Pembrolizumab plus chemotherapy for first-line treatment of advanced triple-negative breast cancer.

Aim: A systematic review and network meta-analysis (NMA) was performed to evaluate the efficacy of first-line treatments for locally recurrent unresectable or metastatic triple-negative breast cancer (TNBC) patients. Materials & methods: Databases were searched for randomized controlled trials evaluating first-line treatments for locally recurrent unresectable or metastatic TNBC patients. NMA was performed to estimate relative treatment effects on overall and progression-free survival between pembrolizumab + chemotherapy and other interventions. Results: NMA including eight trials showed that the relative efficacy of pembrolizumab + chemotherapy was statistically superior to that of other immunotherapy- or chemotherapy-based treatment regimens. Conclusion: Pembrolizumab + chemotherapy confers benefits in survival outcomes versus alternative interventions for the first-line treatment of locally recurrent unresectable or metastatic TNBC patients.

What is this article about? Around 15% of breast cancer patients have the triple-negative breast cancer (TNBC) subtype, which has the worst prognosis. Treatments targeting the immune system, such as pembrolizumab, were recently found to improve the outcomes of patients with cancer that is at an advanced stage or resistant to standard therapies. However, clinical trials evaluating the efficacy of cancer treatments typically compare only two alternative treatments. Therefore, we conducted this study to understand the relative efficacy of several commonly used initial treatments for advanced TNBC by indirectly comparing the results of all available clinical trials that were sufficiently similar. We identified trials by systematically searching the medical literature and analyzed the results of several clinical trials together to estimate the efficacy of pembrolizumab + chemotherapy compared with several other initial treatment regimens for patients with advanced TNBC. What were the results? We identified eight randomized controlled trials evaluating treatment regimens containing chemotherapeutic or immunotherapeutic agents in patients with previously untreated advanced TNBC. Considering all these trials together, pembrolizumab + chemotherapy was found to prolong patient survival to a greater extent than several other treatment regimens including carboplatin, docetaxel, paclitaxel, nab-paclitaxel/paclitaxel, bevacizumab + paclitaxel, ixabepilone + paclitaxel and ixabepilone + bevacizumab depending on the specific set of trials analyzed. What do the results of the study mean? These results indicate that pembrolizumab + chemotherapy has beneficial effects on patient survival compared with other initial treatment regimens for patients with advanced TNBC.

Clinical outcomes for previously treated patients with advanced biliary tract cancer: a meta-analysis.

Aim: A systematic review and meta-analysis were performed to evaluate the efficacy of treatments for previously treated advanced biliary tract cancer (BTC) patients. Materials & methods: Databases were searched for studies evaluating treatments for advanced (unresectable and/or metastatic) BTC patients who progressed on prior therapy. Pooled estimates of objective response rate (ORR), median overall survival (OS) and median progression-free survival (PFS) were calculated using random effects meta-analysis. Results: Across 31 studies evaluating chemotherapy or targeted treatment regimens in an unselected advanced BTC patient population, pooled ORR was 6.9%, median OS was 6.6 months and median PFS was 3.2 months. Conclusion: The efficacy of conventional treatments for previously treated advanced BTC patients is poor and could be improved by novel therapies.

What is this article about? Most patients with biliary tract cancer are identified with advanced disease, and almost all go through a worsening of the disease after their first treatment. For patients who go on to receive their next treatment, current guidelines are unclear regarding the best treatment choice. Therefore, we examined the available medical literature and performed an analysis of multiple studies to calculate overall estimates of the clinical value of standard treatments for these patients. Our goal was to develop a benchmark against which to compare the clinical value of new treatments that are currently being assessed in clinical trials. What were the results? We identified 31 studies assessing standard treatments (involving chemotherapy or molecularly targeted treatments) in previously treated advanced biliary tract cancer patients. Across these studies, the objective tumor response rate was 6.9%, median overall survival was 6.6 months and median progression-free survival was 3.2 months. What do the results of the study mean? These results indicate that there is limited clinical value of standard treatments for patients with advanced biliary tract cancer whose disease worsened after first treatment. This medical need could potentially be met by new treatments, such as immunotherapies that restore the immune system's ability to attack cancer cells and thereby prolong patient survival.

Clinical Outcomes of PD-1/PD-L1 Inhibitors Among Patients With Advanced or Metastatic Non-Small Cell Lung Cancer With BRAF, ERBB2/HER2, MET , or RET Alterations: A Systematic Literature Review.

