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Kamen V. Vlassakov - One of the best experts on this subject based on the ideXlab platform.
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The ultrasound-guided proximal intercostal block: anatomical study and clinical correlation to analgesia for breast surgery.
BMC Anesthesiology, 2019Co-Authors: Nantthasorn Zinboonyahgoon, Panya Luksanapruksa, Sitha Piyaselakul, Pawinee Pangthipampai, Suphalerk Lohasammakul, Choopong Luansritisakul, Sunsanee Mali-ong, Nawaporn Sateantantikul, Theera Chueaboonchai, Kamen V. VlassakovAbstract:Background The ultrasound-guided proximal intercostal block (PICB) is performed at the proximal intercostal space (ICS) between the internal intercostal membrane (IIM) and the Endothoracic Fascia/parietal pleura (EFPP) complex. Injectate spread may follow several routes and allow for multilevel trunk analgesia. The goal of this study was to examine the anatomical spread of large-volume PICB injections and its relevance to breast surgery analgesia.
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The ultrasound-guided proximal intercostal block: anatomical study and clinical correlation to analgesia for breast surgery
BMC Anesthesiology, 2019Co-Authors: Nantthasorn Zinboonyahgoon, Panya Luksanapruksa, Sitha Piyaselakul, Pawinee Pangthipampai, Suphalerk Lohasammakul, Choopong Luansritisakul, Sunsanee Mali-ong, Nawaporn Sateantantikul, Theera Chueaboonchai, Kamen V. VlassakovAbstract:Background The ultrasound-guided proximal intercostal block (PICB) is performed at the proximal intercostal space (ICS) between the internal intercostal membrane (IIM) and the Endothoracic Fascia/parietal pleura (EFPP) complex. Injectate spread may follow several routes and allow for multilevel trunk analgesia. The goal of this study was to examine the anatomical spread of large-volume PICB injections and its relevance to breast surgery analgesia. Methods Fifteen two-level PICBs were performed in ten soft-embalmed cadavers. Radiographic contrast mixed with methylene blue was injected at the 2nd(15 ml) and 4th(25 ml) ICS, respectively. Fluoroscopy and dissection were performed to examine the injectate spread. Additionally, the medical records of 12 patients who had PICB for breast surgery were reviewed for documented dermatomal levels of clinical hypoesthesia. The records of twelve matched patients who had the same operations without PICB were reviewed to compare analgesia and opioid consumption. Results Median contrast/dye spread was 4 (2–8) and 3 (2–5) vertebral segments by fluoroscopy and dissection respectively. Dissection revealed injectate spread to the adjacent paravertebral space, T3 (60%) and T5 (27%), and cranio-caudal spread along the Endothoracic Fascia (80%). Clinically, the median documented area of hypoesthesia was 5 (4–7) dermatomes with 100 and 92% of the injections covering adjacent T3 and T5 dermatomes, respectively. The patients with PICB had significantly lower perioperative opioid consumption and trend towards lower pain scores. Conclusions In this anatomical study, PICB at the 2nd and 4th ICS produced lateral spread along the corresponding intercostal space, medial spread to the adjacent paravertebral/epidural space and cranio-caudal spread along the Endothoracic Fascial plane. Clinically, combined PICBs at the same levels resulted in consistent segmental chest wall analgesia and reduction in perioperative opioid consumption after breast surgery. The incomplete overlap between paravertebral spread in the anatomical study and area of hypoesthesia in our clinical findings, suggests that additional non-paravertebral routes of injectate distribution, such as the Endothoracic Fascial plane, may play important clinical role in the multi-level coverage provided by this block technique.
