**3. Extracranial infectious aneurysms**

Pseudoaneurysm of the cervical portion of the internal carotid artery (ICA) is rare but potentially lethal complication of the deep neck infection. Liston was the first to describe pseudoaneurysm in this area in 1843 (Liston,1843). In 1933, Salinger and Pearlman (Salinger & Pearlman, 1933) published a set of 228 pseudoaneurysm cases. This has been the largest group of patients ever reported. Since the introduction of antibiotic treatment, less than 40 pseudoaneurysm cases have been described. In spite of significant advances in the treatment of ICA pseudoaneurysm, this condition is associated with a poor prognosis.

In addition to the systemic antibiotics treatment, surgical management may include ligation of the aneurysm with or without preserving the adjacent vessel wall and an end-to-end anastomosis of the carotid artery. An acceptable alternative treatment to surgery is a stentgraft or bare stent implantation with/without coil embolisation.

#### **4. Selective cases**

#### **4.1. Case No. 3**

332 Aneurysm

methemoglobine

**A,B** MRI + MRA: Pd T2, MRA axial plane confirmed little area of haemorrhage in the left opercular area, deposits of

**C**

**A B**

**C,** Based on MRA scan, suspicion of pseudoaneurysm in the region of M2,3 segment of the left MCA was confirmed.

**Figure 6.** MRI/MRA diagnostic scan for seizure and headache.

A 56- year-old male, who suffered for one month from sore throat, dysphagia, and left neck stiffness. Parapharyngeal phlegmona was detected on both ultrasound and CT scan, explorative surgery was performed and the patient was put on antibiotics treatment. Ten days later, the patient returned with a painful bulge on his neck. A parapharyngeal abscess

was confirmed on CT scan, with subsequent surgical drainage. The infectious agent cultured from the specimen was Staphylococcus species. Five days later, a small fistula in the lower pole of the surgical scar evolved. Prompt follow- up CT scan revealed pseudoaneurysm at the level of the left carotid bifurcation, 18 mm in size (Fig. 10).

**A B**

**C**

**A,** Selective angiogram before pseudoaneurysm embolisation. Microcatheter is positioned just below the pseudoaneurysm.

**B,** Follow-up angiography after embolisation AP view, pseudoaneurysm exclusion. **C,** 3D-XRA reconstruction after embolisation.

**Figure 8.** Parent artery occlusion embolisation procedure

**Figure 9.** Follow-up MRA

pseudoaneurysm.

**C,** 3D-XRA reconstruction after embolisation.

was confirmed on CT scan, with subsequent surgical drainage. The infectious agent cultured from the specimen was Staphylococcus species. Five days later, a small fistula in the lower pole of the surgical scar evolved. Prompt follow- up CT scan revealed pseudoaneurysm at

**A B**

**A,** Selective angiogram before pseudoaneurysm embolisation. Microcatheter is positioned just below the

**C**

**B,** Follow-up angiography after embolisation AP view, pseudoaneurysm exclusion.

**Figure 8.** Parent artery occlusion embolisation procedure

the level of the left carotid bifurcation, 18 mm in size (Fig. 10).

**A,** Contrast enhanced CT scan in axial view showing large retropharyngeal inflammation with pseudoaneurysm in the bifurcation of the left common carotid artery. **B,** CT scan in MIP projection with large pseudoaneurysm filling

**C,** CT scan in VRT reconstruction with pseudoaneurysm

#### **Figure 10.** Initial CT scan confirming inflammation and pseudoaneurysm

The vascular surgeon and interventional radiologist were consulted and endovascular approach was agreed upon, as the best treatment option at that particular case. The pathological finding was verified with 3D angiography and two interpolated Wallstents 8/29 (Boston Scientific, USA) were implanted into CCA-ICA region (Fig.11,12). Immediate contrast agent stagnation in the pseudoaneurysm sac was observed. The patient was put on Dalteparine, with the dose of 5000 units per day, which was later followed with dual antiplatelet regime. Dual combination of antibiotics was used (cefotaxime and metronidazole) for prolonged treatment.

