Internal Opening Research Articles

A controlled study of MR DWI, FS-PDW, and CE-T1W imaging for the evaluation of the internal opening of anal fistulas.

Anal fistula (AF) is an abnormal tunnel under the skin connecting the anal canal in the colon to the skin of buttocks. Fat-suppressed (FS) proton density-weighted (PDW) imaging is mainly used for the diagnosis of diseases involving bones and joints. Until now, its value in the diagnosis of anal fistula has been rarely reported. To compare three magnetic resonance imaging (MRI) sequences - diffusion-weighted imaging (DWI), FS-PDW), and contrast-enhanced (CE) T1-weighted (T1W) imaging - for the diagnostic value of the internal opening of AF. MRI scans of 132 patients suspected of having AF between December 2021 and April 2023 were retrospectively analyzed. In total, 65 patients who underwent preoperative MRI and were treated surgically were included. The lesion conspicuity and accuracy for featuring AF were calculated by evaluating the three imaging datasets DWI, FS-PDW, and CE-T1W imaging, with surgical findings serving as the reference standard for the presence of fistulas. The statistical analysis included the application of the chi-square test and Kruskal-Wallis test. In 65 patients with AF, 87 internal openings of AF were confirmed. In terms of the diagnostic accuracy of the internal openings, both FS-PDW and CE-T1W imaging sequences were significantly better than DWI sequences, and the difference was statistically significant (P < 0.05). The FS-PDW imaging sequence showed comparable diagnostic performance of the internal opening of AF to CE-T1W imaging, which can provide an important diagnostic basis for clinical procedures.

Perineal fistulation secondary to retained appendicolith: A rare complication of the unaccounted calculus

An approximately 30-year-old male patient presented with perianal fistula disease. Examination under anesthetic revealed a complex extrasphinteric tract with internal opening in the region of the anterior inferior rectum, although an internal opening was not clearly identified. This failed to heal despite defunctioning procedure and packing of the perineal tract. Specialist center review of computed tomography and magnetic resonance imaging revealed a small cavity anterior to the rectum containing a small calcific density with a long tract extending down into the perineum. Seven years earlier, the patient had presented with clinical features of appendicitis. On retrospective review, an appendicolith can be seen on ultrasound and abdominal X ray (AXR). At surgery, the appendix had disintegrated leaving an abscess cavity. The appendicolith was not appreciated or removed and subsequently migrated into the pelvis acting as a source of infection which fistulated to the perineum. Subsequent removal of the calculus resulted in complete healing.

Gastrointestinal: Leveraging intestinal ultrasound to guide endoscopic closure of the internal opening of a vesico-sigmoid fistula in ileo-colonic Crohn's disease.

Gastrointestinal: Leveraging intestinal ultrasound to guide endoscopic closure of the internal opening of a vesico-sigmoid fistula in ileo-colonic Crohn's disease.

Management of a Piriform Sinus Fistula With Chronic Neck Infection in an Adult.

A pyriform sinus fistula (PSF) is a rare congenital anomaly due to failed obliteration of the third or fourth pharyngeal pouch. Diagnosis and management of PSF remains controversial. We present a case of PSF and discuss its diagnosis and management. Case report and literature review. A 26-year-old female with a chronic left lateral neck abscess was diagnosed with a left PSF. She underwent surgery through a combined approach to close the openings of the PSF, internally and externally. We first placed a blunted ET tube into the internal opening of the PSF. We then performed an external transcervical approach to close the PSF at the cricothyroid membrane. Briefly, after a neck debridement and washout of the chronic neck infection, we identified the recurrent laryngeal nerve (RLN) in Lore's triangle. We performed left hemithyroidectomy to facilitate the dissection and protection of the RLN to its entrance into the larynx. A flexible laryngoscope was then inserted into the left piriform sinus through the ET tube to guide external dissection by transillumination. The scar tissue attached to the superior pole of the left thyroid lobe was then ligated and divided along the cricothyroid membrane. Lastly, we cauterized the internal opening of the PSF. The patient has remained recurrence-free for 1.5 years with normal vocal cord mobility. Histopathology revealed presence of a squamous-lined tract adjacent to the thyroid tissue. Surgical treatment for patients with PSF should be aimed at closing the internal and external openings of the PSF, debriding chronic neck infection, and protecting the laryngeal nerves, instead of removing the entire tract. A concurrent hemithyroidectomy facilitates the identification and protection of the RLN, as well as excision of the tract. Differentiation between third and fourth branchial cleft fistulae may not be clinically necessary, as it is unlikely to alter the therapeutic plan.

