Surgical management of a ruptured cirsoid aneurysm: illustrative case

Abstract

BACKGROUND

Cirsoid aneurysms are rare arteriovenous fistulas involving direct connections between scalp arteries and draining veins, often located within the periosteal or temporal fascia, or beneath the galea. First described by Brecht in 1833, these lesions may be congenital or posttraumatic and can occasionally be associated with intracranial vascular malformations.

OBSERVATIONS

A 69-year-old woman with thrombocytopenia developed a large cirsoid aneurysm in the right parieto-occipital subcutaneous region following head trauma. The lesion evolved into a soft tissue hematoma, eventually leading to a spontaneous cutaneous fistula with active, profuse bleeding. An endovascular embolization attempt failed due to complex vascular architecture. Emergency surgical intervention was performed for hematoma evacuation and complete resection of the vascular malformation.

LESSONS

This case is unique in combining several high-risk factors rarely reported together: an acutely ruptured cirsoid aneurysm, severe thrombocytopenia, and failed endovascular embolization due to prohibitive vessel tortuosity. A successful outcome was achieved through rapid multidisciplinary coordination—integrating neurosurgical expertise for definitive nidus excision, hematological optimization, and reconstructive planning to preserve scalp integrity.

https://thejns.org/doi/10.3171/CASE25508

Vascular malformations of the scalp have been described with several terms, including “arteriovenous aneurysm,” “racemose aneurysm,” “pulsating angioma,” “aneurysmal varix,” “plexiform angioma,” and “arteriovenous fistula.” The term “cirsoid aneurysm” was introduced in 1833 by Brecht to describe a fistulous connection between arterial feeders and draining veins of the scalp. These lesions are rare and may be of congenital or traumatic origin, occasionally with connections to intracranial vascular malformations.¹ The management of cirsoid aneurysms is challenging due to complex vascular anatomy, high-flow shunting, and risks such as skin necrosis and hemorrhage. Treatment options include excision, endovascular embolization, direct injection of sclerosing agents, or ligation of feeding vessels.^2,3 We describe an illustrative case of a ruptured cirsoid aneurysm in a thrombocytopenic patient, managed surgically after failed embolization.

Illustrative Case

A 69-year-old female with known thrombocytopenia presented with a large, subcutaneous hematoma on the right parieto-occipital region of the scalp, following minor head trauma. She had a preexisting diagnosis of a cirsoid aneurysm identified years earlier via CTA (Fig. 1A–C). Shortly after hospital admission, a spontaneous skin fistula with copious external bleeding developed.

FIG. 1.

Preoperative coronal T2-weighted MR images (A and B) and MR angiogram (C) showing a serpiginous subcutaneous mass in the right parieto-occipital region. Preoperative carotid angiograms (D–F) demonstrating feeding from the right occipital and right superficial temporal arteries.

An urgent embolization was attempted, but selective catheterization failed due to the tortuosity of the right external carotid artery. The patient was taken to the operating room for emergency hematoma evacuation and excision of the lesion (Fig. 2A).

FIG. 2.

A: Three-dimensional reconstruction of preoperative CT scans showing feeding arteries to the vascular malformation and a large subcutaneous hematoma (size 14 × 10 cm) in the right parieto-occipital region. B: Intraoperative image showing total removal of the cirsoid aneurysm and redundant skin.

A linear scalp incision was made inferior to the swelling. After careful dissection, bipolar coagulation was used to control bleeding. The aneurysm was supplied by branches of the right occipital and superficial temporal arteries, as confirmed on preoperative angiography (Fig. 1D–F). These feeders were coagulated, resulting in devascularization of the lesion. The hematoma was evacuated, and the malformation was excised en bloc, preserving the underlying galea (Fig. 2B). Redundant skin was removed and a transposition flap was used to close the defect.

Postoperatively, the patient was monitored in the ICU and received blood transfusions, platelet concentrates, packed red blood cells, and tranexamic acid; these were continued until suture removal on postoperative day 13 to stabilize hemostasis and prevent rebleeding in the setting of thrombocytopenia. Follow-up CT and angiography studies showed no residual malformation or bleeding (Fig. 3A and B). The patient had no postoperative complications; the wound healed well with a satisfactory cosmetic outcome (Fig. 3C).

FIG. 3.

Postoperative axial (A) and coronal (B) T2-weighted MR images showing total removal of the vascular malformation. Postoperative photograph confirming satisfactory cosmetic results (C).