The therapeutic landscape for patients with advanced or metastatic non-small cell lung cancer (NSCLC) is rapidly evolving due to advances in molecular testing and the development of new targeted therapies and immunotherapies. However, the efficacy of programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors in advanced or metastatic patients with NSCLC whose tumors harbor BRAF V600E mutation, HER2/ERBB2 alteration, MET exon 14 skipping mutation, or RET rearrangement is not completely understood. A systematic literature review was performed to summarize evidence from clinical trials and observational studies on objective response rate, progression-free survival, and overall survival in patients whose tumors express these biomarkers and who were treated with PD-1/PD-L1 inhibitors. Searches of Embase, MEDLINE, conference abstracts, and a clinical trial registry identified a total of 12 unique studies: 4 studies included patients with BRAF V600E mutation, 6 studies included patients with HER2/ERBB2 alteration, 7 studies included patients with MET exon 14 skipping mutation, and 5 studies included patients with RET rearrangement. Across studies, there was heterogeneity in treatment and patient characteristics and a lack of reporting on many important predictive and prognostic factors, including treatment regimens, patients' line of therapy, and tumor PD-L1 expression, which may explain the wide variation in objective response rate, progression-free survival, and overall survival across studies. Therefore, additional studies prospectively evaluating clinical outcomes of PD-1/PD-L1 inhibitors among patients with advanced or metastatic NSCLC whose tumors harbor emerging predictive or prognostic biomarkers are needed to determine whether this class of immunotherapy can provide additional survival benefits for these patients.

Neoadjuvant immunotherapy and chemotherapy regimens for the treatment of high-risk, early-stage triple-negative breast cancer: a systematic review and network meta-analysis.

BACKGROUND: Patients with triple-negative breast cancer (TNBC) are generally younger and more likely to experience disease recurrence and have the shortest survival among all breast cancer patients. Recently, neoadjuvant delivery of the programmed cell death protein-1 inhibitor pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab was approved for patients with high-risk, early-stage TNBC, but this treatment regimen has not been evaluated in head-to-head trials with other neoadjuvant treatment regimens. Therefore, the objective of this study was to estimate the relative efficacy of neoadjuvant pembrolizumab + chemotherapy followed by adjuvant pembrolizumab versus other neoadjuvant treatments for early-stage TNBC through a systematic review and network meta-analysis (NMA). METHODS: EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials, conference abstracts, and clinical trial registries were searched for randomized controlled trials evaluating neoadjuvant treatments for early-stage TNBC. NMA was performed to estimate relative treatment effects among evaluated interventions. RESULTS: Five trials met the inclusion criteria and were included in the NMA. The relative efficacy of neoadjuvant pembrolizumab + chemotherapy followed by adjuvant pembrolizumab was favorable to paclitaxel followed by anthracycline + cyclophosphamide in terms of pathologic complete response (pCR), event-free survival (EFS), and overall survival; paclitaxel + carboplatin followed by anthracycline + cyclophosphamide in terms of pCR and EFS; paclitaxel + bevacizumab followed by anthracycline + cyclophosphamide + bevacizumab in terms of pCR; and paclitaxel + carboplatin + veliparib followed by anthracycline + cyclophosphamide in terms of EFS. CONCLUSIONS: Neoadjuvant pembrolizumab + chemotherapy followed by adjuvant pembrolizumab confers benefits in response and survival outcomes versus alternative neoadjuvant treatments for early-stage TNBC.

Clinical Outcomes for Previously Treated Patients with Advanced Gastric or Gastroesophageal Junction Cancer: A Systematic Literature Review and Meta-Analysis.

