Treating complex nervous system vascular disorders through a "needle stick": origins, evolution, and future of neuroendovascular therapy

Clipping Versus Coiling in Anterior Circulation Ruptured Intracranial Aneurysms: A Meta-Analysis

OBJECTIVE

To evaluate open surgical versus endovascular repair of anterior circulation ruptured intracranial aneurysms based on operative mortality, permanent neurologic deficit, late mortality, and need for reintervention.

METHODS

This meta-analysis included articles published since December 6, 2016, that compared outcomes of the 2 methods. Extracted data were organized in a standard table format, including first author, country, covered study period, publication year, number of patients and patients at follow-up, operative mortality rate (with 30 days from treatment), permanent neurologic deficit (appearing after surgery), late mortality (after 1 month), and reintervention (surgery or coiling) for both groups of patients. Follow-up was at least 1 year.

RESULTS

There were 8 articles that matched our study criteria. The study population was 628 patients; 374 were treated with surgical clipping, and 254 were treated with endovascular coiling. Pooled results showed no statistically significant difference between the 2 groups in terms of operative mortality, permanent neurologic deficit, late mortality, and need for reintervention.

CONCLUSIONS

Selection of the appropriate procedure must be made on the basis of the special characteristics of each case.

Endovascular treatment of subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a common and devastating form of stroke. A large number of patients with aSAH develop angiographic or clinical vasospasm responsible for high morbidity and mortality. Rapid advances in the field of interventional neurology and the development of minimally invasive techniques have resulted in expansion of potential therapeutic applications. Treatment of aSAH has benefited from this rapid advance in the field of endovascular therapies. In the first section of the review, we discuss the therapeutic options and techniques for embolizations of intracranial aneurysms. In the second section, we discuss evolving endovascular treatment methods employed to intervene in delayed complications of cerebral vasospasm in patients with aSAH.

Angiographic results in intracranial aneurysms treated with inert platinum coils

This study was designed in an attempt to identify the risk factors that could be significantly associated with angiographic recurrences after selective endovascular treatment of aneurysms with inert platinum coils. A retrospective analysis of all patients with selective endovascular coil occlusion of intracranial aneurysms was prospectively collected from 1999 to 2003. There were 455 aneurysms treated with inert platinum coils and followed by digital subtraction angiography. Angiographic results were classified according Roy and Raymond's classification. Recurrences were subjectively divided into minor and major. The most significant predictors for angiographic recurrences were determined by ANOVAs logistic regression, Cochran-Mantel-Haenszel test, Fisher exact probability. Short-term (4.3 ± 1.4 months) follow-up angiograms were available in 377 aneurysms, middle-term (14.1 ± 4.0 months) in 327 and long-term (37.4 ± 11.5 months) in 180. Recurrences were found in 26.8% of treated aneurysms with a mean of 21 ± 15.7 months of follow-up. Major recurrences needing retreatment were present in 8.8% during a mean period follow-up of 17.9 ± 12.29 months after the initial endovascular treatment. One patient (0.2%) experienced a bleed during the follow-up period. Recurrences after endovascular treatment of aneurysms with inert platinum coils are frequent, but hemorrhages are unusual. Single aneurysm, ruptured aneurysm, neck greater than 4 mm and time of follow-up were risk factors for recurrence after endovascular treatment. The retreatment of recurrent aneurysm decreases the risk of major recurrences 9.8 times. Long-term angiogram monitoring is necessary for the population with significant recurrence predictors.

Endovascular treatment of intracranial aneurysms: long-term stability, risk factors for recurrences, retreatment and follow-up

It is accepted that endovascular treatment for intracranial aneurysms < 2 cm in diameter is not an alternative option to surgical treatment anymore but has rather gained the place as the first therapeutic option. Still, the long-term efficacy of endovascular aneurysm treatment remains uncertain. This article discusses clinical significance, incidence, risk factors and current management of aneurysm recurrence after endovascular treatment of intracranial aneurysms based on own Hamburg data and review of the literature. It also attempts to address potential solutions and future avenues to improve long-term efficacy of endovascularly treated intracranial aneurysms.

