Ultrasound-guided percutaneous peripheral nerve stimulation: neuromodulation of the suprascapular nerve and brachial plexus for postoperative analgesia following ambulatory rotator cuff repair. A proof-of-concept study

Abstract

Background and objectivesPercutaneous peripheral nerve stimulation (PNS) is an analgesic modality involving the insertion of a lead through an introducing needle followed by the delivery of electric current. This modality has been reported to treat chronic pain as well as postoperative pain following knee and foot surgery. However, it remains unknown if this analgesic technique may be used in ambulatory patients following upper extremity surgery. The purpose of this proof-of-concept study was to investigate various lead implantation locations and evaluate the feasibility of using percutaneous brachial plexus PNS to treat surgical pain following ambulatory rotator cuff repair in the immediate postoperative period.MethodsPreoperatively, an electrical lead (SPR Therapeutics, Cleveland, Ohio) was percutaneously implanted to target the suprascapular nerve or brachial plexus roots or trunks using ultrasound guidance. Postoperatively, subjects received 5 min of either stimulation or sham in a randomized, double-masked fashion followed by a 5 min crossover period, and then continuous stimulation until lead removal postoperative days 14–28.ResultsLeads (n=2) implanted at the suprascapular notch did not appear to provide analgesia, and subsequent leads (n=14) were inserted through the middle scalene muscle and placed to target the brachial plexus. Three subjects withdrew prior to data collection. Within the recovery room, stimulation did not decrease pain scores during the first 40 min of the remaining subjects with brachial plexus leads, regardless of which treatment subjects were randomized to initially. Seven of these 11 subjects required a single-injection interscalene nerve block for rescue analgesia prior to discharge. However, subsequent average resting and dynamic pain scores postoperative days 1–14 had a median of 1 or less on the Numeric Rating Scale, and opioid requirements averaged less than 1 tablet daily with active stimulation. Two leads dislodged during use and four fractured on withdrawal, but no infections, nerve injuries, or adverse sequelae were reported.ConclusionsThis proof-of-concept study demonstrates that ultrasound-guided percutaneous PNS of the brachial plexus is feasible for ambulatory shoulder surgery, and although analgesia immediately following surgery does not appear to be as potent as local anesthetic-based peripheral nerve blocks, the study suggests that this modality may provide analgesia and decrease opioid requirements in the days following rotator cuff repair. Therefore, it suggests that a subsequent, large, randomized clinical trial with an adequate control group is warranted to further investigate this therapy in the management of surgical pain in the immediate postoperative period. However, multiple technical issues remain to be resolved, such as the optimal lead location, insertion technique, and stimulating protocol, as well as preventing lead dislodgment and fracture.Trial registration number NCT02898103.

Pilot Study in Temporary Peripheral Nerve Stimulation in Oncologic Pain

“…The first three patients in our case series demonstrate novel targeting of proximal spinal nerves at the thoracic and lumbar levels with the temporary PNS. Prior studies using this device have targeted peripheral nerves and the brachial plexus to treat pain in the extremities (5,(8)(9)(10). Our approach introduces a unique approach for treating truncal pain using this device by allowing selective targeting of dermatomal patterns as we have demonstrated with post-mastectomy pain syndrome and postherpetic neuralgia.…”

“…Furthermore, in this cohort, we had one lead fracture, which is one of the most common complications with this device (8)(9)(10). Retained fragments only have conditional MRI compatibility, which should be a significant concern in the oncologic population.…”

“…Patient number 5 in our case series demonstrates the first time PNS was successfully used to target the brachial plexus in an active cancer pain patient. In a prior study, analgesia for rotator cuff surgery was successfully performed by targeting the C5 proximal spinal nerve, superior trunk, and the middle trunk (0008). Unfortunately, Patient 5 had progression of her malignancy leading to urgent need for an MRI requiring extraction of the leads at 45 days, 15 prior to the target of 60 days.…”

“…The results and conclusions that can be drawn from this study are limited by the case series nature of the data. Two prior studies using this PNS have studied acute postoperative pain using randomized, crossover studies (0008) (0010) and one prior study looked at chronic postamputation pain using a randomized, controlled trial (0005). Future research should focus on generating additional high‐quality evidence to help identify criteria predictive of successful response to PNS.…”

“…In addition to providing analgesia during stimulation, a unique feature of the device is that it has shown to continue to provide analgesia after extraction of the PNS leads. Currently, data are limited to one randomized‐control trial in postamputation pain (0005), and multiple case series in axial low back pain (6,7), acute postoperative pain after rotator cuff surgery (0008), total knee arthroplasty (0009), and foot surgery (0010). Analgesic benefits up to 12 months (0005) and 4 months (6,7) after extraction of the PNS were noted in postamputation and low back pain patients, respectively.…”