Perforating blood vessel selection in deep inferior epigastric artery perforator flaps

Douglas, Helen E. (2014) Perforating blood vessel selection in deep inferior epigastric artery perforator flaps. MD thesis, University of Glasgow.

Abstract

Introduction: The DIEP flap is a popular choice for breast reconstruction, though selection of
which perforating blood vessel(s) to supply the flap is still largely based on surgeon preference,
with little evidence to support numbers or location of perforators. In addition, many surgeons
routinely discard zone IV of the flap, limiting the size of transferrable tissue. The aim of this
research was to investigate the effect of number and location of perforators within a DIEP flap, on the total pedicle flow and perfusion of zone IV fat and skin.

Methods: This research comprised of two studies; an animal model and a patient study:
1) 20 cranially-based abdominal epigastric perforator flaps were raised in Wistar rats on two
perforators. The perforators were sequentially clamped and released in a randomised order and
total pedicle flow (measured using microvascular flow-probes) and skin perfusion (measured
using laser Doppler Flowmetry) was recorded on the following perforator combinations:
• P1 (superior perforator)
• P2 (inferior perforator)
• P1+2 (both perforators)
In addition, half of the animal flaps were randomised to receive a single (15 minute) period of
pedicle-clamped ischaemic preconditioning after raising, with all measurements repeated to
observe any effect.
2) 13 DIEP flaps were raised in post-mastectomy patients requiring breast reconstruction on two
perforators. These were clamped and released as before to assess perfusion of fat and skin in
zone IV using SPY Indocyanine-green-fluorescence-angiography scans on the same perforator
combinations as in our animal study, listed above.

Results: All data were analysed using non-parametric analyses and revealed that in our animal
model, total pedicle flow was significantly (p<0.001) greater on a single perforator compared to
two but no significant differences were identified in the flap skin perfusion. In our clinical study
a single superior perforator supplied zone IV significantly (p=0.039) better than both
peroforators, though this was not observed with the single inferior perforator. No significant
differences were seen in zone IV skin perfusion. A single period of ischaemic preconditioning
significantly (p<0.05) increased the total pedicle flow, but not the skin perfusion in our rat
model.

Conclusions: Possible reasons for these observed differences could be related to the flow
dynamics and resistances specific to perforator flap anatomy and physiology and the possibility
of vessel shunting in the subcutis.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Keywords: DIEP, flap perfusion, perforator number, perforator location, zone IV, pedicle flow
• Subjects: R Medicine > RD Surgery
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Supervisor's Name: Horgan, Prof Paul
• Date of Award: 2014
• Depositing User: Miss Helen Elizabeth Douglas
• Unique ID: glathesis:2014-5516
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 02 Oct 2014 13:30
• Last Modified: 23 Nov 2015 14:47
• URI: https://theses.gla.ac.uk/id/eprint/5516