Rhomboid Intercostal and Subserratus Plane Block

Home , Erector spinae muscles, Intercostal muscles, Intercostal nerves, Rhomboid major muscle, Rib, Rib cage

8 17 21 – 5 21,22 745 pain associated 24 11,12 open thoracotomy, 21 16 – 13 Prathima Kalasbail, MD,§ The erector spinae plane block ‡ 20 1,2 – 18 METHODS We observed injectate spread between the thoracoscopic surgery, 23 9,10 has been used for analgesia after breast surgery, 3,4 Robert Bolash, MD, The cadaveric specimens were placed in the prone position, In this study, we sought to investigate the injectate spread as Six unembalmed (fresh) adult cadavers representing a range of Chest wall blocks represent an umbrella term wherein a number We previously reported the extent of contrast spread in cadavers † 12 MHz Mindray M7 diagnostic ultrasound system; Mindray RTICLE – nterfacial plane blocks of the chest wall remaindevelopment, in but early stages initial of results show promise in offering alter- intercostal muscles and deepas to the staining serratus of anteriorT3 the muscle, to T8. as lateral One well of cutaneous theacross characteristics of branches different fascial anatomical systems of is areas. the For intercostalto continuity example, the nerves the erector tissue spinae plane musclewith deep in the the tissue upper plane thoracic deepthe area to tissue the is plane rhomboid continuous deep major to muscle, the as serratus well anterior as muscle. Cadaveric Study natives to neuroaxial blocks. with rib fractures, shoulder surgery, Description of the Technique I postmastectomy pain, and postthoracotomy pain. has been used for acuteand postsurgical pain, chronic posttraumatic neuropathic pain pain conditions. with both arms abducted andangle internally rotated to of move the(6 the inferior scapula laterally. A linear ultrasound transducer a proof of concept for the continuitysystems of in posterior a chest cadaveric wall model fascial and evaluateinjection the clinical with response a to retrospective caseand series of subserratus rhomboid plane intercostal (RISS)rhomboid intercostal block block. can We be extended hypothesized caudallying by that the position- needle the tip deepcutaneous to branches the of serratus intercostal muscle nerves tomedially to block deep the T11 to lateral and the stillrami. In extend erector addition, we spinae believe that muscle theper to location of block thoracic the injection the (up- tobranches dorsal low of thoracic) the relative intercostalspread and nerves to clinical may efficacy. the influence both lateral injectate cutaneous body habitus and boththoracic sexes deformities were or chosen.from previous Cadavers the study. All with spine cadavers were known maintained at surgeryfor room temperature were 12 excluded hours beforeblocks injection. were Bilateral performed ultrasound-guided on RISS one each investigator (H.E.). cadaver (n = 12 injections) by of successful approaches haveplane been described. block The serratus anterior following the rhomboid intercostal blocktriangle at one of injection auscultation. point in the DS USA Inc, Mahwah, New Jersey)medial was placed in to the sagittal the plane medial border of the scapula with the orientation A RIGINAL O Pain Management ‡ Volume 43, Number 7, October 2018 Department of Anesthesiology, † • A Cadaveric and Clinical Evaluation REGIONAL ANESTHESIA AND ACUTE PAIN 751) ng abdominal surgery, rib fractures, – Fascial plane blocks are rapidly emerg- mail: [email protected]). ‐ Richard L. Drake, PhD,|| and Nabil Elkassabany, MD, MSCE** 2018;43: 745 Our preliminary cadaveric and clinical data suggest that Rhomboid Intercostal and Subserratus Plane Block For the cadaveric portion of the study, bilateral ultrasound- associated pain, or postoperative incisional chest wall pain. In the cadaveric specimens, we identified staining of the lateral – GA) and consultant fees from Paciracompanies had Pharmaceuticals, Inc. no Those input into anymanuscript preparation. aspect of the present project design or Medical Art and Photography. appear in the printed text andof are this provided in article the on HTML the and journal's PDF Web site versions (www.rapm.org). Medicine Department of General Anesthesia and OutcomesAnesthesiology Research, Institute, Cleveland Clinic, 9500 Euclid Ave, MailE31, Code Cleveland, OH 44195 (e Reg Anesth Pain Med Copyright © 2018 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited. Copyright © 2018 American Society of Regional Anesthesia and Pain Medicine. Unauthorized branches of the intercostal nerves from T3 tomary T9 reaching rami the deep posterior pri- to the erectorseries, spinae dermatomal coverage muscle was medially. observed In in the the clinical anterior hemithorax case visual with analog pain scores less than 5 in patients whoshot underwent both and single- continuous catheter infusions. RISS block anesthetizes the lateral cutaneous branchestercostal of nerves the and thoracic in- can beand used upper in abdominal multiple analgesia. clinical settings for chest( wall chest tube guided RISS blocks were0.5% performed methylcellulose on with india 6present ink. fresh 15 For cadavers patients the with who retrospective 30for underwent case mL RISS heterogeneous series, block of indications we or includi RISS catheter insertion Regional Anesthesia and Pain Medicine Columbia University, New York, NY; and Departments of From the *Departments ofthesiology Institute, General Cleveland Clinic, Anesthesia and and CCLCMUniversity, Cleveland Outcomes Clinic, of Cleveland, OH; Research, Case Western Anes- Reserve Conclusions: H.E. has received unrestricted educational funding from PAJUNK (Norcross, The authors declare no conflict ofAll images interest. are created and used with permission of Cleveland Clinic Center for Supplemental digital content is available for this article. Direct URL citations Copyright © 2018 by American SocietyISSN: of 1098-7339 Regional AnesthesiaDOI: 10.1097/AAP.0000000000000824 and Pain Results: Methods: Background and Objectives: Hesham Elsharkawy, MD, MBA, MSc,* Robert Maniker, MD, ing to provide safe, feasible alternatives toand epidural abdominal pain. analgesia We for define thoracic a newdominal option analgesia, termed for the chest wall rhomboid intercostal and and upper(RISS) subserratus ab- plane block. The RISS tissuemuscle medially plane and extends deep deep to the to serratusscribe the a anterior 2-part muscle erector study proof-of-concept laterally. We to spinae validate de- the RISS block, including a cadaveric study to evaluate injectate spread and a retrospective caseto series assess dermatomal coverage and analgesic efficacy. and Evidence Based Pain ResearchInstitute, and Cleveland §Outcomes Clinic; Research, and Anesthesiology ||Cleveland Clinic LernerCleveland, College OH; of and Medicine, **Department ofSchool Anesthesiology and of Critical Medicine, Care, University Perelman ofAccepted Pennsylvania, for Philadelphia, publication March PA. 10, 2018. Address correspondence to: Hesham Elsharkawy, MD, MBA, MSc,

