Matti Porras

Factors Affecting Formation and Growth of Intracranial Aneurysms A Long-Term Follow-Up Study

Background and Purpose — We sought to investigate factors determining growth rate of unruptured intracranial aneurysms as well as formation of new (de novo) aneurysms in patients from a time period when unruptured aneurysms were not treated surgically. Methods — Eighty-seven patients (79 had ruptured aneurysms clipped at start of follow-up) with 111 unruptured aneurysms as well as an additional 7 patients (2 with and 5 without unruptured aneurysms) who developed new aneurysms were followed from the 1950s to the 1970s until death or subarachnoid hemorrhage or until the last contact. Patients’ cerebral arteries were examined later either with conventional (control) angiography (n=38) and/or, for those alive during 1996–1998, with 3-dimensional CT angiography (n=57). In addition, 10 patients were studied at neuropathological autopsy. Results — Mean±SD duration of follow-up was 18.9±9.4 years (range, 1.2 to 38.9 years). Unruptured aneurysms increased in size ≥1 mm in 39 of the 87 patients (45%) and ≥3 mm in 31 (36%). New aneurysms were found in 15 of the 89 patients and in 5 without an unruptured aneurysm at the beginning of follow-up. Aneurysm rupture was associated very significantly (P <0.001) with aneurysm growth during follow-up. Of several potential risk factors tested, only cigarette smoking (odds ratio [OR], 3.92; 95% CI, 1.29 to 11.93) and female sex (OR, 3.36; 95% CI, 1.11 to 10.22) were, after adjustment for age, significant (P <0.05) independent risk factors for occurrence of aneurysm growth of ≥1 mm. Only cigarette smoking (OR, 3.48; 95% CI, 1.14 to 10.64;P <0.05) was associated with growth of ≥3 mm. Age- and hypertension-adjusted risk factors for aneurysm formation were female sex (OR, 4.73; 95% CI, 1.16 to 19.38) and cigarette smoking (OR, 4.07; 95% CI, 1.09 to 15.15). Conclusions — Women and cigarette smokers are at increased risk for intracranial aneurysm formation and growth. Cigarette smoking in particular hastens aneurysm growth. Cessation of smoking is important for patients with unruptured aneurysms and possibly also for those with a prior subarachnoid hemorrhage.

Natural History of Unruptured Intracranial Aneurysms: A Long-term Follow-up Study

Background and Purpose— Unruptured intracranial aneurysms are increasingly being detected and are a notable healthcare burden. We investigated the long-term natural history of unruptured intracranial aneurysms and risk factors predictive of subsequent rupture. Methods— A total of 142 patients with 181 unruptured intracranial aneurysms diagnosed between 1956 and 1978, when these were not treated, were followed up until death or subarachnoid hemorrhage, or until 2011 to 2012. Annual and cumulative incidences of aneurysm rupture and risk factors for rupture were studied using Kaplan–Meier survival analysis and Cox proportional hazards regression models. Results— The median follow-up time was 21.0 (range, 0.8–52.3) years. During 3064 person-years, there were 34 first episodes of aneurysm rupture, giving an average annual incidence of 1.1%. Eighteen patients died on account of an initial or recurrent aneurysm rupture. The cumulative rate of bleeding was 10.5% (95% confidence interval [CI], 5.2–15.8) at 10 years, 23.0% (95% CI, 15.4–30.6) at 20 years, and 30.1% (95% CI, 21.3–38.9) at 30 years. None of the index aneurysms bled after a follow-up of 25 years. Cigarette smoking (adjusted hazard ratio, 2.44; 95% CI, 1.02–5.88), location of the aneurysm in the anterior communicating artery (adjusted hazard ratio, 3.73; 95% CI, 1.23–11.36), patient age inversely (0.96 per year, 95% CI, 0.92–1.00) and aneurysm diameter ≥7 mm (adjusted hazard ratio, 2.60; 95% CI, 1.13–5.98) independently predicted subsequent aneurysm rupture, as did alcohol consumption (1.27 per 100 g/week; 95% CI, 1.05–1.53; P<0.05), but only in univariable analysis. Conclusions— Cigarette smoking, patient age inversely, and the size and location of the unruptured intracranial aneurysm seem to be risk factors for aneurysm rupture. The risk of bleeding decreases with a very long-term follow-up.

