A flexible, sterile, and cost‐effective retractor system for microsurgery

We read with interest the publications by Di Summa (2009) and by Kuhbier (2011) and propose some short additional notes.1, 2 We also introduce our simple and cost-effective approach for a microretractor system, which is different from the others, but which from our point of view combines their advantages and avoids certain disadvantages. Di Summa et al.2 presented the use of paper clips as microretractors. These paper clips were shaped, kept in place, and stabilized using a needle. They proposed optimal surgical exposure without device bulkiness, combined with advantages such as simplicity, cost-effectiveness, avoidance of sharp tips, or stress on the wounds.1, 2 This is similar to the procedure recommended by Braunstein in the 1960s, of using safety pins as self-retaining microretractors.3 The method by Di Summa et al., as outlined by Kuhbier et al. (2011), had disadvantages of the lack of stiffness, possible oxidation after sterilizing processes, and restrictions due to the short length of the clips.1 Kuhbier et al. themselves described a simple and inexpensive microretractor system using wires of 0.7 mm diameter, which were fixed to a metal frame.1 They claimed that their sterilizable retractors were firm, preventing from deformation and, more importantly, could be used in a more “universal manner” due to the lengths and shapes of the tips.1 With this letter, we introduce a microretractor system, which is a different approach from those mentioned above, but which meets requirements thought to be advantageous. Initially, the sharp tip of a commercially available sterile 20-gauge needle (Sterican, B. Braun Melsungen AG) is bent to obtain a blunt tip (Fig. 1A). The needle can then be divided into three segments by bending it to an angle of nearly 90° at three points: 1) at the base (i.e., transition from plastic to metal), 2) at the end of the first third, and 3) at the end of the second third—thus forming a hook-like shape. The base of the needle is bound with an elasticated silicon loop (Fig. 1A), which can be prepared and sterilized or bought in the form of prefabricated loops (ETHILOOP 1, 3 mm, Ethicon, Nordstedt). We prefer the latter option. The second end of the silicon loop is fixed into position with a second needle (Figs. 1B and 1C). The microretractor composed of a commercially available 20-gauge needle and a silicon loop (A). Bending the needle to the required shape and knotting the silicon band to the microretractor and a second needle (B and C). Note the blunt tip of the microretractor (magnification in B) and the flexible length of the microretractor due to elastic silicone loops (C). [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] Wound retraction may be not the most important scientific topic, but it is of great practical interest. As mentioned by Braunstein et al. (1960) and Halsted,4 “exposure is the key to surgery.” In microsurgical experiments, an effective retraction is essential and is necessarily required for an optimal overview over the surgical field as well as for convenient access to the desired anatomical structures. On the basis of our own experience with a couple of 100 microsurgical experiments, and in agreement with abovementioned publications,1, 2 we summarize the proposed requirements for retractor systems and differentiate between obligatory from optional requirements: Obligatory requirements: a) optimal exposure of the surgical field with adequate size in relation to the surgical field, b) avoidance of tissue damage (e.g., by sharp ends), c) effective retraction without traction on anatomical structures such peripheral nerves and microvessels. Optional requirements: a) simple, b) cost-effective, c) sterilizable, d) flexibility in length and form for different applications. The tip of our microretractor is blunt (Fig. 1B) and, thus, avoids tissue damage. The hook-shape-formed needle avoids bulkiness and provides optimal view of the anatomical structures (Fig. 2), as demanded by Di Summa 2009.2 The microretractor does not lack stiffness and does not suffer from deformation or from possible oxidation (see Kuhbier 2011).1 Furthermore, due to elastic silicone loops with flexible length (Fig. 1C), the traction can be adjusted to the desired application as demanded by Kuhbier (2011).1 Furthermore, the hand of the surgeon can be positioned on the table ensuring hand stability. As the main focus of our work is peripheral nerve surgery (Fig. 2A) with the rat sciatic nerve, we are interested in avoiding any kind of unnecessary traction. However, our microretractor can be used for any kind of surgical procedure, e.g., exposure of the spinal column for spinal cord surgery (Fig. 2B), or of the abdominal wall (Fig. 2C). In our experience, the effectiveness of this system has been proven in more than 300 animal experiments. The procedure is simple due to the use of readily available (and disposable) materials (needles, silicon loops), which are sterile and relatively cheap. Exposure of surgical fields (A–C). Microsurgical exposure for operations on the peripheral nerve system (sciatic nerve; A), spinal cord (B), and abdominal wall (C). All experiments were conducted in accordance with the German federal law regarding the protection of animals. The experimental protocols were approved by the governmental animal care and use committee. Ahmet Bozkurt M.D., Ph.D. [email protected]*, Arne Boecker*, Sabien Van Neerven Ph.D.*, Dan Mon O'dey M.D.*, Christian Opländer Ph.D.*, Gary Brook Ph.D. , Norbert Pallua M.D., Ph.D.*, * Department of Plastic Surgery, Hand Surgery and Burn Center, RWTH Aachen University Hospital, Aachen, Germany, Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany.