Percutaneous embolization of refractory biliocutaneous fistula following radiofrequency ablation: A case report

Abstract

This case report presents a 73-year-old male with recurrent hepatocellular carcinoma who underwent serial surgical and interventional locoregional treatments, which resulted in asymptomatic intrahepatic bile duct dilatation. To address a recurrent tumor close to the pre-existing dilated bile ducts, radiofrequency ablation was performed, leading to a biliocutaneous fistula along the electrode tract. Attempts to close the refractory fistula by percutaneous transhepatic cholangial diversion and balloon dilatation of the stenotic central bile duct were unsuccessful. Ultimately, the fistula was successfully sealed with aggressive management, combining balloon-assisted retrograde fistulography and antegrade fistula embolization. This report aims to raise awareness of complex biliary complications after radiofrequency ablation in patients with preexisting bile duct dilatation, and emphasize the importance of aggressive intervention in cases of refractory biliocutaneous fistula based on our experience.

Introduction

Radiofrequency ablation (RFA) is now a prevailing option for unresectable hepatic tumors. It is also considered safe for low mortality and low morbidity rate. In the literature, the major complication rates were reported to be as low as 2%-5.7% [1]. Hemorrhagic, infectious, and biliary tract damages were the 3 most common complications. Therefore, recognizing and managing the complications become vital for the operator. Interventional radiologic management of complications is less invasive and thus may help patients in broader range of physical condition. Here we will present a case of a rare complication, that has not been documented before, refractory biliocutaneous fistula after RFA, and our management.

Case report

A 73-year-old male with chronic hepatitis C and hepatocellular carcinoma had been treated with segment 5, 6 segmentectomy, intraportal chemotherapy, transcatheter arterial chemoembolization, percutaneous thermal and ethanol ablations. After sequential treatments, there was chronic asymptomatic B3 intrahepatic bile ducts (IHD) dilatation without hyperbilirubinemia (total bilirubin: 0.75 mg/dL). However, a 3.1 × 2.6 cm recurrence was found at segment 3 of the liver, close to the pre-existing dilated IHDs (Fig. 1A).

Fig. 1.

CT demonstration of the recurrent HCC and post RFA change. (A) Recurrent HCC at S3 of liver(arrow) with nearby preexisting intrahepatic bile ducts dilatation(arrowhead). (B) Post CT-guided RFA, axial CT showed the position of electrode and the ablation zone. (C) Multiplanar reformatted CT revealed fistula tract with wall enhancement (dotted line) in oblique axial image. Note that the fistula arose from previous ablation zone to cutaneous entrance of electrode. HCC, hepatocellular carcinoma; RFA, radiofrequency ablation.

Computed tomography (CT)-guided RFA was performed with RF electrode (Big-tip, RF Medical, Korea), using the overlapping technique. The whole procedure was performed smoothly without immediate complications (Fig. 1B).

However, 9 days after RFA, the patient visited our emergent department for progressively abdominal pain with yellowish discharge from RFA cutaneous wound. CT revealed abscess formation at the ablation zone. The multiplanar reformation image showed the fistula tract from the RFA wound extending to the abscess cavity (Fig. 1C). A biliocutaneous fistula due to bile duct injury following RFA was diagnosed.

Initially, retrograde fistulography via the wound failed to identify any bile duct communication. Hence, left-side percutaneous transhepatic cholangial drainage (PTCD) was performed for biliary diversion and evaluating the biliary system. Cholangiography showed proximal stenosis with distal dilatation of B3. After twice percutaneous transhepatic cholangial dilatation at the stenotic site with 4 × 40 and 6 × 40 mm balloons, the wound still leaked with bile-like discharge once the PTCD tube was clamped.

The followings are our strategies to seal this refractory biliocutaneous fistula: Retrograde balloon-assisted fistulogram and antegrade transductal embolization. We performed balloon-assisted fistulogram by inserting a 6-Fr. Foley tube into the wound and block the fistula outlet. The abscess cavity and fistula tract were further opacified after injecting contrast medium via an inflated Foley catheter (Fig. 2A). Meanwhile, an antegrade cholangiogram was performed via the PTCD tract. A suspicious connection to the abscess cavity was noted (Figs. 2B and C), confirming the leak point of the bile duct. Then we injected NBCA (Histoacryl; B. Braun, Melsungen AG, Germany) mixed with Lipiodol in the 1:1 ratio via micro-catheter to fill the fistula tract, abscess cavity, and bile duct. Finally, 2 pushable micro-coils were placed to occlude the inner tract and IHD branch (Fig. 3A).

