MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position

Impact of Preoperative Three-Dimensional Endoanal Ultrasound on the Surgical Outcome of Primary Fistula in Ano. A Multi-Center Observational Study of 253 Patients

PURPOSE

To evaluate the impact of preoperative three-dimensional endoanal ultrasound (3D-EAUS) on the clinical outcome of anal fistula surgery.

METHODS

The research consisted of multi-center retrospective case-control study including 253 consecutive adult patients undergoing surgery for confirmed or suspected primary fistula in ano who had undergone preoperative 3D-EAUS evaluation between January 2011 and January 2021. Main outcome measures were the concordance (K value) between ultrasound results and surgery in the identification of fistulas internal openings, primary tracts and secondary extensions and the 6 and 12 months success rate in patients with concordant and discordant findings.

RESULTS

A good agreement in the identification of the main fistulas characteristics between ultrasound results and operative findings was found. A significant difference (P < .0001; Fisher's exact test) in the success rate was found between patients with concordant and discordant ultrasound results and operative findings in identification or location of internal opening. Particularly, all the 11 (4.8%) patients with discordant results experimented a failure of the surgical procedure at 6 months follow-up. At re-operation, the shift from discordant to concordant results was associated with an 81.8% 12 months success-rate.

CONCLUSION

The three-dimensional endoanal ultrasound preoperative evaluation may have a relevant impact on the outcome of a defined group of patients undergoing surgery for anal fistula, since the careful evaluation of ultrasound results could simplify the internal orifice intra-operative detection and improve the success rate.

The Relevance of the Excessive Perineal Descent in the Obstructed Defecation Syndrome: A Prospective Study of 141 Patients

BACKGROUND

Despite the widely accepted association between excessive straining and perineal descent, the clinical significance of perineal descent in patients with obstructed defecation syndrome is still unclear.

OBJECTIVE

This study aimed to evaluate the prevalence of pathological perineal descent in patients with obstructed defecation syndrome and the impact of perineal descent on symptoms severity.

DESIGN

This was a prospective multicenter uncontrolled study.

SETTINGS

The study involved 3 hospital pelvic-care centers and was conducted from January 2018 to January 2022.

PATIENTS

The study included 141 consecutive adult patients with an obstructed defecation syndrome score of 9 or more and no evidence of organic GI pathology. All the patients underwent dynamic pelvic MRI and, in case of suspected paradoxical puborectalis contraction, anal manometry.

MAIN OUTCOME MEASURES

Main outcome measures were the prevalence of excessive perineal descent and the correlation between perineal descent and obstructed defecation syndrome score.

RESULTS

One hundred twenty-eight patients (90.7%) completed magnetic resonance examination and were included in the analysis. Of these, 18 patients (14.1%) had a physiological perineal descent and 110 (85.9%) had an excessive perineal descent. Excessive perineal descent was found in 46.1% of patients (12/26) with MRI signs of paradoxical puborectalis contraction and in 96% of patients (98/102) with normal puborectalis relaxation. In this latter group of patients, a good correlation between obstructed defecation syndrome score and maximum perineal descent during straining was found (Spearman r test: 0.68; p < 0.0001).

LIMITATIONS

The study was limited by the small sample size and by the strong selection of the study population.

CONCLUSIONS

Excessive perineal descent is a common finding in patients with obstructed defecation syndrome and high symptoms score, occurring almost consistently in patients without paradoxical puborectalis contraction. In these patients, the maximum perineal descent seems to be well correlated with symptoms severity. See Video Abstract at http://links.lww.com/DCR/C135 .

