The role of 3-dimensional anorectal ultrasonography in the assessment of anterior transsphincteric fistula

Use of 3D Anorectal Ultrasonography in the Preoperative Assessment of Complex Anal Fistulas and Patterns of Healing, Failure, and Recurrence After Ligation of the Intersphincteric Fistula Tract (LIFT)

OBJECTIVES

To use three-dimensional anorectal ultrasonography (3D-US) to evaluate the outcome of ligation of the intersphincteric fistula tract (LIFT) in patients with crypto-glandular transsphincteric fistula and describing the patterns of healing, failure, and recurrence rate.

METHODS

After classifying the fistula and determining the length of the sphincter muscle to be transected, the patients were submitted to LIFT. The accuracy of pre- and postoperative 3D-US with 360° endoprobe (16 MHz) with automatic scanning and clinical findings was evaluated against surgical findings. Three outcomes were considered: healing, failure (persistent anal fistula through the original external opening or intersphincteric), and recurrence (reappearance of the anal fistula).

RESULTS

Sixty-three patients of both sexes were evaluated. The 3D-US assessment revealed primary healing in 50 (79.3%) patients, although in 6 (9.5%) cases healing was delayed and the cavity was without communication with the anal canal. The procedure failed in 9 (15.9%) and fistula recurred in 4 (6.3%), all of whom underwent a second surgery based on a new 3D-US, resulting in a 92.3% (12/13) healing rate on 3D-US.

CONCLUSIONS

A 3D-US was found to be useful in the preoperative assessment of fistulas by quantifying the percentage of muscle to be transected, and in the postoperative assessment by identifying healing, types of failure, and recurrence. The 3D-US was accurate and consistent with surgical findings.

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.

Impact of Internal Anal Sphincter Division on Continence Disturbance in Female Patients

BACKGROUND

Few studies measured the pre- and postoperative anatomic and functional anal canal using 3-dimensional endoanal ultrasound and anal manometry and correlated sphincter division with fecal incontinence, severity, and function.

OBJECTIVE

To assess the incidence of fecal incontinence in patients who underwent internal anal sphincter division for anal fissure or intersphincteric anal fistula and correlate severity of symptoms with percentage of divided muscle, anatomical measurements, and anal pressures.

DESIGN

Prospective cohort study.

SETTINGS

Colorectal surgery unit, tertiary referral center.

PATIENTS

Patients underwent clinical assessment using the Cleveland Clinic Florida Fecal Incontinence score for severity of symptoms, manometry, and ultrasound.

MAIN OUTCOMES MEASURES

Ultrasound measurements of length, percentage, and angle of divided internal anal sphincter, anterior external anal sphincter, posterior external anal sphincter plus puborectalis, and gap lengths.

RESULTS

Sixty-three women (mean age, 44 years) were divided into 2 groups: 30 (48%) underwent fistulotomy for intersphincteric anal fistula and 33 (52%) underwent sphincterotomy for chronic anal fissure with high anal resting pressure. Forty-six percent experienced some measure of fecal incontinence after internal anal sphincter division. Incidence of fecal incontinence, severity of symptoms, and angle of the divided internal anal sphincter were similar between the groups. Length and percentage of the divided internal anal sphincter were significantly higher in the intersphincteric anal fistula. External anal sphincter and external anal sphincter plus puborectalis lengths were similar in both groups. Gap length was significantly longer in chronic anal fissures with high anal resting pressure.

LIMITATIONS

Single-institution, exclusion of males.

CONCLUSIONS

Fecal incontinence was reported in half of the patients who underwent internal anal sphincter division. Despite the greater length and percentage of internal anal sphincter division in patients who underwent fistulotomy, incidence and severity of fecal incontinence were similar in both groups. Three-dimensional endoanal ultrasound showed greater gap length in the sphincterotomy group, which may be functionally significant after the division of the shorter internal anal sphincter but with a similar impact on fecal incontinence in both groups.

