Childs Nerv Syst DOI 10.1007/s00381-013-2320-4
ORIGINAL PAPER
Percutaneous endoscopic interlaminar discectomy for pediatric lumbar disc herniation Xiandi Wang & Jiancheng Zeng & Hongfei Nie & Guo Chen & Zhuhai Li & Hushan Jiang & Qingquan Kong & Yueming Song & Hao Liu
Received: 24 October 2013 / Accepted: 5 November 2013 # Springer-Verlag Berlin Heidelberg 2013
Abstract Purpose Percutaneous endoscopic interlaminar discectomy (PEID) is a widely used minimally invasive procedure which shows satisfying outcomes in the adult population. However, pediatric lumbar disc herniations (PLDH) occur in growing spines and are less related to degeneration, which makes them different from the adult disc herniations. This study evaluates the clinical outcomes of PEID in treating PLDH. Methods A prospect study was done in the period from June 2010 to December 2012, which included 29 consecutive pediatric patients with a mean age of 16.4 years (range, 13 to 18 years) who underwent PEID for single level lumbar disc herniation. The following measuring tools were used: visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and Macnab criteria. Results There were no severe complications such as dural tear or nerve root damage found in our study. The mean follow-up period was 19.7 months. The VAS score for leg and back pain decreased dramatically at 1 day postoperatively and kept decreasing until the follow-up visit at 3 months postoperatively, when it became stable at a low level. ODI kept improving until the follow-up visit at 6 months postoperatively when it reached a stable low level. Of the patients, 91 % reported no longer having leg pain and 9 % had occasional leg pain at last follow-up. Conclusions PEID shows a satisfying outcome with a minimal rate of complications. It has the advantages of minimal traumatization and scar formation and is a safe and effective treatment for PLDH. X. Wang : J. Zeng (*) : H. Nie : G. Chen : Z. Li : H. Jiang : Q. Kong : Y. Song : H. Liu Department of Orthopedic Surgery, West China Hospital of Sichuan University, No. 37 Guo Xue Xiang St, 610041 Chengdu, Sichuan, People’s Republic of China e-mail: [email protected]
Keywords Lumbar disc herniation . Pediatric . Treatment . Percutaneous . Endoscopic interlaminar discectomy
Introduction Pediatric lumbar disc herniation (PLDH) is a rare condition which only constitutes approximately 0.5–5 % of all patients undergoing surgery for lumbar disc herniation [6, 24]. Since 1945, when Wahren reported the first surgical treatment for lumbar disc herniation in a 12-year-old boy [25], open discectomy has been used to treat most PLDH cases [18, 27]. In some special cases, such as lumbar disc herniation contains a bony spur or massive central herniated ruptured particle, lumbar interbody fusion is also used [12]. However, problems arise due to trauma of open surgery such as residual low back pain, operation-induced instabilization, and epidural scarring [21, 27]. These problems can result in poor outcomes. Percutaneous endoscopic lumbar discectomy (PELD), which was introduced to clinical use more than 20 years [16] ago, is becoming a more accepted minimally invasive alternative to the open procedure. There are two major techniques of PELD. They are named according to the difference in approach. The first and the most frequently used technique is percutaneous endoscopic transforaminal discectomy (PETD). The representative techniques are Yeung endoscopic spine system (YESS) [26] and transforaminal endoscopic spine system (TESSYS) [9], in which the instruments are inserted and the herniated discs are removed posterolaterally via the intervertebral foramen. The other procedure of PELD is percutaneous endoscopic interlaminar discectomy (PEID). This technique was developed from PETD and first reported by Ruetten [20] in 2006. In this procedure, instruments are inserted in a posterior approach, through the interlaminar window to the herniated discs. Under direct visualization, the herniatied discs can be removed.
Childs Nerv Syst
Previous studies have proven PEID to be safe and effective in managing adult lumbar disc herniations [10, 23]. With regard to intraoperative blood loss, hospital stay, postoperative complications, and epidural scar formation, patients under PEID showed better results than those under conventional open laminectomy and discectomy (OLD) or microendoscopic discectomy (MED), with the same effect in terms of pain relief and recurrence. However, PLDH occurs in growing spines and is less related to degeneration, which makes them different from the adult disc herniations. The purpose of this prospective noncontrolled nonrandomized study was to evaluate the clinical outcomes of PEID in treating PLDH.