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The Ultrasound-guided Proximal Intercostal Block: Anatomical study and clinical correlation to analgesia for breast surgery
2019Co-Authors: Nantthasorn Zinbonyahgoon, Panya Luksanapruksa, Sitha Piyaselakul, Pawinee Pangthipampai, Suphalerk Lohasammakul, Choopong Luansritisakul, Sunsanee Mali-ong, Nawaporn Sateantantikul, Theera Chueaboonchai, Kamen V. VlassakovAbstract:Abstract Background: The ultrasound-guided proximal intercostal block (PICB) is performed at the proximal intercostal space (ICS) between the internal intercostal membrane (IIM) and the Endothoracic Fascia/parietal pleura (EFPP) complex. Injectate spread may follow several routes and allow for multilevel trunk analgesia. The goal of this study was to examine the anatomical spread of large-volume PICB injections and its relevance to breast surgery analgesia. Methods: Fifteen two-level PICBs were performed in ten soft-embalmed cadavers. Radiographic contrast mixed with methylene blue was injected at the 2nd(15ml) and 4th(25ml) ICS, respectively. Fluoroscopy and dissection were performed to examine the injectate spread. Additionally, the medical records of 12 patients who had PICB for breast surgery were reviewed for documented dermatomal levels of clinical hypoesthesia. The records of twelve matched patients who had the same operations without PICB were reviewed to compare analgesia and opioid consumption. Results: Median contrast/dye spread was 4(2-8) and 3(2-5) vertebral segments by fluoroscopy and dissection respectively. Dissection revealed injectate spread to the adjacent paravertebral space, T3 (60%) and T5 (27%), and cranio-caudal spread along the Endothoracic Fascia (80%). Clinically, the median documented area of hypoesthesia was 5(4-7) dermatomes with 100% and 92% of the injections covering adjacent T3 and T5 dermatomes, respectively. The patients with PICB had significantly lower perioperative opioid consumption and trend towards lower pain scores. Conclusions: In this anatomical study, PICB at the 2nd and 4th ICS produced lateral spread along the corresponding intercostal space, medial spread to the adjacent paravertebral/epidural space and cranio-caudal spread along the Endothoracic Fascial plane. Clinically, combined PICBs at the same levels resulted in consistent segmental chest wall analgesia and reduction in perioperative opioid consumption after breast surgery. The incomplete overlap between paravertebral spread in the anatomical study and area of hypoesthesia in our clinical findings, suggests that additional non-paravertebral routes of injectate distribution, such as the Endothoracic Fascial plane, may play important clinical role in the multi-level coverage provided by this block technique. Keywords: Nerve block, paravertebral space, intercostal space, intercostal block, breast surgery.
Toshiyuki Saito - One of the best experts on this subject based on the ideXlab platform.
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Pathways of anesthetic from the thoracic paravertebral region to the celiac ganglion.
Clinical Anatomy, 2002Co-Authors: Toshiyuki Saito, Kumiko Tanuma, Yutaka Tanuma, Shulan Den, Kunihisa Miyakawa, Edward Carney, Christer CarlssonAbstract:Communication between the lower thoracic paravertebral region and the celiac ganglion through the retrocrural space was investigated. After dye was injected into the Endothoracic Fascia in the lower thoracic paravertebral region at the T11 level, its spread to the celiac ganglion was examined in fifteen cadavers. The dye reached the celiac ganglion in nine cadavers (60%) by passing through the retrocrural space, along the greater and lesser splanchnic nerves and through the split in the crus of the diaphragm through which the splanchnic nerves traveled. In the remaining six cadavers, dye spread toward the ganglion along the crus of the diaphragm. In three living subjects the spread of a radio-opaque dye injected in the same manner was studied using 3D-computed tomography. This study confirmed that the radio-opaque dye traveled toward the celiac ganglion along the crus of the diaphragm. From our results we suggest that a fluid communication may exist between the lower thoracic paravertebral region and the celiac ganglion in cadavers and in living humans and that clinicians should be aware of this possible route of spread when administering lower thoracic paravertebral anesthesia.
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Appendectomy in rabbits with extended unilateral anesthesia.
