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Long term results of lumbar sequestrectomy versus aggressive microdiscectomy
Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Long term results of lumbar sequestrectomy versus aggressive microdiscectomy Kadir Kotil a,⇑, Neslihan Sutpideler Köksal b, Selim Kayaci c _ Arel University, Department of Neurologic Sciences, Türkoba Mahallesi Erguvan Sokak No: 26/K, Tepekent, 34537 Büyükçekmece, Turkey T.C. ISTANBUL Istanbul Educational and Research Hospital, Istanbul, Turkey c T.C. Rize Tayyip Erdog˘an University, Rize Merkez, Rize, Turkey a
b
a r t i c l e
i n f o
Article history: Received 11 September 2013 Accepted 13 January 2014 Available online xxxx Keywords: Aggressive microdiscectomy Disc herniation Lumbar Sequestrectomy
a b s t r a c t It remains unknown whether aggressive microdiscectomy (AD) provides a better outcome than simple sequestrectomy (S) with little disc disruption for the treatment of lumbar disc herniation with radiculopathy. We compared the long term results for patients with lumbar disc herniation who underwent either AD or S. The patients were split into two groups: 85 patients who underwent AD in Group A and 40 patients who underwent S in Group B. The patients were chosen from a cohort operated on by the same surgeon using either of the two techniques between 2003 and 2008. The demographic characteristics were similar. The difference in complication rates between the two groups was not statistically significant. During the first 10 days post-operatively, the Visual Analog Scale score for back pain was 4.1 in Group A and 2.1 in Group B, and the difference was statistically significant (p < 0.005). The Oswestry Disability Index score was 11% in Group A and 19% in Group B at the last examination. The reherniation rate was 1.5% in Group A and 4.1% in Group B (p < 0.005). We argue that reherniation rates are much lower over the long term when AD is used with microdiscectomy. AD increases back pain for a short time but does not change the long term quality of life. To our knowledge this is the first study with a very long term follow-up showing that reherniation is three times less likely after AD than S. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Although it has been 85 years since the first disc surgery was performed, new surgical techniques remain unsatisfactory and have disappointed many patients. Discectomy techniques have evolved considerably since Dandy in 1929 [1], but success rates have still not reached the desirable level. O’Connell [2] described an open surgery, which consisted of curettage of all elements of the intervertebral space. Microdiscectomy was popularized by Williams, who described limited or conservative discectomy [3]. There have been very few evidence-based, high quality studies to clarify which of these techniques is more effective, and there is no current consensus. Reherniation rates vary according to the technique used and range between 7% and 26% [4,5]. While the defenders of radical or aggressive microdiscectomy (AD) claim it results in lower than expected reherniation rates, those recommending limited discectomy or sequestrectomy (S) claim better preservation of intervertebral disc height, expected or lower than expected reherniation rates and better quality of life [6,7]. However, most of these studies ⇑ Corresponding author. Tel.: +90 216 360 1226; fax: +90 212 633 1698. E-mail address: [email protected] (K. Kotil).
were based on low quality evidence. In this study, patients receiving either S or AD were evaluated for clinical and radiological parameters at various time points, and the long term results are reported.
2. Materials and methods A total of 165 patients undergoing surgery for lumbar disc disease were divided into two groups: Group A consisted of 85 patients who underwent AD, and Group B consisted of 40 patients who underwent S. Both groups were operated on by one surgeon between February 2003 and May 2008 using one of the two techniques. Patients were evaluated prospectively at two independent practices, one where S was performed and one where AD was performed. The demographic characteristics of the two groups were similar. The mean age of patients in Group A was 41.1 years (range 18–74), and Group B was 39.9 years (range 22–69). The male/ female ratio was 37/48 in Group A and 19/21 in Group B. Thirty-five patients who could not be contacted at any point during the study period were excluded. Patients who had been operated on before, who had other degenerative problems such as spinal
http://dx.doi.org/10.1016/j.jocn.2014.01.012 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
2
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
stenosis, or who had far lateral herniations were also excluded. Patients with single level lumbar disc herniation between L1 and S1 who did not use antipsychotics were included. Group B patients had ruptured discs with sequestrated fragments. All patients who had lumbar disc protrusion were rejected. The patients were questioned by an independent observer at 6, 12, 24 and 60 months after surgery (Fig. 1, 2). Both groups were evaluated clinically and radiographically. The evaluated parameters included pre- and post-operative radiological features, pre and post-operative intervertebral disc height, duration of surgery, complications, analgesic use and reherniation rates. Age, affected lumbar level, male to female ratio and other parameters are given in Table 1. Oswestry
Disability Index (ODI) and Visual Analog Scale (VAS) scores are given in Table 2. Changes in intervertebral disc height and reherniation rates are shown in Table 3. The percentages were calculated as the loss of intervertebral disc height on plain standing radiographs. 2.1. Surgical technique In both groups, the surgical technique was the same up to the posterior longitudinal ligament level. A 3 cm skin incision was made, and when the laminae were reached, a minihemilaminectomy was made with the aid of an operating microscope. The
Fig. 1. (a) Axial and (b) sagittal T2-weighted pre-operative MRI of a patient who underwent aggressive discectomy surgery for L4–L5 disc herniation. (c) Post-operative sagittal T2-weighted MRI at 5.2 years showing a 30% decrease in disc space height. The decrease in foraminal height is minimal (5%) in spite of the decrease in disc space height.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
3
Fig. 2. (a) Axial and (b) sagittal pre-operative T2-weighted MRI of a patient who underwent sequestrectomy surgery for L4–L5 extruded disc herniation. (c) Sagittal MRI showing a normal foraminal height at 5 years.
