Safety and the anatomy of the retroperitoneal lateral corridor with respect to the minimally invasive lateral lumbar intervertebral fusion approach

The Optimal Patient Position on the Surgical Table for Lateral Lumbar Interbody Fusion in Adult Spinal Deformity Using Three-Dimensional Computed Tomography: A Retrospective Study

Introduction

Lateral lumbar interbody fusion (LLIF) techniques have been extensively used in adult spinal deformity surgery. Preoperative knowledge of the optimal position of the patient on the surgical table is essential for a safe procedure. Therefore, this study aims to determine the optimal angle for positioning the patient on the surgical table during LLIF using three-dimensional computed tomography (3DCT).

Methods

Data from 59 patients (2 males, 57 females, mean age 66.3±8.6 years) with adult spinal deformities treated by performing corrective spinal surgery were included in this observational retrospective study. Simulated fluoroscopic images were obtained using 3DCT images rotated from the reference position with the spinous process of S1 as the midline to the position with the spinous process in the center of the bilateral pedicle of T12-L5. The rotation angle of each vertebra was measured and defined as the optimal rotation angle (ORA). The angle that bisected the angle between the maximum and minimum ORA was defined as the optimal mean angle of the maximum and minimum ORA (OMA) and considered the optimal angle for the patient's position on the surgical table, as this position could minimize the rotation angle of the surgical table during surgery. A multiple regression analysis was performed to predict OMA.

Results

Multiple regression analysis revealed the following equation: OMA=1.959+(0.238×lumbar coronal Cobb angle)+(-0.208×sagittal vertical axis).

Conclusions

When the patient is placed on the surgical table by rotating them at the OMA, the rotation of the surgical table can be reduced, ensuring a safe and efficient surgical procedure.

Antepsoas Approaches to the Lumbar Spine

Lumbar interbody fusion (LIF) is a well-established approach in treating spinal deformity and degenerative conditions of the spine. Since its inception in the 20th century, LIF has continued to evolve, allowing for minimally invasive approaches, high fusion rates, and improving disability scores with favorable complication rates. The anterior to the psoas (ATP) approach utilizes a retroperitoneal pathway medial to the psoas muscle to access the L1-S1intervertebral disc spaces. In contrast to the transpsoas arppoach, its primary advantage is avoiding transgressing the psoas muscle and the contained lumbar plexus, which potentially decreases the risk of injury to the lumbar plexus. Avoiding transgression of the psoas may minimize the risk of transient or permanent neurological deficits secondary to lumbar plexus injury. Indications for ATP approaches may expand as it is shown to be a safe and effective method of achieving spinal arthrodesis.

A comparative morphometric analysis of operative windows for performing OLIF among normal and deformity group in lower lumbar spine

PURPOSE

To assess the radiological morphometric parameters of OLIF surgical technique in lower lumbar spine among normal and in patients with adult degenerative spine (levoscoliosis and dextroscoliosis).

METHOD

Standing AP radiographs and MRI in supine position were taken. Patients were divided into 3 groups based on Cobbs' angle into normal, levo and dextro scoliosis. Moros classification was used to calculate bare window (BW), vascular window (VW), Psoas window (PW), psoas major height (pmh) and width (pmw) at lower lumbar levels and measurements were done on PACS.

RESULTS

Seventy five patients (25 in each group) were assessed. BW has trend from L2-L3 > L3-L4 > L4-L5 in dextro and levoscoliosis. PW has trend from L3-L4 > L2-L3 > L4-L5 in levoscoliosis and normal group. VW has trend from L4-L5 > L3-L4 > L2-L3 in dextro and levoscoliosis; pmw has trend from L4-L5 > L3-L4 > L2-L3 in Levo and dextroscoliosis; pmh has trend from L4-L5 > L3-L4 > L2-L3 in levoscoliosis and normal group.

CONCLUSION

BW was noted to be highest at L3-4, lowest at L4-5 in normal group. VW was constant, BW showed a reverse trend with PW across all the levels. Though levoscoliosis group of patients had significantly higher BW, psoas retraction issues are to be kept in mind in view of anatomically taught psoas.

Neutral hip position for the oblique lumbar interbody fusion (OLIF) approach increases the retroperitoneal oblique corridor

BACKGROUND

The prepsoas lateral approach for spinal fusion, oblique lateral lumbar interbody fusion (OLIF), is considered one of the minimally invasive spinal fusion methods and is gaining popularity due to improved outcomes with copious supporting evidence. To date, no publication has studied the various positions of the left hip in actual patients which might affect the retroperitoneal oblique corridor (ROC). The study aimed to find the relevancy of the left hip position and the size of ROC.

