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 Table of Contents  
Year : 2022  |  Volume : 36  |  Issue : 1  |  Page : 53-55

Intraoperative ultrasound-guided serratus anterior plane catheter for postoperative analgesia after breast surgery in a morbidly obese patient

1 Department of Anaesthesiology, Mahatma Gandhi Medical College and Research Institute Sri Balaji Vidyapeeth, Puducherry, India
2 Department of Anaesthesiology, MGM Health Care, Chennai, Tamil Nadu, India

Date of Submission12-Aug-2021
Date of Decision12-Oct-2021
Date of Acceptance27-Nov-2021
Date of Web Publication25-Apr-2022

Correspondence Address:
Dr. Annie Sheeba John
Department of Anaesthesiology, Mahatma Gandhi Medical College and Research Institute,Sri Balaji Vidyapeeth, Puducherry
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijpn.ijpn_70_21

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Inter-fascial plane blocks play a great role as part of the multimodal analgesic regimen for breast surgery. Fascial plane blocks are effective for immediate analgesia, but their use for prolonged postoperative analgesia is not yet explored. We present a hybrid technique of successful placement of intraoperative ultrasound-guided deep serratus anterior plane (SAP) catheter for continuous postoperative analgesia in a morbidly obese patient undergoing breast surgery. A sexagenarian morbidly obese female patient with left carcinoma breast was posted for modified radical mastectomy. The deep serratus anterior fascial plane was more than 9 cms deep and was poorly visualized. Hence, intraoperative catheter was placed under ultrasound guidance and used effectively for 5 days. The static and dynamic pain scores were <4 at all-time points with local anesthetics and nonopioid systemic analgesics. We observed that intraoperative ultrasound-guided SAP catheter can be effectively used for continuous postoperative analgesia in morbidly obese patients undergoing breast surgery.

Keywords: Analgesia, breast cancer, modified radical mastectomy, obesity, opioid, postoperative pain

How to cite this article:
John AS, Sivashanmugam T, Nahar A, Paul J. Intraoperative ultrasound-guided serratus anterior plane catheter for postoperative analgesia after breast surgery in a morbidly obese patient. Indian J Pain 2022;36:53-5

How to cite this URL:
John AS, Sivashanmugam T, Nahar A, Paul J. Intraoperative ultrasound-guided serratus anterior plane catheter for postoperative analgesia after breast surgery in a morbidly obese patient. Indian J Pain [serial online] 2022 [cited 2022 Jul 1];36:53-5. Available from: https://www.indianjpain.org/text.asp?2022/36/1/53/343829

  Introduction Top

Obesity is at the crux of current healthcare problems and it presents a challenge to perioperative physicians owing to the interplay of difficult anatomy and associated comorbidities. The goal of postoperative analgesia, in obese patients undergoing breast surgery, is to provide effective analgesia, early ambulation, and improved respiratory function.[1] The incidence of postmastectomy pain syndrome is 20%–50% and acute postoperative pain is a strong risk factor.[2] Obese patients with sleep-disordered breathing are at risk of opioid-induced ventilatory impairment.[3] Anthropometric changes and body mass index (BMI) >25 kg/m2 are independent risk factors for failed blocks.[4] Fascial plane blocks led to a paradigm shift from central neuraxial blockade to peripheral approaches for breast surgeries.

We present a case where a novel approach of intraoperative ultrasound-guided serratus anterior plane (IOUS-SAP) catheter was used for effective continuous analgesia after breast surgery in a morbidly obese patient.

