Quantitative assessment of pelvic floor alterations following hysterectomy and bilateral adnexectomy using shear wave elastography and ultrasonography: a retrospective case-control study

Introduction

Hysterectomy remains one of the most prevalent gynecological surgeries performed worldwide (1). Although effective for treating various conditions, significant clinical evidence associates the procedure with long-term pelvic floor dysfunction (PFD), including urinary incontinence (UI) and pelvic organ prolapse (POP); the reported incidence of new-onset UI post-hysterectomy is substantial, ranging from 4% to 11%, alongside a measurable risk for future apical prolapse (1). PFD encompasses stress urinary incontinence (SUI), POP, fecal incontinence, pelvic pain, and sexual dysfunction, affecting 43% of postmenopausal women, involving multiple tissues (urethra, bladder, rectum) and anatomical structures (ligaments, muscles) (1). The lifetime prevalence of PFD is 50% in women aged ≥50 years, with 34% developing symptoms post-hysterectomy (1). It significantly impacts women’s daily activities and psychological well-being. Pelvic floor ultrasonography is currently a widely used tool to assess the female pelvic floor, providing insights into anatomical structures and positional changes of pelvic organs (2). Additionally, real-time shear wave elastography (SWE), a well-established tool in muscle research, has increasingly been applied to the study of pelvic floor muscles, with particular emphasis on the levator ani muscle (3,4). Prior studies have reported reduced pelvic floor function following abdominal, laparoscopic, and vaginal hysterectomy (5). The development of PFD after hysterectomy and bilateral adnexectomy is likely influenced by multiple factors. The DeLancey’s hammock hypothesis indicated that normal pelvic floor function is maintained by the coordinated action of various supporting structures, including muscles, ligaments, and fascia within the pelvis (5). Dysfunction in any one structure may be temporarily compensated for by others, but this compensation increases the risk of PFD over time.

Following hysterectomy and bilateral adnexectomy, distinct compartments of the pelvic floor are affected to varying degrees. In the anterior compartment, impaired fascial and ligamentous support to the urethra and bladder results in urethral hypermobility and bladder descent. This is reflected in postoperative changes such as bladder neck distance, bladder neck mobility, posterior bladder wall displacement, and altered urethral inclination angle. In the middle compartment, damage to the pubocervical fascia, uterosacral ligament, and associated structures reduces vaginal support, leading to increased vaginal mobility and a sensation of vaginal bulging.

The proposed mechanisms are multifactorial. The surgery inherently disrupts the structural integrity of the pelvic floor by transecting the cardinal-uterosacral ligament complex, a primary support structure, potentially altering vaginal axis and load distribution. Furthermore, dissection risks injury to the pelvic autonomic plexus, potentially denervating the bladder and urethra (6). When accompanied by bilateral oophorectomy, abrupt surgical menopause induces estrogen deficiency, which can impair urethral mucosal integrity and degrade collagen quality in pelvic tissues (6). However, these factors are often studied in isolation. A central hypothesis is that these insults converge to degrade the fundamental biomechanical properties of the pelvic floor—specifically, its passive elasticity and active contractile stiffness (7). These properties are essential for maintaining continence and structural support during increases in abdominal pressure (7).

However, there is limited research evaluating the post-operative condition of the pelvic floor, and there is a notable scarcity of objective, quantitative data on this topic (4). The purpose of this study was to utilize a combination of SWE and pelvic floor ultrasonography to quantitatively assess post-hysterectomy changes in levator hiatus area (LHA), tissue elasticity, and dynamic pelvic organ support in order to identify early risk factors for PFD and inform the timing of rehabilitation. We present this article in accordance with the STROCSS reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-618/rc).

Methods

Study participants

This is a retrospective case-control study. A total of 133 patients (as per sample size calculation result) from the Department of Obstetrics and Gynecologic Ultrasonography at The Fourth Hospital of Hebei Medical University (Shijiazhuang, China) between December 2021 and October 2022 were included. All participants underwent transabdominal hysterectomy and bilateral adnexectomy for the treatment of benign or malignant gynecological conditions. The case group was categorized into three groups based on the postoperative period: less than 1 year (41 cases), 1–3 years (45 cases), and more than 3 years (47 cases). The control group included 45 healthy participants without a history of hysterectomy or bilateral adnexectomy during the same period. Healthy cases were defined as those without PFD, and the information of the cases was obtained by asking the patient’s medical history and examining pelvic floor ultrasound. Body mass index (BMI; kg/m²): cases and controls were matched within ±1 kg/m² (range, 22–28).