Microscope-integrated near-infrared indocyanine green videoangiography during surgery of intracranial aneurysms: the Helsinki experience.

BACKGROUND Microscope-integrated near-infrared indocyanine green videoangiography (ICG-VA) is a new method of intraoperative blood flow assessment. The objective of this study was to evaluate the reliability of this technique in the evaluation of neck residuals and patency of branches after microneurosurgical clipping of intracranial aneurysms (IAs). METHODS During a period of 14 months, between November 2005 and December 2006, 289 patients with intracranial aneurysms were operated on in our institution. Intraoperative ICG-VA was performed during microneurosurgical clipping of 239 IAs in 190 patients. Postoperative computed tomography and computed tomography angiography (CTA) were performed for all patients. Intraoperative interpretation of ICG-VA in assessing the neck residual or the patency of vessels after clipping of each single aneurysm were recorded and correlated with postoperative CTA and/or digital subtraction angiography. RESULTS Postoperative imaging studies revealed no incomplete occlusions of aneurysm domes. Unexpected neck residuals were observed in 14 aneurysms (6%). There were no parent artery occlusions. Unexpected branch occlusions including both major and minor branching arteries were observed in 15 aneurysms (6%). CONCLUSIONS Indocyanine green videoangiograph is a simple and fast method of blood flow assessment with acceptable reliability. Indocyanine green videoangiograph can provide real-time information to assess blood flow in vessels of different size as well as the occlusion of the aneurysm. Intraoperative assessment of blood flow in the perforating branches is one of the most important advantages. In selected cases such as giant, complex, and deep-sited aneurysms or when the quality of image in ICG-VA is not adequate, other methods of intraoperative blood flow assessment should be considered.

Routine cerebral angiography after surgery for saccular aneurysms: is it worth it?

OBJECTIVE: The objective of this study was to determine whether an angiographically proven rate of saccular intracranial aneurysm occlusion after surgical clipping suggests that postoperative angiography should continue to be used routinely or should be supplanted by intraoperative angiography. These data also should establish a basis for comparing surgery with new endovascular methods of treatment. METHODS: During a 3.5-year period, a consecutive series of 622 patients (955 aneurysms, 808 of which were surgically clipped) who underwent postoperative angiography were studied retrospectively. This series comprised 493 ruptured and 315 unruptured aneurysms. RESULTS: Complete aneurysm closure was achieved in 88% of aneurysms, a neck remnant was discovered in 9%, and a fundus remnant was revealed in 3%. Of 493 ruptured aneurysms, 86% were completely occluded. Of 315 unruptured aneurysms, 91% were completely occluded. The results for clipping of complex aneurysms, i.e., posterior circulation or large to giant aneurysms, were significantly inferior to those for small and anterior circulation aneurysms. In one-third of the large and giant aneurysms, a part of the base was left intentionally because of calcifications or strong wall or to prevent occlusion of any branches. In the series, a significant 5% complication rate of major vessel occlusion was detected. CONCLUSION: Our retrospective analysis revealed that ruptured, posterior circulation, and large/giant aneurysms are more prone to incomplete clipping. Therefore, these aneurysms require postoperative if not intraoperative evaluation with angiography. Many clippings of anterior circulation aneurysms experience unexpected failures, which suggests that intraoperative angiography could be beneficial. This series, which has no selection bias, can be used as a basis to compare the results of other series reporting surgical or endovascular treatment.

Lateral supraorbital approach applied to olfactory groove meningiomas: experience with 66 consecutive patients.

