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| A pump for use with tissue expansion in breast reconstruction
Peter J Anderson, Phillip D Oliver, Phillip 0 Byrne, Neil R McLean Department of Plastic and Reconstructive Surgery and Northern Regional Medical Physics Institute, Newcastle General Hospital, Newcastle upon Tyne
Key words: Breast reconstruction; Pump
Tissue expansion using inflatable plastic expanders is a widely used technique by reconstructive surgeons to produce more skin. The method has wide application including reconstruction following trauma and burns, but the most common use of tissue expanders is in breast reconstruction after mastectomy.
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SURGICAL TECHNIQUE
A pump for use with tissue expansion in breast reconstruction
Peter J Anderson FDSRCS(Ed) FRCS : Specialist Registrar in Plastic and Reconstructive Surgery
Phillip D Oliver HNC : Senior Medical Technologist
Phillip 0 Byrne BSc CEng : Chief Physicist
Neil R McLean MD FRCS : Consultant in Plastic and Reconstructive Surgery
Department of Plastic and Reconstructive Surgery and Northern Regional Medical Physics Institute, Newcastle General Hospital, Newcastle upon Tyne
Key words: Breast reconstruction; Pump
Tissue expansion using inflatable plastic expanders is a widely used technique by reconstructive surgeons to produce more skin. The method has wide application including reconstruction following trauma and burns, but the most common use of tissue expanders is in breast reconstruction after mastectomy.
In this department, breast reconstruction using a tissue expander which can be left as an implant after expansion is complete is regularly used. This technique was first described by Becker (1), and since it was introduced into the department in 1989 has produced excellent cosmetic results with few complications (2). However, the technique has proved so popular that many patients are concurrently requiring expansion and so a weekly clinic has been established.
The technique of tissue expansion traditionally relies on Luer lock syringes and 'butterfly' needles to fill the expanders via a subcutaneous port with sterile saline. At the final stage of reconstruction fluid also has to be withdrawn from an overinflated expander to adjust' a reconstructed breast to provide some ptosis and enhance the end cosmetic result. This process of altering fluid within the expander can be time consuming, particularly when several hundred millilitres of fluid are withdrawn to produce ptosis. To improve the transfer of the normal saline both into and out of the expander we have developed a pump, called the Mammoflow pump, which can be used either for inflation or deflation. |
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Figure 1. The pump with the intravenous giving set attached ready for use in the clinic.
Technique
An intravenous giving set is connected to the pump and a sterile 23G needle is added. Normal saline from a reservoir is connected to the other end and run through the system using the pump prime mechanism, removing all air bubbles. The pump set up ready for use is shown in Fig. 1. The needle is then inserted through the skin, which has been washed in antiseptic by the surgeon, into the subcutaneous injection port, shown diagrammatically in Fig. 2. Inflation is then started. The amount transfused is measured by recording the time of injection (the rate is fixed at 1 ml/s).
To deflate, the pump can simply be reversed, after the sterile saline bag has been removed and a kidney dish positioned to collect the saline. |
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Figure2. Diagram showing the pump's attachments to the sterile saline reservoir and the injection port of the prosthesis.
Discussion
The pump is an experimental pump flow system for filling and emptying implanted breast prostheses. The apparatus has been purposely designed and constructed with patient safety in mind and meets the Regional Medical Physics Equipment construction guidelines and BS 5724. The instrument comprises two independent timing circuits (A and B) which can only be set during the fabrication of the instrument. Timer A is set to 10 min and timer B is set to 10 min 20 s. They are configured so that either one will terminate pump operation, thus acting as a failsafe mechanism. The pump and its control electronics is an original equipment manufacturer's part supplied by Watson-Marlow (Watson-Marlow Ltd, Falmouth, England). The pump interfaces with the timer electronics. Some of the original facilities integral with the pump's control system have been retained. First, the direction of flow can be reversed, which is important in creating ptosis at the final stage of breast reconstruction. Second, the pump prime mechanism has been left unmodified to facilitate use in the clinic.
We have found this innovation to enable more patients to be seen in our tissue expander clinics. There have been no complications since the pump has been used clinically and the clinicians report that their thenar muscles no longer 'ache' at the end of the clinic!
References
- Becker H. Breast reconstruction using an inflatable breast implant with detachable reservoir. Plast Reconstr Surg 1984;
73: 678-83.
- Camilleri I, Malata CM, Stavrianos S, McLean NR. A review of 120 Becker permanent tissue expanders in reconstruction of the breast. Br J Plast Surg 1996; 49: 34651.
A pump for use with tissue expansion in breast reconstruction
Received 8 August 1997 |
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