Ultrasound-guided intermediate cervical plexus block and perivascular local anesthetic infiltration for carotid endarterectomy: A randomized controlled trial

[Common and New Regional Anaesthesia Techniques Under Review - From Head to Abdomen]

By implementation of sonography regional anesthesia became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety during needle placement. Thereby new truncal blocks got enabled. Next to the blocking of specific nerve structures, plane blocks got established which can also be described as interfascial compartment blocks. The present review illustrates published and established blocks in daily practice concerning indications and the procedural issues. Moreover, the authors explain potential risks, complications and dosing of local anesthetics.

Could C3, 4, and 5 Nerve Root Block be a Better Alternative to Interscalene Block Plus Intermediate Cervical Plexus Block for Patients Undergoing Surgery for Midshaft and Medial Clavicle Fractures? A Randomized Controlled Trial

BACKGROUND

Variable innervation of the clavicle is a major challenge in surgery of clavicle fractures with patients under regional anesthesia. An interscalene block (ISB) combined with an intermediate cervical plexus block (ICPB) provides analgesia in clavicle fracture surgery, but this combination does not completely block sensation in the midshaft or medial clavicle. Cervical nerve root block is an alternative to deep cervical plexus block and has recently been used as an analgesic method in the neck and shoulder. Whether it should be used as an alternative for midshaft and medial clavicle fractures is unknown.

QUESTIONS/PURPOSES

In this randomized controlled trial, we compared a C3, 4, and 5 nerve root block to ISB combined with ICPB in surgery of midshaft and medial clavicle fractures in terms of the (1) proportion of patients achieving a sensory block that is sufficient for surgery, (2) onset time and duration of the block, and (3) effectiveness of postoperative analgesia, as measured by pain scores and consumption of analgesics.

METHODS

Between November 2021 and December 2021, we treated 154 patients for clavicle fractures. A total of 122 were potentially eligible, 91 of whom agreed to participate in this study. Twenty-nine patients were excluded because the patients chose general anesthesia or declined to undergo surgery. Ultimately, 62 patients were randomly allocated into the C3, 4, and 5 group or ISB + ICPB group, with 31 patients in each group; there were no dropouts. All patients were analyzed in the group they were randomized to under intention-to-treat principles. The assessor and patients were blinded to randomization throughout the trial. The two groups did not differ in any important ways, including age, gender, BMI, American Society of Anesthesiologists classification, and type of clavicle fracture. The two groups received either an ultrasound-guided C3, 4, and 5 nerve root block with 2, 3, and 5 mL of 0.5% ropivacaine or ultrasound-guided ISB with ICPB with 20 mL of 0.5% ropivacaine. The primary outcome was the proportion of patients in each group with a successful nerveba block who did not receive general anesthesia; this was defined as nerve block success. Secondary outcomes included the onset time and duration of the sensory block, defined as the onset to the moment when the patients felt pain and sought rescue analgesia; pain assessment in terms of the numeric rating scale (NRS) score (range 0 to 10) for pain after nerve block before and during surgery; and the median amount of sufentanil consumed intraoperatively and postoperatively in the recovery room. The dosing of sufentanil was determined by the assessor when the NRS score was 1 to 3 points. If the NRS score was more than 3 points, general anesthesia was administered as a rescue method. Complications after the two inventions such as toxic reaction, dyspnea, hoarseness, pneumothorax, and Horner syndrome were also recorded in this study.

RESULTS

A higher proportion of patients in the C3, 4, and 5 group had a successful nerve block than in the ISB + ICPB group (97% [30 of 31] versus 68% [21 of 31], risk ratio 6 [95% CI 1.5 to 37]; p < 0.01). The median onset time was 2.5 minutes (range 2.0 to 3.0 minutes) in the C3, 4, and 5 group and 12 minutes (range 9 to 16 minutes) in the ISB + ICPB group (difference of medians 10 minutes; p < 0.001). The sensory block duration was 10 ± 2 hours in the C3, 4, and 5 group and 8 ± 2 hours in the ISB + ICPB group (mean difference 2 hours [95% CI 1 to 3 hours]; p < 0.001). The median sufentanil consumption was lower in the C3, 4, 5 group than in the ISB + ICPB (median 5 µg [range 0.0 to 5.0 µg] versus median 0 µg [range 0.0 to 0.0 µg]; difference of medians 5.0 µg; p < 0.001). There were no differences between the two groups regarding NRS scores after nerve blocks and NRS score for incision and periosteum separation, with the minimum clinically important difference set at a 2-point difference (of 10). There were no severe complications in this study.

