CASE REPORT: 

Cystic Artery Pseudoaneurysm (CAP) with hemorrhage is a rare life-threatening condition which can result in mortality if prompt treatment is not provided. Commonly associated with iatrogenic injury, like laparoscopic chocystectomy, it can also be secondary to acute calculus cholecystitis, Idiopathic, in acute pancreatitis and post traumatic. (1,2)

Acute cholecystitis can result in severe inflammation leading to thrombosis of vasa vasorum of the CA leading to vessel wall damage thus formation of pseudoaneurysm (PSA). (3,4) Patients present with obstructive jaundice, upper abdominal pain and Upper GI bleed (Quinke’s Triad), haemobilia and shock (1)(5)

The Cystic artery (CA) primarily originates from the right hepatic artery, supplying the GB and cystic duct in 79% to 89% of the population (Figure 1a and 1b). (6) Coursing through Calot's triangle, passing posterior to the cystic duct before bifurcating into superficial anterior and deep posterior branches at the gallbladder neck, forming extensive vascular network.(6) Variations are common. CA may arise from Left, Common Hepatic, or Gastroduodenal arteries.(7) Studies report double CA  and variations in the artery's course relative to the cystic duct and Calot's triangle.(7)Understanding variations is crucial during endovascular procedures to prevent inadvertent embolization of hepatic artery and other branches.

Endovascular embolization is the minimally invasive procedure done by IR and it is the go-to emergency management for CAP for controlling active bleeds, helps in stabilizing the patients to recover from hemodynamic shock after which patient is further surgically or conservatively managed depending upon etiopathology.

The approach begins with percutaneous access preferentially under USG guidance, commonly via the Common Femoral Artery (CFA) under LA. A 5/6-French sheath is inserted, and a selective angiogram is performed using a catheter such as a Cobra C1 or Simmons S1 to identify the celiac trunk and subsequently the hepatic arterial system. A microcatheter (e.g. Progreat microcatheter 2.9 -2.7 Fr, 130 cms (Terumo Global, Japan) is advanced into the CA using fluoroscopic guidance. Super selective catheterization is critical to prevent non-target embolization and preserve hepatic arterial flow. Embolization is then performed using coils (e.g., detachable or pushable platinum coils), polyvinyl alcohol (PVA) particles, or liquid embolic agents such as N- butyl cyanoacrylate (NBCA) depending on the vessel's anatomy and operator preference.

Post-embolization angiography confirms occlusion of the PSA and cessation of flow. The technique is highly effective, offers rapid hemostasis, and avoids the morbidity associated with surgical intervention.

CASE 1:

Clinical history: A 47y/M patient presented to the surgery casualty with severe abdominal pain in the last 2 days with 3 episodes of melena and 1 episode of hematemesis. He has Tachycardia and hypotension. Hemoglobin- 5.5 gm% and WBC -15,700^x10⁹ /L. LFT revealed bilirubin at 3.4 mg/dL.

Figure 1: 1a- CT Angiography MPR image showing Right hepatic artery ( Blue arrow) and Cystic artery ( Black arrow);  1b- DSA image showing Right Hepatic artery (Orange arrow) and Cystic artery (Blue arrow)

Imaging: USG à Acute calculus cholecystitis with echogenic content in the CBD and mild central IHBRD. CECT showed a distended gall bladder with multiple large calculi (Figure 2a-d) and was surrounding a hypodense sac like structure which showed complete filling of contrast. Lesion measures 28 x 42 x 36 mm and was diagnosed as a CAP probably secondary to acute calculus cholecystitis (Figure 2a-d). There was also suspicion of a rent in the wall of fundus of the gall bladder.

Intervention: Right CFA approach was taken to cannulate Celiac Trunk. A microcatheter was used to cannulate CA(Figure 2 e-h).The cystic artery angiogram revealed a ruptured cystic artery with a large PSA. The microcatheter was taken distally and the PSA was embolized with 25% Cyanoacrylate Glue. (Figure 2 e-h).

Post embolization patient was taken up for laparoscopic cholecystectomy due to risk to post embolization ischemia, perforation and sepsis. A gangrenous GB was seen intraoperatively  and subtotal cholecystectomy was done (Figure2 i-l). The patient returned after 2 weeks with abdominal pain, fever and had developed infected collections in the right hypochondrium and pelvis. The collections were drained and patient was discharged.

Figure 2 – Plain and contrast phase images of CECT abdomen of the patient a&b) Plain CT image showing bilobar intrahepatic biliary radicle dilation( Blue vertical arrow) b) Multiple intraluminal calculi within gall bladder( Blue star) and a calculus at the GB neck( Horizontal blue arrow). c) shows pseudoaneurysm arising from cystic artery (Blue horizontal arrow). D) MPR coronal image

showing cystic artery pseudoaneurysm (Blue horizontal arrow). 2e-f Angiography and trans-arterial embolization of cystic artery. e) Common hepatic artery angiogram showing cystic artery arising from right hepatic artery with large pseudoaneurysm (Horizontal blue arrow) f) Super selective angiogram from distal cystic artery (Blue star) opacifying the pseudoaneurysm (Horizontal blue arrow) g) Glue injection to embolize the pseudoaneurysm (Horizontal blue arrow) h) Post embolization angiogram revealing exclusion of the pseudoaneurysm and cystic artery from circulation. 2i-l)Laparoscopic resection of ruptured gall bladder i) and l) show laparoscopic partial resection of gall bladder k) Resected gall bladder l) extracted calculi.