PURPOSE: Although second-line treatments improve survival compared to best supportive care in patients with advanced gastric cancer with disease progression on first-line therapy, prognosis remains poor. A systematic review and meta-analysis were conducted to quantify the efficacy of second-or-later line systemic therapies in this target population. METHODS: A systematic literature review (January 1, 2000 to July 6, 2021) of Embase, MEDLINE, and CENTRAL with additional searches of 2019-2021 annual ASCO and ESMO conferences was conducted to identify studies in the target population. A random-effects meta-analysis was performed among studies involving chemotherapies and targeted therapies relevant in treatment guidelines and HTA activities. Outcomes of interest were objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) presented as Kaplan-Meier data. Randomized controlled trials reporting any of the outcomes of interest were included. For OS and PFS, individual patient-level data were reconstructed from published Kaplan-Meier curves. RESULTS: Forty-four trials were eligible for the analysis. Pooled ORR (42 trials; 77 treatment arms; 7256 participants) was 15.0% (95% confidence interval (CI) 12.7-17.5%). Median OS from the pooled analysis (34 trials; 64 treatment arms; 60,350 person-months) was 7.9 months (95% CI 7.4-8.5). Median PFS from the pooled analysis (32 trials; 61 treatment arms; 28,860 person-months) was 3.5 months (95% CI 3.2-3.7). CONCLUSION: Our study confirms poor prognosis among patients with advanced gastric cancer, following disease progression on first-line therapy. Despite the approved, recommended, and experimental systemic treatments available, there is still an unmet need for novel interventions for this indication.

Efficacy and safety of treatments for advanced thymic carcinoma after failure of first-line platinum-based chemotherapy: A systematic literature review and meta-analysis.

Thymic carcinoma (TC) is a rare cancer and patients failing initial chemotherapy (relapse/refractory) face limited therapeutic options given no approved options or consensus standard of care. This study aimed to identify and summarize clinical outcomes of all regimens evaluated in clinical trials of relapsed or refractory patients. Interventional trials enrolling advanced TC patients who failed first-line chemotherapy and reported outcomes in this group were eligible for inclusion in our systemic literature review (SLR). Between-study heterogeneity was assessed to determine the feasibility of pooling specific studies and treatments. Objective response rate (ORR), overall survival (OS), progression-free survival (PFS), and duration of response (DOR) endpoints were of interest for meta-analysis. Nineteen trials were identified in the SLR. Three trials with one or two TC patients were removed from our assessment to reduce publication bias. Response rates among studies with at least ten TC patients varied from 9 % to 38 %. Pooled ORRs in patients receiving S-1 (46 patients), sunitinib (46 patients), or pembrolizumab (66 patients) were 28 %, 24 %, and 21 %, respectively. Prolonged duration of response with pembrolizumab was observed with a pooled median of 23.8 months (95 % confidence interval [CI]: 12, not reached). Median PFS of five months or greater was reported in patients treated with sunitinib, lenvatinib, pembrolizumab, capecitabine + gemcitabine, everolimus, or S-1. Median OS of 20 months or greater was reported in trials evaluating S-1 or pembrolizumab; this endpoint was not reached in trials evaluating lenvatinib, regorafenib, or sunitinib. Generalizability of treatment effects is challenging in the research of rare diseases and meta-analysis of clinical outcomes may help to increase precision and relevance of results to the larger TC population. Our study found limited treatment options upon relapse, demonstrating a need for further investigations into novel therapeutics and well-powered clinical trials to better inform on optimal treatments.

Clinical outcomes of chemotherapy-based therapies for previously treated advanced colorectal cancer: a systematic literature review and meta-analysis.

PURPOSE: The purpose of this study was to evaluate clinical outcomes of standard therapies in previously treated, advanced colorectal cancer (CRC) patients. METHODS: A systematic literature review was conducted in Embase, MEDLINE, and CENTRAL databases (January 2000-July 2021), annual oncology conferences (2019-2021), and clinicaltrials.gov to identify studies evaluating the use of licensed interventions in second-line or later settings. The primary outcome of interest was objective response rate (ORR) and secondary outcomes included progression-free survival (PFS) and overall survival (OS). ORR was pooled using the Freeman-Tukey double arcsine transformation. For survival outcomes, published Kaplan-Meier curves for OS and PFS were digitized to re-construct individual patient-level data and pooled following the methodology described by Combescure et al. (2014). RESULTS: Twenty-three trials evaluating standard chemotherapies with or without targeted therapies across 4,791 advanced CRC patients contributed to our meta-analysis. In the second-line setting, the random effects pooled estimate of ORR was 22.4% (95% confidence interval (CI): 18.0, 27.1), median PFS was 7.0 months (95% CI: 6.4, 7.4), and median OS was 14.9 months (95% CI: 13.6, 16.1). In the third-line or later setting, the random effects pooled estimate of ORR was 1.7% (95% CI: 0.8, 2.7), median PFS was 2.3 months (95% CI: 2.0, 2.8), and median OS was 8.2 months (95% CI: 7.1, 9.1). CONCLUSION: Standard treatments have limited efficacy in the second-line or later setting with worsening outcomes in later lines. Given the global burden of CRC, further research into novel and emerging therapeutic options following treatment failure is needed.

