Hemorrhage in pheochromocytoma surgery: evaluation of preoperative risk factors

Objective Pheochromocytoma surgery carries a higher risk of hemorrhage. Our objective was to identify preoperative risk factors for hemorrhage during pheochromocytoma surgery. Methods Patients who underwent surgery and with postoperative pathological confirmation were enrolled. A total of 251 patients from our center were included in the investigation, and 120 patients from the First Affiliated Hospital, Sun Yat-sen University were included as an external validation dataset. Family and medical history, demographics, hemodynamics, biochemical parameters, image data, anesthesia and operation records, postoperative outcomes were collected. Postoperative complications were graded by the Clavien-Dindo classification. Correlation between intraoperative hemorrhage volume and postoperative outcomes was assessed. The features associated with intraoperative hemorrhage were identified by linear regression. All features that were statistically significant in the multiple linear regression were then used to construct models and nomograms for predicting intraoperative hemorrhage. The constructed models were evaluated by Akaike Information Criterion. Finally, internal and external validations were carried out by tenfold cross-validation. Results Intraoperative hemorrhage volume was positively correlated with the postoperative hospitalization time (R = 0.454, P < 0.001) and the Clavien-Dindo grades (R = 0.664, P < 0.001). Features associated with intraoperative hemorrhage were male gender (beta = 0.533, OR = 1.722, P = 0.002), tumor diameter (beta = 0.027, OR = 1.027, P < 0.001), preoperative CCB use (beta = 0.318, OR = 1.308, P = 0.123) and open surgery (beta = 1.175, OR = 3.234, P < 0.001). Validations showed reliable results (internal (R = 0.612, RMSE = 1.355, MAE = 1.111); external (R = 0.585, RMSE = 1.398, MAE = 0.964)). Conclusion More intraoperative hemorrhage is correlated with longer postoperative hospitalization time and more severe postoperative complications. Male gender, larger tumor, preoperative CCB use and open surgery are preoperative risk factors for hemorrhage in PCC surgery.