Surgery of the human cerebrum--a collective modernity

Safe and beneficial surgery of the human cerebrum is arguably one of mankind's most notable achievements and one of the great testimonials to human creativity, intelligence, and character. In many ways, it is a testimony to the climates of civilization that have marked human history. In historical terms, in the year 2007, cranial surgery celebrated its 12,000th birthday, with cranial manipulation for various religious, mystical, and therapeutic reasons being evident in Africa more than 10 millennia before the birth of Christ. This article traces the major developments and attitudes that have laid the foundations of modernity in what is currently surgery and medicine's most exciting and complex technical exercise. It is in fact a 12,000 year prelude to the modernity that we currently enjoy. Before attempting to define our modernity and emerging futurism with reinvention, examination of the prolonged and tedious invention is appropriate for perspective. The following examines and recounts the accrual of data and changes in attitude over the stream of history that have allowed refined surgery of the human cerebrum to become a reality.

Brain aneurysms and arteriovenous malformations: advancements and emerging treatments in endovascular embolization

BACKGROUND AND PURPOSE

Brain aneurysms and vascular malformations can cause cerebral hemorrhages, with devastating consequences for the patients and their families. Since the development of microcatheters and materials used for endovascular embolization, we have witnessed a rapid advancement in the technology and in the number or patients treated with this approach. The aim of this review is to survey recent data relevant to new technologies and emerging treatment strategies in these areas.

SUMMARY OF REVIEW

Clinical trials assessing the safety and efficacy of coil embolization for cerebral aneurysms were based on the use of bare platinum, helical coils. Since then, endovascular operators have been testing and using new materials such as bioactive coils, expandable coils, and complex-shaped coils. Based on the data so far obtained, third and fourth generation coil designs are rapidly emerging and will be ready for clinical application in the near future. Balloon- and stent-assisted coil embolization is enabling the treatment of complex, large-neck aneurysms and the vascular reconstruction of lesions previously considered not treatable. New open- and closed-cell designs allow the navigation and deployment of stents in extremely tortuous vessels. With regards to the embolization of vascular malformations, it is possible to safely navigate microcatheters and microwires through very small arteries previously considered not accessible. In addition, embolization materials such as n-butyl cyanoacrylate and ethylene-vinyl alcohol copolymer are now routinely injected to safely reduce or obliterate large and complex arteriovenous malformations and fistulae.

CONCLUSIONS

Advancements in technology are rapidly improving the endovascular approach to the treatment of cerebral aneurysms and arteriovenous malformations.

Surgical decompression and coil removal for the recovery of vision after coiling and proximal occlusion of a clinoidal segment aneurysm: technical case report

OBJECTIVE

We present the case of a patient with continued deterioration of vision after endovascular treatment of an unruptured clinoidal segment aneurysm. In conjunction with a review of the literature, the findings in this case highlight the need for further refinements in our understanding of pathophysiological changes induced by coiling of cerebral aneurysms, especially those in aneurysms producing signs and symptoms relating to mass effect.

CLINICAL PRESENTATION

The patient is a 45-year-old man who presented with progressive vision loss. Imaging studies revealed a large, clinoidal segment aneurysm. The patient continued to experience progressive vision loss despite treatment with endovascular coiling, proximal occlusion, and high-dose steroid medication.

INTERVENTION

The patient underwent a craniotomy for decompression of the optic nerve and for salvage of vision. Clipping of the distal vessel was performed, and the coil mass was removed. The patient experienced marked improvement of central vision after the surgical procedure.

CONCLUSION

Although endovascular treatment of aneurysms protects most patients from aneurysm rupture, this case illustrates the fact that coiling, followed by proximal occlusion, might fail to alleviate symptoms related to mass effect. Our experience in this case suggests that early surgical decompression may be indicated for patients presenting with progressive visual deterioration.

Emerging Concepts in the Treatment of Intracranial Aneurysms: Stents, Coated Coils, and Liquid Embolic Agents

ENDOVASCULAR TECHNIQUES FOR the treatment of intracranial aneurysms are rapidly evolving. Modifications of more traditional coils have been introduced. Such modifications include newer coils coated with various polymers to increase both coil thrombogenicity and degree of aneurysm packing. In addition, newer coil designs aimed at improving the conformability of the coil to the aneurysm have been used with promising preliminary results. The availability of a newer generation of stents specifically designed for intracranial navigation allows for more effective treatment of aneurysms with wide necks, which usually have been considered unsuitable for optimal endovascular treatment. Endovascular alternatives to coil embolization, such as liquid embolic materials, also have been explored for the treatment of intracranial aneurysms, with varying results. We summarize the rationale for use of these newer devices and early clinical experiences. Areas of current research and future directions of endovascular aneurysm treatment also are discussed.

