Neuromodulation: Technology at the Neural Interface Received: August 30, 2013
Revised: November 2, 2013
Accepted: December 14, 2013
(onlinelibrary.wiley.com) DOI: 10.1111/ner.12158
Anterograde and Retrograde Epidural Paddle Placement Through a Single Laminotomy for the Treatment of Back and Lower Extremity Pain Using Spinal Cord Stimulation: Case Reports and Technical Note Alexander Taghva, MD Objective: Spinal cord stimulation can be effectively used in the treatment of low back pain and extremity pain in failed back surgery syndrome. Ideal targets for stimulation corresponding to paresthesia overlap in the low back versus the extremities may differ in cranial-caudal location. Materials and Methods: We present here a technical report of three cases demonstrating a technique to place anterograde and retrograde epidural paddles through a single laminotomy. Results: Using this technique we were able to cover five spinal levels in each patient, and different stimulation programs at different levels created paresthesia overlap in back versus lower extremity in those patients. Conclusion: Dual paddle placement through a single laminotomy may be a reasonable option for select patients where coverage of anatomically-separated pain regions is necessary. This technique can be performed in most patients without significantly increased morbidity. Keywords: Complex regional pain syndrome, electrode paddle, electrode placement, failed back surgery syndrome, low back pain, spinal cord stimulation, technical report Conflict of Interest: Dr. Taghva is a paid consultant for Boston Scientific.
INTRODUCTION
not exposing the patient to significantly increased morbidity. Three such cases are presented below.
766
Spinal cord stimulation (SCS) is an effective modality for treating neuropathic pain. Persistent back and leg pain following spine surgery, also known as failed back surgery syndrome (FBSS), is the most common indication for SCS in the United States (1). It is typically more difficult to obtain paresthesia overlap in the axial low back pain component of FBSS than the extremity pain component; however, SCS may be effectively used in the treatment of low back pain (2,3). While practice patterns vary between centers, there is some suggestion that thoracic epidural electrodes placed more caudally are more selective for treatment of leg pain, while more cranially placed electrodes are more selective for the treatment of low back pain (4,5). Many patients, however, have components of both back and leg pain, making treatment of both pain components somewhat problematic. Advancements in spinal cord stimulation technology have made it possible to explore a wide range of electrode configurations, particularly combinations of epidural paddles and peripheral field stimulation specifically for the treatment of back pain (6,7). Among these advancements is the advent of 32-contact batteries. One electrode configuration that also may be effective, and will be described here, is the placement of two epidural paddles, one anterograde for optimal back pain coverage and one retrograde for leg coverage. These can be placed through a single incision and laminotomy, thus www.neuromodulationjournal.com
CASE 1 Case 1 is a 70-year-old female with a history of two previous decompressive spine surgeries (lumbar laminectomy) for back, hip, leg, and foot pain that did not improve following surgery. She then had successful treatment of her back pain (by an outside physician) with a T7–8 spinal cord stimulator placement 3 years prior to presentation (70–80% pain relief ). At the time of implant, she had some
Address correspondence to: Alexander Taghva, MD, Orange County Neurosurgical Associates, Neurosurgery, Suite 561, 26732 Crown Valley Pkwy, Mission Viejo, CA 92691, USA. Email: [email protected] Orange County Neurosurgical Associates, Mission Viejo, CA, USA For more information on author guidelines, an explanation of our peer review process, and conflict of interest informed consent policies, please go to http:// www.wiley.com/bw/submit.asp?ref=1094-7159&site=1 Sources of financial support: None. Compliance note: Retrospective chart review for this paper was conducted with ethical approval.
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
DUAL PADDLES THROUGH SINGLE LAMINOTOMY a
b
Figure 1. Preoperative views of case 1. This patient is a 70-year-old female with failed back surgery syndrome originally treated with a T7–8 spinal cord stimulation paddle (a) and subcutaneous electrodes (b).
www.neuromodulationjournal.com
Figure 2. Case 1, postoperative fluoroscopy view. The patient had an additional retrograde T11–12 paddle placed through her original T9 laminotomy for T7–8 paddle placement.