ligamentum flavum was separated from its inferior and superior attachments, and the thick upper layer was excised. Group B patients were operated on using sequestrectomy because they had a small annular defect with a sequestrated fragment. Patients with large annular defects were accepted as candidates for Group A. In AD, the posterior longitudinal ligament (PLL) was opened until the annular defect was reached. Sequestrated fragments were searched for above and below the PLL with a long nerve hook. Then, the disc space was thoroughly curetted until bone was felt at the end plates. The aim of AD is to leave no intervertebral disc
tissue anywhere in the disc space. In S, only the sequestrated nucleus pulposus was removed. In both techniques 25 mg bupivacaine was administered intramuscularly to the surgical field. 2.2. Statistical analysis Age, body weight, pre-operative disc height, VAS values for back and leg pain, ODI, and post-operative disc height were compared with Student’s t-test. The relationship between them was tested with regression analysis. The Kaplan–Meier method was used to determine reherniation rates.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
4
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Table 1 Baseline patient characteristics
Patients, n Age, range (mean) Male/Female Follow-up, months, mean (range) Level operated on L1–L2 L2–L3 L3–L4 L4–L5 L5–S1 Duration of surgery, minutes Length of hospital stay, days Post-operative neurologic deficit
Group A Aggressive discectomy
Group B Sequestrectomy
85 18–74 (41.1) 37/48 60.2 (49–68)
40 22–69 (39.9) 19/21 60.2 (50.5–66)
2 4 15 34 30 46
3 5 5 15 12 35
1.2
0.9
2.3
1.25
Table 3 Reherniation rates and disc height changes in patients undergoing aggressive microdiscectomy (Group A) or sequestrectomy (Group B)
Follow-up time Reherniation Decrease in disc height
Group A Aggressive discectomy
Group B Sequestrectomy
1 year 1.3% 28%
1 year 2.1% 18%
5 years 1.5% 32%
5 years 4.1% 20%
The measurement of the foramina across both groups showed a mean decrease of 5% in height (3.5–8%), which had no clinical or statistical significance (p = 0.06). Patients in Group A needed two different analgesic and anti-inflammatory drugs in the first 10 post-operative days, whereas the patients in Group B needed only one (p = 0.55).
4. Discussion
3. Results Data on 125 patients who had long term follow-up were collected and compared. The mean duration of follow-up was 5.2 years (range 49–68 months). There were two groups of patients: Group A included patients who underwent AD, and Group B included patients who underwent S. The mean duration of surgery was 46 minutes in Group A and 35 minutes in Group B. In terms of complications, there were five peri-operative dural tears in Group A (5.8%), two of which led to foot drop (2.3%). In Group B, there was only one dural tear. In this patient, partial foot-drop evolved to total foot-drop, but near total improvement was observed during post-operative week 2 (1.25%). There was no statistically significant difference in terms of neurological deficit rates (p > 0.0001, Fisher’s exact test). Superficial wound infection was observed in three patients in Group A and two patients in Group B, and these patients were treated on an outpatient basis. The mean duration of hospital stay was 1.2 days in Group A and 0.9 days (20 hours) in Group B (Table 1). Special demands of some patients to lengthen their hospital stay were not included in these calculations. Reherniation rates were found to be 1.3% in Group A and 4.1% in Group B. This was higher than could be explained by the smaller number of patients in Group B (p = 1.00). While leg pain VAS values improved within similar time periods in both groups, back pain VAS values improved earlier in Group B (p = 0.05) (Table 2). Pre-operative disc height values and the post-operative changes in these values are shown in Table 3. The most noteworthy result is the maximal change in disc height at the level of L5–S1. There was no indication that any of the aggressively treated patients went on to spontaneously develop intervertebral fusion.
