Comparison of Craniocaudal Spread of Lumbar Erector Spinae Plane Block With Two Volumes of Local Anesthetics.

BACKGROUND: The erector spinae plane block (ESPB) is a less invasive, safer, and technically easier procedure compared to the conventional neuraxial technique. Although the ESPB is a favored and easy technique compared to neuraxial block, there is no study with a large number of patients describing the exact spread level of injected local anesthetics. OBJECTIVES: The purpose of this study was to identify ESPB spread in the craniocaudal direction and the incidence of spread into the epidural space, psoas muscle, and intravascular system. STUDY DESIGN: Prospective design. SETTING: A tertiary university hospital, pain clinic. METHODS: Right- or left-sided ESPBs (170 at L4) with fluoroscopy subsequent to ultrasound guidance due to acute or subacute low back pain were included. In this study, 10 mL (ESPB 10 mL group, contrast medium 5 mL) or 20 mL (ESPB 20 mL group, contrast medium 7 mL) of a local anesthetic mixture was injected. After confirming a successful interfascial plane spreading under ultrasound guidance, the remaining local anesthetic was injected under fluoroscopic guidance. The spread level of ESPB in the craniocaudal direction and the occurrence of injectate into the epidural space or psoas muscle was assessed using the saved fluoroscopic images. These images were compared between the ESPB 10 mL and ESPB 20 mL groups. Also, the presence or absence of intravascular injection during ESPB was assessed and compared between the ESPB 10 mL and ESPB 20 mL groups. RESULTS: The ESPB 20 mL group had a more extensive caudal distribution of contrast medium than the ESPB 10 mL group. Also, the total number of lumbar vertebral segments was significantly higher in the ESPB 20 mL group than that of the ESPB 10 mL group (1.7 ± 0.4 vs 2.1 ± 0.4, P < 0.001). Among all injections performed in this study, epidural, psoas muscle, and intravascular injections occurred in 2.9%, 5.9%, and 12.9%, respectively. LIMITATIONS: Only the craniocaudal direction was evaluated without evaluating the spread pattern in the medial to lateral direction. CONCLUSION: The ESPB 20 mL group showed a more extensive distribution of contrast medium than that of the ESPB 10 mL group. Inadvertent injections into the epidural space, psoas muscle, and intravascular system were observed. Among them, intravascular system injections were found to be the most common (12.9%).

Comparison of Intravascular Uptake and Technical Ease Between Anteroposterior and Oblique Views During Lumbar Medial Branch Block.

BACKGROUND: Inadvertent intravascular injection of local anesthetics can lead to false-negative results following lumbar medial branch block (MBB) performed to diagnose facet joint origin pain. A previous study demonstrated that the type of approach method could affect the incidence of intravascular injections and technical ease of the procedure. OBJECTIVES: The primary objective of our study was to compare the incidence of inadvertent intravascular injection and technical ease of the MBB between anteroposterior (AP) and oblique (OB) views. STUDY DESIGN: Prospective randomized trial. SETTING: An interventional pain management practice in South Korea. METHODS: The incidence of intravascular uptake of contrast medium was compared using AP and OB fluoroscopic views during lumbar MBB. Injection time, radiation dose, and patient discomfort during lumbar MBB were also compared. Risk factors associated with a longer procedure time and a higher radiation dose were analyzed. RESULTS: The incidence of intravascular injection was 22.5% (23/102) in the AP group and 17.6% (18/102) in the OB group (P = 0.382). A significantly longer injection time and a higher dose of radiation were required to complete 3 levels of MBB in the OB group than in the AP group (45.9 seconds vs 61.9 seconds, P = 0.001; 27.4 centigray [cGy]/cm2 vs 42.2 cGy/cm2, I = 0.004). The OB approach and left side injection were the risk factors associated with a longer total procedure time (odds ratio [OR] = 6.64, 95% CI, 1.99-22.17, P = 0.002; OR = 0.20, 95% CI, 0.06-0.67, P = 0.009, OB and AP, respectively). LIMITATIONS: The physician performing the MBB could recognize the AP or OB fluoroscopic view during procedure. CONCLUSION: The overall incidence rate of intravascular injection during lumbar MBB showed nearly 20% in both approach methods groups. The OB approach and left side MBBs were associated with a longer total procedure time and a higher radiation dose.

