Imbibe - Surgical Technique - ASIS

BMA Surgical Technique
Anterior Iliac Crest Approach

Palpate and mark the anterior superior iliac spine (ASIS). To minimize the amount of tissue traversed by the BMA needle, retract any overhanging skin and subcutaneous fat and grasp the iliac crest between the thimb and fingers.

With a #11 or #15 scalpel, make a stab incision over the iliac crest at a point located 5-6cm posterolateral to the ASIS. The widest distance between the inner and outer tables of the anterior iliac crest is located in the region and best suited for bone marrow aspiration. Needle placement in this area will also avoid any potential injury to the lateral femoral cutaneous nerve which may traverse the iliac crest just proximal to the ASIS in the some individuals. (Fig 1)

Place the sharp-tip BMA needle through the stab incision. Use the needle tip to "palpate" the iliac crest and, once the center of the crest is located, seat the needle tip into the cortical bone with one or two brisk taps with a small, lightweight mallet (Fig 2). Using a mallet to advance the needle through bone is the preferred technique as it affords the surgeon greater control of the needle. Advancing the needle by hand often requires excessive downward force and, should the needle suddenly lose contact with bone, may result in perforation of the abdominal cavity and potential visceral injury. Advance the needle approximately 0.5 to 1.0cm through the cortical bone by tapping with the small mallet.

Angle the BMA needle approximately 35-40 degrees medial from the para-sagittal plane in line with the iliac wing as guaged by palpation. (Fig 3)

Exchange the sharp-tip trocar with the bullet-tip stylet. The bullet-tip stylet is designed to navigate between cortical bone boundries as the rounded tip will deflect the needle back into cancellous bone and minimize risk of cortical perforation.

Advance the needle to a depth of 2.0 to 2.5cm so that the aspiration holes are within bone. Remove the stylet and aspirate 2 to 4cc of marrow using a 10cc or 20cc syringe. Detach the syringe from the needle and replace the bullet-tip stylet.

Advance the needle an additional 2.0 to 2.5cm along the same trajectory and again aspirate 2 to 4cc of marrow. Additional marrow may be obtained using a "fan" technique. Withdraw the needle enough so that it can be redirected 25° cephalad or caudad, then advance the needle to a minimum depth of 2.0 to 2.5cm before aspirating again.