IMPACTO DE LA DIVISIN DEL ESFNTER ANAL INTERNO EN LA ALTERACIN DE LA CONTINENCIA EN PACIENTES DE SEXO FEMENINO

ANTECEDENTES:Pocos estudios han medido el canal anal anatómico y funcional antes y después de la cirugía mediante ecografía endoanal tridimensional y manometría anal, y correlacionado la división del esfínter con la incontinencia fecal, la gravedad y la función.OBJETIVO:Evaluar la incidencia de incontinencia fecal en pacientes sometidos a división del esfínter anal interno por fisura anal o fístula anal interesfinteriana, y correlacionar la gravedad de los síntomas con el porcentaje de músculo dividido, las medidas anatómicas y las presiones anales.DISEÑO:Estudio de cohorte prospectivo.AJUSTE:Unidad de cirugía colorrectal, centro de referencia de tercer nivel.PACIENTES:Pacientes sometidos a una evaluación clínica utilizando la puntuación de incontinencia fecal de Cleveland Clinic Florida para la gravedad de los síntomas, la manometría y la ecografía.PRINCIPALES MEDIDAS DE RESULTADO:Mediciones por ultrasonido de la longitud, el porcentaje y el ángulo del esfínter anal interno dividido y el esfínter anal externo anterior, el esfínter anal externo posterior más el puborrectal y las longitudes del espacio.RESULTADOS:Sesenta y tres mujeres (edad media, 44 años) se dividieron en 2 grupos: 30 (48%) sometidos a fistulotomía por fístula anal interesfinteriana y 33 (52%) sometidos a esfinterotomía por fisura anal crónica con alta presión anal en reposo. El 46% experimentó algún grado de incontinencia fecal después de la división del esfínter anal interno. La incidencia de incontinencia fecal, la gravedad de los síntomas y el ángulo del esfínter anal interno dividido fueron similares entre los grupos. La longitud y el porcentaje del esfínter anal interno dividido fueron significativamente mayores en la fístula anal interesfinteriana. Las longitudes del esfínter anal externo y del esfínter anal externo más el puborrectal fueron similares en ambos grupos. La longitud del espacio fue significativamente mayor en la fisura anal crónica con alta presión anal en reposo.LIMITACIONES:Institución única, exclusión de varones.CONCLUSIÓN:La incontinencia fecal se reportó en la mitad de los pacientes sometidos a división del esfínter anal interno. A pesar de la mayor longitud y porcentaje de división del esfínter anal interno en los pacientes sometidos a fistulotomía, la incidencia y gravedad de la incontinencia fecal fue similar en ambos grupos. La ecografía endoanal tridimensional mostró una mayor longitud del espacio en el grupo de esfinterotomía, lo que puede ser funcionalmente significativo después de la división del esfínter anal interno más corto, pero con un impacto similar en la incontinencia fecal en ambos grupos. (Traducción-Dr. Fidel Ruiz Healy ).

Sphincter damage during fistulotomy for perianal fistulae and its relationship with faecal incontinence

Background

The length of sphincter which can be divided during fistulotomy for perianal fistula is unclear. The aim was to quantify sphincter damage during fistulotomy and determine the relationship between such damage with symptoms and severity of faecal incontinence and long-term quality of life (QOL).

Methods

A prospective cohort study was performed over a 2-year period. Patients with intersphincteric and mid to low transsphincteric perianal fistulas without risk factors for faecal incontinence were scheduled for fistulotomy. All patients underwent 3D endoanal ultrasound (3D-EAUS) pre-operatively and 8 weeks postoperatively. Measurements were taken of pre- and postoperative anal sphincter involvement and division. Anal continence was assessed using the Jorge-Wexner scale and QOL scores pre, 6 and 12 months postoperatively.

Results

Forty-nine patients were selected. A strong correlation between pre- and postoperative measurements was found p < 0.001. A median length of 41% of the external anal sphincter and 32% of the internal anal sphincter was divided during fistulotomy. Significant differences in mild symptoms of anal continence were found with increasing length of external anal sphincter division. But there was no significant deterioration in continence, soiling, or quality of life scores at the 1-year follow-up. Division of over two-thirds of the external anal sphincter was associated with the highest incontinence rates.

