✓Spinal nerve root stimulation is a recently developed form of neuromodulation used for the treatment of chronic pain conditions. Unlike spinal cord stimulation, in which electrical impulses are directed at the dorsal columns, spinal nerve root stimulation guides electrical current directly to one or more nerve roots. There are a variety of techniques by which this can be accomplished, yet no consistent terminology to describe these variations exists. In this review, the authors group the various techniques according to anatomical approach, define each category, describe and illustrate each of the techniques, review the available reports on their uses, and discuss the advantages and disadvantages of each one.
Raqeeb Haque and Christopher J. Winfree
Raqeeb Haque, Christopher Kellner and Robert A. Solomon
The authors describe the cases of 2 patients who underwent extracranial-intracranial bypass surgery for a giant fusiform aneurysm but in whom further surgery was then not necessary because the aneurysm spontaneously thrombosed. The authors hypothesize that this thrombosis was caused by alterations in aneurysm's hemodynamics, leading to a decreased rate of blood flow in the aneurysm. In the older of the 2 cases, more than 10 years after surgery the patient has not required further surgical intervention. Spontaneous thrombosis of a giant fusiform aneurysm is a rare occurrence during extracranial-intracranial bypass, and although continual monitoring is recommended, these patients can remain stable long term.
Peter D. Angevine, Christopher Kellner, Raqeeb M. Haque and Paul C. McCormick
Access to the ventral intradural spinal canal may be required for treatment of a variety of lesions affecting the spinal cord and adjacent intradural structures. Adequate exposure is usually achieved through a standard posterior laminectomy or posterolateral approaches, although formal anterior approaches are used to access lesions in the subaxial cervical spine. Modifications of the standard posterior exposure as well as ventral or ventrolateral approaches are increasingly being used for treating intradural spinal pathologies. In this study, the authors review their experience with 35 consecutive cases of ventral intradural spinal lesions.
Only patients with intradural lesions located completely ventral to the dentate ligament attachments were included in this retrospective study. Patients with the following lesions were excluded from the study: lesions at the level of the filum terminale/cauda equina, lesions with any component that extended dorsally to the dentate ligament, or lesions with extradural extension (that is, dumbbell tumors) below the C-2 level. Between January 2000 and September 2009, a total of 35 patients (age range 17–72 years, mean 42.6 years) with ventral intradural spinal pathology underwent surgery at the authors' institution.
There were 28 intradural extramedullary mass lesions: 15 meningiomas, 12 solitary schwannomas, and 1 neuroenteric cyst. Surgical approaches to these lesions included 23 posterior or posterolateral approaches, 4 anterior approaches with corpectomy followed by tumor resection and reconstruction, and 1 lateral transforaminal resection. No patient had evidence of instability at follow-up, which ranged from 6 months to 8 years in duration. One patient had worsened spinal cord function following surgery. There were 7 patients with intramedullary lesions: 2 hemangioblastomas, 2 cavernous malformations, 2 perimedullary fistulas, and 1 astrocytoma. All but 1 were superficial pia-based lesions arising ventral to the dentate ligament. Five of the 6 pia-based lesions were successfully resected via a standard posterior laminectomy, partial facetectomy with dentate section, and spinal cord rotation. One midline pial lesion was successfully removed with a minimally invasive retropleural thoracotomy. The astrocytoma was resected through an anterior cervical corpectomy, which was followed by instrumented reconstruction. There were no significant complications or neurological morbidity at follow-up (range 9 months–6 years).
Most intradural spinal lesions can be treated with contemporary microsurgical techniques with long-term control or cure of the lesion and preservation of neurological function. Standard posterior approaches provide adequate exposure to safely remove the vast majority of these lesions without the need for a potentially destabilizing resection of the facet or pedicle. Posterior exposures with varying degrees of lateral bone resection, dentate ligament division, and gentle cord rotation may also provide adequate exposure for safe removal of nonmidline ventrolateral superficial pial presenting spinal cord lesions. Nevertheless, in certain cases of ventral intradural lesions, anterior approaches are necessary and should be considered under appropriate circumstances.
