Visualized reamer foraminoplasty in transforaminal endoscopic lumbar discectomy for upward-migrated lumbar disc herniation: a case report with surgical video

Abstract

Introduction and importance:

This article provides a detailed demonstration of the surgical procedure for treating an upward-migrated lumbar disc herniation using a visualized reamer for foraminoplasty during transforaminal endoscopic lumbar discectomy (TELD). Foraminoplasty is a critical step in TELD for achieving adequate decompression and establishing a working channel. The visualized reamer enables surgeons to perform precise foraminoplasty under direct endoscopic visualization.

Case presentation:

This article reports the case of a 65 year-old male patient with a chief complaint of low back pain and radiating pain in the left lower limb for over two years. His Oswestry Disability Index was 71.11%, and his Visual Analog Scale scores were 8 for low back pain and 9 for leg pain. Neurological examination revealed a positive femoral nerve stretch test and grade 3/5 muscle strength in the left quadriceps. Imaging confirmed a highly upward-migrated lumbar disc herniation at the L3/4 level. The patient successfully underwent TELD with a visualized reamer foraminoplasty, resulting in significant postoperative symptom relief and an excellent outcome at the 1-year follow-up.

Clinical discussion:

Two factors likely contributed to the favorable outcome: first, direct endoscopic visualization allowed controlled adjustment of bone resection; second, preemptive soft-tissue coagulation helped maintain a clear surgical field.

Conclusion:

Visualized reamer foraminoplasty can address such challenging cases and could represent a feasible approach in selected patients.

Introduction

Transforaminal endoscopic lumbar discectomy (TELD) is a mainstream minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH)^[1^]. Foraminoplasty, which involves resecting a portion of the superior articular process to enlarge the intervertebral foramen, is often crucial for establishing an adequate working channel and surgical trajectory^[2^]. Traditional foraminoplasty relies on fluoroscopic guidance, lacking direct visualization of neural and vascular structures. Visualized reamer foraminoplasty represents a technical evolution from fluoroscopy-guided to endoscopically visualized foraminoplasty^[3^]. This technique makes TELD a viable option for treating challenging, high-grade migrated LDH. It provides real-time visualization of foraminal anatomy and, when integrated with preoperative imaging, may help plan bone resection more precisely. This technical report describes the application of visualized reamer foraminoplasty in TELD for a highly upward-migrated L3/4 LDH (with the fragment reaching the inferior border of the L3 pedicle), focusing on the surgical details. The complete surgical procedure is demonstrated in the accompanying video. This case report is presented in accordance with the SCARE criteria^[4^].

HIGHLIGHTS

• This case demonstrates a visualized, reamer-assisted foraminoplasty for a highly upward-migrated lumbar disc herniation (the fragment reaches the inferior border of the L3 pedicle).

• The technique provides direct endoscopic visualization during bony decompression, transitioning away from conventional fluoroscopic guidance.

• The visualized reamer enables precise bone resection and simultaneous hemostasis under direct vision.

• The patient achieved significant pain relief and functional improvement at the 1-year follow-up.

• This approach may represent a feasible and potentially advantageous endoscopic option for selected cases of complex, migrated disc herniations.

Case presentation

A 65 year-old male patient was admitted with chief complaints of low back pain and radiating pain along the left lower limb for more than 2 years, with recent aggravation. Functional assessment indicated severe disability, with an Oswestry Disability Index (ODI) score of 71.11%. The Visual Analog Scale (VAS) scores were 8 for back pain and 9 for leg pain. Muscle strength was graded 3/5 in the left quadriceps (Lovett scale). No significant sensory deficits or reflex abnormalities were detected. Past medical history included an appendectomy and hepatitis B.

Preoperative dynamic lumbar radiographs showed degenerative changes. Both lumbar magnetic resonance imaging and computed tomography confirmed a left foraminal disc herniation at L3/4, with the fragment migrating rostrally to the inferior border of the L3 pedicle, compressing the L4 nerve root. No significant calcification was observed (Fig. 1).

Figure 1.

Preoperative imaging of the patient. (A) Preoperative lumbar MR, sagittal view; (B) Preoperative lumbar MR, axial view, in which the circled area indicates the herniated nucleus pulposus; (C) Preoperative lumbar CT, sagittal view; (D) Preoperative lumbar CT, axial view, in which the arrow indicates the herniated nucleus pulposus; (E) Preoperative lumbar CT, coronal view, in which the arrow indicates the upward migration of the herniated nucleus pulposus.

The final diagnosis was L3–4 LDH (upwardly migrated type). TELD with visualized-reamer foraminoplasty was planned.

Clinical discussion

Endoscopic spine surgery faces several inherent challenges. First, the coaxial instrument design in TELD offers a relatively narrow field of view, often necessitating partial foraminoplasty to create adequate working space and an optimal trajectory. Second, TELD is associated with a steep learning curve^[5^]. Inexperienced surgeons may struggle with anatomical identification under endoscopy, increasing the risk of injury to neural and vascular structures^[6^]. Finally, bleeding from bone surfaces or minute vessels during foraminoplasty can lead to a sudden “blood-obscured visual field” phenomenon^[6,7^], compromising surgical continuity and precision.

The visualized reamer foraminoplasty technique directly addresses these limitations. The key feature of the visualized reamer foraminoplasty technique is the transition from fluoroscopy-guided estimation to real-time endoscopic visualization and controlled resection^[8^].

First, after establishing the initial working channel, the technique allows direct endoscopic identification and systematic radiofrequency coagulation of minute vessels within the foramen before bone resection. This preemptive approach reduces the risk of intraoperative bleeding at its source, thereby maintaining a clear and stable visual field for subsequent critical steps^[9^].

Second, under continuous direct visualization, the surgeon can control the extent and angle of bone resection in real-time, enabling safe and precise foraminoplasty. In this case, an enlarged foraminoplasty, including resection of the ventral base of the L4 superior articular process and part of the superior border of the L4 pedicle, was safely performed under direct vision. This strategy created the necessary bony space for adjusting the working channel trajectory and rostral extension, ensuring successful removal of the migrated fragment. Furthermore, visualized foraminoplasty allows for on-demand bone removal, effectively avoiding damage to the facet joint and preserving this crucial stabilizer, which may contribute to maintaining long-term biomechanical stability^[10^] (Fig. 2).

Figure 2.

Intraoperative endoscopic views: (A) Endoscopic identification of the foraminal region before foraminoplasty; (B) Foraminoplasty performed using the visualized reamer; (C) The “sandwich structure” identified after foraminoplasty: the superior articular process superiorly, the ligamentum flavum in the middle, and the intervertebral disc inferiorly; (D) Completion of nerve root decompression.

Follow-up assessments demonstrated significant clinical improvement. The patient’s back pain resolved completely, and left lower limb pain was substantially relieved, with VAS scores decreased to 0 (back) and 2 (leg), respectively. The ODI improved to 17.78%. Only mild residual numbness in the left lower limb persisted, which did not limit daily activities. Postoperative magnetic resonance imaging at three months revealed soft tissue edema in the surgical area; in this case, the edema was asymptomatic and resolved spontaneously by the 1-year follow-up (Fig. 3). No serious complications occurred during the entire follow-up period.

Figure 3.

Postoperative imaging of the patient. (A) Immediate postoperative lumbar MR showing successful removal of the herniated nucleus pulposus, with mild edema in the surgical area; (B) Lumbar MR at 1 year postoperatively showing complete resolution of the surgical-site edema; (C) Immediate postoperative lumbar CT confirming successful removal of the herniated nucleus pulposus, with partial resection of the L4 superior articular process but preservation of the articular surface; (D) Lumbar CT at 1 year postoperatively demonstrating good bony healing of the L4 superior articular process.

Collectively, these clinical and radiographic findings support the value of this technique. This case illustrates the technical feasibility and potential safety of visualized reamer foraminoplasty in the treatment of highly upward-migrated LDH. A summary of representative studies comparing various foraminoplasty techniques is provided in Table 1, which highlights the unique contribution of the present case.

Table 1.

Summary of representative studies on foraminoplasty for lumbar disc herniation.

Author & Year	Type of study	Migration direction	Segment	Approach	Foraminoplasty tool	Sample size	Follow-up (months)	Complications	Outcomes
Hoogland et al[11], 2006	Randomized Controlled Trial	Downward and upward migrated LDH	L2/3, L3/4, L4/5, L5/S1	TELD	TESSYS reamer	280	24	Infection, wound healing, thrombosis, radicular pain, numbness, or weakness	TELD achieves satisfactory clinical outcomes for all types of lumbar disc herniation, and the addition of intradiscal chymopapain injection can further reduce the postoperative recurrence rate.
Choi et al[12], 2018	Case report	Downward migrated LDH	L4/5, L5/S1	TELD + IELD	TESSYS reamer	2	48	None	A combination of transforaminal and interlaminar PELD may be effective for extensive down-migrated disk herniation at L4-L5.
Wu et al[13], 2021	Retrospective study	Downward and upward migrated LDH	L1/2, L2/3, L3/4, L4/5, L5/S1	TELD/ IELD	Endoscopic drills or endoscopic osteotomes	58 (41/17)	60	Recurrence	Full-endoscopic lumbar discectomy has a high success rate for the management of high-grade migrated herniated discs.
Ouyang et al[9], 2021	Retrospective study	Not specified	L3/4, L4/5, L5/S1	TELD	Visualized bone reamer/ traditional reamer	80 (40/40)	17–18	Recurrence	Visualized reamer group reduced fluoroscopy frequency and improved cannulation efficiency.
Shi et al[14], 2024	Retrospective study	Not specified	L4/5, L5/S1	TELD	Visualized trephine/ TESSYS trephines or bone drills	63 (30/33)	12	Dysesthesia, dural tear, recurrence, reoperation	For LDH with bilateral radiculopathy, full-endoscopic visualized foraminoplasty reduces operative time and radiation while improving L5/S1 outcomes.
Yu et al[15], 2025	Retrospective study	Not specified	L4/5, L5/S1	TELD	Progressive bone drilling system (PBDS)/ visualized reaming system (VRS)	798 (432/366)	24	Recurrence, nerve root injury, dural tear, wound complications, revision cases	The visualized reamer technique resulted in lower radiation exposure and operative time compared to a progressive bone drilling system.
Chang et al[16], 2025	Retrospective study	Not specified	L2/3, L3/4, L4/5, L5/S1	TELD	Endoscopic drill (ED)/ extra-endoscopic trephine (EET)	136 (67/69)	12	Neural irritation, dysesthesia, epidural hematoma, recurrence	The EET group had significantly shorter mean operative time and foraminoplasty time than the ED group.
Yang et al[17], 2025	Retrospective study	Upward migrated LDH	L1/2, L2/3, L3/4, L4/5, L5/S1	Converging decompression technique (CDT)/ TELD	Bone drill	66 (27/39)	29	Dysesthesia, radicular leg pain, head pain	CDT offers enhanced endoscopic efficiency and a reduced risk of postoperative nucleus pulposus remnants.
Liu et al[8], 2026	Retrospective study	Not specified	L2/3, L3/4, L4/5, L5/S1	TELD	Visualized reamer/ TESSYS reamer	140 (70/70)	12	Recurrence, dysesthesia	The visualized reamer group reduced fluoroscopy frequency and operative time, and achieved better early postoperative symptom improvement.