The most important complications of lumbar disc surgery are reherniation or recurrence [4,8]. The most widely accepted reasons for these are iatrogenic or spontaneous disc degeneration, stress on the facet capsule, incomplete removal of the degenerated disc material, chronic instability of the segment, and individual factors. In addition, biomechanical factors, including spine length, obesity and the amount of muscle support, may also lead to reherniation [8,9]. Because reherniation continues to be a problem in lumbar disc surgery, several new techniques have been considered during the past few decades in an attempt to achieve the best possible results with minimally invasive surgery. Chemonucleolysis, radiofrequency ablation, and laser ablation are some of the newly applied techniques that have failed to become viable alternatives to discectomy due to low success rates [6,10]. Although minimally invasive disc surgery has many advantages, its most important disadvantage is the inability to prevent reherniation. For this reason, the technique has begun to be questioned. Which technique can best prevent reherniation remains to be determined by studies including high quality evidence and long follow-up times. Most comparative studies in the literature include only low quality evidence. Varying reherniation rates are reported in different case series after S, subtotal discectomy, aggressive discectomy, macrodiscectomy, microdiscectomy and percutaneous endoscopic discectomy [4–6,11–14]. Watters et al. reported, in their metaanalysis of comparative studies, that the conservative technique was not superior to aggressive discectomy and had a 2.5-fold higher reherniation rate [4]. In a review by McGirt et al., the reherniation rate after lumbar discectomy reported by different authors between 1988 and 2006 in 5832 patients was 7%, while it was 3.5% in 6114 patients after AD over the same time period [5]. Carragee et al. reported reherniation rates to be twice as high following a conservative technique compared to the more aggressive approach [15], but Thome et al. [16] found similar rates among their patients
Table 2 Pre and post-operative VAS and ODI scores VAS
Pre-op Post-op
1 year 2 years 5 years
ODI
Group A
Group B
(back, leg) 7.3 (2–8), 5.3 1.9 (1–5), 0.8 1.2 (1–3), 0.4 1.1 (1–2), 0.6
(back, leg) 6.9 (2–9), 6.8 2.1 (1–3), 0.4 1.1 (1–2), 0.2 4.1 (1–7), 4.6
(3–10) (1–3) (1–2) (1–3)
(2–10) (0–2) (0–4) (0–7)
Group A
Group B
38% (15–78) 12% (5–15) 5% (5–12) 11% (5–15)
42% (16–75) 8% (5–15) 12% (5–19) 19% (5–34)
Data are presented as mean (range). ODI = Oswestry Disability Index, Post-op = post-operative, Pre-op = pre-operative, VAS = Visual Analog Scale. Group A = aggressive discectomy, Group B = sequestrectomy.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
at the 1 year follow-up. In Group B, we observed the greatest incidence of reherniation after the second year, although early return to work and a more comfortable post-operative course was constant throughout the follow-up. This contradicts the study of Barth et al. [17] who observed that as follow-up time increases, reherniation rates also increase. In our study, we also observed increasing reherniation rates with longer follow-up times for the S technique, but this was not the case for AD. Although AD provides effective decompression and lower reherniation rates, an important disadvantage is the back pain due to the curettage of the nucleus and end plates. This increases the need for analgesic therapy after surgery [4]. In S, on the other hand, back pain is not the issue, but reherniation is higher than for AD [4]. In our study, back pain was found to be bothersome in the first 10 days after surgery, and it was overcome with intense anti-inflammatory and analgesic drug use. In our patients, peri-operative, intramuscularly injected local anesthetic (prilocaine 25 mg) provided some pain relief in the first days, and anti-inflammatory and analgesic drugs suppressed pain in the following days. In Group A, the back pain VAS value was 5 in the first 10 days but decreased to 2 thereafter. In Group B, the back pain VAS value ranged between 3 and 5 in the first 3 days. Leg pain was negligible in both groups. We found a significant improvement in both VAS and ODI for both groups at the 6 month follow-up. However, in Group B, both VAS and ODI values increased 2 years later. While some authors propose that curettage leads to a decrease in disc space height and lowers the long term quality of life, others claim that these changes occur with normal aging of the disc and are not a cause of pain [18,19]. Yorimitsu et al. investigated long term follow-up results in patients who were observed for a minimum of 10 years after standard discectomy and were evaluated using the Japanese Orthopedic Association scoring system through direct examinations and questionnaires. The final Japanese Orthopedic Association scores for the patients with decreased disc height were significantly lower than those for patients with no decrease. However, the disc height of patients with a recurrent herniation was maintained [20]. McGirt et al. also reported that a decrease in disc space height had no effect on prognosis after 2 years of follow-up [11]. Similarly, in our patients, especially in Group A, a continual decrease in disc space height over time was a cause of pain in the first 6 weeks post-operatively, but it was insignificant in both groups in the long term, after the stabilization period of 6 months. Thus, our patients had no complaints attributable to AD. In this study, the overall mean decrease in disc height was found to be 28% after the first year and 32% after the fifth year; analgesics were no longer needed after 6 months (range 5.5–7.8). Analgesic drug use was intermittent and very minimal in dose. In Group A, the decrease in disc height had stabilized in 96% of patients after 2 years, and no further change was observed at the end of the fifth year. In Group B, on the other hand, the decrease in disc height was much slower and was observed to continue for up to 2 years. In this group, 20% continued to exhibit a decrease in disc height at 5 years, and the stabilization period was of slower onset, but there was no correlation between the decrease in disc space height and back or radicular pain. This difference may be related to post-operative physiotherapy, changes in body weight, surgical technique and concomitant overlooked parameters. In terms of sensory and motor deficit present pre-operatively, we found a similar rate of improvement at 5 years in both groups. A systematic review of the literature suggests that S may result in shorter operative times and a quicker return to work [4]. We did find that the operative time needed to perform S was shorter. The mean duration of hospital stay was 1.2 days in Group A and 0.9 days (20 hours) in Group B.