Conclusions

3D-EAUS is a valuable tool for quantifying the extent of sphincter involvement pre- and postoperatively. Post-fistulotomy faecal incontinence is mild and increases with increasing length of sphincter division but does not affect long-term quality of life.

Establishing the normal ranges of female and male anal canal and rectal wall vascularity with color Doppler anorectal ultrasonography

Study objectives To evaluate blood supply in the anal canal, rectal wall and mesorectal fat of men and women, using color Doppler endorectal sonography to establish normal ranges for vascular parameters.

Methods A prospective cross-sectional study conducted at a tertiary-care hospital recruited asymptomatic volunteers (≤50 years). Vascularity percentage and index were calculated for defined regions.

Results Vascularity percentage and index were significantly higher in the puborectalis, mid-level external and upper internal anal sphincter compared to the low anal canal; these parameters were higher in men than in women at upper and middle levels of the inner anal canal structures. At mid-level, vascularity was greater in the external compared to the internal anal sphincter in both sexes; however, at the upper level it was greater in the puborectalis compared to the internal anal sphincter in women. Vascularity was greater in the rectal wall compared to the mesorectal fat, with no difference between middle and lower levels.

Conclusions Blood supply is highest at upper levels of the anal canal; however, inner structures are better irrigated in men. Moreover, the rectal wall is better irrigated than the mesorectal fat. Establishing normal ranges may permit future comparisons of the studied structures in disease states as well as the hormonal and age related changes.

Anatomical characteristics of anal fistula evaluated by three-dimensional anorectal ultrasonography: is there a correlation with Goodsall's theory?

Purpose We aimed to correlate the course of the anal fistula tract (T), location of the external opening (EO) and internal opening (IO) in anterior (A) and posterior (P) circumference using 3D-US according to Goodsall's rule.

Methods 151 patients with primary cryptoglandular Transsphincteric fistulas were examined with 3D-US and compared with surgical finding. The type of the T (straight or curved), EO and IO were identified and divided into 3 Groups: GI: EO and IO are located in a position; GII: EO and IO are located in P position and GIII: OE and OI are located in the opposite position. The findings were correlated with Goodsall's rule.

Results 74/151(49%) were included in GI, of them, 41 (55%) were male (33/44% had straight tract and 8/11% curved) and 33 (45%) female (15/20%-straight and 18/25%-curved). GII included 68 (45%), of them, 50 (74%) were male (39/57%-straight and 11/15%-curved) and 18 (26%) female (14/20%-straight and 04/8%-curved). GIII = 9 (6%) and all of them had curved tract. The overall concordance between 3D-US and surgical finding was 98% for tract and 96% for IO.

Conclusion The 3D-US findings correlate with the Goodsall's rule in transsphincteric fistulas located in the anterior circumference straight type, in male, while in females the distribution of curved and straight paths is similar. In the posterior circumference no correlation was observed in both the sexes.

Using preoperative three-dimensional endoanal ultrasound to determine operative procedure in patients with perianal fistulas

AIM

Accurate preoperative identification of perianal fistula tracts and internal openings can facilitate the choice of surgical procedure and may lead to improved healing rates. Our aim was to explore the effectiveness of three-dimensional endoanal ultrasound (3D-EAUS) in determining the type of perianal fistula and planning operative management.

METHOD

This was a cohort longitudinal study. Patients with perianal fistulas from January 2017 to January 2018 who underwent 3D-EAUS and subsequent surgery were included. Intra-operative findings were considered as standard for comparison with clinical examination and 3D-EAUS findings. The primary outcome measure was to evaluate the concordance between 3D-EAUS and intra-operative findings and the secondary outcome measure was healing rates.

RESULTS

Sixty-eight patients with a mean age of 43.1 ± 14.1 years were included. Twenty-eight patients had inter-sphincteric (41.2%) and 40 (14 high and 26 low) trans-sphincteric fistulas (58.8%). 3D-EAUS, clinical examination and intra-operative exploration could predict the location of internal openings in 62/68 (91.2%), 48/68 (70.5%) and 56/68 (82.4%) patients, respectively. Hydrogen peroxide (H₂O₂)-enhanced 3D-EAUS accurately predicted the location of internal openings when compared with 3D-EAUS without H₂O₂ (concordance K = 0.963, P = 0.05). High concordance rates were seen between intra-operative and 3D-EAUS findings on the type of perianal fistula. No significant difference was seen between the suggested surgical treatment based on 3D-EAUS and the eventual surgical treatment (P > 0.05). Study limitations were the small sample size and lack of randomization.

CONCLUSION

3D-EAUS may be considered as a first-line investigation for patients with perianal fistulas because of high concordance with intra-operative assessment and facilitation of surgical planning.

Anal Pain of an Unusual Cause: Role of Endoanal Ultrasound

Anal pain is among the most frequent complaints referred in coloproctology clinic. Nevertheless, this symptom may have a great variety of etiopathogenetic causes. This is the first report that highlights the presence of a rare cause of anal pain, originated by ingested seeds. A 65-year-old male had a 4-day history of fever, anal pain, and discharge. A three-dimensional endoanal ultrasound revealed two perianal abscess cavities with central hyperechogenic areas, in the absence of acoustic shadow. The patient underwent examination under epidural anesthesia, where the two cavities were drained endoanally. Two cereal grains (linseed/sunflower seed) were found during the drainage of the abscess. The utilization of endoanal ultrasound in the investigation of perianal pain is a valuable option. In addition, apart from the size and the exact dimensions of abscesses, endoanal ultrasound also permits the clarification even the most remote etiopathogenetic causes of anal pain.

Effects of preoperative endoanal ultrasound on functional outcome after anal fistula surgery

Objective

Endoanal ultrasound (EAUS) is a recommended preoperative investigation for fistula-in-ano (FiA) which aims to provide the best chance of healing and preservation of continence function. This study aims are (1) to assess effect of EAUS on functional outcome and (2) to determine factors associated with clinical outcomes after FiA surgery.

Design

Retrospective analysis of subjects with cryptogenic FiA between January 2011 and December 2016, in a tertiary hospital, was performed by comparing EAUS and no-EAUS groups. Postoperative change in St. Mark’s faecal incontinence severity score (cFISS=FISS at 6 months after surgery–FISS before surgery) were compared. General linear model was used to determine factors associated with cFISS. Binary logistic regression was used to assess factors related to clinical outcomes. A p-value of <0.05 is considered significant.

Results

We enrolled 339 subjects; 109 (M:F 91:18, mean age 41.7±13.6 years) of 115 in EAUS group and 230 in no-EAUS group (M:F 195:35, mean age 42.6±13.0 years). There were higher proportions of recurrent cases (24.8% vs 13.9%, p=0.014) and complex FiA (80.7% vs 50.4%, p=0.001) in EAUS group. Postoperative FISS (mean±SE) were increased in both groups; preoperative versus postoperative FISS were 0.36±0.20 versus 0.59±0.25 in EAUS group (p=0.056) and 0.31±0.12 versus 0.76±0.17 in no-EAUS group (p<0.001). EAUS had significant effects on cFISS in both univariate analysis, F(1,261)=4.053, p=0.045; and multivariate analysis, F(3,322)=3.147, p=0.025, Wilk’s Lambda 0.972. Other associated factors included recurrent fistula (F(3,322)=0.777, p=0.007, Wilk’s Lambda 0.993) and fistula classification (F(3,322)=16.978, p<0.001, Wilk’s Lambda 0.863). After a mean follow-up of 33.6±28.6 weeks, success rate was 63.3%(EAUS) and 60% (no-EAUS), p=0.822. Factors associated with clinical outcomes were fistula complexity, number of tracts, recurrence, number of previous surgery and type of operations. Accuracy of EAUS was 90.8% and not related to clinical outcomes (p=0.522).

