Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 59, Num. 5, 2011, pp. 690-695

Neurology India, Vol. 59, No. 5, September-October, 2011, pp. 690-695

Original Article

Intra procedure rupture of intracranial aneurysm during endovascular coiling: Neurosurgeons' experience and review of the literature

DP Sharma¹, Daljit Singh¹, A Jagetia¹, H Singh¹, M Tandon², P Ganjoo²

¹ Department of Neurosurgery, G B Pant Hospital, New Delhi, India
² Department of Neuroanaesthesia, G B Pant Hospital, New Delhi, India
Correspondence Address: Daljit Singh, Room 529, Academic Block, G B Pant Hospital, New Delhi, India, drdaljit@hotmail.com

Date of Submission: 10-Jul-2011
Date of Decision: 07-Aug-2011
Date of Acceptance: 20-Aug-2011

Code Number: ni11212

PMID: 22019652

DOI: 10.4103/0028-3886.86542

Abstract

Keywords: Cerebral aneurysm, endovascular therapy, intra procedural rupture, subarachnoid hemorrhage

Introduction

Endovascular coiling of the ruptured intracranial aneurysms has become an accepted treatment with good clinical outcomes and provides adequate protection from rebleeding. ^[1] Procedure-related complications mainly include ischemic events and aneurysm rupture. The reported intraoperative rupture of aneurysm during microscopic clipping varies between 15% and 53%. ^{[2],[3],[4],[5]} However, intra procedure rupture (IPR) during endovascular coiling ranges from 2% to 8.8%. ^{[6],[7],[8],[9]} with a procedure-related permanent complication rate of 3.7%. ^[10] Coiling is rapidly gaining its ground in India. However, there are no published Indian data for IPR during endovascular coiling. In this study, we report our experience (neurosurgeons') of IPR in a group of consecutive patients with intracranial aneurysms treated with Guglielmi detachable coils (GDC).

Materials and Methods

Between December 2002 and December 2008, 168 aneurysms were coiled in 150 patients. The decision to treat by endovascular method was made exclusively by the neurosurgeons as both clipping and coiling is performed by the neurosurgeon at our center. Coiling of aneurysm is predominantly based on the morphology and characteristics of the feeding vessels. The posterior circulation aneurysm, small neck, absence of large hematoma requiring evacuation, multiple aneurysms and absence of vasospam were criteria in favor of coiling.

Coiling of aneurysms was performed under general anesthesia. The diagnostic catheter of 5-6 F (Cook, Cordis), micro-guide wires of 10 or 14 size (Transend Boston scientific, Agility EV3) and micro-catheter, Prowlers series Prowler plus (Johnson and Johnson, Miami Lakes, FL, USA) were used during the procedures. The detachment system used included both electric (Boston Scientific, Fremont, CA, USA) and hydrolic (microvention) systems. On several occasions, both types of detachment system were used in a single patient. Initial basket was created with 3D coils and rest of the packing was done till no more coil could be placed or no contrast was visible inside the aneurysm in more than one plane.

Procedure-related rupture was defined as the extrusion of micro-guide wire, micro-catheter or coil outside the lumen of aneurysm with extravasations of contrast, demonstrated on angiography [Figure - 1] and [Figure - 2]. Computed tomography (CT) revealed extravasated contrast as extremely bright density on plain CT scan. Routine CT head was done in all patients [Figure - 3] to see for evidence of hydrocephalus and infarction, if any.

In all the patients with ruptured aneurysm, further use of heparin was stopped immediately and heparin therapy was reversed with protamine (1 ml/kg). Further management was based upon the stage of rupture. In case a microcatheter was in place, delivery of coils was continued until cessation of bleeding or absence of extravasations of contrast was demonstrated angiographically. The anesthetist was requested to lower the BP transiently using Propofol (6-12 mg/kg/hr) infusion, titrated to keep the BP under control.

