Preoperative and intraoperative perfusion magnetic resonance imaging in a RELA fusion-positive anaplastic ependymoma: A case report.

BACKGROUND: Ependymomas are rare neuroepithelial tumors thought to arise from radial glial precursor cells lining the walls of the ventricles and central canal of the brain and spinal cord, respectively. Histopathological classification, according to World Health Organization criteria, has only recently defined the RELA-fusion positive ependymoma. These tumors may account for 70% of supratentorial ependymomas in children and represent an aggressive entity distinct from other ependymomas. CASE DESCRIPTION: Here we present the case of a patient with RELA-fusion positive ependymoma of the frontal lobe in whom we used preoperative and intraoperative magnetic resonance (MR) perfusion imaging. In this first demonstrated intraoperative evaluation of MR perfusion in ependymoma, increased peripheral perfusion of the lesion in a ring-like manner with a discrete cutoff around the surgical margin correlated with intraoperative findings of a clear border between the tumor and brain, as well as pathological findings of increased MIB index and hypercellularity-specifically within solid tumor components. An abnormal perfusion pattern also suggested an aggressive lesion, which was later confirmed on pathological analysis. In addition, intraoperative MR perfusion improved detection of tumor tissue in combination with traditional T1-weighted contrast-enhanced methods, which increased extent of resection. CONCLUSIONS: MR perfusion imaging may be a useful method for delineating tumor aggressiveness and borders, which can be prognostic.

Anterior Cruciate Ligament Reconstruction With Amnion Biological Augmentation.

Anterior cruciate ligament (ACL) ruptures are common and unfortunate injuries for many athletes. The standard therapy for ACL rupture is ACL reconstruction with either autograft, harvested from hamstring or patellar tendon, or allograft tendon from a tissue donor. Advances in tissue engineering have produced interventions to augment the healing process and may have applications when it comes to ACL reconstruction. In this Technical Note and accompanying video, we describe a simple technique to implant an amnion matrix graft with a tendon graft during ACL reconstruction. This procedure uses the proposed anti-inflammatory, scaffolding, and stem cell-producing effects of the amniotic membrane to biologically augment the healing process of an ACL reconstruction.

Graft Retensioning Technique Using an Adjustable-Loop Fixation Device in Arthroscopic Anterior Cruciate Ligament Reconstruction.

Anterior cruciate ligament (ACL) tears are an unfortunate and devastating injury in the athletic patient. Surgical reconstruction of the ACL with a taut graft construct is necessary to restore knee stability and help expedite the patient's return to an active lifestyle. Arthroscopy-assisted ACL reconstruction can be a technically involved procedure, where strong fixation limits graft motion to allow sufficient healing within the tibial and femoral tunnels at the bone-tendon interfaces. Loss of tension in a graft can cause symptomatic anterior or rotatory instability and potential retear of the ACL graft. We describe in this Technical Note and accompanying video a simple and effective technique to implant and retension a tendon graft during ACL reconstruction using a suspensory fixation device. The technical description uses a simple adjustable-loop device to provide strong cortical fixation, along with the unique ability to retension the graft in ACL reconstruction, not otherwise possible with previously described graft fixation techniques.

Arthroscopic Reduction of Tibial Spine Avulsion: Suture Lever Reduction Technique.

Tibial spine avulsion fractures are uncommon knee injuries that predominantly occur in children and young adults. Restoration of anterior cruciate ligament length through surgical reduction and fixation of the fracture is necessary to ensure stability of the knee with suitable range of motion and minimal knee laxity. Arthroscopic repair of tibial spine avulsion fractures is a technically complex procedure, specifically when performing and maintaining the initial anatomic reduction. We describe in this technical note and accompanying video a unique 3-point fixation repair of tibial spine avulsion fractures using an arthroscopic assisted suture lever reduction technique. Our technique is both simple and efficacious in the reduction of tibial spine avulsion fractures to anatomic position by passing the first suture through the anterior cruciate ligament, and subsequently anterior to the avulsion fragment, and then beneath the fragment through a posteriorly placed bone tunnel within the tibial fracture bed.

RNA interference targeting hypoxia-inducible factor 1α via a novel multifunctional surfactant attenuates glioma growth in an intracranial mouse model.

OBJECT: High-grade gliomas are the most common form of adult brain cancer, and patients have a dismal survival rate despite aggressive therapeutic measures. Intratumoral hypoxia is thought to be a main contributor to tumorigenesis and angiogenesis of these tumors. Because hypoxia-inducible factor 1α (HIF-1α) is the major mediator of hypoxia-regulated cellular control, inhibition of this transcription factor may reduce glioblastoma growth. METHODS: Using an orthotopic mouse model with U87-LucNeo cells, the authors used RNA interference to knock down HIF-1α in vivo. The small interfering RNA (siRNA) was packaged using a novel multifunctional surfactant, 1-(aminoethyl) iminobis[N-(oleicylcysteinylhistinyl-1-aminoethyl)propionamide] (EHCO), a nucleic acid carrier that facilitates cellular uptake and intracellular release of siRNA. Stereotactic injection was used to deliver siRNA locally through a guide-screw system, and delivery/uptake was verified by imaging of fluorescently labeled siRNA. Osmotic pumps were used for extended siRNA delivery to model a commonly used human intracranial drug-delivery technique, convection-enhanced delivery. RESULTS: Mice receiving daily siRNA injections targeting HIF-1α had a 79% lower tumor volume after 50 days of treatment than the controls. Levels of the HIF-1 transcriptional targets vascular endothelial growth factor (VEGF), glucose transporter 1 (GLUT-1), c-MET, and carbonic anhydrase-IX (CA-IX) and markers for cell growth (MIB-1 and microvascular density) were also significantly lower. Altering the carrier EHCO by adding polyethylene glycol significantly increased the efficacy of drug delivery and subsequent survival. CONCLUSIONS: Treating glioblastoma with siRNA targeting HIF-1α in vivo can significantly reduce tumor growth and increase survival in an intracranial mouse model, a finding that has direct clinical implications.