Risk of de novo aneurysm formation in patients with unruptured intracranial aneurysms

Risk of de novo aneurysm formation in patients previously diagnosed with a ruptured or unruptured aneurysm: 18-year follow-up

BACKGROUND

Data on de novo aneurysm formation after treatment for intracranial aneurysms remains scarce. We studied the incidence of de novo aneurysm formation in patients who had undergone aneurysm treatment more than 18 years prior to follow-up. As it is a disease affecting a younger patient population more specific guidelines are needed when planning a follow-up regime.

METHODS

The rate of de novo aneurysm formation was assessed with Magnetic Resonance Angiography (MRA) follow-up >18 years after endovascular or microsurgical treatment for an intracranial aneurysm. Variables associated with de novo aneurysm formation were studied using logistic regression. Missing data were imputed using chained random forests. A data-driven model for the prediction of de novo aneurysm was created to calculate the relative variable importance of ten clinical features.

RESULTS

De novo aneurysms were identified in 11/81 (13.6 %) patients, of whom 1 was male, over a median follow-up of 20 years. Sex was the most important variable associated with de novo aneurysm formation. Regarding the development of de novo aneurysm, men displayed an odds ratio (OR) of 0.16 (0.01-0.97), compared with women. OR for mRS score 2 or more was 0.20 (95 % CI 0.01-1.34), and OR for smokers was 3.70 (0.54-31.18). Six out of 11 patients (54.5 %) needed treatment; 1 underwent endovascular treatment (EVT) and 5 underwent microsurgical treatment (MST). The overall annual de novo aneurysm formation rate was 0.92 %.

CONCLUSIONS

This study highlights the need for a longer follow-up imaging monitoring of patients that have previously undergone treatment for an intracranial aneurysm. These data are useful to take into consideration when planning a follow-up strategy.

Assessment of risk factors in de novo aneurysm development

Aneurysms that occur anywhere in intracranial except where primary aneurysms develop, are called “de novo aneurysms”. The risk factors and formation time of de novo aneurysms are not fully known. Congenital, environmental and hemodynamic factors can play a role in aneurysm development. The 43-year-old female patient was operated with the middle cerebral artery superior trunk aneurysm in our clinic. She came to us again after 17 months with a severe headache. In computed cranial tomography angiography, the middle cerebral artery superior trunk placement aneurysm was found to have a partial clip and “de novo aneurysm” was developed. She was re-operated for “de novo aneurysm”. In this study, the risk factors in development of “de novo aneurysms” were discussed in the light of literature through this patient.

LATE ANEURYSM RELAPSE AFTER MICROSURGICAL TREATMENT OF MIDDLE CEREBRAL ARTERY ANEURYSM: A CASE REPORT AND LITERATURE REVIEW OF TREATMENT OPTIONS

Recurrence of intracranial aneurysm after initial microsurgical or endovascular treatment is uncommon. Although the exact etiology remains unknown, recurrent aneurysms may be observed in surgical patients with big and multiple aneurysms, arterial hypertension, non-atherosclerotic cerebrovascular arteriopathies, as well as in those with a familial history of the disease. Such recurrence can occur over a wide period ranging from several months to years after the initial aneurysm treatment. Still, the occurrence delayed by more than 20 years is rather unusual. Herein, we present a case of a 70-year-old female patient who developed late intracranial aneurysm relapse 30 years after successful microsurgical clipping of the middle cerebral artery aneurysm. We also provide a brief review of relevant literature, discussing the etiology and pathophysiology of aneurysm reappearance, as well as different treatment options available. In conclusion, one should always consider the possibility of intracranial aneurysm recurrence regardless of the mode and time of primary surgery. In such a case, a multidisciplinary management approach using flow diverting endovascular techniques is advised in selected patients.

Aneurysmal subarachnoid hemorrhage: long-term trends in incidence and survival in Olmsted County, Minnesota

OBJECTIVE

Recent population-based and hospital cohort studies have reported a decreasing incidence of aneurysmal subarachnoid hemorrhage (aSAH) and declining aSAH-associated case-fatality rates. Principal drivers of these trends are debated, but improvements in smoking cessation and hypertension control may be critical factors.

METHODS

The population-based medical records linkage system of the Rochester Epidemiological Project was used to document aSAH incidence and 30-day case fatality rates during a 20-year study period (1996-2016) in Olmsted County, Minnesota. Incidence rates in the study period were compared with data from a previous Olmsted County study concerning aSAH incidence from 1965 to 1995 and with regional trends in tobacco use.

RESULTS

One hundred nineteen incident cases of aSAH were included. The median age at hemorrhage was 59 years (range 16-94 years), and 74 patients were female (62.2%). The overall average annual aSAH incidence rate was 4.2/100,000 person-years (P-Y). The aSAH incidence rate decreased from 5.7/100,000 in 1996 to 3.5/100,000 P-Y in 2011-2016. The overall aSAH-associated 30-day case-fatality rate was 21.9% and declined by approximately 0.5% annually. An accelerated decline in the fatality rate (0.9%/year) was observed from 2006-2016. Smoking among adult Olmsted County residents decreased from 20.4% in 2000 to 9.1% in 2018.

