Oncovascular Surgery is Effective in the Treatment of Retroperitoneal Tumors Involving Major Blood Vessels; A Single Centre Retrospective Cohort Study

Abstract

Introduction - Radical surgery of tumors invading or intimately surrounding major intra-abdominal blood vessels may necessitate vessel resection and reconstruction and the patients with these tumors are often regarded as inoperable. However, tumors that are adjacent to, but separated from, major vessels with a capsule, can be resected without significant damage to the vessels. The aim of this study was to assess the prognosis of patients with retroperitoneal tumors involving major blood vessels operated with and without a vascular reconstruction. Methods - Patients with retroperitoneal tumors surrounding major vessels resected in the years from 2010 to 2018 were included in this retrospective single centre study. We assessed the radicality of the resection, perioperative complications, late vascular complications and disease-free survival. Descriptive statistics were used. Results - Thirty-one patients were included in this study: 23 sarcomas, 7 other malignant tumors, and 1 desmoid. Twenty required vascular reconstruction and 11 did not. The median (range) age of the patients was 54 (26-79) years. Twenty-two patients were female. In the vascular reconstruction group, 13 resections were primary operations. The resection margins were: 16 marginal; 3 intralesional; and 1 wide. Vessel walls were infiltrated by, or the origin of, the tumor in 7. Aorta reconstructions were performed with polyester prosthesis and IVC reconstructions with autologous vein graft, or allograft. Other reconstructed vessels were the iliac and renal vessels, the coeliac trunk and the hepatic artery. Reconstruction materials for these included autologous vein graft and allograft, as well as polyester and PTFE prosthesis. Temporary warm blood visceral perfusion was achieved during clamping in 4 patients with a previously described technique using axillary inflow. Preoperative embolization was used in 1 tumor. In the early post-operative period, significant venous thrombosis occurred in 2 patients and combined venous and arterial thrombosis occurred in 1. Thrombectomies were successfully performed in all 3. Two patients developed late thrombosis of allograft IVC which required no operative intervention. Importantly, early graft thrombosis was not a predictor of later graft failure. The average follow-up time was 21 ± 5 months (average ± SEM). During follow-up, 6 tumors recurred locally and 7 patients developed metastases. At the end of follow-up, 9 patients were disease-free. Five patients had died of the disease. In the tumor resections that did not require vascular resection, 7 were primary resections. The resection margins were: 7 marginal; 2 intralesional; and data on 2 margins not available. No vascular complications occurred during the early post-operative period or during follow-up. The average follow-up time was 23 ± 6 months. During follow-up, 3 tumors recurred locally and 1 patient developed metastases. At the end of follow-up, 6 patients were disease-free. Three patients had died of the disease. Conclusion - Oncovascular surgery is feasible and effective in the treatment of retroperitoneal tumors involving major blood vessels. Graft reconstructions are associated with a risk of early thrombosis but the risk of graft failure in the medium term follow-up is low. Vascular invasion should not be considered an absolute contra-indication for tumor surgery, since free margins can be achieved in resection of tumors invading major abdominal vessels.