The inclusion criteria were as follows: (I) absence of a history of chronic cough or long-term constipation; (II) no systemic neuromuscular diseases or internal/surgical comorbidities [surgical co-morbidity was defined as complications directly related to the index procedure, including postoperative adhesions confirmed via computed tomography (CT) imaging (n=5] or infections (n=4), and was excluded from analysis (n=9/133) to isolate the impact of primary surgery]; (III) no prior pelvic floor repair surgery; and (IV) hysterectomy not conducted due to POP. The exclusion criterion was pelvic mass ≥10 cm in diameter at diagnosis. The study was registered at the China Clinical Trial Register and ClinicalTrials.gov. This study was conducted with approval from the Ethics Committee of The Fourth Hospital of Hebei Medical University (No. 2024KY140). This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Informed consent was provided by all participants.

Equipment and methods

Equipment

Elastography was conducted using the Aixplorer (SuperSonic Imagine, Aix-en-Provence, France) ultrasound diagnostic system equipped with an SE12-3 transvaginal probe (frequency range, 3–12 MHz). Pelvic floor ultrasonography was conducted using the Resona 8Elite (Mindray, Shenzhen, China) ultrasound diagnostic system, which was fitted with a D8-21 three-dimensional (3D) volume probe (frequency range, 2–8 MHz). Bladder volume was measured using transabdominal ultrasound prior to each measurement (range, 150–200 mL). Residual urine was confirmed <50 mL via post-void residual test.

General characteristics

Data collected from participants included name, age, height, weight, delivery method, number of deliveries, and the presence of PFD conditions. Post-operative PFD symptoms were assessed using the International Consultation on Incontinence Questionnaire-Stress Urinary Incontinence (ICIQ-SUI; 0–21 scale) and Pelvic Organ Prolapse Quantification (POP-Q; 0–4 for each organ). Patients with severe symptoms (ICIQ-SUI ≥10 or POP-Q ≥2) were excluded. Delivery history included mode, duration, and postpartum pelvic floor rehabilitation. Neurological status was verified via Mini-Mental State Examination (MMSE) and Fugl-Meyer. SUI was defined as involuntary leakage of urine from the urethral opening during activities that increase intra-abdominal pressure, such as coughing. Two sonographers examined the participants randomly and in a blinded manner.

Pelvic floor ultrasonography examination

The pelvic floor ultrasonography examination was conducted in accordance with established guidelines, with all images documented for reference. A horizontal line extending through the inferior posterior border of the pubic symphysis and able to penetrate the anterior, middle, and posterior pelvic chambers was used as a reference point to assess pelvic organ descent.

During the resting state, the parameters measured included bladder neck distance, posterior bladder angle, urethral inclination angle, and rectal ampulla distance. Measurements performed during the Valsalva maneuver included bladder neck distance, posterior bladder angle, posterior bladder wall distance, urethral inclination angle, rectal ampulla distance, bladder neck mobility, and urethral rotation angle. The LHA was measured using 3D imaging following the Valsalva maneuver. To assess the integrity of the levator ani muscle, multiple parallel cross-sectional images of the levator ani muscle hiatus were captured during pelvic floor muscle contraction (Figure 1). All patients were examined under the guidance of sonographers, and relevant motor training was performed if necessary.

Figure 1 Measurement of pelvic floor ultrasonography parameters. (A) Measurement of pelvic floor parameters during the resting state. (B) Measurement of pelvic floor parameters during the Valsalva maneuver. (C) Measurement of LHA during the Valsalva maneuver: measurements included the anteroposterior diameter of the levator hiatus. (D) Observation of levator ani muscle integrity: the integrity of the levator ani muscle was observed using 3D TUI mode during the pelvic floor muscle contraction state. 3D, three-dimensional; A, ampulla; C, cervix; E, proximal end of the urethra; LHA, levator hiatus area; R, retrovesical wall; S, symphysis pubis; TUI, tomographic ultrasound imaging; U, orificium urethrae internum; V, lowest point of the retro vesical wall.

