Anal Sphincter Complex Research Articles

Beyond breathless: a case of air infiltrating every cavity

Hawaii attracts 10 million tourists annually, with non-residents accounting for 9% of trauma cases, half of which are water-related. We experienced a SCUBA tank injury, causing extensive trauma from pressurized air release. A 53-year-old female, post-Scuba diving, fell onto a SCUBA tank, causing rapid pressurized air discharge. She presented with perineal pain, bloating, and extensive subcutaneous emphysema. CT revealed air in every possible cavity. Thoracostomies and exploratory laparotomy performed, revealing an 80-90% anal sphincter transection. An overlapping anal sphincteroplasty with diverting loop ileostomy was performed. Recovery was uncomplicated. This unique case involves a traumatic SCUBA tank air release causing extensive damage. The patient avoided direct anorectal entry, preventing catastrophic damage but sustained an anal sphincter complex injury. Air likely entered the peritoneum through the levator ani, causing pneumoperitoneum and pneumothoracies. The extensive damage emphasizes the need for safe water sports practices. The patient’s recovery highlights the human body’s resilience in unique situations.

Effect of Single-Dose Imipramine on Anal Sphincter Tone in Healthy Women: A Randomized, Placebo-Controlled Study Using Anal Acoustic Reflectometry

Introduction and HypothesisDespite the high prevalence of fecal incontinence, existing treatment options may be inadequate. Drugs that enhance the tone of the anal sphincter complex could potentially be an effective pharmacological approach. This study investigated the effect of the tricyclic antidepressant imipramine on anal sphincter tone in healthy women, employing anal acoustic reflectometry as the evaluating method.MethodsIn a double-blind, randomized, placebo-controlled crossover study, 16 healthy female volunteers were randomized to one of two treatment sequences. The participants attended two study visits separated by at least 7 days’ washout. At each visit, they received a single dose of 50 mg imipramine or matching placebo, in alternating order. We assessed the anal opening pressure under the resting state and during voluntary squeezing of the pelvic floor. Measurements were performed pre-dose and 1 h after drug administration, corresponding to the estimated time of peak plasma concentration of imipramine.ResultsAll participants completed the study. In total, 44% of the participants reported at least one adverse effect, primarily anticholinergic. Compared with placebo, imipramine increased anal opening pressure by 15.2 cmH2O (95% confidence interval [CI] 2.0–28.2 cmH2O, p = 0.03) in the resting state and 15.1 (95% CI 4.2–26.0 cmH2O, p = 0.01) cmH2O during squeezing.ConclusionsThe findings indicate that imipramine increases anal sphincter tone in healthy women. However, further research is required to evaluate its clinical impact on individuals with fecal incontinence. This research also demonstrates the effectiveness of using anal acoustic reflectometry for assessing pharmacological effects on anal sphincter function.

Automatic anal sphincter integrity detection from ultrasound images via convolutional neural networks.

The anal sphincter complex comprises the anal sphincter and the U-shaped deep and superficial puborectalis muscle. As an important supporting structure of the posterior pelvic floor, together with its surrounding tissues and muscles, the anal sphincter complex maintains the normal physiological functions of defecation and continence. The plane required for diagnosing anal sphincter injury and the diagnosis of anal sphincter integrity through pelvic floor ultrasound are highly dependent on sonographers' experience. We developed a deep learning (DL) tool for the automatic diagnosis of anal sphincter integrity via pelvic floor ultrasound. A 2D detection network was trained to detect the bounding box of the anal sphincter. The pelvic floor ultrasound image and its corresponding oval mask were input into a 2D classification network to determine the integrity of the anal sphincter. The average precision (AP) and intersection over union (IoU) were used to evaluate the performance of anal sphincter detection. Receiver operating characteristic (ROC) analysis was used to evaluate the performance of the classification model. The Pearson correlation coefficients (r values) of the topmost and bottommost layers detected by the CNN and sonographers were 0.932 and 0.978, respectively. The best DL model yielded the highest area under the curve (AUC) of 0.808 (95% CI: 0.698-0.921) in the test cohort. The results from the CNN agreed well with the diagnostic results of experienced sonographers. We proposed, for the first time, a CNN to obtain the plane required for diagnosing anal sphincter injury on the basis of pelvic floor ultrasound and for preliminarily diagnosing anal sphincter injury.

