Supraclavicular brachial plexus and paravertebral blocks: novel regional anaesthetic technique for brachioaxillary fistula formation with a synthetic graft.

Vascular access formation surgery for renal replacement therapy can be performed under local, regional or general anaesthesia. Regional anaesthesia may offer several advantages, however the sensory innervation to the upper medial arm can be difficult to adequately block. We describe a novel regional anaesthetic technique using both supraclavicular brachial plexus and paravertebral blocks for a multimorbid 73-year-old woman undergoing brachioaxillary fistula formation with a synthetic graft. An ultrasound-guided supraclavicular brachial plexus block was performed, followed by an ultrasound-guided T2/3 level paravertebral block. Adequate sensory blockade for surgery was achieved. Supplemental local anaesthetic infiltration was not required, and the operation was well tolerated by the patient. We consider this to be a valuable regional anaesthetic technique for vascular access formation surgery involving the upper arm.

The role of the medial collateral ligament and posteromedial capsule in controlling knee laxity.

BACKGROUND: The medial aspect of the knee has a complex capsular structure; the biomechanical roles of specific structures are not well understood. HYPOTHESIS: The 3 strong stabilizing structures, the superficial and deep medial collateral ligaments and the posteromedial capsule, make distinct contributions to controlling tibiofemoral laxity. STUDY DESIGN: Controlled laboratory study. METHODS: Changes in knee laxity under anterior-posterior drawer, valgus, and internal-external rotation loads were found by sequential cutting in 18 cadaveric knees. Three cutting sequences allowed the roles of the 3 structures to be seen in isolation and in combination. Some force contributions were also calculated. RESULTS: The posteromedial capsule controlled valgus, internal rotation, and posterior drawer in extension, resisting 42% of a 150-N drawer force when the tibia was in internal rotation. The superficial collateral ligament controlled valgus at all angles and was dominant from 30 degrees to 90 degrees of flexion, plus internal rotation in flexion. The deep collateral ligament controlled tibial anterior drawer of the flexed and externally rotated knee and was a secondary restraint to valgus. CONCLUSION: Distinct roles in controlling tibiofemoral laxity have been found for these structures that vary according to knee flexion and tibial rotation. CLINICAL RELEVANCE: The restraining functions demonstrated provide new information about knee stabilization, which may allow better evaluation of structural damage at the medial aspect of the knee.