Thoracic Cordotomy Research Articles

Open Thoracic Cordotomy for Cancer Pain with Intraoperative Neuromonitoring: A Case Series and Critical Review of the Literature

Cordotomy is a viable option for patients with intractable cancer pain and limited survival. Open thoracic cordotomy is offered when patients are not candidates for percutaneous cordotomy. After the open procedure, traditionally performed purely based on anatomic landmarks, up to 22% of patients experience postoperative limb weakness. The objective of this study is to report our experience with neurophysiology-guided open cordotomy along with a critical review of the literature. Between 2019 and 2022, 5 open thoracic cordotomies were performed in our center. Intraoperative neurophysiologic monitoring was used in all cases to guide the lesion and standard single-level laminectomy or hemilaminectomy was performed for exposure. Outcome measures were retrospectively reviewed focusing on pain control and neurologic status. Existing literature on cordotomy was critically reviewed. There was satisfactory pain relief with preservation of motor function in all 5 cases. Temperature sensation was preserved in all but 1 patient, who lost it after the previous ipsilateral percutaneous cordotomy (PCC). No procedural complications were experienced. We found that the neurophysiology monitoring lesion was guided anterior compared with what would have been lesioned on an anatomic basis. Open thoracic cordotomy is a safe and effective procedure for intractable cancer-related pain. Technical advancements significantly reduced mortality and major morbidity of PCC. Our series suggests that neurophysiology monitoring alters the location of the lesion and may help better targeting of pain fibers within the spinothalamic tract and preserve other long tracts. The safety profile of open cordotomy with neurophysiology compares favorably with the PCC.

Open thoracic cordotomy for intractable cancer pain: a how I do it.

Some cancers of the lower extremity involve nerves and plexuses and can produce extreme drug-resistant noceptive pain. In these cases, open thoracic cordotomy can be proposed. This procedure involves disruption of the spinothalamic tract, which sustains nociceptive pathways. After placement in the prone position, selection of the side to be operated on (contralateral to the pain), and dura exposure, microsurgery is used to section the anterolateral spinal cord quadrant previously exposed by gently pulling on the dentate ligament. Open thoracic cordotomy is a moderate invasive, safe, and effective option for the management of drug-resistant unilateral lower extremity cancer pain in well-selected patients.

Dynamic mapping of the corticospinal tract in open cordotomy and myelomeningocele surgery

ObjectSpinal cord surgeries carry a high risk for significant neurological impairments. The initial techniques for spinal cord mapping emerged as an aid to identify the dorsal columns and helped select a safe myelotomy site in intramedullary tumor resection. Advancements in motor mapping of the cord have also been made recently, but exclusively with tumor surgery. We hereby present our experiences with dynamic mapping of the corticospinal tract (CST) in other types of spinal cord procedures that carry an increased risk of postoperative motor deficit, and thus could directly benefit from this technique. Case reportsTwo patients with intractable unilateral lower extremity pain due to metastatic disease of the sacrum and a thoraco-lumbar chordoma, respectively underwent thoracic cordotomy to interrupt the nociceptive pathways. A third patient with progressive leg weakness underwent cord untethering and surgical repair of a large thoracic myelomeningocele. In all three cases, multimodality intraoperative neurophysiologic testing included somatosensory and motor evoked potentials monitoring as well as dynamic mapping of the CST. ConclusionCST mapping allowed safe advancement of the cordotomy probe and exploration of the meningocele sac with untethering of the anterior-lateral aspect of the cord respectively, resulting in postoperative preservation or improvement of motor strength from the pre-operative baseline. Stimulus thresholds varied likely with the distance between the stimulating probe and the CST as well as with the baseline motor strength in the mapped myotomes.

Open Thoracic Cordotomy as a Treatment Option for Severe, Debilitating Pain

The treatment of patients with debilitating lower extremity or medically refractory quadrant pain presents a challenge for management. Contemporary neuromodulatory therapies may not be affordable or practical, especially in patients with limited life expectancy or from countries with limited resources. We present a small retrospective series to evaluate the role of open thoracic cordotomy as a practice option in the treatment of patients with severe, unilateral, medically refractory pain of the lower abdominal quadrant, hip, or leg. Technical aspects of the procedure, anatomic pathways within the spinal cord, and intraoperative maneuvers are described. The medical records of 9 patients (7 men, 2 women; median age, 57 years) treated between 1998 and 2010 were reviewed. Each patient underwent open thoracic cordotomy after 1998 for severe lower quadrant or lower extremity pain refractory to multiple other treatment modalities. The indications for surgery included cancer-related pain (4 of 9), postherpetic neuralgia (2 of 9), post-spinal cord injury pain (2 of 9), and multiple sclerosis (1 of 9). Six of nine patients reported improvement in their postoperative level of pain after a median follow-up of 31 weeks. Complications included ipsilateral lower extremity weakness, urinary incontinence, and the development of new postcordotomy pain. A higher incidence of complications, including ipsilateral motor weakness, was observed in this series than with previous reports of percutaneous cervical cordotomy (PCC). Although open thoracic cordotomy may be cautiously recommended as a treatment option in certain settings, this procedure should be viewed only as a second-line treatment option in settings where the technology and expertise to perform PCC are available.

