Infrazygomatic Approach Research Articles

Comparison of the feasibility and safety of infrazygomatic and suprazygomatic approaches to pterygopalatine fossa using virtual reality

BackgroundInjections of local anesthetics into pterygopalatine fossa gained popularity for treating acute and chronic facial pain and headaches. Injury of maxillary artery during pterygopalatine fossa injection can result in pseudoaneurysm...

Intra-operative interstitial brachytherapy in a novel infra-zygomatic approach for partially resectable head and neck cancers around the base of skull: A technical note.

To report an intra-operative catheter insertion technique into the base of skull tumor bed following surgical resection for maxillary tumors. A 42-year-old male patient diagnosed with carcinoma of the maxilla was treated with neoadjuvant chemotherapy followed by chemo-radiation using external beam technique combined with brachytherapy boost to post-operative bed. Brachytherapy was delivered via intra-operative catheter placement at the base of skull to residual disease, which was surgically unresectable. Initially, catheters were placed cranio-caudally. This was later changed into an infra-zygomatic approach to improve planning and dose coverage. High-risk clinical tumor volume (CTV) was generated with a 3 mm margin to residual gross tumor. Planning was done using Varian Eclipse brachytherapy planning system, and an optimal plan was generated. An innovative, beneficial, and safe brachytherapy approach is necessary in a difficult and critical area, such as the base of skull. Our novel method of implant insertion through infra-zygomatic approach resulted in a safe and successful procedure.

Percutaneous radiofrequency ablation of peripheral maxillary nerve: Description of new methodology.

Sir, Maxillary nerve is the second most affected branch in trigeminal neuralgia. It is treated with medical drugs like carbamazepine and baclofen. For long-term pain relief, chemical neurolysis and radiofrequency ablation (RFA) are commonly undertaken, of which RFA results in longer duration of pain relief, shorter onset and increased safety.[1] Chemical neurolysis of maxillary nerve can also result in serious complications.[2] RFA in chronic facial pain is being increasingly used with promising results.[3] We describe two patients where percutaneous RFA of peripheral maxillary nerve was undertaken without fluoroscopic/computed tomography (CT) guidance. A 60-year-old female, a diagnosed case of idiopathic trigeminal neuralgia presented with electric, sharp shooting pain of Numerical rating scale (NRS) score 6/10 in the maxillary area with frequent exacerbations for the last two years. She had inadequate pain relief with oral medications such as carbamazepine, pregabalin, baclofen and tramadol/acetaminophen. For long-term relief, RFA of maxillary nerve via percutaneous approach was planned in the block area of the out-patient department (OPD). Anaesthesia machine, resuscitation equipment, monitor and emergency drugs were available in the OPD block area. After taking consent, intravenous line was secured and monitors (pulse oximetry, non-invasive blood pressure, electrocardiography) were attached. Under aseptic precautions, a 22 G radiofrequency needle (Cosman, 10 cm length, active tip – 1 cm) was inserted via coronoid notch on right side, in supine and neutral head position, after infiltration of local anaesthesia. After hitting lateral pterygoid plate, needle was directed 2–3 mm beyond the pterygoid plate antero-superiorly towards the root of the nose [Figure 1]. To identify maxillary nerve, sensory stimulation (50 Hz, 1 mA) was used to elicit paraesthesia in maxillary area, achieved in first attempt at 0.3 mV. Motor involvement was ruled out by 2 Hz and 2 mA. 1 ml of 1% lignocaine was injected which caused paraesthesia in affected area and was followed by RFA of maxillary neve of 3 cycles at 65° for 60 s followed by injection dexamethasone 4 mg. This patient became pain-free for the next six months. All medications were reduced and tablet baclofen and tramadol were stopped.Figure 1: Infrazygomatic approach of maxillary nerve block (left); Radiofrequency generator for ablation of nerve (right)The second case was a 66-year-old male patient of idiopathic trigeminal neuralgia of one year duration with pain refractory to medical management. Maxillary nerve RFA was performed with similar methodology as above. Sensory stimulation was achieved at 0.4 mV and RFA was performed after excluding motor response. The patient was pain-free for the next eight months and his oral medications were considerably reduced. RFA of peripheral branches of the trigeminal nerve (infraorbital, supraorbital, mental and mandibular nerves) was found equally efficacious to RFA of gasserian ganglion through foramen ovale for trigeminal neuralgia; however, RFA of maxillary nerve was not undertaken in the study.[4] In the commonly practised percutaneous infrazygomatic maxillary nerve blockade,[5] a reliable block requires the patient to report paraesthesia by block needle. Electrical stimulation has reported higher sensitivity of nerve identification than paraesthesia[6] which was utilised for RFA of maxillary nerve via CT- guided percutaneous infrazygomatic approach through foramen rotundum.[7] However, this is invasive, has radiation hazards and requires special area. We propose RFA of maxillary nerve via percutaneous infrazygomatic approach and locating it by electrical stimulation. Added advantages are that it has no radiation hazards, is less invasive and it is an OPD block procedure. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Application of ultrasound guidance in the oral and maxillofacial nerve block.