Randomized Controlled Trial on Silicone Intubation in Endoscopic Mechanical Dacryocystorhinostomy (SEND): An 11-year Outcome Report

ABSTRACT Purpose To compare the long-term outcomes of mucosal-sparing mechanical endoscopic dacryocystorhinostomy (MMED) for primary acquired nasolacrimal duct obstruction (PANDO) with or without silicone intubation. Methods An 11-year follow-up study of the Silicone intubation in Endoscopic Dacryocystorhinostomy (SEND) randomized controlled trial (RCT) was conducted at a university-affiliated dacryology clinic from December 2019 to March 2023. Questionnaires on symptoms, anterior segment examination, endoscopic examination with functional endoscopic dye test (FEDT) and FICI grading, and ostial size measurements using Image J software were performed by a masked ophthalmologist. The primary outcome was surgical success, defined by Munk’s score ≤1 and a positive fluorescein endoscopic dye test. Secondary outcomes included risk factors for failure and outcomes of revision surgeries. Results Fifty-three of the original 118 patients were evaluated at 155 ± 21 (136–218) months postoperatively. Seventy-seven percent (46/60) ostia remained successful, including 70% (19/27) of unstented and 82% (27/33) of stented ostia (p = .3). Stented ostia had larger size (p = .003), but this did not confer higher success (p = .14). Successful ostia had higher FICI scores and better ostial dynamicity (p < .05). Ostium movement was the only parameter associated with surgical success on multivariate analysis (OR 13.1, p = .01). Four (1 stented) underwent revision MMED, intraoperative mitomycin-C, and 12-week intubation. All revision ostia were functional after 141 ± 43 months. Conclusions Surgical success of MMED after 11-years was 77%, a notable reduction compared to 96% success at 1-year. Statistical advantage of silicone intubation for primary MMED was not demonstrated, though clinically, stented ostia had a higher success (82% vs 70%). The presence of a dynamic internal common opening was highly associated with long-term surgical success.

Closing the internal opening with a rectal advancement flap increases the efficacy of mesenchymal stem cell injection for complex Crohn's disease anal fistulas.

The efficacy of injections of mesenchymal stem cells (MSC) for anal fistula treatment may be impaired by the persistence of stools passing into the fistula, causing bacterial contamination and a local inflammatory reaction. We aimed to compare remission rates between patients treated by MSC injection with simple sutures and those treated with a rectal advancement flap. This single-center prospective study compared the first patients who underwent internal opening closure with sutures with the subsequent patients treated with a flap. Complete clinical remission was defined as complete closure of the external opening(s) without pain or discharge, and complete radiological remission was defined as a Magnifi-CD score of 0. We compared the first 42 patients who had sutures with the 20 subsequent patients who had an advancement flap. The median follow-up was 15.5 [8.8-24.9]months. The cumulative incidence of complete clinical response at M12 was 53.8% [38.1-69.6%] in the suture group versus 93.3% [77.4-100.0] in the flap group (p < 0.001). The Magnifi-CD score was 0 for 41.7% [25.5-59.2%]) of patients treated with sutures versus 72.7% [39.0-63.9%]) of patients treated with a flap (p=0.093). Anal incontinence score did not differ between the two groups. Practicing an advancement flap was the only significant factor associated with complete clinical remission over time (adjusted HR [95% CI] of 2.6 [1.4-4.9], p = 0.003). Complete clinical remission rates following MSC injection are significantly higher after closure of the internal opening with a rectal flap than after closure with sutures, without consequences on anal continence.

