Complications of Endovascular Treatment in Fibromuscular Dysplasia
Correspondence Address: Source of Support: None, Conflict of Interest: None DOI: 10.4103/0028-3886.299152
Source of Support: None, Conflict of Interest: None
Keywords: Angioplasty, arteriovenous fistula, carotid stenosis, dissecting aneurysm, dissection, endovascular procedure, fibromuscular dysplasia, iatrogenic disease, postoperative complications, renovascular hypertension
Fibromuscular dysplasia (FMD) is a group of idiopathic, non-atherosclerotic, and non-inflammatory diseases of the arterial walls that mainly affect women, leading to small and medium-sized artery stenosis.,
FMD can occur in any artery, although it is more prevalent in the renal and cervical arteries. The clinical presentation varies, depending on the location of the arterial lesions. The most common manifestation is renovascular hypertension secondary to involvement of the renal artery. The FMD of the cervical artery, which mainly affects the internal carotid artery, is rarely symptomatic. In addition, FMD is associated with a substantial risk of formation and rupture of aneurysms, as well as arterial dissection and occlusion, causing a great diversity of signs and symptoms.
The gold standard for diagnosis is digital subtraction angiography (DSA), but this invasive procedure is recommended only for patients who require revascularization during the same procedure.
A 37-year-old male using Amlodipine due to high blood pressure (HBP) for 12 years, presented with sudden severe headache and vomiting. He was admitted 7 days after ictus in the Emergency Room. In his medical history, he denied head trauma, addictions, family history of cerebrovascular event and that there was nothing in history to suggest the central nervous system. Head computed tomography (CT) showed subarachnoid hemorrhage (SAH) in skull base cisterns and4t h ventricle (Fisher IV). Digital subtraction angiography (DSA) in another institution showed multiple tortuosities and ectasias in cervical vessels, and he was referred to our service. He was admitted with Glasgow Come Scale 15, mild stiff neck and no neurological deficit on physical examination (Hunt-Hess I/WFNS I). Magnetic resonance (MR) image rules out other abnormalities. A new DSA (the first one held in the other institution had poor quality) demonstrated two dissecting aneurysms in V3–V4 transition of left vertebral artery (VA), another one in right petrous carotid portion, and a “string-of-beads” pattern with stenosis followed by dilatations in both internal carotid arteries (ICA) (worst in the right side) and in both V2 segments. Similar findings in the right renal artery concluded the diagnosis of fibromuscular dysplasia. All intracranial vessels were normal. Shortly after this second DSA, there was a significant clinical worsening and the patient required intensive care and mechanical ventilation due to urinary focus sepsis, non-biliary pancreatitis, and acute renal failure (both contrast-related), bilateral hydronephrosis grade II and transient thrombocytopenia due to organ dysfunction. On admission, creatinine and urea were 0.9 and 43, respectively. After arteriography, they increased to 3.54 and 142. After clinical improvement without the need for dialysis, on the 37th-day post-ictus a transluminal percutaneous angioplasty (TPA) of dissecting aneurysms was performed without intercurrences [Figure 1]. All our procedures are made under full intravenous heparinization and general anesthesia, preferably via right femoral artery (FA). Two coronary stents were telescoped to cover the aneurysms. The patient was discharged with no neurological deficit, using acetylsalicylic acid (ASA) and Clopidogrel. A control DSA 8 months after showed exclusion of one left VA aneurysm and decrease of the other one, but worsening dilatations and dissecting aneurysm of the right petrous ICA. In addition, a giant dissecting aneurysm in the right subclavian artery was visualized, which did not exist in the first examinations. A puncture hematoma of the right FA following this control DSA was treated conservatively. TPA of right ICA was performed 1 month thereafter, in which was seen a volumous dilatation post dissection of right FA. Two long self-expanding stents covered the petrous aneurysm and other dilatations until the cervical segment, rectifying the diseased arterial segment, but causing a distal kinking with severe stenosis [Figure 2]. After 12 days, a new attempt to right ICA TPA via the left FA was performed unsuccessfully. The plan was to correct the kinking with a telescoped stent, but we could not overcome the stenosis with a new stent. The patient had a new inguinal hematoma, this time on the left side, also without need for local intervention. Both femoral arteries showed typical angiographic changes post complication of dissection [Figure 3]. Regarding the giant subclavian aneurysm, the Vascular Surgery team proposed cervico-thoracotomy and extracorporeal circulation. Faced with the risks, the patient preferred a new endovascular procedure. Two months after the attempted ICA TPA, we performed a TPA of the right subclavian artery via the ipsilateral brachial artery, with good aneurysm coverage by a self-expanding stent [Figure 4]. Ten days after, the patient was admitted to the Emergency Room for brachiobasilic arteriovenous fistula, at the site of the last puncture, which was surgically corrected by the Vascular Surgery team. Control cervical AngioCT 8 months later showed endoleak in the subclavian artery [Figure 5]. In the face of so many post-procedure complications, in addition to risks due to vascular fragility in both endovascular and open surgery interventions, and the patient being completely asymptomatic, we chose not to perform any treatment thereafter, unless he had a cerebrovascular event life-threatening. Follow-up AngioCT performed 5-months after showed no increase of the giant endoleak of right subclavian artery and exclusion of circulation of the aneurysms of left VA and right ICA. The patient keeps asymptomatic in outpatient follow-up, with double antiaggregation.
