Microsurgical Management of Residual and Recurrent Aneurysms After Coiling and Clipping

Abstract

Residual and recurrent aneurysms are difficult quandaries for patients and clinicians because curative occlusion is not achieved and a decision about retreatment must be made, weighing the risks of rupture from a partially treated aneurysm against the risks of further intervention, which can be exponentially more challenging than an untreated aneurysm. In a review of incompletely coiled and recurrent aneurysms managed microsurgically during a 10-year period from 1997 to 2007, we observed a spike in the annual number of treated patients from an average of 3 patients per year to 11 patients in the last year of the study.1 We were concerned that this sharp increase in the incidence of residual and recurrent aneurysms requiring surgery might portend a dangerous problem in the durability of endovascular repair, particularly when more than half of recurrent aneurysms had coils extruded from the aneurysm into the subarachnoid space. Since this review, endovascular case volume has grown steadily as results from the International Subarachnoid Aneurysm Trial (ISAT)2 were replicated in similar randomized trials like the Barrow Ruptured Aneurysm Trial (BRAT).3 In addition, market forces and patient preferences for minimally invasive therapies have reinforced this shift in clinical practice away from open craniotomy.4,5 Increasing endovascular case volume will magnify the problem of aneurysm recurrence and retreatment after initial coiling unless advances in endovascular technology and technique such as stent-assisted or balloon-assisted coiling and flow diverters address this issue. Therefore, we conducted an update of our experience with incompletely coiled and recurrent aneurysms managed microsurgically to measure the magnitude of this problem. In addition, we examined a concurrent experience with incompletely clipped and recurrent aneurysms after clipping also managed microsurgically. This review was intended to better define the indications for surgery, to help select the best first treatment modality, and to elaborate on microsurgical techniques for these challenging aneurysms. METHODS The study was approved by the Institutional Review Board and conducted in compliance with Health Insurance Portability and Accountability Act regulations. The prospectively maintained database for the Vascular Neurosurgery Service at the University of California-San Francisco was searched for patients with aneurysm who had microsurgical treatment after previous endovascular intervention during the 17-year period from December 1997 to December 2014. Medical records, radiographic studies, operative reports, intraoperative photographs, and clinical follow-up evaluations were reviewed retrospectively. Patients were included if their surgery was preceded by incomplete aneurysm coiling or their aneurysm recurred after prior coiling (Gurian group B). Patients were excluded if endovascular therapy was attempted but aborted (Gurian group A) or if they required surgical intervention as a result of a complication arising from an endovascular procedure (Gurian group C). Additionally, the database was searched for patients with aneurysm who had microsurgical treatment for residual or recurrent aneurysm after previous microsurgery either by the senior author or by other referring neurosurgeons. Residual or remnant aneurysms were defined as treated aneurysms, whether endovascularly or microsurgically, with incomplete obliteration or persistent aneurysm filling angiographically immediately after treatment. Recurrent aneurysms were defined as treated aneurysms, whether endovascularly or microsurgically, with incomplete obliteration or persistent filling angiographically at later follow-up (>3 months). Recurrent aneurysms may have arisen from aneurysms that were completely occluded initially and subsequently underwent coil compaction or regrowth or from residual aneurysms that were incompletely occluded initially and subsequently compacted or regrew. Recurrent aneurysms presented as rehemorrhages, with new compressive symptoms, or as findings on surveillance angiography. Aneurysm outcomes were evaluated with postoperative catheter angiography that was interpreted by independent neuroradiologists. Patient outcomes were evaluated by independent research clinicians preoperatively, postoperatively, and at last follow-up with the Glasgow Outcome Scale score. RESULTS Residual and Recurrent Aneurysms After Coiling During the 17-year study period, 3600 aneurysms were treated in a single-surgeon series of 2748 consecutive patients by the senior author (M.T.L.). Of those, 73 patients (2.7%) underwent microsurgical treatment of 73 aneurysms (2.0%) that were either residual or recurrent after