Saber-sheath Trachea Research Articles

Anesthetic Management of a Patient with Saber-Sheath Trachea

Saber-sheath trachea is a deformation of the trachea characterized by a tracheal index of less than 0.67, commonly found in patients with chronic obstructive pulmonary disease (COPD). This condition can lead to symptoms such as shortness of breath, coughing, and recurrent respiratory infections, which may necessitate surgical intervention. We present the case of a 72-year-old male with a left upper pulmonary lobe tumor scheduled for thoracoscopic lobectomy. The patient exhibited severe emphysema and had a tracheal index of 0.28, indicating a significantly narrowed intrathoracic trachea. Preoperative assessments revealed stable vital signs and low risk for perioperative complications, allowing for standard noninvasive monitoring during the procedure. Anesthesia was induced while maintaining spontaneous breathing using inhalation anesthetics. A left-sided double-lumen endotracheal tube was successfully placed for lung isolation. Throughout the surgery, airway pressures remained below 20 cm H<sub>2</sub>O, and the patient tolerated ventilation well. Following the procedure, fiberoptic bronchoscopy confirmed the absence of airway complications. The patient experienced a smooth recovery, was discharged after 6 days, and reported feeling well at the 3-month follow-up. This case underscores the importance of careful anesthetic management in patients with saber-sheath trachea undergoing thoracic surgery.

Approaching Saber-Sheath Trachea in a Patient with Bilateral Vocal Cord Abductor Palsy and Post Tracheostomy Tracheal Stenosis.

Human trachea has variable shapes and the most common are circular and oval-shaped. Other shapes are rare to find and usually related to some diseases. Such as the Saber-sheath shaped trachea, which was commonly attributed to patients with chronic obstructive pulmonary disease (COPD). This case is about a patient who was detected to have dual pathology, bilateral vocal cord abductor palsy, and post-tracheostomy complicated with tracheal stenosis for 40 years. Symptoms worsened in the last three years until he was admitted to the ward. However, upon managing this case with multilevel airway obstruction, we have found out that this patient who did not have COPD, has a Saber-sheath trachea shape. This finding may indicate that the shape is not limited to a certain disease only.

COMPUTED TOMOGRAPHY FEATURES OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE
 ASSOCIATED WITH LUNG CANCER

Relevance: Chronic obstructive pulmonary disease (COPD) associated with lung cancer is common in smoking patients. Computed tomography (CT) is vital in detecting lung cancer, assessing regional lung parenchymal destruction, and airway remodeling in COPD.
 ДИАГНОСТИКА
 40 Онкология и радиология Казахстана, №1 (63) 2022
 The study aimed to determine the CT features of COPD associated with lung cancer.
 Methods: This retrospective study included chest CT exams of 56 patients over the age of 40, with a smoking history of 10 years and more and
 with suspected COPD. 46.43% of patients had CT signs of lung cancer associated with COPD.
 Results: Barrel-shaped chest (19.23%), saber-sheath trachea (7.69%), and bronchiectasis (15.38%) were less common in patients with lung
 cancer. Paraseptal and centrilobular emphysema were diagnosed in 96.15%, bullae – 73.33%. Bronchial narrowing of the lumen and wall thickening were identified for all lobar bronchus, segmental bronchus, and subsegmental bronchus.
 Conclusion: Paraseptal and centrilobular emphysema and bullae in the upper lobes of lungs were predominant CT features in patients with
 COPD associated with lung cancer. Lumen narrowing and wall thickening of lobar bronchus, segmental bronchus, and subsegmental bronchus
 were also revealed.