Comparison of Intravascular Uptake Using Touhy or Quincke Needle During Lumbar Medial Branch Block.

BACKGROUND: Inadvertent intravascular injection of local anesthetics can lead to false negative results following a lumbar medial branch block (MBB) performed to diagnose facet joint origin pain. A previous study demonstrated that the type of needle could affect the incidence of intravascular injection rates. OBJECTIVES: The primary endpoint of this study was to compare the incidence of intravascular injection during lumbar MBB between the Quincke and Touhy needles. The secondary endpoint of this study was to compare the injection time, radiation dose, and patient discomfort during lumbar MBB between the needle types. STUDY DESIGN: Prospective randomized trial. SETTING: An interventional pain management practice in South Korea. METHODS: The incidence of intravascular uptake of contrast medium was compared using the Touhy and Quincke needles under real-time fluoroscopy during lumbar MBB. Injection time, radiation dose, and patient discomfort during lumbar MBB were also compared. RESULTS: The incidence of intravascular injection was 21.8% (21/102) in the Touhy needle group and 21.2% (22/99) in the Quincke needle group. The odds ratio for the association between the needle types and intravascular injection was 1.1. The injection time, radiation dose, and patient discomfort during lumbar MBB were similar between the Touhy and Quincke needle groups. LIMITATIONS: This study was performed from L2 to L4 MBB of the unilateral lumbar region. Although the type of needle assigned to the patient was randomized, 3 needles, which are used for 3 levels of MBB, were identical. CONCLUSIONS: The overall incidence rate of intravascular injection during lumbar MBB was nearly 20% under real-time fluoroscopy for both types of needle. Use of the Touhy needle did not reduce the intravascular injection rate nor the injection time, radiation dose, and patient discomfort.

Local Anesthetic Plasma Concentrations as a Valuable Tool to Confirm the Diagnosis of Local Anesthetic Systemic Toxicity? A Report of 10 Years of Experience.

BACKGROUND: Local anesthetic systemic toxicity (LAST) has been reported as a serious complication of local anesthetic (LA) peripheral injection. The signs and symptoms of LAST are highly variable, and the challenge remains to confirm its diagnosis. In this context, the determination of LA plasma concentration appears as a valuable tool to confirm LAST diagnosis. The aims of this study were to describe observed LA concentrations in patients suspected with LAST and their contribution to diagnostic confirmation. METHODS: We retrospectively reported suspected LAST in patients for which at least one plasma LA concentration was determined to confirm diagnosis of LAST. Data collection came from our pharmacological laboratory's database. Clinical signs and symptoms of toxicity, their onset time and observed LA concentrations were used to confirm LAST diagnosis. RESULTS: 33 patients who presented with suspected LAST after ropivacaine and/or lidocaine administration were included. Prodromal symptoms were observed in 13 patients. Isolated central nervous system (CNS) toxicity occurred in 11 patients, and combined CNS and cardiovascular toxicity occurred in 12. One, two or three venous plasma samples were performed in 11, 3 and 19 patients, respectively. Toxic plasma LA concentrations were observed in three patients, receiving peripheral LA injection using lidocaine (16.1 µg/mL) and ropivacaine (4.2 and 4.8 µg/mL). CONCLUSION: This study presents an important biological and clinical dataset of patients who presented with suspected LAST. Plasma LA concentrations could bring valuable information in the diagnosis of LAST but requires rigorous sample protocols.

Contralateral retrodiscal transforaminal approach for percutaneous epidural adhesiolysis: A technical description and retrospective comparative study.

