CASE REPORT
Ultrasound-Guided S1 Transforaminal Epidural Injection Using the In-Plane Approach and Color Doppler Imaging Donghwi Park, MD Abstract: Recently, several studies have investigated the effectiveness of the ultrasound-guided lumbosacral transforaminal epidural injection. However, the ultrasound-guided S1 transforaminal epidural injection using an out-of-plane approach, which was previously reported, may cause an intestinal injury or intravascular injection because the needle tip tends to be invisible in the out-of-plane approach. In this study, therefore, we report a new method of ultrasound-guided S1 transforaminal epidural injection using the in-plane approach and color Doppler. In addition, we also report the usefulness of color Doppler imaging for finding the S1 foramen and confirming the accuracy of the injection. Key Words: S1 Foramen, Transforaminal Epidural Injection, Ultrasound (Am J Phys Med Rehabil 2017;00:00–00)
lumbosacral transforaminal epidural injection (TFEI) is a A useful treatment for lumbosacral radiculopathies. It is generally performed under x-ray fluoroscopy, which has several 1,2
disadvantages, namely, exposure of the patient to radiation and the need for fluoroscopy equipment.3 Recently, several studies have investigated the effectiveness of ultrasound-guided lumbosacral TFEI.3,4 Among the lumbosacral TFEI techniques, S1 TFEI can be performed easily, unlike other lumbar spine level, because the S1 foramen is easy to find because of its position near the skin.3,4 Although a previous study investigated the usefulness of lumbar TFEI using the in-plane approach, there has been no study of the S1 TFEI using the in-plane approach.5,6 Although a previous study investigated the usefulness of S1 lumbar TFEI, it used the out-of-plane approach.3 The out-of-plane approach may cause an intestinal injury or intravascular injection because the needle tip tends to be invisible.7,8 In this study, therefore, we reported a new method of ultrasound-guided S1 TFEI using the in-plane approach. In addition, we also report the usefulness of color Doppler imaging in finding the S1 foramen and confirming the accuracy of the injection.
CASE REPORT A 57-yr-old woman was seen for referred pain of the right lower limbs that had lasted for 1 mo. She had referred pain stretching out from the lower back to the posterior aspect of the distal lower limb and right sole. Physical examination results at our clinic revealed a positive sign in a straight leg raising test. The patients had no previous history of lumbar spinal From the Department of Rehabilitation Medicine, Daegu Fatima Hospital, Daegu, South Korea. All correspondence and requests for reprints should be addressed to: Donghwi Park, MD, Department of Rehabilitation Medicine, Daegu Fatima Hospital, Ayangro 99, Dong gu, Daegu 41199, Republic of Korea. Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.ajpmr.com). Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0894-9115 DOI: 10.1097/PHM.0000000000000754
surgery. There was no weakness, but there was sensory impairment of the posterior aspect of the right distal lower limb and the lateral heel area. A magnetic resonance image showed a herniated nucleus pulposus between L5 and S1 in the vertebral body. Considering both the radiologic findings and clinical examination, the patients received a diagnosis of herniated nucleus pulposus between L5 and S1 in the vertebral body causing right S1 radiculopathy. Then, the patient agreed to an ultrasound-guided S1 TFEI after a detailed explanation of the disease and treatment.
METHODS The patient was placed in a lateral decubitus position adopting the maximal knee chest position. After aseptic preparation of the puncture site, a 2- to 5-MHz curved ultrasound probe (Samsung Medison, Hongchun, South Korea) was placed in its sterile plastic bag with ultrasound gel, and the probe was positioned longitudinally to the parasacral area, approximately 2 cm lateral to the midline to identify the articular processes of the lower lumbar vertebrae and posterior sacral surface.3 The articular process observed at the extreme caudal side corresponds to the L5/S1 level, and the concavity at the posterior sacral surface located at a slightly caudal site is the S1 posterior sacral foramen.3 The probe was inclined caudally to make sufficient space to insert the needle into the S1 foramen. Unlike other studies, which have reported ultrasoundguided S1 TFEI, we used the in-plane approach, which showed the needle tip and direction of needle movement well. A 100-mm 25G spinal needle (Taechang, Gongju, South Korea) was pointed slightly caudal from the caudal side of the probe and advanced toward the target with ultrasound guidance (Fig. 1A). Because of the artifact of the color Doppler by the needle, such as the twinkling artifact,9 the needle was advanced slowly until the needle tip was located in the S1 foramen without using color Doppler. Then, 2 ml of 1% lidocaine was slowly injected, followed by 1 ml of contrast medium, iohexol (omnipaque 300; Amersham Health, Cork, Ireland) injection using color Doppler. Then, a total 6 ml of mixed 0.5 mg of dexamethasone (South Korea) and normal saline were slowly injected. By using color Doppler imaging,
American Journal of Physical Medicine & Rehabilitation • Volume 00, Number 00, Month 2017
www.ajpmr.com
Copyright © 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
1
Volume 00, Number 00, Month 2017
Park
FIGURE 1. A, Ultrasound image of the S1 and S2 foramen. The needle tip is inserted into the S1 foramen. B–D, Consecutive color Doppler images during S1 TFEI. Arrow, the flow of the injected drug. Arrowhead, superior branch of the lateral sacral artery going through and coming out of the S2 foramen.