Elastography examination

Examination procedure: the patient was in lithotomy position with legs bent and feet apart, exposing the perineum. The participants performed corresponding actions under the guidance of ultrasound doctors. The probe was positioned on the perineum to acquire the midsagittal plane of the pelvic floor, enabling clear visualization of the anorectal angle. The probe was adjusted to form an angle of 40–60° when compared to the horizontal plane. With the anorectal angle centered in the image, the probe was rotated 90° to display the bilateral puborectalis (PR) muscles. These muscles were observed extending from the medial descending ramus of the pubis to the anorectal junction, forming a U shape around the posterior aspect of the rectoanal junction.

Measurements were conducted on the anterior, middle, and posterior regions of the bilateral PR during rest, pelvic floor muscle contraction, and the Valsalva maneuver. Following image stabilization, the real-time SWE mode was activated, with the sampling frame set to encompass the PR at a depth of 1.0–2.5 cm from the skin surface. The image was frozen when the color mapping uniformly filled more than two-thirds of the frame.

Elasticity values were determined using the Q-BOX quantitative analysis system (SuperSonic Imagine), employing a 5-mm diameter measurement box placed within the designated area. For each region, three measurements were obtained, and the mean elasticity value (Emean) was calculated. The mean of each measurement condition was then calculated (Figure 2).

Figure 2 Measurement of elastography parameters. (A) Measurement of elasticity values in the anterior and middle portions of the left PR during the resting state. (B) Measurement of elasticity values in the anterior and middle portions of the right PR during the resting state. (C) Measurement of elasticity values in the anterior and middle portions of the left PR during the pelvic floor muscle contraction state. (D) Measurement of elasticity values in the anterior and middle portions of the right PR during the pelvic floor muscle contraction state. (E) Measurement of elasticity values in the anterior and middle portions of the left PR during the Valsalva state. (F) Measurement of elasticity values in the anterior and middle portions of the right PR during the Valsalva state. PR, puborectalis.

Statistical analysis

Data analysis was conducted using the software SPSS 26.0 (IBM Corp., Armonk, NY, USA). Measurement data were presented as mean ± standard deviation (x¯±s). Comparisons between two groups were conducted using independent t-tests, whereas multiple group comparisons were analyzed using analysis of variance (ANOVA). For intra-group comparisons, paired sample t-tests were used. A P-value <0.05 was considered statistically significant.

Results

Comparison of general characteristics

No statistically significant differences were identified between the case groups and the control group regarding age, height, weight, and the number of deliveries (P>0.05) (Table 1).

Among the 133 patients in the case group, 116 patients underwent hysterectomy and bilateral adnexectomy for malignant conditions, whereas 17 procedures were conducted for benign conditions. Postoperative radiotherapy was administered to nine patients. A history of perineal laceration or episiotomy was documented in 34 patients. Among the case group, 51 patients presented with SUI, 7 with urinary difficulty, 11 with constipation, and 1 with fecal incontinence.

Pelvic floor ultrasonography

Two-dimensional (2D) ultrasonography identified 14 cases of anterior colpocele, one case of enterocele, and six cases of posterior colpocele.

3D ultrasonography indicated that 54 patients exhibited LHA exceeding 20 cm² during the Valsalva maneuver. The normal range for LHA is ≤25 cm² and 20 cm² can be used in Chinese people (5). Tomographic ultrasound imaging did not detect any complete or partial tears of the levator ani muscle.

Comparison of pelvic floor ultrasonography parameters

• Comparisons between the case groups and the control group indicated a decrease in the urethral inclination angle during the resting state and an increase during the Valsalva maneuver, with statistically significant differences (P<0.05). These findings suggest that surgery resulted in changes to the urethral inclination angle (Tables 2,3 ).

