Human cadaver brain infusion skull model for neurosurgical training.

BACKGROUND: Microsurgical technique and anatomical knowledge require extensive laboratory training. Human cadaver models are especially valuable as they supply a good microsurgical training environment simultaneously providing authentic brain anatomy. We developed the "skull infusion model" as an extension of our previous "brain infusion model" taking it a step further maintaining simplicity but enhancing realism. METHODS: Four human cadaveric brains donated for educational purposes were explanted at autopsy. The specimens were prepared cannulating carotid and vertebral arteries with plastic tubings, flushed with abundant water and fixed for 1 month in formaldehyde. They were then enclosed with white silk clothing (emulating the dura mater) and inserted into human skulls cut previously into two pieces. Tap water at a flow rate of 10 L/h was infused through the arterial tubings. RESULTS: Diverse microsurgical procedures were performed by two trainees, including craniotomies with microsurgical approaches and techniques such as sylvian fissure exposure, extra-intracranial and intra-intracranial bypass, approaches to the ventricles and choroidal fissure opening. The water infusion fills the arterial system, leaking into the interstitial and cisternal space and finally moistening the whole specimen. This makes vascular microsurgical techniques become extremely realistic, increasing its compliance making manipulations easier and more authentic. CONCLUSIONS: Standard microsurgical laboratories frequently have difficulties to work with decapitated human cadaver heads but could have human brains readily available. Using the infusion model and inserting it in a human skull makes the environment much more realistic. Its simplicity and inexpensiveness make it a good alternative for developing microsurgical techniques.

Microsurgical cerebral aneurysm training porcine model.

The authors developed a simple reproducible technique for aneurysm creation and adapted it to mimic intracranial dissection conditions using glue application as a pseudo-arachnoid type layer. Ten 1-2-month-old healthy domestic swine were employed under general anesthesia. A novel technique for bifurcation aneurysm creation was developed using two arteries and a vein. After aneurysm creation, diluted sulfuric acid was applied on the dome with a micropipette to increase aneurysm fragility in selected zones. The surgical field was then dried and contact glue was applied around the vascular complex in a circular manner so as to emulate arachnoidal connection fibers. Microsurgical dissection of the aneurysm and surrounding vessels was performed by delicately removing the adhesive substance. Diverse aneurysm clipping techniques, emergency rupture situations and vascular reconstruction procedures were trained. Twenty-two aneurysms were created at several vascular sites, one aneurysm dome ruptured during application of sulfuric acid, two aneurysm models were proved to be thrombosed, two aneurysms ruptured during the dissection and no intraoperative deaths occurred. All aneurysms were clipped in an acceptable manner. This bifurcation aneurysm model provides a novel training system to be used not only by neurosurgeons but also by neurovascular interventionists.

Human cadaver brain infusion model for neurosurgical training.

BACKGROUND: Microneurosurgical technique and anatomical knowledge require extensive laboratory training before mastering these skills. There are diverse training models based on synthetic materials, anesthetized animals, cadaver animals, or human cadaver. Human cadaver models are especially beneficial because they are the closest to live surgery with the greatest disadvantage of lacking hemodynamic factors. We developed the "brain infusion model" to provide a simple but realistic training method minimizing animal use or needs for special facilities. METHODS: Four human cadaveric brains donated for educational purposes were explanted at autopsy. Carotids and vertebral arteries were cannulated with plastic tubes and fixed with suture. Water was flushed through the tubings until the whole arterial vasculature was observed as clean. The cannulated specimens were fixed with formaldehyde. Tap water infusion at a flow rate of 10 L/h was infused through the arterial tubings controlled with a drip regulator filling the arterial tree and leaking into the interstitial and cisternal space. RESULTS: Multiple microneurosurgical procedures were performed by 4 trainees. Cisternal and vascular dissection was executed in a very realistic fashion. Bypass anastomosis was created as well as aneurysm simulation with venous pouches. Vessel and aneurysm clipping and rupture situations were emulated and solution techniques were trained. CONCLUSION: Standard microsurgical laboratories regularly have scarce opportunities for working with decapitated human cadaver heads but could have human brains readily available. The human brain infusion model presents a realistic microneurosurgical training method. It is inexpensive and easy to set up. Such simplicity provides the adequate environment for developing microsurgical techniques.

Microsurgical training on an in vitro chicken wing infusion model.

