Transjugular intrahepatic portosystemic shunt via the caudate lobe portal vein due to anatomic variation: Two case reports

Abstract

BACKGROUND

The target sites for transjugular intrahepatic portosystemic shunt (TIPS) treatment of esophageal and gastric varices are typically the left and right branches of the portal vein and its confluence. In clinical practice, the puncture needle may inadvertently puncture secondary branches or other smaller branches of the portal vein. It was observed that when the caudate lobe portal vein (CLPV) was successfully targeted, a covered stent can be effectively placed.

CASE SUMMARY

This study reports two patients with esophageal and gastric variceal bleeding, who underwent successful TIPS surgery via the CLPV. Covered and bare stents were successfully placed through this rare anatomical variant vessel, and the TIPS channel was established. During the follow-up, portal vein pressure significantly decreased, and no obvious complications were observed. This study indicates that TIPS via CLPV due to anatomic variation is a feasible approach. During the puncture process, it was found that the puncture hit the portal vein of the caudate lobe, allowing for the safe placement of a covered stent without the need for re-puncture.

CONCLUSION

TIPS is safe and effective when the CLPV is used as the puncture target. The intraoperative puncture of this vein allows for the successful deployment of a covered stent, thereby completing the procedure without requiring re-puncture.

Key Words: Caudate lobe portal vein; Portal hypertension; Transjugular intrahepatic portosystemic shunt; Esophageal and gastric variceal bleeding; Case report

Core Tip: This study reports on two patients with esophageal and gastric varices, the successful placement of covered and bare stents through this rare caudate lobe vein (CLPV), and the establishment of a transjugular intrahepatic portosystemic shunt (TIPS) channel. During follow-up, portal vein pressure significantly decreased, with no obvious complications observed. This study demonstrates that due to anatomical variations, performing TIPS through CLPV is a feasible method.

INTRODUCTION

Esophageal and gastric variceal bleeding (EGVB) is a severe complication of cirrhotic portal hypertension, with a relatively high mortality rate. The treatment methods include vasoactive drugs (terlipressin/octreotide), antibiotics for prophylaxis of spontaneous bacterial peritonitis, endoscopic treatment, and interventional treatment[1]. For patients with severe EGVB, in which medication or endoscopic treatment is not effective, transjugular intrahepatic portosystemic shunt (TIPS) can be an alternative treatment modality[2]. Present guidelines recommend TIPS for patients with acute esophagogastric variceal bleeding, who are at high risk (Child-Pugh B with active bleeding or Child-Pugh C < 14). Early TIPS within 72 hours should be performed after initial vasoactive drugs plus endoscopic therapy[1].

Traditionally, the key step of TIPS is to puncture from the hepatic vein or inferior vena cava into the intrahepatic portal vein branches to establish a shunt channel. The target sites are usually the left branch, right branch, and confluence of the portal vein[3]. However, anatomic variations may preclude standard access. Chinese experts’ experience and early studies have suggested that puncturing the left branch of the portal vein after TIPS leads to lower incidences of hepatic encephalopathy (HE), and higher stent patency rates[4]. In real-world scenarios, when performing TIPS without real-time guidance, the needle may accidentally puncture a secondary branch of the portal vein or other smaller branches. In such cases, blood can be aspirated, and the contrast medium would reveal the portal vein’s visibility, allowing the guidewire to pass through this branch into the main portal vein. Abandoning this pathway for another puncture would increase the surgical risk. Therefore, if the curvature of the puncture path is not severe, a covered stent can be placed through this pathway. The two cases reported in the present study involved the puncture of a portal vein branch during the procedure. The imaging revealed the portal vein’s visibility, and the guidewire smoothly entered the main portal vein. Ultimately, TIPS was successfully performed via the caudate lobe portal vein (CLPV) that branched from the main portal vein, providing new clinical references for TIPS application in special anatomical structures, and contributing to a better understanding of TIPS operations. Literature on TIPS via the CLPV is extremely scarce, and its safety profile remains undefined. Therefore, the primary objective of the present study is to evaluate the feasibility, safety, and technical key points of TIPS performed through the CLPV in patients with anatomic variations, based on the present two-case series. Specifically, the present study aims to demonstrate that when the puncture inadvertently targets the CLPV, successful placement of a covered stent can be achieved without re-puncture, thereby providing a practical reference for TIPS in special anatomical settings.