**A,** 3D-XRA reconstruction with MIP projection of the left CCA bifurcation pseudoaneurysm.


#### **Figure 11.** Stenting procedure

**A,** Follow-up CT scan after Wallstent implantation in axial view.

**B,** CT scan in MIP projection after stent implantation-exclusion of pseudoaneurysm.

**C,** CT scan in VRT lateral view with normal perfusion in carotid bifurcation.

**Figure 12.** Follow-up CT scan after stenting procedure with aneurysm exclusion.

**A,B** Normal Wallstent perfusion with pseudoaneurysm thrombosis

**Figure 13.** Ultrasound duplex Doppler follow-up.

The local finding on the vessels was followed with intense ultrasound exams and over the time period of one month, the lesion healed completely with normal carotid vessels patency (Fig. 13).

#### **4.2. Case No. 4**

336 Aneurysm

**A,** 3D-XRA reconstruction with MIP projection of the left CCA bifurcation pseudoaneurysm.

**A B C**

**A B C**

**A B**

**B,** Contrast stagnation in pseudoaneurysm after stenting procedure.

**A,** Follow-up CT scan after Wallstent implantation in axial view.

**A,B** Normal Wallstent perfusion with pseudoaneurysm thrombosis

**Figure 13.** Ultrasound duplex Doppler follow-up.

**B,** CT scan in MIP projection after stent implantation-exclusion of pseudoaneurysm. **C,** CT scan in VRT lateral view with normal perfusion in carotid bifurcation.

**Figure 12.** Follow-up CT scan after stenting procedure with aneurysm exclusion.

**C,** Two interpolated Wallstents implanted in ICA-CCA

**Figure 11.** Stenting procedure

A 17-year-old male with a 5-day history of sore throat, difficult swallowing, pain in the left ear, fever and trismus was examined with CT scan (Fig.14)**.** Inflammation of the left tonsil spreading into the left retrotonsillar and carotid space was confirmed. Laboratory values showed C-reactive protein (CPR) of 175 mg/l and white blood cell count (WBC) of 13,5 x 109/l. Due to worsening of clinical symptoms and continuing fever, an acute tonsillectomy was indicated and tonsillar culture confirmed Neisseria species and Streptoccocus viridans. The patient was discharged on oral Augmentin (Amoxicillinum trihydras and Acidum clavulanicum, Smith Kline Beecham Pharmaceuticals, Worthing, Great Britain) five days later. Laboratory results showed CRP 49 mg/l and WBC 5,8 x 109/l.

**Figure 14.** Axial CT scan confirmed an enlarged left tonsil, with an inhomogeneous saturation after i.v. contrast administration. Defiguration of swallowed air-ways and small abscess signs in tonsillar and retrotonsillar space were observed.

**Figure 15.** The CT scan shows a large area of pseudoaneurysm in the left retrotonsillar space with a high density.

The patient was readmitted one month later, with a severe pain in the left side of his throat and progressive headache. CT scan was performed with administration of 80 ml of a non-ionic contrast media at a 3.5 ml/s flow rate. A large left ICA pseudoaneurysm was revealed as 18x33 mm dense area in the left retrotonsillar space, extending into the left temporomandibular joint (Fig.15). A vascular surgeon was consulted. However, due to inaccessibility of the skull base pseudoaneurysm, the endovascular treatment was selected as a more feasible approach.

Pseudoaneurysm of the left ICA was visualised (Fig. 16A) and carotid bare Wallstent 7 x 40 mm (Boston Scientific, USA) was promptly implanted into the left ICA. A second angiogram 5 minutes later showed a reduction of the pseudoaneurysm perfusion (Fig 16B)**.** The treatment with Plavix 75 mg and ASA100mg / once a day was continued four weeks. Amoxicillin (Amoxicilinum natricum, Lek Pharmaceuticals, Slovakia) and Klimicin (Klindamycin, Lek Pharmaceuticals, Slovakia) were administered for four weeks. The follow up angiogram in four weeks showed an excellent ICA patency and no pseudoaneurysm filling (Fig 16C)**.** CRP was 17 mg/l, WBC was normal. Patient was discharged doing well.

**A,** Angiogram of the left common carotid artery confirmed a large pseudoaneurysm at the level of the scull base. **B,** The Wallstent immediately after the implantation in the left internal carotid artery. **C,** Follow-up angiography after one month confirmed a healed left ICA (C).

**Figure 16.** Procedure and follow-up angiogram

#### **5. Discussion**

Church was the first one to describe an infectious aneurysm in a 13-year-old boy with mitral valve endocarditis in 1869. It has been estimated that infectious aneurysms develop in 3-15% of patients with infectious endocarditis. Intracranial aneurysms are rare in children, accounting for merely 0.5-4.6% of all aneurysms. Several characteristics distinguish them from aneurysms in adults: male predominance; higher incidence of unusual location, such as peripheral or posterior circulation, and a greater count of large or giant aneurysms. These unique features can be attributed to the higher incidence of traumatic, infectious, developmental, and congenital lesions. Subarachnoid haemorrhage is not the exclusive mode of presentation. Neuro-compressive signs and symptoms are frequently observed (Kanaan et al.,1995).

