The glottis and subglottis: an otolaryngologist's perspective

The complexity of the glottic and subglottic region in terms of anatomy and function make this region challenging in evaluation and treatment. A thorough understanding of the complex anatomy is necessary for the management of patients who have dysphonia, vocal fold paralysis, glottic or subglottic stenosis, or complications, which may present after prolonged intubation or surgical interventions in the upper airway and the thorax.     

Treatment of abdominal nerve entrapment syndrome using a nerve stimulator.

Seventy-six patients treated at York Pain Relief Clinic for Abdominal Nerve Entrapment Syndrome (ANES) between 1982 and 1986, using aqueous phenol and nerve stimulator control are reviewed. A questionnaire was sent to all the patients who had been discharged from the clinic to try to confirm that the initial improvements had been maintained and 60 patients replied. Group A (n = 44) had been diagnosed with confidence; 95% had gained complete or partial relief of symptoms. Group B (n = 32) had other symptoms making the diagnosis less certain; 50% gained some relief. Clinical presentation of ANES and the method of treatment are described.     

Implantation of an intercostal nerve stimulator for chronic abdominal pain

Chronic abdominal pain is not uncommon and can be difficult to manage. We present the case of a 17-year-old man with a 4-year history of chronic abdominal pain. The patient had previously undergone abdominal surgery by way of laparoscopic appendicectomy and right nephrectomy for a mal-rotated kidney. The patient continued to suffer right-sided abdominal pain which was not controlled by analgesia. We report the successful implantation of a right D11 intercostal nerve stimulator to control the patient’s pain. This is the first report of an implantable intercostal nerve stimulator to control intractable chronic abdominal pain.     

Vagal nerve stimulation: overview and implications for anesthesiologists

Vagal nerve stimulation is an important adjunctive therapy for medically refractory epilepsy and major depression. Additionally, it may prove effective in treating obesity, Alzheimer's disease, and some neuropsychiatic disorders. As the number of approved indications increases, more patients are becoming eligible for surgical placement of a commercial vagal nerve stimulator (VNS). Initial VNS placement typically requires general anesthesia, and patients with previously implanted devices may present for other surgical procedures requiring anesthetic management. In this review, we will focus on the indications for vagal nerve stimulation (both approved and experimental), proposed therapeutic mechanisms for vagal nerve stimulation, and potential perioperative complications during initial VNS placement. Anesthetic considerations during initial device placement, as well as anesthetic management issues for patients with a preexisting VNS, are reviewed.     

Perivascular brachial plexus block. Ultrasound versus nerve stimulator

Background

Optimizing the needle position using ultrasound (US) instead of electrical nerve stimulation (NSt) is increasingly common for perivascular brachial plexus block. These two methods were compared in a prospective, randomized, single-blinded controlled trial regarding effectiveness and time of onset of peripheral nerve blockade.

Methods

After puncture (penetration of neurovascular sheath and complete insertion of needle) 56 patients were randomly assigned to either the US group (finding the needle tip in transpectoral section, short axis, correction of needle position if local anesthetic spread was insufficient) or the NSt group (target impulse reaction in median, ulnar or radial nerve of 0.3?mA/0.1?ms, if necessary correction of position before injection of local anesthetic) to verify the needle position. All patients received 500?mg 1% mepivacaine. Sensory and motor blocks were tested by single nerve measurements (SNM) 5, 10 and 20?min after finishing the injection, where 0 represents minimal and 2 maximal success of the block.

Results

Single nerve measurements were analyzed using repeated measures ANOVA. The mean results of cumulative SNMs were significantly higher in the US group at all measurement times. Sensitivity US/NSt: 5?min: 3.36±2.32/2.63±1.87; 10?min: 5.45±2.41/4.21±2.45; 20?min: 7.30±2.02/6.43±2.43, p=0.015, motor function US/NSt: 5?min: 3.91±1.81/3.02±1.67; 10?min: 5.27±1.66/4.05±1.70; 20?min: 6.64±1.37/5.50±1.90, p<0.001. At the beginning of surgery complete nerve blockade was achieved in 89% in the US group and 68% in the NSt group (p=0.006), 3 (US) versus 7 (NSt) patients needed supplementation and 3 (US) versus 11 (NSt) patients needed general anesthesia (p=0.022). To achieve the nerve block took approximately 1?min more in the US group (p=0.003).

Conclusion

The use of ultrasound in perivascular brachial plexus blocks leads to significantly higher success rates and shorter times of onset.     

Peripheral nerve block with use of nerve stimulator

The authors describe use of the nerve stimulator in conjunction with a percutaneous exploring needle to achieve peripheral blocks accurately and without injuring the nerve. The nerve stimulator allows accurate nerve blocks without causing paresthesiae and the need for additional anesthetic. This technique decreases the possibility of nerve injury.     

Superficial or deep implantation of motor nerve after denervation: an experimental study--superficial or deep implantation of motor nerve

Neurorraphy, conventional nerve grafting technique, and artificial nerve conduits are not enough for repair in severe injuries of peripheral nerves, especially when there is separation of motor nerve from muscle tissue. In these nerve injuries, reinnervation is indicated for neurotization. The distal end of a peripheral nerve is divided into fascicles and implanted into the aneural zone of target muscle tissue. It is not known how deeply fascicles should be implanted into muscle tissue. A comparative study of superficial and deep implantation of separated motor nerve into muscle tissue is presented in the gastrocnemius muscle of rabbits. In this experimental study, 30 white New Zealand rabbits were used and divided into 3 groups of 10 rabbits each. In the first group (controls, group I), only surgical exposure of the gastrocnemius muscle and motor nerve (tibial nerve) was done without any injury to nerves. In the superficial implantation group (group II), tibial nerves were separated and divided into their own fascicles. These fascicles were implanted superficially into the lateral head of gastrocnemius muscle-aneural zone. In the deep implantation group (group III), the tibial nerves were separated and divided into their own fascicles. These fascicles were implanted around the center of the muscle mass, into the lateral head of the gastrocnemius muscle-aneural zone. Six months later, histopathological changes and functional recovery of the gastrocnemius muscle were investigated. Both experimental groups had less muscular weight than in the control group. It was found that functional recovery was achieved in both experimental groups, and was better in the superficial implantation group than the deep implantation group. EMG recordings revealed that polyphasic and late potentials were frequently seen in both experimental groups. Degeneration and regeneration of myofibrils were observed in both experimental groups. New motor end-plates were formed in a scattered manner in both experimental groups. However, they were more dense in the superficial implantation group than the deep implantation group. It was concluded that superficial implantation has a more powerful contractile capacity than that of deep implantation. We believe that this might arise from the high activity of glycolytic enzymes in peripheral muscle fibers of gastrocnemius muscle, decrease in insufficient intramuscular guidance apparatus, and intramuscular microneuroma formation at the insufficient neuromuscular junction since the motor nerve had less route to muscle fibers.