Open Thoracic Cordotomy as a Viable Treatment Option for Severe, Debilitating, Treatment-Refractory Pain

Open Thoracic Cordotomy as a Viable Treatment Option for Severe, Debilitating, Treatment-Refractory Pain

Bilateral Open Thoracic Cordotomy for Refractory Cancer Pain: A Neglected Technique?

At least 10% of patients with cancer have pain that is refractory to systemic analgesics. For most of these patients, interventional techniques may be of benefit but are often not considered or are difficult to access. Of these techniques, spinal analgesia is most commonly used in Australia and the United Kingdom, and neurosurgical procedures, such as open cordotomy with sectioning of the spinothalamic tract, are rarely used. We describe a case illustrating the successful use of bilateral open thoracic cordotomy in a patient with refractory mixed nociceptive and neuropathic pain secondary to a lumbosacral tumor. We discuss the various interventional options and review the recent literature regarding the use of both percutaneous and open cordotomy for cancer pain.

Is There Still a Role for Open Cordotomy in Cancer Pain Management?

For a small number of cancer patients, good pain control remains difficult to achieve despite adequate assessment and medical management. In nine cases, effective control of intractable pain from malignant pelvic disease was achieved by open thoracic cordotomy. The technique was well tolerated, with no major complications. Eight of the nine patients decreased their median daily oral morphine requirement from 560 mg (range 360–2600 mg) to 160 mg (range 40–1000 mg). Maximal survival time post-cordotomy was 830 days, with a median of 107 days. No patient experienced recurrent pain in the initially painful site. For patients with intractable pain associated with advanced pelvic malignancy, the use of an open cordotomy should be considered when satisfactory pain control is not achieved by medical or minimally invasive methods.

Regeneration of primary sensory axons into the adult rat spinal cord via a peripheral nerve graft bridging the lumbar dorsal roots to the dorsal column.

This study investigated the feasibility of using a peripheral nerve autograft (NAG) to promote and guide regeneration of sensory axons from the caudal lumbar dorsal roots to the rostral dorsal column following a lower thoracic cordotomy in adult rats. After a left hemicordotomy at the T13 vertebra level and ipsilateral L3 and L4 rhizotomies, a peripheral NAG (peroneal nerve) was connected to the distal roots stumps, then implanted into the left dorsal column 10 mm rostral to hemicordotomy site (n = 12). After surgery, all animals of the experimental group experienced complete anesthesia in their left hindlimb. Three months later, a slight response to nociceptive stimulation reappeared in L3 and/or L4 dermatomes in 6 of the 12 experimental animals. None of these animals exhibited self-mutilation. Nine months after surgery, we performed retrograde tracing studies by injecting horseradish peroxidase (HRP) into the left dorsal column 30 mm rostral to the NAG implantation site. In eight animals, we found HRP-stained neurons in the left L3 and/or L4 dorsal root ganglia (DRG). The mean number of HRP-stained neurons per DRG was 71 +/- 92 (range 2-259). In control groups, no HRP-stained neurons were found in L3 or L4 DRG. Histological analysis of the NAG showed evidence of axonal regeneration in all 8 animals with positive retrograde labeling of DRG neurons. However, we did not find a statistical correlation between the number of HRP-stained neurons and the degree of sensory recovery. This study demonstrates that an NAG joining dorsal roots to the dorsal column, thus shunting the original CNS-PNS junction, can support regeneration of central axons from DRG primary sensory neurons into the dorsal column over distances of at least 30 mm despite the inhibitory influence of the CNS white matter.

Effects of experimental spinal cord transection on substance P receptors: A quantitative autoradiography study

The autoradiographic localisation of Substance P (SP) receptors was investigated in the rat spinal cord following cordotomy at the thoracic 8–9 level. The binding of [ 125I]-BH-SP was measured in discrete gray matter structures above (C6-C7 level) and below (L2-L3 level) the injury site, and expressed in fmol/mg protein. There was a statistically significant increase in SP receptor density 1 week after cordotomy in the dorsal horn and in the central canal of lumbar region, in laminae 3-4-5 and also in the ventral horn of cervical spinal cord. Elevated SP receptor density was also noted in cervical ventral horn at 3 weeks after thoracic cordotomy, whereas the increase seen at 1 week was normalized at 3 weeks everywhere else. Since SP concentration has been reported to show a similar localized increase below a spinal transection, the present results are consistent with an up-regulation of SP receptors. A similar direct relationship between SP receptors and SP content appears to occur also in the ventral horn above the injury site.

Distribution of axons showing both enkephalin- and serotonin-like immunoreactivities in the lumbar cord segments of the Japanese monkey ( Macaca fuscata)

Axons exhibiting both enkephalin- and serotonin-like immunoreactivities were observed by the double immunofluorescence method in the lumbar cord segments of the Japanese monkey. Double-labeled axons were seen almost exclusively in the dorsal horn, particularly in lamina I, lamina IIa and the lateral part of lamina V. After thoracic cordotomy, almost all of the double-labeled axons disappeared from the lumbar cord segments.

