The preoperative assessment of preexisting comorbidities and perioperative risk stratification is among the primary challenges for anesthesiologist before any surgery.1 A main goal of the preoperative assessment is to identify patients with increased risk of perioperative complications and mortality so that they can be optimized prior to surgery.2 According to the perceived degree of perioperative risk, specific clinical strategies can be implemented to minimize the inherent risks of surgery, which might require that the surgery be temporarily postponed. Current trends typically dictate predictive and often redundant diagnostic and laboratory analyses, and in many cases, a “defensive medicine” attitude dominates the approach to preoperative screening.3,4

Due to the high costs of diagnostic testing and concerns relates to delaying surgery (e.g., disease progression or clinical deterioration), some have questioned whether postponing surgery to obtain more diagnostic evaluations is clinically warranted.5 Moreover, the utility of routine referrals for medical consultation and clearance before surgery, a common and longstanding practice, has similarly been questioned. Indeed, a recent cohort study in more than 500,000 patients in Ontario, Canada demonstrated that obtaining a preoperative medical consultation was associated with an increase rather than a reduction of adverse postoperative outcomes.6 This surprising finding highlights the need for further research to identify which patient populations might benefit most from preoperative medical consultation, and the processes and interventions best suited to improve postoperative outcomes.

The preoperative risk assessment in patients scheduled for elective intracranial neurosurgical procedures includes several patient-specific factors. For example, inherited or pharmacologic coagulation disorders confer a higher risk of intraoperative bleeding and acute postoperative hematoma7; cardiac arrhythmias can potentiate intraoperative hemodynamic instability8; deep vein thrombosis (DVT) can result in intra- and postoperative pulmonary embolism (PE)9; and hyperglycemia is associated with higher rates of postoperative infection.10 These specific factors are of particular interest in neurosurgical patients because they are often perceived as conferring a higher risk compared to other types of procedures. Accordingly, the presence of one or more of these abnormalities on preoperative evaluation can lead to the postponement of elective brain surgery. Meanwhile, any delay in surgical intervention, even for elective procedures, can lead to unintended but severe disease progression, including aneurysm rupture, progressive neurologic deficits due to mass effects, and seizure activity.11, 12, 13 However, there currently are a lack of data on the evidence to help guide the decision-making process on whether and when to postpone elective craniotomy in patients with certain coexisting preoperative clinical or laboratory disorders.

In this scoping review, we review the available evidence on the prognostic value of preoperative risk assessment before anesthesia for elective craniotomy. Additionally, the conditions and rationale for when postponing surgery might be clinically warranted is critically assessed. Special circumstances, including preoperative chronic aspirin therapy, cardiac arrhythmias, DVT, and hyperglycemia are discussed. The risk of neurosurgical disease progression and a logical approach to balancing medical and surgical risks are similarly discussed.