IntroductionNerve block technology is widely used in clinical practice for pain management. Conventional nerve localization methods, which only rely on palpation to identify anatomical landmarks, require experienced surgeons and can be risky. Visualization technologies like ultrasound guidance can help prevent complications by helping surgeons locate anatomical structures in the surgical area and by guiding the operation using different kinds of images. There are several important and complex anatomical structures in the oral and maxillofacial regions. The current article reviews the application of ultrasound guidance in oral and maxillofacial nerve blocks.MethodsWe searched the literature on the use of ultrasound guidance for the main nerve block techniques in the oral and maxillofacial regions using both PubMed and MEDLINE and summarized the findings.Results and DiscussionA review of the literature showed that ultrasound guidance improves the safety and effectiveness of several kinds of puncture procedures, including nerve blocks. There are two approaches to blocking the mandibular nerve: intraoral and extraoral. This review found that the role of ultrasound guidance is more important in the extraoral approach. There are also two approaches to the blocking of the maxillary nerve and the trigeminal ganglion under ultrasound guidance: the superazygomatic approach and the infrazygomatic approach. The infrazygomatic approach can be further divided into the anterior approach and the posterior approach. It is generally believed that the anterior approach is safer and more effective. This review found that the effectiveness and safety of most oral and maxillofacial nerve block operations can be improved through the use of ultrasound guidance.

Quantification of the Interventional Approaches Into the Pterygopalatine Fossa by Solid Angles Using Virtual Reality

Virtual reality is increasingly used in medicine for diagnostics, for visualisation of complex structures and for preoperative planning. In interventional radiology, minimally invasive approach could be described with a target point representing the desired needle tip position and an array of all possible trajectories leading to it resembling irregular “cone” or “pyramid”. We present a pilot study of planning a minimally invasive posterior infrazygomatic and suprazygomatic approaches into the pterygopalatine fossa using a solid angle as a measure of size of the approach in five virtually reconstructed heads. The minimally invasive approaches were planned by manually drawing the edges of “pyramids” that described each approach in 3D using virtual reality program Tracer. For each head, a transverse diameter was measured and for each approach a solid angle size, average edge length and estimated area on the skin from where the target point could be reached were calculated. We found that, the solid angle of posterior infrazygomatic approach was significantly larger than suprazygomatic approach (p<0.001). Furthermore, the transverse head diameter and solid angle in posterior infrazygomatic approach were negatively correlated (ρ=-0.55, p=0.0002), while transverse head diameter and the estimated area on the skin from where the target point could be reached in the suprazygomatic approach were positively correlated (ρ=0.37, p=0.0206). In conclusion, our findings provide important preliminary evidence on the feasibility of evaluating and comparing different minimally invasive approaches using virtual reality systems, and affirm the validity of solid angle as a measure of the size of the approach.

