This video demonstrates the technique of percutaneous muscle biopsy of the human vastus lateralis using the Weil-Blakesley conchotome.
Percutaneous muscle biopsy using the Weil-Blakesley conchotome is well established in both clinical and research practice. It is a safe, effective and well tolerated technique. The Weil-Blakesley conchotome has a sharp biting tip with a 4 – 6 mm wide hollow. It is inserted through a 5 – 10 mm skin incision and can be maneuvered for controlled tissue penetration. The tip is opened and closed within the tissue and then rotated through 90 -180° to cut the muscle. The amount of muscle obtained following repeated sampling can vary from 20 mg to 290 mg which can be processed for both histology and molecular studies. The wound needs to be kept dry and vigorous physical activity kept to a minimum for approximately 72 hr although normal levels of activity can restart immediately following the procedure. This procedure is safe and effective when close attention is paid to the selection of subjects, full asepsis and post procedure care. Both right and left vastus lateralis are suitable for biopsy dependent on participant preference.
Obtaining skeletal muscle for the diagnosis of a myopathy and other neuromuscular degenerative diseases relies on safe and efficient methods which are acceptable and not incapacitating to patients 1. Historically, methods of obtaining muscle tissue for analysis included open biopsies performed under general anesthesia or from post mortem. These techniques allowed direct visualization of the muscle and permitted a larger piece of muscle to be biopsied. Given the potential disadvantages these techniques have to the patient in terms of hospital stay and recovery, percutaneous 'semi-open' muscle biopsy methods were introduced as alternatives. This technique was first performed by Duchenne (1806-1875), who used a self-constructed needle with a trocar and was able to obtain a muscle sample from a living subject without general anesthesia 2. Since then, various forms of biopsy needles have been used 3,4,5 . However, the biopsy needle developed by Bergstrom in 1962 has been the most commonly used in clinical practice; both in children and adults, as well as in research 6,7,8,9,10. It possesses a sharp trocar, a cutting cannula and a pushing rod to expel the tissue post biopsy. Muscle yields obtained from this procedure have been reported to range from 25 -293 mg after repeated sampling 11,9.
Henriksson introduced the Weil-Blakesley conchotome in 1979 as an alternative semi-open muscle biopsy method (Figure 1) 12. The instrument is a single structure unlike the Bergstrom construct and is designed like a forcep with a sharp biting tip. The tip size can range from 4 mm to 6 mm in width. When the two edges of the biting tip oppose, a hollow is formed that ensures capture of the muscle. The conchotome is inserted through a 5 – 10 mm skin incision and avoids the need for a trocar to penetrate the muscle and the overlying fascia as a scalpel can be used to make a track down to the muscle.
This method allows controlled tissue penetration with a high degree of maneuverability 13,14 . It is especially useful for sites where undue pressure could potentially damage neurovascular or underlying bony structures e.g., at the site of the tibialis anterior 15,14. Muscle yields using the conchotome can be variable and in our practice 20 – 200 mg of muscle has been obtained after repeated sampling. One potential advantage of the conchotome over the Bergstrom needle, in addition to the high degree of maneuverability it offers, is that the biting tip does not need to be sharpened or replaced as often as the trocar of the Bergstrom construct 16 .
The overall goal of muscle biopsy using the Weil Blakesley conchotome is to obtain sufficient amounts of muscle tissue to enable histochemistry and molecular analysis for both diagnostic and research study. It is a simple and safe procedure that can be learned easily. With this technique, muscle suitable for biopsy includes biceps, triceps, deltoid, gastrocnemius, tibialis anterior, soleus and the sacrospinals 17,15,7,18,14 . The outermost part of the vastus lateralis is the most common site used for biopsy as it avoids the main neurovascular structures within the thigh. It is identified approximately two thirds down an imaginary line joining the anterior superior iliac spine and the patella. Muscle morphology data, for example myofibre area, myofibre proportions, capillary density derived from vastus lateralis sampling are widely available in the literature allowing comparison between studies 11,19 .
To ensure participant safety and perform the muscle biopsy efficiently, it is vital to pay attention to critical steps within the protocol.
The participants must be selected after carefully considering the exclusion criteria to avoid complications such as bleeding and poor wound healing. Strict asepsis throughout the procedure is essential. Application of the correct technique will ensure participant comfort, minimize unwanted trauma to participant's tissues and allow a sufficient sample y…
The authors have nothing to disclose.
We wish to thank the study participants for making this work possible and the staff at the NIHR Southampton Biomedical Research Centre and the Wellcome Trust Clinical Research Facility, University Hospital Southampton for assistance with study measurements.
This work was supported by the NIHR Southampton Biomedical Research Centre, Nutrition, the MRC Lifecourse Epidemiology Unit and the University of Southampton. This report is independent research by the NIHR BRC Funding Scheme. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. AMB is supported by a NIHR Clinical Research Fellowship, HPP is supported by the NIHR Southampton Biomedical Research Centre.
Weil-Blakesley conchotome | Gebrüder Zepf Medizintechnik, Dürbheim, Germany | None | 6 mm biting tip |
5 ml 2% lidocaine | Generic use | None | One 5ml vial should suffice for adequate anaesthesia |
Alcohol swab | Generic use | None | |
5 mls syringe | Generic use | None | |
25G and 23G sterile needles | Generic use | None | |
Sterile scalpel size 11 | Generic use | None | |
Sterile gauze squares | Generic use | None | |
Sodium chloride 0.9% 10 ml | Fannin | 1122/002/001 | |
Steri-Drape™ Small Drape with Adhesive Aperture | 3M | 1020 | |
ChloraPrep 2% w/v /70% v/v cutaneous solution | CareFusion | 270400 | Two |
Steri-Strip™ 1/4 inch x 3 in Reinforced Adhesive Skin Closures | 3M | R1541 | |
PRIMAPORE sterile dressing 15cm x 8cm | Smith & Nephew |
66000318 | |
Cotton crepe bandage Hospicrepe 233 7,5 cm x 4,5 m | Hartmann | 915562 | |
Flexible cohesive bandage Co-Plus LF | BSN medical | 2904565 | |
Disposable absorbent sheet | Generic use | None | |
Micropore or transpore tape | Generic use | None | |
Sterile gown with sterile paper towels | Generic use | None | |
Sterile gloves | Generic use | None |