Infectious intracranial pseudoaneurysms develop mostly from the circulating infectious material. The source of this material is obviously located in cardiac valves. Infectious emboli lodges in small distal cerebral arteries and occludes distal arterial flow. Consequently, intense inflammation in the media and adventitia destroys the integrity of the arterial wall and weakens it. The resulting aneurysms are mostly fusiform, eccentric or typical pseudoaneurysms (Chun et al.,2001;Molinari et al.,1973).

338 Aneurysm

The patient was readmitted one month later, with a severe pain in the left side of his throat and progressive headache. CT scan was performed with administration of 80 ml of a non-ionic contrast media at a 3.5 ml/s flow rate. A large left ICA pseudoaneurysm was revealed as 18x33 mm dense area in the left retrotonsillar space, extending into the left temporomandibular joint (Fig.15). A vascular surgeon was consulted. However, due to inaccessibility of the skull base pseudoaneurysm, the endovascular treatment was selected as a more feasible approach.

Pseudoaneurysm of the left ICA was visualised (Fig. 16A) and carotid bare Wallstent 7 x 40 mm (Boston Scientific, USA) was promptly implanted into the left ICA. A second angiogram 5 minutes later showed a reduction of the pseudoaneurysm perfusion (Fig 16B)**.** The treatment with Plavix 75 mg and ASA100mg / once a day was continued four weeks. Amoxicillin (Amoxicilinum natricum, Lek Pharmaceuticals, Slovakia) and Klimicin (Klindamycin, Lek Pharmaceuticals, Slovakia) were administered for four weeks. The follow up angiogram in four weeks showed an excellent ICA patency and no pseudoaneurysm filling (Fig 16C)**.** CRP was 17 mg/l, WBC was normal. Patient was discharged doing well.

**A,** Angiogram of the left common carotid artery confirmed a large pseudoaneurysm at the level of the scull base.

**A B C**

Church was the first one to describe an infectious aneurysm in a 13-year-old boy with mitral valve endocarditis in 1869. It has been estimated that infectious aneurysms develop in 3-15% of patients with infectious endocarditis. Intracranial aneurysms are rare in children, accounting for merely 0.5-4.6% of all aneurysms. Several characteristics distinguish them from aneurysms in adults: male predominance; higher incidence of unusual location, such as peripheral or posterior circulation, and a greater count of large or giant aneurysms. These unique features can be attributed to the higher incidence of traumatic, infectious, developmental, and congenital lesions. Subarachnoid haemorrhage is not the exclusive mode of presentation.

Neuro-compressive signs and symptoms are frequently observed (Kanaan et al.,1995).

**B,** The Wallstent immediately after the implantation in the left internal carotid artery. **C,** Follow-up angiography after one month confirmed a healed left ICA (C).

**Figure 16.** Procedure and follow-up angiogram

**5. Discussion** 

Management of the therapy requires multimodality approach. Basically, there exist three possible options. The first one is a medical management of an unruptured infectious pseudoaneurysm with a long course of intravenous antibiotic therapy. This period is usually 6 weeks but may be longer, depending on the impairment of the host immunity. Endovascular therapy is the first line option for patients with ruptured aneurysms. It is a safer, elegant method which decreases the risk of aneurysm rerupture and makes the possible subsequent surgical treatment more safe. In case of multiple aneurysms, there is a benefit of treating more lesions at the same time. Surgical management is the first option for patients in unstable condition, with large intraparenchymal hematoma and increased ICP. The most common location for surgically treated aneurysms is the MCA territory (Lasjaunias et al.,2005;Lasjaunias & Ter Brugge,1997;Rodesch et al.,1987).

Patients with a history of drug abuse desoxyephedrine (Pervitine), cocaine, heroin etc. are frequently affected with brain haemorrhage. These drugs are stimulating. Drugs potentiates dopamine production, which leads to euphoria and high energy, it also suppresses starvation. This drug leads to sympathetic hyperactivity-induced transient hypertension (Gavin,1991;Grinspoon & Bakalar,1981;Lichtenfeld et al.,1984). Hypertension is a predisposing factor for the development and rupture of vulnerable vessels or infectious pseudoaneurysms, which occur more often in drug addicted persons.