  Table 2

  Comparison of pelvic floor parameters during resting state between the case groups and the control group ($\overline{x}\pm s$</)

  
  

  Groups	Number of cases	Bladder neck distance (cm)	Posterior bladder angle (°)	Urethral inclination angle (°)	Rectal ampulla distance (cm)
  Control group	45	2.92±0.42	123.13±13.46	−23.18±13.49	1.43±0.53
  Less than 1 year group	41	2.81±0.38	121.37±16.04	−11.27±12.46*	1.19±0.40*
  1–3 years group	45	2.73±0.30*	117.53±13.25	−10.24±13.20*	1.39±0.44
  More than 3 years group	47	2.74±0.31*	116.28±16.68*	−6.72±12.58*	1.35±0.42

  *, P<0.05 compared with control group.

  Table 3

  Comparison of pelvic floor parameters during Valsalva state between the case groups and the control group ($\overline{x}\pm s$</)

  
  

  Parameters	Control group	Less than 1 year group	1–3 years group	More than 3 years group
  Number of cases	45	41	45	47
  Bladder neck distance (cm)	1.70±0.62	1.67±0.65	1.25±0.86*#	1.16±0.93*#
  Posterior bladder angle (°)	131.80±31.64	133.31±32.01	132.60±27.69	128.66±24.45
  Posterior bladder wall distance (cm)	1.74±0.69	1.69±0.76	1.33±0.97*	0.99±1.21*#
  Urethral inclination angle (°)	0.02±19.65	9.61±17.72*	17.93±19.66*	21.98±24.14*#
  Rectal ampulla distance (cm)	0.24±0.72	−0.01±0.90	0.08±0.75	0.11±0.74
  Urethral rotation angle (°)	22.05±13.85	24.60±15.38	28.96±19.22	27.74±16.03
  Bladder neck mobility (cm)	1.23±0.70	1.16±0.59	1.49±0.89	1.57±0.87*

  *, P<0.05 compared with control group; ^#, P<0.05 compared with <1 year group.
• Comparisons of the 1–3 years and more than 3 years post-surgery groups demonstrated statistically significant reductions in bladder neck distance and the distance from the posterior bladder wall to the reference line during both rest and the Valsalva maneuver when compared with the control group (P<0.05). These results indicate an increased downward displacement of the bladder position following surgery (Tables 2,3 ).
• Comparisons between the more than 3 years post-surgery group and the control group indicated a significant increase in bladder neck mobility during the Valsalva maneuver (P<0.05), indicating a decline in pelvic floor support capacity with longer postoperative durations (Table 3).
• All case groups exhibited a significant increase in the LHA during the Valsalva maneuver compared to the control group (P<0.05). This finding indicates a reduction in levator ani muscle support strength following surgery (Table 3).

Comparison of real-time SWE parameters

• No statistically significant differences in elasticity values were observed between the left and right PR muscles in the control group during rest, pelvic floor muscle contraction, and Valsalva states (P>0.05). Consequently, data from the left and right PR were combined into a single “PR” dataset for statistical analysis (Table 4).

  Table 4

  Comparison of elasticity values in the anterior, middle, and posterior portions of the left and right PR muscles during three states in the control group ($\overline{x}\pm s$</)

  
  

  Groups	State	Number of cases	Left (kPa)	Right (kPa)
  PR anterior	Rest	45	46.49±18.25	43.33±17.67
  	Anal contraction	45	95.62±25.14	98.26±27.48
  	Valsalva	45	63.72±26.26	69.93±27.30
  PR middle	Rest	45	50.77±16.42	52.59±19.62
  	Anal contraction	45	89.29±19.60	86.42±18.77
  	Valsalva	45	78.09±27.37	82.08±25.13
  PR posterior	Rest	45	43.49±18.51	43.64±18.65
  	Anal contraction	45	71.92±20.43	69.43±18.67
  	Valsalva	45	60.13±20.74	62.79±20.92

  All measurements were performed in supine position with 15° lateral tilt, as per the standardized protocol. PR, puborectalis.
• An analysis of elasticity values across the anterior, middle, and posterior regions of the PR in the control group during the three states indicated the following: during rest and Valsalva states, the middle region exhibited the highest values, followed by the anterior and posterior regions (middle > anterior > posterior). Therefore, elasticity values from the middle region were used for subsequent statistical analysis in these states. During the pelvic floor muscle contraction state, the anterior region revealed the highest values, followed by the middle and posterior regions (anterior > middle > posterior, P<0.05). Thus, elasticity values from the anterior region were used for subsequent analysis in this state (Table 5).

