Inferior mesenteric arteriovenous fistula during treatment with bevacizumab in colorectal cancer patient: A case report

BACKGROUND 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.CASE SUMMARY 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.CONCLUSION Clinicians should keep in mind the probability of severe diarrhea arose from IMAVF in mCRC patients treated with bevacizumab.

Preservation of left colic artery in laparoscopic colorectal operation: The benefit challenge

BACKGROUND During laparoscopic resection for colorectal cancer,there is controversy regarding whether the left colic artery(LCA)should be preserved at its origin.AIM To investigate the prognostic significance of preservation of the LCA in colorectal cancer surgery.METHODS Patients were divided into two groups.The high ligation(H-L)technique(refers to ligation performed 1 cm from the beginning of the inferior mesenteric artery)group consisted of 46 patients,and the low ligation(L-L)technique(refers to ligation performed below the initiation of the LCA)group consisted of 148 patients.Operative time,blood loss,lymph nodes with tumor invasion,postoperative complications and recovery time,recurrence rate,and 5-year survival rate were compared between the two groups.RESULTS The average number of lymph nodes detected in postoperative pathological specimens was 17.4/person in the H-L group and 15.9/person in the L-L group.There were 20 patients(43%)with positive lymph nodes(lymph node metastasis)in the H-L group and 60 patients(41%)in the L-L group.No statistical differences were found between the groups.Complications occurred in 12 cases(26%)in the H-L group and in 26 cases(18%)in the L-L group.The incidences of postoperative anastomotic complications and functional urinary complications were significantly lower in the L-L group.The 5-year survival rates in H-L and L-L groups were 81.7%and 81.6%,respectively,and relapse-free survival rates were 74.3%and 77.1%,respectively.The two groups were similar statistically.CONCLUSION Complete mesenteric resection combined with lymph node dissection around the inferior mesenteric artery root while preserving the LCA is a beneficial surgical approach during laparoscopic resection for colorectal cancer.

Low ligation has a lower anastomotic leakage rate after rectal cancer surgery

BACKGROUND For laparoscopic rectal cancer surgery,the inferior mesenteric artery(IMA)can be ligated at its origin from the aorta[high ligation(HL)]or distally to the origin of the left colic artery[low ligation(LL)].Whether different ligation levels are related to different postoperative complications,operation time,and lymph node yield remains controversial.Therefore,we designed this study to determine the effects of different ligation levels in rectal cancer surgery.AIM To investigate the operative results following HL and LL of the IMA in rectal cancer patients.METHODS From January 2017 to July 2019,this retrospective cohort study collected information from 462 consecutive rectal cancer patients.According to the ligation level,235 patients were assigned to the HL group while 227 patients were assigned to the LL group.Data regarding the clinical characteristics,surgical characteristics and complications,pathological outcomes and postoperative recovery were obtained and compared between the two groups.A multivariate logistic regression analysis was performed to evaluate the possible risk factors for anastomotic leakage(AL).RESULTS Compared to the HL group,the LL group had a significantly lower AL rate,with 6(2.8%)cases in the LL group and 24(11.0%)cases in the HL group(P=0.001).The HL group also had a higher diverting stoma rate(16.5%vs 7.5%,P=0.003).A multivariate logistic regression analysis was subsequently performed to adjust for the confounding factors and confirmed that HL(OR=3.599;95%CI:1.374-9.425;P=0.009),tumor located below the peritoneal reflection(OR=2.751;95%CI:0.772-3.985;P=0.031)and age(≥65 years)(OR=2.494;95%CI:1.080-5.760;P=0.032)were risk factors for AL.There were no differences in terms of patient demographics,pathological outcomes,lymph nodes harvested,blood loss,hospital stay and urinary function(P>0.05).CONCLUSION In rectal cancer surgery,LL should be the preferred method,as it has a lower AL and diverting stoma rate.

Evaluation of characteristics of left-sided colorectal perfusion in elderly patients by angiography

BACKGROUND Handling of the inferior mesenteric artery(IMA)and maintaining anastomotic perfusion are important in radical resection of left-sided colorectal cancer.However,the branching of this artery and the drainage patterns of this vein vary among individuals,and the characteristics and perfusion region of this artery in elderly patients remain unclear.AIM To evaluate the characteristics and perfusion region of the IMA in elderly patients using angiography.METHODS We enrolled 154 patients(>65 years old)who underwent digital subtraction angiography of the IMA.The characteristics,bifurcation,and distribution of the IMA and termination of the anastomotic perfusion of the left colon and rectum were examined using digital subtraction angiography.Collateral arterial arches and the IMA hemoperfusion region were also recorded.Perfusion regions were cross-referenced with clinical and anatomical features by the univariate analysis.RESULTS Of 154 patients,25(16.2%)had IMA lesions.The left colic artery arose independently from the IMA in 44.2%of patients,shared a trunk with the sigmoid artery in 35.1%,shared an opening with the sigmoid and superior rectal arteries in 16.9%,and was absent in 5.1%.The IMA perfusion region stopped at the splenic flexure in 50(32.5%)patients.The collateral circulation existed in the colonic perfusion region,including the marginal artery(Drummond’s artery),the ascending branch of the left colonic artery to supply the transverse colon,and the arc of Riolan with a frequency of 100%,22.7%,and 1.9%,respectively.The IMA perfusion region was independently associated with the comorbidity of atherosclerosis,IMA atherosclerotic lesion,branching pattern,collateral circulation,and marginal artery integrity.CONCLUSION The IMA and its branches are prone to arteriosclerosis,and IMA perfusion may be interrupted at the splenic flexure in elderly patients.The applicability and precision of preoperative angiography for evaluating the IMA branching and perfusion patterns could facilitate geriatric laparoscopic left-sided colorectal cancer surgery with suspicion of poor IMA perfusion.