Desoxyephedrine, cocaine and its metabolites have been proved as potent cerebral vasoconstrictors (Madden & Powers,1990). In animal models and in human volunteers it was demonstrated that even at a low dose, desoxyephedrine and cocaine can induce cerebrovascular dysfunction and cumulative residual effect in which repeated desoxyephedrine exposure produces delayed and/or prolonged formation and growth of an aneurysm, together with narrowing of vessels. In vivo duration of desoxyephedrine and cocaine-induced vasospasm is unclear (Jain,1963;Nanda et al.,2000). Patients with drugrelated aneurysms reportedly have a higher mortality rate than a group of patients with no history of drug abuse.

Pseudoaneurysm of the ICA at the extracranial segment is a rare complication of deep neck area infections, penetrating trauma, tumour invasion and/or radiotherapy. Compared to a true aneurysm, the pseudoaneurysms has no complete native arterial wall. It is composed of extravasated blood that leaked from the area of vessel erosion and is surrounded by inflammatory and fibrous tissues. Pseudoaneurysms of ICA are more frequent in paediatric population. Children are more susceptible to arteritis (Cohen & Rad.,2004). Infection can reach the wall of the carotid artery following a peritonsillar abscesses or pharyngitis. Another pathway for infection may be septicaemia and invasion of the vasa vasorum.

Other possible causes of pseudoaneurysms are penetrating wounds or iatrogenic spread of infection after catheterisation (Alexander et al.,1968; Liston.,1843). The pseudoaneurysms is most likely seen as a result of tonsillitis-induced parapharyngeal abscess, reaching the left ICA adventitia. In our case, ischemia of the carotid artery wall led to its rupture and subsequent development of pseudoaneurysms. We could not exclude a perioperative trauma of ICA during emergency tonsillectomy. Usual bacterial agents causing pseudoaneurysms are *Staphylococcus aureus or Streptococcus pyogenes* (Gralla et al.,2004)*.*

A mycotic carotid pseudoaneurysms most likely present as a growing, pulsatile cervical mass, manifested with dysphagia, odynophagia, and fever. Less frequently, lower cranial nerve palsies, Horner' s syndrome or trismus may occur. Severe and life-threatening complications may include a carotid artery rupture, intermittent massive nasopharyngeal haemorrhage, and septic or non-septic embolic events leading to a neurological deficit. The usual interval between the infection and the pseudoaneurysms development is between 2 and 8 weeks. The treatment of carotid artery pseudoaneurysms is complex. The typical management of an infected pseudoaneurysms is twofold: systemic antibiotic administration (predominantly penicillin or clindamycin) and/or surgery, with either a traditional by-pass, or a ligation of ICA (Gralla et al.,2004; Heyd & Yinnon,1994; Jebara et al.,1991; Naik et al.,1995). Endovascular therapy of a non-infected and infected carotid artery pseudoaneurysms has been increasingly used (Gralla et al.,2004; Oishi et al.,2002). With this treatment, the ICA lumen may be better preserved. Several approaches are available.

The novel technique "parent artery occlusion" is achieved by positioning detachable balloons distally and proximally to the lesion (Serbinenko,1974). However, this approach demands preliminary evaluation of the collateral pathways in the circle of Willis. The occlusion test requires the patient to be awake, in order to monitor possible neurological deficits. The inherent risk of the occlusion test includes development of neurological deficits and/or failure to identify a delayed ischemia. Another endovascular approach preserving the carotid artery lumen is a stent or stent-graft implantation with/or without a coil deposition to the pseudoaneurysms. Since the pseudoaneurysms lacks a true arterial wall, the potential risk of the coils compaction and dislocation is always present. A simple stent or a stent-graft implantation is regarded to be the most effective and faster treatment (Glaiberman et al.,2003;Schonholz et al.,2006).

Choice of the endovascular treatment is mainly influenced by the unfavourable deep location of the pseudoaneurysms nearby the skull base, thus making the conventional surgery more risky. We can initially chose between an uncovered bare stent or two overlapping stents, rather than a covered stentgraft, to minimize the amount of foreign material to be inserted and to lessen the risk of the stentgraft thrombosis or infection.

