Lumen-Apposing Metal Stents in the Management of Complex Pelvic Abscesses

BACKGROUND

Lumen-apposing metal stents (LAMS) are utilized in a wide range of therapeutic gastrointestinal applications. We present our experience with LAMS-assisted drainage of complex pelvic abscesses at a large safety-net hospital.

METHODS

EUS-guided LAMS placements for pelvic abscesses from July 2020 to June 2024 were analyzed. Data were collected on patient demographics, procedure indications, fluid collection size, stent characteristics, stent dwell time, and complications. All cases underwent multidisciplinary review with Surgery and Interventional Radiology (IR) prior to LAMS-assisted drainage; all were deemed not amenable to drainage by IR.

RESULTS

Eleven patients underwent EUS-guided drainage of complex pelvic abscesses with cautery-enhanced LAMS. Diverticulitis was the most common cause of abscesses (n = 6; 55%). The average time from presentation to drainage was 7 days (1-18). The average abscess size was 7.2 cm (3.9-12.0 cm). The most common LAMS size was 15 mm × 10 mm; each was placed through the left colon and rectum with both technical and clinical success. All abscesses completely resolved with a mean stent dwell time of 28 days (17-42 days). After stent removal, the fistula was not routinely closed. No complications such as stent migration, bleeding, or perforation occurred. There were no recurrences and no patients required additional surgical or IR procedures with a mean follow-up of 25 weeks (SD 35.6).

CONCLUSIONS

Adequate drainage is the cornerstone of pelvic abscess management, but IR or surgical access can be challenging, with inadequate drainage and prolonged hospitalization leading to significant morbidity. In our experience, EUS-guided, LAMS-assisted drainage provides a safe and effective alternative for managing pelvic abscesses.

A Multilayer Monte Carlo Model for the Investigation of Optical Path and Penetration Depth at Different Perfusion States of the Colon

There is a great interest in monitoring the oxygen supply delivered to the colon. Insufficient oxygen delivery may lead to hypoxia, sepsis, multiorgan dysfunction and death. For assessing colonic perfusion, more information and understanding is required relating to the light-interaction within the colonic tissue. A multilayer Monte Carlo model of a healthy human colon has been developed to investigate the light-tissue behavior during different perfusion states within the mucosal layer of the colon. Results from a static multilayer model of optical path and reflectance at two wavelengths, 660 nm and 880 nm, through colon tissue, containing different volume fractions of blood with a fixed oxygen saturation are presented. The effect on the optical path and penetration depth with varying blood volumes within the mucosa for each wavelength has been demonstrated. The simulation indicated both wavelengths of photons penetrated similar depths, entering the muscularis layer.

A risk-scoring model for the prediction of delayed bleeding after colorectal endoscopic submucosal dissection

BACKGROUND AND AIMS

Delayed bleeding is an important adverse event after colorectal endoscopic submucosal dissection (ESD). We aimed to investigate the incidence and risk factors of delayed bleeding after colorectal ESD and to develop a risk-scoring model for predicting delayed bleeding.

METHODS

This retrospective study was performed at 5 centers. The derivation and validation cohorts comprised 1189 patients from 1 center and 415 patients from the other 4 centers. We investigated the incidence and risk factors of delayed bleeding. Then, we developed a risk-scoring model for predicting delayed bleeding by using the data of the derivation cohort. We validated the scoring system in the validation cohort.

RESULTS

Delayed bleeding occurred in 34 patients (2.9%) in the derivation cohort. In multivariate analysis, the risk factors of delayed bleeding were tumor location in the rectosigmoid colon (odds ratio [OR], 6.49; 95% confidence interval [CI], 1.96-21.42; P = .002), large tumor (≥30 mm) (OR, 2.10; 95% CI, 1.01-4.40; P = .048), and use of antiplatelet agents except for aspirin alone (OR, 4.04; 95% CI, 1.44-11.30; P = .008). These 3 factors were incorporated into a risk-scoring model for prediction of delayed bleeding. As the score based on this system increased, the incidence of delayed bleeding increased in the validation cohort.

CONCLUSION

The risk-scoring model incorporating tumor location, tumor size, and use of antiplatelet agents can quantitatively predict the risk of delayed bleeding after colorectal ESD.