Lymphaticovenous anastomosis of the caudal thoracic duct to the azygous vein: A feline cadaver study.

OBJECTIVE: The aim of this study was to describe a technique for anastomosis of the thoracic duct (TD) to the azygos vein (AV) using a microvascular anastomotic coupler (MAC) device in feline cadavers. Our hypothesis was that a TD-AV lymphaticovenous anastomosis would be feasible in feline cadavers. STUDY DESIGN: Cadaveric study. ANIMALS: Eight domestic shorthair feline cadavers. METHODS: A left paracostal laparotomy and 9th or 10th intercostal thoracotomy was performed. Contrast media was injected into a mesenteric lymph node and lymphography was used to identify the TD and its branches. The TD and AV were isolated, ligated, and divided with the aid of a surgical microscope. The TD and AV were anastomosed end-to-end using a 1.5 or 2.0 mm MAC. Intraoperative patency was assessed by manipulation of chyle and venous blood across the anastomosis. Mesenteric lymphography was repeated to confirm postoperative anastomotic patency. RESULTS: The TD was identified via lymphography in seven of eight cats. The anastomosis was successful and patency was confirmed via intraoperative assessment and postoperative lymphography in all cats. The median (range) duration for the dissection and anastomosis portions of the procedure was 122 (80-150) min. CONCLUSION: End-to-end anastomosis of the TD to the AV using a MAC was feasible in the feline cadaver without major intraoperative technical challenges. CLINICAL SIGNIFICANCE: Anastomosis of the TD and AV may have application as an alternative treatment for idiopathic chylothorax in cats. By directly connecting the abdominal lymphatics to the central venous system, the stimulus for collateral vessel development around the site of TD ligation may be minimized, which may prevent leakage of chyle through the more cranial lymphatics.

[Surgery for complicated accessory lobe of the azygos vein]. / Khirurgiya oslozhnennoi dobavochnoi doli neparnoi veny.

Congenital anomalies of respiratory system are quite diverse and not all of them are subject to surgical treatment. One example is accessory lobe of the azygos vein. This anomaly usually has no clinical manifestations and requires only follow-up, as well as attention in surgery on the right half of the chest for some other disease. This situation changes when complications occur, for example, purulent-inflammatory process. Therapy is not always effective, and lung tissue destruction requires surgical treatment. Progressive destruction complicates diagnosis and choosing surgical tactics. We present a rare case of severe purulent-inflammatory complication with abscess in accessory lobe of v. azygos. Anatomical abnormalities following this congenital pulmonary anomaly can cause difficulties in surgeries for other intra-thoracic diseases. The situation is especially relevant for thoracoscopic access. This report will be useful for radiologists, pulmonologists and thoracic surgeons.

[Thoracoscopic resection of azygos vein aneurysm]. / Torakoskopicheskoe udalenie anevrizmy dugi neparnoi veny. Redkoe klinicheskoe nablyudenie.

Azygos vein aneurysm is a rare thoracic disease that often mimics posterior mediastinum tumors. Pathogenesis of azygos vein aneurysm is unclear. Discussions about possible causes are still ongoing. Most aneurysms are asymptomatic and diagnosed incidentally during standard examinations. Severe complications of azygos vein aneurysm include rupture with massive bleeding and pulmonary embolism. Contrast-enhanced chest CT and MRI are essential. Differential diagnosis includes tumors, cysts and rare neoplasms of the mediastinum. Treatment algorithm is not established. There are traditional surgical and endovascular methods. We present minimally invasive surgical treatment of azygos vein aneurysm in a 53-year-old woman. The patient underwent thoracoscopic resection of aneurysm. Histological examination revealed a partially thrombosed azygos vein aneurysm.

Normal variations of the superior vena cava and azygos venous system depiction by CT scan in the adult Thai population.

