Application of Stand-Alone Oblique Lateral Interbody Fusion in L4-5 Lumbar Diseases

Summary

This study describes the application of oblique lateral interbody fusion in lumbar spinal surgeries.

Abstract

Lumbar spine diseases often cause lower back pain, lower extremity pain, numbness, and paresthesia. In severe cases, intermittent claudication may occur, affecting the quality of life of patients. Surgery is often required when conservative treatment fails, or when patients' symptoms become unbearable. Surgical treatments include laminectomy and discectomy, as well as interbody fusion. The main purpose of laminectomy and discectomy is to relieve nerve compression; however, recurrence is common due to spinal instability. Interbody fusion improves stability while relieving nerve compression and significantly reduces the risk of recurrence compared to non-fusion surgery. Nonetheless, conventionally posterior intervertebral fusion requires separation of the muscles to expose the operated segment, which causes more trauma to the patient. In contrast, the oblique lateral interbody fusion (OLIF) technique achieves spinal fusion with minimal trauma to the patients and shortens the recovery time. This article introduces procedures of stand-alone OLIF surgery performed in the lumbar spine, providing a reference for other spine surgeons.

Introduction

Lumbar spine disorders are a global economic concern, with affected patients experiencing lower quality of life¹. The treatment of lumbar spine diseases can be divided into two categories: conservative and surgical treatment. Conservative treatment includes rest, oral nonsteroidal drugs, massage, and physical therapy. For instance, studies have shown that estrogen can be used to delay degeneration of the intervertebral disc, thus providing a basis for its treatment of lumbar spine disease^2,3. For patients who have failed in conservative treatment, surgery is typically required to treat lumbar spine diseases. Among the surgical methods used for this cohort, interbody fusion is generally preferred.

Briefly, the techniques reported consist of anterior lumbar interbody fusion (ALIF), direct lateral interbody fusion (DLIF), extreme lateral interbody fusion (XLIF), oblique lateral interbody fusion (OLIF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF)^4,5. Among these surgical approaches, OLIF has its unique advantages. In comparison with DLIF and XLIF, OLIF has been shown to reduce the incidence of postoperative hip flexion weakness and thigh numbness^6,7. Moreover, compared with ALIF, surgeries with OLIF have a lower risk of both postoperative retrograde ejaculation and damage of blood vessels anterior to the vertebral body⁸. Nonetheless, it is worth mentioning that PLIF and TLIF techniques exhibit a good operative field, which could reduce damage to important structures; the placement of pedicle screws used by these methods could reduce the probability of non-fusion of the interbody cage. Nonetheless, compared with OLIF, PLIF and TLIF require intraoperative muscle dissociation and stretching the muscle for an extended period of time, which could result in increased intraoperative blood loss, slow wound healing, and prolonged patient recovery time^9,10,11.

By harnessing the OLIF approach, the intervertebral site can be accessed through the space between the anterior border of the psoas muscle and the major abdominal vessels. The surgery is performed by removing the diseased disc and implanting an interbody cage. Because of the reduced damage to muscle, OLIF can minimize intraoperative blood loss and operation time, shortening patients' postoperative recovery. In addition, earlier studies have shown that the placement of interbody cages can boost restoration of the disc height and patients' physiological curvature of the spine^{6,12,13,14,15,16}. In the present study, the surgical procedures of stand-alone OLIF for the treatment of L4-5 lumbar diseases are introduced in detail.

Protocol

This study has been approved by the Ethics Committee of the Third Hospital of Hebei Medical University. The patients signed informed consent, consented to be filmed, and allowed the investigators to use their surgical data.

1. Patient selection

1. Select patients based on the following inclusion criteria.
   1. Select patients for whom conservative treatment time was longer than 3 months and to which the patients responded poorly.
   2. Select patients whose symptoms and signs were consistent with the imaging findings.
   3. Select patients whose magnetic resonance imaging (MRI) of the lumbar spine shows a width greater than 1 cm between the psoas muscle and the anterior border of the vertebral artery.
   4. Select patients with no significant variants on abdominal vascular examination.
2. Apply the following exclusion criteria.
   1. Exclude patients with spinal canal infection and tumor complications.
   2. Exclude patients with spinal stenosis due to severe facet joint hyperplasia and prolapse of the nucleus pulposus.
   3. Exclude patients with severe lumbar spondylolisthesis greater than grade III.
   4. Exclude patients with a history of abdominal surgery.

2. Preoperative preparation

1. Instruct the patient to undergo lumbar computed tomography (CT), lumbar MRI, and lumbar X-ray examination. Perform cardiovascular and cerebrovascular, and abdominal vascular examinations to identify and better manage risk factors to ensure safety of the operation^17,18.
2. Advise the patient on skin preparation of the surgical site preoperatively, with a fasting requirement of 12 h before the surgery.
3. On the day of the operation, after the administration of general anesthesia with endotracheal intubation, place the patient on the operating table in a right-sided lateral decubitus position.
4. Insert a cushion beneath the right abdomen, which is slightly tilted backward depending on the target intervertebral disc, in order to obtain adequate access to the physiologic OLIF corridor between the psoas muscle and the vena cava anteriorly.
5. Choose the left abdomen of the patient as the surgical area.
6. Ensure that the patient remains in the correct position for the surgery. Secure the patient with tape and confirm the operation stage.