Downloaded from https://journals.lww.com/rapm by BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3TDbD+Y6NAIFrozjKWQj8l6XbVmFhzuacr/89lZJ+iwO2cALi5f5t/w== on 09/23/2018 Downloaded from https://journals.lww.com/rapm by BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3TDbD+Y6NAIFrozjKWQj8l6XbVmFhzuacr/89lZJ+iwO2cALi5f5t/w== on 09/23/2018 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 the tissue plane between the fascial plane between the rhomboid major muscle and the inter- the serratus anterior muscle and the attachments of the serratus to costal muscles. The skin entry point for the first injection was at the rib (Video, Supplemental Digital Content 3, http://links.lww. the T5–T6 level just medial to the scapula (Fig. 1, B and C; Video 1, com/AAP/A269). The same procedure was repeated on the Supplemental Digital Content 1, http://links.lww.com/AAP/A267). contralateral side. Two landmarks verified identification of the T5–T6 level: (1) counting down from the C7 spinous process and (2) identifying the medial part of the spine of the scapula at the T3 level. Cadaveric Anatomic Dissection Next, to identify the subserratus plane, the transducer was The chest walls were dissected in layers from superficial moved caudally and laterally, distal to the inferior angle of (posterior) to deep (anterior) by an anatomist (R.L.D.) 2 hours fol- the scapula behind the posterior axillary line (Fig. 2, A–C). Tissue lowing the injection. The detailed cadaveric dissection is available

FIGURE 2. A, Ultrasound transducer positioning for subserratus plane injection at the T7-8 level. LD indicates latissimus dorsi muscle; RM, rhomboid major muscle; SA, serratus anterior muscle; Trap, trapezius muscle. B, Schematic illustration demonstrating surrounding structures and needle position for subserratus injection at the T7-8 level (right) and corresponding ultrasound image (left). LA indicates local anesthetic; LD, latissimus dorsi muscle; SA, serratus anterior muscle. C, Schematic illustration and sagittal ultrasound image during the performance of the subserratus block at T7-8 demonstrating the surrounding muscle layers and local anesthetic spread. ES indicates erector spinae muscle.