Conclusion

EAUS had favourable effects on functional outcome after FiA surgery while multiple factors were associated with clinical outcomes. EAUS is useful, accurate, inexpensive and can be the first tool for planning of complex and recurrent FiA.

EFSUMB Recommendations for Gastrointestinal Ultrasound Part 3: Endorectal, Endoanal and Perineal Ultrasound

This article represents part 3 of the EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound (GIUS). It provides an overview of the examination techniques recommended by experts in the field of endorectal/endoanal ultrasound (ERUS/EAUS), as well as perineal ultrasound (PNUS). The most important indications are rectal tumors and inflammatory diseases like fistula and abscesses in patients with or without inflammatory bowel disease (IBD). PNUS sometimes is more flexible and convenient compared to ERUS. However, the technique of ERUS is quite well established, especially for the staging of rectal cancer. EAUS also gained ground in the evaluation of perianal diseases like fistulas, abscesses and incontinence. For the staging of perirectal tumors, the use of PNUS in addition to conventional ERUS could be recommended. For the staging of anal carcinomas, PNUS can be a good option because of the higher resolution. Both ERUS and PNUS are considered excellent guidance methods for invasive interventions, such as the drainage of fluids or targeted biopsy of tissue lesions. For abscess detection and evaluation, contrast-enhanced ultrasound (CEUS) also helps in therapy planning.

Preoperative assessment of simple and complex anorectal fistulas: Tridimensional endoanal ultrasound? Magnetic resonance? Both?

PURPOSE

The purpose of the study is to evaluate the diagnostic value of tridimensional endoanal ultrasound (3D-EAUS) and magnetic resonance (MR) in the preoperative assessment of both simple and complex anorectal fistulas.

METHODS

All the patients referred for the treatment of anal fistulas were enrolled in this study and underwent, as preoperative assessment, anamnestic evaluation, clinical examination, and unenhanced and H2O2-enhanced 3D-EAUS and MR. The results of imaging evaluation were compared with surgical findings, considered as reference standard.

RESULTS

During the study period, 124 patients operated on for anal fistulas underwent complete preoperative imaging assessment. Perfect agreement between 3D-EAUS and surgery in the anal fistulas' severity grading was found (K = 1). The fistulas were classified as simple in 68/126 (53.9%) and complex in 58/126 (46.03%) cases, according to fistulas' Parks' classification and the most recent American Guidelines. In both simple and complex anal fistulas, 3D-EAUS did not show a significantly higher accuracy in the evaluation of internal openings, if compared with MR (P = 0.47; McNemar's Chi-square test). In the complex anal fistulas, MR showed a significantly higher accuracy in the evaluation of secondary extensions if compared with 3D-EAUS (P = 0.041; McNemar's Chi-square test), whereas in the simple anal fistulas, no significant difference was found.

CONCLUSION

In the preoperative work-up of patients with anorectal fistulas, 3D-EAUS may represent the first-line diagnostic tool. In cases of fistulas classified as complex by 3D-EAUS, MR may be indicated as adjunctive diagnostic imaging examination, to more carefully describe the fistulas' complete anatomy.

CAN THREE-DIMENSIONAL ANORECTAL ULTRASONOGRAPHY BE INCLUDED AS A DIAGNOSTIC TOOL FOR THE ASSESSMENT OF ANAL FISTULA BEFORE AND AFTER SURGICAL TREATMENT?

BACKGROUND

There is no a clear knowledge concerning the division of any part of the anal sphincter complex and the effect of this procedure on the function of the anal canal during the treatment of perianal fistula.

OBJECTIVE

To evaluate the usefulness of 3D anorectal ultrasound in the assessment of anal fistula, quantifying the length of the sphincter muscle to be transected, selecting patients for different approaches and identifying healing, failure or recurrence after the surgical treatment.

