Reconstructive Techniques for Diaphragm Resection.

A variety of diaphragmatic and non-diaphragmatic pathologies may require resection, reconstruction, or repair of the diaphragm. Adequate reconstruction is crucial in cases of diaphragmatic resection to prevent the herniation of abdominal organs into the chest and to maintain optimal respiratory function. This article aims to provide a detailed overview of the techniques used for surgical diaphragm reconstruction, taking into account factors such as the size and location of the defect, available options for reconstructive materials, potential challenges and pitfalls, and considerations related to the recurrence or failure of the repair.

Assessing Rat Diaphragm Motor Unit Connectivity Outcome Measures as Quantitative Biomarkers of Phrenic Motor Neuron Degeneration and Compensation.

Loss of ventilatory muscle function is a consequence of motor neuron injury and neurodegeneration (e.g., cervical spinal cord injury and amyotrophic lateral sclerosis, respectively). Phrenic motor neurons are the final link between the central nervous system and muscle, and their respective motor units (groups of muscle fibers innervated by a single motor neuron) represent the smallest functional unit of the neuromuscular ventilatory system. Compound muscle action potential (CMAP), single motor unit potential (SMUP), and motor unit number estimation (MUNE) are established electrophysiological approaches that enable the longitudinal assessment of motor unit integrity in animal models over time but have mostly been applied to limb muscles. Therefore, the objectives of this study are to describe an approach in preclinical rodent studies that can be used longitudinally to quantify the phrenic MUNE, motor unit size (represented as SMUP), and CMAP, and then to demonstrate the utility of these approaches in a motor neuron loss model. Sensitive, objective, and translationally relevant biomarkers for neuronal injury, degeneration, and regeneration in motor neuron injury and diseases can significantly aid and accelerate experimental research discoveries to clinical testing.

Breath-by-breath comparison of a novel percutaneous phrenic nerve stimulation approach with mechanical ventilation in juvenile pigs: a pilot study.

About one in three critically ill patients requires mechanical ventilation (MV). Prolonged MV, however, results in diaphragmatic weakness, which itself is associated with delayed weaning and increased mortality. Inducing active diaphragmatic contraction via electrical phrenic nerve stimulation (PNS) not only provides the potential to reduce diaphragmatic muscular atrophy but also generates physiological-like ventilation and therefore offers a promising alternative to MV. Reasons why PNS is not yet used in critical care medicine are high procedural invasiveness, insufficient evidence, and lack of side-by-side comparison to MV. This study aims to establish a minimal-invasive percutaneous, bilateral electrode placement approach for sole PNS breathing and thereby enable, for the first time, a breath-by-breath comparison to MV. Six juvenile German Landrace pigs received general anesthesia and orotracheal intubation. Following the novel ultrasound-guided, landmark-based, 4-step approach, two echogenic needles per phrenic nerve were successfully placed. Stimulation effectiveness was evaluated measuring tidal volume, diaphragmatic thickening and tomographic electrical impedance in a breath-by-breath comparison to MV. Following sufficient bilateral phrenic nerve stimulation in all pigs, PNS breaths showed a 2.2-fold increase in diaphragmatic thickening. It induced tidal volumes in the lung-protective range by negative pressure inspiration and improved dorso-caudal regional ventilation in contrast to MV. Our study demonstrated the feasibility of a novel ultrasound-guided, percutaneous phrenic nerve stimulation approach, which generated sufficient tidal volumes and showed more resemblance to physiological breathing than MV in a breath-by-breath comparison.

Management of Diaphragm Tumors.

Diaphragm tumors are very rare, with secondary tumors being more common than primary tumors. The most common benign primary tumors include lipomas and cysts, and malignant primary tumors include rhabdomyosarcoma and leiomyosarcoma. Endometriosis is the most common benign secondary tumor, followed by malignant tumors with localized spread of disease. In addition, widely metastatic disease has been described. Benign lipomas and cysts can be managed conservatively, but more complex or concerning disease typically requires resection. The diaphragm can often be repaired primarily, though any large defect or tension would indicate the need for mesh or an autologous reconstruction.

Comparative Effect of High-Frequency Nasal Cannula and Noninvasive Ventilation on the Work of Breathing and Postoperative Pulmonary Complication after Pediatric Congenital Cardiac Surgery: A Prospective Randomized Controlled Trial.

