Ever-Present Danger

Uncontrolled intraoperative bleeding is one of the most feared complications in neurosurgery. It has been said that uncontrolled bleeding is the one factor above all others that unnerves surgeons. As a corollary, surgeons who are agile in handling vascular structures and controlling bleeding can deal with most crises that arise in a neurosurgical procedure. Therefore, managing catastrophic bleeding is an invaluable skill, no matter one’s subspecialty or practice.

Intraoperative rupture is an ever-present, unavoidable danger in aneurysm surgery. It occurs in 5 to 10% of aneurysm cases, mostly with fragile, previously ruptured aneurysms in patients with subarachnoid hemorrhage (SAH). It does not diminish with increasing surgical experience of the neurosurgeon performing the operation. However, the timing of intraoperative aneurysmal rupture may well reflect the neurosurgeon’s experience. Ruptures occurring during the initial exposure, or predissection, are more frequent early in one’s experience, typically due to brain retraction with adherent aneurysms such as superiorly projecting ophthalmic artery (OphA) aneurysms stuck to the frontal lobe, inferiorly projecting anterior communicating artery (ACoA) aneurysms stuck to the optic chiasm, or posterior communicating artery (PCoA) aneurysms stuck to the temporal lobe. Avoiding retraction or using it sparingly eliminates these mistakes. Similarly, rupture during clip application becomes less frequent with experience, reflecting the developing sense for when an aneurysm is ready to be clipped. Inadequate dissection of the aneurysm’s neck and poor clip application are responsible for ruptures during clipping that occur in procedures performed by inexperienced neurosurgeons, reflecting a natural fear of intraoperative rupture. The seasoned neurosurgeon is more likely to aggressively manipulate the aneurysm and precipitate rupture during the final dissection maneuvers, preferring an expected rupture of a fully prepared aneurysm over an unexpected rupture during clip application of an under-prepared aneurysm.

Visceral Response

Intraoperative aneurysm rupture elicits an intense rush of emotions: surprise, confusion, regret, tension, frustration, anger, excitement, and desperation. This visceral response can be overwhelming and crippling for neurosurgeons early in their surgery experience. These moments demand calm, clarity, and confidence. The adrenaline rush can interfere with microsurgical mechanics. The situation can force dangerous or hasty maneuvers. Calm is needed to quiet the hands and emotions and to execute the plan methodically. In addition, calm benefits everyone in the operating room, from the nurses passing instruments, to the anesthesiologists administering pressors or blood, to other surgeons assisting with the procedure. Clarity is the quality that enables the thinking required in performing the operation. Confidence is the quality that infuses composure and assures that the sequence of technical steps will lead to a successful aneurysm repair. Calm, clarity, and confidence translate into a swift and efficient rupture response. Over time, the technical response to intraoperative rupture becomes reflexive, and the cognitive response becomes intuitive, but the visceral response to rupture does not seem to vanish. Its intensity fades with experience and anticipation, but it remains a factor to deal with.

Technical Response

An aneurysm that has ruptured intr-aoperatively is no longer untouchable, as it once was. A torn aneurysm trapped with temporary clips can be collapsed and mobilized aggressively. The sac can be entered, suctioned down, and manipulated. The operation accelerates into “final dissection” mode with the urgency normally associated with temporary clipping and cerebral ischemia. As contrarian as it may seem, intraoperative rupture creates opportunity. For example, an ophthalmic artery aneurysm that ruptures before anterior clinoidectomy can sometimes be clipped without clinoidec-tomy by aggressively mobilizing the aneurysm away from the anterior clinoid process (ACP). The stress of the situation should not force the permanent clipping before the aneurysm is adequately prepared. An imperfectly placed clip may be used as a tentative clip to control bleeding from the rupture site, remove temporary clips, and reperfuse the brain. Additional permanent clips can be stacked below the tentative clip, or the tentative clip can be readjusted to finalize the repair.

Cerebral protection with hypothermia and pharmacologic agents is maintained by the anesthesiologists during an intraoperative rupture, and normal or slightly increased blood pressure is maintained during temporary clipping to augment collateral blood flow.

Cognitive Response

The neurosurgeon must continue to think and operate. Intraoperative rupture elicits many questions in the neurosurgeon: Why did the aneurysm rupture? Where is the hole? Why is the aneurysm still bleeding? Where is the other branch artery? How can this be repaired? What was my contingency plan? What did I do when this happened before? All these questions arise while working to control the rupture. Work must continue in order to discern the cause of an aneurysmal rupture, to visualize anatomy under adverse conditions, and to devise a solution. In a surgical field suddenly suffused with blood before an aneurysm has been fully dissected, critical anatomy becomes obscured. The neurosurgeon must see through the blood to find the problem, the undissected anatomy, and the solution. Visual and cognitive insight comes from an appreciation of arterial anatomy and aneurysm pathology. It comes from past aneurysm cases and averted catastrophes during which techniques and tricks have been tried and abandoned or embraced. Every operation on an aneurysm contributes collectively to insight, generating knowledge of aneurysm anatomy that can guide the neurosurgeon when conditions are not so favorable. Answers and solutions during an intraoperative rupture are cognitive, and this cognitive response has to dominate the emotions and guide the hands through critical steps leading from rupture to final clipping. Over time, experience transforms the cognitive response from a forced process to an intuitive one.