Microsurgical management of recurrent intracranial aneurysm after endovascular treatment: a series of 60 consecutive patients

J Neurosurg 141:1235–1243, 2024

The aim of this study was to evaluate the morbidity associated with microsurgical treatment in patients with a recurrent aneurysm to improve their surgical management.

METHODS From 2012 to 2022, among the 3128 patients with ruptured or unruptured intracranial aneurysms managed at the authors’ institution, 954 patients were treated by a microsurgical procedure. Of these 3128 patients, 60 consecutive patients (6.3%) who had a recurrent microsurgically treated aneurysm after previous endovascular treatment were included in this study. Additional microsurgical treatment was considered in case of progressive remnant growth or significant aneurysm recurrence. Intraoperative and postoperative complications were noted. Early (< 7 days) and long-term clinical and radiological monitoring were performed. Good functional outcome was considered as a modified Rankin Scale score < 3.

RESULTS The mean age at initial treatment was 45 years (range 26–65 years). The mean delay between the first treatment and microsurgical treatment of the recurrence was 64 months (range 2 days–296 months). The mean size of the fundus recurrence was 5 mm, and the mean size of the neck recurrence was 4.6 mm. Five patients (8.3%) presented with subarachnoid hemorrhage associated with rupture of the recurrent aneurysm. Three patients died (6%) of aneurysm rupture and/or intensive care complications. The total morbidity rate associated with the microsurgical procedure was 14.5% (8/55) in patients with unruptured recurrent aneurysms. Among these patients, postoperative definitive complications (ischemic lesions) directly related to the microsurgical procedure were present in 3 patients (5.5%). Intraoperative rupture was recorded in these 3 patients. In the 54 surviving patients with unruptured recurrent aneurysms, good functional outcome was noted in 49 (91%). Poor functional outcome was significantly associated with intraoperative rupture.

CONCLUSIONS Microsurgery remains an effective therapeutic option for recurrent intracranial aneurysms. However, in the authors’ experience, postoperative morbidity is higher than in patients with nonrecurrent aneurysms. Therefore, a pretherapeutic multidisciplinary evaluation is mandatory to reduce the potential morbidity associated with the retreatment as much as possible. When endovascular occlusion of the aneurysm requires both stenting and coiling, alternative microsurgical treatment should be carefully evaluated, as microsurgical clipping will become much more challenging in cases of aneurysm recurrence.

A Novel Approach for Free, Affordable, and Sustainable Microsurgery Laboratory Training for Low- and Middle-Income Countries: University of Wisconsin-Madison Microneurosurgery Laboratory Experience

Neurosurgery 94:1311–1323, 2024

In low- and middle-income countries (LMICs), approximately 5 million essential neurosurgical operations per year remain unaddressed. When compared with high-income countries, one of the reasons for this disparity is the lack of microsurgery training laboratories and neurosurgeons trained in microsurgical techniques. In 2020, we founded the Madison Microneurosurgery Initiative to provide no-cost, accessible, and sustainable microsurgery training opportunities to health care professionals from LMICs in their respective countries.

METHODS: We initially focused on enhancing our expertise in microsurgery laboratory training requirements. Subsequently, we procured a wide range of stereo microscopes, light sources, and surgical instrument sets, aiming to develop affordable, high-quality, and long-lasting microsurgery training kits. We then donated those kits to neurosurgeons across LMICs. After successfully delivering the kits to designated locations in LMICs, we have planned to initiate microsurgery laboratory training in these centers by providing a combination of live-streamed, offline, and in-person training assistance in their institutions.

RESULTS: We established basic microsurgery laboratory training centers in 28 institutions across 18 LMICs. This was made possible through donations of 57 microsurgery training kits, including 57 stereo microscopes, 2 surgical microscopes, and several advanced surgical instrument sets. Thereafter, we organized 10 live-streamed microanastomosis training sessions in 4 countries: Lebanon, Paraguay, Türkiye, and Bangladesh. Along with distributing the recordings from our live-streamed training sessions with these centers, we also granted them access to our microsurgery training resource library. We thus equipped these institutions with the necessary resources to enable continued learning and hands-on training. Moreover, we organized 7 in-person no-cost hands-on microanastomosis courses in different institutions across Türkiye, Georgia, Azerbaijan, and Paraguay. A total of 113 surgical specialists successfully completed these courses.