Informed Consent

The necessary informed consent was obtained in this study.

Discussion

Observations

Cirsoid aneurysms of the scalp are rare high-flow arteriovenous malformations (AVMs) characterized by a network of dilated and tortuous vessels resulting from multiple fistulous connections between arterial feeders and draining veins without a normal intervening capillary bed. The term “cirsoid aneurysm” was first introduced by Brecht in 1833 to describe these vascular lesions due to their serpentine, varix-like appearance.¹ Historical reports date back even earlier, with similar scalp lesions noted in 1795 by John Bell, but it was not until the 19th century that they were systematically described and linked to arteriovenous pathology.² They account for less than 8% of all scalp vascular malformations and predominantly affect young adults, with a slight male predominance.^1–3 The origins of cirsoid aneurysms have long intrigued clinicians. In the early literature, these lesions were thought to represent vascular tumors or aneurysmal dilations secondary to trauma. However, over time, with advances in angiography and histopathology, they have been definitively categorized as congenital or acquired AVMs.³ Congenital forms are believed to arise from errors in embryological vascular development, particularly a failure of regression of arteriovenous connections that normally involute during fetal growth.⁴ Acquired forms are most commonly associated with trauma, particularly blunt or penetrating injury to the scalp, which may create direct arteriovenous fistulas between superficial arteries and veins.^5,6 Notably, some authors have reported cirsoid aneurysms appearing after repeated minor trauma, such as hair grooming practices or contact sports.⁷ The etiology is still debated, although both congenital and traumatic origins are accepted.^4,5 Spontaneous scalp AVMs may remain asymptomatic for years, with symptom onset triggered by trauma, hormonal changes, or hemodynamic alterations.^6,7 These lesions typically present in the 2nd to 4th decade of life but can remain asymptomatic for years. Most commonly, cirsoid aneurysms arise in the frontal, temporal, or parietal regions, as these areas are supplied by superficial branches of the external carotid artery, particularly the superficial temporal and occipital arteries. Lesions located in the parieto-occipital region, such as in our case, often involve both arterial systems and may pose particular challenges for surgical access and hemostasis.^2–5 Trauma is a known trigger, especially for acquired forms, while congenital variants are thought to result from persistent embryonic arteriovenous connections that fail to regress during vascular development.^4–6 Clinical presentation varies and can include a pulsatile mass, scalp bruit, throbbing headache, tinnitus, cosmetic deformity, or, less frequently, spontaneous hemorrhage or ulceration. Large or longstanding AVMs may result in overlying skin thinning, necrosis, and secondary infection, complicating treatment.^2,5 The diagnosis is primarily clinical but should be confirmed and further evaluated with imaging. Digital subtraction angiography remains the gold standard for delineating angioarchitecture and assessing connections with intracranial vasculature.^2,6 Noninvasive imaging, such as MRI/MRA or CTA, can provide additional anatomical information but may lack the spatial resolution for definitive treatment planning.^1,6

The treatment of cirsoid aneurysms aims at complete obliteration of the arteriovenous shunting to prevent recurrence, bleeding, and complications. Treatment options include excision, endovascular embolization, direct percutaneous sclerotherapy, or combined approaches.^3,5,7,8 Recurrence after treatment may occur due to incomplete resection or unrecognized collateral supply. Reported recurrence rates range from 10% to 30% when the lesion is not completely excised.^5,9,10 These rates emphasize the importance of achieving total excision of the nidus and all feeding vessels. In older or coagulopathic patients, early and complete resection may be the only way to avoid fatal hemorrhagic events, as endovascular or conservative strategies may be insufficient or unsafe.^5,9 In our case, an attempt at endovascular embolization failed due to the tortuosity of the external carotid artery and the inability to achieve adequate distal catheterization. This outcome highlights the limitations of embolization, particularly when vascular access is challenging or when multiple feeders are involved. Although embolization can serve as a stand-alone treatment or an adjunct to reduce intraoperative bleeding, it often falls short of achieving definitive cure in large, complex lesions.^6,8 Arterial approaches are sometimes unable to reach the nidus due to collateral recruitment and may leave residual shunting.⁵ Endovascular embolization has been successfully used in selected cases with well-defined vascular anatomy and limited collateral circulation. It is less invasive and may be preferred in high-risk surgical candidates. However, embolization alone is associated with higher recurrence rates, ranging from 20% to 40%, especially when used without adjunctive resection.^8–10 The risk of skin necrosis or incomplete nidus obliteration is also increased when embolic agents are used near the dermal vasculature.Excision remains the definitive treatment for accessible scalp AVMs. Key surgical principles include preoperative angiographic mapping, proximal control of feeding arteries, en bloc resection of the malformation, and reconstruction to minimize cosmetic deformity and prevent scalp necrosis.^4,7,8 Surgical treatment is associated with lower recurrence rates—typically less than 10% when complete resection is achieved—and provides immediate removal of the nidus and resolution of symptoms.^7,9 Based on a review article including 242 cases, Sofela et al.¹¹ proposed a management algorithm in which large lesions (> 4 cm) are to be managed with combined excision and endovascular intervention, whereas smaller lesions (< 4 cm) are to be managed with endovascular intervention alone, surgery alone, or both depending on the lesion’s angioarchitecture. Table 1 summarizes the salient data emerging in the literature regarding the endovascular and surgical treatment of cirsoid aneurysms.^11–19 In this case, the surgical strategy involved a linear scalp incision, bipolar coagulation of the feeding arteries (identified via angiography), removal of the hematoma, and total resection of the malformation. The use of a scalp transposition flap provided effective reconstruction with satisfactory cosmetic results.

