Uterine Artery Embolization of Uterine Leiomyomas: Predictive MRI Features of Volumetric Response

Bipedalism and the dawn of uterine fibroids

The high prevalence and burden of uterine fibroids in women raises questions about the origin of these benign growths. Here, we propose that fibroids should be understood in the context of human evolution, specifically the advent of bipedal locomotion in the hominin lineage. Over the ≥7 million years since our arboreal ancestors left their trees, skeletal adaptations ensued, affecting the pelvis, limbs, hands, and feet. By 3.2 million years ago, our ancestors were fully bipedal. A key evolutionary advantage of bipedalism was the freedom to use hands to carry and prepare food and create and use tools which, in turn, led to further evolutionary changes such as brain enlargement (encephalization), including a dramatic increase in the size of the neocortex. Pelvic realignment resulted in narrowing and transformation of the birth canal from a simple cylinder to a convoluted structure with misaligned pelvic inlet, mid-pelvis, and pelvic outlet planes. Neonatal head circumference has increased, greatly complicating parturition in early and modern humans, up to and including our own species. To overcome the so-called obstetric dilemma provoked by bipedal locomotion and encephalization, various compensatory adaptations have occurred affecting human neonatal development. These include adaptations limiting neonatal size, namely altricial birth (delivery of infants at an early neurodevelopmental stage, relative to other primates) and mid-gestation skeletal growth deceleration. Another key adaptation was hyperplasia of the myometrium, specifically the neomyometrium (the outer two-thirds of the myometrium, corresponding to 90% of the uterine musculature), allowing the uterus to more forcefully push the baby through the pelvis during a lengthy parturition. We propose that this hyperplasia of smooth muscle tissue set the stage for highly prevalent uterine fibroids. These fibroids are therefore a consequence of the obstetric dilemma and, ultimately, of the evolution of bipedalism in our hominin ancestors.

Outcome prediction for symptomatic patients with fibroids who underwent uterine artery embolization

PURPOSE

To predict the clinical outcome of symptomatic patients with uterine leiomyomas who underwent uterine artery embolization (UAE), based on clinical and radiological features.

METHODS

Patients with symptomatic uterine leiomyomas who underwent UAE from March 2010 to September 2019 were consecutively included in this retrospective study. Patients with persistent or recurrent symptoms and those who needed repeated UAE, myomectomy, or hysterectomy following the initial treatment were considered to have a poor outcome after UAE. The total and enhancing volume of the dominant leiomyoma in each location and uterine volume were obtained before and after UAE. Univariate and multivariate Cox proportional hazard analyses were used to evaluate the parameters that could predict poor outcome.

RESULTS

A total of 116 patients (mean age, 45 ± 5 years) were included. Forty-six patients (46/116, 39.7%) showed poor outcome. Cox regression analysis showed higher hazard of poor outcome for younger patients vs. older patients (HR: 0.92, p-value: 0.01), patients with adenomyosis vs. patients without adenomyosis (HR: 2.47, p-value < 0.01), patients with adenomyosis thickness > 2.5 cm before UAE vs. patients without adenomyosis (HR: 4.2, p-value < 0.01) and for patients with intramural fibroid enhancement volume > 440 cm3 compared to patients with no intramural fibroids (p-value: 0.06). Multivariate Cox regression analysis including age, the thickness of adenomyosis, and intramural leiomyoma volume of enhancement before UAE was chosen as the best model to predict the outcome.

CONCLUSIONS

Pretreatment clinical and MRI features could identify patients with a higher risk for poor outcome after UAE.

Uterine Artery Embolization for the Treatment of Symptomatic Uterine Fibroids of Different Sizes: A Single Center Experience

The present study aimed to evaluate the clinical and radiological 1-year outcomes of uterine artery embolization (UAE) performed in a selected population of women with symptomatic myomas and who do not wish to conceive. Between January 2004 and January 2018, a total of 62 patients with pre-menopausal status and with no wish to conceive in the future underwent UAE for the treatment of symptomatic fibroids. All the patients underwent magnetic resonance imaging (MRI) and/or transvaginal ultrasonography (TV-US) before and after the procedure at 1-year follow-up. Clinical and radiological parameters were recorded, stratifying the population into 3 groups according to the size of the dominant myoma (group 1: <50 mm; group 2: ≥50 and ≤80 mm; group 3: >80 mm). Mean fibroid diameter was significantly reduced (42.6% ± 21.6%) at 1-year follow-up, with excellent improvements in terms of both symptoms and quality of life. No significant difference was observed regarding baseline dimension and the number of myomas. No major complications were reported (2.5%). The present study confirms the safety and efficacy of UAE in the treatment of symptomatic fibroids in pre-menopausal women with no desire to conceive.

Intelligent Noise Reduction Algorithm to Evaluate the Correlation between Human Fat Deposits and Uterine Fibroids under Ultrasound Imaging

This study aimed to realize the automatic diagnosis of fatty degeneration of uterine fibroids. In this study, the traditional nonlocal means (NLM) algorithm was improved by changing the Euclidean distance and introducing a cosine function and applied to the ultrasonic imaging intelligent diagnosis of patients with fatty degeneration of uterine fibroids. Then, the noise reduction effect of the improved NLM algorithm was evaluated based on several indicators, such as peak signal-to-noise ratio (PSNR), mean square error (MSE), contrast-to-noise ratio (CNR), figure of merit (FOM), and structural similarity (SSIM). The accuracy, sensitivity, specificity, and F1 score were adopted to evaluate the improved NLM algorithm for diagnosing fatty degeneration of uterine fibroids, and the Perona-Malik (PM) algorithm and NLM algorithm were used for comparative analysis. The results showed that after the ultrasound images of patients with uterine fibroids were denoised using the improved NLM algorithm, the PSNR, MSE, CNR, FOM, and SSIM were obviously better than the same indicators of the image processed with the PM algorithm and the NLM algorithm, and the differences were statistically significant (P < 0.05). The diagnosis results of patients with fatty degeneration of uterine fibroids found that there was only one patient with missed diagnosis after the ultrasound image was processed with NLM algorithm, and there was no statistical difference between the improved NLM algorithm and the assisted diagnosis accuracy of the pathological examination results (P > 0.05). The average noise reduction time of the PM algorithm, NLM algorithm, and the improved NLM algorithm was 16.38 ± 4.33 s, 18.01 ± 5.14 s, and 23.81 ± 4.62 s, respectively. The diagnosis rate before improvement was 75.0%, the diagnosis accuracy rate for PM was 79.69%, and that after improvement was 85.94%. In summary, the improved NLM algorithm showed a good noise reduction effect on ultrasound images of patients with uterine fibroids, could improve the diagnosis accuracy of fatty degeneration of uterine fibroids, and could assist clinicians in the ultrasound imaging diagnosis of patients with uterine fibroids.