Journal of Clinical Neuroscience xxx (2015) xxx–xxx

Contents lists available at ScienceDirect

Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn

Review

Minimally invasive redo discectomy for recurrent lumbar disc herniations Evangelos Kogias ⇑, Pamela Franco Jimenez, Jan-Helge Klingler, Ulrich Hubbe Neurosurgery, University Medical Center Freiburg, Breisacherstrasse 64, Freiburg D-79106, Germany

a r t i c l e

i n f o

Article history: Received 7 January 2015 Accepted 14 February 2015 Available online xxxx Keywords: Discectomy Endoscopic Lumbar disc herniation Minimally invasive Recurrent

a b s t r a c t The purpose of this systematic review is to investigate which minimally invasive techniques have been used for discectomy in recurrent lumbar disc herniation (LDH), to present the success and complication rates and to evaluate the advantages and limitations of each technique. Discectomy for recurrent LDH is accompanied by a higher morbidity rate compared with primary LDH. Because of the limited operating field, the majority of surgeons have been discouraged from utilising a minimally invasive approach for revision surgery. Minimally invasive techniques have gained ground in the treatment of primary LDH and an increasing number of patients are expressing interest in such techniques for the treatment of recurrent LDH. Microendoscopic discectomy (MED), endoscopic transforaminal and interlaminar discectomy (ETD and EID) have been used for treatment of recurrent LDH. The reported success rate is 60–95%. Full endoscopic techniques, especially ETD, showed favourable results concerning dural tear rates but have a demanding learning curve. The limitations of ETD include dislocated disc fragments or concomitant lateral recess stenosis, and MED is more effective in these instances. All three techniques have a low delayed instability rate. MED, ETD and EID are safe and efficient treatment options for surgical management of recurrent LDH with good success and low complication rates. At the same time, they offer the advantages of minimally invasive access. Ó 2015 Elsevier Ltd. All rights reserved.

1. Introduction Redo discectomy for recurrent lumbar disc herniation (LDH) is accompanied by a higher morbidity rate compared with surgery for primary herniations. Epidural scar tissue increases the risk of dural tear and nerve root injury [1–4]. Due to distorted anatomy, a more extensive tissue dissection is necessary to enable identification of anatomical landmarks and facilitate safe tissue manipulation. Because of the limited operating field, the majority of surgeons have been discouraged from utilising a minimally invasive approach for revision surgery. Therefore, an open microdiscectomy is still regarded as the standard procedure for recurrent LDH [5–7]. On the other hand, minimally invasive techniques have gained ground in the treatment of primary LDH [8–29] and an increasing number of patients are expressing interest in such techniques for the treatment of recurrent LDH. In addition, minimally invasive surgery has the potential to overcome some drawbacks of conventional surgery. The use of virgin tissue planes via a transmuscular approach could negate the effect of postoperative scarring [30]. In patients with incidental durotomy, the chance of a clinically relevant cerebrospinal fluid ⇑ Corresponding author. Tel.: +49 76127050010; fax: +49 76127050080. E-mail address: [email protected] (E. Kogias).

(CSF) fistula should be lower because the minimal access device leaves no dead space after the muscle retractor is removed. Finally, minimally invasive surgery may minimise bone removal and decrease instability rates [30]. We performed a systematic review of the literature concerning minimally invasive redo discectomy for recurrent LDH. The purpose of this study was to answer the following questions: 1. Which minimally invasive techniques have been used so far to perform redo discectomy for recurrent LDH? 2. What are the success and complication rates of these techniques? 3. What are the advantages and limitations of each technique?

2. Materials and methods We searched the literature in PubMed with the following search terms: [recurrent[All Fields] AND (‘‘lumbosacral region’’[MeSH Terms] OR (‘‘lumbosacral’’[All Fields] AND ‘‘region’’[All Fields]) OR ‘‘lumbosacral region’’[All Fields] OR ‘‘lumbar’’[All Fields]) AND (‘‘hernia’’[MeSH Terms] OR ‘‘hernia’’[All Fields] OR ‘‘herniation’’[All Fields]). From this, we obtained 538 records. We included only articles referring to same side recurrent LDH treated with minimally invasive redo discectomy and excluded

http://dx.doi.org/10.1016/j.jocn.2015.02.028 0967-5868/Ó 2015 Elsevier Ltd. All rights reserved.

