Cop

Eur J Anaesthesiol 2014; 31:305309yr

Fro

CoTe

02ORIGINAL ARTICLESpread of dye after single thoracolumbar paravertebralinjection in infants

A cadaveric study

Andrew A. Albokrinov and Ulbolgan A. FesenkoBACKGROUND Thoracolumbar paravertebral block (PVB)is one method of providing regional anaesthesia for abdomi-nal wall surgery in children. It is common practice whenperforming a PVB for abdominal wall anaesthesia to injecta certain volume of local anaesthetic solution in the para-vertebral space at several levels. This increases the durationof the procedure and makes it more invasive.

OBJECTIVES To determine the character of dye spreadin infants paravertebral space, to check the feasibility ofsingle injection PVB and to determine the optimal volume ofinjectate necessary to cover the paravertebral segmentsresponsible for sensation of the lower abdomen.

DESIGN Experimental study.

SETTING Single centre, University Hospital, April 2013 toAugust 2013.

SUBJECTS Twenty infant cadavers.

INTERVENTION Ultrasound-guided, single thoracolumbarparavertebral injections were performed on infant cadavers.

MAIN OUTCOME MEASURE The total number of para-vertebral segments stained after dye injection and specificight European Society of Anaesthesiology. U

This article is accompanied by the following Invited Com

Lonnqvist P-A, Bosenberg AT. Anatomical dissections are ninformation for regional anaesthesia. Eur J Anaesthesiol 20

m the Regional Childrens Clinic Hospital, Lviv, Ukraine

rrespondence to Andrew A. Albokrinov, MD, Department of Anesthesia and Intensivl: +380672867103; e-mail: albokrinov@mail.ru

65-0215 2014 Copyright European Society of Anaesthesiologyvertebral levels of cephalad and caudad spread of dye in theparavertebral space.

RESULTS Dye was present in the paravertebral spaces ofall cadavers. Spread of dye within the paravertebral spacewas different depending on dye volume. Strong correlationwas found between the volume of injectate and the numberof paravertebral segments involved. The number of spinalnerve roots surrounded with dye corresponded with thenumber of paravertebral segments involved. T11, T12 andL1 nerve roots were stained in all cadavers. The optimalinjectate volume to involve T10-L1 segments was defined as0.2 to 0.3 ml kg1.

CONCLUSION Single thoracolumbar paravertebral injectionat T12-L1 level leads to caudad and cephalad spreadof injectate in a dose-dependent manner. Single injectionthoracolumbar paravertebral injections could be performedfor lower abdomen anaesthesia in infants. We suggestthat a single injection of 0.2 to 0.3 ml kg1 of local anaes-thetic in the thoracolumbar paravertebral space couldprovide adequate coverage of the dermatomes of the lowerabdomen.

Published online 18 March 2014Introduction

Regional anaesthesia for lower abdominal incisions (suchas open inguinal hernia repair, hydrocoele repair, openappendicectomy, open varicocele repair, orchidopexy)can be achieved with spinal, epidural or peripheralregional blocks, such as ilioinguinal-iliohypogastric,transversus abdominis plane (TAP) and thoracolumbarparavertebral block (PVB). Peripheral regional blocksare often the technique of choice in paediatric patientsnauthorized reproduction of this article is prohibited.

mentary:

ot obsolete. Cadaver studies can still provide important14; 31:303304.

e Care, Regional Childrens Clinic Hospital, 79008, Lysenka Str. 31, Lviv, Ukraine

DOI:10.1097/EJA.0000000000000071

mailto:albokrinov@mail.ruhttp://dx.doi.org/10.1097/EJA.0000000000000071

Copyr

306 Albokrinov and Fesenko

Fig. 1

Ultrasound probe and needle position during thoracolumbarparavertebral injection in an infant cadaver.because of the lower incidence of complications ascompared with neuraxial methods,13 and the avoidanceof adverse events such as hypotension and urinaryretention.47 Data from the scientific literature showthat PVB for anaesthesia of the lower abdomenis more effective and reliable than TAP block8 andilioinguinal-iliohypogastric nerve block.9

The safety and efficacy of PVB was demonstrated ina meta-analysis examining thoracic PVB, which showed acomparable analgesic effect and a better complicationprofile of PVB as compared with epidural anaesthesia,6

as well as in reports focusing on PVB for abdominal wallanaesthesia.3,10

It is common practice when performing a PVB forabdominal wall anaesthesia to inject a certain volumeof local anaesthetic solution into the paravertebralspace at several levels in order to achieve anaesthesiaof the corresponding dermatomes.4,1113 There are anumber of scientific publications however, showing theclinical efficacy of a single injection thoracic PVB14 andthe possibility of local anaesthetic solution spread notonly between thoracic segments of the paravertebralspace, but also between thoracic and lumbar para-vertebral spaces.1518 There are data on the spread oflocal anaesthetics when performing thoracic PVB in bothadults6,1822 and children,23 but the nature of spread oflocal anaesthetic or injectate as part of a single injectionthoracolumbar PVB has not yet been studied.

