Uterosacral ligament suspension is an effective treatment for apical pelvic organ prolapse (POP). Miller1 described the use of uterosacral ligaments for this indication in 1927. The vaginal approach to correct POP with uterosacral ligament suspension and the use of native tissue repair does not require an abdominal incision, allowing most patients to be discharged home the day after surgery. However, new-onset neuropathic pain is one of the specific postoperative complications that can arise from uterosacral ligament suspension delaying postoperative discharge and recovery. Neuropathic pain attributable to nerve entrapment may be difficult to discriminate from other causes of postoperative nerve compression. In a study by Flynn et al,2 7 out of 182 patients (3.8%) who underwent uterosacral ligament suspension had development of neuropathic pain in the S2–4 distribution. In our institution, uterosacral ligament suspension is the most common surgery to correct apical POP. This study was performed to estimate incidence, risk factors, and characteristics of neuropathic pain related to nerve entrapment after uterosacral ligament suspension in our patient population.
MATERIALS AND METHODS
A review of our patients who underwent uterosacral ligament suspension from January 2007 to August 2011 was performed. Approval was obtained from the Scott and White Institutional Review Board before initiation of the chart review. Uterosacral ligament suspension cases were performed according to the technique published by Shull et al.3
Briefly, sutures were used to plicate the pubocervical fascia or rectovaginal fascia or both. The remnants of uterosacral ligaments were identified posterior and medial to the ischial spines at the 4 o'clock and 8 o'clock positions.3 Three sutures, usually a delayed absorbable polydioxanone suture, followed by two permanent polyester sutures are placed on uterosacral ligaments on both sides of the pelvis. If pelvic adhesions are encountered or if there is difficulty in placing the suture on one side of the pelvis, then two to six sutures are usually placed on the contralateral side.
In our division, an index of surgical procedures for our patients are collected prospectively with information about the types of surgeries, the staff surgeon, the surgery date, and patient record numbers. This index can be searched for all of the cases during a particular time interval. The medical records and operative reports of all patients who underwent uterosacral ligament suspension were reviewed to extract information for the analysis. Data elements were placed in a spreadsheet format and reviewed for potential errors and missing data a second time. A database without patient identifiers was developed for analysis. Patients with neuropathic pain attributable to nerve entrapment from the procedure were identified. The data elements collected included performing surgeon's dominant hand, side of pain, onset of pain, day of suture removal, number of sutures placed, number of sutures removed, patient age, and body mass index (BMI). Follow-up of patients with nerve entrapment pain was obtained both at postoperative visits and by telephone contact to assess continuation of pain, pain duration, and recurrent POP after removal of suture. These factors were analyzed using Student t test, Mann-Whitney U test, χ2 test, and Gehan Wilcoxon test, with P<.05 as significant.
During the study interval, 515 patients with median age of 63.4 years (range 29–88.5), BMI of 26.8 (range 16.9–45.8), parity of 3 (range 0–10), and preoperative POP quantification stage 3 (range 1–4) underwent the surgical procedure with a mean of 2.9 (range 0–6) sutures placed on the right side and 2.5 (range 0–4) placed on the left side, for a total of 5.5 (range 2–8). Demographics did not differ between groups (Table 1).
Eight patients (1.6%, 95% confidence interval 0.7–3.0%) had postoperative neuropathic pain requiring uterosacral ligament suspensory suture removal from the side affected. All eight had sutures placed bilaterally. The postoperative pain was recognized by the patients after discontinuation of intravenous narcotics on postoperative day 1. The patients described the pain as sharp and stabbing, radiating from the buttocks into the posterior leg, and resulting in difficulty in sitting and walking. Conservative therapy with oral pain medication was attempted in all eight patients, but none had adequate control of their pain. Five of the eight initially had all suspensory sutures on the affected side removed between postoperative days 2 and 6. All had immediate resolution of the pain on awakening from anesthesia. Three patients had only the most lateral suture on the affected side removed in the office between days 1 and 7. Their pain did not resolve completely, so the remaining sutures on the affected side were removed later between postoperative days 2 and 21. Patients reported that their pain markedly improved after removal of all sutures on the affected side. The procedure to remove all the remaining sutures was performed transvaginally with general anesthesia.
