Evaluation of the relationship between intercostal muscle oxygenation measured by near-infrared spectroscopy and exercise capacity in group E COPD patients.

Near-infrared spectroscopy (NIRS) can be used to demonstrate muscle metabolism and oxygenation. NIRS-based oximeters enable the noninvasive measurement of static and dynamic muscle oxygenation. This study aimed to evaluate the relationship between NIRS readings and exercise capacity in group E COPD patients. The prospective study included 40 patients with group E COPD who presented to our outpatient clinic between May 2021 and June 2022. The patients were evaluated with pulmonary function testing, 6-Minute Walk Test (6MWT), echocardiography, and dyspnea and quality of life assessments. NIRS muscle oxygen saturation (SmO2) levels at the start and end of the 6MWT were obtained. 6MWT distance was positively correlated with intercostal SmO2 and fingertip SO2 at the start (R = 0.679, p ≤ 0.001 and R = 0.321, p = 0.04, respectively) and end of the 6MWT (R = 0.693, p ≤ 0.001 and R = 0.635, p ≤ 0.001, respectively) and negatively correlated with the number of hospitalizations due to exacerbations in the last year and mean pulmonary arterial pressure (R = - 0.648, p ≤ 0.001 and R = - 0.676, p ≤ 0.001, respectively). SF-36 score was positively correlated with intercostal SmO2 at the beginning of the 6MWT (R = 0.336, p = 0.03). Intercostal SmO2 levels at the start of the 6MWT positively correlated with diffusing capacity of the lung for carbon dioxide (DLCO) (R = 0.388, p = 0.01) and ratio of DLCO to alveolar volume (DLCO/VA) levels (R = 0.379, p = 0.02), and these correlations persisted more strongly after the 6MWT (R = 0.524, p = 0.01; R = 0.500, p = 0.01, respectively). NIRS is a practical and noninvasive method for measuring muscle oxygenation and can be used as an alternative to 6MWT in the evaluation of exercise capacity in patients with group E COPD.

Respiratory and locomotor muscle blood flow during exercise in health and chronic obstructive pulmonary disease.

NEW FINDINGS: What is the topic of this review? The work presented here focuses mostly on testing the theory of blood flow redistribution from the locomotor to the respiratory muscles during heavy exercise in healthy participants and in patients with COPD. What advances does it highlight? Studies presented and the direct experimental approach to measure muscle blood flow by indocyanine green dye detected by near infrared spectroscopy, show that exercise interferes with respiratory muscle blood flow especially in COPD, but even in healthy. ABSTRACT: We have developed an indicator-dilution method to measure muscle blood flow at rest and during exercise using the light absorbing tracer indocyanine green dye (ICG) injected as an intravenous bolus, with surface optodes placed over muscles of interest to record the ICG signal by near-infrared spectroscopy. Here we review findings for both quadriceps and intercostal muscle blood flow (measured simultaneously) in trained cyclists and in patients with chronic obstructive pulmonary disease (COPD). During resting hyperpnoea in both athletes and patients, intercostal muscle blood flow increased with ventilation, correlating closely and linearly with the work of breathing, with no change in quadriceps flow. During graded exercise in athletes, intercostal flow at first increased, but then began to fall approaching peak effort. Unexpectedly, in COPD, intercostal muscle blood flow during exercise fell progressively from resting values, contrasting sharply with the response to resting hyperpnoea. During exercise at peak intensity, we found no quadriceps blood flow reduction in favour of the respiratory muscles in either athletes or patients. In COPD at peak exercise, when patients breathed 21% oxygen in helium or 100% oxygen, there was no redistribution of blood flow observed between legs and respiratory muscles in either direction. Evidence of decrease in leg blood flow and increase in respiratory muscle flow was found only when imposing expiratory flow limitation (EFL) during exercise in healthy individuals. However, because EFL caused substantial physiological derangement, lowering arterial oxygen saturation and raising end-tidal PCO2 and heart rate, these results cannot be projected onto normal exercise.

