Analgesic Effects of Transversus Thoracic Plane (TTP) Block in Cardiac Surgery - Pilot Study

In February 2015, Ueshima et al published an article regarding ultrasound guided transversus thoracic muscle plane (TTP) block for breast cancer resection. In this article, he showed that branches of the intercostal nerves (Th2-6) dominate the region of the internal mammary area. By administering local anesthetics between the internal intercostal and transversus thoracic muscle, analgesia in the anterior chest and sternum can be obtained. A cadaveric study shows injectate spread from the second to fifth intercostal spaces with a single 15mL injection between the third and fourth ribs next to the sternum. They further published a case series of two patients who successfully underwent median sternotomy for aortic valve replacement and thymoma resection using only the TTP block for analgesia. Fast- track cardiac surgery is now widely practiced, and evidence for its safety and efficacy has spurred its adoption. With the increased demand for health care resources including nursing manpower and ICU beds, postoperative patients are returning to the cardiac surgery intensive care unit (CSICU) on shorter acting anesthetic agents so that they can be awakened, following commands and spontaneously ventilating earlier. The TTP block fits in well with the fast- track paradigm. By providing adequate analgesia for median sternotomy, the TTP block may reduce narcotic requirements and consequent sedation and respiratory depression, hypercapnia and respiratory acidosis, prolonged mechanical ventilation and need for emergency advanced airway interventions.