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

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.

Comparison of MRI and Endoanal Ultrasound in Assessing Intersphincteric, Transsphincteric, and Suprasphincteric Perianal Fistula

OBJECTIVES

Perianal fistula is a common disorder characterized by an anomalous perianal track connecting two epithelialized surfaces, most commonly the anal canal and the perianal skin. Although each has its limitations, magnetic resonance imaging (MRI) and endoanal ultrasound are currently two acceptable modalities for assessing perianal fistula. This study aimed to evaluate the accuracy of MRI and endoanal ultrasonography in diagosing perianal fistula, considering the surgical results as the references.

METHODS

This prospective cohort study was performed on patients with symptomatic perianal fistulas. MRI results of patients reported by the radiologist were collected along with the findings of endoanal ultrasonography performed by a gastroenterologist. These results were compared with surgical findings as the reference standard.

RESULTS

The study enrolled 126 patients. Exactly 222 definitive fistulas were identified during surgery. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ultrasound for perianal fistula were 87.38, 38.46, 92.38, 26.31, and 82.25% respectively; and for MRI were 76.12, 57.69, 93.88, 22.05, and 74.19% respectively. The accuracy of endoanal ultrasound for detecting transsphincteric and intersphincteric fistulas was higher than MRI. In contrast, the diagnostic value of MRI for detecting suprasphincteric fistulas was higher than endoanal ultrasound.

CONCLUSIONS

Using endoanal ultrasonography to diagnose perianal fistulas is a relatively accurate method. This method may be more sensitive than MRI in detecting patients with perianal fistulas and abscesses.

Time-scheduled dotted and solid thread-ligating therapy combined with vacuum sealing drainage for treating high complex anal fistula

OBJECTIVE

To investigate the treatment of high complex anal fistula with time-scheduled dotted and solid thread-ligating therapy combined with vacuum sealing drainage.

METHODS

A retrospective cohort study of 80 patients with high complex anal fistula admitted to the anorectal department of our hospital was conducted. The patients in the control group (n=40) were treated with traditional incision thread-ligating therapy, while the patients in the observation group (n=40) were treated with time-scheduled dotted and solid thread-ligating therapy combined with vacuum sealing drainage. The postoperative wound healing time, clinical efficacy, postoperative pain scores as well as pre- and postoperative anal function and anorectal pressure of patients in the two groups were observed.

RESULTS

The observation group had a shorter wound healing time (P<0.001), lower postoperative pain scores (P<0.05), a lower increase of Wexner score (P<0.001), a higher total effective rate (97.50% vs. 90.00%; P>0.05), a higher anal maximal contraction pressure and a larger high pressure zone than the control group (P<0.05). Compared with those before operation, the Wexner scores of patients in the two groups after operation were increased, while the anal maximal contraction pressure and high pressure zone in the control group were decreased (P<0.001).

CONCLUSION

The treatment of complex high anal fistula with time-scheduled dotted and solid thread-ligating combined with vacuum sealing drainage has short wound healing time, high efficiency, and little influence on the postoperative function of anal sphincter. It is worthy to be popularized in clinic.