10 October 2024: Review Articles
Comprehensive Analysis of UBE-Related Complications: Prevention and Management Strategies from 4685 Patients
Lili Yang1AE, Tong Yu1ABC, Jianhang Jiao1BF, Tingting Hou1FG, Yang Wang1BF, Bin Zhao1CD, Minfei Wu1CE, Weibo Jiang1AEF*DOI: 10.12659/MSM.944018
Med Sci Monit 2024; 30:e944018
Abstract
ABSTRACT: Unilateral biportal endoscopy (UBE) surgery is a minimally invasive approach for treatment of spinal disorders, which usually requires creation of a working and viewing channel on 1 side. The UBE technique has developed rapidly in China in recent years, and many spine surgeons have started to apply it and have shared the initial clinical research results many times at minimally invasive spine conferences. Unfortunately, these studies actually translated into fewer publications. In addition, most patients have good outcomes after UBE surgery, but a minority still experience UBE surgery-related complications, including epidural hematoma, dural sac tears, retroperitoneal effusions, inadequate decompression, postoperative back pain and headache, early recurrence, iatrogenic spinal instability, anemia, and infection, which can prolong hospital stay and seriously affect patient satisfaction. Therefore, this article reviews the complications of UBE surgery for lumbar degenerative diseases and discusses ways to prevent and handle complications associated with UBE to help spine surgeons make smart treatment decisions.
Keywords: endoscopy, Lumbar Stenosis, Familial, Decompression, Surgical
Introduction
Lumbar degenerative diseases are common in spinal surgery and frequently cause lower back and leg pain [1]. They mainly include lumbar disc herniation, lumbar spinal stenosis, and lumbar spondylolisthesis [2–5]. Non-surgical treatments, including bed rest, traction, nutritional neurotropic drug therapy, and non-steroidal anti-inflammatory drug therapy, can effectively alleviate discomfort [1]. However, patients diagnosed with lumbar degenerative diseases who have not responded to over 6 months of conservative treatment typically require surgery [6,7]. In recent years, minimally invasive endoscopic surgery has rapidly developed due to its advantages of minimal trauma, quick recovery, and short hospitalization time [6–10].
The UBE technique is a minimally invasive surgical treatment of spinal disorders, which is performed through 2 channels: a viewing channel for the placement of endoscopes with continuous irrigation and a working channel for the placement of surgical instruments to perform the surgery [7,11]. In 1992, Kambin et al first attempted to apply arthroscopy for the treatment of patients with lumbar disc herniation and lumbar spinal stenosis [12]. In 1996, De Antoni et al presented the first technical report on placement of endoscopy and surgical instruments through 2 separate channels [13]. In 1998, De Antoni et al described the use of arthroscopic magnification, illumination, and irrigation and reported clinical results [14]. In 2013 and 2015, Soliman et al published articles reporting clinical outcomes of lumbar disc herniation and lumbar spinal stenosis treated via 2 separate channels [15,16]. In 2016, Korean scholars first proposed the term “iportal” and named it “UBE” in the published articles, which means “unilateral biportal endoscopy” [2,4]. After 2017, the UBE technique was gradually used for minimally invasive treatment of spinal disorders, such as lumbar spinal stenosis [17], lumbar disc herniation [11], lumbar foraminal stenosis [5], lumbar intraspinal synovial cysts [18], epidural lipomatosis [19], lumbar spondylolisthesis [20], intervertebral space infection [21], and revision surgery [22].
With the gradual increase in number of UBE procedures performed, UBE surgery-related complications have been reported, including epidural hematoma, dural sac tears, retroperitoneal effusions, inadequate decompression, postoperative back pain and headache, early recurrence, iatrogenic spinal instability, anemia, and infection, which can prolong hospital stay and seriously affect patient satisfaction [23]. In China, the UBE technique has developed rapidly in recent years, and many spine surgeons have started to apply it and presented the initial clinical research results at many conferences on minimally invasive spine [8, 24]. Unfortunately, these studies actually translated into fewer publications, especially regarding the prevention and management of UBE surgery-related complications. Therefore, we reviewed the complications of UBE surgery for lumbar degenerative diseases, including disc herniation material and hypertrophy/expansion of degenerative tissues [1]. We also discuss ways to prevent and manage complications associated with UBE to help spine surgeons make good treatment decisions to optimize patient outcomes (Figure 1; Tables 1, 2).
Complications
INCIDENTAL DUROTOMY:
Incidental durotomy is a common complication of UBE surgery, ranging in incidence from 0.9% to 13.2% [3,9,10,15,18,20,23,25–35], and can lead to cerebrospinal fluid leakage, pseudomeningocele, infection, or meningitis if not treated properly [36,37]. The reasons for its occurrence include the following 3 aspects: Firstly, the surgeon’s unfamiliarity with the anatomy under endoscopy or poor hemostasis leading to a blurry surgical field. Incidental durotomy is more likely to occur during blind operations [24,33]. Secondly, in patients with severe lumbar spinal stenosis, incidental durotomy is likely to occur when the ligamentum flavum is removed because the dural sac and the ligamentum flavum are connected by the membranovertebral ligament, which is a mesh-like connective tissue [38]. Thirdly, females, patients over 70 years old, those with lumbar spondylolisthesis, and patients with articular facet cysts are also prone to dural sac injury [39,40]. Scholars have proposed corresponding preventive measures for dural sac injury. Liang et al reduced traction of the dural sac by removing the ligamentum flavum layer-by-layer [8]. Lee et al carefully separated the ligamentum flavum from the membranovertebral ligament using a nerve dissector [28]. Controlling blood pressure during surgery can prevent blurry vision caused by bleeding [28]. Scholars have developed specific management strategies based on the size of dural sac injury. For injuries <4 mm, no intervention is needed during surgery, and the patient should rest in bed for 24 hours postoperatively; for injuries sized 4–12 mm, fibrin sealant patch closure is used, and close observation is required during hospitalization; for injuries >12 mm, suturing is recommended, and regular edge tears can be repaired with a fibrin sealant patch [2].
NERVE ROOT INJURY:
The incidence of nerve root injury in UBE surgery is relatively low, and there has been only 1 report, by Kim et al [41], of L5 nerve root palsy after UBE, which was caused by nerve root compression during interbody fusion through the Kambin triangle in UBE surgery. Other causes are poor endoscopic orientation for inexperienced surgeons, improper surgery, compression of the cauda equina when using oversized surgical instruments for contralateral decompression, and thermal damage from radiofrequency ablation [8]. After nerve root injury, sensory and motor dysfunction may occur, so avoiding nerve root injury is crucial. Preventive measures include completing the articuloplasty before inserting interbody fusion devices through the Kambin triangle approach, reducing the output power of radiofrequency ablation, providing early cadaveric simulation training for inexperienced surgeons to improve their directional sense under endoscopy, and optimizing surgical instruments [8,15].
EPIDURAL HEMATOMA:
Epidural hematoma is a common complication of UBE surgery, with an incidence as high as 24.7%, of which only 1.2% require surgical removal [42]. The causes of epidural hematoma include 4 factors. First, in patients under general anesthesia, extubation stimulation can induce a 50 mmHg increase in systolic blood pressure, which increases the risk of epidural hematoma. Second, high irrigation pressure during surgery can obscure bleeding sites, resulting in inadequate hemostasis. Third, the radicular artery accompanies the nerve root in the extraforaminal region of the intervertebral foramen, and bleeding after injury can be severe, leading to epidural hematoma. Fourth, risk factors for epidural hematoma include obesity, coagulation disorders, advanced age, and the use of non-steroidal anti-inflammatory drugs [26,43–45]. Preventive measures include controlling blood pressure during extubation (in patients under general anesthesia), choosing spinal anesthesia/local anesthesia, controlling irrigation pressure, and ensuring adequate hemostasis by using low-power radiofrequency, bone wax, gelatin sponge, fibrin sealant powder, or gelatin thrombin [8,26,46,47]. For patients with epidural hematoma, those without neurological symptoms can be managed conservatively, with absorption typically occurring within 3 weeks, while those with neurological compression symptoms may require UBE surgery or open surgical clearance [32,48].