COMPUTED TOMOGRAPHY FEATURES OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE ASSOCIATED WITH LUNG CANCER

Relevance: Chronic obstructive pulmonary disease (COPD) associated with lung can-cer is common in smoking patients. Computed
 tomography (CT) is vital in detecting lung cancer, assessing regional lung parenchymal destruction, and airway remodeling in COPD.
 The study aimed to determine the CT features of COPD associated with lung cancer.
 Methods: This retrospective study included chest CT exams of 56 patients over the age of 40 with a smoking history of 10 years and
 more and with suspected COPD. 46.43% of patients had CT signs of lung cancer associated with COPD.
 Results: Barrel-shaped chest (19.23%), saber-sheath trachea(7.69%), and bronchiecta-sis (15.38%) were less common in patients with
 lung cancer. 96.15% were diagnosed with paraseptal and centrilobular emphysema, bullae – 73.33%. Bronchial narrowing of the lumen
 and wall thickening were identified for all lobar bronchus, segmen-tal bronchus, and subsegmental bronchus.
 Conclusion: Paraseptal and centrilobular emphysema and bullae in the upper lobes of the lungs were predominant CT features in
 patients with COPD associated with lung cancer. Lumen narrowing and wall thickening of lobar bronchus, segmental bronchus, and subsegmental bronchus were also revealed.

Saber-sheath trachea - a rare or underdiagnosed morphological variety of the trachea

Introduction. The saber-sheath trachea is characterized by widened anteroposterior and narrowed laterolateral tracheal diameter. It is usually found in patients with chronic obstructive pulmonary disease. The aim of this study was to determine the incidence of this disorder, as well as to gain insight into the basic socio-demographic characteristics of patients and the clinical features of this tracheal deformity. Material and Methods. Endoscopic findings of patients undergoing bronchoscopy at the Institute for Pulmonary Diseases of Vojvodina in the period January 1, 2013 - January 1, 2021 were analyzed. Individual socio-demographic data of patients with the diagnosis of saber-sheath trachea were collected and clinical parameters were analyzed. Results. The analysis of 15.381 bronchoscopic findings showed an incidence of 0.56%, most often in the elderly, predominantly in men, and those who were active or former smokers. The most common comorbidities were chronic obstructive pulmonary disease, cardiovascular diseases, and diabetes. In all cases, this deformity was found as an incidental finding during bronchoscopy that was mostly done for the diagnosis of primary carcinoma of the bronchus. Accordingly, the most common pre-bronchoscopic symptoms were shortness of breath, cough, and chest pain. No significant narrowing of the tracheal lumen was found in any of the patients, nor did this anatomical variety of the trachea affect the length of survival. Conclusion. Although this is a rare disorder, its recognition can guide the clinician to apply additional procedures in order to establish a diagnosis of chronic obstructive pulmonary disease, but also significantly contribute to avoiding potential complications in need of endotracheal intubation.

Saber sheath trachea: A radiological sign of severe airway obstruction

A middle-aged man, chronic smoker, presented with complaints of productive cough & exertional breathlessness (mMRC grade III) for 3 years with frequent episodes of exacerbation in the past. There was no other comorbidity or significant past history. His chest radiograph showed narrowing of trachea. Evaluation with computerized tomography of thorax showed normal extra-thoracic trachea with narrowing of the coronal diameter with increase in the sagittal diameter of the trachea along with thickening and calcification of the tracheal wall seen in saber sheath trachea. Keywords: forced expiratory volume; tracheal narrowing; saber sheath trachea.

Saber sheath trachea in chronic obstructive pulmonary disease patients

Saber sheath trachea is defined as an anteroposterior (sagittal) diameter of intrathoracic trachea exceeding to lateral (coronal) by a ratio of 2:1 as measured at the site 1 cm above the aortic arch and the extra thoracic trachea being normal. It is most commonly seen in males and is considered to be a diagnostic sign of Chronic obstructive pulmonary disease.