Material and methods Patients In this perspective study between June 2010 to December 2012, 586 consecutive patients with symptomatic PELD were treated by endoscopic discectomy in our institute. According to the following criteria, 29 consecutive patients (male/female =21:8) with mean age of 15.9 years (range, 13 to 18 years) were included in our study. All patients administered fullspine X-ray, lumbar computerized tomography (CT), and magnetic resonance imaging (MRI) at admission. The inclusion criteria are (1) single level central or para-midian region disc herniation localized at L4/5 or L5/S1 level, verified by MRI (2) radicular pain, with or without back pain, lasting for at least 3 months, which was consistent with the radiological findings and respond poorly to conservative treatments. The exclusion criteria are (1) lower back pain without radicular pain; (2) instability of lumbar spine; (3) extreme lateral disc herniation; (4) disc infections, like discitis or tuberculosis; (5) lumbar disc herniation with stenosis; (6) narrow internaminar window; and (7) any history of lumbar spine surgery. The study was approved by the Research Ethics Committee of West China Hospital of Sichuan University and was conducted in accordance with the Declaration of Helsinki. All patients provided written informed consent. Surgical technique The procedure was performed under general anesthesia with endotracheal intubation. All patients were given intravenous antibiotic (1,500 mg cefazolin sodium, if a patient was allergic to it, then 1,200 mg clindamycin was used) prophylaxis 30 min preoperatively. After the general anesthesia, the patients were placed on a radiolucent table in the prone position. By adjusting the operating table, the lumbar spine was flexed to make interlaminar window of the target segment wider. Under the posterior–anterior radiograph, the index segment and anatomic structures were identified and the midline was marked along
the tips of the spinous processes. The craniocaudal middle line of the interlaminar window was also marked. A skin incision of 8 mm made at the symptomatic side, about 0.5 cm lateral to the intersection of the aforementioned two lines. From this point on, the procedure was done under lateral radiograph control. The dilator was then inserted with its tip pointed at the lateral edge of interlaminar window until the bony structure (facet joint) was felt. At this site, if the dilator was tilted a little medial to the superficial surface of the ligament flavum (LF), its elasticity could be palpated. A lateral radiograph was taken to make sure the dilator was at the right segment and proper depth. The dilator then made way for the beveled opening operation sheath. After inserting the operation sheath by clockwise rotating until it reached the facet joint (with its beveled opening toward the medial line), the dilator was removed and the endoscope (SPINENDOS, Germany) with continuous normal saline drainage was put in place. Thereafter, the procedure was performed under direct visual control. The LF was the first structure to be seen under the endoscope; its smooth and yellowish surface was different from other tissues (Fig. 1a). At this time, the tip of the operating sheath should be located at the joint of LF and facet joint. Palpation of the hardness of the LF and face joint with blunt dissector under endoscope helped to confirm the edge. Then, with bipolar radiofrequency electrode (Ellman Trigger-flex probe, Ellman International, Hewitt, NY), a hole was made on the most lateral part of the LF. With a drainage pressure of 80 cmH2O, normal saline can enter the epidural space through the hole and push the dural sac away from the LF. Under direct visual control, the operating sheath was advanced using a gentle forward rotating motion until its tip entered the LF (beveled side facing medially). Epidural fat was usually the first intracanal structure to be encountered, and sometimes in cases with huge disc herniation, especially for the extrusions and sequestrations, the herniatied disc can block the line of sight (Fig. 1b). In these cases, partial removal of the discs was needed before the exposure of the nerve root. The herniated disc fragments should be removed along with epidural fat by bipolar radiofrequency electrode and forceps, so that the nerve root and deeper herniated disc can be exposed (Fig. 1c). After the exposure of the nerve root, the lateral margin of the nerve root was dissected by the blunt dissector and the operation sheath was further advanced to the dissected point. Meanwhile, the operation sheath was rotated 180° with the beveled side facing laterally to retract and protect the nerve root. The disc tissues were further removed under direct visual control. After the disc tissues were removed from the shoulder of the nerve root, the operation sheath was slightly retracted and medially tilted to reach the axilla of the nerve root. With beveled side facing laterally to protect the dural sac, more disc tissue was removed until the nerve root was sufficiently decompressed (Fig. 1d). After the decompression, annulopasty was done using the bipolar radiofrequency electrode.
