Long-Term Outcome and Surgical Interventions After Sacral
Neuromodulation Implant for Lower Urinary Tract Symptoms:
14-Year Experience at 1 Center
Ali A. Al-zahrani,* Ehab A. Elzayat and Jerzy B. Gajewski†
From the Departments of Urology, Dalhousie University (AAA, EAE, JBG), Halifax, Nova Scotia, Canada, and University of Dammam (AAA),
Dammam, Saudi Arabia
Purpose: Few reports address the reoperation rate after sacral neuromodulation
implants. We report our long-term results and reoperations during our 14-year
experience with sacral neuromodulation at our center.
Materials and Methods: We retrospectively reviewed the patient database at our
center to assess the long-term outcome, incidence and cause of surgical re-
intervention after InterStim® sacral neuromodulation implantation for lower
urinary tract dysfunction between 1994 and 2008.
Results: A total of 96 sacral neuromodulation devices were implanted in 88
women and 8 men. Indications for implantation were bladder pain syndrome
in 47.9% of cases, urgency urinary incontinence in 35.4% and idiopathic
urinary retention in 16.7%. The explantation rate was 20.8% and median time
to removal was 18.5 months. Reasons for explantation in all subgroups were
poor result in 12 patients, painful stimulation in 6 and radiation of stimula-
tion to the leg in 2. Median long-term followup was 50.7 months. The long-
term success rate was 87.5%, 84.8% and 73% in patients with idiopathic
urinary retention, urgency urinary incontinence and bladder pain syndrome,
respectively. Overall 39% of patients needed revision of the sacral neuromodu-
lation implant. The main reason for revision was loss of stimulation in 58.5%
of cases. The revision rate decreased with the introduction of the tined lead
technique from 50% using lead Model 3092 to 31% using lead Model 3893
(Medtronic, Minneapolis, Minnesota). The battery was changed in 8 patients.
Mean battery life was 101.8 months.
Conclusions: Sacral neuromodulation is a minimally invasive procedure with a
good long-term outcome. The reoperation rate has improved with advances in
surgical technique and equipment.
Key Words: urinary bladder; pain; urinary incontinence, urge;
electric stimulation; prostheses and implants
Abbreviations
and Acronyms
BPS = bladder pain syndrome
FDA = Food and Drug
Administration
GRA = global response
assessment scale
IPG = implanted pulse generator
IUR = idiopathic urinary retention
PNE = percutaneous nerve
evaluation
SNM = sacral neuromodulation
UUI = urgency urinary
incontinence
Submitted for publication June 23, 2010.
Study received institutional ethics board ap-
proval.
* Correspondence: QEII Health Science Cen-
tre, HI Site, 1225B-1796 Summer St., Halifax,
Nova Scotia, B3H 3A7 Canada (telephone: 902-
473-8679; FAX: 902-473-8568; e-mail: ahzhrani@
yahoo.com).
† Financial interest and/or other relationship
with Astellas, Allergan, Medtronic, Lilly and
Pfizer.
THE concept of sacral nerve stimula-
tion was introduced in 1979 by Schmidt
et al.
1
Currently SNM is approved
by the United States FDA for refrac-
tory UUI, urinary frequency/ur-
gency syndrome and nonobstructive
IUR.
2
SNM is also approved in other
countries.
Several studies show the safety
and efficacy of SNM at short-term
and medium term followup but SNM
remains expensive with the addi-
tional costs of reoperation, revision
and battery exchanges.
3
Thus, it is
important to review SNM long-term
outcomes and revision rates. We re-
0022-5347/11/1853-0981/0 Vol. 185, 981-986, March 2011
THE JOURNAL OF UROLOGY
®
Printed in U.S.A.
© 2011 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION AND RESEARCH,INC. DOI:10.1016/j.juro.2010.10.054
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