Sphenopalatine Ganglion Pulsed Radiofrequency for the Treatment of Refractory Chronic SUNCT and SUNA: A Prospective Case Series.

We aimed to evaluate the safety and effectiveness of sphenopalatine ganglion pulsed radiofrequency (SPG-PRF) for the treatment of patients with refractory chronic short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and with cranial autonomic symptoms (SUNA). SPG-PRF is a minimally invasive, non-neurodestructive procedure already tested in refractory chronic cluster headache with mixed outcomes. However, no data have been produced in SUNCT/SUNA. This was a prospective clinical audit of outcomes. Consecutive patients with chronic SUNCT/SUNA refractory to medical treatments and treated with SPG-PRF, were included in the analysis. The SPG-PRF was performed percutaneously via a lateral, infra-zygomatic approach. Responders were defined as patients with a reduction in number and/or severity of headache episodes by ≥30% for ≥3months. Responders to the first procedure were offered to have the treatment repeated. Nine patients (6 female) were analyzed. After a median follow-up of 30months (range 2-30), 7 patients were considered responders to the treatment (77.8%) for a median of 6 months (range: 4-10), 1 patient obtained 40% improvement for 2months, and 1 patient did experience any improvement. No procedure-related immediate or delayed side effects were reported. Three patients (33.3%) experienced a worsening of the head pain for 2-4weeks immediately after the procedure. Four responders had SPG-PRF repeated; a reproducible response was obtained in two of them. In our small series of patients with refractory chronic SUNCT/SUNA, SPG-PRF was a safe and effective treatment modality. The potential reproducible positive effect of subsequent treatments may prevent or delay the use of more invasive and costly interventions for at least a proportion of these patients.

Occipital Nerve Stimulation and Sphenopalatine Ganglion Stimulation for Treatment of Intractable Headache Syndromes.

Headaches are an increasing cause of disability in the world. Intractable headache syndromes affect all age groups but predominantly the middle-aged, working population. Occipital neuralgia is a frequent comorbidity with intractable migraine headaches. Occipital nerve stimulation at the level of nuchal ridge is a reasonable option for these refractory patients. Ultrasound guidance of occipital nerve stimulation can optimize depth placement of leads. Revision surgeries of occipital nerve stimulation are usually performed using surgical leads. Cluster headaches and trigeminal autonomic cephalagias (TACs) are refractory headache conditions that are mediated by sphenopalatine ganglion. Sphenopalatine ganglion stimulation with infrazygomatic approach and fluoroscopic guidance of percutaneous leads can help alleviate pain from cluster headaches and TACs. Innovation in neurostimulation technologies have brought new optimism to these refractory conditions. Efficient and optimal delivery of neurostimulation for intractable headache syndromes requires a multidisciplinary team-based approach for long term compliance and efficacy.

Landmarks For Accurate Sphenopalatine Ganglion Block Via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study

Abstract INTRODUCTION Sphenopalatine ganglion (SPG) block is used for a variety of craniofacial pain syndromes either through the transnasal route or via the infrazygomatic approach. Intraoperative imaging can identify the pterygopalatine fossa (PPF) but not the exact position of the SPG. Accurate localization of the SPG requires knowledge of the relevant anatomical landmarks. METHODS A total of 30 mid sagittal head and neck cadaveric sections were studied. The specimens were fixed in anatomical position and the morphometric data was collected to facilitate correct SPG localization via trans-nasal approach and infrazygomatic approach. The metrical parameters were taken with the help of a digital vernier caliper accurate up to 0.02 mm. RESULTS The sphenopalatine foramen (SPF) was located at an average distance of 55 mm from the anterior nasal spine at a mean angle of 22°. It was at or just superior to the midpoint of a line joining the skull base and the hard palate. The SPG was located 4 mm posterior and 4.7 mm lateral to the SPF at a mean distance of 6.3 mm from the SPF at an inclination of about 50° in both the sagittal and coronal planes. In the infrazygomatic approach, the SPG was between 4.5 and 6.3 cm from the skin and at an angle of about 7° posterior and inferior. These two angles were remarkable in being almost same for all specimens in both the measured planes. CONCLUSION These morphometric measurements will be of help to the clinician for accurate electrode or needle placement for SPG block and in avoiding complications related to inaccurate needle placement.

