Circumferential Transforaminal Endoscopic Lumbar Foraminotomy for 360° Exiting Nerve Root Decompression in Patients with Lumbar Foraminal Stenosis

Summary

This protocol describes circumferential transforaminal endoscopic lumbar foraminotomy for 360° decompression of the exiting nerve root in patients with lumbar foraminal stenosis using a step-by-step, landmark-based approach to achieve adequate bony and soft-tissue decompression.

Abstract

Lumbar foraminal stenosis is a common cause of intractable radiculopathy that may require surgical treatment when conservative management is ineffective. Transforaminal endoscopic lumbar foraminotomy (TELF) has been developed as a minimally invasive alternative to conventional open surgery, offering reduced tissue disruption and faster recovery. However, conventional TELF techniques may provide limited decompression in complex cases involving severe bony stenosis, fibrosis, or postoperative anatomical changes. This protocol describes circumferential TELF (C-TELF), an advanced endoscopic decompression technique designed to achieve 360° decompression of the exiting nerve root (ENR) in patients with lumbar foraminal stenosis. The goal of this protocol is to provide a reproducible, step-by-step method for achieving circumferential neural decompression through a landmark-based transforaminal approach. The technique incorporates sequential bony unroofing, soft-tissue removal, and complete neural mobilization within the foraminal zone. The procedure is performed using a percutaneous transforaminal approach under fluoroscopic guidance and endoscopic visualization. Decompression is conducted sequentially from the lower pedicle to the upper pedicle to enlarge the neural foramen and establish an adequate safety margin around the ENR. By achieving circumferential decompression, this technique aims to minimize residual neural compression and facilitate durable decompression. This protocol provides detailed procedural guidance to support the safe and reproducible implementation of C-TELF, particularly in patients with complex or refractory lumbar foraminal stenosis.

Introduction

Lumbar foraminal stenosis is a common cause of intractable radiculopathy, particularly in older adults and patients who have undergone previous lumbar surgery^1,2. This condition often leads to persistent leg pain, functional disability, and reduced quality of life^3,4. Degenerative changes, including disc collapse, facet hypertrophy, and ligament thickening, contribute to the progressive narrowing of the neural foramen⁵. Although conventional open decompression and fusion surgery can relieve symptoms, these procedures are associa....

Protocol

Institutional Review Board approval was obtained before data extraction, and all procedures were performed in accordance with institutional guidelines for human research. This study was approved by the Institutional Review Board of Kyung Hee University Hospital at Gangdong (Approval No. KHNMC 2026-04-033). The requirement for informed consent was waived because of the retrospective nature of the analysis and the use of de-identified data.

1. Preoperative Planning

1. Evaluate the patient’s symptoms and neurological findings. Confirm radicular pain corresponding to a single ENR.
2. Perform a physical exa....

Results

The overall workflow of C-TELF is illustrated schematically in the lateral view (Figure 1A–1E) and axial view (Figure 2A–2E). These schematics demonstrate the progression from foraminal stenosis with ENR compression (Figures 1A and 2A), through stepwise bony decompression and foraminal unroofing (Figures 1B–1D and 2B–2D