5
5. Conclusions We suggest that reherniation rates are lower over the long term when AD is used. AD decreases back comfort for a short time but does not change the long term quality of life. To our knowledge this is the first study with very long term follow-up showing that reherniation is three times less likely in AD when compared with S. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Dandy WE. Loose cartilage from intervertebral disk simulating tumour of the spinal cord. Arch Surg 1929;19:660–72. [2] O’Connell JE. Protrusions of the lumbar intervertebral disc. A clinical review based on the five hundred cases treated by excision of the protrusion. J Bone Joint Surg Br 1951;33:8–30. [3] Williams RW. Microlumbar discectomy: conservative surgical approach to the virgin herniated lumbar disc. Spine (Phila Pa 1976) 1978;3:175–82. [4] Watters WC 3rd, McGirt MJ. An evidence-based review of the literature on the consequences of conservative versus aggressive discectomy for the treatment of primary disc herniation with radiculopathy. Spine J 2009;9:240–57. [5] McGirt MJ, Ambrossi GL, Datoo G. Recurrent disc herniation and long-term back pain after primary lumbar discectomy: review of outcomes reported for limited versus aggressive disc removal. Neurosurgery 2009;64:338–44 [discussion 344–5]. [6] Mochida J, Toh E, Nomura T, et al. The risks and benefits of percutaneous nucleotomyfor lumbar disc herniation. A 10-year longitudinal study. J Bone Joint Surg Br 2001;83:501–5. [7] Fakouri B, Patel V, Bayley E. Lumbar microdiscectomy versus sequesterectomy/ free fragmentectomy: a long-term (>2 y) retrospective study of the clinical outcome. J Spinal Disord Tech 2011;24:6–10. [8] Wera GD, Dean CL, Ahn UM, et al. Reherniation and failure after lumbar discectomy: a comparison of fragment excision alone versus subtotal discectomy. J Spinal Disord Tech 2008;21:316–9. [9] Mariconda M, Galasso O, Secondulfo V, et al. Minimum 25-year outcome and functional assessment of lumbar discectomy. Spine (Phila Pa 1976) 2006;31:2593–9 [discussion 2600-1]. [10] Schick U, Elhabony R. Prospective comparative study of lumbar sequestrectomy and microdiscectomy. Minim Invasive Neurosurg 2009;52:180–5. [11] McGirt MJ, Eustacchio S, Varga P, et al. A prospective cohort study of close interval computed tomography and magnetic resonance imaging after primary lumbar discectomy: factors associated with recurrent disc herniation and disc height loss. Spine (Phila Pa 1976) 2009;34:2044–51. [12] Kast E, Oberle J, Richter EB. Success of simple sequestrectomy in lumbar spine surgery depends on the competence of the fibrous ring: a prospective controlled study of 168 patients. Spine (Phila Pa 1976) 2008;33:1567–71. [13] Lau D, Han SJ, Lee JG, et al. Minimally invasive compared to open microdiscectomy for lumbar disc herniation. J Clin Neurosci 2011;18:81–4. [14] Vaughan PA, Malcolm BW, Maistrelli GL. Results of L4–L5 disc excision alone versus disc excision and fusion. Spine (Phila Pa 1976) 1988;13:690–5. [15] Carragee EJ, Spinnickie AO, Alamin TF, et al. A prospective controlled study of limited versus subtotal posterior discectomy: short-term outcomes in patients with herniated lumbar intervertebral discs and large posterior anular defect. Spine (Phila Pa 1976) 2006;31:653–7. [16] Thomé C, Barth M, Scharf J, et al. Outcome after lumbar sequestrectomy compared with microdiscectomy: a prospective randomized study. J Neurosurg Spine 2005;2:271–8. [17] Barth M, Weiss C, Thomé C. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 1: evaluation of clinical outcome. Spine (Phila Pa 1976) 2008;33:265–72. [18] Barth M, Diepers M, Weiss C, et al. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 2: radiographic evaluation and correlation with clinical outcome. Spine (Phila Pa 1976) 2008;33:273–9. [19] Loupasis GA, Stamos K, Katonis PG, et al. Seven- to 20-year outcome of lumbar discectomy. Spine (Phila Pa 1976) 1999;24:2313–7. [20] Yorimitsu E, Chiba K, Toyama Y, et al. Long-term outcomes of standard discectomy for lumbar disc herniation: a follow-up study of more than 10 years. Spine (Phila Pa 1976) 2001;26:652–7.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical Study
Long term results of lumbar sequestrectomy versus aggressive microdiscectomy Kadir Kotil a,⇑, Neslihan Sutpideler Köksal b, Selim Kayaci c _ Arel University, Department of Neurologic Sciences, Türkoba Mahallesi Erguvan Sokak No: 26/K, Tepekent, 34537 Büyükçekmece, Turkey T.C. ISTANBUL Istanbul Educational and Research Hospital, Istanbul, Turkey c T.C. Rize Tayyip Erdog˘an University, Rize Merkez, Rize, Turkey a
b
a r t i c l e
i n f o
Article history: Received 11 September 2013 Accepted 13 January 2014 Available online xxxx Keywords: Aggressive microdiscectomy Disc herniation Lumbar Sequestrectomy