  Table 5

  Comparison of elasticity values in the anterior, middle, and posterior portions of the PR muscle during three states in the control group ($\overline{x}\pm s$</)

  
  

  Groups	PR (n)	Rest (kPa)	Anal contraction (kPa)	Valsalva (kPa)
  PR anterior	90	44.91±17.93	96.94±26.22	66.82±26.82
  PR middle	90	51.68±18.01*	87.86±19.13*	80.00±26.31*
  PR posterior	90	43.56±18.47	70.68±19.50#	61.46±20.76#

  *, P<0.05 compared with PR anterior and posterior; ^#, P<0.05 compared with PR anterior. PR, puborectalis.
• A comparison of PR elasticity values across the three states demonstrated the following trend: pelvic floor muscle contraction > Valsalva > rest, with statistically significant differences (P<0.05). These findings indicate that stiffness of the levator ani muscle varies under different conditions, and real-time SWE provides a reliable method for quantifying these variations (Table 6).

  Table 6

  Comparison of PR elasticity values during rest, anal contraction, and Valsalva states in the control group ($\overline{x}\pm s$</)

  
  

  Groups	PR (n)	PR elasticity value (kPa)
  Rest	90	51.68±18.01
  Anal contraction	90	96.94±26.22*
  Valsalva	90	80.08±26.20#

  *, P<0.05 compared with rest and Valsalva states; ^#, P<0.05 compared with rest and anal contraction states. PR, puborectalis.
• The case groups exhibited significantly lower PR elasticity values during the resting state compared to the control group (P<0.05). Additionally, the 1–3 year and more than 3 years post-surgery groups revealed significantly reduced PR elasticity values during the pelvic floor muscle contraction state compared to the control group (P<0.05), indicating a decrease in levator ani muscle elastic stiffness following surgery (Table 7).

  Table 7

  Comparison of PR elasticity values during three states between the case groups and the control group ($\overline{x}\pm s$</)

  
  

  Groups	PR (n)	Rest (kPa)	Anal contraction (kPa)	Valsalva (kPa)
  Control group	90	51.68±18.01	96.94±26.22	80.08±26.20
  Less than 1 year group	82	43.5±15.34*	88.94±30.31	72.65±22.17
  1–3 years group	90	44.4±15.97*	86.1±25.82*	80.55±26.97#
  More than 3 years group	94	46.8±14.17*	82.4±26.34*	78.98±24.02

  *, P<0.05 compared with control group; ^#, P<0.05 compared with <1 year group. PR, puborectalis.

Discussion

This study evaluated postoperative changes in several parameters, including bladder neck distance, urethral inclination angle during the Valsalva maneuver, posterior bladder wall distance, bladder neck mobility, LHA, and PR elasticity values during resting and pelvic floor muscle contraction states at different postoperative intervals (less than 1 year, 1–3 years, and more than 3 years). These findings indicate that patients undergoing hysterectomy and bilateral adnexectomy experience a decline in pelvic floor function compared to healthy participants without surgery, with notable impacts on specific pelvic floor structures.

In the posterior compartment, defects in the rectovaginal fascia permit the descent of peritoneal contents between the vagina and rectum (8). Although this study did not assess changes in vaginal position, the less pronounced rectal descent in the posterior compartment indicates that anterior compartment changes, particularly those affecting bladder position, are more substantial than those in the posterior compartment (9-12). Clinicians should consider implementing rehabilitation to address these potential contributing factors, thereby facilitating patient recovery. A comprehensive, individualized approach that analyzes these factors and develops corresponding interventions is essential to minimizing PFD risk.

This study highlights the utility of 2D and 3D pelvic floor ultrasonography in assessing pelvic floor morphology and functional support in patients following hysterectomy and bilateral adnexectomy. Among the parameters assessed, 2D ultrasonography demonstrated that the postoperative urethral inclination angle decreased during the resting state and increased during the Valsalva maneuver in all case groups compared to the control group. These findings reflect postoperative changes in urethral support and inclination. Furthermore, trends observed across the three groups indicate that hysterectomy and bilateral adnexectomy elevate the risk of developing PFD. However, some researchers noted that the urethral inclination angle has limited specificity and sensitivity as a diagnostic parameter for PFD, with significant variability in measurements across studies due to factors such as body positioning, the degree of bladder filling, and the intensity of the Valsalva maneuver (13,14). Thus, relying solely on the urethral inclination angle may not provide a reliable assessment of pelvic floor conditions in patients who have undergone hysterectomy and bilateral adnexectomy.

