Transsplenic splenoportography and portal venous interventions in pediatric patients

Portal Venous Disease

Portal interventions in pediatric patients present unique difficulties when compared to adult procedures. In addition, children who need a portal intervention require a different workup and clinical management. Based on these elements, the clinical decisions for the study and treatment of these pathologies are different. This review is intended to present a summary of the interventional radiologist's role in treating pediatric portal venous diseases. Focus is placed on the technical elements, patient management and procedural indications while discussing different interventions involving the portal vein, providing some recommendations supported by recent research and the authors' experience.

Recanalization of portal vein thrombosis after pediatric liver transplantation: Efficacy and safety of the transsplenic access

BACKGROUND

Endovascular management of portal vein thrombosis (PVT) is challenging. Transsplenic access (TSA) is growing as an access option to the portal system but with higher rates of bleeding complications. The aim of this article is to evaluate the efficacy and safety of transsplenic portal vein recanalization (PVR) using a metallic stent after pediatric liver transplantation.

MATERIALS AND METHODS

This is a retrospective review of 15 patients with chronic PVT who underwent PVR via TSA between February 2016 and December 2020. Two children who had undergone catheterization of a mesenteric vein tributary by minilaparotomy were excluded from the patency analysis but included in the splenic access analysis. The technical and clinical success of PVR and complications related to the procedure via TSA were evaluated.

RESULTS

Thirteen children with PVT were treated primarily using the TSA. The mean age was 4.1 years (range, 1.5-13.7 years), and the most common clinical presentation was hypersplenism (60%). Technically successful PVR was performed in 11/13 (84.6%) children, and clinical success was achieved in 9/11 (81.8%) children. No major complications were observed, and one child presented moderate pain in the TSA (from a total of 17 TSA). The median follow-up was 48.2 months. The median primary patency was 9.9 months. Primary patency in the first 4 years was 75%, and primary assisted patency was 100% in the follow-up period.

CONCLUSIONS

Transsplenic PVR is a safe and effective method for the treatment of PVT after pediatric liver transplantation.

Safety of Percutaneous Transmesenteric and Transsplenic Access for Portosystemic Shunt Creation in Patients with Portal Vein Obstruction: Single-Center Experience and Review of Literature

PURPOSE

To evaluate the safety of ultrasound-guided percutaneous mesenteric vein access compared to transsplenic portal vein access for portosystemic shunt placement in patients with portal vein obstruction.

MATERIALS AND METHODS

Eight patients underwent portosystemic shunt creation through either a transsplenic (n = 4) or transmesenteric (n = 4) approach. The superior or inferior mesenteric vein was percutaneously accessed under ultrasound guidance using a 21G needle and a 4F sheath. Hemostasis at the mesenteric access site was achieved with manual compression. For transsplenic access, sheath sizes between 6 and 8F were used and tract embolization with gelfoam was performed.

RESULTS

Portosystemic shunt placement was successful in all patients. While there were no bleeding complications with transmesenteric access, hemorrhagic shock requiring splenic artery embolization occurred in one patient in which the transsplenic approach was used.

CONCLUSION

Ultrasound-guided mesenteric vein access seems feasible and a valid alternative to the transsplenic access in case of portal vein obstruction. Level of Evidence Level 4, case series.

Transsplenic tract closure after transsplenic portalvenous access using gelfoam-based tract plugging

BACKGROUND

To assess the feasibility and safety of a gelfoam torpedo plugging technique for embolization of the transsplenic access channel in adult patients following transvenous portal vein interventions.

MATERIALS AND METHODS

Between 09/2016 and 08/2021, an ultrasound guided transsplenic portalvenous access (TSPVA) was established in twenty-four adult patients with a 21-G needle and 4-F microsheath under ultrasound guidance. Afterwards, sheaths ranging from 4-F to 8-F were inserted as needed for the procedure. Following portal vein intervention, the splenic access tract was embolized with a gelfoam-based tract plugging (GFTP) technique. TSPVA and GFTP were performed twice in two patients. Patients' pre-interventional and procedural characteristics were analyzed to assess the feasibility and safety of the plugging technique according Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system. Values are given as median (minimum;maximum). Subgroup analysis of intercostal vs. subcostal puncture site for TSPVA was performed using the two-sided Mann-Whitney-U test or Student's t-test and Fisher's exact test. Level of significance was p < 0.05.

