Costotransverse Foramen Research Articles

Pathways of dye spread after injections in the paraspinal spaces-A cadaveric study.

The erector spinae plane (ESP) block is the most sought-after block since its inception. However, it is more of dorsal rami block with unpredictable ventral diffusion to the paravertebral area. We injected dye in ESP and other paraspinal spaces to study and compare the dye diffusion pattern along the neuroaxis and paraspinal region in human cadavers. In six soft-embalmed cadavers (12 specimens), 20 mL methylene blue dye (erector spinae plane and paravertebral space) or indocyanine green dye (inter-ligament space) was injected bilaterally using an in-plane ultrasound-guided technique at the level of the costotransverse junction of fourth thoracic vertebrae. Dye spread was evaluated bilaterally in the coronal plane in the paravertebral and intercostal spaces from the 1st and the 12th rib. Axial and sagittal sections were performed at the level of the 4th thoracic vertebrae. After cross sections, the extent of dye spread was investigated in ESP, inter-ligament, and paravertebral spaces. The staining of the ventral and dorsal rami and spread into the intercostal spaces was evaluated. ESP injection was mainly restricted dorsal to the costotransverse foramen and did not spread anteriorly to the paravertebral space. The paravertebral injection involved the origin of the spinal nerve and spread laterally to the intercostal space. The inter-ligament space injection showed an extensive anterior and posterior dye spread involving the ventral and dorsal rami. Following ESP injection, there was no spread of the dye anteriorly to the paravertebral space and it only involved the dorsal rami. Inter-ligamentous space injection appears to be the most promising block as dye spread both anteriorly to paravertebral space and posteriorly toward ESP.

Comparison between costotransverse foramen block and thoracic paravertebral block for VATS pulmonary resection: A randomized noninferiority trial

Study objectiveThe present study assessed whether costotransverse foramen block (CTFB) is noninferior to thoracic paravertebral block (TPVB) for postoperative analgesia in video-assisted thoracoscopic surgery (VATS) pulmonary resection. DesignSingle-center, double-blinded, randomized, non-inferiority trial. SettingOperating room and intensive care unit or ward in a tertiary hospital. PatientsPatients aged 20 to 80 years with American Society of Anesthesiology physical status 1 to 3 scheduled for elective VATS pulmonary resection. InterventionsSixty patients were randomly allocated 1:1 to receive CTFB or TPVB using 15 mL aliquots of 0.5% ropivacaine at the T4–5 and T6–7 intercostal levels immediately after the induction of general anesthesia. MeasurementsThe primary outcome was the area under the curve (AUC) of numeric rating scale (NRS, 0 to 10) during 24 h postoperatively (noninferiority limit was 24; NRS 1 per hour). The secondary outcomes included postoperative opioid consumption, rescue analgesic use, postoperative nausea and vomiting, pulmonary function, dermatomal spread of the blockade, and quality of recovery. Main resultsForty-seven patients were included for final analysis. The difference between the mean 24-h AUCs of NRS in the CTFB (34.25 ± 16.30, n = 24) and TPVB (39.52 ± 17.13, n = 23) groups was −5.27 (95% confidence interval [CI], −15.09 to 4.55), with the upper limit of 95% CI being far below the predefined noninferiority margin of 24. There was no significant difference in the dermatomal spread of the blockades between the groups, as both reached the upper and lower most levels of T3 and T7 (median). Additionally, there were no significant differences in other secondary outcomes between the two groups. ConclusionsThe analgesic effect of CTFB was noninferior to that of TPVB during 24 h postoperatively in VATS pulmonary resection. Moreover, CTFB may offer potential safety benefits by keeping the tip of the needle far from the pleura and vascular structure.

Motor block and hypotension following a high thoracic erector spinae plane block.

