Elsevier

World Neurosurgery

Volume 81, Issues 3–4, March–April 2014, Pages 603-608
World Neurosurgery

Peer-Review Report
Endoscopic Vascular Decompression for the Treatment of Trigeminal Neuralgia: Clinical Outcomes and Technical Note

https://doi.org/10.1016/j.wneu.2013.10.036Get rights and content

Objective

This study sought to describe the operative technique and clinical outcomes in a series of 57 patients with trigeminal neuralgia treated with endoscopic vascular decompression (EVD) alone without the use of microscopy at any point.

Methods

A prospective observational study was performed on 57 consecutive patients treated with EVD alone for trigeminal neuralgia from October 2005 to October 2010. Patient outcomes were evaluated with respect to pain abatement, complication rate, length of hospital stay, and overall operative time. Pain outcome was graded using the Barrow Neurological Institute pain intensity score (BNI), with BNI 1 considered an excellent result and BNI 2 or 3 considered a good result. Follow-up ranged from 12 to 72 months, with a mean of 32 months. In addition to reporting these cases, our operative technique for EVD is described in detail.

Results

All 57 patients reported severe preoperative pain (BNI 5); 100% of patients achieved immediate postoperative pain control or complete pain relief (BNI 1 to 3), with 82% obtaining an excellent result of BNI 1, and 18% of patients reported good results of BNI 2 or 3. At follow-up, 56 of 57 patients (98%) reported complete relief or well controlled pain (BNI 1 to 3), with 75% obtaining an excellent result of BNI 1; 23% of patients obtained a good result of BNI 2 or 3. The complication rate was 4%, with no mortality. Mean length of hospital stay was 1.6 days, with a range of 1 to 5 days; mean operative time was 133 minutes.

Conclusions

EVD is a safe and highly effective alternative to the more traditional open microvascular decompression or the more recently developed endoscopically assisted microvascular decompression.

Introduction

Microvascular decompression (MVD) is an accepted and successful treatment modality for medication-resistant trigeminal neuralgia (TGN). Various vascular structures can compress the trigeminal nerve, most commonly at the dorsal root entry zone (DREZ), causing the onset of symptomatology. MVD to separate the trigeminal nerve from the offending vessel has remained a successful surgical treatment modality for TGN 2, 4, 11. Accurate localization of the area of compression is essential to maximize the rate of success for the decompression (4).

Endoscopy has provided the next step in the evolution of the vascular decompression surgical technique. In recent years, the endoscopically assisted MVD (EAMVD) has been shown to be highly successful and has gained popularity 13, 17. This modification of the original procedure involves the traditional craniotomy followed by endoscopic exploration of the localized anatomy. Endoscopy allows for greater detailed visualization of cerebellopontine angle (CPA) vasculature and structures than microscopy alone 12, 14. Several studies have found that endoscopy can accurately find the site of compression in TGN even when missed with microscopy 3, 5, 6, 7, 8. Once the area of neurovascular compromise is identified, the decompression is performed under microscopy. At this point the endoscope can be reintroduced because it allows superior visualization of the area ventral to the DREZ as compared to microscopy 8, 15.

The EAMVD has further evolved with the introduction of endoscopic vascular decompression (EVD). This procedure is performed using endoscopy alone, without the use of microscopy at any point in the procedure. Benefits of EVD include smaller craniotomy, less soft tissue dissection, and less cerebellar retraction, while maintaining optimal visualization of the neurovascular structures in the CPA. In addition, faster patient recovery is observed. The number of reports on this subject are limited; however, those published to date show that EVD is safe and highly effective 1, 8, 9, 10, 18. The purpose of this study was to report the results of the EVD procedure as performed at our institution.

Section snippets

Materials and Methods

A prospective observational study was performed of all 57 patients who underwent EVD at our institution over a 5-year period, October 2005 to October 2010. Institutional review board approval was obtained for this study. All patients had preoperative Barrow Neurological Institute pain intensity score (BNI) scores of 5, had failed medical management, and had undergone preoperative magnetic resonance imaging to rule out CPA mass, aneurysm, etc. The mean age at the time of surgery was 58.3 years,

Instrumentation

In our experience with posterolateral skull base procedures, the endoscope that is primarily preferred for use is a 0° 4.0-mm rigid endoscope (Karl Storz, Tuttlingen, Germany). Upon the conclusion of the operation, a 30° 4.0-mm rigid endoscope (Karl Storz) is occasionally used to inspect the cranial nerve DREZ and surrounding areas. The 30° scope allows visualization of important structures that may be hidden throughout the procedure without the risk of retraction. Visualization of the field is

Results

Baseline characteristics of all 57 patients are shown in Table 2; all 57 patients suffered from severe pain with BNI scores of 5 prior to surgery. The postoperative results in our patients with TGN are shown in Table 3. Forty-seven of the 57 (82%) and 43 of the 57 (75%) patients immediately postoperatively and at 1-month follow-up, respectively, had complete relief of preoperative pain without the need for any medications, a BNI score of 1. One patient had both an immediate postoperative and a

Discussion

The standard open MVD procedure for the treatment of TGN has been and is a highly successful and accepted procedure. The addition of EAMVD provided improved visualization and overall outcomes to the procedure. More recently, several authors have advocated EVD without the use of microscopy at any point. We have found that the EVD procedure is both highly safe and successful, as demonstrated by the BNI pain intensity score.

A landmark study by Barker et al. (2) studied the overall outcomes of the

Conclusions

EVD is a safe and highly effective treatment modality for TGN. This procedure offers comparable results to the traditional MVD as well as EAMVD. In addition, EVD allows for smaller incisions and craniotomies and minimizes brain retraction. Hospital LOS and operative time are relatively short, without compromising the safety of the patient or decreasing the efficacy of the procedure. Future studies regarding cost-effectiveness could provide further support for EVD.

References (18)

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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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