Please cite this article in press as: Kogias E et al. Minimally invasive redo discectomy for recurrent lumbar disc herniations. J Clin Neurosci (2015), http:// dx.doi.org/10.1016/j.jocn.2015.02.028

2

E. Kogias et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx

instrumentation/fusion techniques. We took studies investigating clinical outcomes and complications into consideration. Case reports and reviews were also included. No peer-reviewed journal was excluded and no time interval was set. According to these criteria, only 14 articles proved to be relevant (Fig. 1). Two Chinese articles had to be excluded due to language. The remaining 12 full text articles were eligible for our review study (Table 1). We classified the articles according to the technique used and study type: prospective randomised controlled trial (RCT; n = 1), prospective cohort study (n = 3), retrospective control study (n = 2), observational retrospective study (n = 5) and case report (n = 1). Due to the sparse literature a meta-analysis was not possible. 3. Results Three minimally invasive techniques have been reported for redo discectomy in recurrent LDH: microendoscopic discectomy (MED) and two full endoscopic discectomy techniques, endoscopic interlaminar and endoscopic transforaminal discectomy (EID and ETD, respectively). Four articles referred to MED [31–34] whereas eight articles referred to full endoscopic techniques (EID [35–37] and ETD [30,36–40]). There was also a case report of a small incised MED (sMED) which is actually a variation of the full EID for the L5/S1 level [41]. Most studies were observational retrospective studies (n = 5) [30,34,35,37,38]. There were two retrospective control studies, one comparing MED to transosseous discectomy (TD; a variation of MED) [33], and another comparing ETD to open standard microdiscectomy [40]. There were three prospective cohort studies, one of ETD [39] and two of MED [31,32]. There was only one prospective RCT comparing the open and the full endoscopic discectomy (EID or ETD) [32]. Finally, there was one case report of sMED [41]. The endoscope is used as a visualisation device in all these techniques. The following data were collected from all studies: follow-up duration, success and complication rates (especially

wound infection, dural tear, re-recurrence and secondary instability). Potential advantages and limitations of the techniques are discussed. 3.1. Microendoscopic discectomy In 2003, Le et al. [32] and Isaacs et al. [31] were the first to report 10 patients with recurrent LDH treated with MED. Both authors prospectively evaluated a series of 10 consecutive patients who underwent MED by spine surgeon Richard G. Fessler in Cleveland and Chicago. In this technique, a classical MED approach was used via a slightly more lateral trajectory and docking of the working channel on the medial facet joint. The endoscope was used as the visualisation device. A few millimetres of bone between the medial facet and the dural sac were drilled. Thus, decompression of the lateral recess, mobilisation of the scarred dural sac, identification of the nerve root and fragmentectomy or discectomy could be achieved. The reported success rate was 90% (40% excellent and 50% good) according to the MacNab criteria (Table 2). One patient with CSF leak and one with recurrence were reported. In 2010, Smith et al. [34] reported another series of 16 consecutive patients who were evaluated retrospectively. The success rate was 80%. Two patients with incidental durotomy (12.5%) were reported and were treated with dural sealant only, intraoperatively. No further durotomy-associated complications occurred. In 2013, Nomura et al. [33] introduced a new term, TD, to describe a MED technique where drilling is limited to the plane between the medial facet joint and the scarred dural sac without drilling the remaining hemilamina. They proposed this as an effective means to avoid dural tear in revision surgery. In their study, 30 patients underwent TD and 27 underwent MED. In both groups the Japanese Orthopaedic Association score improved significantly. Two patients with dural tears were reported in the MED group whereas no dural tears occurred in the TD group. This is the largest series, to our knowledge, of recurrent LDH treated with MED

Fig. 1. Flow diagram of the studies included in the present systematic review. LDH = lumbar disc herniation.

Please cite this article in press as: Kogias E et al. Minimally invasive redo discectomy for recurrent lumbar disc herniations. J Clin Neurosci (2015), http:// dx.doi.org/10.1016/j.jocn.2015.02.028

3

E. Kogias et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx Table 1 Studies on recurrent lumbar disc herniations treated with minimally invasive redo discectomy Study, first author, year

Study design

Patients and treatment, n

Follow-up, months

Success rate, %

Dural tear rate, %

Re-recurrence, %

Instability incidence, %

Wound infection incidence, %

Nomura 2013 [33]

Retrospective control Case report Observational retrospective Observational retrospective Observational retrospective Observational retrospective Prospective RCT

30 TD (MED) versus 27 MED 2 sMED (L5/S1) 6 ETD

18.6 versus 48.4 (mean) – 4.5 (mean)