OBJECTIVES: Retrodiscal transforaminal (RdTF) epidural steroid injection (ESI) is clinically comparable to conventional transforaminal ESI and can avoid catastrophic complications. However, it poses a risk of inadvertent intradiscal, intravascular, and intrathecal injections. Therefore, we aimed to evaluate the feasibility of percutaneous epidural adhesiolysis (PEA) using the contralateral (Contra)-RdTF approach. METHODS: The electronic medical records of 332 patients with unilateral lumbar radiculopathy due to foraminal disk pathology were reviewed. Patients were categorized into two groups: Group A (ESI using the RdTF approach) and Group B (PEA using the Contra-RdTF approach). Effective pain relief (EPR; ≥50% pain relief from baseline) in patients was evaluated using the visual analog scale (VAS) at 4 and 12 weeks after the procedure. The presence of unintended fluoroscopic findings and complications was recorded. RESULTS: A total of 119 patients were enrolled in the final analysis: 81 in Group A and 38 in Group B. Both groups showed lesser VAS scores after 4 and 12 weeks than at baseline (p < 0.05). However, the proportion of patients with EPR was significantly greater in Group B after 12 weeks (p = 0.015). No complications, including intrathecal injection, infectious discitis, and neurologic deterioration, were reported. However, inadvertent intradiscal and intravascular injections were reported to be significantly higher in Group A than in Group B (14.8% and 0%, respectively; p = 0.009). CONCLUSIONS: Although applications of this study are limited by its retrospective design, the results suggest that PEA using the Contra-RdTF approach is feasible because it can achieve EPR and avoid unintended fluoroscopic findings.

Unilateral visual impairment after a dental procedure: Case report.

The use of intra-oral local anaesthetics for dental procedures is a widely extended practice that may cause side effects. As such, in rare cases it may cause ocular complications such as diplopia, ptosis, blurry vision, miosis, vision loss, or amaurosis. (Most of them are transient, recovering after several hours or days). A case is presented of a 26 year-old male patient who had visual impairment in the right eye 2 days after a dental procedure was performed. Six months later he had a complete restoration of the previous visual acuity, despite the fact that he had not received any treatment. Several ways have been proposed in the literature that may explain the appearance of ocular complications following these kinds of procedures. In this case, inadvertent intravenous injection is believed to have been the cause.

Laser Doppler Imaging for Treating Vascular Complications from Procedures Involving Dermal Fillers: Case Series and Literature Review.

Vascular occlusion is a rare but severe complication of dermal filler injections. Early treatment of this complication produces better outcomes. Current diagnostic methods for vascular occlusion in the skin are subjective and imprecise; these include capillary refill time, skin color, and reports of pain. This study aimed to assess the use of laser Doppler imaging (LDI) in the evaluation and treatment of vascular complications caused by dermal filler injections. This retrospective study used laser Doppler imaging (LDI) in 13 patients who developed vascular occlusion after facial dermal filler injections, with subsequent follow-up. The precise areas of perfusion observed on LDI were compared with the findings of clinical and photographic evaluation. The results showed that LDI accurately identified areas of vascular occlusion and improved treatment precision among these thirteen patients. The procedure was more precise than visual inspection or photographic evidence. Satisfactory outcomes were achieved for all patients, and no procedure-related complications were reported. Collectively, LDI provides fast, noninvasive, and accurate delineation of areas of vascular occlusion caused by complications of dermal filler injections and avoids several subjective shortcomings of visual and photographic evaluations. Thus, LDI effectively tracks treatment outcomes. However, large-scale studies are required to confirm the present findings.

Accidental Intravascular Local Anesthetic Injection of the Facial Artery.

Local anesthesia techniques are widely used in dentistry because of their numerous advantages, including safety. Several articles have been published on local and systemic complications stemming from the use of local anesthesia, one of which is accidental intravascular injection, usually reported during inferior alveolar nerve blocks. A 58-year-old man presented to the dental office for extraction of the lower left first molar. During delivery of a supplemental injection in the buccal vestibular mucosa to anesthetize the buccal nerve, an accidental intra-arterial injection to the facial artery occurred, causing sudden sharp pain and immediate pallor along the course of the facial artery. The pallor resolved in approximately 20 minutes. Buccal infiltration was repeated successfully, and the tooth was extracted uneventfully. This case appears to be the first report in the literature to describe the accidental intravascular injection of local anesthetic involving the facial artery and discuss its clinical implications.

Unilateral visual impairment after a dental procedure: Case report. / Disminución de la agudeza visual tras un procedimiento odontológico: A propósito de un caso.

The use of intra-oral local anaesthetics for dental procedures is a widely extended practice that may cause side effects. As such, in rare cases it may cause ocular complications such as diplopia, ptosis, blurry vision, miosis, vision loss, or amaurosis. (Most of them are transient, recovering after several hours or days). A case is presented of a 26 year-old male patient who had visual impairment in the right eye 2 days after a dental procedure was performed. Six months later he had a complete restoration of the previous visual acuity, despite the fact that he had not received any treatment. Several ways have been proposed in the literature that may explain the appearance of ocular complications following these kinds of procedures. In this case, inadvertent intravenous injection is believed to have been the cause.

