Unique Considerations for Complete Surgical Analgesia for Below-the-Knee Amputations.

Recent cadaver studies have suggested that posterior femoral cutaneous nerve (PFCN) may contribute to the sensory innervation of the posterior lower leg. Whether this is clinically relevant may be revealed in patients who underwent below-the-knee amputation (BKA) with monitored anesthesia care (MAC) and peripheral nerve blocks. We performed femoral and sciatic nerve blocks for a 55-year-old male patient who underwent BKA and subsequent formalization surgeries as the main surgical analgesia while providing MAC in the operating room. In both cases, the patient could not tolerate surgical incisions in the posteromedial aspect of the lower leg, despite reporting no pain in other areas of the lower leg with surgical stimulation. There may exist a small population of patients in which PFCN makes significant contribution to the sensory innervation of the posterior lower leg. For these patients, the combination of femoral and sciatic nerve blocks may not be adequate in providing surgical analgesia for BKA and related procedures.

Outcomes of Local and Regional Anesthesia for Superficialization of Brachiobasilic Arteriovenous Fistulas.

BACKGROUND: Superficialization, the second stage of a two-stage brachiobasilic arteriovenous fistula (BB-AVF), can be performed under local (LA), regional (RA), or general anesthesia (GA). Given the numerous comorbidities in patients with end-stage renal disease (ESRD), our preference is to use RA or LA when feasible. Our goal was to review the success rate of RA and LA, need for conversion to GA, and cardiac morbidity and mortality for BB-AVF superficialization. METHODS: We performed a retrospective cohort analysis of patients who underwent BB-AVF creation with second-stage superficialization over a 4-year period. The primary outcome measures included need for conversion to GA, myocardial infarction (MI), and 30-day mortality. A secondary outcome was total operative time (time from preoperative briefing to the time the patient left the operating room). We analyzed the data using Fisher Exact test for categorical data and nonparametric analysis for continuous data. RESULTS: There were 42 patients who underwent BB-AVF superficialization. The median age was 56 years, with a mean body mass index of 29. Most patients were male (55%) and predominantly Hispanic/Latino (60%). RA was utilized in 35 patients (83%), LA in 5 (12%), and GA in 2 (5%). The conversion rate from RA to GA was 0% and was 20% (n = 1) from LA to GA. There were no postoperative MI or deaths. There was no significant difference in total operative time (219.6 min for RA, 234.5 min for LA, and 278 min for GA, (P = 0.37)). CONCLUSIONS: Local and/or regional anesthesia can be successfully used in the majority of patients undergoing BB-AVF superficialization. LA and RA are associated with negligible cardiac morbidity and mortality. Conversion from RA to GA is rare. Use of RA does not result in a longer total operative time.

Pre-operative regional block anesthesia enhances operative strategy for arteriovenous fistula creation.

PURPOSE: We aim to assess the effect of regional block anesthesia on vein diameter, type of AVF placement, and fistula size and flow volume. METHODS: 30 patients presenting for AV access procedures were followed prospectively. Vein diameters via venous ultrasound and planned location for AV access were documented. Supraclavicular brachial plexus block was followed by repeat ultrasound and alterations in operative plan were noted. Patients returned to clinic for duplex ultrasound assessment. RESULTS: Average increase from baseline vein diameter with regional block was most pronounced in the lower cephalic (34%), upper cephalic (24.2%), and basilic veins (31.3%) and less in the brachial vein (8.7%). Type of AVF was modified following regional block in 14%. The rate of native AVF placement improved from 89% to 93% with regional block. Twenty-three AVF patients were available for follow-up (mean 24 weeks). Average fistula size was 7.9 mm (CI 6.9-8.9) and all patent fistulas developed flow volume >600 mL/min. Primary patency was attained in 83%. One thrombosis occurred after a basilic artery was lacerated during dialysis access. The average fistula increased 0.33 cm from post-block diameter (SD 0.22, P<.05). CONCLUSIONS: Vein diameter increases significantly in the basilic and cephalic veins following regional block anesthesia and may improve the rate of native fistula placement. Propensity to dilate after regional block anesthesia does not predict size of the fistula.

Efficacy of an ultrasound-guided subsartorial approach to saphenous nerve block: a case series.

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.