Effect of a nondominant perforator on multiterritory perforator flap survival in rats.

BACKGROUND: During flap surgery, the dominant perforator is usually selected as the pedicle. This study investigated the effect of a nondominant perforator on multiterritory perforator flap survival. METHODS: The deep circumflex iliac artery perforator flap (DCIA flap) and intercostal artery perforator flap (ICA flap) were performed (n = 12). Only the pedicle was different between the two flaps. The DCIA flap was based on the right and peripheral DCIA with three dynamic and two potential perforasomes. The ICA flap was based on the right and central ICA with five dynamic perforasomes. All adjacent perforators were ligated except the pedicle. On postoperative day 7, flap viability, angiography findings, and perfusion were compared. RESULTS: Even though the diameter of DCIA (mm) was larger than that of ICA (0.49 ± 0.03 vs. 0.4 ± 0.04; p < .05), the ICA flap survival rate (%) was higher than that of DCIA flap (99.5 ± 0.7 vs. 83.8 ± 3.9; p < .001). Based on a dominant perforator, a necrotic area was observed in the potential perforasomes of the DCIA flap. The choke vessels between the anatomical and dynamic perforasomes dilated postoperatively in the two flaps, whereas the others did not. The perfusion (PU) differences between the DCIA and ICA flaps in the dynamic perforasomes were nonsignificant (average, 342.4 ± 9.1 vs. 347.3 ± 7.3; p > .05). CONCLUSION: Increasing the number of dynamic perforasomes had no effect on flap survival, even based on a nondominant perforator. And the pedicle position affected flap survival.

Spontaneous massive haemothorax in the peri-partum period of an undiagnosed neurofibromatosis type 1 patient - A surgical perspective.

Acute massive haemothorax is a life-threatening situation, which is often associated with a preceding trauma. However, spontaneous haemothorax is a rare occurrence, especially in pregnancy. Spontaneous haemothorax in the immediate post-partum period secondary to a ruptured intercostal AVM is extremely rare more so in the background of an undiagnosed neurofibromatosis. This is a report of a young lady presenting with pleuritis and breathlessness after the delivery of her 1st child. Her management is discussed.

[Severe Hemorrhagic Shock in a 93-Year Old Patient due to a Diagnostic Thoracocentesis]. / Schwerer hämorrhagischer Schock bei einem 93-jährigen Patienten nach diagnostischer Pleurapunktion.

An intercostal artery laceration is a rare iatrogenic complication following thoracocentesis and concerns especially elderly patients. We report a case of a severe hemorrhagic shock in a 93-year old patient due to diagnostic thoracocentesis.

Inspiratory Muscle Training Improves Intercostal and Forearm Muscle Oxygenation in Patients With Chronic Heart Failure: Evidence of the Origin of the Respiratory Metaboreflex.

BACKGROUND: The impact of inspiratory muscle training (IMT) on respiratory and peripheral muscle oxygenation and perfusion during inspiratory muscle fatigue in patients with chronic heart failure (HF) has not been established. METHODS AND RESULTS: Twenty-six patients with chronic HF were randomly assigned to either 8 weeks of IMT or a control group. Inspiratory fatigue was induced by means of a progressive inspiratory resistive loading protocol until there was an inability to sustain inspiratory pressure, when the inspiratory muscle metaboreflex should be activated. The main outcomes were intercostal and forearm muscle oxygen saturation and deoxygenation as measured by means of near-infrared spectroscopy (NIRS) and blood lactate levels. Inspiratory muscle strength was increased by 78% (P <.001) after 8 weeks of participation in the IMT group. IMT attenuated the reduction of oxygen saturation in intercostal and forearm muscles and the increase in blood lactate during respiratory fatigue (P <.001 and P <.05, respectively). These changes were different from the control group (P <.01, P <.05, and P <.05, respectively). After 8 weeks, similar increases in oxygen consumption, mean arterial pressure, heart rate, stroke volume, and cardiac output were observed in both groups during respiratory fatigue. CONCLUSIONS: This randomized controlled clinical trial demonstrates that IMT attenuates the respiratory muscle oxygen demand-delivery mismatch during respiratory fatigue in patients with chronic HF.

