Brian A. O'Shaughnessy

Abdominal complications following kyphosis correction in ankylosing spondylitis

Spinal deformity surgery is associated with high rates of morbidity and a wide range of complications. The most significant abdominal complications following kyphosis correction, while uncommon, can certainly pose significant infectious and hemodynamic risks to the patient. Abdominal compartment syndrome is the most severe of the sequelae. It is the end result of elevated abdominal compartment pressure with physiological compromise and end organ system dysfunction. Although most commonly associated with trauma, abdominal compartment syndrome has also been witnessed following massive fluid shifts, which can occur during adult spinal deformity surgery. In this manuscript, we report on 2 patients with ankylosing spondylitis who developed significant abdominal pathology requiring exploratory laparotomy following kyphosis correction. In addition to describing the details of each case, we propose explanations of the relevant pathophysiology and review diagnostic and treatment strategies for such events. The key to effectively treating such a debilitating complication is to recognize it quickly and intervene rapidly and aggressively.

Chemical meningitis after cerebral aneurysm treatment using two second-generation aneurysm coils: Report of two cases

OBJECTIVE AND IMPORTANCE Dolichoectatic vertebrobasilar artery aneurysms are often extremely difficult, if not impossible, to treat with microneurosurgical clip reconstruction. As such, a Hunterian strategy via vertebral or basilar artery sacrifice is often used. We have encountered a patient in whom deliberate bilateral vertebral artery sacrifice was insufficient to avoid progressive expansion of a giant dolichoectatic vertebrobasilar artery aneurysm. On the basis of a review of the literature, we are unaware of another reported case. CLINICAL PRESENTATION A 60-year-old man presented with signs and symptoms of brainstem compression from a large fusiform aneurysm involving the distal dominant vertebral and proximal basilar arteries. Results of angiographic evaluation were highly characteristic of underlying dolichoectasia. INTERVENTION The patient was treated initially with staged bilateral vertebral artery occlusion and adjunctive posterior circulation revascularization. After this therapy failed, he underwent a trapping procedure and aneurysm deflation. CONCLUSION Unclippable aneurysms of the vertebrobasilar system are formidable lesions. They are not uniformly treatable by direct surgical reconstruction, and their growth is not consistently stabilized by the implementation of a complete Hunterian strategy. Future developments related to the use of endovascular stent technology may offer a more successful treatment approach for patients with these complex cerebrovascular lesions.OBJECTIVE AND IMPORTANCE: In the quest for effective and durable endovascular aneurysm treatment, second-generation aneurysm coils endeavor to increase the biological healing response to the implanted material. We report two cases of large cerebral aneurysms treated concurrently with both available second-generation aneurysm coils and the subsequent development of symptomatic nonbacterial meningitis. CLINICAL PRESENTATION: Two previously healthy patients underwent endovascular treatment for large (≥2 cm) cerebral aneurysms. Both aneurysms were treated using multiple Hydrogel coils (MicroVention, Inc., Aliso Viejo, CA) and Matrix coils (Boston Scientific/Target, Fremont, CA). Careful aseptic technique was observed throughout each procedure, and prophylactic intravenous antibiotics were administered during the perioperative period to both patients. Treatment proceeded uneventfully in both cases with excellent aneurysm occlusion and no immediate postoperative neurological deficits. INTERVENTION: In both cases, the patients were discharged from hospital but quickly were readmitted with stigmata of meningitis. Imaging demonstrated durable occlusion of the aneurysms in both patients and also abnormalities indicative of perianeurysmal and diffuse intracranial inflammatory response. Complete septic workup failed to identify an organism in either patient. Both patients responded to treatment with corticosteroid medication used to modulate the inflammatory response induced by the coil implants. CONCLUSION: Second-generation aneurysm coils were developed to promote more durable occlusion of cerebral aneurysms by promoting more complete volumetric aneurysm occlusion or by eliciting a more prolific inflammatory response. The concurrent use of Hydrogel and Matrix coil systems in large aneurysms may cause an exuberant inflammatory response with both local and systemic manifestations. Although vigilant evaluation and treatment for presumptive bacterial meningitis is required in all such cases, patients respond to immunomodulatory therapy with corticosteroids. More information to understand better the interaction of Hydrogel and Matrix coils is needed.

Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy Presented at the 2012 Joint Spine Section Meeting Clinical article

OBJECT Sagittal spinopelvic malalignment is a significant cause of pain and disability in patients with adult spinal deformity. Surgical correction of spinopelvic malalignment can result in compensatory changes in spinal alignment outside of the fused spinal segments. These compensatory changes, termed reciprocal changes, have been defined for thoracic and lumbar regions but not for the cervical spine. The object of this study was to evaluate postoperative reciprocal changes within the cervical spine following lumbar pedicle subtraction osteotomy (PSO). METHODS This was a multicenter retrospective radiographic analysis of patients from International Spine Study Group centers. Inclusion criteria were as follows: adults (>18 years old) with spinal deformity treated using lumbar PSO, a preoperative C7-S1 plumb line greater than 5 cm, and availability of pre- and postoperative full-length standing radiographs. RESULTS Seventy-five patients (60 women, mean age 59 years) were included. The lumbar PSO significantly improved sagittal alignment, including the C7-S1 plumb line, C7-T12 inclination, and pelvic tilt (p <0.001). After lumbar PSO, reciprocal changes were seen to occur in C2-7 cervical lordosis (from 30.8° to 21.6°, p <0.001), C2-7 plumb line (from 27.0 mm to 22.9 mm), and T-1 slope (from -38.9° to -30.4°, p <0.001). Ideal correction of sagittal malalignment (postoperative sagittal vertical alignment < 50 mm) was associated with the greatest relaxation of cervical hyperlordosis (-12.4° vs -5.7°, p = 0.037). A change in cervical lordosis correlated with changes in T-1 slope (r = -0.621, p <0.001), C7-T12 inclination (r = 0.418, p <0.001), T12-S1 angle (r = -0.339, p = 0.005), and C7-S1 plumb line (r = 0.289, p = 0.018). Radiographic parameters that correlated with changes in cervical lordosis on multivariate linear regression analysis included change in T-1 slope and change in C2-7 plumb line (r(2) = 0.53, p <0.001). CONCLUSIONS Adults with positive sagittal spinopelvic malalignment compensate with abnormally increased cervical lordosis in an effort to maintain horizontal gaze. Surgical correction of sagittal malalignment results in improvement of the abnormal cervical hyperlordosis through reciprocal changes.

Surgical treatment of fixed cervical kyphosis with myelopathy.

Study Design. A retrospective clinical study. Objective. To investigate clinical and radiographic outcomes following the surgical treatment of fixed cervical kyphosis with myelopathy. Summary of Background Data. To our knowledge, a study specifically addressing the surgical treatment of fixed cervical sagittal deformity has never before been published. Methods. Sixteen patients treated surgically for fixed cervical kyphosis and myelopathy were followed for a mean of 4.5 years (range, 25–112 months). The study group consisted of 9 males and 7 females, with an average age of 52 years (range, 31–78 years). The principal etiologies of cervical deformity were prior laminectomy (63%), advanced spondylosis (19%), infection (6%), neuromuscular disease (6%), and metabolic disease (renal osteodystrophy) (6%). All patients were clinically evaluated by the Nurick classification and Odom criteria both before surgery and at the time of most recent follow-up. Radiographic analysis was performed using thin-cut CT scans, dynamic radiographs, and 14 × 36-inch scoliosis films. Results. The mean preoperative cervical Cobb angle as measured from the C2–C7 was +38° and improved to −10° at final follow-up, yielding an average correction of 48°. The mean number of anterior and posterior segments fused was 4.8 (range, 2–6) and 7.2 (range, 3–14), respectively. The mean Nurick score improved from 2.4 before surgery to 1.5 at the time of follow-up. According to Odom criteria, outcomes were as follows: excellent (38%), good (50%), fair (6%), and poor (6%). At the time of most recent follow-up, solid bony arthrodesis and maintenance of correction occurred in all patients; however, revision was required in one patient. Conclusion. The treatment of fixed cervical kyphosis with myelopathy using circumferential spinal osteotomies and instrumented reconstruction is technically demanding; however, restoration and maintenance of a neutral or lordotic cervical profile and excellent clinical outcomes are achievable.

Maximizing the potential of minimally invasive spine surgery in complex spinal disorders.

