An Expert Review of Chest Wall Fascial Plane Blocks for Cardiac Surgery.

The recent integration of regional anesthesia techniques into the cardiac surgical patient population has become a component of enhanced recovery after cardiac surgery pathways. Fascial planes of the chest wall enable single-injection or catheter-based infusions to spread local anesthetic over multiple levels of innervation. Although median sternotomy remains a common approach to cardiac surgery, minimally invasive techniques have integrated additional methods of performing cardiac surgery. Understanding the surgical approach and chest wall innervation is crucial to success in choosing the appropriate chest wall block. Parasternal intercostal plane techniques (previously termed "pectointercostal fascial plane" and "transversus thoracic muscle plane") provide anterior chest and ipsilateral sternal coverage. Anterolateral chest wall coverage is feasible with the interpectoral plane and pectoserratus plane blocks (previously termed "pectoralis") and superficial and deep serratus anterior plane blocks. The erector spinae plane block provides extensive coverage of the ipsilateral chest wall. Any of these techniques has the potential to provide bilateral chest wall analgesia. The relative novelty of these techniques requires ongoing research to be strategic, thoughtful, and focused on clinically meaningful outcomes to enable widespread evidence-based implementation. This review article discusses the key perspectives for performing and assessing chest wall blocks in a cardiac surgical population.

Analysis of the positional relationship of the long thoracic nerve considering clinical treatment.

INTRODUCTION: The long thoracic nerve (LTN) has a risk of being damaged during chest surgery and should be considered when performing anesthesia such as a serratus anterior plane block (SAPB). We analyzed the relationship between landmarks-the fourth to ninth intercostal space (ICS) at the midaxillary line (MAL), through which the distal part of the LTN passes-and the LTN. MATERIALS AND METHODS: We used 25 specimens from 17 embalmed Korean cadavers. The MAL, level of rib and ICS, and regions 5 cm anteroposterior to the MAL (aMAL/pMAL) were established to measure the position of the LTN crossing the MAL, pathway of the LTN, and entering points of the LTN to the SA. RESULTS: The LTN crossed the MAL in 76% of the specimens. The LTN crossed the MAL within the fifth to sixth rib level in 70.8%. Seventy-six percent of the branches entered the SA within the fourth to sixth ICS. The fifth rib and ICS were the most frequent regions aMAL; however, several branches were found pMAL. The LTN entered the SA in 92.6% of the specimens within 3 cm anterior and 1 cm posterior to the MAL. CONCLUSIONS: We set the danger zone as 4 cm near the MAL at the fourth to sixth ICS for thoracotomy. In addition, we proposed the fifth ICS in aMAL at the superficial plane as the alternative injection point for SAPB when blocking the LTN, and the fifth ICS in pMAL at the deep plane to prevent blocking the LTN.

Regional Anesthesia in Cardiac Surgery: An Overview of Fascial Plane Chest Wall Blocks.

Optimal analgesia is an integral part of enhanced recovery after surgery (ERAS) programs designed to improve patients' perioperative experience and outcomes. Regional anesthetic techniques in a form of various fascial plane chest wall blocks are an important adjunct to the optimal postoperative analgesia in cardiac surgery. The most common application of fascial plane chest wall blocks has been for minimally invasive cardiac surgical procedures. An abundance of case reports has been described in the anesthesia literature and reports appear promising, yet higher-level safety and efficacy evidence is lacking. Those providing anesthesia for minimally invasive cardiac procedures should become familiar with fascial plane anatomy and block techniques to be able to provide enhanced postsurgical analgesia and facilitate faster functional recovery and earlier discharge. The purpose of this review is to provide an overview of contemporary fascial plane chest wall blocks used for analgesia in cardiothoracic surgery. Specifically, we focus on relevant anatomic considerations and technical descriptions including pectoralis I and II, serratus anterior, pectointercostal fascial, transverse thoracic muscle, and erector spine plane blocks. In addition, we provide a summary of reported local anesthetic doses used for these blocks and a current state of the literature investigating their efficacy, duration, and comparisons with standard practices. Finally, we hope to stimulate further research with a focus on delineating mechanisms of action of novel emerging blocks, appropriate dosing regimens, and subsequent analysis of their effect on patient outcomes.

