Posterior Fossa Re-Exploration for Recurrent Trigeminal Neuralgia: Operative Findings and Surgical Techniques.

OBJECTIVE: Microvascular decompression (MVD) is considered the first choice for the surgical treatment of trigeminal neuralgia (TN). However, recurrence after MVD is still a problem and a challenge for neurosurgeons. In this study, we share our experience in the posterior fossa re-exploration of the recurrent cases. METHODS: From January 2014 to January 2015, 15 recurrent TN patients who received fossa re-exploration were retrospectively studied. Surgeries were performed by retrosigmoid suboccipital approach. Brainstem auditory evoked potentials (BAEP) were monitored throughout the operation. Intraoperative findings and surgical techniques were recorded. Postoperative outcomes and complications were analyzed. RESULTS: Among the 15 patients, Teflon adhesion was found in 14. Teflon felt displacement was found in 4 patients, and additional Teflon felt was used to interpose. New offending vessels were found in 5 patients. Three of them were small arteries and the other 2 were petrosal veins. After dissected, small pieces of wet gelatin sponge and Teflon felt were implanted respectively to ensure complete decompression. The remaining 6 patients had no vascular compression except severe adhesion, and nerve combing was performed. After surgery, 12 achieved complete pain relief, 2 gained partial pain relief, and 1 failed. Six patients experienced facial numbness postoperatively. There was no hearing impairment or other complications. During the mean 26-month follow-up, no recurrence occurred and all of 6 cases with facial numbness after surgery improved. CONCLUSIONS: Teflon adhesion is a significant cause of recurrent TN. Wet gelatin-assisted method is good for Teflon interposition. If no vascular compression is found during re-exploration, trigeminal nerve combing can be used. Intraoperative BAEP monitoring is helpful to reduce the incidence of hearing loss.

Teflon Might Be a Factor Accounting for a Failed Microvascular Decompression in Hemifacial Spasm: A Technical Note.

BACKGROUND: Although Teflon is widely adopted for microvascular decompression (MVD) surgery, it has never been addressed for failure analysis. This study analyzed the reasons for failed MVDs with emphasis on the Teflon sponge. METHODS: Among the 685 hemifacial spasm cases between 2010 and 2014, 31 were reoperated on within a week because of unsatisfactory outcome, which was focused on in this study. Intraoperative findings regarding Teflon inserts of these repeat MVDs were reviewed. RESULTS: Among the 38 without satisfactory outcomes, 31 underwent repeat MVDs, and they were all spasm free afterwards. Eventually, the final cure rate was 99.2%. It was found in the repeat MVDs that the failure was attributable to the Teflon insert in most of the cases (74.2%) directly or indirectly. It was caused by improper placement (47.8%), inappropriate size (34.8%) and unsuitable shape (17.4%) of the Teflon sponge. CONCLUSION: Although it is not difficult for an experienced neurosurgeon to discover a neurovascular conflict during the MVD process, the size, shape and location of the Teflon sponge should not be ignored. Basically, the Teflon insert is used to keep the offending artery away from the facial nerve root rather than to isolate it. Therefore, the ideal Teflon sponge should be just small enough to produce a neurovascular separation.

[Inhibition of connexin 43-mediated hemichannel activity promotes odontoblast differentiation of human dental pulp cells induced by lipopolysaccharide].

PURPOSE: To investigate the role and mechanism of connexin 43（Cx43）in odontoblast differentiation of human dental pulp cells (hDPCs) induced by lipopolysaccharide (LPS). METHODS: The maxillary first molar injury model of SD rats was established. The expression pattern of Cx43 in dental pulp repair after injury was detected by immunofluorescence(IF) staining. hDPCs was respectively stimulated with 0, 1, 10, 100 and 1 000 ng/mL LPS for 6 h to screen the optimal concentration, and then the expression of Cx43 was inhibited and overexpressed in hDPCs. Quantitative real-time PCR(qRT-PCR) and Western blot(WB) were used to detect the expression of Cx43 and dentin sialophosphoprotein (DSPP), dental matrix protein-1 (DMP-1), osterix (Osx) and extracellular signal-regulated kinase (ERK) activity. Furthermore, hDPCs were treated with specific Cx43 channel inhibitors to investigate the effect of Cx43-mediated channel activity in odontoblast differentiation of hDPCs, and to explore the role and mechanism of Cx43 in regulating odontoblast differentiation of hDPCs induced by LPS. Statistical analysis was performed with SPSS 26.0 software package. RESULTS: IF results showed that Cx43 was mainly expressed in the odontoblast layer in healthy dental pulp tissues. At 3-24 h after tooth injury, the expression of Cx43 decreased and then gradually increased to the normal level; from 3 days to 2 weeks after injury, the expression of Cx43 tended to be down-regulated which was in the odontoblast layer and pulp proper. The expression of DSPP mRNA was significantly up-regulated in the hDPCs stimulated with 10 ng/mL LPS for 6 h(P＜0.01). Inhibition of Cx43 significantly up-regulated the expression of DSPP, DMP-1 and Osx mRNA induced by LPS in hDPCs(P＜0.05), while overexpression of Cx43 obviously inhibited the expression of factors related to LPS-induced odontoblast differentiation(P＜0.01) and the fluorescence intensity of DSPP. 10 ng/mL LPS activated ERK signal in hDPCs, and overexpression of Cx43 significantly attenuated the activity of ERK signal induced by LPS(P＜0.01). Inhibition of Cx43-mediated hemichannel (HC) promoted mRNA expression of factors related to odontoblast differentiation in hDPCs and the activity of ERK signal induced by LPS(P＜0.05), while blocking Cx43-mediated gap junction channel (GJC) inhibited odontoblast differentiation. CONCLUSIONS: Cx43 participates in the regulation of dental pulp repair after injury, and its expression shows a downward trend as a whole. Inhibition of Cx43 or blocking of HC promotes LPS-induced ERK signal activity and odontoblast differentiation of hDPCs.

Treatment of hemimasticatory spasm with microvascular decompression.

Hemimasticatory spasm is a rare disorder characterized by paroxysmal involuntary contraction of the jaw-closing muscles. As the ideology and pathogenesis of the disease are still unclear, there has been no treatment that could give rise to a good outcome so far. Herein, we tried to use surgical management to cure the disease. Six patients with the disease were included in this study. These patients underwent microvascular decompression of the motor fibers of the trigeminal root. After the operation, all faces of the patients felt relaxed at varied degrees, except for 1 patient. Our study showed that microvascular decompression of the trigeminal nerve could lead to a better outcome. However, a control study with a large sample is needed before this technique is widely used.

Intentional replantation combined root resection therapy for the treatment of type III radicular groove with two roots: A case report.

BACKGROUND: A radicular groove is an anatomic malformation that usually initiates at the central fossa, extending along the root at varying lengths and depths and predisposes the involved tooth to a severe periodontal defect. Severe grooves that extend to the root apex often lead to complex combined periodontal-endodontic lesions. They are a serious challenge for doctors to diagnose and treat. CASE SUMMARY: In this report, we described a patient with a maxillary lateral incisor with a deep palatogingival groove with two roots, which led to complex combined periodontal-endodontic lesions. Suggested treatment modalities included curettage of the affected tissues, elimination of the groove by grinding and/or sealing with a variety of filling materials, and surgical procedures. In this case, a combination of endodontic therapy, intentional replantation, and root resection were used, which resulted in periodontal/periradicular healing after 12 mo. CONCLUSION: Intentional replantation and root resection offer a predictable procedure and should be considered a viable treatment modality for the management of palatogingival grooves, especially for two-rooted teeth.