Fecal incontinence patients categorized based on anal pressure and electromyography: Anal sphincter damage and clinical symptoms.

Disruption of external anal sphincter muscle (EAS) is an important factor in the multifactorial etiology of fecal incontinence (FI). We categorize FI patients into four groups based on the location of lesion in neuromuscular circuitry of EAS to determine if there are differences with regards to fecal incontinence symptoms severity (FISI) score, age, BMI, obstetrical history, and anal sphincter muscle damage. Female patients (151) without any neurological symptoms, who had undergone high-resolution manometry, anal sphincter EMG, and 3D ultrasound imaging of the anal sphincter were assessed. Patients were categorized into four groups: Group 1 (normal)-normal cough EMG (>10 μV), normal squeeze EMG (>10 μV), and normal anal squeeze pressure (>124 mmHg); Group 2 (cortical apraxia, i.e., poor cortical activation)-normal cough EMG, low squeeze EMG, and low anal squeeze pressure; Group 3 (muscle damage)-normal cough EMG, normal squeeze EMG, and low anal squeeze pressure; and Group 4 (pudendal nerve damage)-low cough EMG, low squeeze EMG, and low anal squeeze pressure. The four patient groups were not different with regards to the patient's age, BMI, parity, and FISI scores. 3D ultrasound images of the anal sphincter complex revealed significant damage to the internal anal sphincter, external anal sphincter, and puborectalis muscles in all four groups. The FI patients are a heterogeneous group; majority of these patients have significant damage to the muscles of the anal sphincter complex. Whether biofeedback therapy response is different among different patient groups requires study.

Low Anterior Resection Syndrome. Anatomical Changes after Anterior Rectal Resection.

In this editorial, the authors bring to the attention of surgeons a personal point of view with the intention of offering a series of anatomical arguments to explain the high rate of functional complications following ultralow rectal resections, resections dominated by faecal incontinence of various intensities. Having as a starting point the anatomy of the pelvic floor and the posterior perineum, the authors are concerned with the functional outcomes of the sphincter-saving anterior rectal resection, regarding the low and ultralow resection. Technically, a conservative surgery for low rectal cancer has been currently performed. If 25 years ago the abdominoperineal resection was the gold standard for rectal cancer located under 7cm from the anal verge, nowadays the preservation of the anal canal as a partner for colon anastomosis has been accomplished. Progressively, from a desire to preserve the normal passage of stool into the anal canal, as anatomically and physiologically as possible, the distal limit of resection was lowered to 2-4 cm from the anal verge and ultra-low anastomoses were created, within the anal sphincter complex. The stated goal: keep the oncological safety standard and, at the same time, avoid definitive colostomy. Starting from the normal anatomy of the pelvic floor and the anorectal segment, the authors take a look at the alterations of the visceral, muscular, and nerve structures as a consequence of the low anterior resection and, particularly, the ultralow anterior resection. A significant degree of functional outcomes regarding defecation, with the onset of marked disabilities of anal continence, the major consequence being anal incontinence (30-70%), have been noticed. The authors go under review for the main anatomical and physiological changes that accompany anterior rectal resection. Conclusions: Thus, the following questions arise: what is the lower limit of resection to avoid total fecal incontinence? Is total incontinence a greater handicap than colostomy or is it not? The answers cannot be supported by solid arguments at this time, but the need to initiate future studies dedicated to this problem emerges.

P519 Assessment of anal sphincter complex in pregnant patients with non-active perianal Crohns disease