Experimental Animals, 2002Co-Authors: Toshiyuki Saito, Kumiko Tanuma, Yutaka Tanuma, Choichiro Futami, Kazuhiro Shichinohe, Madoka Shimizu, Mitsuru Sasako, James Shafland, Boarderman C. Wang, Christer CarlssonAbstract:Thoracic paravertebral anesthesia was not believed to accompany numbness in the lumbar nerve region. However, we recently discovered that thoracic paravertebral anesthesia could produce analgesia in the lumbar region. We called this block extended unilateral anestheia. In this study, appendectomy was attempted in rabbits with extended unilateral anesthesia. After a catheter was inserted into the Endothoracic Fascia in the paravertebral region on the right side at the level of the 11th thoracic vertebra, a 3-ml dose of 2% mepivacaine was injected repeatedly through the catheter. After an injection of the local anesthetic we could observe motor and sensory paralysis unilaterally from the chest down to the lower limb in all the rabbits, the extended unilateral anesthesia. With this anesthesia, we could accomplish appendectomy. This is the initial report of extended unilateral anesthesia applied to appendectomy in rabbits. We think that this anesthesia could be beneficial in future medical and veterinary use.
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Anatomical bases of the spread of anesthetic solution in the paravertebral region.
Journal of Nippon Medical School, 2002Co-Authors: Toshiyuki SaitoAbstract:An injection of a local anesthetic in the paravertebral region produces an analgesic field on the same side of the body. However, the spread of the anesthetic solution in the Endothoracic Fascia in the paravertebral region is not clearly elucidated yet. One point in question about the block in this region is whether the local anesthetic spreads from the thoracic to the lumbar level of the paravertebral region. We investigated how the anesthetic fluid traveled to the lumbar paravertebral region. A dye was injected into the paravertebral region in the thoracic cavity of cadavers to study the spread of the anesthetic solution. The dye spread into the abdominal cavity through the medial and lateral arcuate ligaments of the diaphragm while the dye also spread in the chest cavity in the Endothoracic Fascia posterior to the parietal pleura. In the abdominal cavity, the dye was found to have spread so widely in the transversalis Fascia that the subcostal, iliohypogastric, ilioinguinal, genitofemoral, lateral femoral cutaneous and femoral nerves, and the celiac ganglion were involved. Although the cadavers were fixed with formalin solution and although there was no blood circulation in the cadavers, the spread of the dye was comparable to the analgesic region produced by anesthetic solution in the human study in previous studies(ref. 3, 4). The functional structure around the vertebral column is yet to be elucidated.
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Extended Unilateral Anesthesia: New Technique or Paravertebral Anesthesia?
Regional anesthesia, 1996Co-Authors: Toshiyuki Saito, Edward T. Gallagher, Stephen Cutler, Kumiko Tanuma, Koki Yamada, Noriyuki Saito, Koichi Maruyama, Christer CarlssonAbstract:Background and Objectives The authors previously reported a case in which injection of local anesthetic posterior to the Endothoracic Fascia at the T11 vertebral level gave rise to extended analgesia in thoracic and lumbar dermatomes. They now report a study in which this type of anesthesia was used in patients undergoing herniorrhaphy. Methods A 12-mL dose of 2% mepivacaine was injected at the T11 level posterior to the Endothoracic Fascia in 15 patients. Results On average, seven dermatomes could be blocked with this dose and with a single injection. Nine patients experienced adequate analgesia and underwent operation with no additional sedation. In three patients the block resulted in inadequate analgesia, and additional sedative drugs were used. Three patients experienced no analgesia and were given general anesthesia. Conclusion Injection of local anesthetic posterior to the Endothoracic Fascia resulted in extended unilateral anesthesia that was adequate for herniorrhaphy in 9 of the 15 patients (60%) studied.
Christer Carlsson - One of the best experts on this subject based on the ideXlab platform.
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Pathways of anesthetic from the thoracic paravertebral region to the celiac ganglion.
Clinical Anatomy, 2002Co-Authors: Toshiyuki Saito, Kumiko Tanuma, Yutaka Tanuma, Shulan Den, Kunihisa Miyakawa, Edward Carney, Christer CarlssonAbstract:Communication between the lower thoracic paravertebral region and the celiac ganglion through the retrocrural space was investigated. After dye was injected into the Endothoracic Fascia in the lower thoracic paravertebral region at the T11 level, its spread to the celiac ganglion was examined in fifteen cadavers. The dye reached the celiac ganglion in nine cadavers (60%) by passing through the retrocrural space, along the greater and lesser splanchnic nerves and through the split in the crus of the diaphragm through which the splanchnic nerves traveled. In the remaining six cadavers, dye spread toward the ganglion along the crus of the diaphragm. In three living subjects the spread of a radio-opaque dye injected in the same manner was studied using 3D-computed tomography. This study confirmed that the radio-opaque dye traveled toward the celiac ganglion along the crus of the diaphragm. From our results we suggest that a fluid communication may exist between the lower thoracic paravertebral region and the celiac ganglion in cadavers and in living humans and that clinicians should be aware of this possible route of spread when administering lower thoracic paravertebral anesthesia.