Pembrolizumab plus chemotherapy for first-line treatment of metastatic nonsquamous non-small-cell lung cancer: a network meta-analysis.

AIM: A systematic review and network meta-analysis were conducted to evaluate the efficacy of pembrolizumab + pemetrexed + platinum relative to other regimens in metastatic nonsquamous non-small-cell lung cancer (NSq-NSCLC). PATIENTS & METHODS: Eligible studies evaluated first-line regimens in NSq-NSCLC patients without known targetable mutations. Relative treatment effects were synthesized with random effects proportional hazards Bayesian network meta-analyses. RESULTS: The hazard ratio (HR) for overall survival (OS) for pembrolizumab + pemetrexed + platinum was statistically significant over all platinum-doublet (HR range: 0.42-0.61), platinum-doublet + bevacizumab (HR range: 0.44-0.53) and platinum-doublet + atezolizumab regimens (HR range: 0.56-0.62). Additionally, pembrolizumab + pemetrexed + platinum numerically improved OS over atezolizumab + paclitaxel + carboplatin + bevacizumab (HR: 0.65; 95% credible interval: 0.43, 1.01). Pembrolizumab + pemetrexed + platinum had 95.6% probability of being the best treatment regimen for OS. CONCLUSION: Pembrolizumab + pemetrexed + platinum is likely the most efficacious first-line regimen for metastatic NSq-NSCLC.

An investigation into quality of life improvement in patients undergoing microvascular decompression for hemifacial spasm.

OBJECTIVE Hemifacial spasm (HFS) is a movement disorder characterized by involuntary spasms of the facial muscles, and it can negatively impact quality of life (QOL). This retrospective study and systematic review with meta-analysis was conducted to investigate the QOL in patients with HFS following intervention with microvascular decompression (MVD) and botulinum toxin (BT). METHODS In the retrospective analysis, a QOL questionnaire was administered to all patients undergoing MVD performed by a single surgeon. The QOL questionnaire included unique questions developed based on the authors' experience with HFS patients in addition to the health-related QOL HFS-8 questionnaire. The authors also report on a systematic review of the English literature providing outcomes and complications in patients with HFS undergoing treatment with either MVD or BT. RESULTS Regarding the retrospective analysis, 242 of 331 patients completed the questionnaire. The mean score of the 10 QOL questions improved from 22.78 (SD 9.83) to 2.17 (SD 5.75) following MVD (p < 0.001). There was significant improvement across all subscales of the questionnaire between pre- and postoperative responses (p < 0.001). Regarding the systematic review, it is reported that approximately 90% of patients undergoing MVD for HFS experience a complete recovery from symptoms, whereas the mean peak improvement of symptoms following treatment with BT is 77%. Furthermore, patients undergoing MVD reported a greater improvement in the mean supplemental index of QOL as compared with patients receiving BT therapy. CONCLUSIONS Microvascular decompression offers a significant improvement in QOL in well-selected patients suffering from HFS, and may offer an increased benefit for QOL over BT injections.

MRI of the Trigeminal Nerve in Patients With Trigeminal Neuralgia Secondary to Vascular Compression.

OBJECTIVE: Trigeminal neuralgia is a debilitating facial pain disorder, frequently caused by vascular compression of the trigeminal nerve. Vascular compression that results in trigeminal neuralgia occurs along the cisternal segment of the nerve. CONCLUSION: Imaging combined with clinical information is critical to correctly identify patients who are candidates for microvascular decompression. The purpose of this article is to review trigeminal nerve anatomy and to provide strategies for radiologists to recognize important MRI findings in patients with trigeminal neuralgia.

A Blinded, Case-Control Trial Assessing the Value of Steady State Free Precession Magnetic Resonance Imaging in the Diagnosis of Trigeminal Neuralgia.

