Welcome to Correspondence Sign in | Join | Help

Serratus-intercostal Plane block. An encouraging approach for breast surgery

Last post 26 Sep 2013, 9:55 PM by Rafael Blanco. 1 replies.
To submit a new response, please Register or Sign in.
Sort Letters: Previous Next
  •  30 Aug 2013, 11:41 PM 1463

    Serratus-intercostal Plane block. An encouraging approach for breast surgery

    Attachment: perezFIGURE1A.jpg

    We read with interest the article by Blanco et al regarding serratus plane block [1] and agree that this is a novel technique. This technique was first described by Fajardo et al at the ESRA Spain Congress 2012 and published in September 2012 [2].

    In 2013 our group published a new ultrasound-guided technique to block the cutaneous branches of the intercostal nerves, injecting local anaesthetic (LA) between serratus anterior (SAM) and external intercostal (EIM) muscles in the mid axillary line [3]. In April 2013 Dieguez et al [4] conducted a prospective observational study in 30 patients scheduled for non-reconstructive breast and axilla surgery.

    We have been performing this block injection for more than three years in a total of 115 patients and prefer to call it Serratus-intercostal plane block (SIFP) because the LA is placed into the fascial plane between SAM and EIM. These offer several advantages over the Blanco approach. These techniques are relatively simple to perform, and may be associated with a lower risk of complications.

    To perform the anterior ultrasound approach, we place the linear probe below the outer third of the clavicle, similar to Fajardo´s Pec´s approach [5]. We identify in the surface plane the pectoralis muscles, the thoraco-acromial artery and cephalic vein, between both muscles, in the deep plane identifying SAM resting on the ribs. We introduce the block needle in plane from medial to lateral, and place the tip of needle between SAM and EIM. A test bolus is then real-time injected to determine the correct position of the tip needle within the serratus-intercostal fascial plane. The injection usually consists of 0,4ml/kg of levobupivacaine 0.375% plus adrenaline 1.200. 000 (5ug/ml). It’s sufficient to fill this fascial plane for an effective blockade of several cutaneous branches of intercostal nerves with minimal risk of toxic effects.

    To perform the lateral approach, we place the probe in the mid-axillary line at level of the 6th intercostal space. In the surface plane we identify the subcutaneous tissue and SAM, in the intermediate plane the intercostal muscles (external, internal and intimate) and in the deep plane ribs, pleura and lung. From caudal to cranial, an in-plane approach, the block needle is inserted until the tip is placed between SAM and IEM and the LA injection is visualized in real-time

    There are some aspects that we would like to highlight in Blanco et al's study. Firstly it was conducted in only 4 volunteers, there is no clinical data to support this technique and these volunteers were not properly monitored (electrocardiogram, NIBP, oxygen saturation). Intravenous access was not established prior blockade. The serratus block results in high systemic absorption of local anaesthetic and we always use LA solution plus adrenaline to reduce systemic absorption. Secondly, it´s unclear as to the amounts of LA injected above and below the serratus muscle. It´s striking that all volunteers showed the same dermatome distribution of sensory loss after LA injection in two different fascial planes. We think that this new block technique is dependent on volume of injectate. We recommend that LA is injected below the serratus muscle for two reasons; i) for greater spread within the serratus-intercostal plane caudally because the injection is located within a little neurovascular space between the SAM and EIM ('sliding space') which is poorly distensible and in which run the perforating lateral intercostal cutaneous branches, and respiratory movements allow the LA to be dispersed along the space, ii) the location of the long thoracic nerve (LTN); this is a pure motor nerve to SAM and may be injured in axillary dissection during surgery, causing winged scapula syndrome, and injecting LA at the level described by Blanco et al may produce temporary palsy of the LTN. We believe this is not an objective but an adverse effect that we can avoid by performing the injection below the SAM..

    We wonder why Blanco et al have changed the Pec´s Block II description [5] from one in which there is one injection of levobupivacaine 0.25% (10ml) between the pectoral muscles and a second 20 ml under pectoralis minor muscle above the SAM.  In this new Pec´s block II description they describe another injection below the SAM.

    Another striking thing regarding Pec´s Block II is that Blanco et al [6] note that the analgesia onset was three minutes on average, and lasted for 8 hours (480 min) however in this paper using levobupivacaine 0.125% the duration of the sensory loss was relatively higher than the Pec´s Block II (270-840 min). Using 0,4 ml/kg of levobupivacaine 0.375% the onset times in our patients are three minutes and lasts about 16 hrs. We have observed in awake patient entire sensory loss over the breast tissue in about 13 minutes.