Abstract Background Pregnant IBD patients are more likely to undergo Cesarean delivery (CS).. Active perianal Crohn’s disease (PCD) is the only Crohns - related indication for CS. The rationale for CS in this group is that active PCD damages the sphincters and therefore a vaginal delivery may exacerbate the damage to the point of fecal incontinence. Pregnant PCD patients with non-active PCD are commonly not offered CS. We suspect that lack of active PCD does not necessarily attest for the physiological function of the anal complex sphincter and that vaginal delivery may exacerbate their condition to the point of incontinence. Therefore, we conducted a prospective trial to examine, prior to delivery, the anatomy and physiology of the sphincter complex in our cohort and weather pregnant patients with non-active PCD suffer from sphincter damageMethods All consecutive pregnant patients with Non-active PCD were enlisted. Patients underwent physical examination, anal manometry and Trans Rectal Ultra Sound (TRUS) before conception or during pregnancy before delivery. Active PCD was defined as: Perianal abscess, fistulas with active drainage, severe fissures and stricture. Non active PCD was defined as history of prior PCD, history of surgery for perianal fistula or old scars from previous abscess drainage. Results There were 13 patients who were enlisted to our study. Table 1 describes the TRUS, Manometry and pregnancy details. There were 9 patients (69%) with evidence of sphincter damage in our cohort including external and/or internal sphincter of at least 30 degrees of the muscle radius. Of them, 6 had posterior damage and 4 had anterior damage. In Manometry all patients had either normal or satisfying results. Three patients were strongly recommended to choose CS due to the sphincter damage. Conclusion patients with non-active PCD and future intent to deliver should be assessed routinely regarding their sphincter complex status. This should include TRUS, manometry and clinical evaluation. We discuss with each patient the advantages and disadvantages of vaginal delivery versus CS, weighing the risk of repeated CS (mainly placenta previa and accreta) against the risk of incontinence. Maternal age, Obstetrical history and estimated fetal weight at delivery are the main factors to consider. Although it is still unclear if detected muscle injury affect clinical incontinence, it is our practice to recommend CS for patients with significant muscle damage. We emphasize our recommendation specifically in patients with anterior damage because potentially delivery damage would be to the same area

Survey of rectal cancer MRI technique and reporting tumour descriptors in the UK: a multi-centre British Society of Gastrointestinal and Abdominal Radiology (BSGAR) audit

To evaluate variation in magnetic resonance imaging (MRI) technique and reporting of rectal cancer staging examinations across the UK. A retrospective, multi-centre audit was undertaken of imaging protocols and information documented within consecutive MRI rectal cancer reports between March 2020 and August 2021, which were compared against American and European guidelines. Inclusion criteria included histologically proven rectal adenocarcinoma and baseline staging MRI rectum only. Fully anonymised data from 924 MRI reports by 78 radiologists at 24 centres were evaluated. Thirty-two per cent of radiologists used template reporting, but these reports offered superior documentation of 13 out of 18 key tumour features compared to free-text reports including T-stage, relation to peritoneal reflection and mesorectal fascia (MRF), nodal status, and presence of extramural venous invasion (EMVI; p<0.027 in each). There was no significant differences in the remaining five features. Across all tumour locations, the tumour relationship to the MRF, the presence of EMVI, and the presence of tumour deposits were reported in 79.5%, 85.6%, and 44% of cases, respectively, and tumour, nodal, and distant metastatic stage documented in 94.4%, 97.7%, and 78.3%. In low rectal tumours, the relationship to the anal sphincter complex was reported in only 54.6%. Considerable variation exists in rectal cancer MRI acquisition and reporting in this sample of UK centres. Inclusion of key radiological features in reports must be improved for risk stratification and treatment decisions. Template reporting is superior to free-text reporting. Routine adoption of standardised radiology practices should now be considered to improve standards to facilitate personalised precision treatment for patients to improve outcomes.

Predicting perineal trauma during childbirth using data from a general obstetric population.

Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population. Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation. Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance. Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.

Efficacy and feasibility of stromal vascular fraction containing adipose derived stem cells obtained from freshly prepared lipoaspirate for treatment of complex anorectal fistulas- A novel approach

