A Clinical Study On Difficult Decompression Operation For Trigeminal Neuralgia

Background and Objective:Trigeminal Neuralgia(TN)is one of the most common facial pain syndromes,and its pathogenesis is not completely clear,which seriously affects the quality of life of patients.In recent years,Microvascular Decompression(MVD)has been widely applied in the treatment of trigeminal neuralgia and has developed into an effective,simple and safe mature technology.However,during clinical operation,part of MVD has certain difficulty due to special vascular compression,abnormal anatomical structure,local severe adhesion and other reasons,which is called dystonic decompression.However,due to the small number of cases of difficult decompression,there is no consensus on the technical method of decompression,and the clinical effect and complication rate are not consistent.In this study,by studying the data of MVD surgery on TN caused by vertebral basilar artery dilatation,extension and compression in recent years and reoperation on TN caused by recurrence after MVD in our center,the indications and technical methods of such MVD surgery were discussed,and the improvement scheme was proposed.Methods:In this study,23 cases of TN caused by VBA compression and 20 cases of TN recurrence after MVD were included,accepted the treatment of microvascular decompression and neurolysis respectively.For the former,the surgery showed the fifth cranial nerve root entry area(REZ),and the large,curved vertebrobasilar artery,the offending vessel,that forced the nerve to move toward the tentorium.Teflon felt was laid between the brainstem and the offending artery,instead of the nerve and the artery,causing the artery to move toward the base of the skull and the ramp.Surgical outcomes were assessed using Barrow neuroinstitute(BIN)pain intensity scale score.The mean follow-up time at a length of 35 months.For the latter,surgery is performed through the original incision and limited neurolysis is recommended to reduce complications.BNI pain intensity score was still used to evaluate preoperative pain and postoperative results.The mean follow-up time at a length of 29.5 months.Results:These patients had preoperative BNI pain scores ranging from IV to V.After VBA compression,19 patients(83%)had no pain and did not need medication(BNI pain score :I).Local pain relief was achieved in 4 patients(BNI pain score: ii-iii),and 3 patients had complete relief within 3 months.The success rate is 96%.Follow-up: 3 patients(13%)experienced pain recurrence(BNI pain score :III,1 patient;IV,1 case;V,1 patient),1 patient received a second microvascular decompression.Mild trigeminal hypoesthesia was the most common complication in 8 patients,and 4 patients had permanent facial hypoesthesia.One patient gradually lost hearing and other temporary neurological disorders,including facial weakness,diplopia and some cerebellum symptoms,all of which disappeared within three to 10 weeks.Of the 20 patients with postoperative recurrence,18(90%)achieved good results(BNI pain score :I)and 2(10%)achieved good results(BNI pain score: ii-iii)during the follow-up of 12-61 months.Facial numbness was found in 5 patients(25%).Other complications included facial weakness(3 cases),hearing loss and tinnitus(1 case),temporary ataxia(1 case),infection(1 case),and postoperative bleeding.In the case of the second operation,2 cases were found to have missed venous diagnosis.Notably,teflon adhesion was found in all cases during the second operation,but no new responsible vessels or displacement of teflon was found.Conclusion:Microvascular decompression is applied to the treatment of vertebral basilar artery dilatation caused Trigeminal neuralgia,but its complications are more than trigeminal neuralgia caused by MVD treatment for arterioles because of the need for more extensive arachnoid separation.New materials with better histocompatibility and better integrated decompression methods should be developed to improve outcomes and reduce postoperative neurological dysfunction.For the recurrence after TN,Teflon adhesion has gradually become the main cause of recurrent TN.The majority of TN patients who suffer from recurrence after MVD achieved a good outcome through repeated neurolysis.The complications of MVD remain problematic,especially facial numbness,but some surgical techniques are helpful in reducing their rates.