CONCLUSIONS

A decline in the incidence of aSAH and 30-day case-fatality rate from 1996 to 2016 was observed, as well as an accelerated decline of the fatality rate from 2006 to 2016. These findings confirm and extend the trends reported by prior studies in the same population. The decrease in aSAH in the years studied paralleled a noticeable reduction in the population smoking rates.

Long-term aneurysm recurrence and de novo aneurysm formation after surgical treatment of unruptured intracranial aneurysms: a cohort study and systematic review

Objective: There is a relative lack of literature on long-term aneurysm recurrence and de novo aneurysm formation following surgical treatment of unruptured intracranial aneurysms. This retrospective single-center cohort study, therefore, analyzes the incidence of aneurysm recurrence, and the incidence of de novo aneurysms formation in patients with at least 10yrs of radiological follow-up. The data are put into the context of a systematic review of the literature.Methods: Patients that underwent surgical treatment of an unruptured intracranial aneurysm at the Basel University Hospital were retrospectively identified. The rate of recurrent or de novo aneurysm formation was assessed for all patients with imaging follow-up ≥10yrs. A systematic review including studies with a mean follow-up period of ≥10yrs was then performed.Results: A total of 95 patients had undergone surgical treatment of an unruptured intracranial aneurysm between 1994 and 2008. Twenty-one patients (22.1%) had available imaging follow-up ≥10yrs (mean: 13.1yrs). In these patients, aneurysm recurrence and de novo aneurysm formation were equally found in 23.8% (n = 5; 1.8%/yr). There was no case of aneurysm rupture from a recurrent or a de novo aneurysm. The systematic literature review covered a combined cohort of 1778 patients over a mean follow-up period of 14.0yrs. In this cohort, the aneurysm recurrence rate was 16.4% (0.7%/yr), and the rate of de novo aneurysm formation was 6.2% (0.4%/yr).Discussion: Despite some discrepancy regarding the incidence, both cohorts show a non-negligible long-term risk of aneurysm recurrence and de novo aneurysm formation, which warrants life-long imaging follow-up.Abbreviations: SD: standard deviation; DSA: digital subtraction angiography; CTA: computed tomography angiography; MRA: magnetic resonance angiography; MCA: middle cerebral artery; ACA: anterior cerebral artery; ACommA: anterior communicating artery; ICA: internal carotid artery; ADPKD: autosomal dominant polycystic kidney disease; MeSH: Medical Subject Headings.

Presymptomatic Screening for Intracranial Aneurysms in Patients with Autosomal Dominant Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES

Intracranial aneurysm rupture is the most devastating complication of autosomal dominant polycystic kidney disease. Whether selective or widespread intracranial aneurysm screening is indicated remains controversial.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Records of 3010 patients with autosomal dominant polycystic kidney disease evaluated at the Mayo Clinic between 1989 and 2017 were reviewed. Those who had presymptomatic magnetic resonance angiography screening were included.

RESULTS

Ninety-four intracranial aneurysms were diagnosed in 75 of 812 (9%) patients who underwent magnetic resonance angiography screening. Sex, age, race, and genotype were similar in the groups with and without aneurysms; hypertension and history of smoking were more frequent in the aneurysm group. Twenty-nine percent of patients with aneurysms compared with 11% of those without aneurysms had a family history of subarachnoid hemorrhage (P<0.001). Most aneurysms were small (median diameter =4 mm; range, 2-12 mm); 85% were in the anterior circulation. During a total imaging follow-up of 469 patient-years, de novo intracranial aneurysms were detected in five patients; eight intracranial aneurysms grew (median =2 mm; range, 1-3 mm). During a total clinical follow-up of 668 patient-years, seven patients had preemptive clipping or coil embolization; no intracranial aneurysms ruptured. During a total clinical follow-up of 4783 patient-years in 737 patients with no intracranial aneurysm detected on the first magnetic resonance angiography screening, two patients had an intracranial aneurysm rupture (0.04 per 100 person-years; 95% confidence interval, 0 to 0.10). The rate of intracranial aneurysm rupture in large clinical trials of autosomal dominant polycystic kidney disease was 0.04 per 100 patient-years (95% confidence interval, 0.01 to 0.06).

CONCLUSIONS

Intracranial aneurysms were detected by presymptomatic screening in 9% of patients with autosomal dominant polycystic kidney disease, more frequently in those with familial history of subarachnoid hemorrhage, hypertension, or smoking. None of the patients with and two of the patients without aneurysm detection on screening suffered aneurysmal ruptures. The overall rupture rate in our autosomal dominant polycystic kidney disease cohort was approximately five times higher than that in the general population.