Postoperative changes in bladder neck distance, posterior bladder wall distance, and bladder neck mobility, as observed in this study, indicate an increased downward displacement of the bladder. The bladder neck distance, defined as the distance from the bladder neck to the horizontal line at the inferior posterior margin of the pubic symphysis, serves as an indicator of bladder position and the degree of descent, potentially correlating with postoperative anterior colpocele.

3D pelvic floor ultrasonography indicated that all case groups exhibited a larger LHA compared to the control group. LHA is recognized as a key parameter for evaluating PFD in pelvic floor ultrasonography. An increase in LHA has been strongly associated with the development of PFD, with larger LHA values correlating to greater dysfunction, as reported by Dietz et al. (15). The findings from this study indicate that hysterectomy and bilateral adnexectomy lead to a reduction in levator ani muscle support capacity, impairing its ability to resist pelvic organ descent caused by abdominal pressure and thereby increasing the risk of PFD.

In the more than 3 years post-surgery group, the average LHA reached 20.26 cm², exceeding the normal threshold, indicating that pelvic floor condition deteriorates over time. This aligns with previous magnetic resonance imaging studies, which reported increased anteroposterior and transverse diameters of the levator ani muscle hiatus as early as 3 months after hysterectomy, indicating early postoperative LHA enlargement (16). In this study, 42% of patients in the case group had an LHA greater than 20 cm², a relatively high proportion, emphasizing the importance of LHA as a key parameter in screening for PFD in patients following hysterectomy and bilateral adnexectomy.

This study used elastography to assess levator ani muscle stiffness by measuring the elasticity values of the PR muscle. PR elasticity measures translate directly to function. Good elasticity allows for support and recoil. Motor control is the nervous system’s tool to actively increase stiffness when needed. Voluntary contraction counteracts displacement by actively pulling structures into place, whereas the Valsalva maneuver merely pushes down. Finally, the loss of this crucial elastic property is a cornerstone in the development of UI. Statistical analysis demonstrated that differences in the stiffness of the pelvic floor muscles between the anterior, middle, and posterior sites at rest may be related to differences in the amount of gravity that each site needs to resist, with the mid-pubic rectus site potentially resisting more gravity than the other two due to the absence of an attachment point, and thus it may also have a low-frequency neural impulse input at rest that maintains a slight muscle tension, resulting in elevated stiffness.

Although the primary focus of pelvic floor biomechanics research has often been on the anterior attachment region of the PR—a critical site for understanding avulsion risk (17)—our findings suggest this single-site approach provides an incomplete picture of functional integrity. Our results demonstrate that the middle region of the levator ani complex exhibits the greatest stiffness, particularly during the Valsalva maneuver. This indicates that the middle region plays a dominant role in maintaining pelvic support under elevated intra-abdominal pressure, a primary function of the pelvic floor. Therefore, although anterior attachment integrity is undoubtedly important, exclusively measuring elasticity at the anterior point may overlook the significant biomechanical contribution of the middle region (18). Our finding of high middle-region stiffness suggests that even in the absence of a clinical avulsion, impaired function or elasticity in this central area could be a critical and previously underemphasized factor in the development of poor pelvic organ support and incontinence following hysterectomy. This expands the potential biomechanical markers for dysfunction beyond the status of the anterior attachment site.

The findings of this study suggest that PR elasticity measurements during real-time SWE should be obtained from different portions of the PR muscle depending on the state: the middle portion should be assessed during resting and Valsalva states, as it best reflects tissue stiffness, whereas the anterior portion should be measured during the pelvic floor muscle contraction state, when maximal muscle force is exerted.