The results of an improved method of surgical treatment of extrasphincter fistulas of the rectum

Aim. To study the effectiveness of using a collagen haemostatic membrane in the surgical treatment of extrasphincteric pararectal fistulae.Materials and Methods. This paper presents the results of the examination and surgical treatment of 100 patients with extrasphincteric pararectal fistulas, and we performed a comparative analysis of three applied methods of surgical treatment of the above-mentioned rectal fistulas: the ligating method, which was performed in 31 patients; a method using the movement of the mucosa according to Maslyak (39 patients), and the proposed method with closing the internal opening using a cologenic hemostatic membrane (30 patients).Results. When using traditional methods of surgical treatment of ESPC, the recurrence rate was 11.4%, and US - 22.9% of cases. When the authors used the method of excision of the fistula using a cologenic haemostatic membrane to close the internal opening, rectal sphincter insufficiency was noted in 13.3% and recurrence in -6.7% of cases.Conclusions. The developed method of using a collagen hemostatic membrane to close the internal opening of the fistula minimises the frequency of disease recurrence. This method of surgical treatment of extrasphincteric rectal fistulas using a collagen hemostatic membrane is a sphincter-sparing procedure, reduces anal sphincter insufficiency and is a promising method of surgical treatment of extrasphincteric pararectal fistulas.

Transanal circumferential pouch advancement for treatment of pouch vaginal fistulae

BackgroundIleal pouch anal anastomosis (IPAA) circumferential pouch advancement (CPA) involves full-thickness transanal 180–360° dissection of the distal pouch, allowing the advancement of healthy bowel to cover the internal opening of a vaginal fistula. We aimed to describe the long-term outcomes of this rare procedure.MethodsPatients with IPAA who underwent transanal pouch advancement for any indication between 2009 and 2021 were included. Demographics, operative details, and outcomes were reviewed. An early fistula was defined as occurring within 1 year of IPAA construction. Clinical success was defined as resolution of symptoms necessitating CPA, pouch retention, and no stoma at the time of follow-up. Figures represent the median (interquartile range) or frequency (%).ResultsOver a 12-year period, nine patients were identified; the median age at CPA was 41 (36–44) years. Four patients developed early fistula after index IPAA, and five developed late fistulae. The median number of fistula repair procedures prior to CPA was 2 (1–2). All patients were diagnosed with ulcerative colitis at the time of IPAA and all late patients were re-diagnosed with Crohn’s disease. Four (44.4%) patients had ileostomies present at the time of surgery, three (33.3%) had one constructed during surgery, and two (22.2%) never had a stoma. The median follow-up time was 11 (6–24) months. Clinical success was achieved in four of the nine (44.4%) patients at the time of the last follow-up.ConclusionsTransanal circumferential pouch advancement was an effective treatment for refractory pouch vaginal fistulas and may be offered to patients who have had previous attempts at repair.

Endoscopic diagnostic and therapeutic management of branchial cleft fistula type III & IV: a single tertiary centre experience.

To date, recurrent neck abscesses associated with branchial anomalies are treated using a variety of techniques. Management strategies may include various imaging modalities and surgical methods. Endoscopic assessment and electrocauterization are the preferred diagnostic modalities and treatment strategies that have recently gained widespread acceptance and popularity. This was a retrospective review on patients' medical record from 2016 to 2023. Seven patients underwent endoscopic cauterization at our centre, a tertiary academic institution. Five of the patients (71.5%) achieved complete remission. Two patients experienced recurrence within 6 months that necessitated re-cauterization once but subsequently recovered completely. Currently, endoscopic management is the preferred approach compared to the typical open neck excision surgery as it is significantly less invasive, resulting in lesser morbidity and similar success rates. At presentation, all of them had ultrasound neck that suggestive of neck abscess. Computed tomography or magnetic resonance imaging unable to provide adequate information about the side of internal opening of fistula where only 3 out of 7 patients demonstrated tract up to the ipsilateral region of pyriform fossa. Management outcomes of this limited case series showed the potential benefits of endoscopic cauterization as the minimally invasive therapeutic method for recurrent neck abscesses caused by third and fourth branchial cleft fistulas but also to suggest the possibility as the first diagnostic tool prior to imaging studies.