Dear Editor, Erector spinae plane blocks (ESPBs) are becoming more prevalent in clinical practice for postoperative pain control following truncal procedures. ESPBs are often quoted as being easy to perform and having few complications. We describe a patient with a thoracic epidural spread after administering an ultrasound-guided unilateral high thoracic ESPB for a video-assisted thoracoscopic procedure (VATS). A 62-year-old woman with chronic smoking, hypertension, and asthma was scheduled for an elective right VATS upper lobectomy for a malignant lesion. Her body weight was 78 kg, and she had no functional limitations. After obtaining informed consent, standard Canadian Anesthesia Society monitors were applied. She received preprocedural 1 mg of intravenous midazolam. The block was performed in the block room by an anesthesia resident under an experienced attending anesthesiologist’s supervision. In a sitting position, right ESB was performed using a linear ultrasound transducer oriented in the parasagittal plane. An out-of-plane approach was used due to the shorter needling distance, thus mitigating discomfort. After contacting the T4 TP, 20 ml of 0.5% ropivacaine was injected, and a local anesthetic was seen spreading deep to the erector spinae muscle. She was transferred to the operating room following an uneventful 10 min of monitoring in the block room. Upon directing the patient to move from the stretcher to the operating table, she noted having decreased bilateral lower limb sensation and motor weakness. Physical exam revealed decreased strength in hip flexion and a bilateral truncal sensory from T4 to L4 dermatomes. Her blood pressure had dropped to 73/36. She did not have any shortness of breath, chest pain, or light headedness. An awake radial arterial line was placed, and a phenylephrine infusion was initiated at 20 mcg/min. With her blood pressure stabilized, the decision was made to proceed with surgery. With surgical stimulation, she was able to wean off the phenylephrine infusion. She had no motor weakness or sensory loss following an uncomplicated 3 h long VATS lobectomy. In the post-anesthetic care unit (PACU), Pain scores were between 4 and 6, and blood pressure was 99/66. In a review, the incidence of complications of ESPBs is 0.2%, including bilateral lower limb weakness, motor block, transient apathy, aphasia, dizziness, loss of consciousness due to systemic toxicity and pneumothorax.[1] Selvi et al.[2] reported an unexpected motor weakness following bilateral T11 ESPB, and De Cassai et al.[3] reported near-complete lower extremity immobility following bilateral L3 ESPB for lumbar laminectomy. Our patient experienced bilateral motor and sensory block along with significant hypotension 15 min after a high unilateral thoracic ESPB. Given the symmetrical nature of the blockade and its resolution, we postulated that the local anesthetic injected had spread to the epidural space via the costotransverse foramen.[3] This may be related to the orientation and the angulation of the needle. Such a precipitous and unexpected drop in blood pressure could result in hemodynamic instability and cardiac compromise in some patients. Although seemingly rare, caution must be taken. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

The pathway of injectate spread during thoracic intertransverse process (ITP) block: Micro-computed tomography findings and anatomical evaluations

Study objectiveTo investigate the mechanism of action of the thoracic intertransverse process (ITP) block. DesignThree-dimensional micro-computed tomography (3D micro-CT) study and cadaveric evaluation. SettingA translational research unit for anatomy and analgesia in a university hospital. PatientsTwelve embalmed and three non-embalmed human cadavers were used in this study. MeasurementsMicro-CT images of the mid-thoracic paravertebral space and its adjacent ligamentous tissues were acquired and 3D images were reconstructed. Manual dissection and histologic examination of these structures complemented the images. To confirm our findings, the dye-spreading pattern after ultrasound-guided ITP injection of 20 mL dye solution at T4-T5 was evaluated. Main resultsMicro-CT and histologic findings showed that the costotransverse foramen (the medial slit of the superior costotransverse ligament) and the costotransverse space (between the rib and the transverse process) were potential pathways to the thoracic paravertebral space during ITP block. Single-level ITP injection with a dye solution resulted in a multilevel segmental paravertebral spread in cadaveric evaluation. ConclusionsThe space posterior to the superior costotransverse ligament, the target area for ITP blocks, has potential anatomical pathways to the thoracic paravertebral space. The costotransverse foramen and the costotransverse space provided the anatomical conduit for the anterior and intersegmental paravertebral spread of the ITP block.

Parascapular Sub-Iliocostalis Plane Block: Comparative Description of a Novel Technique for Posterior Rib Fractures.

