Portal vein thrombolysis and closure of competitive shunts following liver transplantation

Vascular complications after liver transplantation: contemporary approaches to detection and treatment. A literature review

Vascular complications (VCs) after liver transplantation (LT) are rare but are one of the most dreaded conditions that can potentially lead to graft loss and recipient death. This paper has analyzed the international experience in the early diagnosis of various VCs that can develop following LT, as well as the optimal timing and methods of treatment of these complications.

The Management of Portal Vein Thrombosis after Adult Liver Transplantation: A Case Series and Review of the Literature

Background: Portal vein thrombosis (PVT) after adult liver transplantation (LT) is a rare but serious complication with no consensus on the ideal treatment. We report a case series and a comprehensive review of the literature on PVT after LT to discuss the therapeutic options. Methods: The clinical data of 360 adult patients (≥18 years of age) who underwent LT from January 2017 to January 2020 were reviewed, and a comprehensive search of PubMed and Web of Science was conducted. Patients diagnosed with PVT after LT were identified, and relevant risk factors and therapies were analyzed. Results: Among the 360 patients, 7 (1.94%) developed PVT after LT. Onset of PVT within one week after LT was found in six patients (85.71%). Four of the seven patients with PVT received systemic anticoagulation (low molecular weight heparin and warfarin) therapy. Minimally invasive interventional therapies combined with systemic anticoagulation (heparin and warfarin) were applied for three patients, two of whom died because of severe abdominal hemorrhage and liver failure. Of the 33 cases reported in the literature, minimally invasive interventional therapy combined with systematic anticoagulation or sclerotherapy were the most-used methods (20/33). Systemic anticoagulation was administered to four patients, and surgical operation (thrombectomy; portosystemic shunt and retransplantation) was performed for nine patients. Among these 33 patients, 4 eventually died. Conclusions: Interventional therapy combined with systemic anticoagulation is a good choice for the management of PVT after LT, and in our experience, systemic anticoagulation alone can also have a positive effect for early PVT patients.

Portal vein thrombosis in cirrhosis: diagnosis, natural history, and therapeutic challenges

Portal vein thrombosis (PVT) is a frequent complication in cirrhosis and its prevalence increases with disease severity. Several factors are involved in the development and progression of PVT. The challenge for the management of PVT is the precise evaluation of the bleeding risk as opposed to life-threatening extension of thrombosis. Nevertheless, the impact on the progression and outcome of liver disease is unclear. A critical evaluation of the available data discloses that treating PVT in cirrhotics is safe and effective. However, there are open issues, such as which anticoagulant could represent a safer therapeutic option, and when and for how long this treatment should be administered to cirrhotic patients with PVT.

Interventional Treatment of Severe Portal Vein Thrombosis after Living-Donor Liver Transplantation

Portal vein thrombosis (PVT) is a rare complication of liver transplantation which can lead to graft failure and patient death. Treatment can be difficult, especially in cases of PVT from the intrahepatic portal vein to the proximal jejunal veins. A 55-year-old woman had undergone living-donor liver transplantation with splenectomy for end-stage liver cirrhosis due to hepatitis C with hepatocellular carcinoma. Ten months after transplantation, massive ascites and slight abdominal pain developed, and computed tomography revealed a PVT between the intrahepatic portal vein and the superior mesenteric vein. Repeated interventional radiology procedures were used in combination with thrombolysis, thrombectomy, and metallic stent replacement to obtain favorable portal flow to the graft. Five years after being treated, the patient is well, with favorable portal flow having been confirmed. In conclusion, repeated and assiduous interventional radiological treatment combined with thrombolytic therapy, thrombectomy, and metallic stent replacement could be important for severe PVT.

Percutaneous Transhepatic Thrombectomy and Pharmacologic Thrombolysis of Mesenteric Venous Thrombosis

Mesenteric venous occlusion is a rare yet highly morbid condition that is traditionally treated with anticoagulation while surgery serves as the last resort. Percutaneous intervention provides an effective option with relatively low mortality and morbidity. We herein describe use of transhepatic percutaneous thrombectomy and pharmacologic thrombolysis in treating two cases of symptomatic mesenteric venous thrombosis. These cases underscore the fact that transhepatic thrombectomy and thrombolysis are a highly effective strategy for treating acute symptomatic mesenteric venous thrombosis. Several percutaneous techniques are also reviewed.

