Possibilities of surgical treatment of pancreatic head neuroendocrine neoplasms with major venous invasion

Aim – to demonstrate the feasibility and relative safety of resection of the portal and/or superior mesenteric veins invaded by tumor during surgical treatment of the neuroendocrine neoplasm of the pancreatic head, as well as the feasibility of simultaneous resection of the liver for resectable metastases in patients with stage IV disease during primary surgery and at disease progression of any stage following surgical treatment.

Material and methods. Surgical treatment of 16 patients with neuroendocrine neoplasm of the pancreatic head with invasion of the superior mesenteric and/or portal veins of stages III-IV of high and moderate differentiation (G1 and G2) included a standard gastropancreoduodenal resection in 87.5% cases, extended gastropancreoduodenal resection with aortocaval lymph node dissection in 6.25% cases, and pancreatectomy in 6.25% cases. During the standard operation, in one female patient (6.25%) segmental resection of the liver was performed to remove the metastasis. The rate of portal vein resection was 6.25%, superior mesenteric vein, 50%, both major veins, 43.8%. Neoadjuvant treatment was not administered, while adjuvant XELOX treatment was administered to 3 (18.8%) patients. The statistic processing of the study results was performed in Statistica for Windows v.10 and SPSS v21. The obtained differences were deemed statistically significant at р≤0.05 (≥95% accuracy). In order to calculate the survival rate, the Kaplan-Meier method was used with log-rank test evaluation of significance of differences.

Results. The rate of R0 surgical treatment was 93.8%, the rate of complications of surgical treatment of Clavien-Dindo class III and above was 43.8% with the total rate of all complications of 75%. The main complications included gastric stasis (50.1%), arrosive hemorrhage (18.8%), acute gastrointestinal ulcer hemorrhage (18.8%), pneumonia (18.8%). The rate of postoperative thrombosis of the portal and/or superior mesenteric vein was 12.5%, leakage of the pancreato-digestive anastomosis was 12.5%, leakage of the bilio-digestive anastomosis, 6.3%, pancreatic fistula, 12.5%. Relaparotomy was performed in 2 (12.5%) patients who later died due to complications of surgical treatment (leakage of the pancreato-digestive anastomosis with arrosive hemorrhage). Disease progression was seen in 10 (62.5%) of the patients within 3 to 69.3 months, the median time before identification of progression being 39.7 [7.1; 52.8] months, and mortality from progression being 50%. Local recurrence developed in 12.5% patients, metastases in the retroperitoneal lymph nodes in 6.25%, metastases in the liver in 43.75%, in two cases, liver resection due to metastases was performed. In cases of progression, all patients received antineoplastic therapy with analogs of prolonged somatostatin. The median overall survival was 70.1 months, progression-free survival, 49.2 months, one-year survival was 81.2% and 78.6%, respectively, three-year survival, 68.2% and 63.5%, five-year, 68.2% and 36.3%, ten-year, 20.55% and 18.1%.

Conclusion. The outcomes of surgical treatment of patients with neuroendocrine neoplasm of the pancreatic head with invasion of the portal and/or superior mesenteric vein show the feasibility, relative safety and efficiency of resection of these major veins. In the majority of patients, surgical treatment may be performed in the radical volume and extended by liver resection in the event of resectable metastases. Considering the relatively favorable prognosis of the disease, liver resection for resectable metastases and disease progression may be performed: it is safe, it improves quality of life of patients, and extends the period without tumor manifestations.