The flow regimes of two parallel-connected chambers respectively with a mechanical extractor and a buoyancy source

This research studies the ventilation flow patterns and density stratification in two parallel-connected chambers which respectively have a mechanical extractor and a localized buoyancy source. Two parallel-connected chambers are denoted as the forced and extracted chambers. The forced chamber having a continuous localized buoyancy source is located upstream, and the extracted chamber having a mechanical extractor is located downstream. Two chambers are interconnected by an internal connection opening and are connected to the exterior in a parallel manner through their own connection openings. The effects of the adjoining chamber having a mechanical extractor on the ventilation flow patterns and density stratification in the space are investigated in this study. The flow driving forces include the buoyant and inertial forces in this ventilated space. The buoyant force results from the buoyancy source, and the inertial force is due to the mechanical extractor. This research uses the theoretical analysis approach and the laboratory reduced-scale model to investigate this problem. This paper focuses on the ventilation flow patterns in the steady state and discusses different flow regimes due to the adjoining extracted chamber effect. The internal connection opening level and orientation between two chambers are discussed in this study. Three flow regimes, the small (or reduced), transition, and large (or enhanced) flow regimes, are found in two parallel-connected chambers and there is a range of critical flow rates to determine the flow regime when the internal connection opening is located in a partition wall as investigated in this research. If the internal connection opening is located in a horizontal ceiling, a clear-cut critical flow rate is expected and only two flow regimes exist. This study discusses the characteristics of different flow regimes in the space of two parallel-connected chambers. The paper presents three derived theoretical models and analogous salt-bath experimental results for three flow regimes, and comparisons between them show reasonable agreement.

Efficacy of injection of autologous adipose tissue in the treatment of patients with complex and recurrent fistula-in-ano of cryptoglandular origin

BackgroundAdipose tissue injections, a rich source of mesenchymal stem cells, have been successfully used to promote anal fistula healing. This study aimed to investigate the efficacy of adipose tissue injection in treating patients with complex and recurrent fistulas of cryptoglandular origin.MethodsWe conducted a prospective, single-center, open-label, non-randomized, interventional clinical trial from January 2020 to December 2022. We enrolled nine patients, who were evaluated after at least 12 months of follow-up. All patients had seton removal, fistula tract excision or curettage, and a mucosal flap if possible or, alternatively, an internal opening suture. We used a commercially available system to collect and process adipose tissue prior to injection. This system allowed the collection, microfragmentation, and filtration of tissue.ResultsSelected cases included six men and three women with a median age of 42 (range 31–55) years. All patients had an extended disease course period, ranging from 3 to 13 (mean 6.6) years, and a history of multiple previous surgeries, including two to eight interventions (a mean of 4.4 per case). All fistulas were high transsphincteric, four cases horseshoe and two cases with secondary suprasphincteric or peri-elevator tract fistulas. Six cases (66%) achieved complete fistula healing at a mean follow-up of 18 (range 12–36) months. Three cases (33.3%) experienced reduced secretion and decreased anal discomfort.ConclusionsIn patients with complex and recurrent fistulas, such as the ones described, many from palliative treatments with setons, the adjuvant injection of adipose tissue might help achieve complete healing or improvement in a significant percentage of cases.ClinicalTrialsThe study protocol was prospectively registered on ClinicalTrials.gov (NCT 04750499).

Mesenchymal stem cell therapy for therapy refractory complex Crohn’s perianal fistulas: a case series

