. However, the rate of posttransplant acute kidney injury was significantly lower in patients in the intervention group (0 cases vs 12 cases; odds ratio = 0.73; 95% confidence interval, 0.59-0.90). Patients with no SRS intervention (n = 36) were followed radiologically for 1 year posttransplant, with follow-up data showing complete resolution of spontaneous splenorenal shunt in just 4 patients (15%) and no changes in the remaining patients.

CONCLUSIONS

Peritransplant interventions for spontaneous splenorenal shunt may reduce posttransplant acute kidney injury. In patients without intervention, spontaneous splenorenal shunt predominantly persisted 1 year posttransplant.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Advances in research of spontaneous splenorenal shunt in patients with liver cirrhosis

Liver cirrhosis is the end stage of various chronic liver diseases. Spontaneous splenorenal shunt (SSRS) refers to abnormal blood vessels from the splenic vein to the renal vein, which are rich and thickened. SSRS formation may be due to the dilatation of pre-existing venules or neovascularization. SSRS can effectively reduce portal vein pressure, but it can also lead to a decrease of hepatic perfusion, which may be one of the reasons for insufficient hepatic perfusion after liver transplantation. In addition, toxic substances in the blood cannot be fully metabolized by the liver and directly enter the systemic circulation, leading to the development of hepatic encephalopathy. The treatment methods for SSRS include intervention and operation.

Donor Risk Index Has an Impact in Intraoperative Measure of Hepatic Artery Flow and in Clearance of Indocyanine Green: An Observational Cohort Study

BACKGROUND

The increase in indications for liver transplantation has led to acceptance of donors with expanded criteria. The donor risk index (DRI) was validated with the aim of being a predictive model of graft survival based on donor characteristics. Intraoperative arterial hepatic flow and indocyanine green clearance (plasma clearance rate of indocyanine green [ICG-PDR]) are easily measurable variables in the intraoperative period that may be influenced by graft quality. Our aim was to analyze the influence of DRI on intraoperative liver hemodynamic alterations and on intraoperative dynamic liver function testing (ICG-PDR).

METHODS

This investigation was an observational study of a single-center cohort (n = 228) with prospective data collection and retrospective data analysis. Measurement of intraoperative flow was made with a VeriQ flowmeter based on measurement of transit time (MFTT). The ICG-PDR was obtained from all patients with a LiMON monitor (Pulsion Medical Systems AG, Munich, Germany). DRI was calculated using a previously validated formula. Normally distributed variables were compared using Student's t test. Otherwise, the Mann-Whitney U test or Kruskal-Wallis test was applied, depending on whether there were 2 or more comparable groups. The qualitative variables and risk measurements were analyzed using the chi-square test. P < .05 was considered statistically significant.

RESULTS

DRI score (mean ± SD) was 1.58 ± 0.31. The group with DRI >1.7 (poor quality) had an intraoperative arterial flow of 234.2 ± 121.35 mL/min compared with the group having DRI < 1.7 (high quality), with an intraoperative arterial flow of 287.24 ± 156.84 mL/min (P = .02). The group with DRI >1.70 had an ICG-PDR of 14.75 ± 6.52%/min at 60 minutes after reperfusion compared to the group with DRI <1.70, with an ICG-PDR of 16.68 ± 6.47%/min at 60 minutes after reperfusion (P = .09).

CONCLUSION

Poor quality grafts have greater susceptibility to ischemia-reperfusion damage. Decreased intraoperative hepatic arterial flow may represent an increase in intrahepatic resistance early in the intraoperative period.