Portal interventions in liver transplant recipients

Portal vein interventions in liver transplant recipients represent a group of interventions in the management of several disease entities including portal vein stenosis, portal vein thrombosis, and recurrent liver cirrhosis with portal hypertension with and without gastric varices. The procedures performed in these patient populations include portal vein angioplasty with or without stent placement for portal vein stenosis, portal vein thrombolysis with or without stent placement for portal vein thrombosis, transjugular intrahepatic portosystemic shunts or splenic embolization for cirrhosis, and balloon-occluded retrograde transvenous obliteration for gastric varices. This article discusses these disease entities and the minimal invasive procedures used in their management.

Treatment of postoperative main portal vein and superior mesenteric vein thrombosis with balloon angioplasty and/or stent placement

BACKGROUND

Thrombolysis and mechanical thrombectomy have been used to treat postoperative main portal vein and superior mesenteric vein thrombosis.

PURPOSE

To evaluate the safety and efficacy of balloon angioplasty and/or stent placement without thrombolysis or thrombectomy for treating such thromboses.

MATERIAL AND METHODS

Fourteen patients with postoperative main portal vein or superior mesenteric vein thrombosis underwent percutaneous transhepatic balloon angioplasty and/or stent placement without thrombolysis or thrombectomy. The rates of technical and clinical success, major complications, and recurrence were evaluated retrospectively.

RESULTS

Initial technical success was achieved in 13 of the 14 patients (93%). After the procedures, these 13 patients showed brisk portal inflow, without a significant amount of residual thrombus in the stented lumen or embolism. One patient was considered to be a technical failure despite showing a brisk portal inflow because 50% stenosis and partial residual thrombus remained in the stented lumen. Initial clinical success was achieved in 13 patients. One patient with technical success died of acute respiratory distress syndrome 8 days after the procedure, whereas one patient with technical failure achieved clinical success. One patient experienced acute rethrombosis 8 days after the procedure. During the median follow-up period of 16.3 months, rethrombosis occurred in six patients (43%), including one patient with acute rethrombosis.

CONCLUSION

Balloon angioplasty and/or stent placement without thrombolysis or thrombectomy may be a safe and effective treatment modality for postoperative main portal vein and superior mesenteric vein thrombosis.

Is there a role for anticoagulants in portal vein thrombosis management in cirrhotic patients?

IMPORTANCE OF THE FIELD

Portal vein thrombosis (PVT) is one of the principal complications of liver cirrhosis. The estimated prevalence is < 1% in patients with a compensated disease; this increases to 8 - 25% in candidates for liver transplantation. Many determinants may influence PVT clinical presentation and its outcome.

AREAS COVERED IN THIS REVIEW

We report the actual knowledge regarding management of PVT and analyze the different therapeutic approaches, focusing particularly on the use of anticoagulants and their implications in the complex clinical setting of liver cirrhosis. We also describe the possible available preemptive strategies, as an early prophylactic management based on clinical, biochemical or radiological parameters may in the future reduce PVT incidence and complications, ameliorating patients' outcome.

WHAT THE READER WILL GAIN

The importance of an accurate PVT diagnosis and its implications in PVT management; a description of the different available therapeutic tools, their efficacy and their possible risks in different typologies of patients; the principal elements to choose a correct individualized therapy for PVT patients.

TAKE HOME MESSAGE

The challenge for clinicians is the early identification of PVT, in order to prevent frightening complications, such as variceal bleeding or mesenteric infarction, and to provide the best therapeutic management.

Vascular steal of the portal vein after orthotopic liver transplant: intraoperative sonographic diagnosis

Spontaneous splenorenal shunts (SSRSs) are portosystemic connections between the splenic vein and the left renal vein (LRV) that develop commonly in patients with portal hypertension. (1) They reportedly occur in 18% to 19% of patients evaluated for a liver transplant. (2),(3) As the liver become more cirrhotic, a major steal phenomenon may occur, whereby blood is shunted from the high-resistance venous bed of the liver to the lower systemic pressure of the LRV. (4) Not infrequently, an SSRS will go undetected during orthotopic liver transplantation because dissection is limited to the right upper quadrant. The importance of these shunts may be underappreciated preoperatively by the radiologist. Usually, if small, these shunts will involute without incident when the lower-resistance allograft is implanted. (5),(6) Larger varices, those greater than 10 mm at the level of transition into the LRV, are more likely to steal blood from the liver, causing allograft failure and possibly death. (4),(7),(8) It is therefore important to document on preoperative imaging the size and location of portosystemic varices in any patient being evaluated for liver transplantation. We present a case in which intraoperative sonography showed a large SSRS that impaired hepatic portal inflow after transplantation, ultimately resulting in the patient's death.