CONCLUSION

Based on our analysis of the data, a C3, 4, and 5 nerve root block was better than ISB combined with ICPB for surgery to treat medial shaft and medial clavicle fractures. When choosing the anesthesia method, however, the patient's basic physiologic condition and possible complications should be considered.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Regional Anesthesia for Vascular Surgery and Pain Management

Patients undergoing vascular surgery tend to have significant systemic comorbidities. Vascular surgery itself is also associated with greater cardiac morbidity and overall mortality than other types of noncardiac surgery. Regional anesthesia is amenable as the primary anesthetic technique for vascular surgery or as an adjunct to general anesthesia. When used as the primary anesthetic, regional anesthesia techniques avoid complications associated with general anesthesia in this challenging patient population. In this article, the authors describe regional anesthetic techniques for carotid endarterectomy, arteriovenous fistula creation, lower extremity bypass surgery, and amputation.

Application of Ultrasound-Guided Cervical Plexus Block in Type I Thyroid Cartilage Laryngoplasty and Vocal Cord Medialization Surgery

BACKGROUND

Under the background that cervical plexus block (CPB) is often adopted for type I thyroid cartilage laryngoplasty (TCL) and vocal cord medialization (VCM), the present study sought to investigate whether ultrasound-guided CPB (USCPB) could improve the efficiency of type I TCL and VCM.

METHODS

Patients with TCL were enrolled and subjected to deep and superficial USCPBs. Intravenous dexmedetomidine pumping was used to assist the painless sedation and ensure the patients to be awake for phonation during surgery. Blood pressure, electrocardiogram, heart rate (HR), and blood oxygen saturation (SpO2) of patients were recorded. The complications, like local anesthetic toxicity and total spinal anesthesia, were monitored.

RESULTS

All patients underwent CPB without infiltration anesthesia and complication. The use of Sufentanil at the dose of 5-10 μg was reported in 2 of 15 patients. No Horner syndrome was discovered in patients after anesthesia, and total intravenous anesthesia with intravenous pumping of dexmedetomidine was effective. During surgery, HR, diastolic blood pressure and mean blood pressure were barely changed, but systolic blood pressure was decreased.

CONCLUSION

Ultrasound-guided CPB with the intravenous dexmedetomidine pumping is a safe anesthesia method for patients during TCL.

Anastomoses (Superficial Cervical Ansa) Between the Cervical Plexus and Peripheral Facial Nerve Branches: Implications for Regional Anesthesia in Carotid Endarterectomies - Anatomical Study

Purpose

Sensory innervation in the carotid triangle involves the cervical plexus, cranial nerves, and the sympathetic trunk. This innervation also applies to skin incision, including various anatomical structures with potentially different innervation, such as the skin (dermatomes), the platysma (myotomes), and the superficial layer of the cervical fascia (fasciotomes), as well as retromandibular retractor insertion (co-innervation: V, VII). The aim of this anatomical study was to develop an injection technique for carotid endarterectomies to additionally block anastomoses between the transverse cervical nerve (TCN), the cervical branch VII (CB VII), and the marginal mandibular branch VII (MMB VII). These anastomoses are also termed superficial cervical ansa (SCA).

Materials and Methods

Preparations (n=16) were performed on unembalmed donor cadavers (n=8). Subplatysmal injections (each using 5 mL of Alcian blue) were performed cranially within the carotid triangle between the anterior margin of the sternocleidomastoid muscle and the submandibular gland.

Results

Anastomoses between the TCN, CB VII, and MMB VII were stained in all preparations (n=16).

Conclusion

This anatomical study presents an ultrasound-guided subplatysmal SCA block to optimize, in addition to a cervical plexus block, the quality of anesthesia for carotid endarterectomies.

Influence of Anatomic Conditions on Efficacy and Safety of Combined Intermediate Cervical Plexus Block and Perivascular Infiltration of Internal Carotid Artery in Carotid Endarterectomy: A Prospective Observational Trial

Ultrasound-guided intermediate cervical plexus blockade with perivascular infiltration of the carotid artery bifurcation perivacular block (PVB) is a reliable technique for regional anesthesia in carotid endarterectomy (CEA). We investigated the effect of the carotid bifurcation level (CBL) on PVB efficacy and safety in patients undergoing CEA. This prospective observational cohort study included 447 consecutive CEA patients who received PVB over a 6-y period. Vascular and neurologic puncture-related complications were recorded. The CBL was localized at the low level (C4 and C5 vertebra, low-level [LL] group) in 381 (85.2%) patients and at the high level (C2 and C3 vertebra, high-level [HL] group) in 66 (14.8%) patients. Local anesthetic supplementation by surgeons was necessary in 64 (14.3%) patients in the LL group and 38 (59.4%) patients in the HL group (p < 0.001) and was associated with a higher rate of central neurologic complications in the HL group (p = 0.031). Therefore, the efficacy of the PVB may be influenced by the CBL.