Childs Nerv Syst Fig. 1 Endoscopic view of a 13-year-old male patient with disc herniation of L5/S1 on the right side. a The ligament flavum is exposed (triangle). b The right S1 nerve root (thin arrow) is compressed by protruded nucleus pulposus (thick arrow), which blocked the endoscopic vision. c After partial discectomy, the nerve root (thin arrow) is exposed and hyperemia can be seen with left nucleus pulposus (thick arrow). d After removal of the nucleus pulposus, the nerve root (thin arrow) is decompressed and annulus fibrosus rupture (star) is closed by bipolar radiofrequency electrode
Any bleeding was checked before removing endoscope, and afterward, 40 mg methylprednisolone was injected around the decompressed nerve root through the operating sheath. The operating sheath was then removed, and a single stitch was given to close the incision and a sterile band-aid was applied. The patients were ambulatory 2 h after the surgery with the protection of a waist support and were discharged the next day. Outcome evaluation To evaluate the pain and functional status of the patients, a trained nurse was assigned to evaluate the visual analog scale (VAS) for back pain and leg pain and to aid patients to finish the Oswestry Disability Index (ODI) questionnaires before surgery and in the follow-ups. The ODI questionnaires we used in our study were versions 2.0, with Section 8 (sex life) omitted [4]. Since there is usually no sex in this age group and it is socially unacceptable to ask pediatric patients questions like this. The scoring system was adjusted to make our results comparable with the complete version [4]. Six follow-ups were given to the patients at 1 day, and at 1, 3, 6, and 12 months after the surgery. At month 3 and at the final follow-up, an MRI was obtained to evaluate the decompression of the nerve root. Macnab criteria were used to evaluate the overall satisfaction of the patients at last follow-up. Statistical analyses Continuous variables were presented as mean ± SD; student’s t test was used to analyze continuous variables. Statistical
analyses were performed using SPSS software, version 19.0 (SPSS Inc, Chicago, IL, USA) for Windows. All comparisons were two-tailed and a p value
ORIGINAL PAPER
Percutaneous endoscopic interlaminar discectomy for pediatric lumbar disc herniation Xiandi Wang & Jiancheng Zeng & Hongfei Nie & Guo Chen & Zhuhai Li & Hushan Jiang & Qingquan Kong & Yueming Song & Hao Liu
Received: 24 October 2013 / Accepted: 5 November 2013 # Springer-Verlag Berlin Heidelberg 2013
Abstract Purpose Percutaneous endoscopic interlaminar discectomy (PEID) is a widely used minimally invasive procedure which shows satisfying outcomes in the adult population. However, pediatric lumbar disc herniations (PLDH) occur in growing spines and are less related to degeneration, which makes them different from the adult disc herniations. This study evaluates the clinical outcomes of PEID in treating PLDH. Methods A prospect study was done in the period from June 2010 to December 2012, which included 29 consecutive pediatric patients with a mean age of 16.4 years (range, 13 to 18 years) who underwent PEID for single level lumbar disc herniation. The following measuring tools were used: visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and Macnab criteria. Results There were no severe complications such as dural tear or nerve root damage found in our study. The mean follow-up period was 19.7 months. The VAS score for leg and back pain decreased dramatically at 1 day postoperatively and kept decreasing until the follow-up visit at 3 months postoperatively, when it became stable at a low level. ODI kept improving until the follow-up visit at 6 months postoperatively when it reached a stable low level. Of the patients, 91 % reported no longer having leg pain and 9 % had occasional leg pain at last follow-up. Conclusions PEID shows a satisfying outcome with a minimal rate of complications. It has the advantages of minimal traumatization and scar formation and is a safe and effective treatment for PLDH. X. Wang : J. Zeng (*) : H. Nie : G. Chen : Z. Li : H. Jiang : Q. Kong : Y. Song : H. Liu Department of Orthopedic Surgery, West China Hospital of Sichuan University, No. 37 Guo Xue Xiang St, 610041 Chengdu, Sichuan, People’s Republic of China e-mail: [email protected]
Keywords Lumbar disc herniation . Pediatric . Treatment . Percutaneous . Endoscopic interlaminar discectomy