CONCLUSION: Our novel approach of providing microsurgery training kits in combination with live-streamed, offline, and in-person training assistance enables sustainable microsurgery laboratory training in LMICs.

Seven bypasses simulation set: description and validity assessment of novel models for microneurosurgical training

J Neurosurg 138:732–739, 2023

Microsurgical training remains indispensable to master cerebrovascular bypass procedures, but simulation models for training that accurately replicate microanastomosis in narrow, deep-operating corridors are lacking. Seven simulation bypass scenarios were developed that included head models in various surgical positions with premade approaches, simulating the restrictions of the surgical corridors and hand positions for microvascular bypass training. This study describes these models and assesses their validity.

METHODS Simulation models were created using 3D printing of the skull with a designed craniotomy. Brain and external soft tissues were cast using a silicone molding technique from the clay-sculptured prototypes. The 7 simulation scenarios included: 1) temporal craniotomy for a superficial temporal artery (STA)–middle cerebral artery (MCA) bypass using the M4 branch of the MCA; 2) pterional craniotomy and transsylvian approach for STA-M2 bypass; 3) bifrontal craniotomy and interhemispheric approach for side-to-side bypass using the A3 branches of the anterior cerebral artery; 4) far lateral craniotomy and transcerebellomedullary approach for a posterior inferior cerebellar artery (PICA)–PICA bypass or 5) PICA reanastomosis; 6) orbitozygomatic craniotomy and transsylvian-subtemporal approach for a posterior cerebral artery bypass; and 7) extended retrosigmoid craniotomy and transcerebellopontine approach for an occipital artery–anterior inferior cerebellar artery bypass. Experienced neurosurgeons evaluated each model by practicing the aforementioned bypasses on the models. Face and content validities were assessed using the bypass participant survey.

RESULTS A workflow for model production was developed, and these models were used during microsurgical courses at 2 neurosurgical institutions. Each model is accompanied by a corresponding prototypical case and surgical video, creating a simulation scenario. Seven experienced cerebrovascular neurosurgeons practiced microvascular anastomoses on each of the models and completed surveys. They reported that actual anastomosis within a specific approach was well replicated by the models, and difficulty was comparable to that for real surgery, which confirms the face validity of the models. All experts stated that practice using these models may improve bypass technique, instrument handling, and surgical technique when applied to patients, confirming the content validity of the models.

CONCLUSIONS The 7 bypasses simulation set includes novel models that effectively simulate surgical scenarios of a bypass within distinct deep anatomical corridors, as well as hand and operator positions. These models use artificial materials, are reusable, and can be implemented for personal training and during microsurgical courses.

The middle communicating artery: a novel fourth-generation bypass for revascularizing trapped middle cerebral artery bifurcation aneurysms

J Neurosurg 134:1879–1886, 2021

The anterior and posterior communicating arteries are natural connections between arteries that enable different adjacent circulations to redistribute blood flow instantly in response to changing supply and demand. An analogous communication does not exist in the middle cerebral circulation. A middle communicating artery (MCoA) can be created microsurgically between separate middle cerebral artery (MCA) trunks, enabling flow to redistribute in response to changing supply and demand. The MCoA would draw blood flow from an adjacent circulation such as the external carotid circulation. The MCoA requires the application of fourth-generation techniques to reconstruct bi- and trifurcations after occluding complex MCA trunk aneurysms.

In this report, the authors describe two recent cases of complex MCA biand trifurcation aneurysms in which the occluded efferent trunks were revascularized by creating an MCoA. The first MCoA was created with a “double-barrel” superficial temporal artery–M2 segment bypass and end-to-end reimplantation of the middle and inferior MCA trunks. The second MCoA was created with an external carotid artery–radial artery graft–M2 segment interpositional bypass and end-to-side reimplantation of the inferior trunk onto the superior trunk. Both aneurysms were occluded, and both patients experienced good outcomes.

