Ultrasound-Guided Suprazygomatic Nerve Blocks to the Pterygopalatine Fossa: A Safe Procedure

The Ganglia of the Head and Neck: Clinical Relevance for the Interventional Pain Physician

PURPOSE OF REVIEW

The purpose of this article is to provide a comprehensive review of the ganglia of the head and neck and their role in the interventional management of chronic headaches and facial pain disorders.

RECENT FINDINGS

Interventions targeting the sphenopalatine, stellate and gasserian ganglia are well described in the literature for headaches and facial pain disorders. There is a growing body of evidence supporting use of these techniques for clinical conditions outside of pain such as post-traumatic stress disorder and Long COVID symptoms. These findings increase the potential applications of such procedures, making them more relevant to the interventional physician tasked with managing symptoms in difficult to treat medical conditions. Nerve blocks of the head and neck are used for diagnostic and therapeutic purposes in the management of headaches and facial pain disorders. Headaches, whether acute or chronic, are common pain conditions with a wide-range of etiologies and are often difficult to treat. Chronic facial pain can have a variety of underlying causes, including direct or indirect nerve damage, infection, inflammation, and muscle dysfunction. Traditional pain management strategies such as medications and physical therapy often fail or are associated with significant adverse effects. Interventions such as nerve blocks and neuroablative procedures have shown promise in managing headaches and facial pain by directly targeting the underlying causes. This review article summarizes the most recent evidence regarding the efficacy, safety, applications and limitations of these interventional pain management techniques.

Effectiveness of Low-Volume Versus High-Volume Ropivacaine for Ultrasound-Guided Maxillary Nerve Block in Double-Jaw Surgery: A Randomized Non-inferiority Trial

BACKGROUND

Ultrasound-guided maxillary nerve block (UGMNB) is applied in oral and maxillofacial surgery to improve perioperative analgesia, decrease the risk of postoperative nausea and vomiting, and enhance recovery. However, the optimum volume of ropivacaine used for UGMNB is undetermined. Thus, it was hypothesized that in patients undergoing double-jaw surgery, low- and high-volume ropivacaine reduces perioperative pain with similar efficacy.

METHODS

Adults undergoing double-jaw surgery were enrolled in a randomized non-inferiority trial to receive a bilateral single-injection UGMNB with 2 mL (low-volume [LV] group) or 5 mL (high-volume [HV] group) of 0.375% ropivacaine on each side. A visual analog scale (VAS) score for maxillary pain at 2 h postoperatively was taken as the primary outcome. VAS score for maxillary and mandibular pain at 2, 4, 6, 8, 12, 24, and 48 h postoperatively, hemodynamic changes intraoperatively, consumption of intraoperative opioids and sedatives, vasoactive medication use, extubation time, postoperative rescue analgesia, time to the first analgesia, postoperative nausea and vomiting and UGMNB-related complications within 48 h post-surgery were assessed as the secondary outcomes.

RESULTS

Sixty-four adults were included. The maxillary pain score in the LV group was not inferior to that in the HV group at 2 h postoperatively, with a non-inferiority margin of 1 (mean difference - 0.1; 95% confidence interval [CI] - 0.6 to 0.8, P = 0.414 for non-inferiority). Maxillary and mandibular pain demonstrated no difference in the measured times between groups. The incidence of postoperative nausea was significantly higher in the LV group than that in the HV group at 6-24 h (12 (37.5%) vs. 5 (15.6%), P = 0.048). Moreover, no differences in intraoperative hemodynamic parameters, medications during anesthesia, time to extubation, rescue analgesia, time to the first analgesia, and postoperative vomiting were observed. Only one patient in the LV group was observed to have maxillary nerve block-related complications.

CONCLUSIONS

To conclude, the efficacy of UGMNB with 2 mL of 0.375% ropivacaine has the same efficacy as the 5 mL drug in reducing perioperative pain in patients undergoing double-jaw surgery.

LEVEL OF EVIDENCE I

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 .