LA RELEVANCIA DEL DESCENSO PERINEAL EXCESIVO EN EL SNDROME DE DEFECACIN OBSTRUIDA UN ESTUDIO PROSPECTIVO DE PACIENTES

ANTECEDENTES:A pesar de la asociación ampliamente aceptada entre el esfuerzo excesivo y el descenso perineal, la importancia clínica del descenso perineal en pacientes con síndrome de defecación obstruida aún no está clara.OBJETIVO:Evaluar la prevalencia del descenso perineal patológico en pacientes con síndrome de defecación obstruida y el impacto del descenso perineal en la severidad de los síntomas.DISEÑO:Este fue un estudio prospectivo multicéntrico no controladoENTORNO CLINICO:El estudio involucró a tres centros hospitalarios de atención pélvica y se llevó a cabo entre enero de 2018 y enero de 2022.PACIENTES:El estudio incluyó a 141 pacientes adultos consecutivos con puntuación del síndrome de defecación obstruida ≥ 9 y sin evidencia de patología gastrointestinal orgánica. A todas las pacientes se les realizó resonancia magnética pélvica dinámica y, en caso de sospecha de contracción puborrectal paradójica, manometría anal.PRINCIPALES MEDIDAS DE RESULTADO:Las principales medidas de resultado fueron la prevalencia del descenso perineal excesivo y la correlación entre el descenso perineal y la puntuación del síndrome de defecación obstruida.RESULTADOS:Ciento veintiocho (90,7%) pacientes completaron el examen de resonancia magnética y fueron incluidos en el análisis. De estos, 18 (14,1%) presentaron descenso perineal fisiológico y 110 (85,9%) descenso perineal excesivo. Se encontró descenso perineal excesivo en el 46,1% (12/26) de los pacientes con signos de contracción puborrectal paradójica en la resonancia magnética y en el 96% (98/102) de los pacientes con relajación puborrectal normal. En estos últimos pacientes se encontró una buena correlación entre la puntuación del síndrome de defecación obstruida y el descenso perineal máximo durante el esfuerzo (prueba r de Spearman: 0,68; p < 0,0001).LIMITACIONES:El estudio estuvo limitado por el pequeño tamaño de la muestra y por la fuerte selección de la población de estudio.CONCLUSIONES:El descenso perineal excesivo es un hallazgo común en pacientes con síndrome de defecación obstruida y alto puntaje de síntomas, ocurriendo casi constantemente en pacientes sin contracción puborrectal paradójica. En estos últimos pacientes el descenso perineal máximo parece estar bien correlacionado con la severidad de los síntomas. Consulte Video Resumen en http://links.lww.com/DCRC135 . (Traducción- Dr. Francisco M. Abarca-Rendon ).

Static and Dynamic Magnetic Resonance Imaging in Female Pelvic Floor Dysfunction: Correlation With Pelvic Organ Prolapse Quantification

BACKGROUND

Pelvic organ prolapse (POP) is clinically assessed and staged commonly by the pelvic organ prolapse quantification (POP-Q) system. Dynamic magnetic resonance imaging (MRI) of the pelvic floor is an emerging modality for anatomical and functional assessment of the pelvic floor and staging of POP. The purpose of this study was to correlate the dynamic MRI findings with POP-Q examination for the staging of POP in each pelvic compartment by comparing various anatomic points.

METHODS

A prospective observational study of the comparative cross-sectional design was conducted among patients who underwent MRI of the pelvic floor and POP-Q at our institute. A total of 50 patients were included. Anatomical landmarks in the three compartments were analyzed in relation to standard reference lines on dynamic MRI and compared with POP-Q measurements.

RESULTS

Most of our patients had multicompartment disease (70%). When compared to POP-Q, MRI has a strong correlation for quantification of anterior (0.723) and middle (0.525) compartments and a weak correlation (0.232) for posterior compartment prolapse.

CONCLUSION

POP-Q examination is based on the various points within the vaginal canal, and all the points do not represent a true anatomic landmark. MRI, on the other hand, is based on a true anatomical plane and gives detailed information about various structures in all three compartments. Thus, MRI also helps bridge the gap between various referring specialties in treating pelvic floor disorders.

Magnetic Resonance Imaging of the Gastrointestinal Tract: Current Role, Recent Advancements and Future Prospectives