This report introduces the concept of the MCoA and demonstrates two variations. Angioarchitectural and technical elements include the donation of flow from an adjacent circulation, a communicating bypass, the application of fourth-generation bypass techniques, and a minimized ischemia time. The MCoA construct is ideally suited for rebuilding bi- and trifurcated anatomy after trapping or distally occluding complex MCA aneurysms.

Prospective validation of a molecular prognostication panel for clival chordoma

J Neurosurg 130:1528–1537, 2019

There are currently no reliable means to predict the wide variability in behavior of clival chordoma so as to guide clinical decision-making and patient education. Furthermore, there is no method of predicting a tumor’s response to radiation therapy.

METHODS A molecular prognostication panel, consisting of fluorescence in situ hybridization (FISH) of the chromosomal loci 1p36 and 9p21, as well as immunohistochemistry for Ki-67, was prospectively evaluated in 105 clival chordoma samples from November 2007 to April 2016. The results were correlated with overall progression-free survival after surgery (PFSS), as well as progression-free survival after radiotherapy (PFSR).

RESULTS Although Ki-67 and the percentages of tumor cells with 1q25 hyperploidy, 1p36 deletions, and homozygous 9p21 deletions were all found to be predictive of PFSS and PFSR in univariate analyses, only 1p36 deletions and homozygous 9p21 deletions were shown to be independently predictive in a multivariate analysis. Using a prognostication calculator formulated by a separate multivariate Cox model, two 1p36 deletion strata (0%–15% and > 15% deleted tumor cells) and three 9p21 homozygous deletion strata (0%–3%, 4%–24%, and ≥ 25% deleted tumor cells) accounted for a range of cumulative hazard ratios of 1 to 56.1 for PFSS and 1 to 75.6 for PFSR.

CONCLUSIONS Homozygous 9p21 deletions and 1p36 deletions are independent prognostic factors in clival chordoma and can account for a wide spectrum of overall PFSS and PFSR. This panel can be used to guide management after resection of clival chordomas.

 

Double-barrel STA to proximal MCA bypass and proximal parent artery occlusion for a fusiform superior clinoidal ICA aneurysm

Acta Neurochirurgica (2018) 160:1939–1943

Blood flow replacement and parent artery occlusion are alternative treatments of complex fusiform superior clinoidal ICA aneurysms. While double-barrel STA to proximal MCA bypass is a conventional approach among these reported bypass algorithms, its technical details remain underexplored.

Method We have applied the double-barrel STA to proximal MCA bypass and parent artery occlusion to treat a 45-year-old female patient with a right fusiform superior clinoidal ICA aneurysm. The technical nuances of this approach are reported.

Conclusion We show that double-barrel STA to proximal MCA bypass and proximal parent artery occlusion can be alternative treatments of complex fusiform superior clinoidal ICA aneurysms.

Cerebral Revascularization for Aneurysms in the Flow-Diverter Era

Neurosurgery 80:759–768, 2017

Cerebral bypass has been an important tool in the treatment of complex intracranial aneurysms. The recent advent of flow-diverting stents (FDS) has expanded the capacity for endovascular arterial reconstruction.

OBJECTIVE: We investigated how the advent of FDS has impacted the application and outcomes of cerebral bypass in the treatment of intracranial aneurysms.

METHODS: We reviewed a consecutive series of cerebral bypasses during aneurysm surgery over the course of 10 years. FDS were in active use during the last 5 years of this series. We compared the clinical characteristics, surgical technique, and outcomes of patients who required cerebral bypass for aneurysm treatment during the preflow diversion era (PreFD) with those of the postflow diversion era (PostFD).

RESULTS: We treated 1061 aneurysms in the PreFD era (from July 2005 through June 2010) and 1348 in the PostFD era (from July 2010 through June 2015). Eighty-five PreFD patients (8%) and 45 PostFD patients (3%) were treated with cerebral bypass. PreFD patients had better baseline functional status compared to PostFD patients with average preoperative modified Rankin Scale score of 0.55 in PreFDand 1.18 in PostFD.

CONCLUSION: After the introduction of FDS, cerebral bypass was performed in a lower proportion of patients with aneurysms. Patients selected for bypass in the flow-diverter era had worse preoperative modified Rankin Scale scores indicating a greater complexity of the patients. Cerebral bypass in well-selected patients and revascularization remains an important technique in vascular neurosurgery. It is also useful as a rescue technique after failed FDS treatment of aneurysms.

