Surgical Management of Postradiation, Dropped Head Spinal Deformity in Patients with Head and Neck Cancer.

BACKGROUND: Dropped head syndrome is a morbid condition that affects daily functionality, causing pain and dysphagia and respiratory compromise. Reported causes of dropped head syndrome include neuromuscular disorders, iatrogenic from cervical spine surgery, and idiopathic and postradiation for head and neck cancers. Management of this spinal disorder remains challenging, as the complication rates are high. We present our series of 7 patients who underwent surgical correction of dropped head syndrome, all resulting from radiation for head and neck cancers. METHODS: This was a retrospective review of 7 patients who underwent surgery between 2016 and 2019 for dropped head syndrome secondary to postradiation cervical spine deformity. Clinical variables were obtained from medical records. Radiographic parameters pre- and postsurgery including T1 slope, sagittal vertical axis, and C2-C7 cervical lordosis were examined. RESULTS: Seven patients were included in the study, with an average age 69 years. Two patients underwent traction preoperatively. Five patients had posterior fixation and fusion only and 2 patients had a combined anterior and posterior fixation and fusion. Overall, there was improvement in average pre/postoperative sagittal vertical axis (6.96 cm to 3.04 cm), T1 slope (33.61° to 24.34°), and C2-C7 lordosis (-21.65° to -0.03°). CONCLUSIONS: Surgical correction of postradiation dropped head spinal deformity involving anterior and posterior fixation with osteotomies provides improvement in functional and radiographic outcomes as shown in our series. These cases are technically challenging and have a high rate of perioperative complications. Approaches must be tailored to the patient with attention to their specific surgical and radiation history.

Failures in Thoracic Spinal Fusions and Their Management.

Instrumented fixation and fusion of the thoracic spine present distinct challenges and complications including pseudarthrosis and junctional kyphosis. When complications arise, morbidity to the patient can be significant, involving neurologic injury, failure of instrumentation constructs, as well as iatrogenic spinal deformity. Causes of fusion failure are multifactorial, and incompletely understood. Most likely, a diverse set of biomechanical and biologic factors are at the heart of failures. Revision surgery for thoracic fusion failures is complex and often requires revision or extension of instrumentation, and frequently necessitates complex soft tissue manipulation to manage index level injury or to augment the changes of fusion.

Vascularized Rib Bone Grafting: Indications, Techniques, and Clinical Outcomes.

Pseudarthrosis is a difficult complication often seen in patients with complex spinal pathology. To supplement existing neurosurgical approaches to cervicothoracic spinal instrumentation and fusion, novel vascularized rib bone grafts can be utilized in patients at high risk for failed spinal fusion. In this article, we discuss the indications, benefits, surgical technique, feasibility, and limitations of using rib vascularized rib bone grafts to augment spinal fusion.

Vascularized Bone Grafts for Spinal Fusion-Part 2: The Rib.

BACKGROUND: Pseudoarthrosis, or failure to achieve bony union, is a well-known complication of spinal fusion operations. Rates range from 5% to 40% and are influenced by both patient and technical factors. Patients who do not achieve complete fusion may experience a return or worsening of their preoperative pain. For patients with complicated pathologies, vascularized bone grafts (VBGs) have been shown to provide better outcomes than nonvascularized bone grafts (N-VBGs). OBJECTIVE: To enhance an instrumented spinal fusion by the innovative technique presented herein that utilizes a rotated, pedicled VBG from the left eighth rib under the paraspinous musculature into the midlumbar posterolateral gutter. METHODS: For posterior approaches, the rib can be easily accessed and rotated into the appropriate strut position. The rib is dissected out, identifying and preserving the neurovascular bundle medially. The rib is then tunneled medially and appropriately positioned as the spinal graft, with the curve providing anatomic kyphosis or lordosis, depending on the surgical location. It is then successfully fixated with plates and spinal screws. RESULTS: In our limited experience to date, vascularized rib grafting procedures augment fusion and reduce operating room time and bleeding compared to free flap procedures. No patients have experienced complications related to these grafts. CONCLUSION: Pedicled vascularized rib grafts can be utilized to provide the advantages of a vascularized bone flap in complicated pathologies requiring spinal fusion as far as the L2-L3 level, without the morbidity associated with free tissue transfer.