we observed the flow of the injected material to determine whether the injection had been successful or not (Figs. 1B–D). After the S1 TFEI, the patient felt numbness from the left gluteal area to the posterior aspect of the distal lower limb and experienced mild improvement of referred pain. After the injection, the distribution of contrasts was confirmed by fluoroscopy (Figs. 2A, B). One week after the ultrasound-guided S1 TFEI, the patient showed improvement of the referred pain from visual analogue scale 5 to 1. This study conforms to all CONSORT guidelines and reports the required information accordingly (see Supplementary Checklist, http://links.lww. com/PHM/A426).
DISCUSSION By using ultrasound in S1 transforaminal epidural injection, the radiation exposure can be overcome. However, in
S1 TFEI using the out-of-plane approach, which was previously reported, the depth of the needle position was not visible. As a result, the out-of-plane approach cannot be free from complications, such as bowel perforation or intravascular injection. Unlike the out-of-plane approach, however, the inplane approach described in our report can show a complete view of the needle, which can reduce the complications of ultrasound-guided S1 TFEI. Moreover, in our report, we used color Doppler imaging in the ultrasound-guided S1 TFEI. To our knowledge, there has been no report about the usefulness of color Doppler imaging in ultrasound-guided S1 TFEI. There are several advantages when color Doppler imaging is used in ultrasound-guided S1 TFEI. First, the S1 and S2 foramens are found easily by using this method. Although it may be difficult to find the S1 foramen for clinicians who are not familiar with ultrasound-guided S1 TFEI, finding the superior
FIGURE 2. A and B, Contrast distribution was shown in fluoroscopy after ultrasound-guided S1 TFEI. Contrast raise until L5/S1 intervertebral disc (arrow). The contrast distribution pattern showed a successful ultrasound-guided S1 TFEI.
2
www.ajpmr.com
© 2017 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Volume 00, Number 00, Month 2017
branch of the lateral sacral artery passing through the S1 and S2 foramen in color Doppler imaging may help clinicians locate the S1 foramen (Figs. 2B–D) because the superior branch of the lateral sacral artery, which originates from the posterior division of the internal iliac artery, enters the S1 and S2 foramina.10 A second advantage is that the injection was started with color Doppler ultrasound imaging that allowed the detection of the intraforaminal flow of the injected drug or the extraforaminal placement of the injected drug by using the characteristics of color Doppler to detect the flow and express it in color.11 Unlike the out-of-plane approach, the needle tip cannot enter the epidural space because of the angle of needle insertion. In addition, there was a limitation to verify the contrast distribution and rule out intravascular injection, because S1 TFEI using color Doppler is not a method established by many studies. However, we showed that ultrasound-guided S1 TFEI using the in-plane approach and color Doppler imaging could be successful through examining the contrast distribution in fluoroscopy after the ultrasound-guided S1 TFEI. Therefore, if there is no fluoroscopy equipment available or there is a reason to avoid exposure to radiation, ultrasound-guided S1 TFEI can be considered as one of the treatment options for patients with S1 radiculopathies.
© 2017 Wolters Kluwer Health, Inc. All rights reserved.
