Neurosurg Rev DOI 10.1007/s10143-016-0810-z ORIGINAL ARTICLE Paradigms for single-patient multimodality treatment for cerebral aneurysms: single-center eleven-year experience Abdullah Alobaid 1 & Erez Nossek 2 & Katherine Wagner 1 & Avi Setton 1 & Amir R. Dehdashti 1 & David Langer 3 & David Chalif 1 Received: 11 October 2016 / Revised: 12 December 2016 / Accepted: 28 December 2016 # Springer-Verlag Berlin Heidelberg 2017 Abstract Endovascular and surgical techniques are conventional options for treating intracranial aneurysms, but criteria for selecting an optimal approach for individual patients remain variable across practitioners and institutions. While endovascular and surgical approaches are generally used alone, both modalities combined in single patients can produce efficacious outcomes. The aim of this study was to evaluate outcomes of combined, concomitant endovascular and surgical modalities in the treatment of multiple and/or complex aneurysms in single patients. Indications, sequencing rationale, and categorization for multimodality treatments are reviewed. All intracranial aneurysms treated at our institution from 2004 to 2014 were reviewed. Single patients who had undergone concomitant endovascular and surgical treatments were eligible for participation in our study. Demographic data and clinical presentation parameters, including location, size, and morphological features of lesions, treatment sequencing, and outcomes were recorded. Our cohort consisted of 27 patients with 57 aneurysms who received concomitant endovascular and surgical treatment of their aneurysm(s). One patient arrived to us after he had an aneurysm clipped at an outside institution and then required treatment for a contralateral ruptured aneurysm. 66.7% of patients were diagnosed with subarachnoid hemorrhage. These were subdivided according to therapeutic approach: clipping and coiling (CL+ CO), clipping and stenting (CL+ST), bypass and endovascular parent vessel occlusion (PVO) (BY+PVO), attempted clipping then stenting, and bypass followed by stenting. Glasgow Outcome Scale was as follows: CL-CO-Multiple, 4.17 (five in unruptured patients, 3.75 in ruptured); CO-CLMultiple, five (all patients had a ruptured aneurysm); CL-COSingle, three (all patients had a ruptured aneurysm); CO-CLSingle, five (all patients had a ruptured aneurysm). No patients suffered a new neurological deficit as a result of treatment. A total of two mortalities were documented. Concomitant, mutimodality endovascular and surgical therapy may offer a safe and potentially more effective paradigm than single modality approaches for the management of multiple, complex, or Bfailed^ aneurysm treatments in selected patients. Keywords Aneurysm . Bypass . Brain . Clipping . Coiling . Endovascular: microsurgery . Subarachnoid hemorrhage Introduction * David Chalif dchalif@nshs.edu 1 Department of Neurosurgery, Hofstra Northwell School of Medicine, and Northwell Health, 300 Community Drive, 9 Tower, Manhasset, NY, USA 2 Division of Neurosurgery, Maimonides Medical Center, Brooklyn, NY, USA 3 Department of Neurosurgery, Hofstra Northwell School of Medicine, and Northwell Health, Lenox-Hill Hospital, NY, USA Cerebral aneurysm rupture is the most common cause of spontaneous subarachnoid hemorrhage (SAH), which has a morbidity rate of 8–20% and mortality rate of 37–57% [17]. Historically, surgical clipping remained the treatment of choice for cerebral aneurysm until the early 1990s when endovascular coiling became part of standard care [4, 15]. Over the last 20 years, the emergence of endovascular modalities has revolutionized the treatment of ruptured aneurysms [4]. Additionally, cerebral revascularization and parent vessel occlusion (PVO) are efficacious techniques when Neurosurg Rev treating complex aneurysms with poor collateral circulation that cannot be directly clipped [7]. The original International Subarachnoid Aneurysm Trial (ISAT) study and its follow-up study, although controversial and criticized, have clearly led to a culture change in the selection of treatment modalities for specific aneurysms [15, 16]. Despite these findings, the purported superiority of coiling over clipping and newer endovascular devices has not been validated in all patients whose clinical presentations may differ from those of the original ISAT cohort [8]. Based on these issues, major institutional differences and bias, surgeon preference and experience, morphologic and anatomic considerations, and vigorous debate continue over the selection of specific