Predicting balloon shape in percutaneous microcompression : an observational comparative analysis of Meckel's cave imaging and balloon morphology.

Achieving a pear-shaped balloon holds pivotal significance in the context of successful percutaneous microcompression procedures for trigeminal neuralgia. However, inflated balloons may assume various configurations, whether it is inserted into Meckel's cave or not. The absence of an objective evaluation metric has become apparent. To investigate the relationship between the morphology of Meckel's Cave and the balloon used in percutaneous microcompression for trigeminal neuralgia and establish objective criteria for assessing balloon shape in percutaneous microcompression procedures. This retrospective study included 58 consecutive patients with primary trigeminal neuralgia. Data included demographic, clinical outcomes, and morphological features of Meckel's cave and the balloon obtained from MRI and Dyna-CT imaging. MRI of Meckel's cave and Dyna-CT of intraoperative balloon were modeled, and the morphological characteristics and correlation were analyzed. The reconstructed balloon presented a fuller morphology expanding outward and upward on the basis of Meckel's cave. The projected area of balloon was strongly positively correlated with the projected area of Meckel's cave. The Pearson correlation coefficients were 0.812 (P<0.001) for axial view, 0.898 (P<0.001) for sagittal view and 0.813 (P<0.001) for coronal view. Similarity analysis showed that the sagittal projection image of Meckel's cave and that of the balloon had good similarity. This study reveals that the balloon in percutaneous microcompression essentially represents an expanded morphology of Meckel's cave, extending outward and upward. There is a strong positive correlation between the volume and projected area of the balloon and that of Meckel's cave. Notably, the sagittal projection image of Meckel's cave serves as a reliable predictor of the intraoperative balloon shape. This method has a certain generalizability and can help providing objective criteria for judging balloon shape during percutaneous microcompression procedures.

Protocol for a systematic mapping review of surgical and pharmacological interventions for the treatment of trigeminal neuralgia.

Introduction: Trigeminal neuralgia is a painful neuropathic disorder characterized by sudden electric shock-like pain that significantly impacts patients' quality of life. Multiple treatment alternatives are available, including medical and surgical options but establishing the optimal course of action can be challenging. To enhance clinical decision-making for trigeminal neuralgia treatment, it is imperative to organize, describe and map the available systematic reviews and randomized trials. This will help identify the best treatment alternatives supported by evidence and acknowledge potential knowledge gaps where future research is needed. Objective: This systematic mapping review aims to provide up-to-date evidence on the different surgical and pharmacological treatment alternatives used for trigeminal neuralgia. Methods: A search will be systematically conducted on the Epistemonikos database to identify potentially eligible systematic reviews. Additionally, a search will be made in PubMed, CENTRAL, and EBSCO to identify randomized controlled trials assessing pharmacological and surgical treatment interventions for trigeminal neuralgia. Two independent reviewers will screen and select the studies. Data on the different treatment alternatives and reported outcomes in the included studies will be extracted using standardized forms. Following extraction, descriptive statistical methods will be used to analyze the data. The final output of this study will include an evidence map that will illustrate the connections between different treatments and their respective outcomes, providing a clear depiction of the evidence landscape. Expected results: This study expects to map, describe and assess the methodological quality of the available systematic reviews and trials on pharmacological interventions and neurosurgical procedures for treating trigeminal neuralgia. It will present the results in an evidence map that organizes the available evidence based on their different interventions and outcomes. This evidence map will serve as a visual tool to assist healthcare professionals and patients to understand evidence-based treatment options and their implications for managing this medical condition. Introducción: La neuralgia del trigémino es un trastorno neuropático doloroso caracterizado por un dolor súbito y agudo, similar a una descarga eléctrica, que impacta significativamente en la calidad de vida. Dada la variedad de tratamientos disponibles, médicos y quirúrgicos, es crucial organizar y mapear la evidencia proveniente de revisiones sistemáticas y ensayos clínicos para orientar las decisiones clínicas. Esto permite identificar tratamientos respaldados por evidencia y señalar áreas de investigación futura. Objetivo: El propósito de esta revisión sistemática de mapeo es proporcionar una visión actualizada de la evidencia existente en relación con las diversas opciones de tratamiento quirúrgico y farmacológico empleadas en el manejo de la neuralgia del trigémino. Métodos: Se realizará una búsqueda sistemática en la base de datos Epistemonikos para identificar potenciales revisiones sistemáticas. Adicionalmente, se buscará en PubMed, CENTRAL y EBSCO ensayos clínicos aleatorizados que evalúen intervenciones de tratamiento farmacológico y quirúrgico para la neuralgia del trigémino. Dos revisores independientes cribarán y seleccionarán los estudios. Se extraerán datos sobre las diferentes alternativas de tratamiento y los resultados reportados en los estudios incluidos utilizando formularios estandarizados. Tras la extracción, se utilizarán métodos estadísticos descriptivos para analizar los datos. El producto final de este estudio incluirá un mapa de evidencia que ilustrará las conexiones entre los diferentes tratamientos y sus respectivos resultados, proporcionando una representación clara del panorama de la evidencia. Resultados esperados: Los resultados que se extraerán de este mapeo sistemático incluyen identificar y describir las diferentes alternativas, tanto farmacológicas como quirúrgicas, que existen para el tratamiento de la neuralgia del trigémino. Además, se planea presentar un mapa de evidencia que se basará en los ensayos clínicos aleatorizados y revisiones sistemáticas, el cual mostrará la evidencia de manera organizada entre las diferentes intervenciones y sus desenlaces. Este mapa de evidencia servirá como una herramienta visual que ayudará a los profesionales de la salud y los pacientes a comprender mejor las opciones de tratamiento respaldadas por la evidencia y sus consecuencias en el manejo de esta condición médica.