A Comparison of Transnasal Versus Ultrasound-Guided Suprazygomatic Approaches for Sphenopalatine Ganglion Blocks in Persistent Idiopathic Facial Pain

BACKGROUND AND OBJECTIVES

The majority of patients with persistent idiopathic facial pain (PIFP) do not respond to conservative treatment and thus require alternative therapeutic modalities. This study compared the effects of transnasal and ultrasound (US)-guided suprazygomatic approaches for sphenopalatine ganglion (SPG) block on pain management in refractory PIFP.

METHODS

This study included 38 patients with PIFP who underwent transnasal (Group T, n = 18) and US-guided suprazygomatic (Group U, n = 20) SPG block. Numeric Rating Scale (NRS) and Head Impact Test-6 (HIT-6) were used to assess therapeutic efficacy. Clinical evaluations were performed according to the scores recorded at baseline, 1 h, 1 week, and 4 weeks.

RESULTS

Transnasal and US-guided suprazygomatic SPG blocks in patients with PIFP provided effective and successful treatment results between groups at 1 h, 1 week, and 4 weeks compared to baseline ( P < 0.001). However, when NRS scores were compared at 1 h and 4 weeks, the US-guided suprazygomatic block provided significantly better pain relief ( P = 0.041 and P = 0.030, respectively). No adverse effects were observed, except transient facial paresthesia described in two patients in Group U.

CONCLUSIONS

This retrospective study concluded that US-guided suprazygomatic SPG block can provide effective pain relief in PIFP patients at 4-week follow-up. This method can be regarded as an alternative treatment option, given that it is both safe and simple to apply.

Rationale and Design for the BLOCK-SAH Study (Pterygopalatine Fossa Block as an Opioid-Sparing Treatment for Acute Headache in Aneurysmal Subarachnoid Hemorrhage): A Phase II, Multicenter, Randomized, Double-Blinded, Placebo-Controlled Clinical Trial with a Sequential Parallel Comparison Design

BACKGROUND

Acute post-subarachnoid hemorrhage (SAH) headaches are common and severe. Management strategies for post-SAH headaches are limited, with heavy reliance on opioids, and pain control is overall poor. Pterygopalatine fossa (PPF) nerve blocks have shown promising results in treatment of acute headache, including our preliminary and published experience with PPF-blocks for refractory post-SAH headache during hospitalization. The BLOCK-SAH trial was designed to assess the efficacy and safety of bilateral PPF-blocks in awake patients with severe headaches from aneurysmal SAH who require opioids for pain control and are able to verbalize pain scores.

METHODS

BLOCK-SAH is a phase II, multicenter, randomized, double-blinded, placebo-controlled clinical trial using the sequential parallel comparison design (SPCD), followed by an open-label phase.

RESULTS

Across 12 sites in the United States, 195 eligible study participants will be randomized into three groups to receive bilateral active or placebo PPF-injections for 2 consecutive days with periprocedural monitoring of intracranial arterial mean flow velocities with transcranial Doppler, according to SPCD (group 1: active block followed by placebo; group 2: placebo followed by active block; group 3: placebo followed by placebo). PPF-injections will be delivered under ultrasound guidance and will comprise 5-mL injectates of 20 mg of ropivacaine plus 4 mg of dexamethasone (active PPF-block) or saline solution (placebo PPF-injection).

CONCLUSIONS

The trial has a primary efficacy end point (oral morphine equivalent/day use within 24 h after each PPF-injection), a primary safety end point (incidence of radiographic vasospasm at 48 h from first PPF-injection), and a primary tolerability end point (rate of acceptance of second PPF-injection following the first PPF-injection). BLOCK-SAH will inform the design of a phase III trial to establish the efficacy of PPF-block, accounting for different headache phenotypes.

Efficacy of ultrasound guided sphenopalatine ganglion block in management of emergence agitation after sinoscopic nasal surgery: a randomized double-blind controlled study

BACKGROUND

Nasal surgery has a reported high incidence of agitation during emergence from general anesthesia. Emergence Agitation (EA) increases the risk of surgical site bleeding, falling off the operating table, removal of catheters and intravenous lines, and self-extubation. This study investigated the role of nerve block in EA.