Twenty-three published series (more than 50 patients) with data regarding the incidence and outcomes of IPR were identified and the data were compared with our findings. ^{[6],[7],[9],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30]}

Results

In the 6-year study period, 168 aneurysms were coiled in 150 [77 (52%) males and 73 (48%) females; mean age 47 years (range 9-78 years)] patients. Subarachnoid hemorrhage (SAH) was the indication for treatment in all patients. Eighteen of the patients had incidental unruptured aneurysms. Of the treated aneurysms, the size of the aneurysm was: medium (7-10 mm) in 80 (49%), large (12-15 mm) in 45 (26%), small (3-6 mm) in 26 (15%) and gain (>25 mm) in 17 (10%) patients.

The characteristics of the five patients with procedure-related aneurysm rupture are listed in [Table - 1]. The incidence of procedure-related aneurysm rupture per treated aneurysm was 2.97%. Two patients survived with no neurological deficits, whereas three died within 24-96 h after the complication, resulting in a procedure-related mortality rate of 1.78%. Average treatment delay was 4.3 days after SAH (range 1-23 days). The average treatment delay of the procedure in the ruptured aneurysm was not different from the rest of the treated patients. The size of the aneurysms with IPR were less than 6 mm in all except one, and this difference was statistically significant according to the Mann-Whitney U-test (P < 0.001). Morphologically, the ruptured aneurysms had the following features: two aneurysms had smooth wall margin, two had irregular wall and one was bi-lobed. Morphology of the aneurysm had no statistical correlation with IPR (P < 0.03).

The incidence of IPR was greater in the ruptured aneurysm than in the non-ruptured incidental aneurysm (P < 0.05). Of the five patients with IPR, four patients had a history of SAH. Three aneurysms ruptured during placement of the micro-guide wire (n = 1) or micro-catheter (n = 2), and one during placement of first coil and another during placement of second coil.

Acute hemodynamic changes, i.e. sudden alterations in pulse rate and rise in BP, were seen in four patients (major bleed). In one patient, a minor bleed was detected without any hemodynamic changes (case 2). External ventricular drain was put in two cases. The location of the unruptured aneurysm (case no.5) with IPR was at the left internal carotid artery (ICA), and was of 16 mm size. At admission, this patient had accelerated hypertension and was put on two antihypertensives (Ca+ channel blocker, angiotensin inhibitors); however, her BP was still uncontrolled for several days. Systolic BP shot up to 200 mmHg during placement of the micro-catheter. Rupture of the aneurysm had happened due to micro-catheter just before the first coil could be placed inside the aneurysm. As the micro-catheter was inside the aneurysm sac, coiling was continued till no filling was seen. However, her BP remained high despite intravenous sodium nitropruside (1 μg/kg/mt). The patient had severe ICA spasm resulting in massive infarct and died on day 3 post-procedure.

Discussion

The reported incidence of intra-operative rupture of aneurysm ranged between 15% and 53%. ^{[2],[3],[4],[5]} Most of the intra-operative ruptures occurred during dissection of the aneurysm. However, the stage of the procedure at which rupture occurs during coiling is not known. During clipping, intra-operative aneurysmal rupture can be managed by the application of temporary clip proximally or distally and direct pressure on carotid artery, whereas these manoeuvres cannot be performed in IPR during coiling. Moreover, the patient is heparinised during the endovascular procedure, which may result in failure of spontaneous arrest of bleeding and IPR can be fatal.

Procedure-related aneurysm rupture during endovascular coiling data are summarized in[Table - 2].^{[6],[7],[9],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30]} Procedure-related rupture occurred in 3.24% of the patients who had endovascular coiling, similar to the findings in our study (2.97%) [Table - 2]. Of the 163 patients with aneurysm rupture, 107 patients had a good outcome, one patient was in vegetative state and 55 patients died (1.09%). Of the 3645 patients treated for ruptured aneurysm (SAH), IPR occurred with 149 aneurysms, where it was with two aneurysms in 917 unruptured aneurysms (incidental). This difference was highly significant (P < 0.001) thus identifying ruptured aneurysm (SAH) as a risk factor for procedure-related rupture. Nguyen et al.^[25] reported that very small aneurysms (<3 mm) were found to be five times more likely to be associated with procedure-related rupture. Our study also suggests that small aneurysm size is associated with a higher incidence of procedure-related rupture, similar to the earlier reports. ^{[21],[22],[25]}

Although reversal of heparinization and further delivery of coils are likely to stop angiographically observed bleeding, more than one-third of the patients (1.09%) in this group had died as a direct result of this complication [Table - 2]. If it is assumed that a 2% mortality rate is acceptable for detachable coil-treated cerebral aneurysms, it is clear that rupture during treatment is a substantial cause of procedure-related deaths. As noted by Sluzewski et al.,^[22] the clinical outcome of IPR reflects all or none phenomenon: patients either do very well or die, which is probably related to the rapidity with which hemostasis can be achieved (or not) and ICP controlled (or not).