Copyright © 2018 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited. Regional Anesthesia and Pain Medicine • Volume 43, Number 7, October 2018 Rhomboid Intercostal Subserratus Block as supplemental material (Cadaveric Clarification, Supplemental was administered (0.5% ropivacaine or bupivacaine for single- Digital Content 4, http://links.lww.com/AAP/A270, and Supplemen- shot blocks or 0.2% ropivacaine for patients receiving catheters). tal Digital Content 5, http://links.lww.com/AAP/A271). We dissected The target landmark was the plane located superficial to the inter- the trapezius from its attachment on the spinous processes to expose costal muscles. The injectate was visualized to spread both crani- the rhomboid major and minor muscles. Next, the latissimus dorsi ally and caudally throughout the subserratus tissue plane, noting muscle was reflected laterally. The erector spinae muscles were then the injectate volume pushing the serratus anterior muscle away reflected cranially to identify the thoracic transverse processes and from the external intercostal muscle (External Photos, Supple- the origins of the dorsal rami. mental Digital Content 6, http://links.lww.com/AAP/A272). The lateral cutaneous branches of the intercostal nerves were In subjects undergoing a continuous infusion, a 19-gauge, 40-cm identified at the midaxillary line in the tissue plane deep to the catheter (Arrow by Teleflex; Teleflex, Morrisville, North Carolina) serratus anterior muscle. Subsequently, ribs T2 to T12 were re- was then introduced into the subserratus plane and advanced moved at the articular surface of the transverse processes to visu- 3 to 5 cm beyond the needle tip. The catheter tip position was alize any staining in the intercostal spaces. confirmed with injection of 5 mL of 0.2% ropivacaine under The axillary space was identified between the pectoralis mi- direct ultrasound visualization (Video, Supplemental Digital nor muscle anteriorly and subscapularis muscle posteriorly. Below Content 7, http://links.lww.com/AAP/A273). Catheters were the eighth thoracic level, the upper part of the external oblique secured with sterile adhesive dressing. muscle was identified and removed to identify the tissue plane lo- Additional outcome data were obtained from the electronic cated superficial to the external intercostal muscles and traversing medical record including the extent of sensory dermatomal cover- around the anterior axially line. All key steps of the dissection age as determined by a loss of cold sensation to ice, duration of an- were photographed. algesia, and pain scores using visual analog score before and after the block. Clinical Case Series The Cleveland Clinic Institutional Review Board approved a RESULTS OF THE CADAVERIC STUDY retrospective review of cases performed between April 2016 and Six cadavers were included in the study (3 male, 3 female) August 2017. Written informed consent for the nerve block proce- with body mass indices between 28 and 44 kg/m2. We identified dures were obtain from all patients. Patients were positioned in the the tissue plane between the rhomboid major and minor muscles, lateral decubitus position with the painful/operative side up and serratus anterior muscle, external intercostal muscle, and external were monitored with standard American Society of Anesthesiolo- oblique muscles from T2 to T12. In addition, we identified the lat- gists monitoring. A rhomboid intercostal injection was performed eral branches of the intercostal nerves from T2 to T12 and dorsal using a 17-gauge Tuohy needle utilizing the same technique as de- rami deep to the erector spinae muscle at midline. scribed above in the cadaveric study. Five to 10 mL of local anes- We observed staining of the subserratus tissue plane from T2 thetic (0.5% ropivacaine or bupivacaine) was administered to to T9 and variable staining of the lateral branches of the intercostal patients receiving a single-shot block or 5 to 10 mL of 0.2% nerves from T2 to T10 (see below) (Fig. 3A). Contrast was observed ropivacaine in patients receiving a catheter. The rhomboid inter- coursing medially, reaching the location of the exiting posterior costal component of the block was performed as a single-shot in- primary rami deep to the erector spinae muscle (Fig. 3B). Cranially, jection at the level of T3 to T6, depending on desired dermatomal contrast staining deep to the rhomboid major and minor stopped at coverage, whereas the subserratus plane component was per- the levator scapula muscle in all specimens and was not observed formed next, as either a single-shot injection or continuous cathe- beyond the serratus posterior superiorly, in proximity to the T2 ter technique. The subserratus plane injection was performed in a level. Laterally and cranially, contrast extended to the clavipectoral similar fashion as described in the cadaveric model, with the nee- fascia inside the axilla in 7 specimens (Fig. 3C), and inferiorly dle target at the level of T4 to T10 (again depending on desired to the level of T10 around the insertion of the serratus posterior dermatomal coverage). When the subserratus plane was reached inferior muscle and origin of the external oblique muscle in (at the lower angle of the scapula), 15 to 20 mL of local anesthetic 10 specimens (Fig. 3C).

