Complications of Mesh Sacrocolpopexy and Rectopexy: Imaging Review.

Sacrocolpopexy and rectopexy are commonly used surgical options for treatment of patients with pelvic organ and rectal prolapse, respectively. These procedures involve surgical fixation of the vaginal vault or the rectum to the sacral promontory with mesh material and can be performed independently of each other or in a combined fashion and by using an open abdominal approach or laparoscopy with or without robotic assistance. Radiologists can be particularly helpful in cases where patients' surgical histories are unclear by identifying normal sacrocolpopexy or rectopexy mesh material and any associated complications. Acute complications such as bleeding or urinary tract injury or stricture are generally evaluated with CT. More chronic complications such as mesh extrusion or exposure with or without fistulization to surrounding structures are generally evaluated with MRI. Other complications can have a variable time of onset after surgery. Patients with suspected bowel obstruction are generally evaluated with CT. Those with suspected infection, abscess formation, and discitis or osteomyelitis may be evaluated with MRI, although CT evaluation may be appropriate in certain scenarios. The authors review the sacrocolpopexy and rectopexy surgical techniques, discuss appropriate imaging protocols for evaluation of patients with suspected complications, and illustrate the normal appearance and common complications of these procedures. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Allogenic stem cells for Crohn's anal fistulas: Treating early improves the deep remission rate.

AIM: The aim of this study was to evaluate the real-life clinical and radiological efficacy of darvadstrocel injection into complex perianal fistulas in Crohn's disease. Secondary endpoints were to assess symptomatic efficacy, adverse effects and factors associated with complete combined clinical-radiological response (deep remission). METHODS: After marketing the product in France, all first patients treated consecutively were included. A complete clinical response was defined by a complete closure of all external openings with no discharge on pressure. A complete radiological response (MRI), evaluated at least after six months of follow-up, was defined by a completely fibrotic sequela without abscess. A deep remission was defined as the association of a complete clinical response with a complete radiological response. RESULTS: A total of 43 patients were included (M/F: 22/21, median age 37 [26-45] years). The fistulas were already drained with seton(s) and were on biologic treatment. After a median follow-up of 383 (359-505) days, 28 (65%) patients showed a clinical response (22 complete and 6 partial) and 16 (37%) achieved a deep remission. The Perineal Disease Activity Index decreased significantly after treatment: 39 (91%) patients reported symptomatic improvement in terms of discharge, pain, and induration, and 28 (65%) no longer had any perineal symptoms. No severe adverse events were reported. A short history of Crohn's disease <3 years was significantly associated with deep remission (OD 4.5 [1.0-19.1], p = 0.04). CONCLUSION: Darvadstrocel injection resulted in a clinical response for two thirds of patients and deep remission for one third. A shorter duration of Crohn's disease was associated with deep remission.

Fractal analysis improves tumour size measurement on computed tomography in pancreatic ductal adenocarcinoma: comparison with gross pathology and multi-parametric MRI.

OBJECTIVES: Tumour size measurement is pivotal for staging and stratifying patients with pancreatic ductal adenocarcinoma (PDA). However, computed tomography (CT) frequently underestimates tumour size due to insufficient depiction of the tumour rim. CT-derived fractal dimension (FD) maps might help to visualise perfusion chaos, thus allowing more realistic size measurement. METHODS: In 46 patients with histology-proven PDA, we compared tumour size measurements in routine multiphasic CT scans, CT-derived FD maps, multi-parametric magnetic resonance imaging (mpMRI), and, where available, gross pathology of resected specimens. Gross pathology was available as reference for diameter measurement in a discovery cohort of 10 patients. The remaining 36 patients constituted a separate validation cohort with mpMRI as reference for diameter and volume. RESULTS: Median RECIST diameter of all included tumours was 40 mm (range: 18-82 mm). In the discovery cohort, we found significant (p = 0.03) underestimation of tumour diameter on CT compared with gross pathology (Δdiameter3D = -5.7 mm), while realistic diameter measurements were obtained from FD maps (Δdiameter3D = 0.6 mm) and mpMRI (Δdiameter3D = -0.9 mm), with excellent correlation between the two (R2 = 0.88). In the validation cohort, CT also systematically underestimated tumour size in comparison to mpMRI (Δdiameter3D = -10.6 mm, Δvolume = -10.2 mL), especially in larger tumours. In contrast, FD map measurements agreed excellently with mpMRI (Δdiameter3D = +1.5 mm, Δvolume = -0.6 mL). Quantitative perfusion chaos was significantly (p = 0.001) higher in the tumour rim (FDrim = 4.43) compared to the core (FDcore = 4.37) and remote pancreas (FDpancreas = 4.28). CONCLUSIONS: In PDA, fractal analysis visualises perfusion chaos in the tumour rim and improves size measurement on CT in comparison to gross pathology and mpMRI, thus compensating for size underestimation from routine CT. KEY POINTS: • CT-based measurement of tumour size in pancreatic adenocarcinoma systematically underestimates both tumour diameter (Δdiameter = -10.6 mm) and volume (Δvolume = -10.2 mL), especially in larger tumours. • Fractal analysis provides maps of the fractal dimension (FD), which enable a more reliable and size-independent measurement using gross pathology or multi-parametric MRI as reference standards. • FD quantifies perfusion chaos-the underlying pathophysiological principle-and can separate the more chaotic tumour rim from the tumour core and adjacent non-tumourous pancreas tissue.

[Anal fistulas: Sparing the sphincter]. / Fistules anales, épargner le sphincter.

