Ultrasound-guided erector spinae plane block versus paravertebral block in breast cancer patients undergoing mastectomy with immediate reconstruction - a non-inferiority trial.

In breast cancer treatment, surgery plays a central role in combination with
chemotherapy, radiation and immunotherapy. Surgery may vary from conservative
breast sparing interventions to large radical mastectomies with axillary lymph
node dissection that require reconstructive (prosthetic) surgery. In many
instances, reconstruction is not performed immediately, but immediate
reconstruction is possible and offers many advantages to patients.
The Antoni van Leeuwenhoek hospital performs a large proportion (77%) of
mastectomies with immediate reconstruction in the Netherlands. The combination
of mastectomy with immediate reconstruction in one operation offers an extra
challenge with regards to pain control. Post-operative pain is often treated
with opioids, which has systemic side effects (nausea and vomiting). Opioids
also inhibit cell-mediated immunity, which is a principal defense against
cancer. Regional anesthetic techniques are often performed to reduce opioid
consumption and enhance postoperative recovery.
The current standard for regional anesthesia for breast surgery is the
paravertebral block (PVB). This technique has the potential for severe
complications such as epidural hematoma, hemo- or pneumothorax. The erector
spinae plane block (ESP) was first described in 2016 as a novel regional
anesthetic technique for acute and chronic thoracic pain. The site of injection
is distant from the pleura, major blood vessels, and spinal cord; hence, the
ESP block has relatively few contraindications and has therefore been suggested
as an alternative to PVB when contra-indications, such as a bleeding diathesis,
are present.
Multiple studies have shown a decrease in opioid consumption in patients
undergoing mastectomy, when ESP was compared to placebo. ESP has also been
shown to be non-inferior to PVB for pain relief in patients undergoing
thoracotomy. To date, only two studies have compared ESP to PVB for breast
surgery, with conflicting results. In this study, we would like to investigate
whether ESP can be considered non-inferior to PVB with regards to pain relief
and use of opioids

The objective of this study is to assess the non-inferiority of analgesic
efficacy of ESP vs PVB for patients undergoing unilateral mastectomy followed
by immediate reconstruction.

A prospective, double-blinded, single centre, randomized controlled
non-inferiority trial.

Pre-operative ultrasound guided single shot paravertebral block versus
ultrasound guided single shot erector spinae plane block.

The burden for the patient is comparable to standard care with low risk. All
patients receive an injection of subcutaneous local anaesthetics followed by
insertion of a needle to perform PVB or ESP while the patient is awake or
lightly sedated. The complication risk of the intervention (ESP) is lower than
the risk of the standard technique (PVB) for local anaesthetic toxicity,
epidural hematoma, hemato- and pneumothorax. The ESP is performed at a greater
distance of spinal cord, nerve roots and blood vessels compared to the PVB. ESP
has been show to provide analgesia compared to placebo in patients undergoing
breast surgery. It has been shown to be a safe block that is easy to learn and
requires less time to perform.(1) The patients are under general anaesthesia
during surgery under constant monitoring of vital parameters. They receive
patient-controlled opioid analgesia as rescue medication if needed and are
monitored by ward nurses and a physician assistant that has specialised in pain
medicine following discharge from the recovery room.