CC BY-NC-ND 4.0 · Asian J Neurosurg 2022; 17(04): 672-675
DOI: 10.1055/s-0042-1757222
Case Report

A Case of Pseudoaneurysm of the Superficial Temporal Artery Causing a Massive Subcutaneous Hematoma after Craniotomy

Masaki Tatano
1   Department of Neurosurgery, Kagawa Rosai Hospital, Marugame, Kagaw, Japan
,
Seiya Hayashi
1   Department of Neurosurgery, Kagawa Rosai Hospital, Marugame, Kagaw, Japan
,
Masatoshi Yunoki
1   Department of Neurosurgery, Kagawa Rosai Hospital, Marugame, Kagaw, Japan
,
Michiari Umakoshi
1   Department of Neurosurgery, Kagawa Rosai Hospital, Marugame, Kagaw, Japan
,
Koji Hirashita
1   Department of Neurosurgery, Kagawa Rosai Hospital, Marugame, Kagaw, Japan
,
Kimihiro Yoshino
1   Department of Neurosurgery, Kagawa Rosai Hospital, Marugame, Kagaw, Japan
› Author Affiliations
 

Abstract

We present a case of a ruptured pseudoaneurysm of the superficial temporal artery (STA) after surgery for intracranial hemorrhage. To our knowledge, only three similar cases have been reported. A 47-year-old man underwent left frontal craniotomy for a left frontal subcortical hematoma. The left STA was not identified during the surgery, and no STA bleeding was observed. The postoperative course was uneventful for 20 days, until the patient experienced a left-side headache and noticed a subcutaneous mass. The mass increase in size within 1 hour and arterial hemorrhage was observed through a tear in the wound. Findings on subsequent contrast computed tomography were consistent with a ruptured pseudoaneurysm arising from the left STA. Emergency evacuation of the hematoma and STA ligation were performed. Pathological findings were consistent with a pseudoaneurysm. STA pseudoaneurysms occasionally grow rapidly and can cause massive hematoma. Surgeons should carefully monitor for evidence of a pseudoaneurysm after craniotomy, even in the absence of intraoperative bleeding from the STA.


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Introduction

A superficial temporal artery (STA) pseudoaneurysm after a craniotomy is rare, with only 16 cases reported in the literature—the majority of these were found in subcutaneous pulsatile and painless masses.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] Herein, we report a case of an STA pseudoaneurysm with severe subcutaneous bleeding after craniotomy, and provide a review of the literature. To our knowledge, only three similar cases have been reported.[6] [9] [10]


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Case History

A 47-year-old man with a history of hypertension was brought to the emergency department of our hospital due to sudden onset of headache, right hemiparesis, and consciousness disturbance (20 JCS: Japan Coma Scale).

On arrival, the head computed tomography (CT) scan showed a left subcortical hemorrhage ([Fig. 1A]). Craniotomy was performed on the same day.

Zoom Image
Fig. 1 (A) Axial image of head computed tomography on admission. Intracranial hematoma was detected in the left frontal lobe. (B, C) Photographs before the second surgery. Severe subcutaneous swelling was identified in the left frontal region (▲). The superficial temporal artery (STA) was palpable on the occipital side of the skin incision (—). A pulsative portion of the subcutaneous mass was identified on the frontal side of the STA (△). A pulsatile portion of the mass was identified on the frontal side of the STA.

For the first surgery, a coronal skin incision was made, and a right frontal craniotomy was performed. A microscope was introduced to aid removal of the hematoma located directly below the craniotomy. For skin closure, a 3–0 absorbent thread (Vicryl plus 3.0; Ethicon Co., Somerville, New Jersey, USA) was used subcutaneously, while a stapler was used superficially. During the period from skin incision to closure, the left STA was preserved posterior to the skin incision, and the surgery was completed without damage to the STA.

The postoperative course was good, with mild paralysis of the right upper and lower limbs and clear consciousness. Normal blood pressure was maintained by oral administration of a calcium channel blocker. The surgical wound was in good condition, and the hooks were removed on the 7th postoperative day. On the 20th day after surgery, the patient noted pain and swelling of the wound, despite no prior reports of wound swelling. The swelling gradually worsened within 1 hour, the sutures tore, and bleeding was observed. An emergency head CT scan (plain and contrast) revealed a 13 × 21 × 22 mm aneurysm in the parietal branch of the left STA with a marked subcutaneous hematoma ([Fig. 1B,C]). Because the patient experienced a severe headache, emergency surgery was performed. There were no abnormal findings on preoperative blood tests, including blood coagulation and fibrinolysis function.