OBJECTIVE: High-resolution magnetic resonance imaging (MRI) may be a useful and readily available adjunct in identifying trigeminal neuralgia secondary to vascular contact (TNVC). This study evaluated the reliability and predictive ability of 1.5-tesla steady state free precession (SSFP) MRI sequences for the diagnosis of symptomatic vascular contact and response to operative intervention in patients with TNVC. METHODS: We performed a blinded, case-matched control trial evaluating SSFP MRI sequences in consecutive patients with unilateral TNVC with operatively proven vascular contact of the trigeminal nerve compared with healthy control subjects matched on age, sex, and laterality of the pathologic neurovascular complex. Interrater reliability was compared between 2 blinded, expert reviewers. Predictive ability of MRI was assessed in regard to accuracy, discrimination, and clinical utility. RESULTS: Inclusion criteria were met by 44 patients (22 consecutive patients with TNVC and 22 matched control subjects). Interrater reliability ranged from fair to excellent for vessel contact (κ = 0.40), location (κ = 0.81), type (κ = 0.72), and multiplicity (κ = 0.31). Vascular contact on MRI sequences did not differ significantly between cases and controls (75% vs. 82%, P = 0.30). MRI demonstrates accurate (Brier 0.15) and good discriminatory ability for clinical response after microvascular decompression (area under the receiver operating characteristic curve 0.81, 95% confidence interval = 0.6-1.0). Decision-curve analysis demonstrated that MRI could result in a net reduction of 5 cases likely to be unsuccessful per 100 patients treated. CONCLUSIONS: These results suggest the utility of SSFP MRI lies not in the diagnosis of TNVC, but rather in stratifying the likelihood of response to microvascular decompression in patients with characteristic symptoms.

Reduction in high-frequency hearing loss following technical modifications to microvascular decompression for hemifacial spasm.

OBJECT: Microvascular decompression is a safe and effective procedure to treat hemifacial spasm, but the operation poses some risk to the patient's hearing. While severe sensorineural hearing loss across all frequencies occurs at a low rate in experienced hands, a recent study suggests that as many as one-half of patients who undergo this procedure may experience ipsilateral high-frequency hearing loss (HFHL), and as many as one-quarter may experience contralateral HFHL. While it has been suggested that drill-related noise may account for this finding, this study was designed to examine the effect of a number of techniques designed to protect the vestibulocochlear nerve from operative manipulation on the incidence of HFHL. METHODS: Pure-tone audiometry was performed both preoperatively and postoperatively on 67 patients who underwent microvascular decompression for hemifacial spasm during the study period. A change of greater than 10 dB at either 4 kHz or 8 kHz was considered to be HFHL. Additionally, the authors analyzed intraoperative brainstem auditory evoked potentials from this patient cohort. RESULTS: The incidence of ipsilateral HFHL in this cohort was 7.4%, while the incidence of contralateral HFHL was 4.5%. One patient (1.5%; also included in the HFHL group) experienced an ipsilateral nonserviceable hearing loss. CONCLUSIONS: The reduced incidence of HFHL in this study suggests that technical modifications including performing the procedure without the use of fixed retraction may greatly reduce, but not eliminate, the occurrence of HFHL following microvascular decompression for hemifacial spasm.

Hemifacial spasm caused by an aberrant jugular branch of the ascending pharyngeal artery.

We present the first report of a case of hemifacial spasm caused by an anomalous, enlarged branch of the ascending pharyngeal artery and treated with microvascular decompression. Clinicians must appreciate unusual causes of hemifacial spasm so that patients are not denied a curative operation due to atypical radiographic findings.

Thin-slice T2 MRI imaging predicts vascular pathology in hemifacial spasm: a case-control study.

Hemifacial spasm (HFS) is a condition that may severely reduce patients' quality of life. We sought to determine the sensitivity and specificity of thin-slice T2 magnetic resonance imaging (MRI) for detecting vascular compression in HFS patients. Prospective information was collected on 28 patients with HFS who presented to our center between March 2011 and March 2012 with thin-slice T2 MR imaging. The sensitivity and specificity for differentiating patients from controls were calculated. Sensitivities were 78.6% and 92.9% for the blinded radiologists and 75% for the partially blinded neurosurgeon. Specificities were 42.9% and 28.6% for the blinded radiologists and 75% for the partially blinded neurosurgeon. Magnetic resonance imaging of the facial nerve can guide clinicians in selecting patients who are good surgical candidates. Thin-slice T2 MRI should be viewed as supportive rather than diagnostic.

Microvascular decompression for hemifacial spasm in patients >65 years of age: an analysis of outcomes and complications.