© 2014 International Neuromodulation Society
767
reduction of her leg pain as well (50% pain relief ). Over time, her hip, leg, and foot pain became refractory to stimulation, and peripheral field stimulation was attempted by another pain physician to address the hip pain (Fig. 1). This was ultimately unsuccessful. She presented to us after she had lost coverage of her back pain (due to lead becoming disconnected from battery). She was offered revision of her original system and explant of her peripheral field stimulation leads, along with implantation of a retrograde thoracolumbar lead to address her hip, leg, and foot pain. The patient declined further trialing for her hip/foot pain, as she had had several prior revisions and interventions and was interested in a single-surgery option only. The patient was taken to OR for revision. The field stimulation leads in her low back were explanted, and the disconnected tail of the paddle was connected to a 32-contact accommodating battery (Spectra; Boston Scientific, Valencia, CA, USA). The prior laminotomy site was reexplored, and the original laminotomy was extended caudally to expose virgin dura. A 2 × 8 contact epidural paddle (Artisan; Boston Scientific) was passed in a retrograde fashion to the T11–12 level (Fig. 2). An intraoperative electromyogram of the legs with stimulation of the paddle was obtained to evaluate the bilaterality of the paddle (the patient did not tolerate awake testing). Operative time was under two hours, and blood loss was minimal. The patient was discharged home on postoperative day 2. Postoperatively, the patient had excellent coverage of her painful areas (100% coverage) and good pain relief (80% pain relief ). It is of note that stimulation parameters were given such that the programs optimized for back pain coverage had a central stimulation point near the T7–8 interspace, and programs optimized for leg coverage had a central stimulation point near mid-body T11 (Fig. 3). At three-month follow-up, the patient continues to have good pain relief.
Neuromodulation 2014; 17: 766–770
TAGHVA
a
b
c
Figure 3. Programming screenshots for case 1. a. Paddle configuration and levels input into programming interface. Paddle configuration on anterograde paddle optimized for low back coverage. b. Central point of stimulation as calculated by programming algorithm, marked with “C”. This corresponds to mid to lower T7. c. Central point of stimulation optimized for leg coverage, marked with “B,” corresponding to top of T11.
CASE 2
768
Case 2 is a 39-year-old female who fell from stadium bleachers five years prior to presentation. At the time of her injury she had bilateral ankle fractures as well a traumatic herniated L5–S1 disc. She was treated with multiple bilateral ankle surgeries and a front– back L5–S1 fusion at an outside institution. She continued to have intractable back pain and leg pain following the spine surgery and had a revision of the construct, including removal of hardware by her original surgeon. Her pain persisted despite hardware removal. Furthermore, she had persistent ankle pain following her ankle surgeries. At the time of evaluation by us, she was felt to have a picture primarily consistent with complex regional pain syndrome (CRPS) but with components of back pain that resembled FBSS. She underwent a spinal cord stimulation percutaneous trial at an outside facility where coverage of her back pain was achieved at T5–6 and her leg and ankle pain at mid-body T9. She did very well during her trial, with 80–90% reduction of pain over one week. We discussed with the patient a T7–8 laminotomy for placement of an anterograde T5–6 paddle and a retrograde paddle covering the bottom of T8 through T10 (Artisan; Boston Scientific). We also discussed with the patient that we would have expected coverage of both her back and ankle pain with more caudally placed leads, but given the excellent results of her trial we elected to proceed with epidural paddle placement mirroring the trial. The patient was taken to surgery for T7–8 laminotomy with T5–6 and T8–10 paddle placement. Due to patient factors (morbid obesity), anesthesia deferred awake testing. In placing the retrograde paddle, we were unable to advance past the T9–10 interspace (Fig. 4). Surgical time was under two hours, and blood loss was 100 cc. Postoperatively, the patient did well, with coverage of her back, leg, and ankle pain. Overall pain relief was 70–80%. Again, separate programs were utilized for back and lower extremity pain. Back pain received optimal coverage at T6 and lower extremity coverage was best near the bottom of T9 (Fig. 5). www.neuromodulationjournal.com
Figure 4. Case 2, postoperative view. A T7/8 laminotomy was performed for placement of a T5–6 anterograde paddle followed by a T8–9 retrograde paddle.