This review focuses on the role of magnetic resonance imaging (MRI) in the evaluation of the gastrointestinal tract (GI MRI), analyzing the major technical advances achieved in this field, such as diffusion-weighted imaging, molecular imaging, motility studies, and artificial intelligence. Today, MRI performed with the more advanced imaging techniques allows accurate assessment of many bowel diseases, particularly inflammatory bowel disease and rectal cancer; in most of these diseases, MRI is invaluable for diagnosis, staging, and disease monitoring under treatment. Several MRI parameters are currently considered activity biomarkers for inflammation and neoplastic disease. Furthermore, in younger patients with acute or chronic GI disease, MRI can be safely used for short-term follow-up studies in many critical clinical situations because it is radiation-free. MRI assessment of functional gastro-esophageal and small bowel disorders is still in its infancy but very promising, while it is well established and widely used for dynamic assessment of anorectal and pelvic floor dysfunction; MRI motility biomarkers have also been described. There are still some limitations to GI MRI related to high cost and limited accessibility. However, technical advances are expected, such as faster sequences, more specific intestinal contrast agents, AI analysis of MRI data, and possibly increased accessibility to GI MRI studies. Clinical interest in the evaluation of bowel disease using MRI is already very high, but is expected to increase significantly in the coming years.

Current diagnostic tools and treatment modalities for rectal prolapse

Rectal prolapse is a circumferential, full-thickness protrusion of the rectum through the anus. It is a rare condition, and only affects 0.5% of the general population. Multiple treatment modalities have been described, which have changed significantly over time. Particularly in the last decade, laparoscopic and robotic surgical approaches with different mobilization techniques, combined with medical therapies, have been widely implemented. Because patients have presented with a wide range of complaints (ranging from abdominal discomfort to incomplete bowel evacuation, mucus discharge, constipation, diarrhea, and fecal incontinence), understanding the extent of complaints and ruling out differential diagnoses are essential for choosing a tailored surgical procedure. It is crucial to assess these additional symptoms and their severities using preoperative scoring systems. Additionally, radiological and physiological evaluations may explain some vague symptoms and reveal concomitant pelvic disorders. However, there is no consensus on or standardization of the optimal extent of dissection, type of procedure, and materials used for rectal fixation; this makes providing maximum benefits to patients with minimal complications difficult. Even recent publications and systematic reviews have not recommended the most appropriate treatment options. This review explains the appropriate diagnostic tools for different conditions and summarizes the current treatment approaches based on existing literature and expert opinions.

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.

Mini-review: Modern Concept of Pelvic Organ Prolapse

Symptomatic pelvic organ prolapse (POP) has been increasing in recent years for both developed and developing countries. By 2050, as the adult population grows, the number of women with symptomatic POP will increase by 46%. Due to the increasing number of complications after surgery among women with POP, the current understanding of treatment has become extremely important for researchers and practitioners. There are many novel conservative and surgical treatment approaches under investigation. However, some primary surgical treatments show an approximate 30–50% risk of repeated pelvic floor reconstruction. Therefore, the review aims to summarize several conservative treatment options and identify critical areas of need for future research.

Consensus Definitions and Interpretation Templates for Magnetic Resonance Imaging of Defecatory Pelvic Floor Disorders: Proceedings of the Consensus Meeting of the Pelvic Floor Disorders Consortium of the American Society of Colon and Rectal Surgeons, the Society of Abdominal Radiology, the International Continence Society, the American Urogynecologic Society, the International Urogynecological Association, and the Society of Gynecologic Surgeons

The Pelvic Floor Disorders Consortium (PFDC) is a multidisciplinary organization of colorectal surgeons, urogynecologists, urologists, gynecologists, gastroenterologists, radiologists, physiotherapists, and other advanced care practitioners. Specialists from these fields are all dedicated to the diagnosis and management of patients with pelvic floor conditions, but they approach, evaluate, and treat such patients with their own unique perspectives given the differences in their respective training. The PFDC was formed to bridge gaps and enable collaboration between these specialties. The goal of the PFDC is to develop and evaluate educational programs, create clinical guidelines and algorithms, and promote high quality of care in this unique patient population. The recommendations included in this article represent the work of the PFDC Working Group on Magnetic Resonance Imaging of Pelvic Floor Disorders (members listed alphabetically in Table 1). The objective was to generate inclusive, rather than prescriptive, guidance for all practitioners, irrespective of discipline, involved in the evaluation and treatment of patients with pelvic floor disorders.