METHODS

A prospective study included patients with primarily cryptogenic transsphincteric anal fistula assessed by fecal Incontinence score, tri-dimensional anorectal ultrasound and anal manometry before and after surgery. Based on 3D-AUS, patients with ≥50% external sphincter or external sphincter+puborectalis muscle involvement in males and ≥40% external sphincter or external sphincter+puborectalis muscle in females were referred for the ligation of the intersphincteric tract (LIFT) or seton placement and subsequent fistulotomy; and with <50% involvement in males and <40% in females were referred to one-stage fistulotomy. After surgery, the fibrosis (muscles divided) and residual muscles were measured and compared with the pre-operative.

RESULTS

A total of 73 patients was included. The indication for the LIFT was significantly higher in females (47%), one-stage fistulotomy was significantly higher in the males (46%) and similar in seton placement. The minor postoperative incontinence was identified in 31% of patients underwent sphincter divided and were similar in both genders. The 3D-AUS identified seven failed cases.

CONCLUSION

The 3D ultrasound was shown to be an effective method in the preoperative assessment of anal fistulas by quantifying the length of muscle to be divided, as the results were similar at the post-operative, providing a safe treatment approach according to the gender and percentage of muscle involvement. Additionally, 3D ultrasound successfully identified the healing tissue and the type of failure or recurrence.

Three-dimensional endoanal ultrasound for diagnosis of perianal fistulas: Reliable and objective technique

AIM: To evaluate accuracy of three-dimensional endoanal ultrasound (3D-EAUS) as compared to 2D-EAUS and physical examination (PE) in diagnosis of perianal fistulas and correlate with intraoperative findings.

METHODS: A prospective observational consecutive study was performed with patients included over a two years period. All patients were studied and operated on by the Colorectal Unit surgeons. The inclusion criteria were patients over 18, diagnosed with a criptoglandular perianal fistula. The PE, 2D-EAUS and 3D-EAUS was performed preoperatively by the same colorectal surgeon at the outpatient clinic prior to surgery and the fistula anatomy was defined and they were classified in intersphincteric, high or low transsphincteric, suprasphincteric and extrasphincteric. Special attention was paid to the presence of a secondary tract, the location of the internal opening (IO) and the site of external opening. The results of these different examinations were compared to the intraoperative findings. Data regarding location of the IO, primary tract, secondary tract, and the presence of abscesses or cavities was analysed.

RESULTS: Seventy patients with a mean age of 47 years (range 21-77), 51 male were included. Low transsphincteric fistulas were the most frequent type found (33, 47.1%) followed by high transsphincteric (24, 34.3%) and intersphincteric fistulas (13, 18.6%). There are no significant differences between the number of IO diagnosed by the different techniques employed and surgery (P > 0.05) and, there is a good concordance between intraoperative findings and the 2D-EAUS (k = 0.67) and 3D-EAUS (k = 0.75) for the diagnosis of the primary tract. The ROC curves for the diagnosis of transsphincteric fistulas show that both ultrasound techniques are adequate for the diagnosis of low transsphincteric fistulas, 3D-EAUS is superior for the diagnosis of high transsphincteric fistulas and PE is weak for the diagnosis of both types.

CONCLUSION: 3D-EAUS shows a higher accuracy than 2D-EAUS for assessing height of primary tract in transsphincteric fistulas. Both techniques show a good concordance with intraoperative finding for diagnosis of primary tracts.

Role of tridimensional endoanal ultrasound (3D-EAUS) in the preoperative assessment of perianal sepsis

PURPOSE

The aim of this study was to evaluate the accuracy of tridimensional endoanal ultrasound (3D-EAUS) in the diagnosis of perianal sepsis comparing the results with the surgical findings, considered as reference standard.

METHODS

From January 2009 to January 2013, all the patients referred for the assessment and treatment of perianal sepsis with suspected anorectal origin were enrolled in the study. All patients gave informed written consent. Prior to surgery, all the patients underwent anamnestic evaluation, clinical examination, and unenhanced and H2O2-enhanced 3D-EAUS. Surgery was performed by a colorectal surgeon blinded to the 3D-EAUS results.

