Evidence map›Paper›PMID 42263141›Full record

ArticleLasers in surgery and medicine2026

Laparoscopic Methylene Blue Photodynamic Therapy for Intraabdominal Infection: A Preclinical Feasibility Study in a Rabbit Model of Perforated Appendicitis.

Timothy M Baran, Korry T Wirth, Matthew M Byrne, Benjamin Gertsen, Eric Y Wang, Darrian S Hawryluk, Martin S Pavelka, Nicole A Wilson

Abstract read
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In one paragraph

Article in Lasers in surgery and medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Timothy M BaranDepartment of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA.
Korry T WirthDepartment of Biomedical Engineering, University of Rochester, Rochester, New York, USA.
Matthew M ByrneDepartment of Surgery, University of Rochester Medical Center, Rochester, New York, USA.
Benjamin GertsenDepartment of Surgery, University of Rochester Medical Center, Rochester, New York, USA.
Eric Y WangDepartment of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA.
Darrian S HawrylukDepartment of Biomedical Engineering, University of Rochester, Rochester, New York, USA.
Martin S PavelkaDepartment of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York, USA.ORCID https://orcid.org/0000-0003-3265-8555
Nicole A WilsonDepartment of Biomedical Engineering, University of Rochester, Rochester, New York, USA.

Funding

Photodynamic therapy for perforated appendicitisR21AI178152 · NIAID · UNIVERSITY OF ROCHESTER · PI BARAN, TIMOTHY M, WILSON, NICOLE APRIL · 2023 to 2024
$411k
American Pediatric Surgical AssociationNational Institute of Allergy and Infectious Diseases R21 AI178152NIAID NIH HHS R21 AI178152
6 · The paper itself

Abstract

objectivesPerforated appendicitis commonly results in intra-abdominal infection requiring prolonged antibiotic therapy. Intraoperative antimicrobial adjuncts are limited, and photodynamic therapy (PDT) may provide a targeted, resistance-independent approach. This study evaluated the feasibility, safety, and preliminary antimicrobial effects of laparoscopic methylene blue photodynamic therapy (MB-PDT) for intra-abdominal disinfection in a rabbit model of perforated appendicitis. MATERIALS AND

methodsNew Zealand White rabbits (n = 19) underwent surgically induced perforated appendicitis via appendiceal ligation and electrocautery perforation. Animals subsequently received laparoscopic MB-PDT (n = 9) or control treatment (methylene blue lavage without laser illumination; n = 10) 24-40 h after perforation. MB-PDT consisted of peritoneal lavage with methylene blue (300 µg/mL) followed by 665-nm laser illumination at 20 mW/cm

resultsFourteen rabbits developed peritonitis, and 10 animals completed follow-up (PDT n = 7, control n = 3). Laparoscopic MB-PDT delivery was technically feasible and no histologic evidence of off-target photodynamic injury to abdominal organs was identified. Changes in bacterial burden were not significantly different between MB-PDT and control animals (p = 0.18). Body temperature showed a non-significant trend toward reduction following MB-PDT (-0.37°C ± 1.32°C) compared with controls (0.26°C ± 0.76°C; p = 0.27). In vitro MB-PDT produced significant reductions in bacterial burden across all isolated species (p < 0.001), with the most resistant Gram-positive isolate, Enterococcus faecalis, demonstrating greater susceptibility than Gram-negative species.

conclusionLaparoscopic MB-PDT was technically feasible and safe in a rabbit model of perforated appendicitis. Although a reduction in bacterial burden was not observed in vivo, MB-PDT produced strong antimicrobial activity in vitro against all bacterial species isolated from infected animals. These findings establish a preclinical technical platform for intra-abdominal MB-PDT and highlight the importance of optimized light-delivery strategies for future translational studies.

Indexed as

AppendicitisIntraabdominal InfectionsLaparoscopyMethylene BluePhotochemotherapyPhotosensitizing AgentsAnimalsDisease Models, AnimalFeasibility StudiesMaleRabbitsMethylene BluePhotosensitizing Agentsantimicrobial photodynamic therapyappendicitislaparoscopymethylene blueperitonitisphotodynamic therapy

Identifiers

PMID42263141
PMCPMC13482868

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.