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Posterior Lumbar Interbody Fusion (PLIF)

Introduction The technique of posterior lumbar interbody fusion (PLIF) is an important technique in the current spine surgeon’s armamentarium. That being said, the surgery is still defined by its level of technical difficulty and controversy exists regarding the safety of PLIF compared with other approaches to the intervertebral space. The first in-depth description of a PLIF was described by Cloward, as an operation where the disk…

Mini-Open Anterior Lumbar Interbody Fusion (ALIF)

Introduction The anterior lumbar interbody fusion (ALIF) is a powerful and versatile tool for obtaining interbody fusion for a variety of conditions. Anterior fusion for disk disease was first described by Burns, and Harmon first described a retroperitoneal approach in 1950. The current mini-open perirectus approach was first described by Crock. Since that time many studies have been released using this approach for a variety of…

Intraoperative Image-Guided Navigation for Lumbar Interbody Fusion

Introduction Minimally invasive spine surgery has gained much popularity in recent years owing to the reductions in patient morbidity, length of hospital stay, and costs. Although these short-term outcomes have seen marked improvements, there has been little improvement in the long-term outcomes when comparing minimally invasive lumbar interbody fusion (MIS-LIF) to open techniques. When first developed, MIS-LIF required extensive fluoroscopy to ensure accurate interbody cage placement…

Relevant Surgical Anatomy of the Lateral and Anterior Lumbar Spine

Introduction Anterior and lateral approaches to the lumbar spine are performed with increasing frequency and for a wider range of indications. To avoid complications and maximize patient outcomes, a clear understanding of the anatomy encountered during these approaches is necessary. Here we consider the bony, vascular, and neural anatomy most pertinent to the anterior and lateral transpsoas approaches. Bony and Ligamentous Anatomy The lumbar spine consists…

Complications and Avoidance in Lumbar Interbody Fusions

Introduction As with any surgical procedure, interbody fusions are associated with unique complications. Given the wide variety of approaches utilized when performing an interbody fusion, it is important to recognize common complications associated with each specific technique. Recognition of these complications allows the surgeon to utilize a more protective surgical approach to limit perioperative complications. Furthermore, recognition of common complications better enables the surgeon to inform…

General Indications and Contraindications

Introduction This chapter provides an overview of the contemporary literature on lumbar interbody fusion (LIF) instrumentation based on the Spine Patient Outcome Research Trial, Swedish Spinal Stenosis Study, and a recent New England Journal of Medicine article on clinical outcomes. Preoperative factors influencing the surgical outcome are discussed, along with five basic tenets of LIF based on: (1) presence and extent of concurrent listhesis at the…

Surgical Innovations

Pearls Advances in knowledge regarding the natural history of iAVMs and indications for surgery have enhanced patient selection for specific treatment modalities. Imaging modalities allow for precise determination of nidus size, intranidal aneurysm presence, and characterization of arterial feeders and draining veins. Understanding of blood pressure goals, as well as advances in anesthetic and neurocritical care, has decreased postoperative complications. The use of digital subtraction angiography…

Molecular Biology and Novel Treatments of Intracranial AVMs

Acknowledgments We thank the staff of Neuroscience Publications at Barrow Neurological Institute for assistance with manuscript preparation. Pearls The dynamic nature of iAVMs is ascribed to complex molecular and physiologic processes that contribute to their growth, regression, remodeling, and de novo recurrence. Endothelial cell–specific, somatic-activating mutations in the KRAS gene contribute to the formation of sporadic iAVMs. Hereditary hemorrhagic telangiectasia is the most prevalent genetic syndrome…

Radiosurgical Innovations

Pearls Stereotactic radiosurgery is a reasonable and well-studied treatment strategy for AVM patients. Treatment success and complication profiles are a function of AVM nidus, cortical eloquence, and overall AVM flow. Strong predictive models remain an area of research. Innovations in radiosurgery involve the use of radiosensitizers, staging dosage, and volumetric targeting for AVMs exceeding 3 cm, and an evolving role for adjunctive endovascular embolization. Concluding case…

