Spinal Robotics in Single-Position Lateral Surgery: A Narrative Review of Key Concepts and Considerations.

Anterior column realignment via anterior, oblique, or lateral lumbar interbody fusion is increasingly recognized as a powerful mechanism for indirect decompression and sagittal realignment in flexible deformity. Single-position lateral surgery is a popular variation that places patients in the lateral decubitus position, allowing concomitant placement of lateral interbodies and posterior segmental instrumentation without the need for repositioning the patient. The addition of robotics to this technique can help to overcome ergonomic limitations of the placement of pedicle screws in the lateral decubitus position; however, its description in the literature is relatively lacking. In this review we aim to discuss the indications, advantages, and pitfalls of this approach.

Robotic-assisted single-position lateral for multilevel circumferential lumbar interbody fusion: how I do it.

BACKGROUND: Lateral lumbar interbody fusion supplemented with insertion of pedicle screws is a surgical procedure that has gained popularity in the last years, becoming an important tool in the armamentarium of spine surgeons. In recent years, there is a trend to complete both procedures in a single position, thus avoiding flipping the patient prone to insert the pedicle screws. METHODS: We describe a step-by-step workflow of the robotic-assisted technique for multilevel lateral lumbar interbody fusion supplemented with posterior instrumentation. The surgical procedure is performed in a single lateral position. For access to L4-5 or L5-S1, an oblique abdominal incision is performed in the same position, and the desired disc space is approached through an oblique or anterior corridor in the retroperitoneal space. CONCLUSION: Robotic-assisted single-position lateral for multilevel circumferential lumbar interbody fusion is a safe and effective procedure in patients where lumbar stabilization is required. This technique provides patients with a faster recovery and low risk of complications.

Transitioning from lateral to the prone transpsoas approach: flatten the learning curve by knowing the nuances.

Prone transpsoas lateral lumbar interbody fusion is the newest frontier in surgical approach to the lumbar spine. Prone positioning facilitates segmental lordosis and facile posterior segmental fixation. However, even in experienced hands, transitioning from a lateral decubitus to prone position necessitates alterations to the traditional technique. In this video, the authors highlight the nuances of adopting the prone transpsoas lateral lumbar interbody fusion technique and strategies to overcome them. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2224.

Postoperative spinal alignment comparison of lateral versus supine patient position L5-S1 anterior lumbar interbody fusion.

PURPOSE: Over the past decade, alternative patient positions for the treatment of the anterior lumbar spine have been explored in an effort to maximize the benefits of direct anterior column access while minimizing the inefficiencies of single or multiple intraoperative patient repositionings. The lateral technique allows for access from L1 to L5 through a retroperitoneal, muscle-splitting, transpsoas approach with placement of a large intervertebral spacer than can reliably improve segmental lordosis, though its inability to be used at L5-S1 limits its overall adoption, as L5-S1 is one of the most common levels treated and where high levels of lordosis are optimal. Recent developments in instrumentation and techniques for lateral-position treatment of the L5-S1 level with a modified anterior lumbar interbody fusion (ALIF) approach have expanded the lateral position to L5-S1, though the positional effect on L5-S1 lordosis is heretofore unreported. The purpose of this study was to compare local and regional alignment differences between ALIFs performed with the patient in the lateral (L-ALIF) versus supine position (S-ALIF). METHODS: Retrospective, multi-center data and radiographs were collected from 476 consecutive patients who underwent L5-S1 L-ALIF (n = 316) or S-ALIF (n = 160) for degenerative lumbar conditions. Patients treated at L4-5 and above with other single-position interbody fusion and posterior fixation techniques were included in the analysis. Baseline patient characteristics were similar between the groups, though L-ALIF patients were slightly older (58 vs. 54 years), with a greater preoperative mean L5-S1 disk height (7.8 vs. 5.8 mm), and with less preoperative slip (6.6 vs. 8.5 mm), respectively. 262 patients were treated with only L-ALIF or S-ALIF at L5-S1 while the remaining 214 patients were treated with either L-ALIF or S-ALIF at L5-S1 along with fusions at other thoracolumbar levels. Lumbar lordosis (LL), L5-S1 segmental lordosis, L5-S1 disk space height, and slip reduction in L5-S1 spondylolisthesis were measured on preoperative and postoperative lateral X-ray images. LL was only compared between single-level ALIFs, given the variability of other procedures performed at the levels above L5-S1. RESULTS: Mean pre- to postoperative L5-S1 segmental lordosis improved 39% (6.6°) and 31% (4.9°) in the L-ALIF and S-ALIF groups, respectively (p = 0.063). Mean L5-S1 disk height increased by 6.5 mm (89%) in the L-ALIF and 6.4 mm (110%) in the S-ALIF cohorts, (p = 0.650). Spondylolisthesis, in those patients with a preoperative slip, average reduction in the L-ALIF group was 1.5 mm and 2.2 mm in the S-ALIF group (p = 0.175). In patients treated only at L5-S1 with ALIF, mean segmental alignment improved significantly more in the L-ALIF compared to the S-ALIF cohort (7.8 vs. 5.4°, p = 0.035), while lumbar lordosis increased 4.1° and 3.6° in the respective groups (p = 0.648). CONCLUSION: Use of the lateral patient position for L5-S1 ALIF, compared to traditional supine L5-S1 ALIF, resulted in at least equivalent alignment and radiographic outcomes, with significantly greater improvement in segmental lordosis in patients treated only at L5-S1. These data, from the largest lateral ALIF dataset reported to date, suggest that-radiographically-the lateral patient position can be considered as an alternative to traditional ALIF positional techniques.