A comparison of PR elasticity values across the three states revealed the following trend: pelvic floor muscle contraction > Valsalva > rest. This pattern aligns with principles of muscle biomechanics, as skeletal muscle length and tension vary with contraction and stretching. Studies measuring biceps brachii stiffness via real-time SWE demonstrated that elasticity values during active contraction were higher than those during passive contraction caused by elbow flexion, with both exceeding values recorded in the functional muscle position (19). Additional studies have reported that PR elasticity values during the Valsalva maneuver increased more than twofold compared to the resting state, reinforcing that real-time SWE is a reliable method for quantifying levator ani muscle stiffness (20).

The present study identified decreased PR elasticity values during both resting and pelvic floor muscle contraction states in the case group compared to the control group. These findings indicate a reduction in muscle tension during pelvic floor relaxation and contraction states following surgery, potentially reflecting diminished contractile function of the pelvic floor muscles. Previous studies into levator ani muscle function after hysterectomy have been limited and have primarily relied on assessments of muscle morphology to infer function. For example, some studies have assessed PR thickness and echogenicity using 2D ultrasound to assess levator ani muscle function, but these approaches lack quantitative precision (21).

This study introduced real-time SWE as a tool to quantify PR elastic stiffness, providing direct evidence of postoperative changes in muscle strength. Moreover, the findings demonstrate that levator ani muscle tension decreases in the early postoperative period, highlighting the importance of early pelvic floor strength assessments and rehabilitation treatments soon after hysterectomy. Real-time SWE has been shown to be an effective and sensitive method for evaluating the condition of the levator ani muscle. Our findings demonstrate that SWE can identify patients with biomechanical deficits, such as PR elasticity loss, that are strongly correlated with a high risk of developing incontinence. Therefore, we propose that SWE should be used not as a screening tool for all, but as a risk-stratification tool in post-operative care. For patients who are asymptomatic but found to have significantly reduced elasticity on post-operative SWE, early guided rehabilitation should be considered as a proactive measure to mitigate their high risk of future PFD. This approach reserves intervention for a high-risk subgroup rather than advocating for universal prevention.

The study further demonstrated that changes in PR elasticity, bladder neck position, bladder neck mobility, and LHA were more pronounced in the more than 3 years post-surgery group compared to other post-surgery groups. Certain parameters exhibited significant changes solely in this group, indicating that levator ani muscle tension, pelvic organ position, and pelvic floor support strength progressively deteriorate with increasing postoperative duration. Moreover, these structural and functional changes appear to occur after a latency period. These findings are consistent with prior research, such as a study involving 566 participants, which reported a progressive increase in PFD incidence over 5–14 years following total hysterectomy (22). This represents a direction for future research.

Regarding the limitations of our study, age, delivery history, comorbidities, cancer treatments, and pre-existing pelvic floor symptoms were not evaluated as confounding variables. Another limitation is that in the case group, both malignant patients and benign patients were included, and given that surgery for malignancy is more extensive than surgery for benign conditions, this could cause data issues, and it should be further categorized into sub-groups in future studies. In this study, due to case number limitation, this was not evaluated further. Furthermore, general measurement variability in pelvic floor ultrasound may also have influenced the results (23). In future studies, we plan to incorporate more detailed anatomical considerations—such as pelvic venous anatomy and plexus variations—to achieve more accurate and comprehensive findings (24).

Conclusions

The combined application of real-time SWE and pelvic floor ultrasonography quantitatively revealed that hysterectomy with bilateral adnexectomy is associated with significant long-term alterations in pelvic floor structure and function. Our findings demonstrate a progressive decline in PR elasticity and increased bladder neck mobility over time, suggesting a potential biomechanical basis for the development of PFD post-surgery. This comprehensive assessment strategy not only provides objective biomarkers for evaluating surgical outcomes but also holds promise for identifying at-risk patients who may benefit from targeted pelvic floor rehabilitation, thereby informing personalized postoperative management strategies.

Acknowledgments

We would like to acknowledge the hard and dedicated work of all the staff that implemented the intervention and evaluation components of the study.

Footnote

Reporting Checklist: The authors have completed the STROCSS reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-618/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-618/dss

Funding: This study was supported by Medical Science Research Project of Hebei (Grant No. 20250755).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-618/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted with approval from the Ethics Committee of The Fourth Hospital of Hebei Medical University (No. 2024KY140). This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from all participants.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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