Intramuscular Circulation of the Lumbar Multifidus in Different Trunk Positions on Standing.

A deficiency in lumbar muscle blood circulation is considered to be a major risk factor for non-specific low back pain. The aim of this study was to investigate changes in relative circulation over time in the lumbar multifidus in different positions on sitting.Twelve healthy subjects (7 males, 5 females, average age: 20.9 years) without low back pain for the past 12 months were recruited. Near-infrared spectroscopy (NIRS) was used to non-invasively measure total haemoglobin (Total-Hb) and oxygenated haemoglobin (Oxy-Hb) in the lumbar multifidus at the L5-S1 segment. Subjects were asked to move into either 60-degree trunk-flexed or 20-degree trunk-extended position from the starting (standing in neutral) position in 3 s, timed by a metronome, and to maintain these positions for 30 s. The measurements of Total-Hb and Oxy-Hb were compared at -3 (neutral position), 0, 10, 20, and 30 s in each flexed and extended position on sitting.In flexion, Total-Hb and Oxy-Hb of the lumbar multifidus were significantly decreased from a neutral (-3 s) to flexed (0 s) position (Total-Hb: p = 0.002, Oxy-Hb: p = 0.004); however, there were no significant differences in the flexed position. In extension, Total-Hb and Oxy-Hb of the lumbar multifidus were significantly increased from 0 to 10 s (Total-Hb: p < 0.001, Oxy-Hb: p < 0.001); however, there were no significant differences from the neutral (-3 s) to extended (0 s) position, or from 10 to 30 s.The results of this study indicate that the intramuscular circulation of the lumbar multifidus decreases immediately once the trunk starts moving into a flexed position on sitting. On the other hand, the intramuscular circulation of the lumbar multifidus increases for up to 10 s once the trunk starts moving into an extended position.

Spontaneous infarction of lumbar roots, vertebrae and paravertebral muscles.

Ischemic injury to the lumbosacral nerve roots and plexus is a rare condition resulting from thrombosis of one or several lumbar arteries. As the arterial supply of the spine presents great variations between subjects, the clinical presentation of lumbar thrombosis is highly variable depending on the relative involvement of nerve roots, bones or muscles. Diagnosis can be challenging, especially in the acute phase, as different structures can be simultaneously involved. The identification of an enlarged vessel centered in the area of tissue damage can help with the final diagnosis. We present the case of a 59-year-old woman who presented with spontaneous incomplete cauda equina syndrome due to diffuse lumbar nerve root infarction. On imaging, acute lumbar artery thrombosis was confirmed, and in addition to nerve roots, adjacent vertebral and paraspinal muscle infarctions were also present.

Pedicled Multifidus Muscle Flap To Treat Inaccessible Dural Tear In Spine Surgery: Technical Note And Preliminary Experience.

OBJECTIVE: To assess the usefulness, feasibility, and limitations of pedicled multifidus muscle flaps (PMMFs) for the treatment of inaccessible dural tears during spine surgery. METHODS: The technique of PMMF harvesting was investigated together with relevant anatomy. We prospectively evaluated 8 patients treated with the PMMF technique between January 2017 and December 2019. Results were compared with a retrospective series of 9 patients treated with a standard technique between January 2014 and December 2016. Inclusion criteria were inaccessible dural tear or dural tear judged not amenable to direct repair because of tissue loosening. Exclusion criteria were surgical treatment of intradural disease. Clinical and demographic data of all patients were collected. Clinical evaluations were performed according to American Spinal Injury Association criteria and Oswestry Disability Index. Preoperative and postoperative computed tomography was performed in all patients. The primary end point was wound healing (cerebrospinal fluid leakage, infection, and fluid collection); secondary end points were neurologic outcome and complications. RESULTS: Control group: 1 death as a result of wound infection secondary to cerebrospinal fluid fistula and 2 patients needed lumbar subarachnoid drain; neurologic outcome: 3 patients improved and 6 were unchanged. Flap group: no wound-related complications were observed; neurologic outcome: 3 patients improved and 5 were unchanged. No flap-related complications were described. Flap harvesting was feasible in all cases, with an average 20 minutes adjunctive surgical time. CONCLUSIONS: The PMMF technique was feasible and safe; in this preliminary experience, its use is associated with lower complications as a result of dural tears but larger series are needed to confirm its effectiveness.

Conus Medullaris Infarction Involving the Paraspinal Muscles and Nerve Roots.

Spinal cord infarctions account for less than 1% of all strokes. The segmental artery supplies the spinal cord, vertebrae, nerve roots, and paraspinal muscles. To our knowledge, this is the first case of spinal cord infarction involving multiple distinct infarcts at various sites, including the lumbar vertebrae, conus medullaris, dorsal thoracolumbar spinal cord, paraspinal muscles, and nerve roots.

