Consistency of neurovascular relationship between multimodal image fusion 3D reconstruction and intraoperative findings of microvascular decompression for primary trigeminal neuralgia

Objective To investigate the value of three-dimensional time-flying magnetic resonance angiography (3D-TOF-MRA) and three-dimensional fast imaging employing steady-state acquisition sequence (3D-FIESTA) fusion three-dimensional image in identification of offending vessels of primary trigeminal neuralgia (PTN). Methods A total of 48 patients with PTN who underwent microvascular decompression (MVD) from January 2016 to June 2019 at Department of Neurosurgery, Affiliated Hospital of Qingdao University were retrospectively enrolled into this study. All patients underwent 3D-TOF-MRA and 3D-FIESTA sequence examinations before operation. The 3D-slicer software was used to fuse 3D-TOF-MRA and 3D-FIESTA sequence images and conduct three-dimensional reconstruction. Using MVD as a standard, 3D-TOF-MRA, 3D-FIESTA and fused images were evaluated to determine the offending vessels and their compressive degree on the nerves. Results In MVD, except for 1 patient who had no offending vessel, the other 47 patients had clear offending vessels. The offending vessels were merely arteries in 40 cases, veins in 2, and both arteries and veins in 5. The 3D-TOF-MRA results showed that 5 patients had no offending vessels, and the remaining 43 patients had arteries as offending vessels. The 3D-FIESTA showed that 4 cases had no offending vessels; the offending vessels were arteries in 36 cases, veins in 3 cases, and both arteries and veins in 5 cases. The fused images showed that there were 2 cases without offending vessels; the offending vessels were arteries in 39 cases, veins in 2 cases, and both arteries and veins in 5 cases. Using the MVD as the standard, the accuracy of 3D-TOF-MRA, 3D-FIEST and fusion 3D images for determining the presence/absence offending vessels was 91.7% (44/48), 93.8% (45/48) and 97.9%(45/48), respectively. The accuracy of correct identification of offending vessels by 3D-TOF-MRA, 3D-FIEST and fused images was 54.2% (26/48), 89.6% (43/48) and 93.8% (45/48), respectively. Compared with intraoperative findings, those 3 types of images commonly showed lighter degree of nerve compression, and the differences were statistically significant (all P<0.05). Conclusion Compared with 3D-TOF-MRA and 3D-FIESTA single sequences, the fused images seem to be more accurate in identification of the offending vessels of PTN, which, however, is still associated with underestimation of the nerve compression degree. Key words: Trigeminal neuralgia; Offending vessel; Three-dimensional time-of-flight magnetic resonance angiography; Three-dimensional fast imaging employing steady-state acquisition; Microva-scular decompression

Objective To investigate the value of MR diffusion tensor imaging (DTI) in assessment of the microstructural changes of the trigeminal nerve, and analyze it's correlation with the degree of vascular compression. Methods Thirty-four patients with trigeminal neuralgia from November 2015 to April 2017 were retrospectively analyzed in this study. And they were treated by microvascular decompression (MVD). There were 11 cases of grade Ⅰ, 16 cases of grade Ⅱ and 7 cases of grade Ⅲ according to the severity of the contact between nerves and vessels during the operation. All of them were scanned with three dimensional time-of-flight (3D-TOF) sequences, three dimensional fast imaging employing steady state acquisition (3D-FIESTA) sequences and DTI before undergoing surgical decompression. According to the preoperative MR scans, the trigeminal nerves were divided into the healthy side without neurovascular contact (25 cases) and the healthy side with a neurovascular contact (9 cases).The DTI parameters of the trigeminal nerve, including the anisotropic fraction (FA) and the ADC values were obtained. Comparison of the FA and ADC values of the trigeminal nerve between the different stages of the affected side was performed with single factor analysis of variance, and the paired samples t test was used to compare the difference of FA and ADC values of bilateral trigeminal nerve. The difference of FA and ADC values between the asymptomatic side with or without vascular contact was compared with independent sample t test. Spearman correlation analysis was used to evaluate the correlation between DTI parameters and the degree of compression. Results The FA values of patients with grades Ⅰ, Ⅱ and Ⅲ were 0.311±0.009, 0.308±0.007 and 0.299±0.009 respectively, and there was significant difference among different levels (F=5.269, P 0.05) . The FA values of bilateral trigeminal nerves in healthy side without neurovascular contact and in healthy side with neurovascular contact were statistically significant (t=-32.528,-25.178, P 0.05). There were no statistically significant differences in the FA and ADC values between the two groups on the healthy side of the trigeminal nerve (P>0.05) . The FA value was negatively correlated with the degree of vascular compression (r=-0.453, P 0.05). Conclusion DTI imaging can be used to evaluate the degree of trigeminal nerve injury. More obvious vascular compression leads to lower FA value. Key words: Trigeminal neuralgia; Magnetic resonance imaging; Blood vessels