Saber-sheath trachea as a challenge for safe surgery: A case report

Introduction. Saber-sheath trachea is a rare malformation of the trachea marked with coronal narrowing with concomitant widening of sagittal diameter, with a sagittal-to-coronal diameter ratio exceeding 2:1. As tracheal rings are stiff and do not collapse around the tube, the intubation is difficult. Case Report. A 53-year-old female was referred to our hospital due to failed intubation at the local hospital during a planned surgery of skin melanoma. The patient was scheduled for surgery in our hospital, her case was presented to a panel of anesthesiologists and she was prepared for surgery. The intubation failed again, even though a video-assisted laryngoscope and endotracheal tube with 5 mm internal diameter was used. The anesthesiologist noticed that the endotracheal tube entered the trachea only 2 cm due to strong resistance, so further intubation was not an option in order to avoid damaging the trachea. The surgery was performed in local anesthesia with analgosedation. Later on, computed tomography was done, because of suspected pathological process compressing trachea, but the radiologist described the anomaly as saber-sheath trachea. One year later, the patient presented with axillary lymph node metastases and needed another surgery. This time the anesthesiologist knew about the trachea malformation, anticipated difficult intubation and used i-gelTM for airway management. Conclusion. Despite the fact that numerous methods have been developed for the purpose of identifying patients at risk of difficult intubation, there are many unexpected airway pathologies that can lead to failed intubation. Adequate preoperative assessment, knowledge of Guidelines for Difficult Intubation Management, availability of supraglottic airway devices, and cooperation between the surgeon and anesthesiologist, are crucial to successful patient management.

The Frequency of Acquired and Age-Related Tracheal Deformations: a Retrospective Study of CT Scan Findings

Background: Changes of the anatomy of the trachea occur during aging and as a result of a large goiter, cardiac or pulmonary diseases and smoking. These changes may cause difficulties in endotracheal intubation.Methods: In this retrospective study, we analyzed the frequency of acquired deformations, as seen in chest CT scan of 200 adult patients. The radiographic findings were studied, as well as the patients’ demographic variables and co-morbidities.Results: Acquired deformation of the trachea was found only in patients that were older than 50 years. In 117 patients 50 to 90 year-old three types of deformations were found: “S-shape” trachea in 83 patients (71%), horizontal left main bronchus with wide angle main carina in 24 patients (20.5%) and saber-sheath trachea in 10 patients (8.5%). Conclusions: Acquired deformation of the trachea is frequent in patients older than 50. Studying the patient’s chest CT scan may assist the physician in performing endotracheal intubation cautiously and safely.

Medical image of the week: saber sheath trachea

Medical image of the week: saber sheath trachea

Medical image of the week: bullous emphysema

Figure 2. Panel A: Coronal view of chest computed tomography (CT) in lung widows showing multiple large lucent spaces of lung parenchyma destruction interspersed normal lung tissue. Panel B: Axial view of chest CT showing coronal narrowing of the trachea with widening of the sagittal diameter (arrow). This is known as a saber sheath trachea which is pathognomonic of chronic obstructive pulmonary disease.

Computed tomography findings of tracheobronchial system diseases: a pictorial essay.

The diseases affecting the trachea and main bronchi can be categorized into congenital or acquired abnormalities and also into focal or diffuse diseases. Major congenital bronchial abnormalities cover accessory cardiac bronchus and tracheal bronchus. Tracheobronchial strictures, such as post-intubation and post-infectious stenosis and tracheobronchial neoplasms are regarded as focal diseases, whereas tracheobronchomegaly, relapsing polychondritis, tracheobronchopathia osteochondroplastica, amyloidosis, granulomatosis with polyangiitis, tracheobronchomalacia, saber-sheath trachea and tracheobronchitis associated with ulcerative colitis are examples of diffuse diseases. Computed tomography (CT) is the best non-invasive method for evaluation of tracheobronchial lesions. In this pictorial review we aimed to demonstrate CT features of central airway diseases.

