Hepatic artery pseudoaneurysm following percutaneous transhepatic cholangiogram: an extremely rare complication

Abstract

A 72-year-old female patient who was admitted for ischaemic stroke had developed ascending cholangitis. Percutaneous transhepatic cholangiogram was performed to drain the infected bile, but this was complicated by haemorrhagic shock and hepatic haematoma. Mesenteric angiogram showed right hepatic artery (RHA) pseudoaneurysm which was embolised, there by stopping her bleeding. RHA is normally located posterior to common bile duct (CBD). An uncommon location of RHA is anterior to CBD, which can lead to haemorrhagic complications during percutaneous cholangiogram.

Background

Percutaneous transhepatic cholangiogram (PTC) is a procedure in which the obstructed biliary tract was drained off the infected bile. Iatrogenic hepatic artery pseudoaneurysm is an extremely rare complication of PTC which can happen with variations in normal location of blood vessels around common bile duct (CBD). Knowledge of these variations is important to prevent fatal haemorrhage during or post-PTC.

Case presentation

A 72-year-old woman with a medical history of Roux-en-Y gastric bypass (RYGB) surgery was admitted due to ischaemic stroke. Four days after admission, she complained of right upper quadrant pain. Her temperature was 39^oC, heart rate was 110 beats/min, blood pressure was 106/65 mm Hg and respiratory rate was 16 breaths/min. Blood workup revealed a leukocytosis of 16×10⁹/L, total bilirubin of 3.6 mg/dL, alkaline phosphatase of 700 U/L, aspartate transaminase of 300 U/L and alanine transaminase of 650 U/L. Ultrasound of the abdomen showed pericholecystic fluid and gallbladder wall thickening and dilated CBD with a diameter of 11 mm, suggestive of cholecystitis and choledocholithiasis (figures 1 and 2). She was started on ceftriaxone and metronidazole for ascending cholangitis, based on Tokyo criteria for cholangitis, 2013 and IDSA guidelines for intra-abdominal infections. Her condition quickly progressed to septic shock over the next 24 hours. Because of her prior gastric bypass, PTC was performed to relieve the obstruction. Seven hours post-procedure, she became increasingly unresponsive and code blue was called.

Figure 1.

Ultrasound of the gallbladder showing pericholecystic fluid with gall stones. Asterisk: sludge in gallbladder with wall oedema. Arrows: gallstones.

Figure 2.

Ultrasound of the gallbladder showing common bile duct (CBD) dilatation. Arrow: dilated CBD of 11 mm diameter.

Investigations

Blood workup showed a drop in haemoglobin from 106-56 g/L. She was deemed to be in haemorrhagic shock and was transfused with 4 units of packed cells. CT abdomen revealed haemorrhagic ascites and a subcapsular hepatic haematoma (figure 3). Mesenteric angiogram was performed which showed traumatic pseudoaneurysm of the right hepatic artery (RHA) with arteriovenous shunting to right hepatic vein (figure 4A,B).

Figure 3.

CT scan of abdomen with hepatic haematoma. Asterisk: hepatic haematoma.

Figure 4.

Mesenteric angiogram showing hepatic artery aneurysm and subsequent embolisation. (A) Traumatic hepatic artery arteriovenous malformations seen on mesenteric angiogerm. (B) Resolution of pseudoaneurysm post-gel foam embolisation. Arrow: right hepatic artery pseudoaneurysm. Dotted arrow: percutaneous transhepatic cholangiogram tube. Asterisk: guide wire. Cross: disappearance of pseudoaneurysm post-gel foam embolisation.

Treatment

Outcome and follow-up

On her 2 months follow-up visit, she complained of low-grade fevers and failure to thrive. She was admitted twice for these complaints over a duration of 4 months and workup for fever of unknown origin including CBC, comprehensive metabolic panel, blood and urine cultures, tuberculosis tests, chest X-ray were unremarkable. She was treated with a 14-day course of vancomycin and piperacillin–tazobactam during each of these admissions. CT scan of her abdomen during her third hospitalisation revealed a 4×5 cm sub-hepatic abscess in the same place where she had haematoma before (figure 5). Drainage of the abscess revealed blood mixed with pus. Fluid culture showed vancomycin-resistant Enterococcus explaining why she did not respond to broad-spectrum antibiotics before. She was started on daptomycin and completed 14-day course. Because of her prolonged hospital stay, she was deconditioned and was discharged to short-term rehabilitation facility. She recovered uneventfully from the rehabilitation facility and was discharged home after 2 weeks.

Figure 5.

CT scan of abdomen showing hepatic abscess. Arrow: hepatic abscess.

She was seen in her primary care physician’s office on 11 March 2019 for a routine follow-up visit, and then again on 13 May 2019 for the same, and was doing well without any complaints of abdominal pain.

The RHA was subsequently embolised with gel foam and haemostasis is secured (figure 4A,B). Post-procedure she recovered uneventfully and was discharged to rehabilitation facility, after 15 days of intensive care unit stay.

