• Ultrasonography
• Nerve Block
• Lower Extremity

Sciatic nerve block is usually used for lower limb surgery. The ultrasound-guided approach for popliteal sciatic nerve block facilitated its visualization, but recognition of the nerve and appropriate needle insertion for performing ultrasound-guided nerve blocks can be challenging for novice trainees. Ethically, a trainee should not be performing an invasive procedure on a patient until after considerable practice on a phantom.1 Ultrasound phantoms are widely used for ultrasound regional anesthesia practice. The development of phantoms allowed an easy training and a reproducible method that has been shown to improve trainees’ skills.2 It is though expensive and may not be affordable for low-income and middle-income countries.

In this letter, we describe a low-cost, high-fidelity sciatic nerve block phantom for training.

For phantom construction, we used an open chicken breast in which we inserted the different elements. The chicken breast represented the muscles of the popliteal region. The grounded turkey meat was used to create the nerves: tibial and commom peroneal branches, which were enveloped in a portion of a glove to mimic the paranerve. For tibial vessels, we used intravenous tubes of different diameters filled with ultrasound gel. Vessels were separated from nerve by placing a sheath of chicken breast to approach the sonoanatomy. The chicken breast was then folded over these elements.

The primary purpose of this model was to recognize sonoanatomy of popliteal sciatic region and to recognize sciatic nerve and learn the appropriate insertion of the needle.

We used this model during a training session for anesthesia residents with a 7 Mhz linear probe of Mindray TE7 ^ACE ultrasound machine.

By positioning a linear transducer, we were able to visualize sciatic nerve surrounded by its sheath and to have a dynamic image showing the two branches joining each other. This model allowed trainees to practice locating sciatic nerve with its two branches (peroneal and tibial) until they meet in the popliteal region and to insert the needle in the right place (figure 1).

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Figure 1

Sonoanatomy of sciatic nerve block and needle progression.

The cost of this model is less than £5, it was usable multiples times on the same day.

We developed a low-cost, high-fidelity sciatic nerve bloc phantom with easy-to-find material and a low cost.

Low-cost models for ultrasound-guided anesthesia have been used for nerve blocks or for venous cannulation in anesthesia teaching.3 ,4 Some authors used gelatin models for low-cost phantoms,5 gelatin model was limited by a rapid decomposition of the gelatin. We use chicken breast for its low cost and high fidelity in mimicking muscles and its resistance to decomposition compared with other models in the literature. In his low-cost model, Sparks et al used an ethernet cable to represent the nerve, his model although creating a high-fidelity image was limited by a shadowing image behind the nerve.6 For our model, the choice of grounded turkey meat offered a honeycomb image of a large nerve and the possibility to find the two branches of the nerves. Otherwise, surrounding the meat with a portion of gloves, which is thin and soft, offered a realistic image of the sheath of the nerve.

We found that this model was easy to construct and to use for popliteal sciatic nerve block teaching under ultrasonographic guidance. It was cost-effective and reproducible for multiple teaching sessions.

Making these models available can enhance learning, especially in low-income and middle-income countries to strengthen learning and generalize the use of simulation-based training.