Intravenous injection of dexamethasone is non-inferior to perineural administration for popliteal sciatic nerve and saphenous nerve blocks: A randomized, controlled, triple-blind study

Background

The aim of this study was to assess whether intravenous dexamethasone was noninferior to perineural dexamethasone as an adjuvant to ropivacaine for a combination of saphenous and sciatic nerve blocks in patients undergoing foot and ankle surgery.

Methods

This was a prospective, blinded, randomized noninferiority study. Seventy-five patients, aged 18-75 years, with an American Society of Anesthesiologists (ASA) physical status I-III who underwent foot and ankle surgery were involved. Patients scheduled for ultrasound-guided popliteal sciatic nerve block and saphenous nerve block were randomized to receive 0.375% ropivacaine with 7.5 mg of dexamethasone perineurally (Dex-PN), 10 mg of dexamethasone intravenously (Dex-IV) or neither (Placebo). The primary outcome was the duration of analgesia. The major secondary outcomes were the composite pain intensity and opioid consumption score at 0-48 h intervals after anesthesia.

Results

The mean analgesic duration was 26.2 h in the Dex-IV group and 27.9 h in the Dex-PN group (duration difference, -1.7; 95% CI, -3.8 to 0.43; P = 0.117), and both durations were significantly longer than that in the placebo group (17.6 h, P < 0.001). Conditions for establishing non-inferiority were met.

Conclusions

Our findings indicate that a single 10-mg intravenous dose of dexamethasone was noninferior to the combined dose of ropivacaine plus deaxmethasone in terms of duration of analgesia for foot and ankle surgery.

Effects of two different topographic approaches for combined sciatic and femoral nerve block in calves, guided by ultrasound and neurostimulation

To evaluate the sensory and motor effects promoted by a combined sciatic and femoral nerve block in calves using two approaches. Six calves were used, in a crossover study. Ultrasound combined with neurostimulation, was used to perform the following block combinations: the proximal approach (PA), which consisted of the association of the parasacral approach (sciatic nerve block) and ventral to the ilium approach (femoral nerve block); distal approach (DA) consisted of the association of a lateral approach to the pelvic limb approach (sciatic nerve block), and an inguinal approach, underneath the femoral trigone (femoral nerve block). Pressure algometry and motor function of the limb where evaluated. Mechanical nociceptive threshold (MNT) increase, and ataxia duration means were 9.5 ± 0.7 kg and 10.4 ± 3.9 hr for PA and 10.4 ± 3.9 kg and 12.7 ± 1.9 hr for DA, respectively with no significant difference. There was no significant difference between MNT elevation time and the duration of ataxia using the same approach. The DA treatment showed significant MNT elevation in 72% of the tested regions, while the PA treatment showed an elevation in 100% regions tested. Topographic approaches closer to where the spinal nerves emerge produced a larger desensitised area.

Enlarging premaxillary mass: A unique manifestation of extranodal diffuse B-cell lymphoma

Lymphomas are the most common nonepithelial malignancy in the head and neck region. Among these, non-Hodgkin Lymphoma (NHL) is the most prevalent, and diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype. NHL is known for its propensity for extranodal involvement, which can affect any anatomical location. The presence of perineural spread is frequently encountered in head and neck malignancies, including lymphomas. We report a case of a 40-year-old male with an enlarging infraorbital facial mass with associated erythema, pain, and paresthesia, which was subsequently found to be extranodal DLBCL with retrograde perineural spread along the infraorbital nerve.

Anaesthetic considerations for elective cesarean section in a patient with a giant Tarlov cyst

Tarlov cysts are a pathological dilatation of the meninges. Their incidence is more frequent in women between 30 and 50 years of age. The imaging test of choice for diagnosis is MRI. Of unknown etiology, most cases are asymptomatic, but symptoms of radicular irritation, among others, may occur. The therapeutic possibilities are multiple, reserving surgical excision as the last option. We report a case of successful spinal anaesthesia for elective cesarean section in a patient with a giant Tarlov cyst but with potential airway compromise, in whom the risks of general anaesthesia would be increased. Anaesthetic management presents a challenge for the anesthesiologist, especially in situations where the patient presents an increased anaesthetic risk for general anaesthesia, as is the case in the obstetric patient.