BACKGROUND: Various forms of commonly used noninvasive respiratory support strategies have considerable effect on diaphragmatic contractile function which can be evaluated using sonographic diaphragm activity parameters. OBJECTIVE: To compare the magnitude of respiratory workload decreased as assessed by thickening fraction of the diaphragm and longitudinal diaphragmatic strain while using high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) modes [nasal intermittent positive pressure ventilation (NIPPV) and bilevel positive airway pressure (BiPAP)] in pediatric patients after cardiothoracic surgery. METHODOLOGY: This prospective randomized controlled trial was performed at a tertiary care surgical intensive care unit in postcardiac surgery patients aged between 1 and 48 months, who were randomly allocated into three groups: 1) HFNC (with flows at 2 L/kg/min), 2) NIPPV via RAMS cannula in PSV mode (pressure support 8 cmH2O, PEEP 5 cmH2O), and 3) BiPAP in nCPAP mode (CPAP of 5 cmH2O). Measurements were recorded at baseline after extubation (R0) and subsequently every 12 hourly (R1, R2, R3, R4, R5) at 12, 24, 36, 48, and 60 hours respectively until therapy was discontinued. RESULTS: Sixty patients were included, with 20 patients each in the NIPPV group, HFNC group, and BiPAP group. Longitudinal strain at crura of diaphragm was lower in the BiPAP group as compared to HFNC group at R2-R4 [R2 (-4.27± -2.73 vs - 8.40± -6.40, P = 0.031), R3 (-5.32± -2.28 vs -8.44± -5.6, P = 0.015), and R4 (-3.8± -3.42 vs -12.4± -7.12, P = 0.040)]. PFR was higher in HFNC than NIPPV group at baseline and R1-R3[R0 (323 ± 114 vs 264 ± 80, P = 0.008), R1 (311 ± 114 vs 233 ± 66, P = 0.022), R2 (328 ± 116 vs 237 ± 4, P = 0.002), R3 (346 ± 112 vs 238 ± 54, P = 0.001)]. DTF and clinical parameters of increased work of breathing remain comparable between three groups. The rate of reintubation (within 48 hours of extubation or at ICU discharge) was 0.06% (1 in NIPPV, 1 in BiPAP, 2 in HFNC) and remain comparable between groups (P = 1.0). CONCLUSION: BiPAP may provide better decrease in work of breathing compared to HFNC as reflected by lower crural diaphragmatic strain pattern. HFNC may provide better oxygenation compared to NIPPV group, as reflected by higher PFR ratio. Failure rate and safety profile are similar among different methods used.

Surgical Diaphragm: Anatomy and Physiology.

The diaphragm is a musculoaponeurotic structure separating the thoracic and abdominal cavities. It plays important roles in both respiration and maintaining gastrointestinal function. A careful consideration of anatomy should be taken during surgical procedures to minimize injury to this crucial organ.

Management of Traumatic Diaphragmatic Injuries.

Diaphragm injuries are rarely seen injuries in trauma patients and are difficult to diagnose. With improving technology, computed tomography has become more reliable, but with increasing rates of non-operative management of both penetrating and blunt trauma, the rate of missed diaphragmatic injury has increased. The long-term complications of missed injury include bowel obstruction and perforation, which can carry a mortality rate as high as 85%. When diagnosed, injuries should be repaired to reduce the risk of future complications.

Management of Diaphragm Paralysis and Eventration.

An elevated diaphragm may be due to eventration or paralysis. Diaphragm elevation is often asymptomatic and found incidentally on imaging. Fluoroscopic testing can be used to differentiate eventration (no paradoxic motion) from paralysis (paradoxic motion). Regardless of etiology, a diaphragm plication is indicated in all symptomatic patients with an elevated diaphragm. Plication can be approached either from a thoracic or abdominal approach, though most thoracic surgeons perform minimally invasive thoracoscopic plication. The goal of plication is to improve lung volumes and decrease paradoxic elevation of the hemidiaphragm. Diaphragm plication is safe, has excellent outcomes, and is associated with symptom improvement.

Imaging of the Diaphragm: A Primer.

The diaphragm is a critical musculotendinous structure that contributes to respiratory function. Disorders of the diaphragm are rare and diagnostically challenging. Herein, the author reviews the radiologic options for the assessment of the diaphragm.

An indocyanine green fluorescence-guided operation for diagnosing and treating pleuroperitoneal communication.