ANAL FISTULAS: SPARING THE SPHINCTER. Fistulotomy is the most used treatment for anal fistula. It is very effective with a cure rate of over 95% but carries a risk of incontinence. This has led to the development of various sphincter sparing techniques. The injection of biological glue or paste and the insertion of a plug have disappointing results and are expensive. The rectal advancement flap is still practised because of its cure rate of around 75% but it may result in some incontinence. Intersphincteric ligation of the fistula track and laser treatment are widely practised in France with cure rates between 60 and 70%. Video-assisted anal fistula treatment as well as injections of adipose tissue, stromal vascular fraction, platelet-enriched plasma and/or mesenchymal stem cells are emerging techniques for which even better results are expected.

FISTULES ANALES, ÉPARGNER LE SPHINCTER. La fistulotomie est le traitement le plus souvent utilisé dans la fistule anale. Elle est très efficace, avec un taux de guérison supérieur à 95 %, mais expose à un risque d'incontinence. Cela a conduit au développement de diverses techniques d'épargne sphinctérienne. L'injection de colle ou de pâte biologique ainsi que la mise en place d'un plug ont des résultats finalement décevants et un coût élevé. Le lambeau rectal d'avancement est encore pratiqué en raison de son taux de guérison aux alentours de 75 %, mais il peut se solder par quelques troubles séquellaires de la continence. La ligature intersphinctérienne du trajet fistuleux et le laser sont largement pratiqués en France, avec des taux de guérison oscillant entre 60 et 70 %. Le traitement vidéo-assisté du trajet fistuleux ainsi que les injections périfistuleuses de tissu adipeux, de fraction vasculaire stromale, de plasma enrichi en plaquettes et/ou de cellules souches mésenchymateuses sont des techniques émergentes dont on espère de meilleurs résultats encore.

[The rôle of MRI in exploration anorectal pathologies]. / Place de l'IRM pour explorer les pathologies anorectales.

PLACE DE L'IRM POUR EXPLORER LES PATHOLOGIES ANORECTALES. L'imagerie par résonance magnétique (IRM) est l'un des examens d'imagerie les plus utiles à l'exploration des pathologies ano rectales. Elle est complémentaire de l'examen clinique et de l'endo scopie. Elle permet de fournir des données indispensables à une prise en charge optimale du patient par le proctologue, le chirurgien ou l'oncologue en fonction de la nature de l'atteinte anale ou rectale. Il est nécessaire de respecter les différentes indications de cet examen, qui ont été bien définies pour chaque pathologie par les différentes sociétés savantes. Le protocole de l'IRM varie en fonction de la zone explorée et de la pathologie suspectée. C'est pourquoi il est indispensable de fournir au radiologue les informations nécessaires telles que la suspicion diagnostique, les données cliniques, ainsi que les résultats des examens complémentaires déjà réalisés. Les indications les plus fréquentes de l'IRM en proctologie sont les tumeurs anales et rectales. L'IRM permet le bilan initial de l'extension locorégionale de la tumeur ainsi que le suivi oncologique précoce et tardif grâce à l'étude comparative des examens de surveillance par rapport au bilan initial. L'IRM est indispensable pour l'exploration des suppurations anopérinéales complexes, en particulier liées à la maladie de Crohn. Elle permet la réalisation du bilan lésionnel initial ainsi que le contrôle post-drainage. En cas de suspicion de maladie de Verneuil ou de sinus pilonidal infecté, l'IRM participe à l'orientation vers le diagnostic étiologique. La déféco-IRM est une variante particulière de l'IRM pelvienne et périnéale. Elle fait partie du bilan des dysfonctions du plancher pelvien, car elle permet l'étude du comportement des différents organes pelviens au cours des efforts de poussée et de défécation. Les fissures anales et les thromboses hémorroïdaires sont les causes les plus fréquentes de douleurs anales. Leur diagnostic est purement clinique. En cas d'examen proctologique normal, l'IRM sert à chercher une autre cause à ces douleurs.

THE ROLE OF MRI IN EXPLORATION ANORECTAL PATHOLOGIES. Magnetic resonance imaging (MRI) is one of the most useful imaging modalities for the exploration of anorectal pathologies. It is complementary to the clinical examination and endoscopy. It provides essential elements for optimal care of the patient by the proctologist, the surgeon or the oncologist depending on the nature of the anal or rectal condition. It is necessary to respect the different indications of this exam which have been well defined for each pathology by the different scientific societies. The MRI protocol varies depending on the site to be investigated and the pathology suspected. Therefore, it is essential to provide the radiologist with the necessary information such as the diagnostic suspicion, clinical findings, and the results of previous paraclinical examinations. MRI ensures the initial assessment of the locoregional extension of the tumor as well as the early and late oncological follow-up thanks to the comparative study of the surveillance examinations with the initial exam. MRI is essential for the assessment of complex anoperineal suppurations, in particular those related to Crohn's disease. It is necessary for the initial lesional assessment and for the post-drainage control. In case of suspicion of Verneuil's (hidradenitis suppurativa) disease or infected pilonidal sinus, MRI helps to orientate towards the right etiological diagnosis. MR defecating proctography is a particular variant of pelvic and perineal MRI. It is performed as part of the assessment of pelvic floor dysfunctions because it allows the study of the dynamics of the different pelvic organs during straining and defecation. Anal fissures and hemorrhoidal thrombosis are the most frequent etiologies of anal pain. Their diagnosis is purely clinical. If the proctological examination is normal, MRI is used to search for other causes of anal pain.