INADEQUATE DECOMPRESSION AND EARLY RECURRENCE:
Inadequate decompression can lead to the neurological compression symptoms persisting postoperatively, necessitating a repeat operation. The primary reason for this is the discrepancy between preoperative imaging assessment and the actual extent of decompression during surgery, often seen with residual ligamentum flavum on the proximal and contralateral sides [49,50]. Preventive measures mainly involve careful preoperative imaging review to evaluate the localization of disc herniation and spinal stenosis. During surgery, the extent of decompression should match the neurocompression sites indicated by imaging, with intraoperative fluoroscopic guidance if necessary. Additionally, selecting the correct surgical approach is crucial in preventing inadequate decompression. Typically, the side of the body with the worse symptoms is chosen as the surgical approach, while in special cases, a contralateral sublaminar approach can be selected (unilateral foraminal stenosis+lateral recess stenosis, unilateral foraminal stenosis+lateral recess stenosis+bilateral central canal/lateral recess stenosis, simultaneous unilateral lateral recess stenosis+foraminal stenosis+lateral recess stenosis). Other methods include improving surgical instruments and enhancing surgical techniques [4,51].
Early recurrence after UBE surgery for degenerative lumbar disease occurs in about 2.3% of cases, usually within days to weeks postoperatively [24]. Lack of surgical experience leading to residual nucleus pulposus, inadequate decompression, and severe degeneration of the nucleus pulposus are the main reasons for early recurrence [15,23]. Preventive measures include thorough decompression and reconstruction of the fibrous ring [23]. Patients with early recurrence can initially undergo conservative treatment, but may require a second surgery if conservative measures are ineffective [15,23].
POSTOPERATIVE LOW BACK PAIN AND HEADACHE:
Postoperative back pain after UBE surgery can be classified into persistent back pain (>2 weeks) and short-term back pain (<2 weeks) based on the duration of pain. Soliman et al [15] reported a case of persistent back pain after UBE surgery, which was attributed to inappropriate patient selection (lumbar instability combined with lumbar disc herniation) rather than the UBE technique itself. A small number of patients experience short-term back pain after UBE surgery, most of which can be relieved with symptomatic treatment. The main cause of short-term postoperative back pain is multifidus muscle injury, which is related to friction from surgical instruments, prolonged surgical duration, high irrigation pressure, and inadequate drainage during surgery [52]. Preventive and treatment measures include strictly adhering to surgical indications, shortening the surgical duration, controlling irrigation pressure to less than 30 mmHg, using irrigation fluid with isotonic saline, and administering mannitol and methylprednisolone for 1–2 days postoperatively [15,52].
Postoperative headache is due to increased pressure in the dural sac and the cranium caused by the pressure of the irrigation water [4,31,53]. Additionally, excessive irrigation pressure can induce discomfort symptoms such as neck pain, dizziness, blurred vision, and drowsiness [4,28]. Therefore, the primary method to prevent postoperative headache is to reduce the irrigation pressure. The operation can be performed under continuous gravity irrigation without using an irrigation pump [53]. If an irrigation pump is used, the pressure should be ≤30 mmHg, and there should be a pause of 3 minutes after every 60 minutes of irrigation [15,54]. Moreover, shortening the operation time can prevent postoperative headache [31].