Therapeutic advances in interventional neurology

Rapid advances in the field of interventional neurology and the development of minimally invasive techniques have resulted in a great expansion of potential therapeutic applications. We discuss therapeutic interventional neurology as applied in clinical practice in one of the two possible ways: 1) embolization leading to occlusion of blood vessels; and 2) revascularization leading to reopening of blood vessels. These procedures can be applied to a broad range of cerebrovascular diseases. In the first section of this review, we will explore the evolution of these interventions to occlude aneurysms, arteriovenous malformations, neurovascular tumors, and injuries. In the second section, revascularization in acute ischemic stroke, stenosis, and dural venous thrombosis will be discussed.

The evolution and future of minimalism in neurological surgery

INTRODUCTION

The evolution of the field of neurological surgery has been marked by a progressive minimalism. This has been evident in the development of an entire arsenal of modern neurosurgical enterprises, including microneurosurgery, neuroendoscopy, stereotactic neurosurgery, endovascular techniques, radiosurgical systems, intraoperative and navigational devices, and in the last decade, cellular and molecular adjuvants.

AIMS

In addition to reviewing the major developments and paradigm shifts in the cyclic reinvention of the field as it currently stands, this paper attempts to identify forces and developments that are likely to fuel the irresistible escalation of minimalism into the future. These forces include discoveries in computational science, imaging, molecular science, biomedical engineering, and information processing as they relate to the theme of minimalism.

DISCUSSION

These areas are explained in the light of future possibilities offered by the emerging field of nanotechnology with molecular engineering.

Endovascular treatment of cerebrovascular diseases and intracranial neoplasms

Cerebrovascular diseases are an important cause of morbidity and mortality worldwide. Endovascular treatment has emerged as a minimally invasive approach to treat cerebrovascular diseases and possibly intracranial neoplasms. Practice patterns for selection of patients for endovascular treatment are continuously being modified on the basis of new information derived from clinical studies. In this review, I discuss the various endovascular treatments for diseases such as ischaemic stroke, carotid and intracranial stenosis, intracranial aneurysms, arteriovenous malformations, malignant gliomas, and meningiomas.

Treatment of aneurysms with wires and electricity. A historical overview

✓✓ Endovascular treatment of aneurysms has only recently become an accepted therapeutic modality. Nonetheless, treatment of aneurysms with the aid of various foreign bodies such as needle and wire insertion with or without electrical current has been reported since the first half of the 19th century. In 1832 Phillips induced clot formation in the femoral and carotid arteries of dogs by leaving needles in the arteries for variable lengths of time. Simultaneously, in France, Velpeau had proposed using “l'acupuncture des arteres dans le traitement des anevrismes.” Later, Phillips and Pelrequin connected the offending needles to a source of electrical current in an attempt to increase thrombus formation and aneurysm occlusion. Subsequently, Moore introduced the concept of packing the aneurysm with wire inserted through a needle transfixed to the vessel wall. To this method, Corradi added electrical current. Widely known as the Moore—Corradi technique, it was used in ensuing years with variable success. The early phase of endovascular aneurysm treatment culminated when Blakemore and Moore treated a case of symptomatic cavernous sinus aneurysm by passing wire through the patient's orbit. These pioneering cases combined with technological advances in the diagnosis of intracranial aneurysms paved the way for further refinements in coil embolization of aneurysms.

[Giant supratentorial intracranial aneurysms. Analysis of 22 cases]

INTRODUCTION

Giant intracranial aneurysms represent 2 to 5% of all aneurysms. They are well characterized from the anatomical and clinical point of view. Their natural history shows its potential lethality. Surgical treatment of giant aneurysms is a challenge for neurosurgeons.