BackgroundAnal fistulas are relatively common. Despite diverse treatment modalities and tremendous advance and optimization of surgical approaches, considerable recurrence and high failure rates are not uncommon especially after surgery for complex anal fistulas. Therefore, autologous adipose-derived stem cell therapy for the treatment of complex perianal fistula can be an innovative and promising option with potential high cure rate and long-term healing. AimTo assess the efficacy and feasibility intralesional administration of stromal vascular fraction containing autologous, adipose-derived stem cells prepared from fresh lipoaspirate for management of complex and recurrent anal fistula. MethodsTotally, 28 patients with complex perianal fistulas were enrolled in this prospective case-series study from March 2018 and August 2022. They were 22 male and 6 females patient) with 38.8 years average ages (ranges from 26 to 54 years). All patients were assigned to receive intralesional injection with autologous freshly prepared adipose-derived stem cells from lipoaspirate suction in a concentration of 1 × 107 cell/ml. The healing of fistulas, confirmed by clinical assessment and magnetic resonance imaging was evaluated at week 6 weeks, 12 weeks and 6 months after treatment. If no evidence of healing was not seen at 6 weeks, a second dose of same concentration was administered. In addition to fistula healing, adverse effect (functional outcomes), complications and procedure safety were also evaluated. ResultsThe overall healing rate of fistulas treated by injection of ADSCs was 60.7% (17/28), while healing rate after first injection was 50% (14/28) and after second injection was 30% (3/10).Three patients were lost after first injection. During the follow up period of 6 months none of the patients who showed complete healing, recorded relapse of their fistulas (recurrence 0%). Further, none of the patients recorded complications or adverse reactions related to stem cell therapy during the study and none of them had worsening fecal incontinence during follow-up period. Postoperative pain assessed by.VAS score was significantly low (>3). Fecal continence assessed by Wexner score of all patients was not changed or affected. ConclusionsInjection of complex perianal fistulas by freshly prepared autologous ADSCs could be a valid and effective treatment modality. It is safe, feasible and minimally invasive procedure that lacks the risk of injury to anal sphincter complex, unlike other surgical procedures that endanger the anal continence.Further, second dose of ADSCs injection could improve the rate of healing, without adding adverse effects.

Evaluation of Anal Sphincter with High Resolution Anorectal Manometry and 3D Reconstruction in Patients with Anorectal Malformation

Background: Patients with anorectal malformation (ARM) need long-term follow-up, in order to evaluate fecal continence; the main predictors of longer-term success are the type of ARM, associated anomalies and sacral integrity. Three-Dimensional High Resolution Anorectal Manometry (3D-HRAM) gives detailed information on pressure on the anal complex profile. Our objective was to analyze anal sphincter activity in ARM patients with 3D-HRAM establishing the correlation between manometric and clinical data. Methods: Forty ARM patients were submitted to 3D-HRAM: manometric, anatomical and clinical scores were correlated with each other and with the bowel management response (BM). Results: A positive correlation between all scores and types of ARM was found: in high ARM and in patients with spinal anomalies (regardless to ARM type) lower scores were reported and even after BM they did not achieve good continence. Conclusions: 3D-HRAM gives detailed data on the functional activity of the anal sphincter complex. Our study revealed a correlation between manometric parameters and clinical outcomes, confirming spinal malformations and ARM type as the most important prognostic risk factors for a bad outcome. Specific sphincteric defects can also be explored with manometry, allowing for tailored bowel management strategies.

COMPLEX FISTULAS IN ANO: SETON PLACEMENT AN EFFECTIVE SOLUTION TO TRICKY ENIGMA SHORT

Fistulas in ano is an abnormal connection between anal canal and perianal skin. There are two subtypes occur on the basis of course of fistulous tract and involvement of external anal sphincter simple and complex. Complex fistula is challenging to manage due to risk of recurrence and fecal incontinence even in experienced hands. A myriad of surgical procedures are available in armamentarium of surgeon for ages and placement of seton is the one of answer to this complex clinical entity. Seton placement preserve the fecal continence and prevent recurrence. We here presenting our experience of managing 116 cases with seton placement over three years duration at a tertiary care centre. In our series recurrence rate was around 10% without any fecal incontinence. Seton placement is a safe option for managing complex fistula in Ano.

Treatment of Rectovaginal Fistula.