Blister Aneurysms of the Internal Carotid Artery: Microsurgical Results and Management Strategy

Neurosurgery (2017) 80 (2): 235-247

Blister aneurysms of the supraclinoid internal carotid artery (ICA) are challenging lesions with high intraoperative rupture rates and significant morbidity. An optimal treatment strategy for these aneurysms has not been established.

OBJECTIVE: To analyze treatment strategy, operative techniques, and outcomes in a consecutive 17-year series of ICA blister aneurysms treated microsurgically.

METHODS: Seventeen patients underwent blister aneurysm treatment with direct clipping, bypass and trapping, or clip-reinforced wrapping.

RESULTS: Twelve aneurysms (71%) were treated with direct surgical clipping. Three patients required bypass: 1 superficial temporal artery to middle cerebral artery bypass, 1 external carotid artery to middle cerebral artery bypass, and 1 ICA to middle cerebral artery bypass. One patient was treated with clip-reinforced wrapping. Initial treatment strategy was enacted 71% of the time. Intraoperative rupture occurred in 7 patients (41%), doubling the rate of a poor outcome (57% vs 30% for patients with and without intraoperative rupture, respectively). Severe vasospasm developed in 9 of 16 patients (56%). Twelve patients (65%) were improved or unchanged after treatment, and 10 patients (59%) had good outcomes (modified Rankin Scale scores of 1 or 2).

CONCLUSION: ICA blister aneurysms can be cautiously explored and treated with direct clipping as the first-line technique in the majority of cases. Complete trapping of the parent artery with temporary clips and placing permanent clip blades along normal arterial walls enables clipping that avoids intraoperative aneurysm rupture. Trapping/bypass is used as the second-line treatment, maintaining a low threshold for bypass with extensive or friable pathology of the carotid wall and in patients with incomplete circles of Willis.

 

Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms

Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms

J Neurosurg 124:1275–1286, 2016

Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (ECIC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed.

Methods: Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA’s origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included.

Results: During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 ICIC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients.

Conclusions: PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one-quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.

Application of intraoperative motor evoked potential monitoring during giant internal carotid artery aneurysm surgery using prolonged temporary occlusion

Application of intraoperative motor evoked potential monitoring during giant internal carotid artery aneurysm surgery using prolonged temporary occlusion

Acta Neurochir (2015) 157:1833–1840

Clipping and bypass surgery are common therapeutic options for the management of giant internal carotid artery (ICA) aneurysms. However, potential ischemic risks may be exaggerated by prolonged temporary occlusion (PTO) during the surgery. Monitoring motor-evoked potentials (MEPs) is a sensitive technique for detecting potential ischemia intraoperatively. This preliminary study was designed to evaluate the effectiveness of applying MEP monitoring during giant ICA aneurysm surgery using PTO.

Methods From July 2009 to July 2012, 11 patients with giant ICA aneurysms who could not pass the preoperative hemodynamic evaluations were enrolled in this study. MEP monitoring was utilized intraoperatively in all cases. Clipping was performed if there were no significant MEP changes under PTO. A variant extracranial-to-intracranial (EC-IC) bypass was performed if there was reproducible loss of MEP signals after PTO or unclippable anatomic features.

Results Five patients underwent clipping alone and six underwent bypass. There were no significant differences in baseline clinical data between the two groups. The overall percentage of patients with good outcomes (Glasgow Outcome Score≥4) improved from 72.7 % (8/11) postoperatively to 90.9 % (10/11) after 26.0±9.5 months of follow-up. There were no significant differences between the clipping and bypass groups regarding short- and long-term outcomes (p=0.545 and p=1.000).

Conclusions MEP monitoring is useful for evaluating the safety of PTO, surgical strategy, and outcomes of giant ICA aneurysm surgery. Direct clipping during safe PTO under intraoperative MEP monitoring is applicable for giant ICA aneurysms. Its use achieved favorable outcomes by indicating the need for bypass surgery.

