Critical reappraisal of anorectal function tests in patients with faecal incontinence who have failed conservative treatment

ACR Appropriateness Criteria® Pelvic Floor Dysfunction in Females

Pelvic floor disorders including pelvic organ prolapse (POP), urinary dysfunction, defecatory dysfunction, and complications after pelvic floor surgery are relatively common in the female population. Imaging tests are obtained when the initial clinical evaluation is thought to be incomplete or inconclusive or demonstrates findings that are discordant with patients' symptoms. An integrated imaging approach is optimal to evaluate the complex anatomy and dynamic functionality of the pelvic floor. Fluoroscopic cystocolpoproctography (CCP) and MR defecography are considered the initial imaging tests of choice for evaluation of POP. Fluoroscopic voiding cystourethrography is considered the initial imaging test for patients with urinary dysfunction. Fluoroscopic CCP and MR defecography are considered the initial imaging test for patients with defecatory dysfunction, whereas ultrasound pelvis transrectal is a complementary test in patients requiring evaluation for anal sphincter defects. MRI pelvis without and with intravenous contrast, MRI pelvis with dynamic maneuvers, and MR defecography are considered the initial imaging tests in patients with suspected complications of prior pelvic floor surgical repair. Transperineal ultrasound is emerging as an important imaging tool, in particular for screening of pelvic floor dysfunction and for evaluation of midurethral slings, vaginal mesh, and complications related to prior pelvic floor surgical repair. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The relationships between the results of contemporary tests of anorectal structure and sensorimotor function and the severity of fecal incontinence

BACKGROUND

Diagnostic investigations for fecal incontinence (FI) assess the structure and sensorimotor function of the anorectum. Investigations include anorectal manometry, anorectal sensory testing, pudendal nerve terminal motor latencies (PNTML), and endoanal sonography. The severity of FI and results of investigations are often discordant and the rate of symptom resolution following treatment remains <40%. High-resolution anorectal manometry (HRAM) and three-dimensional endoanal ultrasound (3D-US) have been introduced during the last decade. This study aims to assess the strength of relationships between contemporary investigation results and FI severity.

METHODS

Adults presenting for investigation of FI were assessed using the St Mark's FI severity score (SMIS), HRAM, anorectal sensory testing, PNTML, and 3D-US.

KEY RESULTS

246 patients were included. There were significant relationships between the SMIS and HRAM (resting pressure r_s = -0.23, 95% CI = (-0.34, -0.11), P < .001; squeeze pressure (r_s  = -0.26, 95% CI = (-0.37, -0.14), P < .001) and 3D-US (anterior EAS length r_s = -0.22, 95% CI = (-0.34, -0.09), P = .001). The relationships between SMIS and HRAM had a greater effect size in those with urge-predominant symptoms (resting pressure: r_s = -0.40, 95% CI = (-0.57, -0.20), P < .001, squeeze pressure: r_s = -0.34, 95% CI = (-0.52, -0.12), P = .003). Overall, the variance in SMIS accounted for by anorectal investigations was 8.6% (R² = 0.098, adjusted R² = 0.086, P < .001).

CONCLUSIONS AND INFERENCES

Anorectal investigations are not strong predictors of FI severity. These findings may reflect the multifactorial, heterogeneous pathophysiology of FI, the limitations of the SMIS and anorectal investigations, and contributing factors extrinsic to the anorectum.

Continuous vs stepwise anal acoustic reflectometry: An improved technique for physiological measurement of anal sphincter function?

BACKGROUND

Anal acoustic reflectometry (AAR) is a technique for measuring the physiological profile of the anal canal, primarily the internal anal sphincter. Evaluation of a new continuous method, recently developed for the urethra, would enable its future application for investigation of rectal reflexes.

METHODS

Patients aged 18 and over with fecal incontinence (FI) were included. Stepwise AAR parameters were compared with continuous opening pressure (Op, cmH₂ O), opening elastance (Oe, cmH₂ O/mm² ), closing pressure (Cp, cmH₂ O), closing elastance (Ce, cmH₂ O/mm² ), hysteresis (Hys, [%]), squeeze opening pressure (SqOp, cmH₂ O), and squeeze opening elastance (SqOe, cmH₂ O/mm² ). Vaizey incontinence and Manchester Health Questionnaire scores were also collected.