CASE PRESENTATION

Chief complaints

Case 1: A 41yearold female patient was diagnosed with posthepatitis B cirrhosis and hypersplenism in 2015, and underwent partial splenic artery embolization. Three years later, the patient suddenly experienced massive hematemesis.

Case 2: A 32-year old man with posthepatitis B decompensated cirrhosis and esophagogastric varices presented with recurrent hematemesis and melena.

History of present illness

Case 1: The patient was diagnosed with post-hepatitis B cirrhosis and hypersplenism in 2015, and underwent one session of partial splenic artery embolization. In February 2018, the patient suddenly vomited blood, approximately 1000 mL in total. The patient’s Child-Pugh score was 7 (class B), the indication was recurrent variceal bleeding, despite the endoscopic band ligation and vasoactive drugs, and the endoscopy revealed multiple large gastric varices, making the patient suitable for TIPS treatment with no contraindications.

Case 2: The patient experienced intermittent colicky pain in the upper abdomen for more than two days, which has been gradually worsening in intensity. The abdominal pain was associated with nausea and vomiting.

History of past illness

Case 1: The patient had no significant past medical or surgical history.

Case 2: The patient had no significant past history, or any illness or surgery.

Physical examination

Case 1: On admission, the patient had no jaundice, ascites, or HE, but presented with an anemic appearance and chronic liver disease facies.

Case 2: Physical examination on admission revealed an anemic appearance and chronic liver disease facies, with no jaundice, ascites, or HE.

Laboratory examinations

Case 1: The blood tests revealed the following: White blood cells (WBC), 3.66 × 10⁹/L; hemoglobin (HGB), 48.00 g/L; hematocrit (HCT), 14.30%; platelets (PLT), 27.00 × 10⁹/L. The Child-Pugh score was 7 points.

Case 2: The blood tests revealed the following: WBC, 1.40 × 10⁹/L; red blood cells, 2.40 × 10¹²/L; HGB, 46.00 g/L; HCT, 16.80%; PLT, 43.00 × 10⁹/L. The Child-Pugh score was assessed at 7 points.

Imaging examinations

Case 1: The endoscopy revealed esophageal varices and gastric varices (Lesmi, gf D1.0 Rf0 GII)[1], according to Chinese guidelines. The enhanced computed tomography (CT) revealed liver cirrhosis, splenomegaly, ascites, and portal hypertension.

Case 2: The endoscopy revealed esophageal and gastric varices (Lesmi, gf D1.0 Rf0 GII). The enhanced CT revealed liver cirrhosis, splenomegaly, and portal hypertension, with minimal retroperitoneal effusion.

FINAL DIAGNOSIS

Case 1

Decompensated hepatitis B cirrhosis with esophagogastric variceal bleeding; hemorrhagic anemia; status post splenic artery embolization.

Case 2

Decompensated hepatitis B cirrhosis with esophageal and gastric variceal rupture hemorrhage due to portal hypertension.

TREATMENT

Case 1

The patient’s Child-Pugh score was 7 (class B), the indication was recurrent variceal bleeding, despite the endoscopic band ligation and vasoactive drugs, and the endoscopy revealed multiple large gastric varices, making the patient suitable for TIPS treatment with no contraindications. During surgery and after puncture, the needle was withdrawn while applying mild negative suction, and venous blood was aspirated. After injecting the contrast medium, the CLPV was visualized. Guided by a wire, the 5F catheter smoothly entered the main portal vein. The portal vein angiography revealed that the CLPV originated from the main portal vein, with a diameter of 4.50 mm and a portal pressure of 48.00 cmH₂O. Next, balloon dilation of the puncture tract was performed, followed by placement of an 8 mm × 80 mm covered stent (BARD, United States), with its front end located approximately 0.50 cm within the main portal vein. Then, an 8 mm × 100 mm bare stent (BARD, United States) was implanted, extending 1 cm beyond each end of the covered stent, and gastric coronary vein embolization was carried out during the procedure. The digital subtraction angiography (DSA) and CT images are presented in Figure 1.