Christopher P. Kellner, Raqeeb M. Haque, Philip M. Meyers, Sean D. Lavine, E. Sander Connolly Jr. and Robert A. Solomon
Complex aneurysms of the basilar artery (BA) apex can be successfully treated using surgical occlusion of the proximal BA. Since the introduction of the Guglielmi detachable coil in 1991, the focus on treating BA aneurysms has been on using endovascular techniques. Outcomes with endovascular techniques have been less than optimal for large and complex aneurysms. The authors therefore report on their current 22-year experience with surgical BA occlusion for complex BA aneurysms and long-term outcome.
Fifteen patients underwent surgical BA occlusion at Columbia University Medical Center for complex basilar apex aneurysms between 1987 and 2009. The clinical records of each patient were reviewed for details of presentation, hospital course, operative intervention, and outcome.
Postoperatively, all patient encounters were recorded at discharge, at the 1-month and 1-year follow-up evaluations, and at long-term outcome. Twelve (80%) of 15 patients experienced no new postoperative neurological deficits. Three patients presenting with severe neurological impairment (modified Rankin Scale [mRS] score > 3) made excellent recoveries (mRS Scores 1–2) at long-term follow-up. One patient died, 1 suffered a stroke during the postoperative angiogram which resulted in hemiparesis, and 1 suffered internuclear ophthalmoplegia which resolved by the 1-month follow-up. Long-term follow-up occurred at an average of 3 ± 4.5 years, ranging from 2 months (for a recently treated patient) to 18 years. The average mRS score at long-term follow-up was 1 ± 1.5. No patient experienced postoperative hemorrhage, rebleeding, or delayed neurological deterioration.
Surgical occlusion of the BA is an effective treatment option offering a high rate of angiographic cure in a single procedure for patients with complex BA aneurysms. The ability to surgically perform point occlusion of the BA without impairment of brainstem perforators, while maintaining collateral blood flow to the posterior circulation branch vessels, may provide an advantage compared with endovascular treatments.
Raqeeb Haque, Teresa J. Wojtasiewicz, Paul R. Gigante, Mark A. Attiah, Brendan Huang, Steven R. Isaacson and Michael B. Sisti
The goal of this article was to show that a combination of facial nerve–sparing microsurgical resection and Gamma Knife surgery (GKS) for expansion of any residual tumor can preserve good facial nerve function in patients with recurrent vestibular schwannoma (VS).
Records of individuals treated by a single surgeon with a facial nerve–sparing technique for a VS between 1998 and 2009 were retrospectively analyzed for tumor recurrence. Of the 383 patients treated for VS, 151 underwent microsurgical resection, and 20 (13.2%) of these patients required postoperative retreatment for a significant expansion of residual tumor after microsurgery. These 20 patients were re-treated with GKS.
The rate of preservation of good facial nerve function (Grade I or II on the House-Brackmann scale) in patients treated with microsurgery for VS was 97%. Both subtotal and gross-total resection had excellent facial nerve preservation rates (97% vs 96%), although subtotal resection carried a higher risk that patients would require retreatment. In patients re-treated with GKS after microsurgery, the rate of facial nerve preservation was 95%.
In patients with tumors that cannot be managed with radiosurgery alone, a facial nerve–sparing resection followed by GKS for any significant regrowth provides excellent facial nerve preservation rates.
Omar M. Uddin, Raqeeb Haque, Patrick A. Sugrue, Yousef M. Ahmed, Tarek Y. El Ahmadieh, Joel M. Press, Tyler Koski and Richard G. Fessler
Back pain is an increasing concern for the aging population. This study aims to evaluate if minimally invasive surgery presents cost-minimization benefits compared with open surgery in treating adult degenerative scoliosis.