  Case Report Top

This case is reported after obtaining written informed consent from the patient. A sexagenarian female weighing 114 kg and height of 156 cm (BMI = 46.8 kg/m2) diagnosed with carcinoma left breast was scheduled for modified radical mastectomy [Figure 1]. The patient was on treatment for multiple comorbidities nd also had symptoms suggestive of sleep-disordered breathing (STOP-BANG score = 6).
Figure 1: Patient with difficult anatomy due to obesity

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Our preliminary plan was general anesthesia with thoracic epidural analgesia, but discernible landmarks could not be identified on a scout scan performed. A scout scan of the thoracic paravertebral space and consequently the Pectoralis nerve and SAP was done. The target area of the above blocks was more than > 9 cm deep and poorly visualized [Figure 2]a. Since the issue was the depth of the injection targets, surgical removal of the breast tissues would expose the pectoral and serratus anterior muscle (SAM) and align the target within the resolution range of the probe [Figure 2]b. Hence, we decided to place the IOUS-SAP catheter below SAM after mastectomy and axillary dissection but before skin closure.
Figure 2: Sono-anatomy image of the serratus anterior plane. (a) = Preoperative sono-anatomy image (Depth = 9 cms). (b) = Intraoperative sono-anatomy image (Depth = 2 cms). (c) = Intraoperative probe position and procedure. (d) = Serratus Anterior Plane with needle and catheter in position. (a) serratus anterior muscle, (b) intercostal muscles, (c) lung parenchyma, (d) Ribs, (e) needle, (f) epidural catheter

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The patient received general anesthesia with endotracheal intubation as per institutional protocol. A high-frequency linear array transducer (HFL 50, 15–6MHz), X-Porte ultrasound system (SonoSite X-Porte, Sonosite Inc., Bothell, WA, USA) was used for scanning. The Ultrasound probe and 30 cm of cable were immersed in a freshly prepared Cidex® OPA solution for 15 min before the procedure.[5] The probe was then washed with saline and draped with sterile transparent plastic sleeve. The sterile gel was used as coupling medium between the probe-sleeve interface and 5% povidone-iodine solution between the probe-SAM interface. Following aseptic precaution, the probe was placed on the SAM at the level of the 5th rib and traced to the 3rd rib along the mid-axillary line in an oblique sagittal plane [Figure 2]c. An 18G Touhy's needle was inserted in an in-plane approach and advanced till the outer surface of the rib. The needle position was confirmed by hydro-dissection with 5 ml saline and a potential space was created between SAM and 3rd rib with 10 ml of 0.1% ropivacaine. Subsequently, a 20G epidural catheter was threaded 5 cms beyond the needle tip to place the catheter tip at the 2nd intercostal space (ICS) [Figure 2]d. The catheter was fixed with loose sutures on the SAM and also on the skin laterally away from the incision.

An infusion with 0.1% [email protected] ml/h and intravenous paracetamol 1 g 6th hourly was given for the first two postoperative days (POD) followed by oral paracetamol 650 mg 6th hourly subsequently. Pain score was assessed using a verbal numeric rating scale (VNRS) ranging from 0 to 10. Intravenous tramadol 50 mg was assigned as rescue analgesic when VNRS >4. The static and dynamic pain was maintained <4 at all assessment time points. The catheter was removed on POD5 and no postoperative complications were noted.

  Discussion Top

In this report, we have described the novel placement and outcome analysis of SAP catheter. To our literary knowledge, this is the first report of IOUS-guided placement of deep-SAP catheter for continuous analgesia following breast surgery.

Increased axillary fat and large breasts in obese patients make the identification of structures difficult for preoperative SAP block. Tissue edema due to surgical dissection and loose redundant skin after mastectomy makes poor target visualization, for the postoperative block. Studies on SAP block for breast surgeries were either as preoperative single-shot block or infiltration below SAM by the surgeon, which is short-acting.[6] These pitfalls can be overcome by placing a catheter intra-operatively, after mastectomy.