Figure 1 Case 1. A: Operation procedures of transjugular intrahepatic portosystemic shunt; The preoperative computed tomography shows the thickened caudate lobe portal vein (CLPV); B: The stent enters the portal vein trunk via the CLPV; C: The stent was located in the CLPV, and the caudate lobe had no obvious atrophy; D: The color Doppler ultrasound examination revealed good blood flow filling in the stent within the CLPV. V0: Main portal vein trunk; V1: Left portal vein branch; V2: Right portal vein branch; V3: CLPV; CS: Covered stent; CL: Hepatic caudate lobe.

Case 2

Due to multiple large gastric varices, and after failure of medical (terlipressin + proton-pump inhibitor) and endoscopic control within 12 hours, an emergency TIPS procedure was performed. During surgery, portography was conducted after aspirating venous blood via puncture, and guiding the 5F catheter through a guidewire into the main portal vein via the CLPV. It was revealed that the CLPV originated from the main portal vein, with a diameter of 4.20 mm and a portal pressure of 32.00 cmH₂O. The puncture accurately entered the CLPV, and subsequently the main portal vein. Balloon dilation of the puncture tract, followed by placement of an 8 mm × 80 mm covered stent (Fluency^®; BARD, Murray Hill, NJ, United States) over the portal vein puncture site, was performed. Then, two uncovered stents (8 mm × 60 mm and 8 mm × 80 mm; E-Luminexx^®, BARD) were placed, each extending 2 cm beyond the covered stent, while simultaneously embolizing the coronary vein of the stomach. The DSA and CT results are presented in Figure 2.

Figure 2 Case 2. A: Operation procedures of transjugular intrahepatic portosystemic shunt. The puncture targeted the caudate lobe portal vein (CLPV); B: The CLPV diverges directly from the portal vein trunk; C: The stent enters the portal vein trunk via the CLPV; D: The stent was located in the CLPV, and the caudate lobe had no obvious atrophy. V0: Main portal vein trunk; V1: Left portal vein branch; V2: Right portal vein branch; V3: CLPV; CS: Covered stent; CL: Hepatic caudate lobe.

OUTCOME AND FOLLOW-UP

Case 1

The re-angiography revealed an unobstructed TIPS shunt and good visualization of the right atrium, with the portal pressure reduced to 26.00 cmH₂O. Postoperatively, the patient’s Child-Pugh score increased to 8 points. On the third day, post-surgery, thrombosis in the right branch of the portal vein was observed, which resolved after 12 days of low-molecular-weight heparin calcium anticoagulation therapy. Then, the patient was switched to 10 mg of rivaroxaban, once daily, with food for six months. Stent patency was evaluated by color Doppler at one, three and six months, and every six months thereafter. The HE was assessed using the West-Haven criteria and psychometric HE score at each visit. The follow-up conducted until December 2024 revealed satisfactory blood flow through the stent, with the highest blood flow velocity inside the stent being 96.33 cm/seconds No adverse events, such as HE or gastrointestinal bleeding, were observed during this period.

Case 2

The repeated portography revealed an unobstructed TIPS shunt, good visualization of the right atrium, and a portal pressure of 26.00 cmH₂O. Postoperatively, the Child-Pugh score improved to an A grade. No adverse events were observed during regular monitoring and follow-up. The follow-up conducted until December 2024 indicated good color Doppler flow within the stent, with a peak velocity of 112.30 cm/seconds.

