Colon cancer is of of the most frequent pathologies treated by General Surgeons worldwide. Oncologic resection, open or laparoscopic, is the only surgical treatment usually offered to patients. While reading some case reports from International Journal of Surgery Case Reports, I found one interesting case published by Shintaro Akabane et al from Hiroshima, Japan.
They treated a 48 yo female patient diagnosed with a moderately differentiated adenocarcinoma of the ascending colon, without metastases. The particularity of this patient was an intraluminal filling defect from the ileocolic vein to the superior mesenteric vein (SMV) in the CT scan. A PET/CT was performed revealing a abnormal uptake of FDG from the ileocolic vein to the SMV. Diagnosis: ascending colon cancer with tumour thrombosis of the SMV.
Tumour thrombosis of the SMV is a risk for liver metastases.
The authors decided to go further than the most of us surgeons. They performed a right hemicolectomy plus tumour thrombectomy of the SMV and a greater saphenous vein (GSV) grafting (Figure). Operation took 334 minutes (5,56 hours) and blood loss was 210 ml. Staging was pT3N0M0. AngioCT at day seven confirmed the patency of the graft and SMV. Adjuvant chemotherapy was offered to the patient and 8 courses were accomplished. At 17 months of follow-up she is free of disease.
This is the first case report of a tumour thrombectomy of the SMV. Tumour thrombosis is rare, with an incidence of 1,7% in advanced colorectal carcinoma. According to the authors, only seven and five cases of tumour thrombosis of SMV and inferior mesenteric vein (IMV), respectively, have been reported in colorectal carcinoma patients. From those 12 cases, 25% had liver metastases after primary tumour resection. This data favours the vein tumour thrombosis as a possible risk factor for liver metastases development. In this setting, chemotherapy should be offered after primary tumour resection.
Thrombectomy of the SMV and a GSV grafting was performed with a right hemicolectomy for colon cancer.
PET/CT was probably crucial in the diagnosis. It revealed an abnormal FDG uptake from the ileocolic vein to the SMV. This image was essential to diagnose a tumour thrombosis and differentiate it from a common clot. In the present day, PET/CT is indicated in the presence of liver metastases. However, with the data from this case report a question arises:
Should we perform a PET/CT in the presence of a CT image of venous thrombosis even if there are no liver metastases?
After reading the case report I will definitely do it.
PET/CT differentiated a tumour thrombosis from a common clot.
The authors consider that with the tumour thrombectomy and GSV grafting it was possible to avoid massive small bowel resection and short bowel syndrome. Do not forget that SMV is crucial for venous drainage of small bowel. Some more questions arise in me: Will this technique be validated in future case reports? Will this procedure be the future treatment of this rare cases of tumour thrombosis? Will it become the gold standard of care? If yes, who would perform it?
This last question is the most actual. Would the general surgeon be able to do it? Would be the vascular surgeon? Would both be needed? Well... In Portugal the majority of the vascular surgeons do not treat mesenteric ischemia, they do not work with the mesenteric vessels, they do not perform mesenteric revascularization nor aortomesenteric bypass... So, they would not do a tumour thrombectomy of the SMV either, I think. This let us with the general surgeon.
Would the general surgeon be able to do it? Would be the vascular surgeon? Would both be needed?
In there era of the subspecialization, how will the general surgeon learn how to do it? With whom will he learn if there are such a few cases? How many cases will he need to perform before knowing how to do it correctly (learning curve)? Gaining experience in vascular surgery (treatment of varicose veins and peripheral arterial disease) may be one answer. Transplant experience may also be helpful since there are many vascular anastomosis included. These experiences may give the surgeon the ability, the skills, the comfort to handle vessels and to perform a tumour thrombectomy of the SMV and a GSV grafting even if he had never performed one before.
Gaining skills in different procedures and pathologies may give the surgeon the ability to be better in his comfort area. Only surgeons with experience in several different areas (outside their comfort zone) are able to innovate to a higher level. Comfort is the enemy of progress!
Link to ScienceDirect:
Dr. Carlos Eduardo Costa Almeida
General Surgeon