Viability of Anastomoses With Coupler in Extra-Intracranial Bypass

Viability of Anastomoses With Coupler in Extra-Intracranial Bypass- Cadaveric Study

Operative Neurosurgery 11:235–242, 2015

The time required to perform an anastomosis in extra-intracranial bypass is approximately 20 to 60 minutes. The search for alternative methods to reduce the ischemic time remains vital.

OBJECTIVE: To evaluate Coupler anastomosis for extra-intracranial bypass in cadavers.

METHODS: In 8 fresh adult cadavers, the saphenous vein and radial artery were used as donor vessels. The superficial temporal and the extracranial internal and external carotid arteries were dissected. A wide craniotomy with a sylvian fissure opening was performed, exposing the middle cerebral and supraclinoid internal carotid arteries. The Coupler devices were tested in all 8 cadavers. The diameter of the donor and recipient vessels as well as the time required to perform the anastomosis were measured. Bypass permeability was evaluated by injecting saline solution under pressure, checking for leaks.

RESULTS: The anastomoses were successfully performed in all specimens. The size of the head of the fitting Coupler required the performance of a wide craniotomy (6 · 6 cm) and a wide opening of the sylvian fissure. The time required to perform each anastomosis ranged from 4 to 7 minutes, being easier with the radial artery than with the saphenous vein.

CONCLUSION: Coupler devices are helpful to perform the anastomoses, because they significantly reduce ischemia time. Their use is easier at the M1 segment, just before the bifurcation and after takeoff of the lenticulostriate arteries, and in the M2 segment. It would be advisable to have a smaller coupling system, allowing maneuverability in the deeper areas where space is limited.

Management of complex intracranial aneurysms with bypass surgery


Complex aneurysms bypass surgery_93 patients

Neurosurg Rev (2015) 38:109–120

Despite advances in microsurgery and the development of new endovascular techniques, the treatment of complex intracranial aneurysms remains a daunting challenge for neurosurgeons. In the present study, we retrospectively reviewed our experience of bypass surgery in the treatment of 93 cases of complex intracranial aneurysms.

A series of 93 consecutive cases of complex intracranial aneurysms were treated with bypass surgery between April 2004 and July 2013. Radial artery (RA) grafts were used in 58 cases, saphenous vein (SV) grafts in 16 cases, and occipital artery (OA) grafts in 6 cases, while the remaining 13 cases were managed with superficial temporal artery (STA) grafts. In this series, the aneurysms were excised after trapping in 32 cases with mass effect and neural compression. Proximal occlusion of the parent artery was performed in 22 cases of fusiform or giant dissecting aneurysms with subsequent retrograde flow to avoid compromise of the perforators nearby. Trapping was performed after bypass surgery in the remaining 39 cases. Postoperative angiographies were performed in 91 patients and patency of the bypass graft and obliteration of the aneurysms were confirmed in 89 patients. Patency of the bypass could not be confirmed in the remaining two patients, of which one presented with cerebral infarction due to graft occlusion, and the other remained asymptomatic. Within 1 month after surgery, 88 patients had good outcome, four patients needed assistance for daily living, and one death occurred due to brainstem infarction. In 77 patients with a mean follow-up of 3.0 years, 72 patients had good outcome, 4 patients needed assistance for daily living, and 1 death occurred unrelated to surgery.

Complex intracranial aneurysms present unique therapeutic challenges that require thorough surgical planning, individualized treatment strategies, and refined neurovascular techniques for successful outcome. Proper use of bypass surgery is imperative in preserving the parent artery and its major perforators. The internal maxillary artery, used as a donor in a bypass, is an effective method due to its shorter distance from the recipient vessels and relatively large diameter with resulting higher flow rate.

Twenty-Year Follow-up of Flow Reversal and Revascularization for a Giant Serpentine Basilar Artery Aneurysm

Twenty-Year Follow-up of Flow Reversal and Revascularization for a Giant Serpentine Basilar Artery Aneurysm

Operative Neurosurgery 10:E493–E497, 2014

Current microsurgical and endovascular therapies have offered little advancement for the treatment of complex vertebrobasilar aneurysms. The outcome of patients with these rare lesions has remained poor, despite sometimes heroic measures.