RESULTS

The study population's age was 56 (29;71) years and 54% were female patients. Primary liver disease was predominantly liver cirrhosis with 62% of the patients. Pre-interventional model for end-stage liver disease score was 9 (6;25), international normalized ratio was 1.15 (0.86;1.51), activated partial thromboplastin time was 33s (26s;52s) and platelet count was 88.000/µL (31.000;273.000/µL). Ascites was present in 76% of the cases. Craniocaudal spleen diameter was 17cm (10cm;25cm). Indication for TSPVA was assisted transjugular intrahepatic portosystemic shunt placement in 16 cases and revision in two cases, portal vein stent placement in five cases and variceal embolization in three cases. TSPVA was successfully established in all interventions; interventional success rate was 85% (22/26). The splenic access time was 33min (10min;133min) and the total procedure time was 208min (110min;429min). Splenic access was performed with a subcostal route in 11 interventions and with an intercostal route in 15 interventions. Final sheath size was 4-F in 17 cases, 5-F in three cases, 6-F in five cases, 7-F in two cases and 8-F in one case. A median of two gelfoam cubes was used for GFTP. TSPVA- and GFTP-related complications occurred in 4 of 26 interventions (15%) with a subcapsular hematoma of the spleen in two patients (CIRSE grade 1), access-related infection in one patient (CIRSE grade 3) and both in one patient (CIRSE grade 3). In detail, one access-related complication occurred in a patient with subcostal TSPVA (CIRSE grade 1 complication) and the other three complications occurred in patients with intercostal TSPVA (one CIRSE grade 1 complication and two CIRSE grade 3 complication) (p = 0.614). No patient required interventional or surgical treatment due to puncture tract bleeding.

CONCLUSION

Gelfoam-based plugging of the puncture tract was feasible and safe for transsplenic access in adult patients undergoing percutaneous portal vein interventions. The lack of major bleeding complications and complete absorption of the gelatine sponge make it a safe alternative to transjugular and transhepatic access and re-interventions via the splenic route.

Transsplenic Portal System Catheterization: Review of Current Indications and Techniques

Multiple diseases of the portal system require effective portal vein access for endovascular management. While percutaneous transhepatic and transjugular approaches remain the standard methods of portal vein access, transsplenic access (TSA) has gained recognition as an effective and safe technique to access the portal system in patients with contraindications to traditional approaches. Recently, the utility of percutaneous TSA has grown, with described treatments including recanalization of chronic portal vein occlusion, placement of stents for portal vein stenosis, portal vein embolization of the liver, embolization of gastric varices, placement of complicated transjugular intrahepatic portosystemic shunts, and interventions after liver transplant. The authors provide a review of percutaneous TSA, including indications, a summary of related portal vein diseases, and the different techniques used for access and closure. In addition, an imaging-based review of technical considerations of TSA interventions is presented, with a review of potential procedural complications. With technical success rates that mirror or rival the standard methods and reported low rates of major complications, TSA can be a safe and effective option in clinical scenarios where traditional approaches are not feasible. ^©RSNA, 2022.

Direct percutaneous access to an omental vein for embolization of Roux-en-Y limb varices in a child

An 11-year-old boy with a history of hepatoblastoma treated with chemotherapy, radiation therapy, and liver transplantation presented with bleeding from Roux-en-Y limb varices. The transhepatic approach for portal intervention posed a risk of liver graft injury. An omental vein that was dilated as a collateral vein due to portal hypertension was found and compressible under ultrasound. The omental vein was percutaneously punctured, and the varices were embolized through a jejunal vein. No complication occurred. Direct percutaneous access to the portal venous system is a useful technique for portal embolization.

Closure of Transsplenic Access Tracts Using Tract Embolics: Success, Clinical Outcomes, and Complications in a Tertiary Center

Purpose The aim of the study was to evaluate the safety and effectiveness of transsplenic venous access closure.

Materials and Methods Twenty patients (mean age: 51.8 years; range: 28–72), underwent 21 transsplenic venous access procedures over 4 years in this retrospective study. Comorbidities, active hemorrhage, anticoagulation, coagulation parameters, platelets, indications for transsplenic access, needle gauge, sheath size, variceal embolization method, tract embolization method, bleeding complications, and transfusion requirements and additional procedures to manage bleeding complications were recorded.

Results Preprocedure comorbidities included portal hypertension (n = 18/20, 90%), portal vein thrombosis (n = 14/20, 70%), hemorrhage (n = 6/20, 30%), splenic vein thrombosis (n = 7/20, 35%), anticoagulation (n = 2/20, 10%), and sinistral portal hypertension (n = 2/20,10%). Mean baseline international normalized ratio was 1.3 (range: 1–1.9), platelets 122 (range: 18–492). Most common transsplenic access indications were gastric varices with nonpatent portosystemic shunt (n = 11/21, 52%) and portal vein targeting for transjugular intrahepatic portosystemic shunt (n = 8, 38%). Most common access sheath sizes were 4-French (n = 5, 24%) and 6-French (n = 6, 29%). Fifteen procedures (71%) involved variceal embolization. Transsplenic tracts were embolized with microfibrillar collagen alone (n = 7), coils and microfibrillar collagen (n = 8), or others (n = 6). Based on the Society of Interventional Radiology adverse event classification system, embolization complications included one major (splenic artery pseudoaneurysm and a splenic vein pseudoaneurysm) and three moderate (19%) adverse bleeding events, which required blood transfusion.

Conclusion Transsplenic venous access tract embolization is a safe and moderately effective method to achieve tract hemostasis, with an overall clinical failure rate of 20%.

