Radiation Exposure in Transjugular Intrahepatic Portosystemic Shunt Creation

Radiomics Analysis of Preprocedural CT Imaging for Outcome Prediction after Transjugular Intrahepatic Portosystemic Shunt Creation

PURPOSE

To evaluate the role of radiomics in preoperative outcome prediction in cirrhotic patients who underwent transjugular intrahepatic portosystemic shunt (TIPS) using "controlled expansion covered stents".

MATERIALS AND METHODS

This retrospective institutional review board-approved study included cirrhotic patients undergoing TIPS with controlled expansion covered stent placement. From preoperative CT images, the whole liver was segmented into Volumes of Interest (VOIs) at the unenhanced and portal venous phase. Radiomics features were extracted, collected, and analyzed. Subsequently, receiver operating characteristic (ROC) curves were drawn to assess which features could predict patients' outcomes. The endpoints studied were 6-month overall survival (OS), development of hepatic encephalopathy (HE), grade II or higher HE according to West Haven Criteria, and clinical response, defined as the absence of rebleeding or ascites. A radiomic model for outcome prediction was then designed.

RESULTS

A total of 76 consecutive cirrhotic patients undergoing TIPS creation were enrolled. The highest performances in terms of the area under the receiver operating characteristic curve (AUROC) were observed for the "clinical response" and "survival at 6 months" outcome with 0.755 and 0.767, at the unenhanced and portal venous phase, respectively. Specifically, on basal scans, accuracy, specificity, and sensitivity were 66.42%, 63.93%, and 73.75%, respectively. At the portal venous phase, an accuracy of 65.34%, a specificity of 62.38%, and a sensitivity of 74.00% were demonstrated.

CONCLUSIONS

A pre-interventional machine learning-based CT radiomics algorithm could be useful in predicting survival and clinical response after TIPS creation in cirrhotic patients.

Establishment of Diagnostic Reference Levels in Portuguese Interventional Radiology departments

PURPOSE

To establish Portuguese Diagnostic Reference Levels (DRLs), for six body fluoroscopy guided interventional procedures (FGIP).

METHOD

A retrospective study was conducted in five interventional departments most representative of Interventional Radiology (IR) practice. Dose values, in terms of air kerma area product (PKA in Gy.cm2), air kerma at the patient entrance reference point (Ka,r in mGy), and exposure parameters (fluoroscopy time (FT) and number of cine runs) were collected. Examinations were selected per procedure (at least 20), according to the antero-posterior and lateral diameter mean value (±5 cm), measured on previous Computed Tomography (CT) examinations.

RESULTS

Data of 489 body FGIP show a large variation on dose values per procedure and per department. National DRLs in terms of PKA were 20.2 Gy.cm2 for Percutaneous transhepatic biliary drainage (PTBD), 98.2 Gy.cm2 for Bronchial artery embolisation (BAE), 247.7 Gy.cm2 for Transarterial chemoembolisation (TACE), 331.6 Gy.cm2 for Inferior epigastric arteries embolisation (IEAE), 312.0 Gy.cm2 for Transjugular intrahepatic portosystemic shunt (TIPS) and 19.3 Gy.cm2 for Endovascular treatment of femoral popliteal arteries (ETFPA).

CONCLUSIONS

This is the first study reporting Interventional Radiology DRLs in Portugal and we propose preliminary national estimates for the six more common body FGIP. The results of this study will be presented and discussed with all Portuguese IR departments, to promote procedures optimisation.

Right vs left portal branch puncture in TIPS creation with controlled expansion covered stent: comparison of hemodynamic and clinical outcomes

PURPOSE

To retrospectively compare outcomes of TIPS performed by puncturing left portal vein (LPV) vs right portal vein (RPV) to access the portal system.

MATERIALS AND METHODS

One hundred ninety-three consecutive patients underwent TIPS with controlled expansion covered stent by using the LPV (37 patients) or the RPV (156 patients). Patients were followed until the last clinical evaluation, liver transplantation, or death.