Retrogasserian trigeminal radiofrequency-thermorhizotmoy for trigeminal neuralgia.

Based on a personal experience of 4200 surgeries, radiofrequency thermocoagulation is useful lesional treatment for those trigeminal neuralgias (TNs) not amenable to microvascular decompression (idiopathic or secondary TNs). Introduced through the foramen ovale, behind the trigemnial ganglion in the triangular plexus, the needle is navigated by radiology and neurophysiological testing to target the retrogasserian fibers corresponding to the trigger zone. Heating to 55-75 °C can achieve hypoesthesia without anaesthesia dolorosa if properly controlled. Depth of anaesthesia varies dynamically sedation for cannulation and lesioning, and awareness during neurophysiologic navigation. Proper technique ensures long-lasting results in more than 75% of patients.

Letter to the editor: "A nomogram based on radiomics and clinical information to predict prognosis in percutaneous balloon compression for the treatment of trigeminal neuralgia: a retrospective cohort study of published cases".

This critique evaluates a recent study on a nomogram based on radiomics and clinical data to predict the prognosis of percutaneous balloon compression (PBC) for trigeminal neuralgia (TN), focusing on its strengths, weaknesses, and suggestions for future research. It acknowledges the innovative approach's potential to personalize treatment and improve outcomes, but raises concerns about the study's retrospective nature, sample size limitations, and challenges in implementing radiomics in clinical practice. Overall, although the nomogram offers promise, further validation in larger cohorts is essential to confirm its utility and reliability. Future research should prioritize prospective multicenter studies with standardized protocols, collaborative efforts among institutions, and innovative techniques to advance our understanding and management.

Comparison of initial percutaneous balloon compression versus radiofrequency thermocoagulation followed by percutaneous balloon compression in the treatment of trigeminal neuralgia. / 首次经皮球囊压迫术与射频热凝术后再行经皮球囊压迫术治疗三叉神经痛的比较.