Fig. 2.

Comprehensive visualization of biliocutaneous fistula using combined retrograde fistulography and antegrade cholangiography. (A) 6-Fr. Foley (as shown in yellow dotted line) was inserted into the wound and the balloon was inflated to block the fistula outlet. Then, contrast medium was injected via inflated Foley for fistulography. Under this manipulation, the abscess cavity and fistula tract were further opacified. (B) A KMP angiocatheter, also known as Kumpe Access Catheter (Cook Medical) was introduced along the PTCD tract and negotiated into proximal IHD branch, which revealed suspicious connection to abscess cavity. (C) A micro-catheter was inserted further into the aforementioned branch and the abscess cavity was better opacified after injecting contrast medium into micro-catheter. IHD, intrahepatic bile ducts; PTCD, percutaneous transhepatic cholangial drainage.

Fig. 3.

Successful embolization of a refractory biliocutaneous fistula. (A) Antegrade transhepatic embolization was performed with NBCA glue for abscess cavity filling and micro-coils for inner fistula tract and short segment of IHD. (B) Follow-up CT demonstrated dense deposition of NBCA in abscess cavity and fistula tract. IHD, intrahepatic bile ducts; NBCA, histoacryl.

A significant reduction of the fistula output, and the gradual cutaneous wound healing was found after weeks. Follow-up CT showed dense deposition of NBCA within the fistula tract (Fig. 3B). The PTCD catheter was removed without the recurrence of the fistula. The patient expired due to terminal cirrhosis and hepatocellular carcinoma 19 months later.

Discussion

The most common complication of RFA is intra-abdominal bleeding, followed by infection and biliary tract damage [1,2]. Fistula formations after RFA were relatively rare and have been reported as biliopleural fistula or bilioperitoneal fistula. By far, there is no documented biliocutaneous fistula as complication of RFA after literature review.

To prevent such complications, we should beware of pre-existing biliary dilatation, especially when the expected ablation zone is in the vicinity of biliary dilatation. Asymptomatic upstream IHD dilatation is occasionally encountered after RFA [3], like in our case. However, it should still be taken into consideration when making treatment planning. There is a risk of biliary fistula formation after RFA under this circumstance. Moreover, patients with biliary abnormalities were reported with a higher incidence of post-RFA liver abscess [1]. Discreet planning of ablation electrode placement, choosing alternative treatments such as transcatheter arterial chemoembolization, or irreversible electroporation may play a role in preventing such complication. There are 2 critical steps in managing this kind of complication: (1) Identify the point of leakage, and (2) embolization technique.

When we perform fistulography, it is common to inject contrast medium from the easily identified fistula outlet, which worked successfully in enterocutaneous fistula. However, when dealing with presumably higher inner tract pressure, immature tract, or fistula in the inflammatory process, it could be challenging to obtain fistulography with this manipulation alone. Balloon-assisted injection may work. By inflating a balloon to occlude the outer opening of fistula, accompanying with contrast medium injection, fistulogram can therefore be obtained. In our case, a 6-Fr. Foley catheter was applied for the aforementioned purpose.

After we identify the fistula tract, it comes to the issue of sealing it. We suggest the aggressive intervention of biliary injury when stenosis of the central bile duct is also encountered. Transhepatic antegrade fistula embolization assist to seal the fistula tract permanently. Interventional radiologic embolization of fistulas was reported in enterocutaneous fistulas and biliary fistulas [4]. The embolic agents include histoacryl (NBCA), fibrin glue, ethylene vinyl alcohol copolymer (Onyx), coils and covered stent [4], [5], [6], [7], [8]. Among those embolic agents, NBCA is commonly used, with higher fistula closure rate and no documented complication. In our case, we injected NBCA glue to fill the fistula cavity, followed by placing micro-coils to occlude the leaking bile duct. In literature review, 4 cases of biliocutaneous fistulas successfully sealed by interventional radiologic management have been reported [4,8,9]. The causes of such fistulas formation include Whipple operation for pancreatic tumor, hepatic surgery for hydatid disease, and prolonged percutaneous biliary drainage. In those cases, the chosen embolic agents were NBCA with or without the combination of micro-coils.

In summary, there is no documented post-RFA biliocutaneous fistula before. We recommend increase alertness of preexisting bile duct dilatation when planning treatment and aggressive intervention of biliary injury when central stenosis is also encountered. Balloon assisted retrograde fistulography with antegrade fistula embolization using NBCA and micro-coils could offer effective result.

Patient consent

Written informed consent was obtained from the patient's legal representative for the publication.