The aim of this study was to determine the patternof injectate spread in infants paravertebral spaces, tocheck the feasibility of a single injection for PVB andto determine the optimal volume of injectate necessaryto cover the paravertebral segments responsible forsensation of lower abdomen.

MethodsApproval was obtained from the Lviv RegionalChildrens Hospital Ethics Committee (Protocol #3,dated April 4, 2013, chairperson O. Burda, MD, PhD).Consent was obtained from the parents of all participantsfor dye injection and autopsy, including soft tissuedissection, but excluding dissection of spine. The studywas conducted using 20 fresh, unembalmed infantcadavers including 12 males and eight females [medianage at death 7 months (range 1 to 13 months), medianbody mass 4550 g (range 2100 to 8100 g)]. Cadavers weredivided into five equal groups, depending on the amountof dye injected into paravertebral space (0.1, 0.2, 0.3, 0.4,and 0.5 ml kg1). Unilateral injection of dye into theparavertebral space was performed prior to cadavericdissection. The vertebral level was estimated bypalpation of C7 spinous process and counting caudally.The PVB was performed under ultrasound guidanceusing a 5 to 10 MHz linear-array probe (SonoSite Titan;ight European Society of Anaesthesiology. UnEur J Anaesthesiol 2014; 31:305309SonoSite Inc., Washington, USA). The thoracolumbararea was scanned with the cadaver in the prone positionand the probe located in the transverse axis. The trans-verse process of the T12 vertebra and the psoas musclewere identified. A 10 cm, 20-gauge Quincke spinal needle(Becton-Dickinson, New Jersey, USA) was insertedlaterally to the probe. The needle was advanced using atransverse, in-plane visualisation technique in alateromedial direction until the needle tip appearedbetween the transverse process and dorsal aspect of thepsoas muscle. At that point, a single shot of methylene bluedye 1% in distilled water was injected (Figs 1 and 2).

After dissection of the cadaver and removal of viscera, thespread of dye within the paravertebral space was studied.The primary outcome of the study was the total numberof paravertebral segments stained after dye injection andthe specific vertebral levels of cephalad and caudadspread of dye within the paravertebral space. Other datacollected included the spread of dye to the intercostalspaces, anterior to the vertebral bodies and contralateralparavertebral space.

Statistical analysis was performed using STATISTICA6.0 software (StatSoft Inc., Tulsa, USA). Pearsonscorrelation coefficient was calculated for the amountof dye injected and the stained segments of the para-verbetral space, anterior dye spread and contralateraldye spread.authorized reproduction of this article is prohibited.

Cop

Spread of dye after single thoracolumbar paravertebral injection 307

Fig. 2

Ultrasound image of thoracolumbar paravertebral injection. N, needle;SP, spinous process; TP, tranverse process.ResultsAll 20 cadavers were examined. The transverse processesof T12 vertebra and the psoas muscles were locatedultrasonographically in all cases. Dye was present inthe paravertebral spaces of all cadavers. The numberof nerve roots, sympathetic ganglia and rami communi-cantes stained with dye correlated with injected volume.A typical picture of the observed dye spread is shownin Fig. 3.

Both cephalad and caudad spread of dye was observedin all cadavers. Cephalad spread was associated withthoracic spinal nerve root and intercostal space stain-ing. Caudad spread was associated with lumbar plexusnerve root and dorsal surface of psoas muscle staining.yright European Society of Anaesthesiology. U

Fig. 3

Th12ContralateralPVS spread

Anterior spread

Intercostalspread

Th12 NRL1 NRL2 NR

Psoas

Spread of dye after thoracolumbar (T12-L1) paravertebral injectate0.3 ml kg1 with psoas muscle dissected. NR, nerve root; PVS,paravertebral space.Strong correlation was found between the volume of dyeinjected and the extent of its cephalad and caudad spread(r 0.97, P< 0.05). The extent of paravertebral spacestaining in relation to injectate volume is shown in Fig. 4.

The number of spinal nerve roots surrounded with dyecorresponded to the number of paravertebral segmentsinvolved. T11, T12 and L1 nerve roots were stainedin all cases. Both anterior and contralateral spread ofdye was observed, with an incidence correlating withdye volume (r 0.88 and 0.89, respectively, P< 0.05).Dye was present in the intercostal spaces in all cases.The level of intercostal spread corresponded to the levelof thoracic paravertebral space spread (Table 1).

