Internal validation and decision curve analysis of a preoperative nomogram predicting a postoperative complication in pheochromocytoma surgery: An international study

Abstract

Objectives: To develop a preoperative nomogram that would predict the risk of a postoperative complication for pheochromocytoma patients undergoing adrenalectomy using an international database. Methods: We retrospectively analyzed preoperative variables and postoperative outcomes in patients who underwent adrenalectomy for pheochromocytoma in three institutions from 2000 to 2017. Internal validation of a generated nomogram was carried out with receiver operating characteristics, calibration plots, and decision curve analyses. Results: A total of 153 patients who had undergone 166 adrenalectomies were included in the study. Overall, post-adrenalectomy complications were seen in 30% of patients, whereas 9.6% of patients sustained a Clavien ≥3a complication. Independent predictors of a complication were a history of hypertension, body mass index, tumor size, and Charlson Comorbidity Index score. On internal validation, the multivariable model generated a nomogram that predicted a postoperative complication or clinically hemodynamic event with an area under the curve of 0.86, showed good calibration and had an overall net benefit. Conclusions: An internally validated nomogram combining body mass index, Charlson Comorbidity Index score and tumor size can predict the probability of a postadrenalectomy complication in those with and without hypertension. The model, the first of its kind in pheochromocytoma surgery, identifies patients at risk of a postoperative complication at the time of their presentation with pheochromocytoma.

Surgical outcomes in the pheochromocytoma surgery. Results from the PHEO-RISK STUDY

“…There are several plausible explanations for this wide range, including referral biases, differences in the de nition of complications and in the type of complications reported, and importantly, the decade of the performed research as it is known that a signi cant reduction in pheochromocytoma surgical treatment morbidity and mortality has taken place over recent decades [20]. In agreement with our study, series evaluating the severity of complications found similar gures of grade III and IV complications in the Clavien-Dindo score [10][9] [11], although in some series severe complications occurred in up to 31% of the cases [8].…”

“…Patients with tumours larger than 5 cm also had an increased risk of complications, but it was related to a greater functionality of the tumour. Tumour size is a well-known risk factor for postoperative [8] [10][16] [31][32] [24] and intraoperative complications [11][24][27] [33]. However, this relationship seemed to be due the real reason why size is associated with complications seemed to be related to a higher production of catecholamines in our study.…”

“…In accordance with our results, Namekawa et al [16] showed that urinary epinephrine and norepinephrine were correlated with prolonged hypotension after tumour resection. Nevertheless, con icting results have been described, some authors observed that urinary epinephrine (OR 1.18; 95% CI 1.04-1.35) and dopamine (OR 4.38; 95% CI 1.21-15.86), but not norepinephrine were independent risk factors for hypotension [17], and even some studies did not nd any in uence of the amount of catecholamines secretion and risk of postoperative hypotension [8] [10].…”

Editorial Comment from Dr Utsumi et al. to Internal validation and decision curve analysis of a preoperative nomogram predicting a postoperative complication in pheochromocytoma surgery: An international study

“…Phillips et al. developed and internally validated a novel nomogram to predict a postoperative complication in PC surgery 4 . The Charlson Comorbidity index, a positive history of hypertension, tumor size and body mass index (BMI), which are incorporated into their nomogram, seem to be reasonable predictors.…”

Editorial Comment from Dr Santo and Dr Nishimoto to Internal validation and decision curve analysis of a preoperative nomogram predicting a postoperative complication in pheochromocytoma surgery: An international study

“…This international study by Phillips et al . is a multicenter retrospective cohort study that proposed for the first time a nomogram to predict the risk of postoperative complications of pheochromocytoma 4 . The authors analyzed 156 patients receiving adrenalectomy either by an open, laparoscopic or robotic measure.…”