### **6. Conclusion**

Intracranial infectious pseudoaneurysms can occur not only in connection with a heart disease or HIV patients, but they also frequently occur in younger patients with the history of drug abuse or in prematurely born patients. Last but not least, multimodality approach is inevitable in the treatment of ruptured or unruptured infectious pseudoaneurysms. Teamwork brings the largest benefit for the successful future outcome.

In the extracranial area, infectious pseudoaneurysms of ICA have traditionally been treated with a surgical resection of the lesion, in addition to the extended i.v. antibiotic course. Recent advances in interventional radiology, together with the development of new materials, opened up a wide spectrum of new endovascular treatment options. A more radical approach involves a complete occlusion of the affected ICA with detachable balloons. It is also possible to conclude, that intra-arterial stent placement offers less invasive option with preservation of the vessel lumen. The use of either a dense-mash bare stent or a coated stentgraft promises to be a particularly appropriate choice in young individuals presenting with a surgically inaccessible ICA pseudoaneurysms.

#### **Author details**

340 Aneurysm

nerve palsies, Horner'

(Glaiberman et al.,2003;Schonholz et al.,2006).

**6. Conclusion** 

Other possible causes of pseudoaneurysms are penetrating wounds or iatrogenic spread of infection after catheterisation (Alexander et al.,1968; Liston.,1843). The pseudoaneurysms is most likely seen as a result of tonsillitis-induced parapharyngeal abscess, reaching the left ICA adventitia. In our case, ischemia of the carotid artery wall led to its rupture and subsequent development of pseudoaneurysms. We could not exclude a perioperative trauma of ICA during emergency tonsillectomy. Usual bacterial agents causing pseudoaneurysms are *Staphylococcus aureus or Streptococcus pyogenes* (Gralla et al.,2004)*.*

A mycotic carotid pseudoaneurysms most likely present as a growing, pulsatile cervical mass, manifested with dysphagia, odynophagia, and fever. Less frequently, lower cranial

complications may include a carotid artery rupture, intermittent massive nasopharyngeal haemorrhage, and septic or non-septic embolic events leading to a neurological deficit. The usual interval between the infection and the pseudoaneurysms development is between 2 and 8 weeks. The treatment of carotid artery pseudoaneurysms is complex. The typical management of an infected pseudoaneurysms is twofold: systemic antibiotic administration (predominantly penicillin or clindamycin) and/or surgery, with either a traditional by-pass, or a ligation of ICA (Gralla et al.,2004; Heyd & Yinnon,1994; Jebara et al.,1991; Naik et al.,1995). Endovascular therapy of a non-infected and infected carotid artery pseudoaneurysms has been increasingly used (Gralla et al.,2004; Oishi et al.,2002). With this

treatment, the ICA lumen may be better preserved. Several approaches are available.

The novel technique "parent artery occlusion" is achieved by positioning detachable balloons distally and proximally to the lesion (Serbinenko,1974). However, this approach demands preliminary evaluation of the collateral pathways in the circle of Willis. The occlusion test requires the patient to be awake, in order to monitor possible neurological deficits. The inherent risk of the occlusion test includes development of neurological deficits and/or failure to identify a delayed ischemia. Another endovascular approach preserving the carotid artery lumen is a stent or stent-graft implantation with/or without a coil deposition to the pseudoaneurysms. Since the pseudoaneurysms lacks a true arterial wall, the potential risk of the coils compaction and dislocation is always present. A simple stent or a stent-graft implantation is regarded to be the most effective and faster treatment

Choice of the endovascular treatment is mainly influenced by the unfavourable deep location of the pseudoaneurysms nearby the skull base, thus making the conventional surgery more risky. We can initially chose between an uncovered bare stent or two overlapping stents, rather than a covered stentgraft, to minimize the amount of foreign

Intracranial infectious pseudoaneurysms can occur not only in connection with a heart disease or HIV patients, but they also frequently occur in younger patients with the history of drug abuse or in prematurely born patients. Last but not least, multimodality approach is

material to be inserted and to lessen the risk of the stentgraft thrombosis or infection.

s syndrome or trismus may occur. Severe and life-threatening

Václav Procházka, Tomáš Jonszta, Daniel Czerný and Jan Krajča *Radiodiagnostic Institute FN Ostrava Poruba, Czech Republic* 

Michaela Vávrová *Radiodiagnostic department MNOF Ostrava, Czech Republic* 

Tomáš Hrbáč *Neurosurgery department FN Ostrava Poruba, Czech Republic* 

#### **7. References**