At surgery, the STA was palpable caudal to the prior skin incision ([Fig. 2A]). Additionally, a pulsating spot was observed on the frontal side of the STA within the area of severe head swelling ([Fig. 2A,B]). This area was considered to be a pseudoaneurysm ([Fig. 2A]). The skin incision was extended caudally, and the STA was identified. During removal of as much of the hematoma as possible, arterial bleeding was observed from the hematoma area. Thus, the secured STA was temporarily blocked and the prior skin incision was fully opened to sufficiently remove the hematoma. The STA was then traced distally, and was found to be disrupted within the hematoma, with the distal end identified nearby. Both ends were collected for pathology and ligated with silk thread.

Zoom Image
Fig. 2 An axial (A) and coronal (B) view of gadolinium-enhanced computed tomography (CT) before the second surgery showing a left subcutaneous hematoma (↓). A pool of contrast medium (⇩) was identified in the hematoma, which was consistent with a pseudoaneurysm. (C) Three-dimensional CT angiography revealed a pool of contrast medium arising from the left superficial temporal artery.

Pathology showed true blood vessels with elastic fibers ([Fig. 3A,B]). Membranous tissue with calcification consisting of some fibrous tissue was also observed ([Fig. 3A,B]). The area was diagnosed as a pseudoaneurysm because elastic fibers were not identified.

Zoom Image
Fig. 3 Histopathological examination of the surgical specimen. (A) Hematoxylin and eosin staining (×40 magnification). (B) Elastica van Gieson staining (×40 magnification). In the true vessel wall, internal elastic fibers were identified by Elastica van Gieson staining (▲). The area of the membranous tissue was diagnosed as a pseudoaneurysm because no elastic fibers were identified (△).

After the second surgery, the patient's headache improved, and the hooks were removed on the 7th day. There was no recurrence of subcutaneous swelling. The patient was transferred to a rehabilitation hospital at 14 days after the second surgery.


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Discussion

In head and neck aneurysms, the frequency of STA pseudoaneurysms was reported as 0.5 to 2.5%,[17] of which approximately 75% were caused by blunt head trauma.[18] This is because the STA runs just below the scalp, on top of the hard skull, making it vulnerable to trauma.[17] [18] Damage to the arterial wall can result in hematoma formation beneath the scalp, while in some cases blood flow may remain between the hematoma cavity and the vessel lumen. In this condition, the hematoma is absorbed and a fibrous coating develops around it, forming a pseudoaneurysm.[17] [18] Histological findings in our case showed evidence of true blood vessels and fibrous tissue, without elastic fibers, in the excised area, which was consistent with a pseudoaneurysm.

Reports of pseudoaneurysms after craniotomy are rare, with only 16 cases in the literature ([Table 1]).[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] Reported causes of STA damage include subcutaneous suture needles, hook retractor, or three-point pin fixators.[6] [7] [8] [13] [16] Systemic diseases including hemophilia or vasculitis, and background such as triple H therapy after subarachnoid hemorrhage, are also risk factors for pseudoaneurysms.[6] [9] [11] [12] Furthermore, even if there is only endothelial damage without bleeding, surgical manipulation or electrocoagulation may lead to formation of fusiform dilatation and subsequent minor bleeding, resulting in pseudoaneurysm formation.[1] [5] [8] [13] In our case, the STA was not injured during surgery and was clearly distant from the site of the Mayfield 3-point pin fixator. Thus, the pseudoaneurysm in present case may have resulted from microtrauma to the intima caused by surgical manipulation or electrocautery.[1] [3] Alternatively, the STA may have been injured during subcutaneous closure, resulting in a small unnoticed bleed that caused the pseudoaneurysm.[1] [5] [8] [13]

Table 1

Reported cases of pseudoaneurysm of the STA after craniotomy

Author

Sex

Age

Cause of craniotomy

Cause of STA injury

Duration (days)[a]

Rupture of pseudoaneurysm

Treatment

Shimoda et al (1988)[11]

Male

17 yo

Removal of intracranial hematoma

Unknown

40

No

Embolization

Fernández-Portales et al (1999)[4]

Male

51 yo

Clipping for ruptured aneurysm

Pin head holder

35

+

Extirpation

Tsutsumi et al (2000)[13]

Male

48 yo

Clipping for ruptured aneurysm

Possibly suture needle

40

No

Extirpation

Lee et al (2002)[8]

Male

52 yo

Clipping for ruptured aneurysm

Possibly suture needle

110

No

Extirpation

Hakan et al (2011)[5]

