Letter: Management of Major Arterial Injuries: A Critical Complication of Endoscopic Endonasal Surgery

To the Editor: We read with great interest the article by Emengen et al1 on “Management of Major Arterial Injuries: A Critical Complication of Endoscopic Endonasal Surgery.” The authors provide a valuable 27-year institutional experience, highlighting the incidence, management, and outcomes of 15 major arterial injuries among 5640 endonasal endoscopic procedures. Major vascular injury during endoscopic endonasal surgery represents one of the most devastating complications in skull base surgery with significant morbidity and mortality.2 Its incidence is estimated to occur between 0% and 3.4% of these procedures.3-6 However, the exact rate is believed to be much higher. In a survey of skull base neurosurgeons, at least 20% of them experienced internal carotid artery (ICA) injury in their endoscopic endonasal patients.7 The series Emengen et al1 underscores the rarity of major vascular injury (0.2%) and provides a contemporary overview of the management paradigm of this devastating complication. The authors describe their use and show case examples of the utilization of gelatin-thrombin matrix (Floseal®) as part of their intraoperative hemostatic strategy; however, the reliance on such agents (Floseal® or Surgifoam™) in the context of major arterial hemorrhage warrants critical re-examination. Gelatin-based products, although familiar to neurosurgeons, especially in managing venous bleeding, carry significant risks when applied in arterial injuries. It is also unclear what is meant by “low flow” or “high flow” arterial bleeding in their paper. The size of the arterial lesion is certainly important, but all arterial injuries are, by definition, high flow. Successful management of intraoperative ICA injury depends on rapid identification of the bleeding point, preservation of visualization, and achieving hemostasis. Gelatin-thrombin matrices embolize, swell, and diffuse within the surgical field, making them ideal for low pressure venous bleeding of the cavernous sinus.8-11 Owing to their injectable nature, these agents are semifluid. When pressed against an actively bleeding arterial defect, there is a significant risk of intraluminal entry and distal showering embolization into the intracranial vasculature. Various studies have linked their use to thromboembolic events, including ischemic strokes, blindness, and death.12 In our experience, if these agents are introduced to the ICA lumen, even a small volume of intravascular matrix could precipitate devastating hemispheric infarction (Figure 1).FIGURE 1.: Axial computed tomography showing the air density appearance of embolized Surgifoam (arrows, A) and resultant multifocal infarcts (B).Given the serious nature of ICA injury, the ideal management begins with optimal preparation and studying of individual patient anatomy and pathology. Knowledge of the ICA course and segments from an endoscopic endonasal perspective is vital to avoid its injury.13 Multidisciplinary collaboration and detailed complication management checklists begin before each case.14 In addition, it is important to analyze each case and its vascular anatomy in an individualized manner and select those who would benefit from preoperative balloon test occlusion after careful study of collaterals such as the anterior communicating and posterior communicating arteries.15 Intraoperatively, the utilization of neuronavigation and Doppler ultrasound is vital to map the ICA course, especially when the anatomy is distorted by tumor or in poorly pneumatized sinuses. When an injury occurs, rapid activation of the ICA injury protocol is important, and the endovascular suite should be readily alerted. Adequate maintenance of the blood pressure and careful neuromonitoring of the patients electroencephalogram and somatosensory evoked potential is paramount. The importance of dynamic endoscopy is vital for proper visualization and identification of the bleeding site. Cottonoid tamponade, supported by oxidized cellulose, if necessary, achieves compression and allows for visualization of the bleeding site. If a small area of bleeding (e.g., avulsion injury) is visualized, bipolar cauterization of the bleeding site should be attempted to seal off the bleeding site. Sometimes, direct clipping of the bleeding site could be performed with preservation of the parent vessel. However, in most of the cases, and as reported in the literature, the use of crushed muscle from the lateral abdomen, thigh, temporalis, or anterior capitis muscle is necessary for adequate control of the bleeding. Immediately following hemostasis, rapid transition to the endovascular suite is vital for ICA evaluation, possible stenting, or vessel sacrifice.16 Emengen et al1 conclude by calling for standardized algorithms for arterial injury management during endoscopic endonasal surgery. We, as well as others, have reported such algorithms in the literature and encourage skull base surgeons to familiarize themselves with such algorithms.4,17 We strongly emphasize that such algorithms must explicitly discourage the use of Surgifoam or Floseal in the setting of major arterial hemorrhage. Their indiscriminate use risks obscuration, embolization, and significant morbidity and mortality to the patients.