Microsurgical techniques using human placenta

Abstract

Training in microsurgical techniques is the first step to allow procedures in the central nervous system. One of them is the dissection of human placenta. Others include mannequin head 1 , virtual reality environment 2 , animal and cadaver dissections 3 . The human placenta is a maternalfetal structure constituted of a bigger fetal portion and a smaller maternal portion. The fetal membranes and the placenta are responsible for protection, nutrition, breath, excretion and hormone production 4 . The placenta usually shows an ovoid shape with a 16-20 cm diameter and a 2-3 cm thickness 4 . It weighs between 500 and 600 gr 4 . The umbilical cord is usually composed of a vein and two arteries. The fetal surface has a fetal corion -amniotic membrane which is very similar to the cerebral arachnoid and a rich vascular component with 1-6 mm diameter vessels 4 . The anterior cerebral artery has 1-3 mm diameter and the medium cerebral artery one is between 2.4 and 4.6 mm. On the other hand, the vertebral artery has 0.92-4.09 mm diameter, the posterior cerebral and the lower posterior cerebelar arteries ones are between 0.65 and 1.78 mm.Therefore, the human placenta is an excellent material for microsurgical technique training 3,5,6 . METHOdThis study was developed at the Microsurgery Laboratory of the Hospital Beneficência Portuguesa de São Paulo and was also approved by the local ethics committee.Twenty-five human placentas were analyzed to check if they were suitable for microvascular exercising. The available length and diameter of the vessel were measured and different microvascular anastomoses were performed. The used microsurgical materials were 3,5,6 : forceps; microsurgery scissors; microsurgical knife; microsurgery needle holders; vascular clip appliers; neurovascular surgery clips; suture thread 10.0; Insulin syringe and needle; saline solution 0.9%.

Low-flow and high-flow neurosurgical bypass and anastomosis training models using human and bovine placental vessels: a histological analysis and validation study

“…One bovine placenta provides an average of 6 large bifurcations for carotid surgery simulations and more than enough smaller vessels for microanastomosis training. Although human placenta was proposed for microanastomosis training in 1979 by Goldstein,11 28 and recently reported as a substrate for producing models of arterial aneurysms, 20,25 the use of bovine placental vessels as a model for microvascular training and simulation of bypass with interposition grafts similar to ICA-vascular graft-MCA bypass has not been reported.…”

Human Placenta Aneurysm Model for Training Neurosurgeons in Vascular Microsurgery

“…24 Their use has been adopted in many surgical specialties, including neurosurgery, but only for microanastomosis practice. 25 For the purposes of cerebrovascular training, the vessels are of a caliber and branching pattern similar to those found in the brain, and the overlying membranes are similar (although somewhat thicker) to the arachnoid membranes. The feel of the tissue and strength of the placenta in the laboratory are subjectively much like that of the living brain.…”

Microsurgical training model with nonliving swine head. Alternative for neurosurgical education

“…A review in the literature depicts several models described for surgical education, including human cadaveric specimens 6 , resected human tissues 9 , live animals 10 , synthetic materials, and nonliving animals. The main disadvantages of using human cadavers are the cost and the difficulty associated to the obtainment.…”