treatment techniques, including clipping versus coiling versus stent-assisted coiling, for different disease profiles of patients with both unruptured aneurysms and aneurysmal SAH. Our experience suggests that the optimal intervention for each individual should be based on both clinical and demographic criteria, such as specific aneurysm morphologies, aneurysm locations, age, comorbidities, and other risk factors. In some institutions, clipping and coiling are administered as alternate therapies to different populations in an attempt to balance the utilization of various modalities. Additionally, some institutions and geographic areas are biased towards one treatment modality or another. Alternatively, clipping and coiling can be employed in a complementary multimodality approach in treating single or multiple aneurysms in a single patient. Integrative interventions require a collaborative, cohesive, multidisciplinary approach between the endovascular and surgical teams [1]. The aim of this study was to evaluate the effectiveness of concomitant multimodality endovascular and surgical techniques in the management of complex aneurysms in single patients. As part of our effort to develop a paradigm for single-patient multimodality treatment, we discuss the indications, rationale for patient selection and treatment sequencing, and outcome of concomitant endovascular and surgical intervention in pre-selected patients. Materials and methods Cases of ruptured and incidental cerebral aneurysms that were treated in North Shore University Hospital from 2004 to 2014 were retrospectively reviewed. Only single patients who had undergone concomitant multimodality treatments with both open microsurgery and endovascular modalities were included in the analysis. In this study, endovascular treatments were defined as coiling, balloon-assisted coiling, stenting, stenting with associated coiling, or PVO (parent vessel occlusion). Diagnostic angiograms as well as angioplasties alone were excluded from our armamentarium of endovascular interventions used in this analysis. Patients that were treated with stent-assisted coiling or with a flow diverter stent were prepared preoperatively as follows: patients were started on dual antiplatelet therapy (daily clopidogrel 75 mg and salicylic acid 325 mg) 5 days prior to the procedure. A response was confirmed using P2Y12 assay (VerifyNow™; Accumetrics, San Diego, CA) which was obtained in all patients directly preceding the procedure and thereafter daily until discharge. Surgical treatment encompassed direct microsurgical clipping, attempted microsurgical clipping, and/or bypass. Patients who received external ventricular drains, shunts, or decompressive craniectomies as their only neurosurgical treatment were excluded from the analysis. Demographic and clinical presentation parameters, including initial presentation (such as grade of SAH, symptomatic versus incidental aneurysm), location, size, and morphological characteristics of lesions, treatment sequencing, and outcomes were recorded. Patients were categorized based on a treatment paradigm of various combinations of endovascular and surgical therapies formulated and utilized at our center. An MRA is performed at 3–6 months, and if this is acceptable, a formal angiogram is performed at 1 year post-procedure. The outcome of each patient was then assessed using the Glasgow Outcome Scale (GOS) [19]. Results A total of 1493 aneurysms were treated at our institution between 2004 and 2014. 69.8% of our cases were SAH, while 31.2% of patients had non-ruptured aneurysms. Over the last 11 years with a combined microsurgical/endovascular team, 54.8% of aneurysms underwent direct microsurgical treatment and 45.2% were treated with endovascular techniques. During this period, 35 patients met the eligibility criteria of receiving concomitant multimodality treatment in a single patient. Of this group, eight patients were excluded due to lack of clinical follow-up, leaving 27 patients with a total of 56 aneurysms (including one mycotic aneurysm) available for the final analysis. Aneurysm locations were MCA (M1, MCA bifurcation, M2) 19 (31.5, ACA (A1, AComm, A2) 11 (19.3%), PComm 8 (14.3%), ICA bifurcation 5 (8.7%), superior hypophyseal artery 6 (10.5%), ophthalmic artery 3 (5.3%), superior cerebellar artery 2 (3.5%), and basilar artery 1, dural ring 1, posterior cerebral artery 1, and pericallosal artery 1 (each 1.75%). Mean aneurysmal size was 7.2 mm, ranging from 2 to 35 mm. The cohort was comprised of 70% females and 