a b s t r a c t It remains unknown whether aggressive microdiscectomy (AD) provides a better outcome than simple sequestrectomy (S) with little disc disruption for the treatment of lumbar disc herniation with radiculopathy. We compared the long term results for patients with lumbar disc herniation who underwent either AD or S. The patients were split into two groups: 85 patients who underwent AD in Group A and 40 patients who underwent S in Group B. The patients were chosen from a cohort operated on by the same surgeon using either of the two techniques between 2003 and 2008. The demographic characteristics were similar. The difference in complication rates between the two groups was not statistically significant. During the first 10 days post-operatively, the Visual Analog Scale score for back pain was 4.1 in Group A and 2.1 in Group B, and the difference was statistically significant (p < 0.005). The Oswestry Disability Index score was 11% in Group A and 19% in Group B at the last examination. The reherniation rate was 1.5% in Group A and 4.1% in Group B (p < 0.005). We argue that reherniation rates are much lower over the long term when AD is used with microdiscectomy. AD increases back pain for a short time but does not change the long term quality of life. To our knowledge this is the first study with a very long term follow-up showing that reherniation is three times less likely after AD than S. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Although it has been 85 years since the first disc surgery was performed, new surgical techniques remain unsatisfactory and have disappointed many patients. Discectomy techniques have evolved considerably since Dandy in 1929 [1], but success rates have still not reached the desirable level. O’Connell [2] described an open surgery, which consisted of curettage of all elements of the intervertebral space. Microdiscectomy was popularized by Williams, who described limited or conservative discectomy [3]. There have been very few evidence-based, high quality studies to clarify which of these techniques is more effective, and there is no current consensus. Reherniation rates vary according to the technique used and range between 7% and 26% [4,5]. While the defenders of radical or aggressive microdiscectomy (AD) claim it results in lower than expected reherniation rates, those recommending limited discectomy or sequestrectomy (S) claim better preservation of intervertebral disc height, expected or lower than expected reherniation rates and better quality of life [6,7]. However, most of these studies ⇑ Corresponding author. Tel.: +90 216 360 1226; fax: +90 212 633 1698. E-mail address: [email protected] (K. Kotil).
were based on low quality evidence. In this study, patients receiving either S or AD were evaluated for clinical and radiological parameters at various time points, and the long term results are reported.
2. Materials and methods A total of 165 patients undergoing surgery for lumbar disc disease were divided into two groups: Group A consisted of 85 patients who underwent AD, and Group B consisted of 40 patients who underwent S. Both groups were operated on by one surgeon between February 2003 and May 2008 using one of the two techniques. Patients were evaluated prospectively at two independent practices, one where S was performed and one where AD was performed. The demographic characteristics of the two groups were similar. The mean age of patients in Group A was 41.1 years (range 18–74), and Group B was 39.9 years (range 22–69). The male/ female ratio was 37/48 in Group A and 19/21 in Group B. Thirty-five patients who could not be contacted at any point during the study period were excluded. Patients who had been operated on before, who had other degenerative problems such as spinal
http://dx.doi.org/10.1016/j.jocn.2014.01.012 0967-5868/Ó 2014 Elsevier Ltd. All rights reserved.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
2
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
stenosis, or who had far lateral herniations were also excluded. Patients with single level lumbar disc herniation between L1 and S1 who did not use antipsychotics were included. Group B patients had ruptured discs with sequestrated fragments. All patients who had lumbar disc protrusion were rejected. The patients were questioned by an independent observer at 6, 12, 24 and 60 months after surgery (Fig. 1, 2). Both groups were evaluated clinically and radiographically. The evaluated parameters included pre- and post-operative radiological features, pre and post-operative intervertebral disc height, duration of surgery, complications, analgesic use and reherniation rates. Age, affected lumbar level, male to female ratio and other parameters are given in Table 1. Oswestry
Disability Index (ODI) and Visual Analog Scale (VAS) scores are given in Table 2. Changes in intervertebral disc height and reherniation rates are shown in Table 3. The percentages were calculated as the loss of intervertebral disc height on plain standing radiographs. 2.1. Surgical technique In both groups, the surgical technique was the same up to the posterior longitudinal ligament level. A 3 cm skin incision was made, and when the laminae were reached, a minihemilaminectomy was made with the aid of an operating microscope. The
Fig. 1. (a) Axial and (b) sagittal T2-weighted pre-operative MRI of a patient who underwent aggressive discectomy surgery for L4–L5 disc herniation. (c) Post-operative sagittal T2-weighted MRI at 5.2 years showing a 30% decrease in disc space height. The decrease in foraminal height is minimal (5%) in spite of the decrease in disc space height.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
3
Fig. 2. (a) Axial and (b) sagittal pre-operative T2-weighted MRI of a patient who underwent sequestrectomy surgery for L4–L5 extruded disc herniation. (c) Sagittal MRI showing a normal foraminal height at 5 years.