DISCUSSION

According to Kumon’s research[5], the caudate lobe consists of the Spiegel lobe, caudate lobe process, and paracaval portion (PCP), with the PCP located ventrally to the inferior vena cava within the liver. Typically, the caudate lobe is supplied by a single portal vein branch, accounting for 80%, in which approximately 70% originates from the transverse part of the left portal branch and 30% originates from the right portal trunk[5]. However, for the two reported cases, the CLPV branched directly from the main portal trunk before dividing into the left and right portal veins, which is extremely rare in literature. During TIPS, the puncture needle might enter the biliary tract, artery, or extracapsular areas (including the extracapsular portal vein, hepatic fissure, inferior vena cava, peritoneal cavity, etc.). Repeated punctures of the hepatic parenchyma can lead to abdominal bleeding, biliary bleeding, hepatic parenchymal bleeding, and bile peritonitis. In order to minimize puncture attempts, when blood reflux is observed during the puncture, gently push the contrast agent to check. If it is the portal vein, use a guidewire to explore. A successful puncture is indicated when the guidewire smoothly enters the main portal trunk. Through this path, a stent-graft can be placed. For the two patients, during the TIPS puncture, blood reflux was observed, and the contrast agent revealed portal vein branches. The guidewire smoothly entered the main portal trunk during exploration. During balloon dilation, a long narrow segment at the portal vein end was noted. Initially, it was thought that the puncture directly hit the main portal trunk. However, the later imaging revealed that it entered the main portal trunk via the CLPV. The greatest risk was rupture and bleeding of the CLPV, which would have been uncontrollable due to its relatively small size. Fortunately, the guidewire successfully entered the main portal trunk, and the stent-graft was promptly placed, effectively sealing the potential bleeding point, and mitigating this severe risk. This operational experience provides valuable examples for managing risks in similar surgeries, emphasizing the importance of preparing for possible vascular rupture during TIPS procedures under special anatomical pathways, such as ensuring stable guidewire positioning, and having the stent-graft ready. This also highlights the need for cautious operation during critical steps, such as balloon dilation, close cooperation between the surgeon and assistant, and careful observation of vascular changes. Indeed, the latest guidelines also recommend the use of real-time imaging navigation systems to enhance the safety and accuracy of surgery when dealing with complex or anatomical variations[6].

Due to the damage to the liver structure and function caused by cirrhosis, TIPS surgery often leads to complications, such as liver dysfunction and HE due to changes in hemodynamics[7]. For the two cases reported in the present study, the portal vein directly branched into the CLPV before dividing into the left and right branches of the portal vein, which is extremely rare in literature. The previous study conducted by Luo et al[8] revealed that in 48 cases (including six cast specimens), there were a total of 174 portal veins in the caudate lobe, with an average of 3-6 ± 0.50 per case: 98 portal veins originated from the left branch of the portal vein (56.32%), 46 portal veins originated from the bifurcation of the portal vein (26.43%), and 30 portal veins originated from the right branch of the portal vein (17.24%), among which 23 portal veins originated from the right posterior branch of the portal vein (13.23%). This indicates that there are numerous portal vein branches in the caudate lobe, providing rich blood supply. Thus, blocking one branch has a limited impact. In comparison, placing a covered stent in the portal vein that originated directly from the main trunk of the portal vein has more advantages. During the follow-up, neither of the two patients presented with signs of ischemic necrosis or atrophy of the caudate lobe, and the liver function was not significantly affected. This suggests that future follow-ups should closely monitor the morphology and function of the caudate lobe using imaging and liver function indicators for comprehensive assessment, in order to promptly identify potential issues, and take appropriate measures[6]. A recent multi-center study also supports this, indicating that appropriate stent placement does not negatively affect liver function, and effectively reduces portal pressure[9]. This outcome provides some safety basis for performing TIPS via the CLPV, offering a feasible rescue route when conventional branches are inaccessible.

The use of covered stents contributes to the safety of TIPS performed via the CLPV. Compared with stent placement in the right or left portal vein branches, deploying a covered stent in the CLPV has lesser impact on the portal venous flow territory of the liver. The present follow-up data further indicated that the CLPV approach does not adversely affect shunt patency. Collectively, these findings suggest that TIPS via the CLPV is both safe and effective.

Limitations

The present study is a single-center report with only two cases. Potential publication bias exists, since only successful procedures were included. Long-term outcomes (> 5 years) and comparative risk-benefit analyses against other alternative accesses remain to be validated in larger cohorts.

CONCLUSION

The present study demonstrates the feasibility and safety of performing TIPS through the CLPV pathway, allowing for the successful placement of a covered stent without the need for re-puncture when the CLPV is hit during puncture. Timely and accurate observation, and meticulous, smooth operation during surgery are essential to ensure its successful implementation.