30% males and had a mean age of 54.3 years. Presentation Of the 27 patients in the study group, 18 (66.7%) presented with SAH and nine (33.3%) presented with unruptured Neurosurg Rev aneurysms. Of these nine, seven aneurysms (23.3%) were discovered incidentally, one was found secondary to the mass effect (3.33%) that was causing cognitive and gait disturbances, and another was detected during a workup for visual disturbances and suspected optic nerve compression (3.33%). Demographic characteristics are presented in Table 1. Multimodality single-patient treatments Patients were assigned to the following categories based on their treatment modalities (Tables 1 and 2): (1) clipping and coiling (CL+CO) (n = 17), (2) clipping and stenting (CL+ST) (n = 6), this group includes one attempted clipping followed by successful stenting, (3) bypass and endovascular PVO (BY+PVO) (n = 2), (4) and (5) two underwent bypass followed by stenting (n = 2). As noted previously, patients receiving stents at our institution undergo pre-procedural treatment with aspirin and clopidogrel until a P2Y12 assay indicates that their platelet function has diminished sufficiently. In patients with ruptured aneurysms, such treatment may be delayed in light of acute hemorrhage. The CL+CO group was subdivided into four categories (Tables 1 and 3): (1a) initial clipping followed by coiling of a different aneurysm (CL-CO-Multiple (n = 6), (1b) initial coiling with clipping of a different aneurysm (CO-CLMultiple) (n = 4), (1c) clipping followed by coiling of residual/recanalized aneurysm (CL-CO-Single) (n = 4), and (1d) coiling followed by clipping for residual/recanalized aneurysm (CO-CL-Single) (n = 3). All patients who underwent stent-assisted coiling of an aneurysm initially had previous or subsequent surgical intervention. Patients in the CL-CO-M group harbored one or more additional aneurysm that were not accessible during the original surgery, but were deemed suitable for coiling. In the CO-CL-M group, all of the patients presented with a SAH and received coiling of the diagnosed or presumed ruptured aneurysm prior to microsurgical treatment of any additionally identified abnormalities. Outcomes Outcomes, as measured by scores on the GOS, were assessed for each group and recorded as follows: (Table 2) CL-COMultiple, 4.17; CO-CL-Multiple, five; CL-CO-Single, three; CO-CL-Single, five. Stenting patients showed a mean GOS of 4.8, whereas bypass patients had a mean GOS of four. Tables 2 and 3 also stratify outcomes based on the presence of subarachnoid hemorrhage. The clinical follow-up period ranged from 1 week to 48 months (mean 23 months). The patient with 1-week follow-up expired 1 week after final treatment, as described later. A total of 23 patients (85%) of the cohort received follow-up with angiographic evaluation within 1 week to 48 months after the initial presentation. Of these 23 patients, 21 (91%) exhibited no evidence of residual aneurysm at last follow-up. During the study time frame, all of the patients in the CoilClip-Single group underwent procedures to clip either a residual (2) or recanalized (1) aneurysm. One patient in the ClipCoil group experienced a re-rupture of a previously clipped aneurysm and underwent a second craniotomy for clipping of it and subsequent coiling of residual aneurysm. Two mortalities (10%) occurred in our series. The first patient was a 55-year-old female, who presented with an Hunt-Hess grade 3 SAH from a ruptured right ophthalmic artery aneurysm. She was first treated with a decompressive craniectomy followed by surgical clipping of the aneurysm. The aneurysm was re-ruptured post-clipping, and the patient received coiling but never recovered and eventually expired. The second patient was a 30-year-old man who previously had suffered a subarachnoid hemorrhage from a ruptured rightsided superior hypophyseal artery aneurysm. The aneurysm was clipped at an outside institution. He presented to our hospital 3 years later with a re-rupture and HH grade 5 SAH. Diagnostic evaluation could not confirm if the aneurysm had recanalized or if it had initially been only partially clipped. The patient’s condition failed to improve after coiling, and he expired 1 week after the procedure. Complications in this series’ patients included deep vein thrombosis, superficial thrombophlebitis, groin hematomas, urinary tract infections, septicemia, and an epidural abscess/empyema. No patients developed a new, permanent neurological deficit postoperatively or following an endovascular procedure. Additionally, patients who underwent multiple endovascular procedures did not develop clinically or radiographically significant strokes. Illustrative cases Case 1: CL-CO multiple A 64-year-old female presented with 1-day history of partial right oculomotor nerve palsy along with Bthe worst headache of her life.