Seventy-one patients with adult degenerative scoliosis received 2-stage, multilevel surgical correction through either a minimally invasive spine surgery (MIS) approach with posterior instrumentation (n = 38) or an open midline (Open) approach (n = 33). Costs were derived from hospital and rehabilitation charges. Length of stay, blood loss, and radiographic outcomes were obtained from electronic medical records. Functional outcomes were measured with Oswestry Disability Index (ODI) and visual analog scale (VAS) surveys.
Patients in both cohorts were similar in age (AgeMIS = 65.68 yrs, AgeOpen = 63.58 yrs, p = 0.28). The mean follow-up was 18.16 months and 21.82 months for the MIS and Open cohorts, respectively (p = 0.34). MIS and Open cohorts had an average of 4.37 and 7.61 levels of fusion, respectively (p < 0.01). Total inpatient charges were lower for the MIS cohort ($269,807 vs $391,889, p < 0.01), and outpatient rehabilitation charges were similar ($41,072 vs $49,272, p = 0.48). MIS patients experienced reduced length of hospital stay (7.03 days vs 14.88 days, p < 0.01) and estimated blood loss (EBL) (EBLMIS = 470.26 ml, EBLOpen= 2872.73 ml, p < 0.01). Baseline ODI scores were lower in the MIS cohort (40.03 vs 48.04, p = 0.03), and the cohorts experienced similar 1-year improvement (ΔODIMIS = −15.98, ΔODIOpen = −21.96, p = 0.25). Baseline VAS scores were similar (VASMIS = 6.56, VASOpen= 7.10, p = 0.32), but MIS patients experienced less reduction after 1 year (ΔVASMIS = −3.36, ΔVASOpen = −4.73, p = 0.04). Preoperative sagittal vertical axis (SVA) were comparable (preoperative SVAMIS = 63.47 mm, preoperative SVAOpen = 71.3 mm, p = 0.60), but MIS patients had larger postoperative SVA (postoperative SVAMIS = 51.17 mm, postoperative SVAOpen = 28.17 mm, p = 0.03).
Minimally invasive surgery demonstrated reduced costs, blood loss, and hospital stays, whereas open surgery exhibited greater improvement in VAS scores, deformity correction, and sagittal balance. Additional studies with more patients and longer follow-up will determine if MIS provides cost-minimization opportunities for treatment of adult degenerative scoliosis.
Richard C. E. Anderson, Michael M. McDowell, Christopher P. Kellner, Geoffrey Appelboom, Samuel S. Bruce, Ivan S. Kotchetkov, Raqeeb Haque, Neil A. Feldstein, E. Sander Connolly Jr., Robert A. Solomon, Philip M. Meyers and Sean D. Lavine
Conventional cerebral angiography and treatment for ruptured arteriovenous malformations (AVMs) in children are often performed in a delayed fashion. In adults, current literature suggests that AVM-associated aneurysms may be more likely to hemorrhage than isolated AVMs, which often leads to earlier angiography and endovascular treatment of associated aneurysms. The nature of AVM-associated aneurysms in the pediatric population is virtually unknown. In this report, the authors investigate the relationship of associated aneurysms in a large group of children with AVMs.
Seventy-seven pediatric patients (≤ 21 years old) with AVMs were treated at the Columbia University Medical Center between 1991 and 2010. Medical records and imaging studies were retrospectively reviewed, and associated aneurysms were classified as arterial, intranidal, or venous in location. Clinical presentation and outcome variables were compared between children with and without AVM-associated aneurysms.
A total of 30 AVM-associated aneurysms were found in 22 children (29% incidence). Eleven were arterial, 9 intranidal, and 10 were venous in location. There was no significant difference in the rate of hemorrhage (p = 0.91) between children with isolated AVMs (35 of 55 [64%]) and children with AVM-associated aneurysms (13 of 22 [59%]). However, of the 11 children with AVM-associated aneurysms in an arterial location, 10 presented with hemorrhage (91%). An association with hemorrhage was significant in univariate analysis (p = 0.045) but not in multivariate analysis (p = 0.37).