Two mammalian species in which the intercostal nerves innervate the serratus anterior or scalenus muscles together with the cervical nerves: an important clue to clarify the homology of cervico-thoracic trunk muscles in mammals.

The levator scapulae, rhomboideus, and serratus anterior muscles (as a group referred to the dorsal shoulder girdle muscles) and the scalenus muscles in mammals are usually innervated by cervical nerves. However, in koalas, the serratus anterior is additionally innervated by the lateral cutaneous branch of the first intercostal nerve. In cats, as in some other mammalian species, a part of the scalenus muscle (scalenus longus muscle) is innervated by the lateral cutaneous branches of the intercostal nerves. A precise comparison of the innervating nerves at the same segment in these two cases could clarify the homological relationship between the cervical and thoracic trunk muscles. In this context, the aim of this study was to follow the nerve fibers included in the nerves supplying the dorsal shoulder girdle and scalenus muscles up to the level of the spinal nerve roots in two koalas and two cats. The resultant observations revealed that both of the nerves to the serratus anterior in koalas and to the scalenus muscles in cats from the lateral cutaneous branch of the intercostal nerve occupy the same position in the spinal roots as the cervical nerve branches to the dorsal shoulder girdle muscles and the thoracic nerve branches to the external intercostal muscle. Based on these results, the axial trunk muscles in the cervico-thoracic region could be classified as follows: the scalenus and dorsal shoulder girdle muscles belong to the same lateral axial trunk muscle group as the external intercostal muscle, and are clearly distinguished from the medial group, such as the internal and innermost intercostal muscle.

Bloqueos de pared anterior de tórax en cirugía de cáncer de mama: estudio comparativo retrospectivo de casos y controles / Chest wall blocks for breast cancer surgery: A retrospective comparative case-control study

Objetivos: Determinar eficacia analgésica perioperatoria de bloqueos de la pared anterior del tórax (BLOC) en cirugía de cáncer de mama (CCM), valorando requerimientos de opioides intraoperatorio, intensidad de dolor y necesidad de analgesia durante las primeras 24 h del postoperatorio. Materiales y métodos: Estudio retrospectivo comparativo de casos y controles. Se revisaron 112 historias de pacientes sometidas a CCM durante marzo-octubre del 2016. El grupo 1 estuvo conformado por 25 pacientes sometidas a CCM bajo anestesia general total intravenosa (TIVA)+BLOC; el grupo 2 por 24 pacientes sometidas a CCM bajo TIVA. Se excluyó a pacientes que recibieron otro tipo de técnica anestésica locorregional, anestesia inhalatoria u otro opioide diferente de fentanilo. Resultados: Los requerimientos de fentanilo intraoperatorio (μg/kg/h) fueron menores en el grupo 1 que en grupo 2 (TIVA+BLOC: 0,486±0,561; TIVA: 2,415+0,922); no se administró fentanilo durante el acto anestésico-quirúrgico en el 48% de las pacientes del grupo 1. Solo se registraron puntuaciones menores en la intensidad del dolor medida con la escala verbal numérica (EVN) en el grupo 1 a las 6 y 12 h poscirugía. Conclusiones: El uso de BLOC redujo significativamente los requerimientos de opioides intraoperatorios. No hubo diferencias en los requerimientos de analgesia suplementaria durante las primeras 24 h

Objectives: To determine the analgesic effect of chest wall blocks (BLOCs) in breast cancer surgery (BCS) by measuring intraoperative opioid requirements, pain intensity and supplementary analgesia requirements during the first 24hours after surgery. Materials and methods: Retrospective comparative case-control study. We reviewed 112 medical records of patients who underwent BCS from March to October 2016. Group 1 was composed of 25 patients who underwent BCS under total intravenous anaesthesia (TIVA) and BLOCs; group 2 was composed of 24 patients with BCS under TIVA. Patients who underwent another type of locoregional anaesthetic technique, received inhaled anaesthesia or an opioid other than fentanyl were excluded. Results: Intraoperative fentanyl requirements (μg/kg/hour) were much lower in group 1 (TIVA+BLOCs: 0.486+0.561, TIVA: 2.415+0.922). Fentanyl was not administered during anaesthesia/surgery in 48% of patients in group 1. Group 1 reported lower scores on the numeric verbal scale (NVS) of pain at 6 and 12hours after surgery. Conclusions: The use of BLOCs reduced intraoperative opioid requirements, but there was no difference in the requirements for supplementary analgesia during the first 24hours

Rhomboid Intercostal and Subserratus Plane Block: A Cadaveric and Clinical Evaluation.