The Value and Application of Personalized Needle Modification in Percutaneous Infrazygomatic Radiofrequency in Isolated Maxillary Nerve Pain through the Foramen Rotundum

Background: Percutaneous infrazygomatic radiofrequency (PIR) is a common approach used to block isolated maxillary nerve (V2) pain through the foramen rotundum (FR) in patients with trigeminal neuralgia (TN). Nevertheless, when using this method, there is a risk of accidental penetration of the superior orbital fissure (SOF) and the optic canal (OC) that may result in the injury of the vessels and nerves in that area, and in some severe cases may lead to blindness. According to the blocking of the external orifice of the FR and whether a curved needle was used, combined angle deviation from the path of percutaneous infrazygomatic approach, the FR to the SOF or the OC in the treatment of V2 pain, in which no research has reported the angle, we analyzed the value and application of personalized needle modification in PIR in isolated maxillary nerve pain through the FR. Objectives: The following study examined the relationship between the FR and the SOF, and analyzed the clinical significance of personalized needle modification in computed tomography (CT)-guided PIR ablation of the maxillary nerve through the FR in patients with TN. Study Design: Randomized, review, clinical research study. Setting: Department of Anesthesiology and Pain Medical Center, Jiaxing, China. Methods: Three-dimensional reconstruction was performed in 88 patients and 136 patients with PIR ablation in isolated maxillary nerve pain through the FR. According to the blocking of the external orifice of the FR and whether a curved needle was used, patients were divided into 4 groups: curvedneedle blocking group (CB), straight-needle blocking group (SB), straight needle no-blocking group (SN), and curved-needle no-blocking group (CN). Results: The results obtained revealed minimum H (shortest diameter of the FR) = 1.0 mm and minimum L (length of the FR tubes) = 3.7 mm. The distance between the external orifice of the FR and the SOF (FS) was 5.16 ± 1.33 mm. The angle A (between the radiofrequency needle and the sagittal plane) was 39 ± 3.95°; the angle between the canthomeatal line and the CT scan line (ACT) was 58.99 ± 6.23°; the puncture depth (LS) was 63.99 ± 4.24 mm; the deviation angle of the misplacement into the SOF (SAF) was 2.96 ± 0.71°; the deviation angle of the misplacement into the OC (OAF) was 4.95 ± 0.73°. In addition, the postoperative Numeric Rating Scale scores in the CB group were significantly lower compared with the SB group, whereas the probability of entering the SOF in the CB group was significantly lower compared with the SB group. The total number of punctures in the SN group was less than that in the CN group. Limitations: Additional clinical data should be collected to preserve the results in future work. Conclusions: The distance between the FR and the SOF or the OC was only few millimeters, and slight angle error could lead to the SOF and the OC. For patients with blockage in the path, the treatment of radiofrequency with personalized needle modification could improve the curative effect and reduce the risk of accidental SOF penetration. Key words: Trigeminal neuralgia, foramen rotundum, superior orbital fissure, radiofrequency, personalized needle modification

Clinical anatomy of the maxillary nerve block in pediatric patients.