OBJECTIVES

This study evaluated the effect of ultrasound-guided sphenopalatine ganglion block (SPGB) on EA after sinoscopic nasal surgery. The primary outcome was the incidence of EA. Secondary outcomes included the quality of the surgical field, bleeding volume, inhalational anesthesia, MAC, VAS in the PACU, postoperative analgesia duration, and total 24 -h opioid consumption.

PATIENTS AND METHODS

This double-blind, randomized controlled study enrolled 120 patients, of whom 110 completed the study. They were randomly allocated into two equal groups: G1, which received general anesthesia and a bilateral sphenopalatine ganglion block (SPBG) with 5 mL lidocaine 2% on each side, and G2 (control), which received general anesthesia and a bilateral sphenopalatine saline injection of 5 mL on each side.

RESULTS

A significant decrease in the incidence of EA was found in G1 compared to G2 (20% vs. 64%). Intraoperative bleeding volume was significantly lower, and surgical field quality was significantly higher in G1 compared to G2. Pain severity was significantly lower in G1 in the PACU, and 24 h postoperative opioid consumption was significantly reduced compared to G2. Additionally, postoperative analgesia duration was significantly longer in G1 than in G2 (9 h vs. 3 h).

CONCLUSION

SPGB effectively reduced EA incidence, severity, and duration after sinoscopic nasal surgery. Furthermore, SPGB reduced intraoperative bleeding, improved surgical field quality, prolonged postoperative analgesia, and reduced 24 -h opioid consumption after sinoscopic nasal surgery.

REGISTRATION

National Clinical Trial Registry, NCT04168879.

Pain Assessment Following Opioid Administration in Aneurysmal Subarachnoid Hemorrhage Associated Headache

Background: Headache is a debilitating complication following an aneurysmal subarachnoid hemorrhage (aSAH). Despite its impact on morbidity and quality of life, limited evidence characterizes the effectiveness of opioids. Objective: The aim of this study was to evaluate opioid associated reduction in pain scores in patients with aSAH-associated headache. Methods: This is a retrospective study of adult patients with an aSAH, Hunt and Hess grades I - III, admitted to a neurosciences intensive care unit. Descriptive and inferential statistics were used to characterize headache treatment strategies and opioid associated reduction in pain scores. Results: Opioids were used in up to 97.6% of patients for the management of aSAH-associated headache. Median reduction in pain after opioid administration was -1 (IQR: -3-0). Correlation between opioid dose and change in pain scores was negligible (rs = .01). Overall, 68.8% of patients were discharged on an opioid analgesic with predictive factors being severe headache (OR 2.52; 1.04 - 6.14) and oral morphine milligram equivalents ≥60 mg per day during the hospital stay (OR 3.02; 1.22 - 7.47). Conclusions: Opioids were associated with a small reduction in pain when assessed via the NRS. An increased opioid dose did not correlate with a greater reduction in assessed pain scores. A high percentage of patients remained on opioids throughout hospitalization and were eventually discharged on an opioid. The impact of discharge opioid prescriptions and risk of opioid persistence creates a cause for concern. It is imperative that we seek improved pain management strategies for aSAH-associated headache.

Ultrasound-guided trigeminal nerve approach at the level of the pterygopalatine fossa in cat cadavers

OBJECTIVE

To describe an ultrasound-guided suprazygomatic approach to the trigeminal nerve block in cat cadavers.

STUDY DESIGN

Prospective descriptive study.

ANIMALS

Ten feline cadaver heads.

METHODS

A 25:75 methylene blue-iopamidol mixture (0.1 mL cm-1 cranium length) was injected into 10 cadaver heads using an ultrasound-guided suprazygomatic approach. A computed tomography (CT) scan was performed to identify contrast presence at the orbital fissure, foramen rotundum and ovale, followed by anatomical dissection to identify staining of the pterygopalatine fossa (PPF), extraconal retrobulbar area, mandibular and maxillary nerves. Descriptive statistics were used to summarize results.