Clinical applications of pelvic floor imaging: opinion statement endorsed by the society of abdominal radiology (SAR), American Urological Association (AUA), and American Urogynecologic Society (AUGS)

Pelvic floor dysfunction is prevalent, with multifactorial causes and variable clinical presentations. Accurate diagnosis and assessment of the involved structures commonly requires a multidisciplinary approach. Imaging is often complementary to clinical assessment, and the most commonly used modalities for pelvic floor imaging include fluoroscopic defecography, magnetic resonance defecography, and pelvic floor ultrasound. This collaboration opinion paper was developed by representatives from multiple specialties involved in care of patients with pelvic floor dysfunction (radiologists, urogynecologists, urologists, and colorectal surgeons). Here, we discuss the utility of imaging techniques in various clinical scenarios, highlighting the perspectives of referring physicians. The final draft was endorsed by the Society of Abdominal Radiology (SAR), American Urogynecologic Society (AUGS), and the American Urological Association (AUA).

Underestimation of pelvic organ prolapse in the supine straining position, based on magnetic resonance imaging findings

Objective

Pelvic organ prolapse (POP) is clinically diagnosed in the supine position, where the effect of gravity is simulated by having the patients put strain on their pelvic floor. The objective of this study was to determine the degree of POP underestimation in the supine position based on magnetic resonance imaging (MRI) findings.

Methods

This prospective study was conducted with symptomatic POP grade ≥ 2 patients. Fifteen female patients were examined with an MRI system that allows supine and upright imaging. The differences between supine and upright in distances of the bladder neck, cervix, and pouch of Douglas from the pubococcygeal line (PCL) were estimated, together with changes in the genital hiatal area. Patients were scanned at rest and during straining. All distances were compared using the Wilcoxon ranking test.

Results

All mean distances from the PCL increased from the supine–strain to the upright–rest and from the supine–strain to the upright–strain position. These distances were found in the supine and upright positions: the bladder descended 1.3 cm to 1.4 cm, the cervix 1.1 cm to 2.2 cm, and the pouch of Douglas 0.8 cm to 1.5 cm respectively (all p values <0.05). The hiatal area was larger in the upright–strain position (mean 42.0 cm²; SD ±14.8) than during the supine–strain position (mean 33.5 cm²; SD ±14.5), with a p value of 0.02.

Conclusion

Upright MRI scanning of patients with POP grade ≥ 2 both at rest and during straining shows a significantly larger extent of the prolapse than that observed during supine straining.

Systematic review with meta-analysis: defecography should be a first-line diagnostic modality in patients with refractory constipation

BACKGROUND

Defecography is considered the reference standard for the assessment of pelvic floor anatomy and function in patients with a refractory evacuation disorder. However, the overlap of radiologically significant findings seen in patients with chronic constipation (CC) and healthy volunteers is poorly defined.

AIM

To systematically review rates of structural and functional abnormalities diagnosed by barium defecography and/or magnetic resonance imaging defecography (MRID) in patients with symptoms of CC and in healthy volunteers.

METHODS

Electronic searches of major databases were performed without date restrictions.

RESULTS

From a total of 1760 records identified, 175 full-text articles were assessed for eligibility. 63 studies were included providing data on outcomes of 7519 barium defecographies and 668 MRIDs in patients with CC, and 225 barium defecographies and 50 MRIDs in healthy volunteers. Pathological high-grade (Oxford III and IV) intussuscepta and large (>4 cm) rectoceles were diagnosed in 23.7% (95% CI: 16.8-31.4) and 15.9% (10.4-22.2) of patients, respectively. Enterocele and perineal descent were observed in 16.8% (12.7-21.4) and 44.4% (36.2-52.7) of patients, respectively. Barium defecography detected more intussuscepta than MRID (OR: 1.52 [1.12-2.14]; P = 0.009]). Normative data for both barium defecography and MRID structural and functional parameters were limited, particularly for MRID (only one eligible study).

CONCLUSIONS

Pathological structural abnormalities, as well as functional abnormalities, are common in patients with chronic constipation. Since structural abnormalities cannot be evaluated using nonimaging test modalities (balloon expulsion and anorectal manometry), defecography should be considered the first-line diagnostic test if resources allow.

Dynamic MRI of the pelvic floor: comparison of performance in supine vs left lateral body position

OBJECTIVE:

To investigate the performance of MR-defecography (MRD) in lateral body position as an alternative to supine position.