RESULTS

Demographics and clinical characteristics of the two groups were comparable. The median follow-up was 9.6 months (range 0.1-50.6). Portosystemic pressure gradient (PSG) before TIPS 15.7 mmHg ± 4.7 in RPV group (RPVG) vs 15.4 mmHg ± 4.5 in LPV group (LPVG) (p = 0.725). After TIPS, PSG 6.3 mmHg ± 2.8 in RPVG vs 6.2 mmHg ± 2.2 (p = 0.839). In LPVG, the stent was dilated to 8-mm in 95% of patients vs 77% of RPVG (p = 0.015). Two (5.4%) and 22 (14%) patients underwent TIPS revision in LPVG and RPVG (p = 0.15). The incidence of overt HE was 13% in LPVG and 24% in RPVG (p = 0.177). Rebleeding occurred in 3 of 49 patients (6%) with variceal bleeding as an indication: 2/41 patients (4.9%) in RPVG vs 1/8 patients (12.5%) in LPVG (p = 0.417). Among 126 patients with refractory ascites 20 patients (15.9%) needed paracentesis 3 months after the procedure: 18/101 patients (17.8%) in RPVG vs 2/25 patients (8%) in LPVG (p = 0.231). Thirty-seven patients (19%) died: 32 (21%) in RPVG and 5 (14%) in LPVG (p = 0.337).

CONCLUSION

Compared with RPV puncture, in TIPS created through the LPV, the targeted PSG was reached with a smaller stent diameter. However, no significant difference in clinical outcomes was observed.

KEY POINTS

• A LPV approach for TIPS creation does not lead to better control of complications of portal hypertension as compared to a RPV approach.

Indian College of Radiology and Imaging Evidence-Based Guidelines for Interventions in Portal Hypertension and Its Complications

Portal hypertension is a complication of chronic liver disease. Various radiological interventions are being done to aid in the diagnosis of portal hypertension; further, an interventional radiologist can offer various treatments for the complications of portal hypertension. Diagnosis of portal hypertension in its early stage may require hepatic venous pressure gradient measurement. Measurement of gradient also guides in diagnosing the type of portal hypertension, measuring response to treatment and prognostication. This article attempts to provide evidence-based guidelines on the management of portal hypertension and treatment of its complications.

Transjugular intrahepatic portosystemic shunt with transhepatic portal vein puncture guided by ultrasound: a technical alternative

OBJECTIVE

Evaluation of an alternative technique to perform transjugular intrahepatic portosystemic shunt (TIPS), using abdominal ultrasound to guide portal puncture.

METHODS

Retrospective analysis of TIPS performed from January 2014 to December 2018 in an interventional radiology service. TIPS were performed according to the classic technique, except at the moment of portal branch puncture, when abdominal ultrasound was used to guide it, visualized its path within the parenchyma in real-time. Qualitative and quantitative variables were analyzed considering a 95% confidence interval and application of the Student's t-test with a significance level of P < 0.05.

RESULTS

Forty-one TIPS were performed. The technical success rate of ultrasound guidance in portal puncture was 100.0%. After its performance, a reduction in the portosystemic pressure gradient was observed, with an initial gradient average of 18.8 mmHg (12-25 ± 3.6 mmHg) and a final gradient of 9.2 mmHg (5-14 ± 2.4 mmHg). The mean values for the TIPS execution time, fluoroscopy time and the radiation dose, verified through the dose area product, were 65.2 ± 46.7 min, 25 ± 14.1 min and 85.6 ± 70 Gy cm2, respectively. There were no complications related to the inadvertent puncture of nontarget structures or deaths due to complications resulting from TIPS.

CONCLUSION

The results demonstrate that the portal transhepatic puncture guided by the abdominal ultrasound is an effective and safe procedure and results in time of execution, time of fluoroscopy and radiation dose below the current reference values of the conventional procedure.

