Comparison of diagnostic criteria for significant anal sphincter defects between endoanal and transperineal ultrasound

OBJECTIVE

To evaluate the agreement between three-dimensional endoanal ultrasound (EAUS) and four-dimensional transperineal ultrasound (TPUS) in measuring anal sphincter defect angle.

METHODS

This was a secondary analysis of the PERINEAL study, which evaluated the effect of perineal wound infection on anal sphincter integrity. Women were reviewed once a week, until their perineal wound had healed or for up to a maximum of 16 weeks. At each visit, both EAUS and TPUS (the latter at rest and on maximum pelvic floor muscle contraction (PFMC)) were performed to evaluate the presence of external (EAS) and internal (IAS) anal sphincter defect and measure the defect size. The largest angle size of a defect at the same sphincter level was analyzed. A defect was deemed significant if it was > 30°. Kappa coefficient (κ), intraclass correlation coefficient and standard error of measurement (SEM) were calculated, using EAUS as the reference standard.

RESULTS

In 73 women scanned at weekly intervals, a total of 250 EAUS and 250 TPUS scans were performed. An EAS defect was found in 55 (22.0%) EAUS images and 47 (18.8%) TPUS images. An IAS defect was found in 26 (10.4%) images on both modalities. There was excellent agreement (κ = 0.87) between TPUS and EAUS in diagnosing the presence of an EAS defect and perfect agreement (κ = 1.00) in diagnosing the presence of an IAS defect. TPUS performed at rest had poor and moderate agreement with EAUS in measuring EAS and IAS defect size, respectively, with respective SEMs of ± 16.1° and ± 27.9°. TPUS performed during maximum PFMC had poor and moderate agreement with EAUS in measuring EAS and IAS defect size, respectively, with respective SEMs of ± 16.5° and ± 26.4°. Based on the SEMs, if the diagnostic cut-off of 30° for defect size on TPUS was used, an incorrect diagnosis of significant EAS defect could occur in approximately 9-36% of women and an incorrect diagnosis of a significant IAS defect could occur in approximately 4-15% of women, using EAUS as the reference.

CONCLUSIONS

This is the first study to compare directly anal sphincter defect angle measurements obtained on EAUS and TPUS. A cut-off angle of 30° should not be used for the diagnosis of a significant residual anal sphincter defect during TPUS examination. Further research is required to determine the optimal defect cut-off angle for TPUS. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A prospective trial of the THD SphinKeeper® for faecal incontinence

AIM

THD SphinKeeper® is an emerging surgical technique for faecal incontinence (FI). The safety, indications and efficacy of the procedure are still being investigated. The aim of this study is to present the first experience of SphinKeeper® in Australia.

METHOD

This was a prospective single-centre observational study of patients undergoing SphinKeeper® implantation between February 2018 and September 2019. Baseline demographics, intraoperative and postoperative complications, Cleveland Clinic Faecal Incontinence Score, St Mark's Incontinence Score, Faecal Incontinence Quality of Life score (FIQOL), anorectal manometry and endo-anal ultrasound were assessed preoperatively and 3 and 12 months after implantation.

RESULTS

Thirteen patients (2 male, 11 female) underwent implantation during the study period. Anal sphincter defects were present in 13 (76.9%) patients [external anal sphincter (EAS) defect, 2 (15.4%); internal anal sphincter (IAS) defect 4 (30.8%); EAS + IAS defect, 4 (30.8%)]. Median follow-up was 32 months (range 18-37 months). There were four complications: one intraoperative (rectal perforation) and three postoperative (one implant extrusion, two implants that required removal due to malposition). At 12 months, an average of 9/10 implants remained ideally placed in each patient. THD SphinKeeper® insertion was associated with an improvement in coping/behaviour as measured using FIQOL (p = 0.047). However, the procedure did not improve FI scores or anorectal manometry parameters.

CONCLUSION

In this study, SphinKeeper® marginally improved symptoms of FI but there was no significant impact on anorectal manometric measurements. Larger-scale studies are needed to determine the patient cohort most likely to benefit from this procedure.

Is pelvic floor muscle contractility an important factor in anal incontinence?

OBJECTIVE

Pelvic floor muscle contractility (PFMC) may contribute to anal continence. The aim of this study was to assess the association between clinical and sonographic measures of PFMC and anal incontinence (AI) symptoms, after controlling for anal sphincter and levator ani muscle (LAM) trauma.

