U-shaped durotomy for midline posterior fossa tumor removal: technical note and evaluation of results.

BACKGROUND: The classical dura opening for midline posterior fossa tumors in and around the 4th ventricle and the craniocervical junction is a Y-shaped incision. Several potential problems are associated with this technique. We used a technical variant, the U-shaped durotomy, previously described by Rhoton, offering several advantages. We report on the surgical results of the technique in a consecutive series of posterior fossa cases in children and adolescents. METHODS: In all midline posterior fossa approaches, a U-shaped dural incision is standard in our institution. All cases were retrospectively analyzed regarding hydrocephalus, placement of EVD or lumbar drain, need for ETV or shunting during follow-up, and frequency of duraplasty, of pseudomeningocele, of primary watertight dural closure, of CSF leakage, and of venous sinus hemorrhage at opening. RESULTS: Fifty pediatric patients were included. In all easy occipital sinus, control was achieved and no additional dural retraction for tumor exposure required. In 49/50 patients, a primary watertight dura closure without duraplasty was achieved, also in re-do cases with previous U-shaped opening. One patient received a small periostium graft after having had a duraplasty following Y-shaped opening beforehand. No CSF fistula ever occurred and no pseudomeningocele was detected in any follow-up MRI. CONCLUSION: The U-shaped durotomy for dorsal midline approach to the 4th ventricle and craniocervical junction provides wide exposure to all tumors and allows for primary and watertight dura closure. Compared to published results and complications of classic Y-shaped dural opening, this method of durotomy and closure seems most advantageous.

Recovery of long-term paresis following resection of WHO grade II gliomas infiltrating the pyramidal pathway.

Recent publications had reported high rates of preoperative neurological impairments in WHO grade II gliomas (GIIG) that significantly affect the quality of life. Consequently, one step further in the analysis of surgical outcome in GIIG is to evaluate if surgery is capable to improve preoperative deficits. Here are reported two cases of GIIG infiltrating the primary motor cortex and pyramidal pathway that had a long-term paresis before surgery. Both patients were operated with intraoperative electrical stimulation mapping, with identification and preservation of the primary motor cortex and pyramidal tract. Despite the long-lasting paresis, both cases had a significant improvement of motor function after surgery. Knowledge of this potential recovery before surgery is of major significance for planning the surgical strategy in GIIG. Two possible predictors of motor recovery were analyzed: 1) reconstruction of the corticospinal tract with diffusion tensor imaging tractography is indicative of anatomo-functional integrity, despite tract deviation and infiltration; 2) intraoperative identification of motor response by electrostimulation confirms the presence of an intact peritumoral tract. Thus, resection should stop at this boundary even in cases of long lasting preoperative hemiplegia.

Fiber dissection and diffusion tensor imaging tractography study of the temporoparietal fiber intersection area.

BACKGROUND: Lesion studies and recent surgical series report important sequelae when the inferior parietal lobe and posterior temporal lobe are damaged. Millions of axons cross through the white matter underlying these cortical areas; however, little is known about the complex organization of these connections. OBJECTIVE: To analyze the subcortical anatomy of a specific region within the parietal and temporal lobes where 7 long-distances tracts intersect, ie, the temporoparietal fiber intersection area (TPFIA). METHODS: Four postmortem human hemispheres were dissected, and 4 healthy hemispheres were analyzed through the use of diffusion tensor imaging--based tractography software. The different tracts that intersect at the posterior temporal and parietal lobes were isolated, and the relations with the surrounding structures were analyzed. RESULTS: Seven tracts pass through the TPFIA: horizontal portion of the superior longitudinal fasciculus, arcuate fasciculus, middle longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, optic radiations, and tapetum. The TPFIA was located deep to the angular gyrus, posterior portion of the supramarginal gyrus, and posterior portion of the superior, middle, and inferior temporal gyri. CONCLUSION: The TPFIA is a critical neural crossroad; it is traversed by 7 white matter tracts that connect multiple areas of the ipsilateral and contralateral hemisphere. It is also a vulnerable part of the network in that a lesion within this area will produce multiple disconnections. This is valuable information when a surgical approach through the parieto-temporo-occipital junction is planned. To decrease surgical risks, a detailed diffusion tensor imaging tractography reconstruction of the TPFIA should be performed, and intraoperative electric stimulation should be strongly considered.

[Establishment of a modified surgical safety checklist for the neurosurgical patient: Initial experience in 400 cases]. / Implantación de la lista de verificación quirúrgica de la Organización Mundial de la Salud modificada para el paciente neuroquirúrgico: experiencia inicial en 400 casos.

INTRODUCTION: Adverse events during diagnostic and therapeutic procedures and medical errors associated with them are an important source of patient morbidity. In an attempt to reduce these, the WHO has proposed a series of measures applicable to medical and surgical patients. Within these last ones is the surgical safety checklist (SSC), a brief questionnaire that does not increase healthcare costs, is accessible to all surgical centres and can be adapted to each specific environment. OBJECTIVES: To evaluate the effectiveness of establishing a modified WHO SSC on the safety and quality of care of the neurosurgical patient in a third-level university hospital. MATERIAL AND METHODS: The SSC was applied to a series of 400 scheduled surgeries between May 2009 and May 2010. During the initial 6 months, 183 surgical procedures were performed (group 1). All adverse events detected in this period were studied with a root-cause analysis methodology (RCA) and, according to its results, corrective measures were introduced. After that, 217 procedures were performed (group 2). RESULTS: We recorded 51 events in 44 surgeries (11%). We were able to correct 88.23% of them before surgery was initiated, avoiding any consequence in the normal management of the case. In Group 1, incidents were noted in 15.3% of the procedures. The RCA suggested that 37.8% of the events had a human cause, followed by problems related to material resources and equipment in 29.7%, and organisational reasons in 21.6%. Incidence of events was reduced in group 2 to 7.4% (P=.01). Corrective measures prevented the appearance of perioperative events in 1 out of 13 procedures. CONCLUSIONS: The SSC is an effective tool for improving safety in neurosurgical patients, which can be established in surgical departments of any hospital without increasing healthcare costs or operative time.