Patients' Radiation Shielding in Interventional Radiology Settings: A Systematic Review

As a result of the increasing risk of developing radiation-related complications, many approaches aimed at reducing this risk and enhancing the outcomes of the patient, doctor or device operator have been developed. In this systematic review, we aim to discuss previous investigations that studied patient shielding or protection within the context of selected interventional radiology procedures. We included original studies that used K_a,r, and P_KA for the assessment of the outcomes of two procedures: transjugular intrahepatic portosystemic shunt creation (TIPS) and hepatic arterial chemoembolization (HAE). A thorough search strategy was conducted on relevant databases to identify all relevant studies. We included 13 investigations, including 12 cross-sectional studies and one randomized controlled trial. Significant diversity was found among all these studies in terms of the used modalities, which made them hard to compare. However, almost all studies agreed that using novel imaging and interventional modalities is useful when obtaining better outcomes and reducing patient radiation exposure. The use of ultrasound-guided procedures and providing adequate lead curtains has also been recommended by the identified studies in order to minimize the frequency of radiation exposure. The reported K_a,r, and P_KA were also variable between studies and were discussed within this study. Our findings indicate that unified guidelines for patient radiation shielding should be urgently investigated.

Portal vein puncture-related complications during transjugular intrahepatic portosystemic shunt creation: Colapinto needle set vs Rösch-Uchida needle set

Transjugular portal vein puncture is considered the riskiest step in TIPS creation with possible incidence of portal vein puncture-related complications (PVPC). The Colapinto and the Rösch-Uchida needle sets are two different needle sets currently available. To date, there have been no randomized control trials or systematic reviews which compare the incidence of PVPC when using the two different needle sets. The aim of this literature review is to assess the rate of PVPC associated with the different needle sets used in the creation of TIPS. From the described search, 1500 articles were identified and 34 met the inclusion criteria. Outcome measured was the prevalence of PVPC using the different needle sets. Overall 212 (3.6%) PVPC were reported in 5865 patients; 142 (3.5%) reported in 4000 cases using the Rösch-Uchida set and 70 (3.7%) in 1865 patients using the Colapinto set (p = 0.69). PVPC in TIPS creation are not related to the choice of needle set used in the procedure. To our knowledge, this is the first review of its kind, the results of which support the theory that while the rate of PVPC is influenced by many factors, choice of needle set does not seem to be one of them.

Ultrasound-guided portal vein puncture during Transjugular Intrahepatic Portosystemic Shunt: Technique and experience of a quaternary liver transplant hospital

INTRODUCTION

Portal hypertension (PH) is associated with complications including refractory ascites and variceal haemorrhage and can be treated endovascularly with a Transjugular Intrahepatic Portosystemic Shunt (TIPS). Portal vein puncture during TIPS using real-time transabdominal ultrasound guidance is one of many portal vein puncture techniques and is seldom used compared with other methods. The purpose of this manuscript is to describe this technique and its associated procedural outcomes at a quaternary liver transplant hospital.

METHODS

Clinical data of all patients who underwent ultrasound-guided TIPS at our institution between 1 January 2009 and 1 January 2019 were retrospectively obtained from electronic medical records and reviewed. Patient demographics, indications, procedural outcomes and complications were recorded.

RESULTS

Forty-four ultrasound-guided TIPS procedures were performed during the study period. The most common indication for TIPS was refractory ascites (n = 26; 57%) and variceal haemorrhage (n = 12; 26%). Technical success rate was 100%. No intraprocedural complications occurred. Periprocedural complication rate was 35% (n = 16) with encephalopathy (n = 8; 17%) and sepsis (n = 5; 11%) the most common. One patient with sepsis died. No other TIPS-related deaths occurred. Median fluoroscopy time, contrast volume, air kerma and dose area product values for all procedures were 35 minutes (IQR 24-51), 100 ml (IQR 70-160), 0.95 Gy (IQR 0.50-1.53) and 127 Gycm² (IQR 68.75-206), respectively.

CONCLUSION

Transabdominal ultrasound-guided portal vein puncture during TIPS is safe and technically feasible. When compared to fluoroscopically guided methods, it is associated with lower intraprocedural complication rates, fluoroscopy times, contrast volumes and radiation doses in our experience. Radiation doses, FTs and contrast volumes were also considerably lower than recommended limits.

