Thoracic Paravertebral Block
Indications: Commonly used for thoracoabdominal procedures, either open or laparoscopic. Can be done as either a single-shot block or catheter. Unilaterally or bilaterally. TPVB’s and catheters have been used for thoracotomies (TEF, CCAM), cardiopulmonary bypass, renal surgery, pectus repairs, appendectomies, pyloromyotomies, and everything in between. One case report even described the use of a paravertebral catheter for ipsilateral upper extremity T1 coverage.
Special Considerations: Catheters are considered a viable alternative to patients with contraindications to TEA. PVB provides ipsilateral somatic and sympathetic coverage of multiple contiguous thoracic levels without the risk of epidural-related unintentional spinal cord damage. If more than 2-3 dermatomes are needed, multiple injections may be required.
Anatomic Boundaries: The paravertebral space is a wedge-shaped space bounded medially by the vertebral body/intervertebral foramen, anterolaterally by the pleura, and posteriorly by the costotransverse ligaments (though recent evidence suggests that the SCTL is actually porous and may allow posteriorly injected LA to flow into the paravertebral space, à la the MTP block)
Coverage: Ipsilateral somatic and sympathetic of thoracic nerve roots (most sources suggest 2-3 levels for single injection)
Patient Position: Can be performed in the sitting position (if awake and cooperative); if sedated, can be done in either a lateral or prone position. Bear in mind, that your choice of positioning should be determined by your preferred ultrasound probe orientation (transverse vs parasagittal) and preferred needling technique (in-plane vs out-of-plane).
Technique: Probe – Linear; Needle – In-plane or Out-of-plane; Transverse or Parasagittal
Transverse: The probe is placed transversely between the ribs, ideally at the intended thoracic nerve root level to be blocked. The pleura should be identified and the probe advanced medially until the pleura courses anteriorly (visible on the ultrasound as the pleura diving down on the screen). The transverse process may be visualized as an echogenic ledge with and accompanying acoustic shadow (sound waves cannot travel through the bone). Once identified, the needle can be advanced either in-plane or out-of-plane toward the paravertebral space. In our practice, we prefer in-plane. The needle is advanced medially towards the paravertebral space until it is deep to the costotransverse ligament or internal intercostal membrane (if either are visible). After (-) aspiration, LA can be injected. Pleural depression is a telltale visual clue that you’re injecting in the correct location.
Parasagittal: The probe is placed parasagittally, similar to performing an ESP block. After identification of the transverse process (tombstone shaped), the pleura and Superior Costotransverse Ligament (SCTL) should be identified. The “wedge-shaped” paravertebral space is sandwiched between these two structures. After identification of the paravertebral space, advance the needle in-plane until the tip is just anterior to the SCTL (beneath) and posterior the pleura (above). After (-) aspiration, LA solution can be injected. Pleural depression can also be seen when injecting parasagittally confirming you’re injecting in the correct location.
Potential Complications:
Blocks
Intravascular injection or injury
Pneumothorax (0-1%)
In a recent paper by PRAN, they had over 1,085 combined PVB/PVC without a case of PTX
Bleeding / infection at needle insertion site
Horner’s Syndrome
Catheters
Catheter leakage (5.9%)
Dislodgement of catheter (4.9%)
Skin irritation (2.9%)
Catheter occlusion (1.5%)
Minor bleeding (1%)
Seizure (0.18%)
Epidural Hematoma (0.18%)
Patient Positioning, Probe Orientation, and Ultrasound Imaging
Positioning: if cooperative (awake vs sedated)- sitting; if anesthetized, can be done prone vs. in lateral (can do one transverse and the other paramedian from same position for blocks)
Parasagittal
TP: Transverse Process; IIM: Internal Intercostal Muscle; SCTL: Superior Costotransverse Ligament
Transverse
IIM: Internal Intercostal Membrane; EIM: External Intercostal Muscle; TP: Transverse Process
Through the pioneering work of Braun, Finsterer, Pauchet, and Käppis the PCB was thoroughly and comprehensively described over 100 years ago. Yet, it was abandoned. The PVB was considered:
“highly complicated, time consuming and tedious, which would not, in itself, be a disadvantage if anesthesia were not so often incomplete and never produced the type of ‘abdominal silence’ resulting from the use of ether narcosis or spinal anesthesia... Indeed, the patient undergoing an operation under paravertebral nerve block anesthesia may quite properly be regarded as having two operations, the first, paravertebral nerve block, being performed without anesthesia.”
Not exactly mincing words, are they?