OBJECTIVES: There are a variety of minimally invasive interventional treatments for trigeminal neuralgia, and the efficacy evaluation is different. The preferred treatment scheme is still controversial. This study aims to investigate the differences in treatment effects between patients with primary trigeminal neuralgia (PTN) treated with percutaneous balloon compression (PBC) for the first intervention and patients with pain recurrence after radiofrequency thermocoagulation (RT) who then received PBC for PTN, and to offer clinicians and patients more scientifically grounded and precise treatment alternatives. METHODS: We retrospectively analyzed 103 patients with PTN admitted to the Department of Pain Management of the Second Affiliated Hospital of Guangxi Medical University from January 2020 to December 2021, including 49 patients who received PBC for the first time (PBC group) and 54 patients who received PBC for pain recurrence after RT (RT+PBC group). General information, preoperative pain score, intraoperative oval foramen morphology, oval foramen area, balloon volume, duration of compression, and postoperative pain scores and pain recurrence at each time point on day 1 (T1), day 7 (T2), day 14 (T3), 1 month (T4), 3 months (T5), and 1 year (T6) were collected and recorded for both groups. The differences in treatment effect, complications and recurrence between the 2 groups were compared, and the related influencing factors were analyzed. RESULTS: The differences of general information, preoperative pain scores, foramen ovale morphology, foramen ovale area, T1 to T3 pain scores between the 2 groups were not statistically different (all P>0.05). The balloon filling volume in the PBC group was smaller than that in the RT+PBC group, the pain scores at T4 to T6 and pain recurrence were better than those in the RT+PBC group (all P<0.05). Pain recurrence was positively correlated with pain scores of T2 to T6 (r=0.306, 0.482, 0.831, 0.876, 0.887, respectively; all P<0.01). CONCLUSIONS: The choice of PBC for the first intervention in PTN patients is superior to the choice of PBC after pain recurrence after RT treatment in terms of treatment outcome and pain recurrence.

The Primary Afferents of Trigeminal Autonomic Reflex May not be Nociceptive: A Case Report.

Autonomic symptoms have been long noticed coming along with pain in the head, e.g. Trigeminal Neuralgia, trigeminal autonomic cephalalgias. The symptoms show up during pain attacks, so they are assumed to be activated by the nociceptive afferents of the trigeminal nerve. Here, we present a case with hypersalivation as the complication after percutaneous balloon compression for trigeminal neuralgia, although the patient was pain-free after the treatment. A 71-year-old female with excessive salivation on the affected side after percutaneous balloon compression is described. The patient underwent microvascular decompression several years ago, and both the microvascular decompression and the preoperative imaging examination confirmed that there was no offending vessel at the root entry zone of the trigeminal nerve. After the percutaneous balloon compression, the patient was free of pain, but the autonomic symptoms (hypersalivation) still showed up. The autonomic symptoms which usually came along with pain presented solely as post-percutaneous balloon compression complication in the case. Contrary to popular belief, for the patient who was pain-free after percutaneous balloon compression, the transiently overactivated nerve fibers that led to hypersalivation were not nociceptive afferents of the trigeminal nerve.

A novel indicator to predict the outcome of percutaneous stereotactic radiofrequency rhizotomy for trigeminal neuralgia patients: diffusivity metrics of MR-DTI.

Magnetic resonance-diffusion tensor imaging (MR-DTI) has been used in the microvascular decompression and gamma knife radiosurgery in trigeminal neuralgia (TN) patients; however, use of percutaneous stereotactic radiofrequency rhizotomy (PSR) to target an abnormal trigeminal ganglion (ab-TG) is unreported. Fractional anisotropy (FA), mean and radial diffusivity (MD and RD, respectively), and axial diffusivity (AD) of the trigeminal nerve (CNV) were measured in 20 TN patients and 40 healthy control participants immediately post PSR, at 6-months, and at 1 year. Longitudinal alteration of the diffusivity metrics and any correlation with treatment effects, or prognoses, were analyzed. In the TN group, either low FA (value < 0.30) or a decreased range compared to the adjacent FA (dFA) > 17% defined an ab-TG. Two-to-three days post PSR, all 15 patients reported decreased pain scores with increased FA at the ab-TG (P < 0.001), but decreased MD and RD (P < 0.01 each). Treatment remained effective in 10 of 14 patients (71.4%) and 8 of 12 patients (66.7%) at the 6-month and 1-year follow-ups, respectively. In patients with ab-TGs, there was a significant difference in treatment outcomes between patients with low FA values (9 of 10; 90%) and patients with dFA (2 of 5; 40%) (P < 0.05). MR-DTI with diffusivity metrics correlated microstructural CNV abnormalities with PSR outcomes. Of all the diffusivity metrics, FA could be considered a novel objective quantitative indicator of treatment effects and a potential indicator of PSR effectiveness in TN patients.

A nomogram based on radiomics and clinical information to predict prognosis in percutaneous balloon compression for the treatment of trigeminal neuralgia.