Case 2:

Clinical history: A 42 yr/M with complaints of right hypochondriac pain for past 2 days with  fever for past 24 hours. Hypotension with deranged LFT and elevated WBC counts was noted.

Imaging: USG revealed thickened edematous GB wall and heterogenous content within lumen. Eccentric foci of color uptake with ying yang sign seen was intraluminally (Figure 3 a). CT angiography showed a contrast filled saccular lesion measuring 12*9*14 mm within GB lumen with pericholecystic fluid collection and definitive rent in GB fundus. (Figure 3 b-d).

Intervention: Using right CFA approach celiac and common hepatic arteries were cannulated. CA was cannulated using Progreat microcatheter (Terrumo). Angiography showed the pseudoaneurysm. The embolization was attempted using pushable coils however the coils migrated into PSA sac.The feeder was embolized using 20% Cyanoacrylate Glue + Lipiodol combination. Post embolization runs showed complete exclusion of the lesion from the arterial system (Figure3 e-h). Patient was transferred to surgery where the Cholecystectomy was done as there was already a rent in the GB fundus. Patient then discharged.

Figure 3– 3a showing Ying yang sign within  gallbladder lumen (Blue arrow). 3b showing a hyperenhancing pseudoaneurysm in the GB lumen (Horizontal bluearrow). 3c- MPR sagittal section showing pseudoaneurysm (Horizontal blue arrow). 3d- MPRimage showing course of cystic artery (Vertical blue arrow). 3e- Figure shows origin and course of Cysticc artery (Blue vertical arrow); 3f- Figure shows pseudoaneurysm, from Cystic artery(Blue star) and super selectively cannulated cystic artery using microcatheter. 3g- Coil mass within pseudoaneurysm (Blue Arrow); 3h- Figure showing glue cast with embolized pseudoaneurysm.

Case 3:

Clinical History: A 30Y/M patient who had blunt abdominal trauma to the upper right quadrant developed severe pain, deranged LFT and anemia.

Imaging: CECT showed a small intraluminal GB PSA with GB wall edema and heterodense content within the GB and pericholecystic minimal free fluid. (Figure 4 a&b).

Intervention: Using right CFA approach celiac trunk and common hepatic artery were cannulated. Using microcatheter CA was super selectively cannulated and angiographic runs taken which showed a small pseudoaneurysm arising from the branch of cystic artery. The feeder branch was embolized using pushable coil 2*7 mm. (Nester, Cook,US) with occlusion of front and backdoor accesses (Figure 4 c &d). Patient was then transferred to Surgery and was then taken up for cholecystectomy. Post procedure patient was discharged successfully and is doing well.

Figure 4: a- CECT angio, arterial phase showing a pseudoaneurysm within GB lumen (Bluearrow); b- Pericholecystic hepatic hypodensities and pericholecystic fluid collecttion; c-Superselective cyctic artery run showing pseudoaneurysm (Blue arrow); d- Coil embolization of the feeder artery.

Case 4:

Clinical History: A 28-year-old female who had acute on chronic pancreatitis and had underwent laparotomy and peritoneal wash presented with bloody output from one of her drains and a rapidly falling hemoglobin

Imaging: CECT showed a small intraluminal GB PSA within the gall bladder neck with peri-cholecystic free fluid. (Figure 5a). There is a large peripherally enhancing collection extending from infrahepatic region, along  right paracolic gutter into pelvis (Figure 5b)

Intervention: Using right CFA approach celiac trunk and common hepatic artery were cannulated. Using microcatheter CA was super selectively cannulated and angiographic runs taken which showed a small pseudoaneurysm arising from the branch of cystic artery (Figure 5 c). The cystic artery was embolized using 20% Cyanoacrylate Glue with occlusion of front and backdoor accesses (Figure 5d). Patient was then transferred to Surgery and was kept under observation where she gradually improved and she did not develop ischemic cholecystitis. She was later taken up for laparotomy (1 week later) and drainage of the collection with peritoneal wash and cholecystectomy, however she eventually succumbed to hospital associated infections.

Figure 5: a- CT angio, arterial phase coronal MIP imagesshowing a pseudoaneurysm within GB neck (Blue arrow); b- CECT venous phase coronal images showing Large peripherally enhancing collection extending from infrahepatic region, along  right paracolic gutter into pelvis (blue arrow); c- Superselective cyctic artery run showing pseudoaneurysm (Blue arrow); d- Glue cast post glue embolization.