Risk stratification for outpatient parathyroidectomy and predictors of postoperative complications.
BACKGROUND
The mainstay of treatment for primary hyperparathyroidism is surgery. Hypocalcemia after parathyroidectomy is common and poses a significant challenge, leading to increased patient morbidity and health care costs. While several groups have found predictor factors for hypocalcemia, none have created a risk stratification model. Here, we recognize important factors and optimal cut-off values that can allow risk stratification of patients.


METHODS
A single-institution retrospective chart review of 339 patients that underwent parathyroidectomy from 2009 to 2012 was conducted. Pre-operative, intra-operative, and post-operative data were collected. A non-routine outcome was defined as post-operative admission, outpatient hypocalcemia-related complication, or inpatient hypocalcemia-related complication. The preoperative or intraoperative factors of patients that experienced a non-routine outcome were compared to those that did not. Optimal cut-off values were determined for preoperative and intraoperative factors and a risk stratification method was created.


RESULTS
A total of 39 patients experienced a non-routine outcome including 24 postoperative admissions, 2 inpatient hypocalcemia-related complications, and 17 outpatient hypocalcemia-related complications. Patients with a non-routine outcome displayed a trend toward preoperative hypercalcemia (calcium >11.0mg/dL) than not (p=0.0543). The median preoperative parathyroid hormone (PTH) level was significantly higher among patients with a non-routine outcome (p=0.0037). Furthermore, the median percent decrease in PTH at 20min intraoperatively among patients with a non-routine outcome was significantly higher compared to those that did not (p=0.0421). The optimal cut-off value for preoperative PTH was 129pg/mL and for median percent decrease in intraoperative PTH at 20min was 90.7% for predicting a non-routine outcome. A risk stratification model was created based on these data.


CONCLUSIONS
Our analysis reveals that patients with larger intraoperative decrease in PTH levels (greater than 90.7% drop at 20min), higher preoperative hypercalcemia (greater than 11mg/dL), and higher preoperative PTH levels (greater than 129pg/mL) are more likely to experience a non-routine outcome during outpatient parathyroidectomy. Patients can be risk stratified based on this criteria.
Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY. Electronic address: sarah.kidwai@mountsinai.org.
Sarah M
SM
Kidwai
Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY.
Arjun K
AK
Parasher
Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY.
Yan W
YW
Ho
Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY.
Marita S
MS
Teng
Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY.
Eric M
EM
Genden
D017677:Age Distribution; D000368:Aged; D000556:Ambulatory Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000175:diagnosis / Q000601:surgery*; D006996:Hypocalcemia / Q000209:etiology / Q000503:physiopathology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010045:Outpatients / Q000706:statistics & numerical data; D010281:Parathyroid Hormone / Q000378:metabolism; D016105:Parathyroidectomy / Q000009:adverse effects / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D016896:Treatment Outcome
D010281:Parathyroid Hormone