Future efforts should focus on defining its learning curve, establishing a precise control system for bone resection volume, and ultimately developing patient-specific protocols based on individual foramen morphology.

Conclusion

In summary, this case report illustrates the application of visualized reamer foraminoplasty for a highly upward-migrated L3/4 disc herniation. In this case, direct endoscopic visualization appeared to facilitate precise bony decompression and effective intraoperative hemostasis.

The patient demonstrated significant improvement in pain and functional scores postoperatively, with 1-year follow-up imaging confirming adequate decompression and preserved facet structures. Although based on a single case, our experience suggests that visualized reamer foraminoplasty may represent a feasible minimally invasive option for selected patients with highly migrated LDH (Supplemental Digital Content Video, available at: https://links.lww.com/IJSCR/A132.

Ethical approval

The study involving humans were approved by Ethics Committee of Guangdong Provincial Hospital of Chinese Medicine. The studies were conducted in accordance with the local legislation and institutional requirements. The waiver was granted on the grounds that the research involved only the secondary analysis of pre-existing, de-identified clinical data, entailed no additional interventions or foreseeable risks to the participants, and ensured that no personally identifiable information would be disclosed. This waiver was reviewed and approved by the Ethics Committee of Guangdong Provincial Hospital of Chinese Medicine (Approval No. ZE2025-151-01).

Consent

Written informed consent for participation was not required from the participants or the participants’ legal guardians/next of kin because the requirement for written informed consent was waived for this retrospective study.

Sources of funding

The author(s) declared that financial support was received for this work and/or its publication. This work was supported by the National Natural Science Foundation of China (Grant No. 82274554); the Special Project for the Key Laboratory of Traditional Chinese Medicine Science and Technology Research of Guangdong Provincial Hospital of Chinese Medicine (Grant No. YN2024MS001); the Special Project for Traditional Chinese Medicine Science and Technology Research of Guangdong Provincial Hospital of Chinese Medicine (Grant No. YN2023ZH05); the Chinese Medicine Leading Talents Project (Qihuang Scholar, No. [2022]6 of the Department of TCM Education of China); Lin Dingkun’s Guangdong Province Famous Traditional Chinese Medicine Inheritance Studio Construction Project (No. 0103030912); the Project of the Administration of Traditional Chinese Medicine of Guangdong Province (No. Z155080000004); the Lingnan Orthopedic School Inheritance Studio Construction Project (No. E43607); the Special Project for the Inheritance of Ancient Literature and Characteristic Techniques of Traditional Chinese Medicine of the National Administration of Traditional Chinese Medicine (No. GZYRKJ [2022]242); the Chinese Medicine Guangdong Laboratory (Hengqin Laboratory) Science and Technology Incubation Project (Grant No. NHQL2024PZ007); the Outstanding Clinical Technical Talent Program of Guangdong Provincial Hospital of Chinese Medicine; and the Elite Clinical Technical Talent Program of Guangdong Provincial Hospital of Chinese Medicine.

Author contributions

H.L. and Y.H.: Wrote the initial draft, collected the patient data, and performed imaging analysis. Z.K.: Made a video. D.L. and Y.L.: Designed the study. Y.L.: Performed the surgery, provided overall guidance, and critically revised the manuscript. All authors reviewed and approved the final manuscript.

Conflicts of interest disclosure

The authors declare no conflict of interest.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Yong-Jin Li.

Provenance and peer review

Unsolicited article; externally peer reviewed.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy restrictions.