Preoperative -blockade versus no blockade for pheochromocytoma-paraganglioma patients undergoing surgery: a systematic review and updated meta-analysis

Background: Surgical resection of pheochromocytomas and paragangliomas (PPGLs) is associated with a significant risk of intraoperative hemodynamic instability and cardiovascular complications. alpha-blockade remains the routine preoperative medical preparation despite controversies over the lack of evidence. We presented an updated meta-analysis to ulteriorly evaluate the potential efficacy of preoperative alpha-blockade versus no blockade for PPGL patients undergoing surgery. Materials and methods: Randomized and nonrandomized comparative studies assessing preoperative alpha-blockade for PPGL surgery in adults were identified through a systematic literature search via MEDLINE, Embase, Web of Science, and CENTRAL up to November 2022. Outcome data of intraoperative hemodynamic parameters and major postoperative events were extracted. Mean difference and risk ratio were synthesized as appropriate for each outcome to determine the cumulative effect size. Results: Fifteen nonrandomized studies involving 3542 patients were finally eligible. Intraoperatively, none of the analyzed hemodynamic parameters differed between patients with or without alpha-blockade: maximum and minimum systolic blood pressure, hypertensive and hypotensive hemodynamic instability episodes, and peak heart rate, subgroup analysis of normotensive PPGL patients yielded similar results with the overall effects. Postoperatively, alpha-blockade was associated with prolonged hypotension and vasopressor usage (risk ratio: 4.21, 95% CI: 1.17-15.18, P = 0.03). ICU admission, length of stay, overall cardiovascular morbidity, and mortality were similar between the two groups. Conclusions: Preoperative alpha-blockade ensured neither more stable intraoperative hemodynamics nor better perioperative outcome over no blockade for PPGL surgery. However, large-volume randomized controlled trials are still warranted to ascertain these findings.