Vascularized Spinous Process Graft Rotated on a Paraspinous Muscle Pedicle for Lumbar Fusion: Technique Description and Early Clinical Experience.

BACKGROUND: Vascularized bone grafts (VBGs) are described as having superior osteogenicity, osteoconductivity, and osteoinductivity compared with other graft types and have been used in high-risk patients to augment arthrodesis. Pedicled VBGs are rotated on an intact vascular pedicle and therefore maintain all the benefits of VBGs but avoid many of the challenges and additional morbidity of free-tissue transfer. This study describes a novel surgical technique for rotating vascularized spinous process into the posterolateral space for augmenting arthrodesis in patients undergoing posterolateral fusion (PLF). METHODS: A technique is described for rotating the spinous process into the posterolateral space on an intact vascular pedicle of paraspinal muscle. Early clinical and radiographic outcomes are reported for 4 patients who have undergone this procedure. RESULTS: Four patients were treated with a single or 2-level PLF combined with posterior, anterior, or lateral interbody fusion and vascularized spinous process graft. Three-month postoperative computed tomography scans demonstrated a dislodged graft in 1 patient and successful arthrodesis in 3 patients. Additional operative time taken for graft harvest and implantation ranged from 22 minutes for the first patient to 6 minutes for the fourth patient. CONCLUSIONS: Rotation of vascularized spinous process graft for augmentation of posterolateral arthrodesis in the lumbar spine is a potentially safe, effective surgical technique that results in successful arthrodesis in as little as 3 months but requires further study. This technique is expected to add little additional time or morbidity to the traditional lumbar PLF because it requires no separate incision or additional bone removal.

Cadaveric Nerve and Artery Proximity to Sacrospinous Ligament Fixation Sutures Placed by a Suture-Capturing Device.

OBJECTIVE: To simulate sacrospinous ligament fixation on cadaveric specimens, describe the surrounding retroperitoneal anatomy, and estimate the risk to nerves and arteries for the purposes of optimizing safe suture placement. METHODS: Sacrospinous ligament fixation was performed on eight fresh-tissue female cadavers using a Capio ligature capture device. Distances from placed sutures to the following structures were measured: ischial spine; fourth sacral root; pudendal nerve; the nerve to coccygeus muscle; the nerve to levator ani muscle; inferior gluteal artery; and internal pudendal artery. Periligamentous anatomy was examined in an additional 17 embalmed cadaver dissections. RESULTS: Sacrospinous ligament length was not seen to differ significantly between sides. The fourth sacral spinal nerve was seen most commonly associated with the medial third of the ligament, whereas the pudendal nerve and the nerves to coccygeus and levator ani muscles were associated with the lateral third. The inferior gluteal artery was seen leaving the greater sciatic foramen a median 15.8 mm (range 1.8-48.0, CI 14.9-22.3) above the ligament, whereas the internal pudendal artery exited just above the ischial spine. The two sets of sutures were placed 20.5 mm (range 9.2-34.4, CI 19.7-24.7) and 24.8 mm (range 12.4-46.2, CI 24.0-30.0) medial to the ischial spine, respectively. No structures were directly damaged by placed sutures. The nerves to coccygeus and levator ani were closest and arteries farthest from the placed sutures. CONCLUSION: The middle segment of the sacrospinous ligament has the lowest incidence of nerves and arteries associated with it. This study confirms that the nerves supplying the pelvic floor muscles are at a higher risk from entrapment than the pudendal nerve.

A non-invasive magnetic resonance imaging approach for assessment of real-time microcirculation dynamics.

We present a novel, non-invasive magnetic resonance imaging (MRI) technique to assess real-time dynamic vasomodulation of the microvascular bed. Unlike existing perfusion imaging techniques, our method is sensitive only to blood volume and not flow velocity. Using graded gas challenges and a long-life, blood-pool T 1-reducing agent gadofosveset, we can sensitively assess microvascular volume response in the liver, kidney cortex, and paraspinal muscle to vasoactive stimuli (i.e. hypercapnia, hypoxia, and hypercapnic hypoxia). Healthy adult rats were imaged on a 3 Tesla scanner and cycled through 10-minute gas intervals to elicit vasoconstriction followed by vasodilatation. Quantitative T 1 relaxation time mapping was performed dynamically; heart rate and blood oxygen saturation were continuously monitored. Laser Doppler perfusion measurements confirmed MRI findings: dynamic changes in T 1 corresponded with perfusion changes to graded gas challenges. Our new technique uncovered differential microvascular response to gas stimuli in different organs: for example, mild hypercapnia vasodilates the kidney cortex but constricts muscle vasculature. Finally, we present a gas challenge protocol that produces a consistent vasoactive response and can be used to assess vasomodulatory capacity. Our imaging approach to monitor real-time vasomodulation may be extended to other imaging modalities and is valuable for investigating diseases where microvascular health is compromised.