Imaging Predictors for Rupture

Pearls The effective assessment of iAVMs relies on both MRI (parenchymal imaging) and catheter angiography. Directed evaluation of these studies provides predictors of AVM rupture risk. Treatment response to open surgery, endovascular embolization, or radiosurgery requires imaging assessment. AVM location, angiographic risk factors (including nidal aneurysms), and overall venous sufficiency of the brain determine AVM bleeding and treatment risk. The presence of venous outflow obstruction or…

The Value of a Registry

Pearls The management of iAVMs is controversial. The randomized control trial (RCT) results from ARUBA (A Randomised Trial of Arteriovenous Malformations) have added to this controversy. Registry-based studies are observational studies focused on a specific clinical disease, patient population, or treatment. Registry-based studies are more inclusive than RCTs. Registries for iAVMs exist, but there is a need for more focus and an organized multicenter approach. Introduction…

Intraoperative AVM Rupture

Acknowledgment We thank the staff of Neuroscience Publications at Barrow Neurological Institute for assistance with manuscript preparation. Pearls Intraoperative bleeding from an iAVM is best categorized as arterial, venous, or nidal. Arterial bleeding is best managed with bipolar cautery directly at the source. Venous injury can occur if a main draining vein is mistaken for an artery, so careful study of the vessel and attention to…

Residual AVMs

Pearls The treatment of residual iAVMs is complex and best avoided with appropriate planning and execution of the initial procedure(s). Intraoperative angiography, indocyanine green fluorescence, and provocative hypertension are very useful for ruling out residual iAVM at the time of surgery. Subtotal obliteration after radiosurgery—with no visible nidus but a persistent draining vein—needs to be followed judiciously and is not considered an AVM cure. Resection of…

Pediatric AVMs

Pearls Pediatric iAVMs tend to present as symptomatic lesions. Early management centers around general principles of intracranial pressure management, assessment of need for hematoma evacuation, and identification of high-risk angiographic features. Symptomatic pediatric iAVMs carry a much more substantial risk and should be managed aggressively with a multimodal approach that may include embolization, surgical removal, or stereotactic radiosurgery. Although AVMs have long been considered congenital lesions,…

AVMs of the Sylvian Fissure

Pearls Sylvian fissure AVMs are very frequently related to eloquent cortex anatomically or by virtue of vascular anatomy. Permanent morbidity after resection ranges from 0% to 34%. Classification is based upon anatomical location within (pure sylvian) or around (perisylvian) the sylvian fissure and associated eloquent brain. A multimodal approach (embolization, surgery, radiosurgery, observation) should be meticulously evaluated in cases of these high-risk lesions. This AVM location…

Callosal and Periventricular AVMs

Pearls Callosal and periventricular AVMs are quite rare. Their deep location and association with critical neurovascular structures indicate patients should seek help from experienced centers. Indications for treatment are similar to those for all other iAVM locations. Radiosurgery, although less effective at obliteration, should be considered. A thorough understanding of the surgical anatomy is required for the treatment of these complex lesions. Introduction Intracranial arteriovenous malformations…

Posterior Fossa AVMs

Epidemiology and Natural History Posterior fossa AVMs are rare lesions. Previous series have estimated that they make up approximately 15%–18% of all intracranial AVMs. This group can be further divided into brainstem and cerebellar AVMs. Cerebellar AVMs ( Fig. 32.1 ) represent the majority of posterior fossa AVMs, comprising approximately 70% of these lesions. Brainstem AVMs have separately been estimated to represent only 6%–8%. Together, these…

Treatment of Eloquent Cortex AVMs

Pearls Eloquent (functional) cortex includes motor, sensory, visual, and speech areas as well as the thalamus, brainstem, and cerebellar peduncles. Awake craniotomy to map functional cortex is rarely used in AVM surgery. Noninvasive or minimally invasive methods to define functional cortex include MRI, functional MRI, diffusion tensor imaging, and Wada testing. Functional mapping is of equal importance to all treatment modalities: observation, stereotactic radiosurgery, embolization, and…

Giant Intracranial AVMs

Pearls Giant iAVMs are a rare entity. They can be symptomatic due to bleeding as well as through steal phenomena. Treatment is almost always multimodality, with an emphasis on mitigating bleeding risk and palliation of symptoms. Cure is rare. Giant iAVMs are by definition Spetzler-Martin grade IV or V, with microsurgical resection carrying a high rate of morbidity and mortality. Staged embolization and radiosurgery are reasonable…