RESULTS

Thirty-two patients, 26 females were analyzed. Median age: 60 (range, 32-75). Median AAR parameters of Op (37.50 vs 35.15, P = .031), Oe (1.31 vs 0.84, P < .0001), Ce (1.11 vs 0.88, P < .0001), Hys (37.75 vs 19.04, P < .0001), and SqOe (1.27 vs 1.06, P = .005) were significantly higher with the continuous method. Cp (22.70 vs 27.22, P = .003) is lower and SqOp (96.87 vs 59.47, P = .71) not significantly different. The continuous technique had superior repeatability between cycles for all AAR parameters except Oe, which was equivalent and continuous SqOp had a stronger negative correlation with Vaizey score than stepwise (-0.46, P = .009 vs -0.37, P = .038).

CONCLUSIONS

The differences seen between the two techniques are likely to be related to the rate of stretch. The continuous technique appears to represent a more physiological measurement of anal sphincter function than the stepwise technique particularly in the assessment of voluntary squeeze function.

Relationships between the results of anorectal investigations and symptom severity in patients with faecal incontinence

PURPOSE

Anorectal dysfunction is the focus of diagnostic investigations for faecal incontinence. However, severity of incontinence and anorectal investigation results can be discordant. The aim of this study was to define the relationships between anorectal investigation results and incontinence severity to determine which measures, if any, were predictive of incontinence severity.

METHODS

Patients presenting for investigation of faecal incontinence completed a symptom questionnaire, anorectal manometry, rectal sensation, pudendal nerve terminal motor latency, and endoanal ultrasound. Bivariate analyses were conducted between the Jorge-Wexner score and investigation results. Subgroup analyses were performed for gender and symptom subtypes (urge, passive, mixed). A multiple regression analysis was performed.

RESULTS

Five hundred and thirty-eight patients were included. There were weak correlations between the Jorge-Wexner score and maximal squeeze pressure [r = - 0.24, 95%CI(- 0.31, - 0.16), p < 0.001], and resting pressure [r = - 0.18, (95%CI(- 0.26, - 0.10), p < 0.001]. In men only, there were significant associations between the Jorge-Wexner score and endoanal sonography [IAS defects: t(113) = - 2.26, p = 0.03, d = 0.58, 95%CI(- 4.38, - 0.29)] and rectal sensation (MTV: r_s = - 0.24, 95%CI(- 0.41, - 0.06), p = 0.01). No substantial differences were observed in the urge/passive/mixed subgroup analyses. Multiple regression analysis included three variables: age (β = 0.02, p = 0.17), maximal resting pressure (β = - 0.01, p = 0.28), and maximal squeeze pressure (β = - 0.01, p < 0.01). The variance in the Jorge-Wexner score accounted for by this model was < 10%, (R² = 0.07, p = < 0.01, adjusted R² = 0.06).

CONCLUSION

Anorectal investigations cannot predict the severity of faecal incontinence. This may be due to limitations of diagnostic modalities, the heterogeneity of anorectal dysfunction in these patients, or contributing factors which are extrinsic to the anorectum.

Increased yield pressure in the anal canal during sacral nerve stimulation: a pilot study with the functional lumen imaging probe

BACKGROUND

Sacral nerve stimulation (SNS) is a well-established treatment for fecal incontinence but its mode of action remains obscure. Anal sphincter function is usually evaluated with manometry but resistance to distension may be a more appropriate parameter than luminal pressure. The functional lumen imaging probe allows detailed description of distension properties of the anal canal. Our objective in this study was to characterize the impact of SNS on distension properties of the anal canal in patients with idiopathic fecal incontinence.

METHODS

We studied 10 women (median age 64 [44-79] years) with idiopathic fecal incontinence at baseline and during SNS. The luminal geometry of the anal canal was examined with the FLIP at rest and during squeeze and the distensibility of the anal canal was investigated during filling of the bag.

KEY RESULTS

All patients were successfully treated with SNS and the mean Wexner Incontinence Score was reduced from 14.9 ± 4 to 7.1 ± 4.8 (P<.001). The pressure required to open the narrowest point of the anal canal during distension (yield pressure) increased from 14.5 ± 12.2 mmHg at baseline to 20.5 ± 13.3 mmHg during SNS (P<.01). The pressure-strain elastic modulus increased non-significantly from 2.2 ± 0.5 to 2.9 ± 1.6 kPa, indicating increased stiffness of the anal canal.

CONCLUSION AND INFERENCES

The yield pressure and the resistance to distension increased in response to SNS for idiopathic fecal incontinence. This will inevitably increase the resistance to flow through the anal canal, which may contribute to the benefits of sacral nerve stimulation.

Rectal tone and compliance affected in patients with fecal incontinence after fistulotomy

AIM: To investigate the anal sphincter and rectal factors that may be involved in fecal incontinence that develops following fistulotomy (FIAF).