BackgroundMesenchymal stem cell treatment (MST) has emerged as a new therapeutic strategy for Crohn’s perianal fistulas. It has been demonstrated that a fibrotic tract on MRI with a MAGNIFI-CD score ≤ 6 is the best predictor for long-term clinical closure. Therefore, the aim of the current study was to analyse the effectiveness of MST for complex Crohn’s perianal fistulas based on MRI.MethodsConsecutive patients with complex Crohn’s perianal fistulas, previously failing both anti-TNF treatment and surgical closure, who had surgical closure of the internal opening with MST were included. The primary endpoint was radiological remission of the fistula(s) defined as a MAGNIFI-CD ≤ 6 on MRI, read by an experienced radiologist.ResultsBetween December 2019 and March 2023, 30 patients (15 males) with 48 fistula tracts were included with a median follow-up of 16.5 months. Radiological remission was achieved in thirteen patients (43.3%) after a median follow-up of 5.0 months (IQR 3.0–6.0). The median MAGNIFI-CD at baseline was 15.0 (IQR 7.0–20.0) which significantly decreased to 8.0 (IQR 3.0–15.0) after treatment (p = 0.001). Clinical closure was achieved in 21 patients (70.0%). Three patients (14.3%) developed a recurrence during long-term FU, all with clinically closed fistula(s), but no radiological remission. The median PDAI decreased significantly from 10.5 (IQR 7.0–14.0) to 4.0 (IQR 0.0-7.3) (p = 0.001).ConclusionMST is a promising treatment strategy for therapy refractory Crohn’s perianal fistulas, resulting in > 40% radiological remission, clinical closure in 70% and a significant improvement in quality of life. No recurrences were seen in patients with radiological remission.

Subtotal fistulectomy and sliding anoderm flap: A new sphincter-sparing technique for anal fistula.

The underlying causes of failure or recurrence after ligation of the intersphincteric fistula tract are postulated to be refistulization, breakdown of the closure wound in the intersphincteric plane and faecal contents entering the internal opening, thereby causing recurrent infection. The aim of this study is to demonstrate the outcomes of subtotal fistulectomy with sliding anoderm flaps to prevent refistulization. This retrospective study used prospectively collected data. Patients with transsphincteric or intersphincteric fistulas were enrolled between August 2021 and July 2023. An anal manometric study was performed before and after surgery. Faecal incontinence was evaluated using the faecal incontinence severity index (FISI). Failure was defined as nonhealing of the surgical wound or fistula. Fifty-one patients who underwent subtotal fistulectomy with a sliding anoderm flap were included. After a median follow-up of 12 months (range 4-27 months), primary healing was achieved in 49 patients (96%). Two patients experienced treatment failure, while none developed postoperative recurrence. The median healing time was 10 weeks (range 6-24 weeks). The FISI scores did not change significantly after the surgery. The median resting pressure significantly reduced after surgery [125 cmH2O (range 59-204 cmH2O) vs. 99 cmH2O (range 36-176 cmH2O); p = 0.0001]. The median squeeze pressure significantly decreased after surgery [356 cmH2O (range 137-579 cmH2O) vs. 329 cmH2O (range 72-594 cmH2O; p = 0.005)]. Subtotal fistulectomy with a sliding anoderm flap showed excellent healing rates with no postoperative deterioration of anal function.

Accuracy prediction of Goodsall's rule for anal fistulas of crypotogladular origin, is still standing?

Treatment of anal fistulas is still a challenging task because of high recurrence and risk of incontinence. Identification of internal fistula opening is paramount for successful treatment. Goodsall's rule is commonly used to predict the course of fistula and internal opening. However, its accuracy has been questioned by many investigators and its role became a controversial topic. This is a case series prospective study in which 320 consecutive patients with anal fistula with Mean age 48.9± 6 years ages (ranges from 16 to 64years) and mean body mass index 24.8± 5.5 average 18.5-30.6) were enroled. Goodsall's rule was applied to all fistulas according to the site of external fistula opening. Location of internal fistula opening as suggested by Goodsall's rule then compared to the exact location of internal opening identified by perineal or pelvic MRI and intraoperative findings. to assess the accuracy and positive predictive value of the Goodsall's rule in predicting the internal opening of the tract. The overall accuracy rate, positive predictive value (PPV), sensitivity and specificity of Goodsall's rule in this study were 74.75%, 77.1, 74.5, and 72.05, respectively. The accuracy in predicting the internal fistula opening was 52.4% in anterior tracts and 73% in posterior tracts. Goodsall's rule was found to be more accurate in posterior fistulas than anterior fistulas and in short superficial fistulas rather than in long and high fistulas. Goodsall's rule was accurate in 74.75% of anal fistulas. It was more accurate for posterior long fistulas and anterior short and superficial fistulas. Patients with long (>3cm) anterior fistulas defied Goodsall's rule when they found to have fistulas tracking to a midline anterior origin. Further, short posterior fistulas were found to open more commonly in a direct radial course rather to midline posteriorly.