We describe a new analgesic technique, parascapular sub-iliocostalis plane block (PSIP), for lateral-posterior rib fractures as an alternative to other regional techniques in a high-risk patient who suffered a decompensation of her cardiorespiratory function after posterior chest trauma. We performed a continuous ultrasound-guided left PSIP block in the sub-iliocostalis plane next to the fourth rib to optimize analgesia and minimize complications. The patient had total pain relief with marked improvement in her cardiorespiratory condition. No complications were reported. The efficacy of the PSIP block may potentially depend on different mechanisms of action: (1) direct action in the fracture site by craniocaudal myofascial spread underneath the erector spinae muscle (ESM); (2) spread to deep layers through tissue disruption caused by trauma, to reach the proximal intercostal nerves; (3) further medial spread through deeper layers to the midline to block the posterior and ventral spinal nerves; (4) medial spread below the ESM, to reach the posterior spinal nerves (more reliably than rhomboid intercostal / sub-serratus [RISS] block); and (5) lateral spread in the sub-serratus (SS) plane to reach the lateral cutaneous branches of the intercostal nerves; while avoiding significant negative hemodynamic effects associated with techniques such as the paravertebral block (PVB), erector spinae plane (ESP) block or its variations, or thoracic epidural analgesia (TEA). A comparative comprehensive overview of the regional techniques described for posterior chest trauma is presented, including TEA, PVB, ESP block, retrolaminar block, mid-point to transverse process block, costotransverse foramen block, RISS, and serratus anterior plane (SAP) block.

Anatomical basis of erector spinae plane block: a dissection and histotopographic pilot study

PurposeErector spinae plane (ESP) block is an interfascial blockade used in different clinical scenarios. This study investigated the ventral extent of dye diffusion in ESP block.MethodsThe ultrasound-guided ESP block was bilaterally performed with an injection at the T5 vertebral level (21-Gauge, 50 mm needle), using diluted black tissue marking dye (20 mL; 1:4 ratio with standard saline solution) instead of local anesthetic on two fresh-frozen corpses within the body donation program of the University of Padova. Subsequently, the gross anatomical dissection was performed by a combined posterior plus anterior approach, and the histotopographic examination completed.ResultsMacroscopically by gross anatomical dissection, the dye spreading ranged on the dorsal side of the chest from T2/3 to T10/11 with an extension up to 10 cm laterally, and on the ventral side of the chest from T2/3–T9/10. Microscopically by histotopographic examination, the dye diffused ventrally to the intercostal spaces (2–3 and 5–6 spaces on the right and left, respectively) by following the blood vessels coupled to the dorsal nerve passing through the costotransverse foramen.ConclusionsThe anterior pathway of dye diffusion from the site of injection within the erector spinae muscle group during an ESP block seems to follow the blood vessels and dorsal rami of spinal nerves, suggesting the passing through the costotransverse foramen to reach the anterior paravertebral space and the intercostal nerves. These findings display an anterior histotopographic diffusion of dye resembling a paravertebral block.

The Novel Costotransverse Foramen Block Technique: Distribution Characteristics of Injectate Compared with Erector Spinae Plane Block

Background: The costotransverse foramen (CTF) is a space continuous with the paravertebral space. We hypothesized that injections passing through the CTF will result in a successful injectate spread to the paravertebral space. Objectives: We investigated patterns of dye spread to assess characteristics of neural blockade following ultrasound-guided CTF and erector spinae plane (ESP) injection in an anatomic and clinical study. Study Design: Prospective cadaveric study, and case studies. Setting: University hospital. Methods: Six soft cadavers were studied. The boundaries of the CTF and the needle pathway of CTF injection were identified in the first cadaver. The CTF and ESP injections were performed on either the left or right sides of the T4 vertebral level in cadavers 2 to 6. Fifteen milliliters of 0.2% methylene blue was injected in each block, and the spread of dye was assessed by anatomic dissection. We also report 2 case studies of CTF and ESP blocks. Results: Cadaver studies of CTF injection demonstrate that with injection to the inferior aspect of the base of the transverse process, the dye mainly passes anteriorly through the CTF into the paravertebral space, with minimal track-back to the deep back muscles. Consistent sensory blockade was achieved in 2 case studies. With the ESP injection, the spread of dye was observed cephalocaudad to the fascia of the erector spinae muscle, with no dye spreading within the paravertebral space in all cadavers. Limitations: Prospective case series. Conclusions: CTF block was consistently associated with a mainly anterior spread of injectate into the paravertebral space that involved the thoracic spinal nerves, and minimal posterior spread of injectate to the deep back muscles. Key words: Thoracic vertebrae, rib cage, paraspinal muscle, nerve block, joints