Ultrasound-Guided Portal Vein Access and Percutaneous Wire Placement in the Portal Vein Are Associated With Shorter Procedure Times and Lower Radiation Doses During TIPS Placement

BACKGROUND. TIPS placement is an effective method for treating a number of complications of portal hypertension. Although this complex procedure has been firmly established in treatment algorithms, more data are needed to determine the most efficient and safest ways to perform the procedure. OBJECTIVE. The purpose of this study was to determine the effect of three different techniques of portal vein (PV) cannulation during TIPS placement on procedure efficiency. METHODS. The medical records of patients who underwent TIPS creation between 2005 and 2019 were reviewed. On the basis of the PV access technique used, patients were grouped as follows: group 1 (G1) included patients who underwent a transabdominal ultrasound (US)-guided technique to obtain PV access, group 2 (G2) consisted of those who underwent fluoroscopically guided wedged hepatic portography, and group 3 (G3) included those who underwent percutaneous US-guided PV guidewire placement for fluoroscopic targeting. RESULTS. Of the 264 patients who underwent TIPS creation, 54 (20.5%) were in G1, 172 (65.1%) were in G2, and 38 (14.4%) were in G3. The mean (± SD) fluoroscopic time in G1 (34.8 ± 16.6 minutes) did not differ from that in either G2 (38.9 ± 20.8 minutes; p = .09) or G3 (29.5 ± 14.6 minutes; p = .06). However, G2 patients had significantly longer fluoroscopic times than G3 patients (p = .005). The mean total anesthesia time in G1 (190.2 ± 45.6 minutes) did not differ from that in G2 (199.7 ± 59.5 minutes; p = .15). However, G3 had a mean anesthesia time (162.6 ± 39.7 minutes) that was significantly shorter than that in both G1 (p = .003) and G2 (p < .001). The mean contrast volume was significantly lower in G1 than in G2 (67.9 ± 36.8 mL vs 87.1 ± 42.9 mL; p = .005). More intrahepatic needle passes were required in G2 (median, 4 passes; interquartile range [IQR], 1-7 passes) than in G1 (median, 2 passes; IQR, 1-4 passes; p = .004) and G3 (median, 2 passes; IQR, 1-7.25 passes; p = .04). When complications in G1 and G3 were pooled, this cohort had significantly fewer complications than G2 (p = .01). CONCLUSION. Ultrasound-guided PV access and percutaneous PV guidewire placement for fluoroscopic targeting during TIPS creation are associated with shorter procedure and fluoroscopic times and potentially decreased complications. CLINICAL IMPACT. The present study helps interventional radiologists understand the safest and most efficient way to access the PV, which is a key step during TIPS placement.

Transjugular intrahepatic portosystemic shunt in cirrhosis: An exhaustive critical update

More than five decades after it was originally conceptualized as rescue therapy for patients with intractable variceal bleeding, the transjugular intrahepatic portosystemic shunt (TIPS) procedure continues to remain a focus of intense clinical and biomedical research. By the impressive reduction in portal pressure achieved by this intervention, coupled with its minimally invasive nature, TIPS has gained increasing acceptance in the treatment of complications of portal hypertension. The early years of TIPS were plagued by poor long-term patency of the stents and increased incidence of hepatic encephalopathy. Moreover, the diversion of portal flow after placement of TIPS often resulted in derangement of hepatic functions, which was occasionally severe. While the incidence of shunt dysfunction has markedly reduced with the advent of covered stents, hepatic encephalopathy and instances of early liver failure continue to remain a significant issue after TIPS. It has emerged over the years that careful selection of patients and diligent post-procedural care is of paramount importance to optimize the outcome after TIPS. The past twenty years have seen multiple studies redefining the role of TIPS in the management of variceal bleeding and refractory ascites while exploring its application in other complications of cirrhosis like hepatic hydrothorax, portal hypertensive gastropathy, ectopic varices, hepatorenal and hepatopulmonary syndromes, non-tumoral portal vein thrombosis and chylous ascites. It has also been utilized to good effect before extrahepatic abdominal surgery to reduce perioperative morbidity and mortality. The current article aims to review the updated literature on the status of TIPS in the management of patients with liver cirrhosis.