OBJECTIVE: To develop a clinical-radiomics nomogram based on clinical information and radiomics features to predict the prognosis of percutaneous balloon compression (PBC) for the treatment of trigeminal neuralgia (TN). METHODS: The retrospective study involved clinical data from 149 TN patients undergoing PBC at Zhongnan Hospital, Wuhan University from January 2018 to January 2022. The free open-source software 3D Slicer was used to extract all radiomic features from the intraoperative X-ray balloon region. The relationship between clinical information and TN prognosis was analyzed by univariate logistic analysis and multivariate logistic analysis. Using R software, the optimal radiomics features were selected using the least absolute shrinkage and selection operator (Lasso) algorithm. A prediction model was constructed based on the clinical information and radiomic features, and a nomogram was visualized. The performance of the clinical radiomics nomogram in predicting the prognosis of PBC in TN treatment was evaluated using the area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: A total of 149 patients were eventually included. The clinical factors influencing the prognosis of TN in univariate analysis were compression severity score and TN type. The lasso algorithm Max-Relevance and Min-Redundancy(mRMR) was used to select two predictors from 13 morphology-related radiomics features, including elongation and surface-volume ratio. A total of 4 predictors were used to construct a prediction model and nomogram. The AUC was 0.886(95% confidence interval (CI), 0.75 to 0.96), indicating that the model's good predictive ability. DCA demonstrated the nomogram's high clinical applicability. CONCLUSION: Clinical-radiomics nomogram constructed by combining clinical information and morphology-related radiomics features have good potential in predicting the prognosis of TN for PBC treatment. However, this needs to be further studied and validated in several independent external patient populations.

Letter to the editor: A prospective cohort study on perioperative percutaneous balloon compression for trigeminal neuralgia: safety and efficacy analysis.

This study evaluated the safety and efficacy of Percutaneous Balloon Compression (PBC) for managing Trigeminal Neuralgia (TN) during the perioperative period in 400 patients. The results indicated no significant difference in postoperative pain relief between male and female patients, although female patients experienced more complications. PBC demonstrated effectiveness regardless of prior treatment, such as PBC, Microvascular Decompression (MVD), or Radiofrequency Thermocoagulation (RFT). Despite its efficacy, PBC has drawbacks, including an increased risk of complications in females and challenges in achieving standardized compression parameters. Compared to other surgical techniques for TN, PBC offers advantages in minimally invasive intervention, but has limitations, particularly in recurrent TN after MVD or RFT. While promising, the lack of standardized protocols and focus on short-term outcomes limits the generalizability of the findings. In conclusion, PBC represents a significant advancement in TN management, providing high initial pain relief rates with minimal invasiveness. However, further research is necessary to standardize procedures, address complications, and evaluate the long-term efficacy for a comprehensive understanding of its role in TN treatment.

Chronic Constriction Injury of the Distal Infraorbital Nerve (DIoN-CCI) in Mice to Study Trigeminal Neuropathic Pain.

Animal models remain necessary tools to study neuropathic pain. This manuscript describes the distal infraorbital nerve chronic constriction injury (DIoN-CCI) model to study trigeminal neuropathic pain in mice. This includes the surgical procedures to perform the chronic constriction injury and the postoperative behavioral tests to evaluate the changes in spontaneous and evoked behavior that are signs of ongoing pain and mechanical allodynia. The methods and behavioral readouts are similar to the infraorbital nerve chronic constriction injury (IoN-CCI) model in rats. However, important changes are necessary for the adaptation of the IoN-CCI model to mice. First, the intra-orbital approach is replaced by a more rostral approach with an incision between the eye and the whisker pad. The IoN is thus ligated distally outside the orbital cavity. Secondly, due to the higher locomotor activity in mice, allowing rats to move freely in small cages is replaced by placing mice in custom-designed and constructed restraining devices. After DIoN ligation, mice exhibit changes in spontaneous behavior and in response to von Frey hair stimulation that are similar to those in IoN-CCI rats, i.e., increased directed face grooming and hyperresponsiveness to von Frey hair stimulation of the IoN territory.

Balloon Pressure and Clinical Effectiveness of Percutaneous Microballoon Compression in the Treatment of Primary Trigeminal Neuralgia.

