Opioid-free anesthesia within an enhanced recovery after surgery pathway for minimally invasive lumbar spine surgery: a retrospective matched cohort study.

OBJECTIVEEnhanced recovery after surgery (ERAS) and multimodal analgesia are established care models that minimize perioperative opioid consumption and promote positive outcomes after spine surgery. Opioid-free anesthesia (OFA) is an emerging technique that may achieve similar goals. The purpose of this study was to evaluate an OFA regimen within an ERAS pathway for lumbar decompressive surgery and to compare perioperative opioid requirements in a matched cohort of patients managed with traditional opioid-containing anesthesia (OCA).METHODSThe authors performed a retrospective analysis of prospectively collected data. They included 36 patients who underwent lumbar decompression under their ERAS pathway for spinal decompression between February and August 2018. Eighteen patients who received OFA were matched in a 1:1 ratio to a cohort managed with a traditional OCA regimen. The primary outcome was total perioperative opioid consumption. Postoperative pain scores (measured using the numerical rating scale [NRS]), opioid consumption (total morphine equivalents), and length of stay (time to readiness for discharge) were compared in the postanesthesia care unit (PACU). The authors also assessed compliance with ERAS process measures and compared compliance during 3 phases of care: pre-, intra-, and postoperative.RESULTSThere was a significant reduction in total perioperative opioid consumption in patients who received OFA (2.43 ± 0.86 oral morphine equivalents [OMEs]; mean ± SEM), compared to patients who received OCA (38.125 ± 6.11 OMEs). There were no significant differences in worst postoperative pain scores (NRS scores 2.55 ± 0.70 vs 2.58 ± 0.73) or opioid consumption (5.28 ± 1.7 vs 4.86 ± 1.5 OMEs) in the PACU between OFA and OCA groups, respectively. There was a clinically significant decrease in time to readiness for discharge from the PACU associated with OFA (37 minutes), although this was not statistically significantly different. The authors found high overall compliance with ERAS process measures (91.4%) but variation in compliance according to phase of care. The highest compliance occurred during the preoperative phase (94.71% ± 2.88%), and the lowest compliance occurred during the postoperative phase of care (85.4% ± 5.7%).CONCLUSIONSOFA within an ERAS pathway for lumbar spinal decompression represents an opportunity to minimize perioperative opioid exposure without adversely affecting pain control or recovery. This study reveals opportunities for patient and provider education to reinforce ERAS and highlights the postoperative phase of care as a time when resources should be focused to increase ERAS adherence.

Lumbar microdiscectomy complication rates: a systematic review and meta-analysis.

OBJECT Lumbar microdiscectomy and its various minimally invasive surgical techniques are seeing increasing popularity, but a systematic review of their associated complications has yet to be performed. The authors sought to identify all prospective clinical studies reporting complications associated with lumbar open microdiscectomy, microendoscopic discectomy (MED), and percutaneous microdiscectomy. METHODS The authors conducted MEDLINE, Scopus, Web of Science, and Embase database searches for randomized controlled trials and prospective cohort studies reporting complications associated with open, microendoscopic, or percutaneous lumbar microdiscectomy. Studies with fewer than 10 patients and published before 1990 were excluded. Overall and interstudy median complication rates were calculated for each surgical technique. The authors also performed a meta-analysis of the reported complications to assess statistical significance across the various surgical techniques. RESULTS Of 9504 articles retrieved from the databases, 42 met inclusion criteria. Most studies screened were retrospective case series, limiting the number of studies that could be included. A total of 9 complication types were identified in the included studies, and these were analyzed across each of the surgical techniques. The rates of any complication across the included studies were 12.5%, 13.3%, and 10.8% for open, MED, and percutaneous microdiscectomy, respectively. New or worsening neurological deficit arose in 1.3%, 3.0%, and 1.6% of patients, while direct nerve root injury occurred at rates of 2.6%, 0.9%, and 1.1%, respectively. Hematoma was reported at rates of 0.5%, 1.2%, and 0.6%, respectively. Wound complications (infection, dehiscence, orseroma) occurred at rates of 2.1%, 1.2%, and 0.5%, respectively. The rates of recurrent disc complications were 4.4%, 3.1%, and 3.9%, while reoperation was indicated in 7.1%, 3.7%, and 10.2% of operations, respectively. Meta-analysis calculations revealed a statistically significant higher rate of intraoperative nerve root injury following percutaneous procedures relative to MED. No other significant differences were found. CONCLUSIONS This review highlights complication rates among various microdiscectomy techniques, which likely reflect real-world practice and conceptualization of complications among physicians. This investigation sets the framework for further discussions regarding microdiscectomy options and their associated complications during the informed consent process.

