As transforaminal percutaneous endoscopic lumbar discectomy (PELD) becomes more aggressively implemented, the risk for dural tears may increase and lead to severe neurological sequelae. Diagnostic and management strategies for these situations, however, have not been established. This report describes an unrecognized dural tear during transforaminal PELD. A 38‐year‐old woman sustained an unrecognized dural tear during transforaminal PELD at the L4‐5 level. Postoperative radicular symptoms were initially misdiagnosed as recurrent lumbar disc herniation. Despite revision PELD, symptoms were not resolved. The patient underwent endoscopic exploration at the authors’ clinic to examine the cause of radicular pain, which revealed a small dural tear and nerve root entrapment at the lateral aspect of the dura. Open repair using interbody fusion was performed at the L4‐5 level. The dural tear was primarily closed and the pinched nerve root was relieved. The patient’s pain symptoms improved, and she was discharged after adequate wound care. Although PELD is an effective and safe minimally invasive technique, incidental dural tears can occur. Surgeons should be aware of the risks for dural damage and have comprehensive knowledge of clinical features. Early diagnosis with a high level of suspicion is essential to preventing long‐term neurological sequelae.
Dural tear during spine surgery is clinically common and one of several critical complications. The prevalence of dural tears in lumbar spine surgery is approximately 1.8% to 17.4% [
Because minimally invasive spine surgery is a leading trend in the field of spinal treatment, endoscopic spine surgery (ESS) is widely used to treat degenerative lumbar disc disease. Percutaneous endoscopic lumbar discectomy (PELD) is an endoscopic technique that is considered safe and effective, with the advantage of less trauma to healthy tissues. Theoretically, the risk for dural tear is lower in endoscopic discectomy due to minimal retraction of the dural sac. However, as selective endoscopic discectomy for extruded lumbar disc herniation (LDH) is widely performed, dural tears can occur [
A 38‐year‐old woman presented with right buttock pain radiating to her right lower extremity. She underwent right transforaminal PELD 2 months previously at another hospital. Preoperative magnetic resonance imaging (MRI) revealed moderate right central disc protrusion at the L4‐5 level. According to operative records from the previous hospital, selective endoscopic discectomy after a percutaneous transforaminal foraminoplastic approach was performed. The report stated that the herniated disc fragment was completely removed under endoscopic visualization. However, the patient’s complaints of pain radiating down to the right lower extremity persisted after surgery. Despite conservative management, her symptoms did not resolve. She then underwent repeat PELD 1 month later for suspected recurrent LDH. The surgeon removed more disc fragments and confirmed neural decompression on the endoscopic view. A few days later, her back pain and right lower extremity pain worsened, and she visited the authors’ spine clinic.
The patient experienced right lower extremity radiculopathy, with a visual analog score (VAS) of 9 in the L4 and L5 dermatome areas. A straight leg raise test could not be performed due to severe radiculopathy. Motor power of right ankle dorsiflexion and the great toe in extension was grade 4.
Plain radiography revealed spondylolisthesis L4 on L5 and disc space narrowing at L4‐5. The repeat MRI 2 months after the operation revealed a right‐sided central disc protrusion without signs of infection, but the high signal intensity in the intradiscal space and the small defect point at the right subarticular zone were suggestive of dural tears at the L4–L5 level (
A dural tear is a common complication of microscopic open lumbar spinal surgery. In contrast, dural damage after endoscopic lumbar spinal surgery is rare [
The PELD technique has advanced from indirect disc decompression to selective fragment removal and direct decompression [
Most dural tears occur in either the percutaneous approach or in the selective endoscopic discectomy step. In this case, dural tears may have occurred in the foraminoplastic approach step before the discectomy step. The initial surgeon did not recognize the sign of dural tear from the surgical field or the patient’s response. Moreover, the location of the dural tears was the lateral side of the dura, which was not in direct contact with the disc. According to surgical records and the zone of the defect, the dural tears in this case may have occurred during the transforaminal foraminoplastic approach. A definitive diagnosis of dural tear was delayed and, eventually, the patient had to undergo unnecessary revision PELD before the final surgery of open sural repair and interbody fusion surgery.
In water‐based ESS, small dural tears may be overlooked due to constant saline irrigation of the surgical field. If unrecognized or untreated, dural tears can develop nerve root impingement or further herniation, causing permanent neurological sequelae or disability. Therefore, a high level of suspicion and knowledge of the clinical features of dural tears is essential.
Intraoperative dural damage can be detected by direct visualization of the dural defect. The nerve root can be exposed or herniated through the dural defect, such as neural herniation, in open surgery [
If the patient complained of severe recurrent or persistent radicular pain after PELD, dural tears should be suspected. In particular, when the nature of the pain is atypical or resembles non‐dermatomal electric shock, it may be a sign of nerve root impingement due to the dural defect. L‐spine MRI should be performed, and the clinical course should be carefully examined.
There may be some typical radiographic findings of dural tears in PELD. CSF collection in the disc space may manifest as a high signal intensity on T2‐weighted MRI [
The risk for dural tears may increase in cases of recurrent, migrated, or high‐canal compromising LDH. Sophisticated dissection of the tight adhesion between the disc material and dural membrane may be difficult in these cases. Regarding the surgeon factor, aggressive dissection and decompression may increase the risk for dural tears. In their learning curve or during the training period, surgeons may experience difficulty with appropriate instrumental manipulation in the endoscopic surgical field.
In most cases, dural tears in PELD can be avoided by using preventive strategies. First, accurate knowledge of the endoscopic surgical anatomy is essential. The anatomical layer, including the dural sac, epidural fat, posterior longitudinal ligament, torn annulus, and herniated disc material, should always be distinguished. The barrier or space between the dural sac and herniated disc should be precisely dissected before selective discectomy. Second, the surgeon should be highly familiar with the features of the endoscopic instruments. Delicate instrumental manipulation should be essential in two‐dimensional endoscopic vision. Finally, the endpoint of the procedure should be free mobilization and pulsation of the neural tissue. The direct and full exposure of neural tissues may be challenging and dangerous in a risky case. Instead, restoration of dural pulsation and mobilization may be useful, even though some adhered disc materials remain.
Despite the best efforts of the surgeon, an incidental dural tear may occur. Early detection and adequate management are essential to prevent long‐term sequelae [
Dural tear is a unique complication of PELD. As this minimally invasive technique becomes increasingly accessible and practical, the incidence of unexpected dural damage is also likely to increase. Unrecognized dural tear(s) can cause significant disability and/or neurological deficits. Therefore, surgeons should carefully consider the clinical characteristics and management “know‐how” of accidental/incidental dural injury during PELD.
The authors would like to thank Kyung-Hee Jang and Uhn Lee for their support and assistance.
Magnetic resonance imaging (MRI) findings on admission. Ⓐ T2-weighted sagittal image revealing mild disc protrusion with hyperintense signal changes in the disc space at the level of L4-5 (arrowheads). Ⓑ T2-weighted axial image revealing intradiscal high signal intensity and small defect point at the right subarticular zone suggestive of dural tears (arrow).
Operative findings. Ⓐ The initial picture of a dural defect after facetectomy. Note the dural tear filled with fibrin glue applied in the endoscopic exploration. Ⓑ A tethered nerve root and cerebrospinal fluid (CSF) leakage through the defect was found. Ⓒ The dural defect is repaired using 6-0 prolene and fibrin glue.