IATROGENIC SPINAL INSTABILITY:
The incidence of iatrogenic lumbar instability after UBE surgery is only 0.25% [23], but proactive prevention is essential due to the possible progression to lumbar spondylolisthesis, which severely affects the patient’s quality of life and may even require a second operation. In 2 studies by Kim et al, the UBE technique was used to treat 55 patients with lumbar spinal stenosis and 31 patients with lumbar foraminal stenosis. Among them, 17 patients with l lumbar spinal stenosis had lumbar spondylolisthesis (grade I) preoperatively. The follow-up durations were 2 years and 1 year, respectively, and at the final follow-up, no cases of spinal instability were observed [5,34]. Therefore, Kim et al concluded that UBE technique decompression has little impact on lumbar spine stability [34]. The key to preventing iatrogenic instability is to minimize bony structural damage [23]. Unilateral lumbar spondylolysis without neurological symptoms and unilateral facet joint injuries can be observed during follow-up. However, for patients with progressive lumbar spondylolisthesis accompanied by severe low back pain or neurological compression symptoms, spinal fusion surgery is required [23,55].
COMPLICATIONS ASSOCIATED WITH INTERBODY FUSION:
UBE lumbar interbody fusion (ULIF) refers to lumbar interbody fusion performed after UBE decompression. Two primary concerns with ULIF are the fusion rate under aqueous medium and the avoidance of nerve root injury during implantation of the interbody fusion devices. The fusion rate of ULIF was satisfactory in the short-term follow-up. In 2017, Heo et al conducted a retrospective analysis of 69 patients with degenerative lumbar disease treated with ULIF and achieved a 100% interbody fusion rate at 13-month follow-up [20]. Kim et al retrospectively analyzed 14 patients with degenerative lumbar disease treated with ULIF and also achieved a 100% fusion rate [41]. Gatam et al divided 145 patients with lumbar spondylolisthesis into ULIF (n=72) and minimally invasive lumbar interbody fusion (MIS-TLIF) (n=73) groups, and found that the fusion rates in the ULIF and MIS-TLIF groups were 92.7% and 93.3%, respectively, at a follow-up of 12 months (P>0.05) [10]. UBE offers the advantage of a 30° angle to observe the superior and inferior endplates, which facilitates thorough removal of the cartilage while avoiding damage to the endplates, which is conducive to interbody fusion [56]. Additionally, Kim et al reported a case of postoperative lower limb paralysis due to L5 nerve root compression by an interbody fusion device implanted via the Kambin triangle approach [41]. Therefore, it is necessary to prevent nerve root injury in ULIF surgery. Common methods include implanting interbody fusion devices after foraminoplasty and using height-adjustable interbody fusion devices [39,56].
RETROPERITONEAL EFFUSIONS:
Retroperitoneal effusions can be classified as retroperitoneal hydrops and retroperitoneal hematoma [23,39,57,58]. The incidence of retroperitoneal hydrops after UBE is reported to be 0.5~2.3%, although no cases of retroperitoneal hematoma have been reported [39,57]. The causes of retroperitoneal hydrops include prolonged operation time, high irrigation pressure, leakage of irrigation fluid into the intermuscular space due to radiofrequency coagulation injury to the paraspinal muscles, and inadvertent advancement of the endoscope into the iliolumbar ligament ventral to the transverse process, causing injury to the psoas major muscle and leading to irrigation fluid entry into the retroperitoneal space [23,39,52]. Methods for preventing retroperitoneal hydrops include reducing irrigation pressure, using low-power radiofrequency output, avoiding advancement of the endoscope into the ventral side of the iliolumbar ligament, and shortening the surgical duration [23,52,57,58]. Low-volume retroperitoneal hydrops can be spontaneously absorbed with conservative treatment, whereas cases of significant retroperitoneal hydrops require prolonged hospitalization and intermittent perirenal drainage [23,57]. There have been no reported cases of retroperitoneal hematoma caused by injury to the radicular artery in UBE surgery. However, if such an incident occurs, the management approach can be guided by the case of retroperitoneal hematoma after percutaneous endoscopic lumbar discectomy reported by Ahn et al [58]. Small hematomas (<100 mL) can be managed conservatively, but large diffuse hematomas compressing abdominal organs may require open exploration for hematoma evacuation.