Evaluation of the correlation between trigeminal nerve atrophy and trigeminal neuralgia using multimodal image fusion: A single-center retrospective study

Objective To demonstrate the spatial relationship between intracisternal segment of trigeminal nerve and adjacent vessels in patients with primary trigeminal neuralgia and to assess the effectiveness of magnetic resonance imaging (MRI) for diagnosis of the neurovascular contact.Methods 89patients underwent trigeminal nerve decompression operation from January 2011 to November 2012.Preoperative 1.5T MRI with axial time-of-flight (TOF) sequence and constructive interference in steady state (CISS) sequence were performed.And then the bilateral spatial relationship between intracisternal segment of trigeminal nerve and adjacent vessels were studied.The surgical video recordings were golden standards for comparative analysis of the different results between TOF,CISS and CISS + TOF.Results Confirmed by the operative video recordings,the contact vessels were superior cerebellar artery in 32 cases (35.6％),anterior inferior cerebellar artery in 3 cases (3.3％),vein in 8 cases (8.9％),composite vessels in 44 cases (48.9％),no obvious vascular in 3 cases (3.3％).The accuracies of TOF,CISS,and CISS + TOF to for the diagnosis of the neuralgia side were 56.7％,53.4％ and 56.2％,respectively.The sensitivities of TOF,CISS,and CISS + TOF for the diagnosis of the existence of contact vessels on the neuralgia sides were 74.7％,85.1％ and 93.1％,respectively.The difference between TOF and CISS + TOF was statistically significant.However,the consistency of all three groups for the diagnosis of the type of contact vessels was low,from 0％ to 55.6％.Conclusions Preoperative MRI could not accurately determine the trigeminal neuralgia pain in which side.The combined CISS and TOF sequence examination could accurately determine whether the contact vessels existed on the neuralgia sides.But in this study MRI examination could not accurately determine the types of contact vessels. Key words: Trigeminal neuralgia ; Magnetic resonance imaging; Microvascular decompression

Objective To explore the incidence of operation complications and clinical curative effect of microsurgical vascular decompression on treatment of patients with common cranial nerve diseases. Methods One hundred and sixty-six patients with hemifacial spasm and 45 patients with primary trigeminal neuralgia, admitted to our hospital from September 2006 to May 2011, were collected in our study; all the patients underwent microvascular decompression via a posterior sigmoid sinus key hole approach. Complications were analyzed after surgery for trigeminal neuralgia and hemifacial spasm patients to find the difference on complications between these 2 diseases. And at least 3-month clinical follow-up after microvascular decompression surgery was carried out to note the differences on disappearance of cranial nerve symptoms between 3 d and 3 months after the surgery. Results Postoperative fever in the patients with hemifacial spasm and trigeminal neuralgia was seen in 51 and 14 patients, prosopoplegia in 7 and 1 patient, hearing impairment in 4 and 2 patients, incisional cerebrospinal fluid leakage in 5 and 2 patients, and intracranial infection in 3 and 2 patients, respectively. Symptom disappearance was noted in 109 patients with hemifacial spasm 3 d after the surgery and in 153 patients 3 months after surgery with a cure rate up to 92.2%; 44 patients with disappearance of symptoms during the 3rd d to the 3rd months of surgery had delayed healing. The symptom disappearance was observed in 40 patients with trigeminal neuralgia 3 d after the surgery and in 42 patients 3 months after the surgery, with a cure rate reaching 93.3%. Conclusion No significant difference in the incidence of operation complications is noted between patients with trigeminal neuralgia and hemifacial spasm treated by microvascular decompression via posterior sigmoid sinus key hole approach; the surgery enjoys exact effectiveness： and postoperative patients with hemifacial spasm may gradually get recovery in a short term. Key words: Hemifacial spasm; Trigeminal neuralgia; Microvascular decompression; Posterior sigmoid sinus approach

Multimodal image fusion–guided microvascular decompression for hemifacial spasm: a comparative clinical study