Five years of experience in using the laser coagulation method in the treatment of trans- and extrasphincter fistulas of the rectum

THE AIM OF the STUDY was to study the results of surgical treatment of patients with trans- and extrasphincter fistulas of the rectum using laser coagulation, depending on the method of closure of the internal fistula opening.PATIENTS AND METHODS: within the framework of scientific research conducted at the NMIC of Coloproctology named after A.N. During a 5-year period, 121 patients underwent surgical interventions using laser coagulation of the fistula passage in combination with 3 different options for closing the internal fistula opening.43 patients were included in the group of laser coagulation of the fistula course in combination with its ligation in the intersphincter space (LT+PSMP), 47 – in the group of laser coagulation of the fistula with plasty of the internal fistula opening with a mucomuscular flap (LT+SML), 31 - in the group of laser thermocoagulation of the fistula course with suturing of the internal fistula opening with separate seams (LT+UVC). The average age of patients is 42 (20-70) years. Men - 82, women -39. The average follow-up period was 19 (3-52) months. In the perioperative period (before surgery, 1 and 2 months after the intervention), patients underwent ultrasound monitoring to assess the healing process of fistulas and early detection of relapses of the disease. To assess the effect of operations on the functional state of the rectal occlusion apparatus before the intervention and 3 months after the operation, patients underwent sphincterometry.RESULTS: in the LT+PSMP group, fistula healing was noted in 33/43 (76.7%) patients, in the LT+SML group - in 33/47 (70.2%) patients, in the LT+UVS group – in 17/31 (54.8%) patients (p=0.129). The only established factor that demonstrated a statistically significant effect on the frequency of positive results in the LT+PSMP group was the diameter of the internal fistula opening. Thus, with a fistula hole diameter of more than 3 mm, a positive result was achieved in 24 (54.5%) of 44 patients, and with a hole diameter of less than3.0 mm, the fistula course healed in 58 (75.3%) of 77 cases (p=0.025).The average length of a bed day (Iu) was 3.5. Complications during surgery and the immediate postoperative period were recorded in only 3 (2.5%) cases.CONCLUSION: Over the five-year period of application, the laser coagulation method has proven itself as a sphincter-sparing intervention that can compete with traditional methods of treating rectal fistulas in a selected group of patients. Regardless of the method of closing the internal fistula opening, the technique has demonstrated a high level of safety. The best rates of healing were recorded when laser coagulation was combined with ligation of the fistula in the intersphincter space (76.7%), however, the search for the most reliable way to isolate the fistula from the lumen of the rectum should be continued.

Modal and random vibration responses of composite overwrapped pressure vessels with various geodesic dome trajectories

In the current study, Composite Overwrapped Pressure Vessels (COPVs) with various geodesic dome profiles have been built and their modal and random vibration responses were numerically examined. In this regard, geodesic dome profiles were established for five different polar opening radii of 10, 15, 20, 25, and 30 mm, and thus the impacts of fibre orientations on vibration characteristics depending on the filament winding trajectories were discovered. Furthermore, non-prestressed modal and random vibration responses for COPVs, as well as prestressed vibration behaviours under 50, 100, and 150 Bar internal pressure, were investigated and thus the effects of internal pressure severity on dynamic characteristics were identified. The study found that higher polar opening radius triggered a reduction in the natural frequencies, and these reductions were linked to an increment in the filament winding angle, and a consequent deterioration in the structural stiffness of COPVs. On the other hand, raising the internal pressure severity shifts the natural frequencies to higher frequencies, which are also attributed to ascended structural stiffness. Furthermore, it was established that internal pressure severity and polar opening radius had a coupled effects on the modal and random responses, and that both parameters should be evaluated simultaneously.

