Management and outcomes of surgical site tuberculosis infection due to infected bone graft in spine surgery: a single-institution experience and 1-year postoperative follow-up.

OBJECTIVE: In 2021, several patients across the United States received bone allograft contaminated with Mycobacterium tuberculosis (TB). TB is typically a pulmonary infection with many possible extrapulmonary manifestations, including skeletal tuberculosis. However, TB is a rare causative organism of postoperative surgical site infection. Iatrogenic skeletal TB infections are not widely reported in the medical literature; therefore, treatment and associated outcomes are relatively unknown. In this series, the authors report 6 cases of patients who received a mesenchymal stem cell-enhanced bone graft infected with TB at their institution, including the clinical courses, imaging findings, management plans, and outcomes at 1 year postoperatively. METHODS: A retrospective review was performed of 6 consecutive patients who underwent spinal fusion surgery at the authors' institution and received bone graft from a lot contaminated with TB. Collected data included patient demographic characteristics, indications for surgery, surgical procedures performed, timing of contamination discovery, medical treatment, and follow-up information including reoperation, healing progress, and imaging findings. RESULTS: Five of 6 patients (83.3%) eventually tested positive for TB via interferon-gamma release assay or wound culture. They experienced significant complications, including surgical site infections with neck swelling, pain, dysphagia, and wound dehiscence. Extensive soft-tissue infection was common; however, significant bony involvement was not observed. Surgical wound debridement was required in 4 patients, and all patients received medical management with standard RIPE (rifampin, isoniazid pyrazinamide, pyridoxine, and ethambutol) therapy for 8 weeks with extension of rifampin and isoniazid for scheduled 12 months. All patients (excluding 1 patient who died of COVID-19) showed signs of improvement with adequately healing wounds at the most recent follow-up at a median (range) of 12 (6-13) months postoperatively. To date, no patients have developed pulmonary TB. CONCLUSIONS: Direct inoculation with TB via contaminated bone grafts resulted in a high rate of severe soft-tissue infection, although extensive skeletal and pulmonary involvement has not been observed at 1 year postoperatively; this review includes the longest reported follow-up period for this TB outbreak. Medical management remains the mainstay of therapy for these patients, with most patients showing recovery with oral antibiotic therapy. The severity of these infections arising from mesenchymal stem cell-containing bone allografts that undergo an alternative sterilization process than standard allografts raises concerns regarding the added risks of infection, which should be weighed against the expected benefits of these grafts.

Minimally invasive lateral transpsoas approach for spinal discitis and osteomyelitis.

We present a series of patients with discitis and osteomyelitis who were surgically treated via a minimally invasive lateral transpsoas approach to the lumbar spine. Surgical treatment for spinal discitis and osteomyelitis presents challenges because of comorbidities that are common in patients undergoing this procedure. A retrospective review found six patients who met strict operative criteria including instability, intractable pain, neurological deficit, and disease progression. All patients were non-ambulatory before surgery because of intractable back pain. The patients underwent standard lateral minimally invasive surgery using either the extreme lateral interbody fusion (NuVasive, San Diego, CA, USA) or direct lateral interbody fusion (Medtronic Sofamor Danek, Memphis, TN, USA) system. The patients underwent debridement with a discectomy and partial or complete corpectomy, with polyetheretherketone or titanium cage placement. Two patients had additional posterior fixation with percutaneous pedicle screws, and none had immediate perioperative complications. The postoperative CT scans demonstrated satisfactory debridement and hardware placement. All patients experienced significant pain improvement and could ambulate within a few days of surgery. So far, the 1 year follow-up data have demonstrated stable hardware with solid fusion and continued pain improvements. One patient demonstrated hardware failure secondary to refractory infection, 2 months postoperatively, and required additional posterior decompression and debridement with pedicle screw fixation. The lateral transpsoas approach permits debridement and fixation coupled with percutaneous pedicle screw fixation to further stabilize the spine in a minimally invasive fashion. Due to the significant comorbidities in this patient population, a minimally invasive approach is a suitable surgical technique. A close follow-up period is necessary to detect early hardware failure which may necessitate more extensive treatment.