JOA score improvement in both groups – 66.6

0 versus 7.4 – 0

0

0

0

– 0

– 0

– 0

10 EID

0

10

0

0

32 EID, 9ETD

14.4 ± 9.9 60 (mean ± SD) 16 (mean) 90.2

4.9

4.9

0

0

16 MED

14.7 (mean) 81

12.5

0

0

0

50 open versus 21 ETD versus 29 EID

24

4.8 versus 9.5 versus 4 versus 0 3.4 versus 0

Retrospective control Prospective cohort Observational retrospective Prospective cohort Prospective cohort

25 ETD versus 29 open 262 ETD

34.2 (mean) No significant difference in VAS and ODI improvement 24 86

6 versus 0 versus 2 0 versus 7 0

43 ETD

31 (mean)

10 MED 10 MED

Koga 2012 [41] Eloqayli 2012 [38] Kim 2012 [35] Shin 2011 [37] Smith 2010 [34] Ruetten 2009 [36]

Lee 2009 [40] Hoogland 2008 [39] Ahn 2004 [30] Isaacs 2003 [31] Le 2003 [32]

86% (open) versus 95% (ETD + EID)

6 versus 0 versus 0

4 versus 10

4 versus 3.4 0

4.6

0.4

0

0

0

0

0

13.1 (mean) 90

10

10

0

0

18.5 (mean) 90

10

10

0

0

81.4

- = no data, EID = endoscopic interlaminar discectomy, ETD = endoscopic transforaminal discectomy, JOA = Japanese Orthopaedic Association, MED = microendoscopic discectomy, ODI = Oswestry disability index, open = open microdiscectomy, RCT = randomised controlled trial, SD = standard deviation, sMED = small incised MED, TD = transosseous discectomy, VAS = visual analog scale.

Table 2 Modified MacNab criteria for assessment of clinical outcome after microdiscectomy Excellent No pain, no restriction of mobility, return to normal work and level of activity Good Occasional nonradicular pain, relief of presenting symptoms, able to return to modified work Fair Some improved functional capacity, still handicapped and/or unemployed Poor Continued objective symptoms of root involvement, additional operative intervention needed at index level irrespective of length of postoperative follow-up

(n = 57; TD is a variation of MED). Despite the fact that Nomura et al. were the first to make this distinction between TD and MED, drilling only along the medial aspect of the facet and ignoring the hemilamina, it should not be regarded as an innovation since the patient series of R.G. Fessler in 2003 were operated on in exactly the same way [31,32]. However, one should acknowledge their annotation as a technical remark that may improve the complication rates of revision MED. 3.2. Endoscopic transforaminal discectomy In this technique, a posterolateral approach through unscarred tissue planes is used. The endoscope is introduced through the foramen. An annulotomy is performed in order to create a working intradiscal tunnel. The spinal canal is inspected anteriorly. The herniated disc is then removed with special forceps [25,30]. The ETD has been used for the treatment of recurrent LDH with low complication and high success rates [30,36,39]. Ahn et al. [30] reported 43 patients and Hoogland et al. [39] 262 patients. In the prospective cohort study by Hoogland et al., the success rate was 86% and the recurrence rate was 4.6%. Only one patient with instability and subsequent fusion was reported (0.4%). The follow-up was 2 years. In the retrospective series by Ahn et al. [30] the success rate was 81.4%. These authors evaluated age as a positive

prognostic factor with favourable outcomes in patients younger than 40 years. Duration of symptoms less than 3 months was also associated with favourable outcomes. A coexisting lateral recess stenosis could be identified as a negative prognostic factor with a lower success rate after ETD. No patients with dural tears were reported in either series. Lee et al. [40] compared 25 patients treated with ETD and 29 with open microdiscectomy. Both groups showed good outcomes for recurrent LDH, but ETD had advantages in terms of shorter operating times, hospital stays, and disc height preservation, as well as a lower complication rate (4% compared to 10%). The dural tear rate was nil in the ETD group, with two patients reported in the open microdiscectomy group. Ruetten et al. [36] reported lower morbidity rates and faster rehabilitation with the endoscopic techniques compared to open microdiscectomy within a prospective RCT. Overall complication rates in the microdiscectomy group were 21% versus 6% in the full endoscopic (EID or ETD) group, with a dural tear rate of 6% in the microdiscectomy versus 2% in the interlaminar versus 0% in the transforaminal group. Conclusively, ETD seems to be an effective technique to treat patients with recurrent LDH with success rates of about 80–85%. This technique can be performed under local anaesthesia and uses a lateral approach through virgin tissues. The negligible rate of wound infection or dural tear indicates major advantages. Furthermore, bone removal within this technique is minimal so that segmental instability only rarely occurs following ETD. Drawbacks of the technique are the prolonged learning curve and the inefficiency in patients with coexisting stenosis [30]. The issue of localisation of the sequestrated disc fragment has not been adequately discussed in the literature concerning recurrent LDH but it is generally accepted that ETD, despite its obvious advantages, is not the optimal solution for every recurrent LDH. Ruetten et al. [36] used transforaminal access only in patients who had a herniated fragment between the lower edge of the cranial pedicle and the middle part of the caudal pedicle and when the iliac crest did not prohibit the lateral approach. EID and MED have no such