METHODS

This was a retrospective study of 1383 women assessed at a tertiary center between 2013 and 2016. All patients underwent an interview, including the St Mark's incontinence score (SMIS) in those who reported AI symptoms, a clinical examination, including assessment of PFMC using the modified Oxford scale (MOS), and four-dimensional translabial ultrasound (TLUS). Sonographic measures of PFMC, i.e. cranioventral shift of the bladder neck (BN) and reduction of anteroposterior (AP) diameter of the levator hiatus, were measured offline using ultrasound volumes obtained at rest and on maximum pelvic floor contraction. The reviewer was blinded to all clinical data.

RESULTS

Of the 1383 patients assessed during the study period, seven were excluded due to missing imaging data, leaving 1376 for analysis. Mean age of the participating women was 55 years and mean body mass index was 29 kg/m² . AI was reported by 221 (16.1%) women, with a mean SMIS of 11.8. Mean MOS grade was 2.3. On TLUS, mean BN cranioventral shift was 5.9 mm and mean AP diameter reduction was 8.1 mm. LAM avulsion and significant external anal sphincter (EAS) defect were diagnosed in 24.8% and 8.7% patients, respectively. On univariate analysis, sonographic measures of PFMC were not associated with AI. Lower MOS grade was associated with symptoms of AI; however, statistical significance was lost on multivariate analysis.

CONCLUSION

Clinical and sonographic measures of PFMC were not significantly associated with AI symptoms after controlling for EAS and LAM trauma. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Is levator trauma an independent risk factor for anal incontinence?

AIM

To determine the role of levator ani trauma in anal incontinence (AI), whilst controlling for anal sphincter injury.

METHODS

The records of 1273 patients who had attended a tertiary urogynaecology unit between 1st of January to 31st December 2016 were reviewed. AI was assessed using St Mark's score and visual analogue scale (VAS). Levator muscle and anal sphincter trauma were examined by translabial ultrasound using tomographic imaging, with archived data sets investigated blinded against all clinical data. A complete avulsion was diagnosed if at least three central tomographic slices showed an abnormal muscle insertion, rated separately for each side. A significant anal sphincter defect was diagnosed if at least four out of six slices showed a defect of ≥ 30°.

RESULTS

Avulsion was associated with St Mark's score (P = 0.005) and VAS bother of AI (P = 0.022) both on univariate analysis and when controlling for external anal sphincter (EAS) trauma on translabial imaging, forceps, body mass index (BMI) and age (P = 0.011 and P = 0.04, respectively). AI expressed as a binary variable was significantly associated with avulsion on univariate analysis (P = 0.011), although the association became nonsignificant after controlling for anal sphincter trauma, age, BMI and forceps delivery (P = 0.084).

CONCLUSION

In this retrospective observational study, we found a weak association between levator ani avulsion and measures of AI, which largely remained significant when controlling for anal sphincter trauma. However, given the large data set, any clinical effect of levator trauma on AI is likely to be minor.

Faecal incontinence in patients with a sphincter defect: comparison of sphincteroplasty and sacral nerve stimulation

AIM

Sphincteroplasty (SP) is used to treat faecal incontinence (FI) in patients with a sphincter defect. Although sacral nerve stimulation (SNS) is used in patients, its outcome in patients with a sphincter defect has not been definitively evaluated. We compared the results of SP and SNS for FI associated with a sphincter defect.

METHOD

Patients treated by SNS or SP for FI with an associated sphincter defect were retrospectively identified from an Institutional Review Board approved prospective database. Patients with ultrasound evidence of a sphincter defect were matched by age, gender and body mass index. The main outcome measure was change in the Cleveland Clinic Florida Faecal Incontinence Score (CCF-FIS).

RESULTS

Twenty-six female patients with a sphincter defect were included in the study. The 13 patients in each group were similar for age, body mass index, initial CCF-FIS and the duration of follow-up. No differences were observed in parity (P = 1.00), the rate of concomitant urinary incontinence (P = 0.62) or early postoperative complications. Within-group analysis showed a significant reduction of the CCF-FIS among patients having SNS (15.9-8.4; P = 0.003) but not SP (16.9-12.9; P = 0.078). There was a trend towards a more significant improvement in CCF-FIS in the SNS than in the SP group (post-treatment CCF-FIS 8.4 vs 12.9, P = 0.06). Net improvement in CCF-FIS was not significantly different between the groups (P = 0.06).

CONCLUSION

Significant improvement in CCF-FIS was observed in patients treated with SNS but not SP patients. A trend towards better results was seen with SNS.