Ligation versus no ligation of spontaneous portosystemic shunts during liver transplantation: Audit of a prospective series of 66 consecutive patients

The management of large spontaneous portosystemic shunt (SPSS) during liver transplantation (LT) is a matter of debate. The aim of this study is to compare the short-term and longterm outcomes of SPSS ligation versus nonligation during LT, when both options are available. From 2011 to 2017, 66 patients with SPSS underwent LT: 56 without and 10 with portal vein thrombosis (PVT), all of whom underwent successful thrombectomy and could have portoportal reconstruction. The SPSS were either splenorenal (n = 40; 60.6%), left gastric (n = 16; 24.2%), or mesenterico-iliac (n = 10; 15.1%). Following portoportal anastomosis, the SPSS was ligated in 36 (54.4%) patients and left in place in 30 (45.5%) patients, based on the effect of the SPSS clamping/unclamping test on portal vein flow during the anhepatic phase. Intraoperatively, satisfactory portal flow was obtained in both groups. Primary nonfunction (PNF) and primary dysfunction (PDF) rates did not differ significantly between the 2 groups. Nonligation of SPSS was significantly associated with a higher rate of postoperative encephalopathy (P < 0.001) and major postoperative morbidity (P = 0.02). PVT occurred in 0 and 3 patients in the ligated and nonligated shunt group, respectively (P = 0.08). A composite end point, which included the relevant complications in the setting of SPSS in LT (ie, PNF and PDF, PVT, and encephalopathy) was present in 16 (44.4%) and 22 (73.3%) patients of the ligated and nonligated shunt group, respectively (P = 0.02). Patient (P = 0.05) and graft (P = 0.02) survival rates were better in the ligated shunt group. In conclusion, the present study supports routine ligation of large SPSS during LT whenever feasible. Liver Transplantation 24 505-515 2018 AASLD.

Renoportal Anastomosis in Left Lateral Lobe Living Donor Liver Transplantation: A Pediatric Case

In adult liver transplantation, renoportal anastomosis (RPA) has been introduced as a useful technique for patients with grade 4 portal vein thrombosis and a splenorenal shunt. Here, we report a pediatric case in which RPA allowed a left lateral lobe living donor liver transplantation (LDLT) despite portal vein thrombosis and a large splenorenal shunt. At 36 days old, the patient underwent a Kasai operation for biliary atresia. At 17 months old, she underwent LDLT because of repetitive cholangitis. Pretransplant examinations revealed a large splenorenal shunt and portal vein thrombosis. Simple end-to-end portal reconstruction and clamping of the collateral route after removing the thrombosis were unsuccessful. Thus, RPA was performed using a donor superficial femoral vein as an interpositional graft. The portal vein pressure was 20 mm Hg after arterial reperfusion. Ligation of the splenic artery reduced the portal vein pressure. Although she developed severe acute cellular rejection and chylous ascites, there were no signs of portal vein complications. She was discharged 73 days after transplantation without any signs of renal dysfunction. The patient's condition was good at her last follow-up, 22 months after transplantation. To our knowledge, this is the youngest case of RPA in pediatric left lateral lobe LDLT. Additionally, this is the first case of RPA with splenic artery ligation and using the donor's superficial femoral vein as the venous graft for RPA. Although long-term follow-up is necessary, RPA could be a salvage option in LDLT in infants if other methods are unsuccessful.

Tips and pitfalls in direct ligation of large spontaneous splenorenal shunt during liver transplantation

Patients with large spontaneous splenorenal shunts (SRSs) prove challenging during liver transplantation (LT), regardless of organizing portal vein (PV) thrombosis. Here, we detail the clinical outcomes of 26 patients who underwent direct ligation of large SRSs during LT. Direct ligation of large SRS was applied in poor portal flow during LT. We performed temporary test clamping of the SRS before direct ligation and applied PV pressure monitoring in patients who showed signs of portal hypertension, such as bowel edema. We retrospectively reviewed and evaluated their clinical outcomes. Among 843 patients who underwent LT between 2010 and 2015, 26 (3.1%) underwent direct ligation of SRS without any intraoperative event. Mean preoperative Model for End-Stage Liver Disease score was 16.7 ± 9.0. The main PV diameter on preoperative computed tomography was 8.3 ± 3.4 mm (range, 3.0-14.0 mm). SRS was easily identified at just below the distal pancreas and beside the inferior mesenteric vein in all patients. Accompanying PV thrombectomy was done in 42.3% of patients. Among 26 patients, massive and prolonged ascites was evident in 15.4% (n = 4) postoperatively. They were all living donor LT recipients with a small PV diameter (4.0-6.7 mm). Except for 1 patient who underwent splenic artery embolization, ascites was tolerable and well controlled by conservative management. There was a 7.7% rate of major complications related to direct ligation, including reoperation due to combined ligation of SRS along with a left renal vein at the confluence. Except for 1 hospital mortality due to sepsis, 25 patients (96.2%) are alive with no evidence of further PV complications. In conclusion, direct ligation of large SRS during LT is a safe and feasible method to overcome the effects of a large SRS. Liver Transplantation 23 899-906 2017 AASLD.