^ CT scan was negative for SAH, but lumbar puncture was positive for xanthochromia. CTA and formal subtracted angiogram demonstrated a 3-mm wide neck right posterior communicating artery aneurysm with an associated large posterior communicating artery, a 2-mm right anterior choroidal aneurysm, and a 4-mm left ophthalmic artery aneurysm (Fig. 1). Based on the patient’s clinical presentation and configuration of her lesions, right microsurgical clipping was considered the safest option. The patient underwent a right-sided pterional craniotomy, in which the right posterior communicating artery (PCOM) aneurysm was clipped with a 7-mm straight clip and the right anterior choroidal artery was clipped with a mini right-angled clip. The patient tolerated the procedure very well and did not suffer any post-operative Demographic data R superior hypophyseal artery— partially clipped 9 15 15 Incidentally found, treated 2007 (OSH) 15 SAH, HH1 M ACA—clipped/coiled 30 SAH, HH1 SAH, HH3 M 44 15 Incidentally found F F 66 15 SAH, HH2 15 Incidentally found L ICA Additional aneurysms found on long-term follow-up 52 F 64 7T SAH, HH4 Found when patient presented with SAH SAH, HH2 M 70 R MCA—clipped Acomm—stent-assisted coiling R ophthalmic—observed L superior hypophyseal—observed L ICA bifurcation—clipped L superior hypophyseal—monitored R PComm and R ICA bifurcation— stent-assisted coiling R Pcomm—clipped L ophthalmic—stent-assisted coiling R MCA bifurcation—clipped R MCA, M1—coiled R pericallosal—monitored L MCA—monitored L superior Hypophyseal Artery— attempted clipping, successful stenting 15 15 Mass effect - Found on workup for cognitive impairment, trouble walking Incidentally found 15 Incidentally found SAH, HH1, and stroke Clipping + coiling – single (CL-CO-Single) 53 M Acomm—clipped/coiled F 58 Clipping + stenting (CL+ST) 43 F Bilateral MCA—clipped Basilar—stent-assisted coiling Bypass + stent-assisted coiling 52 F L MCA bifurcation—bypass and stent-assisted coiling 74 F R ICA L MCA (M2) aneurysm—bypass × 2 and endovascular occlusion 13 F 64 5 5 5 18 days between craniotomy and coiling of residual aneurysm Approximately 3 years between craniotomy and coiling Partial clipping and endovascular coiling performed on same day 1 5 2 1 month between craniotomy and 5 stent-assisted coiling 3 months between clipping of R MCA 5 bifurcation aneurysm and stent-assisted coiling of R M1 aneurysm 2 weeks between attempted clipping 5 and stent-assisted coiling 15 years between craniotomy and stent-assisted coiling 2 months between clipping surgeries 10 years between last surgery and coiling 8 months between craniotomy and stent-assisted coiling 3 months between L M3-M3 bypass 5 and stent-assisted coiling 8 days between clipping proximal M1, 4 ECA-ICA bypass and stent-assisted coiling Patient suffered re-rupture and was ultimately declared brain dead. Patient’s course complicated by hemiplegia, septicemia; transferred to OSH Aneruysm found to be dissecting at surgery. Patient required pre-treatment w/ anti-platelet therapy. Patient developed septicemia and DVT prior to discharge to rehabilitation This patient initially presented with a SAH and a complex, partially thrombosed aneurysm. She was shunted before treatment several months later. Mycotic aneurysm Last GOS Comments 3 9 months from SAH and shunting to treatment 1 day between bypass surgery (A2-A2) and endovascular occlusion of the R A1 segment and aneurysm 4 2 days between initial bypass and subsequent revision surgery 1 day between surgery and parent vessel occlusion Admission GCS Time between treatments 13 Presenting symptom Bypass + endovascular occlusion 53 F R ACA (A1) complex aneurysm— SAH, HH3 bypass, then endovascular occlusion Age (years) Sex Aneurysm(s) and treatment Table 1 Neurosurg Rev F F F 55 65 R MCA—clipped L M1—coiled L SCA—monitored R ACA—monitored R ophthalmic—clipped L A1-AComm junction—coiled 15 15 15 15 15 15 15 15 10 15 Incidentally found Visual loss SAH, HH2 SAH, HH2 SAH, HH2 SAH, HH1 SAH, HH2 Found unruptured SAH, HH4 SAH, HH1 5 4 4 5 5 1 year between coiling and craniotomy 5 2 months between craniotomies 5 months between coiling and 5 craniotomy 8 days between coiling and craniotomy 5 10 days between coiling of L Pcomm and clipping