ligamentum flavum was separated from its inferior and superior attachments, and the thick upper layer was excised. Group B patients were operated on using sequestrectomy because they had a small annular defect with a sequestrated fragment. Patients with large annular defects were accepted as candidates for Group A. In AD, the posterior longitudinal ligament (PLL) was opened until the annular defect was reached. Sequestrated fragments were searched for above and below the PLL with a long nerve hook. Then, the disc space was thoroughly curetted until bone was felt at the end plates. The aim of AD is to leave no intervertebral disc
tissue anywhere in the disc space. In S, only the sequestrated nucleus pulposus was removed. In both techniques 25 mg bupivacaine was administered intramuscularly to the surgical field. 2.2. Statistical analysis Age, body weight, pre-operative disc height, VAS values for back and leg pain, ODI, and post-operative disc height were compared with Student’s t-test. The relationship between them was tested with regression analysis. The Kaplan–Meier method was used to determine reherniation rates.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
4
K. Kotil et al. / Journal of Clinical Neuroscience xxx (2014) xxx–xxx
Table 1 Baseline patient characteristics
Patients, n Age, range (mean) Male/Female Follow-up, months, mean (range) Level operated on L1–L2 L2–L3 L3–L4 L4–L5 L5–S1 Duration of surgery, minutes Length of hospital stay, days Post-operative neurologic deficit
Group A Aggressive discectomy
Group B Sequestrectomy
85 18–74 (41.1) 37/48 60.2 (49–68)
40 22–69 (39.9) 19/21 60.2 (50.5–66)
2 4 15 34 30 46
3 5 5 15 12 35
1.2
0.9
2.3
1.25
Table 3 Reherniation rates and disc height changes in patients undergoing aggressive microdiscectomy (Group A) or sequestrectomy (Group B)
Follow-up time Reherniation Decrease in disc height
Group A Aggressive discectomy
Group B Sequestrectomy
1 year 1.3% 28%
1 year 2.1% 18%
5 years 1.5% 32%
5 years 4.1% 20%
The measurement of the foramina across both groups showed a mean decrease of 5% in height (3.5–8%), which had no clinical or statistical significance (p = 0.06). Patients in Group A needed two different analgesic and anti-inflammatory drugs in the first 10 post-operative days, whereas the patients in Group B needed only one (p = 0.55).
4. Discussion
3. Results Data on 125 patients who had long term follow-up were collected and compared. The mean duration of follow-up was 5.2 years (range 49–68 months). There were two groups of patients: Group A included patients who underwent AD, and Group B included patients who underwent S. The mean duration of surgery was 46 minutes in Group A and 35 minutes in Group B. In terms of complications, there were five peri-operative dural tears in Group A (5.8%), two of which led to foot drop (2.3%). In Group B, there was only one dural tear. In this patient, partial foot-drop evolved to total foot-drop, but near total improvement was observed during post-operative week 2 (1.25%). There was no statistically significant difference in terms of neurological deficit rates (p > 0.0001, Fisher’s exact test). Superficial wound infection was observed in three patients in Group A and two patients in Group B, and these patients were treated on an outpatient basis. The mean duration of hospital stay was 1.2 days in Group A and 0.9 days (20 hours) in Group B (Table 1). Special demands of some patients to lengthen their hospital stay were not included in these calculations. Reherniation rates were found to be 1.3% in Group A and 4.1% in Group B. This was higher than could be explained by the smaller number of patients in Group B (p = 1.00). While leg pain VAS values improved within similar time periods in both groups, back pain VAS values improved earlier in Group B (p = 0.05) (Table 2). Pre-operative disc height values and the post-operative changes in these values are shown in Table 3. The most noteworthy result is the maximal change in disc height at the level of L5–S1. There was no indication that any of the aggressively treated patients went on to spontaneously develop intervertebral fusion.