Intrahepatic arterial localizer guided transjugular intrahepatic portosystemic shunt placement: Feasibility, efficacy, and technical success assessed by a case series-a STROBE- compliant article

Transjugular intra-hepatic portosystemic shunts (TIPS) had been considered a standard procedure in patients suffering from portal hypertension. The most challenging step in TIPS placement is blind puncture of the portal vein. We had established a localization method by introducing an Intra-Hepatic Arterial based puncture directing Localizer (IHAL) with the assistance of the enhanced computed tomography (CT) reconstruction. This study aimed to evaluate the feasibility, efficacy, and technical success of this method.From June 2018 to August 2018, 10 consecutive patients suffering from refractory ascites or esophageal gastric bleeding by liver cirrhosis were included in this retrospective study to evaluate feasibility, efficacy, and technical success of enhanced CT assisted IHAL-guided puncture of the portal vein. As a control, 10 patients receiving TIPS placement before Jun 2018 with cone beam CT (CBCT)-guided puncture were included to compare the reduction of portal-systemic pressure gradient (PSPG), portal entry time (PET), the number of puncture, dose area product (DAP) and contrast medium consumption.Technical success was 100% in the study group (IHAL-guided group) and in 90.0% of the control group (CBCT-guided group). Appropriate IHAL point could be achieved in all patients under the enhanced CT reconstruction assistance. The median number of punctures and DAP in IHAL group were significantly less than those in CBCT group. The reduction of PSPG, PET, and contrast medium consumption in IHAL group showed no significant differences than those in CBCT group.Enhanced CT reconstruction assisted IHAL-guided portal vein puncture is technically feasible and a reliable tool for TIPS placement resulting in a significant reduction of the number of punctures and DAP.

Patient Radiation Dose Reduction Considerations in a Contemporary Interventional Radiology Suite

PURPOSE

We sought to evaluate patient radiation exposure during complex liver interventional procedures performed with newer angiography equipment.

MATERIALS AND METHODS

We conducted a retrospective study of transjugular intrahepatic portosystemic shunt (TIPS) creations and liver tumor embolizations performed in our new angiography suite (Discovery IGS740, GE Healthcare). T tests were used to compare air kerma-area product (P_KA) and reference plane air kerma (K_a,r) in the new room versus data from historical rooms and previous studies (including the RAD IR study). Results were expressed as medians [interquartile ranges (Q1, Q3)].

RESULTS

From February 2015 to June 2016, 134 complex liver interventional procedures were performed in the new room, including 14 TIPS creations, 60 hepatic tumor arterial embolizations (HAEs), 26 Y90 mappings (Y90m), and 34 Y90 radioembolizations (Y90). K_a,r (Gy) values were as follows: TIPS, 0.65 (0.24, 1.15); HAE, 0.89 (0.49, 1.49); Y90m, 0.54 (0.38, 0.94); Y90, 0.46 (0.21, 1.06). P_KA (Gy·cm²) values were as follows: TIPS, 148.2 (66.7, 326.5); HAE, 142.6 (88, 217.8); Y90m, 148.3 (98.2, 247); Y90, 90.8 (43.9, 161.5). K_a,r and P_KA were lower in the new room than in historical rooms [K_a,r and P_KA reductions: TIPS, 58 and 49%; HAE, 31 and 39%; Y90m, 58 and 52%; Y90, 49 and 56% (p < 0.05)] and versus the RAD IR study [K_a,r and P_KA reductions: TIPS, 64 and 43%; HAE, 26 and 40% (p < 0.05)].

CONCLUSIONS

Using the latest technology and image processing tools enables significant reduction in radiation exposure during complex liver interventional procedures.

Transjugular intrahepatic portosystemic shunt creation: three-dimensional roadmap versus CO2 wedged hepatic venography

OBJECTIVES

The blind portal vein puncture remains the most challenging step during transjugular intrahepatic portosystemic shunt (TIPS) creation. We performed a prospective randomised clinical trial to compare three-dimensional (3D) roadmap with CO₂ wedged hepatic vein portography for portal vein puncture guidance.