Portomesenteric and portosystemic venous reconstructions in children using balloon-expandable endoprostheses

BACKGROUND

Portomesenteric and portosystemic venous occlusive disease may lead to portomesenteric hypertension, variceal bleeding, ascites and hypersplenism. Data regarding endovascular reconstructive strategies in children, however, are limited.

OBJECTIVE

To report technical success, outcome and patency of portomesenteric and portosystemic venous reconstruction using VIABAHN VBX balloon-expandable endoprostheses in pediatric patients.

MATERIALS AND METHODS

Five pediatric patients (median age: 15 years, range: 4-18 years), including 3 (60%) boys and 2 (40%) girls, with portomesenteric or portosystemic venous occlusion or recurrent stenosis, underwent balloon-expandable stent graft reconstruction. Presenting symptoms included acute variceal bleeding, without (n = 2, 40%) or with (n = 1, 20%) splenomegaly, and transfusion-dependent chronic melena (n = 1, 20%). One patient was asymptomatic (n = 1, 20%). Preprocedural imaging included Doppler ultrasound and contrast-enhanced computed tomography (CT) in all patients. Initial imaging showed 4 (80%) occlusions and 1 (20%) recurrent stenosis greater than 50%. Technical aspects of the reconstructions, technical successes, clinical outcomes and adverse events were recorded. Technical success was defined as completion of stent graft reconstruction. Adverse events were categorized according to Society of Interventional Radiology criteria. Clinical success was defined as resolution of the presenting symptoms and/or prevention of portal hypertensive sequela.

RESULTS

Venous reconstruction was technically successful in all five patients. Stent graft locations included the main portal vein in 2 (40%), the superior mesenteric vein in 1 (20%), autologous Meso-Rex shunt in 1 (20%) and splenocaval shunt in 1 (20%). Six stent grafts were placed (two stent grafts placed in a single patient). Stent grafts had a median diameter of 7 mm (range: 6-10 mm) and a median length of 59 mm (range: 19-79 mm). Median fluoroscopy time was 36.6 min (range: 13.4-95.8 min) and median air kerma was 301.0 mGy (range: 218.0-1,148.2 mGy). No adverse events occurred. Median clinical follow-up was 18 months (range: 6-29 months). Median imaging follow-up was 17 months (range: 2-29 months). Clinical success was achieved in all patients and maintained during the follow-up period. One patient required follow-up intervention with superior mesenteric vein side extension with a self-expanding bare metal stent due to perigraft stenosis detected on CT 3 months after stent placement. There were no stent graft occlusions.

CONCLUSION

Portomesenteric and portosystemic venous reconstruction using balloon-expandable stent grafts in pediatric patients was feasible and clinically successful in this preliminary experience. Additional studies are warranted.

Angiographic diagnosis for accurate assessment of congenital porto-systemic shunt and extrahepatic portal vein obstruction in children

BACKGROUND

Congenital porto-systemic shunt (CPSS) is a rare disease and can cause fatal complications. Accurate angiographic assessment is mandatory for proper treatment. Although technically difficult, we developed assessment techniques and assessed their accuracy. One technique came from evaluating patients with extrahepatic portal vein obstruction (EHPVO).

METHODS

We conducted a single center retrospective study to evaluate the efficacy of angiographic diagnostic procedure for the assessment of CPSS and EHPVO, and its impact on patients' subsequent interventions and clinical course. Eight patients with CPSS and two patients with EHPVO who underwent diagnostic angiography were included. Assessment of the intrahepatic portal vein was performed in all patients. The route of the shunt, and portal vein pressure under shunt occlusion, were also evaluated for patients with CPSS. Evaluation was first attempted with a balloon angiographic catheter (standard method). Three additional techniques were performed as needed: (i) direct wedge-catheter injection without balloon inflation, (ii) use of occlusion balloon in two patients, and (iii) hybrid angiography with sheath placement directly into the superior mesenteric vein.

RESULTS

The standard method was sufficient in four patients. On the other hand, all three techniques were required in two patients each. One lost contact during follow up, but all other patients underwent optimal intervention. There were no complications related to the angiographic procedure.

CONCLUSIONS

Use of direct wedge-catheter injection without balloon inflation, occlusion balloon, and hybrid catheterization improved the diagnostic yield in patients with CPSS or EHPVO.

Pediatric Hepatobiliary Interventions in the Setting of Intrahepatic Vascular Malformations, Portal Hypertension, and Liver Transplant

Within the broad spectrum of pediatric hepatobiliary disorders, hepatic vascular malformations, portal hypertension, and hepatic transplant interventions pose numerous challenges. The role of interventional radiology within each of these conditions is discussed herein, beginning with endovascular management of high flow hepatic vascular malformations. Next, while becoming less common in adult populations, surgical portoportal and portosystemic shunts remain prevalent in many pediatric centers. Shunt anatomy is reviewed along with endovascular management techniques for shunt dysfunction. Next, the growing experience with pediatric transjugular intrahepatic portosystemic shunt placement is reviewed along with tips for success in pediatric patients. Finally, pediatric hepatic transplant interventions are discussed with technical notes pertinent to split liver anatomy.