DiscussionThere are controversies in the scientific literature aboutthe anatomy of the paravertebral space, the possibility ofinjectate spread between thoracic and lumbar para-vertebral spaces, and the number of injections neededto achieve adequate anaesthesia of the abdominal wall.Several studies advocate multiple injection techniques inPVB for thoracic and abdominal wall anaesthesia basedon clinical and radiographic signs of superior distributionof local anaesthetic.3,13,24

Lonnqvist and Hildingsson25 described the T12 vertebralbody and transverse processes as the caudal boundaryof the thoracic paravertebral space and insisted thatlocal anaesthetic solution cannot spread caudally tothe T12-L1 intervertebral disc due to the origin of thepsoas muscle. Several studies, however, describe theconnection of thoracic and lumbar paravertebral spaces.Thoracolumbar spread of injectate via the medial andlateral arcuate ligaments of the diaphragm to theretroperitoneal space in relation to the anterior surfaceof the psoas major and quadratus lumborum muscles wasobserved by Saito et al.2628 The authors suggest that inthis case, local anaesthetic effects may occur becauseof blockade of peripheral nerves originating from thelumbar plexus rather than blockade of spinal nerve roots.Tighe et al.29 noted that the endothoracic fascia dividesthe paravertebral space into two compartments: anteriorsubserous (extrapleural) and subendothoracic. As itcontinues inferiorly it runs with the fascia transversalisof the abdomen dorsal to the diaphragm through themedial and lateral arcuate ligaments and the aortic hiatus.Batra et al.30 hypothesised that this endothoracic fasciacould be the anatomical basis for thoracolumbar injectatespread. The authors believe that injection of local anaes-thetic in the lower thoracic paravertebral space posteriorto the endothoracic fascia can lead to its spread inferiorlythrough the medial and lateral arcuate ligaments to theretroperitoneal space behind the fascia transversalis,where the lumbar spinal nerves lie.

The results of our study show that the thoracic and lumbarparavertebral spaces in infants are anatomically connectednauthorized reproduction of this article is prohibited.Eur J Anaesthesiol 2014; 31:305309

Copyr

308 Albokrinov and Fesenko

Fig. 4

0.1

L5

L4

L3

L2

L1

Th12

Th11

Th10

Th9

Th8

Th7

Th6

0.2 0.3 0.4 0.5 ml/kg

The extent of paravertebral space staining in relation to injectate volume. Values shown are median (range).despite the presence of borders such as the origin of thepsoas muscle (from vertebral bodies, lateral aspects of discsbetween them and transverse processes of T12-L5).25,31

Taking into account the fact that T10-L1 spinal nerveroots must be blocked to provide analgesia for lowerabdominal surgery and based on the spread of dye withinthe paravertebral space after a single PVB injectionat T12-L1, our study suggests that 0.2 to 0.3 ml kg1 oflocal anaesthetic solution would provide adequate spreadwithin the paravertebral space. Larger doses of localanaesthetic or a PVB at a more cephalad level, may beconsidered for regional anaesthesia for unilateral upperabdominal surgery.

The study by Lonnqvist and Hesser32 that included18 paediatric patients, suggested 0.5 ml kg1 of local anaes-thetic as an optimal dose to cover at least five thoracicparavertebral segments. Our results show that smallerdoses of 0.2 and 0.3 ml kg1 were sufficient in all casesto cover five and six thoracolumbar segments, respectively.This discrepancy in suggested dosing may be because ofthe possible peculiarities of injectate spread in differentight European Society of Anaesthesiology. Un

Table 1 Spread of dye in the paravertebral space, intercostal spaces, anspace

0.1 ml kgS1 0.2 ml kgS1 0.3 ml k

Median (range) number ofsegments of paravertebralspace stained

3.0 (3 to 4) 5.5 (5 to 6) 6.0 (6 t

Unilateral intercostal spread (%) 100 100 100Anterior spread (%) 50 75 100Contralateral paravertebral

space spread (%)0 25 25

Eur J Anaesthesiol 2014; 31:305309age groups (neonates versus infants), because of differentcontrast media (dye versus radiopaque contrast) or becauseof bias from the small number of patients in our study.