Introduction Pediatric lumbar disc herniation (PLDH) is a rare condition which only constitutes approximately 0.5–5 % of all patients undergoing surgery for lumbar disc herniation [6, 24]. Since 1945, when Wahren reported the first surgical treatment for lumbar disc herniation in a 12-year-old boy [25], open discectomy has been used to treat most PLDH cases [18, 27]. In some special cases, such as lumbar disc herniation contains a bony spur or massive central herniated ruptured particle, lumbar interbody fusion is also used [12]. However, problems arise due to trauma of open surgery such as residual low back pain, operation-induced instabilization, and epidural scarring [21, 27]. These problems can result in poor outcomes. Percutaneous endoscopic lumbar discectomy (PELD), which was introduced to clinical use more than 20 years [16] ago, is becoming a more accepted minimally invasive alternative to the open procedure. There are two major techniques of PELD. They are named according to the difference in approach. The first and the most frequently used technique is percutaneous endoscopic transforaminal discectomy (PETD). The representative techniques are Yeung endoscopic spine system (YESS) [26] and transforaminal endoscopic spine system (TESSYS) [9], in which the instruments are inserted and the herniated discs are removed posterolaterally via the intervertebral foramen. The other procedure of PELD is percutaneous endoscopic interlaminar discectomy (PEID). This technique was developed from PETD and first reported by Ruetten [20] in 2006. In this procedure, instruments are inserted in a posterior approach, through the interlaminar window to the herniated discs. Under direct visualization, the herniatied discs can be removed.
Childs Nerv Syst
Previous studies have proven PEID to be safe and effective in managing adult lumbar disc herniations [10, 23]. With regard to intraoperative blood loss, hospital stay, postoperative complications, and epidural scar formation, patients under PEID showed better results than those under conventional open laminectomy and discectomy (OLD) or microendoscopic discectomy (MED), with the same effect in terms of pain relief and recurrence. However, PLDH occurs in growing spines and is less related to degeneration, which makes them different from the adult disc herniations. The purpose of this prospective noncontrolled nonrandomized study was to evaluate the clinical outcomes of PEID in treating PLDH.
Material and methods Patients In this perspective study between June 2010 to December 2012, 586 consecutive patients with symptomatic PELD were treated by endoscopic discectomy in our institute. According to the following criteria, 29 consecutive patients (male/female =21:8) with mean age of 15.9 years (range, 13 to 18 years) were included in our study. All patients administered fullspine X-ray, lumbar computerized tomography (CT), and magnetic resonance imaging (MRI) at admission. The inclusion criteria are (1) single level central or para-midian region disc herniation localized at L4/5 or L5/S1 level, verified by MRI (2) radicular pain, with or without back pain, lasting for at least 3 months, which was consistent with the radiological findings and respond poorly to conservative treatments. The exclusion criteria are (1) lower back pain without radicular pain; (2) instability of lumbar spine; (3) extreme lateral disc herniation; (4) disc infections, like discitis or tuberculosis; (5) lumbar disc herniation with stenosis; (6) narrow internaminar window; and (7) any history of lumbar spine surgery. The study was approved by the Research Ethics Committee of West China Hospital of Sichuan University and was conducted in accordance with the Declaration of Helsinki. All patients provided written informed consent. Surgical technique The procedure was performed under general anesthesia with endotracheal intubation. All patients were given intravenous antibiotic (1,500 mg cefazolin sodium, if a patient was allergic to it, then 1,200 mg clindamycin was used) prophylaxis 30 min preoperatively. After the general anesthesia, the patients were placed on a radiolucent table in the prone position. By adjusting the operating table, the lumbar spine was flexed to make interlaminar window of the target segment wider. Under the posterior–anterior radiograph, the index segment and anatomic structures were identified and the midline was marked along