METHODS:

22 consecutive patients (16 females; mean age 51 ± 19.4) with obstructed defecation and 20 healthy volunteers (11 females; mean age 33.4 ± 11.5) underwent MRD in a closed-configuration 3T-MRI in supine and lateral position. MRD included T₂ weighted images at rest and during defecation after filling the rectum with 250 ml water-based gel. Measurements were performed in reference to the pubococcygeal line and grade of evacuation was assessed. Image quality (IQ) was rated on a 5-point-scale (5 = excellent).

RESULTS:

In patients grades of middle and posterior compartment descent were similar in both body positions (p > 0.05). Grades of anterior compartment descent were significantly higher in lateral position (21/22 vs 17/22 patients with normal or small descent, p < 0.034). In volunteers grades of descent were similar for all compartments in supine and lateral position (p > 0.05). When attempting to defecate in supine position 6/22 (27%) patients showed no evacuation, while in lateral position only 3/22 (14%) were not able to evacuate. IQ in patients was equal at rest (4.4 ± 0.5 and 4.7 ± 0.6, p > 0.05) and slightly better in supine compared to the lateral position during defecation (4.5 ± 0.4 vs 3.9 ± 0.9, p < 0.017). IQ in volunteers was equal in supine and lateral position (p > 0.05).

CONCLUSION:

In lateral position, more patients were able to evacuate with similar grades of pelvic floor descent compared to supine position. MRD in lateral position may be a valuable alternative for patients unable to defecate in supine position.

ADVANCES IN KNOWLEDGE:

In lateral position, more patients were able to evacuate during MRD. MRD in lateral position may be an alternative for patients unable to defecate in supine position.

Internal rectal prolapse: Definition, assessment and management in 2016

Internal rectal prolapse (IRP) is a well-recognized pelvic floor disorder mainly seen during defecatory straining. The symptomatic expression of IRP is complex, encompassing fecal continence (56%) and/or evacuation disorders (85%). IRP cannot be characterized easily by clinical examination alone and the emergence of dynamic defecography (especially MRI) has allowed a better comprehension of its pathophysiology and led to the proposition of a severity score (Oxford score) that can guide management. Decision for surgical management should be multidisciplinary, discussed after a complete work-up, and only after medical treatment has failed. Information should be provided to the patient, outlining the goals of treatment, the potential complications and results. Stapled trans-anal rectal resection (STARR) has been considered as the gold standard for IRP treatment. However, inconsistent results (failure observed in up to 20% of cases, and fecal incontinence occurring in up to 25% of patients at one year) have led to a decrease in its indications. Laparoscopic ventral mesh rectopexy has substantial advantages in solving the functional problems due to IRP (efficacy on evacuation and resolution of continence symptoms in 65-92%, and 73-97% of patients, respectively) and is currently considered as the gold standard therapy for IRP once the decision to operate has been made.

Change in Image Quality According to the 3D Locations of a CBCT Phantom

A patient's position changes in every CBCT scan despite patient alignment protocols. However, there have been studies to determine image quality differences when an object is located at the center of the field of view (FOV). To evaluate changes in the image quality of the CBCT scan according to different object positions, the image quality indexes of the Alphard 3030 (Alphard Roentgen Ind., Ltd., Kyoto, Japan) and the Rayscan Symphony (RAY Ind., Ltd., Suwon, Korea) were measured using the Quart DVT_AP phantom at the center of the FOV and 6 peripheral positions under four types of exposure conditions. Anterior, posterior, right, left, upper, and lower positions 1 cm offset from the center of the FOV were used for the peripheral positions. We evaluated and compared the voxel size, homogeneity, contrast to noise ratio (CNR), and the 10% point of the modulation transfer function (MTF10%) of the center and periphery. Because the voxel size, which is determined by the Nyquist frequency, was within tolerance, other image quality indexes were not influenced by the voxel size. For the CNR, homogeneity, and MTF10%, there were peripheral positions which showed considerable differences with statistical significance. The average difference between the center and periphery was up to 31.27% (CNR), 70.49% (homogeneity), and 13.64% (MTF10%). Homogeneity was under tolerance at some of the peripheral locations. Because the CNR, homogeneity, and MTF10% were significantly affected by positional changes of the phantom, an object's position can influence the interpretation of follow up CBCT images. Therefore, efforts to locate the object in the same position are important.