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Appendectomy in rabbits with extended unilateral anesthesia.
Experimental Animals, 2002Co-Authors: Toshiyuki Saito, Kumiko Tanuma, Yutaka Tanuma, Choichiro Futami, Kazuhiro Shichinohe, Madoka Shimizu, Mitsuru Sasako, James Shafland, Boarderman C. Wang, Christer CarlssonAbstract:Thoracic paravertebral anesthesia was not believed to accompany numbness in the lumbar nerve region. However, we recently discovered that thoracic paravertebral anesthesia could produce analgesia in the lumbar region. We called this block extended unilateral anestheia. In this study, appendectomy was attempted in rabbits with extended unilateral anesthesia. After a catheter was inserted into the Endothoracic Fascia in the paravertebral region on the right side at the level of the 11th thoracic vertebra, a 3-ml dose of 2% mepivacaine was injected repeatedly through the catheter. After an injection of the local anesthetic we could observe motor and sensory paralysis unilaterally from the chest down to the lower limb in all the rabbits, the extended unilateral anesthesia. With this anesthesia, we could accomplish appendectomy. This is the initial report of extended unilateral anesthesia applied to appendectomy in rabbits. We think that this anesthesia could be beneficial in future medical and veterinary use.
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Extended Unilateral Anesthesia: New Technique or Paravertebral Anesthesia?
Regional anesthesia, 1996Co-Authors: Toshiyuki Saito, Edward T. Gallagher, Stephen Cutler, Kumiko Tanuma, Koki Yamada, Noriyuki Saito, Koichi Maruyama, Christer CarlssonAbstract:Background and Objectives The authors previously reported a case in which injection of local anesthetic posterior to the Endothoracic Fascia at the T11 vertebral level gave rise to extended analgesia in thoracic and lumbar dermatomes. They now report a study in which this type of anesthesia was used in patients undergoing herniorrhaphy. Methods A 12-mL dose of 2% mepivacaine was injected at the T11 level posterior to the Endothoracic Fascia in 15 patients. Results On average, seven dermatomes could be blocked with this dose and with a single injection. Nine patients experienced adequate analgesia and underwent operation with no additional sedation. In three patients the block resulted in inadequate analgesia, and additional sedative drugs were used. Three patients experienced no analgesia and were given general anesthesia. Conclusion Injection of local anesthetic posterior to the Endothoracic Fascia resulted in extended unilateral anesthesia that was adequate for herniorrhaphy in 9 of the 15 patients (60%) studied.
Giuseppe Miserocchi - One of the best experts on this subject based on the ideXlab platform.