of R Pcomm 8 months between coiling and clipping 5 6 months between coiling and clipping 5 5 years between coiling and clipping 5 5 months between clipping and coiling 5 1 week between clipping and coiling Post-operative epidural empyema The R PComm aneurysm was not amenable to coiling because of its morphology. Residual aneurysm was clipped after the coiling in these 2 patients. This aneurysm recanalized and required another treatment. Patient requested endovascular treatment rather than a second surgery Patient expired in rehabilitation facility shortly after discharge This patient had a L MCA aneurysm treated electively and presented later with a new, ruptured R AComm aneurysm. Patient presented with re-rupture of previously clipped aneurysm, underwent a second craniotomy, and then coiling of the residual. Last GOS Comments 1 1 month between emergent craniectomy and clipping of R ophthalmic artery aneurysm and coiling of L aneurysm 4 months between clipping and coiling 5 10 years between craniotomy and coiling (OSH) 15 7T 7 years between elective surgery and coiling Approximately 8 years between craniotomies and 28 days between 2nd craniotomy and coiled 15 9T 15 Admission GCS Time between treatments SAH, HH1 Found after SAH, unruptured SAH, HH4 following TSP sx for pituitary tumor Incidentally found Later SAH, HH4 Found when patient presented with SAH Previously clipped, OSH SAH, HH1 SAH, HH4 2004 SAH, HH2 2012 Presenting symptom F female, M male, L left, R right, ACA anterior cerebral artery, Acomm anterior communication artery, ICA internal carotid artery, MCA middle cerebral artery, Pcomm posterior communicating artery, SCA superior cerebellar artery, SAH subarachnoid hemorrhage, HH Hunt-Hess, TSP sx transsphenoidal surgery, OSH outside hospital L ICA bifurcation—clipped L MCA—monitored R MCA—coiled 48 F L MCA—clipped R PComm—coiled 54 F R Acomm—clipped R SCA—coiled Coiling + clipping – single (CO-CL-Single) 52 F L MCA—coiled and clipped 61 M AComm—coiled and clipped 38 F L Pcomm—coiled and clipped R dural ring—monitored Coiling + clipping – multiple (CO-CL-Multiple) 50 M L PComm—coiled R PComm—clipped L MCA—monitored 50 M Acomm—coiled Bilateral MCA —clipped 38 F L Pcomm—coiled R ICA bifurcation—clipped 50 F R superior hypophyseal artery—coiled L Pcomm—clipped M 55 Clipping + coiling – multiple (CL-CO-Multiple) 61 F Left MCA—clipped R Acomm—coiled Left Pcomm—monitored 66 L superior hypophyseal artery— partially coiled L ACA—clipped × 2 and coiled Age (years) Sex Aneurysm(s) and treatment Table 1 (continued) Neurosurg Rev Neurosurg Rev Table 2 Categorization/quantification of all single-patient multimodality treatments for cerebral aneurysms (GOS) Surgery Endovascular Clipping Attempted clipping Bypass Total 0 17 (4.24) 2 unruptured (5) 15 ruptured with two mortalities (4.13) Stent-assisted coiling 5 (5) 1 (5) 3 unruptured (5) Patient with SAH 2 ruptured (5) 0 17 (4.24) 2 unruptured (5) 15 ruptured with two mortalities (4.13) 2 (4.5) Both unruptured 8 (4.9) 5 unruptured (4.8) 3 ruptured (5) Occlusion 0 0 Total 22 (4.46) 5 unruptured (5) 18 ruptured (4.24) 1 (5) Ruptured 2 (3.5) Both patients ruptured 4 (4) 2 unruptured (4.5) 2 ruptured (3.5) 2 (3.5) Both patients ruptured 27 (4.37) Unruptured 7 (4.86) Ruptured 20 (4.2) Coiling complications. She remained hospitalized, and 10 days later, she underwent pipeline stenting/coiling for treatment of the left ophthalmic aneurysm. This procedure required pre-treatment with aspirin and clopidogrel to reduce the risk of stent thrombosis and re-stenosis associated with bare metal stents [14]. Her post-intervention course was unremarkable, and she was discharged home. The patient recovered completely. No residual filling of any aneurysm was observed at her 1-year angiogram (Fig. 2) Case 2: bypass/stent A 74-year-old female who was treated conservatively for an incidental 5-cm right internal carotid artery aneurysm presented at our clinic. After 1 year, she started developing significant hemispheric edema, resulting in failure to thrive, as well as multiple falls. The angiogram showed a giant right internal carotid artery (ICA) bifurcation aneurysm that incorporated both M1 and A1 vessels (Fig. 3). Since the lesion was not amenable to direct repair due to its size, we decided to implement staged treatment as the most viable course. In the first stage, we performed extracranial-toTable 3 Clipping and coiling (CL+CO) categorization intracranial (EC-IC) bypass from the right external carotid artery to the right M3, using a radial artery