Discussion

This protocol describes a structured and reproducible technique for circumferential TELF. Radiculopathy caused by lumbar foraminal stenosis is common and often debilitating. Despite open surgery and minimally invasive procedures, incomplete decompression remains a common cause of persistent or recurrent symptoms. Therefore, circumferential decompression of the ENR is important for achieving reliable clinical outcomes^19,21. Although C-TELF evolved from previously .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
4K Camera Head	Olympus	CH-S400-XZ-EB	Endoscopic visualization
Biopsy Forceps, Blakesley	Joimax	BFS323061	Forceps
Biopsy Forceps, Spoon	Joimax	THF322541	Forceps
Biopsy Forceps, Spoon, angled	Joimax	THF322041	Forceps
Closing Cap for Joimax Endoscopes	Joimax	TCC150700	Working-channel endoscope accessory
Computed tomography scanner	GE HealthCare (Korea)	Revolution Frontier	Used for assessing bony stenosis, osteophytes, and pedicle morphology
Conscious sedation medication	Bukwang R&D	Midazolam 5 mg/5 mL	Used during the procedure while preserving patient feedback
Dynamic X-ray system	Philips	Zenition 70	Used for evaluating segmental instability
Endo-Flexprobe, standard	Joimax	TEFP32020	Steerable probe
Endo-Kerrison-Shaft, 40°	Joimax	EKS32351540	Endoscopic punch
Endo-Kerrison-Shaft, 90°	Joimax	EKS32351590	Endoscopic punch
Endoscopic burr tip	NSK	PDS-1CD330-35	Straight coarse diamond burr, special long, 3.5 mm; used with Primado2 drill system
Endoscopic probe	Joimax	TEFH45025	Used for nerve root and dural sac dissection
Fluoroscopy unit/C-arm	Philips	Zenition 70	Used for target-level localization, needle placement, and working-sheath position verification
Floseal Hemostatic Matrix	Baxter	ADS201844 (5 mL Kit)	Hemostasis
Grasper Forceps, Spoon	Joimax	THG323555	Forceps
Guidewire	Mantiz	A1B-1037	Used for sequential dilation and working-sheath placement
Guiding Rod, conical with center and eccentric bore	Joimax	GRD226315	Access instrument
Guiding Tube, conical, green	Joimax	GTC232838	Access instrument
Guiding Tube, conical, red	Joimax	GTC215363	Access instrument
Guiding Tube, conical, yellow	Joimax	GTC224353	Access instrument
Local anesthetic	Huons	Lidocaine 2%	Used at the skin entry site
Lumbar magnetic resonance imaging scanner	Philips	MR7700	Used for identifying foraminal or extraforaminal nerve root compression
Metal Hammer	Joimax	TMH200170B	Instrument advancement
NiTi Nerve Hook, superelastic	Joimax	TNH322533	Nerve hook
Palm Handle	Joimax	TRPH25100	Instrument handle
Postoperative magnetic resonance imaging scanner	Philips	MR7700	Used when postoperative imaging is required to evaluate decompression or suspected complications
Pressure-controlled irrigation pump	CONMED Corporation	10K	Pressure maintained at 30–60 mmHg
Primado2 Drill System	Nakanishi	P200-CU-100	Endoscopic burr system; operated with a straight 3.5-mm coarse diamond burr at approximately 80,000 rpm
Primado2 Foot Controller	Nakanishi	FC-73	Endoscopic burr system controller
Primado2 Slim Motor Handpiece	Nakanishi	P200-SMH-HS	Endoscopic burr system handpiece
Reamer Push-Ejector, green	Joimax	RPE280380	Bone reamer system
Reamer Push-Ejector, red	Joimax	RPE280600	Bone reamer system
Reamer Push-Ejector, yellow	Joimax	RPE280500	Bone reamer system
Scope Working Tube Distance Ring for TESSYS, iLESSYS, MultiZYTE Scopes	Joimax	SWTDR6312	Working-tube accessory
Selective nerve root block needle	BD	408360	Used for diagnostic selective nerve root block
Semi-Flexible Grasper Forceps	Joimax	TFG322522U	Steerable forceps
Sequential dilator (2.5 mm OD)	Joimax	GRC221025	Length: 220 mm; inner diameter: 1.0 mm; outer diameter: 2.5 mm
Sequential dilator (3.9 mm OD)	Joimax	GTC202838	Length: 205 mm; inner diameter: 2.6 mm; outer diameter: 3.9 mm
Sequential dilator (5.2 mm OD)	Joimax	GTC194353	Length: 195 mm; inner diameter: 4.2 mm; outer diameter: 5.2 mm
Sequential dilator (6.3 mm OD)	Joimax	GTC185363	Length: 185 mm; inner diameter: 5.3 mm; outer diameter: 6.3 mm
Silicone Sealing Cap for Luer-Lock, blue	Joimax	JMSDL001	Sealing cap
Skin closure materials	Ethicon	VCP311	Vicryl 3-0 subcutaneous suture; Steri-Strip skin closure; Neodressing (9 × 7 cm)
Spinal needle	TaeChang Industrial Co., Ltd.	SP.QB 21G × 90 mm	Used for transforaminal access to the foraminal zone
Stopper	Joimax	JFST061427	Accessory
TESSYS Cleaning Wire	Joimax	TCW40010	Cleaning accessory
TESSYS Endo-Flexprobe Handle	Joimax	TEFH45025	Probe handle
TESSYS Foraminoscope, combo	Joimax	FS6342181C	Working-channel endoscope; 30° viewing angle; 4.7-mm working channel
TESSYS Foraminoscope, ocular	Joimax	FS6342181O	Working-channel endoscope; 30° viewing angle; 4.7-mm working channel
TESSYS Guiding Rod, blunt, green	Joimax	GRB251025	Access instrument
TESSYS Guiding Rod, blunt, red	Joimax	GRB252050	Access instrument
TESSYS Guiding Rod, blunt, yellow	Joimax	GRB251540	Access instrument
TESSYS Guiding Rod, conical, green	Joimax	GRC241025	Access instrument
TESSYS Guiding Rod, conical, red	Joimax	GRC242050	Access instrument
TESSYS Guiding Rod, conical, yellow	Joimax	GRC241540	Access instrument
TESSYS Guiding Rod, curved, green	Joimax	GRT241025S	Access instrument
TESSYS Guiding Rod Forceps	Joimax	GRF182500	Access instrument
TESSYS Reamer Handle XT, cannulated Quick-Lock-System, pull-release	Joimax	RHC108590	Reamer handle
TESSYS Steel Ruler	Joimax	TSR25010	Measurement tool
TESSYS XT Working Tube with Handle, fenestrated	Joimax	WTS217500	Working sheath
TESSYS XT Working Tube with Handle, fenestrated, 45°	Joimax	WTS217503	Working sheath
Trigger-Flex	Elliquence	DTF-40	Hemostasis/tissue ablation; power setting: 1–60 W; foot-switch activation
Tweezers	Joimax	JAF180023	Tissue handling
Vaporflex Bipolar	Joimax	JVP32024	Hemostasis/tissue ablation; power setting: 1–60 W; foot-switch activation
VISERA 4K UHD 31-inch LCD Monitor	Olympus	LMD-X310S	Endoscopic visualization
VISERA 4K UHD Camera Control Unit	Olympus	OTV-S400	Endoscopic visualization
VISERA 4K Xenon Light Source	Olympus	CLV-S400	Endoscopic illumination