Optimal guiding methods for transjugular intrahepatic portosystemic shunt creation: Characteristics of intravascular ultrasound vs other techniques

Abstract

A recent study in World Journal of Hepatology examined the use of intravascular ultrasound (IVUS) for transjugular intrahepatic portosystemic shunt (TIPS) creation. The study concluded that IVUS significantly reduces procedure time, radiation exposure, and the number of needle passes compared to conventional fluoroscopic guidance. IVUS offers real-time visualization of the portal vein, but challenges remain in terms of equipment costs and the operator learning curve. TIPS creation techniques vary widely in clinical practice, where methods, such as conventional fluoroscopy, three-dimensional image fusion, electromagnetic navigation, and IVUS, are commonly employed. In this editorial, we provide a comparative analysis of these methods based on clinical experience and the literature. By evaluating the strengths and limitations of each technique, we aim to inform clinical decision-making and enhance procedural outcomes. Future developments in TIPS creation are likely to focus on hybrid techniques that combine the strengths of IVUS, electromagnetic navigation, and real-time image fusion, potentially leading to more precise, cost-effective, and accessible methods.

Key Words: Transjugular intrahepatic portosystemic shunt; Intravascular ultrasound; Portal hypertension; Fluoroscopic; Three-dimensional image fusion

Core Tip: This study compares intravascular ultrasound (IVUS) with conventional techniques for transjugular intrahepatic portosystemic shunt (TIPS) creation. IVUS reduces procedure time, radiation exposure, and needle passes while enhancing precision. Despite higher initial costs, IVUS offers long-term savings through faster procedures and reduced complications. Emerging technologies, such as artificial intelligence integration and miniaturized devices, promise to further improve IVUS-guided TIPS, making it a potentially cost-effective and universally applicable method in the future.

INTRODUCTION

In this article, we discuss the study by Hung et al[1], which we read with great interest in the latest issue of this journal. Cirrhosis, the most common clinical outcome of chronic liver diseases, represents a significant global health concern and often leads to complications such as portal hypertension[2,3]. Transjugular intrahepatic portosystemic shunt (TIPS) is a crucial method for managing portal hypertension, playing a key role in treating complications such as variceal bleeding and ascites[4]. The creation of TIPS is the first and most critical step in the procedure, and with multiple available techniques, selecting the optimal method is essential for achieving the best outcomes.

EVIDENCE-BASED COMPARISON BETWEEN INTRAVASCULAR ULTRASOUND AND OTHER TECHNIQUES

Various imaging guidance techniques have been explored for TIPS creation, such as fluoroscopic (conventional), three-dimensional (3D) image fusion [cone beam computed tomography/angio-computed tomography (CT)], electromagnetic navigation and intravascular ultrasound (IVUS), each offering distinct benefits and challenges[5]. Conventional fluoroscopy remains the standard method for TIPS, but it often requires multiple blind needle passes and prolonged radiation exposure[6]. Hybrid angio-CT and cone-beam CT fusion, for example, can overlay 3D vascular roadmaps on live fluoroscopy, reducing the radiation dose and procedure time[7]. A study comparing angio-CT guidance revealed that it significantly shortened the portal access time and fluoroscopy exposure, with typical portal puncture attempts of approximately 4–5[8]. Electromagnetic navigation, when combined with ultrasound, has shown promising results; in an animal study, electromagnetic tracking yielded successful TIPS in 5/8 subjects (approximately 62.5%), with evidence of a steep learning curve[9]. However, all these advanced methods generally require specialized equipment and training, and while they reduce blind manoeuvres, they are still limited by accessibility and cost.

In comparison, IVUS offers real-time sonographic visualization of the portal vein, providing highly accurate guidance during TIPS creation. IVUS has demonstrated superior procedural metrics, such as reducing the average number of needle passes from 6 to 2, as well as decreasing radiation exposure (174 mGy vs 981 mGy) and fluoroscopy time (19 minutes vs 34 minutes). Furthermore, IVUS has been shown to reduce overall procedure time (86 minutes vs 125 minutes) and needle-related complications, with a reported capsular perforation rate of only 9%, whereas conventional techniques have a rate of 34%[10-12]. Although IVUS has higher per-case costs mainly due to expensive probes (approximately $2100 each), it offers savings in other areas, such as reduced contrast use and shorter hospital stays. A recent analysis revealed that IVUS-guided TIPS resulted in net savings of approximately $656 per case due to faster procedure times and shorter recovery periods[13]. Although IVUS has a relatively high initial cost, its effectiveness and efficiency make it a strong alternative to conventional fluoroscopy, with growing adoption in specialized centers. A comparison between IVUS and other techniques is shown in Table 1[6-11,13].