Extended locoregional use of intercostal artery perforator propeller flaps.

Besides conventional flaps, intercostal artery perforator flaps have been reported to cover trunk defects. In this report the use of anterior intercostal artery perforator (AICAP) flap, lateral intercostal artery perforator (LICAP) flap and dorsal intercostal artery perforator (DICAP) flap for thoracic, abdominal, cervical, lumbar and sacral defects with larger dimensions and extended indications beyond the reported literature were reevaluated. Thirty-nine patients underwent surgery between August 2012 and August 2014. The age of the patients ranged between 16 and 79 with a mean of 49 years. The distribution of defects were as follows; 12 thoracic, 8 parascapular, 3 cervical, 8 abdominal, 4 sacral and 4 lumbar. AICAP, LICAP and DICAP flaps were used for reconstruction. Fifty-two ICAP flaps were performed on 39 patients. Flap dimensions ranged between 6 × 9 cm and 14 × 35 cm. Twenty-six patients had single flap coverage and 13 patients had double flap coverage. Forty-six flaps have been transferred as propeller flaps and 6 flaps have been transferred as perforator plus flap. Forty flaps (75%) went through transient venous congestion. In one DICAP flap, 30% of flap was lost. No infection, hematoma or seroma were observed in any patient. Follow-up period ranged between 3 and 32 months with a mean of 9 months. The ICAP flaps provide reliable and versatile options in reconstructive surgery and can be used for challenging defects in trunk.

[Interventional Radiological Treatment of Intercostal Artery Bleedings - a Retrospective Analysis]. / Interventionell-radiologische Behandlung von Interkostalarterienblutungen ­ eine retrospektive Analyse.

Background Intercostal artery bleedings are potentially fatal injuries. Apart from conservative and surgical treatment options, emergency interventional radiological treatment can also be performed. We report our experience with emergency intercostal artery embolisation. Materials and Methods Patients with acute arterial bleedings from the intercostal artery who were treated interventionally over a period of 7 years were identified retrospectively. Technical and clinical success, clinical and procedural parameters as well as overall survival were analysed. Results Between 2010 and 2017, a total of 27 embolisation procedures was performed in 24 patients (14 male, mean age 65.7 ± 13.9 years). The majority of patients suffered from iatrogenic intercostal artery bleedings (n = 17; 70.1%; especially after thoracocentesis). In five cases, thoracoscopic surgery was attempted prior to intervention but was unsuccessful. Primary technical success was obtained in 25/27 interventions. In two cases, there was re-bleeding via collateral arteries so that re-intervention became necessary (secondary technical success). In 15 cases, secondary surgery after successful interventional treatment was necessary to evacuate the haematoma/haemothorax. Intercostal artery embolisation was clinically successful in 23/24 patients. One patient died despite technically successful embolisation, due to extensive haemothorax. One case of spinal ischaemia was observed as a major complication. Conclusion Intercostal artery embolisation is an effective interventional radiological emergency measure in patients with acute bleeding and is an alternative to surgical treatment even after attempted, unsuccessful surgery. Because of potentially severe complications, the interventional procedure should be performed by an experienced interventionalist.

Successful lung lobectomy for a lung cancer following thoracic endovascular aortic repair for a thoracic aortic aneurysm: report of a case.

Lung cancer and a thoracic aortic aneurysm were detected simultaneously in a 79-year-old male patient with diabetes. The aneurysm was first treated by thoracic endovascular aortic repair. A right lower lobectomy was subsequently performed after the blood flow of the bronchial and intercostal arteries was confirmed by computed tomographic angiography. The bronchial stump was covered with an intercostal muscle flap. The patient's postoperative course was uneventful. Thoracic endovascular aortic repair is a useful and less invasive treatment for such cases, but a blood flow evaluation of the aortic branches should be done following this procedure before a lung resection is considered.