Minimally invasive spine surgery in the treatment of thoracolumbar and lumbar spine trauma.

Thoracolumbar and lumbar trauma account for the majority of traumatic spinal injuries. The mainstay of current treatments is still nonoperative therapy with bracing. Classic treatment algorithms reserved absolute surgical intervention for spinal trauma patients with neurological compromise or instability. Relative indications included incapacitating pain and obesity/body habitus making brace therapy ineffective. In the past decade, minimally invasive surgical (MIS) techniques for spine surgery have been increasingly used for degenerative conditions. These same minimally invasive techniques have seen increased use in trauma patients. The goal of minimally invasive surgery is to decrease surgical morbidity through decreased soft-tissue dissection while providing the same structural stability afforded by classic open techniques. These minimally invasive techniques involve percutaneous posterior pedicle fixation, vertebral body augmentation, and utilization of endoscopic and thoracoscopic techniques. While MIS techniques are somewhat in their infancy, an increasing number of studies are reporting good clinical and radiographic outcomes with these MIS techniques. However, the literature is still lacking high-quality evidence comparing these newer techniques to classic open treatments. This article reviews the relevant literature regarding minimally invasive spine surgery in the treatment of thoracolumbar and lumbar trauma.

Effects of intradiscal vacuum phenomenon on surgical outcome of lateral interbody fusion for degenerative lumbar disease.

OBJECTIVE The authors investigated whether the presence of intradiscal vacuum phenomenon (IVP) results in greater correction of disc height and restoration of segmental lordosis (SL). METHODS A retrospective chart review was performed on every patient at the University of South Florida's Department of Neurosurgery treated with lateral lumbar interbody fusion between 2011 and 2015. From these charts, preoperative plain radiographs and CT images were reviewed for the presence of IVP. Preoperative and postoperative posterior disc height (PDH), anterior disc height (ADH), and SL were measured at disc levels with IVP and compared with those at disc levels without IVP using the t-test. Linear regression was used to evaluate the factors that predict changes in PDH, ADH, and SL. RESULTS One hundred forty patients with 247 disc levels between L-1 and L-5 were treated with lateral lumbar interbody fusion. Among all disc levels treated, the mean PDH increased from 3.69 to 6.66 mm (p = 0.011), the mean ADH increased from 5.45 to 11.53 mm (p < 0.001), and the mean SL increased from 9.59° to 14.55° (p < 0.001). Significantly increased PDH was associated with the presence of IVP, addition of pedicle screws, and lack of cage subsidence; significantly increased ADH was associated with the presence of IVP, anterior longitudinal ligament (ALL) release, addition of pedicle screws, and lack of subsidence; and significantly increased SL was associated with the presence of IVP and ALL release. CONCLUSIONS IVP in patients with degenerative spinal disease remains grossly underreported. The data from the present study suggest that the presence of IVP results in increased restoration of disc height and SL.

Retroperitoneal oblique corridor to the L2-S1 intervertebral discs: an MRI study.