Splenectomy during whole liver transplantation: a morbid procedure which does not adversely impact long-term survival

BACKGROUND

Indications for splenectomy (SP) during whole liver transplantation (LT) remain controversial and SP is often avoided because of common complications. We aimed to evaluate specific complications of these combined procedures.

METHODS

Data were retrospectively analysed. Splenectomy was performed in patients with splenorenal shunt and/or splenic artery aneurysms or hypersplenism. Patients undergoing simultaneous transplantation and splenectomy (LTSP group) were matched to a non-splenectomy group (LT group).

RESULTS

Between 1994 and 2013, we included 47 and 94 patients in LTSP and LT groups, respectively. The LTSP patients had a higher rate of pre-LT portal vein thrombosis (PVT). The LTSP group had a longer operative time and greater blood loss. Mean follow-up was 101 months and 5-year survivals were identical (LTSP 85% vs LT 88%, p = 0.831). Hospital morbidity and rejection incidence were comparable, whereas de novo PVT (34% vs 2%, p < 0.0001) and infection (47% vs 25%, p = 0.014) rates were higher after SP.

CONCLUSION

Splenectomy during LT is technically demanding and exposes recipients to a higher thrombosis rate, therefore portal vein patency must be specifically assessed postoperatively. In selected recipients, SP can be performed without increased mortality but at the price of worsening outcome as evidenced by greater risk of infection and PVT.

Portosystemic collaterals in living donor liver transplantation: What is all the fuss about?

Portosystemic collaterals are a common finding in patients with cirrhosis undergoing liver transplantation. Recently, there has been a renewed interest regarding their significance in the setting of living donor liver transplantation (LDLT) due to concerns of graft hypoperfusion or hyperperfusion and its impact on early posttransplant outcomes. Presence of these collaterals has greater significance in the LDLT setting when compared with the deceased donor liver transplantation setting as dictated by the difference in the physiology of partial liver grafts. We discuss current thinking of portal flow dynamics and the techniques for dealing with this clinical problem. Liver Transplantation 23 537-544 2017 AASLD.

Radiologic evaluation of portal steal phenomenon in recipients of liver transplantation

It is important to maintain adequate portal flow and to prevent the detrimental effect of portosystemic shunt in recipients following liver transplantation. The purpose of this article is to present a comprehensive review of portosystemic shunts and to illustrate such phenomenon demonstrated on radiologic studies such as Doppler ultrasound, computed tomography, and portogram. It is important for radiologists to be aware of such phenomenon not only in preoperative evaluation of the recipients but also in postoperative screening to detect recurrence of the phenomenon.

Spontaneous Splenorenal Shunt in Liver Transplantation: Results of Left Renal Vein Ligation Versus Renoportal Anastomosis

BACKGROUND

Management of portal inflow to the graft in patients with spontaneous splenorenal shunts (SRS) is a matter of concern especially in case of large varices (more than 1 cm). In case of portal vein (PV) thrombosis (PVT), renoportal anastomosis (RPA) directly diverts the splanchnic and renal venous blood assuring a good portal inflow to the graft. Disconnection of the portacaval shunt by left renal vein ligation (LRVL) is another option but requires a patent PV. The indication of primary RPA rather than LRVL in patients with small native PV, especially in case of large graft, should be questioned in these complex cases of liver transplantation.