Integrative management of high transsphincteric fistula-in-ano with a rectal opening: A case report

Abstract Transsphincteric fistula is a type of complex anal fistula, often considered a refractory surgical condition, which has the potential to produce complications, such as recurrent infections, abscess formation, and incontinence. A 48-year-old male farmer was diagnosed with a high transsphincteric fistula abscess with a secondary rectal opening based on clinical examination and magnetic resonance imaging findings. Under saddle block, incision and drainage of fistula abscess was performed, followed by threading of Apamarga Kshara Sutra (medicated seton) between the abscess cavity and the primary internal opening at 6 o’clock on the dentate line. Another internal opening was also identified in the lower rectum, left as it is. Panchavalkala Kwatha for sitz bath once a day, Varunadi Kwatha 20 mL twice a day orally, Kachanar Guggulu (500 mg) two tablets three times a day, and Apamarga Kshara Tail (AKT) dressing was prescribed for 124 days to facilitate optimal healing and management. Prophylactic as well as therapeutic antibiotics and analgesics were administered for 7 days. The fistula took 103 days for complete healing with a unit healing time of 0.251 day/cm3. Medicated seton on the dentate line facilitated drainage of the infected gland and healed the secondary rectal opening. Ischiorectal abscess cavity healed by secondary intention. This case report demonstrates that a high transsphincteric fistula-in-ano with a rectal opening can be successfully managed without fistulotomy to treat the secondary rectal opening. Chemical debridement of the infected anal gland was achieved by a medicated seton, and a new seton was replaced every 7 days until the cutting and healing of the fistula track. It also facilitated the drainage of the exudate. Wound management by AKT and adjuvant medicament supported faster recovery.

Evaluation of unenhanced three-dimensional endoanal ultrasound scan in preoperative assessment of perianal sepsis

Background: Perianal sepsis which includes perianal fistula and abscess is a common clinical condition that requires thorough preoperative evaluation to decrease the recurrence rate and to plan relevant surgery according to the anatomy of the fistula. MRI and 3D EAUS are two important preoperative investigations that delineate the anatomy of simple and complex fistula tracts. Due to lower cost and easier use 3D EAUS is a safe and reliable first-line investigation in evaluating perianal abscess. Methods: This is a retrospective and prospective analysis of patients with perianal sepsis who underwent pre-operative unenhanced 3D-EAUS in the departments of Colorectal surgery, Gastrointestinal surgery, and General surgery in our hospital. A B-K medical 2052 transducer was used for the study and the surgical assessment was done by multiple surgeons from multiple departments. Results: A total of 255 patients were assessed. The accuracy for primary fistula tracts and internal opening was 83.53% and 88.62% respectively. The kappa coefficient of correlation was k=0.70 (substantial agreement) for the fistula tract and k=0.81 (near perfect agreement) for the internal opening. The sensitivity, and specificity of primary tracts and internal openings were calculated. Transphincteric fistulas were 57% in our study. Conclusions: Unenhanced 3D EAUS is a reliable first-line investigation in preoperative evaluation of perianal fistula and abscess. Transphincteric fistula is the most common type of fistula. There is a high chance of correlation for the primary tract if a non-colorectal specialist performs the fistula surgery after 3D-EAUS without blinding.

DLPL Sphincter Saving Laser Surgery for Complex Anal Fistula - A Gold Standard Procedure. Study of 40 Cases

