Carbon dioxide-based portography: an alternative to conventional imaging with the use of iodinated contrast medium

Prevention and treatment of hepatic encephalopathy during the perioperative period of transjugular intrahepatic portosystemic shunt

Transjugular intrahepatic portosystemic shunt (TIPS) is an established procedure for treating the complications of portal hypertension in liver cirrhosis. While the pathogenesis of postoperative TIPS-related hepatic encephalopathy (HE) has yet to be fully understood, intraoperative portosystemic shunts may provide a pathological basis for the occurrence of postoperative HE in patients with liver cirrhosis. Studies at home and abroad have expressed mixed opinions about TIPS-related HE. This study presents a literature review on the risk factors for and prevention and treatment of perioperative TIPS-related HE in patients with liver cirrhosis, aiming to optimize the procedure and reduce the incidence of postoperative HE.

Influence of different portal vein branches on hepatic encephalopathy during intrahepatic portal shunt via jugular vein

This letter is regarding the study titled ‘Targeted puncture of left branch of intrahepatic portal vein in transjugular intrahepatic portosystemic shunt (TIPS) to reduce hepatic encephalopathy’. Prior to the approval of TIPS dedicated stents (Viatorr stents) in China in October 2015, Fluency covered stents were typically used. As Fluency covered stents have a strong support force and axial elastic tension, a ‘cap’ may form if the stent is located too low at the end of the hepatic vein or too short at the end of the portal vein during surgery, leading to stent dysfunction. Since the blood shunted by the stent is from the main trunk of the portal vein, the correlation between the incidence of postoperative hepatic encephalopathy and the location of the puncture target (left or right portal vein branch) is worth discussion. Notably, no studies in China or foreign countries have proven the occurrence of left and right blood stratification after the accumulation of splenic vein and mesenteric blood flow in the main trunk of the portal vein in patients with cirrhotic portal hypertension.

Portal flow diversion based on portography is superior than puncture site in the prediction of overt hepatic encephalopathy after TIPS creation

Background

Targeted puncture of an appropriate portal venous branch during transjugular intrahepatic portosystemic shunt (TIPS) procedure may reduce the risk of postprocedural overt hepatic encephalopathy (HE). This study aimed to describe blood distribution under portography and combined it with puncture site to determine portal flow diversion, and to evaluate its prognostic value in predicting post-TIPS overt HE.

Methods

In this retrospective analysis of patients with cirrhosis undergoing TIPS, we included 252 patients to describe blood distribution under portography and 243 patients to assess the association between portal flow diversion and post-TIPS overt HE.

Results

At the first stage, 51 (20.2%) patients were identified as type A (unilateral type with the right portal branch receives blood from splenic vein [SV]), 16 (6.4%) as type B (unilateral type with the right branch receives blood from superior mesenteric vein [SMV]) and 185 (73.4%) as type C (fully mixed type). At the second stage, 40 patients were divided into the SV group, 25 into the SMV group and 178 into the mixed group. Compared with the mixed group, the risk of post-TIPS overt HE was significantly higher in the SMV group (adjusted HR 3.70 [95% CI 2.01–6.80]; p < 0.001), whereas the SV group showed a non-significantly decreased risk (adjusted HR 0.57 [95% CI 0.22–1.48]; p = 0.25). Additionally, the SMV group showed a substantial increase in ammonia level at 3 days and 1 month after procedure.

Conclusions

Our results support the clinical use of portal flow diversion for risk stratification and decision-making in the management of post-TIPS overt HE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02447-y.

Clinical efficacy of transjugular intrahepatic portosystemic shunt created through left or right branches of the portal vein: A meta-analysis

Background and aim

Transjugular intrahepatic portosystemic shunt (TIPS) is a technique successfully used to treat portal hypertension and its complications. However, the choice of the branch, left (L) or right (R), of the portal vein resulting in a better outcome is still under debate. Therefore, this meta-analysis aims to evaluate which branch has a better curative effect on patients treated with TIPS.

Methods

PubMed, EMBASE, Web of science, Cochrane Library databases, Wanfang database and CBM were used for our search in October 2019 and updated in June 2021. The following parameters were used in evaluation: overall mortality, hepatic encephalopathy, shunt dysfunction, variceal rebleeding and rate of postoperative ascites.

Results

There were seven studies included. The sample size was 1940. A lower risk of mortality was observed in TIPS-L-treated patients compared with TIPS-R-treated ones (OR ​= ​0.65, 95% CI ​= ​0.50–0.85, p ​= ​0.002). A lower risk of shunt dysfunction was observed in TIPS-L-treated patients compared with TIPS-R-treated ones (OR ​= ​0.53, 95% CI ​= ​0.33–0.87, p ​= ​0.01). And the TIPS-L group had a significantly higher hepatic encephalopathy-free rate than the TIPS-R group (OR ​= ​0.59, 95% CI ​= ​0.44–0.78, p ​= ​0.0002). However, the rate of rebleeding (OR ​= ​0.75, 95% CI ​= ​0.55–1.03, p ​= ​0.07) and incidence of postoperative ascites (OR ​= ​1.14, 95% CI ​= ​0.86–1.51, p ​= ​0.38) was not statistically significant between the two groups.

Conclusions

Based on the currently available evidence, the technique of TIPS through the left branch of the portal vein can significantly reduce the occurrence of overall postoperative mortality, hepatic encephalopathy and shunt dysfunction.