FIGURE 3. A, Cadaveric dissection showing spread of blue dye injectate in the subserratus tissue plane and staining of the lateral branches of the intercostal nerves. LCB indicates lateral cutaneous branches of intercostal nerves; SA, serratus anterior muscle. B, Cadaveric dissection showing spread of blue dye injectate in the tissue plane deep to the erector spinae muscle (ES) staining the T6 and T7 dorsal rami of the spinal nerves (DR). C, Cadaveric dissection showing spread of blue dye injectate in the floor of the axilla, deep to the serratus anterior muscle (SA) up to the level of the second rib and dye reaching inferiorly to T10 around the insertion of the inferior portion of the serratus posterior muscle (SPI) and origin of the external oblique muscle (EO). LCB indicates lateral cutaneous branches of intercostal nerves; LD, latissimus dorsi muscle.

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

The lateral branches of the intercostal nerves stained con- either incisional or nonincisional pain of the chest wall, including sistently across all specimens from T4 to T8. Ten specimens rib fracture (2 patients), chest tube (2 patients), upper abdominal demonstrated consistent staining of T2 and T3. Nine specimens surgery (7 patients), cancer pain (1 patient), lung transplant (2 pa- demonstrated consistent staining of T9 and T10 deep to the up- tients), and pneumonectomy (1 patient). The points of injection per slips of the external oblique muscle (Fig. 4). Below the were tailored to the anatomic location of pain, with rhomboid in- eighth thoracic level the lower 4 slips of the serratus anterior tercostal injection points ranging from T3 to T6 and subserratus muscle interdigitate at their origins with the upper 5 slips of plane injection point ranging from T4 to T10 (Fig. 5, A and B). the external oblique muscle.25 Also below the eighth thoracic Dermatomal cold sensory deficits were consistently achieved level, the serratus anterior muscle ends and this tissue plane be- from T5 to T9, with the most cephalad coverage to T2 and the comes deep to the latissmus dorsi and the upper part of the ex- most caudal coverage to T12. The dermatomal coverage included ternal oblique muscle. the anterior hemithorax extending from 4 cm lateral of the midline In 8 specimens, faint staining of the tissue plane deep to the at the medial extent, laterally to the axilla, and on the posterior erector spinae muscles from T4 to T8 was observed and continued hemithorax extending to the midscapular line 4 cm medial to the to the tissue plane posterior to the thoracic transverse processes. In posterior axillary line. Data for pain scores before the procedure, 4 specimens, staining stopped at the lateral edge of the erector spinae, mean pain scores measured after block, and the dermatomal levels and no staining was observed deep to the erector spinae muscle covered in patients are listed in Table 1. The average duration of (Cadaveric Clarification, Supplemental Digital Content 4, http:// analgesia for single-shot blocks was 16 hours, and the average du- links.lww.com/AAP/A270). ration of catheter infusion was 3.6 days. No patients experienced We were able to identify the dorsal rami of the thoracic intercos- any adverse reactions resulting from the blocks or catheters, in- tal nerves of T6 and T7 as they emerge between the tips of adjacent cluding pneumothorax, hypotension, urinary retention, upper transverse processes in only 2 cadavers (Fig. 3B). No specimens or lower extremity weakness, or insertion site bleeding or infection demonstrated intercostal nerve staining within the intercostal spaces (Detailed Patients Management, Supplemental Digital Con- either anteriorly or posteriorly. Staining was seen in the floor of the tent 8, http://links.lww.com/AAP/A274). axilla in nine specimens, deep to the