HIFU treatment for fibroids does not increase risk for pelvic adhesions

High-intensity focused ultrasound (HIFU) for the treatment of uterine fibroids does not significantly increase the risk of pelvic adhesions, according to the results of a small retrospective Chinese study in the International Journal of Hyperthermia.

A total of 2,619 patients with uterine fibroids underwent either hysterectomy, myomectomy or cesarean section at Suining Central Hospital of Sichuan province in China between October 2010 and March 2020. But 810 of these patients were excluded from the analysis because of a documented history of pelvic infections, endometriosis, prior abdominopelvic surgery or gynecological malignancies.¹

Among the remaining 1,809 patients with uterine fibroids, 96 patients had prior HIFU treatment (HIFU group), whereas 1,713 patients had neither HIFU nor surgical treatment (control group).

In the HIFU group, pelvic adhesions were detected in 43.75% of patients (n = 42), compared to 36.14% of patients (n = 619) in the control group. Among those in the HIFU group who developed pelvic adhesions, 26 had multiple uterine fibroids and 16 had a solitary fibroid. The average size of the fibroids was 4.21 cm.

Among the 54 patients in the HIFU group who did not have pelvic adhesions, 24 had multiple uterine fibroids and 30 had a solitary fibroid. The average size of the fibroids was 3.84 cm.

The study noted prevalence of adhesions between the HIFU group and the control group for the following sites: uterus (19.8 vs. 18.6%), ovaries (3.1% vs. 1.6%), fallopian tubes (4.2 vs. 6.9%), pouch of Douglas (5.2% vs. 2.4%), bladder (4.2% vs. 2.6%), and bowel (7.3% vs. 4.0%).

No statistically significant difference was observed in the incidence of adhesions between the two groups (P = 0.132). In addition, there was no significant difference observed between the two groups in location of pelvic adhesions or severity of adhesions (P > 0.05).

However, in the HIFU group, patients with more than two abortions and lesions > 4 cm were more likely to have pelvic adhesions (P < .05). Furthermore, in the HIFU group, the total energy used for fibroid ablation, treatment and ultrasound times and energy-efficient factor were significantly higher in patients with adhesions than without adhesions.

Conversely, in the HIFU group, the nonperfused volume ratio was significantly lower than in patients without pelvic adhesions. “Therefore, the risk of pelvic adhesions after HIFU seems related to the delivery ultrasound energy,” wrote the authors.

The prevalence of adhesions in patients without documented previous surgery, pelvic infections, or endometriosis was 36.54% in the study cohort (661/1809).

“The impact of pelvic adhesions on patients has been a concern for all surgeons,” wrote the authors. “Pelvic adhesions can lead to chronic pelvic pain, infertility, intestinal obstruction, and might increase the risk of postoperative chemotherapy failure.”

Nonetheless, a recent survey of adhesion awareness among gynecological surgeons in European hospitals surmised that anti-adhesion agents were too expensive to be employed routinely in gynecological surgery.

“Over the last decades, HIFU has been widely used to treat different types of solid tumors, especially uterine fibroids,” wrote the authors. “As a noninvasive treatment, this technique can be used precisely to ablate tumors, thus decreasing the risk of pelvic adhesions in clinical practice.”

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Reference

1. Liu X, Dong X, Yan M, Huang G, He J. High-intensity focused ultrasound (HIFU) for the treatment of uterine fibroids: does HIFU significantly increase the risk of pelvic adhesions? Int J Hyperthermia. 2020;37(1):1027-1032. doi: 10.1080/02656736.2020.1811903