Management of portal venous complications after liver transplantation

The postoperative vascular complications following liver transplantation, specifically portal venous complications, have been well documented. These complications, which include portal venous stenosis and thrombosis, can be potentially devastating and lead to graft failure. The interventional techniques in managing these complications are relatively new and have been developed only in the past 15 to 20 years. Additionally with the increasing numbers of split liver and living related transplants that are being performed, so has the incidence of portal venous complications increased. This article is a review of the current interventional techniques used in managing portal venous complications in the posttransplant patient. The topics covered include portal vein angioplasty, stenting, and thrombolysis with a description of the variety of techniques used to perform these procedures. The review also covers management of portal hypertension by creating a transjugular intrahepatic portosystemic shunt (TIPS).

Percutaneous Transhepatic Portography for the Treatment of Early Portal Vein Thrombosis After Surgery

We treated three cases of early portal vein thrombosis (PVT) by minimally invasive percutaneous transhepatic portography. All patients developed PVT within 30 days of major hepatic surgery (one case each of orthotopic liver transplantation, splenectomy in a previous liver transplant recipient, and right extended hepatectomy with resection and reconstruction of the left branch of the portal vein for tumor infiltration). In all cases minimally invasive percutaneous transhepatic portography was adopted to treat this complication by mechanical fragmentation and pharmacological lysis of the thrombus. A vascular stent was also positioned in the two cases in which the thrombosis was related to a surgical technical problem. Mechanical fragmentation of the thrombus with contemporaneous local urokinase administration resulted in complete removal of the clot and allowed restoration of normal blood flow to the liver after a median follow-up of 37 months. PVT is an uncommon but severe complication after major surgery or liver transplantation. Surgical thrombectomy, with or without reconstruction of the portal vein, and retransplantation are characterized by important surgical morbidity and mortality. Based on our experience, minimally invasive percutaneous transhepatic portography should be considered an option toward successful recanalization of early PVT after major liver surgery including transplantation. Balloon dilatation and placement of a vascular stent could help to decrease the risk of recurrent thrombosis when a defective surgical technique is the reason for the thrombosis.

Portal vein stenosis and occlusion stenting after liver transplantation in two adults

We report two cases of percutaneous transhepatic stenting of the portal vein to treat stenosis and occlusion disclosed 5 and 18 months, respectively, after orthotopic liver transplantation in two adult patients. If long-term patency is satisfactory, this technique should allow long-term management of portal vein stenosis and occlusion without the use of thrombolysis.

Portal vein thrombosis in patients undergoing orthotopic liver transplantation: intraoperative endovascular radiological procedures

PURPOSE

To evaluate the usefulness of endovascular procedures for portal vein complications during orthotopic liver transplantation (OLT).

MATERIALS AND METHODS

Between May 1994 and November 2004, we performed 504 OLTs in 464 adults. Seventy-eight patients (16.8%) presented with portal vein thrombosis (PVT). This analysis of patients from May 2000 to September 2004 included 10 patients with PVT, who were treated with endovascular techniques due to low portal flow. We compared this group with patients who were treated surgically with attention to rethrombosis and survival rates. If portal vein problems were due to obstruction, a venoplasty and primary stent placement were performed. We also embolized with coils or surgically ligated remaining competitive portosystemic shunts.

RESULTS

Perfusion problems in the allograft were solved in all cases. We placed seven stents and embolized six competitive shunts. One anastomotic dysfunction was repaired. None of the patients died or rethrombosed during surgery or follow-up.

CONCLUSION

Endovascular techniques during OLT can resolve some liver graft perfusion problems due to PVT and "steal" phenomena, especially with unsatisfactory eversion thromboendovenectomy in patients with grade IV PVT. Although primary permeability of stents has been good, these results need to be confirmed.