Six (75%) of these eight patients had pain on the side opposite to the operating surgeon's dominant hand, which is not different from chance (95% confidence interval 35–97%). Patient characteristics did not differ between groups (Table 1), nor did the number of sutures placed on either side (P≥.45). None of the eight had recurrent POP after suture removal, with a median follow-up of 5 months (range 0.12–3.7 years). This recurrence rate is comparable with that for patients without suture removal (Table 1) who were followed-up for similar durations.
Several cadaveric studies have shown entrapment of S1 to S4 nerves are likely the cause of neuropathic pain after uterosacral ligament suspension attributable to their close proximity to the uterosacral ligaments.4–7 In our study, 1.6% of our patients undergoing uterosacral ligaments suspension had postoperative neuropathic pain. The postoperative pain was recognized by the patients after discontinuation of intravenous narcotics on postoperative day 1. Similar to the pain characteristics described by Flynn et al,2 our patients described the pain as sharp and stabbing, radiating from the buttocks into the posterior leg, and resulting in difficulty in sitting and walking.
In contrast to the study by Flynn et al2 in which four out of seven patients were treated with physical therapy or gabapentin (or both) and oral pain medication with eventual relief of symptoms, none of our patients received conservative treatment for more than 21 days before proceeding to suture removal. In addition, removing only the most lateral suture did not relieve the pain. The pain resolved only after all sutures were removed on the affected side. Fortunately, all eight affected patients had bilaterally uterosacral ligament suspension performed and removal of sutures was not associated with subsequent recurrent POP in the short-term. However, it is plausible that sutures placed in the more proximal or sacral portion of the uterosacral ligament may be more likely to result in sacral nerve entrapment and neuopathic pain. Also, if the sutures are placed higher or more ventrally or too deeply into the pelvic sidewall, then injury to the sacral nerves is more likely (Fig. 1).
Confounding factors that can contribute to the diagnosis of “neuropathic pain” after uterosacral ligament suspension are prolonged or improper lithotomy positioning, retroperitoneal hematomas, and preoperative chronic back pain especially with a history of radicular lower extremity pain. We believe that neuropathic pain that is adequately controlled with nonsteroidal antiinflammatory drugs, oral narcotics, and neuromodulators (eg, gabapentin) is unlikely to be secondary to suture entrapment. We would anticipate that such pain would resolve with continued nonsurgical management. However, we believe that neuropathic pain that arises from suture entrapment can be managed most effectively by removing all sutures on the affected side. In our experience, this results in rapid and complete resolution of the pain. Although not faced with this situation to date, if a unilateral uterosacral ligament suspension was performed and neuropathic pain occurred, then we would consider aggressive conservative management for 3 to 4 weeks. If there was no improvement, then we would consider returning to the operating room to remove all but the most lateral and distal uterosacral ligament suture. If the pain persisted without improvement over the next 1 to 2 weeks, then we would remove the remaining delayed absorbable suture, hopefully in the office. Obviously, if all uterosacral ligament suspension sutures are removed from a unilateral suspension, then recurrent POP is likely.
Baseline demographic information between those patients who had development of neuropathic pain and those who did not have development of neuropathic pain did not differ in age, BMI, preoperative POP quantification stage, parity, and the number of sutures placed on either side. The surgeon's dominant hand is an interesting factor we analyzed. Six (75%) of these eight patients had pain on the side opposite to the operating surgeon's dominant hand. However, the sample size is too small to be statistically significant.
In conclusion, prompt recognition of the postoperative nerve entrapment pain after uterosacral ligament suspension following discontinuation of intravenous narcotics on postoperative day 1 is critical. The patients described the pain as sharp and stabbing, radiating from the buttocks into the posterior leg, with resulting difficulty in sitting and walking. These symptoms may not respond to conservative medical management and delaying suture removal may contribute to persistent pain. In our cohort, the pain resolved after all sutures were removed on the affected side. The removal of sutures was not associated with recurrent POP in the short-term when uterosacral ligament suspensory sutures are placed bilaterally.
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