Introduction: Complex anal fistula (CAF) is a complex condition to treat because of the possibility of recurrence and impoverished continence. DLPL (Distal laser proximal ligation), is a novel approach to treating difficult anal fistula that involves suturing the proximal portion of the fistula tract close to the internal opening and using a diode laser to close the distal part of the fistula tract. This study aimed to evaluate the clinical efficacy and safety of DLPL Sphincter Saving Laser Surgery for Complex Anal Fistula. Aim of the study: The aim of this study was to evaluate the clinical efficacy and safety of DLPL Sphincter Saving Laser Surgery for Complex Anal Fistula - A Gold Standard Procedure in a study of 40 cases. Methods: This study was a prospective observational study that investigated the outcomes of DLPL (Distal Laser Proximal Ligation) for patients with complex anal fistula. The patients met clinical diagnosis of complex anal fistula according to the Parks classification, age of 10 years or more, and failure of previous conservative or surgical treatments. The patients were followed up at 3 and 6 months after the surgery, and assessed using fistulogram, endo anal ultrasound, MRI. Result: The study enrolled 40 patients (35 males and 5 females) with mean age being 31.25 years. 31 (77.50%) patients had non-specified histopathology. 2 (5.00%) patients had Chron’s disease, 2 (5.00%) patients had F.B Granuloma, and 5 (12.50%) patients had Tuberculosis. The patients were assessed using fistulogram, endo anal ultrasound, MRI. After 6 months, the patients were followed up and 38 (95.00%) patients had no recurrence, only 2 (5.00%) patients had recurrence. Conclusion: The results showed high success rate and low complication rate of DLPL for complex anal fistula. Therefore, this study concluded that DLPL is a safe and effective sphincter-saving technique for complex anal fistula, and that it may be considered as a gold standard procedure for this challenging c

P541 Long-term follow-up results of darvadstrocel for complex perianal fistulas in patients with Crohn's disease: 3-year outcomes from a Japanese phase 3 study

Abstract Background Darvadstrocel (DVS), a suspension of expanded human allogeneic mesenchymal stem cells extracted from adipose tissue, is for the treatment of complex perianal fistulas in patients with Crohn's disease (CD). In Japan, DVS was approved in 2021 based on the Japanese phase 3 study Week 52 data combined with the pivotal study ADMIRE-CD data. Patients who participated in the Japanese study were monitored for 3 years, and we report the results at Week (W) 156. Methods This was an open-label, uncontrolled, phase 3 study (converted to a post-marketing clinical study after approval) conducted from March 2019 to February 2023 in Japan. Subjects had complex Crohn’s perianal fistulas (CPF) refractory to conventional treatments with a maximum of 2 internal openings (IO) and 3 external openings (EO). The fistula tract was curetted approximately 2-3 weeks before DVS administration, and a drainage seton was placed. On the day of administration, seton was removed, fistula tracts were curetted again, and IO was sutured. A total of 24 mL of DVS (including 120x106 cells) was administered around the IO and into the wall of fistula tracts. During the 2-year follow-up period after W52, medical and surgical treatment for CD and CPF was given as needed, and subjects were assessed every 6 months. Results 22 Japanese patients were enrolled from 9 sites. The mean (SD) age was 36.4 (10.4) years, 63.6% were male, and the mean (SD) duration of CD was 11.3 (6.6) years. By W156, most frequently reported adverse events (AE) were anal fistula (7/22), proctalgia (7/22), and nasopharyngitis (6/22). New serious AE occurred after W52 were found in 9 subjects: COVID-19 (4), CD (2), perianal fistula, small bowel obstruction, premature labour (1 each). None of these were considered DVS-related. At W156, the combined remission rate (clinical and MRI assessment) was 15/22 (68.2%, 95% CI [48.7%, 87.6%]), clinical remission rate (clinical assessment) was 15/22 (68.2%, 95% CI [48.7%, 87.6%]), response rate (no drainage from ≥50% of treated EOs) was 20/22 (90.9%, 95% CI [78.9%, 100.0%]), and relapse rate (at least 1 relapse by W156 after achieving remission at W52) was 3/15 (20.0%, 95% CI [0.0%, 40.2%]). Mean Perianal Disease Activity Index (PDAI) total score (SD) was 4.8 (2.2) at baseline, which was decreased to 2.1 (2.1) at W52, and 1.7 (2.0) at W156. Mean Crohn's Disease Activity Index (CDAI) total score (SD) was 94.3 (60.1) on the day of administration, which was decreased to 73.7 (73.6) at W52, and 71.4 (51.2) at W156. Conclusion This is the first prospectively observed clinical outcomes in CPF for 3 years after DVS administration. There were no new safety findings, and fistula remission observed at W52 was maintained until W156.