Anil Nanda
Anil Nanda
Anil Nanda
Clinical Study
a r t i c l e i n f o a b s t r a c t
Article history: The aim of our study was to evaluate the long term efficacy of microvascular decompression (MVD) and
Received 14 September 2014 gamma knife radiosurgery (GKRS) with respect to pain relief and patient satisfaction. Both these modal-
Accepted 29 November 2014 ities are accepted modalities of treatment for intractable trigeminal neuralgia. We excluded deceased
patients, those who had a prior intervention and those requiring an additional intervention following ini-
tial treatment. A total of 69 patients were included in the study. Of these, 49 patients underwent treat-
Keywords: ment by GKRS and 20 by MVD. Pain status was assessed using the Barrow Neurological Institute (BNI)
Long term outcomes
pain scale. The median follow up was 5.3 years. There was no significant difference between the two
Microvascular decompression
Patient satisfaction
groups with respect to initial pain relief (100% MVD, 84% GKRS; p = 0.055). There was no significant dif-
Radiosurgery ference in pain recurrence between the two groups (39% GKRS, 20% MVD; p = 0.133). At last follow up, 85%
Trigeminal neuralgia of patients who underwent MVD had total pain relief (BNI scale I) compared to only 45% of GKRS patients
(p = 0.002). There was no significant difference in the patient satisfaction with respect to undergoing the
same procedure again (90% MVD, 69% GKRS; p = 0.1) and recommending it to family members (95% MVD,
84% GKRS; p = 0.2). MVD offered total pain relief in a significantly higher number of patients than GKRS.
There was no significant difference in the patient satisfaction rate between the two groups.
Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction two prospective studies [2,3] which have compared MVD and
GKRS. In one study the results did not reach statistical significance
In one of the epidemiological studies conducted in the USA, the [2]. In another study, [3] MVD was superior to GKRS in achieving
incidence rate of trigeminal neuralgia was 4.3 per 100,000 popula- pain free status. We also identified only two patient satisfaction
tion and the age adjusted rate for women was significantly higher surveys with regards to MVD or GKRS [3,4]. Out of these, only
than that for men [1]. Medical management is the main stay of one compares MVD and GKRS in terms of patient satisfaction [3].
therapy for idiopathic trigeminal neuralgia and surgery is indicated Our study is the second such satisfaction survey.
when medical therapy fails. Various surgical treatment modalities MVD and GKRS are both accepted modalities of treatment for
include microvascular decompression (MVD), balloon compres- intractable trigeminal neuralgia. The aim of our study was to eval-
sion, radiofrequency thermocoagulation, glycerol rhizolysis, partial uate the long term efficacy of both these modalities with respect to
sensory rhizotomy (posterior fossa), cryotherapy and neurectomy pain relief and patient satisfaction. We attempted to evaluate the
or alcohol injections. Of all these surgical modalities, MVD is more pain relief patterns after treatment for trigeminal neuralgia follow-
popular and it is the only non ablative technique. Gamma knife ing GKRS and MVD.
radiosurgery (GKRS) is gaining popularity for treating idiopathic
trigeminal neuralgia not only due to its non-invasive nature but
also because patients can be discharged on the same day with 2. Methods
acceptable results.
We performed this study due to the lack of available literature The study was approved by our Institutional Review Board.
with respect to efficacy of both MVD and GKRS treatment modal- Patients were briefed about the survey and after getting verbal
ities and patient satisfaction. To our knowledge, there are only consent from the patient, a telephone interview with a standard-
ized questionnaire was conducted. Telephone interviews were
conducted to assess the pain status and complete the patient satis-
⇑ Corresponding author. Tel.: +1 318 675 6404; fax: +1 318 675 6867. faction survey. Pain status was assessed using the Barrow
E-mail address: ananda@lsuhsc.edu (A. Nanda). Neurological Institute (BNI) pain scale. Patient satisfaction with
http://dx.doi.org/10.1016/j.jocn.2014.11.028
0967-5868/Ó 2015 Elsevier Ltd. All rights reserved.
