Value of Partial Sensory Rhizotomy in the Microsurgical Treatment of Trigeminal Neuralgia Through Retrosigmoid Approach

Partial sensory rhizotomy in recurrent trigeminal neuralgia. Our experience and literature review

BACKGROUND AND OBJECTIVE

Trigeminal Neuralgia (NT) is a common pathology in Neurosurgery. It can be classified as idiopathic or secondary to other pathologies, such as Multiple Sclerosis (MS). Several surgical treatments have been described, some of them being replaced by more modern techniques. Partial sensory rhizotomy (PSR), described by Dandy is a technique replaced by other techniques due to its permanent side effects. We present our experience with this technique in patients with recurrent NT.

METHODS AND MATERIALS

A retrospective review is carried out on five patients who underwent surgery at our center from 2018 to 2023 using the PSR technique.

RESULTS

All the patients intervened showed significant clinical improvement, except one patient who required reintervention due to uncontrolled pain. According to the Barrow Neurological Institute (BNI) scale, 80% (4/5) of patients showed improvement from grade V to grades I/II except for one of them. This patient suffered from MS. Additionally, one patient presented a corneal ulcer after surgery due to impairment of the corneal reflex.

CONCLUSION

In our experience, PSR is a valid treatment option in selected patients with recurrent TN. It has a low incidence of complications with an adequate surgical technique and anatomical knowledge of the region. To the best of our knowledge, we are one of the few centers in Spain to publish our results with PSR in the last ten years. We report good results in pain control withdrawing medication in 80% (4/5) of the operated patients.

A systematic review on the efficacy of adjunctive surgical strategies during microvascular decompression for trigeminal neuralgia without intraoperative evidence of neurovascular conflict

Aim of the present study was to conduct a comprehensive review of surgical strategies that can be offered to patients with trigeminal neuralgia undergoing microvascular decompression (MVD) surgery and without intraoperative evidence of neurovascular conflict, with a high pre-operative suspicion of conflict lacking intraoperative confirmation, or individuals experiencing recurrence after previous treatment. This systematic review followed established guidelines (PRISMA) to identify and critically appraise relevant studies. The review question was formulated according to the PICO (P: patients; I: intervention; C: comparison; O: outcomes) framework as follows. For patients with trigeminal neuralgia (P) undergoing MVD surgery (I) without demonstrable preoperative neurovascular conflict, high suspicion of conflict but no intraoperative confirmation or recurrence after previous treatment (C), do additional surgical techniques (nerve combing, neurapraxia, arachnoid lysis) (O) improve pain relief outcomes (O)? The search of the literature yielded a total of 221 results. Duplicate records were then removed (n = [76]). A total of 143 papers was screened, and 117 records were excluded via title and abstract screening; 26 studies were found to be relevant to our research question and were assessed for eligibility. Upon full-text review, 17 articles were included in the review, describing the following techniques; (1) internal neurolysis (n = 6) (2) arachnoid lysis/adhesiolysis (n = 2) (3) neurapraxia (n = 3) (4) partial rhizotomy of the sensory root (n = 4) (5) pontine descending tractotomy (n = 2). The risk of bias was assessed using the ROBINS-I (Risk of Bias in Non-randomized Studies - of Interventions) assessment tool. While the described techniques hold promise, further research is warranted to establish standardized protocols, refine surgical approaches, and comprehensively evaluate long-term outcomes.

Efficacy and safety of microvascular decompression with or without partial sensory rhizotomy: a comprehensive meta-analysis and systematic review in treating trigeminal neuralgia