METHODS

Between March 2017 and May 2017, 30 patients were enrolled and randomly allocated to the study group (3D roadmap) or the control group (CO₂ wedged hepatic vein portography).

RESULTS

Technical success of TIPS procedures was achieved in all 30 patients. The mean number of needle passes was significantly lower in the study group (2.0 ± 1.0) compared to the control group (3.7 ± 2.5; p = 0.021). A total of six (40%) patients in the study group and three (20%) in the control group required only one puncture for the establishment of TIPS. There were no significant differences in total fluoroscopy time (p = 0.905), total procedure time (p = 0.199) and dose-area product (p = 0.870) between the two groups.

CONCLUSIONS

3D roadmap is a safe and technically feasible means for portal vein puncture guidance during TIPS creation, equivalent in efficacy to CO₂ wedged hepatic vein portography. This technique could reduce the number of needle passes, thereby simplifying the TIPS procedure.

KEY POINTS

• 3D roadmap can be used to guide portal vein puncture. • Compared with CO ₂ venography, 3D roadmap reduced the number of needle passes. • 3D roadmap has a potential to simplify the TIPS procedure.

Use of transabdominal ultrasound-guided transjugular portal vein puncture on radiation dose in transjugular intrahepatic portosystemic shunt formation

PURPOSE

Transjugular intrahepatic portosystemic shunt (TIPS) creation is used to treat portal hypertension complications. Often the most challenging and time-consuming step in the procedure is the portal vein (PV) puncture. TIPS procedures are associated with prolonged fluoroscopy time and high patient radiation exposures. We measured the impact of transabdominal ultrasound guidance for PV puncture on duration of fluoroscopy time and dose.

METHODS

We retrospectively analyzed the radiation dose for all TIPS performed over a four-year period with transabdominal ultrasound guidance for PV puncture (n=212, with 210 performed successfully and data available for 206); fluoroscopy time, dose area product (DAP) and skin dose were recorded.

RESULTS

Mean fluoroscopy time was 12 min 9 s (SD, ±14 min 38 s), mean DAP was 40.3±73.1 Gy·cm2, and mean skin dose was 404.3±464.8 mGy.

CONCLUSION

Our results demonstrate that ultrasound-guided PV puncture results in low fluoroscopy times and radiation doses, which are markedly lower than the only published dose reference levels.

Consensus conference on TIPS management: Techniques, indications, contraindications

The trans jugular intrahepatic Porto systemic shunt (TIPS) is no longer viewed as a salvage therapy or a bridge to liver transplantation and is currently indicated for a number of conditions related to portal hypertension with positive results in survival. Moreover, the availability of self-expandable polytetrafluoroethylene (PTFE)-covered endoprostheses has dramatically improved the long-term patency of TIPS. However, since the last updated International guidelines have been published (year 2009) new evidence have come, which have open the field to new indications and solved areas of uncertainty. On this basis, the Italian Association of the Study of the Liver (AISF), the Italian College of Interventional Radiology-Italian Society of Medical Radiology (ICIR-SIRM), and the Italian Society of Anesthesia, Analgesia and Intensive Care (SIAARTI) promoted a Consensus Conference on TIPS. Under the auspices of the three scientific societies, the consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Bergamo on June 4th and 5th, 2015. The final statements presented here were graded according to quality of evidence and strength of recommendations and were approved by an independent jury. By highlighting strengths and weaknesses of current indications to TIPS, the recommendations of AISF-ICIR-SIRM-SIAARTI may represent the starting point for further studies.

Transjugular Intrahepatic Portosystemic Shunts in Patients with Cirrhosis with Refractory Ascites: Comparison of Clinical Outcomes by Using 8- and 10-mm PTFE-covered Stents