Endovascular treatment of splenomesenteric-portal vein thromboses during orthotopic liver transplantation

Extensive splanchnic venous thrombosis in patients undergoing orthotopic liver transplantation (OLT) continues to have a substantial impact on surgical complexity and perioperative morbidity and mortality rates. This report presents an experience in eight patients with splanchnic venous thrombosis treated by means of splanchnic vessel recanalization, primary stent placement, and closure of spontaneous competitive shunts during OLT. In all cases, portal perfusion in the allograft was adequate, portal hypertension was solved, and no complications were observed. None of the patients died during surgery or follow-up. The results reported here need to be confirmed in future studies.

Imaging and radiological interventions of portal vein thrombosis

Portal vein thrombosis (PVT) is diagnosed by imaging methods. Once diagnosed by means of ultrasound, Doppler ultrasound can be performed to distinguish between a benign and malignant thrombus. If further information is required, magnetic resonance angiography or contrast-enhanced computed tomography is the next step, and if these tests are unsatisfactory, digital subtraction angiography should be performed. Many papers have been published dealing with alternative methods of treating PVT, but the material is fairly heterogeneous. In symptomatic non-cavernomatous PVT, recanalization using local methods is recommended by many authors. Implantation of transjugular intrahepatic portosystemic shunt is helpful in cirrhotic patients with non-cavernomatous PVT in reducing portal pressure and in diminishing the risk of re-thrombosis. In noncirrhotic patients with recent PVT, some authors recommend anticoagulation alone. In chronic thrombotic occlusion of the portal vein, local measures may be implemented if refractory symptoms of portal hypertension are evident.

Successful minimally invasive management of late portal vein thrombosis after splenectomy due to splenic artery steal syndrome following liver transplantation: a case report

Portal vein thrombosis (PVT) after liver transplantation (OLT), which occurs in 1% to 2.7% of cases, can compromise patient and graft survival. Percutaneous transhepatic portal vein angioplasty offers an option to treat PVT, diminishing surgically related morbidity and the need for retransplantation. We describe a case of late PVT after OLT, which was successfully treated by a minimally invasive percutaneous transhepatic approach using both mechanical fragmentation and pharmacologic lysis of the thrombus followed by anticoagulation. The patient has had a good clinical course with normal graft function and patent portal blood flow at 6-month follow-up. This case report confirms the possibility of successful recanalization of the portal vein in a patient with late PVT after liver transplantation. Sustained anticoagulation/antiaggregation therapy for at least 6 months after the procedure is advisable.

Applications of percutaneous mechanical thrombectomy in transjugular intrahepatic portosystemic shunt and portal vein thrombosis

Portal vein thrombosis (PVT) is an uncommon cause for presinusoidal portal hypertension. PVT can be caused by one of three broad mechanisms: (1) spontaneous thrombosis when thrombosis develops in the absence of mechanical obstruction, usually in the presence of inherited or acquired hypercoagulable states; (2) intrinsic mechanical obstruction because of vascular injury and scarring or invasion by an intrahepatic or adjacent tumor; or (3) extrinsic constriction by adjacent tumor, lymphadenopathy or inflammatory process. Usually, several combined factors are necessary to result in PVT. The consequences of portal vein thrombosis are mostly related to the extension of the clot within the vein. Gastrointestinal bleeding from gastroesophageal varices is the most frequent presentation. Noninvasive imaging techniques are currently used for the screening of patients and the initial diagnosis of PVT. The invasive techniques are reserved for cases when noninvasive techniques are inconclusive, before percutaneous interventional treatment, or in preoperative assessment of patients who are candidates for surgery. Recanalization of the portal vein with anticoagulation alone may not be consistent or appropriate in highly symptomatic patients. Catheterization of the superior mesenteric artery (SMA) is helpful for diagnosis as well as for therapy by allowing the intra-arterial infusion of thrombolytic drugs in the same setting. Direct transhepatic portography allows precise determination of the degree of stenosis and extension within the portal vein, as well as pressure measurements. Thrombotic occlusions of the portal, mesenteric, and splenic veins can be managed by mechanical thrombectomy (MT) or pharmacologic thrombolysis. Underlying occlusions because of organized or refractory thrombus or fixed venous stenosis are best corrected by balloon angioplasty and stent placement. Access into the portal venous system can also be established through creating a transjugular intrahepatic portosystemic shunt (TIPS). Creating a TIPS is also important in the setting of PVT associated with cirrhosis to decompress portal hypertension and improve portal venous flow. PVT involving the portal, splenic, and/or mesenteric veins can also complicate a preexisting TIPS in which case the shunt can be readily used as therapy access. Several techniques may be used to recanalize the shunt and portal venous system, including thrombolytic therapy, balloon angioplasty/embolectomy, suction embolectomy, basket extraction of clots, and mechanical thrombectomy with a variety of devices. Advantages of MT include the potential to rapidly remove thrombus without the need for prolonged thrombolytic infusions, and reducing the potential life-threatening complications of thrombolytic therapy. Possible drawbacks include the risk of intimal or vascular trauma to the portal vein, which may promote recurrent thrombosis.

