Congenital True Aneurysm of the Right Superficial Temporal Artery.

INTRODUCTION: Superficial temporal artery aneurysms (STAAs) occur in 1% of arterial aneurysms; mostly (95%) are pseudoaneurysms following trauma; true aneurysms are rare (5%); forty-five cases are reported. AIM: To report a rare case of a congenital STAAA. CASE REPORT: A67-year-old patient recalled the existence of a true-histologically evidenced- aneurysm of the right superficial temporal artery since his childhood denying any head injury; it was resected through a horizontal skin incisure. Brain arteries' magnetic imaging was negative.
CONCLUSION: Spontaneous or congenital STAAs have to be removed respecting forehead lines. Intracranial vasculature must be investigated.

INTRODUCTION

Superficial temporal artery aneurysm (STAA) is an apparent, pulsatile, commonly painless, swelling under the skin, over the route of STA. Its excision is dictated to prevent bleeding, or for cosmetic reasons, as in this case.

AIM

To report a rare case of a STAA along with a review of the literature are discussed.

CASE REPORT

A 67-year-old man recalls a painless, pulsatile swelling at the right forehand over the eyebrow, since his childhood, denying any head trauma; its size 4cm in length and 2 cm in width) remained the same for many decades. No nerve dysfunction existed. Proximal STA compression resulted in pulse elimination and minimization of the arterial Doppler signal. The aneurysm was excised under general anesthesia, following a horizontal and curved at its lateral end, skin incision. Both artery’s ends were ligated using 3.0 silk suture. The temporal muscle was repaired with 4.0 polyglactin suture. Semi-mattress stitches (4.0 nylon) used for skin closure, were removed on the 4th postoperative day. The patient was discharged some hours following surgery with no postoperative local circulatory deficiency nor any nerve dysfunction (Figure 1).

Figure 1.

Superficial temporal artery aneurysm at the right temporal region, before surgery,after excision and at the 4th postoperative day

Histology revealed that all three arterial wall layers were intact with partial atherosclerotic changes, defining the lesion as a true STAA (Figure 2). Brain magnetic resonance angiography (MRA) was negative (Figure 3).

Figure 2.

Histology of the superficial temporal artery aneurysm

Figure 3.

Magnetic resonance angiography of the brain vasculature was negative

DISCUSSION

Since the first STAA case reported by Bartholin in 1740, most STAAs are pseudoaneurysms (95%) usually occurring in young men and elderly people, after accidental falls, due to the shallow STA route. While according to Delen1,approximately 400 posttraumatic STA pseudoaneurysms are reported, only 34 true aneurysms are published. The etiology includes atherosclerosis, usually met in the elderly, occasionally with hemodynamic wall stress (1-3). Congenital arterial wall defects due to arterial elastic membrane alterations, seems to be a primary cause for true aneurysms; according to Kawai (4) there is a high ratio of patients under 20 years of age with spontaneous STAAs; this strengthens the congenital component (1, 2). In the case of the patient we present here, we assume that his true aneurysm was congenital due to his history- a fast flow malformation, according to Hamburg classification (3).

Superficial TAAs appear equally in both sexes; few are painful or accompany other extracranial or intracranial aneurysms (Table 1) (1, 2, 4, 5-20). Few are related to subarachnoid hemorrhage and intracranial aneurysms, to Ehlers-Danlos and Marfan syndromes, or multicystic kidney (1, 2). Intracranial vessel investigation is justified in patients with true STAAs (2).

Table 1.