POSTOPERATIVE ANEMIA AND INFECTION:
Anemia is an easily overlooked problem after UBE surgery because the usual method of assessing blood loss is estimated blood loss, whereas occult blood loss is the main cause of anemia after UBE surgery [59]. Kim HS et al [60], Kim SK et al [49], and Heo et al [20] recorded 53.63±10.08 ml, 34.67±16.92 ml, and 85.5±19.41 ml average estimated blood loss in 30, 60, and 69 patients with degenerative lumbar spine disease who underwent UBE surgery, respectively. However, Wang et al investigated occult blood loss in 136 patients who underwent UBE surgery and found that the estimated blood loss was 278.2±85.2 mL, while the occult blood loss was as high as 469.5±195.3 mL, and they found that 38.9% (42 of 136 cases) of patients had postoperative anemia [61]. Preoperative and postoperative routine blood tests can help to detect the anemia status of patients at an early stage. Shortening the operation time and using hemostatic drugs are also effective methods to reduce blood loss and prevent anemia [62,63]. In addition, paying attention to the patient’s age, blood volume, postoperative hematocrit, and fibrinogen level helps to determine whether patients have risk factors for occult blood loss [61].
The infection rate in endoscopic spine surgery is significantly lower than in open surgery (0~1.4% vs 0.7~12%) because endoscopic surgery is performed under continuous irrigation with physiologic saline [64,65]. Only 2 cases of infection after UBE procedures have been reported in the literature. Park et al reported 1 case (1.4%, 1/71) but did not mention how it was managed [33]. Kim et al reported 1 case (0.01%, 1/797) which improved after UBE surgery for abscess drainage [23]. Risk factors for incision infection in traditional spinal surgery include advanced age, high BMI, underlying diseases, diabetes, long operation time, prolonged drainage time, preoperative hypocalcemia, low albumin level, and postoperative anemia [64,65]. These risk factors should also be taken into account during UBE surgery to avoid infections.
Future Directions
Future, needs for development of UBE surgery are to optimize UBE endoscopic instruments to enable more complex spinal surgeries, and to integrate UBE with artificial intelligence, big data, and robotics, making UBE surgery more digital and intelligent.
Conclusions
UBE surgery is an effective method for treating lumbar degenerative diseases. Various complications associated with UBE surgery can affect patient satisfaction. However, most complications can be resolved through proactive prevention strategies.
References
1. Donnally CJ, Hanna A, Varacallo M, Lumbar degenerative disk disease. [Updated 2023 Aug 4]: StatPearls [Internet], 2024, Treasure Island (FL), StatPearls Publishing Available from: https://www.ncbi.nlm.nih.gov/books/NBK448134/
2. Choi DJ, Jung JT, Lee SJ, Biportal endoscopic spinal surgery for recurrent lumbar disc herniations: Clin Orthop Surg, 2016; 8; 325-29
3. Huang YH, Lien FC, Chao LY, Full endoscopic uniportal unilateral laminotomy for bilateral decompression in degenerative lumbar spinal stenosis: Highlight of ligamentum flavum detachment and survey of efficacy and safety in 2 years of follow-up: World Neurosurg, 2020; 134; e672-e81
4. Hwa Eum J, Hwa Heo D, Son SK, Park CK, Percutaneous biportal endoscopic decompression for lumbar spinal stenosis: A technical note and preliminary clinical results: J Neurosurg Spine, 2016; 24; 602-7