Development and Usability of a Virtual Reality-Based Filler Injection Training System.

PURPOSE: As filler procedures have increased in popularity, serious injection-related complications (e.g., blindness and stroke) have also increased in number. Proper and effective training is important for filler procedure safety; however, limitations exist in traditional training methods (i.e. anatomical illustrations and cadaver studies). We aimed to describe the development process and evaluate the usability of a virtual reality (VR)-based aesthetic filler injection training system. MATERIALS AND METHODS: We developed the virtual reality hardware for the training system and a short guide, with a lecture regarding safe filler injection techniques. One hundred clinicians who attended a conference tested the training system. Participants completed system usability scale (SUS) and satisfaction questionnaires. RESULTS: Nearly half of the participants were aged 35-50 years, and 38% had more than 5 years of aesthetic experience. The mean SUS score was 59.8 (standard deviation, 12.23), with no significant differences among the evaluated subgroups. Approximately 76% of participants provided SUS scores of more than 51, indicating acceptable usability. Participants aged 35-50 years were more likely to rate the system as having poor usability than were those aged < 35 years (odds ratio = 5.20, 95% confidence interval: 1.35-20.08). CONCLUSIONS: This study was the first to develop and explore the usability of a VR-based filler training system. Nearly three-fourths of participants indicated that the training system has an acceptable level of usability. However, assessments in precise target audiences and more detailed usability information are necessary to further refine the training system. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Intravascular injections of adenoassociated viral vector serotypes rh10 and PHP.B transduce murine sciatic nerve axons.

Adenoassociated viral vectors provide a safe and robust method for expression of transgenes in nondividing cells such as neurons. Intravenous injections of these vectors provide a means of transducing motoneurons of peripheral nerves. Previous research has demonstrated that serotypes 1, rh10 and PHP.B can transduce motor neuron cell bodies in the spinal cord, but has not quantified expression in the peripheral nerve axon. Axonal labeling is crucial for optogenetic stimulation and detection of action potentials in peripheral nerve. Therefore, in this study, serotypes 1, PHP.B, and rh10 were tested for their ability to label axons of the murine sciatic and tibial nerve following intravenous injection. Serotype rh10 elicits expression in 10% of acetylcholine transferase positive axons of the sciatic nerve in immunohistochemically-stained sections. Serotype rh10 transduces a variety of axon diameters from <1-12 µm, while PHP.B transduces larger axons of diameter (4-16 µm). Expression was not seen with serotype 1. These results show the potential of serotypes PHP.B and rh10 delivery of transgenic products to axons of the peripheral nerve.

Influence of needle-insertion depth on epidural spread and clinical outcomes in caudal epidural injections: a randomized clinical trial.

BACKGROUND: A caudal epidural steroid injection (CESI) is a commonly used method to improve symptoms of lumbosacral pain. We compared the achievement of successful epidurograms and patient-reported clinical outcomes following different needle-insertion depths during CESI. METHODS: For the conventional method group, the needle was advanced into the sacral canal. For the alternative method group, the needle was positioned immediately after penetration of the sacrococcygeal ligament. Epidural filling patterns and vascular uptake during fluoroscopy were determined to verify successful epidural injection. Procedural pain scores were investigated immediately after the procedure. Pain scores and patient global impression of symptom change were evaluated at 1-month follow-up. RESULTS: Assessments were completed by 127 patients (conventional method, n=64; alternative method, n=63). The incidence of intravascular injection was significantly lower in the alternative method group than in the conventional method group (3.2% vs 20.3%, P=0.005). Procedural pain during needle insertion was significantly lower in the alternative method group (3.7±1.3 vs 5.3±1.2, P<0.001). Epidural contrast filling patterns were similar in both groups. One-month follow-up pain scores and patient global impression of symptom change were comparable in both groups. CONCLUSION: Compared with the conventional method, the alternative method for CESI could achieve similar epidural spread and symptom improvement. The alternative technique exhibited clinical benefits of a lower rate of intravascular injection and less procedural pain.

Cutaneous refractile foreign body microemboli with intravascular injection of oral medication.