Rare Bilateral Variation of the Posterior Intercostal Arteries

BackgroundThe thoracic aorta usually gives off the 3rd to 11th pairs of posterior intercostal arteries (PIA) and 1 pair of subcostal arteries. The first two pairs of PIA typically originate via the highest intercostal artery via the costocervical trunk of the subclavian artery. The PIA supply blood to the intercostal spaces, spinal cord and spinal nerve roots.A bilateral branching anomaly in multiple PIA were observed in an 81 year‐old male cadaver during routine dissection. The thoracic aorta gave rise to asymmetrical common PIA trunks at different levels on both sides. Five common PIA trunks were found arising from the thoracic aorta and a descending branch of the right vertebral artery was also observed. Two common PIA trunks were observed on the right side branching from the thoracic aorta. The first common PIA trunk supplied the 4th through 7th intercostal spaces while the second common PIA supplied the 10th and 11th intercostal spaces. The 8th and 9th PIAs were direct branches off the thoracic aorta as normal. Three common PIA trunks were observed on the left side originating from the thoracic aorta. The first common trunk supplied the 3rd through 5th intercostal spaces. The second supplied the 6th and 7th intercostal spaces. The third trunk was observed to supply the 11th intercostal space as well as the subcostal region. Another vascular variation observed included a branch from the right vertebral artery that descended inferiorly and dorsally toward the first four ribs through the right costotransverse foramen. This descending branch of the vertebral artery gave off branches to supply the second, third, and fourth intercostal spaces on the right side. While common trunks of PIA have been reported to be highly prevalent, there are normally 1–2 common trunks found in a typical thorax. Thus, a cadaver that displays up to 5 common trunks of PIA in a singular thorax is a rare occurrence. Also anomalous is the presentation of a direct branch of the vertebral artery that courses dorsal to ribs while supplying several intercostal spaces. Understanding such anomalies has important clinical implications to interventional radiologists during thoracic cavity procedures as well as spine and thoracic surgeries.Support or Funding InformationCenter for Anatomical Science and Education, Department of Surgery, Saint Louis University School of MedicineThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A Cadaveric Study Investigating the Mechanism of Action of Erector Spinae Blockade.

Erector spinae block is an ultrasound-guided interfascial plane block first described in 2016. The objectives of this cadaveric dye injection and dissection study were to simulate an erector spinae block to determine if dye would spread anteriorly to the involve origins of the ventral and dorsal branches of the spinal nerves. In 10 unembalmed human cadavers, 20 mL of 0.25% methylene blue dye was injected bilaterally into the plane between the fifth thoracic transverse process and erector spinae muscle. An in-plane ultrasound-guided technique with the transducer orientated longitudinally was used. During dissection, superficial and deep muscles were identified, and extent of dye spread was documented in cephalocaudal and lateral directions. The ventral and dorsal rami of spinal nerves and dorsal root ganglion at each level were examined to determine if they were stained by dye. There was extensive cephalocaudad and lateral spread of dye deep and superficial to the erector spinae muscles. Except for 1 injection (from 20), the ventral rami were not stained by the dye. In only 2 injections did the dye track posteriorly through the costotransverse foramen to the dorsal root ganglion. In all other cases, the dorsal root ganglia were not involved in the dye injection. The dye stained the dorsal rami posterior to the costotransverse foramen. There was no spread of dye anteriorly to the paravertebral space to involve origins of the ventral and dorsal branches of the thoracic spinal nerves. Dorsal ramus involvement was posterior to the costotransverse foramen.

Right vertebral artery as the fourth branch of the aortic arch

The present report describes an anomalous case of the right vertebral artery arising as the last branch of the aortic arch identified in a 76-year-old Japanese male cadaver during dissection in the anatomical laboratory of Kanazawa Medical University. The aortic arch itself coursed normally but the right vertebral artery was uniquely situated at the fourth branch next to the brachiocephalic artery, the left common carotid artery, and the left subclavian artery. The anomalous right vertebral artery branched into the esophageal branch, the prevertebral branch, and the second right posterior intercostal artery, and finally entered the first costotransverse foramen at the thoracic region as it passed upward through the first to the seventh transverse foramina of the cervical vertebra. The left vertebral artery was normal. The development of the right vertebral artery may be described as follows: (i) the distal portion of the right dorsal aorta, which usually disappears, persisted and became united, via post-costal longitudinal anastomosis; (ii) the right dorsal aorta between the seventh and eighth intersegmental arteries lost its connection to the main structure; and (iii) the fusion of the originally paired dorsal aorta extended around the 11th segment, which was two segments away from the normal portion of the structure.

