REGIONAL ANESTHESIA AND ACUTE PAIN ORIGINAL ARTICLE Rhomboid Intercostal and Subserratus Plane Block A Cadaveric and Clinical Evaluation Hesham Elsharkawy, MD, MBA, MSc,* Robert Maniker, MD,† Robert Bolash, MD,‡ Prathima Kalasbail, MD,§ Richard L. Drake, PhD,|| and Nabil Elkassabany, MD, MSCE** 09/23/2018 on BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3TDbD+Y6NAIFrozjKWQj8l6XbVmFhzuacr/89lZJ+iwO2cALi5f5t/w== by https://journals.lww.com/rapm from Downloaded nterfacial plane blocks of the chest wall remain in early stages of Downloaded Background and Objectives: Fascial plane blocks are rapidly emerg- Idevelopment, but initial results show promise in offering alter- ing to provide safe, feasible alternatives to epidural analgesia for thoracic natives to neuroaxial blocks.1,2 from and abdominal pain. We define a new option for chest wall and upper ab- Chest wall blocks represent an umbrella term wherein a number https://journals.lww.com/rapm dominal analgesia, termed the rhomboid intercostal and subserratus plane of successful approaches have been described. The serratus anterior (RISS) block. The RISS tissue plane extends deep to the erector spinae plane block3,4 has been used for analgesia after breast surgery,5–8 muscle medially and deep to the serratus anterior muscle laterally. We de- postmastectomy pain,9,10 thoracoscopic surgery,11,12 pain associated scribe a 2-part proof-of-concept study to validate the RISS block, including with rib fractures, shoulder surgery,13–16 open thoracotomy,17 a cadaveric study to evaluate injectate spread and a retrospective case series and postthoracotomy pain.18–20 The erector spinae plane block21 to assess dermatomal coverage and analgesic efficacy. 21,22 by has been used for acute postsurgical pain, posttraumatic pain BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3TDbD+Y6NAIFrozjKWQj8l6XbVmFhzuacr/89lZJ+iwO2cALi5f5t/w== Methods: For the cadaveric portion of the study, bilateral ultrasound- and chronic neuropathic pain conditions.21 guided RISS blocks were performed on 6 fresh cadavers with 30 mL of We previously reported the extent of contrast spread in cadavers 0.5% methylcellulose with india ink. For the retrospective case series, we following the rhomboid intercostal block at one injection point in the present 15 patients who underwent RISS block or RISS catheter insertion triangle of auscultation.23 We observed injectate spread between the for heterogeneous indications including abdominal surgery, rib fractures, intercostal muscles and deep to the serratus anterior muscle, as well – chest tube associated pain, or postoperative incisional chest wall pain. as staining of the lateral cutaneous branches of intercostal nerves Results: In the cadaveric specimens, we identified staining of the lateral T3 to T8. One of the characteristics of fascial systems is the continuity branches of the intercostal nerves from T3 to T9 reaching the posterior pri- across different anatomical areas. For example, the tissue plane deep mary rami deep to the erector spinae muscle medially. In the clinical case to the erector spinae muscle in the upper thoracic area is continuous series, dermatomal coverage was observed in the anterior hemithorax with with the tissue plane deep to the rhomboid major muscle, as well as visual analog pain scores less than 5 in patients who underwent both single- the tissue plane deep to the serratus anterior muscle.24 shot and continuous catheter infusions. In this study, we sought to investigate the injectate spread as Conclusions: Our preliminary cadaveric and clinical data suggest that a proof of concept for the continuity of posterior chest wall fascial RISS block anesthetizes the lateral cutaneous branches of the thoracic in- systems in a cadaveric model and evaluate the clinical response to tercostal nerves and can be used in multiple clinical settings for chest wall injection with a retrospective case series of rhomboid intercostal and upper abdominal analgesia. and subserratus plane (RISS) block. We hypothesized that the (Reg Anesth Pain Med 2018;43: 745–751) rhomboid intercostal block can be extended caudally by position- ing the needle tip deep to the serratus muscle to block the lateral cutaneous branches of intercostal nerves to T11 and still extend medially deep to the erector spinae muscle to block the dorsal rami. In addition, we believe that the location of the injection (up- per thoracic to low thoracic) relative to the lateral cutaneous From the *Departments of General Anesthesia and Outcomes Research, Anes- branches of the intercostal nerves may influence both injectate thesiology Institute, Cleveland Clinic, and CCLCM of Case Western Reserve spread and clinical efficacy. University, Cleveland