endovascular coiling. A female predominance was observed, with 58 women and 15 men at a mean age of 49 years (range, 15-77 years; Table 1). Overall, 64 patients (88%) presented with subarachnoid hemorrhage (SAH), and the remainder presented with mass effect symptoms from giant aneurysms, with headache, or with incidental aneurysms.TABLE 1: Residual and Recurrent Aneurysms After CoilingAnterior cerebral artery (ACA) aneurysms were the most common (22, 30%), followed by posterior cerebral artery (PCA; 12, 16%) and middle cerebral artery (MCA; 10, 14%) aneurysms. Seventeen aneurysms (23%) were in the posterior circulation. Four aneurysms (5%) were large, and 7 (10%) were giant. Thirty-two patients (44%) had known residual aneurysms after endovascular coiling and were referred immediately for microsurgical treatment. Four of these patients (12%) rehemorrhaged after the coiling procedural before their referral. The remaining 41 patients (56%) had recurrent aneurysms after endovascular coiling. The median interval from initial endovascular treatment to microsurgery for a recurrent aneurysm was 2 years. Of the recurrent aneurysms, 35 (85%) were referred after the recurrence was demonstrated on surveillance angiography; 3 (7%) were referred after developing new or progressive symptoms from mass effect; and 3 patients (7%) presented with recurrent SAH. Most residual and recurrent aneurysms (59, 81%) were retreated with microsurgical clipping alone. Of those, 72% were clipped below coils that compacted enough to reform a soft, clippable neck (Figures 1 and 2). Another 6% had coils in the neck, and the clips were placed across loops of coil. Another 9% also had coils in the neck, and the clips were placed against the coil mass. Aneurysm transection with coil mobilization and/or extraction was required in 12% to facilitate clip placement (Figures 3 and 4). Bypass was required in 8 patients (11%) (Figure 5), and 1 giant posterior cerebral artery aneurysm was trapped without bypass (Table 1). Wrapping was used early in the series (the last wrapped aneurysm was in 2005) as a last resort when other methods of aneurysm exclusion failed.FIGURE 1: This case demonstrates simple clipping of a recurrent aneurysm. A, this 47-year-old woman had a ruptured left ophthalmic artery that was coiled successfully (left internal carotid artery injection, 3-dimensional reconstruction, lateral view). B, surveillance angiography demonstrated coil compaction at 6 months (left internal carotid artery injection, digital subtraction angiogram, lateral view). C, the anterior clinoid process covered the proximal neck. D, clinoidectomy exposed the neck and optic nerve. E, the aneurysm was clipped with 2 clips below the compacted coil mass, and (F) the compressive coil mass was removed. G, postoperative angiography (left internal carotid artery injection, 3-dimensional rotational angiogram, anteroposterior view) confirmed complete aneurysm occlusion.FIGURE 2: This case demonstrates tandem clipping of a recurrent left posterior communicating artery aneurysm after stent-assisted coiling. A, surveillance angiography in this 49-year-old woman demonstrated aneurysm recurrence and regrowth (left internal carotid artery injection, digital subtraction angiogram, lateral view and [B] anteroposterior view). C, intraoperatively, the Neuroform stent was seen through the wall of the internal carotid artery, and coils were extruded into the subarachnoid space. D, the aneurysm was clipped with a fenestrated clip on the proximal neck and a straight clip closing the fenestration distally. E, extruded coils extended into the temporal lobe, which was stained with hemosiderin from the initial subarachnoid hemorrhage. F, indocyanine green videoangiography showed the tines of the stent, complete aneurysm occlusion, and preservation of anterior choroidal artery.FIGURE 3: This case demonstrates clipping of a residual anterior communicating artery (ACoA) aneurysm after coil extraction. A, this 34-year-old man's coiling procedure after subarachnoid hemorrhage was complicated by aneurysm perforation and rehemorrhage. The procedure was stopped, and residual aneurysm remained (left carotid injection, digital subtraction angiography, lateral view and [B] 3-dimensional reconstruction, lateral view). C, intraoperatively, coils perforated through the dome of the aneurysm superiorly, and intrasaccular coils filled the neck. D, after trapping of the ACoA complex with temporary clips, the aneurysm was transected, and the coil mass was pulled upward out of the aneurysm. E and F, the softened neck was clipped with a straight clip, and the untreated anterior lobe was clipped with 4 stacked clips. G, postoperative angiography (right internal carotid artery injection, digital subtraction angiography, right anterior oblique