MRI review of female pelvic fistulizing disease

[Rectovaginal fistulas : Differentiated diagnostics and treatment]

Rectovaginal fistulas (RVF) represent less than 5% of anorectal fistulas. The classification of RVF is based on the localization (low vs. high) and the etiology. The most frequent causes of RVF are birth trauma, Crohn's disease, previous surgery and pelvic irradiation. In most cases a clinical diagnostic assessment is sufficient. Additionally, endosonography is a reliable tool to detect sphincter defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are reserved for special situations (e.g., RVF related to anastomotic leakage, after pelvic irradiation or associated with complex perianal fistulizing Crohn's disease). The surgical treatment is primarily oriented to the localization and etiology. Surgical techniques range from local procedures (e.g., endorectal advancement flap repair, transvaginal or transperineal closure) up to more invasive tissue interposition (e.g., bulbocavernosus muscle fat tissue flap or transposition of the gracilis muscle). In "high" RVF transabdominal approaches such as coloanal anastomosis, pull through procedures or omental interposition are indicated. All surgical procedures show high recurrence rates. Several operations are mostly necessary and a stoma creation is often required.

MRI of the ileal pouch

Ileal pouch surgery is the surgical gold standard treatment for patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). However, ileal pouch surgery is a technically challenging procedure and is associated with high morbidity. Clinical presentations of pouch complications are often nonspecific but imaging can identify many of these complications and is essential in clinical management. This paper will focus on magnetic resonance imaging (MRI) of the ileal pouch, including recommended MRI protocol and approach to imaging interpretation with an emphasis on those ileal pouch complications particularly well evaluated with MRI.

Scale- and Slice-aware Net (S2 aNet) for 3D segmentation of organs and musculoskeletal structures in pelvic MRI

PURPOSE

MRI of organs and musculoskeletal structures in the female pelvis presents a unique display of pelvic anatomy. Automated segmentation of pelvic structures plays an important role in personalized diagnosis and treatment on pelvic structures disease. Pelvic organ systems are very complicated, and it is a challenging task for 3D segmentation of massive pelvic structures on MRI.

METHODS

A new Scale- and Slice-aware Net ( S 2 aNet) is presented for 3D dense segmentation of 54 organs and musculoskeletal structures in female pelvic MR images. A Scale-aware module is designed to capture the spatial and semantic information of different-scale structures. A Slice-aware module is introduced to model similar spatial relationships of consecutive slices in 3D data. Moreover, S 2 aNet leverages a weight-adaptive loss optimization strategy to reinforce the supervision with more discriminative capability on hard samples and categories.

RESULTS

Experiments have been performed on a pelvic MRI cohort of 27 MR images from 27 patient cases. Across the cohort and 54 categories of organs and musculoskeletal structures manually delineated, S 2 aNet was shown to outperform the UNet framework and other state-of-the-art fully convolutional networks in terms of sensitivity, Dice similarity coefficient and relative volume difference.

CONCLUSION

The experimental results on the pelvic 3D MR dataset show that the proposed S 2 aNet achieves excellent segmentation results compared to other state-of-the-art models. To our knowledge, S 2 aNet is the first model to achieve 3D dense segmentation for 54 musculoskeletal structures on pelvic MRI, which will be leveraged to the clinical application under the support of more cases in the future.

Guided tour of hidden tracts in the pelvis: exploring pelvic fistulas

Background

Fistulas are an abnormal connection between two or more epithelial surfaces. When fistulization between adjacent structures occurs in the pelvis, there is almost invariably significant associated morbidity and impact on a patient’s quality of life. Imaging may aid in the diagnosis of pelvic fistulas and is essential to identify any associated pathology, define the course of the fistula, and aid in pre-surgical planning.

Purpose

This article aims to review the wide array of clinical and imaging presentations of fistulas in the pelvis, with a focus on the radiologists’ role in managing this challenging entity.

Methods

This article will review each classification type of fistula.

Results

Pelvic fistula is a devastating condition that causes significant morbidity and evaluation can be challenging.

Conclusions

Imaging, and particularly MRI, plays a vital role in the diagnosis, characterizing the course of a fistula and demonstrating associated complications, which are essential to guide treatment decisions.

Reliability of the application of transvaginal color Doppler ultrasound in the identification of pelvic tumors in women of childbearing age

Background

Recently, transvaginal color Doppler ultrasound (TVCDU) has been widely used in the diagnosis of pelvic tumors. This study aimed to assess the reliability of the application of TVCDU in the identification of pelvic tumors in women of childbearing age.

Methods

The clinical data of 209 patients with pelvic tumors at childbearing age admitted to our hospital from January 2016 to December 2019 were retrospectively analyzed. The ultrasound signs, color Doppler ultrasound score (CDUS), and resistance index (RI) of benign and malignant pelvic tumors diagnosed by TVCDU were analyzed. The value of transabdominal color Doppler ultrasound (TACDU) and TVCDU in the diagnosis of benign and malignant pelvic tumors was calculated.