BACKGROUND AND OBJECTIVES: Fascial plane blocks are rapidly emerging to provide safe, feasible alternatives to epidural analgesia for thoracic and abdominal pain. We define a new option for chest wall and upper abdominal analgesia, termed the rhomboid intercostal and subserratus plane (RISS) block. The RISS tissue plane extends deep to the erector spinae muscle medially and deep to the serratus anterior muscle laterally. We describe a 2-part proof-of-concept study to validate the RISS block, including a cadaveric study to evaluate injectate spread and a retrospective case series to assess dermatomal coverage and analgesic efficacy. METHODS: For the cadaveric portion of the study, bilateral ultrasound-guided RISS blocks were performed on 6 fresh cadavers with 30 mL of 0.5% methylcellulose with india ink. For the retrospective case series, we present 15 patients who underwent RISS block or RISS catheter insertion for heterogeneous indications including abdominal surgery, rib fractures, chest tube-associated pain, or postoperative incisional chest wall pain. RESULTS: In the cadaveric specimens, we identified staining of the lateral branches of the intercostal nerves from T3 to T9 reaching the posterior primary rami deep to the erector spinae muscle medially. In the clinical case series, dermatomal coverage was observed in the anterior hemithorax with visual analog pain scores less than 5 in patients who underwent both single-shot and continuous catheter infusions. CONCLUSIONS: Our preliminary cadaveric and clinical data suggest that RISS block anesthetizes the lateral cutaneous branches of the thoracic intercostal nerves and can be used in multiple clinical settings for chest wall and upper abdominal analgesia.

Erector Spinae Plane Block for Surgery of the Posterior Thoracic Wall in a Pediatric Patient.

OBJECTIVE: Historically, regional anesthesia for surgery on the posterior thoracic wall has been limited to neuraxial and paravertebral nerve blocks. The erector spinae plane (ESP) block is a novel technique that anesthetizes the dorsal rami of the spinal nerves innervating the posterior thoracic wall. We report the use of the ESP block for this clinical application in a pediatric patient. CASE REPORT: A healthy 3-year-old girl was scheduled for resection of a giant paraspinal lipoma extending over the T4-T7 dermatomes. She received a preoperative single-shot ESP block at the level of the T1 transverse process; this level was chosen to avoid the lipoma and cover the planned surgical incision over the T2-T8 dermatomes. Hemodynamic stability and excellent pain control perioperatively were obtained with minimal anesthetic requirements and no systemic analgesics apart from fentanyl administered for induction of anesthesia. Return to normal function (ambulation, feeding, and communication) was achieved within 2 hours after surgery. A pain score of 0 on the FLACC (Face, Legs, Activity, Cry, Consolability) scale was maintained until discharge from the hospital 4 hours after the surgery. First analgesic use was 18 hours after hospital discharge. No complications were reported. CONCLUSIONS: The ESP block is an effective option for surgery on the posterior thoracic wall. The opioid- and anesthetic-sparing effects exhibited in this case facilitated rapid postoperative recovery and early discharge.

An anatomical evaluation of the serratus anterior plane block.

The serratus anterior plane block has been described for analgesia of the hemithorax. This study was conducted to determine the spread of injectate and investigate the anatomical basis of the block. Ultrasound-guided serratus anterior plane block was performed on six soft-fix embalmed cadavers. All cadavers received bilateral injections, on one side performed with 20 ml latex and on the other with 20 ml methylene blue. Subsequent dissection explored the extent of spread and nerve involvement. Photographs were taken throughout dissection. The intercostal nerves were involved on three occasions with dye, but not with latex. The lateral cutaneous branches of the intercostal nerve contained dye and latex on all occasions. The serratus plane block appears to be mediated through blockade of the lateral cutaneous branches of the intercostal nerves. Anatomically, serratus plane block does not appear to be equivalent to paravertebral block for rib fracture analgesia.