Objective To explore the risk factors of recurrence of trigeminal neuralgia (TN) after microvascular decompression (MVD). Methods Four hundred patients with primary TN were treated with MVD from January 2012 to December 2014 in the Department of Neurosurgery of Jining First People’s Hospital were selected and divided into recurrence group (36 cases) and non-recurrence group (364 cases). Multivariate logistic regression was used to analyze the risk factors of MVD recurrence in TN patients. Results Thirty-six patients recurred within 2 years after operation. The recurrence rate in females (9.4%) was higher than that in males (8.0%). The recurrence rate in non-vascular compression group (40.0%) was higher than that in vascular compression group (8.6%). The recurrence rates in pain branches were V2-3 (13.4%), V2 (12.5%), V1 (9.1%), V3 (7.5%), V1-2-3 (4.4%), V1-2 (4.3%) and V1-3 (0.0%) respectively. The difference was statistically significant (P<0.05). Multivariate logistic regression analysis showed that gender, vascular compression and pain branches were risk factors for postoperative recurrence. The recurrence rate of MVD in female, V2-3、V2、V3 and non-vascular compression patients was high. Conclusion Sex, vascular compression and pain branches were the main factors affecting recurrence of primary TN after MVD alone. Key words: Trigeminal neuralgia; Microvascular decompression; Pain zone; Recurrence

To explore the application value of preoperative multimodal image fusion technique in microvascular decompression (MVD) surgery via the suboccipital retrosigmoid approach. Comprehensive data of 13 patients with primary trigeminal neuralgia (TN) and 13 patients with hemifacial spasm (HFS) treated by MVD surgery via the suboccipital retrosigmoid approach at the Department of Neurosurgery in Zhuhai People's Hospital from January 2021 to December 2021 were retrospectively analyzed. Preoperatively, all patients underwent cranial thin-section computed tomography and magnetic resonance examinations. Three-dimensional (3D) digital images of the skull, brainstem, nerves, and blood vessels were constructed by the 3D-slicer software or RadiAnt DICOM Viewer, which were then applied to design the surgical approach and surgical plan. The multimodal image fusion results, clinical characteristics, intraoperative data, surgical outcomes, and complications of all patients were summarized. The 3D digital images after fusion reconstruction can vividly show the anatomical relationship between the skull, brainstem, nerves, and blood vessels and was helpful to tailor the surgical strategy. All 26 patients underwent a smooth surgery. During the surgery, the key points were accurately located, the corners of the transverse sinus and sigmoid sinus were completely exposed, and no venous sinus injury occurred in all 26 patients. The key point was approximately located at the top point of the digastric groove, 12.3±0.46mm vertically above and 6.3±0.6mm laterally to the Frankfurt horizontal plane. The average cranial opening time was 30.4 (±3.6) min, and the mean operating time was 104.7 (±12.1) min. The diameter of the bone window was about 2.0 cm-3.0cm, and the bone flap was restored. Among the 13 patients with primary TN, 12 (92.3%) exhibited complete relief of pain and 1 had significant relief. Complications of surgery included facial sensory numbness in 1 case, vertigo in 2 cases, and herpes at the corners of the mouth in 1 case. Of the 13 patients with HFS, 12 (92.3%) had complete relief of facial twitching symptoms and 1 had significant relief, and the complications included mild facial palsy in 2 (15.4%) cases and facial sensory numbness in another 2 (15.4%) cases. The mean follow-up time after surgery ranged from 6-16months, and 1 of 26 patients experienced recurrence of HFS during the follow-up period. Preoperative multimodal image fusion technology can provide adequate preoperative assessment for patients and assistance in designing surgical approaches, which is an important guideline for MVD surgery via the suboccipital retrosigmoid approach for primary TN and facial muscle spasm.