Female

58 yo

Clipping for ruptured aneurysm

Unknown

4 d

No

Extirpation

Bobinski et al (2004)[2]

Male

74 yo

Clipping for ruptured aneurysm

Unknown

17

No

Injection of thrombin glue

Wang et al (2011)[14]

Male

28 yo

Clipping for ruptured aneurysm

Possibly suture needle

25

No

Extirpation

Terterov et al (2012)[12]

Male

31 yo

Clipping for ruptured aneurysm

Possibly suture needle (triple H)

22

No

Coil embolization andsealed with liquid Onyx

Kobayashi et al (2013)[7]

Female

41 yo

Microvascular decompression

Pin head holder

71

No

Extirpation

Honda et al (2013)[6]

Male

57 yo

Clipping for ruptured aneurysm

Possibly suture needle (triple H)

1

+

Emergency surgery

Wright et al (2015)[15]

Male

78 yo

Removal of meningioma

Unknown

21

No

Coiling

Madhusudan et al (2015)[9]

Male

57 yo

Removal of high-grade glioma

Possibly suture needle (vasculitis)

8

+

Emergency surgery

Anania et al (2018)[1]

Unknown

3 wo

Surgery for craniosynostosis

Unknown

17

No

Extirpation

Entezami et al (2019)[3]

Male

83 yo

Removal of high-grade glioma

Unknown

Na

+

Embolized and surgery

Zheng et al (2021)[16]

Male

36 yo

Removal of epidural hematoma

Fish hook retractor

1

No

Extirpation

Shields et al (2021)[10]

Male

38 yo

Surgery for cerebrospinal fluid leak repair

Unknown

14

+

Emergency surgery

Present case

Male

47 yo

Removal of intracranial hematoma

Unknown

20

+

Emergency surgery

Abbreviations: STA, superficial temporal artery; wo, weeks old; yo, years old.


a The duration until the subcutaneous mass was identified after surgery.


The risk factors and probability of pseudoaneurysm rupture are unknown. Nevertheless, massive bleeding was reported in 4 of 16 cases of pseudoaneurysm after craniotomy (25%),[6] [9] [10] which is not uncommon. In these four cases of massive hemorrhage, including the present case, no obvious pulsatile mass was observed prior to the pseudoaneurysm rupture. However, this may be because careful monitoring for pseudoaneurysm formation was not performed after the first surgery. Thus, careful monitoring of the wound after craniotomy may allow for earlier and less invasive treatment.


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Conclusion

Pseudoaneurysms of the STA after craniotomy may result in a severe subcutaneous hematoma that requires surgical removal. After craniotomy, the patient should be carefully monitored for the appearance of pseudoaneurysms in the surgical wound, even if there is no intraoperative bleeding from the STA.


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Conflicts of Interest

None declared.

Ethical Approval

The report was approved by the institutional review board of Kagawa Rosai Hospital (R2–9). The patient provided written informed consent for this case report.


Address for correspondence

Masatoshi Yunoki, MD, PhD
Department of Neurosurgery, Kagawa Rosai Hospital
3-3-1 Joto-cho, Marugame, Kagaw, 763-8502
Japan   

Publication History

Article published online:
15 December 2022

© 2022. Asian Congress of Neurological Surgeons. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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Zoom Image
Fig. 1 (A) Axial image of head computed tomography on admission. Intracranial hematoma was detected in the left frontal lobe. (B, C) Photographs before the second surgery. Severe subcutaneous swelling was identified in the left frontal region (▲). The superficial temporal artery (STA) was palpable on the occipital side of the skin incision (—). A pulsative portion of the subcutaneous mass was identified on the frontal side of the STA (△). A pulsatile portion of the mass was identified on the frontal side of the STA.
Zoom Image
Fig. 2 An axial (A) and coronal (B) view of gadolinium-enhanced computed tomography (CT) before the second surgery showing a left subcutaneous hematoma (↓). A pool of contrast medium (⇩) was identified in the hematoma, which was consistent with a pseudoaneurysm. (C) Three-dimensional CT angiography revealed a pool of contrast medium arising from the left superficial temporal artery.
Zoom Image
Fig. 3 Histopathological examination of the surgical specimen. (A) Hematoxylin and eosin staining (×40 magnification). (B) Elastica van Gieson staining (×40 magnification). In the true vessel wall, internal elastic fibers were identified by Elastica van Gieson staining (▲). The area of the membranous tissue was diagnosed as a pseudoaneurysm because no elastic fibers were identified (△).