The use of perineural dexamethasone and transverse abdominal plane block for postoperative analgesia in cesarean section operations under spinal anesthesia: an observational study

Background

During transverses abdominal plane block (TAP) procedure to provide analgesia in cesarean section (CS) operation, the use of perineural dexamethasone as an additive agent may improve pain relief and may cause a prolonged block duration. This study aims to investigate whether perineural dexamethasone, when added to bupivacaine local anesthetic agent during a TAP block, may provide adequate pain relief without adverse events.

Methods

This is a prospective cohort study of fifty-eight patients undergoing elective CS with spinal anesthesia. We hypothesized to perform bilateral TAP block using perineural dexamethasone as an additive agent. The patients were randomly divided into two groups using a systematic random sampling method. While one group of patients received perineural dexamethasone of 8 mg additive agent together with bupivacaine 0.25% 40 ml (Group TAPD), the other group received only bupivacaine 0.25% 40 ml in TAP block (Group TAPA). The primary outcomes are the period for the first request of postoperative pain relief medication and the numerical rating scale (NRS) pain intensity scores at 2, 6, 12, and 24 h after surgery. The secondary outcomes are comparing the 24-h tramadol and diclofenac analgesic requirements and the incidences of side effects on postoperative day one. A p-value of < 0.05 is statistically significant.

Results

The time to first analgesic request was 8.5 h (8.39–9.79) in the TAPD group versus 5.3 h (5.23–5.59) in the TAPA group, respectively. (p < 0.001) The median NRS scores were significantly reduced in the TAPD group compared to the TAPA group at 6, 12, and 24 h after surgery (p-values < 0.001). The total analgesics consumption over 24 h postoperatively was lower in Group TAPD compared to Group TAPA (p < 0.05).

Conclusion

An additive agent of perineural dexamethasone at a dose of 8 mg during bilateral TAP block for elective CS operation under spinal anesthesia provided better pain relief on postoperative day 1.

Decompression of Cavernous Sinus for Trigeminal Neuropathic Pain From Perineural Spread of Tumor: 2-Dimensional Operative Video

Head and neck malignancies with perineural spread are rare. Patients can present with neuropathic pain and cranial nerve palsies.1 Skull base approaches for surgical decompression are a consideration for patients to provide symptom relief.2 We demonstrate a frontotemporal extradural approach for a patient with worsening visual symptoms and refractory neuropathic pain in the V1, V2, and V3 distributions and briefly review the relevant anatomy.3-7  A 41-yr-old female with a poorly differentiated carcinoma of the head and neck with an infiltration of the cavernous sinus and perineural spread along the trigeminal nerve presented with severe neuropathic facial pain and anesthesia. She had previously undergone radiosurgery. Magnetic resonance imaging (MRI) demonstrated an interval increase in perineural disease within the cavernous sinus with extension intradurally. Her pain was medically refractory. A 2-dimensional intraoperative video illustrates the microsurgical decompression of her perineural invasion along the skull base as a palliative procedure. The patient recovered well postoperatively and had a symptomatic improvement in her pain and visual symptoms. Her preoperative facial numbness persisted postoperatively as expected. Postoperative imaging demonstrates a gross total resection of the intradural component of the tumor with decompression and expected expansion of the cavernous sinus. Because of the retrospective nature of this report, informed consent was not required. Images within the video have been reproduced from Fukuda et al4 with permission from © Georg Thieme Verlag KG; and Matsuo et al5 by permission of the Congress of Neurological Surgeons.

Orbital Exenteration: A 23-year Report

PURPOSE

Orbital exenteration is a psychologically and anatomically disfiguring procedure which indicated in some patients with malignant or progressive diseases of orbital and periorbital area. In this study, we reviewed 176 patients that underwent orbital exenteration.