5. Kim JE, Choi DJ, Park EJ, Clinical and radiological outcomes of foramina decompression using unilateral biportal endoscopic spine surgery for lumbar foraminal stenosis: Clin Orthop Surg, 2018; 10; 439-47
6. Chen Z, Zhou H, Wang X, Complications of unilateral biportal endoscopic spinal surgery for lumbar spinal stenosis: A meta-analysis and systematic review: World Neurosurg, 2023; 170; e371-e79
7. Yang L, Zhou L, Wang G, Unilateral Bi/multi-portal endoscopy for the treatment of complicated lumbar degenerative diseases with utilization of uniaxial spinal endoscope, instead of arthroscope: Technique note and clinical results: Clin Interv Aging, 2023; 18; 1295-308
8. Liang J, Lian L, Liang S, Efficacy and complications of unilateral biportal endoscopic spinal surgery for lumbar spinal stenosis: A meta-analysis and systematic review: World Neurosurg, 2022; 159; e91-e102
9. Ito Z, Shibayama M, Nakamura S, Clinical comparison of unilateral biportal endoscopic laminectomy versus microendoscopic laminectomy for single-level laminectomy: A single-center, retrospective analysis: World Neurosurg, 2021; 148; e581-e88
10. Gatam AR, Gatam L, Mahadhipta H, Unilateral biportal endoscopic lumbar interbody fusion: A technical note and an outcome comparison with the conventional minimally invasive fusion: Orthop Res Rev, 2021; 13; 229-39
11. Tian D, Liu J, Zhu B, Unilateral biportal endoscopic technique for lumbar disc herniation and lumbar spinal stenosis: Chin J Orthop, 2020; 12; 1155-64
12. Kambin P, Arthroscopic microdiscectomy: Arthroscopy, 1992; 8; 287-95
13. De Antoni DJ, Claro ML, Poehling GG, Translaminar lumbar epidural endoscopy: Anatomy, technique, and indications: Arthroscopy, 1996; 12(3); 330-34
14. DeAntoni DJ, Claro ML, Poehling GG, Hughes SS, Translaminar lumbar epidural endoscopy: Technique and clinical results: J South Orthop Assoc, 1998; 7; 6-12
15. Soliman HM, Irrigation endoscopic discectomy: A novel percutaneous approach for lumbar disc prolapse: Eur Spine J, 2013; 22; 1037-44
16. Soliman HM, Irrigation endoscopic decompressive laminotomy. A new endoscopic approach for spinal stenosis decompression: Spine J, 2015; 15; 2282-89
17. Liu JJ, Zhu B, Chen LEfficacy comparison of unilateral biportal endoscopic decompression and extended interlaminar fenestration for lumbar lateral recess stenosis: Zhonghua Yi Xue Za Zhi, 2022; 102; 801-7
18. Lin GX, Huang P, Kotheeranurak V, A systematic review of unilateral biportal endoscopic spinal surgery: Preliminary clinical results and complications: World Neurosurg, 2019; 125; 425-32
19. Kang SS, Lee SC, Kim SK, A novel percutaneous biportal endoscopic technique for symptomatic spinal epidural lipomatosis: Technical note and case presentations: World Neurosurg, 2019; 129; 49-54
20. Heo DH, Son SK, Eum JH, Park CK, Fully endoscopic lumbar interbody fusion using a percutaneous unilateral biportal endoscopic technique: Technical note and preliminary clinical results: Neurosurg Focus, 2017; 43; E8
21. Hsu TL, Yang CJ, Pao JL: J Int Med Res, 2022; 50; 3000605221085405
22. Lewandrowski KU, Ransom NA, Yeung A, Subsidence induced recurrent radiculopathy after staged two-level standalone endoscopic lumbar interbody fusion with a threaded cylindrical cage: A case report: J Spine Surg, 2020; 6; S286-S93
23. Kim W, Kim SK, Kang SS, Pooled analysis of unsuccessful percutaneous biportal endoscopic surgery outcomes from a multi-institutional retrospective cohort of 797 cases: Acta Neurochir (Wien), 2020; 162; 279-87
24. Zhu B, Tian D, Chen L, Development and application of unilateral biportal endoscopy in lumbar diseases: Chin J Orthop, 2020; 40; 1030-38