Rectovaginal fistula (RVF) is a challenging complication with unsatisfactory success and a significant burden for the patients. With insufficient clinical data due to the rare entity, the present state of treatments for RVFs was reviewed especially form the point of factors to determine management, classifications, principle of treatment, conservative and surgical treatments with outcomes. Size, fistula localization and etiology, type of fistula; "simple" or "complex," status of anal sphincter complex and surrounding tissue, presence or absence of inflammation, presence of diverting stoma, previous attempted repair and radiation therapy, patient's condition with co-morbidities, and surgeon's experience are important factors to determine the management of RVF. The inflammation should initially subside in cases with infection. Starting with conservative surgical options and interposing healthy tissue for complex or recurrent fistulas, invasive procedures will be performed if conservative treatment failed. Conservative treatment may be effective in RVFs with minimal symptoms and should be done for small RVFs for a 36 months usual period. Anal sphincter damage might need a repair of sphincter muscles along with RVF repair. Diverting stoma can initially be constructed in patients with severe symptoms and larger RVFs to relief the patient's pain. Simple fistula is usually indicated for local repair. Local repairs to transperineal and transabdominal approaches can be used for complex RVFs. Interposition of healthy, well-vascularized tissue can be required for more complex fistulas and abdominal procedures for high RVFs.

Impact of sex and aging on radiographic and functional parameters of the anal sphincter complex in patients with accidental bowel leakage.

Treatment outcomes for accidental bowel leakage (ABL) may be influenced by age-related sarcopenia. We sought to determine if thickness of the anal sphincter complex on endoanal ultrasound correlated with function in women and men with ABL and if women demonstrated age-related anal sphincter thinning. Consecutive patients with ABL presenting to our pelvic floor clinic from 2012 to 2017 were included. Clinical data were obtained from medical records. External anal sphincter (EAS), imaged by endoanal ultrasound at proximal, mid and distal locations, and IAS thickness were measured at 12, 3, 6, and 9 o'clock; puborectalismuscle(PRM) was measured at 4, 6, and 8 o'clock; and averaged. Anorectal manometry was conducted when clinically indicated. Data were compared using Mann-Whitney tests and linear regression. Results are reported as mean ± SD or median (IQR). Women (n = 136) were younger than men (n = 26) (61 ± 13vs. 67 ± 13 years, p = 0.02). More women than men had pelvic surgery and less had colorectal surgery, spinal disorders, or a history of smoking (p < 0.05). Eighty-two percentageof women had an anal sphincter defect versus 31% of men (p < 0.01). All anal sphincter complex components were thinner in women than men with lower squeeze and resting pressures (p < 0.03), even in nulliparous women. Mean resting pressure was lower in older 6.1 (4.6-7.8) versusyounger women 8.3 (5.0-12.9) mmHg, p = 0.04. Women, even nulliparous, with ABL demonstrate thinner and weaker anal sphincters than men, Aging correlated with an increase in anal sphincter thickness, suggesting that age-related changes in the intrinsic components of the anal sphincter complex associated with ABL are complex and are not always well demonstrated on endoanal ultrasound.

ROLE OF MRI IN EVALUATION OF GRADE IV PERIANAL FISTULA (ACCORDING TO SAINT JAMES'S UNIVERSITY HOSPITAL CLASSIFICATION)

Introduction- Fistula-in-ano can be dened as a hollow tract or cavity which is lined by granulation tissue. It is crucial to properly assess these stula-in-ano because surgical intervention must be aimed at not only eradication of stulous tract thereby eradication of source of infection but also at the maintenance of continence which depends on intergrity of anal-sphincter complex. MR stulography has the distinct advantage of not only depicting the stulous tract but also in demonstrating the extent of transmural inammatory process secondary tracts/ramications and abscesses. The aim of the study is to evaluate role of MRI in appropriate diagnosis of Grade IV perianal stulae – Complicated transsphincteric stulae (Saint James's University Hospital Classication) with its post operative correlation. Around 19 patients who were Methodologydiagnosed with grade IV perianal stula (according to Saint James classication) on MR stulogram in the Department of Radiology were included in the study and followed up with their post operative data. A male preponderance Results And Discussion - reported in our study, correlating well with studies by others like Kakani SS et al., Daabis N et al. and Abbas et al. Purulent perianal discharge was common presenting complaints. Most common location for internal opening was posterior position which was also seen in a study by Choudhary J, Kaushal L, Rajput P. Out of the total 19 patients, extrasphincteric abscess/collection was more commonly found in the patients. Majority of the patients had secondary tracts and ramications. In this study accuracy for correct localization of internal opening was (93.33%), identication of ramications/secondary tracts was (92.85 %) and abscesses/collection was (90 %) as compared to operative ndings which correlated well with studies by Singh K et al., Daabis et al. and Madireddy et all MRI is a useful modality for diagnosis and successful mana . Conclusion- gement of grade IV perianal stula. MRI helps in detailed assessment of the number &amp; extent of the stulous tracts and their relationship to anal sphincter complex, including ramications, thereby reducing the recurrence &amp; complications and improving the prognosis.