Pleuroperitoneal communication occurs when ascites moves from the abdominal cavity to the pleural cavity via a diaphragmatic fistula. Managing large pleural fluid volumes is challenging, often requiring an operation. Identifying small diaphragmatic fistulas during the operation can be problematic, but ensuring their detection improves outcomes. This video tutorial presents a recent empirical case in which we successfully identified and closed a pleuroperitoneal contact using a thoracoscopic surgical procedure aided by indocyanine green fluorescence imaging. The patient, a 66-year-old woman, was hospitalized due to acute dyspnoea from a right thoracic pleural effusion during hepatic ascites treatment for cirrhosis. Because ascites decreased with pleural fluid drainage, surgical intervention was considered due to suspicion of a pleuroperitoneal connection. During the operation, indocyanine green was injected intraperitoneally, and near-infrared fluorescence-guided thoracoscopy pinpointed the location of the diaphragmatic fistula. The fistula was sutured and reinforced with a polyglycolic acid sheet and fibrin glue. Detecting the fistula intraoperatively is crucial to prevent recurrence, and the indocyanine green fluorescence method is a safe and effective technique for detecting small fistulas.

Approach to Acute Traumatic and Nontraumatic Diaphragmatic Abnormalities.

Acute diaphragmatic abnormalities encompass a broad variety of relatively uncommon and underdiagnosed pathologic conditions, which can be subdivided into nontraumatic and traumatic entities. Nontraumatic abnormalities range from congenital hernia to spontaneous rupture, endometriosis-related disease, infection, paralysis, eventration, and thoracoabdominal fistula. Traumatic abnormalities comprise both blunt and penetrating injuries. Given the role of the diaphragm as the primary inspiratory muscle and the boundary dividing the thoracic and abdominal cavities, compromise to its integrity can yield devastating consequences. Yet, diagnosis can prove challenging, as symptoms may be vague and findings subtle. Imaging plays an essential role in investigation. Radiography is commonly used in emergency evaluation of a patient with a suspected thoracoabdominal process and may reveal evidence of diaphragmatic compromise, such as abdominal contents herniated into the thoracic cavity. CT is often superior, in particular when evaluating a trauma patient, as it allows rapid and more detailed evaluation and localization of pathologic conditions. Additional modalities including US, MRI, and scintigraphy may be required, depending on the clinical context. Developing a strong understanding of the acute pathologic conditions affecting the diaphragm and their characteristic imaging findings aids in efficient and accurate diagnosis. Additionally, understanding the appearance of diaphragmatic anatomy at imaging helps in differentiating acute pathologic conditions from normal variations. Ultimately, this knowledge guides management, which depends on the underlying cause, location, and severity of the abnormality, as well as patient factors. ©RSNA, 2024 Supplemental material is available for this article.

[Quality of life in patients with postoperative unilateral diaphragm relaxation]. / Kachestvo zhizni patsientov s odnostoronnei relaksatsiei diafragmy posle khirurgicheskogo lecheniya.

OBJECTIVE: To evaluate the quality of life before and after video-assisted thoracoscopic plication of relaxed dome of diaphragm. MATERIAL AND METHODS: The study included 17 patients operated on for unilateral relaxation of diaphragm. We analyzed quality of life in preoperative period, 1, 3, 6 and 12 months after surgery using the SF-36 and EuroQ-5D-5L questionnaires. To assess the impact of abnormality on respiratory function, we estimated diaphragm position, spirometry data and SGRQ scores. RESULTS: FVC increased by 16.5% after 1 month, 19.5% after 6 months and 20.1% after 12 months. In addition, FEV1 significantly increased (by 12.6% after 1 month, 10.1% after 6 months and 12.7% after 12 months). Mean values of diaphragm elevation in postoperative period decreased by 25.5-25.6%. According to the SF-36 and EuroQ-5D-5L questionnaires, physical and psychological health components significantly increased within a month after surgical treatment. According to the SGRQ questionnaire, influence of disease on overall status decreased a month after surgery as evidences by lower total score (p<0.05). CONCLUSION: Objective and survey data revealed significant improvement in quality of life after surgery. A trend towards higher quality of life was demonstrated by all questionnaires in a month after surgery.

Diaphragm thickness and mobility elicited by two different modalities of inspiratory muscle loading in heart failure participants: A randomized crossover study.

OBJECTIVES: To analyze diaphragmatic thickness, at end-inspiration and end-expiration, diaphragmatic thickening index and mobility via US under two different modalities of inspiratory muscle loading, in two different modalities of inspiratory muscle loading and different load intensities at full-vital capacity maneuvers and the relationship between diaphragmatic thickness with pulmonary function tests in participants with HF. METHODS: This randomized crossover trial, enrolled with 17 HF subjects, evaluated diaphragm thickness (Tdi, mm), fractional thickness (TFdi, %), and mobility (mm) US during low and high intensities (30% and 60% of maximal inspiratory pressure-MIP) with two modalities of inspiratory muscle loading mechanical threshold loading (MTL) and tapered flow-resistive loading (TFRL). RESULTS: Both MTL and TFRL produced a increase in Tdi, but only with high intensity loading compared to baseline-2.21 (0.26) vs. 2.68 (0.33) and 2.73 (0.44) mm; p = .01. TFdi was greater than baseline under all conditions, except during low intensity of TFRL. Diaphragm mobility was greater than baseline under all conditions, and high intensity of TFRL elicited greater mobility compared to all other conditions. Additionally, baseline Tdi was moderately correlated with pulmonary function tests. CONCLUSIONS: MTL and TFRL modalities elicit similar increases in diaphragm thickness at loads, but only during high intensity loading it was greater than baseline. Diaphragm mobility was significantly greater than baseline under both loads and devices, and at high intensity compared to low intensity, although TFRL produced greater mobility compared to modalities of inspiratory muscle loading. There is an association between diaphragm thickness and pulmonary function tests.

