Size and measurement technique both matter: accuracy of preoperative physical exam and computed tomography in predicting hernia size and current procedural terminology codes for incisional hernia

Abstract

Background: In 2023, new current procedural terminology (CPT) codes were introduced for anterior abdominal wall hernias based on hernia size, reducibility, and recurrence. When insurance prior authorization is required for hernia repair, it is necessary to estimate the size of the hernia to provide the appropriate CPT code. The aim of this study is to determine whether or not preoperative physical exam (PE) and imaging accurately predict the intraoperative size and thereby CPT code.

Methods: A prospectively maintained, single-institution hernia database was queried for patients undergoing elective incisional hernia repair from 2023 to 2024. Hernia size from most recent preoperative PE and CT scan within six months of surgery (if available) were compared to the intraoperative size. The percent congruence was determined between preoperative PE/CT and operative size/CPT code. Standard descriptive statistics were used.

Results: 145 patients underwent incisional hernia repair during the study period. One quarter (24.8%) of the hernias were recurrent and 11.7% were incarcerated. Preoperatively, 59.3% of patients had a CT scan available for review and 74.5% of patients had size documented on PE. Mean defect size was 5.5 × 5.3 cm by CT, 6.1 × 4.9 cm by PE, and 10 × 5.8 cm by intraoperative measurement (p < 0.01). In 46.9% of cases, the CPT code was different than that predicted on PE or CT; 97.2% of these discordant patients had hernias that are larger than predicted, and 43.4% had multiple smaller defects noted in the operative report.

Conclusion: Since the inception of the 2023 hernia CPT update, greater than four in ten patients had an operative CPT code that did not match the CPT code predicted on PE and CT. When CPT incongruence existed, hernia size intraoperatively was frequently larger than predicted and was associated with swiss cheese defects. A larger hernia CPT code may lead to increased out-of-pocket cost for patients who require preauthorization.

Keywords: Abdominal wall reconstruction; CPT code; CT scan; Hernia; Ventral hernia.