Role of magnetic resonance imaging in diagnosis and grading of perianal fistulas

Background: Fistula-in-ano can be defined as a hollow tract or cavity which is lined by granulation tissue. In case of fistula-in-ano, one end of this fistula opens in the anal canal whereas the other end is located in perianal area. Fistula-in-ano can considerably affect quality of life of an individual because of perianal discharge of blood and pus. Imaging of these fistulas is an important part of management and MR imaging is important in assessing relationship between the fistulous tract and sphincter muscles. Moreover, MR imaging can reliably demonstrate transmural inflammation, secondary tracts/ramifications, and abscesses which cannot be diagnosed on the basis of conventional fistulography. Aims and Objectives: The aim of the study was to evaluate role of MRI in diagnosis and grading of perianal fistulae. Materials and Methods: This was a retrospective observational study, in which 60 patients with fistula-in-ano were included on the basis of a predefined inclusion and exclusion criteria. MR imaging of patients was done by 1.5 T MRI machine. Before MR imaging normal saline was injected in the fistulous tract from secondary/external opening, that is, opening around perianal area. Three plane images were obtained in all the cases. T1W, T2W, and STIR image sequences were obtained parallel to pelvic diaphragm. Coronal cuts were imaged parallel to anal canal. FAT suppressed T1W and T2W images in all cases. Type and grade of fistula were determined in all the cases. P < 0.05 was taken as statistically significant. Results: Out of total 60 patients, there were 46 (76.66%) males and 14 (23.33%) were females with a M:F ratio of 1:0.30. The mean age of male and female patients was found to be 41.93±8.96 years and 44.04±7.46 years, respectively. The most common type of fistula was found to be trans-sphincteric fistula which was seen in 31 (51.6%) cases followed by intersphencteric fistula 22 (36.6%). Extrasphincteric and suprasphincteric fistulae were relatively uncommon and were seen in 4 (6.66%) and 3 (5%) cases, respectively. MRI was accurate in diagnosis of the tract with position of internal opening and any abscess cavity or secondary tract in 23 patients. Therefore, the diagnostic accuracy of MRI was found to be 95.4%. Conclusion: MRI is an excellent tool in assessment of perianal fistula. It not only helps in precisely locating fistulous tract but also can demonstrate relationship between the fistulous tract and sphincter muscles. Moreover, it can very well demonstrate transmural inflammation, secondary tracts/ramifications, and abscesses which cannot be assessed by conventional fistulograms.

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.

Perianal Inflammation or Something More?

Perianal fistulae are commonly complicated by abscesses and ramifications, which have well-recognized imaging morphology. Less commonly, atypical findings of solid enhancing mass-like lesions with no fluid component are associated with chronic and recurrent fistulae, the etiology of which includes inflammatory masses as well as locally aggressive malignancy. The latter predicts poorer prognosis and warrants extensive surgical resection. The reading radiologist must identify the unusual appearance, be aware of the possible etiologies, and if appropriate recommend prompt tissue sampling to exclude malignancy. This is pertinent as it determines surgical management, which is crucial in achieving a potential curative outcome.

Role of Diffusion-Weighted Imaging in the Evaluation of Perianal Fistulae

Background Magnetic resonance imaging (MRI) is the imaging modality of choice for evaluating perianal fistulae, due to its ability to show the relationship of perianal fistulae with anal sphincters, fistula extensions, secondary ramifications and associated complications. Aim To evaluate the role of diffusion-weighted MRI in the evaluation of perianal fistulae. Settings and Design A hospital-based cross-sectional study. Materials and Methods The study group composed of 47 patients of perianal fistula. MRI with diffusion-weighted imaging (DWI) was performed with Philips 0.5 T Ingenia scanner. DWI with different b-values (b = 50, b = 400, and b = 800 smm2) were obtained. The MRI findings were correlated with local clinical examination and or surgical findings. Statistical Analysis Used Chi-square test, independent samples t-test, and receiver operating characteristic curve analysis. Result Fifty-nine perianal fistulas in 47 patients were included in the study sample. The visibility of perianal fistula on DWI was less than T2-weighted (T2W) and combined DWI-T2W images. Distinctly visualized (visibility score 2) perianal fistulas were observed in 47 fistulas (79.6%) on DWI, 54 (91.5%) on T2W, and 58 (98.3%) on DWI-T2W images. The mean of apparent diffusion coefficient (ADC) values of active fistula was 0.972 ± 0.127 [SD] 10−3 mm2/s and inactive was 1.232 ± 0.185 [SD] 10−3 mm2/s with a significant difference (p-value < 0.0005). A cut-off mean ADC value of 1.105 × 10−3 mm2/s was used to differentiate active from the inactive fistula with a sensitivity of 87.5% and specificity of 73.3%. Conclusion Combined DWI-T2W evaluation had a better performance in the detection of fistula than DWI or T2W alone. DWI with mean ADC calculation had a good performance in differentiating active from the inactive fistulas.