CLINICAL PRESENTATION: The authors report a case of a 65-year-old man who 20 years earlier had presented with symptoms suggestive of brainstem compression. Imaging at the time revealed a giant, serpentine aneurysm of the basilar artery. The patient was treated with superficial temporal artery to superior cerebellar artery bypass and decompression of the aneurysm contents. Twenty years after this treatment, the patient remains functionally intact with few sequelae from his treatment or the pathology. Follow-up imaging reveals thrombosis of the aneurysm without ischemic damage to the brainstem.

CONCLUSION: This case demonstrates that good functional outcomes are possible for select complex posterior circulation aneurysms by using flow reversal and revascularization; however, at this time, we are unable to predict for which patients this strategy will be successful.

KEY WORDS:

Revascularization and Aneurysm Surgery: Techniques, Indications, and Outcomes in the Endovascular Era

Revascularization and Aneurysm Surgery

Neurosurgery 74:482–498, 2014

Given advances in endovascular technique, the indications for revascularization in aneurysm surgery have declined.

OBJECTIVE: We sought to define indications, outline technical strategies, and evaluate the outcomes of patients treated with bypass in the endovascular era.

METHODS: We retrospectively reviewed all aneurysms treated between September 2006 and February 2013.

RESULTS: We identified 54 consecutive patients (16 males and 39 females) with 56 aneurysms. Aneurysms were located along the cervical internal carotid artery (ICA) (n = 1), petrous/cavernous ICA (n = 1), cavernous ICA (n = 16), supraclinoid ICA (n = 7), posterior communicating artery (n = 2), anterior cerebral artery (n = 4), middle cerebral artery (MCA) (n = 13), posterior cerebral artery (PCA) (n = 3), posterior inferior cerebellar artery (n = 4), and vertebrobasilar arteries (n = 5). Revascularization was performed with superficial temporal artery (STA) to MCA bypass (n = 25), STA to superior cerebellar artery (SCA) (n = 3), STA to PCA (n = 1), STA-SCA/STA-PCA (n = 1), occipital artery (OA) to PCA (n = 2), external carotid artery/ICA to MCA (n = 15), OA to MCA (n = 1), OA to posterior inferior cerebellar artery (n = 1), and in situ bypasses (n = 8). At a mean clinical follow-up of 18.5 months, 45 patients (81.8%) had a good outcome (Glasgow Outcome Scale 4 or 5). There were 7 cases of mortality (12.7%) and an additional 9 cases of morbidity (15.8%). At a mean angiographic follow-up of 17.8 months, 14 bypasses were occluded. Excluding the 7 cases of mortality, the majority of aneurysms (n = 42) were obliterated. We identified 7 cases of residual aneurysm and recurrence in 6 patients at follow-up.

CONCLUSION: Given current limitations with existing treatments, cerebral revascularization remains an essential technique for aneurysm surgery.

Giant Intracranial Aneurysms: Evolution of Management in a Contemporary Surgical Series

Neurosurgery 69:1261–1271, 2011 DOI: 10.1227/NEU.0b013e31822bb8a6

Many significant microsurgical series of patients with giant aneurysms predate changes in practice during the endovascular era.

OBJECTIVE: A contemporary surgical experience is presented to examine changes in management relative to earlier reports, to establish the role of open microsurgery in the management strategy, and to quantify results for comparison with evolving endovascular therapies.

METHODS: During a 13-year period, 140 patients with 141 giant aneurysms were treated surgically. One hundred aneurysms (71%) were located in the anterior circulation, and 41 aneurysms were located in the posterior circulation.

RESULTS: One hundred eight aneurysms (77%) were completely occluded, 14 aneurysms (10%) had minimal residual aneurysm, and 16 aneurysms (11%) were incompletely occluded with reversed or diminished flow. Three patients with calcified aneurysms were coiled after unsuccessful clipping attempts. Eighteen patients died in the perioperative period (surgical mortality, 13%). Bypass-related complications resulted from bypass occlusion (7 patients), aneurysm hemorrhage due to incomplete aneurysm occlusion (4 patients), or aneurysm thrombosis with perforator or branch artery occlusion (4 patients). Thirteen patients were worse at late follow-up (permanent neurological morbidity, 9%; mean length of follow-up, 23 6 1.9 months). Overall, good outcomes (Glasgow Outcome Score 5 or 4) were observed in 114 patients (81%), and 109 patients (78%) were improved or unchanged after therapy.