RESULTS

A total of 20 injections were performed. Of these, 1/20 misinjection occurred and excluded from further reporting. The volume of injectate was 0.9 (0.9-1.1) mL [median (range)]. Staining of the PPF, extraconal space, maxillary and mandibular nerves over more than 6 mm was achieved in 19/19 (100%), 18/19 (95%), 17/19 (89%) and 19/19 (100%) of injections, respectively. CT showed presence of contrast within 5 mm of the orbital fissure, foramen rotundum and ovale in 18/19 (95%), 19/19 (100%) and 19/19 (100%) of the injections, respectively. No intracranial migration was observed.

CONCLUSIONS AND CLINICAL RELEVANCE

This cadaver study illustrates that the suprazygomatic ultrasound-guided trigeminal nerve injection technique can successfully stain the PPF, retrobulbar cone extraconally, mandibular and maxillary nerves. Consequently, this technique has the potential to be used in vivo in cats to desensitize areas innervated by the trigeminal nerve.

Effective regional anesthesia for pediatric surgical care

This review highlights the significant role of pediatric regional anesthesia in optimizing perioperative care and improving surgical outcomes. We examine common local anesthetics, adjuvant medications, and techniques. Safety, efficacy, adverse events, and controversies are addressed while spotlighting the broad utility of regional anesthesia to contribute to better outcomes and quality of life for pediatric surgical patients and their families.

Demystifying the Suprazygomatic Maxillary Nerve Block in Paediatric Cleft Palate Surgery

OBJECTIVE

To consider the clinical anatomy, safety and effectiveness of the suprazygomatic maxillary nerve block in cleft palate surgery.

DESIGN

Observational case series.

SETTING

Single cleft centre in the United Kingdom.

PARTICIPANTS

Patients born with a cleft palate (with or without a cleft lip) undergoing palatal surgery between the ages of 9 months and 18 years.

INTERVENTION

Introduction of suprazygomatic maxillary nerve (SZMN) block using ropivacaine 0.2% into clinical protocol in February 2023.

MAIN OUTCOME MEASURES

Peri-procedure complications and post-operative opioid administration.

RESULTS

The clinical anatomy of the SZMN block is described in a stepwise and pictorial approach from superficial to deep structures. 43 patients underwent surgical interventions involving the palate (either intravelar veloplasty, Furlow palatoplasty or bilateral myomucosal buccinator flaps for palatal lengthening). 22 patients had a general anaesthetic and local anaesthetic infiltration and 21 had an additional SZMN block. There were no local or systemic complications associated with the SZMN block. There was no difference in the total dosing of post-operative (P = .79) opioids between the groups.

CONCLUSIONS

We demonstrate the feasibility and safety of this procedure without the use of ultrasound guidance in a heterogenous group of paediatric patients undergoing palatal surgery. Regional anaesthesia should be considered as part of the multi-modal analgesic strategy, although it may be difficult to demonstrate a change in opioid use in clinical settings where enhanced recovery techniques are established, and opioid use is already low.

Evaluation of ultrasound-guided suprazygomatic maxillary nerve block in functional endoscopic sinus surgery for postoperative pain relief: A randomised controlled trial

Background and Aims

Postoperative pain can impede functional recovery and delay hospital discharge after functional endoscopic sinus surgery (FESS). The study aimed to assess the efficacy of ultrasound (USG)-guided suprazygomatic maxillary nerve block (SZMNB) for postoperative pain in FESS.

Methods

Forty-eight adult patients between 18 and 65 years of age with American Society of Anesthesiologists physical status I and II and scheduled to undergo FESS were enroled in this randomised controlled study. Patients were randomly allocated to either receive USG-guided SZMNB with general anaesthesia (n = 24) or general anaesthesia alone (n = 24). The numerical rating scale (NRS) pain score in the immediate postoperative period was recorded as the primary outcome. A total of 24 h postoperative rescue analgesic consumption, surgeon satisfaction score, postoperative haemodynamics, and postoperative complications were noted as secondary outcomes.