Clinic, Cleveland, OH; †Department of Anesthesiology, Columbia University, New York, NY; and Departments of ‡Pain Management and Evidence Based Pain Research and §Outcomes Research, Anesthesiology METHODS Institute, Cleveland Clinic; and ||Cleveland Clinic Lerner College of Medicine, on 09/23/2018 Cleveland, OH; and **Department of Anesthesiology and Critical Care, Perelman Cadaveric Study School of Medicine, University of Pennsylvania, Philadelphia, PA. Accepted for publication March 10, 2018. Six unembalmed (fresh) adult cadavers representing a range of Address correspondence to: Hesham Elsharkawy, MD, MBA, MSc, body habitus and both sexes were chosen. Cadavers with known Department of General Anesthesia and Outcomes Research, Anesthesiology Institute, Cleveland Clinic, 9500 Euclid Ave, Mail Code thoracic deformities or previous spine surgery were excluded E31, Cleveland, OH 44195 (e‐mail: [email protected]). from the study. All cadavers were maintained at room temperature H.E. has received unrestricted educational funding from PAJUNK (Norcross, for 12 hours before injection. Bilateral ultrasound-guided RISS GA) and consultant fees from Pacira Pharmaceuticals, Inc. Those blocks were performed on each cadaver (n = 12 injections) by companies had no input into any aspect of the present project design or manuscript preparation. one investigator (H.E.). The authors declare no conflict of interest. All images are created and used with permission of Cleveland Clinic Center for Description of the Technique Medical Art and Photography. Supplemental digital content is available for this article. Direct URL citations The cadaveric specimens were placed in the prone position, appear in the printed text and are provided in the HTML and PDF versions with both arms abducted and internally rotated to move the inferior of this article on the journal's Web site (www.rapm.org). angle of the scapula laterally. A linear ultrasound transducer Copyright © 2018 by American Society of Regional Anesthesia and Pain – Medicine (6 12 MHz Mindray M7 diagnostic ultrasound system; Mindray ISSN: 1098-7339 DS USA Inc, Mahwah, New Jersey) was placed in the sagittal plane DOI: 10.1097/AAP.0000000000000824 medial to the medial border of the scapula with the orientation Regional Anesthesia and Pain Medicine • Volume 43, Number 7, October 2018 745 Copyright © 2018 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited. Elsharkawy et al Regional Anesthesia and Pain Medicine • Volume 43, Number 7, October 2018 FIGURE 1. A, Ultrasound transducer positioning for performance of the rhomboid intercostal injection at the T5-6 level. LD indicates latissimus dorsi muscle; Trap, trapezius muscle. B, Schematic illustration demonstrating surrounding structures and needle position for rhomboid intercostal injection at the T5-6 level (right) and corresponding ultrasound image (left). IM indicates intercostal muscles; LA, local anesthetic; RM, rhomboid major muscle; Trap, trapezius muscle. C, Schematic illustration of an axial section at the level of T5-6 demonstrating needle position and injectate spread during rhomboid intercostal injection. ES indicates erector spinae muscle; R, rhomboid muscle; SA, serratus anterior muscle; SS, subscapularis muscle. marker directed cranially. The transducer was then rotated so layers were identified from superficial to deep: latissimus dorsi, the cranial end was directed slightly medially and the caudal serratus anterior, intercostal muscles between ribs, pleura, and end laterally to produce an oblique sagittal view (paramedian lung (Muscle Layers, Supplemental Digital Content 2, http://links. sagittal oblique) approximately 1 to 2 cm medial to the medial lww.com/AAP/A268). The needle was inserted at the same skin scapular border (Fig. 1A). entry site as was used for the rhomboid intercostal injection but The following structures were identified from superficial to directed caudally and laterally beyond the inferior angle of the deep: trapezius muscle, rhomboid major muscle, intercostal muscles scapula. If the needle tip did not reach beyond the inferior edge of between ribs, pleura, and lung. The tissue plane between the rhom- the scapula (eg, obese and tall habitus), a new skin entry point boid major and intercostal muscles was identified. A 17-gauge Tuohy medial to the lower angle of the scapula and posterior axillary line needle was advanced in plane from a superomedial-to-inferolateral was used. Twenty milliliters of 0.5% methylcellulose with india ink direction, through the trapezius and rhomboid major muscles. Ten was injected in the tissue plane between the serratus anterior and milliliters of 0.5% methylcellulose with india ink was injected in external intercostal muscle, hydrodissecting