Michael Wang, University of Miami Health System, USA, has pioneered the awake minimally invasive transforaminal lumbar interbody fusion (TLIF), using the liposomal bupivacaine Exparel (Pacira), a single-dose non-opioid analgesic, to control postoperative pain. He spoke to Spinal News International about why the combination of Exparel and minimally invasive methods could change the nature of spinal surgery.
Why is this medication of interest to you as a spine surgeon?
Exparel is changing the way we deal with patients’ pain. In the past, we surgeons have relied heavily on opioid analgesics to control postoperative pain. While effective, these medications have many side effects. Exparel is a single-dose, non-opioid local analgesic which is comprised of bupivacaine encased in liposomes (DepoFoam, Pacira). The DepoFoam delivery system allows the bupivacaine to release over an extended period of time and provide patients with postoperative pain management for up to 72 hours, which is usually the most difficult phase of the recovery process.
How have you been using it?
In terms of specific procedures, we have been using liposomal bupivacaine in awake minimally invasive TLIFs—a procedure which we feel is the tip of the iceberg for our method. This method involves placing pedicle screws and rods into the lumbar spine with minimal need for opioid analgesics. If we can demonstrate success in this highly complex surgical model, the applications in other surgical indications may also be promising.
What are the benefits of the awake minimally invasive TLIF?
For spine surgery, the reduced trauma and faster recovery time is very important. Lumbar fusion procedures are typically open and result in a length of stay of three or four days. It is very painful and there is a lot of trauma as the surgeon has to go through a great deal of soft tissue to access the spine. Minimally invasive surgery has improved several outcomes, and brought hospital stays down to one day. The surgical technique and improved local analgesia are synergistic, producing a “win-win” situation for patients and physicians.
If we are able to send patients home the next day, or even the same day after the surgery, then they can get back to their lives and begin their recovery. This means that they have a lower risk of developing complications associated with longer, more invasive surgeries and lengthier hospital stays. The approach allows for more ambulatory outpatient care with less concern over peri- and postoperative pain control. With existing minimally invasive surgeries, we are seeing more outpatient procedures, but not with the patient getting up and walking right away. With our awake minimally invasive TLIF method, patients are getting up and walking almost immediately because they have reduced trauma to the muscles in the back and well-managed pain as a result of receiving liposomal bupivacaine.
The improved function and shorter hospital stays also impact costs. I published a study showing that using a minimally invasive technique can reduce the cost of a TLIF from US$78,000 (open) to US$70,000. Then we compared those outcomes with our awake procedure with Exparel, and we saw costs fall to the US$50,000 range per procedure. The length of stay was reduced from 3–4 days to 1.2 days, which is a significant improvement over both the open and typical procedures. Each administration of the medication costs US$300 and we are saving up to US$20,000 per hospitalisation by being able to send people home faster. Also, remember that these costs vary by geography, and in South Florida for example, costs are approximately twice as high as the rest of the USA with regards to almost all aspects of healthcare.
How does Exparel compare to other pain medications?
So far results have been very encouraging. My colleague Karthik Madhavan presented results of a 16-patient pilot study at the annual meeting of the North American Spine Society (NASS; 12–15 November 2014, San Francisco, USA) comparing the use of Exparel to Marcaine in open spine surgeries. He found that patients treated with Exparel consumed up to 50% fewer narcotics postoperatively and scored four fewer points on the 1-10 pain scale. Five out of eight patients treated with Exparel were able to walk 150 feet, compared to two out of eight patients treated with Marcaine at the same postoperative time point.
Postoperative narcotic use is a hugely important issue. Every person has a certain therapeutic window for how much opiate they can be given, and this may or may not be enough to achieve effective pain control. Using Exparel allows us to significantly reduce pain from the start of the recovery, meaning that patients need fewer opiates postoperatively, and it expands this therapeutic window, leading to more comfortable patients.
Are there risks associated with the use of Exparel?
As is the case with any medication, there are potential risks. As with regular bupivacaine, it is vital to avoid putting Exparel directly into the intrathecal space and/or injecting it intravascularly.
Will your method become the new standard for spine surgeons?
With any new technique or medications, physicians proceed with caution and skepticism until they have first-hand experience or evidence-based data. That said, as minimally invasive surgical techniques become more common, there is a growing excitement about combining cutting-edge techniques with new pharmaceuticals that can improve patient function and satisfaction, while reducing costs and complications. The bottom line is that pain is the reason most patients need spine surgery, and fear of postsurgical pain is one of the major reasons patients avoid surgery. Exparel has made us re-examine current standards and reset expectations for pain control.
When I show my peers examples of our work, they are incredibly surprised by our results. The awake minimally invasive TLIF procedure with Exparel has allowed us to achieve things that we have not yet been able to with existing pain management methods. So far, we have used it in select situations where it has been a major component of doing surgery in a revolutionary way. I think that when used appropriately, Exparel is a game changer and could have a very significant impact on how we treat our patients.
Infiltration of Exparel for postoperative analgesia following awake minimally invasive TLIF
Michael Wang and Karthik Madhavan, University of Miami/Jackson Memorial Hospital, Department of Neurological Surgery.
- Incision site: Percutaneous access sites for pedicle screws (8mm incisions).
- Before making the incision, we infiltrate the skin with about 10cc of lidocaine 1%/Marcaine 0.25% with epinephrine to produce intraoperative analgesia.
- We expand the volume of a 20ml vial of Exparel with 20ml of preservative-free normal sterile saline to a total volume of 40ml.
- Before the Jamshidi needle insertion, we use an 18G spinal needle to administer 10cc of liposomal bupivacaine at each site. Care must be taken to avoid inadvertent intravascular or intrathecal administration.
- We avoid infiltrating the foramen and take precautions to stay above the transverse process.
- No narcotics are used during the procedure.
- Patients receive Percocet at discharge either on the same day or following overnight observation in the hospital.
The Association for Collaborative Spine Research is conducting a multicentre prospective, randomised control trial with two centres performing minimally-invasive TLIF (patient controlled analgesia vs liposomal bupivacaine) and two centres performing open TLIF (patient controlled analgesia vs liposomal bupivacaine).