Results

The median (interquartile range) of the NRS pain score in the immediate postoperative period was 0 (0-0.25)[95% confidence interval (CI): 0, 0.08] in the block group compared to 2 (1.75-3) [95% CI: 1.60, 2.40] in the control group, P < 0.001]. Pain scores were significantly reduced at all time intervals till 24 h after surgery (P < 0.001). None of the patients required rescue analgesia in the block group. In contrast, eight patients required diclofenac 75 mg intravenous as rescue analgesia within 1 h of surgery and ten patients within 1-6 h of surgery in the control group. Other secondary outcomes were comparable between groups (P > 0.05).

Conclusion

The USG-guided SZMNB provides excellent postoperative analgesia for patients undergoing FESS without significant side effects.

Suprazygomatic Maxillary Nerve Blocks and Opioid Requirements in Pediatric Adenotonsillectomy: A Randomized Clinical Trial

Importance

Pain management following pediatric adenotonsillectomies is opioid-inclusive, leading to potential complications.

Objective

To investigate the use of suprazygomatic maxillary nerve (SZMN) blocks to reduce pain and opioid use after pediatric intracapsular adenotonsillectomy and to measure recovery duration and incidence of complications.

Design, Setting, and Participants

This was a randomized, blinded, prospective single-center tertiary pediatric hospital that included 60 pediatric patients (2-14 years old) scheduled for intracapsular adenotonsillectomy from November 2021 to March 2023. Patients were excluded for having combined surgical procedures, developmental delay, coagulopathy, chronic pain history, known or predicted difficult airway, or unrepaired congenital heart disease. Participants were randomized to receive bilateral SZMN blocks (block group) or not (control group).

Intervention

SZMN block administered bilaterally under general anesthesia for intracapsular adenotonsillectomy.

Primary Outcomes and Measures

Opioid consumption, FLACC (Face, Legs, Activity, Cry, Consolability) scores, and rates of opioid-free postanesthesia care unit (PACU) stay. Secondary outcomes were recovery duration and incidence of adverse effects, ie, nausea, vomiting, block site bleeding, and emergency delirium.

Results

The study population included 53 pediatric patients (mean [SD] age, 6.5 [3.6] years; 29 [55%] females; 24 [45%] males); 26 were randomly assigned to the SZMN block group and 27 to the control group. The mean (SD) opioid morphine equivalent consumption during PACU stay was 0.15 (0.14) mg/kg for the 27 patients in the control group compared with 0.07 (0.11) mg/kg for the 26 patients in the block group (mean difference, 0.08; 95% CI, 0.01-0.15; Cohen d, 0.64). The block group had a higher incidence of opioid-free PACU stays (n = 7 patients; 58%) compared with the control group (n = 15 patients; 26%) (mean difference, 32%; 95% CI, 5%-53%). Patients in the block group experienced lower FLACC scores (0.7 vs 1.6; mean difference, 0.9; 95% CI, 0.2-1.6; Cohen d, 0.7). The overall occurrence of adverse events was similar in the 2 groups, with no reported nerve block-related complications.

Conclusions and Relevance

The results of the randomized clinical trial indicate that SZMN blocks are a useful adjunct tool for managing postoperative pain in pediatric intracapsular adenotonsillectomy. Use of these blocks during adenotonsillectomy provided clinically meaningful reductions of postoperative opioid consumption with a low risk of complications.

Trial Registration

ClinicalTrials.gov Identifier: NCT04797559.

Ultrasound-guided sphenopalatine ganglion block for effective analgesia during awake fiberoptic nasotracheal intubation: A case report

BACKGROUND

Awake fiberoptic nasotracheal intubation (AFNI) is the preferred airway management strategy for patients with difficult airways. However, this procedure can cause significant physical and psychological distress. This case report explores the application of a sphenopalatine ganglion (SPG) block as an alternative analgesic modality to mitigate the discomfort associated with AFNI.

CASE SUMMARY

A 63-year-old female with a history of right maxillary osteosarcoma underwent craniotomy for a suspected malignant brain lesion. The patient's medical history included prior surgery, chemotherapy, and radiation therapy, resulting in significant jaw impairment and limited neck mobility. Considering the anticipated airway challenges, AFNI was planned. A SPG block was performed under real-time ultrasound guidance, providing effective analgesia during nasotracheal intubation.