Techniques for placement of grid and strip electrodes for intracranial epilepsy surgery monitoring: Pearls and pitfalls.

BACKGROUND: Placement of intracranial strip and grid electrodes for recording cortical electrocorticography is important as part of the workup of patients who are being considered for resective epilepsy surgery. In recent decades, the indications and techniques for intracranial epilepsy monitoring have been refined. METHODS: In this article, the authors describe the techniques for intraoperative placement of grid and strip electrodes for extraoperative study of a seizure focus. RESULTS: Methods to enhance the efficacy of this technique while minimizing complications are reviewed. CONCLUSIONS: Intracranial epilepsy monitoring with grid and strip electrodes is a useful tool for the planning of resective epilepsy surgery. Techniques to advance the safety and minimize complications will lead to improved outcomes.

Strategies to maximize resection of complex, or high surgical risk, low-grade gliomas.

OBJECT: Early and aggressive resection of low-grade gliomas (LGGs) leads to increased overall patient survival, decreased malignant progression, and better seizure control. This case series describes the authors' approach to achieving optimal neurological and surgical outcomes in patients referred by outside neurosurgeons for stereotactic biopsy of tumors believed to be complex or a high surgical risk, due to their diffuse nature on neuroimaging and their obvious infiltration of functional cortex. METHODS: Seven patients underwent individualized neuroimaging evaluation preoperatively, which included routine brain MRI with and without contrast administration for intraoperative neuronavigation, functional MRI with speech and motor mapping, diffusion tensor imaging to delineate white matter tracts, and MR perfusion to identify potential foci of higher grade malignancy within the tumor. Awake craniotomy with intraoperative motor and speech mapping was performed in all patients. Tumor removal was initiated through a transsylvian approach for insular lesions, and through multiple corticotomies in stimulation-confirmed noneloquent areas for all other lesions. Resection was continued until neuronavigation indicated normal brain, cortical or subcortical stimulation revealed functional cortex, or the patient began to experience a minor neurological deficit on intraoperative testing. RESULTS: Gross-total resection was achieved in 1 patient and subtotal resection (> 80%) in 6 patients, as assessed by postoperative MRI. Over the average follow-up duration of 31 months, no patient experienced a progression or recurrence. Long-term seizure control was excellent in 6 patients who achieved Engel Class I outcomes. Neurologically, all 7 patients experienced mild temporary deficits or seizures that completely resolved, and 1 patient continues to have mild expressive aphasia. CONCLUSIONS: Significant resection of diffuse, infiltrating LGGs is possible, even in presumed eloquent cortex. Aggressive resection maximizes seizure control and does not necessarily cause permanent neurological deficits. Individualized preoperative neuroimaging evaluation, including tractography and awake craniotomy with intraoperative speech and motor mapping, is an essential tool in achieving these outcomes.

Malignant peripheral nerve sheath tumor of the abducens nerve and a review of the literature.

BACKGROUND: Malignant peripheral nerve sheath tumors are rare, and intracranial occurrences are even more rare. Treatment strategies have varied widely. This article reports the first case of a malignant peripheral nerve sheath tumor of the abducens nerve and provides a literature review that includes 61 cases of intracranial malignant peripheral nerve sheath tumors. Data were analyzed based on age, sex, treatment, survival, immunohistochemical staining, location, tumor grade, and neurofibromatosis association. These tumors more often affect male persons, and the patients affected have a mean age of 39 years. Most patients underwent subtotal or gross total resection and radiation. Intracranial location varied, but most tumors occurred in the cerebellopontine angle. The literature shows that intracranial malignant peripheral nerve sheath tumors are a heterogeneous group. Their association with neurofibromatosis is less clear than that of their extracranial counterparts. Prognosis is poor, but surgical resection and radiation can enhance chances for longer survival. Our aim was to elucidate information about these tumors. CASE DESCRIPTION: A 30-year-old woman presented with a 6-month history of headaches and diplopia. RESULTS: Neurological examination revealed no focal deficit. Imaging revealed a heterogeneously enhancing retroclival mass without bony destruction. The tumor originated from the ipsilateral abducens nerve and extended into the Dorello canal; it adhered to the brainstem and cranial nerves. Pathology was consistent with low-grade malignant peripheral nerve sheath tumor. CONCLUSIONS: At 3-month follow-up, the patient walked with a cane with no further deficits except mild ataxia, which resolved within 6 months. Magnetic resonance imaging revealed a small residual tumor adherent to the basilar artery. At 1-year follow-up and after ocular surgery to correct lateral rectus palsy, the patient was neurologically intact.