Discussion

Endoscopic retrograde cholangiopancreatography is the frequently used procedure to relieve CBD obstruction in patients who are septic due to cholangitis. Roux-en-Y anatomy often precludes access to the duodenal ampulla using a conventional endoscope due to the length of bowel that must be traversed. For instance, in the case of RYGB, the endoscope must initially go through the oesophagus, proximal gastric pouch, and the efferent or the Roux limb, which is the connection between the proximal gastric pouch and the jejunum, and is usually 100–150 cm in length. Then, the endoscope should navigate the acute angle at the jejunojejunostomy into the biliopancreatic limb up to the ampulla of vater which is an additional 50–100 cm.^{1 2} Manoeuvring through this altered anatomy could be challenging and time consuming especially in an unstable patient. PTC is a very reasonable first line choice in these patients.

PTC usually is a well-tolerated procedure. In a study of 364 patients by Oh et al, the overall incidence of complications was found to be 12.9%.³ Reported complications of PTC are cholangitis (2%), sepsis (0.4%), bile leak, haemobilia (0.2%), catheter migration, rupture of sinus tract, injury to CBD, haemoperitoneum (4.7%).^3–5 Choi et al published a study of 3110 patients who underwent percutaneous biliary drainage and hepatic arterial injuries were noted in 1.9% of patients.⁶ It is reported that left sided percutaneous biliary drainage is an independent risk factor for hepatic arterial injury and right sided drainage is preferred when appropriate.^{6 7} Hepatic artery pseudoaneurysm secondary to PTC is an extremely rare entity. There are case reports of RHA pseudoaneurysm following liver transplantation, pancreatic surgeries or biliodigestive anastomosis procedures.⁸ Hepatic arterial injuries can be managed by angiographic embolisation which is 95.8% effective clinically.⁶ Microcoils, cyanoacrylate gel, gelatin sponge pledgets, inflatable balloons are widely used for this purpose. Embolisation can be complicated by hepatic infarction and abscess development in the haematomas.⁹

The common hepatic artery arises from celiac artery and gives rise to proper hepatic artery (PHA) and gastroduodenal artery. Portal vein is formed by superior mesenteric vein and splenic vein (figure 6A). Normally, the PHA runs anterior to the portal vein and to the left of CBD (figure 6B). The RHA which branches from proper hepatic artery runs posterior to CBD (figure 6C). A relatively uncommon variant of RHA location is anterior to CBD (figure 6D). The prevalence of this anomaly was found to be up to 15% in a study of 300 patients by Talpur et al.¹⁰ Other variants of RHA anatomy are replaced RHA arising from superior mesenteric artery or celiac trunk or an accessory RHA. Widely used Michel’s classification of hepatic vasculature anomalies studied in 200 cadavers noted that the prevalence of replaced RHA is up to 3.7%.^{11 12} This classification has not described the anterior location of RHA to CBD. In a literature review of 19 013 cases by Noussios et al, replaced RHA has a frequency of 11%–21%, and accessory right and left hepatic artery has a frequency of 0.8%–8%.¹³

Figure 6.

Graphic representation of common bile duct and its surrounding structures. (A–C) Depicts normal anatomical organisation. (D) Depicts unusual anterior location of RHA to CBD. aRHA, anomalous right hepatic artery; CBD, common bile duct; CHA, common hepatic artery; CHD, common hepatic duct; LHA, left hepatic artery; PHA, proper hepatic artery; PV, portal vein; RHA, right hepatic artery; SMV, superior mesenteric vein; SV, splenic vein.

Knowledge of these variants is of utmost importance while performing hepatobiliary or pancreatic surgeries, due to the associated risks of accidental ligation of biliary vasculature and subsequent ischaemia of the anastomosis. Often, computerised tomographic angiography of the mesenteric vasculature to delineate the vascularity helps anticipate the possible anomalies in pre-operative settings.¹³ However, this is not cost-effective in the setting of radiological procedures like percutaneous cholangiogram. Hence, it is important to consider these variants in every patient undergoing emergency biliary drainage through PTC. When such an anomaly presents, there is a chance that the RHA could be injured while performing PTC. If this goes undetected at the time of PTC, it can result in a potentially life-threatening aneurysm or pseudoaneurysm which can result in haemorrhagic shock and rapid deterioration. Knowledge of these anatomical variants helps to prevent such complications.

Patient’s perspective.

Patient’s husband: I thought it’s a simple procedure. I was aware she was very sick; but I did not expect her to bleed into her abdomen. But I should appreciate the promptness of the doctors when she became unresponsive.

Learning points.

• Right hepatic artery (RHA) is the chief source of blood supply to bile duct.

• Injury to RHA could happen during percutaneous transhepatic cholangiogram when RHA is locatedanterior to common bile duct.

• It is very important to bear this in mind while performing percutaneous transhepatic cholangiogram and observe the patient for any haemorrhagic complications.