Sphenoid sinusitis complicated by extensive septic thrombosis after coiling of a ruptured intracranial aneurism

Abstract

We report here the case of a 40-year-old man who presented with sphenoid sinusitis complicated by jugular and cerebral venous thrombosis and intracranial infection 6 weeks after coiling of an anterior choroidal artery aneurysm. The pathogeny of this unusual and severe complication is discussed.

Background

When feasible, the first-choice treatment of intracranial ruptured aneurysm is endovascular embolisation. The most frequent complications after coiling are thromboembolic events and intraoperative rupture.¹ Infectious complications are very rare. In a series of 2918 cerebral angiograms and neurointerventional procedures done without prophylactic antibiotics, Kelkar et al² reported three infections (0.1%) attributable to the procedure, all localised at the femoral artery puncture site. Despite the anatomical proximity between the intracranial spaces and the sphenoid sinus, no sphenoid sinusitis occurring after endovascular treatment of an intracranial aneurysm has been reported so far. In this paper, we report the case of a patient presenting with sphenoid sinusitis complicated by extensive thrombosis of the cavernous sinus 6 weeks after coiling of a choroidal artery aneurysm. The objectives of the paper are to draw attention on this potential complication of endovascular embolisation and to discuss the physiopathogeny of this uncommon complication.

Case presentation

A 40-year-old patient with no medical history or active disease was brought by his wife to the emergency service for sudden onset of confusion and somnolence (day 0). An afebrile meningeal syndrome led to the discovery on CT scan and cerebral CT angiography of a Fisher IV, World Federation of Neurologic Surgeons (WFNS) 2 subarachnoid haemorrhage due to a ruptured aneurysm of the left anterior choroidal artery. At that time, the sphenoid sinus was empty (as were all the other sinuses), with no inflammatory signs such as mucosal thickening or bony remodelling (figure 1).

Figure 1.

CT scan on day 0. (A) Sphenoid sinus is empty, with no bony remodelling (white arrow). (B) Ruptured aneurysm of the left choroidal artery (white arrowhead).

The patient was treated emergently with coiling of the ruptured aneurysm. The embolisation was total with no complication. An external ventricular drain was placed on day 1 and pulled on day 13. No antibiotic prophylaxis was prescribed. The patient was extubated on day 1 and required no nasogastric tube. On day 11, a CT scan showed incomplete filling of the left sphenoid sinus (figure 2). This was felt to be inconsequential. The patient was discharged from intensive care unit (ICU) on day 14 with no ischaemic complications or objective neurological deficit or damage. Aspirin (100 mg/day) was prescribed for 3 months after the procedure.

Figure 2.

Axial (A) and sagittal (B) CT scan on day 11 showing an incomplete filling of the left sphenoid sinus (white arrow). Note the coils after embolisation of the aneurism (white arrowhead).

On day 23, the patient began to report mild intermittent headaches and chills. No fever was found initially, and the patient’s sporadic headaches were felt to be consistent with the recent neurosurgical procedure. Neurological examination revealed no abnormalities. A CT scan was performed, showing left sphenoid filling similar to the previous CT scan. A bony erosion of the posterior wall could be seen, but no intracranial fluid collection or thrombosis. The cavernous sinus was unremarkable. The patient’s primary care physician prescribed amoxicillin, and on day 27, he added oral corticosteroids (1 mg/kg prednisone) for 5 days, with a notable but brief (4-day) improvement. From day 32, the antibiotics and corticosteroids had been discontinued.

Nevertheless, the patient continued to complain of sporadic but increasingly frequent pain and chills. On day 38, his general and neurological examinations were felt to be benign. On day 46, the patient presented again to the emergency department for violent headaches, chills and a fever of 40°C. Neither neurological deficit nor cranial nerve damage was observed. Blood tests revealed an inflammatory syndrome and leucocytosis with a left shift consistent with an acute bacterial infection. Cerebral and facial CT scans were performed, showing sphenoid sinusitis with a 5.0 cm×2.0 mm left anterior temporal subdural empyema. CT angiography and MRI showed an abscess in the sella turcica and a left cavernous sinus thrombosis extending to the right cervical jugular vein and right sigmoid sinus up to the inferior petrosal sinus and to the left superficial middle cerebral vein, directly connected to the left anterior temporal empyema by the left sphenoparietal sinus. There was a bony defect of the sellar floor, connecting the infected sphenoid sinus with the sella (figures 3 and 4).