BACKGROUND: Primary trigeminal neuralgia (PTN) is a type of chronic neuropathic pain disorder caused by neurovascular compression. Percutaneous balloon compression (PBC) is a widely used method for the treatment of PTN. OBJECTIVES: To examine the correlation of balloon pressure (BP) during percutaneous microballoon compression (PBC) with postoperative pain relief and complications in the treatment of primary trigeminal neuralgia (PTN). STUDY DESIGN: Forty-five patients diagnosed with PTN and treated with PBC were recruited. The BP was recorded at 2 time points: when the balloon achieved the ideal pear shape (initial BP [IBP]) and when the pressure was maintained for 2 min (final BP [FBP]). SETTING: This study was conducted at the Department of Pain and Rehabilitation of the Second Affiliated Hospital at the University of South China in Hunan, China. METHODS: The patients' Barrow Neurological Institute (BNI) pain intensity score, BNI facial numbness score, masticatory muscle weakness score, and recurrence were recorded before and after surgery. The receiver operating characteristic (ROC) curves were generated for the IBP to predict treatment effectiveness, severe facial numbness, and severe masticatory muscle weakness. RESULTS: The BNI pain intensity score, BNI facial numbness score, and masticatory muscle weakness score were significantly decreased after surgery (all P < 0.001). IBP was positively correlated with the difference between IBP and FBP (P < 0.01). Both IBP and the difference between IBP and FBP were negatively correlated with the BNI pain intensity score and positively correlated with the BNI facial numbness score and masticatory muscle weakness score (P < 0.01). The IBP and the difference between the IBP and FBP were significantly lower in patients experiencing recurrence than in the nonrecurrent group (P < 0.05). The areas under the ROC curves of the IBP for predicting effective pain relief, severe facial numbness, and severe masticatory muscle weakness were 0.875, 0.980, and 0.988, respectively. LIMITATIONS: The sample size was relatively small, and the follow-up time was short. The correlations between the BP and other factors, such as filling amount, Meckel's cavity, and the size of the foramen ovale, were not investigated. The impact of the BP on long-term postoperative outcomes was not explored. CONCLUSIONS: An intraoperative BP of 138.65-153.90 KPa can be maintained for effective PBC treatment without causing serious complications.

Riveting technique in percutaneous balloon compression for trigeminal neuralgia remedy.

BACKGROUND: The percutaneous balloon compression (PBC) is a safe and simple treatment for trigeminal neuralgia. It works by compressing the Gasserian ganglion to block pain signals from the trigeminal nerve. To ensure effectiveness, it is important to focus the compression on the lower part of the balloon. OBJECTIVE: To validate the efficacy of a riveting technique, specifically pulling an inflated balloon, in order to apply enhanced compression on the ganglion. METHODS: To compare this novel technique with the conventional approach, a retrospective investigation was conducted on consecutive PBCs performed in our department between 2019 and 2022. For postoperative outcome assessment, efficacy was defined as achieving a VAS score of 0 or an improvement exceeding 5 points. Postoperative numbness was graded as none, mild, or severe based on its impact on daily life and tolerance level. RESULTS: Excluding cases with missed follow-up, a total of 179 participants were included in the study, and their follow-up period ranged up to 40 months. Postoperatively, symptomatic remission was achieved by 98.1% (52/53) of patients in the riveting technique group compared to 87.3% (110/126) in the conventional group (P<0.05). At the last follow-up period, with recurrence observed over time, the long-term efficacy of riveting and conventional groups were 94.3% and 74.6%, respectively (P<0.05). The majority of cases in both groups experienced ipsilateral facial numbness immediately following PBC, which appeared to diminish after 3 months in both groups without significant difference between them (P>0.05).

Radiosurgical Decompression of Trigeminal Nerve and Its Correlation with Functional Outcome in Tumor-Related Trigeminal Neuralgia.