TABLE 1.

Comparison of endovascular and surgical treatment of cirsoid aneurysms according to current literature

Aspect	Endovascular Embolization	Excision
Invasiveness	Minimally invasive	Invasive
Success in complete cure	60–80% (variable by anatomy)	>90% w/ complete resection
Recurrence rate	20–40%	<10% w/ total resection
Risk of skin necrosis	Higher (due to dermal embolization)	Lower w/ proper planning
Cosmetic outcome	Variable	Good w/ reconstruction
Suitability for emergencies	Limited	Preferred
Use in coagulopathy	May be safer initially	Riskier but definitive
Adjunct role	Useful to reduce intraop bleeding	Often combined w/ embolization

Despite underlying thrombocytopenia, the patient was managed successfully with platelet and red blood cell transfusions and antifibrinolytic therapy with tranexamic acid for 13 days postoperatively. This hematological support stabilized hemostasis and minimized the risk of rebleeding.^20,21 Long-term follow-up is essential to monitor for recurrence or late complications; imaging surveillance with Doppler ultrasound or CTA at 3–6 months and annually for 2–3 years is recommended, particularly in patients with coagulopathies or incomplete embolization. A multidisciplinary approach is essential for optimal outcomes, particularly in complex cases involving bleeding, coagulopathy, or failed prior treatment. Neurosurgeons, interventional radiologists, plastic surgeons, and hematologists should collaborate to tailor individualized and definitive treatment plans.

Lessons

This case is unique in combining several high-risk factors rarely reported together: an acutely ruptured cirsoid aneurysm, severe thrombocytopenia, and failed endovascular embolization due to prohibitive vessel tortuosity. These conditions created an urgent, complex surgical scenario in which the risks of uncontrolled hemorrhage were compounded by coagulopathy and the absence of a viable minimally invasive option. A successful outcome was achieved through rapid multidisciplinary coordination—integrating neurosurgical expertise for definitive nidus excision, hematological optimization with targeted transfusion support, and reconstructive planning to preserve scalp integrity.

The experience highlights that in select, high-risk patients, prompt surgery can be lifesaving even when standard preoperative embolization is not possible. It reinforces the importance of maintaining surgical readiness for scalp AVMs, recognizing rupture as a neurosurgical emergency, and adapting treatment plans to comorbidities without compromising the goal of complete lesion removal.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: De Paulis, Catapano, Di Vitantonio, Luzzi, Dehcordi, Ricci, Galzio. Acquisition of data: De Paulis, Di Vitantonio, Luzzi, Gallieni, Dehcordi, Ricci. Analysis and interpretation of data: De Paulis, Di Vitantonio, Luzzi, Dehcordi, Ricci. Drafting the article: De Paulis, Ricci. Critically revising the article: all authors. Reviewed submitted version of manuscript: De Paulis, Di Vitantonio, Luzzi, Gallieni, Dehcordi, Galzio. Approved the final version of the manuscript on behalf of all authors: De Paulis. Administrative/technical/material support: Di Vitantonio. Study supervision: all authors.

Correspondence

Danilo De Paulis: Hospital of the Sea, Naples, Italy. d.depaulis@alice.it.