3. Starting the operation

1. Place a square locator on the left abdomen of the patient. Ensure the upper and lower edges of the locator correspond to the upper and lower vertebral bodies of the diseased intervertebral disc, and the anterior and posterior edges correspond to the anterior and posterior edges of the diseased intervertebral disc.
2. Confirm the projection of the target segment on the patient's skin with X-ray fluoroscopy. Mark the surgical site (Figure 1).
3. After identifying the surgical site, disinfect the incision area, lay sheets, and prepare surgical instruments.
4. Make a 4-5 cm skin incision parallel to the external oblique muscle fibers. Separate the aponeurosis of the external oblique muscle, the transverse abdominis, and the transverse abdominal fascia bluntly with fingers (Figure 2).
5. Use long-handled forceps to clamp the peanut-like gauze mass to expose the surgical intervertebral space between the abdominal vascular sheath and the psoas major muscle.
6. After completing exposure of the target intervertebral space, insert Kirschner wire and perform intraoperative X-ray examinations to confirm that the exposed segment is the surgical segment (Figure 3A).
7. After completing identification of the intervertebral space, insert the dilation tubes successively for expansion. Confirm the position of the expansion channel by intraoperative X-ray (Figure 3B).
8. Attach the retractor to the operating table using the universal arm and operating table clips. Ensure that the channel does not move during the surgery, and then place the working light.
9. Use a long-handled sharp knife to remove the annulus fibrosus, and long-handled nucleus pulposus forceps to remove the diseased disc tissue (Figure 3C).
10. Clean the intervertebral space with a scraper and curette to clear the residual disc tissue in the surgical segment.
11. After cleaning the intervertebral space, use a spreader to open a collapsed intervertebral space.
12. Use a bone rasp to remove the cartilage layer on the surface of the endplate until the bony surface bleeds.
13. Place an appropriately sized intervertebral exploration device into the disc. Perform intraoperative X-ray fluoroscopies to determine the appropriate fusion device size (Figure 3D,E).
14. After determining the appropriate device size, add allogeneic bone to the interbody cage of the same size and implant the cage under X-ray fluoroscopy (Figure 3F,G).
15. After placing the interbody cage, suture the wound layer by layer. Use No. 10, No. 4, and No. 1 thread to suture the muscle, fascia, and surgical incision, respectively (Figure 3H). Compress the surgical incision with gauze.
16. Prescribe an anti-inflammatory (cefazolin) once a day for 3 days to prevent infection after the patient returns to the ward. Use antithrombotic drugs (low-molecular weight heparin sodium) to prevent deep vein thrombosis of the lower limbs on the 2nd postoperative day, once a day for 3 days.

4. Postoperative care

1. Instruct the patient to rest in bed. Perform deep vein color Doppler on the third postoperative day.
2. Instruct the patient to walk on the ground with the assistance of a lumbar brace, usually within 3 days post-operation if the deep vein color Doppler shows no deep vein thrombosis in the lower extremities.
3. Change the antithrombotic medication to twice daily if an intramuscular vein thrombosis is present on a deep vein ultrasound of the lower extremities.
4. Contact Vascular Surgery for treatment if the deep vein ultrasound of the lower extremities shows a deep vein thrombosis. Perform the lower-extremity rehabilitation exercise as reported previously^19,20.

Results

Studies from other groups have shown that, compared to other methods, OLIF surgery has the advantages of a shorter operative time and less intraoperative blood loss (Table 1). Importantly, patients who undergo OLIF surgery recover faster than the commonly used TLIF surgery group^12,21,22. Our research group has monitored 42 patients with degenerative lumbar spondylolisthesis (DLS) undergoing OLIF surgery for more...

Discussion

Since formally introduced by Silvestre in 2012²³, OLIF has gradually attracted the attention of spine surgeons due to the various advantages over other methods used in treating lumbar spine diseases^{6,12,13,16,21,22}. OLIF significantly improved patients' disc height and lordotic angle, which may be due ...

Materials

Name	Company	Catalog Number	Comments
Bipolar electrocoagulation tweezers	Juan'en Medical Devices Co.Ltd	BZN-Q-B-S	1.2 x 190 mm
Bone rasp	DePuy Synthes	03.809.849	35 x 8 mm
Cefazolin	Cspc Pharmaceutical Group Limited		1.0 g
Computed Tomography	PHILIPS
Curette	Qingniu	20739.01	300 x Ø9 x 5°
Curette	DePuy Synthes	03.809.873	6 mm
Dilation tubes	DePuy Synthes	03.809.913	140 mm
High frequency active electrodes	ZhongBangTianCheng	GD-BZ	GD-BZ-J1
Interbody cage	DePuy Synthes	08.809.273S	55 x 22 x 13 mm
Intervertebral exploration device	DePuy Synthes	03.809.233	13 mm
Kirschner wire	Qingniu
Lighting cable	DePuy Synthes	03.612.031
Lighting sheet	DePuy Synthes	03.809.925S
Low Molecular Weight Heparin Sodium Injection	Cspc Pharmaceutical Group Limited		0.4 mL
MRI	PHILIPS
Scraper	DePuy Synthes	03.809.833	13 mm
Spreader	DePuy Synthes	03.809.877	50 x 13 mm
Surgical film	3L	SP4530	45 x 30 cm
Ultrasound Color Doppler	PHILIPS
Universal arm	DePuy Synthes	03.809.941
Universal arm operating table clips	DePuy Synthes	03.809.942
X-ray machine	GE healthcare