MATERIAL AND METHODS

Twenty-two patients were operated on through pterional craniotomy, specialized neuroanesthesia and microneurosurgical technics. Auxiliary methods like transitory clipping and retrograde decompression-suction technique were applied. Patients were followed at intensive care units and they were evaluated three months after the operation. Nineteen patients were in the fourth and sixth decade of life. Seventeen were females. Aneurysms were located at middle cerebral artery bifurcation; paraclinoidal carotid artery; proximal anterior cerebral artery and carotid bifurcation. Ninety one percent of aneurysms were clipped. Retrograde decompression-suction technique was performed in thirteen cases.

RESULTS

Seventeen patients had good outcome and one patient died (4.5%). There were 6 postoperative complications and in four disappeared three months later.

CONCLUSIONS

Giant aneurysms were operated on following main neurosurgical rules helped by auxiliar procedures to reduce aneurysms size and wall, aneurysms tension. New knowledge about giants aneurysms and the development of new techniques will permit better results.

Neurosurgical management of intracranial aneurysms previously treated with endovascular therapy

OBJECTIVE

With the increased use of endovascular therapy, an increasing number of patients with incompletely treated intracranial aneurysms are presenting for further surgical management. This study reviews our experiences with such patients.

METHODS

During a 7-year period, 38 patients with 40 intracranial aneurysms who were initially treated with endovascular therapy underwent surgical obliteration of refractory or recurrent lesions. All patients were recorded in a prospective registry, and their clinical data and imaging studies were analyzed retrospectively.

RESULTS

Twenty-six anterior and 14 posterior circulation aneurysms were treated. Four aneurysms were on the cavernous internal carotid artery, 13 were on the distal internal carotid artery, 6 were on the anterior communicating artery complex, 2 were on the middle cerebral artery, 3 were on the posteroinferior cerebellar artery, 1 was at the vertebrobasilar junction, 3 were on the superior cerebellar artery, 4 were at the basilar apex, 2 were on the posterior cerebral artery, and 1 was on the distal vertebral artery. Two pseudoaneurysms-one on the petrocavernous segment of the internal carotid artery and one on the distal VA-also were treated. The median time until recurrence was 6 months. Thirty-one aneurysms were clip-ligated, and six were treated with trapping. Three extracranial-intracranial bypasses were performed. One aneurysm was treated with muslin wrapping. Two aneurysms required the use of surgical approaches that involved hypothermic circulatory arrest. Nine aneurysms required coil mass extraction and/or complex vascular reconstruction to complete lesion obliteration. All aneurysms except the single wrapped aneurysm were successfully excluded from the intracranial circulation. Two deaths occurred as a result of the operative procedures, and another patient died as a result of subarachnoid hemorrhage-induced massive myocardial infarction. Ultimately, 86.8% of patients achieved an excellent or good recovery.

CONCLUSION

With endovascular therapy assuming an increasing role in the treatment of patients with intracranial aneurysms, more lesions that are refractory to initial treatment will require surgical management. Our experience indicates that good results are attainable, although technical challenges are frequently encountered.

Endovascular restorative neurosurgery: a novel concept for molecular and cellular therapy of the nervous system

The amalgam of molecular biology and neurosurgery offers immense promise for neurorestoration and the management of neurodegenerative deficiencies, developmental disorders, neoplasms, stroke, and trauma. This article summarizes present strategies for and impediments to gene therapy and stem cell therapy of the central nervous system and advances the concept of a potential new approach, namely endovascular restorative neurosurgery. The objectives of gene transfer to the central nervous system are efficient transfection of host cells, selective sustained expression of the transgene, and lack of toxicity or immune excitation. The requisite elements of this process are the identification of candidate diseases, the construction of vehicles for gene transfer, regulated expression, and physical delivery. In the selection of target disorders, the underlying genetic events to be overcome, as well as their spatial and temporal distributions, must be considered. These factors determine the requirements for the physical dispersal of the transgene, the duration of transgene expression, and the quantity of transgene product needed to abrogate the disease phenotype. Vehicles for conveying the transgene to the central nervous system include viral vectors (retroviruses, lentiviruses, adenoviruses, adeno-associated viruses, and herpes simplex virus), liposomes, and genetically engineered cells, including neural stem cells. Delivery of the transgene into the brain presents several challenges, including limited and potentially risky access through the cranium, sensitivity to volumetric changes, restricted diffusion, and the blood-brain barrier. Genetic or cellular therapeutic agents may be injected directly into the brain parenchyma (via stereotaxy or craniotomy), into the cerebrospinal fluid (in the ventricles or cisterns), or into the bloodstream (intravenously or intra-arterially). The advantages of the endovascular route include the potential for widespread distribution, the ability to deliver large volumes, limited perturbation of neural tissue, and the feasibility of repeated administration.