Comparative study of indocyanine green-R15, Child-Pugh score, and model for end-stage liver disease score for prediction of hepatic encephalopathy after transjugular intrahepatic portosystemic shunt

BACKGROUND

Hepatic encephalopathy (HE) remains an enormous challenge in patients who undergo transjugular intrahepatic portosystemic shunt (TIPS) implantation. The preoperative indocyanine green retention rate at 15 min (ICG-R15), as one of the liver function assessment tools, has been developed as a prognostic indicator in patients undergoing surgery, but there are limited data on its role in TIPS.

AIM

To determine whether the ICG-R15 can be used for prediction of post-TIPS HE in decompensated cirrhosis patients with portal hypertension (PHT) and compare the clinical value of ICG-R15, Child-Pugh score (CPS), and model for end-stage liver disease (MELD) score in predicting post-TIPS HE with PHT.

METHODS

This retrospective study included 195 patients with PHT who underwent elective TIPS at Beijing Shijitan Hospital from January 2018 to June 2019. All patients underwent the ICG-R15 test, CPS evaluation, and MELD scoring 1 wk before TIPS. According to whether they developed HE or not, the patients were divided into two groups: HE group and non-HE group. The prediction of one-year post-TIPS HE by ICG-R15, CPS and MELD score was evaluated by the areas under the receiver operating characteristic curves (AUCs).

RESULTS

A total of 195 patients with portal hypertension were included and 23% (45/195) of the patients developed post-TIPS HE. The ICG-R15 was identified as an independent predictor of post-TIPS HE. The AUCs for the ICG-R15, CPS, and MELD score for predicting post-TIPS HE were 0.664 (95% confidence interval [CI]: 0.557-0.743, P = 0.0046), 0.596 (95%CI: 0.508-0.679, P = 0.087), and 0.641 (95%CI: 0.554-0.721, P = 0.021), respectively. The non-parametric approach (Delong-Delong & Clarke-Pearson) showed that there was statistical significance in pairwise comparison between AUCs of ICG-R15 and MELD score (P = 0.0229).

CONCLUSION

The ICG-R15 has appreciated clinical value for predicting the occurrence of post-TIPS HE and is a choice for evaluating the prognosis of patients undergoing TIPS.

Targeted puncture of left branch of intrahepatic portal vein in transjugular intrahepatic portosystemic shunt to reduce hepatic encephalopathy

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) is currently used for the treatment of complications of portal hypertension. The incidence of hepatic encephalopathy (HE) remains a problem in TIPS placement. It has been reported that the right branch mainly receives superior mesenteric venous blood while the left branch mainly receives blood from the splenic vein. We hypothesized that targeted puncture of the left portal vein would divert the non-nutritive blood from the splenic vein into the TIPS shunt; therefore, targeted puncture of the left branch of the intrahepatic portal vein during TIPS may reduce the risk of HE.

AIM

To evaluate the influence of targeted puncture of left branch of portal vein in TIPS on HE.

METHODS

A retrospective analysis of 1244 patients with portal-hypertension-related complications of refractory ascites or variceal bleeding who underwent TIPS from January 2000 to January 2013 was performed. Patients were divided into group A (targeting left branch of portal vein, n = 937) and group B (targeting right branch of portal vein, n = 307). TIPS-related HE and clinical outcomes were analyzed.

RESULTS

The symptoms of ascites and variceal bleeding disappeared within a short time. By the endpoint of follow-up, recurrent bleeding and ascites did not differ significantly between groups A and B (P = 0.278, P = 0.561, respectively). Incidence of HE differed significantly between groups A and B at 1 mo (14.94% vs 36.80%, χ² = 4.839, P = 0.028), 3 mo (12.48% vs 34.20%, χ² = 5.054, P = 0.025), 6 mo (10.03% vs 32.24%, χ² = 6.560, P = 0.010), 9 mo (9.17% vs 31.27%, χ² = 5.357, P = 0.021), and 12 mo (8.21% vs 28.01, χ² = 3.848, P = 0.051). There were no significant differences between groups A and B at 3 years (6.61% vs 7.16%, χ² = 1.204, P = 0.272) and 5 years (5.01% vs 6.18%, χ² = 0.072, P = 0.562). The total survival rate did not differ between groups A and B (χ² = 0.226, P = 0.634, log-rank test).

CONCLUSION

Targeted puncture of the left branch of the intrahepatic portal vein during TIPS may reduce the risk of HE but has no direct influence on prognosis of portal-hypertension-related complications.

Use of carbon dioxide as an intravascular contrast agent: A review of current literature

Use of X-ray contrast allows us to differentiate between two or more adjacent structures on radiographic studies. The X-ray contrast agent can be the one with increase X-ray absorption, like iodine and a barium X-ray contrast agent or the one with decrease X-ray absorption like air and carbon dioxide contrast agent. Each contrast agent possesses different risks and benefits in various ways. Carbon dioxide as an intravascular contrast agent can be used as an alternative intravascular contrast agent and has superior results in some cases. In patients with renal dysfunction or iodinated contrast allergy, the use of Iodinated Contrast Agent poses the risk of considerable morbidity. Similarly, use of Gadolinium is discouraged in subject with severe renal dysfunction. Use of carbon dioxide (CO₂) as an intravascular contrast, offers an alternative in such patients for certain procedures, as it is not nephrotoxic and it does not incite allergic reactions. It is inexpensive, readily available and due to its unique physical properties, it can be used to image a wide variety of vascular beds and chambers. The aim of this paper is to systemically review the current literature to describe the indications, contraindications, adverse effects, instruments, precautions, latest methodologies and data supporting for the use of CO₂ as a contrast agent.