Left renal vein ligation: a technique to mitigate low portal flow from splenic vein siphon during liver transplantation

Portal vein complications and outcomes following pediatric liver transplantation: Data from the Society of Pediatric Liver Transplantation

Children who undergo liver transplantation are at risk for portal vein complications (PVCs) including thrombosis (PVT) and stenosis (PVS). Using multicenter data from the Society of Pediatric Liver Transplantation, we analyzed the prevalence, timing, and risk factors for PVC following a first liver transplantation, and assessed the potential impact of PVC on patient outcomes. Our cohort included 4278 patients, of whom 327 (7.6%) developed PVC. Multivariate analysis discovered several factors independently associated with PVC: younger recipient age, lower weight at time of transplantation, diagnosis of biliary atresia (BA), receiving a technical variant graft (TVG), warm ischemia time over 3 h, PVT in the recipient's pretransplantation native liver, and concurrent hepatic artery thrombosis (all p < 0.05). Subgroup analysis of those with BA found higher prevalence in patients transplanted at less than 2 years of age and those with TVGs. There was no difference in PVC prevalence among patients with BA with vs. without prior Kasai portoenterostomy. Most PVT (77.7%) presented within 90 days after transplantation. Patients with PVC had a higher risk of graft failure (23.9% vs. 8.3%; adjusted hazard ratio [HR], 3.08; p < 0.001) and a higher risk of death (16.4% vs. 8.9%; adjusted HR, 1.96; p = 0.01). Recurrence after retransplantation was similar to the overall prevalence in the cohort (8.2%). Our results recognize the common occurrence of PVC following pediatric liver transplantation, describe independently associated risk factors, and determine that patients with PVC have worse outcomes. Further studies are needed to improve PVC prevention, detection, and management strategies.

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.

Collaterals in portal hypertension: anatomy and clinical relevance

Portal hypertension is a key pathophysiology of chronic liver diseases typified with cirrhosis or noncirrhotic portal hypertension. The development of collateral vessels is a characteristic feature of impaired portal hemodynamics. The paraumbilical vein (PUV), left gastric vein (LGV), posterior gastric vein (PGV), short gastric vein (SGV), splenorenal shunt (SRS), and inferior mesenteric vein (IMV) are major collaterals, and there are some rare collaterals. The degree and hemodynamics of collateral may affect the portal venous circulation and may compensate for the balance between inflow and outflow volume of the liver. Additionally, the development of collateral shows a relation with the liver function reserve and clinical manifestations such as esophageal varices (EV), gastric varices, rectal varices and the other ectopic varices, hepatic encephalopathy, and prognosis. Furthermore, there may be an interrelationship in the development between different collaterals, showing additional influences on the clinical presentations. Thus, the assessment of collaterals may enhance the understanding of the underlying pathophysiology of the condition of patients with portal hypertension. This review article concluded that each collateral has a specific function depending on the anatomy and hemodynamics and is linked with the relative clinical presentation in patients with portal hypertension. Imaging modalities may be essential for the detection, grading and evaluation of the role of collaterals and may help to understand the pathophysiology of the patient condition. Further investigation in a large-scale study would elucidate the basic and clinical significance of collaterals in patients with portal hypertension and may provide information on how to manage them to improve the prognosis as well as quality of life.

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.

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.

Complex liver retransplantation to treat graft loss due to long-term biliary tract complication after liver transplantation: A case report

BACKGROUND

Loss of graft function after liver transplantation (LT) inevitably requires liver retransplant. Retransplantation of the liver (ReLT) remains controversial because of inferior outcomes compared with the primary orthotopic LT (OLT). Meanwhile, if accompanied by vascular complications such as arterial and portal vein (PV) stenosis or thrombosis, it will increase difficulties of surgery. We hereby introduce our center's experience in ReLT through a complicated case of ReLT.

CASE SUMMARY

We report a patient who suffered from hepatitis B-associated cirrhosis and underwent LT in December 2012. Early postoperative recovery was uneventful. Four months after LT, the patient’s bilirubin increased significantly and he was diagnosed with an ischemic-type biliary lesion caused by hepatic artery occlusion. The patient underwent percutaneous transhepatic cholangial drainage and repeatedly replaced intrahepatic biliary drainage tube regularly for 5 years. The patient developed progressive deterioration of liver function and underwent liver re-transplant in January 2019. The operation was performed in a classic OLT manner without venous bypass. Both the hepatic artery and PV were occluded and could not be used for anastomosis. The donor PV was anastomosed with the recipient’s left renal vein. The donor hepatic artery was connected to the recipient’s abdominal aorta. The bile duct reconstruction was performed in an end-to-end manner. The postoperative process was very uneventful and the patient was discharged 1 mo after retransplantation.