Classical trigeminal neuralgia (TN), caused by vascular compression of the nerve root, is a severe cause of pain with a considerable impact on a patient's quality of life. While microvascular decompression (MVD) has lower recurrence rates when compared with partial sensory rhizotomy (PSR) alone, refractoriness can still be as high as 47%. We aimed to assess the efficacy and safety profile of MVD + PSR when compared to standalone MVD for TN. We searched Medline, Embase, and Web of Science following PRISMA guidelines. Eligible studies included those with ≥ 4 patients, in English, published between January 1980 and December 2023, comparing MVD vs. MVD + PSR for TN. Endpoints were pain cure, immediate post-operative pain improvement, long-term effectiveness, long-term recurrence, and complications (facial numbness, hearing loss, and intracranial bleeding). We pooled odds ratios (OR) with 95% confidence intervals with a random-effects model. I2 was used to assess heterogeneity, and sensitivity and Baujat analysis were conducted to address high heterogeneity. Eight studies were included, comprising a total of 1,338 patients, of whom 1,011 were treated with MVD and 327 with MVD + PSR. Pain cure analysis revealed a lower likelihood of pain cure in patients treated with MVD when compared to patients treated with MVD + PSR (OR = 0.30, 95% CI: 0.13 to 0.72). Immediate postoperative pain improvement assessment revealed a lower likelihood of improvement in the MVD group when compared with the MVD + PSR group (OR = 0.31, 95% CI: 0.10 to 0.95). Facial numbness assessment revealed a lower likelihood of occurrence in MVD alone when compared to MVD + PSR (OR = 0.08, 95% CI: 0.04 to 0.15). Long-term effectiveness, long-term recurrence, hearing loss, and intracranial bleeding analyses revealed no difference between both approaches. Our meta-analysis identified that MVD + PSR was superior to MVD for pain cure and immediate postoperative pain improvement for treating TN. However, MVD + PSR demonstrated a higher likelihood of facial numbness complications. Furthermore, identified that hearing loss and intracranial bleeding complications appear comparable between the two treatments, and no difference between long-term effectiveness and recurrence.

Internal neurolysis versus intraoperative glycerin rhizotomy for trigeminal neuralgia

OBJECTIVE

Internal neurolysis (IN) and intraoperative glycerin rhizotomy (ioGR) are emerging surgical options for patients with trigeminal neuralgia without neurovascular contact. The objective of this study was to compare the neurological outcomes of patients who underwent IN with those of patients who underwent ioGR.

METHODS

The authors retrospectively reviewed all patients who underwent IN or ioGR for trigeminal neuralgia at our institution. Patient demographic characteristics and immediate postoperative outcomes, as well as long-term neurological outcomes, were compared.

RESULTS

Of 1044 patients who underwent open surgical treatment for trigeminal neuralgia, 56 patients underwent IN and 91 underwent ioGR. Of these 147 patients, 37 had no evidence of intraoperative neurovascular conflict. All patients who underwent IN and 96.7% of patients who underwent ioGR had immediate postoperative pain relief. At last follow-up, patients who underwent IN had lower Barrow Neurological Institute (BNI) pain intensity scores (p = 0.05), better BNI facial numbness scores (p < 0.01), and a greater degree of pain improvement (p = 0.05) compared with those who underwent ioGR. Patients who underwent IN also had significantly lower rates of symptomatic pain recurrence (p < 0.01) at last follow-up over an average of 9.5 months.

CONCLUSIONS

IN appears to provide patients with a greater degree of pain relief, lower rates of facial numbness, and lower rates of pain recurrence compared with ioGR. Future prospective studies will better characterize long-term pain recurrence and outcomes.

Trigeminal Neuralgia: Current Approaches and Emerging Interventions

Trigeminal neuralgia (TN) has been described in the literature as one of the most debilitating presentations of orofacial pain. This review summarizes over 150 years of collective clinical experience in the medical and surgical treatment of TN. Fundamentally, TN remains a clinical diagnosis that must be distinguished from other types of trigeminal neuropathic pain and/or facial pain associated with other neuralgias or headache syndromes. What is increasingly clear is that there is no catch-all medical or surgical intervention that is effective for all patients with trigeminal neuralgia, likely reflective of the fact that TN is likely a heterogenous group of disorders that jointly manifests in facial pain. The first-line treatment for TN remains anticonvulsant medical therapy. Patients who fail this have a range of surgical options available to them. In general, microvascular decompression is a safe and effective procedure with immediate and durable outcomes. Patients who are unable to tolerate general anesthesia or whose medical comorbidities preclude a suboccipital craniectomy may benefit from percutaneous methodologies including glycerol or radiofrequency ablation, or both. For patients with bleeding diathesis due to blood thinning medications who are ineligible for invasive procedures, or for those who are unwilling to undergo open surgical procedures, radiosurgery may be an excellent option-provided the patient understands that maximum pain relief will take on the order of months to achieve. Finally, peripheral neurectomies continue to provide an inexpensive and resource-sparing alternative to pain relief for patients in locations with limited economic and medical resources. Ultimately, elucidation of the molecular mechanisms underlying trigeminal neuralgia will pave the way for novel, more effective and less invasive therapies.