Mechanism of rupture

Various mechanisms have been proposed to explain IPR: fluctuation in blood pressure, intraluminal pressure following injection into the aneurysm or perforation of aneurysm by micro-catheter, coil or micro-guide wire. ^{[6],[31],[32]} Another postulated mechanism was that there can be diversion of blood flow by the coil, resulting in a weaker portion of the aneurysm wall to rupture. ^[33]

Data from a large meta-analysis suggests ruptured aneurysm as a risk factor for IPR. ^[5] Chronic obstructive pulmonary disease (COPD), coronary artery disease and hyperlipidemia were identified as predictors of IPR. Chronic airways obstruction increases the risk of IPR in patients undergoing coil embolization. ^[27] Smoking is another recognized risk factor for aneurysm growth and rupture and is positively correlated with the intensity of smoking. ^[34],[35] Genetic and acquired alfa 1-antitrypsin deficiency, as well as increased levels of matrix metalloproteinases, have also been implicated in the pathogenesis of ruptured intracranial aneurysms. ^{[35],[36],[37]}

It is unclear during which stage of the endovascular procedure IPR happens. Most iatrogenic ruptures reported in the literature are because of coils or guide-wires. Rupture can happen from the first to the last coil. ^{[6],[15],[21],[22],[38]} What causes aneurysmal rupture is still unclear. When the wire is removed from the catheter, the potential energy within the catheter's loop inadvertently propels the catheter tip forward with smaller aneurysms. It is more difficult to deploy early coil without directly impinging on the aneurysmal wall; this impingement can result in aneurysmal rupture. ^[26] The mechanism of rupture can be further understood by the careful observation of aneurysm on the monitor during coiling. It has been clearly shown that the micro-catheter makes several movements within the sac during the procedure. These motions are inevitable and are more visible during the initial coil placement. There is a change in axis of micro-catheter during coil deployment, which is more so at the initial stages. The recoil of the micro-catheter can be due to storage of potential energy, which can lead to rupture [Figure - 4]. The micro-catheter becomes more stable with subsequent coils in place and, hence, there are lesser chances of rupture at a later stage of coiling. Larger aneurysms tend to rupture when numerous coils are placed, resulting in catheter wedging between deposited coils and the aneurysmal wall. Re-rupture in the large lesions, however, could also occur from careless handling of the wire or catheter. Although balloon-assisted coiling is often helpful for wide-necked aneurysm, inflation of a balloon across an aneurysm neck may cause rupture. ^[22],[26]

Management of IPR

Several techniques are now available to gain control of an IPR. If rupture occurs early during coiling, heparin therapy should immediately be reversed with protamine sulfate. Further coil embolization should be attempted with precision and safety. Further coil packing of the aneurysm usually stops hemorrhage if the rupture was a result of coil herniation. ^[26] In the case described by Willinsky and ter Brugge, ^[39] aneurysm perforation by micro-catheter was treated by leaving the catheter in place and introducing a second micro-catheter without disturbing the (i.e., "plug in the dike") the first catheter. Vessel sacrifice is another technique that can be used to safely control aneurysmal hemorrhage in endovascular-related rupture. An elevation in intracranial pressure immediately after aneurysmal rupture may be catastrophic and can be managed by external ventricular drainage. ^[26]

Conclusions

Procedure related rupture during endovascular coiling occur in 2.97% of procedure and is responsible for 1.78% treatment related deaths. Risk factors are small aneurysm size, previous SAH. The outcome of treatment of aneurysm with coiling is safe in the hands of neurosurgeons.

References

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