Peripheral nerve blocks in the cervical region: from anatomy to ultrasound-guided techniques

Cervical plexus nerve blocks have been employed in various head and neck operations. Both adequate anaesthesia and analgesia are attained in clinical practice. Nowadays, ultrasound imaging in regional anaesthesia is driven towards a certain objective that dictates high accuracy and safety during the implementation of peripheral nerve blocks. In the cervical region, ultrasound-guided nerve blocks have routinely been conducted only for the past few years and thus only a small number of publications pervade the current literature. Moreover, the sonoanatomy of the neck, the foundation stone of interventional techniques, is very challenging; multiple muscles and fascial layers compose a complex of compartments in a narrow anatomic region, in which local anaesthetics are injected. Therefore, this review intends to deliver new insights into ultrasound-guided peripheral nerve block techniques in the neck. The sonoanatomy of the cervical region, in addition to the cervical plexus, cervical ganglia, superior and recurrent laryngeal nerve blocks are comprehensively discussed.

[Peripheral truncal blocks-Overview and assessment]

By implementation of sonography for regional anesthesia, truncal blocks became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety and helps to avoid complications during needle placement. Additionally, complex punctures are possible that were associated with higher risk using landmarks alone. Next to the blocking of specific nerve structures, interfascial and compartment blocks have also become established, whereby the visualization of individual nerves and plexus structures is not of relevance. The present review article describes published and clinically established puncture techniques with respect to the indications and procedures. The clinical value is reported according to the scientific evidence and the analgesic profile. Moreover, the authors explain potential risks, complications and dosing of local anesthetic agents.

Regional Anesthesia in Neuroanesthesia Practice

Regional anesthesia has been an undervalued entity in neuroanesthetic practice. However, in the past few years, owing to the development of more advanced techniques, drugs and the prolific use of ultrasound guidance, the unrecognised potential of these modalities have been highlighted. These techniques confer the advantages of reduced requirements for local anesthetics, improved hemodynamic stability in the intraoperative period, better pain score postoperatively and reduced analgesic requirements in the postoperative period. Reduced analgesic requirement translates into lesser side effects associated with analgesic use. Furthermore, the transition from the traditional blind landmark-based techniques to the ultrasound guidance has increased the reliability and the safety profile. In this review, we highlight the commonly practised blocks in the neuroanesthesiologist's armamentarium and describe their characteristics, along with their individual particularities.

Cervical plexus block

Cervical plexus blocks (CPBs) have been used in various head and neck surgeries to provide adequate anesthesia and/or analgesia; however, the block is performed in a narrow space in the region of the neck that contains many sensitive structures, multiple fascial layers, and complicated innervation. Since the intermediate CPB was introduced in addition to superficial and deep CPBs in 2004, there has been some confusion regarding the nomenclature and definition of CPBs, particularly the intermediate CPB. Additionally, as the role of ultrasound in the head and neck region has expanded, CPBs can be performed more safely and accurately under ultrasound guidance. In this review, the authors will describe the methods, including ultrasound-guided techniques, and clinical applications of conventional deep and superficial CPBs; in addition, the authors will discuss the controversial issues regarding intermediate CPBs, including nomenclature and associated potential adverse effects that may often be neglected, focusing on the anatomy of the cervical fascial layers and cervical plexus. Finally, the authors will attempt to refine the classification of CPB methods based on the target compartments, which can be easily identified under ultrasound guidance, with consideration of the effects of each method of CPB.

Unilateral cervical plexus block for prosthetic laryngoplasty in the standing horse

BACKGROUND

Locoregional anaesthetic techniques can facilitate certain surgeries being performed under standing procedural sedation. The second and third spinal cervical nerves (C2, C3) are part of the cervical plexus and provide sensory innervation to the peri-laryngeal structures in people; block of these nerves might permit laryngeal lateralisation surgery in horses.

OBJECTIVES

To describe the anatomical basis for an ultrasound-guided cervical plexus block in horses. To compare this block with conventional local anaesthetic tissue infiltration in horses undergoing standing prosthetic laryngoplasty.

STUDY DESIGN

Cadaveric study followed by a double-blinded prospective clinical trial.

METHODS

A fresh equine cadaver was dissected to characterise the distribution of C2 and C3 to the perilaryngeal structures on the left side. A second cadaver was utilised to correlate ultrasound images with the previously identified structures; a tissue marker was injected to confirm the feasibility of an ultrasound-guided approach to the cervical plexus. In the clinical study, horses were assigned to two groups, CP (n = 17; cervical plexus block) and INF (n = 17; conventional tissue infiltration). Data collection and analyses included time to completion of surgical procedure, sedation time, surgical field conditions and surgeon's perception of block quality.

RESULTS

We confirmed that C2 and C3 provided innervation to the perilaryngeal structures. The nerve root of C2 was identified ultrasonographically located between the longus capitis and the cleidomastoideus muscles, caudal to the parotid gland. The CP group was deemed to provide better (P<0.0002) surgical conditions with no differences in the other variables measured.

MAIN LIMITATIONS

Further studies with larger numbers of horses may be necessary to detect smaller differences in surgical procedure completion time based on the improved surgical filed conditions.

CONCLUSIONS

For standing unilateral laryngeal surgery, a cervical plexus block is a viable alternative to tissue infiltration and it improves the surgical field conditions.