BACKGROUND: Microneurovascular anastomosis and aneurysm clipping require extensive training before mastering the technique and are a surgical challenge. We developed the "infused chicken wing method" to provide a simple but realistic training method minimizing animal use and need for special facilities for animal care and anesthesia. METHODS: Fresh chicken wings were used in this model. The main brachial artery was cannulated, and water was infused at 140 mm Hg followed by anatomical neurovascular dissection. Multiple microsurgical training exercises were performed under microscope vision including terminoterminal, lateroterminal, laterolateral vascular anastomosis, and nerve anastomosis. Different complexity aneurysms were created using venous patches, clipping, rupture, and vascular reconstruction techniques were performed. RESULTS: This novel training model is inexpensive, easily obtainable, and no live animals are required. The diameter and characteristics of arteries and veins used are similar to those of the human brain. Great microsurgical technique progress may be obtained. CONCLUSIONS: The infused chicken wing artery model presents a realistic microvascular training method. It is inexpensive and easy to set up. Such simplicity provides the adequate environment for developing microsurgical technique.

Percutaneous thermocoagulation intradiscal techniques for discogenic low back pain.

STUDY DESIGN: Systematic review. OBJECTIVE: To systematically review the evidence on the efficacy, effectiveness, and safety of percutaneous thermocoagulation intradiscal techniques for discogenic low back pain. SUMMARY OF BACKGROUND DATA: The intervertebral disc is thought to be the source of pain in a relevant proportion of cases of low back pain (LBP). Two percutaneous thermocoagulation intradiscal techniques have been described to treat discogenic LBP: percutaneous intradiscal radiofrequency thermocoagulation (PIRFT) and intradiscal electrothermal therapy (IDET). METHODS: An electronic search was performed in MEDLINE, EMBASE, and the Cochrane Library databases up to 2005, to identify nonrandomized controlled trials and randomized controlled trials (RCTs) on those techniques. All relevant studies were methodologically assessed independently by 3 reviewers. RCTs were assessed following the criteria recommended by the Cochrane Back Review Group. A qualitative synthesis of results was performed. RESULTS: Six studies were included with a total of 283 patients. Two open, nonrandomized trials (95 patients) showed positive results for IDET compared with rehabilitation and PIRFT. Results from 2 RCTs showed no differences between PIRFT and placebo, and between different PIRFT techniques. Two RCTs compared IDET with placebo. One suggested differences only in pain and in disability, while the best quality RCT showed no differences. CONCLUSIONS: The available evidence does not support the efficacy or effectiveness of percutaneous thermocoagulation intradiscal techniques for the treatment of discogenic low back pain.

The influence of fear avoidance beliefs on disability and quality of life is sparse in Spanish low back pain patients.

STUDY DESIGN: Correlation between previously validated questionnaires. OBJECTIVES: To assess the influence of fear avoidance beliefs (FAB) on disability and quality of life in Spanish low back pain (LBP) patients. SUMMARY OF BACKGROUND DATA: FAB has shown to be a major determinant of disability in LBP patients in Northern European and Anglo-Saxon cultural environments. There are no data on its influence on Latin-Mediterranean patients. METHODS: The study was done in 12 primary care and 9 hospital services from seven different regions of Spain, with 209 patients who were in a potentially active working situation and visited the National Health Service for LBP. None was excluded and the sample was balanced for acute, subacute, and chronic patients. On their first visit and 14 days later, patients were given two independent Visual Analogue Scales (VAS) for LBP and leg pain, as well as the validated Spanish versions of the Fear Avoidance Beliefs (FABQ), Roland-Morris (RMQ), and SF-12 questionnaires. RESULTS: Correlations between LBP, leg pain, FABQ, disability, and quality of life were moderate on day 1 (r = 0.320-0.564) and stronger on day 15 (r = 0.457-0.637). All of them were statistically highly significant (P = 0.000). Regression models showed that LBP severity explains 33% of disability on day 1 and 20% on day 15, while FAB only explains 6% on day 1 and 2% on day 15. FAB does not explain mental quality of life. It explains only 5% of physical quality of life on day 1 and 4% on day 15. There was no interaction between FAB and chronicity, and FABQ values on day 1 did not predict disability or quality of life at day 15. CONCLUSIONS: As opposed to what has been shown in other cultural settings, FAB have virtually no clinical relevance in Spanish LBP patients who are treated in the National Health Service and who are in a potentially active working situation. The influence of FAB on disability is minimal and much less than that of pain severity, and their contribution to the patient's quality of life is irrelevant. Further studies should explore the potential value of FAB in other Latin-Mediterranean countries.