Pneumomediastinum and the aortic nipple: the clinical relevance of the left superior intercostal vein.

This article discusses the appearance of the "aortic nipple" in chest radiography, and reviews the embryology and anatomy of the left superior intercostal vein which causes the appearance of an "aortic nipple." This radiological sign is useful in differentiating certain thoracic pathologies, such as pneumomediastinum, pneumopericardium, and medial pneumothorax. Pneumomediastinum is an encompassing term describing the presence of air in the mediastinum, and may arise from a wide range of pathological conditions. Despite the well-described imaging of pneumomediastinum, it is sometimes difficult to differentiate from other conditions such as pneumopericardium and medial pneumothorax. A separate finding, "aortic nipple" is the radiographic term used to describe the lateral nipple-like projection from the aortic knob present in a small number of individuals. The aortic nipple corresponds to the end-on appearance of the left superior intercostal vein coursing around the aortic knob, and may be mistaken radiologically for lymphadenopathy or a neoplasm. Despite their relative independence, the aortic nipple is defined by new contours in cases of pneumomediastinum, taking on an "inverted aortic nipple" appearance. In this position, the inverted aortic nipple may facilitate radiographic discrimination of pneumomediastinum from similar conditions. This study aims to review the common clinical and radiographic features of both pneumomediastinum and the aortic nipple. The radiologic appearance of the aortic nipple occurring in unison with pneumomediastinum, and its potential role as a tool in the differentiation of pneumomediastinum from similarly presenting conditions will also be described.

Thoracoscopic and endovascular management of retained haemothoarx associated with an intercostal artery pseudoaneurysm.

Intercostal artery pseudoaneurysm (IAP) is a rare entity and may complicate a percutaneous intervention through an intercostal space or follow thoracic trauma. Its rupture into the pleural space can give rise to haemothorax, which if untreated may lead to a retained haemothorax (RH). Traditionally both the IAP and the RH are managed by a thoracotomy. We report a patient who developed an IAP with haemothorax following a trauma. The diagnosis was established by computed tomography. The patient was treated by endovascular embolisation of the IAP followed by thoracoscopic decortications of the RH.

Physician-performed ultrasound can accurately screen for a vulnerable intercostal artery prior to chest drainage procedures.

BACKGROUND AND OBJECTIVE: Laceration of the intercostal artery during pleural procedures is a rare but serious complication. This study evaluates the utility of thoracic ultrasound (US) to screen for a vulnerable vessel compared with the gold standard computed tomography (CT). METHODS: Before undergoing contrast-enhanced CT chest, thoracic US was performed on 50 patients with a high-end and portable machine, and an attempt made to visualize the vessel at three positions across the back to the axilla. These positions were labelled with radio-opaque fiducial markers. On both US and CT images, the location of the vessel at each position, relative to the overlying rib, was calculated and compared. RESULTS: The vessel was unshielded by a rib according to CT in 114 of the 133 positions. The sensitivity, specificity and negative predictive value of portable US to image the vessel, when it was within the intercostal space on CT, was 0.86, 0.30 and 0.27 respectively. The performance of a high-end machine was not significantly different. The median time required for a pulmonologist to locate the vessel was 42 s and 18 s for the portable and high-end US respectively. CONCLUSIONS: US can be used to screen for a vulnerable vessel prior to pleural procedures, in a time amenable to use in clinical practice. Further, it is achievable by a pulmonologist using a portable US machine. If thoracentesis or chest tube insertion is being performed on a patient at increased risk of bleeding, screening for a vulnerable vessel with US prior to beginning the procedure is recommended.

The posterior intercostal vein: a thermoregulatory gateway to the internal vertebral venous plexus.