The acute effects of integrated myofascial techniques on lumbar paraspinal blood flow compared with kinesio-taping: A pilot study.

BACKGROUND: Myofascial techniques and Kinesio Taping are therapeutic interventions used to treat low back pain. However, limited research has been conducted into the underlying physiological effects of these types of treatments. OBJECTIVES: The purpose of this study was to compare the acute effects of integrated myofascial techniques (IMT) and Kinesio Tape (KT) on blood flow at the lumbar paraspinal musculature. METHODS: Forty-four healthy participants (18 male and 26 female) (age, 26 ± SD 7) volunteered for this study and were randomly assigned to one of three interventions, IMT, KT or a control group (Sham TENS). Paraspinal blood flow was measured at the L3 vertebral level, using Near Infrared Spectroscopy (NIRS), before and after a 30-min treatment. Pain Pressure Threshold (PPT) was also measured before and after treatments. RESULTS: A one-way ANOVA indicated a significant difference between groups for O2Hb [F (2-41) = 41.6, P < 0.001], HHb [F (2-41) = 14.6, P < 0.001] and tHb [F (2-41) = 42.2, P < 0.001]. Post hoc tests indicated that IMT was significantly greater, from the KT and the control treatments (P < 0.001), for changes in O2Hb, HHb, and tHb. There were no significant differences for PPT [F (2-41) = 2.69, p = 0.08], between groups. CONCLUSIONS: This study demonstrated that IMT increases peripheral blood flow at the paraspinal muscles in healthy participants compared to KT and sham TENS. The change in blood flow had no impact on pain perception in the asymptomatic population group.

Microsurgical Fenestration and Paraspinal Muscle Pedicle Flaps for the Treatment of Symptomatic Sacral Tarlov Cysts.

OBJECTIVE: Sacral Tarlov cysts are rare causes of sciatic and sacrococcygeal pain and neurologic deficits. Although several microsurgical treatments have been described, the optimal treatment has yet to be determined. We describe our initial experience with symptomatic lesions combining 1) cyst fenestration and imbrication and 2) filling the epidural space using vascularized paraspinous muscle flaps rotated into the cystic cavity. METHODS: We retrospectively reviewed all consecutive cases of symptomatic giant sacral Tarlov cysts treated with microsurgery at our institution between 2003 and 2011. The main outcome measure was self-reported symptom relief. Postoperative imaging, surgical complications, and subsequent treatments were also recorded. RESULTS: Thirty-five patients were treated. Mean age was 52 years. All patients presented with a chief complaint of sacral-perineal pain. The mean cyst size was 3.6 cm (largest diameter). Follow-up beyond the initial hospital stay was available in 86% (median 8 months). Ninety-three percent reported improvement in pain at some point during the postoperative course but 50% of those developed recurrent pain symptoms. Postoperative imaging was available in 69% of the patients in whom 92% showed complete obliteration (25%) or reduction in cyst size (67%). CONCLUSIONS: The combination of microsurgical cyst fenestration and the use of vascularized muscle pedicle flaps to fill the cystic cavity and the epidural space results in obliteration or reduction in size of the majority of cysts and is associated with initial improvement in pain in most patients. However, delayed recurrence of pain was common with this technique.

Indirect Neuromonitoring of the Spinal Cord by Near-Infrared Spectroscopy of the Paraspinous Thoracic and Lumbar Muscles in Aortic Surgery.

Paraplegia remains the most devastating complication of open and endovascular thoracic/thoracoabdominal aortic aneurysm (TAA/A) repair. However, the assessment of currently available neuromonitoring modalities remains challenging and difficult to interpret. Near-infrared spectroscopy (NIRS) has been introduced as a strategy for noninvasive, real-time monitoring of the paraspinous collateral network (CN) to detect potential spinal cord ischemia at our institution. Prior to TAA/A repair, a cerebrospinal fluid catheter is placed and four NIRS optodes are bilaterally positioned on the patient's back to transcutaneously monitor regional muscle oxygenation at the thoracic and lumbar levels. Indirect surveillance of the spinal cord by NIRS seems to be a tempting option with increasing evidence supporting the CN concept.

[A case of conus medullaris infarction expanding to the vertebral bodies, major psoas and erector spinae muscles].