RESULTS

A total of 212 patients with suspected perianal suppurations were assessed during the study period. In 12 patients, the H2O2-enhanced 3D-EAUS was not performed, and so, they were excluded from the study. Very good agreement between 3D-EAUS and examination under anesthesia (EUA) in the classification of primary fistula tracts (kappa = 0.93) and in the identification of fistula internal opening (kappa = 0.97) was found. There was a good concordance (kappa = 0.71) between 3D-EAUS and surgery in the detection of fistula secondary extensions. The overall sensitivity and specificity of 3D-EAUS in the diagnosis of perianal sepsis were 98.3 and 91.3% respectively.

CONCLUSION

3D-EAUS is a safe and reliable technique in the assessment of perianal sepsis. It may assist the surgeon in delineating the fistula tract anatomy and in determining the origin of sepsis, supporting the preoperative planning of definitive and appropriate surgical therapy.

DO CHANGES IN ANAL SPHINCTER ANATOMY CORRELATE WITH ANAL FUNCTION IN WOMEN WITH A HISTORY OF VAGINAL DELIVERY?

Objectives To evaluate anal sphincter anatomy using three-dimensional ultrasonography (3-DAUS) in incontinent women with vaginal delivery, correlate anatomical findings with symptoms of fecal incontinence and determine the effect of vaginal delivery on anal canal anatomy and function. Methods Female with fecal incontinence and vaginal delivery were assessed with Wexner’s score, manometry, and 3DAUS. A control group comprising asymptomatic nulliparous was included. Anal pressure, the angle of the defect and length of the external anal sphincter (EAS), the anterior and posterior internal anal sphincter (IAS), the EAS + puborectal and the gap were measured and correlated with score. Results Of the 62, 49 had fecal incontinence and 13 were asymptomatic. Twenty five had EAS defects, 8 had combined EAS+IAS defects, 16 had intact sphincters and continence scores were similar. Subjects with sphincter defects had a shorter anterior EAS, IAS and longer gap than women without defects. Those with a vaginal delivery and intact sphincters had a shorter anterior EAS and longer gap than nulliparous. We found correlations between resting pressure and anterior EAS and IAS length in patients with defects. Conclusions Avaliar a anatomia do esfíncter anal usando ultra-sonografia tridimensional (3D-US) em mulheres incontinentes com parto vaginal, correlacionar os achados anatômicos com sintomas de incontinência fecal e, determinar o efeito do parto vaginal sobre a anatomia e função do canal anal.

Methods for preoperative assessment of anal fistula

Anal fistula is one of the most common perianal diseases, and methods for its preoperative assessment are diverse. Traditional methods include physical examination, probing, Goodsall's law, methylene blue test, and so on. Although traditional methods play a role, their accuracy for complex anal fistulas is low. Therefore, their application must be combined with other methods. Fistulography fails to depict the relationship of the fistula to the sphincter complex, and computed tomography lacks specificity to distinguish between fistula and surrounding muscle tissue. Both methods are rarely used now. Magnetic resonance imaging and three-dimensional anorectal endosonography have become routine preoperative examinations and play an important role for guiding precise surgery. However, they also have their own shortcomings. In this paper, we will summarize a variety of methods for preoperative assessment of anal fistula.

Advanced EUS imaging for early detection of pancreatic cancer

Endoscopic ultrasound (EUS)-fine needle aspiration remains the gold standard for diagnosing pancreatic malignancy. However, in a subset of patients, limitations remain in regards to image quality and diagnostic yield of biopsies. Several new devices and processors have been developed that allow for enhancement of the EUS image. Initial studies of these modalities do show promise. However, cost, availability, and overall incremental benefit to EUS-fine needle aspiration have yet to be determined.

[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.

Quantifying the extent of fistulotomy. How much sphincter can we safely divide? A three-dimensional endosonographic study

PURPOSE

To quantify the longitudinal division of the internal anal sphincter (IAS) and external anal sphincter (EAS) after fistulotomy using three-dimensional endoanal ultrasound (3D-EAUS) and correlate the results with postoperative faecal incontinence.

