Blog with interesting cases and/or problems related to anesthesia with discussion based on best evidence in the literature.

February 16, 2014

Anterior Iliac Creast (AIC) autologous bone graft and pain control in orthopedic surgery-a new indication for TAP?

A 47 year old male returned to the outpatient surgery center for revision of his distal radius fracture. The plan was to take a bone graft from his iliac crest as part of the revision.  Pain from autologous iliac crest grafting can be severe and can result in chronic post surgical pain. Chronic pain from this procedure was reported to occur in 31% of patients in one study [3]. There is some indication that it can affect duration of hospitalization [2].  Local injection of LA can help reduce acute pain, but, it lasts for only several hours at most. A rational approach to provide longer term pain control may be approrpriate. A transversus abdominus plane block (TAP) block may provide pain control in the pertinent area.  It has been shown that a well placed TAP block can provide reliable sensory block from T9 to L1 [1].  The iliac crest lies within the T12 to L1 dermatomal area.  At this point there is only one study looking at the effectiveness of the TAP block for iliac crest bone graft surgery.  Thirty three consecutive patients were followed after iliac crest bone graft surgery with preoperative TAP blocks using US.  Ropivacaine 15 mL (0.33%) was injected.  Pain was monitored at 1, 6, 12, 24 and 48 hours after surgery.  Patients were again interviewed about pain 18 months after surgery.  They found a median VAS score of 0 at all periods of assessment.  They also found that 80% of patients reported no complaint of pain from the iliac crest graft site. The authors concluded that this is an appropriate technique for pain control after iliac crest bone graft.

The TAP block is really just another version of the old style iliohypogastric ilioinguinal nerve block performed blindly by locating the ASIC and moving medially and cranially 2 cm each.  After two pops, and injection is made.  However, the blind technique has a higher failure rate than newer technques utilizing US.  Placing the probe as depicted below, just above the iliac crest, the external and internal abdominal oblique muscles will become apparent.  Just below these two, the third muscle layer of the abdominal wall, is the transversus abdominus muscle.  An injection of LA (I use 30 mL) will separate the TA plane.  You should look for the TA muscle to press down into the peritoneum.  After placing the LA, inserting a catheter for continuous infusion is quite simple if you choose to do this.

I placed a TAP block in the patient under GETA at the end of the case.  In recovery he did not experience any pain at all from the graft site.

1.  Mitchell AU, Torup H, et al.  Effective dermatomal blockade after subcostal transversus abdominis plane block. Dan Med. 2012; j59/3.

2. J?ger M, Westhoff A, Wild R: Knochenspanentnahme am Becken. Techniken und Probleme. Orthop?de 2005; 34: 994.
3.  Sasso RC, LeHuec JC et al.  Iliac crest bone graft donor site pain after anterior lumbar interbody fusion: a prospective patient satisfaction outcome assessment.  J Spinal Disord Tech;2005:77-81.
4. Heary RF, Schlenk RP, Sacchieri TA, Barone D, Brotea C. Persistent iliac crest donor site pain: independent outcome assessment. Neurosurgery. 2002; 50(3):510-517.