view, and [H] 3-dimensional reconstruction, left anterior oblique view) confirmed complete aneurysm occlusion.FIGURE 4: This case demonstrates clipping of a recurrent anterior communicating artery aneurysm after coil extraction. A, this 44-year-old woman presented with subarachnoid hemorrhage, was initially coiled, and had 2 recurrences that were retreated with additional coiling (right internal carotid artery [ICA] injection, digital subtraction angiography, lateral view). B, an attempted retreatment of her third recurrence with stent-assisted coiling resulted in intraprocedural perforation before stent placement (right ICA injection, digital subtraction angiography, anteroposterior view; note guidewires in both ICAs). C, intraoperatively, the aneurysm was densely packed with some coil extrusion inferior in the interoptic triangle. D, the aneurysm was transected, and coils were densely adherent to the posterior neck. E, most but not all of these adherent coil fragments were removed, and (F) the transected neck was closed with clips across these strands of coil. Note the bilateral A2 anterior cerebral arteries (ACAs) and a midline accessory ACA. G, postoperative angiography (right internal carotid artery injection, digital subtraction angiography, right anterior oblique view, and [H] 3-dimensional reconstruction, right anterior oblique view) confirmed complete aneurysm occlusion.FIGURE 5: This case demonstrates treatment of a recurrent posterior inferior cerebellar artery aneurysm with trapping and bypass. A, this 69-year-old woman had coil compaction identified on surveillance angiography (left vertebral artery injection, digital subtraction angiography, lateral view and [B] anteroposterior view). C, the aneurysm neck was atherosclerotic, and the inflow and outflow arteries were at right angles, making clipping difficult. D, these arteries were transected and reanastomosed end to end. E, the coiled aneurysm was left in situ to avoid manipulation of the lower cranial nerves, and (F) the anastomosis filled well, (G) as confirmed on postoperative angiography (left vertebral artery injection, digital subtraction angiography, lateral view).Bypasses included 2 extracranial-to-intracranial bypasses: superficial temporal artery-to-PCA (1 patient with a giant basilar artery apex aneurysm) and a cervical internal carotid artery (ICA)-to-MCA bypass with a saphenous vein graft (1 patient with a giant ophthalmic artery aneurysm). Three in situ bypasses were performed: reimplantation of the posterior inferior cerebellar artery (PICA) onto the vertebral artery (2 patients with PICA aneurysms, 1 of which was giant) and an anterior temporal artery-to-MCA bypass (1 patient with a fusiform MCA aneurysm). One PICA aneurysm recurrence was excised and reanastomosed. Two intracranial-to-PICA bypasses were performed. In the first case, a radial artery graft was connected proximally to the A1 anterior cerebral artery (ACA), and the MCA efferent trunks coming from the aneurysm were reimplanted onto the graft (double-reimplantation technique). In the second case, an allograft saphenous vein graft was connected proximally to the M2 MCA and distally to the A2 ACA branches of an anterior communicating artery (ACoA) aneurysm. Once the bypasses were completed, 4 aneurysms were trapped, 3 were proximally clip occluded, and 1 was treated with additional coils. Complete angiographic aneurysm occlusion was achieved in 65 patients (89%). Incomplete aneurysm occlusion was observed in 2 residual and 1 recurrent aneurysm (4%) treated with direct clipping. Incomplete aneurysm occlusion was observed in the 5 wrapped aneurysms, of which 4 had angiographic follow-up and these 4 aneurysms remained radiographically stable. One patient with a large, broad-necked recurrent basilar bifurcation aneurysm was treated with a superficial temporal artery-PCA bypass only to aggressively coil the recurrent aneurysm and to protect the PCA territory if the involved P1 origin was occluded. This aneurysm was incompletely obliterated after coiling. Seven of the 8 bypasses were patent. Three patients died in the perioperative period (surgical mortality, 4%). One patient had an MCA aneurysm that was incompletely coiled at an outside institution and reruptured, and she was transferred while in coma. She died despite uncomplicated clipping of her aneurysm. One patient with a giant basilar bifurcation aneurysm recurred after coiling with aneurysm growth, coil compaction, and progressive obtundation. Superficial temporal artery-PCA bypass and additional coiling of the aneurysm failed to reverse his deterioration, and support was withdrawn. One patient died of ischemic complications related to vasospasm. Patient outcomes were favorable, with good outcomes (Glasgow Outcome Scale score, 5 or 4) observed in 65 