The most important complications of lumbar disc surgery are reherniation or recurrence [4,8]. The most widely accepted reasons for these are iatrogenic or spontaneous disc degeneration, stress on the facet capsule, incomplete removal of the degenerated disc material, chronic instability of the segment, and individual factors. In addition, biomechanical factors, including spine length, obesity and the amount of muscle support, may also lead to reherniation [8,9]. Because reherniation continues to be a problem in lumbar disc surgery, several new techniques have been considered during the past few decades in an attempt to achieve the best possible results with minimally invasive surgery. Chemonucleolysis, radiofrequency ablation, and laser ablation are some of the newly applied techniques that have failed to become viable alternatives to discectomy due to low success rates [6,10]. Although minimally invasive disc surgery has many advantages, its most important disadvantage is the inability to prevent reherniation. For this reason, the technique has begun to be questioned. Which technique can best prevent reherniation remains to be determined by studies including high quality evidence and long follow-up times. Most comparative studies in the literature include only low quality evidence. Varying reherniation rates are reported in different case series after S, subtotal discectomy, aggressive discectomy, macrodiscectomy, microdiscectomy and percutaneous endoscopic discectomy [4–6,11–14]. Watters et al. reported, in their metaanalysis of comparative studies, that the conservative technique was not superior to aggressive discectomy and had a 2.5-fold higher reherniation rate [4]. In a review by McGirt et al., the reherniation rate after lumbar discectomy reported by different authors between 1988 and 2006 in 5832 patients was 7%, while it was 3.5% in 6114 patients after AD over the same time period [5]. Carragee et al. reported reherniation rates to be twice as high following a conservative technique compared to the more aggressive approach [15], but Thome et al. [16] found similar rates among their patients
Table 2 Pre and post-operative VAS and ODI scores VAS
Pre-op Post-op
1 year 2 years 5 years
ODI
Group A
Group B
(back, leg) 7.3 (2–8), 5.3 1.9 (1–5), 0.8 1.2 (1–3), 0.4 1.1 (1–2), 0.6
(back, leg) 6.9 (2–9), 6.8 2.1 (1–3), 0.4 1.1 (1–2), 0.2 4.1 (1–7), 4.6
(3–10) (1–3) (1–2) (1–3)
(2–10) (0–2) (0–4) (0–7)
Group A
Group B
38% (15–78) 12% (5–15) 5% (5–12) 11% (5–15)
42% (16–75) 8% (5–15) 12% (5–19) 19% (5–34)
Data are presented as mean (range). ODI = Oswestry Disability Index, Post-op = post-operative, Pre-op = pre-operative, VAS = Visual Analog Scale. Group A = aggressive discectomy, Group B = sequestrectomy.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012
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at the 1 year follow-up. In Group B, we observed the greatest incidence of reherniation after the second year, although early return to work and a more comfortable post-operative course was constant throughout the follow-up. This contradicts the study of Barth et al. [17] who observed that as follow-up time increases, reherniation rates also increase. In our study, we also observed increasing reherniation rates with longer follow-up times for the S technique, but this was not the case for AD. Although AD provides effective decompression and lower reherniation rates, an important disadvantage is the back pain due to the curettage of the nucleus and end plates. This increases the need for analgesic therapy after surgery [4]. In S, on the other hand, back pain is not the issue, but reherniation is higher than for AD [4]. In our study, back pain was found to be bothersome in the first 10 days after surgery, and it was overcome with intense anti-inflammatory and analgesic drug use. In our patients, peri-operative, intramuscularly injected local anesthetic (prilocaine 25 mg) provided some pain relief in the first days, and anti-inflammatory and analgesic drugs suppressed pain in the following days. In Group A, the back pain VAS value was 5 in the first 10 days but decreased to 2 thereafter. In Group B, the back pain VAS value ranged between 3 and 5 in the first 3 days. Leg pain was negligible in both groups. We found a significant improvement in both VAS and ODI for both groups at the 6 month follow-up. However, in Group B, both VAS and ODI values increased 2 years later. While some authors propose that curettage leads to a decrease in disc space height and lowers the long term quality of life, others claim that these changes occur with normal aging of the disc and are not a cause of pain [18,19]. Yorimitsu et al. investigated long term follow-up results in patients who were observed for a minimum of 10 years after standard discectomy and were evaluated using the Japanese Orthopedic Association scoring system through direct examinations and questionnaires. The final Japanese Orthopedic Association scores for the patients with decreased disc height were significantly lower than those for patients with no decrease. However, the disc height of patients with a recurrent herniation was maintained [20]. McGirt et al. also reported that a decrease in disc space height had no effect on prognosis after 2 years of follow-up [11]. Similarly, in our patients, especially in Group A, a continual decrease in disc space height over time was a cause of pain in the first 6 weeks post-operatively, but it was insignificant in both groups in the long term, after the stabilization period of 6 months. Thus, our patients had no complaints attributable to AD. In this study, the overall mean decrease in disc height was found to be 28% after the first year and 32% after the fifth year; analgesics were no longer needed after 6 months (range 5.5–7.8). Analgesic drug use was intermittent and very minimal in dose. In Group A, the decrease in disc height had stabilized in 96% of patients after 2 years, and no further change was observed at the end of the fifth year. In Group B, on the other hand, the decrease in disc height was much slower and was observed to continue for up to 2 years. In this group, 20% continued to exhibit a decrease in disc height at 5 years, and the stabilization period was of slower onset, but there was no correlation between the decrease in disc space height and back or radicular pain. This difference may be related to post-operative physiotherapy, changes in body weight, surgical technique and concomitant overlooked parameters. In terms of sensory and motor deficit present pre-operatively, we found a similar rate of improvement at 5 years in both groups. A systematic review of the literature suggests that S may result in shorter operative times and a quicker return to work [4]. We did find that the operative time needed to perform S was shorter. The mean duration of hospital stay was 1.2 days in Group A and 0.9 days (20 hours) in Group B.