CASE 3 Case 3 is a 41-year-old female with a several-year history of low back pain and right shin and foot pain. The foot pain began after a crush injury to the right lower extremity, but the low back pain was felt to be degenerative in origin. The combination of pain made it difficult for the patient to walk or stand for any significant length of time. The patient was trialed by an outside pain physician for the presumed CRPS component of her foot pain. During the trial, the
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
DUAL PADDLES THROUGH SINGLE LAMINOTOMY
a
b
c
Figure 5. Programming screenshots for case 2. a. Paddle configuration and levels input into programming interface. Paddle configuration on anterograde paddle optimized for low back coverage. b. Central point of stimulation as calculated by programming algorithm, marked with “A”. This corresponds to top of T6. c. Central point of stimulation optimized for leg coverage, marked with “D,” corresponding to bottom of T9.
patient was found to have significant pain relief of the low back component of her pain at T9; however, the stimulation intensity required to obtain foot coverage at this level generated uncomfortable thigh paresthesias. This patient was taken to surgery for T10–11 laminotomy with a plan for dual paddle placement (Artisan; Boston Scientific). Awake testing was performed intraoperatively. Optimal back coverage was obtained at T9, while optimal right foot coverage was obtained at L1 (Fig. 6). Postoperatively, the patient had good back coverage and foot coverage with individual programs (>80% pain relief ), and coverage was obtained of these areas without intervening thigh stimulation, which the patient found troublesome during her trial. It is of note that her low back coverage was managed with a lower frequency (40 Hz) than her presumed CRPS foot pain (60 Hz). The patient maintains good coverage at three-month follow-up.
DISCUSSION
www.neuromodulationjournal.com
Figure 6. Case 3, postoperative view. A T10/11 laminotomy was performed for placement of a T9 anterograde paddle followed by an L1 retrograde paddle.
This paper, being primarily a technical note, is limited in scope. Primarily, given the relatively short follow-up at this time as well as the small number of patients, it may be difficult to generalize this approach to the FBSS patient population at large. Also, we typically
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
769
The treatment of complex pain patterns, including axial back pain, remains an area of active inquiry in neuromodulation. Specifically in the treatment of FBSS, coverage of the axial back pain component of pain remains problematic. Different strategies for addressing this issue include use of multiple column paddles and/or independent current sources to selectively recruit low back fibers as well as the use of subcutaneous electrodes to capture low back coverage (2,3,6–9). Here we present another strategy, use of a single stimulation center to capture low back fibers and another, more caudally, to capture leg fibers. Moreover, we present a technique to establish this arrangement of electrodes without significant alteration of surgical technique, incision size, or surgical morbidity.
TAGHVA advocate intraoperative testing, which was impractical in two of these patients. That being said, the unique circumstances of the patients here (incomplete coverage with field stimulation and single epidural paddle in case 1, success with low back coverage with a highly placed paddle in case 2, and disconnected regions of pain in case 3) allowed us to explore a two-paddle approach. In case 1, a more caudally placed paddle appeared to rescue ineffective field stimulation. In case 2, spanning a larger segment of the thoracic spine allowed us to selectively stimulate back and leg fibers. In case 3, the patient was interested in an option to obtain back and foot coverage without intervening thigh paresthesia. Furthermore, we were able to provide different stimulation frequencies for different pain etiologies. While some authors advocate more caudally placed paddles (T8–10) in general for low back pain (3,6), in our two patients, separate programs for back and leg coverage suggested different anatomical “sweet spots” for coverage. The availability of 32-contact batteries has made a two-paddle approach somewhat more feasible, as two 16-contact paddles may be used without addition of another implanted pulse generator. However, use of two 8-contact paddles with a 16-contact battery may be reasonable as well and is common in certain applications (e.g., dual sacral paddles for pelvic pain). The role of percutaneous trialing may potentially be expanded as well. While the patients described here had obtained trials at 1–2 contiguous levels, in patients with complex patterns of pain, trials may be performed at noncontiguous levels to isolate optimal areas for pain relief of different body areas. Granted, follow-up in these patients is still relatively short and the number of patients presented here is small, and this is a major limitation of this article. On a technical note, we have demonstrated that one can obtain five levels of vertebral body coverage (skipping a level where the laminotomy is performed) through a standard surgical technique. With anterograde and retrograde paddle tails abutting each other, a few options exist for managing the mess of wires. In cases 1 and 2, we brought the tails of one paddle out to the left and those of the other to the right. In case 3, we straddled the tails of the anterograde paddle around the tails of the retrograde paddle, and one can consider interleaving the tails of the paddles as well. Another technical caveat which arose in the review of this article is that the bony removal of the lower lamina must be somewhat increased to prevent too steep an insertion angle of the retrograde paddle, as this may lead to spinal cord injury. There are also potential technical limitations with this approach. First, in patients with prior cylindrical lead placement, epidural scarring may make retrograde paddle placement somewhat more difficult. We have found that this can generally be overcome by widening of the laminotomy site. In severe cases of scarring, a “skip laminotomy” 1–2 levels below may be necessary. This technique is widely used in cases with scarring in anterograde placement as well. Similarly, widening of the lower laminotomy may be necessary in placing a three-column or larger paddle, and we have used this approach to place a retrograde paddle when awake testing intraoperatively necessitated a more caudal paddle placement than planned preoperatively. As wider paddle combinations become more feasible as battery capacity for
electrodes from manufacturers increases, we still believe an anterograde–retrograde paddle approach may be valid, as it appears the limiting factor in placement of paddles in two different directions is the intersection of the tails of the paddles rather than the width of the paddles themselves. In summary, while more study and follow-up needs to be performed, a combination of anterograde and retrograde paddles through a single laminotomy may be a valid option for select patients.
Acknowledgments I would like to thank the anonymous referees of this article for the suggestions related to the technical caveats in this article. These have certainly increased the quality of this work.
Authorship Statement Dr. Taghva treated the patients and prepared the manuscript.
How to Cite this Article Taghva A. 2014. Anterograde and Retrograde Epidural Paddle Placement Through a Single Laminotomy for the Treatment of Back and Lower Extremity Pain Using Spinal Cord Stimulation: Case Reports and Technical Note. Neuromodulation2014; 17: 766–770
REFERENCES 1. North RB, Linderoth B. Spinal cord stimulation for chronic pain. In: Quinones-Hinojosa A, ed. Schmidek & Sweet: operative neurosurgical techniques: indications, methods, and results, Vol. 2. Philadelphia: Elsevier Saunders, 2012:1455–1468. 2. Barolat G, Oakley JC, Law JD, North RB, Ketcik B, Sharan A. Epidural spinal cord stimulation with a multiple electrode paddle lead is effective in treating intractable low back pain. Neuromodulation 2001;4:59–66. 3. North RB, Kidd DH, Olin J et al. Spinal cord stimulation for axial low back pain: a prospective, controlled trial comparing dual with single percutaneous electrodes. Spine (Phila Pa 1976) 2005;30:1412–1418. 4. Barolat G, Massaro F, He J, Zeme S, Ketcik B. Mapping of sensory responses to epidural stimulation of the intraspinal neural structures in man. J Neurosurg 1993;78:233–239. 5. Deer TR. Atlas of implantable therapies for pain management. New York: Springer, 2011. 6. Reverberi C, Dario A, Barolat G. Spinal cord stimulation (SCS) in conjunction with peripheral nerve field stimulation (PNfS) for the treatment of complex pain in failed back surgery syndrome (FBSS). Neuromodulation 2013;16:78–82, discussion 83. 7. Mironer YE, Hutcheson JK, Satterthwaite JR, LaTourette PC. Prospective, two-part study of the interaction between spinal cord stimulation and peripheral nerve field stimulation in patients with low back pain: development of a new spinal-peripheral neurostimulation method. Neuromodulation 2011;14:151–154, discussion 155. 8. North RB, Kidd DH, Olin J, Sieracki JN, Petrucci L. Spinal cord stimulation for axial low back pain: a prospective controlled trial comparing 16-contact insulated electrodes with 4-contact percutaneous electrodes. Neuromodulation 2006;9:56–67. 9. Sankarasubramanian V, Buitenweg JR, Holsheimer J, Veltink PH. Staggered transverse tripoles with quadripolar lateral anodes using percutaneous and surgical leads in spinal cord stimulation. Neurosurgery 2013;72:483–491.
770 www.neuromodulationjournal.com
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
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Revised: November 2, 2013
Accepted: December 14, 2013
(onlinelibrary.wiley.com) DOI: 10.1111/ner.12158
Anterograde and Retrograde Epidural Paddle Placement Through a Single Laminotomy for the Treatment of Back and Lower Extremity Pain Using Spinal Cord Stimulation: Case Reports and Technical Note Alexander Taghva, MD Objective: Spinal cord stimulation can be effectively used in the treatment of low back pain and extremity pain in failed back surgery syndrome. Ideal targets for stimulation corresponding to paresthesia overlap in the low back versus the extremities may differ in cranial-caudal location. Materials and Methods: We present here a technical report of three cases demonstrating a technique to place anterograde and retrograde epidural paddles through a single laminotomy. Results: Using this technique we were able to cover five spinal levels in each patient, and different stimulation programs at different levels created paresthesia overlap in back versus lower extremity in those patients. Conclusion: Dual paddle placement through a single laminotomy may be a reasonable option for select patients where coverage of anatomically-separated pain regions is necessary. This technique can be performed in most patients without significantly increased morbidity. Keywords: Complex regional pain syndrome, electrode paddle, electrode placement, failed back surgery syndrome, low back pain, spinal cord stimulation, technical report Conflict of Interest: Dr. Taghva is a paid consultant for Boston Scientific.
INTRODUCTION
not exposing the patient to significantly increased morbidity. Three such cases are presented below.
766
Spinal cord stimulation (SCS) is an effective modality for treating neuropathic pain. Persistent back and leg pain following spine surgery, also known as failed back surgery syndrome (FBSS), is the most common indication for SCS in the United States (1). It is typically more difficult to obtain paresthesia overlap in the axial low back pain component of FBSS than the extremity pain component; however, SCS may be effectively used in the treatment of low back pain (2,3). While practice patterns vary between centers, there is some suggestion that thoracic epidural electrodes placed more caudally are more selective for treatment of leg pain, while more cranially placed electrodes are more selective for the treatment of low back pain (4,5). Many patients, however, have components of both back and leg pain, making treatment of both pain components somewhat problematic. Advancements in spinal cord stimulation technology have made it possible to explore a wide range of electrode configurations, particularly combinations of epidural paddles and peripheral field stimulation specifically for the treatment of back pain (6,7). Among these advancements is the advent of 32-contact batteries. One electrode configuration that also may be effective, and will be described here, is the placement of two epidural paddles, one anterograde for optimal back pain coverage and one retrograde for leg coverage. These can be placed through a single incision and laminotomy, thus www.neuromodulationjournal.com
CASE 1 Case 1 is a 70-year-old female with a history of two previous decompressive spine surgeries (lumbar laminectomy) for back, hip, leg, and foot pain that did not improve following surgery. She then had successful treatment of her back pain (by an outside physician) with a T7–8 spinal cord stimulator placement 3 years prior to presentation (70–80% pain relief ). At the time of implant, she had some
Address correspondence to: Alexander Taghva, MD, Orange County Neurosurgical Associates, Neurosurgery, Suite 561, 26732 Crown Valley Pkwy, Mission Viejo, CA 92691, USA. Email: [email protected] Orange County Neurosurgical Associates, Mission Viejo, CA, USA For more information on author guidelines, an explanation of our peer review process, and conflict of interest informed consent policies, please go to http:// www.wiley.com/bw/submit.asp?ref=1094-7159&site=1 Sources of financial support: None. Compliance note: Retrospective chart review for this paper was conducted with ethical approval.
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
DUAL PADDLES THROUGH SINGLE LAMINOTOMY a
b
Figure 1. Preoperative views of case 1. This patient is a 70-year-old female with failed back surgery syndrome originally treated with a T7–8 spinal cord stimulation paddle (a) and subcutaneous electrodes (b).
www.neuromodulationjournal.com
Figure 2. Case 1, postoperative fluoroscopy view. The patient had an additional retrograde T11–12 paddle placed through her original T9 laminotomy for T7–8 paddle placement.
© 2014 International Neuromodulation Society
767
reduction of her leg pain as well (50% pain relief ). Over time, her hip, leg, and foot pain became refractory to stimulation, and peripheral field stimulation was attempted by another pain physician to address the hip pain (Fig. 1). This was ultimately unsuccessful. She presented to us after she had lost coverage of her back pain (due to lead becoming disconnected from battery). She was offered revision of her original system and explant of her peripheral field stimulation leads, along with implantation of a retrograde thoracolumbar lead to address her hip, leg, and foot pain. The patient declined further trialing for her hip/foot pain, as she had had several prior revisions and interventions and was interested in a single-surgery option only. The patient was taken to OR for revision. The field stimulation leads in her low back were explanted, and the disconnected tail of the paddle was connected to a 32-contact accommodating battery (Spectra; Boston Scientific, Valencia, CA, USA). The prior laminotomy site was reexplored, and the original laminotomy was extended caudally to expose virgin dura. A 2 × 8 contact epidural paddle (Artisan; Boston Scientific) was passed in a retrograde fashion to the T11–12 level (Fig. 2). An intraoperative electromyogram of the legs with stimulation of the paddle was obtained to evaluate the bilaterality of the paddle (the patient did not tolerate awake testing). Operative time was under two hours, and blood loss was minimal. The patient was discharged home on postoperative day 2. Postoperatively, the patient had excellent coverage of her painful areas (100% coverage) and good pain relief (80% pain relief ). It is of note that stimulation parameters were given such that the programs optimized for back pain coverage had a central stimulation point near the T7–8 interspace, and programs optimized for leg coverage had a central stimulation point near mid-body T11 (Fig. 3). At three-month follow-up, the patient continues to have good pain relief.
Neuromodulation 2014; 17: 766–770
TAGHVA
a
b
c
Figure 3. Programming screenshots for case 1. a. Paddle configuration and levels input into programming interface. Paddle configuration on anterograde paddle optimized for low back coverage. b. Central point of stimulation as calculated by programming algorithm, marked with “C”. This corresponds to mid to lower T7. c. Central point of stimulation optimized for leg coverage, marked with “B,” corresponding to top of T11.
CASE 2
768
Case 2 is a 39-year-old female who fell from stadium bleachers five years prior to presentation. At the time of her injury she had bilateral ankle fractures as well a traumatic herniated L5–S1 disc. She was treated with multiple bilateral ankle surgeries and a front– back L5–S1 fusion at an outside institution. She continued to have intractable back pain and leg pain following the spine surgery and had a revision of the construct, including removal of hardware by her original surgeon. Her pain persisted despite hardware removal. Furthermore, she had persistent ankle pain following her ankle surgeries. At the time of evaluation by us, she was felt to have a picture primarily consistent with complex regional pain syndrome (CRPS) but with components of back pain that resembled FBSS. She underwent a spinal cord stimulation percutaneous trial at an outside facility where coverage of her back pain was achieved at T5–6 and her leg and ankle pain at mid-body T9. She did very well during her trial, with 80–90% reduction of pain over one week. We discussed with the patient a T7–8 laminotomy for placement of an anterograde T5–6 paddle and a retrograde paddle covering the bottom of T8 through T10 (Artisan; Boston Scientific). We also discussed with the patient that we would have expected coverage of both her back and ankle pain with more caudally placed leads, but given the excellent results of her trial we elected to proceed with epidural paddle placement mirroring the trial. The patient was taken to surgery for T7–8 laminotomy with T5–6 and T8–10 paddle placement. Due to patient factors (morbid obesity), anesthesia deferred awake testing. In placing the retrograde paddle, we were unable to advance past the T9–10 interspace (Fig. 4). Surgical time was under two hours, and blood loss was 100 cc. Postoperatively, the patient did well, with coverage of her back, leg, and ankle pain. Overall pain relief was 70–80%. Again, separate programs were utilized for back and lower extremity pain. Back pain received optimal coverage at T6 and lower extremity coverage was best near the bottom of T9 (Fig. 5). www.neuromodulationjournal.com
Figure 4. Case 2, postoperative view. A T7/8 laminotomy was performed for placement of a T5–6 anterograde paddle followed by a T8–9 retrograde paddle.
CASE 3 Case 3 is a 41-year-old female with a several-year history of low back pain and right shin and foot pain. The foot pain began after a crush injury to the right lower extremity, but the low back pain was felt to be degenerative in origin. The combination of pain made it difficult for the patient to walk or stand for any significant length of time. The patient was trialed by an outside pain physician for the presumed CRPS component of her foot pain. During the trial, the
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
DUAL PADDLES THROUGH SINGLE LAMINOTOMY
a
b
c
Figure 5. Programming screenshots for case 2. a. Paddle configuration and levels input into programming interface. Paddle configuration on anterograde paddle optimized for low back coverage. b. Central point of stimulation as calculated by programming algorithm, marked with “A”. This corresponds to top of T6. c. Central point of stimulation optimized for leg coverage, marked with “D,” corresponding to bottom of T9.
patient was found to have significant pain relief of the low back component of her pain at T9; however, the stimulation intensity required to obtain foot coverage at this level generated uncomfortable thigh paresthesias. This patient was taken to surgery for T10–11 laminotomy with a plan for dual paddle placement (Artisan; Boston Scientific). Awake testing was performed intraoperatively. Optimal back coverage was obtained at T9, while optimal right foot coverage was obtained at L1 (Fig. 6). Postoperatively, the patient had good back coverage and foot coverage with individual programs (>80% pain relief ), and coverage was obtained of these areas without intervening thigh stimulation, which the patient found troublesome during her trial. It is of note that her low back coverage was managed with a lower frequency (40 Hz) than her presumed CRPS foot pain (60 Hz). The patient maintains good coverage at three-month follow-up.
DISCUSSION
www.neuromodulationjournal.com
Figure 6. Case 3, postoperative view. A T10/11 laminotomy was performed for placement of a T9 anterograde paddle followed by an L1 retrograde paddle.
This paper, being primarily a technical note, is limited in scope. Primarily, given the relatively short follow-up at this time as well as the small number of patients, it may be difficult to generalize this approach to the FBSS patient population at large. Also, we typically
© 2014 International Neuromodulation Society
Neuromodulation 2014; 17: 766–770
769
The treatment of complex pain patterns, including axial back pain, remains an area of active inquiry in neuromodulation. Specifically in the treatment of FBSS, coverage of the axial back pain component of pain remains problematic. Different strategies for addressing this issue include use of multiple column paddles and/or independent current sources to selectively recruit low back fibers as well as the use of subcutaneous electrodes to capture low back coverage (2,3,6–9). Here we present another strategy, use of a single stimulation center to capture low back fibers and another, more caudally, to capture leg fibers. Moreover, we present a technique to establish this arrangement of electrodes without significant alteration of surgical technique, incision size, or surgical morbidity.
TAGHVA advocate intraoperative testing, which was impractical in two of these patients. That being said, the unique circumstances of the patients here (incomplete coverage with field stimulation and single epidural paddle in case 1, success with low back coverage with a highly placed paddle in case 2, and disconnected regions of pain in case 3) allowed us to explore a two-paddle approach. In case 1, a more caudally placed paddle appeared to rescue ineffective field stimulation. In case 2, spanning a larger segment of the thoracic spine allowed us to selectively stimulate back and leg fibers. In case 3, the patient was interested in an option to obtain back and foot coverage without intervening thigh paresthesia. Furthermore, we were able to provide different stimulation frequencies for different pain etiologies. While some authors advocate more caudally placed paddles (T8–10) in general for low back pain (3,6), in our two patients, separate programs for back and leg coverage suggested different anatomical “sweet spots” for coverage. The availability of 32-contact batteries has made a two-paddle approach somewhat more feasible, as two 16-contact paddles may be used without addition of another implanted pulse generator. However, use of two 8-contact paddles with a 16-contact battery may be reasonable as well and is common in certain applications (e.g., dual sacral paddles for pelvic pain). The role of percutaneous trialing may potentially be expanded as well. While the patients described here had obtained trials at 1–2 contiguous levels, in patients with complex patterns of pain, trials may be performed at noncontiguous levels to isolate optimal areas for pain relief of different