Ultrasound-Guided S1 Transforaminal Injection
REFERENCES 1. Macnab I: Negative disc exploration. An analysis of the causes of nerve-root involvement in sixty-eight patients. J Bone Joint Surg Am 1971;53:891–903 2. Tajima T, Furukawa K, Kuramochi E: Selective lumbosacral radiculography and block. Spine (Phila Pa 1976) 1980;5:68–77 3. Sato M, Mikawa Y, Matuda A: Ultrasound and electrical nerve stimulation-guided S1 nerve root block. J Anesth 2013;27:775–7 4. Gofeld M, Bristow SJ, Chiu SC, et al: Ultrasound-guided lumbar transforaminal injections: feasibility and validation study. Spine 2012;37:808–12 5. Galiano K, Obwegeser AA, Bodner G, et al: Real-time sonographic imaging for periradicular injections in the lumbar spine: a sonographic anatomic study of a new technique. J Ultrasound Med 2005;24:33–8 6. Sahu DK, Sharma A, Kothari K, et al: Ultrasound-guided fluoroscopic-verified lumbar transforaminal epidural injection: a clinical evaluation of technique. Indian J Pain 2016;30:158–61 7. Park D, Ryu JS: Authors' response to Letter to the Editor “Ultrasound-Guided C7 Cervical Medial Branch Block Using the In-Plane Approach”. Am J Phys Med Rehabil 2017; doi: 10.1097/PHM.0000000000000695. [Epub ahead of print] 8. Goodman BS, Posecion LW, Mallempati S, et al: Complications and pitfalls of lumbar interlaminar and transforaminal epidural injections. Curr Rev Muscoskelet Med 2008; 1:212–22 9. Tsao TF, Wu YL, Yu JM, et al: Color Doppler twinkling artifact of calcified cardiac valves in vitro: a not well known phenomenon in echocardiography. Ultrasound Med Biol 2011;37:386–92 10. Ergur I, Akcali O, Kiray A, et al: Neurovascular risks of sacral screws with bicortical purchase: an anatomical study. Eur Spine J 2007;16:1519–23 11. Migliore A, Bizzi E, Massafra U, et al: A new technical contribution for ultrasound-guided injections of sacro-iliac joints. Eur Rev Med Pharmacol Sci 2010;14:465–9
www.ajpmr.com
Copyright © 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
3
Ultrasound-Guided S1 Transforaminal Epidural Injection Using the In-Plane Approach and Color Doppler Imaging Donghwi Park, MD Abstract: Recently, several studies have investigated the effectiveness of the ultrasound-guided lumbosacral transforaminal epidural injection. However, the ultrasound-guided S1 transforaminal epidural injection using an out-of-plane approach, which was previously reported, may cause an intestinal injury or intravascular injection because the needle tip tends to be invisible in the out-of-plane approach. In this study, therefore, we report a new method of ultrasound-guided S1 transforaminal epidural injection using the in-plane approach and color Doppler. In addition, we also report the usefulness of color Doppler imaging for finding the S1 foramen and confirming the accuracy of the injection. Key Words: S1 Foramen, Transforaminal Epidural Injection, Ultrasound (Am J Phys Med Rehabil 2017;00:00–00)
lumbosacral transforaminal epidural injection (TFEI) is a A useful treatment for lumbosacral radiculopathies. It is generally performed under x-ray fluoroscopy, which has several 1,2
disadvantages, namely, exposure of the patient to radiation and the need for fluoroscopy equipment.3 Recently, several studies have investigated the effectiveness of ultrasound-guided lumbosacral TFEI.3,4 Among the lumbosacral TFEI techniques, S1 TFEI can be performed easily, unlike other lumbar spine level, because the S1 foramen is easy to find because of its position near the skin.3,4 Although a previous study investigated the usefulness of lumbar TFEI using the in-plane approach, there has been no study of the S1 TFEI using the in-plane approach.5,6 Although a previous study investigated the usefulness of S1 lumbar TFEI, it used the out-of-plane approach.3 The out-of-plane approach may cause an intestinal injury or intravascular injection because the needle tip tends to be invisible.7,8 In this study, therefore, we reported a new method of ultrasound-guided S1 TFEI using the in-plane approach. In addition, we also report the usefulness of color Doppler imaging in finding the S1 foramen and confirming the accuracy of the injection.