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From morphological heterogeneity at alveolar level to the overall mechanical lung behavior: an in vivo microscopic imaging study
Physiological Reports, 2014Co-Authors: Enrico Mazzuca, Caterina Salito, Ilaria Rivolta, Andrea Aliverti, Giuseppe MiserocchiAbstract:In six male anesthetized, tracheotomized, and mechanically ventilated rabbits, we imaged subpleural alveoli under microscopic view (60×) through a “pleural window” obtained by stripping the Endothoracic Fascia and leaving the parietal pleura intact. Three different imaging scale levels were identified for the analysis on increasing stepwise local distending pressure ( P ld) up to 16.5 cmH2O: alveoli, alveolar cluster, and whole image field. Alveolar profiles were manually traced, clusters of alveoli of similar size were identified through a contiguity‐constrained hierarchical agglomerative clustering analysis and alveolar surface density (ASD) was estimated as the percentage of air on the whole image field. Alveolar area distributions were remarkably right‐skewed and showed an increase in median value with a large topology‐independent heterogeneity on increasing P ld. Modeling of alveolar area distributions on increasing P ld led to hypothesize that absolute alveolar compliance (change in surface area over change in P ld) increases fairly linearly with increasing initial alveolar size, the corollary of this assumption being a constant specific compliance. Clusters were reciprocally interweaved due to their highly variable complex shapes. ASD was found to increase with a small coefficient of variation (CV
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Alveolar mechanics studied by closed-chest in-vivo microscopy
European Respiratory Journal, 2013Co-Authors: Enrico Mazzuca, Caterina Salito, Ilaria Rivolta, Andrea Aliverti, Giuseppe MiserocchiAbstract:In vivo microscopy is a useful tool to study lung alveolar mechanics (Schiller et al. Crit Care Med 2001; 29: 1049–1055). A new surgical approach is here proposed to image changes in alveolar morphology through the intact pleura in order to partition between elastic and surface tension (γ) forces involved in lung volume change. In 6 male anesthetized, tracheotomized and mechanically ventilated rabbits, a “pleural window” was opened by stripping the Endothoracic Fascia (Fig. 1a). Subpleural alveoli were observed under microscopic view (60x) during stepwise inflation/deflation maneuvers, starting from FRC. Alveolar areas were measured through a custom software and median values from all rabbits were used to produce an overall local distending pressure Pld-alveolar radius curve (Fig. 1b). A mathematical model, based on an asymptotic increase of γ with increasing radius from a minimal value γ to a maximum γmax, allowed to derive surfactant (Pγ) and elastic (Pel) contributions to Pld. Alveolar radius increased up to a maximum at a local distending pressure of 10 cmH2O with negligible hysteresis. Experimental data are well fitted by computed curves for Pγ, with (γ; γmax) values ranging from (3; 15) up to (3; 21) dynes/cm. Our results suggest that Pγ is only responsible for alveolar distension within a lung volume change from FRC up to ∼80% of inspiratory capacity. An increase in Pel only allows a further minor increase in alveolar volume. ![Figure][1] [1]: pending:yes
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Microvascular pressure profile in intact in situ lung.
Journal of Applied Physiology, 1992Co-Authors: Daniela Negrini, Christopher Gonano, Giuseppe MiserocchiAbstract:We measured the microvascular pressure profile in lungs physiologically expanded in the pleural space at functional residual capacity. In 29 anesthetized rabbits a caudal intercostal space was cleared of its external and internal muscles. A small area of Endothoracic Fascia was surgically thinned, exposing the parietal pleura through which pulmonary vessels were clearly detectable under stereomicroscopic view. Pulmonary microvascular pressure was measured with glass micropipettes connected to a servo-null system. During the pressure measurements the animal was kept apneic and 50% humidified oxygen was delivered in the trachea. Pulmonary arterial and left atrial pressures were 22.3 +/- 1.5 and 1.6 +/- 1.5 (SD) cmH2O, respectively. The segmental pulmonary vascular pressure drop expressed as a percentage of the pulmonary arterial to left atrial pressure was approximately 33% from pulmonary artery to approximately 130-microns-diam arterioles, 4.5% from approximately 130- to approximately 60-microns-diam arterioles, approximately 46% from approximately 60-microns-diam arterioles to approximately 30-microns-diam venules, approximately 9.5% from 30- to 150-microns-diam venules, and approximately 7% for the remaining venous segment. Pulmonary capillary pressure was estimated at approximately 9 cmH2O.
