Clinical trial NCT05487820: Detecting Tissue Ischemia in Reconstruction Flaps by a Novel CO2 Biosensor (DIMENSION-study)
Official title: Detecting Tissue Ischemia in Reconstruction Flaps by a Novel CO2 Biosensor (DIMENSION-study); An Open, Prospective, Intervention Study
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Ischemia
Blood Circulation Disorder
Biosensing Techniques
Surgery
Keywords: Ischemia
Biosensor
Reconstructive
Surgery
Carbon dioxide
Flap
Lead sponsor: Oslo University Hospital
Sponsor class: OTHER
Collaborators: name: Sensocure AS
First posted: 2022-08-04
Enrollment: 160
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: Prospective, interventional. Hundred-and-sixty (56) patients will receive tissue CO2 monitoring in a reconstructed flap after reconstructive flap surgery.
Primary purpose: DIAGNOSTIC

Brief summary: The investigators will test if changes in CO2 is detected postoperatively in ischemic tissue in a reconstructed flap.

IscAlert is measuring continuously CO2 in muscular and subcutaneous tissue. IscAlert is inserted distal to the operative field into normal muscle and/or subcutaneous tissue in the reconstructed flap. Local tissue CO2 and temperature will be monitored continuously postoperatively until maximal 10 days.

If a reduced or totally obstructed blood flow appear (thrombosis), an increase in tissue CO2 and a lower local temperature will emerge rapidly as a sign of ischemia. This will be detected by the sensor which will alarm the investigators.

This will lead to assessment of the reconstructed flap and if restricted blood flow is diagnosed, a reoperation or other intervention will be performed. 56 patients will be enrolled to undergo the procedures. The IscAlert will be removed from the patient before the patient is discharged from the hospital or a maximum of 10 days (the event that occurs first). 360 devices are planned to be used in this clinical study.

Detailed description: This is an open, prospective, interventional, single-center clinical investigation designed to examine the feasibility and safety of the IscAlert™ device in patients scheduled for reconstructive flap surgery. 56 will be enrolled to undergo the procedures using a total of 350 devices depending on the injuries. IscAlert is 0.8 mm in diameter and in vitro testing, shows stable and accurate measurements of pCO2. More than 200 animal experiments have been done with the sensor. The experiments have shown that the sensor detects ischemia (Increased CO2-measurements) in real time in the following organs and tissues: Brain, heart, liver, kidneys, pancreas, intestines, musculature and subcutaneous tissue. Sensitivity and specificity are close to 100%. The sensors are inserted into tissue by a split needle technique. The split needle is the size of a 3-gauge peripheral venous catheter. In animal studies, no complications have been detected when using the sensor. The IscAlert sensors are connected to an electronics unit that is fixed to the skin with an adhesive plaster or glue outside the sterile area. The electrical signals are redirected to a PC approved for clinical use which continuously records tissue pressures of CO2. IscAlert is inserted into normal muscle and/or subcutaneous tissue distal on the reconstructed flap to be operated at the end of surgery. The insertion is far away from the operating field. The insertion is done under sterile conditions in accordance with standard sterility criteria at the hospital. No pain during insertion will occur because of insertion is performed during general anesthesia. Also, the insertion can be compared to an intramuscular injection. Postoperatively, the IscAlert sensor will continuously monitoring tissue CO2 and temperature. If ischemia occur, for examples caused by a thrombus, an increase in tissue CO2 and a lower temperature will evolve. This will be detected by the sensor which will alarm the investigators. This will lead to assessment of the reconstructed flap and if restricted blood flow is diagnosed, a reoperation or other intervention will be performed. The IscAlert will be removed from the patient before the patient is discharged from the hospital or a maximum of 10 days (the event that occurs first). Approximately 360 devices are planned to be used in this clinical study. One of the sensors will be used as a control inserted into neighboring tissue.

The primary objective is to compare CO2-levels in the reconstructed flap in individuals who has undergone reconstructed flap surgery and investigate if CO2-level is different in patient diagnosed with obstructed blood flow vs. patients with sufficient blood flow in the reconstructed flap.

Our hypotheses are:

1. The IscAlert™ device will be able to detect the presence of ischemia in the reconstructed flap by increased pCO2 levels and decrease in tissue temperature, measured by IscAlert™.
2. By using the IscAlert™ device monitoring ischemic events, an early treatment for ischemia could lead to higher incidence of reconstructed flap survival rates, and less revision surgery caused by thrombosis.
3. No clinically significant bleeding or infection will occur using IscAlert™ in this clinical study.

Eligibility criteria: Inclusion Criteria:

* Patients must be scheduled for reconstructive flap surgery
* surgery
* Patients must be ≥ 18 years
* Patients must be able to give written signed informed consent

Exclusion Criteria:

• Another study interfering with current study

Primary outcomes:
measure: Tissue CO2-level
timeFrame: 10 days
Secondary outcomes:
measure: Bleeding
timeFrame: 10 days
measure: Infection
timeFrame: 30 days
measure: Length of stay at hospital
timeFrame: 30 days
measure: Time to reduced blood flow in reconstructed flap
timeFrame: 30 days
measure: Number of re-operations
timeFrame: 30 days
Other outcomes:
measure: Number of pack-years
timeFrame: 30 days
measure: Warm ischemia time
timeFrame: 12 hours
measure: Intravenous fluid
timeFrame: 12 hours
measure: Vasoactive drugs
timeFrame: 12 hours
measure: Arterial CO2 level
timeFrame: 10 days
measure: Arterial PH level
timeFrame: 10 days
measure: Arterial lactate level
timeFrame: 10 days
measure: Arterial HCO3 level
timeFrame: 10 days
measure: End-tidal level of CO2
timeFrame: 10 days
measure: IscAlert functionality
timeFrame: 10 days
measure: Physical examination of the reconstructed flap - capillary filling
timeFrame: 10 days
measure: Physical examination of the reconstructed flap - color
timeFrame: 10 days
measure: Physical examination of the reconstructed flap - SpO2
timeFrame: 10 days
measure: Physical examination of the reconstructed flap - temperature
timeFrame: 10 days
measure: SpO2
timeFrame: 10 days
measure: Examination of the reconstructed flap - Doppler
timeFrame: 10 days
Locations:
city: Oslo
country: Norway
facility: Oslo University Hospital
Study officials:
affiliation: Oslo University Hospital
name: Magne Røkkum, MD, Ph.D
role: PRINCIPAL_INVESTIGATOR
References: