Hypocalcemia after total laryngectomy: incidence and risk factors.

OBJECTIVES/HYPOTHESIS: Hypocalcemia is common in the initial period after total laryngectomy. The purpose of the present study was to study the incidence of and risk factors for postlaryngectomy hypocalcemia at our institution. STUDY
DESIGN: Retrospective review of 65 consecutive total laryngectomies.
METHODS: Clinical data and calcium levels for the first postoperative week were collected. Biochemical hypocalcemia was defined as any corrected calcium level of < 2.0 mmol/l in the first postoperative week. Severe hypocalcemia was defined as a calcium of < 1.8 mmol/l, or symptoms of hypocalcemia. Risk factors for hypocalcemia were studied.
RESULTS: Five cases were excluded due to concomitant abdominal surgery (3), preoperative hypocalcemia (1), and no postoperative calcium levels (1). A total of 43% of patients had postoperative biochemical hypocalcemia. On univariate analysis, bilateral neck dissection was significant for hypocalcemia (P = 0.02), with pT4 classification having borderline significance (P = 0.07). On multivariate analysis, bilateral neck dissection (P = 0.02) and salvage surgery were significant (P = 0.03), with pT4 stage again having borderline significance (P = 0.05). Extent of thyroidectomy, extent of pharyngectomy, and preoperative tracheostomy were not significant. Fifteen patients (25%) had severe hypocalcemia. There were no significant risk factors for severe hypocalcemia identified.
CONCLUSIONS: Hypocalcemia is common after total laryngectomy, particularly in the postradiotherapy setting and in patients undergoing bilateral neck dissection. Preservation of one thyroid lobe does not appear to significantly reduce the risk.