Injection drug abuse (IDA) is known to cause a spectrum of systemic and cutaneous complications. Despite the increasing incidence of IDA around the world, there is a paucity of literature discussing cutaneous complications from a dermatopathologic perspective. We present a case of a 35-year-old male with a complex medical history of Von Willebrand disease, Beçhet disease and diverticular disease. Following a sigmoidectomy/colostomy for diverticular perforation, he presented with fever and an indurated right arm displaying livedoid purpura. The right distal fingertips showed purpura with focal ulceration. A punch biopsy of the right wrist did not show evidence of inflammatory vasculitis or pyogenic infection, but instead showed a focus of polarizing, refractile material occluding a dilated arterial lumen within the mid-dermis. The patient admitted to injecting a suspension of crushed ondansetron (Zofran) tablets into the antecubital area to control post-operative nausea. It is known that direct intravascular injection of foreign material can cause distal ischemia and necrosis, either by local vasoconstriction, thrombosis, or formation of microemboli, as in this patient. Our objective is to bring awareness to this rarely reported phenomenon, and to raise clinical suspicion for IDA when confronted with such a unique vasculopathic pattern.

Experience and Management of Intravascular Injection with Facial Fillers: Results of a Multinational Survey of Experienced Injectors.

BACKGROUND: Intravascular injection leading to skin necrosis or blindness is the most serious complication of facial injection with fillers. It may be underreported and the outcome of cases are unclear. Early recognitions of the symptoms and signs may facilitate prompt treatment if it does occur avoiding the potential sequelae of intravascular injection. OBJECTIVES: To determine the frequency of intravascular injection among experienced injectors, the outcomes of these intravascular events, and the management strategies. METHODS: An internet-based survey was sent to 127 injectors worldwide who act as trainers for dermal fillers globally. RESULTS: Of the 52 respondents from 16 countries, 71 % had ≥11 years of injection experience, and 62 % reported one or more intravascular injections. The most frequent initial signs were minor livedo (63 % of cases), pallor (41 %), and symptoms of pain (37 %). Mildness/absence of pain was a feature of 47 % of events. Hyaluronidase (5 to >500 U) was used immediately on diagnosis to treat 86 % of cases. The most commonly affected areas were the nasolabial fold and nose (39 % each). Of all the cases, only 7 % suffered moderate scarring requiring surface treatments. Uneventful healing was the usual outcome, with 86 % being resolved within 14 days. CONCLUSION: Intravascular injection with fillers can occur even at the hands of experienced injectors. It may not be always associated with immediate pain or other classical symptoms and signs. Prompt effective management leads to favorable outcomes, and will prevent catastrophic consequences such as skin necrosis. Intravascular injection leading to blindness may not be salvageable and needs further study. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Accuracy of live fluoroscopy to detect intravascular injection during lumbar transforaminal epidural injections.

BACKGROUND: Complications following lumbar transforaminal epidural injection are frequently related to inadvertent vascular injection of corticosteroids. Several methods have been proposed to reduce the risk of vascular injection. The generally accepted technique during epidural steroid injection is intermittent fluoroscopy. In fact, this technique may miss vascular uptake due to rapid washout. Because of the fleeting appearance of vascular contrast patterns, live fluoroscopy is recommended during contrast injection. However, when vascular contrast patterns are overlapped by expected epidural patterns, it is hard to distinguish them even on live fluoroscopy. METHODS: During 87 lumbar transforaminal epidural injections, dynamic contrast flows were observed under live fluoroscopy with using digital subtraction enhancement. Two dynamic fluoroscopy fluoroscopic images were saved from each injection. These injections were performed by five physicians with experience independently. Accuracy of live fluoroscopy was determined by comparing the interpretation of the digital subtraction fluoroscopic images. RESULTS: Using digital subtraction guidance with contrast confirmation, the twenty cases of intravascular injection were found (the rate of incidence was 23%). There was no significant difference in incidence of intravascular injections based either on gender or diagnosis. Only five cases of intravascular injections were predicted with either flash or aspiration of blood (sensitivity = 25%). Under live fluoroscopic guidance with contrast confirmation to predict intravascular injection, twelve cases were predicted (sensitivity = 60%). CONCLUSIONS: This finding demonstrate that digital subtraction fluoroscopic imaging is superior to blood aspiration or live fluoroscopy in detecting intravascular injections with lumbar transforaminal epidural injection.