A comparison of ultrasound-guided high intensity focused ultrasound for the treatment of uterine fibroids in patients with an anteverted uterus and a retroverted uterus

Figures & data

Figure 1. Monitoring ultrasound images obtained from a 42-year-old patient with an anteverted uterus. The bladder was filled with 150 mL of normal saline. (A) Pre-HIFU ultrasound image showed a 4.3 × 4.0 × 3.8 cm uterine fibroid located at the anterior wall of the uterus (arrow). (B) Intra-HIFU ultrasound image showed a significant greyscale change area in the fibroids (arrow).

Figure 2. Monitoring ultrasound images obtained from a 39-year-old patient with a retroverted uterus. The bladder was filled with 300 mL of normal saline and lay between the uterus and abdominal wall. (A) Pre-HIFU ultrasound image showed a 4.1 × 3.9 × 3.8 cm of uterine fibroid located at the posterior wall of the uterus (arrow). (B) Intra-HIFU ultrasound image showed a significant greyscale change area in the fibroids (arrow).

Figure 3. Contrast-enhanced MR images obtained from a patient with an anteverted uterus. (A) A pre-procedure contrast-enhanced MR image showed a 8.0 × 6.8 × 6.7 cm fibroid located at the anterior wall of the uterus (arrow). (B) Contrast-enhanced MRI obtained 1 day after HIFU showed the non-perfused volume ratio was 91% (arrow).

Figure 4. Contrast-enhanced MR images obtained from a patient with a retroverted uterus. (A) A pre-procedure contrast-enhanced MR image showed a 4.1 × 3.8 × 3.7 cm fibroid located at the anterior wall of the uterus (arrow). (B) Contrast-enhanced MRI obtained 1 day after HIFU showed the non-perfused volume ratio was 100% (arrow).

Table 1. Baseline characteristics of 442 patients with a solitary uterine fibroid in either an anteverted uterus or a retroverted uterus. Data are numbers or mean value ± SD. No significant difference was observed between the two groups (P > 0.05).

Variables	With an anteverted uterus	With a retroverted uterus	P
No. of patients	221	221
Age (years)	41.5 ± 6.1	41.8 ± 5.8	0.107
MRI T2 signal intensity of fibroids: hyper/iso/hypointensity	0/0/221	0/0/221	1.000
Diameter of fibroids (cm)	3.8 ± 1.4	3.7 ± 1.3	0.155
Volume of uterus (cm^3)	33.7 ± 40.0	31.6 ± 35.2	0.128

Table 2. Treatment results of HIFU for patients with fibroids in an anteverted uterus or a retroverted uterus.

Variables	With anteverted uterus (N = 221)	With retroverted uterus (N = 221)	P
Sonication power* (W)	386.4 ± 26.6	379.4 ± 34.6	0.002
Sonication time (s)	520.1 ± 400.1	567.8 ± 370.5	0.572
Sonication time/h* (s/h)	520.8 ± 130.1	518.6 ± 123.0	0.204
Room time (min)	57.7 ± 37.3	64.2 ± 34.7	0.338
Total energy used* (J)	303208.9 ± 1005273.4	216403.7 ± 147476.7	0.019
Post-HIFU lesion volume (cm^3)	31.0 ± 38.1	29.1 ± 35.3	0.111
NPV (cm^3)	27.1 ± 33.9	25.1 ± 33.1	0.212
NPV ratio* (%)	87.7 ± 11.8	85.2 ± 18.7	0.00

NPV, non-perfused volume.

* Significant difference was observed between the two groups, P < 0.05.

Table 3. Incidence rates of adverse effects during the HIFU procedure. No significant difference was observed between the two groups (P > 0.05).

Variable	With an anteverted uterus (N = 221)	With a retroverted uterus (N = 221)	P
Transient leg pain (%)	12.2	14.0	0.331
Sciatic/buttock pain (%)	39.4	71.5	0
Lower abdominal pain (%)	68.8	57.9	0.012
Skin ‘hot’ sensation (%)	47.5	26.7	0
Groin pain (%)	2.7	12.7	0

Table 4. Incidence rates of adverse effects and complications immediately after HIFU treatment. Skin burn was observed in five (2.3%) patients with a retroverted uterus; Resection was performed in two of them. One patient with a retroverted uterus reported leg pain.

Variables	With an anteverted uterus (N = 221)	With a retroverted uterus (N = 221)	P
Fever (%)	0	0	1
Lower abdominal pain (%)	17.2	19.5	0.312
Sciatic/buttock pain* (%)	4.5	14.0	0.001
Leg pain/numbness (%)	0	0.5	0.5
Vaginal discharge (%)	5.0	7.2	0.214
Skin burn* (%)	0	2.3	0.031

* Significant difference was observed between the two groups, P < 0.05.