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Parenchymal stress affects interstitial and pleural pressures in in situ lung
Journal of Applied Physiology, 1991Co-Authors: Giuseppe Miserocchi, Daniela Negrini, Christopher GonanoAbstract:After resecting the intercostal muscles and thinning the Endothoracic Fascia, we micropunctured the lung tissue through the intact pleural space at functional residual capacity (FRC) and at volumes above FRC to evaluate the effect of increasing parenchymal stresses on pulmonary interstitial pressure (Pip). Pip was measured at a depth of approximately 230 microns from the pleural surface, at 50% lung height, in 12 anesthetized paralyzed rabbits oxygenated via a tracheal tube with 50% humidified O2. Pip was -10 +/- 1.5 cmH2O at FRC. At alveolar pressure of 5 and 10 cmH2O, lung volume increased by 8.5 and 19 ml and Pip decreased to -12.4 +/- 1.6 and -12.3 +/- 5 cmH2O, respectively. For the same lung volumes held by decreasing pleural surface pressure to about -5 and -8.5 cmH2O, Pip decreased to -17.4 +/- 1.6 and -23.8 +/- 5 cmH2O, respectively. Because Pip is more negative than pleural pressure, the data suggest that in intact pulmonary interstitium the pressure of the liquid phase is primarily set by the mechanisms controlling interstitial fluid turnover.
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Direct measurement of interstitial pulmonary pressure in in situ lung with intact pleural space.
Journal of Applied Physiology, 1990Co-Authors: Giuseppe Miserocchi, Daniela Negrini, Christopher GonanoAbstract:We developed an experimental approach to measure the pulmonary interstitial pressure with the micropuncture technique in in situ lungs with an intact pleural space. Experiments were done in anesthetized paralyzed rabbits that were oxygenated via an endotracheal tube with 50% humidified oxygen and kept in either the supine or the lateral position. A small area of an intercostal space was cleared of the intercostal muscles down to the Endothoracic Fascia. Subsequently a "pleural window" was opened by stripping the Endothoracic Fascia over a 0.2-cm2 surface and leaving the parietal pleura (approximately 10 microns thick). Direct micropuncture through the pleural window was performed with 2- to 3-microns-tip pipettes connected to a servo-null pressure-measuring system. We recorded pleural liquid pressure and, after inserting the pipette tip into the lung, we recorded interstitial pressure from subpleural lung tissue. Depth of recording for interstitial pressure averaged 263 +/- 122 (SD) microns. We report dat...
Sunsanee Mali-ong - One of the best experts on this subject based on the ideXlab platform.
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The ultrasound-guided proximal intercostal block: anatomical study and clinical correlation to analgesia for breast surgery.
BMC Anesthesiology, 2019Co-Authors: Nantthasorn Zinboonyahgoon, Panya Luksanapruksa, Sitha Piyaselakul, Pawinee Pangthipampai, Suphalerk Lohasammakul, Choopong Luansritisakul, Sunsanee Mali-ong, Nawaporn Sateantantikul, Theera Chueaboonchai, Kamen V. VlassakovAbstract:Background The ultrasound-guided proximal intercostal block (PICB) is performed at the proximal intercostal space (ICS) between the internal intercostal membrane (IIM) and the Endothoracic Fascia/parietal pleura (EFPP) complex. Injectate spread may follow several routes and allow for multilevel trunk analgesia. The goal of this study was to examine the anatomical spread of large-volume PICB injections and its relevance to breast surgery analgesia.