Single-Position Fluoroscopy-Guided Lateral Lumbar Interbody Fusion With Intraoperative Computed Tomography-Navigated Posterior Pedicle Screw Fixation: Technical Report and Literature Review.

Lateral lumbar interbody fusion (LLIF) is a powerful tool in minimally invasive spine surgery with high rates of fusion, excellent indirect decompression, and deformity correction. LLIF offers advantages compared with anterior lumbar interbody fusion including a more favorable complication profile. Traditionally, the interbody fusion is performed in the lateral position and fluoroscopy-assisted pedicle screw fixation performed with the patient repositioned prone. The evolution of both pedicle screw technology and intraoperative navigation has enhanced the feasibility of single (lateral)-position surgery. Early reports using fluoroscopy-assisted pedicle screws and computer or robotic navigation suggest this technique can be performed safely and accurately. The purpose of this brief report is to provide the technical steps, workflow, as well as pearls and pitfalls for single-position LLIF with true intraoperative computed tomography navigation-guided percutaneous pedicle screw fixation. A case example is included for illustration.

How Long Should a Patient Stay in Lateral Position for Unilateral Spinal Anesthesia with Hyperbaric Bupivacaine? / 대한마취과학회지

BACKGROUND: In searching for a differential spinal block between dependent and nondependent sides, we evaluated the influence of the duration of lateral decubitus on the spread of hyperbaric bupivacaine during spinal anesthesia. METHODS: Spinal anesthesia with 1.2 ml of hyperbaric 0.5% bupivacaine (6 mg) was administered with a 25-gauge Whitacre unidirectional needle to 50 ASA 1 patients undergoing unilateral knee arthroscopy. The patients were allocated randomly to three groups according to the duration of lateral decubitus after spinal injection in the lateral position operation side dependent: Group 1, 10 min in lateral decubitus then supine; Group 2, 20 min in lateral decubitus then supine; Group 3, 30 min in lateral decubitus then supine. Sensory and motor block (pinprick/modified Bromage scale) as well as skin temperature were compared between the dependent and nondependent sides. Circulatory variables were recorded for 10 min after being turned supine. RESULTS: The sensory block between dependent and nondependent sides were significantly different in Group 3. In Group 1, the level of maximum sensory block was higher than Group 3 on nondependent side. There was no difference in the number of patients having achieved Grade 3 and 0 motor block among three groups on dependent and nondependent sides. The skin temperature in lateral decubitus was significantly higher on the dependent side than nondependent side in three groups. In Groups 1 and 2, the skin temperatures of nondependent side were increased after turned supine, but that was maintained during supine position in Group 3. The circulatory variables were stable in all 50 patients. CONCLUSIONS: We conclude that when a small dose of 0.5% hyperbaric bupivacaine is injected into patients in the lateral position, complete unilateral spinal anesthesia is achieved when the patients arekeep in a lateral position for more than 30 min after spinal injection.