Figure 3.

Axial (A) and sagittal (B) CT scan on day 46 showing a complete filling of the left sphenoid sinus with a bony erosion of the sellar floor (white arrow).

Figure 4.

Axial T1 weighted MRI after contrast on day 46 showing sella turcica fluid collection extending to the left cavernous sinus (A, white arrow) and a left temporal empyema (B, white arrowhead).

The patient was transferred to the ENT emergency department, where a sphenoidotomy was performed, releasing abundant pus. In the sphenoid sinus, exposure of the pituitary dura was observed through a non-surgical bony defect of the sellar floor. The microbiological analysis of the purulent secretions isolated Streptococcus constellatus with no antibiotic resistance. A lumbar puncture ruled out intracranial hypertension and meningitis, as the cerebrospinal fluid was sterile. Therapeutic anticoagulation was initiated, and intravenous antibiotic therapy with ceftriaxone (2 g two times per day) and metronidazole (500 mg three times per day) was administered for 5 days, followed by oral antibiotic treatment with amoxicillin (2 g four times per day)+metronidazole (500 mg three times per day) for 6 weeks. Antivitamin K therapeutic anticoagulation was initiated for 6 months, and antiplatelet aggregant therapy (aspirin 100 mg/day) was continued for a total of 3 months after the aneurysm coiling.

Outcome and follow-up

Additional follow-up and monitoring included a pulmonary CT angiogram, revealing no pulmonary embolism, and a cardiac echography, showing no infectious endocarditis. Cerebral CT angiography 48 hours after initiating anticoagulation showed stability of the thrombosis with no cerebral infarction or haemorrhage. The cavernous sinus thrombosis decreased in 5 days but did not disappear. The inflammatory syndrome diminished (C reactive protein (CRP) decreased more than 50% in 5 days), as well as the polymorphonuclear blood cell count, which normalised in 5 days. Blood cultures remained sterile.

Finally, the patient was discharged on postoperative day 10. Follow-up CT scan 1 month later showed complete resolution of the cavernous sinus thrombosis and the cerebral venous thrombosis.

Discussion

The pathogenesis of this severe infection is not clear. The first possibility is that the sinusitis and all the complications were caused by the coiling of the aneurism. In 2016, Cossu et al³ reported a total of six cases of cerebral abscesses secondary to the treatment of cerebral aneurysms, with seven others after neuro-endovascular procedures for cerebral arterio-venous malformations or dural arterio-venous fistulae. All were coiled. Compared with our case, a concomitant infection (leading to suspected hematogenous dissemination) was found in three out of six cases. Percutaneous infection could naturally be presumed due to the presence of Streptococcus or Staphylococcus. The timing reported for the development of cerebral infection (from 2 weeks to 3.5 years) was consistent with our observation. All the infections were localised near the area of coiling or previous ischemia, but none involved a paranasal sinus or the cavernous sinus. The authors suggested that the subarachnoid haemorrhage might increase the inflammation. This could enhance permeability of the blood–brain barrier to infection at a particularly risky time, when percutaneous catheters and foreign material are being used. The larger the haemorrhage, the greater the inflammation might be, and thus the risk of infection. In our case, the haemorrhage was scored Fisher IV, that is, a significant haemorrhage with intraventricular bleeding.³

Another hypothesis would be that the patient developed a nosocomial bacterial rhinosinusitis in the ICU, unrelated to coil embolisation. Indeed, sinusitis is a frequent event in critically ill patients.⁴ The fact that the pathogen was S. constellatus—namely a bacteria commonly found in the upper respiratory tract—further supports this hypothesis. However, none of the ‘classical’ risk factors of nosocomial sinusitis (eg, prolonged endotracheal intubation and nasogastric tube placement) were present in our case. In this scenario, the coiling of the aneurism might still have played a role in the spread of infection: the local inflammation caused by the coiling of the ruptured aneurism would explain the unusual course of the sinusitis, with the development of a bony erosion and of septic thrombosis.