METHODS: Eleven patients with FIAF were compared with 11 patients with idiopathic fecal incontinence and with 11 asymptomatic healthy subjects (HS). All of the study participants underwent anorectal manometry and a barostat study (rectal sensitivity, tone, compliance and capacity). The mean time since surgery was 28 ± 26 mo. The postoperative continence score was 14 ± 2.5 (95%CI: 12.4-15.5, St Mark’s fecal incontinence grading system).

RESULTS: Compared with the HS, the FIAF patients showed increased rectal tone (42.63 ± 27.69 vs 103.5 ± 51.13, P = 0.002) and less rectal compliance (4.95 ± 3.43 vs 11.77 ± 6.9, P = 0.009). No significant differences were found between the FIAF patients and the HS with respect to the rectal capacity; thresholds for the non-noxious stimuli of first sensation, gas sensation and urge-to-defecate sensation or the noxious stimulus of pain; anal resting pressure or squeeze pressure; or the frequency or percentage of relaxation of the rectoanal inhibitory reflex. No significant differences were found between the FIAF patients and the patients with idiopathic fecal incontinence.

CONCLUSION: In patients with FIAF, normal motor anal sphincter function and rectal sensitivity are preserved, but rectal tone and compliance are impaired. The results suggest that FIAF is not due to alterations in rectal sensitivity and that the rectum is more involved than the anal sphincters in the genesis of FIAF.

ACR Appropriateness Criteria pelvic floor dysfunction

Pelvic floor dysfunction is a common and potentially complex condition. Imaging can complement physical examination by revealing clinically occult abnormalities and clarifying the nature of the pelvic floor defects present. Imaging can add value in preoperative management for patients with a complex clinical presentation, and in postoperative management of patients suspected to have recurrent pelvic floor dysfunction or a surgical complication. Imaging findings are only clinically relevant if the patient is symptomatic. Several imaging modalities have a potential role in evaluating patients; the choice of modality depends on the patient's symptoms, the clinical information desired, and the usefulness of the test. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions; they are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals, and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Pelvic floor muscle training for bowel dysfunction following colorectal cancer surgery: A systematic review

AIMS

To identify, evaluate and synthesize the evidence examining the effectiveness of pelvic floor muscle training (PFMT) on bowel dysfunction in patients who have undergone colorectal cancer surgery.

METHODS

Eight electronic databases (MEDLINE 1950-2014; CINAHL 1982-2014; EMBASE 1980-2014; Scopus 1823-2014; PsycINFO 1806-2014; Web of Science 1970-2014; Cochrane Library 2014; PEDro 1999-2014) were systematically searched in March 2014. Reference lists of identified articles were cross referenced and hand searched. Randomized controlled trials, cohort studies and case series were included if they investigated the effects of conservative treatments, including PFMT on bowel function in patients with colorectal cancer following surgery. Two reviewers independently assessed the risk of bias of studies using the Newcastle-Ottawa Scale (NOS).

RESULTS

Six prospective non-randomized studies and two retrospective studies were included. The mean (SD) NOS risk of bias score was 4.9 (1.2) out of 9; studies were limited by a lack of non-exposed cohort, lack of independent blinded assessment, heterogeneous treatment protocols, and lack of long-term follow-up. The majority of studies reported significant improvements in stool frequency, incontinence episodes, severity of fecal incontinence, and health-related quality of life (HRQoL) after PFMT. Meta-analysis was not possible due to lack of randomized controlled trials.

CONCLUSIONS

Pelvic floor muscle training for patients following surgery for colorectal cancer appears to be associated with improvements in bowel function and HRQoL. Results from non-randomized studies are promising but randomized controlled trials with sufficient power are needed to confirm the effectiveness of PFMT in this population.

[Anorectal diagnostics for proctological diseases]

The majority of proctological diseases can be defined by a structured evaluation of the symptoms and a physical examination. Magnetic resonance imaging (MRI) and anal endosonography can detect complex anal fistulas with a high accuracy but MRI should be preferred because of its objective visualization. Functional anorectal disorders are multifactorial and show morphological and functional irregularities in different compartments of the pelvic floor which is why MR defecography is now one of the most important methods in diagnostic algorithms. Interpreting the results of anal endosonography, anal manometry and neurophysiological testing is highly demanding because of large interindividual variability. Scores are used for objective measurement of symptom severity and quality of life. In clinical practice, well validated scores evaluated in large patient groups with predetermined circumstances are needed. Bringing together morphological results with scores based on subjective perception is required to optimize diagnostics and therapy evaluation in proctology.