Middle cerebral artery aneurysms in children: case series and review.

OBJECT: Pediatric intracranial aneurysms are rare lesions that differ from their adult counterparts. Aneurysms involving the middle cerebral artery (MCA) are particularly challenging to treat in children, as they are often fusiform and cannot undergo direct clipping alone. The authors recently treated a patient with a heavily calcified, dysplastic, left-sided MCA aneurysm. The present study was performed to evaluate the authors' previous operative and follow-up experience with these difficult lesions. METHODS: The authors performed a review of a prospectively maintained database of all aneurysms treated at Methodist Hospital in Indianapolis, Indiana, from January 1990 through November 2010. Relevant operative notes, clinical charts, and radiological reports were reviewed for all patients 18 years of age or younger. RESULTS: A total of 2949 patients with aneurysms were treated over the study period, including 28 children (0.95%). Seven children harbored MCA aneurysms. Five of these 7 aneurysms (71.4%) were fusiform. Two patients were treated with direct clipping, 2 underwent parent vessel occlusion without bypass, and 3 underwent aneurysm trapping with extracranial-intracranial vessel bypass. Long-term follow-up data were available in 6 cases. All 6 patients had a 1-year follow-up Glasgow Outcome Scale score of 5. Long-term radiological follow-up was available in 4 patients. One patient required a reoperation for a recurrent aneurysm 4 years after the initial surgery. CONCLUSIONS: Middle cerebral artery aneurysms in children are often fusiform, giant, and incorporate the origins of proximal artery branches. Direct clipping may not be possible; trapping of the lesion may be required. Children seem to tolerate surgical trapping with or without bypass extremely well. Aggressive therapy of these rare lesions in children is warranted, as even patients presenting with a poor clinical grade may have excellent outcomes. Long-term surveillance imaging is necessary because of the risk of aneurysm recurrence.

Endovascular treatment and radiographic follow-up of proximal traumatic intracranial aneurysms in adolescents: case series and review of the literature.

PURPOSE: Traumatic intracranial aneurysms are rare lesions that are relatively more common in the pediatric population. Proximal traumatic aneurysms occur near the skull base. Direct surgical repair of these lesions is difficult due to the anatomically confined area, clinical status of a head injury patient, and the transmural nature of the injury. These lesions often lack a definable neck or wall suitable for clipping. While the indications and capabilities of endovascular treatment continue to expand, there are unanswered questions about the durability of treatment, especially in young patients. There are few reports examining the radiographic outcomes of endovascular treatment specifically for traumatic intracranial aneurysms. Therefore, we examined our experience treating these rare proximal lesions in an adolescent population. METHODS: A retrospective review of prospectively collected data from 2000-2008 in a large, multidisciplinary neurovascular and trauma center was performed. RESULTS: Three pediatric patients received endovascular treatment for traumatic intracranial aneurysms near the skull base. All patients had successful obliteration of their lesion without vessel sacrifice; however, two patients required multiple procedures for coil compaction or refilling of the aneurysm. There were no complications or ischemic events related to treatment. Follow-up imaging ranged from 6 months to 3.5 years. CONCLUSIONS: Traumatic intracranial aneurysms at the skull base can be successfully treated with endovascular methods; however, close follow-up is necessary.