A. Nanda et al. / Journal of Clinical Neuroscience 22 (2015) 818–822 819
respect to whether they would undergo the same procedure again 3.4. Pain relief patterns
and/or recommend it to family members was assessed at the end
of telephone interview. The follow up was calculated from the date No pain relief was noted in eight patients (16.3% GKRS, 0 MVD).
of the initial procedure to the telephone interview. Pain relief improvement of one grade was noted in two patients
In our study, a BNI score I (no trigeminal pain, no medication) (4.1% GKRS, 0 MVD). Pain relief improvement of two grades was
was considered as total pain relief. We divided the pain relief pat- noted in three patients (4.1% GKRS, 5% MVD). Total pain relief
terns into the following categories: no pain relief, pain relief (without initial recurrence) was noted in 33 patients (36.7%
improvement of one grade, pain relief improvement of two grades, GKRS, 75% MVD) (Fig. 1).
pain relief improvement of three grades, total pain relief, initial Twenty-three patients (33.3%) developed pain recurrence at
pain relief–recurrence–total pain relief, initial pain relief–recur- some point (38.8% GKRS, 20% MVD). The initial pain relief–recur-
rence–partial improvement, initial pain relief–recurrence–no rence–total pain relief pattern was noted in six patients (8.2%
improvement. GKRS, 10% MVD). The initial pain relief–recurrence–partial
We excluded deceased patients, those who had a prior interven- improvement pattern was noted in 13 patients (22.4% GKRS, 10%
tion and those requiring an additional intervention following initial MVD). The initial pain relief–recurrence–no improvement pattern
treatment. Patients with more than one procedure were excluded in was noted in four patients (8.2% GKRS, 0 MVD).
order to reduce the bias which may arise due to the second
procedure and the status of total pain relief. A total of 230 patients 3.5. Patient satisfaction survey-Would you elect to undergo same
underwent treatment for idiopathic trigeminal neuralgia at our procedure again
institute. Of these 230 patients, 148 (64.3%) underwent a single
treatment, 73 (31.7%) underwent treatment twice and only nine Fifty-two (75.4%) patients were happy to undergo the same pro-
(3.9%) underwent treatment three times. Of the 148 single treat- cedure again. With regards to GKRS, only 69.4% were happy to
ment patients, only 121 were alive at the last follow up when the undergo the same procedure and 90% of MVD patients. There
interview was conducted and were included in the study. Of these was no significant difference between GKRS and MVD patients in
121 patients, successful telephone interview was obtained with only terms of satisfaction with respect to undergoing the same proce-
69. A standardized questionnaire was used to assess the patient sat- dure again (p = 0.190, chi-squared test).
isfaction rate and status of pain at the time of interview. We also
reviewed the medical records to determine the initial pain status
3.6. Patient satisfaction survey-Would you recommend to family and
following the procedure as well as pain recurrence.
friends
Fig. 1. Pain relief patterns for patients who underwent microvascular decompression (MVD) and gamma knife radiosurgery (GKRS) for trigeminal neuralgia are shown for the
following categories: total pain relief without initial recurrence (A), pain relief improvement of one grade (B), pain relief improvement of two grades (C), initial pain relief–
recurrence–total pain relief (D), initial pain relief–recurrence–partial improvement (E), initial pain relief–recurrence–no improvement (F). n = 69.
Broggi et al. [8] found that the recurrence rate was 15.3% (follow up In the study by Kimball et al. [17] at 10 years 50% of the patients
1–7 years). In another study, at 5 years 38% of the MVD patients had good pain control when GKRS was used as repeat procedure
had a recurrence of neuralgia [9]. Kondo [10] found a recurrence for trigeminal neuralgia. In another study by Riesenburger et al.
rate of 8% with minimum follow up more than 5 years. In a recent [18] a good treatment outcome from initial GKRS was achieved
study by Sarsam et al. [11], complete pain relief was achieved in in 58.5% patients for whom the mean follow up period was 48
71% at 10 years. In another study, 64% of patients who underwent months (range: 36–66). In another study by Little et al. [19] when
MVD remained completely pain free 20 years postoperatively [12]. GKRS was used as the primary treatment, 45% of the patients were
In a series of 947 patients, of whom 362 had Kaplan Meier analysis, pain free at 7 years. Gellner et al. [20] studied the role of repeat
Sindou et al. found that the probability of cure (no pain and no GKRS with a mean follow up of 5.4 years after repeat radiosurgery.