The anatomical connection between the thoracic para-vertebral and intercostal spaces and the extensive spreadof dye to these spaces after PVB was shown by Cowieet al.16 and Burns et al.33 We also observed dye spreadfrom paravertebral to intercostal spaces in all cases.Spread of injectate anterior to the vertebra is describedby Lonnqvist and Hesser,32 Cowie et al.16 and Karmakaret al.18 and our data support their findings. Injectatespread to the contralateral paravertebral space is shownby Lonnqvist and Hesser,32 in a case report of Karmakaret al.34 and by Gadsden et al.35 Our study supports thesedata and suggests that the incidence of contralateraldye spread is volume dependent and that a bilateralblock may be possible, especially when using highvolumes of local anaesthetic.

Epidural spread of local anaesthetic through the inter-vertebral foraminae was also observed by Richardsonand Lonnqvist.2 Some authors describe an incidenceauthorized reproduction of this article is prohibited.

terior surface of vertebral column and in contralateral paravertebral

gS1 0.4 ml kgS1 0.5 ml kgS1

Pearsonscorrelation

coefficient (r) P value

o 7) 7.0 (6 to 8) 8.0 (712) 0.97

Cop

Spread of dye after single thoracolumbar paravertebral injection 309of epidural injectate spread of up to 40% after thoracicPVB in adults.16,35 It is unclear whether contralateralparavertebral dye spread in infants occurs throughthe epidural space or across the anterior surface ofvertebral column, or both. We were unable to examinethis aspect because of a lack of parental consent forspine dissection.

Data on paravertebral injectate spread in childrenand adolescents must be obtained to find out the natureof dye spread in these age groups and the feasibilityof performing single injection thoracolumbar PVB foranaesthesia of the abdomen.

Thoracolumbar PVB at T12-L1 in infant cadavers leadsto caudad and cephalad dye spread in a dose-dependentmanner. Single injection thoracolumbar paravertebralblockade could be performed to provide regionalanaesthesia of the lower abdomen in infants. This studysuggests that a single injection of 0.2 to 0.3 ml kg1 oflocal anaesthetic in the thoracolumbar paravertebralspace could provide adequate coverage of the derma-tomes of the lower abdomen.

Acknowledgements relating to this articleAssistance with the article: none.

Financial support and sponsorship: none.

Conflicts of interest: none.

Presentation: none.

References1 Ecoffey C, Lacroix F, Giaufre E, et al. Epidemiology and morbidity of

regional anesthesia in children: a follow-up one-year prospective surveyof the French-Language Society of Paediatric Anaesthesiologists(ADARPEF). Paediatr Anaesth 2010; 20:10611069.

2 Richardson J, Lonnqvist PA. Thoracic paravertebral block. Br J Anaesth1998; 81:230238.

3 Eck JB, Cantos-Gustafsson A, Ross AK, Lonnqvist PA. Whats new inpediatric paravertebral analgesia. Techn Reg An Pain Manag 2002;6:131135.

4 Naja ZM, Hassan MJ, Oweidat M, et al. Paravertebral blockade vs generalanesthesia or spinal anesthesia for inguinal hernia repair. Middle East JAnesthesiol 2001; 16:201210.

5 Akcaboy EY, Akcaboy ZN, Baydar M, Gogus N. Ambulatory inguinal herniarepair: paravertebral block versus spinal anesthesia. Reg Anesth Pain Med2007; 32:31.

6 Davies RG, Myles PS, Graham JM. A comparison of the analgesic efficacyand side-effects of paravertebral vs epidural blockade for thoracotomy:a systematic review and meta-analysis of randomized trials. Br J Anaesth2006; 96:418426.

7 Jankovic Z. Transversus abdominis plane block: the Holy Grail ofanaesthesia for (lower) abdominal surgery. Period biol 2009; 111:203208.

8 Melnikov AL, Bjoergo S, Kongsgaard UE. Thoracic paravertebral blockversus transversus abdominis plane block in major gynecological surgery:a prospective, randomized, controlled, observer-blinded study. Local RegAnesth 2012; 5:5561.

9 Naja ZM, Raf M, El-Rajab M, et al. A comparison of nerve stimulator guidedparavertebral block and ilio-inguinal nerve block for analgesia after inguinalherniorrhaphy in children. Anaesthesia 2006; 61:10641068.yright European Society of Anaesthesiology. U10 Lonnqvist PA, MacKenzie J, Soni AK, et al. Paravertebral blockade failurerate and complications. Anaesthesia 1995; 50:813815.

11 Hadzic A. Textbook of regional anesthesia and acute pain management,1st ed. New York: McGraw-Hill Professional; 2006; Chapter 43. Thoracic& Lumbar Paravertebral Block.