the tips of the spinous processes. The craniocaudal middle line of the interlaminar window was also marked. A skin incision of 8 mm made at the symptomatic side, about 0.5 cm lateral to the intersection of the aforementioned two lines. From this point on, the procedure was done under lateral radiograph control. The dilator was then inserted with its tip pointed at the lateral edge of interlaminar window until the bony structure (facet joint) was felt. At this site, if the dilator was tilted a little medial to the superficial surface of the ligament flavum (LF), its elasticity could be palpated. A lateral radiograph was taken to make sure the dilator was at the right segment and proper depth. The dilator then made way for the beveled opening operation sheath. After inserting the operation sheath by clockwise rotating until it reached the facet joint (with its beveled opening toward the medial line), the dilator was removed and the endoscope (SPINENDOS, Germany) with continuous normal saline drainage was put in place. Thereafter, the procedure was performed under direct visual control. The LF was the first structure to be seen under the endoscope; its smooth and yellowish surface was different from other tissues (Fig. 1a). At this time, the tip of the operating sheath should be located at the joint of LF and facet joint. Palpation of the hardness of the LF and face joint with blunt dissector under endoscope helped to confirm the edge. Then, with bipolar radiofrequency electrode (Ellman Trigger-flex probe, Ellman International, Hewitt, NY), a hole was made on the most lateral part of the LF. With a drainage pressure of 80 cmH2O, normal saline can enter the epidural space through the hole and push the dural sac away from the LF. Under direct visual control, the operating sheath was advanced using a gentle forward rotating motion until its tip entered the LF (beveled side facing medially). Epidural fat was usually the first intracanal structure to be encountered, and sometimes in cases with huge disc herniation, especially for the extrusions and sequestrations, the herniatied disc can block the line of sight (Fig. 1b). In these cases, partial removal of the discs was needed before the exposure of the nerve root. The herniated disc fragments should be removed along with epidural fat by bipolar radiofrequency electrode and forceps, so that the nerve root and deeper herniated disc can be exposed (Fig. 1c). After the exposure of the nerve root, the lateral margin of the nerve root was dissected by the blunt dissector and the operation sheath was further advanced to the dissected point. Meanwhile, the operation sheath was rotated 180° with the beveled side facing laterally to retract and protect the nerve root. The disc tissues were further removed under direct visual control. After the disc tissues were removed from the shoulder of the nerve root, the operation sheath was slightly retracted and medially tilted to reach the axilla of the nerve root. With beveled side facing laterally to protect the dural sac, more disc tissue was removed until the nerve root was sufficiently decompressed (Fig. 1d). After the decompression, annulopasty was done using the bipolar radiofrequency electrode.
Childs Nerv Syst Fig. 1 Endoscopic view of a 13-year-old male patient with disc herniation of L5/S1 on the right side. a The ligament flavum is exposed (triangle). b The right S1 nerve root (thin arrow) is compressed by protruded nucleus pulposus (thick arrow), which blocked the endoscopic vision. c After partial discectomy, the nerve root (thin arrow) is exposed and hyperemia can be seen with left nucleus pulposus (thick arrow). d After removal of the nucleus pulposus, the nerve root (thin arrow) is decompressed and annulus fibrosus rupture (star) is closed by bipolar radiofrequency electrode
Any bleeding was checked before removing endoscope, and afterward, 40 mg methylprednisolone was injected around the decompressed nerve root through the operating sheath. The operating sheath was then removed, and a single stitch was given to close the incision and a sterile band-aid was applied. The patients were ambulatory 2 h after the surgery with the protection of a waist support and were discharged the next day. Outcome evaluation To evaluate the pain and functional status of the patients, a trained nurse was assigned to evaluate the visual analog scale (VAS) for back pain and leg pain and to aid patients to finish the Oswestry Disability Index (ODI) questionnaires before surgery and in the follow-ups. The ODI questionnaires we used in our study were versions 2.0, with Section 8 (sex life) omitted [4]. Since there is usually no sex in this age group and it is socially unacceptable to ask pediatric patients questions like this. The scoring system was adjusted to make our results comparable with the complete version [4]. Six follow-ups were given to the patients at 1 day, and at 1, 3, 6, and 12 months after the surgery. At month 3 and at the final follow-up, an MRI was obtained to evaluate the decompression of the nerve root. Macnab criteria were used to evaluate the overall satisfaction of the patients at last follow-up. Statistical analyses Continuous variables were presented as mean ± SD; student’s t test was used to analyze continuous variables. Statistical
analyses were performed using SPSS software, version 19.0 (SPSS Inc, Chicago, IL, USA) for Windows. All comparisons were two-tailed and a p value