body areas. Granted, follow-up in these patients is still relatively short and the number of patients presented here is small, and this is a major limitation of this article. On a technical note, we have demonstrated that one can obtain five levels of vertebral body coverage (skipping a level where the laminotomy is performed) through a standard surgical technique. With anterograde and retrograde paddle tails abutting each other, a few options exist for managing the mess of wires. In cases 1 and 2, we brought the tails of one paddle out to the left and those of the other to the right. In case 3, we straddled the tails of the anterograde paddle around the tails of the retrograde paddle, and one can consider interleaving the tails of the paddles as well. Another technical caveat which arose in the review of this article is that the bony removal of the lower lamina must be somewhat increased to prevent too steep an insertion angle of the retrograde paddle, as this may lead to spinal cord injury. There are also potential technical limitations with this approach. First, in patients with prior cylindrical lead placement, epidural scarring may make retrograde paddle placement somewhat more difficult. We have found that this can generally be overcome by widening of the laminotomy site. In severe cases of scarring, a “skip laminotomy” 1–2 levels below may be necessary. This technique is widely used in cases with scarring in anterograde placement as well. Similarly, widening of the lower laminotomy may be necessary in placing a three-column or larger paddle, and we have used this approach to place a retrograde paddle when awake testing intraoperatively necessitated a more caudal paddle placement than planned preoperatively. As wider paddle combinations become more feasible as battery capacity for
electrodes from manufacturers increases, we still believe an anterograde–retrograde paddle approach may be valid, as it appears the limiting factor in placement of paddles in two different directions is the intersection of the tails of the paddles rather than the width of the paddles themselves. In summary, while more study and follow-up needs to be performed, a combination of anterograde and retrograde paddles through a single laminotomy may be a valid option for select patients.
Acknowledgments I would like to thank the anonymous referees of this article for the suggestions related to the technical caveats in this article. These have certainly increased the quality of this work.
Authorship Statement Dr. Taghva treated the patients and prepared the manuscript.
How to Cite this Article Taghva A. 2014. Anterograde and Retrograde Epidural Paddle Placement Through a Single Laminotomy for the Treatment of Back and Lower Extremity Pain Using Spinal Cord Stimulation: Case Reports and Technical Note. Neuromodulation2014; 17: 766–770
REFERENCES 1. North RB, Linderoth B. Spinal cord stimulation for chronic pain. In: Quinones-Hinojosa A, ed. Schmidek & Sweet: operative neurosurgical techniques: indications, methods, and results, Vol. 2. Philadelphia: Elsevier Saunders, 2012:1455–1468. 2. Barolat G, Oakley JC, Law JD, North RB, Ketcik B, Sharan A. Epidural spinal cord stimulation with a multiple electrode paddle lead is effective in treating intractable low back pain. Neuromodulation 2001;4:59–66. 3. North RB, Kidd DH, Olin J et al. Spinal cord stimulation for axial low back pain: a prospective, controlled trial comparing dual with single percutaneous electrodes. Spine (Phila Pa 1976) 2005;30:1412–1418. 4. Barolat G, Massaro F, He J, Zeme S, Ketcik B. Mapping of sensory responses to epidural stimulation of the intraspinal neural structures in man. J Neurosurg 1993;78:233–239. 5. Deer TR. Atlas of implantable therapies for pain management. New York: Springer, 2011. 6. Reverberi C, Dario A, Barolat G. Spinal cord stimulation (SCS) in conjunction with peripheral nerve field stimulation (PNfS) for the treatment of complex pain in failed back surgery syndrome (FBSS). Neuromodulation 2013;16:78–82, discussion 83. 7. Mironer YE, Hutcheson JK, Satterthwaite JR, LaTourette PC. Prospective, two-part study of the interaction between spinal cord stimulation and peripheral nerve field stimulation in patients with low back pain: development of a new spinal-peripheral neurostimulation method. Neuromodulation 2011;14:151–154, discussion 155. 8. North RB, Kidd DH, Olin J, Sieracki JN, Petrucci L. Spinal cord stimulation for axial low back pain: a prospective controlled trial comparing 16-contact insulated electrodes with 4-contact percutaneous electrodes. Neuromodulation 2006;9:56–67. 9. Sankarasubramanian V, Buitenweg JR, Holsheimer J, Veltink PH. Staggered transverse tripoles with quadripolar lateral anodes using percutaneous and surgical leads in spinal cord stimulation. Neurosurgery 2013;72:483–491.
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Neuromodulation 2014; 17: 766–770
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