Minimally invasive surgery (MIS) in the spine was primarily developed to reduce approach-related morbidity and to improve clinical outcomes compared with those following conventional open spine surgery. Over the past several years, minimally invasive spinal procedures have gained recognition and their utilization has increased. In particular, MIS is now routinely used in the treatment of degenerative spine disorders and has been shown to be as effective as conventional open spine surgeries. Although the procedures are not yet widely recognized in the context of complex spine surgery, the true potential in minimizing approach-related morbidity is far greater in the treatment of complex spinal diseases such as spinal trauma, spinal deformities, and spinal oncology. Conventional open spine surgeries for complex spinal disorders are often associated with significant soft tissue disruption, blood loss, prolonged recovery time, and postsurgical pain. In this article the authors review numerous cases of complex spine disorders managed with MIS techniques and discuss the current and future implications of these approaches for complex spinal pathologies.

Thoracic pedicle subtraction osteotomy for fixed sagittal spinal deformity.

Study Design. A retrospective clinical study. Objective. To find the corrective capacity of a thoracic pedicle subtraction osteotomy (PSO), determine if segmental correction is dependent on level, and to compute the impact of thoracic PSO on regional and global spinal balance. Summary of Background Data. PSO is a technique popularized in the lumbar spine primarily for the correction of fixed sagittal imbalance. Despite several studies describing the clinical and radiographic outcome of lumbar PSO, there is no study in literature reporting its application in the thoracic spine. Methods. We retrospectively analyzed patients with fixed thoracic kyphosis who underwent thoracic PSOs for sagittal realignment. Segmental pedicle screw instrumentation and intraoperative neurophysiologic monitoring was used in all patients. Data acquisition was performed by reviewing medical charts and radiographs to determine sagittal correction (segmental/regional/global) and complications. Clinical outcome using the Scoliosis Research Society-22 (SRS-22) instrument was determined by interview. Results. A total of 25 thoracic PSOs were performed (mean: 1.7 PSOs/patient, range: 1–3) in 15 patients (9 M/6 F). The study population had an average age of 56 years (range, 36–81 years) and was followed up after surgery for a mean of 3.5 years (range, 24–75 months). The osteotomies were carried out in the proximal thoracic spine (T2–T4, n = 6), midthoracic spine (T5–T8, n = 12), and distal thoracic spine (T9–T12, n = 7). Mean correction at the PSO for all 25 levels was 16.3° ± 9.6°. Stratified by region of the spine, thoracic PSO correction was as follows: T2–T4 = 10.7° ± 15.8°, T5–T8 = 14.7° ± 4.6°, and T9–T12 = 23.9° ± 4.1°. Mean thoracic kyphosis (T2–T12 Cobb angle) was improved from 75.7° ± 30.9° to 54.3° ± 21.4° resulting in a significant regional sagittal correction of 21.4° ± 13.7° (P < 0.005). Global sagittal balance was improved from 106.1 ± 56.6 to 38.8 ± 37.0 mm yielding a mean correction of 67.3 ± 54.7 mm (P < 0.005). One patient, in whom there was segmental translation during osteotomy closure, had a decline in intraoperative somatosensory-evoked potentials. No patient sustained a temporary or permanent neurologic deficit after surgery. The mean SRS-22 Questionnaire score at final follow-up was 82.4 ± 10.2. Conclusion. Thoracic PSO can be performed safely. Segmental sagittal correction appears to vary based on the region of the thoracic spine the PSO is performed. The distal thoracic segments, which more closely resemble lumbar segments in morphology, rendered the greatest sagittal correction after PSO, approximately 24°. There was no case of neurologic injury associated with thoracic PSO, and clinical outcomes according to the SRS-22 instrument were generally favorable.

Suboccipital Retrosigmoid Approach for Removal of Vestibular Schwannomas: Facial Nerve Function and Hearing Preservation

IN THIS REPORT, we discuss the pertinent bony, arachnoid, and neurovascular anatomy of vestibular schwannomas that has an impact on the surgical technique for removal of these tumors, with the goal of facial nerve and hearing preservation. The surgical technique is described in detail starting with anesthesia, positioning, and neurophysiological monitoring and continuing with the exposure, technical nuances of tumor removal, hemostasis, and closure. Positive prognostic factors for hearing preservation are also highlighted.

Techniques for operative correction of proximal junctional kyphosis of the upper thoracic spine.