serratus anterior muscle up to the level of the second rib and posterior to the clavipectoral fascia. In 2 of these 9 specimens, there was faint staining within the DISCUSSION axilla and around the axillary artery. No staining was observed We demonstrate that injection in the tissue plane located be- within the axilla in 3 specimens. We did not identify the lateral tween the rhomboid and intercostal muscles and then deep to the pectoral, medial pectoral, long thoracic, or thoracodorsal nerves scapula and serratus anterior muscle targets the lateral cutaneous (summarized in Fig. 4). We did not observe any evidence of branches of the ventral rami of thoracic intercostal nerves. Spread epidural or paravertebral spread. extends medially deep to the erector spinae tissue plane and superficial to the thoracic transverse processes at the point where the dorsal rami of the thoracic intercostal nerves emerge between PATIENT OUTCOMES the tips of adjacent transverse processes T3 to T9. This case series included 15 patients. Clinical data are sum- In addition, we provide cadaveric evidence that the tissue marized in Table 1. Four patients received single-shot blocks, plane deep to the erector spinae muscle, rhomboid muscles, and 11 patients received continuous catheters. Indications were serratus anterior muscles, latissimus dorsi, and the upper part of the external oblique muscle is continuous. To our knowledge, this has not been described as one continuous tissue plane. The RISS block leads to reproducible dermatomal analgesic coverage of the thorax upper abdomen and can be useful for cancer pain, postoperative pain after thoracotomy, chest tube– associated pain, rib fracture pain, and upper abdominal incisional pain and as a supplement to a patchy thoracic epidural. We observed no extension to the intercostal nerves. The thoracodorsal and long thoracic nerves lie superficial to the serratus anterior muscle and should therefore be spared using the RISS block. In the cadaveric component of the study, we noted less consistent spread to the dorsal rami which is congruent with results of the clinical component of the study wherein the posterior midline area was not blocked consistently in all patients. Given that this injection is made into an interfascial plane, the final needle location for injection can be varied, depending on desired dermatomal coverage. Specifically, the rhomboid intercostal plane injection can be made anywhere from approximately T3 to T6 (rhomboid major and minor muscles originate at the C7– T5 spinous processes medially and course inferolaterally to insert at the medial border of the scapula at the T2 to T6 level), and the subserratus plane injection can be made anywhere from approxi- FIGURE 4. Histogram, the extent of tissue staining in mately T4 to T10 (serratus anterior muscle originates at the T1– cadaveric specimens. Nerve staining was consistently seen across T9 ribs and inserts along the medial border of the scapula). The all specimens from T4 to T8. Ten specimens demonstrated consistent staining of T2 and T3. Nine specimens demonstrated rhomboid intercostal tissue plane overlaps with the subserratus tis- consistent staining of T9 and T10 deep to the upper slips of the sue plane laterally and communicates from T1 to T5. external oblique muscle. Nine specimens demonstrated staining We posit that the RISS combination block can be considered of the axilla. as an alternative approach to, or modification of, the serratus

Copyright © 2018 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited. einlAetei n anMedicine Pain and Anesthesia Regional 08Aeia oit fRgoa nshsaadPi Medicine Pain and Anesthesia Regional of Society American 2018 © Copyright © 2018 American Society of Regional Anesthesia and Pain Medicine. Unauthorized reproduction of this article is prohibited.