In this case, sphenoid sinusitis resulted in cavernous sinus thrombosis and, from downstream to upstream, multiple cerebral septic thromboses. Though septic cavernous thrombosis is a classical complication of sphenoid sinusitis, it is very rare.⁵ The bacterial pathogen recovered might suggest part of the answer. S. constellatus is an ordinary bacterium that colonises the upper respiratory tract and oral cavity. It is likely capable of forming abscesses, but it has been reported to form septic thrombophlebitis with a higher proportion of septic cavernous sinus thrombosis. According to the literature, this case may be the 13th case of S constellatus-related thrombophlebitis and the ninth in the cavernous sinus.^{6 7}

Fish et al⁸ also found 13 cases of intracranial abscesses after embolisation from 1945 to 2018 and emphasised the fact that infection might be more likely when an aneurysm is ruptured, and suggested that antibiotic prophylaxis should be used in such cases. In 2018, Ko et al⁹ reported another case after coiling of a paraophthalmic aneurysm. Nevertheless, infections after such procedures remain so exceptional that no consensus on antibiotic prophylaxis exists. Burkhardt et al¹⁰ found two groin infections out of 549 endovascular neurointerventions (including 306 aneurysm embolisations) and no cerebral infections. One patient had received antibiotic prophylaxis (1/265), while the other had not (1/284). In our case, it is difficult to know if antibiotic prophylaxis would have helped preventing the infection: as discussed before, it is also possible that the coiling was not the primary cause of the sphenoid sinusitis. However, the close proximity between the coils and the infected sinus raises the question of a potential secondary infection of the coils. The coils should then be considered as an infected foreign body and surgical removal of the material should be discussed. Luckily, the infection was controlled by surgical drainage and antibiotics in our patient.

In summary, the combination of regional fragility post-aneurysm coiling, sphenoid sinusitis after bedrest and an aggressive microorganism capable of septic thrombosis and abscesses might explain our patient’s case.

Patient’s perspective.

I don't remember anything from my ruptured aneurysm, absolutely nothing. I can't even tell if it was daylight or if I was alone or not. I was petrified and I did not even understand what I was afraid of. I could see that my hands were free but yet it was impossible for me to move them. I heard noises that I could not identify, people who spoke, and I, alone. The most important thing is that I could not to understand if I was dead or alive. My wife will explain to me later how I ended up in this state: it seems that I was alone at my home and that we had a completely normal telephone conversation but apparently I no longer knew who she was, and I no longer knew who I was either but I had mostly complained of a very strong head pain and very great fatigue. I have only a few memories of this first hospitalisation except the phrase “you can go out”. Arrived at my house after this first hospitalisation, a few hours after a horrible headache arrived. I had the impression that my head was going to explode and I could not stand the light either. My condition has worsened day by day. Death was back, thinking to have escaped it for the first time. The next morning, I was transferred to another hospital for sinus drainage. That night when I was told that I had to be operated on urgently, I sincerely believed that my last hour had come. I saw myself condemned or greatly diminished when I considered myself at 40 still a young and healthy man with the life ahead of me and I hoped to have survived my rupture of aneurysm. The days which followed the sinus drainage were very difficult. Morally, I did not see the end. A year later, I'm still on an anticoagulant for thrombosis and I'm taking treatment for my depression: the nightmares haven't really disappeared. I was terrified of what had happened to me, but I am still terrified of what could still happen to me. Sometimes I wonder how I'm still alive. I thank those doctors who dare to step out of their comfort zones and be curious enough to make things happen.

Learning points.

• Sphenoid sinusitis can occur following coiling of an intracranial aneurism, with a risk of intracranial complications.

• The sphenoid sinus should therefore be carefully assessed after endovascular embolisation of an intracranial aneurism.

• If a sphenoid sinusitis is detected on post-embolisation imaging, it might be necessary to consider antibiotic treatment, or at least a close clinical and radiological follow-up to prevent further complications.