5
5. Conclusions We suggest that reherniation rates are lower over the long term when AD is used. AD decreases back comfort for a short time but does not change the long term quality of life. To our knowledge this is the first study with very long term follow-up showing that reherniation is three times less likely in AD when compared with S. Conflicts of Interest/Disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Dandy WE. Loose cartilage from intervertebral disk simulating tumour of the spinal cord. Arch Surg 1929;19:660–72. [2] O’Connell JE. Protrusions of the lumbar intervertebral disc. A clinical review based on the five hundred cases treated by excision of the protrusion. J Bone Joint Surg Br 1951;33:8–30. [3] Williams RW. Microlumbar discectomy: conservative surgical approach to the virgin herniated lumbar disc. Spine (Phila Pa 1976) 1978;3:175–82. [4] Watters WC 3rd, McGirt MJ. An evidence-based review of the literature on the consequences of conservative versus aggressive discectomy for the treatment of primary disc herniation with radiculopathy. Spine J 2009;9:240–57. [5] McGirt MJ, Ambrossi GL, Datoo G. Recurrent disc herniation and long-term back pain after primary lumbar discectomy: review of outcomes reported for limited versus aggressive disc removal. Neurosurgery 2009;64:338–44 [discussion 344–5]. [6] Mochida J, Toh E, Nomura T, et al. The risks and benefits of percutaneous nucleotomyfor lumbar disc herniation. A 10-year longitudinal study. J Bone Joint Surg Br 2001;83:501–5. [7] Fakouri B, Patel V, Bayley E. Lumbar microdiscectomy versus sequesterectomy/ free fragmentectomy: a long-term (>2 y) retrospective study of the clinical outcome. J Spinal Disord Tech 2011;24:6–10. [8] Wera GD, Dean CL, Ahn UM, et al. Reherniation and failure after lumbar discectomy: a comparison of fragment excision alone versus subtotal discectomy. J Spinal Disord Tech 2008;21:316–9. [9] Mariconda M, Galasso O, Secondulfo V, et al. Minimum 25-year outcome and functional assessment of lumbar discectomy. Spine (Phila Pa 1976) 2006;31:2593–9 [discussion 2600-1]. [10] Schick U, Elhabony R. Prospective comparative study of lumbar sequestrectomy and microdiscectomy. Minim Invasive Neurosurg 2009;52:180–5. [11] McGirt MJ, Eustacchio S, Varga P, et al. A prospective cohort study of close interval computed tomography and magnetic resonance imaging after primary lumbar discectomy: factors associated with recurrent disc herniation and disc height loss. Spine (Phila Pa 1976) 2009;34:2044–51. [12] Kast E, Oberle J, Richter EB. Success of simple sequestrectomy in lumbar spine surgery depends on the competence of the fibrous ring: a prospective controlled study of 168 patients. Spine (Phila Pa 1976) 2008;33:1567–71. [13] Lau D, Han SJ, Lee JG, et al. Minimally invasive compared to open microdiscectomy for lumbar disc herniation. J Clin Neurosci 2011;18:81–4. [14] Vaughan PA, Malcolm BW, Maistrelli GL. Results of L4–L5 disc excision alone versus disc excision and fusion. Spine (Phila Pa 1976) 1988;13:690–5. [15] Carragee EJ, Spinnickie AO, Alamin TF, et al. A prospective controlled study of limited versus subtotal posterior discectomy: short-term outcomes in patients with herniated lumbar intervertebral discs and large posterior anular defect. Spine (Phila Pa 1976) 2006;31:653–7. [16] Thomé C, Barth M, Scharf J, et al. Outcome after lumbar sequestrectomy compared with microdiscectomy: a prospective randomized study. J Neurosurg Spine 2005;2:271–8. [17] Barth M, Weiss C, Thomé C. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 1: evaluation of clinical outcome. Spine (Phila Pa 1976) 2008;33:265–72. [18] Barth M, Diepers M, Weiss C, et al. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 2: radiographic evaluation and correlation with clinical outcome. Spine (Phila Pa 1976) 2008;33:273–9. [19] Loupasis GA, Stamos K, Katonis PG, et al. Seven- to 20-year outcome of lumbar discectomy. Spine (Phila Pa 1976) 1999;24:2313–7. [20] Yorimitsu E, Chiba K, Toyama Y, et al. Long-term outcomes of standard discectomy for lumbar disc herniation: a follow-up study of more than 10 years. Spine (Phila Pa 1976) 2001;26:652–7.
Please cite this article in press as: Kotil K et al. Long term results of lumbar sequestrectomy versus aggressive microdiscectomy. J Clin Neurosci (2014), http://dx.doi.org/10.1016/j.jocn.2014.01.012