It is well known that myocardial ischemia leads to Regional Wall Motion Abnormalities (RWMAs) and reversible depression of Left Ventricular (LV) systolic function. Transoesophageal Echocardiography (TEE) is an established tool for early diagnosis of new RWMAs. However, evaluation of RWMAs by echocardiography is largely qualitative and relies on visual assessment of wall segments. Evaluation of LV systolic function and Ejection Fraction (EF) is more reproducible and accurate with Real-Time 3D Echocardiography (RT3DE) as compared with two-dimensional and M-mode techniques. Primary advantages for RT3DE are fast and largely automated volumetric analysis of LV function and LV volumes, without geometric assumptions and risk of underestimating volumes in foreshortened views. This case illustrates the use of intraoperative RT3DE during coronary artery bypass surgery to objectively assess: LV systolic function with LV volumes and RWMAs and improvement in cardiac synchronization following coronary reperfusion.

Purpose

The saphenous nerve, a branch of the femoral nerve, is a pure sensory nerve that supplies the anteromedial aspect of the lower leg from the knee to the foot. There is limited evidence of the effectiveness of ultrasound-guided techniques to block the saphenous nerve. We therefore undertook a retrospective case series to investigate the efficacy of an ultrasound-guided subsartorial approach to saphenous nerve block.

Methods

During a four-month period, all patients receiving a subsartorial saphenous nerve block for lower extremity surgery at our institution had their medical records reviewed. Patient demographics and data were recorded, including block characteristics, intraoperative anesthetic management, pre-block, post-block, and postoperative pain scores, as well as postoperative analgesic dosing. Preoperative block success was defined by minimal intraoperative analgesic administration and a pain score of 0 in the postanesthesia care unit not requiring analgesic supplementation. Postoperative block success was defined by reduction of pain score to 0 without need for additional analgesic dosing.

Results

Thirty-nine consecutive patients were identified as receiving an ultrasound-guided subsartorial saphenous nerve block. Overall, this ultrasound-guided technique was found to have a 77% success rate.

Conclusion

This case series shows that an ultrasound-guided subsartorial approach to saphenous nerve blockade is a moderately effective means to anesthetize the anteromedial lower extremity. The success rate is based on stringent criteria with an endpoint of postoperative analgesia. A randomized prospective study would provide a more definitive answer regarding the efficacy of this technique for surgical anesthesia.