transplanted graft with concurrent M1 vessel occlusion. After 1 week, in the same admission, the patient underwent endovascular stentassessed coiling for the aneurysm. The stent was passed from the ICA to the proximal A1 in order to protect flow to the anterior cerebral artery. During hospitalization, the patient developed left hemiparesis, septicemia, and deep vein thrombosis (DVT). She was eventually discharged to rehabilitation. After 7 months, she was living at home and experiencing mild left-sided weakness (GOS, 4). Her angiogram revealed complete occlusion of the aneurysm, along with a patent EC-IC bypass and patent stent from the ICA to the A1 segment (Fig. 4). Case 3: CO-CL-Single A 53-year-old woman presented with a HH grade 2 SAH. CT scan showed left Sylvian SAH, and angiography demonstrated a 7-mm L M1 segment aneurysm. The aneurysm was treated acutely with endovascular coils with a good result (Fig. 5). Follow-up angiography in 6 months Categories Number of patients Mean GOS Clipping followed by coiling of a different aneurysm (CL-CO-Multiple) 6 4.17 2 unruptured 2 unruptured (5) 4 ruptured 4 4 ruptured (3.75) 5 All ruptured aneurysms 4 4 ruptured 3 All ruptured aneurysms 3 All ruptured aneurysms 5 Coiling followed by clipping of a different aneurysm (CO-CL-Multiple) Clipping followed by coiling of residual/ recanalized aneurysm (CL-CO-Single) Coiling followed by clipping for residual/ recanalized aneurysm (CO-CL-Single) Total All ruptured aneurysms All ruptured aneurysms 17 4.23 2 unruptured 2 unruptured (5) 15 ruptured with two mortalities 15 ruptured with two mortalities (4.13) Neurosurg Rev Fig. 1 a Right posterior communicating artery aneurysm (arrow) and right anterior choroidal artery aneurysm (arrowhead). b Left ophthalmic artery aneurysm (arrow) demonstrated a small triangular remnant, and subsequent angiography at 9 months demonstrated increased size of the remnant and coil compaction (Fig. 6). The patient underwent craniotomy and microsurgical clipping of the residual aneurysm (Fig. 7). The patient made a complete recovery and remained neurologically intact. Discussion Treatment protocols for patients with multiple or complex aneurysms using either surgical or endovascular therapies remain controversial and sometimes significantly vary across institutions. Paradigms of aneurysm treatment are often formulated on a case-by-case basis, but some experts advocate the use of one type of therapy over another in individual patients and, under some circumstances, in a clinic population as a whole. Geographic and institutional biases apply as well. We have found, in selected patients at our institution, an effective treatment paradigm using concomitant multimodality treatments. The use of this treatment paradigm in single patients takes various forms as we have presented and can vary significantly in timing interval between treatments depending on the clinical setting and factors (Table 1). Two decades ago, Marks et al. proposed that a combined surgical and endovascular approach to achieve aneurysm obliteration is feasible in cases where the shape or location of the lesion prohibits the usefulness of either technique alone [13]. Other authors have echoed similar recommendations for the multimodality management of complex or large intracranial aneurysms [13, 12, 6]. Recent evidence suggests that neither an endovascular nor a surgical approach alone is optimal, as each category of therapeutic modalities carries its own risk for certain morbidities and even mortality [4]. Our early results demonstrate that single-patient concomitant endovascular or surgical therapy might be advantageous when the intervention is based on an individualized, single-patient-oriented decision tree. Fig. 2 a Skull x-ray demonstrating both the clips (arrowhead) and pipeline (arrow). b Follow-up right ICA injection. c Follow-up left ICA Neurosurg Rev Fig. 3 a Lateral right ICA angiogram. b 3D right ICA angiogram demonstrating giant ICA bifurcation aneurysm incorporating both the M1 and A1 segments Additionally, in the current era, hybrid angiographic surgical operation suites can help facilitate the seamless and successful complementary utilization of endovascular and surgical modalities in single patients [4]. The literature and our clinical experience both reveal specific indications for integrating endovascular and surgical modalities in appropriate candidate patients. Indications for specific concomitant treatment strategies are based on clinical features, morphological and anatomical characteristics, and