Anatomical landmarks in children are mostly extrapolated from studies in adults. Despite this, complex regional anesthetic procedures are frequently performed on pediatric patients. Sophisticated imaging techniques are available but the exact position, course and/or relationships of the structures are best understood with appropriate anatomical dissections. Maxillary nerve blocks are being used for peri-operative analgesia after cleft palate repair in infants. However, the best approach for blocking the maxillary nerve in pediatric patients has yet to be established. To determine the best approach for blocking the maxillary nerve within the pterygopalatine fossa. In an attempt to define an optimal approach for maxillary nerve block in this age group three approaches were simulated and compared on 10 dried pediatric skulls as well as 30 dissected pediatric cadavers. The needle course, including depth and angles, to block the maxillary nerve, as it exits the skull at the foramen rotundum within the pterygopalatine fossa, was measured and compared. Two groups were studied: Group 1 consisted of skulls and cadavers of neonates (0-28days after birth) and Group 2 consisted of skulls and cadavers from 28days to 1year after birth. No statistically significant difference (P>0.05) was found between the left and right side of each skull or cadaver. Only technique B, the suprazygomatic approach from the frontozygomatic angle towards the pterygopalatine fossa, exhibited no statistical significance (P>0.05) when other measurements made on the skulls and cadavers were compared. Technique A, a suprazygomatic approach from the midpoint on the lateral border of the orbit, as well as technique C, an infrazygomatic approach with an entry at a point on a vertical line extending along the lateral orbit wall, showed statistical significant differences when measurements of the skulls and cadavers were compared. On the basis of these findings technique B produces the most consistent data for age groups 1 and 2 and supports the clinical findings recently reported.

Anatomic Landmarks and Morphometric Measurements for Accurate Localization of the Sphenopalatine Ganglion via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study

ABSTRACT Objective Sphenopalatine ganglion (SPG) block is used for a variety of craniofacial pain syndromes either through the trans-nasal route or via the infrazygomatic approach. Intraoperative imaging can identify the pterygopalatine fossa (PPF) but not the exact position of the SPG. Accurate localization of the PG requires knowledge of the relevant anatomical landmarks. Materials and methods Thirty mid sagittal head and neck cadaveric sections were studied and the morphometric data was te correct SPG localization via trans-nasal roach and infrazygomatic approach. Results The sphenopalatine foramen (SPF) was located at an average distance of 55 mm from the anterior nasal spine at a mean angle of 22°. It was at or just superior to the midpoint of a line joining the skull base and the hard palate. The SPG was located 4 mm posterior and 4.7 mm lateral to the SPF at a mean distance of 6.3 mm from the SPF at an inclination of about 50° in both the sagittal and coronal planes. In the infrazygomatic approach, the SPG was between 4.5 and 6.3 cm the skin and an angle of about 7° posterior and inferior. Conclusion These morphometric measurements will be of help to the clinician for accurate electrode or needle placement for SPG block and in avoiding complications related to inaccurate needle placement. How to cite this article Gupta T, Aggarwal A, Sahni D. Anatomic Landmarks and Morphometric Measurements for Accurate Localization of the Sphenopalatine Ganglion via the Transnasal and Infrazygomatic Approaches: A Cadaveric Study. J Postgrad Med Edu Res 2014;48(1):14-18.

Electrical Stimulation of Sphenopalatine Ganglion for Acute Treatment of Cluster Headaches