Effect of regional spinal cord blood flow and central control in recovery from spinal cord injury.

Forty-two cats were subjected to decerebration, thoracic and lumbar laminectomies, and isolation of the sciatic nerves. Spinal evoked potentials in response to bilateral sciatic nerve stimulation were recorded at L-3, and the spinal cord blood flow (SCBF) was measured by the hydrogen clearance technique. Thoracic cordotomy did not alter the lumbar SCBF or the central conduction time as determined by spinal evoked potentials. Thoracic cordotomy significantly lowered the lumbar spinal cord injury threshold. Continuous sciatic nerve stimulation increased the lumbar SCBF in normal and traumatized animals; however, it did not affect the spinal cord injury threshold as measured by recovery of the spinal evoked potentials. It appears that rostral spinal cord integrity is far more significant in recovery from spinal cord injury than the maintenance of regional SCBF.

Intraspinal course of descending serotoninergic pathways innervating the rodent dorsal horn and lamina X.

Although numerous studies have discussed serotoninergic pathways projecting from the brainstem to the spinal cord, the intraspinal course of these descending axons remains a matter of debate. One of the difficulties with traditional immunohistochemical methods is that the interpretation of results has been subjective. We have therefore employed a computer-assisted image-processing system to provide objective measurements of serotonin immuno-reactivity within the rodent dorsal horn and lamina X caudal to unilateral thoracic cordotomy in order to establish the intraspinal course of descending serotoninergic fibers. Lesion analysis combined with computer-determined optical density measurements, high-power microscopic examination, and camera lucida drawings demonstrated that the predominant serotoninergic pathway terminating within the dorsal horn courses unilaterally within the dorsal portion of the dorsolateral funiculus. The thoracic dorsal horn may receive a slightly greater contribution from the contralateral side than the lumbar dorsal horn. Lamina X receives serotoninergic innervation both from fibers descending within the ipsilateral dorsolateral funiculus and from more ventrally located ipsilateral pathways, and it also contains serotonin derived from other sources.

Small-caliber skeletal muscle fibers do not suffer necrosis in mdx mouse dystrophy.

The prevalence of internal nuclei in muscle fibers (centronucleation), which is a reliable cumulative index of all prior muscle fiber necrosis, was measured at different ages in different muscles of mdx mice and was correlated with muscle fiber diameter. The prevalence of centronucleated fibers (as percentage of total number of fibers) rose gradually after age 20 days until it reached a peak level of 80% at age 60 days. No significant centronucleation (or necrosis) was observed in the following circumstances: in 4 different limb muscles before age 15 days, in leg muscles that were denervated by peripheral nerve section or rendered immobile by high thoracic cordotomy at 15 days, or in rotator extraocular muscles throughout the animals' life span. In these situations, muscle fiber diameter remained below approximately 20 micron. The mechanism by which small-diameter fibers are resistant to necrosis in mdx dystrophy is unknown, but a similar situation exists in hamster and Duchenne muscular dystrophy.

The site of the integration of muscular activity and respiration.

Acutely decerebrate (midcollicular) cats do not, or rarely if ever, walk spontaneously; nor do they show phasic movements of progression. After low thoracic cordotomy in a Schiff-Sherrington preparation with enhanced forelimb rigidity, approximately 50% of the preparations begin to show spontaneous locomotory movements in the forelimbs. In some cases these movements are in periodic bursts, and at these times are associated with waxing hyperpnea beginning before the onset of the forelimb movements. This indicates the presence of an intrinsic exercise hyperpnea mechanism mediated within the central nervous system in centers caudal to the hypothalamus.

Experimental core-like lesions and nemaline rods. A correlative morphological and physiological study.

Core-like lesions and nemaline rods were produced in type I extrafusal muscle fibers of rat soleus by Achilles tenotomy. In tenotomized solei the aggregate of motor unit activity was reduced. The continuous pattern of motor unit activity characterizing normal soleus was changed to a phasic pattern. Sciatic neurotomy or thoracic cordotomy at the time of tenotomy prevented the lesions and abolished motor unit activity in the soleus for a few days. Neuronal activation of muscle fibers appears essential for the development of core-like lesions and rods. Recoil of tenotomized muscle also seems necessary. The experimental central lesions resemble and differ from human central cores and targets. Experimental and human nemaline rods are morphologically indistinguishable. A common pathogenic mechanism in the formation of the human and the experimental lesions was not identified.

Percutaneous thoracic and high cervical cordotomy by the anterior approach.

Percutaneous thoracic and high cervical cordotomy by the anterior approach.

Upper thoracic cordotomy for relief of pain; postmortem correlation of spinal incision with analgesic levels in 18 cases.

White, James C. M.D.; Richardson, Edward P. Jr. M.D.; Sweet, William H. M.D. Author Information