Saber-sheath trachea as a marker of severe airflow obstruction in chronic obstructive pulmonary disease

Saber-sheath trachea is a specific radiographic parameter for chronic obstructive pulmonary disease (COPD), which consists of marked coronal narrowing associated with sagittal widening (tracheal index<2/3-0.67). The aim of this study was to investigate the correlation between saber-sheath trachea and clinical-radiological findings in a group of patients with COPD of varying severity. We evaluated the chest radiographs of 71 patients with COPD distributed as follows: GOLD class I, 8/71 (11.3%); class II, 34/71 (47.9%); class III, 16/71(22.5%); class IV, 13/71 (18.3%). In 52/71 (73.2%) patients we also evaluated chest computed tomography (CT) scans. We analyzed the prevalence of saber-sheath trachea and its correlation with the Tiffenau index, GOLD stage and radiological signs of COPD. Moreover, we evaluated the sensitivity, specificity and accuracy of chest radiography as compared to CT taken as the gold standard, and the correlation between the radiographic and CT tracheal index. Saber-sheath trachea was found in 18/71 (25.4%) patients, with a greater prevalence in patients with lower Tiffenau Index (p=0.02), GOLD stages III-IV and visual severity score 3 (severe) on chest CT. Saber-sheath trachea was not found to be related to other radiological signs of COPD. The sensitivity, specificity and accuracy values of radiography were 72.2, 97.0 and 88.5%, with perfect concordance between the radiographic and CT tracheal index (p<0.00001). Saber-sheath trachea is linked to the functional severity of airway obstruction, but not to other radiological signs of COPD. Thus, evaluation of the trachea at chest radiography is strongly recommended.

The relationships between tracheal index and lung volume parameters in mild-to-moderate COPD

BackgroundAlthough elongated morphological changes in the trachea are known to be related to lung function in chronic obstructive pulmonary disease (COPD), whether the tracheal morphological changes are associated with airflow limitations or overinflation of the lung in the early stages of COPD has not yet been determined. Thus, our aim was to investigate the association of tracheal index (TI) with lung function parameters, including lung volume parameters, in COPD patients with mild-to-moderate airflow limitations. Materials and methodsA retrospective study was conducted in 193 COPD patients with GOLD grades 1–2 (post-bronchodilator forced expiratory volume in 1s [FEV1]≥50% predicted with FEV1/forced vital capacity ratio≤70%; age range, 40–81) and 193 age- and gender-matched subjects with normal lung function as a control group (age range, 40–82). Two independent observers measured TI at three anatomical levels on chest radiographs and CT scans. ResultsCompared with the control group, TI was reduced significantly and “saber-sheath trachea” was observed more frequently in COPD patients. Patients with GOLD grade 2 disease had a lower TI than those with GOLD grade 1. TI had apparent inverse correlations with total lung capacity, functional residual capacity, and residual volume, regardless of the anatomical level of the trachea. Even after adjustments for covariates, this association persisted. ConclusionsTI is reduced even in mild-to-moderate COPD patients, and TI measured on chest CT shows significant inverse relationships with all lung volume parameters assessed, suggesting that tracheal morphology may change during the early stages of COPD.

Saber-sheath trachea in a patient with bronchiolitis obliterans syndrome after lung transplantation

Chronic rejection remains a major source of morbidity and mortality following lung transplantation. The clinical characteristics of chronic rejection involves bronchiolitis obliterans syndrome (BOS), which leads to progressive airway obstruction. Changes in intrathoracic tracheal dimensions and shape are commonly present in the setting of airway obstruction, leading to the narrowing of the intrathoracic trachea in the coronal plane with anteroposterior lengthening characteristic of the saber-sheath trachea deformity. We present a 64-year-old man who underwent left lung transplantation for idiopathic pulmonary fibrosis who later developed saber-sheath trachea as a result of chronic airway obstruction due to BOS.