Objective To investigate the related factors affecting the efficacy of microvascular decompression (MVD) in the treatment of primary trigeminal neuralgia (TN). Methods MVD was performed in 120 patients with primary TN and single factor χ2 test and Logistic regression analysis were performed on the clinical data to evaluate the independent risk factors influencing the efficacy of MVD in the treatment of primary TN. Results The pain completely disappeared in 101 cases, the pain was relieved in 16 cases and the unhealed in 3 cases. Sixty cases had pure arterial compression,57 cases had venous compression, and 3 cases had no obvious responsibility vessel. Complete elimination of pain in the patients with venous compressionwaslower than that in patients with pure arterial oppression: 73.7% (42/57) vs. 86.7% (52/60), and the difference was statistically significant (P < 0.05). The complete pain relief rate in patients with V2 bronchial pain was lower than that in other pain distribution areas: 13/19 vs. 87.1%(88/101), With significant difference (P < 0.05). In patients with V2 bronchitis, the responsible vessels were mostly compressed from the ventral surface of the trigeminal nerve, and the difference was statistically significant (P < 0.05). Logistic regression analysis showed, Venous compression and V2 pain were the independent risk factors influencing the clinical efficacy of MVD in the treatment of primary TN. Conclusions Patients with venous compression and V2 pain are less likely to havegood postoperative outcomes, and venous compression and V2 painare independent risk factors. In patients with V2 pain, the responsible vasculature tends to ventrally massage the trigeminal nerve, which is a new study direction of refractory V2 pain. Key words: Trigeminal neuralgia; Vein; Microvascular decompression; Maxillary branch; Analysis of curative effect

Objective To study the clinical value of microvascular decompression(MVD)through the retrosigmoid approach in the treatment of primary trigeminal neuralgia. Methods The clinical data of 769 patients with primary trigeminal neuralgia undergoing MVD through the retrosigmoid approach was retrospectively analyzed to evaluate the therapeutic effect of the treatment. Results MVD was accomplished in 769 patients with primary trigeminal neuralgia.Neuralgia was totally relieved in 743 patients,significantly relieved in 17 patients and not relieved in 9 patients after the treatment.Operative mortality occurred in none ofthe cases.The patients were followed up for 6 to 180 months,during which period 46 patients were found to experience recurrent neuralgia,and 9 ofthem wgre cured after a second operation. Conclusion MVD is a safe and effective surgical approach causing minimal invasiveness and lower recurrence rate, and can serve as the primary option for treatment of primary trigeminal neuralgia. Key words: Trigeminal neuralgia; Microvascular decompression; Follow-up

To explore the alarming effect of intraoperative neuroelectrophysiological monitoring in microvascular decompression (MVD) for primary trigeminal neuralgia. In 2014, a total of 44 patients with an initial diagnosis of primary trigeminal neuralgia were consecutively recruited for surgery. And 41 of them with an intraoperative confirmation of primary trigeminal neuralgia underwent MVD. Intraoperative neuroelectrophysiological monitoring was employed for brainstem auditory evoked potentials (BAEPs), spontaneous electromyogram for obicularis oculi, obicularisoris and masseter muscles. The real-time alarming report was offered to the operator who adjusted operations accordingly. There were abnormal changes in 23 cases (56.10%) with a total of 77 instances (BAEPs 27, trigeminal nerve 32, facial nerve 18). The outcomes were no facial pain (n=26), pain relief (n=15) and facial numbness (n=6, two with concurrent hearing disturbance). And the rates of facial pain disappearance and sequela occurrence were much better than those in controls without monitoring. Intraoperative neuroelectrophysiological monitoring helps enhance the MVD effect and decrease operative squela through alarming reporting.

Objective To analyze the therapeutic effects of microvaseular decompression on primary trigeminal neuralgia. Methods The general clinical data,culprit vessels and therapeutic effects of the surgical interventions were analyzed in 181 patients(aged from 24 to 79 years with a mean of54.9 years,including 78 male and 103 female patients)with established diagnosis of primary trigeminal neuralgia admitted from January,2000 to Deceber,2007. Results Blood type O was present in 43.65%of the 181 patients with trigeminal neuralgia,which had an increasing tendency compared to the national norm(33.8%).The morbidity ratio between the right and left side was 1.8:l in these patients.Forty-five patients(24.86%)were identified to have more than 2 culprit vessels.The culprit vessels included the superior cerebellar artery(96 cases),posterior inferior cerebellar artery(7 cases),anterior inferior cerebellar artery(25 cases),arteries communicated with veins(25 cases),internal auditory artery (13 cases),basilar artery(15 cases),vertical artery(9 cases),exclusive veins(15 cases,mainly vena pelrosa and bridging vein)and unknown vessels(9 cases).of the 181 cases,171(94.48%)were cured within one month,9(4.97%)showed relieved symptoms but required drug therapy,and 1 was in vegetative state(0.55%). Conclusions Patients with blood type O may have greater chance of developing primary trigeminal neuralgia.Microvascular decompression is an ideal treatment for primary trigeminal neuralgia,and clear identification of the culprit vessels can be crucial for decreasing the postoperative recurrence. Key words: Trigoninal neuralgia; Microvascular decompression; Therapeutic effects