METHODS

From 1998 to 2012, 17 patients with RPA and 15 patients with LRVL were transplanted in our center. We compared these 2 techniques for short- and long-term results.

RESULTS

The rate of preliver transplantation PVT (76% vs 27%) and graft weight (1538 ± 383 g vs 1293 ± 216 g) was significantly higher in the RPA group. Renoportal anastomosis was performed in 4 cases of small but patent PV. Three-month mortality, morbidity, and massive ascitis were similar. No patient was retransplanted. One year after transplantation, PV diameter was still larger in RPA group. Three-year survival was similar (RPA: 79% vs LRVL: 53%, P = 0.1).

CONCLUSIONS

In cirrhotic patients transplanted with large splenorenal shunts, RPA and LRVL reach similar survivals. In case of complete PVT and failure of thrombectomy, the RPA offers satisfactory long-term results.

A central approach to splenorenal shunt in pediatric living donor liver transplantation

The management of LSRS is a crucial problem to ensure a sufficient PV flow during pediatric LT. Although several techniques have been indicated to solve this problem, a more appropriate approach to LSRS is still needed in pediatric LT. We herein present a modified surgical approach to the ligation of LSRS via the left side of the IVC for a nine-month-old boy with severe portal hypertension and a history of Kasai portoenterostomy. LSRS was identified and exposed through the left side of the IVC and the dorsal surface of the pancreas from the superior side of the body of the pancreas. The post-operative course was uneventful with an excellent PV flow. The central approach for the ligation of LSRS is worth considering as an alternative procedure for a patient with collateral vessels and a history of multiple laparotomies.

Influence of splenorenal shunt on long-term outcomes in cirrhosis

OBJECTIVE

To examine the clinical effect of splenorenal shunt (SRS) on the long-term outcomes in patients with cirrhosis.

METHODS

The study consisted of 162 cirrhosis patients (male 85, female 77; 62.6 ± 11.7 years). The clinical findings and prognosis were examined with respect to portal hemodynamics including collateral vessel patterns, with or without the presence of SRS or short gastric vein (SGV). Median observation period was 30 months.

RESULTS

The incidence was 18.5% for SRS and 10.5% for SGV. Decompensated cirrhosis was significantly more frequent in patients with SRS (22/30) than those with SGV (5/17, p = 0.0034), and in patients with SRS >5.5 mm (14/15) or >95 ml/min (14/15) (both, median values) than those with SRS <5.5 mm (8/15, p = 0.013) or <95 ml/min (8/15, p = 0.013). Cumulative overall survival rate was 87.4% at 1 year, 73.4% at 3 years, and 59.1% at 5 years. There was no significant difference in the cumulative survival rate according to the development of SRS: 80% at 1 year, 66.6% at 3 years, and 58.3% at 5 years in patients with SRS; 94.1% at 1 year, 87.4% at 3 years, and 72.8% at 5 years in patients with SGV; 88.3% at 1 year, 73.1% at 3 years, and 58% at 5 years in patients without SGV/SRS; 94.1% at 1 year, 87.4% at 3 years, and 72.8% at 5 years in patients with SGV (overall, p = 0.2).

CONCLUSION

In spite of no significant effect on the prognosis in cirrhosis, careful management may be necessary for the patients with SRS because of potential poor liver function demonstrated by the close linkage between the presence of SRS and decompensation.

Portal venous perfusion steal causing graft dysfunction after orthotopic liver transplantation: serial imaging findings in a successfully treated patient

A 53-year-old male with hepatocellular carcinoma underwent orthotopic liver transplantation. Preoperative computed tomography revealed main portal vein luminal narrowing by flat thrombi and the development of cavernous transformation. On post-transplantation day 1, thrombotic portal venous occlusion occurred, and emergency thrombectomy was performed. Subsequent Doppler ultrasonography and contrast-enhanced ultrasonography confirmed the restoration of normal portal venous flow. The next day, however, decreased portal venous velocity was observed via Doppler ultrasonography, and serum liver enzymes and bilirubin levels remained persistently elevated. Direct portography identified massive perfusion steal through prominent splenorenal collateral veins. Stent insertion and balloon angioplasty of the portal vein were performed, and subsequent Doppler ultrasonography demonstrated normalized portal flow parameters. Afterwards, the serum liver enzymes and bilirubin levels rapidly normalized.