The Level of Tuffier's Line of Korean Adults in the Lateral Decubitus Position with the Position of "Forehead-to-knees" / 대한마취과학회지

BACKGREOUND: Tuffier's line has been a guide for lumbar puncture. Usually lumbar puncture or epidural anesthesia was performed in the lateral decubitus position with the "forehead-to-knees" position. The purpose of this study was to identify the accuracy with which the spinal level could be predicted from this external mark in the "forehead-to-knees" position. METHODS: Two hundred and twenty-four patients (112 male and 112 female patients) undergoing investigation for back pain were examined. The standard antero-posterior lumbar spine film was taken in the supine position. The lateral lumbar spine film was taken in the lateral decubitus with the "forehead-to-knees" position. These films were examined after being reported upon by a radiologist. The iliac crest was identified and a horizontal line drawn between the highest points using a ruler. The level of Tuffier's line of each age group in supine or "forehead-to-knees" position and relationship with aging were observed. RESULTS: The point coincided with the L4-5 interspace (61%), L4 (20%), and L5 (19%) in the supine, L4-5 (48%), L5 (46%), L4 (5%), and L5S1 (0.4%) in the "forehead-to-knees" position. The Tuffier's line of men were higher than women. The Tuffier's line in the "forehead-to-knees" position went higher with aging in women. CONCLUSIONS: The Tuffier's line was most frequently the L4-5 interspace in supine and "forehead-to-knees" positions. The Tuffier's line in the "forehead-to-knees" was lower than the supine position. The Tuffier's line of men were higher than women of all age groups in the supine position. The Tuffier's line in the "forehead-to-knees" position went higher with aging in women. The Tuffier's line in the supine position in women and of both positions in men did not show any relation with age.

The Phantom Limb Sensation Expressed by Spinal Anesthesia / 대한마취과학회지

BACKGROUND: Phantom limb sensation is an unusual position sense of the extremity during nerve block that the position of extremity is misinterpreted as being flexed, or elevated, when actually they are in neutral position. Whether it is from the fixation of proprioceptive input at the time of motor blockade or from unmasking of the pattern which has been already present in the CNS is still controversial. We perfomed this study under the assumption that phantom limb sensation can still be reproduced without the influence of position at the time of nerve blockade. METHODS: Thirty-six patients scheduled for elective orthopedic surgery were randomly assigned. For 26 patients, spinal anesthesia was performed with hyperbaric 0.5% tetracaine or bupivacaine at lateral decubitus position and the position was changed to supine immediately. Existence of phantom limb sensation and the level of anesthesia was recorded at 10 and 20 minutes after injection of local anesthetics. For 10 patients, same local anesthetics were injected after patient's legs were straightened in lateral decubitus position. RESULTS: Forteen out of 26 patients whose position were changed to supine immediately after the injection of local anesthetics experienced phantom limb sensations. Five out of 10 patients whose legs were kept straight before the injection of local anesthetics experienced phantom limb sensations. Previous history of trauma was positively related to the expression of phantom limb sensation. CONCLUSION: Our data showed that the expression of phantom limb sensation is reproducible. And this was not related to the position at the time of spinal anesthesia. Trauma seems to be an important factor related to the expression of phantom limb sensation.

Is There Any Difference in Arterial Oxygenation between the Right and Left Thoracic Surgery under the Different One Lung Ventilation Mode? / 대한마취과학회지

BACKGROUND: Use of one lung anesthesia for thoracic surgery may compromize PaO2. The aim of this study was to compare the shunt and oxygenation effects of the application of CPAP and CPAP/PEEP between right and left thoracic surgery under one lung anesthesia. METHODS: 10 patients for right thoracic surgery were selected as group 1, and 10 patients for left thoracic surgery were selected as group 2. Measurements in each group, were made during each of the following stage. First 30 minutes, One lung anesthesia alone with 50% oxygen (control value), next 30 minutes, CPAP 10 cmH2O to upper lung with 50% oxygen (CPAP), and then CPAP 10 cmH2O to upper lung and PEEP 10 cmH2O to down lung with 50% oxygen for 30 minutes (CPAP/PEEP). RESULTS: PaO2 in CPAP and CPAP/PEEP were significantly increased as compare to control value at both group (P<0.05). Shunt percentage in CPAP and CPAP/PEEP were significantly decreased as compare to control value at both group (P<0.05). But, no statistically significant differences were observed between right and left thoracic surgery group in the PaO2 and shunt percentage. CONCLUSIONS: We confirmed that CPAP and CPAP/PEEP during one lung ventilation is thought to be effective method in preventing hypoxemia, but no differences were observed between right and left thoracic surgery group.