Real-Time Tissue Perfusion Monitors

Using T-Stat in Vascular Surgery

(click on chart to enlarge)

Early visual signs of ischemia are unreliable.

Noninvasive measures such as Doppler flow, pulsatility, and capillary refill are imperfect predictors of outcome, while invasive tests (such as lactate) respond slowly and cannot be used for real-time management.

Venous saturation is well correlated with clinical outcome, …yet until now, Svo2 could not be locally measured at specific end-organs, and thus was not available for assessm ent during vascular procedures.

At multiple centers, the use of tissue oxim eters has been shown to reduce the incidence of organ failure and death due to low or im paired delivery of oxygen to tissues and organs. Continuous monitoring reduces progression to infarction and allows real-time assessment of embolization, stent placement and cardiac surgery in multiple studies. You can watch tissue oxygenation change as stents, staples and sutures are placed and detect deterioration before irreversible injuries occur.


What do tissue saturation readings mean?

T-Stat values below 40% in adults, and below 35% in children, have been shown to lead to metabolic acidosis via lactic acid production. If left untreated, T-Stat values below 30% may rapidly lead to tissue death.

Use of the T-Stat 303 in Abdominal Aortic Aneurism (AAA) Repair 

AAA repair, whether open or EVAR, carries a 2% incidence of post-operative colon ischemia.

Using the 5mm T-Stat catheter, placed rectally, the tissue saturation of colonic mucosa can be monitored in real-time during the procedure in order to detect any circulatory compromise during the procedure, when perfusion can be restored before the tissue becomes irreversibly damaged.

In multi-center studies, it has been demonstrated that patients who develop interoprative colon ischemia that is detected by the T-Stat and repaired, go on to normal recoveries, and avoid the 55% mortality rate typically associated with colon ischemia detected post-operatively.