OBJECT The purpose of this study was to analyze MR images of the lumbar spine and document: 1) the oblique corridor at each lumbar disc level between the psoas muscle and the great vessels, and 2) oblique access to the L5-S1 disc space. Access to the lumbar spine without disruption of the psoas muscle could translate into decreased frequency of postoperative neurological complications observed after a transpsoas approach. The authors investigated the retroperitoneal oblique corridor of L2-S1 as a means of surgical access to the intervertebral discs. This oblique approach avoids the psoas muscle and is a safe and potentially superior alternative to the lateral transpsoas approach used by many surgeons. METHODS One hundred thirty-three MRI studies performed between May 4, 2012, and February 27, 2013, were randomly selected from the authors' database. Thirty-three MR images were excluded due to technical issues or altered lumbar anatomy due to previous spine surgery. The oblique corridor was defined as the distance between the left lateral border of the aorta (or iliac artery) and the anterior medial border of the psoas. The L5-S1 oblique corridor was defined transversely from the midsagittal line of the inferior endplate of L-5 to the medial border of the left common iliac vessel (axial view) and vertically to the first vascular structure that crossed midline (sagittal view). RESULTS The oblique corridor measurements to the L2-5 discs have the following mean distances: L2-3 = 16.04 mm, L3-4 = 14.21 mm, and L4-5 = 10.28 mm. The L5-S1 corridor mean distance was 10 mm between midline and left common iliac vessel, and 10.13 mm from the first midline vessel to the inferior endplate of L-5. The bifurcation of the aorta and confluence of the vena cava were also analyzed in this study. The aortic bifurcation was found at the L-3 vertebral body in 2% of the MR images, at the L3-4 disc in 5%, at the L-4 vertebral body in 43%, at the L4-5 disc in 11%, and at the L-5 vertebral body in 9%. The confluence of the iliac veins was found at lower levels: 45% at the L-4 level, 19.39% at the L4-5 intervertebral disc, and 34% at the L-5 vertebral body. CONCLUSIONS An oblique corridor of access to the L2-5 discs was found in 90% of the MR images (99% access to L2-3, 100% access to L3-4, and 91% access to L4-5). Access to the L5-S1 disc was also established in 69% of the MR images analyzed. The lower the confluence of iliac veins, the less probable it was that access to the L5-S1 intervertebral disc space was observed. These findings support the use of lumbar MRI as a tool to predetermine the presence of an oblique corridor for access to the L2-S1 intervertebral disc spaces prior to lumbar spine surgery.

Is the lateral jack-knife position responsible for cases of transient neurapraxia?

OBJECTIVE: The lateral jack-knife position is often used during transpsoas surgery to improve access to the spine. Postoperative neurological signs and symptoms are very common after such procedures, and the mechanism is not adequately understood. The objective of this study is to assess if the lateral jack-knife position alone can cause neurapraxia. This study compares neurological status at baseline and after positioning in the 25° right lateral jack-knife (RLJK) and the right lateral decubitus (RLD) position. METHODS: Fifty healthy volunteers, ages 21 to 35, were randomly assigned to one of 2 groups: Group A (RLD) and Group B (RLJK). Motor and sensory testing was performed prior to positioning. Subjects were placed in the RLD or RLJK position, according to group assignment, for 60 minutes. Motor testing was performed immediately after this 60-minute period and again 60 minutes thereafter. Sensory testing was performed immediately after the 60-minute period and every 15 minutes thereafter, for a total of 5 times. Motor testing was performed by a physical therapist who was blinded to group assignment. A follow-up call was made 7 days after the positioning sessions. RESULTS: Motor deficits were observed in the nondependent lower limb in 100% of the subjects in Group B, and no motor deficits were seen in Group A. Statistically significant differences (p < 0.05) were found between the 2 groups with respect to the performance on the 10-repetition maximum test immediately immediately and 60 minutes after positioning. Subjects in Group B had a 10%-70% (average 34.8%) decrease in knee extension strength and 20%-80% (average 43%) decrease in hip flexion strength in the nondependent limb. Sensory abnormalities were observed in the nondependent lower limb in 98% of the subjects in Group B. Thirty-six percent of the Group B subjects still exhibited sensory deficits after the 60-minute recovery period. No symptoms were reported by any subject during the follow-up calls 7 days after positioning. CONCLUSIONS: Twenty-five degrees of right lateral jack-knife positioning for 60 minutes results in neurapraxia of the nondependent lower extremity. Our results support the hypothesis that jack-knife positioning alone can cause postoperative neurological symptoms.