Associated aneurysms are present in nearly a third of children with AVMs, and when arterially located, are more likely to present with hemorrhage. These data suggest that early angiography with endovascular treatment of arterial-based aneurysms in children with AVMs may be indicated.
Gary L. Gallia, Raqeeb Haque, Ira Garonzik, Timothy F. Witham, Yevgeniy A. Khavkin, Jean Paul Wolinsky, Ian Suk and Ziya L. Gokaslan
✓ Although radical resection prolongs the disease-free survival period, surgical management of primary sacral tumors is challenging because of their location and often large size. Moreover, in cases of lesions for which a radical resection necessitates total sacrectomy, reconstruction is required. The authors have previously described a modified Galveston technique in which a liaison between the spine and pelvis is achieved using lumbar pedicle screws and Galveston rods embedded into the ilia; additionally, a transiliac bar reestablishes the pelvic ring. Although this reconstruction technique achieves stabilization, several biomechanical limitations exist. In the present report the authors present the case of a patient who underwent spinal pelvic reconstruction after a total sacrectomy was performed to remove a giant sacral chordoma. They describe a novel spinal pelvic reconstruction technique that addresses some of the biomechanical limitations.
Raqeeb M. Haque, Hani R. Malone, Martin W. Bauknight, Michael A. Kellner, Alfred T. Ogden, John H. Martin, Kurenai Tanji and Christopher J. Winfree
Despite extensive study, no meaningful progress has been made in encouraging healing and recovery across the site of spinal cord injury (SCI) in humans. Spinal cord bypass surgery is an unconventional strategy in which intact peripheral nerves rostral to the level of injury are transferred into the spinal cord below the injury. This report details the feasibility of using spinal accessory nerves to bypass cervical SCI and intercostal nerves to bypass thoracolumbar SCI in human cadavers.
Twenty-three human cadavers underwent cervical and/or lumbar laminectomy and dural opening to expose the cervical cord and/or conus medullaris. Spinal accessory nerves were harvested from the Erb point to the origin of the nerve's first major branch into the trapezius. Intercostal nerves from the T6–12 levels were dissected from the lateral border of paraspinal muscles to the posterior axillary line. The distal ends of dissected nerves were then transferred medially and sequentially inserted 4 mm deep into the ipsilateral cervical cord (spinal accessory nerve) or conus medullaris (intercostals). The length of each transferred nerve was measured, and representative distal and proximal cross-sections were preserved for axonal counting.
Spinal accessory nerves were consistently of sufficient length to be transferred to caudal cervical spinal cord levels (C4–8). Similarly, intercostal nerves (from T-7 to T-12) were of sufficient length to be transferred in a tension-free manner to the conus medullaris. Spinal accessory data revealed an average harvested nerve length of 15.85 cm with the average length needed to reach C4–8 of 4.7, 5.9, 6.5, 7.1, and 7.8 cm. The average length of available intercostal nerve from each thoracic level compared with the average length required to reach the conus medullaris in a tension-free manner was determined to be as follows (available, required in cm): T-7 (18.0, 14.5), T-8 (18.7, 11.7), T-9 (18.8, 9.0), T-10 (19.6, 7.0), T-11 (18.8, 4.6), and T-12 (15.8, 1.5). The number of myelinated axons present on cross-sectional analysis predictably decreased along both spinal accessory and intercostal nerves as they coursed distally.
Both spinal accessory and intercostal nerves, accessible from a posterior approach in the prone position, can be successfully harvested and transferred to their respective targets in the cervical spinal cord and conus medullaris. As expected, the number of axons available to grow into the spinal cord diminishes distally along each nerve. To maximize axon “bandwidth” in nerve bypass procedures, the most proximal section of the nerve that can be transferred in a tension-free manner to a spinal level caudal to the level of injury should be implanted. This study supports the feasibility of SAN and intercostal nerve transfer as a means of treating SCI and may assist in the preoperative selection of candidates for future human clinical trials of cervical and thoracolumbar SCI bypass surgery.