Latissimus Dorsi Myocutaneous Flap Procedure in a Swine Model

Abstract

Background

As surgical research expands in both breadth and scope, translational models become increasingly important. The accessibility, reproducibility, and clinical applicability of translational models is of vital importance to ensure adequate and accurate research. Though different flap models have been described, the literature lacks an in-depth, technical description of an easy large-animal preclinical model. We here describe the procedure for elevation of a latissimus dorsi flap in a swine. This flap contains muscle and skin that can be isolated on a vascular pedicle, transferred as a free flap, perfused, or innervated/denervated as dictated by the needs of the experiment.

Methods

Five different latissimus dorsi flaps were elevated in miniature swine. Careful attention was paid to anatomical landmarks and optimal placement of incision, dissection, and retraction. Temporary ischemia with vascular clamping was performed along with serial digital and infrared imaging both intra- and postoperatively. In three of the flaps with induced ischemia, the animal was observed for a 30-day follow up with daily photodocumentation and intermittent biopsy.

Results

A reproducible latissimus flap model was designed with optimized conditions. In the animals in which flaps were followed postoperatively, complete healing was seen within 30 days without evidence of procedure-related ischemia or loss of motor function.

Conclusion

We have identified and described a pre-clinical large animal flap model that can be easily reproduced for translational studies of multiple scientific areas including flap-based repair, ischemia, ischemia reperfusion, and operative technique. This provides an important model for ready replication in preclinical studies of many varieties.

Keywords:

• Latissimus flap
• myocutaneous flap
• swine flap
• swine latissimus

Acknowledgements

We would like to acknowledge the contributions and assistance in the large animal operations of the entire Johns Hopkins VCA Laboratory team as well as our veterinarian colleagues – specifically Dr. Jessica Izzi – and the veterinary technicians Melanie Adams, Kristy Koenig, and Gabriella Dancourt. We would like to acknowledge the support of the Army, Navy NIH, Air Force, VA and Health Affairs regarding the AFIRM II effort under award CTA05: W81XWH-13-2. The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick MD 21702-5014 is the awarding and administering acquisition office. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the Department of Defense.

Author contributions

JWE performed the operations, collected data, wrote and revised the manuscript.

SAJF performed the operations, collected data, wrote and revised the manuscript.

FM assisted with experiment and critical revision of the manuscript.

YG assisted with experiment and critical revision of the manuscript.

DV assisted with experimental design and critical revision of the manuscript.

SEB performed histologic analysis and assisted with critical revision of the manuscript.

GB assisted with experimental design and critical revision of the manuscript.

DSC performed the operations, assisted with experimental design and critical revision of the manuscript.