METHODS

We recruited 40 consecutive patients who needed diagnostic MRI from the out-patient clinic. MRI scan from L2 to L5 was performed in the supine, right lateral decubitus with hip flexion, and right lateral decubitus with hip in a neutral position. The retroperitoneal oblique corridor (ROC) was measured at the intervertebral disc level and compared.

RESULTS

ROC of the hip in neutral position was significantly larger than hip flexion in all levels (p < 0.05); there was no significant difference in the ROC among levels (p = 0.22). ROC seems to be largest at L2/3 followed by L3/4 and L4/5 respectively in all positions.

CONCLUSIONS

The retroperitoneal oblique corridors of L2 to L5 were significantly increased when the hip is in the neutral position, while the psoas cross-sectional area and anterior thickness were minimized in this position. Surgeons might benefit from a neutral position of the left hip in the oblique lateral lumbar interbody fusion (OLIF) procedure. In conclusion, the retroperitoneal oblique corridors of L2 to L5 were significantly increased when the hip is in the neutral position, while the psoas cross-sectional area and anterior thickness were minimized in this position. Surgeons might benefit from a neutral position of the left hip in the oblique lateral lumbar interbody fusion procedure.

COMPARATIVE STUDY OF LUMBAR PLEXUS PATH ON THE LEFT AND RIGHT SIDES THROUGH THE PSOAS MUSCLE

ABSTRACT Objective: Spine surgery with a minimally invasive lateral approach and validate possible anatomical differences between the right and left sides. Methods: Four measurements (cm) were taken on 38 cadavers: the distance between the lumbar plexus and the transverse process (L4-L5) and the distance between the lumbar plexus and the midline of the lumbar spine, both on the right and left sides. Results: The mean distance between the lumbar plexus and the transverse process of L4-L5 was 1.03 cm and the distance to the midline was 3.99 cm for the right side. The averages of the left side were 1.13 cm and 3.38 cm, respectively. There is statistical difference between the sides (p<0.05) using the non-parametric Wilcoxon test. Conclusions: The authors suggest that the transverse process might be used as an anatomical landmark to define the surgical approach through the psoas muscle. Level of Evidence IV; Cadaveric study.

Patient Care During Minimally Invasive Lateral Spine Surgery: 1.7 www.aornjournal.org/content/cme

Perioperative nurses care for patients undergoing a wide range of surgical procedures. One fast-growing surgical specialty is spine surgery performed using minimally invasive techniques. Patients may be candidates for minimally invasive spine surgery based on their presenting signs and symptoms and medical imaging test results. Open anterior and posterior surgical approaches to spine surgery are how surgeons traditionally have performed these procedures. However, new technology has enabled a minimally invasive lateral approach to the spine. This approach minimizes many of the risks and challenges associated with both the anterior and posterior approaches. Minimally invasive lateral interbody fusion requires the perioperative nurse to have a thorough understanding of the necessary patient positioning, spinal anatomy, and OR suite setup to ensure a safe and successful surgical experience for the patient.

Complications on minimally invasive oblique lumbar interbody fusion at L2-L5 levels: a review of the literature and surgical strategies

Fusion is the cornerstone in the treatment of an unstable degenerative lumbar spinal disease. Various techniques have been developed. Amongst these techniques exists the oblique lumbar interbody fusion (OLIF), which is the ante-psoas approach. Adequate restoration of disc height with large cages placed in the intervertebral space, indirect decompression, and correction of sagittal and coronal alignment can be achieved with OLIF procedure with the advantage of minimal risk for the psoas muscle and lumbar plexus. Nevertheless, this technique entails complications directly associated with the anatomical location where the fusion takes place. This surgical area is a window between the left lateral border of the aorta, or the left common iliac artery, and the anterior belly of the left psoas muscle. Vascular complications associated with the injury of the main vessels, segmental artery or iliolumbar vein of the lumbar spine have been reported, as well as urologic lesions due to ureter transgression, amongst others. Although these complications have been described in the literature, an article that complements this information with technical advice for its avoidance is yet to be published. This article is a review of the most frequent complications associated with the OLIF procedure in L2-L5 lumbar levels, as well as a description of technical strategies for the prevention of such complications.