METHODS

This was a retrospective study of medical records from all patients who underwent orbital exenteration from March 1991 to March 2014 in oculoplastic department at an eye care center. Demographic data, diagnosis, site of primary involvement and technique of surgery were determined in patients.

RESULTS

One hundred seventy-six cases of orbital exenteration were included that had documented histopathology. The age of patients ranged from 1 to 91 years (mean age ± standard deviation, 55.43 ± 27 years). Ninety-seven (55.11%) males and 79 (44.88%) females were included. Fifteen different tumors were identified. The most common indication was patients with basal cell carcinoma 49 (28%) followed by 41 (23.5%) squamous cell carcinomas, 35 (20%) retinoblastoma, and 13 (7%) adenoid cystic carcinomas. In total, adnexal malignancies were the most common tumors, secondarily involving the orbit. Eyelids 89 (50.5%) and the globe 43 (24%) were the most frequent site of involvement. Three types of exenteration were performed, based on available data of 129 operation sheets, 46 (35.7%) subtotal, 62 (48.1%) total, and 21 (16.3%) cases of extensive exenterations. In total 97 cases were evaluated pathologically for perineural involvement, of which perineural invasion was noted in 9 (7%) reports.

CONCLUSIONS

Frequency of exenteration in our center has increased in past 3 years and the majority of cases were eyelid basal cell carcinoma. Patient education considering periocular lesions can help in earlier diagnosis of malignant lesions and therefore reducing the number of exenteration.

Cross-sectional area of the median nerve after intraneural vs perineural low volume administration

INTRODUCTION

To recognise the relationship between the needle tip and the median nerve during peripheral nerve block is of interest to avoid neural damage. However, signs of intraneural injection are not clearly established. The aim of this study was to define the changes observed in the peripheral nerve after the intraneural or perineural administration of 1ml of solution.

MATERIAL AND METHODS

Ultrasound guided median nerve blocks were performed in the forearm of 10 fresh cadavers on 60 occasions (3 per forearm). They were randomised into the intraneural (n=30) or perineural (n=30) location of the needle tip, after the consensus of location by 7 specialists. After 1ml of solution was injected an evaluation was made of the changes in the cross-sectional area of the nerve, as well as the displacement along the nerve.

RESULTS

The cross-sectional area of the median nerve was increased in both groups, however, the increase was significantly higher in the intraneural group (perineural 0.007±0.013cm2 vs. intraneural 0.032±0.021cm2, P<.0001). An increase of more than 27% of the area ensures an intraneural injection in the median nerve according to the ROC curve analysis. Both proximal and distal diffusion were observed more frequently in the intraneural group (proximal: 86% vs 14%, P<.0001, Distal: 43% vs 4%, P<.0001).

CONCLUSIONS

Based on this experimental study, it is concluded that the injection of a small volume (1ml) allows to discriminate the disposition of the intraneural vs perineural needle in a high percentage of cases. Therefore, it is suggested that this "dose test" should be considered in the safety algorithms if it is required to reduce the incidence of intraneural injection.

Extensive perineural spread of an intrapelvic sciatic malignant peripheral nerve sheath tumor: a case report

Perineural spread has been described in multiple neoplasms of neural and non-neural origin. The peripheral nervous system may represent a highway by which tumors can spread throughout the body. Malignant peripheral nerve sheath tumor (MPNST) is a neoplasm arising from peripheral nerves with high rates of local recurrence and distant metastases, leading to a poor 5-year overall survival. In many cases, the optimal treatment involves wide en bloc excision with negative margins as well as chemotherapy and radiation. Even in cases of negative surgical margins, recurrence rates are high, suggesting possible skip lesions or very distant infiltration along the involved nerve. We report a case of high-grade MPNST of the sciatic nerve with post-mortem dissection and histopathologic characterization of perineural spread of microscopic disease to sites significantly proximal and distal to areas with evidence of gross disease, which may help to explain the high rates of local and distal recurrence in MPNST.