OBJECTIVEThe lateral supraorbital approach for safely and completely removing olfactory groove meningiomas was assessed. METHODSBetween September 1997 and June 2008, a total of 656 meningiomas were operated on by the senior author (JH) at the Department of Neurosurgery, Helsinki University Central Hospital; 66 were olfactory meningiomas. We retrospectively analyze the clinical data, radiological findings, surgical treatment, histology, and outcome of all the olfactory groove meningioma patients and discuss the operative techniques used. RESULTSSixty-six patients were operated on by the lateral supraorbital approach. The median preoperative Karnofsky Performance Scale score was 80 (range, 40–100). Three patients were redo cases in which the primary operation had been performed elsewhere. Seemingly complete tumor removal was achieved in 60 patients (91%); there was no surgical mortality. Postoperatively, 6 patients (9%) had cerebrospinal fluid leakage, 5 (8%) had new visual deficits, 4 (6%) had wound infections, 4 (6%) had cotton granulomas, and 1 (2%) had a postoperative hematoma. The median Karnofsky score at discharge was 80 (range, 40–100). Six patients had recurrent tumors; 3 underwent reoperations after an average of 21 months (range, 1–41 months); 1 was treated with radiosurgery, and 2 were only followed. During the median follow-up time of 45 months (range, 2–128 months), there were 4 recurrences (6%) diagnosed on average 32 months (range, 17–59 months) after surgery. CONCLUSIONThe lateral supraorbital approach can be used safely for olfactory groove meningiomas of all sizes with no mortality and relatively low morbidity. Surgical results and tumor recurrence with this fast and simple approach are similar to those obtained with more extensive, complex, and time-consuming approaches.

Relationship of local infarctions to cognitive and psychosocial impairments after aneurysmal subarachnoid hemorrhage.

OBJECTIVE:Previous studies suggest that cognitive and psychosocial impairments after subarachnoid hemorrhage (SAH) result from diffuse brain damage caused by the initial bleeding rather than from focal lesions. We describe the relationship of local infarctions to these impairments and explore how well test and questionnaire results explain psychosocial outcome. METHODS:A total of 170 patients, selected from a consecutive series of patients with aneurysmal SAH, underwent neurological and neuroradiological examinations, and 138 of them were assessed with neuropsychological tests and questionnaires 1 year after SAH. RESULTS:Patients with left and bilateral infarctions performed worse on verbal memory tests than the other patients, and patients with left infarctions had more impaired working capacity than those with no infarction. The indices of the severity of SAH were related to reductions in both working capacity and social activity but less clearly to poor test performances. Whereas the modified Rankin scale was the most important correlate of working capacity, performance on cognitive tests was associated with return to work, and questionnaire ratings of mental impairments correlated with reduced working capacity and decreased social activity. CONCLUSION:Left-hemisphere infarctions cause deficits in verbal memory and working capacity. The severity of SAH is associated with impairments in working capacity and social activity rather than with specific cognitive deficits. Patients’ and partners’ opinions on patients’ mental impairments could provide complementary information to clinical grades and cognitive tests in the evaluation of outcome after SAH.

Functional results of facial nerve suture after removal of acoustic neurinoma: analysis of 25 cases.

The facial nerve is sometimes severed during the removal of acoustic neurinomas, either intentionally to ensure complete removal, or unintentionally because of difficulties in identification. In such cases we have, if possible, sutured the nerve stumps microsurgically, either end to end or by use of an intervening nerve graft. We analyzed the outcome of 25 instances of facial nerve suturing in a series of 219 patients operated on for acoustic neurinoma from 1979 to 1987. The first signs of recovery appeared at an average of 12 months, and there was continued improvement for several years. Recovery was graded from 1 to 6. The anastomosis was successful in 24 of the 25 sutured nerves, in that at least some facial movement and tone were restored (Grade 5 or higher). In 11 of the 25 cases, facial appearance at rest and with movement was moderately good (Grade 2 or 3). A Grade 1 result, with no perceivable facial dysfunction, was never achieved. Typically, oral muscles showed the most improvement and frontal muscles the least. Facial appearance was better at rest than with movement, which was always complicated by some degree of synkinesis. Closure of the eye was so good in 13 of the 25 cases that neither tarsorrhaphy nor an eyelid spring was necessary. When the facial nerve is severed, intraoperative suture is recommended, because it provides a chance for moderately good restoration of facial appearance.

Anatomic features of distal anterior cerebral artery aneurysms: a detailed angiographic analysis of 101 patients.