CONCLUSION

With the development of surgical techniques, portal thrombosis and arterial occlusion are no longer contraindications for ReLT.

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.

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.

A Case of Left Renal Vein Ligation in a Patient with Solitary Left Kidney Undergoing Liver Transplantation to Control Splenorenal Shunt and Improve Portal Venous Flow

Patient: Male, 51

Final Diagnosis: Liver cirrhosis by hepatitis virus C and hepatocellular carcinoma

Symptoms: Ascites

Medication: —

Clinical Procedure: Liver transplantantion

Specialty: Surgery

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.

Nontumoral portal vein thrombosis in patients awaiting liver transplantation

Portal vein thrombosis (PVT) occurs in approximately 2%-26% of the patients awaiting liver transplantation (LT) and is no longer an absolute contraindication for LT. Nearly half of PVT cases are accidentally found during the LT procedure. The most important risk factor for PVT development in cirrhosis may be the severity of liver disease and reduced portal blood flow. Whether other inherited or acquired coagulation disorders also play a role is not yet clear. The development of PVT may have no effect on the liver disease progression, especially when it is nonocclusive. PVT may not increase the risk of wait-list mortality, but it is a risk factor for poor early post-LT mortality. Anticoagulation and transjugular intrahepatic portosystemic shunt (TIPS) are 2 major treatment strategies for patients with PVT on the waiting list. The complete recanalization rate after anticoagulation is approximately 40%. The role of TIPS to maintain PV patency for LT as the primary indication has been reported, but the safety and efficacy should be further evaluated. PVT extension and degree may determine the surgical technique to be used during LT. If a "conventional" end-to-end portal anastomotic technique is used, there is not a major impact on post-LT survival. Post-LT PVT can significantly reduce both graft and patient survival after LT and can preclude future options for re-LT.

Renal venous hypertension

Renal venous hypertension usually seen in young, otherwise healthy individuals and can lead to significant overall morbidity. Aside from clinical findings and physical examination, diagnosis can be made with ultrasound, computed tomography, or magnetic resonance conventional venography. Symptoms and haemodynamic significance of the compression determine the ideal treatment method. This review of the literature discusses normal and pathological developmental aspects of renocaval venous segment and related circulatory disorders, summarizes congenital and acquired changes in left renal vein and their impact on development of renal venous hypertension. Also will be discussed surgical tactics of portosystemic shunting and their potential effects on renal hemodynamics.

Analysis of factors associated with portal vein thrombosis in pediatric living donor liver transplant recipients

The technique of vascular reconstruction plays a major role in the outcome of living donor liver transplantation (LDLT). An increased use of vascular grafts (VGs) as replacements for sclerotic portal veins has become a standard technique for our group. The aim of this study was to analyze the factors associated with portal vein thrombosis (PVT) in pediatric LDLT. We performed a retrospective analysis of 486 primary pediatric LDLT procedures performed between October 1995 and May 2013. VGs used for portal reconstruction included living donor inferior mesenteric veins, living donor ovarian veins, recipient internal jugular veins, deceased donor iliac arteries, and deceased donor iliac veins. Thirty-four patients (7.0%) developed PVT. The incidence of PVT dropped from 10.1% to 2%; the overall utilization of VGs increased from 3.5% to 37.1%. In a multivariate analysis, only the use of VGs remained an independent risk factor for the occurrence of PVT (hazard ratio = 7.2, 95% confidence interval = 2.8-18.7, P < 0.001). There was no difference in survival rates between patients with PVT and patients without PVT. No patient with PVT underwent retransplantation. In conclusion, the use of VGs was independently associated with the development of PVT. Over time, there was a reduction in the incidence of early PVT in this cohort, and there was a trend toward a reduction in total PVT. The occurrence of isolated PVT in this study was not associated with decreased patient or graft survival.