Congenital Fusion of Dens to T3 Vertebra in Klippel-Feil Syndrome.

BACKGROUND: Patients with Klippel-Feil syndrome may present with neurologic complaints such as neck pain, radiculopathy and gait instability. Here we describe surgical management of a patient with congenital fusion of the occipital-cervical region and also block circumferential fusion of dens to T3 with spinal cord compression. This report is the first of its kind with such extensive fusion. CASE DESCRIPTION: Our patient was a 56 year-old female, who presented with neck pain and tingling in all extremities. On exam, she had a short neck, prominent jaw with extremely limited range of motion in neck and features of myelopathy. CT showed fusion of the dens to T3 vertebrae. Patient underwent sub-occipital craniectomy, C1 laminectomy and Occiput to T5 posterior fixation and fusion with neurologic improvement. CONCLUSION: This is the first reported case of Klippel-Feil syndrome with fusion of all cervical vertebrae down to T3. We recommend surgery for advanced cases of myelopathy or radiculopathy due to stenosis and spinal instability.

Cervical Intradural Disc Herniation: Case Report and Operative Video.

Cervical intradural disc herniation (CIDH) is a rare presentation of an intradural disc herniation. We present a case of CIDH with associated surgical video depicting an anterior surgical approach to treatment. Patient presentation, relevant radiographic imaging, surgical exposure and technique, and cerebrospinal fluid leak complication and prevention are discussed.

Clinical Translation of the LevelCheck Decision Support Algorithm for Target Localization in Spine Surgery.

Recent work has yielded a method for automatic labeling of vertebrae in intraoperative radiographs as an assistant to manual level counting. The method, called LevelCheck, previously demonstrated promise in phantom studies and retrospective studies. This study aims to: (#1) Analyze the effect of LevelCheck on accuracy and confidence of localization in two modes: (a) Independent Check (labels displayed after the surgeon's decision) and (b) Active Assistant (labels presented before the surgeon's decision). (#2) Assess the feasibility and utility of LevelCheck in the operating room. Two studies were conducted: a laboratory study investigating these two workflow implementations in a simulated operating environment with 5 surgeons, reviewing 62 cases selected from a dataset of radiographs exhibiting a challenge to vertebral localization; and a clinical study involving 20 patients undergoing spine surgery. In Study #1, the median localization error without assistance was 30.4% (IQR = 5.2%) due to the challenging nature of the cases. LevelCheck reduced the median error to 2.4% for both the Independent Check and Active Assistant modes (p < 0.01). Surgeons found LevelCheck to increase confidence in 91% of cases. Study #2 demonstrated accuracy in all cases. The algorithm runtime varied from 17 to 72 s in its current implementation. The algorithm was shown to be feasible, accurate, and to improve confidence during surgery.

Spontaneous pituitary adenoma occurring after resection of a Rathke's cleft cyst.

Rathke's cleft cysts (RCC) are benign cystic lesions that originate from remnants of the epithelial lining of Rathke's pouch. RCC are known rarely to occur together with a concomitant pituitary adenoma. Here, we report a patient with a pituitary adenoma arising in the same location as a previously-resected RCC, 3 years post-operatively, and review the literature of "collision" sellar lesions. Consecutive transsphenoidal operations from a single-center between 2008 and 2016 were reviewed to identify patients with pituitary adenoma arising after surgical resection of RCC, and a systematic search of the literature was also performed to identify such patient reports, as well as reports of concomitant pituitary adenoma and RCC. Of 837 transsphenoidal operations from our own experience, one patient with pituitary adenoma occurring after RCC resection was identified and is reported here. A systematic review of the literature resulted in identification of 34 patients with concomitant RCC and pituitary adenoma and no incidents of pituitary adenoma occurring after resection of RCC. Concomitant occurrence of RCC and pituitary adenoma was more commonly diagnosed in women (61%), at a median age of diagnosis of 44 years. The RCC histological analysis in these patients consistently described ciliated columnar or cuboidal epithelium. Although rare, the presence of a new, pathologically-distinct lesions in the sella after prior surgical treatment, is possible. During post-operative monitoring, physicians should consider that what appears as a "recurrent" lesion may actually be growth of a new and entirely different lesion.