post-treatment settings related to complex cases of subarachnoid hemorrhage and cerebral aneurysms [4]. Our cohort included six patients who received clipping followed by coiling for one or more different aneurysms and five patients who underwent clipping followed by stent-assessed coiling. Our analysis additionally identified four patients who underwent coiling followed by clipping for different types of aneurysms, all of which presented with SAH from an aneurysm that was coilable. The subsequent aneurysms in the series were treated surgically, as these lesions required more complex endovascular options or were not amenable to Fig. 4 a Skull x-ray demonstrating the coil mass, the occluding M1 segment clip (arrow), and the stent from ICA to the A1 segment (arrowhead). b AP right CCA injection demonstrating patent EC (arrow) to M3 segment bypass and patent ICA to A1 segment stenting (arrowhead). No visible aneurysm is detectable endovascular treatment modalities. Based on our clinical assessment, these lesions appeared to be surgically accessible with limited anticipated morbidity, such as small MCA bifurcation aneurysms. Other combined treatment paradigms included coiling of Bfailed^ clipping treatments and clipping of failed coiling treatments. Additionally, the combined use of bypass and endovascular techniques was included. Only a few published reports in the literature discuss concomitant single-patient treatments [6, 9–12, 13]. The literature referable to multimodality single-patient treatments has focused primarily on the treatment of single complex aneurysms or on subsequent revision needed to correct the failure of one modality or the other, rather than an overall paradigm and decision making tree that varies over both time and different clinical settings. Microsurgeons and endovascular surgeons have placed minimal emphasis on concomitant strategies for treating multiple aneurysms as an integrative paradigm of aneurysm management. In a comprehensive review, Lawton et al. examined more than 500 aneurysms, of which 77 patients harboring 96 aneurysms met the selection criteria for undergoing multimodality Neurosurg Rev Fig. 5 a, b Rotated 3D angiographic images (b, c) demonstrate a 6.5-mm aneurysm of the left MCA arising at an opercular branch (arrow). The aneurysm appears to have a discrete neck Fig. 6 a, b Nine-month followup angiography demonstrates compaction of the coil mass with opening of the base of the aneurysm (arrow) treatment [12]. The authors subdivided the therapeutic approaches, generating eight unique categories: (1) selective revascularization and endovascular aneurysm occlusion (n = 23), (2) endovascular and surgical trapping (n = 1), (3) Fig. 7 a The aneurysm is identified through a microsurgical transSylvian approach. The compacted coil mass is visualized. The proximal aspect of the aneurysm is patent (arrow). b Elevation of the inferior aspect of the dome with a microdissector reveals the branch vessel (arrow). c Definitive clipping is achieved flush to the MCA with a side-angled clip with complete preservation of the branch vessel (arrow) Neurosurg Rev clipping of the aneurysm after attempted or incomplete coiling (n = 22), (4) coiling after attempted or incomplete clipping (n = 5), (5) clipping of recurrent aneurysm after coiling (n = 6), (6) coiling of recurrent aneurysm after clipping (one patient), (7) clipping and coiling of multiple remote aneurysms (n = 13), and (8) coiling after previous unrelated surgery (n = 6). In contrast to our series (mean size 7.2 mm), large, giant, or complex lesions accounted for 70% of the aneurysms encountered in this study. Complete angiographic occlusion was achieved in 95% of the entire patient population. Overall, a good outcome was attained in 86% of the lesions and in 66 patients who achieved a GOS score of four or five. Seven patients experienced treatment related mortality (9.1%), while four patients (5.2%) had permanent treatment-associated neurological morbidity [12]. The multimodality approach has become increasingly important in the management of giant and complex aneurysms, including paraclinoid aneurysms [2, 4], giant aneurysms, [9, 18] and other complex aneurysms [10]. Endovascular therapy in patients with giant aneurysms who have passed a balloon test occlusion (BTO) can provide a safe route for PVO to Fig. 8 Single-patient, multimodalidy treatment for cerebral aneurysms. a A posterior communicating artery aneurysm is subtotally clipped. The distal filling luminal portion of the aneurysm is