METHODS

A prospective, consecutive study was performed from December 2008 to October 2010. All patients underwent 3D-EAUS before and 8 weeks after surgery. Thirty-six patients with simple perianal fistula were included. Patients with an intersphincteric or low transphincteric fistula (<66% sphincter involved) without risk factors for incontinence underwent fistulotomy. The outcome measures were the longitudinal extent of division of the IAS and EAS in relation to total sphincter length and continence (Jorge and Wexner scores).

RESULTS

One-year follow-up revealed a 0% recurrence rate. There was a strong correlation between preoperative 3D-EAUS measurement of fistula height with intraoperative and postoperative 3D-EAUS measurement of IAS and EAS division (p < 0.001). The relationship between the level of EAS division and faecal incontinence showed a significant difference in incontinence rates between fistulotomies limited to the lower two thirds of the EAS and those above this level. Five patients (13.9%) had worse anal continence after surgery, although this was mild in all patients (<3/20 Jorge and Wexner scale). There was no significant difference in continence scores before and after surgery (p > 0.05).

CONCLUSIONS

In patients without risk factors, division of the EAS during fistulotomy limited to the lower two thirds of the EAS is associated with excellent continence and cure rates.

Endoanorectal ultrasonography

Endoanorectal ultrasonography (EARUS) may be used for diagnosing various anorectal disorders. EARUS is easy to perform, has a short learning curve, and causes less discomfort than routine digital examination. Anal sphincters can be clearly visualized, and one can easily distinguish between the internal (hypoechoic) and external (hyperechoic) anal sphincters. Other pelvic floor structures, like the puborectalis muscle, can also be visualized. The use of contrast agents can increase the accuracy of EARUS in the assessment of perianal fistulae. In addition, EARUS is an excellent alternative to expensive magnetic resonance imaging. Besides its use in incontinence and perianal sepsis, the presence of slight or massive submucosal invasion in early rectal cancer may be imaged in greater detail. With 3-dimensional EARUS, it is possible to diagnose the anorectal diseases, in multiplane, with high spatial resolution, adding important information about the therapeutic decision. The normal sonographic anatomy of the anorectum, sonographic findings of anorectal diseases, and indications and limitations of endosonography with complementary techniques such as transvaginal and transperineal ultrasound are reviewed in this article.

Anatomic characteristics of anal fistula on three-dimensional anorectal ultrasonography

BACKGROUND

Surgery for anal fistula is often associated with continence disorders due to the transection of sphincter muscles. Extensive knowledge of anal canal anatomy and anal fistula can help prevent this outcome.

OBJECTIVE

This study aimed to correlate the anatomical conformation of the anal canal, the fistula track, and the internal opening according to sex and hemicircumference (anterior vs posterior) by use of 3-dimensional ultrasonography.

METHODS

One hundred sixty-five patients with fistula were evaluated with 3-dimensional ultrasound and grouped according to sex, fistula type, internal opening, and track position. Fistulas were transsphincteric in 128 subjects and intersphincteric in 37 subjects. The study measured the external and internal anal sphincter, the puborectalis, the distance from the internal opening to the distal edge of the external and internal sphincter, the length of the internal and external sphincter compromised by the track, and the percentage of compromised muscle.

RESULTS

The anal canal muscles were longer in males. The distance from the internal opening to the internal sphincter was greater for the posterior hemicircumference. The point where the fistulous track crossed the anterior external sphincter was similar for the 2 sexes, but the percentage of compromised muscle was greater in females. The point where the fistulous track crossed the internal sphincter was similar for the 2 sexes, but the percentage of compromised internal sphincter was greater in males for the posterior hemicircumference. The study was limited by the absence of testing for interobserver and intraobserver agreement.

CONCLUSION

The anal canal muscles are longer in males and the pectinate line is asymmetrical. In females, the percentage of compromised external sphincter was greater in the anterior hemicircumference because of the shorter external sphincter, whereas in males the percentage of compromised internal sphincter was greater in the posterior hemicircumference.