INTRODUCTION: Few data are available to quantify the risks and benefits of microvascular decompression (MVD) in elderly patients with hemifacial spasm. METHODS: Twenty-seven patients >65 years of age and 104 younger patients who underwent MVD for hemifacial spasm (HFS) over a 3-year period were analyzed retrospectively and compared. RESULTS: Twenty-six (96.3%) elderly patients and 93 of 104 (89.4%) young patients reported a spasm-free status at a mean follow-up of 26.5 months after MVD. No significant difference in spasm-free status was noted. Cranial nerve complications and other major complications were compared, with no significant differences observed. CONCLUSIONS: Although this study does not offer definitive inclusion or exclusion criteria or clearly establish the safety of MVD for HFS in the elderly, our experience suggests that many elderly patients with HFS can undergo MVD safely, with outcomes and risk profiles similar to those of younger patients.

The utility of calcium phosphate cement in cranioplasty following retromastoid craniectomy for cranial neuralgias.

BACKGROUND: Following retromastoid craniectomy for microvascular decompression of the fifth or seventh cranial nerve, the preferred method and value of cranioplasty remains disputed. METHODS: In this study, we report the functional outcome of calcium phosphate cranioplasty following first-time microvascular decompression in 79 consecutive patients who underwent operations over a one-year period. RESULTS: No patient experienced a deep infection, cerebrospinal fluid leak or undue incisional pain at long-term follow-up. Additionally, all patients stated that they were satisfied with the cosmetic outcome. DISCUSSION: Although this technique is unlikely to affect the rates of infection and postoperative pain, we believe that the low rate of CSF leak provides a unique advantage over other currently used methods of closing retromastoid craniectomies.

Microvascular decompression for elderly patients with trigeminal neuralgia: a prospective study and systematic review with meta-analysis.

OBJECT: Because the incidence of trigeminal neuralgia (TN) increases with age, neurosurgeons frequently encounter elderly patients with this disorder. Although microvascular decompression (MVD) is the only etiological therapy for TN with the highest initial efficacy and durability of all treatments, it is nonetheless associated with special risks (cerebellar hematoma, cranial nerve injury, stroke, and death) not seen with the commonly performed ablative procedures. Thus, the safety of MVD in the elderly remains a concern. This prospective study and systematic review with meta-analysis was conducted to determine whether MVD is a safe and effective treatment in elderly patients with TN. METHODS: In this prospectively conducted analysis, 36 elderly patients (mean age 73.0 ± 5.9 years) and 53 nonelderly patients (mean age 52.9 ± 8.8 years) underwent MVD over the study period. Outcome and complication data were recorded. The authors also conducted a systematic review of the English literature published before December 2009 and providing outcomes and complications of MVD in patients with TN above the age of 60 years. Pooled complication rates of stroke, death, cerebellar hematoma, and permanent cranial nerve deficits were analyzed. RESULTS: Thirty-one elderly patients (86.1%) reported an excellent outcome after MVD (mean follow-up 20.0 ± 7.0 months). Twenty-five elderly patients with Type 1 TN were compared with 26 nonelderly patients with Type 1 TN, and no significant difference in outcomes was found (p = 0.046). Three elderly patients with Type 2a TN were compared with 12 nonelderly patients with Type 2a TN, and no significant difference in outcomes was noted (p = 1.0). Eight elderly patients with Type 2b TN were compared with 15 nonelderly patients with Type 2b TN, and no significant difference in outcomes was noted (p = 0.086). The median length of stay between cohorts was compared, and no significant difference was noted (2 days for each cohort, p = 0.33). There were no CSF leaks, no cerebellar hematomas, no strokes, and no deaths. Eight studies (1334 patients) met the inclusion criteria for the meta-analysis. For none of the complications was the incidence significantly more frequent in elderly patients than in the nonelderly. CONCLUSIONS: Although patient selection remains important, the authors' experience and the results of this systematic review with meta-analysis suggest that the majority of elderly patients with TN can safely undergo MVD.

Microvascular decompression after failed Gamma Knife surgery for trigeminal neuralgia: a safe and effective rescue therapy?