Using urinary bFGF and TIMP3 levels to predict the presence of juvenile pilocytic astrocytoma and establish a distinct biomarker signature.

OBJECTIVE The authors report the use of urinary biomarkers as a novel, noninvasive technique to detect juvenile pilocytic astrocytomas (JPAs), capable of distinguishing JPAs from other CNS diseases, including other brain tumors. Preliminary screening of an array of tumors implicated proteases (including matrix metalloproteinases [MMPs]) and their inhibitors (tissue inhibitors of metalloproteinase [TIMPs]) as well as growth factors (including basic fibroblast growth factor [bFGF]) as candidate biomarkers. These data led the authors to hypothesize that tissue inhibitor of metalloproteinase 3 (TIMP3) and bFGF would represent high-probability candidates as JPA-specific biomarkers. METHODS Urine was collected from 107 patients, which included children with JPA (n = 21), medulloblastoma (n = 17), glioblastoma (n = 9), arteriovenous malformations (n = 25), moyamoya (n = 14), and age- and sex-matched controls (n = 21). Biomarker levels were quantified with enzyme-linked immunosorbent assay, tumor tissue expression was confirmed with immunohistochemical analysis, and longitudinal biomarker expression was correlated with imaging. Results were subjected to univariate and multivariate statistical analyses. RESULTS Using optimal urinary cutoff values of bFGF > 1.0 pg/µg and TIMP3 > 3.5 pg/µg, multiplexing bFGF and TIMP3 predicts JPA presence with 98% accuracy. Multiplexing bFGF and MMP13 distinguishes JPA from other brain tumor subtypes with up to 98% accuracy. Urinary biomarker expression correlated with both tumor immunohistochemistry and in vitro tumor levels. Urinary bFGF and TIMP3 decrease following successful tumor treatment and correlate with changes in tumor size. CONCLUSIONS This study identifies 2 urinary biomarkers-bFGF and TIMP3-that successfully detect one of the most common pediatric brain tumors with high accuracy. These data highlight potential benefits of urinary biomarkers and support their utility as diagnostic tools in the treatment of children with JPA.

Gamma Knife surgery targeting the resection cavity of brain metastasis that has progressed after whole-brain radiotherapy.

OBJECT: Salvage treatment of large, symptomatic brain metastases after failure of whole-brain radiotherapy (WBRT) remains challenging. When these lesions require resection, there are few options to lower expected rates of local recurrence at the resection cavity margin. The authors describe their experience in using Gamma Knife surgery (GKS) to target the resection cavity in patients whose tumors had progressed after WBRT. METHODS: The authors retrospectively identified 143 patients in whom GKS had been used to target a brain metastasis resection cavity between 2000 and 2005. Seventy-nine of these patients had undergone WBRT prior to resection and GKS. The median patient age was 53 years, and the median prescribed dose was 18 Gy (range 8-24 Gy), with resection cavities of relatively larger volume (> 15 cm3). The GKS dose was prescribed at the 40 to 95% isodose contour (mode 50%). Local recurrence within 1 cm of the treatment volume occurred in four (5.1%) of 79 cases. The median duration of time to local recurrence was 6.1 months (range 2-13 months). The median duration of time to occurrence of distant metastases following GKS of the resection cavity was 10.8 months (range 2-86 months). Carcinomatous meningitis developed in four (5.1%) of 79 cases. Symptomatic radionecrosis requiring surgical treatment occurred in three (3.8%) of 79 cases. The median duration of survival following GKS of the resection cavity was 69.6 weeks. The median 2- and 5-year survival rates were 20.2 and 6.3%, respectively. CONCLUSIONS: When metastases progress after WBRT and require resection, GKS targeting the resection cavity is a viable strategy. In 75 (94.9%) of 79 cases, GKS of the resection cavity in patients in whom WBRT had failed appears to have achieved its goal of local disease control.