Accurate placement of parieto-occipital shunt ventricular catheter: use of craniometrics and technical note.

PURPOSE: Ventriculoperitoneal shunt insertion is one of the most commonly performed procedures in neurosurgery but has a relatively high complication rate. One important source of complications is shunt malposition from erroneous placement of the parieto-occipital burr hole or poor shunt trajectory. There are significant variations in the freehand parieto-occipital approach amongst neurosurgeons that are derived from variations in technique or experience. The patient's skull shape or size is also often not taken into consideration if fixed measurements are used to define the burr hole entry point. The authors suggest a variation to the technique of ventricular catheter placement by relying on the patient's own craniometrics and skull landmarks. METHODS: The technique is illustrated and supported by analysis of a case series of 25 patients undergoing shunt placement. RESULTS: By this method, all shunts were positioned in the lateral ventricle. Using a 3-point scale, the catheter position was evaluated: grade 1, free floating in cerebrospinal fluid; grade 2, touching the choroid plexus or ventricular wall; and grade 3, tip within the parenchyma. The catheter position was grade 1 in sixteen (64%) cases and grade 2 in nine (36%) cases; none was grade 3. Only one shunt malfunction occurred from proximal shunt obstruction in the series. CONCLUSION: The use of this technique aims to reduce operator and patient variability as contributors to shunt malposition, to increase user reproducibility and decrease the learning curve for trainees. Further prospective study could be designed to validate the technique.

Consent for spine surgery: an observational study.

BACKGROUND: The tension between the ideal of informed consent and the reality of the process is under-investigated in spine surgery. Guidelines around consent imply a logical, plain-speaking process with a clear endpoint, agreement and signature yet surgeons' surveys and patient interviews suggest that surgeons' explanation is anecdotally variable and patient understanding remains poor. To obtain a more authentic reflection of practice, spine surgeons obtaining 'informed consent' for non-instrumented spine surgery were studied via video recording and risk/benefit discussions were analysed. METHODS: A prospective observational study was conducted at a single neurosurgical institution. Twelve video recordings involving six surgeons obtaining an informed consent for non-instrumented spine surgery were transcribed verbatim and blindly analysed using descriptive quantification and linguistic ethnography. RESULTS: Ten (83%) consultations discussed surgical benefit but less than half (41%) quantified the likelihood of benefit from surgery. The most discussed risks were nerve damage or paralysis (92%), bleeding (92%), infection (92%), cerebrospinal fluid leak (83%) and bowel and bladder dysfunction (75%). Surgeons commonly used a quantitative statement of risk (58%) but only half of the risks were explained in words patients were likely to understand. CONCLUSIONS: This study highlights inconsistencies in the way spine surgeons explain risks and obtain informed consent for 'simple' spine procedures in a real-world setting. There are wide disparities in the provision of informed consent, which may be encountered in other surgical fields. Direct observation and qualitative analysis can provide insights into the limitations of current informed consent practice and help guide future practice.

How I do it: 3D exoscopic endoscope-assisted microvascular decompression.

BACKGROUND: Microvascular decompression (MVD) is an effective treatment for drug-resistant trigeminal neuralgia and hemifacial spasm. However, failure of symptomatic improvement can arise from difficulties in identifying and/or decompressing the offending vessel. Microscopic and endoscopic techniques have been used to improve visualisation and safety of the procedure but there are limitations to each technique. METHOD: A 3D exoscopic endoscope-assisted MVD technique is described, including advice on potential pitfalls. CONCLUSION: Compared with the standard microscope-assisted techniques, the 3D exoscopic endoscope-assisted MVD offers an improved visualisation without compromising the field of view within and outside the surgical field.

Cranial Nerve Nomenclature: Historical Vignette.

The nomenclature of the 12 cranial nerves as we know it today was developed over a series of anatomic findings by some of history's most famous anatomists from Galen to Von Soemmerring. In this paper, we review the literature to present an overview of the remarkable historical journey that brought our forefathers to trace the pathway of individual cranial nerves from origin to destination. In particular, we discuss the evolution of the naming of the cranial nerves and highlight relevant eponymous descriptions. We also include some poignant illustrations of cranial nerves by ancient anatomists that set the scene to their discoveries. In reviewing this legacy, we summarize the important product of centuries of discoveries and investigations and the limitations of cranial nerve classification systems.

Sacral intraosseous lipoma: a case report.

Sacral tumors are one of the most challenging lesions of the spine to study and manage. Surgical resection techniques are often difficult due to the regional anatomy, in addition to tumor involvement of neural and structural elements. The surgical goals are influenced by tumor pathology but this can be made more complicated by a difficult diagnostic process. The authors present the rare entity of a sacral lipoma and the radiological and histological features which highlight this condition.