medication) was 74% at 15 years follow up [13]. In another large Pain relief was noted in 72.7% of the patients. In the series by Park
series, when patients were followed for more than 5 years, the long et al. [21] with a minimum follow up of 3 years 94.1% of the
term pain relief after MVD for those with typical trigeminal neural- patients had a good treatment outcome at the last follow up. In
gia was excellent in 73% and good in an additional 7%, for an overall the study by Han et al. [22] the actuarial recurrence free survival
significant pain relief in 80% of patients [14]. In the series by Kolluri rates were 84.8%, 76.1%, 69.6%, 63.0% and 45.8% at 1, 2, 3, 4 and
et al. [15] 78% were pain free at follow up of 5 years. 5 years after radiosurgery. In the study by Regis et al. [23], at 5
years 58% of the patients remained pain free and 83% had no tri-
4.2. Long term results after GKRS geminal nerve disturbance. In another study by Urgosik et al.
[24] initial successful results were achieved in 96% of patients with
In a long term study by Dhople et al. [16] 81% of patients report- complete pain relief in 80.4%. Relief was achieved after a median
ed initial pain relief and actuarial rates of freedom from treatment latency of 3 months (range: 1 day–13 months). GKRS failed in 4%
failure at 1, 3, 5, and 7 years were 60, 41, 34, and 22%, respectively. of patients. Pain recurred in 25% of patients after a median latent
A. Nanda et al. / Journal of Clinical Neuroscience 22 (2015) 818–822 821
interval of 36 months (range: 6–94). The initial success rate after a and those undergoing MVD were a full decade younger. Proper
second GKRS was 89%, and 58% of patients were pain free. age-matched comparison studies between the MVD and GKRS
may reveal if there is a true difference in efficacy. Future prospec-
4.3. Comparison of MVD and GKRS tive studies may also aid in identifying predictors or outcome vari-
ables which will help clinicians to decide on the optimal treatment
There are very few studies in the literature in which authors modality. Though such predictors have been studied in some
have compared the results of MVD with GKRS [2,25]. Pollock [25] recent series [26,27], they are lacking high quality evidence.
retrospectively reviewed experiences with 77 patients of which
49 underwent MVD and 28 GKRS. With a mean follow up of 2.15
years, respective actuarial rates of pain relief at 1 and 3 years post 5. Conclusions
treatment were 75% and 72% for MVD, and 59% and 59% for GKRS
(p = 0.01). Brisman [2] performed a prospective cohort study of From our study, MVD offered total pain relief in significantly
MVD and GKRS in a series of 85 patients. With a short clinical fol- higher number of patients than GKRS. There was no significant dif-
low up he reported 12 and 18 month pain relief rates of 68 and 68% ference in the rates of patient satisfaction between the two groups
for MVD, respectively, and 58% and 24% for GKRS. These results did although there was a trend for greater satisfaction after MVD. Our
not reach a statistical significance (p = 0.089). In another study by observations regarding long term efficacy of MVD are similar to
Linskey et al. [3] the largest prospective cohort comparative analy- those published in the literature, but there is a lack of high quality
sis with the longest clinical follow up, MVD was significantly supe- evidence to support the clinical practice. Properly matched
rior to GKRS in achieving and maintaining a pain free status in prospective studies or randomized controlled trials are needed to
those with trigeminal neuralgia. This is consistent with our study help clinicians in selecting the appropriate mode of treatment
where the proportion of patients with total pain relief was sig- and improving the patient outcomes.
nificantly higher in the MVD group compared with the GKRS group.
Though the proportion of patients with recurrent pain in our study
Conflicts of Interest/Disclosures
was high in GKRS patients, when compared with the MVD group,
this did not reach a statistical significance.
The authors declare that they have no financial or other con-
flicts of interest in relation to this research and its publication.
4.4. Patient satisfaction survey
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