Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 59, Num. 2, 2011, pp. 313-314

Neurology India, Vol. 59, No. 2, March-April, 2011, pp. 313-314

Letter to Editor

Lumbar nerve root hernia: An unusual complication of micro-endoscopic discectomy

Pankaj Sharma, Alok Ranjan, Rahul Lath

Department of Neurosurgery, Apollo Health City, Hyderabad, India

Correspondence Address: Rahul Lath, Department of Neurosurgery, Apollo Health City, Hyderabad, India, rahullath@hotmail.com

Date of Submission: 18-Nov-2010
Date of Decision: 17-Jan-2010
Date of Acceptance: 08-Feb-2011

Code Number: ni11092

PMID: 21483151

DOI: 10.4103/0028-3886.79172

Sir,

Over the past two decades, minimally invasive lumbar disc surgery is being increasingly performed for lumbar disc prolapse, including recurrent lumbar disc herniation. ^[1],[2],[3] The small surgical scar, less intraoperative blood loss, early ambulation, and less average duration of hospital stay are quoted benefits of microendoscopic discectomy (MED). ^[1],[4] Complications like dural tear, cerebrospinal fluid (CSF) leak, recurrent disc prolapse are similar to the conventional microdiscectomy. However, recent studies suggest a higher incidence of dural tear and recurrent herniation with MED when compared to microdiscectomy or open-discectomy. ^{[1],[4],[5],[6]} We report an unusual complication of MED.

A 37-years-old male was admitted with the right sciatica with no neurological deficits and was bedridden due to severe pain. Magnetic resonance imaging (MRI) of the lumbar spine showed a right paracentral prolapsed disc at L5/S1 level causing compression over the right S1 root. He also had changes at other disc levels which were not co-relating with his pain [Figure - 1]. He underwent a MED under general anesthesia. The surgery was uneventful; however a small dural abrasion was seen on the ventrolateral dura at the level of disc. There was no CSF leak. Postoperatively, he recovered well and was completely relieved of the right leg pain. After 48 hours, he complained of similar episodic pain in the right leg for which analgesics were escalated. The straight leg raising test was negative. Since there was no relief in his pain with the medications, an MRI of the lumbar spine was repeated which showed adequate decompression of the root [Figure - 2]. He was continued on analgesics and supportive physiotherapy. Measures like root block and epidural steroid injection were tried, with temporary relief of the pain. As conservative management was not effective, re-exploration was done on 10 ^th postoperative day. A right hemilaminectomy was done and per-operatively there was no CSF noticed during initial dissection. On further exploration, we found a nerve root herniating out from the dural sac through a well-defined smooth margin dural defect on the ventrolateral dura [Figure - 3] and [Figure - 4]. The root was replaced in the dural sac after opening the dorsal dura and the defect in the ventral dura was closed. The repair was augmented with fat patch and fibrin glue. Patient recovered well after second surgery and was completely pain free at the last follow-up 3 months later.

Lumbar nerve root hernia has been described following percutaneous endoscopic lumbar discectomy (PELD) ^[7] and hemilaminectomy with discectomy. ^[8] In a recent study of 816 patients who underwent PELD, 9 patients (1.1%) had symptomatic dural tears. ^[7] Three of these were detected intraoperatively, while the remaining six cases were not recognized during the procedure. All patients required open procedures and repair of the dural tears. The patients with lumbar root hernia had a poor outcome with neurological sequale. We report this case so that in cases of recurrent leg pain after lumbar disc surgery, in addition to a recurrent disc prolapse, the possibility of a lumbar root hernia should be suspected especially if the postoperative MRI scan does not show any significant fragment. In our patient, we suspect that there was a small dural abrasion/tear in the ventrolateral dura with intact arachnoid through which a lumbar root gradually herniated and enlarged the defect. Although we did not notice any CSF leak or dural tear during the first surgery, if noticed this must be repaired to prevent this complication. Since the root was in the defect, there was no CSF leak. We suggest even small dural tears with intact arachnoid and no evident CSF leak must be repaired to prevent lumbar nerve root herniation.

References

1.	Wu X, Zhuang S, Mao Z, Chen H. Microendoscopic discectomy for lumbar disc herniation: surgical technique and outcome in 873 consecutive cases. Spine 2006;31:2689-94.  Back to cited text no. 1  [PUBMED]  [FULLTEXT]
2.	Ranjan A, Lath R. Microendoscopic discectomy for prolapsed lumbar intervertebral disc. Neurol India 2006;54:190-4.  Back to cited text no. 2  [PUBMED]
3.	Isaacs RE, Podichetty V, Fessler RG. Microendoscopic discectomy for recurrent disc herniations. Neurosurg 2003;15:E11.  Back to cited text no. 3
4.	Jhala A, Mistry M. Endoscopic lumbar discectomy:experience of first100 cases. Indian J Orthop 2010;44:184-90.  Back to cited text no. 4  [PUBMED]
5.	Teli M, Lovi A, Brayda-Bruno M, Zagra A, Corriero A, Giudici F, Minoia L. Higher risk of dural tears and recurrent herniation with lumbar micro-endoscopic discectomy. Eur Spine J 2010;19:443-50  Back to cited text no. 5
6.	Matsumoto M, Hasegawa T, Ito M, Aizawa T, Konno S, Yamagata M, et al. Incidence of complications associated with spinal endoscopic surgery: Nationwide survey in 2007 by the Committee on Spinal Endoscopic Surgical Skill Qualification of Japanese Orthopaedic Association. J Orthop Sci 2010;15:92-6.  Back to cited text no. 6  [PUBMED]  [FULLTEXT]
7.	Ahn Y, Lee HY, Lee SH, Lee JH. Dural tears in percutaneous endoscopic lumbar discectomy. Eur Spine J 2011;20:58-64.  Back to cited text no. 7  [PUBMED]  [FULLTEXT]
8.	Nishi S, Hashimoto N, Takagi Y, Tsukahara T. Herniation and entrapment of a nerve root secondary to an unrepaired small dural laceration at lumbar hemilaminectomies. Spine (Phila Pa 1976). 1995;20:2576-9.  Back to cited text no. 8  [PUBMED]

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