Long-distance crude oil and gas pipelines depend on a chain of assurance extending from material acceptance and girth-weld qualification to corrosion surveillance, defect assessment and intervention. These activities are frequently managed as separate programmes, although an undetected construction deviation can later appear as an integrity threat, while uncertain inspection data can distort repair priorities. This critical review examines research published between 2020 and 2025 to develop a joined-up, risk-based quality assurance and integrity management approach for Saudi Arabian transmission corridors. Thirty DOI-traceable scholarly contributions were evaluated through a structured thematic synthesis covering degradation mechanisms, construction controls, in-line inspection, probabilistic risk assessment, digital monitoring and decision governance. The literature supports combining threat-specific inspection with verified asset records and consequence-sensitive maintenance planning; it does not support indiscriminate use of predictive algorithms without representative field validation. An evidence-led framework is proposed in which construction quality records, spatially referenced condition measurements and uncertainty-aware risk calculations inform proportionate actions. Particular attention is given to desert soils, variable route exposure, crossings, corrosion protection and high-consequence pipeline sections. The contribution is a practical decision architecture, not an untested claim of predictive accuracy or a Saudi field trial. Recommendations identify how owners can improve auditability, target scarce inspection resources and preserve confidence in decisions throughout the asset lifecycle.