Not until 1979, with a paper by Eason and Wyatt, was there a critical reappraisal of the PVB. And while I was able to find at least one abstract describing PVB use in children from 1987, it wasn’t until 1992 that Per-Arne Lönnqvist made another startling leap forward describing continuous paravertebral catheters in children, the youngest only 7 months old!
By now, the effectiveness of the PVB feels firmly established in the minds of contemporary anesthesiologists, and in many cases it is considered to be a viable alternative to TEA for patients undergoing thoracic surgery. Having said that, there is still some work to be done to clarify the volume and number of injections needed for effective analgesia. A paper by Yanovski et al looking at the spread of local in a 10 year old with a PVC found that 10mL of contrast (in addition to a cumulative volume of 13mL of LA or 0.575 mL/kg) spread from T4-T5 to T10-T11. While studied in adults, Termpornlert et al looked at contrast spread in three different catheter approaches: intercostal transverse-in-plane (IC), transverse process sagittal out-of-plane (TS), and paralaminar in-plane (PL). They found that the catheter tip was found at a different thoracic vertebral level from the intended level of needle insertion in 50%, 10% and 50% of patients using the IC, TS and PL approaches, respectively. After injection of 10mL of contrast, they also found variability in the number of vertebral levels with visible spread, though there was a weak correlation between visible dye spread and sensory loss. While there were discernible differences in visible spread and sensory loss, none were statistically significantly. Furthermore, this was a very small study so it may be hard to draw any definitive conclusions about the ideal approach.
A recent study by Seidel et al looked at injection techniques for cadaveric single-shot PVBs—landmark vs two USG techniques (transverse vs sagittal). They also looked at two different injectate volumes: 10 vs 20 mL of solution. They found that the spread of the injectate in single-shot TPVBs is volume-dependent, spreading cranio-caudally, laterally (intercostal), and medially (into the epidural space), though they found that the craniocaudal spread is not predictable. While this has not been studied explicitly in children since the routine use of ultrasound, Lönnqvist et al found that 0.25ml/kg of injected radio-opaque dye was found to cover 5.7 segments via a landmark technique. As such, they recommended an initial bolus dose of 0.5 ml/kg of LA to reliably cover at least five segments. With the advent of ultrasound, and with most blocks now done under GA, injecting smaller volumes at more specific locations may be preferred for a more exacting and consistent spread. A paper from 2016 by Naja et al came to the same relative conclusion.
A recent meta-analysis by Page et al looked at the effectiveness of PVB in abdominal procedures. They included six trials for a total of 358 patients for various common pediatric abdominal procedures. They looked at pain scores, rescue analgesia, and adverse events compared to other regional anesthetic alternatives, such as local injection, ilioinguinal nerve block, caudals and epidurals. While the patients with PVB had only minimally improved pain scores, there were less patients in the PVB group requiring rescue analgesics. Both parental and surgeon satisfaction scores were also higher in the PVB group. It was hypothesized that perhaps the lack of lower motor weakness (unlike a caudal or epidural), coupled with the slightly longer pain relief might explain the parental satisfaction. As for the surgeons, though the PVB takes longer than most alternatives and might delay surgery, it may be that parental satisfaction might have been an influence in their overall satisfaction.
In summary, PVB/PVC are a reliable, relatively safe regional technique that offers significant pain relief comparable to neuraxial techniques without risk of spinal injury or lower extremity weakness.
Thompson, M.E. and Haynes, B., 2015. Ultrasound-guided thoracic paravertebral block catheter experience in 2 neonates. Journal of clinical anesthesia, 27(6), pp.514-516.
Clermidi, P., Bellon, M., Skhiri, A., Jaby, O., Vitoux, C., Peuchmaur, M. and Bonnard, A., 2017. Fast track pediatric thoracic surgery: Toward day-case surgery?. Journal of pediatric surgery, 52(11), pp.1800-1805.
El Shora, H.A., El Beleehy, A.A., Abdelwahab, A.A., Ali, G.A., Omran, T.E., Hassan, E.A. and Arafat, A.A., 2020. Bilateral paravertebral block versus thoracic epidural analgesia for pain control post-cardiac surgery: a randomized controlled trial. The Thoracic and cardiovascular surgeon, 68(05), pp.409-415.
Narasimhan, P., Kashyap, L., Mohan, V.K., Arora, M.K., Shende, D., Srinivas, M., Kashyap, S., Nath, S. and Khanna, P., 2019. Comparison of caudal epidural block with paravertebral block for renal surgeries in pediatric patients: A prospective randomised, blinded clinical trial. Journal of clinical anesthesia, 52, pp.105-110.