P303 Local Application of Autologous Platelet-rich Plasma leads to Sustained Healing of Crohn’s Perianal Fistulae – One Year follow-up Results from a Single Center Pilot Study

Background Failure of wound repair and dysregulated inflammation in considered to play a key role in the persistence of Crohn’s perianal fistulae (pCD). Few preliminary reports suggest that autologous platelet-rich plasma (PRP) can enhance wound repair and may be effective in treating pCD. Therefore, the aim of our study was to determine the efficacy of autologous PRP in the treatment of pCD. Methods A prospective, uncontrolled, single center study in a referral IBD center was conducted between July 2018 and March 2021. Adult Crohn′s disease patients with pCD failing on antibiotics, immune suppression and/or biologics were eligible for the study. All patients had non-cutting setons for a minimal period of 6 weeks prior study intervention. Autologous PRP was separated by centrifugation 60 ml of peripheral blood in Harvest SmartPrep© System at the time of operation. After the seton removing, internal openings were closed by PDS 2/0 single suture and PRP was injected close to internal openings and fistula tracts. Patients were examined at outpatient clinic at week 1, month 1, 3, 6 and 12. Any suspected side-effects of the treatment were noted. Treatment effect was assessed by perianal Crohn Disease Activity Index (PCDAI assessed at baseline, month 1, 3, 6, 12) and van Assche MRI score (assessed at baseline and month 6 and 12). The primary end-point was complete healing at month 6 defined as closure of all external fistula openings and absence of abscess on MRI. The secondary end-point was sustained response at month 12. Results In total, 25 patients (pts) with pCD were included (mean age 36 years, range 21-61; 15 men). The majority of pts were using antiTNF biologics (9 adalimumab, 9 infliximab), 4 pts were treated by ustekinumab, one by vedolizumab, two patients were on immunomodulators monotherapy. By March 2021, 24 patients finished the 6 months and 21 patients the 12 months follow-up. The primary end-point of complete healing at month 6 was reached by 18 out of 24 pts (75%). All but one patients with complete healing had persistent complete healing at 12 months follow-up. Baseline PCDAI (median 5, range 2-15) decreased significantly as early as at month 1 (median 1, range 0-8; p&lt;0.001) and remained further stable over 12 months. Van Assche MRI score decreased significantly from median of 9 (range 3-18) at baseline to 5 (range 0-18) and 5.5 (range 0-18) at month 6 (p=0.001) and 12 (p=0.03); respectively. Conclusion Local application of autologous platelet-rich plasma leads to rapid healing of difficult-to-treat Crohn’s perianal fistulae in 75% of patients and this effect is sustained up to minimal period of one year.

Management of of complex fistula-in-ano by a IFTAK technique - case report

Ksharsutra is a Medicated seton which is made by coating the Barbour thread with 21 coatings of Kshara i.e. an herbal alkaline powder, turmeric and latex of Euphorbia nerrifolia. Ksharsutra application is a minimal invasive well established procedure in management of fistula-in-ano. Research on Ksharsutra started since 1968 and it is being used till date with high success rate. In this case report the patient was asymptomatic before 15 years but then a boil developed at perianal region which spontaneously bursted and pus discharge was seen from the boil. Patient was diagnosed with Grade 5 St. James’s university hospital classification of perianal fistulae. This was a case of high anal horse shoe fistula. In this case Fistulectomy or Fistulotomy would cause incontinence. So in this case the Ksharsutra was used but with a modification of classical technique called as IFTAK (Interception of fistulous track with application of Ksharsutra) technique. In which a window was created at 6o’ clock and intersphincteric tract was identified and in that tract Ksharsutra was placed. This technique cures such types of complex Fistula in ano with minimal tissue damage and duration of healing is also reduced.