Effect of adding diaphragmatic breathing to corrective exercises on kyphotic angle and diaphragmatic excursion in postmenopausal kyphotic women: A randomized controlled trial.

BACKGROUND: Age-related thoracic kyphosis can impair posture, diaphragmatic excursion, respiratory function, and overall quality of life (QoL). PURPOSE: This randomized controlled trial aimed to compare the effects of corrective exercises alone versus combined with diaphragmatic breathing exercises on thoracic kyphosis, diaphragmatic excursion, thoracic pain, and QoL in postmenopausal kyphotic women. METHODS: Forty postmenopausal women diagnosed with thoracic kyphosis were randomly divided into two groups. Group A received corrective exercises for 12 weeks (n = 20), while Group B received both diaphragmatic breathing exercises and corrective exercises for the same duration (n = 20). Primary outcome measures were thoracic kyphosis angle and diaphragmatic excursion, while secondary outcome measures were thoracic pain and QoL. Both groups were assessed pre- and post-intervention using a flexible curve ruler for the thoracic kyphosis angle, ultrasonography for the diaphragmatic excursion, the visual analog scale for thoracic pain, and the Arabic version of the QoL Questionnaire of the European Foundation for Osteoporosis for QoL. RESULTS: Both groups showed significant within-group improvements in all measures post-intervention (p < 0.05). Between-group comparisons post-intervention revealed no significant differences (p > 0.05) except for diaphragmatic excursion, where Group B showed significantly greater improvement (p < 0.05). CONCLUSIONS: A 12-week program of corrective exercises alone or combined with diaphragmatic breathing exercises significantly improved kyphosis angle, thoracic pain, and QoL in postmenopausal kyphotic women. The addition of diaphragmatic breathing exercises provided further benefits by increasing diaphragmatic excursion to a greater degree compared with corrective exercises alone.

Subdiaphragmatic phrenic nerve supply: A systematic review.

OBJECTIVE: The aim of this systematic review is to study the subdiaphragmatic anatomy of the phrenic nerve. MATERIALS AND METHODS: A computerised systematic search of the Web of Science database was conducted. The key terms used were phrenic nerve, subdiaphragmat*, esophag*, liver, stomach, pancre*, duoden*, intestin*, bowel, gangli*, biliar*, Oddi, gallbladder, peritone*, spleen, splenic, hepat*, Glisson, falciform, coronary ligament, kidney, suprarenal, and adrenal. The 'cited-by' articles were also reviewed to ensure that all appropriate studies were included. RESULTS: A total of one thousand three hundred and thirty articles were found, of which eighteen met the inclusion and exclusion criteria. The Quality Appraisal for Cadaveric Studies scale revealed substantial to excellent methodological quality of human studies, while a modified version of the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias Tool denoted poor methodological quality of animal studies. According to human studies, phrenic supply has been demonstrated for the gastro-esophageal junction, stomach, celiac ganglia, liver and its coronary ligament, inferior vena cava, gallbladder and adrenal glands, with half of the human samples studied presenting phrenic nerve connections with any subdiaphragmatic structure. CONCLUSIONS: This review provides the first systematic evidence of subdiaphragmatic phrenic nerve supply and connections. This is of interest to professionals who care for people suffering from neck and shoulder pain, as well as patients with peridiaphragmatic disorders or hiccups. However, there are controversies about the autonomic or sensory nature of this supply.

The diaphragmatic electrical activity during spontaneous breathing trial in patients with mechanical ventilation: physiological description and potential clinical utility.