A 77-year-old woman presented with conus medullaris and cauda equina syndrome following a sudden pain in the bilateral lower abdomen and right buttock. Lumbar magnetic resonance imaging (MRI) showed not only a conus medullaris lesion, but also several lesions in the vertebral bodies (L1, L2), right major psoas muscle, right multifidus muscle and bilateral erector spinae muscles. As these areas receive blood supply from each branch of the same segmental artery, we considered all of the lesions as infarctions that were a result of a single parent vessel occlusion. It is known that a vertebral body lesion can be accompanied by a spinal cord infarction, but in combination with infarction of a muscle has not been reported. This is the first report of a concomitant spinal cord and muscle infarction revealed by MRI. It is noteworthy that a spinal cord infarction could expand not only to neighboring vertebral bodies, but also to muscles.

Influence of two types of self-retaining retractors on multifidus muscle blood flow during dorsolateral thoracolumbar hemilaminectomy in dogs.

OBJECTIVES: To assess the influence of the use of Gelpi and Grevel retractors on multifidus muscle blood flow during hemilaminectomy, using a dorsolateral approach, for acute disc extrusion in dogs as measured by laser speckle contrast imaging (LSCI). METHODS: Blood flow in the multifidus muscles was measured intra-operatively using LSCI prior to insertion of the retractors, immediately after hemilaminectomy and removal of the retractors, and after 10 minutes of lavage of the surgical site. Plasma creatine kinase levels were measured preoperatively and 12-24 hours postoperatively. RESULTS: Muscular blood flow was significantly decreased following retraction and remained lower than initial values 10 minutes after lavage in all dogs. The decrease in blood flow was significantly greater with Gelpi retractors (n = 8) than with Grevel retractors (n = 10). No significant relation was found between the duration of retraction and postoperative changes in creatine kinase levels or blood flow. CLINICAL SIGNIFICANCE: Findings in this study demonstrate a drop in blood flow within the multifidus muscles using the dorsolateral approach regardless of retractor type used. Gelpi retractors seem to have greater influence on muscular blood flow than Grevel retractors. Further studies are warranted to confirm this second finding.

Repositioning suture of the erector spinae muscle for lumbar spine surgery via the posterior approach: a prospective randomized study.

We prospectively studied the effectiveness of the repositioning suture of the erector spinae muscle for lumbar spine surgery using the posterior approach. 393 patients undergoing lumbar spine surgery were randomized to receive the repositioning or conventional suture of the erector spinae muscle. Time to stitch removal and drainage volume was recorded at 24 and 48 h after operation. Hemoglobin loss rate was determined at 48 h post operation and the rate of malunion (redness, swelling and effusion at stitch removal and would disruption after stitch removal) was recorded. Low back pain was evaluated using the visual analog scale (VAS) preoperatively and 6 and 12 months after operation. Time to stitch removal was comparable in lumbar spine surgery patients receiving the repositioning or conventional suture of the erector spinae muscle (P > 0.05). Compared with the conventional suture, the repositioning suture was associated with significantly reduced drainage volume both at 24 (P < 0.01) and 48 h after operation (P < 0.05). Hemoglobin loss rate at 48 h post operation was also markedly lower in lumbar spine surgery patients receiving the repositioning suture than in those receiving the conventional suture (P < 0.01 or 0.05). Furthermore, the malunion rate in lumbar spine surgery patients using the repositioning suture was markedly lower than that in the conventional group (P < 0.05 or 0.001). There was no difference in preoperative VAS scores in both the groups (P > 0.05). Compared with the conventional suture, the repositioning suture was associated with significantly reduced VAS scores both at 24 and 48 h after operation (P < 0.01 in both). The repositioning suture of the erector spinae muscle is superior to the conventional suture in posterior lumbar spine surgery with marked lessened pain and reduced drainage volume.

The arterial supply of the cervical and thoracic spinal muscles and overlying skin: Anatomical study with implications for surgical wound complications.

Postoperative spinal wound dehiscence is a significant complication following the posterior midline approach. It is postulated that this approach disrupts the vasculature supplying the paraspinal muscles and overlying skin. Although the spinal vasculature has been investigated previously, the smaller arterioles have not been described in the context of the posterior midline approach. Eight cadaveric neck and posterior torso specimens were dissected after injection with a radio-opaque lead oxide mixture and subsequent radiographs taken were analyzed. The deep cervical, vertebral, superficial cervical, and occipital arteries consistently supplied the cervical paraspinal muscles. The latter two arteries also vascularized the overlying skin. The deep cervical arteries were found to be located lateral to the C3 to C6 vertebrae, vulnerable to damage with the posterior approach. In the thoracic region, the superior and posterior intercostal arteries consistently supplied the spinal muscles. In all specimens, two small anastomotic vessels posterior to the laminae were found connecting the intercostal artery perforators. Both the arterial perforators and their anastomotic channels were situated in the surgical field and susceptible to damage with the posterior approach. It is likely that the disruption in spinal vasculature contributes to the multifactorial problem of wound dehiscence with the posterior midline approach.