Study Design. Retrospective study of a consecutive series of patients treated for proximal junctional kyphosis (PJK) of the upper thoracic and cervicothoracic spine. Objective. To discuss corrective techniques for the management of symptomatic kyphosis at the junction of fused and mobile segments of the upper thoracic and cervicothoracic spine in patients who complain of pain, neurological deficit, ambulatory difficulty, and/or social isolation. Summary of Background Data. PJK is an unfortunately common, but important, complication seen in long instrumented fusions to the upper thoracic and cervicothoracic spine. Although often asymptomatic, its incidence and prevalence warrant a discussion on treatment options for symptomatic patients. Methods. After the institutional review board confirmed approval, we retrospectively analyzed patients who received treatment of PJK from 2003 to 2009. Segmental instrumentation and intraoperative neurophysiological monitoring were used in all patients. Data acquisition was performed by reviewing electronic medical records and radiographs. Inclusion criteria were patients who underwent surgical correction of PJK of the cervicothoracic and upper thoracic spine and had more than 2-year follow-up. Preoperative lumbar lordosis, preoperative thoracic kyphosis, pre- and postoperative sagittal balance, and sagittal proximal junctional Cobb angle were obtained. All corrective procedures were performed in 2 stages, each patient receiving cervical traction between cases. Results. Inclusion criteria were met in 7 patients (5 women and 2 men), with mean age of 55 years (range, 18–80 years). Six patients received multilevel Smith-Petersen osteotomies, with 2 patients receiving rib osteotomies, and 1 patient received a vertebral column resection. The mean preoperative and postoperative proximal junctional Cobb angles were 45° (range, 14°–89.7°) and 14° (range, 3.0°–38.0°), respectively. The mean degree of correction was 31° (range, 11°–79.2°). All patients had maintained or improved sagittal balance. No patient sustained a temporary or permanent neurological deficit after correction related to surgery. All patients had 2-year follow-up, and there were no mortalities. Conclusion. For a selected cohort of patients who develop PJK of the upper thoracic and cervicothoracic spine, osteotomies, cervical traction, and intraoperative manual reduction provide a significant improvement of proximal junctional Cobb angles. To our knowledge, this is the first study to address treatment for symptomatic patients with this condition.

Posterior vertebral column subtraction osteotomy: A novel surgical approach for the treatment of multiple recurrences of tethered cord syndrome - Technical note

Recurrent tethered cord syndrome (TCS) has been reported to develop in 5-50% of patients following initial spinal cord detethering operations. Surgery for multiple recurrences of TCS can be difficult and is associated with significant complications. Using a cadaveric tethered spinal cord model, Grande and colleagues demonstrated that shortening of the vertebral column by performing a 15-25-mm thoracolumbar osteotomy significantly reduced spinal cord, lumbosacral nerve root, and terminal filum tension. Based on this cadaveric study, spinal column shortening by a thoracolumbar subtraction osteotomy may be a viable alternative treatment to traditional surgical detethering for multiple recurrences of TCS. In this article, the authors describe the use of posterior vertebral column subtraction osteotomy (PVCSO) for the treatment of 2 patients with multiple recurrences of TCS. Vertebral column resection osteotomy has been widely used in the surgical correction of fixed spinal deformity. The PVCSO is a novel surgical treatment for multiple recurrences of TCS. In such cases, PVCSO may allow surgeons to avoid neural injury by obviating the need for dissection through previously operated sites and may reduce complications related to CSF leakage. The novel use of PVCSO for recurrent TCS is discussed in this report, including surgical considerations and techniques in performing PVCSO.

Pedicled omental flaps as an adjunct in the closure of complex spinal wounds.

Study Design. A retrospective clinical study. Objective. To evaluate the safety and efficacy of using an omental flap in complex spine reconstruction in patients at high-risk for wound dehiscence. Summary of Background Data. Postoperative wound dehiscence represents a major cause of morbidity in patients undergoing instrumented spinal reconstruction. A variety of approaches for the prevention and treatment of this problem have been previously described in the literature; however, the use of omental flaps has received little attention. Methods. In this retrospective analysis, 5 patients were studied both clinically and radiographically. The study population included 4 women and 1 man, with a mean age of 49 years (range, 31–67 years). All patients underwent an omental flap procedure at the time of spinal reconstruction because of significant soft tissue defects or active spinal infection. Mean clinicoradiographic follow-up was 53 months (range, 36–115 months). Results. At the time of follow-up, all patients had well-healed surgical wounds with an acceptable structural and esthetic result. One patient in the study group experienced minor supra-fascial wound dehiscence. In terms of spinal outcome, all patients achieved successful bony arthrodesis; 1 patient, however, developed symptomatic adjacent segment degeneration and was treated by extension of the fusion construct. Conclusion. In patients undergoing thoracolumbar surgery who are at high risk of spinal wound dehiscence, closure using a pedicled omental flap is a viable procedure that may limit the risk of dehiscence and improve outcome.