Dysmenorrhea and infertility are the primary symptoms of endometriosis. Lignocaine (lidocaine, xylocaine) is an anesthetic that stabilizes membranes by blocking the action potential. The drug is used topically to induce local and regional anesthesia and also intravenously for treatment of ventricular arrhythmias. Lignocaine stabilizes cell membranes of nerve endings on intraperitoneal macrophages and other inflammatory cells in endometriotic implants and eutropic endometrium. Previous studies have shown that, when administered through the fallopian tubes before ovulation, lignocaine could be useful as a fertility agent in women with endometriosis and may also reduce endometriosis-related menstrual pain and dysmenorrhea.
The aim of this randomized, double-blind controlled study was to investigate the effect of Ringer-lignocaine administered through the fallopian tubes (pertubation) on dysmenorrhea in women with endometriosis. The study was conducted at 3 sites in Stockholm, Sweden. All participants had either peritoneal or ovarian endometriosis as confirmed by laparoscopy. Primary inclusion criteria included dysmenorrhea or pelvic pain (defined as a pain score of >50 mm on the visual analog scale) and patency of the fallopian tubes. Subjects were randomized to receive preovulatory pertubation with Ringer-lignocaine solution (n= 24) or Ringer solution alone (placebo, n = 18) in 3 sequential menstrual cycles. The solutions were infused through the uterine cavity and the fallopian tubes using an intracervical balloon catheter. Pain was assessed before and after the treatments and up to 9 menstrual cycles after the last pertubation. Reduction of the visual analog scale pain score 50% or more was defined as a success. The success rate in the groups was compared at different time points with Fisher exact test.
The intention-to-treat population was composed of 42 patients, 34 of whom remained in the per protocol analysis. With intention-to-treat analysis, the success rate was 41.7% (10/24) in the lignocaine group versus 16.7% (3/18) in the placebo group (95% confidence interval, −7.3% to 36.2%; P = 0.10). With the per protocol analysis, however, the success rate in the lignocaine group was 45% (9/20) versus 7.1% (1/14) in the placebo group (95% confidence interval, −2.6% to 44.8%; P = 0.024). The improvement in the success rate persisted for 9 months in 4 of the 9 patients (44%) in the lignocaine group. Pertubation treatments were well tolerated, with no treatment-related adverse events.
These findings suggest that pertubation with lignocaine may provide a new treatment option for managing menstrual pain and dysmenorrhea in patients with endometriosis and maintains the possibility of pregnancy.