The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part II--concepts for future development, 2003 and beyond

The future development of the neurosurgical operative environment is driven principally by concurrent development in science and technology. In the new millennium, these developments are taking on a Jules Verne quality, with the ability to construct and manipulate the human organism and its surroundings at the level of atoms and molecules seemingly at hand. Thus, an examination of currents in technology advancement from the neurosurgical perspective can provide insight into the evolution of the neurosurgical operative environment. In the future, the optimal design solution for the operative environment requirements of specialized neurosurgery may take the form of composites of venues that are currently mutually distinct. Advances in microfabrication technology and laser optical manipulators are expanding the scope and role of robotics, with novel opportunities for bionic integration. Assimilation of biosensor technology into the operative environment promises to provide neurosurgeons of the future with a vastly expanded set of physiological data, which will require concurrent simplification and optimization of analysis and presentation schemes to facilitate practical usefulness. Nanotechnology derivatives are shattering the maximum limits of resolution and magnification allowed by conventional microscopes. Furthermore, quantum computing and molecular electronics promise to greatly enhance computational power, allowing the emerging reality of simulation and virtual neurosurgery for rehearsal and training purposes. Progressive minimalism is evident throughout, leading ultimately to a paradigm shift as the nanoscale is approached. At the interface between the old and new technological paradigms, issues related to integration may dictate the ultimate emergence of the products of the new paradigm. Once initiated, however, history suggests that the process of change will proceed rapidly and dramatically, with the ultimate neurosurgical operative environment of the future being far more complex in functional capacity but strikingly simple in apparent form.

The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part I-prehistory to 2003

Despite its singular importance, little attention has been given to the neurosurgical operative environment in the scientific and medical literature. This article focuses attention on the development of neurosurgery and the parallel emergence of its operative setting. The operative environment has, to a large extent, defined the "state of the art and science" of neurosurgery, which is now undergoing rapid reinvention. During the course of its initial invention, major milestones in the development of neurosurgery have included the definition of anatomy, consolidation of a scientific basis, and incorporation of the practicalities of anesthesia and antisepsis and later operative technical adjuvants for further refinement of action and minimalism. The progress, previously long and laborious in emergence, is currently undergoing rapid evolution. Throughout its evolution, the discipline has assimilated the most effective tools of modernity into the operative environment, leading eventually to the entity known as the operating room. In the decades leading to the present, progressive minimalization of manipulation and the emergence of more refined operative definition with increasing precision are evident, with concurrent miniaturization of attendant computerized support systems, sensors, robotic interfaces, and imaging devices. These developments over time have led to the invention of neurosurgery and the establishment of the current state-of-the-art neurosurgical operating room as we understand it, and indeed, to a broader definition of the entity itself. To remain current, each neurosurgeon should periodically reconsider his or her personal operative environment and its functional design with reference to modernity of practice as currently defined.

[Aneurysms surgery in the patients aged seventy to eighty years]

Elderly patients are a growing population group in developing countries because of optimal health care. 13% of Cuba population is older than sixty years and it is expected to grow to 20% in 2005. Subarachnoid hemorrhage secondary to ruptured aneurysms in geriatric patients carries a high mortality but a few patients are selected for surgical treatment. Manuel Ascunce Domenech Hospital attended 1112 patients older than 60 years between January 1994 and December 2001. Of these there were 96 patients with symptomatic intracranial aneurysms and we selected 30 for surgical treatment. They were all in clinical grades I and II of the WFNS scale. They had good health to face surgery and familiar consent. The size and location of the aneurysms were not considered among the exclusion criteria. Aneurysms were mainly localized at posterior communicating and middle cerebral arteries. There were two deaths, one due to a medical cause an the other to the surgical procedure. 74% of the patients obtained satisfactory outcome six month after the operation. The clue is to not consider age as a negative point for surgery. Surgical procedures can be performed in patients with good clinical grade (WFNS). New technical advances, stroke units, accurately selected patients and minimal invasive surgical methods will help to obtain good results.