patients (89%). At the last follow-up evaluation (mean duration, 6 years), 67 patients (92%) were improved or unchanged. Three patients (4%) were worse neurologically after surgery. One patient had a new visual field deficit after clipping of a recurrent ophthalmic artery aneurysm. One patient developed unilateral leg weakness caused by her MCA-to-ACA bypass occluding and causing an ischemic infarct. One patient developed short-term memory difficulty after clipping of an enlarging residual, previously ruptured ACoA aneurysm. Residual and Recurrent Aneurysms After Microsurgical Clipping During the 17-year study period in which 3600 aneurysms were treated in a single-surgeon series of 2748 consecutive patients, 6 patients (0.2%) returned to the operating room for re-exploration and clipping of a residual aneurysm seen on postoperative angiography. The mean patient age was 53 years (range, 38-72 years), and patients were evenly divided between men and women. All 6 patients presented with SAH. Aneurysms were located as follows: ACoA, 4 patients; superior hypophyseal artery, 1 patient; and midbasilar trunk, 1 patient. Five residual aneurysms were completely clipped during the second surgery, and the aneurysm in 1 patient reruptured during re-exploration of a midbasilar artery aneurysm, and the patient later died. An additional 14 patients were initially treated microsurgically by an outside neurosurgeon and were referred with recurrent aneurysms for microsurgical treatment. Their mean age was 54 years (range, 29-69 years); all but 1 were female; and all of them presented with SAH. Twelve of these patients' aneurysms were previously clipped, and 2 were wrapped. The median time between initial surgery and reoperation for recurrence was 13 years (range, 0.4-32 years). Six recurrences were discovered with surveillance imaging; 2 were discovered on imaging for headaches; and 6 patients (40%) presented with new SAH. Aneurysm recurrences occurred at the posterior communicating artery (PCoA) in 4 patients, supraclinoid ICA in 3, basilar bifurcation in 2, ACoA in 2, MCA in 2, and SCA in 1 patient. Overall, 12 recurrent aneurysms were completely clipped. One fusiform ICA aneurysm required a cervical ICA-MCA bypass and trapping, and 1 recurrent giant basilar artery aneurysm could not be clipped and later underwent successful stent-assisted coil embolization. Twelve patients with recurrent aneurysms (86%) were improved or unchanged after surgery. One patient developed significant vasospasm and mild aphasia after clipping of a recurrent PCoA aneurysm. Another patient's recurrent SCA aneurysm presented with a Hunt-Hess grade IV SAH, and although the aneurysm was completely clipped, she remained in coma, and care was withdrawn. Four additional patients were initially treated microsurgically by the senior author, had recurrence of their clipped aneurysms, and were subsequently treated endovascularly. One 29-year-old patient had a giant and dysplastic basilar bifurcation aneurysm that ruptured and was clip reconstructed with a good angiographic result, but the aneurysm recurred 4 years later on the efferent P1 PCA segment with the formation of a serpentine aneurysm. This was treated endovascularly with coiling of the channel and has been stable for 3 years. A second 66-year-old patient with a dolichoectatic, giant basilar trunk aneurysm had a large PCoA that was proximally clip occluded. Her aneurysm failed to thrombose completely, and she was treated with 2 separate stages of coil embolization of the enlarging aneurysm sac. A third 34-year-old woman presented with a ruptured P1-P2 PCA aneurysm that was proximally clip occluded. Although the aneurysm thrombosed completely, she returned with a new oculomotor nerve palsy and recanalization of the aneurysm through the PCoA. She tolerated coiling of the aneurysm despite occlusion of the contribution of the PCoA to the PCA territory. Finally, a fourth 53-year-old patient presented with a supraclinoid ICA aneurysm that recurred 23 years after PCoA aneurysm clipping. The aneurysm was clipped completely but recurred a second time 7 years later and was treated with stent-assisted coiling. All 4 of these patients remained stable clinically after their endovascular therapies. Rehemorrhage of Recurrent Aneurysms A total of 14 patients (14%) in this experience rehemorrhaged from residual or recurrent aneurysms after coiling and clipping (Table 2), including 4 patients with residual aneurysms after coiling, 3 patients with recurrent aneurysms after coiling, and 6 patients with recurrent aneurysms after surgical clipping. The median time to rehemorrhage was 1.1 years for previously coiled recurrent aneurysms and 15.5 years for previously clipped recurrent aneurysms. Aneurysm recurrence and rehemorrhage adversely affected patient