BACKGROUNDS: Increased respiratory drive has been demonstrated to correlate with weaning failure, which could be quantified by electrical activity of the diaphragm (EAdi). We described the physiological process of EAdi-based parameters during the spontaneous breathing trial (SBT) and evaluated the change of EAdi-based parameters as potential predictors of weaning failure. METHODS: We conducted a prospective study in 35 mechanically ventilated patients who underwent a 2-hour SBT. EAdi and ventilatory parameters were continuously measured during the SBT. Diaphragm ultrasound was performed before the SBT and at the 30 min of the SBT. Three EAdi-based parameters were calculated: neuro-ventilatory efficiency, neuro-excursion efficiency and neuro-discharge per min. RESULTS: Of the thirty 35 patients studied, 25 patients were defined as SBT success, including 22 patients weaning successfully and 3 patients reintubated. Before the SBT, neuro-excursion efficiency differed significantly between two groups and had the highest predictive value for SBT failure (AUROC 0.875, p < 0.01). Early increases in EAdi were observed in SBT, which are more prominent in SBT failure group. One minute, changes in EAdi and neuro-discharge per min also predicted weaning outcome (AUROCs 0.944 and 0.918, respectively). CONCLUSIONS: EAdi-based parameters, especially neuro-excursion efficiency and changes in neuro-discharge per min, may detect impending weaning failure earlier than conventional indices. EAdi monitoring provides physiological insights and a more tailored approach to facilitate successful weaning. Further research should validate these findings and explore the utility of combined EAdi and diaphragm ultrasound assessment in weaning ICU patients from mechanical ventilation. TRIAL REGISTRATION: Registered at ClinicalTrials.gov on 20 September 2022 (Identifier: NCT05632822).

Effect of Individualized PEEP Guided by Driving Pressure on Diaphragm Function in Patients Undergoing Laparoscopic Radical Resection of Colorectal Cancer: A Randomized Controlled Trial.

BACKGROUND The concept of driving pressure (ΔP) has been established to optimize mechanical ventilation-induced lung injury. However, little is known about the specific effects of setting individualized positive end-expiratory pressure (PEEP) with driving pressure guidance on patient diaphragm function. MATERIAL AND METHODS Ninety patients were randomized into 3 groups, with PEEP set to 0 in group C; 5 cmH2O in group F; and individualized PEEP in group I, based on esophageal manometry. Diaphragm ultrasound was performed in the supine position at 6 consecutive time points from T0-T5: diaphragm excursion, end-expiratory diaphragm thickness (Tdi-ee), and diaphragm thickening fraction (DTF) were measured. Primary indicators included diaphragm excursion, Tdi-ee, and DTF at T0-T5, and the correlation between postoperative DTF and ΔP. Secondary indicators included respiratory mechanics, hemodynamic changes at intraoperative d0-d4 time points, and postoperative clinical pulmonary infection scores. RESULTS (1) Diaphragm function parameters reached the lowest point at T1 in all groups (P<0.001). (2) Compared with group C, diaphragm excursion decreased, Tdi-ee increased, and DTF was lower in groups I and F at T1-T5, with significant differences (P<0.05), but the differences between groups I and F were not significant (P>0.05). (3) DTF was significantly and positively correlated with mean intraoperative ΔP in each group at T3, and the correlation was stronger at higher levels of ΔP. CONCLUSIONS Individualized PEEP, achieved by esophageal manometry, minimizes diaphragmatic injury caused by mechanical ventilation based on lung protection, but its protection of the diaphragm during laparoscopic surgery is not superior to that of conventional ventilation strategies.

Morphological comparative study of canine and feline diaphragms: Effect of bodyweight, body condition score, gender, age and breed.

The canine diaphragm is a muscular and tendinous dome-like plate and is largely involved in digestive and respiratory functions. Very few studies compared morphology of the diaphragm between dogs and cats and no studies have investigated the effects of individual factors on this morphology. So the aim of this study was to (1) study the effects of individual factors on the morphology of the diaphragm and (2) to compare its morphology between cats and dogs. Surface measurements of 86 diaphragms were performed. The tendinous centre (TC), the lumbar part of the peripheral muscular (LP) and the sternal and costal parts of the peripheral muscular (SCPM) were measured. Measurement ratios (surface of anatomical part of the diaphragm/total surface of the diaphragm) were used for statistical analysis (TC%S, LP%S, SCPM%S). The SCPM%S are significantly lower, and the LP%S are significantly higher when bodyweight increases in dogs and cats. The TC%S are significantly lower when the body condition score of dogs increases. The SCPM%S are significantly higher, and therefore, the TC%S and LP%S lower in brachycephalic animals as opposed to mesocephalic animals. The TC%S are significantly higher in dogs than in cats and the SCPM%S are significantly higher in cats than in dogs. This study proposed a cartography of the diaphragm morphology in cats and dogs taking into account individual animal factors. Significant differences in the diaphragm morphology between cats and dogs and between mesocephalic and brachycephalic animals were found. Further studies are necessary to confirm these results and to investigate the consequences of these variations.