The Effect of Dosing of Stromal Cell-Derived Factor 1 on Anal Sphincter Regeneration.

Aim: The aim of this study is to investigate if a high dose of the stromal cell-derived factor-1 (SDF-1) plasmid improves outcome in a minipig model of chronic anal sphincter injury. Methods: Twenty-two female minipigs underwent excision of the posterior hemicircumference of the anal sphincter complex and were allowed to recover for 6 weeks. They were randomly allocated (n = 6) to receive either 5% dextrose (sham) or 2, 4, or 8 mg of SDF-1 plasmid at the defect site. Two control pigs received no surgery/treatment. Outcome measures included anal manometry at preinjury/pretreatment and 2, 4, and 8 weeks after treatment, recording the mean of eight pressure channels and the posterior channel alone, histopathology using Masson's trichrome, and immunohistochemistry using PGP9.5 for staining of neural structures, and CY3 staining for blood vessels. Data are expressed as mean ± standard error. Manometry analysis used two-way analysis of variance (ANOVA) followed by the Holm-Sidak test. Quantification of muscle/fibrosis was analyzed with a Kruskal-Wallis one-way ANOVA on ranks. Results: Posterior anal pressures were significantly decreased in sham treated animals compared with controls (p = 0.04). In contrast, mean anal pressures at the four time points were not significantly different between groups (p > 0.05). The defect area of the sham treated group showed irregular muscle bundles, while all three SDF-1 treatment groups show organized muscle bundles, with the most organization in the higher dose groups. Quantification of Masson-stained slides showed no statistically significant differences between groups, but did show increased muscle volume in the area of defect in the treatment groups compared with sham. PGP9.5 and CY3 staining showed increased fluorescence in the higher dose groups compared with sham treatment. Conclusion: A single higher dose of the plasmid encoding SDF-1 may increase muscle volume in the area of a chronic defect. Impact statement Fecal or bowel incontinence as a result of a torn anal sphincter complex remains undetected for many years. The resulting defect does not respond well to surgical repair. Regenerating the anal sphincter complex with functional muscle has been a long-term goal. Stem cells home to a site of a chronic injury and cause regeneration when a cell signaling mechanism is available. Stromal cell-derived factor-1 is one such cytokine that has been well researched by us and others to have this effect. It is easy to use clinically and has been used in other applications in humans and considered safe.

Detection of Occult Anal Sphincter Injuries in Primipara by 2D Transperineal Ultrasound and its Clinical Association: A Cohort Study

Introduction: Endoanal Ultrasound (EAUS), the gold standard for the detection of occult Obstetric Anal Sphincter Injuries (OASI) has limited clinical application due to its intrusiveness and need for specialised equipment and personnel. A 2D Transperineal Ultrasound (TPU) is simple, non invasive and shows a high degree of agreement with EAUS. Few studies have evaluated the use of 2D TPU in determining the incidence and clinical outcomes of occult OASI in primigravida. Aim: To study the incidence, risk factors, and clinical outcome of occult obstetric anal sphincter injury using 2D TPU in primigravida. Materials and Methods: The present cohort study was conducted in the Department of Obstetrics and Gynaecology in collaboration with the Department of Radiology at Guru Teg Bahadur Hospital, Delhi, India, from November 2018 to April 2020. A total of 200 low risk primigravida ≥36 weeks period of gestation underwent baseline TPU of the anal sphincter complex antenatally and on day 2 postpartum. On the basis of difference between pre and postdelivery measurements, they were divided into group I (n=91): women with occult OASI (diagnosed as thinning of the internal and External Anal Sphincter (EAS), interruption in the anal sphincter, alteration in mucosa and half-moon sign) and group II (n=109): no OASI. Group I was followed at two and six weeks postpartum with TPU and clinical tests were applied at 6 weeks to assess clinical outcomes of sphincter injury. Data was analysed using Chi-square test/Fisher’s-exact test for qualitative parameters, Analysis of Variance (ANOVA) for comparison of predelivery and postpartum measurements; and multiple logistic regression for determining sphincter injury determinants. Results: Incidence of occult OASI was 91/200 (45.5%). Significant risk factors for OASI were lower baseline thickness of anal sphincter, position of baby (p=0.028), longer duration of second stage of labour (p&lt;0.001), greater length and angle of episiotomy (p&lt;0.001) and greater baby weight (p=0.042). Group I had significantly lower pelvic floor muscle strength testing score (p&lt;0.001), Digital Rectal Examination Scoring System (DRESS) resting (p=0.013) and squeeze scores (p=0.008), weaker muscle contraction (p&lt;0.001), reduced anal sphincter tone, and was more clinically symptomatic at six weeks postpartum. Conclusion: The technique of 2D TPU is simple and feasible to detect OASI. Women, who sustain OASI, can be followed up in perineal clinic more meticulously, using TPU for pelvic floor rehabilitation.