Purpose To compare the efficacy and complications of transjugular intrahepatic portosystemic shunt (TIPS) creation performed by using a 10-mm or an 8-mm-diameter polytetrafluoroethylene (PTFE)-covered stent in a consecutive series of patients with cirrhosis with refractory ascites (RA). Materials and Methods The institutional review board approved this retrospective study and informed consent was waived. One hundred seventy-one patients with RA (mean age, 58.7 years ± 10.3; 95% confidence interval [CI]: 57.2 years, 60.3 years) had undergone TIPS placement by using 10-mm (60 patients) or 8-mm (111 patients) covered stent between January 2004 and December 2012. Median follow-up time was 16.8 months (range, 3.4-84.8 months). Hemodynamic changes, incidence of hepatic encephalopathy, and long-term (>3 months) need for paracentesis after TIPS placement were evaluated and calculated by using the Kaplan-Meier method and were compared by using the log-rank test. Results Pre-TIPS demographics and clinical characteristics of the two groups were comparable. The portosystemic gradient before TIPS was 17.0 mm Hg ± 4.2 (95% CI: 15.9 mm Hg, 18.1 mm Hg) in the 10-mm group versus 16.1 mm Hg ± 3.7 (95% CI: 15.4 mm Hg, 16.8 mm Hg) in the 8-mm group (P = .164). After TIPS, the portosystemic gradient was 6.5 mm Hg ± 3.4 (95% CI: 5.7 mm Hg, 7.4 mm Hg) in the 10-mm group versus 7.5 mm Hg ± 2.6 (95% CI: 6.9 mm Hg, 7.9 mm Hg) in the 8-mm group (P = .039). The long-term need for paracentesis was greater in the 8-mm group (64 of 111 patients [58%] vs 18 of 60 patients [31%], P = .003). Overall, hepatic encephalopathy was similar in both groups (45 of 111 patients [41%] vs 26 of 60 patients [44%], P = .728). Conclusion A10-mm PTFE-covered stent leads to better control of RA secondary to portal hypertension in patients with cirrhosis, compared with an 8-mm stent, without increasing the incidence of hepatic encephalopathy. ^© RSNA, 2017.

Diagnostic hepatic haemodynamic techniques: safety and radiation exposure

BACKGROUND & AIMS

Hepatic venous pressure gradient (HVPG) and transjugular liver biopsy (TJLB) are increasingly used in the management of patients with liver disease. We aimed to describe the safety profile of these procedures, providing data on the intra- and periprocedure complications, radiation exposure and amount of iodinated contrast material used.

METHODS

In 106 consecutive patients undergoing HVPG and TJLB data on fluoroscopy time (FT), absorbed radiation dose, equivalent effective dose (mSv) and volume of iodinated contrast material (ICM) were prospectively collected and reviewed, together with clinical and laboratory data. Incidence and severity of procedure-related complications were assessed. In 28 hospitalised patients, creatinine values after 72 hours of the procedure were reviewed to identify contrast-induced nephropathy (CIN).

RESULTS

Median effective radiation dose was 5.4 mSv (IQR 10 mSv). A total 28.3% of patients exceeded an effective exposure of 10 mSv and 9.4% exceeded 20 mSv. Only age and BMI correlated with radiation dose (R = .327, P=.001 and R = .410, P<.0001 respectively), and only BMI remained independently associated with an exposure over 20 mSv. Procedure-related complications occurred in eight patients (7.5%), and were minor in six cases. Median ICM volume was 12.5 mL. 6/28 patients met the diagnostic criteria for CIN.

CONCLUSIONS

Hepatic venous pressure gradient and Transjugular liver biopsy show a good safety profile and radiation exposure associated with these procedures is in most of the cases low. In hepatic haemodynamic procedures, efforts should be made to reduce the radiation dose in patients with overweight/obesity and to use the minimal possible ICM volume in patients with acute-on-chronic liver failure.

Radiation dose reduction during transjugular intrahepatic portosystemic shunt implantation using a new imaging technology

OBJECTIVE

To compare patient radiation dose in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) implantation before and after an imaging-processing technology upgrade.

METHODS

In our retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), total fluoroscopy time and contrast agent were collected from an age- and BMI-matched collective of 108 patients undergoing TIPS implantation. 54 procedures were performed before and 54 after the technology upgrade. Mean values were calculated and compared using two-tailed t-tests. Two blinded, independent readers assessed DSA image quality using a four-rank likert scale and the Wilcoxcon test.

