A study of current methods for the in vivo assessment of free flaps
Research type
Research Study
Full title
A study of current methods for the in vivo assessment of free flaps
IRAS ID
336344
Contact name
Dariush Nikkhah
Contact email
Sponsor organisation
City St. George's, University of London
Clinicaltrials.gov Identifier
N/A, N/A
Duration of Study in the UK
1 years, 4 months, 7 days
Research summary
Reconstructive surgery with free flaps has made significant strides, yet vascular thrombosis, primarily venous thrombosis within 48 hours post-surgery, remains a critical concern. Early detection and intervention are imperative to rescue compromised flaps. Clinical assessments, such as temperature, skin colour, capillary refill, and tissue turgor, blood flow (via laser doppler flow (LDF) device) are the conventional monitoring methods, but a universally accepted gold standard is lacking. In this study, we propose to investigate physiological features of free flap utilising optical sensors to better understand which of the aforementioned assessments are most important to flap monitoring.
The 48 hour post-surgery is of utmost interest, as this is the window of time where most transplanted free flap would fail, yet continuous monitoring to identify the most critical time points in this period is widely unavailable due mainly to the lack of resources.
Our mission is to understand the physiological features with a sensor incorporating photoplethysmography (PPG) to assess blood flow in free flaps. Readings from this sensor will be assessed against the LDF and other clinical assessments in standard practice.The PPG system comprises two key components:
(a) Optical Sensor: This detects photoplethysmographic signals and estimates flap arterial blood oxygen saturation.
(b) Instrumentation and Software: These facilitate signal acquisition, processing, and analysis for optical data.
Our approach aims to enhance free flap procedure monitoring, ensuring early thrombosis detection and intervention. This collaborative effort holds promise for improved patient outcomes in plastic reconstruction surgeries. We plan to study up to 100 patients in total.
REC name
London - Dulwich Research Ethics Committee
REC reference
25/LO/0464
Date of REC Opinion
23 Sep 2025
REC opinion
Further Information Favourable Opinion