Saber-sheath trachea of patients with coal worker's pneumonoconiosis combined with emphysema

目的 用螺旋CT(SCT)测量气管、主支气管内径,探讨煤工尘肺肺气肿患者气管的变化.方法 选择124例煤工尘肺并发肺气肿患者为肺气肿组,41例尘肺无肺气肿患者为尘肺组,60例健康人为对照组,进行SCT扫描,分别测量气管横断面积(Ta),冠状径(Tc),矢状径(Ts),气管指数(Ti),胸廓指数(Thi)和左、右主支气管内径(Bl、Br).结果 肺气肿患者气管Ts(24.81±2.67)mm、Thi(0.43±0.10)明显大于尘肺组和对照组,差异有统计学意义(P＜0.05或P＜0.01),Ta(263.62±72.69)mm2、Tc(17.63±2.56)mm、Ti(0.73±0.15)和Bl(11.07±2.13)mm、Br(12.18±2.16)mm,明显小于尘肺组和对照组,差异有统计学意义(P＜0.05或P＜0.01);尘肺组气管Ts(23.33±2.45)mm、Thi(0.38±0.08)明显大于对照组,Tc(19.50±2.37)mm、Ti(0.84±0.10)和Bl(11.83±1.89)mm、Br(13.04±2.07)mm明显小于对照组,差异均有统计学意义(P＜0.05或P＜0.01).随着肺气肿程度的加重,剑鞘气管发生率增加,差异有统计学意义(P＜0.01).结论 Ti减小是煤工尘肺肺气肿气管的主要变化,SCT测量气管Ti的变化可作为判断尘肺肺气肿程度的一个间接指标。

Successful Bronchoscopic Balloon Dilation of Nonmalignant Tracheobronchial Obstruction Without Fluoroscopy

To evaluate the safety and efficacy of bronchoscopic balloon dilation (BBD) without fluoroscopy for relief of tracheobronchial obstruction. We performed a retrospective study of all adult patients who underwent BBD without fluoroscopy at the Tulane University Hospital and Clinic between July 1, 1997, and June 30, 2002. Twenty-four patients (mean [+/- SD] age, 58 +/- 14 years; 80% men) underwent 59 BBD procedures without fluoroscopy for the following conditions: iatrogenic tracheal stenosis (80%); saber-sheath trachea (4%); bronchial stenosis resulting from lung transplantation (4%); sarcoidosis (4%); Wegener granulomatosis (4%); and idiopathic stenosis (4%). All BBD procedures were performed via a rigid bronchoscope (61%) or a flexible bronchoscope (39%) without fluoroscopy. BBD was often combined with mechanical debridement (64%), stent placement (47%), or laser photoresection (19%), although in 26% of cases BBD was the only intervention. During the 59 procedures, 71 different balloon catheters were deployed a total of 112 times (deployment was defined as any use of balloon dilation in a different location, for a different purpose, or to a different inflation diameter). These 112 deployments were performed for primary dilation (49%), dilation prior to stent placement (28%), and stent seating (22%). Improvement in stenosis was achieved immediately postprocedure in all 59 procedures (100%). One balloon ruptured during inflation without clinically significant effect, and no other complications occurred. BBD without fluoroscopy for the relief of nonmalignant tracheobronchial obstruction can be safely performed through a rigid or flexible bronchoscope. It can be used alone or as an adjunct to other therapeutic modalities. In this series, 100% of airway obstructions were improved, and there were no clinically significant complications. BBD of a tracheobronchial obstruction without fluoroscopy is safe, efficacious, and cost-effective.