Factors affecting long-term survival after en-bloc resection of lung cancer invading the chest wall.

Several reports emphasize the importance of en-bloc resection as the optimal surgical treatment of lung cancer with chest wall invasion. We investigated possible factors which could affect long-term survival following radical resection of these tumors. Between 1981 and 1998, 100 patients (90 male; ten female), with a median age of 60 years (36-84), underwent radical en-bloc resection of non-small cell lung cancer (NSCLC) with chest wall involvement. Patients with superior sulcus tumors invading the thoracic inlet were excluded from this series. There were 43 squamous and 57 non-squamous tumors. The median number of resected ribs was three (1-5). Lung resection included 73 lobectomies, two bilobectomies, 18 pneumonectomies and seven segmentectomies. Chest wall resection also extended to the sternum in one patient, the transverse process in one, the costotransverse foramen and hemivertebrae in two. All patients had a complete resection. Sixty-three patients received postoperative radiotherapy and 12 received chemotherapy. Histological data, including differentiation and depth of chest wall invasion, were carefully reviewed. The effect of various factors on survival were studied. There were four in-hospital deaths. Lymph node involvement was negative on surgical specimens in 65 patients, and 28 patients had positive N1 nodes; the final histology revealed seven N2 diseases. Chest wall invasion was limited to the parietal pleura in 29 patients and included intercostal muscles, bones and extrathoracic muscles in 67, 24 and seven cases, respectively. The overall 2-year survival rate was 41%. The 5-year survival for patients with N0, N1 and N2 disease was 22, 9 and 0%, respectively. A local recurrence occurred in 13 patients, with four having a new resection and 45 patients developing systemic metastases. The nodal status (N0-1 vs. N2; P=0. 026) and the number of resected ribs(<2 vs. >2; P=0.03) were survival predictors in univariate analysis. By multivariate analysis, the two independent factors affecting long-term survival were the histological differentiation (well vs. poorly differentiated; P=0. 01) and the depth of chest wall invasion (parietal pleura vs. others; P=0.024). Histological differentiation and depth of chest wall involvement were the main factors affecting long-term survival in this series. The role of induction chemotherapy for tumors with poor prognosis should be investigated.

Management of tumor adherent to the vertebral column

Twelve patients with non-small cell lung cancer had tumors that were adherent to the vertebral column and clinically suspected of invading the bone. All were free of mediastinal node involvement as assessed by pretreatment mediastinoscopy. All received 3000 rads of preoperative radiation followed by en bloc resection of the lung and a tangential portion of the involved vertebral bodies. A complete mediastinal lymphadenectomy was also performed. Three patients had true Pancoast's syndrome and in the remaining nine the tumor was located above T6 with the majority in the apex of the chest. Resectability was based on the absence of tumor extension into the costotransverse foramen and the extent of vertebral body involvement. Detailed studies of the decalcified surgical specimen show that the tumor extended into the cortex in two patients, periosteum in six, parietal in three, and up to the visceral pleura in one. Six patients are alive after 1 to 11 years (four beyond 5 years) without evidence of recurrent tumor and arthritic pain. The overall 5- and 10-year survival rate (Kaplan-Meier method) was 42%. In patients with tumors adherent to the vertebral body and no evidence of roentgenographic erosion, the en bloc removal of the lung and the involved portion of the vertebral body is required for complete excision and is associated with long-term survival without sequelae.

The accessory costotransverse foramen: a radioanatomical study.

One hundred fifty-six anatomical specimens of cervical vertebrae and 55 C1 and 53 C2 vertebrae were examined for the presence of an accessory costotransverse foramen. We also reviewed 60 cervical spine computed tomographic (CT) scans. The variations of the costotransverse and accessory foramen are discussed. The frequency of the latter is 19% in the anatomical specimens and 45% in CT scans. The local anatomy and the excellent visualization on axial transverse CT are stressed.