Mini-open pedicle subtraction osteotomy as a treatment for severe adult spinal deformities: case series with initial clinical and radiographic outcomes.

OBJECTIVE Pedicle subtraction osteotomy (PSO) is a powerful but high-risk surgical technique for destabilizing the spine for deformity correction in both the sagittal and coronal planes. Numerous reports have demonstrated the benefits of this technique for realigning the spine in a physiological posture; however, the open surgical technique is associated with a high complication rate. In this report the authors review data obtained in a series of patients who underwent PSO through a less invasive approach. METHODS Sixteen patients with severe coronal- and/or sagittal-plane deformities were treated in this series. Conservative measures had failed in all cases and patients had undergone a single-level PSO or extended PSO at L-2 or L-3. Fixation was accomplished using percutaneous instrumentation and interbody or facet joint fusions were used at the remaining levels. None of the procedures were aborted or converted to a traditional open procedure. Standard clinical and radiographic measures were used to assess patient outcomes. RESULTS Mean age was 68.8 years and mean follow-up duration was 17.7 months. An average of 7.6 levels were fused, and 50% of the patients had bilateral iliac screw fixation, with all constructs crossing both the thoracolumbar and lumbosacral junctions. Operative time averaged 356 ± 50 minutes and there was a mean blood loss of 843 ± 339 ml. The leg visual analog scale score improved from a mean of 5.7 ± 2.7 to one of 1.3 ± 1.6, and the back visual analog scale score improved from a mean of 8.6 ± 1.3 to one of 2.4 ± 2.1. The Oswestry Disability Index score improved from a mean of 50.1 ± 14.4 to 16.4 ± 12.7, representing a mean reduction of 36.0 ± 16.9 points. The SF-36 physical component summary score changed from a mean of 43.4 ± 2.6 to one of 47.0 ± 4.3, and the SF-36 mental component summary score changed from a mean of 46.7 ± 3.6 to 46.30 ± 3.0. Coronal alignment improved from a mean of 27.9 ± 43.6 mm to 16.0 ± 17.2 mm. The lumbar Cobb angle improved from a mean of 41.2° ± 18.4° to 15.4° ± 9.6°, and lumbar lordosis improved from 23.1° ± 15.9° to 48.6° ± 11.7°. Pelvic tilt improved from a mean of 33.7° ± 8.6° to 24.4° ± 6.5°, and the sagittal vertical axis improved from 102.4 ± 73.4 mm to 42.2 ± 39.9 mm. The final lumbar lordosis-pelvic incidence difference averaged 8.4° ± 12.1°. There were 4 patients who failed to achieve less than or equal to a 10° mismatch on this parameter. Ten of the 16 patients underwent delayed postoperative CT, and 8 of these had developed a solid arthrodesis at all levels treated. A total of 6 complications occurred in this series. There were no cases of symptomatic proximal junction kyphosis. CONCLUSIONS Advancements in minimally invasive technique have resulted in the ability to manage increasingly complex deformities with hybrid approaches. In this limited series, the authors describe the results of utilizing a tissue-sparing mini-open PSO to correct severe spinal deformities. This method was technically feasible in all cases with acceptable radiographic outcomes similar to open surgery. However, high complication rates associated with these deformity corrections remain problematic.

Minimally invasive resection of lumbar intraspinal synovial cysts via a contralateral approach: review of 13 cases.

OBJECT: The authors sought to determine patient-related outcomes after minimally invasive surgical (MIS) lumbar intraspinal synovial cyst excision via a tubular working channel and a contralateral facet-sparing approach. METHODS: All the patients with a symptomatic lumbar intraspinal synovial cyst who underwent surgery at the University of Iowa Hospitals and Clinics with an MIS excision via a contralateral approach were treated between July 2010 and August 2014. There was a total of 13 cases. Each patient was evaluated with preoperative neurological examinations, lumbar spine radiography, MRI, and visual analog scale (VAS) scores. The patients were evaluated postoperatively with neurological examinations and VAS and Macnab scores. The primary outcomes were improvement in VAS and Macnab scores. Secondary outcomes were average blood loss, hospital stay duration, and operative times. RESULTS: There were 5 males and 8 females. The mean age was 66 years, and the mean body mass index was 28.5 kg/m(2). Sixty-nine percent (9 of 13) of the cysts were at L4-5. Most patients had low-back pain and radicular pain, and one-third of them had Grade 1 spondylolisthesis. The mean (± SD) follow-up duration was 20.8 ± 16.9 months. The mean Macnab score was 3.4 ± 1.0, and the VAS score decreased from 7.8 preoperatively to 2.9 postoperatively. The mean operative time was 123 ± 30 minutes, with a mean estimated blood loss of 44 ± 29 ml. Hospital stay averaged 1.5 ± 0.7 days. There were no complications noted in this series. CONCLUSIONS: The MIS excision of lumbar intraspinal synovial cysts via a contralateral approach offers excellent exposure to the cyst and spares the facet joint at the involved level, thus minimizing risk of instability, blood loss, operative time, and hospital stay. Prospective randomized trials with longer follow-up times and larger cohorts are needed to conclusively determine the superiority of the contralateral MIS approach over others, including open or ipsilateral minimally invasive surgery.

Retroperitoneal oblique corridor to the L2-S1 intervertebral discs in the lateral position: an anatomic study.

OBJECT: Access to the intervertebral discs from L2-S1 in one surgical position can be challenging. The transpsoas minimally invasive surgical (MIS) approach is preferred by many surgeons, but this approach poses potential risk to neural structures of the lumbar plexus as they course through the psoas. The lumbar plexus and iliac crest often restrict the L4-5 disc access, and the L5-S1 level has not been a viable option from a direct lateral approach. The purpose of the present study was to investigate an MIS oblique corridor to the L2-S1 intervertebral disc space in cadaveric specimens while keeping the specimens in a lateral decubitus position with minimal disruption of the psoas and lumbar plexus. METHODS: Twenty fresh-frozen full-torso cadaveric specimens were dissected, and an oblique anatomical corridor to access the L2-S1 discs was examined. Measurements were taken in a static state and with mild retraction of the psoas. The access corridor was defined at L2-5 as the left lateral border of the aorta (or iliac artery) and the anterior medial border of the psoas. The L5-S1 corridor of access was defined transversely from the midsagittal line of the inferior endplate of L-5 to the medial border of the left common iliac vessel and vertically to the first vascular structure that crosses midline. RESULTS: The mean access corridor diameters in the static state and with mild psoas retraction, respectively, were as follows: at L2-3, 18.60 mm and 25.50 mm; at L3-4, 19.25 mm and 27.05 mm; and at L4-5, 15.00 mm and 24.45 mm. The L5-S1 corridor mean values were 14.75 mm transversely, from midline to the left common iliac vessel and 23.85 mm from the inferior endplate of L-5 cephalad to the first midline vessel. CONCLUSIONS: The oblique corridor allows access to the L2-S1 discs while keeping the patient in a lateral decubitus position without a break in the table. Minimal psoas retraction without significant tendon disruption allowed for a generous corridor to the disc space. The L5-S1 disc space can be accessed from an oblique angle consistently with gentle retraction of the iliac vessels. This study supports the potential of an MIS oblique retroperitoneal approach to the L2-S1 discs.