Please cite this article in press as: Kogias E et al. Minimally invasive redo discectomy for recurrent lumbar disc herniations. J Clin Neurosci (2015), http:// dx.doi.org/10.1016/j.jocn.2015.02.028

4

E. Kogias et al. / Journal of Clinical Neuroscience xxx (2015) xxx–xxx

limitations. In patients with primary LDH, difficulties in resecting dislocated herniated fragments in the spinal canal have also been reported [23,25,26,42]. 3.3. Endoscopic interlaminar discectomy In this technique the obturator is inserted via a slightly lateral trajectory into the interlaminar space. The scar tissue at the superiolateral triangle of the primary laminectomy is removed. After epidural fat is found, scar tissue resection is continued in all directions in search of the herniated disc fragment [35–37]. Shin et al. [37] reported a series of 41 patients with recurrent LDH who were treated with full endoscopic techniques: 32 with EID and nine with ETD. The overall success rate was 90.2% after a mean follow-up of 16 months. The dural tear and re-recurrence rates were both 4.9%. Instability and wound infection did not occur. Kim et al. [35] reported 10 patients treated with EID with a success rate of 60% after a mean follow-up of 14.4 months. The re-recurrence rate was 10%. Finally, in the prospective RCT by Ruetten et al. [36] the EID group had a dural tear rate of 2% compared with 0% in the ETD group and 6% in the open group. Patient satisfaction in the full endoscopic groups (ETD and EID) was 95%, which was not significantly different from the open group with 86%. 3.4. sMED: An alternative EID approach for L5/S1 Finally, an EID approach has been introduced for the L5/S1 segment where the transforaminal approach is sometimes hindered due to the iliac crest. The technique is called sMED and only two patients with recurrent LDH are reported with successful treatments from this technique [41]. 4. Discussion Since 2003, there have been 12 articles reporting minimally invasive discectomy for recurrent LDH in the literature. Due to the sparse literature we could not perform a formal meta-analysis. The minimally invasive techniques reported are endoscopic, MED, ETD and EID. The reported success rates are 60–95% (Table 1). There is only one prospective RCT [36] with 2 years follow-up comparing open microdiscectomy to full endoscopic techniques (ETD and EID) for recurrent LDH. In this RCT, there was no statistically significant difference in the outcomes between the two techniques. The endoscopic technique proved advantageous in complication rates and postoperative rehabilitation. In another retrospective controlled study [40] there was also no difference in the clinical outcomes between open microdiscectomy and ETD, but ETD showed an advantage in dural tear rate. All authors conclude that their surgical technique offers adequate exposure of the pathology and is equally effective in its treatment. MED, ETD and EID offer all the benefits of minimally invasive surgery, namely minimal approach related traumatisation and bleeding, shorter hospital stays and low postoperative pain, while at the same time drawbacks of the open standard microdiscectomy can be overcome [30–32,40]. The use of virgin tissue planes via a slightly lateral (MED) or transforaminal approach (ETD) may bypass epidural scarring and decrease the morbidity of adhesiolysis, and especially the dural tear rate. Moreover, even in patients with dural tears, the collapse of the transmuscular working channel after removal of the instrument further minimises the risk of a CSF fistula. With the ETD technique, dural tears are reported to be nil [30,39]. Whether this is absolutely true or not is debatable. Continuous saline irrigation during endoscopic surgery may lead to underdiagnosing of dural tears intraoperatively. Since the

possibility of a CSF fistula is negligible due to the collapse of the transmuscular working channel [22,28,43], some intraoperative dural tears might be missed this way. But the decisive fact is of course that in ETD, dural tears and CSF fistulas seem to be irrelevant. With ETD, the instability rate is reported to be

Minimally invasive redo discectomy for recurrent lumbar disc herniations.

The purpose of this systematic review is to investigate which minimally invasive techniques have been used for discectomy in recurrent lumbar disc her...
436KB Sizes 2 Downloads 9 Views