TABLE 1. Summary of Cases

Patient RI Injectate SS Injectate Dermatomal Visual Analog Score Duration of Age, y/Sex Pathology Technique Volume* RI Location Vo l u m e * SS Location Coverage (Pre → Post) Analgesia Single-shot blocks

1. 81/M T4–T8ribfractures Block 10mL T6 10mL T9 T2–T9 10 → 212h•

2. 64/F Chest tube Â2 Block 10 mL T6 20 mL T9 T4–T10 9 → 212h 2018 October 7, Number 43, Volume 3. 77/F Chest tube Â2Block10mLT6–T7 10 mL T9 T3–T8 10 → 416h 4. 69/M Subcostal incision Block 10 mL T6 10 mL T10 T5–T10 10 → 224h Catheter infusions 5. 42/F Ventral hernia repair Catheter 10 mL T6 10 mL T6–T7 T4–T9 8 → 34d 6. 57/F VATS, pneumonectomy, and 6th rib resection Catheter 10 mL T4–T5 10 mL T6–T7 T4–T9 9 → 34d 7. 51/M Cancer pain at T3–T6 right lateral chest wall Catheter 10 mL T4–T5 10 mL T6–T7 T3–T9 10 → 22d 8. 41/F Open cholecystectomy Catheter 10 mL T6 10 mL T8 T5–T12 10 → 45d 9. 92/F T4–T7 rib fractures Catheter 20 mL T3–T4 15 mL T6–T7 † 10 → 2‡ 2d 10. 77/M Open pancreaticoduodenectomy Bilateral catheters 10 mL per side T5 10 mL per side T7–T8 Right: T6–T10 9 → 52d Left: T8–T11 11. 57/F Open adrenalectomy Bilateral catheters 10 mL per side T5 10 mL per side T6–T7 Right: T7–T12 2–4Post§ 3d Left: T8–T10 12. 66/M Left lung transplant Catheter 10 mL T3–T4 10 mL T4–T5 T3–T6 9 → 36d 13. 57/F Open adrenalectomy Bilateral catheters 10 mL per side T5 10 mL per side T7 Right: T7–T11 8 → 33d Left: T6–T10 14. 65/M Right lung transplant Catheter 10 mL T4 10 mL T6 T4–T8 9 → 44d 15. 54/M Liver wedge resection Bilateral catheters 10 mL per side T5 10 mL per side T8 Right: T7–T11 7 → 05d Left: T6–T10

*For patients receiving single-shot blocks, 0.5% bupivacaine was injected; for patients receiving a catheter, ropivacaine 0.2% was injected as a bolus through the needle with the volume listed here followed by an Block Subserratus Intercostal Rhomboid infusion of ropivacaine 0.2% at a basal rate of 4 to 8 mL/h and a bolus of 6 to 12 mL every 60 minutes through RI catheters. †Unable to attain due to language barrier. ‡Using FACES scale, interpreter, and daughter interpretation due to language barrier. §Block was performed under general anesthesia; therefore, preprocedure pain score is not applicable. RI indicates rhomboid intercostal; SS, subserratus plane; VATS, video-assisted thoracoscopic surgery. 749 Elsharkawy et al Regional Anesthesia and Pain Medicine • Volume 43, Number 7, October 2018

FIGURE 5. A, Computed tomography with reconstructed 3-dimensional image demonstrating the RISS catheter tip located at the midaxillary line adjacent to T10. B, Computed tomography scan with reconstructed 3-dimensional image demonstrating catheter insertion point at the level of T7 at a point medial to the inferior edge of the scapula and deep to the latissimus dorsi and serratus anterior muscles. The tip of the catheter is positioned near the midaxillary line at approximately the T10 level. These images are of patient 5 from Table 1 who had RISS catheter placed for inadequate T8-9 epidural coverage.