Imaging of Thoracic Neurogenic Tumors.

OBJECTIVE: Thoracic neurogenic neoplasms may be a diagnostic challenge both clinically and radiologically, ranging from benign, incidentally discovered tumors to aggressive, symptomatic malignancies. These tumors may originate from any nervous structure within the chest and are derived from cells of the nerve sheath, autonomic ganglia, or paraganglia. The nervous anatomy of the thorax is complex, and neurogenic tumors may be found in any mediastinal compartment or in the chest wall. Furthermore, neurogenic tumors may indicate one of many syndromes, particularly when they are multiple. CONCLUSION: This article illustrates the complex anatomy of the nervous system within the chest and details important epidemiologic and pathophysiologic features as an approach to neurogenic tumors of the thorax. Key imaging features of neurogenic tumors occurring in the chest are identified, focusing on distinguishing characteristics and the relative advantages of available imaging modalities to further refine a differential diagnosis.

Does a minimal invasive approach reduce anterior chest wall numbness and postoperative pain in plate fixation of clavicle fractures?

BACKGROUND: Fractures of the clavicle present very common injuries with a peak of incidence in young active patients. Recently published randomized clinical trials demonstrated an improved functional outcome and a lower rate of nonunions in comparison to non-operative treatment. Anterior chest wall numbness due to injury of the supraclavicular nerve and postoperative pain constitute common surgery related complications in plate fixation of displaced clavicle fractures. We recently developed a technique for mini open plating (MOP) of the clavicle to reduce postoperative numbness and pain. The purpose of this study was to analyze the size of anterior chest wall numbness and the intensity of postoperative pain in MOP in comparison to conventional open plating (COP) of clavicle fractures. METHODS: 24 patients (mean age 38.2 ± 14.2 yrs.) with a displaced fracture of the clavicle (Orthopaedic Trauma Association B1.2-C1.2) surgically treated using a locking compression plate (LCP) were enrolled. 12 patients underwent MOP and another 12 patients COP. Anterior chest wall numbness was measured with a transparency grid on the second postoperative day and at the six months follow-up. Postoperative pain was evaluated using the Visual Analog Scale (VAS). RESULTS: Mean ratio of skin incision length to plate length was 0.61 ± 0.04 in the MOP group and 0.85 ± 0.06 in the COP group (p < 0.05). Mean ratio of the area of anterior chest wall numbness to plate length was postoperative 7.6 ± 5.9 (six months follow-up 4.7 ± 3.9) in the MOP group and 22.1 ± 19.1 (16.9 ± 14.1) in the COP group (p < 0.05). Mean VAS was 2.6 ± 1.4 points in the MOP group and 3.4 ± 1.6 points in the COP group (p = 0.20). CONCLUSIONS: In our study, MOP significantly reduced anterior chest wall numbness in comparison to a conventional open approach postoperative as well as at the six months follow-up. Postoperative pain tended to be lower in the MOP group, however this difference was not statistically significant. TRIAL REGISTRATION: ClinicalTrials.gov NCT02247778 . Registered 21 September 2014.

Modulation of chest wall intermuscular coherence: effects of lung volume excursion and transcranial direct current stimulation.