Tracheal Intubation in Patients with "Saber-Sheath" Trachea

In Response: We thank Drs. Mackenzie and Asai for their comments on our case report. We feel that Dr. Mackenzie's proposal, to add additional air to the tracheal cuff in an effort to centralize the tracheal lumen of the double-lumen endotracheal tube, is a good idea and should be tried in a similar situation. It would seem prudent to monitor cuff pressure if this is attempted. We had filled our tracheal cuff with air via the minimal leak technique and had no evidence of a tracheal cuff leak at the time of the obstruction. We agree that segments of U-shaped tracheas as defined by Dr. Mackenzie are common, and that considerable variability of shape is also common within each trachea [1,2]. The "saber-sheath" trachea as defined by Greene and Lechner [3] had an internal coronal diameter one-half or less of the corresponding sagittal diameter, and this finding occurred over the length of the intrathoracic trachea. Our case report met this definition on review of our posteroanterior and lateral chest radiographs and at multiple levels of the intrathoracic trachea on chest computed axial tomographs. We apologize if omission of this information caused confusion. In people without chronic obstructive pulmonary disease (COPD), saber-sheath trachea is clearly rare [4]. It seems to be present primarily in a small percentage of older men with COPD [3,5]. We agree with Dr. Mackenzie's assertion that chest computed axial tomographs will give a more accurate representation of the shape and variations in diameter of the trachea than conventional chest radiographs. Our point, and that of Dr. Asai, was that clinically significant narrowing of segments of the trachea can frequently be identified by routine chest radiographs, and this potential should not be overlooked [6]. In response to Dr. Asai's letter, the patient had no complication postthoracotomy attributable to the endotracheal tubes. His doublelumen tube was changed to a single-lumen 7.0 Fr tube at the end of the case uneventfully. He was extubated on the third postoperative day; chest tubes were removed by the fourth postoperative day without a persistent pneumothorax. We do not agree with Dr. Asai's implication that intubation in patients with "saber-sheath" trachea should be avoided if general anesthesia is required. To date, there are no reports of tracheal damage from intubation in these patients. We are concerned that the alternatives of mask of laryngeal mask airway ventilation may not adequately ventilate some of these patients, considering that the majority of them have COPD. We feel that control of the airway by intubation with a conventional single-lumen endotracheal tube, having an external diameter shorter than the most narrow diameter of the trachea, if clinically indicated, is appropriate. Joseph Bayes, MD Eliot M. Slater, MD Peter S. Hedberg, MD Dexter Lawson, MD Department of Anesthesiology, Salem Hospital, Salem, MA 01970-2768

CT of Saber-Sheath Trachea

The diagnosis of saber-sheath trachea is easy at CT due to its cross-sectional imaging, but the significance of this CT sign has not been evaluated in the diagnosis of chronic obstructive pulmonary disease (COPD). Various signs of COPD were compared between a series of 20 patients with a saber-sheath trachea at CT (tracheal index < or = 66%) and a group of 20 pneumologic control patients without saber-sheath trachea (tracheal index > or = 70%). These signs included clinical and standard radiographic indices of COPD, sternum-spine distance and 3 functional tests of COPD: forced expiratory volume in one second, carbon monoxide diffusing lung capacity, and functional residual capacity (FRC). A significant difference was found between the 2 groups, concerning the values of FRC (p < 10(-4)) and of sternum-spine distance (p < 10(-2)). The tracheal index was significantly correlated with the FRC values (r = -0.611; p < 10(-5)) and with the sternum-spine distance (r = -0.322; p < 0.05). No other significant difference was observed. It is concluded that saber-sheath trachea is basically a sign of hyperinflation.

CT of saber-sheath trachea

The diagnosis of saber-sheath trachea is easy at CT due to its cross-sectional imaging, but the significance of this CT sign has not been evaluated in the diagnosis of chronic obstructive pulmonary disease (COPD). Various signs of COPD were compared between a series of 20 patients with a saber-sheath trachea at CT (tracheal index ≤ 66%) and a group of 20 pneumologic control patients without saber-sheath trachea (tracheal index ≥ 70%). These signs included clinical and standard radiographic indices of COPD, sternum-spine distance and 3 functional tests of COPD: forced expiratory volume in one second, carbon monoxide diffusing lung capacity, and functional residual capacity (FRC). A significant difference was found between the 2 groups, concerning the values of FRC (p<10−4) and of sternum-spine distance (p<10−2). The tracheal index was significantly correlated with the FRC values (r= −0.611; p<10−5) and with the sternum-spine distance (r= −0.322; p<0.05). No other significant difference was observed. It is ...