outcomes, with a median final Glasgow Outcome Scale score of 4 for patients experiencing SAH from recurrent aneurysms compared with a median of 5 for those with recurrent aneurysms that were diagnosed with surveillance imaging.TABLE 2: Hemorrhage Rates Associated With Residual and Recurrent AneurysmsDISCUSSION Clinical Trends This microsurgical experience with 97 residual and recurrent aneurysms in 97 patients, 73 of whom had residual/recurrent aneurysms after coiling, is one of the largest reported in the literature.6-13 However, this review spanned 17 years with an average of 4 to 5 coil residual/recurrence cases per year and accounted for only 2% of all aneurysms treated microsurgically. Therefore, aneurysm recurrence and retreatment after coiling have not become the expansive problem that we once feared, even with the frequent extrusion of coils observed intraoperatively. In an earlier publication, we projected that residual/recurrent aneurysms would increase in incidence as a result of the following: a growing endovascular case volume; neurologists and neurosurgeons joining interventional neuroradiologists in acquiring endovascular competencies; patients preferring less invasive aneurysm therapy; community hospitals building comprehensive stroke and aneurysm centers with low case volumes and diminished technical expertise; and cost savings derived from shortened hospitalizations that appeal to and the incidence of residual/recurrent aneurysms has remained stable from our surgical Although we not retreatment of residual/recurrent aneurysms from an endovascular our findings that advances in coil and stent-assisted coiling, and flow with endovascular have recurrences and microsurgical retreatment in and of Aneurysm and recurrences were treated 4 more than clip and recurrences in our which is with the superior and durability of microsurgical (Table A clip across an aneurysm neck the the bifurcation and that can and the wall In coils the aneurysm but the neck open and separate the coils to or the coils and the artery from and the wall in some Incomplete aneurysm occlusion is a significant problem after coiling that to both and In complete occlusion was achieved in of endovascular patients compared with of microsurgical patients The large number of neck and incomplete in endovascular patients to and 15 during the first year after treatment and an additional 7 and 2 after the first The rehemorrhage was in endovascular patients than in microsurgical patients, in whom were 13 in 3: Rates of Recurrent and Residual and Recurrent Subarachnoid Hemorrhage and Aneurysm After study a similar in rehemorrhage in endovascular patients and in microsurgical The complete aneurysm occlusion was in microsurgical patients and only in endovascular patients, and the annual rehemorrhage with of coil with completely occluded aneurysms, with to occlusion, and with Rehemorrhage in coiled patients from in the first year to but recurrences and were retreatment during the first retreatment during the second and were less in microsurgical in the first year and results from also identified significant in aneurysm occlusion and for coiling and clipping at 3 and retreatment and for coiling and clipping at 1 and and for coiling and clipping at 3 more outcomes in demonstrated that the early of coiling with in outcomes with anterior aneurysms. with of patients randomized to of patients randomized to coiling had Scale Therefore, randomized trials for their early patient outcomes, but incomplete aneurysm occlusion, rehemorrhages, and final outcomes and to the early with endovascular The of and durability with endovascular aneurysm may not to a large or growing number of microsurgical cases of residual/recurrent aneurysms, but these in the of initial aneurysm for Residual and Recurrent Aneurysms The and our (Table rehemorrhage risks from residual/recurrent aneurysms after coiling and clipping and for intervention when surveillance of aneurysm patients is Patients with coiled aneurysms be angiographically at 6 months and 2 years after with additional follow-up when even residual/recurrent aneurysm is Patients with clipped aneurysms be angiographically immediately and 5 years after not only for recurrences but also for new aneurysm Patients with aneurysms, angiographic and are further at years and The of aneurysm formation is by to be in patients with treated aneurysm. from clipped aneurysm recurrences with median of 13 years in our experience and years in the experience of which the for recurrences new that from a aneurysm. The soft, of an untreated aneurysm is by a and a of at the neck. can both endovascular and microsurgical more difficult. The of intraprocedural or intraoperative rupture is less with coiled aneurysms in our but the coil mass is Aneurysm recurrences the that