Table 1 Comparison between intravascular ultrasound and other techniques.

Technique	Safety/efficacy (metrics)	Cost/resources	Learning curve	Availability/adoption	Ref.
Fluoroscopic (conventional)	Technical success: 95–100%; number of punctures: 5-6 times or more; radiation dose: High (over 30 minutes fluoroscopy); complication rate: Relatively higher (5%-30%)	Low capital cost–uses standard angio suite and catheters; no special disposables	Well-established; standard IR training applies	Universal (standard practice in all centers)	Partovi et al[6], Farsad et al[10], Kao et al[11]
3D image fusion (CBCT/angio-CT)	Technical success: Virtually 100%; number of punctures: 4-5 times on average; radiation dose: Relatively lower; complications rate: Relatively lower (0%-5%)	Very high capital equipment (hybrid angio-CT or advanced Carm with CBCT; minimal extra disposables beyond baseline	Moderate–steep: Operator must learn new 3D overlay/navigation tools	Limited to centers with hybrid angio-CT or CBCT capability (growing in major hospitals)	Nadjiri et al[7], Rouabah et al[8]
Electromagnetic navigation	Technical success: Animal studies showed 62% success (5/8 pigs) with a learning curve; number of punctures: None on humans; radiation dose: Low (approximately 15 minutes fluoroscopy); complications rate: No puncture complications reported in limited series	Prototype devices; requires special electromagnetic-transmitter and instrumented needle; likely expensive developmental equipment	Steep: Systems are experimental. Operators require training in electromagnetic tracking use	Not commercially available for transjugular intrahepatic portosystemic shunt; limited to research settings	Isfort et al[9]
IVUS	Technical success: Virtually 100%; number of punctures: 2 times on average; radiation dose: Relatively lower; complications rate: Relatively lower (0%-15%)	Requires IVUS console ($30–100K+) and single-use IVUS probes (approximately $2100 each); disposable cost is substantial amortization and maintenance also factors	Moderate: Operators need ultrasound skills, but some IRs use IVUS in other contexts. Trainee availability is variable	Commercially available (e.g., from Philips, Siemens); adoption growing in tertiary centers, but not yet universal	Farsad et al[10], Kao et al[11], Triana et al[13]

CBCT: Cone beam computed tomography; CT: Computed tomography; IR: Interventional radiology; IVUS: Intravascular ultrasound; 3D: Three-dimensional.

FUTURE POTENTIAL OF IVUS AND EMERGING TECHNOLOGIES FOR TIPS CREATION

Future advancements are expected to focus on enhancing IVUS resolution for real-time 3D intraluminal visualization, integrating artificial intelligence (AI) for automated anatomical mapping, and miniaturizing devices to improve manoeuvrability in complex anatomies (e.g., portal vein thrombosis or Budd-Chiari syndrome)[14,15]. Additionally, combining IVUS with advanced imaging modalities such as intracardiac echocardiography or contrast-enhanced ultrasound could further refine portal vein targeting, particularly in technically challenging cases[16].

Emerging technologies are poised to complement IVUS-guided TIPS by addressing unmet needs in terms of precision and accessibility. 3D printing, for example, enables patient-specific hepatic models for preoperative planning, potentially reducing intraoperative errors and optimizing stent placement[17]. AI-driven predictive models are being explored to personalize stent sizing and post-TIPS hemodynamic management, leveraging data from IVUS-derived metrics such as vessel diameter and flow dynamics. Another frontier is the development of "smart" stents with embedded sensors to monitor shunt patency and pressure gradients noninvasively, reducing reliance on Doppler ultrasound or invasive venography[18]. These innovations, combined with IVUS, may redefine TIPS as a minimally invasive, image-guided intervention with near-universal applicability. As evidence for these technologies, multidisciplinary collaboration between interventional radiologists, engineers, and data scientists will be critical for translating preclinical breakthroughs into clinical workflows.

CONCLUSION

IVUS provides significant advantages in TIPS creation, but other techniques also have distinct characteristics and should be selected based on specific clinical needs. Future advancements in imaging and technology are expected to further refine these methods, improving precision and accessibility in TIPS procedures.