Should temporary extracorporeal continuous portal diversion replace meso/porta-caval shunts in “small-for-size” syndrome in porcine hepatectomy?

AIM: To investigate the feasibility of temporary extracorporeal continuous porta-caval diversion (ECPD) to relieve portal hyperperfusion in “small-for-size” syndrome following massive hepatectomy in pigs.

METHODS: Fourteen pigs underwent 85%-90% liver resection and were then randomly divided into the control group (n = 7) and diversion group (n = 7). In the diversion group, portal venous blood was aspirated through the portal catheter and into a tube connected to a centrifugal pump. After filtration, the blood was returned to the pig through a double-lumen catheter inserted into the internal jugular or subclavian vein. With the conversion pump, portal venous inflow was partially diverted to the inferior vena cava through a catheter inserted via the gastroduodenal vein at 100-130 mL/min. Portal hemodynamics, injury, and regeneration in the liver remnant were compared between the two groups.

RESULTS: Compared to the control group, porta-caval diversion via ECPD significantly mitigated excessive portal venous flow and portal vein pressure (PVP); the portal vein flow (PVF), hepatic artery flow (HAF), and PVP in the two groups were not significantly different at baseline; however, the PVF (431.8 ± 36.6 vs 238.8 ± 29.3, P < 0.01; 210.3 ± 23.4 vs 122.3 ± 20.6, P < 0.01) and PVP (13.8 ± 2.6 vs 8.7 ± 1.4, P < 0.01; 15.6 ± 2.1 vs 10.1 ± 1.3, P < 0.05) in the control group were significantly higher than those in the diversion group, respectively. The HAF in the control group was significantly lower than that in the diversion group at 2 h and 48 h post hepatectomy, and ECPD significantly attenuated injury to the sinusoidal lining and hepatocytes, increased the regeneration index of the liver remnant, and relieved damage that the liver remnant suffered due to endotoxin and bacterial translocation.

CONCLUSION: ECPD, which can dynamically modulate portal inflow, can reduce injury to the liver remnant and facilitate liver regeneration, and therefore should replace permanent meso/porta-caval shunts in “small-for-size” syndrome.

Hepatic hemodynamic changes during liver transplantation: A review

Liver transplantation is performed in the recent decades with great improvements not only technically but also conceptually. However, there is still lack of consensus about the optimal hemodynamic characteristics during liver transplantation. The representative hemodynamic parameters include portal vein pressure, portal vein flow, and hepatic venous pressure gradient; however, there are still others potential valuable parameters, such as total liver inflow and hepatic artery flow. All the parameters are correlated closely and some internal modulating mechanisms, like hepatic arterial buffer response, occur to maintain stable hepatic inflow. To distinguish the unique importance of each hepatic and systemic parameter in different states during liver transplantation, we reviewed the published data and also conducted two transplant cases with different surgical strategies applied to achieve ideal portal inflow and pressure.

Hepatic encephalopathy in a liver transplant recipient with stable liver function

Postshunt hepatic encephalopathy after liver transplantation (LT) is an infrequent condition and is commonly associated with portal occlusion or stenosis and the presence of a patent portosystemic shunt. Portal vein stenosis (PVS) or thrombosis (PVT) are uncommon complications after LT. The overall frequency of both complications is reported to be less than 3%. When PVS or PVT develop early after LT, the occlusion of the portal vein can have catastrophic consequences to the graft including acute liver failure and graft loss. Late PVT/PVS are asymptomatic in approximately 50% of the cases and mainly diagnosed by a routine ultrasound. Symptomatic postshunt hepatic encephalopathy (HE) is a very infrequent condition after LT that has been scarcely reported in the literature. We present here the case of a liver recipient with normal graft function who presented with hepatic encephalopathy 3 months after LT with stable liver function but a severe portal stenosis and the presence of a spontaneous portosystemic shunt whose successful endovascular treatment was followed by the complete resolution of the HE.