Lateral branches of the 2nd to 6th IC nerves are the target nerves, which branches out between the posterior-axillary and mid-axillary line.[7] Although superficial-SAP blocks the long thoracic and thoracodorsal nerve, these are more congruent for thoracotomies. The ribs, which can be easily identified, act as a sonographic landmark for the deep-SAP block. Furthermore, respiratory movements aid drug spread. A lower incidence of catheter migration and displacement makes this plane well suited for catheter placement.[6] In contrast to the conventional drug delivery point at the 5th ICS, we placed the catheter tip at the 2nd ICS to facilitate more cephalad spread. Spread of injectate in deep-SAP showed that only 7% of the cadavers had a cephalad spread up to 2nd ICS whereas 100% had caudal spread up to subcostal margin.[8]

A study reported effective pain relief with SAP catheter infusion of 0.2% Ropivacaine (5 ml/h) for multiple rib fractures.[9] We doubled the volume and halved the concentration to block more segments, as volume of the drug contributes majorly to the extent of spread in the SAP.[10]

IOUS imaging though rarely practiced by anesthesiologists is an emerging application used by the surgeon to assess and plan resection of diseased areas. In this patient we encountered challenges with the routine technique regional anesthesia technique and this new IOUS approach reduced the target depth from 9 cms to 2 cms, which improved visualization and technique.

Proper sterilization of ultrasound probe and aseptic precautions is important, as this is an intra-operative procedure. Sterilization of transducer with ethylene oxide or immersion in 2% glutaraldehyde along with sterile coupling gel, sleeve, and povidone-iodine can re-enforce asepsis.[5] We conclude that IOUS-SAP catheter placement is an innovative approach which can be effectively used for continuous postoperative analgesia for breast surgeries in patients with difficult sono-anatomy. Further validation through randomized clinical studies is required to test the clinical utility and reliability of this technique.

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


Conflicts of interest

There are no conflicts of interest.

  References Top

Schug SA, Raymann A. Postoperative pain management of the obese patient. Best Pract Res Clin Anaesthesiol 2011;25:73-81.  Back to cited text no. 1
Tait RC, Zoberi K, Ferguson M, Levenhagen K, Luebbert RA, Rowland K, et al. Persistent post-mastectomy pain: Risk factors and current approaches to treatment. J Pain 2018;19:1367-83.  Back to cited text no. 2
Macintyre PE, Loadsman JA, Scott DA. Opioids, ventilation and acute pain management. Anaesth Intensive Care 2011;39:545-58.  Back to cited text no. 3
Ingrande J, Brodsky JB, Lemmens HJ. Regional anesthesia and obesity. Curr Opin Anaesthesiol 2009;22:683-6.  Back to cited text no. 4
Basseal JM, Westerway SC, Juraja M, van de Mortel TF, McAuley TE, Rippey J. Guidelines for reprocessing ultrasound transducers by the Australasian society for ultrasound in medicine and the Australasian college for infection prevention and control. AJUM 2017;20:30–40.  Back to cited text no. 5
Hards M, Harada A, Neville I, Harwell S, Babar M, Ravalia A, et al. The effect of serratus plane block performed under direct vision on postoperative pain in breast surgery. J Clin Anesth 2016;34:427-31.  Back to cited text no. 6
Franco CD, Inozemtsev K. Refining a great idea: The consolidation of PECS I, PECS II and serratus blocks into a single thoracic fascial plane block, the SAP block. Reg Anesth Pain Med 2019:rapm-2019-100745.  Back to cited text no. 7
Daga V, Narayanan MK, Dedhia JD, Gaur P, Crick H, Gaur A. Cadaveric feasibility study on the use of ultrasound contrast to assess spread of injectate in the serratus anterior muscle plane. Saudi J Anaesth 2016;10:198-201.  Back to cited text no. 8
Rose P, Ramlogan R, Madden S, Lui A. Serratus anterior plane block home catheter for posterior rib fractures and flail chest. Can J Anaesth 2019;66:997-8.  Back to cited text no. 9
Biswas A, Castanov V, Li Z, Perlas A, Kruisselbrink R, Agur A, et al. Serratus plane block: A cadaveric study to evaluate optimal injectate spread. Reg Anesth Pain Med 2018;43:854-8.  Back to cited text no. 10


  [Figure 1], [Figure 2]


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