anterior plane block and erector spinae plane block and can be cadaveric results is warranted. Second, our cadaveric technique used when those blocks are not feasible because of technical is- did not involve insertion of a catheter, as was performed in the ma- sues or proximity to the wound. Furthermore, the RISS block jority of the clinical cases presented. The clinical case series was a may offer some advantages over the pectoral nerves blocks and su- limited retrospective review. The RISS block has recognized dis- perficial serratus plane blocks. The site of injection for these advantages. First, there is inconsistent blockade of the axilla. Sec- blocks is close to the incision for many procedures, including ond, we did not observe analgesia in distributions of the anterior breast surgery, thoracotomy, pneumonectomy, and chest tube cutaneous branches of the intercostal nerves or the supraclavicular placement. This creates technical challenges in performing post- nerves, and the block did not cover the midline anteriorly or pos- operative blocks as well as logistic challenges in placing catheters teriorly. Third, the thoracodorsal nerve is not blocked, potentially preoperatively because they may interfere with the sterile surgical limiting use as monotherapy for latissimus dorsi flap creation. field. The point of injection for RISS block is distant from most Like other chest wall interfacial plane blocks, RISS block did surgical incisions, and a catheter is unlikely to interfere with the not demonstrate staining of the intercostal nerves and therefore surgical field. lacks visceral analgesic coverage, limiting its utility for visceral Another advantage of the RISS block over the serratus plane and neuropathic pain.26 block is that it consistently blocks the lateral cutaneous branches Cadaveric studies provide detailed anatomic findings that are of the intercostal nerves in the mid and lower thoracic dermatomes not possible in live subjects, but study in live subjects via a ran- and thus can be utilized for upper abdominal surgery. Unlike the domized trial is needed, wherein comparison with paravertebral superficial serratus plane block, the RISS block does not block block or other interfascial plane blocks can assess outcomes and the long thoracic nerve and thus should avoid potential winging identify failure rates. of the scapula. The RISS block also has easily identifiable ultrasound landmarks (intercostal muscles and ribs), is amenable to CONCLUSIONS catheter insertion, and utilizes injection points that can be adjusted This initial description and evaluation of the RISS block to match the coverage area to the site of the inciting pain. demonstrates the concept of continuity between chest wall fascial For the cadaveric injections, we selected 0.5% methylcellulose planes with consistent spread of injectate to the lateral cutaneous and india ink, as their physical characteristics are approximate to branches of the T4 to T9 intercostal nerves in cadavers and consis- that of local anesthetics. In addition, we used unembalmed fresh hu- tent analgesia from the T5 to T8 dermatomes in a clinical case se- man cadavers at room temperature to maintain tissue elasticity as ries, showing promise for this block in providing chest wall and close as possible to live human tissue. All 12 cadaveric injections upper abdominal wall analgesia. were performed at the same location, and contrast spread was uni- form. In the clinical portion of the study, injection points were tai- ACKNOWLEDGMENTS lored to fit the dermatomal distribution of pain. This sample of The authors acknowledge the contribution of Dr Rahul 15 patients was not large enough to analyze for a correlation be- Renapurkar, Sections of Thoracic and Cardiovascular Imaging, tween injectate location and resultant dermatomal spread. None- Imaging Institute, Cleveland Clinic, to the reconstructed com- theless, the patient with the most cephalad injection point puted tomography images presented in this article. (patient 12, Table 1) developed the most cephalad dermatomal – coverage (T3 T6), whereas the patient with the most caudad REFERENCES injectate locations (patient 4, Table 1) developed the most caudad dermatomal coverage (T5–T10). Further study is warranted to 1. Forero M, Rajarathinam M, Adhikary S, Chin KJ. Continuous erector evaluate the correlation between injectate or catheter location spinae plane block for rescue analgesia in thoracotomy after epidural and resultant dermatomal coverage. We consider the 2-point injec- failure: a case report. A A Case Rep. 2017;8:254–256. tion as a dissecting technique for the interfascial planes. Both in- 2. Li NL, Yu BL, Hung CF. Paravertebral block plus thoracic wall block jections are not needed for all patients if the desired dermatomal versus paravertebral block alone for analgesia of modified radical coverage is small because the 2 tissue planes are continuous. mastectomy: a retrospective cohort study. PLoS One. 2016;11:e0166227. We recognize several limitations to both the cadaveric and 3. Blanco R, Parras T, McDonnell JG, Prats-Galino A. Serratus plane block: a patient case series. First, cadaveric evidence may not directly pre- novel ultrasound-guided thoracic wall nerve block. Anaesthesia. 2013;68: dict clinical outcomes; thus, cautious interpretation of the 1107–1113.