Ligation of left renal vein for spontaneous splenorenal shunt to prevent portal hypoperfusion after orthotopic liver transplantation

We report a case of recovered portal flow by ligation of the left renal vein on the first postoperative day after orthotopic liver transplantation of a 54-year-old female with alcoholic liver cirrhosis, chronic kidney failure, and spontaneous splenorenal shunt. After reperfusion, Doppler ultrasonography showed almost total diversion of the portal flow into the existing splenorenal shunt, but because of severe coagulopathy and diffuse bleeding, ligation of the shunt was not attempted. A programmed relaparotomy was performed on the first postoperative day, and the left renal vein was ligated just to the left of the inferior vena cava. Portal flows subsequently increased to 37 cm/sec, and the patient presented a good and stable liver function. We conclude that patients with known preoperative splenorenal shunts should be closely monitored, and if the portal flow becomes insufficient, ligation of the left renal vein should be attempted in order to optimize the portal perfusion of the liver.

Cavoportal hemitransposition for unrecognized spontaneous mesocaval shunt after liver transplantation: a case report

Spontaneous portosystemic shunts can steal the blood away from the portal system. This may result in graft dysfunction or even loss following liver transplantation and can be sorted by shunt occlusion based on intraoperative flow measurements. Herein, we present an alternative technique with cavoportal hemitransposition performed for unrecognized spontaneous mesocaval shunt with 'portal steal' syndrome and primary graft nonfunction diagnosed first day following the transplant. This was chosen as a rescue strategy because an attempt to locate the shunt during relaparotomy was unsuccessful. As there was no improvement, emergency liver retransplantation with preservation of the cavoportal hemitransposition was performed on the fourth day after the primary transplant with good long-term outcome. We conclude that cavoportal hemitransposition during or after liver transplantation can be used to provide an adequate inflow into the donor portal vein if the shunting vessels responsible for the steal cannot be located and dealt with at surgery.

New surgical approach to large splenorenal shunt in living donor liver transplantation: diversion of SMV and SPV blood flow

INTRODUCTION

The management of a large splenorenal shunt is important because it affects recipient outcome, particularly in living donor liver transplantation.

METHODS

To manage large splenorenal shunts in living donor liver transplantation, we diverted superior mesenteric vein and splenic portal vein blood flow by ligation at the root of the splenic portal vein.

RESULT

This procedure was applied for five patients in whom superior mesenteric vein blood flow had been completely stolen by a splenorenal shunt preoperatively. Postoperative course was excellent in all cases.

CONCLUSION

This technique completely prevents morbidity related to large splenorenal shunts after living donor liver transplantation.

Portal vein complications after pediatric liver transplantation

Relatively few pediatric donors are available in relation to the number of children waiting for a liver transplant. This limited number of pediatric donor livers leads to the use of adult livers, usually requiring more complex portal vein (PV) anastomoses. These anastomoses are complicated by differences in PV caliber between donors and recipients, as well as by limitations of PV length, which may be inadequate to reach the recipient spleno-mesenteric junction. Three types of post-transplant complications result from these complexities: 1) anomalies of the portal flow; 2) stenosis of the PV anastomosis; and 3) PV thrombosis. Abnormal portal flow may rarely need a specific intervention, but persistent stenosis or appearance of signs of portal hypertension need to be corrected. Balloon dilatation and placement of a stent are usually successful to repair stenosis. Portal vein thromboses are in general diagnosed in the immediate post-operative period and frequently lead to re-transplantation; however, thrombolytic therapy should be attempted in children without major signs of liver necrosis. When intra-hepatic portal vein(s) are permeable, despite extrahepatic PV thrombosis, a Meso-Rex shunt may be the indicated therapy.