CONCLUSION

The SPG block represents a promising analgesic approach in AFNI, offering potential benefits in alleviating pain involving the nasal and nasopharyngeal regions as well as improving patient cooperation.

Refractory primary and secondary headache disorders that dramatically responded to combined treatment of ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks and non-invasive vagus nerve stimulation: a case series

In 1981, Devoghel achieved an 85.6% success rate in treating patients with treatment-refractory cluster headaches with alcoholization of the pterygopalatine ganglion (PPG) via the percutaneous suprazygomatic approach. Devoghel's study led to the theory that interrupting the parasympathetic pathway by blocking its transduction at the PPG could prevent or treat symptoms related to primary headache disorders (PHDs). Furthermore, non-invasive vagus nerve stimulation (nVNS) has proven to treat PHDs and has been approved by national regulatory bodies to treat, among others, cluster headaches and migraines.In this case series, nine desperate patients who presented with 11 longstanding treatment-refractory primary headache disorders and epidural blood patch-resistant postdural puncture headache (PDPH) received ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks (PPGB), and seven also received nVNS. The patients were randomly selected and were not part of a research study. They experienced dramatic, immediate, satisfactory, and apparently lasting symptom resolution (at the time of the writing of this report). The report provides the case descriptions, briefly reviews the trigeminovascular and neurogenic inflammatory theories of the pathophysiology, outlines aspects of these PPGB and nVNS interventions, and argues for adopting this treatment regime as a first-line or second-line treatment rather than desperate last-line treatment of PDPH and PHDs.

Acute Headache Management for Patients with Subarachnoid Hemorrhage: An International Survey of Health Care Providers

BACKGROUND

Severe headaches are common after subarachnoid hemorrhage. Guidelines recommend treatment with acetaminophen and opioids, but patient data show that headaches often persist despite multimodal treatment approaches. Considering an overall slim body of data for a common complaint affecting patients with SAH during their intensive care stay, we set out to assess practice patterns in headache management among clinicians who treat patients with SAH.

METHODS

We conducted an international cross-sectional study through a 37-question Web-based survey distributed to members of five professional societies relevant to intensive and neurocritical care from November 2021 to January 2022. Responses were characterized through descriptive analyses. Fisher's exact test was used to test associations.

RESULTS

Of 516 respondents, 329 of 497 (66%) were from North America and 121 of 497 (24%) from Europe. Of 435 respondents, 379 (87%) reported headache as a major management concern for patients with SAH. Intensive care teams were primarily responsible for analgesia during hospitalization (249 of 435, 57%), whereas responsibility shifted to neurosurgery at discharge (233 of 501, 47%). Most used medications were acetaminophen (90%), opioids (66%), corticosteroids (28%), and antiseizure medications (28%). Opioids or medication combinations including opioids were most frequently perceived as most effective by 169 of 433 respondents (39%, predominantly intensivists), followed by corticosteroids or combinations with corticosteroids (96 of 433, 22%, predominantly neurologists). Of medications prescribed at discharge, acetaminophen was most common (303 of 381, 80%), followed by opioids (175 of 381, 46%) and antiseizure medications (173 of 381, 45%). Opioids during hospitalization were significantly more prescribed by intensivists, by providers managing higher numbers of patients with SAH, and in Europe. At discharge, opioids were more frequently prescribed in North America. Of 435 respondents, 299 (69%) indicated no change in prescription practice of opioids with the opioid crisis. Additional differences in prescription patterns between continents and providers and while inpatient versus at discharge were found.

CONCLUSIONS

Post-SAH headache in the intensive care setting is a major clinical concern. Analgesia heavily relies on opioids both in use and in perception of efficacy, with no reported change in prescription patterns for opioids for most providers despite the significant drawbacks of opioids. Responsibility for analgesia shifts between hospitalization and discharge. International and provider-related differences are evident. Novel treatment strategies and alignment of prescription between providers are urgently needed.