Chest wall muscle recruitment varies as a function of the breathing task performed. However, the cortical control of the chest wall muscles during different breathing tasks is not known. We studied chest wall intermuscular coherence during various task-related lung volume excursions in 10 healthy adults (34 ± 15 yr; 2 men, 8 women) and determined if transcranial direct current stimulation (tDCS) could modulate chest wall intermuscular coherence during these tasks. Simultaneous assessment of regional intercostal and oblique electromyographic activity was measured while participants performed standardized tidal breathing, speech, maximum phonation, and vital capacity tasks. Lung volume and chest wall kinematics were determined using variable inductance plethysmography. We found that chest wall area of intermuscular coherence was greater during tidal and speech breathing compared with phonation and vital capacity (all P < 0.05) and between tidal breathing compared with speech breathing (P < 0.05). Anodal tDCS increased chest wall area of intermuscular coherence from 0.04 ± 0.09 prestimulation to 0.18 ± 0.19 poststimulation for vital capacity (P < 0.05). Sham tDCS and cathodal tDCS had no effect on coherence during lung volume excursions. Chest wall kinematics were not affected by tDCS. Our findings indicate that lung volume excursions about the midrange of vital capacity elicit a greater area of chest wall intermuscular coherence compared with lung volume excursions spanning the entire range of vital capacity in healthy adults. Our findings also demonstrate that brief tDCS may modulate the cortical control of the chest wall muscles in a stimulation- and lung volume excursion task-dependent manner but does not affect chest wall kinematics in healthy adults.

An anatomic study of structure and innervation of the serratus anterior muscle.

BACKGROUND: The structure and function of the serratus anterior muscle are partitioned into three parts. If the morphological characteristics in each part can be demonstrated in more detail, the cause of dysfunction will probably be identifiable more accurately. The purpose of this study was to demonstrate the details of the structure and innervation in each part of the serratus anterior muscle. MATERIALS AND METHODS: This macroscopic anatomic study was conducted using ten sides from five cadavers. The structure and innervation in each part of this muscle were examined. RESULTS: In the superior part, the independent branch was divided from a branch innervating the levator scapulae muscle. In the middle part, the long thoracic nerve descended on one-third of the anterior region between the origin and insertion. In the inferior part, the long thoracic nerve which ramified into many branches and branches from the intercostal nerves were distributed on all sides. CONCLUSION: This study demonstrated that the innervation of the serratus anterior muscle was different in each part. The difference indicates that the superior part has an intimate relation with the levator scapulae muscle while the middle and inferior parts could be the actual serratus anterior muscle. Moreover, the distribution of branches from the intercostal nerves shows that the inferior part has a connection with some trunk elements. Understanding these characteristics of innervation is useful to identify the cause of dysfunction. In addition, we assert that the constant distribution of branches from the intercostal nerves is significant for the morphology.

Recovery of sensation in the anterior chest area after bilateral axillo-breast approach endoscopic/robotic thyroidectomy.

BACKGROUND: There is concern that endoscopic/robotic thyroidectomy could impair anterior chest skin sensation. Here, this possibility was assessed. PATIENTS AND METHODS: Fifty-one patients who underwent bilateral axillo-breast approach endoscopic/robotic thyroidectomy were asked 8 to 115 days (median: 29 d) later to undergo Semmes-Weinstein pressure threshold testing and to complete a questionnaire. Patient clinicopathological details were extracted. RESULTS: Twenty-one patients (41.2%) showed sensory impairment (sum of sensory changes ≥ 1). The average sum of sensory change (scale of 0 to 95) was 1.4 (range, 0 to 8). Impaired patients did not differ from unimpaired patients in any clinicopathological parameter except for time from operation. Compared with 1 month postsurgery, there was significantly less sensory impairment 3 months postsurgery (P=0.0083). The questionnaires yielded similar observations. CONCLUSIONS: The temporary and mild nature of the sensory change in the anterior chest area will relieve surgeons and patients from concerns that bilateral axillo-breast approach endoscopic/robotic thyroidectomy could permanently impair chest sensation.

Treatment of chronic chest wall pain in a patient with Loeys-Dietz syndrome using spinal cord stimulation.

OBJECTIVE: Spinal cord stimulation (SCS) has been used with increased frequency for the treatment of intractable pain including chronic chest pain. METHODS: The patient with a history of Loeys-Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain underwent an uneventful SCS trial with percutaneous epidural placement of two temporary eight-electrode leads placed at the level of T3-T4-T5. RESULTS: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and rechargeable generator four weeks later and reported sustained pain relief at 12-month follow-up visit. CONCLUSION: SCS provides an effective, alternative treatment option for select patients with Loeys-Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain who have failed conservative treatment. SCS may provide pain relief with advantages over conservative treatments and more invasive techniques.