Perianal Fistula: An Overview

Perianal fistula is a common inflammatory condition in the general population and affects the area around the anal canal. Although most cases are benign, they cause serious morbidity and require surgical treatment due to a high risk of recurrence. MR imaging is a gold standard technique for the evaluation of perianal fistulas and provides accurate information on the anatomy of the anal canal, its relationship to the anal sphincter complex, accurate identification of secondary tracts or abscesses, and reporting associated complications. MR imaging can help monitor treatment effects and determine treatment methods. Crohn's disease-related fistulas often require medical rather than surgical treatment. The radiologist is required to know the anatomy and MR imaging findings of the perianal fistula to present an accurate diagnosis to the clinician.

Obstetric Perineal Trauma and Episiotomy

Obstetric lacerations are a common complication of vaginal delivery. Lacerations can lead to chronic pain and urinary and fecal incontinence. Perineal lacerations are defined by the depth of musculature involved, with fourth-degree lacerations disrupting the anal sphincter and the underlying rectal mucosa and first-degree lacerations having no perineal muscle involvement. Late third-trimester perineal massage can reduce lacerations in primiparous women; perineal support and massage and warm compresses during the second stage of labor can reduce anal sphincter injury. Conservative care of minor hemostatic first- and second-degree lacerations without anatomic distortion reduces pain, analgesia use, and dyspareunia. Minor hemostatic lesions with anatomic disruption can be repaired with surgical glue. Second-degree lacerations are best repaired with a single continuous suture. Lacerations involving the anal sphincter complex require additional expertise, exposure, and lighting; transfer to an operating room should be considered. Limited evidence suggests similar results from overlapping and end-to-end external sphincter repairs. Postdelivery care should focus on controlling pain, preventing constipation, and monitoring for urinary retention. Acetaminophen and nonsteroidal anti-inflammatory drugs should be administered as needed. Opiates should be avoided to decrease risk of constipation; need for opiates suggests infection or problem with the repair. Osmotic laxative use leads to earlier bowel movements and less pain during the first bowel movement. Simulation models are recommended for surgical technique instruction and maintenance, especially for third- and fourth-degree repairs.

Predicting perineal trauma during childbirth using data from a general obstetric population

Background: Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population. Methods: Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation. Results: Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance. Conclusions: Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.

Scar endometriosis: Looking beyond the diagnosis - A case series

Scar endometriosis usually affects the abdominal wall or the perineum. Virtually all cases are linked with some form of surgical manipulation. Although the clinical diagnosis of scar endometriosis may be straightforward with classical symptomology, imaging with ultrasound and MRI are important for the determination of its extent, which is imperative for adequate preoperative planning. In addition, assessment of perineal scar endometriosis also requires the identification of anal sphincter complex involvement, which can significantly impact the surgical approach. Radiology plays a vital role in its diagnosis in atypical clinical scenarios.Contribution: This series of four cases describes the morphology and highlights the importance of imaging in the surgical management of scar endometriosis; three with abdominal wall involvement and one with the involvement of perineum.