25. Hong YH, Kim SK, Suh DW, Lee SC, Novel instruments for percutaneous biportal endoscopic spine surgery for full decompression and dural management: a comparative analysis: Brain Sci, 2020; 10(8); 516
26. Kim JE, Choi DJ, Park EJ, Risk factors and options of management for an incidental dural tear in biportal endoscopic spine surgery: Asian Spine J, 2020; 14; 790-800
27. Park HJ, Kim SK, Lee SC, Dural tears in percutaneous biportal endoscopic spine surgery: Anatomical location and management: World Neurosurg, 2020; 136; e578-e85
28. Lee HG, Kang MS, Kim SY, Dural injury in unilateral biportal endoscopic spinal surgery: Global Spine J, 2021; 11; 845-51
29. Heo DH, Ha JS, Lee DC, Repair of incidental durotomy using sutureless nonpenetrating clips via biportal endoscopic surgery: Global Spine J, 2022; 12; 452-57
30. Park SM, Park J, Jang HS, Biportal endoscopic versus microscopic lumbar decompressive laminectomy in patients with spinal stenosis: A randomized controlled trial: Spine J, 2020; 20; 156-65
31. Czigleczki G, Nagy Z, Padanyi C, Banczerowski P, Biportal endoscopic technique in the treatment of spinal stenosis: Early clinical experiences and results: Neurol Res, 2020; 42; 1085-88
32. Kim JE, Choi DJ, Unilateral biportal endoscopic decompression by 30 degrees endoscopy in lumbar spinal stenosis: Technical note and preliminary report: J Orthop, 2018; 15; 366-71
33. Park MK, Park SA, Son SK, Clinical and radiological outcomes of unilateral biportal endoscopic lumbar interbody fusion (ULIF) compared with conventional posterior lumbar interbody fusion (PLIF): 1-year follow-up: Neurosurg Rev, 2019; 42; 753-61
34. Kim JE, Choi DJ, Clinical and radiological outcomes of unilateral biportal endoscopic decompression by 30 degrees arthroscopy in lumbar spinal stenosis: Minimum 2-year follow-up: Clin Orthop Surg, 2018; 10; 328-36
35. Kang SS, Kim JE, Choi DJ, Park EJ, Pseudomeningocele after biportal endoscopic spine surgery: A case report: J Orthop, 2020; 18; 1-4
36. Lin CH, Lin SM, Lan TY, Pao JL, Pneumocephalus with conscious disturbance after full endoscopic lumbar diskectomy: World Neurosurg, 2019; 131; 112-15
37. Choi G, Kang HY, Modi HN, Risk of developing seizure after percutaneous endoscopic lumbar discectomy: J Spinal Disord Tech, 2011; 24; 83-92
38. Chen R, Shi B, Zheng X, Anatomic study and clinical significance of the dorsal meningovertebral ligaments of the thoracic dura mater: Spine (Phila Pa 1976), 2015; 40; 692-98
39. Wang MC, Yu KY, Zhang JG, Wang YPProgression and clinical application in unilateral biportal endoscopic: Zhonghua Wai Ke Za Zhi, 2020; 58; 892-96 [in Chinese]
40. Takahashi Y, Sato T, Hyodo H, Incidental durotomy during lumbar spine surgery: Risk factors and anatomic locations: Clinical article: J Neurosurg Spine, 2013; 18; 165-69
41. Kim JE, Choi DJ, Biportal endoscopic transforaminal lumbar interbody fusion with arthroscopy: Clin Orthop Surg, 2018; 10; 248-52
42. Kim JE, Choi DJ, Park EJ, Evaluation of postoperative spinal epidural hematoma after biportal endoscopic spine surgery for single-level lumbar spinal stenosis: Clinical and magnetic resonance imaging study: World Neurosurg, 2019; 126; e786-e92
43. Yamada K, Abe Y, Satoh S, Large increase in blood pressure after extubation and high body mass index elevate the risk of spinal epidural hematoma after spinal surgery: Spine (Phila Pa 1976), 2015; 40; 1046-52
44. Kim JE, Choi DJ, Kim MC, Park EJ, Risk factors of postoperative spinal epidural hematoma after biportal endoscopic spinal surgery: World Neurosurg, 2019; 129; e324-e29
