Background: A number of patients with periampullary carcinoma deemed resectable on preoperative CT have their curative-intent surgery aborted on the basis of intraoperative findings.

Objective: This study sought to identify imaging and clinical factors associated with aborted curative-intent Whipple procedures for periampullary adenocarcinoma.

Methods: Ten U.S., Canadian, and French institutions contributed data to this retrospective case-control study of 360 adults (220 men, 140 women; mean age, 68.6 ± 8.4 [SD] years) with periampullary adenocarcinoma who underwent curative-intent Whipple procedures between January 2016 and December 2022. A total of 180 patients for whom the procedure was aborted (cases) were matched by sex and 5-year age blocks with 180 patients for whom the procedure was completed (controls). Covariates included cancer type, tumor size and resectability on CT, CT reconstruction slice thickness including by phase, number of phases, multiplanar imaging, reconstruction at the workstation, possible metastases reported, structured versus unstructured report, reporting radiologist's experience, hepatic steatosis, preoperative liver MRI, endoscopic ultrasound, ERCP, multidisciplinary review, neoadjuvant therapy and response, and serum CA 19-9 and CEA levels. Logistic regression was performed with ORs and 95% CIs.

Results: Whipple procedures were most frequently aborted due to metastases (67% [121/180]), followed by locally unresectable disease (28% [50/180]). Serum CA 19-9 levels of 37 U/mL or more were associated with aborted Whipple procedures with an OR of 3.75 (95% CI, 1.22–12.77) that increased to 5.47 (95% CI, 1.80–18.62) when a cutoff of 200 U/mL was applied. CT slice thickness ranged from 0.5 mm to 5 mm. CT examinations that used only slice thicknesses of 2.5 mm or more were independently associated with aborted Whipple procedures (OR = 4.28 [95% CI, 1.37–15.00]), including when assessing only pancreatic ductal adenocarcinoma. No other variables showed statistically significant association.

Conclusion: Elevated serum CA 19-9 levels and preoperative CT using only slice thickness of 2.5 mm or more were associated with aborted curative-intent Whipple procedures. Many other imaging and clinical factors did not show an association.

Clinical Impact: If curative-intent surgery is planned in patients with periampullary carcinoma, preoperative CT should be performed using reconstructions smaller than 2.5 mm to reduce the likelihood of incorrect staging.