Results

There were 150 cases with benign pelvic tumors and 59 cases with malignant tumors. Most benign tumors had an intact capsule and regular shape, were mainly cystic, and were rarely accompanied by ascites; meanwhile, malignant tumors were mostly non-capsular and irregular in shape, mainly solid or cystic, and were often accompanied by ascites. There were significant differences in the above-mentioned ultrasound signs between benign and malignant tumors (P<0.05). The CDUS score of benign pelvic tumors was significantly lower than that of malignant tumors, and the RI value was significantly higher than that of the malignant tumors (P<0.05). The sensitivity, specificity, and accuracy of TACDU in the diagnosis of benign pelvic and malignant tumors were 83.33%, 84.75%, and 83.73%, respectively; and the sensitivity, specificity, and the accuracy of TVCDU in the diagnosis of benign pelvic and malignant tumors were 95.33%, 88.14%, and 93.30%, respectively; thus TVCDU had a superior performance compared to TACDU, especially in sensitivity and accuracy (P<0.05).

Conclusions

The sensitivity and accuracy of TVCDU in the differential diagnosis of benign pelvic and malignant tumors in women at childbearing age were significantly higher than those of TACDU. The combined application of CDUS and RI can further improve the accuracy in the diagnosis of pelvic tumors.

Assessment of the Clinical Usefulness of Preoperative Computed Tomography in Colorectal Cancer Patients Who Received Unplanned Reoperation

Background

In the unplanned reoperation of colorectal cancer patients, computed tomography (CT) is increasingly utilized to locate postoperative complications and previously unlocalized lesions. The purpose of this study is to explore the application of CT in the mortality and complications of the reoperation of colorectal cancer. Patients and Methods. We performed a retrospective review of collected data from the colorectal surgeries of 90 identified colorectal cancer patients who received an unplanned reoperation from 2010 to 2018. Patients were stratified according to those with preoperative CT imaging (CT group, n = 36) and those without preoperative CT imaging (NCT group, n = 54). Twenty-four statistical indicators of each patient were studied, including their preoperative risk, surgical characteristics, and postoperative outcomes, and satisfaction was evaluated. All data were statistically analysed for predicting postoperative complications by univariate and multivariate logistic regression analyses.

Results

Ninety patients received an unplanned reoperation in the study, and 40% (36/90) of these patients underwent preoperative CT examination. Patients' risk factors were similar between CT and NCT groups. Preoperative imaging was more commonly performed for reoperative new anastomosis + ileostomy but less common for reoperative Dixon's procedure. The operative duration of the NCT group was longer (139 vs. 104 min, respectively, P = 0.01). Preoperative NCT examination (OR 1.24; 95% CI = 1.09-1.42; P = 0.01) was an independent predictor of postoperative complications. Importantly, three patients died after an unplanned reoperation for colorectal cancer, which occurred only in the NCT group (5.6% vs. 0.0%, P = 0.01).

Conclusion

The use of conventional preoperative CT optimizes the choice of the surgical site and the strategy of laparotomy, so as to reduce the length of operation. Preoperative imaging evaluation should be performed for patients undergoing repeat abdominal surgery.

Best Practices in Robotic-assisted Repair of Vesicovaginal Fistula: A Consensus Report from the European Association of Urology Robotic Urology Section Scientific Working Group for Reconstructive Urology

CONTEXT

Surgical repair of a vesicovaginal fistula (VVF) has been described extensively in the literature for several decades. Advances in robotic repair have been adopted since 2005.

OBJECTIVE

A consensus review of existing data based on published case series, expert opinion, and a survey monkey.

EVIDENCE ACQUISITION

This document summarizes the consensus group meeting and survey monkey results convened by the European Association of Urology Robotic Urology Section (ERUS) relating to the robotic management of VVF.

EVIDENCE SYNTHESIS

Current data underline the successful robotic repair of supratrigonal nonobstetric VVF. The panel recommends preoperative marking of the fistula by a guidewire or ureteral catheter, and placement of a protective ureteral JJ stent. An extravesical robotic approach usually provides a good anatomic view for adequate and wide dissection of the vesicovaginal space, as well as bladder and vaginal mobilization. Careful sharp dissection of fistula edges should be performed. Tension-free closure of the bladder is of utmost importance. Tissue interposition seems to be beneficial. The success rate of published series often reaches near 100%. An indwelling bladder catheter should be placed for about 10 d postoperatively.

CONCLUSIONS

When considering robotic repair for VVF, it is essential to establish the size, number, location, and etiology of the VVF. Robotic assistance facilitates dissection of the vesicovaginal space, harvesting of a well-vascularized tissue flap, and a tension-free closure of the bladder with low morbidity for the patient being operated in the deep pelvis with delicate anatomical structures.

PATIENT SUMMARY

Robotic repair of a vesicovaginal fistula can be applied safely with an excellent success rate and very low morbidity. This confirms the use of robotic surgery for vesicovaginal fistula repair, which is recommended in a consensus by the European Association of Urology Robotic Section Scientific Working Group for reconstructive urology.

MRI anatomy and pathology of the anal canal

The normal function of the anal sphincter complex is crucial for quality of life, as it is the mechanism by which fecal continence is maintained. Additionally, the anal sphincter complex is an integral part of the coordinated effort of defecation. As imaging plays an important role in assessment of pathologic conditions involving the anal region, understanding the normal anatomy of the anal sphincter complex is important for correct image interpretation and accurate diagnosis. This review discusses the anatomy and function of the anal sphincter complex, important technical considerations for MRI, and various inflammatory, infectious, and neoplastic processes, as well as pathologic structural conditions that affect the anal region. Level of Evidence: 5 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:1018-1032.