coiling. coil compaction may not enough for clip A large coil mass will of clip or the clip the neck and the or The of aneurysm recurrence the of endovascular or microsurgical Coiling is when recurrent aneurysm can be packed and clipping is when the recurrence is and is neck for clipping. Clipping is also when the recurrence is not compaction but because aneurysms have that are at of further recurrences with coiling. Clipping this dysplastic and is to be more Although difficult to coil extrusion may also aneurysm wall and surgery additional A of would help with surgical We a between compaction and coil (Figure is the of the aneurysm the not the to the is the of the coil mass, at the of the aneurysm at the of compaction, to the neck but to the of clip or clip coil is in the to the clip in other the of between the of clip A of coil to compaction with the of an aneurysm. A coil mass an or of aneurysm on which the clip is Aneurysms with coil and compaction have a for compaction of which clip the clip the aneurysm neck, and can or In a previous of 13 aneurysms with a compaction were not to simple clipping and required complex clipping after or coil or techniques or In 6 of 8 aneurysms with a compaction were to simple may the of recurrent aneurysms after coiling. is the of the aneurysm the not the to the is the of the coil mass, at the aneurysm at the of compaction, to the neck but to the of clip A of coil to compaction of with aneurysm also Aneurysms with fusiform or branches at the might be Aneurysms with compaction might not have room for clip and a in surgery might more compaction and clipping Microsurgical The microsurgical treatment of coiled aneurysms is direct with the clip below across a or in the neck, or against a coil mass in the neck. A previously coiled aneurysm not to the and complete of the neck with clips like a aneurysm Clipping a residual/recurrent aneurysm is simple and when is but aneurysms an aneurysm can be to coils away from the neck or into a clippable This is best by the at the to to the coil mass, to to the and to of at the neck. coils through a in the dome is and the extraction is Complete extraction of coils is not coils are when left the aneurysm and coils to be only enough to the neck and the can be from residual aneurysms that are but recurrences have that coils Aneurysm transection complete trapping with temporary clips and of This technique can be complicated by incomplete proximal and during the repair, adherent arteries or difficulty in the neck after the aneurysm, and of the coils to the neck. time can be arteries are to are and the decision to this is an aneurysm can be in with aneurysm trapping or proximal occlusion, or or occlusion not the aneurysm completely but aneurysm through With the of extracranial-to-intracranial in situ and bypasses with saphenous or radial artery the territory of the artery of aneurysm can be In to aneurysm a bypass can be time is and direct aneurysm can be We were more to for the bypass the extraction with aneurysms. with or and of the aneurysm wall and is a treatment of last Although of the wrapped aneurysms in our experience has or surgery, we have away from this technique and have not wrapped residual/recurrent aneurysms during the last years. of Aneurysm the best to with residual/recurrent aneurysms is to them by initially the better aneurysm treatment. with residual/recurrent aneurysms after coiling low and large and giant and of like coiled aneurysms and clipping more the aneurysm. Aneurysm recurrence through such as at the MCA bifurcation are than at other and through such as at the basilar bifurcation forces are more to ACoA aneurysms were more to and recurrences in our of the artery or of arteries can and obliteration The initial of aneurysm treatment is best by a of aneurysm with in both endovascular and microsurgical therapies. must be not to treatment risks but also to and is to select endovascular therapy for those aneurysms with that treatment and is also to select microsurgery for those aneurysms with endovascular that could be coiled but may not be obliterated completely and may have an recurrence treatment will avoid the of a coil recurrence or for aneurysm therapy are and in the these challenging and good that the of aneurysm recurrence with other In the endovascular microsurgical treatment of residual and recurrent aneurysms is in a number of therapy is with significant of residual/recurrent aneurysms with a defined of rehemorrhage and Microsurgical treatment of residual/recurrent aneurysms is and in the of with a requiring including dome transection with coil extraction and trapping with bypass. of the initial treatment modality, patients with treated aneurysms at for aneurysm aneurysm and and is when angiographic surveillance is The have or in of the or in this