CONCLUSION: A heavy reliance on bypass techniques plus indirect giant aneurysm occlusion distinguishes this contemporary surgical experience from earlier ones, and obviates the need for hypothermic circulatory arrest. Experienced neurosurgeons can achieve excellent results with surgery as the ‘‘first-line’’ management approach and endovascular techniques as adjuncts to surgery.

Microsurgery for Previously Coiled Aneurysms: Experience With 81 Patients

Neurosurgery 68:140–154, 2011 DOI: 10.1227/NEU.0b013e3181fd860e

Residual and recurrent intracranial aneurysms after endovascular treatment with Guglielmi detachable coils may necessitate a microsurgical occlusion.

OBJECTIVE: To analyze the microsurgical technique and describe how the location, morphology, and appearance of the coiled aneurysm affect the technique.

METHODS: We retrospectively analyzed 81 patients with 82 previously coiled aneurysms treated microsurgically at 2 Finnish neurosurgical university hospitals in Helsinki and Kuopio between July 1995 and August 2009. Seven videos were selected to demonstrate the microsurgical strategy in various locations.

RESULTS: Fifty-eight aneurysms (71%) were located at anterior circulation and 24 (29%) at posterior circulation. Fifteen patients were operated on within the first month (early surgery) after coiling, whereas 66 were treated later (late surgery). Complete or partial removal of coils during surgery may facilitate clipping, but is significantly (P, .001) more difficult to accomplish in late surgery. Removal of coils may also increase the chance of poor outcome. Chance of poor outcome also increased with intraoperative aneurysm rupture, size of the aneurysm, and posterior circulation location. Good clinical outcome (same or better clinical condition 3 months after surgery) was achieved in 71 patients (88%). After microsurgery, 4 patients were severely disabled and 6 patients died, 3 of them because of poor clinical condition.

CONCLUSION: Complete microsurgical occlusion of the residual aneurysm is possible. However, in large or giant aneurysms direct microsurgery is a challenging high-risk procedure, and we recommend that these patients be referred to a dedicated neurovascular center to minimize surgical complications. Even in experienced hands, use of different bypass procedures may be the best option for demanding growing lesions, especially those in the posterior circulation.

Treatment of Distal Posterior Cerebral Artery Aneurysms: A Critical Appraisal of the Occipital Artery-to-Posterior Cerebral Artery Bypass

Neurosurgery 67:16-26, 2010 DOI: 10.1227/01.NEU.0000370008.04869.BF

This is the largest contemporary series of distal posterior cerebral artery (PCA) aneurysms treated by use of endovascular coiling and stenting as well as surgical clipping, clip wrapping, and bypass techniques. We propose a new treatment paradigm.

METHODS:The location, size, type of aneurysm, clinical presentation, treatment, complications, and outcomes associated with 34 distal PCA aneurysms in 33 patients (15 females, 18 males; mean age, 44 years) were reviewed retrospectively.

RESULTS: The most common presenting symptom was headache in 19 (58%) followed by contralateral weakness or numbness in 6 (18%) and visual changes in 4 (12%). Eight aneurysms were giant. Of the remaining 26 aneurysms, 17 were fusiform/dissecting, 5 were saccular, and 4 were mycotic. Treatment was primarily endovascular in 22 patients, 12 of whom also had a concomitant surgical bypass procedure. Nine patients underwent microsurgical clipping, and 3 underwent combined treatment of clipping and coiling and/or stenting. There were no significant differences in outcomes between the groups (P = .078). The recurrence rate in patients undergoing coiling was 22% and 0% in patients undergoing clipping. Fourteen aneurysms (41%) involved treatment with an occipital artery-to-PCA bypass or an onlay graft. Compared with their preoperative status, these patients had significantly worse outcomes than those without a bypass (P = .013).

CONCLUSION: Bypass techniques for the treatment of distal PCA aneurysms are associated with a higher rate of complications than once thought. In our new treatment paradigm, bypass is a last resort and reserved for patients in whom balloon-test occlusion fails, who refuse parent-vessel sacrifice, and who cannot undergo primary stenting with coiling or clip wrapping.