Radiology in liver transplantation

Imaging studies are becoming essential in the management of orthotopic liver transplantation (LT). They have a very important role in the preoperative evaluation and selection of suitable candidates. At the same time, they are essential in the early detection of postoperative complications, the recognition of which allows the prompt institution of appropriate therapeutic measures. Timely recognition of complications improves the success of LT; furthermore, some complications can be treated with interventional radiologic procedures, avoiding additional surgery. This article reviews the current application of diagnostic and interventional imaging in liver transplantation, both for cadaveric and living donor transplants.

Hepatofugal flow in the portal venous system: pathophysiology, imaging findings, and diagnostic pitfalls

Hepatofugal flow (ie, flow directed away from the liver) is abnormal in any segment of the portal venous system and is more common than previously believed. Hepatofugal flow can be demonstrated at angiography, Doppler ultrasonography (US), magnetic resonance imaging, and computed tomography (CT). The current understanding of hepatofugal flow recognizes the role of the hepatic artery and the complementary phenomena of arterioportal and portosystemic venovenous shunting. Detection of hepatofugal flow is clinically important for diagnosis of portal hypertension, for determination of portosystemic shunt patency and overall prognosis in patients with cirrhosis, as a potential pitfall at invasive arteriography performed to evaluate the patency of the portal vein, and as a contraindication to specialized imaging procedures (ie, transarterial hepatic chemoembolization and CT during arterial portography). Hepatofugal flow is generally diagnosed at Doppler US without much difficulty, but radiologists should beware of pitfalls that can impede correct determination of flow direction in the portal venous system.

Percutaneous mechanical fragmentation and stent placement for the treatment of early posttransplantation portal vein thrombosis

BACKGROUND

Early portal vein thrombosis is a rare but severe complication of liver transplantation requiring retransplantation or at least surgical thrombectomy, both hampered by high morbidity and mortality.

METHODS

We describe of a case of successful long-term recanalization of early posttransplantation portal vein thrombosis by a minimally invasive percutaneous transhepatic angiographic approach using both mechanical fragmentation and pharmacological lysis of the thrombus followed by stent placement.

RESULTS

Mechanical fragmentation and contemporaneous local urokinase administration resulted in complete removal of the clot; the use of a vascular stent after balloon dilatation allowed restoration of normal blood flow to the liver after 9 months of follow-up.

CONCLUSIONS

This case report confirms the possibility of successful recanalization of the portal vein after early posttransplantation thrombosis by a minimally invasive angiographic approach. Balloon dilatation and placement of a vascular stent could help to decrease the risk of recurrent thrombosis.

Limitations of percutaneous techniques in the treatment of portal vein thrombosis

New therapeutic alternatives to portal vein thrombosis (PVT) include the percutaneous, transhepatic infusion of fibrinolytic agents, balloon dilatation, and stenting. These maneuvers have proven to be effective in some cases with acute, recent PVT. We have treated two patients with acute PVT via transhepatic or transjugular approaches and by using pharmacologic and mechanical thrombolysis and thrombectomy. Although both patients clinically improved, morphologic results were only fair and partial rethrombosis was observed. The limitations of percutaneous procedures in the recanalization of acute PVT in noncirrhotic patients are discussed.