OBJECTIVEDistal anterior cerebral artery (DACA) aneurysms have special anatomic features such as small size, broad base with originating branches, association with anterior cerebral artery (ACA) anomalies, and multiple aneurysms. Our aim is to evaluate incidences of these findings from pretreatment angiograms to help both microsurgical and endovascular treatment planning. METHODSWe performed detailed angiographic analysis of 101 consecutive patients diagnosed with DACA aneurysms from 1998 to 2007 in the Department of Neurosurgery at the Helsinki University Central Hospital in Helsinki, Finland. All patients underwent either digital subtraction angiography (n = 39) or computed tomographic angiography (n = 62). RESULTSOf the 101 patients, 50 patients (50%) had multiple aneurysms, 7 patients (7%) had multiple DACA aneurysms, and 1 patient (1%) had an associated arteriovenous malformation. The 108 DACA aneurysms were found in seven different locations: frontobasal branches (n = 2); A2 segment (n = 5); A3 segment inferior to genu of corpus callosum (n = 19), anterior to genu of corpus callosum (n = 70), and superior to genu of corpus callosum (n = 1); A4 or A5 segments (n = 7); and distal branches (n = 4). Mean sizes were 7.4 mm (range, 2–35 mm) and 4.2 mm (range, 1–9 mm) for the 67 ruptured and 41 unruptured aneurysms, respectively. A broad base, wider than the parent artery, was seen in 68% of patients, and 94% of patients had a branch origin at the base. The neck-to-dome ratio was 1:1 in 25% of patients. Anomalies of the ACA were seen in 23 patients (23%): azygos ACA in 4 patients (4%), bihemispheric ACA in 15 patients (15%), and triplication of ACA in 4 patients (4%). CONCLUSIONThe special neurovascular features and frequent ACA anomalies, best identified from computed tomographic angiography or rotational digital subtraction angiography, must be taken into account when planning occlusive treatment of DACA aneurysms.

Early surgery for ruptured cerebral arteriovenous malformations

Acute surgery on cerebral arteriovenous malformations (AVMs) has seldom been reported or used. We reviewed 49 patients of ages 2 months to 78 years (mean 32.8 years), 32 male (65%) and 17 female (35%), treated acutely (within 4 days of bleed) in Helsinki Neurosurgery during 1997-2002. The following variables were assessed in regards to the outcome (Glasgow outcome score; GOS; 2-3 months after bleed): age, sex, Hunt and Hess Grade (HH), Spetzler-Martin Grade (SMG), location of AVM, size of intraparenchymal haematoma (ICH), and presence of intraventricular haemorrhage (IVH). Most of the patients were in a poor clinical condition on admission (two thirds were HH 4-5). 45 (92%) patients underwent extirpation of AVM and evacuation of ICH, within 4 days after bleed. Over 55% had good functional outcome. GOS correlated significantly with HH (p = 0.001), age (p = 0.006), and IVH (p = 0.049). On the other hand, SMG, location of AVM, and size of haematoma did not significantly predict the outcome. Microneurosurgery with preoperative embolization has made possible the excision of 90% of AVMs. It is our experience that it can be done acute and early, and it saves lives as compared to natural history of cerebral AVMs or late surgery, and accelerates rehabilitation of the patients.

Early ischemic lesion on computed tomography : predictor of poor outcome among survivors of aneurysmal subarachnoid hemorrhage

OBJECT Identifying ischemic lesions after subarachnoid hemorrhage (SAH) is important because the appearance of these lesions on follow-up imaging correlates with a poor outcome. The effect of ischemic lesions seen on computed tomography (CT) scans during the first days of treatment remains unknown, however. METHODS In 156 patients with SAH, clinical course and outcome, as well as the appearance of ischemic lesions on serial CT scans, were prospectively monitored for 3 months. At 3 months after SAH, magnetic resonance imaging was performed to detect permanent lesions that had not been visible on CT. RESULTS Of the 53 patients with no lesions on any of the follow-up CT scans, four (8%) had a poor outcome. Of the 52 patients with a new hypodense lesion on the first postoperative day CT, 23 (44%) had a poor outcome. Among the remaining 51 patients with a lesion appearing later than the first postoperative morning, 10 (20%) had a poor outcome (p < 0.001). After adjusting for patient age; clinical condition on admission; amounts of subarachnoid, intracerebral, and intraventricular blood; and plasma glucose and D-dimer levels, a hypodense lesion on CT on the first postoperative morning was an independent predictor of poor outcome after SAH (odds ratio 7.27, 95% confidence interval 1.54-34.37, p < 0.05). CONCLUSIONS A new hypodense lesion on early postoperative CT seems to be an independent risk factor for poor outcome after SAH, and this early lesion development may be more detrimental to clinical outcome than a later lesion occurrence.