Reported cases of true superficial temporal artery aneurysms (1,2,4-7,10-33). NR: No reference, W:Woman. M:Man, ECA:External carotid artery, STA: Superficial temporal artery, OA: Occipital artery

A/A	Author/Year	Age/Sex	Pain	Size increase	Other aneurysms
1	Brown & Mehner/19425	34/M	No	Yes	No
2	Martin & Shoemaker/ 19556	60/M	No	Yes	No
3	Yonetani et al/19556	63/W	No	Yes	No
4	Tamaki & Matsumoto/19807	57/M	Yes	Yes	No
5	Suzuki et al/19807	13/W	No	Yes	No
6	Buckspan & Rees/19867	70/M	No	Yes	No
7	Nishioka et al/19888	14/M	No	Yes	No
8	Ezoe et al/19888	22/M	Yes	Yes	No
9	Ikeda & Watanabe/19988	15/M	No	Yes	No
10	Uchida & Sakuma/19999	34/M	No	Yes	No
11	Endo et al/20009	85/M	No	Yes	No
12	Porcellini et al/20019	24/W	No	No	No
13	Ohta et al/200310	55/M	No	No	Intracranial
14	Riaz/200410	65/M	No	Yes	No
15	Riaz/200410	77/M	No	No	No
16	Ysa et al/20084	59/W	Yes	Yes	No
17	Kawabori et al/200911	78/W	No	Yes	No
18	Piffaretti/200911	62/W	No	No	No
19	Piffaretti/200911	47/M	No	Yes	STA
20	Karam et al/201011	34/W	No	Yes	No
21	Sakamoto/201112	77/W	No	Yes	No
22	Bozkurt et al/201113	62/M	Yes	No	No
23	Nair et al/201114	84/W	No	No	No
24	Mousa et al/201115	72/W	No	Yes	No
25	Moriyama et al/201116	67/W	No	Yes	No
26	Park et al/201217	57/W	No	Yes	No
27	Sloane et al/201311	32/M	No	Yes	No
28	Kawai et al/20142	65/M	No	Yes	Intracranial
29	Kawai et al/20142	76/W	No	No	No
30	Kawai et al/20142	57/W	No	Yes	ECA, STA, OA
31	Pejkic et al/201418	NR	Yes	Yes	No
32	Kim/201419	44.7/6W/6M	No	Yes	STA
33	Zivkovic et al/20151	20/M	No	Yes	No
34	Delen et al/20161	79/W	No	No	Intracranial
35	Kotsis et al/2017	67/M	No	No	No

Commonly, patients with STAAs present with a pulsatile painful or nonpainful mass at some point along the artery, throbbing headache or ear discomfort or with dizziness, bleeding, or rarely neurologic deficits, as facial nerve paralysis (1, 2, 4).

Differential diagnosis includes lipoma, hematoma, lymphadenopathy, supraorbital nerve neuroma, dural arteriovenous fistula, arteritis, cysts, neoplastic disease as facial nerve schwannoma, parotid gland tumor, meningocele, pericranial sinus and subcutaneous abscess (2, 4). Occasionally STAA resembles a parotid mass involving the facial nerve, that may require superficial parotidectomy (1).

Diagnosis is confirmed by history, physical examination, Doppler study, and imaging such as ultrasonography; studies such as CTA, 3D-CTA and MRA may be used to identify the lesion and to investigate other intracranial lesions. Needle aspiration or core biopsy of the artery must be avoided (4, 11).

The risk of sudden rupture and bleeding of a STAA is a concern; though no similar case has been published as the forehead skin is thick and firm; most STAAS are removed before rupture due to their early detection; aesthetical improvement, pain or discomfort are reasons for treatment. Although no criteria/guidelines are established, surgery is the gold standard, with a skin incision that respects the skin lines as in this presented case; the parallel to frontal lines incision followed by cranial and caudal arterial resulted in scar elimination. Excision, and feeders’ ligation is recommended; no vessel reconstruction is necessary. Super selective catheter embolization with glue or thrombin injection has been used where the depth of the artery or its contiguity to the facial nerve and the parotid gland complicate surgery; however, there is the risk of embolism and the less cosmetic result due to the remnant thrombosed aneurysm (4, 7, 11).

CONCLUSION

Congenital STAAs have to be resected, as all removable congenital malformations. Spontaneous or post traumatic STAAs have also to be removed to avoid complications or discomfort. Skin incisions have to respect forehead/temporal skin lines. Intracranial vasculature must be investigated.