    In conclusion, we think that this technique could become an effective alternative to paravertebral blocks or thoracic epidurals, is feasible, safe and results in a low complication rate. A single injection blocks many dermatomes at once. More randomised studies are required.


    M. Fajardo Pérez

    P. Alfaro de la Torre

    Hospital Universitario del Tajo, Aranjuez,



    S. López 

    Hospital Abente y Lago. Complexo Hospitalario Universitario A Coruña.


    F.J. Garcia

    Hospital General de Segovia



    Email: mfajadoperez@yahoo.es

    No external funding and no competing interests declared.


    1. Blanco R, Parras T, McDonnell JG, Prats-Galino, A. (2013), Serratus plane block: a novel ultrasound-guided thoracic wall nerve block. Anaesthesia. doi: 10.1111/anae.12344
    2. Fajardo M, García FJ, López S, Diéguez P, Alfaro P. Analgesic combined lateral and anterior cutaneous branches of the intercostal nerves ultrasound block in ambulatory breast surgery. Cirugia Mayor Ambulatoria 2012; 17: 95-104.
    3. Fajardo M, López S, Diéguez P, Alfaro P, García FJ. A new ultrasound-guided cutaneous intercostal branches nerves block for analgesia after non-reconstructive breast surgery. Cirugia Mayor Ambulatoria 2013; 18: 3-6.
    4. Diéguez P, Fajardo M, López S, Alfaro P, Pensado A. Ultrasound-assisted approach to blocking the intercostal nerves in the mid-axillary line for non-reconstructive breast and axilla surgery. Revista Espanola de Anestesiologia Reanimacion 2013 Jun 3. pii: S0034-9356(13)00094-7. doi: 10.1016/j.redar.2013.04.002
    5. Pérez MF, Migue JG, de la Torre PA.A new approach to pectoralis block. Anaesthesia 2013; 68: 430.
    6. Blanco R, Fajardo M, Parras Maldonado T. Ultrasound description of Pecs II (modified Pecs I): a novel approach to breast surgery. Revista Espanola de Anestesiologia Reanimacion 2012; 59: 470–5.




    Figure. A) patient in position.B) Ultrasound image of the anterior chest wall, showing the serratus anterior muscle (SAM), intercostals muscles (ICM),pectoralis major muscle (PMM), and pectoralis minor muscle(pmm).

    Published with the written consent of the patient.



  •  26 Sep 2013, 9:55 PM 1489 in reply to 1463

    Re: Serratus-intercostal Plane block. An encouraging approach for breast surgery

    Attachment: Fig.1.jpg

    The first time an ultrasound-located midline approach was described to block the intercostal nerves at the mid axillary line was by myself in 2011(Fig 1a). I remember teaching Fajardo the Pecs I block in 2011  (Fig. 1b is from our original paper [2]). This is a medial to lateral approach.

    In 2012 we also described the Pecs II block where the first injection is again from medial to lateral [3]. In this block the key element is to enter the axilla. Our research focused on the best plane to achieve this, either above or below the serratus anterior muscle. We are criticised for using a small number of volunteers without adequate monitoring and for not providing clinical data. This is an initial report and we fully agree that further investigation into the serratus plane block must be undertaken. We performed sensory mapping and determined the duration of action. We did provide intravenous access and monitored vital signs. In both planes we obtained the same sensory distribution. This seems unsurprising to us, as it is well known that the intercostal nerves have to pass through both planes to innervate the skin.

    In the Pecs II approach the local anaesthetic is placed above the fourth rib for reasons of safety. The duration of action we reported is related to the fact that epinephrine was not used. We also injected into different compartments with different pharmacokinetics.

    Rafa Blanco

    Corniche Hospital

    Abu Dhabi, UAE.

    Email: rafablanco@mac.com

    No external funding and no competing interests declared.


    1. Blanco R, Garrido Garcıa M, Dieguez Garcıa P, et al. Eficacia analgesica del bloqueo de los nervios pectorales en cirugıa de mama. Cirugia Mayor Ambulatoria 2011; 16: 89–93.

    2. Blanco R. Thoracic blocks. Manua; de anestesia regional y econoanatmia avanzada. Spain: Ene Ediciones, 2011. pp 104. ISBN 9788485395880

    3. Blanco R, Fajardo M, Parras Maldonado T. Ultrasound description of Pecs II (modified Pecs I): a novel approach to breast surgery. Revista Espanola de Anestesiologia y Reanimacion 2012; 59: 470–5.


    Fig.1 Location of the intercostals at mid axillary line as published in 2011 (a) and Pecs approach as published in the original paper (b) [2]. 

    Published with the written consent of the patient.

View as RSS news feed in XML