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The ultrasound-guided proximal intercostal block: anatomical study and clinical correlation to analgesia for breast surgery
BMC Anesthesiology, 2019Co-Authors: Nantthasorn Zinboonyahgoon, Panya Luksanapruksa, Sitha Piyaselakul, Pawinee Pangthipampai, Suphalerk Lohasammakul, Choopong Luansritisakul, Sunsanee Mali-ong, Nawaporn Sateantantikul, Theera Chueaboonchai, Kamen V. VlassakovAbstract:Background The ultrasound-guided proximal intercostal block (PICB) is performed at the proximal intercostal space (ICS) between the internal intercostal membrane (IIM) and the Endothoracic Fascia/parietal pleura (EFPP) complex. Injectate spread may follow several routes and allow for multilevel trunk analgesia. The goal of this study was to examine the anatomical spread of large-volume PICB injections and its relevance to breast surgery analgesia. Methods Fifteen two-level PICBs were performed in ten soft-embalmed cadavers. Radiographic contrast mixed with methylene blue was injected at the 2nd(15 ml) and 4th(25 ml) ICS, respectively. Fluoroscopy and dissection were performed to examine the injectate spread. Additionally, the medical records of 12 patients who had PICB for breast surgery were reviewed for documented dermatomal levels of clinical hypoesthesia. The records of twelve matched patients who had the same operations without PICB were reviewed to compare analgesia and opioid consumption. Results Median contrast/dye spread was 4 (2–8) and 3 (2–5) vertebral segments by fluoroscopy and dissection respectively. Dissection revealed injectate spread to the adjacent paravertebral space, T3 (60%) and T5 (27%), and cranio-caudal spread along the Endothoracic Fascia (80%). Clinically, the median documented area of hypoesthesia was 5 (4–7) dermatomes with 100 and 92% of the injections covering adjacent T3 and T5 dermatomes, respectively. The patients with PICB had significantly lower perioperative opioid consumption and trend towards lower pain scores. Conclusions In this anatomical study, PICB at the 2nd and 4th ICS produced lateral spread along the corresponding intercostal space, medial spread to the adjacent paravertebral/epidural space and cranio-caudal spread along the Endothoracic Fascial plane. Clinically, combined PICBs at the same levels resulted in consistent segmental chest wall analgesia and reduction in perioperative opioid consumption after breast surgery. The incomplete overlap between paravertebral spread in the anatomical study and area of hypoesthesia in our clinical findings, suggests that additional non-paravertebral routes of injectate distribution, such as the Endothoracic Fascial plane, may play important clinical role in the multi-level coverage provided by this block technique.
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The Ultrasound-guided Proximal Intercostal Block: Anatomical study and clinical correlation to analgesia for breast surgery
2019Co-Authors: Nantthasorn Zinbonyahgoon, Panya Luksanapruksa, Sitha Piyaselakul, Pawinee Pangthipampai, Suphalerk Lohasammakul, Choopong Luansritisakul, Sunsanee Mali-ong, Nawaporn Sateantantikul, Theera Chueaboonchai, Kamen V. VlassakovAbstract:Abstract Background: The ultrasound-guided proximal intercostal block (PICB) is performed at the proximal intercostal space (ICS) between the internal intercostal membrane (IIM) and the Endothoracic Fascia/parietal pleura (EFPP) complex. Injectate spread may follow several routes and allow for multilevel trunk analgesia. The goal of this study was to examine the anatomical spread of large-volume PICB injections and its relevance to breast surgery analgesia. Methods: Fifteen two-level PICBs were performed in ten soft-embalmed cadavers. Radiographic contrast mixed with methylene blue was injected at the 2nd(15ml) and 4th(25ml) ICS, respectively. Fluoroscopy and dissection were performed to examine the injectate spread. Additionally, the medical records of 12 patients who had PICB for breast surgery were reviewed for documented dermatomal levels of clinical hypoesthesia. The records of twelve matched patients who had the same operations without PICB were reviewed to compare analgesia and opioid consumption. Results: Median contrast/dye spread was 4(2-8) and 3(2-5) vertebral segments by fluoroscopy and dissection respectively. Dissection revealed injectate spread to the adjacent paravertebral space, T3 (60%) and T5 (27%), and cranio-caudal spread along the Endothoracic Fascia (80%). Clinically, the median documented area of hypoesthesia was 5(4-7) dermatomes with 100% and 92% of the injections covering adjacent T3 and T5 dermatomes, respectively. The patients with PICB had significantly lower perioperative opioid consumption and trend towards lower pain scores. Conclusions: In this anatomical study, PICB at the 2nd and 4th ICS produced lateral spread along the corresponding intercostal space, medial spread to the adjacent paravertebral/epidural space and cranio-caudal spread along the Endothoracic Fascial plane. Clinically, combined PICBs at the same levels resulted in consistent segmental chest wall analgesia and reduction in perioperative opioid consumption after breast surgery. The incomplete overlap between paravertebral spread in the anatomical study and area of hypoesthesia in our clinical findings, suggests that additional non-paravertebral routes of injectate distribution, such as the Endothoracic Fascial plane, may play important clinical role in the multi-level coverage provided by this block technique. Keywords: Nerve block, paravertebral space, intercostal space, intercostal block, breast surgery.