The internal vertebral venous plexus (IVVP) plays a putative role in thermoregulation of the spinal cord. Cold cutaneous venous blood may cool, while warm venous blood from muscles and brown fat areas may warm the spinal cord. The regulating mechanisms for both cooling and warming are still unknown. Warm venous blood mainly enters the IVVP via the intervertebral veins. In the thoracic area these veins are connected to the posterior intercostal veins. In this study, anatomical structures were investigated that might support the mechanisms by which warmed venous blood from the intercostal muscles and the recently described paravertebral patches of brown adipose tissue are able to drain into the vertebral venous plexus. Therefore, tissue samples from human cadavers (n = 21) containing the posterior intercostal vein and its connections to the IVVP and the azygos veins were removed and processed for histology. Serial sections revealed that the proximal parts of the posterior intercostal veins contained abundant smooth muscle fibers at their opening into the azygos vein. Furthermore, the walls of the proximal parts of the posterior intercostal veins contain plicae that allow the vessel to dilate, thereby allowing it to serve as a pressure chamber. It is suggested that a cold induced closure of the intercostal/azygos opening can result in retrograde blood flow from the proximal posterior intercostal vein towards the IVVP. This blood flow would be composed of warm blood from the paravertebral brown adipose tissue and blood containing metabolic heat from the muscles draining into the intercostal veins.

Thoracic ultrasound demonstrates variable location of the intercostal artery.

BACKGROUND: Ultrasound (US) guidance is advocated to reduce complications from thoracocentesis or intercostal catheter (ICC) insertion. Although imaging of the intercostal artery (ICA) with Doppler US has been reported, current thoracic guidelines do not advocate this, and bleeding from a lacerated ICA continues to be a rare but serious complication of thoracocentesis or ICC insertion. OBJECTIVES: It was the aim of this study to describe a method to visualise the ICA at routine US-guided thoracocentesis and map its course across the posterior chest wall. METHOD: The ICA was imaged in 22 patients undergoing US-guided thoracocentesis, at 4 positions across the back to the axilla. Its location, relative to the overlying rib, was calculated as the fraction of the intercostal space (ICS) below the inferior border of that rib. RESULTS: An ICA was identified in 74 of 88 positions examined. The ICA migrated from a central 'vulnerable' location within the ICS near the spine (0.28, range 0.21-0.38; p < 0.001) towards the overlying rib (0.08, range 0.05-0.11; p < 0.001) in the axilla. CONCLUSIONS: The ICA can be visualised with US and is more exposed centrally within the ICS in more posterior positions; however, there is a marked variation between individuals, such that the ICA may lie exposed in the ICS even as far lateral as the axilla. Future studies need to identify which patients are at risk for a 'low-lying' ICA to further define the role of US imaging of the ICA during thoracocentesis or ICC insertion.

Posterior intercostal hemorrhage following median sternotomy.

We report two cases of patients who underwent cardiac surgery and suffered from posterior intercostal artery bleeding. Both cases were treated by transcatheter arterial embolization.

Posterior intercostal artery tortuosity and collateral branch points: a cadaveric study.

Publications report observing tortuosity in the posterior intercostal arteries of elderly patients. Studies also describe the size and course of the collateral intercostal arteries. This information is clinically significant when performing thoracentesis and video-assisted thorascopic surgery. To the best of our knowledge, no studies have examined arterial tortuosity or described collateral artery origins relative to bony landmarks. The purpose of this study was to define a safe surgical zone for thoracic access using palpable external bony landmarks. A total of 348 intercostal spaces (3rd-8th) of 29 male and female embalmed cadavers were dissected from the vertebral body to the mid-axillary line to observe the posterior intercostal artery and its collateral branch. The origins of the collateral intercostal arteries relative to the midline of thoracic spinous processes were measured. Mild to moderate tortuosity (arterial curves covering 25- -50% of the intercostal space) was observed in at least one posterior intercostal artery in the majority of cadavers. The origins of the collateral intercostal arteries were variable relative to the midline. Additional collateral intercostal arteries distal to the primary collateral branch were observed, most commonly in the 5th intercostal space, which is used in video-assisted thorascopic surgery and thoracentesis. Tortuosity is common in the 3rd to the 8th posterior intercostal arteries, especially in individuals over the age of 60 years. Given the findings of this study, we recommend that any procedure involving placement of a surgical instrument into these intercostal spaces does so at least 120 mm lateral to the midline of the spinous processes. We also recommend pre-procedure ultrasound (intercostal scan) of the posterior and collateral intercostal arteries when performing non-emergent thoracentesis and video-assisted thorascopic surgery, particularly in patients over 60 years of age.