Loftus, P.D., Elder, C.T., Russell, K.W., Spanos, S.P., Barnhart, D.C., Scaife, E.R., Skarda, D.E., Rollins, M.D. and Meyers, R.L., 2016. Paravertebral regional blocks decrease length of stay following surgery for pectus excavatum in children. Journal of pediatric surgery, 51(1), pp.149-153.
Splinter, W.M. and Thomson, M.E., 2010. Somatic paravertebral block decreases opioid requirements in children undergoing appendectomy. Canadian Journal of Anesthesia/Journal canadien d'anesthésie, 57(3), pp.206-210.
Mata-Gómez, J., Guerrero-Domínguez, R., García-Santigosa, M. and Ontanilla, A., 2015. Ultrasound-guided paravertebral block for pyloromyotomy in 3 neonates with congenital hypertrophic pyloric stenosis. Revista brasileira de anestesiologia, 65, pp.302-305.
Salviz, E.A., Akman, N., Sivrikoz, N., Demir, K., Aydin, A. and Tuğrul, K.M., 2015. An exceptional indication for bilateral thoracic paravertebral block performance in a pediatric patient. Agri, 27(3), pp.168-169.
Cho, T.H., Kim, S.H., Jehoon, O., Kwon, H.J., Kim, K.W. and Yang, H.M., 2021. Anatomy of the thoracic paravertebral space: 3D micro-CT findings and their clinical implications for nerve blockade. Regional Anesthesia & Pain Medicine.
Costache I, de Neumann L, Ramnanan CJ, Goodwin SL, Pawa A, Abdallah FW, McCartney CJL. The mid-point transverse process to pleura (MTP) block: a new end-point for thoracic paravertebral block. Anaesthesia. 2017 Oct;72(10):1230-1236. doi: 10.1111/anae.14004. Epub 2017 Aug 1. PMID: 28762464.
Vecchione, T., Zurakowski, D. and Boretsky, K., 2016. Thoracic paravertebral nerve blocks in pediatric patients: safety and clinical experience. Anesthesia & Analgesia, 123(6), pp.1588-1590.
Walker, B.J., Long, J.B., Sathyamoorthy, M., Birstler, J., Wolf, C., Bosenberg, A.T., Flack, S.H., Krane, E.J., Sethna, N.F., Suresh, S. and Taenzer, A.H., 2018. Complications in pediatric regional anesthesia: an analysis of more than 100,000 blocks from the pediatric regional anesthesia network. Anesthesiology, 129(4), pp.721-732.
Meeker, W.R., 1925. Splanchnic Anesthesia: An Analysis of Forty-Two Cases. Archives of Surgery, 10(2), pp.699-719.
Eason, M.J. and Wyatt, R., 1979. Paravertebral thoracic block—a reappraisal. Anaesthesia, 34(7), pp.638-642.
Gilbert, J., 1987. THORACIC PARAVERTEBRAL BLOCK-A METHOD OF PAIN CONTROL. Critical Care Medicine, 15(4), p.445.
Lönnqvist, P.A., 1992. Continuous paravertebral block in children: initial experience. Anaesthesia, 47(7), pp.607-609.
Yanovski, B., Gat, M., Gaitini, L. and Ben-David, B., 2013. Pediatric thoracic paravertebral block: roentgenologic evidence for extensive dermatomal coverage. Journal of clinical anesthesia, 25(3), pp.214-216.
Termpornlert, S., Sakura, S., Aoyama, Y., Wittayapairoj, A., Kishimoto, K. and Saito, Y., 2020. Distribution of injectate administered through a catheter inserted by three different approaches to ultrasound-guided thoracic paravertebral block: a prospective observational study. Regional Anesthesia & Pain Medicine, 45(11), pp.866-871.
Seidel, R., Wree, A. and Schulze, M., 2020. Thoracic-paravertebral blocks: comparative anatomical study with different injection techniques and volumes. Regional Anesthesia & Pain Medicine, 45(2), pp.102-106.
Lönnqvist, P.A. and Hesser, U., 1993. Radiological and clinical distribution of thoracic paravertebral blockade in infants and children. Pediatric Anesthesia, 3(2), pp.83-87.
Naja, Z.M., El-Rajab, M., Al-Tannir, M.A., Ziade, F.M., Tayara, K., Younes, F. and Lönnqvist, P.A., 2006. Thoracic paravertebral block: influence of the number of injections. Regional Anesthesia & Pain Medicine, 31(3), pp.196-201.
Page, E.A. and Taylor, K.L., 2017. Paravertebral block in paediatric abdominal surgery—a systematic review and meta-analysis of randomized trials. BJA: British Journal of Anaesthesia, 118(2), pp.159-166.