Published online Nov 15, 2020. doi: 10.4251/wjgo.v12.i11.1364
Peer-review started: June 24, 2020
First decision: August 9, 2020
Revised: August 20, 2020
Accepted: September 22, 2020
Article in press: September 22, 2020
Published online: November 15, 2020
Processing time: 140 Days and 16.1 Hours
Fistula formation is a severe adverse event related to antiangiogenetic agents such as bevacizumab and inferior mesenteric arteriovenous fistula (IMAVF) is a result of acquired factor, especially colon surgery. However, IMAVF occurs very rarely and there are few reports in patients during chemotherapy. We report a case of a patient who developed IMAVF during treatment with bevacizumab in metastatic colorectal cancer (mCRC) after colon surgery.
An 81-year-old man was diagnosed with descending colon cancer and underwent left hemicolectomy without any complications. He was definitely diagnosed with high-risk stage 2 and received tegafur-uracil plus leucovorin as adjuvant chemotherapy. Three years and 6 mo after the operation, the cancer relapsed with peritoneal dissemination. The patient underwent CyberKnife radiosurgery targeting the recurrent tumor and received chemotherapy with S-1 plus bevacizumab. At 1 year after chemotherapy, he complained of severe diarrhea, which is suspected drug-induced colitis. As diarrhea worsened despite the termination of treatment, he underwent colonoscopy and computed tomography (CT) scans that revealed edematous change from sigmoid to rectosigmoid colon. CT scans also revealed an aneurysm adjacent to the inferior mesenteric vein and multidetector CT angiography showed the IMAVF. Elective angiography confirmed the diagnosis of an IMAVF and it was successfully treated by arterial embolization. The patient resumed chemotherapy with only S-1 6 mo after embolization.
Clinicians should keep in mind the probability of severe diarrhea arose from IMAVF in mCRC patients treated with bevacizumab.
Core Tip: Gastrointestinal perforation and fistula formation are s bevacizumab-induced serious adverse events (SAEs). Arteriovenous fistula may occur during bevacizumab treatment via the action of antiangiogenetic agent. Inferior mesenteric arteriovenous fistula (IMAVF) arises from acquired factors especially colon surgery, although there has been no report related to chemotherapy including bevacizumab. We report a case of IMAVF in metastatic colorectal cancer (mCRC) during bevacizumab treatment. This patient complained of severe diarrhea caused by ischemic colitis due to IMAVF. As fistula may be lethal complications, clinicians should pay attention to SAEs including IMAVF for mCRC patients during bevacizumab treatment.