The authors concluded that the benefits and harms of different surgical treatments for trigeminal neuralgia varied. Microvascular decompression had the highest rate of long-term patient satisfaction and the lowest recurrence rate. The reliance upon potentially-biased observational studies reporting differing results means that the authors’ conclusions may not be reliable.

To evaluate the long-term effects of surgical treatments for patients with trigeminal neuralgia.

MEDLINE, EMBASE and the Cochrane Library were searched to February 2007; the search terms were reported. In addition, reference lists were screened.

Studies that evaluated surgical treatments for patients with primary idiopathic trigeminal neuralgia, and assessed mortality and peri- and post-operative complications, were eligible for inclusion. Studies had to include at least 30 patients, include less than 10% of patients who received treatment more than once with any procedure, follow up patients for a median or mean of at least 5 years, report diagnostic criteria for patients, and define success, recurrence and other outcomes.

The included studies evaluated the following surgical procedures: microvascular decompression (MVD), radiofrequency thermorhizotomy (RF-TR), percutaneous balloon microcompression (PBC), stereotactic radiosurgery (SRS), glycerol rhizotomy (GR) and partial sensory rhizotomy (PSR). The average duration of follow-up ranged from 5 to 20 years. The review assessed acute pain relief (defined as complete relief without medication), average pain-free duration, recurrence (defined as return of any pain or pain requiring medication), and failure rates and complications.

Two reviewers independently selected studies according to the above criteria.

The authors stated that only studies meeting the minimum quality inclusion criteria reported (see Study Selection) were included.

For each study, means and standard deviations of event rates were extracted for continuous data where possible and tabulated.

The authors did not state how the data were extracted for the review, or how many reviewers performed the data extraction.

The studies were grouped by surgical treatment. The average acute pain relief rate, pain-free rate and recurrence rate were reported for each surgical treatment. The overall mean rate with 95% confidence interval (CI) was calculated for each outcome over all surgical treatments. Where there were sufficient data, Kaplan-Meier survival curves were constructed for pain-free survival for each surgical treatment. Differences between surgical treatments were assessed by comparing means, calculating odds ratios and comparing rates of specific complications. Results from studies that compared two or more treatments were discussed separately.

Twenty-eight observational studies (n=10,493) were included.

MVD (16 studies, n=4,884): acute pain relief rates ranged from 76.4 to 98.2% (average 91.05%, 10 studies), follow-up pain-free rates ranged from 62 to 89% (average 76.6%) and recurrence rates ranged from 4 to 38% (average 18.3%). The major complications were hearing loss (1 to 19%) and mortality (0.37%, 17 out of 4,906 patients).

RF-TR (9 studies, n=4,683): acute pain relief rates ranged from 81 to 98% (average 90.3%, 5 studies), follow-up pain-free rates ranged from 20 to 83% (average 50.4%) and recurrence rates ranged from 18.1 to 80% (average 45.9%). This type of surgery was associated with the greatest number of complications, the most common being facial hyperaesthesia (5 to 98%), corneal hyperaesthesia (5 to 18%) and trigeminal motor weakness (4 to 24%); other complications included anaesthesia dolorosa, meningitis and accidental vascular injuries.

PBC (2 studies, n=577): acute pain relief rates were 97% and 100% (average 98.5%), the average follow-up pain-free rate was 80.4% and the average recurrence rate was 19.6%. The major complication was symptomatic dysaesthesia; other complications were facial hyperaesthesia (4 to 72%), corneal hyperaesthesia (4%) and trigeminal motor weakness (66%).

SRS (1 study, n=107): the acute pain relief rate was 80.4%, the follow-up pain-free rate was 58% and the recurrence rate was 25%. The major complication was hyperaesthesia (20% after first SRS and 32% after second).

GR (2 studies, n=167): the average acute pain relief rate was 63%, the average follow-up pain-free rate was 38.5% and the average recurrence rate was 62.5%. The major complication was sensory deficit.

PSR (2 studies, n=95): the average acute pain relief rate was 79%, the average follow-up pain-free rate was 52.5% and the average recurrence rate was 39%. The most common complications were facial hyperaesthesia (100%) and hearing loss (25%).

MVD appeared to be associated with similar rates of acute pain relief and follow-up pain-free rates as PBC, and significantly higher rates of acute pain relief than RF-TR, SRS, and PSR and GR (p<0.001 for both). MVD was associated with the lowest recurrence rate (p<0.001)

Other results were also reported.

The benefits and harms of different surgical treatments for trigeminal neuralgia varied. MVD had the highest rate of long-term patient satisfaction and the lowest recurrence rate.

The review question was stated clearly. Three relevant databases were searched but no attempts to minimise publication bias were reported. It was not clear if any language restrictions were applied. Methods were used to minimise reviewer error and bias in the selection of studies, but it was not clear whether similar steps were taken in the extraction of data. Only studies meeting certain minimum quality criteria were included but, since no further validity assessment was conducted, the results from these studies and any synthesis might not be reliable. Patient characteristics were not reported so it is unclear how generalisable these results are. Grouping the studies by type of surgery and reporting ranges of values of outcomes was appropriate. However, averaging data from studies reporting widely differing results is questionable, as is using the data from observational studies to compare surgical treatments. Patient satisfaction did not appear to have been systematically assessed yet this outcome was referred to in the conclusion. The reliance upon potentially-biased observational studies reporting differing results means that the authors’ conclusions may not be reliable.

Practice: The authors stated that MVD may be considered the treatment of choice for experienced surgical teams to offer to appropriate patients; RF-TR is suitable for patients who cannot tolerate general anaesthesia or have recurrent pain; GR may be suitable only for elderly high-risk patients; SRS may be reasonable for patients unwilling or unable to undergo more invasive procedures; and there is no indication for PSR to be used in preference to MVD.

Research: The authors state that multicentre randomised controlled trials are required to evaluate surgical treatments for trigeminal neuralgia.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.