CPT code 37145 defines an open surgical procedure to create a renoportal venous anastomosis — a direct connection between the renal vein and the portal vein — most often used to restore portal inflow to a transplanted liver graft when the native portal vein is stenosed or occluded. Nationally, this code represents a high-acuity, hospital-based operative intervention typically carried out by transplant or vascular surgeons and carries implications for coverage, inpatient billing, and specialized perioperative care.

Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context and service setting, common billing modifiers and coding considerations, and what to expect in terms of payer coverage themes and documentation priorities. The publication also summarizes related billing and policy issues that affect reimbursement and authorization for high-complexity transplant-related vascular procedures. This resource is intended to inform coding staff, billing managers, and clinical leaders about the procedural definition, site-of-service expectations, and areas where payer policies and documentation frequently influence claim outcomes. Data not available in the input for specific payer rates, ICD-10 pairings, and associated taxonomies is noted where relevant.