A 53-year-old woman presented with left-sided abdominal pain, nausea and vomiting for the past 3 months with associated loss of appetite and weight. On physical examination, there was a large, ill-defined, firm mass at the epigastrium. Ultrasonography showed heterogeneously hypoechoic filling defect within the dilated main portal vein. The filling defect showed florid signals on Doppler mode and it appeared to be an extension of a larger periportal mass. Contrast enhanced abdominal computed tomography confirmed a large distal gastric mass infiltrating into the periportal structures, including the main portal vein and the splenic vein. Esophagogastroduodenoscopy performed 2 days later showed an irregular, exophytic mass extending from the antrum into the first part of duodenum. The mass was deemed inoperable. Histopathological examination showed gastric adenocarcinoma. She was started on anticoagulant, chemotherapy and pain management. Follow-up computed tomography 4 months later showed liver metastases and formation of collateral blood vessels.
Methods: A hybrid fuzzy multiple-criteria decision-making (FMCDM) process, consisting of the Analytic Hierarchy Process (AHP) and fuzzy Technique for Order of Preference by Similarity to Ideal Solution (fuzzy TOPSIS) method, is structured to aggregate the different criteria and rank different ELV alternatives in this complicated evaluation. In order to use the most profound knowledge and judgment of a professional expert team, this qualitative assessment highlights the importance of supportive information.
Results: The results obtained indicate that experts have considered the country-specific information as a reliable reference in their decisions. Among different key evaluation criteria in effluent standard setting, the highest experts' priority is "Environmental protection". For both the conventional and toxic pollutants, the influence of all other criteria namely "Economic feasibility", "Technology viability" and "Institutional capacity", as constraining criteria in developing countries, have not reduced the responsibility towards the environmental objectives. In ELVs ranking, experts have made their decisions with respect to the specific characteristics of each pollutant and the existing capacities and constraints of the country, without emphasizing on any specific reference.
Conclusions: This systematic and transparent approach has resulted in defensible country-specific ELVs for the Iron and Steel industry, which can be developed for other sectors. As the main conclusion, this paper demonstrates that FMCDM is a robust tool for this comprehensive assessment especially regarding the data availability limitations in developing countries.