Objective To summarize and analyze the efficacy of microvascular decompression (MVD) for cerebral neurovascular compression syndrome and its postoperative complications. Methods MVD was performed in 39 patients with cerebral neurovascular compression syndrome, including 19 with trigeminal neuralgia, 18 with facial spasm and 2 with glossopharyngeal neuralgia. The surgical techniques and prevention of postoperative complications were analyzed. Results The immediate relief of pain was succeed in 17 with trigeminal neuralgia and 2 with glossopharyngeal neuralgia and the spasm was eliminated in 16 with facial spasm right after the operation. No hematoma, infection, cerebrospinal fluid leakage or death appeared and the total effectiveness rate was 94.87%. Follow-up was performed in 34 with an average of 1.58 years and 32 were recorded with good results. Conclusion MVD for cerebral neurovascular compression syndrome is safe, minimally invasive and effective. It is by far the first choice in the treatment of cerebral neurovascular compression syndrome. Key words: Microvascular decompression; Trigeminal neuralgia; Facial spasm; Glossopharyngeal neuralgia

Objective To explore the technique and effectiveness of microvascular decompression (MVD) or microvascular decompression + partial sensory rhizotomy (PSR) on the treatment of primary trigeminal neuralgia (TN).Methods 210 TN patients undergoing posterior fossa craniotomies for TN were retrospectively studied,among which there're 142 cases underwent MVD and the other 68 cases underwent MVD + PSR.Results Of the MVD group,pain vanished in 128(90.1％ ),obviously relieved in 9,and a total of 137(96.5％ ) cases were profited from MVD after operation.In the 82 cases with a follow-up more than 2 years,pain vanished in 74,pain sometime occurred in 5 which could be relieved by oral medicine (carbamazepine),the last 3 cases could not be controlled effectively by medicine.Of the MVD + PSR group,pain completely vanished in 67 cases,not changed in 1 case.In the 47 cases with a follow-up more than 2 years,pain sometime occurred in 2 which could be relieved by carbamazepine,the others were completely pain - free.The short - term pain - free rate in MVD + PSR group (98.5％ ) was obviously higher than the MVD group (90.1％ ),P ＜ 0.05.After a follow - up more than 2 years,the former was still higher than the later in the rate of 95.7％ and 90.1％ respectively,but there was no significant difference in statistics.Conclusions MVD + PSR was obviously superior to MVD in completely eliminating pain in short -term period after operation,the former still has a higher pain- free rate than the later in two years after operation,however,longer pain -free rate need even longer time to follow up;identifying the responsible vascular exactly and handling it reasonably were the key to both groups; there are both merits and shortcomings in MVD or MVD + PSR,so how to choose a more suitable surgical method depends on the findings in operation,the patient's own opinion and conditions should also be considered prudently before operation. Key words: Trigeminal neuralgia ; Microvascular decompression ; Sensory rhizotomy ;

Surgical outcome after microvascular decompression (MVD) for primary trigeminal neuralgia (TN) has been demonstrated as being related to the characteristics of the neurovascular compression (NVC), especially to the degree of compression exerted on the root. Therefore, preoperative determination of the NVC features could be of great value to the neurosurgeon, for evaluation of conflicting nature, exact localization, direction and degree of compression. This study deals with the predictive value of MRI in detecting and assessing features of vascular compression in 100 consecutive patients who underwent MVD for TN. The study included 100 consecutive patients with primary TN who were submitted to a preoperative 3D MRI 1.5 T with T2 high-resolution, TOF-MRA, and T1-Gadolinium. Image analysis was performed by an independent observer blinded to the operative findings and compared with surgical data. In 88 cases, image analysis showed NVC features that coincided with surgical findings. There were no false-positive results. Among 12 patients that did not show NVC at image analysis, nine did not have NVC at intraoperative observation, resulting in three false-negative cases. MRI sensitivity was 96.7% (88/91) and specificity 100% (9/9). Image analysis correctly identified compressible vessel in 80 of the 91 cases and degree of compression in 77 of the 91 cases. Kappa-coefficient predicting degree of root compression was 0.746, 0.767, and 0.86, respectively, for Grades I (simple contact), II (distortion), and III (marked indentation; p < 0.01). 3D T2 high-resolution in combination with 3D TOF-MRA and 3D T1-Gadolinium proved to be reliable in detecting NVC and in predicting the degree of the root compression.