The Effect of Local Analgesia on Postoperative Gluteal Pain in Patients Undergoing Sacrospinous Ligament Fixation: A Randomized Trial

Sacrospinous ligament fixation (SSLF) is commonly performed to treat apical prolapse. Pelvic organ prolapse (POP) is a complaint for which as many as 11% of women seek surgical intervention in their lifetimes (2). SSLF is associated with shorter operating time, improved patient recovery time, fewer complications and decreased costs compared to an abdominal approach (3).This procedure is associated with postoperative nerve pain in 6.1% to 15.3% of SSLF procedures, due to impingement of the S3 to S5 nerve roots that course over the mid-portion of the coccygeus muscle-sacrospinous ligament (C-SSL) complex (1). 89% of the nerve fibers to the coccygeus and/or levator ani muscles (S3) course over the midportion of the C-SSL complex, just proximal to the intended location for suspension (4). This resulting nerve entrapment or injury may then lead to gluteal and perineal pain, parasthesias and muscle weakness (1). This pain may persist 6 weeks in up to 15% of patients,but most patients can be managed with conservative therapies, such as medications, TPIs and/or pelvic floor physical therapy (3).

A myofascial trigger point is a hyperirritable area in skeletal muscle that is painful on compression and can give rise to characteristic referred pain and tenderness, motor dysfunction and autonomic phenomena (5). TPIs are a treatment used in cases of chronic myofascial nerve pain and involve injection of the involved muscle(s), typically with local anesthetics and corticosteroids (5). The mechanism of action of TPIs occurs by mechanical disruption of abnormal contractile elements, dilution of nociceptive substances by the infiltrated anesthetic, and induction of muscle fiber trauma that subsequently releases intracellular potassium. Additionally, injections interrupt the positive feedback loop that perpetuates pain and a vasodilatory effect of anesthetic helps to remove excess metabolites (5). The benefits of this local combined pain control method are two-fold: the local anesthetic offers rapid pain relief for several hours while the corticosteroid provides delayed pain control, often lasting three to five weeks (6). The use of such local analgesia is not typically standard of care at the time of a sacrospinous ligament fixation, but may be a helpful adjunct therapy.

A recent case report noted significant improvement in a patient's pelvic pain after she received three therapeutic pudendal nerve perineal injections using the combination of a local anesthetic and steroid (bupivicaine 0.25% and triamcinolone 40 mg); two injections were placed at the ischial spine and one in Alcock's canal (7). Similarly, another randomized controlled trial found that injection of slow-release corticosteroid (triamcinolone) and lidocaine in the anatomic region around the sacrospinous ligament's insertion on the ischial spine (i.e., also in the area of SSL colpopexy) significantly reduced pain intensity and number of pain locations in women with persistent, debilitating sacral low back pain, even spanning up to two years after pregnancy and childbirth (8).

There is a paucity of data examining interventions to potentially ameliorate the postoperative transient gluteal pain often associated with sacrospinous ligament colpopexy. The only comparable study to date examined the injection of 0.25% bupivicaine at the time of sacrospinous ligament colpopexy and found that such an intervention did not reduce patient's perceptions of postoperative gluteal pain, but did potentially reduce the need for medication after surgery (1). Our study aims to determine if a compounded TPI (9cc 0.5% marcaine and 1cc Kenalog) improves postoperative gluteal pain scores and minimizes use of narcotic pain medications in the postoperative period.