12 Naja ZM, Raf M, El-Rajab M, et al. Nerve stimulator-guided paravertebralblockade combined with sevoflurane sedation versus general anesthesiawith systemic analgesia for postherniorrhaphy pain relief in children.Anesthesiology 2005; 103:600605.

13 Ozkan D, Akkaya T, Comert A, et al. Paravertebral block in inguinal herniasurgeries: two segments or 4 segments? Reg Anesth Pain Med 2009;34:312315.

14 Kaya FN, Turker G, Mogol EB, Bayraktar S. Thoracic paravertebral blockfor video-assisted thoracoscopic surgery: single injection versus multipleinjections. J Cardiothorac Vasc Anesth 2012; 26:9094.

15 Berta E, Spanhel J, Gabrhelik T, Lonnqvist PA. Paraverteral block inchildren. Tech Reg Anesth Pain Manag 2007; 11:247254.

16 Cowie B, McGlade D, Ivanusic J, Barrington MJ. Ultrasound-guidedthoracic paravertebral blockade: a cadaveric study. Anesth Analg 2010;110:17351739.

17 Eid HEA. Paravertebral block: an overview. Curr Anaesth Crit Care 2009;20:6570.

18 Karmakar MK, Gin T, Ho AM. Ipsilateral thoraco-lumbar anaesthesia andparavertebral spread after low thoracic paravertebral injection. Br JAnaesth 2001; 87:312316.

19 Cheema S, Ilsley D, Richardson J, Sabanathan S. A thermographic study ofparavertebral analgesia. Anaesthesia 1995; 50:118121.

20 Cheema S, Richardson J, McGurgan P. Factors affecting the spread ofbupivacaine in the adult thoracic paravertebral space. Anaesthesia 2003;58:684711.

21 Naja MZ, Ziade MF, El Rajab M, et al. Varying anatomical injection pointswithin the thoracic paravertebral space: effect on spread of solution andnerve blockade. Anaesthesia 2004; 59:459463.

22 Saito T, Den S, Cheema SP, et al. A single-injection, multisegmentalparavertebral block extension of somatosensory and sympathetic block involunteers. Acta Anaesthesiol Scand 2001; 45:3033.

23 Lonnqvist PA. Plasma concentration of lignocaine after thoracicparavertebral blockade in infants and children. Anaesthesia 1993;48:958960.

24 Naja ZM, El-Rajab M, Al-Tannir MA, et al. Thoracic paravertebral block:influence of the number of injections. Reg Anesth Pain Med 2006;31:196201.

25 Lonnqvist PA, Hildingsson U. The caudal boundary of the thoracicparavertebral space. A study in human cadavers. Anaesthesia 1992;47:10511052.

26 Saito T, Den S, Tanuma K, et al. Anatomical bases for paravertebralanesthetic block: fluid communication between the thoracic and lumbarparavertebral regions. Surg Radiol Anat 1999; 21:359363.

27 Saito T, Gallagher ET, Yamada K, et al. Broad unilateral analgesia.Reg Anesth 1994; 19:360361.

28 Saito T, Gallagher ET, Cutler S, et al. Extended unilateral anesthesia. Newtechnique or paravertebral anesthesia? Reg Anesth 1996; 21:304307.

29 Tighe SQ, Greene MD, Rajadurai N. Paravertebral block. Contin EducAnaesth Crit Care Pain 2010; 10:133137.

30 Batra RK, Krishnan K, Agarwal A. Paravertebral block. J Anaesth ClinPharmacol 2011; 27:511.

31 Mannion S, Barrett J, Kelly D, et al. A description of the spread of injectateafter psoas compartment block using magnetic resonance imaging.Reg Anesth Pain Med 2005; 30:567571.

32 Lonnqvist PA, Hesser U. Radiological and clinical distribution of thoracicparavertebral blockade in infants and children. Pediatr Anesth 1993;3:8387.

33 Burns DA, Ben-David B, Chelly JE, Greensmith JE. Intercostally placedparavertebral catheterization: an alternative approach to continuousparavertebral blockade. Anesth Analg 2008; 107:339341.

34 Karmakar MK, Kwok WH, Kew J. Thoracic paravertebral block: radiologicalevidence of contralateral spread anterior to the vertebral bodies. Br JAnaesth 2000; 84:263265.

35 Gadsden JC, Lindenmuth DM, Hadzic A, et al. Lumbar plexus block usinghigh-pressure injection leads to contralateral and epidural spread.Anesthesiology 2008; 109:683688.nauthorized reproduction of this article is prohibited.Eur J Anaesthesiol 2014; 31:305309

Spread of dye after single thoracolumbar paravertebral injection ininfantsIntroductionMethodsResultsDiscussionAcknowledgements relating to this article

References