BACKGROUND: Target selection during Gamma Knife radiosurgery (GKRS) in cases of tumor-related trigeminal neuralgia is always debatable. We analyzed the correlation of regression of tumor size and degree of release of the nerve with long-term pain control. METHODS: Between March 2012 and March 2023, 50 cases of tumor-related trigeminal neuralgia were treated with GKRS (tumor was targeted). Radiological findings after GKRS were categorized into 3 types: 1) tumor volume remained same or decreased, additional segment of nerve not seen; 2) tumor volume decreased, additional segment of trigeminal nerve seen, but tumor still adherent to the nerve; 3) tumor volume decreased, adjacent nerve seen completely separated from tumor. Pain score before and after GKRS (Barrow Neurological Institute I-III: good; Barrow Neurological Institute IV and V: poor) was correlated with these subgroups. RESULTS: At median follow-up of 46.5 months, 18 cases showed type 1 radiological response, 23 showed type 2 response, and 9 showed type 3 response. Good pain control was achieved in 10 (55.5%) patients with type 1, 15 (65.21%) with type 2, and 7 (77.8%) with type 3 responses. The outcome differences among these 3 groups were not statistically significant (P = 0.519). Five patients with type 3 radiological response were off medication, which was statistically better than type 1 and type 2 radiological responses, with 3 patients (P = 0.012) and 2 patients (P = 0.002), respectively, still receiving medication. CONCLUSIONS: Tumor volume reduction after GKRS may be associated with good pain control in tumor-related trigeminal neuralgia. Further, this allows visualization of additional segment of nerve that can be targeted in a second session for treating recurrent or failed cases.

Anatomic Variations of Foramen Ovale as a Predictor of Successful Cannulation in Percutaneous Trigeminal Rhizotomies.

BACKGROUND AND OBJECTIVES: Percutaneous trigeminal rhizotomies are common treatment modalities for medically refractory trigeminal neuralgia (TN). Failure of these procedures is frequently due to surgical inability to cannulate the foramen ovale (FO) and is thought to be due to variations in anatomy. The purpose of this study is to characterize the relationships between anatomic features surrounding FO and investigate the association between anatomic morphology and successful cannulation of FO in patients undergoing percutaneous trigeminal rhizotomy. METHODS: A retrospective analysis was conducted of all patients undergoing percutaneous trigeminal rhizotomy for TN at our academic center between January 1, 2010, and July 31, 2022. Preoperative 1-mm thin-cut computed tomography head imaging was accessed to perform measurements surrounding the FO, including inlet width, outlet width, interforaminal distance (a representation of the lateral extent of FO along the middle fossa), and sella-sphenoid angle (a representation of the coronal slope of FO). Mann-Whitney U tests assessed the difference in measurements for patients who succeeded and failed cannulation. RESULTS: Among 37 patients who met inclusion criteria, 34 (91.9%) successfully underwent cannulation. Successful cannulation was associated with larger inlet widths (median = 5.87 vs 3.67 mm, U = 6.0, P = .006), larger outlet widths (median = 7.13 vs 5.10 mm, U = 14.0, P = .040), and smaller sella-sphenoid angles (median = 52.00° vs 111.00°, U = 0.0, P < .001). Interforaminal distances were not associated with the ability to cannulate FO surgically. CONCLUSION: We have identified morphological characteristics associated with successful cannulation in percutaneous rhizotomies for TN. Preoperative imaging may optimize surgical technique and predict cannulation failure.

A prospective cohort study on perioperative percutaneous balloon compression for trigeminal neuralgia: safety and efficacy analysis.

With the recent emergence of percutaneous balloon compression (PBC) as a promising treatment for trigeminal neuralgia (TN), there is a growing need for research on its safety and efficacy. This study was designed to evaluate the safety and efficacy of PBC in the treatment of TN patients during the perioperative period. This study involved a total of 400 TN patients who were selected and treated with PBC at our institution. The clinical data and short-term outcomes were analyzed based on sex, initial PBC treatment for TN, and subsequent PBC treatment for recurrent TN after previous PBC or microvascular decompression (MVD) or radiofrequency thermocoagulation (RFT). No statistically significant difference was found when comparing postoperative pain relief between male and female patients with TN. Nevertheless, female patients were found to be more vulnerable than male patients to abnormal facial sensations (P = 0.001), diplopia (P = 0.015), postoperative headache (P = 0.012), and hyposmia (P = 0.029). Additionally, it was observed that there was no substantial difference in the postoperative pain relief rate between the first-time PBC group and PBC for recurrent TN patients postoperatively following procedures such as PBC, MVD, and RFT. In conclusion, this study has shown that PBC treatment is effective in managing TN in both males and females, regardless of whether the treatment was administered as a primary intervention or following prior surgical procedures such as PBC, MVD, or RFT. Nonetheless, it is noted that the risk of postoperative complications appears to be higher in female patients compared to male patients.