RESULTS

The new technology demonstrated a significant reduction of 57% of mean DAP (402.8 vs. 173.3Gycm², p<0.001) and a significant reduction of 58% of mean AK (1.7 vs. 0.7Gy, p<0.001) compared to the precursor technology. Time of fluoroscopy (26.4 vs. 27.8min, p=0.45) and amount of contrast agent (109.4 vs. 114.9ml, p=0.62) did not differ significantly between the two groups. The DSA image quality of the new technology was not inferior (2.66 vs. 2.77, p=0.56).

CONCLUSIONS

In our study the new imaging technology halved radiation dose in patients undergoing TIPS maintaining sufficient image quality without a significant increase in radiation time or contrast consumption.

Utility of Intravascular US-Guided Portal Vein Access during Transjugular Intrahepatic Portosystemic Shunt Creation: Retrospective Comparison with Conventional Technique in 109 Patients

PURPOSE

To compare safety and effectiveness of intravascular ultrasound (US)-guided portal vein access during transjugular intrahepatic portosystemic shunt (TIPS) creation with conventional TIPS technique.

MATERIALS AND METHODS

In this retrospective study, TIPS creation using intravascular US guidance in 55 patients was compared with conventional TIPS creation in 54 patients by 10 operators over a 3-year period. Operators were classified as experienced if they had performed ≥ 20 TIPS procedures at the beginning of the study period. Time to portal vein access, total radiation dose, and needle pass-related capsular perforation were recorded.

RESULTS

Baseline demographic characteristics of patients were similar (P > .05). Mean time to portal venous access was 46 minutes ± 37 for conventional TIPS and 31 minutes ± 19 for intravascular US-guided TIPS (P = .007). Intravascular US guidance allowed significantly shorter times (48 min ± 30 vs 28 min ± 16; P = .01) to portal vein access among operators (n = 5) with limited experience but failed to achieve any significant time savings (44 min ± 43 vs 34 min ± 22; P = .89) among experienced operators (n = 5). Needle pass-related capsular perforation occurred in 17/54 (34%) patients with conventional TIPS and 5/55 (9%) patients with intravascular US-guided TIPS (P = .004). Radiation dose was 2,376 mGy ± 1,816 for conventional TIPS and 1,592 mGy ± 1,263 for intravascular US-guided TIPS (P = .004).

CONCLUSIONS

Intravascular US-guided portal vein access during TIPS creation is associated with shorter portal vein access times, decreased needle pass-related capsular perforations, and reduced radiation dose.

Three-dimensional C-arm CT-guided transjugular intrahepatic portosystemic shunt placement: Feasibility, technical success and procedural time

OBJECTIVES

Establishment of transjugular intrahepatic portosystemic shunts (TIPS) constitutes a standard procedure in patients suffering from portal hypertension. The most difficult step in TIPS placement is blind puncture of the portal vein. This study aimed to evaluate three-dimensional mapping of portal vein branches and targeted puncture of the portal vein.

METHODS

Twelve consecutive patients suffering from refractory ascites by liver cirrhosis were included in this retrospective study to evaluate feasibility, technical success and procedural time of C-arm CT-targeted puncture of the portal vein. As a control, 22 patients receiving TIPS placement with fluoroscopy-guided blind puncture were included to compare procedural time.

RESULTS

Technical success could be obtained in 100 % of the study group (targeted puncture) and in 95.5 % of the control group (blind puncture). Appropriate, three-dimensional C-arm CT-guided mapping of the portal vein branches could be achieved in all patients. The median number of punctures in the C-arm CT-guided study group was 2 ± 1.3 punctures. Procedural time was significantly lower in the study group (14.8 ± 8.2 min) compared to the control group (32.6 ± 22.7 min) (p = 0.02).

CONCLUSIONS

C-arm CT-guided portal vein mapping is technically feasible and a promising tool for TIPS placement resulting in a significant reduction of procedural time.

KEY POINTS

• C-arm CT-mapping of the portal vein for 3D TIPS guidance is feasible. • Targeted punctures of the portal vein by C-arm CT reduce procedural time. • A decreased number of punctures could improve patient safety.