Case Author(s): Richard Held, M.D. and Keith Fischer, M.D. , 4/25/06 . Rating: #D3, #Q4
Diagnosis: Colon Cancer metastatic to liver with variant arterial anatomy
Brief history:
53 year old male with colon cancer.
Images:
Tc99m-MAA injected into an hepatic infusion pump implanted in the abdominal wall
View main image(mc) in a separate image viewer
View second image(mc).
Perfusion images fused with an abdominal CT scan
View third image(an).
Selective visceral angiogram
Full history/Diagnosis is available below
Diagnosis: Colon Cancer metastatic to liver with variant arterial anatomy
Full history:
53 year old male with colon cancer and hepatic metastases who had a hepatic chemotherapy infusion pump implanted in the abdominal soft tissues. The pump and its catheter were surgically implanted with the catheter placed in the gastroduodenal artery, which was ligated during the procedure to prevent back flow into other viseral vessels. The catheter tip is positioned at the origin of the gastroduodenal artery in the common hepatic artery. As part of the routine evaluation of the pump, prior to its use, the pump was accessed and injected with Tc99m-MAA. This is done to confirm that the chemotherapy will be delivered, to the entire liver and not to other organs such as lungs (through intra-tumor AV shunting), stomach, gall bladder, or duodenum.
Radiopharmaceutical:
Tc99m-MAA
Findings:
The initial study (NOT SHOWN) showed possible abnormal distribution of MAA to the duodenum and stomach.
A second study (Image 1)was performed to confirm these findings, and SPECT images were fused with a previous CT scan (Image 2) for more precise localization of abnormal uptake. This confirmed the abnormal gastric and duodenal perfusion by the implanted pump.
An angiogram (Image 3)was then performed to assess the visceral arterial anatomy. This examination showed a variant accessory gastroduodenal artery arising from the right hepatic artery, which was implicated as the cause of the abnormal distribution from the scintigraphic examination. This was successfully embolized with coils.
Finally, a third injection through the pump with Tc99m-MAA was performed (Image 4), and showed resolution of the abnormal gastric and duodenal activity.
Discussion:
Variant anatomy of the hepatic arterial system is very common and has been classified by Michaels in his classic description. The variant anatomy depicted in this case; however, is an extremely rare accessory gastroduodenal artery. The significance of identifying such variant anatomy is important with respect to toxic effects of chemotherapy being infused by the pump to the stomach and duodenum.
Followup:
The repeat perfusion study showed no abnormal distribution of activity in the stomach or small intestine. The hepatic arterial chemotherapy infusion pump can then be filled with a chemotherapy agent to treat the patient.
View followup image(mc).
Repeat Tc99m-MAA hepatic perfusion pump injection after coiling of the accessory GDA
Major teaching point(s):
Beware of variant arterial anatomy in the upper GI system. An injection of Tc-99m MAA through the pump will confirm the correct positioning of the perfusion catheter and demonstrate that only the liver is perfused.
ACR Codes and Keywords:
References and General Discussion of (Anatomic field:Gasterointestinal System, Category:Neoplasm, Neoplastic-like condition)
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Case number: mc003
Copyright by Wash U MO