45. Choi CM, Chung JT, Lee SJ, Choi DJ, How I do it? Biportal endoscopic spinal surgery (BESS) for treatment of lumbar spinal stenosis: Acta Neurochir (Wien), 2016; 158; 459-63
46. Altun I, An experimental study of histopathologic effects of hemostatic agents used in spinal surgery: World Neurosurg, 2016; 90; 147-53
47. Kim JE, Yoo HS, Choi DJ: Biomed Res Int, 2020; 2020; 4801641
48. Anno M, Yamazaki T, Hara N, Ito Y, The incidence, clinical features, and a comparison between early and delayed onset of postoperative spinal epidural hematoma: Spine (Phila Pa 1976), 2019; 44; 420-23
49. Kim SK, Kang SS, Hong YH, Clinical comparison of unilateral biportal endoscopic technique versus open microdiscectomy for single-level lumbar discectomy: A multicenter, retrospective analysis: J Orthop Surg Res, 2018; 13; 22
50. Choi DJ, Choi CM, Jung JT, Learning curve associated with complications in biportal endoscopic spinal surgery: Challenges and strategies: Asian Spine J, 2016; 10; 624-29
51. Heo DH, Lee N, Park CW, Endoscopic unilateral laminotomy with bilateral discectomy using biportal endoscopic approach: Technical report and preliminary clinical results: World Neurosurg, 2020; 137; 31-37
52. Ahn JS, Lee HJ, Park EJ, Multifidus muscle changes after biportal endoscopic spinal surgery: Magnetic resonance imaging evaluation: World Neurosurg, 2019; 130; e525-e34
53. Kim JE, Choi DJ, Park EJJ, Biportal endoscopic spinal surgery for lumbar spinal stenosis: Asian Spine J, 2019; 13; 334-42
54. Choi CM, Biportal endoscopic spine surgery (BESS): Considering merits and pitfalls: J Spine Surg, 2020; 6; 457-65
55. Debnath UK, Freeman BJ, Grevitt MP, Clinical outcome of symptomatic unilateral stress injuries of the lumbar pars interarticularis: Spine (Phila Pa 1976), 2007; 32; 995-1000
56. Heo DH, Hong YH, Lee DC, Technique of biportal endoscopic transforaminal lumbar interbody fusion: Neurospine, 2020; 17; S129-S37
57. Choi DJ, Kim JE, Jung JT, Biportal endoscopic spine surgery for various foraminal lesions at the lumbosacral lesion: Asian Spine J, 2018; 12; 569-73
58. Ahn Y, Kim JU, Lee BH, Postoperative retroperitoneal hematoma following transforaminal percutaneous endoscopic lumbar discectomy: J Neurosurg Spine, 2009; 10; 595-602
59. Miao KS, Ni S, Zhou XJ, Hidden blood loss and its influential factors after total hip arthroplasty: J Orthop Surg Res, 2015; 10; 36
60. Kim HS, Choi SH, Shim DM, Advantages of new endoscopic unilateral laminectomy for bilateral decompression (ULBD) over conventional microscopic ULBD: Clin Orthop Surg, 2020; 12; 330-36
61. Wang H, Wang K, Lv B, Analysis of risk factors for perioperative hidden blood loss in unilateral biportal endoscopic spine surgery: A retrospective multicenter study: J Orthop Surg Res, 2021; 16(1); 559
62. Lei F, Li Z, He W, Hidden blood loss and the risk factors after posterior lumbar fusion surgery: A retrospective study: Medicine (Baltimore), 2020; 99; e20103
63. Sasaji T, Horaguchi K, Shinozaki N, Postoperative anemia following posterior decompression surgery for lumbar spinal canal stenosis: Tohoku J Exp Med, 2013; 229; 1-4
64. Pull ter Gunne AF, Cohen DB, Incidence, prevalence, and analysis of risk factors for surgical site infection following adult spinal surgery: Spine (Phila Pa 1976), 2009; 34; 1422-28
65. Fei Q, Li J, Lin J, Risk factors for surgical site infection after spinal surgery: A meta-analysis: World Neurosurg, 2016; 95; 507-15
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