obliterated with endovascular coils. b A broad based anterior communicating artery aneurysm is coiled. Coil compaction is noted on delayed angiogram and definitive and complete obliteration is achieved with a fenestrated clip placed parallel to the anterior communicating artery. c An anterior communicating artery aneurysm is treated definitely with endovascular coils. A middle cerebral artery aneurysm is treated with microsurgical clipping. d An ophthalmic artery aneurysm is treated with a stent/coil technique, and an anterior communicating artery aneurysm is treated with definitive microsurgical clipping. e A dysplastic proximal middle cerebral artery aneurysm is treated with bypass and endovascular obliteration. f Multiple modalities that can be used on single patients are illustrated: clipping, coiling, stenting, endovascular occlusion, and bypass. g A decompressive craniectomy is used a primary treatment modality followed by endovascular coiling of a middle cerebral artery aneurysm Neurosurg Rev make surgical debulking of the lesion easier [4]. Stenting technology, in particular, has allowed for substantial improvement in the management of aneurysms with endovascular coiling. However, this technique is not considered universally efficacious due to the risk of complications such as aneurysm rupture/perforation and thromboembolic events necessitating further intervention [4]. In order to minimize the potential for adverse events, bypass followed by endovascular occlusion might be the most viable alternative for the treatment of these challenging aneurysms [10]. Several reports in the literature have addressed multimodality interventions of coiling followed by clipping in the treatment of residual disease or recurrence [3, 5, 12, 20]. With advancements in endovascular technology, particularly the use of stents and flow diverters, the use of coiling for this purpose has diminished over the last decade. In the current clinical climate, the indication for an approach utilizing coiling followed by clipping is usually reserved for either a correction of failed endovascular treatment or a salvage initial treatment of a patient with a high grade SAH patient or a patient presenting with severe spasm [3]. In order to have merit, our paradigm should be universally applicable in a healthcare center specializing in the treatment of cerebral aneurysms. The open and endovascular teams (if they are separate) should be cohesive. Ideally, this model should encourage cross-specialty exchange, allowing clinicians to collaborate in their selection of specific combinations of endovascular and surgical treatments potentially indicated for particular patients. We have proposed a concomitant multimodality paradigm that neurosurgeons may use in the treatment of SAH, especially in challenging cases. The findings in our series are clinically relevant to the treatment of complex aneurysms, particularly multiple aneurysms, and are summarized in the following section (Fig. 8). The current study has only reviewed a relatively small cohort of patients and clearly represents a starting point for a larger analysis. Additionally, as endovascular techniques evolve (for example, BY^ stenting, endosaccular treatments, and also the use of newer stent technology), our treatment paradigms may change and multimodality treatments may decrease. We believe firmly that there will always be a role for microsurgical treatments for selected aneurysms and that future Bhybrid^ surgeons must be adequately trained in advanced microsurgical techniques. Conclusions Concomitant multimodality single-patient surgical and endovascular interventions to treat complex aneurysms represent an innovative and important paradigm in aneurysm management and can be efficacious in selected single patients in a variety of clinical, anatomic, outcome, and treatment scenarios. Emerging findings increasingly support the safety and efficacy of an integrative single-patient multimodality approach to the treatment of difficult aneurysms, particularly complex, multiple lesions in the same individual. This hybrid strategy requires a collaboration between interventionalists and neurosurgeons in matching specific clinical circumstances of candidate patients with individually tailored paradigms of integrative concomitant multimodality treatment. Funding There was no funding, institutional, or national grant associated with this project. Conflict of interest The authors declare that they have no conflict of interest. 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