From portal to splanchnic venous thrombosis: What surgeons should bear in mind

The present study aims to review the evolution of surgical management of portal (PVT) and splanchnic venous thrombosis (SVT) in the context of liver transplantation over the last 5 decades. PVT is more commonly managed by endovenous thrombectomy, while SVT requires more complex technical expedients. Several surgical techniques have been proposed, such as extensive eversion thrombectomy, anastomosis to collateral veins, reno-portal anastomosis, cavo-portal hemi-transposition, portal arterialization and combined liver-intestinal transplantation. In order to achieve satisfactory outcomes, careful planning of the surgical strategy is mandatory. The excellent results that are obtained nowadays confirm that, even extended, splanchnic thrombosis is no longer an absolute contraindication for liver transplantation. Patients with advanced portal thrombosis may preferentially be referred to specialized centres, in which complex vascular approaches and even multivisceral transplantation are performed.

Renal blood flow before and after portosystemic shunt in children with portal hypertension

INTRODUCTION

Variceal haemorrhage in children with extrahepatic portal hypertension is best controlled by an effective decompressive shunt, but long-term follow up of children who have had splenorenal shunt due to extrahepatic portal hypertension (EHPH) gave evidence for assuming the risk of renal venous hypertension (RVH).

PURPOSE

To study renal hemodynamic before and after portal decompression.

METHODS

The results of 144 portosystemic shunt operations were followed from 2005 to 2013. Seventy-two patients applied central splenorenal shunt (CSS) with splenectomy, ten side-to-side splenorenal shunt without splenectomy (SRSss), ten patients assessed the distal splenorenal shunt (DSS). Forty-three iliacomesenterial anastomosis (IMA) and in nine cases performed mesocaval anastomosis (MCA). Children had a standard pre- and postoperative work up including gastrointestinal endoscopy, Doppler ultrasonography (US), multi-slice computed tomography (MSCT) and renography.

RESULTS

In 11 (15.2 %) patients after CSS on duplex, Doppler study revealed signs of impeded venous outflow on the left renal vein (LRV). At long-term follow-up PI and RI of left renal artery remained at high numbers (1.48 ± 0.17 and 0.72 ± 0.19, p ≤ 0.05, respectively) after the CSS. Venous blood flow in the LRV at the hilum showed slower speed performance in groups of CSS and after IMA. After DSS, these signs have not been detected. Four patients after IMA on US Doppler and CT angiography revealed dilated left testicular and ovarian veins, with retrograde blood flow in them, which clinically manifested as left flank pain, macro- and microhematuria, varicocele and ovaricocele.

CONCLUSION

The study shows that CSS and IMA more negatively effect on hemodynamics of left kidney and symptoms of RVH obviously due to shunting the large amounts of blood from a system of high pressure to a low.

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.

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.

The causes, risk factors, and outcomes of early relaparotomy after living-donor liver transplantation

BACKGROUND

Although early relaparotomy of the recipient after living-donor liver transplantation (LDLT) is a significant event, its causes, risk factors, and outcomes are still unclear.

METHODS

A retrospective analysis of 284 cases of adult-to-adult LDLT was performed.

RESULTS

The incidence of early relaparotomy of the recipient was 9.2% (n=26). The reasons for relaparotomy were divided into three groups: postoperative bleeding (n=11, 42.3%), insufficient portal venous flow (n=5, 19.2%), and other (n=10, 38.5%). The 6-month graft survival rates of patients in the early laparotomy and nonlaparotomy groups were 61.5% and 88.4%, respectively (P<0.0001). Patients with postoperative bleeding experienced a significantly higher mortality rate (54.6%) than those with other reasons for early relaparotomy (13.3%; P=0.0231). Multivariate analysis showed that a model for end-stage liver disease score of greater than 20 (odds ratio [OR], 9.06; P=0.0434) and an operative blood loss of greater than 15 L (OR, 9.06; P=0.0434) were significant risk factors for graft loss after early relaparotomy. In patients with patent major shunt vessels (>1 cm in diameter, n=31), portal venous flow of less than 1.0 L/min at the end of surgery was a significant risk factor for early relaparotomy to ligate the remaining shunt vessels (OR, 50.5; P=0.0188).

CONCLUSIONS

Early relaparotomy of the recipient is significantly associated with poor graft survival after LDLT. Massive intraoperative blood loss and high model for end-stage liver disease score were associated with poor graft survival in the relaparotomy group.

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.