Covered stent-graft repair of the brachiocephalic arteries: technical note

OBJECTIVE

The use of a covered stent-graft to repair disruptions of the cervical carotid and vertebral arteries is described. This device maintains vessel patency while effectively excluding pseudoaneurysms, arteriovenous fistulae, and other breaches in the integrity of the arterial wall.

METHODS

Patient 1 bled from a large rent in the proximal common carotid artery as a result of tumor invasion. Patient 2 developed a vertebral arteriovenous fistula after a stab injury to the neck. Patient 3 developed cerebral infarction and an enlarging pseudoaneurysm of the internal carotid artery, also after a stab wound to the neck.

RESULTS

All three patients were treated with the Wallgraft endoprosthesis (Boston Scientific, Watertown, MA). In each case, the vessel wall defect was repaired while antegrade flow through the artery was preserved or restored. No neurological complications occurred as a result of stent-graft deployment.

CONCLUSION

Covered stent-grafts offer an alternative to endovascular occlusion of the parent vessel, thereby expanding the therapeutic options for patients with extracranial cerebrovascular disease. These three cases highlight the usefulness and versatility of these devices for endoluminal reconstruction of the brachiocephalic vasculature.

Stent-assisted endoluminal revascularization for the treatment of intracranial atherosclerotic disease

Since the inception of intravascular stents in the 1960s, marked technological advancements have yielded stents that can be navigated through tortuous cerebral vessels. Numerous applications for intracranial stenting are being developed at an exciting pace. One such application that has shown promise in several small series is the use of stents for endoluminal revascularization of severe intracranial stenosis that is refractory to medical therapy. Prior to the introduction of endovascular approaches for this condition, complex bypass procedures were often necessary to restore adequate blood flow to hypoperfused parenchyma. In the following article, we review endovascular techniques for stenting of intracranial atherosclerotic disease. Patient selection, vascular access, medical management, and future directions are discussed.

Basilar apex aneurysms: surgical results and perspectives from an initial experience

OBJECTIVE

To demonstrate that well-trained neurosurgeons can successfully treat patients with basilar apex aneurysms, to encourage young neurosurgeons in appropriate clinical environments to develop this expertise, and to describe a personal experience with an initial series.

METHODS

In a consecutive series of 500 aneurysms treated surgically over 3.5 years, 57 aneurysms in 56 patients were located at the basilar apex, 47% of which were large or giant in size.

RESULTS

Most aneurysms (77%) were treated by direct clipping through an orbitozygomatic-pterional transsylvian approach. The surgical mortality rate was 9%, and permanent neurological morbidity associated with treatment occurred in 5%. Good outcomes (Glasgow Outcome Scale score 5 or 4) were achieved in 84%. Good outcomes increased from 79% in the first half of the series to 90% in the second half, and the mortality rate decreased from 21 to 4%.

CONCLUSION

Young neurosurgeons can acquire technical proficiency with basilar apex aneurysms while achieving optimal patient outcomes. Young neurosurgeons with the right training, talent, and temperament are needed to deal with those patients with basilar aneurysms who require surgery and with a possible shortage of basilar aneurysm surgeons in the future. The learning curve is characterized by increased temporary clipping, better perforator dissection, and more sophisticated permanent clipping technique. The path to proficiency can be as demanding mentally as it is technically.

2001: Things to come

THIS ARTICLE DISCUSSES elements in the definition of modernity and emerging futurism in neurological surgery. In particular, it describes evolution, discovery, and paradigm shifts in the field and forces responsible for their realization. It analyzes the cyclical reinvention of the discipline experienced during the past generation and attempts to identify apertures to the near and more remote future. Subsequently, it focuses on forces and discovery in computational science, imaging, molecular science, biomedical engineering, and information processing as they relate to the theme of minimalism that is evident in the field. These areas are explained in the light of future possibilities offered by the emerging field of nanotechnology with molecular engineering.