CASE REPORT A 57-yr-old woman was seen for referred pain of the right lower limbs that had lasted for 1 mo. She had referred pain stretching out from the lower back to the posterior aspect of the distal lower limb and right sole. Physical examination results at our clinic revealed a positive sign in a straight leg raising test. The patients had no previous history of lumbar spinal From the Department of Rehabilitation Medicine, Daegu Fatima Hospital, Daegu, South Korea. All correspondence and requests for reprints should be addressed to: Donghwi Park, MD, Department of Rehabilitation Medicine, Daegu Fatima Hospital, Ayangro 99, Dong gu, Daegu 41199, Republic of Korea. Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.ajpmr.com). Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0894-9115 DOI: 10.1097/PHM.0000000000000754
surgery. There was no weakness, but there was sensory impairment of the posterior aspect of the right distal lower limb and the lateral heel area. A magnetic resonance image showed a herniated nucleus pulposus between L5 and S1 in the vertebral body. Considering both the radiologic findings and clinical examination, the patients received a diagnosis of herniated nucleus pulposus between L5 and S1 in the vertebral body causing right S1 radiculopathy. Then, the patient agreed to an ultrasound-guided S1 TFEI after a detailed explanation of the disease and treatment.
METHODS The patient was placed in a lateral decubitus position adopting the maximal knee chest position. After aseptic preparation of the puncture site, a 2- to 5-MHz curved ultrasound probe (Samsung Medison, Hongchun, South Korea) was placed in its sterile plastic bag with ultrasound gel, and the probe was positioned longitudinally to the parasacral area, approximately 2 cm lateral to the midline to identify the articular processes of the lower lumbar vertebrae and posterior sacral surface.3 The articular process observed at the extreme caudal side corresponds to the L5/S1 level, and the concavity at the posterior sacral surface located at a slightly caudal site is the S1 posterior sacral foramen.3 The probe was inclined caudally to make sufficient space to insert the needle into the S1 foramen. Unlike other studies, which have reported ultrasoundguided S1 TFEI, we used the in-plane approach, which showed the needle tip and direction of needle movement well. A 100-mm 25G spinal needle (Taechang, Gongju, South Korea) was pointed slightly caudal from the caudal side of the probe and advanced toward the target with ultrasound guidance (Fig. 1A). Because of the artifact of the color Doppler by the needle, such as the twinkling artifact,9 the needle was advanced slowly until the needle tip was located in the S1 foramen without using color Doppler. Then, 2 ml of 1% lidocaine was slowly injected, followed by 1 ml of contrast medium, iohexol (omnipaque 300; Amersham Health, Cork, Ireland) injection using color Doppler. Then, a total 6 ml of mixed 0.5 mg of dexamethasone (South Korea) and normal saline were slowly injected. By using color Doppler imaging,
American Journal of Physical Medicine & Rehabilitation • Volume 00, Number 00, Month 2017
www.ajpmr.com
Copyright © 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
1
Volume 00, Number 00, Month 2017
Park
FIGURE 1. A, Ultrasound image of the S1 and S2 foramen. The needle tip is inserted into the S1 foramen. B–D, Consecutive color Doppler images during S1 TFEI. Arrow, the flow of the injected drug. Arrowhead, superior branch of the lateral sacral artery going through and coming out of the S2 foramen.
we observed the flow of the injected material to determine whether the injection had been successful or not (Figs. 1B–D). After the S1 TFEI, the patient felt numbness from the left gluteal area to the posterior aspect of the distal lower limb and experienced mild improvement of referred pain. After the injection, the distribution of contrasts was confirmed by fluoroscopy (Figs. 2A, B). One week after the ultrasound-guided S1 TFEI, the patient showed improvement of the referred pain from visual analogue scale 5 to 1. This study conforms to all CONSORT guidelines and reports the required information accordingly (see Supplementary Checklist, http://links.lww. com/PHM/A426).