Percutaneous mesenteric venous thrombectomy and thrombolysis: successful treatment followed by liver transplantation

Mesenteric vein thrombosis (MVT) is a rare cause of intestinal ischemia. Because of its nonspecific symptoms, diagnosis is often delayed. We describe a patient with liver cirrhosis who developed acute MVT while waiting for liver transplantation. Surgical intervention carried a high risk because of her underlying cirrhosis. Mesenteric venous thrombectomy and thrombolysis were performed with an AngioJet (Possis Medical, Minneapolis, MN) thrombectomy device and streptokinase infusion through transjugular route. The patient subsequently received an orthotopic liver transplant. We also present a review of the literature about the occurrence and treatment options for MVT.

Percutaneous thrombolysis and stent placement for the treatment of portal vein thrombosis after liver transplantation: long-term follow-up

BACKGROUND

The durable use of percutaneous minimally invasive techniques for the treatment of portal venous thrombosis after liver transplant has not been widely described. This report illustrates two cases in which percutaneous thrombolysis, angioplasty, and endovascular stent placement were successfully used to treat portal vein thrombosis in patients with recent liver transplants.

METHODS

Liver dysfunction was initially manifested by the elevation of liver enzymes or the development of marked ascites and confirmed in both cases by sonography and angiography. The occluded portal vein was accessed by either a transjugular transhepatic puncture or direct transhepatic catheterization. Intraportal thrombolytic infusion, angioplasty, and stent placement were accomplished without complication.

RESULTS

At the most recent follow-up, portal vein patency had been maintained for 2.5 and 4.5 years.

CONCLUSIONS

These results demonstrate the technical feasibility and long-term patency of angioplasty and endovascular stent placement for the treatment of portal vein thrombosis in liver transplant recipients.

Embolization of nonvariceal portosystemic collaterals in transjugular intrahepatic portosystemic shunts

Percutaneous embolization of large portosystemic collaterals was performed in three patients following placement of a transjugular intrahepatic portosystemic shunt in order to improve hepatopetal portal flow. Improved hepatic portal perfusion was achieved in these cases, thereby theoretically reducing the risk of chronic hepatic encephalopathy.

Intraoperative placement of a Wallstent for portal vein stenosis and thrombosis after liver transplantation

We report a case of orthotopic liver transplantation, in which portal vein thrombosis developed in the immediate postoperative period. Surgical thrombectomy and intraoperative placement of a large caliber Wallstent resulted in long-term patency. The unique feature of this case is the intraoperative placement of the stent via the inferior mesenteric vein under fluoroscopic guidance. The use of a large caliber (16 mm) stent obviated the need for postoperative anticoagulation.

Comparison of ultrasound, CT, and MR imaging in the evaluation of candidates for TIPS

To compare ultrasound (US), CT, and MRI in the evaluation of hepatic vascular anatomy, portal and splenic venous flow, and collateral pathways (varices and spontaneous shunts) in candidates for transjugular intrahepatic portosystemic shunting (TIPS), 17 patients with history of refractory variceal bleeding or intractable ascites underwent duplex US, contrast-enhanced CT, and MRI before TIPS. The appearance of portal and hepatic anatomy was graded from 1 (not visible) to 4 (excellent visualization) independently by four radiologists. Presence and direction of portal and splenic venous flow, and presence and location of varices and spontaneous portosystemic shunts were also assessed. Results and effects of interobserver variation were assessed for significance using Friedman's ANOVA and Wilcoxon's signed-rank test. MRI yielded higher scores than CT or US for hepatic veins (P < .0001) and inferior vena cava (P < .0001). MRI and CT scored better than US for portal vein branches (P = .012) and splenic vein (P = .0038). All tests demonstrated the main portal vein well, with no statistically significant difference. US and MRI were more sensitive than CT for detecting portal vein flow and direction (US 76%, CT 0%, MRI 82%). MRI was most sensitive for splenic vein flow and direction (US 41%, CT 0%, MRI 76%). CT and MRI were more sensitive than US in detecting varices (US 5%, CT 50%, MRI 58%) and spontaneous shunts (US 13%, CT 75%, MRI 75%). Interobserver variation did not influence results significantly P = .3691). MRI provides the most useful information and may be the preferred single imaging test prior to TIPS.