Intercostal muscle blood flow limitation during exercise in chronic obstructive pulmonary disease.

RATIONALE: It has been hypothesized that, because of the high work of breathing sustained by patients with chronic obstructive pulmonary disease (COPD) during exercise, blood flow may increase in favor of the respiratory muscles, thereby compromising locomotor muscle blood flow. OBJECTIVES: To test this hypothesis by investigating whether, at the same work of breathing, intercostal muscle blood flow during exercise is as high as during resting isocapnic hyperpnea when respiratory and locomotor muscles do not compete for the available blood flow. METHODS: Intercostal and vastus lateralis muscle perfusion was measured simultaneously in 10 patients with COPD (FEV1 = 50.5 ± 5.5% predicted) by near-infrared spectroscopy using indocyanine green dye. MEASUREMENTS AND MAIN RESULTS: Measurements were made at several exercise intensities up to peak work rate (WRpeak) and subsequently during resting hyperpnea at minute ventilation levels up to those at WRpeak. During resting hyperpnea, intercostal muscle blood flow increased with the power of breathing to 11.4 ± 1.6 ml/min per 100 g at the same ventilation recorded at WRpeak. Conversely, during graded exercise, intercostal muscle blood flow remained unchanged from rest up to 50% WRpeak (6.8 ± 1.3 ml/min per 100 g) and then fell to 4.5 ± 0.8 ml/min per 100 g at WRpeak (P = 0.003). Cardiac output plateaued above 50% WRpeak (8.4 ± 0.1 l/min), whereas vastus lateralis muscle blood flow increased progressively, reaching 39.8 ± 7.1 ml/min per 100 g at WRpeak. CONCLUSIONS: During intense exercise in COPD, restriction of intercostal muscle perfusion but preservation of quadriceps muscle blood flow along with attainment of a plateau in cardiac output represents the inability of the circulatory system to satisfy the energy demands of locomotor and respiratory muscles.

Perforator-Based Intercostal Artery Muscle Flap: A Novel Approach for the Treatment of Tracheoesophageal or Bronchoesophageal Fistulas.

SUMMARY: Postoperative tracheoesophageal or bronchoesophageal fistulas represent a major surgical challenge. The authors report the description of an original perforator-based intercostal artery muscle flap, aiming to cover all types of intrathoracic fistulas, from any location, in difficult cases such as postoperative fistulas after esophagectomy in an irradiated field. Between June of 2016 and January of 2019, eight male patients were treated with a perforator-based intercostal artery muscle flap. All had previous surgery for esophageal cancer and developed a tracheoesophageal or bronchoesophageal fistula during the perioperative course. The mean patient age was 55.9 ± 8.8 years. All patients received neoadjuvant chemotherapy and seven received neoadjuvant radiation therapy. A perforator-based intercostal artery muscle flap, with a mean skin paddle size of 9.86 × 5 cm, was harvested. The median operative time was 426.50 minutes. The tracheoesophageal or bronchoesophageal fistula was successfully and definitively occluded in three patients; two patients experienced recurrence; and one patient underwent re operation. At 1 year, five patients were alive (62.5 percent), and among them, three (37.5 percent) were free from any intrathoracic complications. Three patients died, because of massive digestive bleeding, mesenteric ischemia, and multiorgan failure, respectively. The perforator-based intercostal artery muscle flap, like the Taylor flap in abdominoperineal reconstruction, could become a workhorse flap for all intrathoracic reconstructions, as it can always be harvested, even if a previous thoracotomy has ruined most of the options. This surgical technique, easily feasible, reliable, and reproducible, became our first option for all postoperative tracheoesophageal or bronchoesophageal fistula patients during the postoperative course following esophagectomy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.