*Postoperative hypophosphatemia is common after HPB surgery and challenges the traditional model of phosphate consumption by the regenerating liver.* --- ### Essential Takeaway Hypophosphatemia after hepatectomy has traditionally been attributed to increased phosphate uptake during liver regeneration. However, postoperative hypophosphatemia is typically preceded by **renal phosphate wasting (hyperphosphaturia)**, suggesting the mechanism is not simply hepatic phosphate consumption. --- ### Clinical Pattern Typical trajectory: - **POD1:** increased urinary phosphate wasting - **POD2:** serum phosphate nadir - **POD3–5:** gradual recovery In one prospective cohort: | Operation | POD2 Phos <2.4 mg/dL | | :----------------: | :------------------: | | Major hepatectomy | 93% | | Minor hepatectomy | 77% | | Pancreatectomy | 83% | | Laparotomy/control | 80% | The presence of hypophosphatemia after pancreatectomy and laparotomy further supports a systemic mechanism rather than liver regeneration alone. --- ### Mechanism #### Traditional Model Liver regeneration → increased ATP demand → hepatic phosphate uptake → hypophosphatemia #### Updated Model Surgical stress / regenerative signaling → renal phosphate wasting → hypophosphatemia The exact mediator remains unclear. NAMPT has been proposed as a potential phosphaturic factor, while classic phosphate regulators (FGF-23 and PTH) do not appear to explain the phenomenon. --- ### Clinical Significance After hepatectomy, postoperative hypophosphatemia may represent an expected metabolic response rather than simply an electrolyte abnormality. Absence of the expected phosphate decline after major hepatectomy has been associated with: - [[Post-Hepatectomy Liver Failure (PHLF)|post-hepatectomy liver insufficiency]] - increased postoperative mortality **Clinical pearl:** The liver is probably not just “eating phosphate” to regenerate — postoperative phosphate handling appears to reflect a broader systemic response involving renal phosphate wasting. >[!info] >- The liver is not just “eating phosphate” to regenerate. >- Postoperative phosphate handling appears to reflect a broader systemic response involving renal phosphate wasting. --- ### References >[!quote]- Selected References >- Zheng J, Glezerman IG, Sadot E, et al. Hypophosphatemia after Hepatectomy or Pancreatectomy: Role of the Nicotinamide Phosphoribosyltransferase. J Am Coll Surg. 2017. DOI: 10.1016/j.jamcollsurg.2017.06.012. [PMID: 28690207](https://pubmed.ncbi.nlm.nih.gov/28690207/) --- **Page Information** Last Updated: June 2026 Maintained by: HPB Compendium Editorial Board