DISCUSSION By using ultrasound in S1 transforaminal epidural injection, the radiation exposure can be overcome. However, in
S1 TFEI using the out-of-plane approach, which was previously reported, the depth of the needle position was not visible. As a result, the out-of-plane approach cannot be free from complications, such as bowel perforation or intravascular injection. Unlike the out-of-plane approach, however, the inplane approach described in our report can show a complete view of the needle, which can reduce the complications of ultrasound-guided S1 TFEI. Moreover, in our report, we used color Doppler imaging in the ultrasound-guided S1 TFEI. To our knowledge, there has been no report about the usefulness of color Doppler imaging in ultrasound-guided S1 TFEI. There are several advantages when color Doppler imaging is used in ultrasound-guided S1 TFEI. First, the S1 and S2 foramens are found easily by using this method. Although it may be difficult to find the S1 foramen for clinicians who are not familiar with ultrasound-guided S1 TFEI, finding the superior
FIGURE 2. A and B, Contrast distribution was shown in fluoroscopy after ultrasound-guided S1 TFEI. Contrast raise until L5/S1 intervertebral disc (arrow). The contrast distribution pattern showed a successful ultrasound-guided S1 TFEI.
2
www.ajpmr.com
© 2017 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Volume 00, Number 00, Month 2017
branch of the lateral sacral artery passing through the S1 and S2 foramen in color Doppler imaging may help clinicians locate the S1 foramen (Figs. 2B–D) because the superior branch of the lateral sacral artery, which originates from the posterior division of the internal iliac artery, enters the S1 and S2 foramina.10 A second advantage is that the injection was started with color Doppler ultrasound imaging that allowed the detection of the intraforaminal flow of the injected drug or the extraforaminal placement of the injected drug by using the characteristics of color Doppler to detect the flow and express it in color.11 Unlike the out-of-plane approach, the needle tip cannot enter the epidural space because of the angle of needle insertion. In addition, there was a limitation to verify the contrast distribution and rule out intravascular injection, because S1 TFEI using color Doppler is not a method established by many studies. However, we showed that ultrasound-guided S1 TFEI using the in-plane approach and color Doppler imaging could be successful through examining the contrast distribution in fluoroscopy after the ultrasound-guided S1 TFEI. Therefore, if there is no fluoroscopy equipment available or there is a reason to avoid exposure to radiation, ultrasound-guided S1 TFEI can be considered as one of the treatment options for patients with S1 radiculopathies.
© 2017 Wolters Kluwer Health, Inc. All rights reserved.
Ultrasound-Guided S1 Transforaminal Injection
REFERENCES 1. Macnab I: Negative disc exploration. An analysis of the causes of nerve-root involvement in sixty-eight patients. J Bone Joint Surg Am 1971;53:891–903 2. Tajima T, Furukawa K, Kuramochi E: Selective lumbosacral radiculography and block. Spine (Phila Pa 1976) 1980;5:68–77 3. Sato M, Mikawa Y, Matuda A: Ultrasound and electrical nerve stimulation-guided S1 nerve root block. J Anesth 2013;27:775–7 4. Gofeld M, Bristow SJ, Chiu SC, et al: Ultrasound-guided lumbar transforaminal injections: feasibility and validation study. Spine 2012;37:808–12 5. Galiano K, Obwegeser AA, Bodner G, et al: Real-time sonographic imaging for periradicular injections in the lumbar spine: a sonographic anatomic study of a new technique. J Ultrasound Med 2005;24:33–8 6. Sahu DK, Sharma A, Kothari K, et al: Ultrasound-guided fluoroscopic-verified lumbar transforaminal epidural injection: a clinical evaluation of technique. Indian J Pain 2016;30:158–61 7. Park D, Ryu JS: Authors' response to Letter to the Editor “Ultrasound-Guided C7 Cervical Medial Branch Block Using the In-Plane Approach”. Am J Phys Med Rehabil 2017; doi: 10.1097/PHM.0000000000000695. [Epub ahead of print] 8. Goodman BS, Posecion LW, Mallempati S, et al: Complications and pitfalls of lumbar interlaminar and transforaminal epidural injections. Curr Rev Muscoskelet Med 2008; 1:212–22 9. Tsao TF, Wu YL, Yu JM, et al: Color Doppler twinkling artifact of calcified cardiac valves in vitro: a not well known phenomenon in echocardiography. Ultrasound Med Biol 2011;37:386–92 10. Ergur I, Akcali O, Kiray A, et al: Neurovascular risks of sacral screws with bicortical purchase: an anatomical study. Eur Spine J 2007;16:1519–23 11. Migliore A, Bizzi E, Massafra U, et al: A new technical contribution for ultrasound-guided injections of sacro-iliac joints. Eur Rev Med Pharmacol Sci 2010;14:465–9
www.ajpmr.com
Copyright © 2017 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
3