Cluster headaches (CH) are primary headaches marked by repeated short-lasting attacks of severe, unilateral head pain and associated autonomic symptoms. Despite aggressive management with medications, oxygen therapy, nerve blocks, as well as various lesioning and neurostimulation therapies, a number of patients are incapacitated and suffering. The sphenopalatine ganglion (SPG) has been implicated in the pathophysiology of CH and has been a target for blocks, lesioning, and other surgical approaches. For this reason, it was selected as a target for an acute neurostimulation study. Six patients with refractory chronic CH were treated with short-term (up to 1 hour) electrical stimulation of the SPG during an acute CH. Headaches were spontaneously present at the time of stimulation or were triggered with agents known to trigger clusters headache in each patient. A standard percutaneous infrazygomatic approach was used to place a needle at the ipsilateral SPG in the pterygopalatine fossa under fluoroscopic guidance. Electrical stimulation was performed using a temporary stimulating electrode. Stimulation was performed at various settings during maximal headache intensity. Five patients had CH during the initial evaluation. Three returned 3 months later for a second evaluation. There were 18 acute and distinct CH attacks with clinically maximal visual analog scale (VAS) intensity of 8 (out of 10) and above. SPG stimulation resulted in complete resolution of the headache in 11 attacks, partial resolution (>50% VAS reduction) in 3, and minimal to no relief in 4 attacks. Associated autonomic features of CH were resolved in each responder. Pain relief was noted within several minutes of stimulation. Sphenopalatine ganglion stimulation can be effective in relieving acute severe CH pain and associated autonomic features. Chronic long-term outcome studies are needed to determine the utility of SPG stimulation for management and prevention of CH.

Sphenopalatine Ganglion Radiofrequency Ablation for the Management of Chronic Cluster Headache

Chronic cluster headache patients are often resistant to pharmacological management. Percutaneous radiofrequency ablation (RFA) of the sphenopalatine ganglion (SPG) was shown before to improve episodic cluster headache but not chronic cluster headache. We were interested to examine the effect of such intervention in patients with intractable chronic cluster headache who failed pharmacological management. Fifteen patients with chronic cluster headache, who experienced temporary pain relief following SPG block, underwent percutaneous RFA via the infrazygomatic approach under fluoroscopic guidance. Collected data include demographic variables, onset and duration of the headache, mean attack intensity (MAI), mean attack frequency (MAF), and pain disability index (PDI) before and up to 18 months after procedure. At 1-, 3-, 6-, 12-, 18-month follow-up, the MAI was 2.6, 3.2, 3.2, 3.4, 4.2, respectively (P < .0001, P < .0001, P < .0001, P < .0005, P < .003, respectively). The PDI improved from 55 (baseline) to 17.2 and 25.6 at 6 and 12 months respectively (P < .001). The MAF improved from 17 attacks/week to 5.4, 6.4, 7.8, 8.6, 8.3 at 1-, 3-, 6-, 12-, 18-month follow-up visits (P < .0001, P < .0001, P < .0001, P < .002, P < .004, respectively). Our data showed that percutaneous RFA of the SPG is an effective modality of treatment for patients with intractable chronic cluster headaches. Precise needle placement with the use of real-time fluoroscopy and electrical stimulation prior to attempting radiofrequency lesioning may reduce the incidence of adverse events.

Efficacy of sphenopalatine ganglion blockade in 66 patients suffering from cluster headache: a 12- to 70-month follow-up evaluation.

This study was conducted to evaluate the efficacy, based on 12- to 70-month follow-up data, of radiofrequency (RF) lesions of the sphenopalatine ganglion made in patients suffering from cluster headache. Sixty-six patients suffering from either episodic (Group A, 56 patients) or chronic (Group B, 10 patients) cluster headache who were not responsive to pharmacological management were treated by RF lesioning in the sphenopalatine ganglion. Complete relief of pain was achieved in 34 (60.7%) of 56 patients in Group A and in three (30%) of 10 patients in Group B. No relief was found in eight patients (14.3%) in Group A and in four (40%) in Group B. The mean time of follow up was 29.1 +/- 10.6 months in Group A and 24 +/- 9.7 months in Group B, ranging from 12 to 70 months. With regard to side effects and complications, temporary postoperative epistaxis was observed in eight patients and a cheek hematoma in 11 patients; a partial RF lesion of the maxillary nerve was inadvertently made in four patients. Nine patients complained of hypesthesia of the palate, which disappeared in all cases within 3 months. The authors conclude that RF lesioning in the sphenopalatine ganglion via the infrazygomatic approach may be performed in patients suffering from cluster headache that does not respond to pharmacological therapy.