McCormack, in 1958, reported a pathological description of fibromuscular hyperplasia in four patients with renovascular hypertension. In 1965, Hunt observed that the disease was heterogeneous and not necessarily associated with hyperplasia, and introduced the term FMD.
Since the earliest studies, FMD has always been considered a more prevalent disease in females. Recent studies have further corroborated this assertion: Plouin and Kadian-Dodov, in 2016, with a prevalence of 84% and 93.5%, respectively; and Lather, in 2017, with 94.1%.
Three main types of renal FMD were identified according to the arterial wall layer that is mainly affected: Intimal (about 10% of cases of renal artery FMD), medial (80–90%), and adventitia (<5%). However, these categories are not mutually exclusive, since the involvement of more than one layer in the same diseased artery is not uncommon. Cervico-cephalic FMD is classified angiographically into four subtypes: Multifocal, unifocal, tubular, and atypical. Multifocal, with a typical string-of-beads pattern, is the most common angiographic presentation and histologically corresponds to medial FMD. Our patient fits in angiographic classification of multifocal FMD, but we don × t have the histopathological analysis, since no open surgery for the affected vessels was carried out.
FMD can affect several arterial sites, the most common being cervical and renal. There are several reports of involvement of the mesenteric, axillary, iliac, hepatic, intracranial and, in some cases, coronary arteries. In a case series review conducted by Persu, the prevalence of involvement of two or more arterial sites varied from 16 to 28%. For this reason, it is recommended the investigation of secondary lesions in patients with FMD, mainly in renal and cervical arteries. The involvement of so many arteries affected by the FMD of our patient makes this a rare and unprecedented case.
The clinical presentation is variable, not only by the multiple sites of involvement, but also by the large number of complications. Kadian-Dodov carried out a study with 921 patients with FMD, which 384 of them (41.7%) had aneurysms (21.7% of cases) and arterial dissections (25.7%), in addition to 5.8% with simultaneous involvement. In this same study, the most commonly identified aneurysm sites reflected the most frequently affected arterial beds by the FMD: The renal (34%) and extracranial carotid arteries (31%). Intracranial circulation was the third most common site, occurring in 21.5% of all patients with aneurysms and 4.7% of the 921 patients in the study.
Our patient had no intracranial arteries affected by the disease, but the initial diagnosis was secondary to subarachnoid hemorrhage. Although the dissecting aneurysms of the lfVA were extracranial, just they could account for bleeding in the 4th ventricle and base cisterns. The diagnosis of renal FMD, however, could have been made up to 12 years earlier, if underwent to investigation of HBP in young.
Lather, in 2017, underwent an angiographic review of 669 women diagnosed with FMD in the USA, showing a 12.9% prevalence of intracranial aneurysms. There was no difference in the comparison between the different FMD sites: Renal involvement with prevalence of 11.9%, cervical with 13.7% and mixed with 13.2%. If we compare with the prevalence in the general population, with rates of 3.2%, it becomes clear the strong relation of the development of intracranial aneurysms with all forms of FMD.
Spontaneous cervical artery dissections are a common cause of stroke in young and middle-aged adults and are associated with FMD in about 15% of cases, and the most frequent dissections are in the extracranial carotid (63.7%) and vertebral arteries (20.7%).
The management of FMD patients with drug therapy is well established, either with antiplatelet aggregators or anticoagulants. Surgical/endovascular treatment is indicated in patients with symptomatic or critical FMD, and may be directed to complications. In renal FMD, options are available in the presence of renovascular hypertension, renal ischemic atrophy or presence of lesions in other sites. In cervical FMD, the indications are more individualized, because of the low possibility of disease progression and, generally, they are directed to the complications. Among the endovascular possibilities are the use of coils for aneurysms and TPA and stents for dissections or critical FMD.
Finally, we recognize a structural flaw in this clinical case. Problems of the Brazilian public health system made the patient submit to more endovascular procedures than recommended. There is a limit of exams, procedures and materials per month and per hospitalization for each patient.
Because FMD is a disease of unknown cause, it remains a therapeutic challenge because it does not have specific treatment. Currently, the therapy is directed to complications: Aneurysms and arterial dissections. Although endovascular/surgical treatment is well established for symptomatic complications or those that cause a serious risk to the patient, more studies are needed regarding the treatment of asymptomatic lesions. The follow-up of these patients with DSA, Doppler or AngioCT/MR is indissoluble, due to the great possibility of progression of the disease and its complications.
The vascular fragility of patients with fibromuscular dysplasia of cervical arteries predisposes to dissection, stenosis and occlusion, in addition to being related to intracranial aneurysms. All these vascular malformations may present spontaneous complications, with cerebral hemorrhage or stroke, or secondary to iatrogenesis. Endovascular procedures should be well indicated, and reserved only for treatment of symptomatic lesions.
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The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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