Neuroimaging of Meckel's cave in normal and disease conditions

Abstract

Meckel’s cave is a dural recess in the posteromedial portion of the middle cranial fossa that acts as a conduit for the trigeminal nerve between the prepontine cistern and the cavernous sinus, and houses the Gasserian ganglion and proximal rootlets of the trigeminal nerve. It serves as a major pathway in perineural spread of pathologies such as head and neck neoplasms, automatically upstaging tumours, and is a key structure to assess in cases of trigeminal neuralgia. The purpose of this pictorial review is threefold: (1) to review the normal anatomy of Meckel’s cave; (2) to describe imaging findings that identify disease involving Meckel’s cave; (3) to present case examples of trigeminal and non-trigeminal processes affecting Meckel’s cave.

Teaching points

• Meckel’s cave contains the trigeminal nerve between prepontine cistern and cavernous sinus.

• Assessment is essential for perineural spread of disease and trigeminal neuralgia.

• Key imaging: neural enhancement, enlargement, perineural fat/CSF effacement, skull base foraminal changes.

Systematic review and meta-analysis of the efficacy of perineural local anaesthetic catheters after major lower limb amputation

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effects of using an intraoperatively placed perineural catheter (PNC) with a postoperative local anaesthetic infusion on immediate and long-term outcomes after lower limb amputation.

METHODS

A systematic review of key electronic journal databases was undertaken from inception to January 2015. Studies comparing PNC use with either a control, or no PNC, were included. Meta-analysis was performed for postoperative opioid use, pain scores, mortality, and long-term incidence of stump and phantom limb pain. Sensitivity analysis was performed for opioid use. Quality of evidence was assessed using the GRADE system.

RESULTS

Seven studies reporting on 416 patients undergoing lower limb amputation with PNC usage (n = 199) or not (n = 217) were included. Approximately 60% were transtibial amputations PNC use reduced postoperative opioid consumption (standardised mean difference: -0.59, 95% CI -1.10 to -0.07, p = .03), maintained on sensitivity analysis for large (p = .03) and high-quality (p = .003) studies, but was marginally lost (p = .06) on studies enrolling patients with peripheral arterial disease only. PNC treatment did not affect postoperative pain scores (p = .48), in-hospital mortality (p = .77), phantom limb pain (p = .28) or stump pain (p = .37). GRADE quality of evidence for all outcomes was very low.

CONCLUSION

There is poor-quality evidence that PNC usage significantly reduces opioid consumption following lower limb amputation, without affecting other short- or long-term outcomes. Well-performed randomised studies are required.

Interleukin-10 conjugated electrospun polycaprolactone (PCL) nanofibre scaffolds for promoting alternatively activated (M2) macrophages around the peripheral nerve in vivo

Macrophages play a key role in tissue regeneration following peripheral nerve injury by preparing the surrounding parenchyma for regeneration, however, they can be damaging if the response is excessive. Interleukin 10 (IL-10) is a cytokine that promotes macrophages toward an anti-inflammatory/wound healing state (M2 phenotype). The bioactive half-life of IL-10 is dependent on the cellular microenvironment and ranges from minutes to hours in vivo. Our objective was to extend the in vivo bioavailability and bioactivity of IL-10 by attaching the protein onto nanofibrous scaffolds and demonstrating increased expression levels of M2 macrophages when placed around healthy intact peripheral nerves. IL-10 was adsorbed and covalently bound to electrospun poly(ε-caprolactone) (PCL) nanofibrous scaffolds. In vivo bioavailability and bioactivity of IL-10 was confirmed by wrapping IL-10 conjugated nanofibres around the sciatic nerves of Wistar rats and quantifying M2 macrophages immunohistochemically double labelled with ED1 and either arginase 1 or CD206. IL-10 remained immobilised to PCL scaffolds for more than 120 days when stored in phosphate buffered saline at room temperature and for up to 14d ays when implanted around the sciatic nerve. IL-10 conjugated nanofibres successfully induced macrophage polarisation towards the M2 activated state within the scaffold material as well as the adjacent tissue surrounding the nerve. PCL biofunctionalised nanofibres are useful for manipulating the cellular microenvironment. Materials such as these could potentially lead to new therapeutic strategies for nervous tissue injuries as well as provide novel investigative tools for biological research.