OBJECT: Stereotactic radiosurgical rhizolysis using Gamma Knife surgery (GKS) is an increasingly popular treatment for medically refractory trigeminal neuralgia. Because of the increasing use of GKS for trigeminal neuralgia, clinicians are faced with the problem of choosing a subsequent treatment plan if GKS fails. This study was conducted to identify whether microvascular decompression (MVD) is a safe and effective treatment for patients who experience trigeminal neuralgia symptoms after GKS. METHODS: From their records, the authors identified 29 consecutive patients who, over a 2-year period, underwent MVD following failed GKS. During MVD, data regarding thickened arachnoid, adhesions between vessels and the trigeminal nerve, and trigeminal nerve atrophy/discoloration were noted. Outcome and complication data were also recorded. RESULTS: The MVD procedure was completed in 28 patients (97%). Trigeminal nerve atrophy was noted in 14 patients (48%). A thickened arachnoid was noted in 1 patient (3%). Adhesions between vessels and the trigeminal nerve were noted in 6 patients (21%) and prevented MVD in 1 patient. At last follow-up, 15 patients (54%) reported an excellent outcome after MVD, 1 (4%) reported a good outcome, 2 (7%) reported a fair outcome, and 10 patients (36%) reported a poor outcome. After MVD, new or worsened facial numbness occurred in 6 patients (21%). Additionally, 3 patients (11%) developed new or worsened troubling dysesthesias. CONCLUSIONS: Thickened arachnoid, adhesions between vessels and the trigeminal nerve, and trigeminal nerve atrophy/discoloration due to GKS did not prevent completion of MVD. An MVD is an appropriate and safe "rescue" therapy following GKS, although the risks of numbness and troubling dysesthesias appear to be higher than with MVD alone.

Microvascular decompression in patients with isolated maxillary division trigeminal neuralgia, with particular attention to venous pathology.

OBJECT: The authors have the clinical impression that patients with isolated V2, or maxillary division, trigeminal neuralgia (TN) are most often women of a younger age with atypical pain features and a predominance of venous compression as the pathology. The aim of this study was to evaluate a specific subgroup of patients with V2 TN. METHODS: Among 120 patients who underwent microvascular decompression (MVD) for TN in 2007, data were available for 114; 6 patients were lost to follow-up. Patients were stratified according to typical (Burchiel Type 1), mixed (Burchiel Type 2a), or atypical (Burchiel Type 2b) TN. A pain-free status without medication was used to determine the efficacy of MVD. All patients were contacted in June 2008 and again in January 2009 at 12-24 months after surgery (median 18.4 months) and asked to rate their response to MVD as excellent (complete pain relief without medication), fair (complete pain relief with medication or some relief with or without medication), or poor (continued pain despite medication; that is, no change from their preoperative baseline pain status. RESULTS: Of 114 patients, 14 (12%) had isolated V2 TN. Among these 14 were 2 typical (14%), 1 mixed (7%), and 11 atypical cases (79%) of TN. Among the remaining 100 cases were 37 typical (37%), 14 mixed (14%), and 49 atypical cases (49%) of TN. In the isolated V2 TN group, all patients were women as compared with 72% of women in the larger group of 100 patients (p = 0.05, chi-square test). The average age in the isolated V2 TN group was 51.2 years (median 48.1 years) versus 54.2 years (median 54.0 years) in the remainder of the group (p = NS, unpaired Student t-test). In the isolated V2 TN group, there was a predominance of atypical pain cases (79%) versus 49% in the remainder of the group, and this finding trended toward statistical significance (p = 0.07, chi-square test). Venous contact or compression (partly or wholly) was noted in 93% of the patients with isolated V2 versus 69% of the remainder of the group (p = 0.13, chi-square test). The likelihood of excellent outcomes in the patients with V2 TN (71%) was compared with that in typical pain cases (79%) among patients in the rest of the group (that is, the bestoutcome group), and no difference was found between the 2 groups (p = 0.8, chi-square test). CONCLUSIONS: The authors confirmed that patients with isolated V2 TN were more likely to be female, tended toward an atypical pain classification with venous pathology at surgery, and fared just as well as those presenting with typical pain.

Utility of intraoperative electromyography in microvascular decompression for hemifacial spasm: a meta-analysis.

OBJECT: In this paper, the authors' goal was to determine the utility of monitoring the abnormal muscle response (AMR) or "lateral spread" during microvascular decompression surgery for hemifacial spasm. METHODS: The authors' experience with AMR as well as the data available in the English-language literature regarding resolution or persistence of AMR and the resolution or persistence of hemifacial spasm at follow-up was pooled and subjected to a meta-analysis. RESULTS: The pooled OR revealed by the meta-analysis was 4.2 (95% CI 2.7-6.7). The chance of a cure if the AMR was abolished during surgery was 4.2 times greater than if the lateral spread persisted. CONCLUSIONS: The AMR should be monitored routinely in the operating room, and surgical decision-making in the operating room should be augmented by the AMR.