4. Daga V,Narayanan MK, Dedhia JD, Gaur P, Crick H, Gaur A. Cadaveric 15. May L, Hillermann C, Patil S. Rib fracture management. BJA Education. feasibility study on the use of ultrasound contrast to assess spread of 2016;16:26–32. injectate in the serratus anterior muscle plane. Saudi J Anaesth.2016;10: 16. Moll V,Groff R, Budhrani G, Sathiyakumar A, McKenzie-Brown AM. – 198 201. Bilateral serratus anterior plane block facilitates ventilator weaning in 5. Hards M, Harada A, Neville I, et al. The effect of serratus plane block patient with rib cage pain. Crit Care Med. 2016;44:561. performed under direct vision on postoperative pain in breast surgery. 17. Okmen K, Okmen BM, Uysal S. Serratus anterior plane (SAP) block used JClinAnesth. 2016;34:427–431. for thoracotomy analgesia: a case report. Korean J Pain.2016;29:189–192. 6. Ohgoshi Y, Yokozuka M, Terajima K. Serratus-intercostal plane block for 18. Madabushi R, Tewari S, Gautam SK, Agarwal A, Agarwal A. Serratus brest surgery [in Japanese]. Masui.2015;64:610–614. anterior plane block: a new analgesic technique for post-thoracotomy pain. 7. Bhoi D, Pushparajan HK, Talawar P, Kumar A, Baidya DK. Serratus Pain Physician.2015;18:E421–E424. anterior plane block for breast surgery in a morbidly obese patient. 19. Khalil AE, Abdallah NM, Bashandy GM, Kaddah TA. Ultrasound-guided J Clin Anesth. 2016;33:500–501. serratus anterior plane block versus thoracic epidural analgesia for 8. Khemka R, Chakraborty A, Ahmed R, Datta T, Agarwal S. thoracotomy pain. J Cardiothorac Vasc Anesth. 2017;31:152–158. Ultrasound-guided serratus anterior plane block in breast reconstruction surgery. A A Case Rep. 2016;6:280–282. 20. Barbera C, Milito P, Punturieri M, Asti E, Bonavina L. Serratus anterior plane block for hybrid transthoracic esophagectomy: a pilot study. JPain 9. Zocca JA, Chen GH, Puttanniah VG, Hung JC, Gulati A. Res.2017;10:73–77. Ultrasound-guided serratus plane block for treatment of postmastectomy pain syndromes in breast cancer patients: a case series. Pain Pract.2017; 21. Forero M, Adhikary SD, Lopez H, Tsui C, Chin KJ. The erector spinae 17:141–146. plane block: a novel analgesic technique in thoracic neuropathic pain. RegAnesthPainMed.2016;41:621–627. 10. Piracha MM, Thorp SL, Puttanniah V, Gulati A. “A tale of two planes”: deep versus superficial serratus plane block for postmastectomy pain 22. Searle RD, Simpson MP,Simpson KH, Milton R, Bennett MI. Can chronic syndrome. Reg Anesth Pain Med. 2017;42:259–262. neuropathic pain following thoracic surgery be predicted during the postoperative period? Interact Cardiovasc Thorac Surg. 2009;9:999–1002. 11. Kwon WK, Choi JW, Kang JE, et al. Long thoracic nerve block in video-assisted thoracoscopic wedge resection for pneumothorax. Anaesth 23. Elsharkawy H, Saifullah T, Kolli S, Drake R. Rhomboid intercostal block. Intensive Care. 2012;40:773–779. Anaesthesia. 2016;71:856–857. 12. Broseta AM, Errando C, De Andres J, Diaz-Cambronero O, Ortega-Monzo 24. Wilke J, Krause F, Vogt L, Banzer W. What is evidence-based about J. Serratus plane block: the regional analgesia technique for thoracoscopy? myofascial chains: a systematic review. Arch Phys Med Rehabil.2016;97: Anaesthesia. 2015;70:1329–1330. 454–461. 13. Kunhabdulla NP, Agarwal A, Gaur A, Gautam SK, Gupta R, Agarwal A. 25. Nasu H, Yamaguchi K, Nimura A, Akita K. An anatomic study of structure Serratus anterior plane block for multiple rib fractures. Pain Physician. and innervation of the serratus anterior muscle. Surg Radiol Anat.2012;34: 2014;17:E553–E555. 921–928. 14. Womack J, Varma MK. Serratus plane block for shoulder surgery. 26. Mayes J, Davison E, Panahi P, et al. An anatomical evaluation of the Anaesthesia. 2014;69:395–396. serratus anterior plane block. Anaesthesia. 2016;71:1064–1069.