BACKGROUND: Identification of normal variations to the thoracic central venous system anatomy is essential in radiological intervention and cardiothoracic surgery to prevent complications. PURPOSE: To estimate the prevalence and pattern of normal variations of superior vena cava (SVC) and azygos venous system as well as factors associated with normal variations of SVC. MATERIAL AND METHODS: Venous-phase chest CT of 1336 patients were retrospectively reviewed. Age, sex, and underlying disease were recorded. SVC diameter and cross-sectional area were measured to evaluate for associations with normal variations. RESULTS: The prevalence of normal anatomical variations of SVC and azygos venous system were 0.3% and 1.5%, respectively. Duplicated SVC was the most common variations. The most common variation for the azygos venous system was the connection between the hemiazygos and accessory hemiazygos veins draining into the left brachiocephalic vein (12/1336 cases, 0.9%). The median (interquartile range [IQR]) cross-sectional area compared between normal SVC (297.2 mm2) and duplicated SVC (223.5 mm2) showed a statistically significant difference (P = 0.033). CONCLUSION: This study determined the prevalence of rare normal variations of the azygos venous system, a connection between the hemiazygos and accessory hemiazygos veins draining into the left brachiocephalic vein. The prevalence of normal variations of the SVC and azygos venous system in the adult Thai population was similar with that of previous publications. Cross-sectional area was the only factor with a significant association with SVC variations.

A revamped MIC-McKeown operation without removing azygos vein arch, bronchial artery and vagus nerve trunk.

BACKGROUND: The purpose of this study was to investigate the effect of our revamped MIE-McKeown operation on postoperative gastrointestinal function recovery. METHODS: This revamped MIE-McKeown operation without removing azygos vein arch, bronchial artery and vagus nerve trunk and with the tubular stomach buried throughout esophageal bed and azygos arch, has been implemented from July 2020 to July 2021 by the same medical team of Gaozhou People's Hospital thoracic surgery for 13 times. Preoperative clinical data, main intraoperative indicators and postoperative complications were observed. RESULTS: All patients had esophageal malignant tumors at the level of middle and lower thoracic non-azygous venous arch, with preoperative clinical stage CT1-2N0M0 stage i-ii. V-vst test was performed on the 7th postoperative day, and 10 patients were found to have no loss of safety/efficacy. There were 2 cases with impaired efficacy and no impaired safety, 1 case with impaired safety. There were 1 cases of pulmonary infection, 1 cases of anastomotic fistula combined with pleural and gastric fistula, 2 cases of hoarseness, 2 cases of arrhythmia, 10 cases of swallowing function were grade i, 2 cases of swallowing function were grade iii, 1 case of swallowing function was grade iv in watian drinking water test one month after operation. CONCLUSIONS: Merit of this revamped MIE-McKeown operation is well preserving the integrity of azygos arch of vagus nerve and bronchial artery, and it is technically safe and feasible. No postoperative mechanical obstruction of thoracostomach, huge thoracostomach and gastrointestinal dysfunction occurs.

A reappraisal of pediatric thoracic surface anatomy.

Accurate knowledge of surface anatomy is essential for physical examination, invasive procedures, and anatomy education. Individual factors such as age make surface landmarks variable so accurate descriptions are needed. The aim of this study is to describe age-related surface landmarks for intrathoracic structures in children. A total of 156 thoracic computed tomography scans of children aged 0-18 years were categorized into six groups, and the associations between major intrathoracic structures and surface landmarks were analyzed. Sternal angle is an accurate surface landmark for the azygos vein-superior vena cava junction in all age groups. However, the aortic arch (except in the 0-1 year group), the bifurcation of the pulmonary trunk and the tracheal bifurcation in those aged 15-18 years were not within this plane. The left brachiocephalic vein was located behind the ipsilateral sternoclavicular joint except in the 1-3 years group, and the right was behind it in children older than 6 years. The apex of heart was at the 5th intercostal space level in the 0-1 and 12-18 years groups; however, it was higher in the other groups. The lower borders of the lungs were at the sixth costal cartilage level in the midclavicular line, eighth intercostal space level in the midaxillary line, and T12 adjacent to the vertebral column in the 15-18 years group; the lower borders were at higher levels in younger children. Defining the variations in surface anatomy by in vivo studies will increase its clinical and pedagogical value.

Cadaveric dissection of connection between accessory hemiazygos vein and left brachiocephalic vein.

PURPOSE: The azygos system of veins has many anatomical variations that can impact mediastinal and vascular interventions. While radiological reports on these are of great clinical value, this study is among the first to present a high-quality cadaveric dissection of a rare anatomical variant to supplement previously published radiologic studies. The azygos venous system consists of the azygos vein (AV), hemiazygos vein (HAV), and the accessory hemiazygos vein (AHAV), which develop from the last portion of the posterior cardinal veins. The normal anatomical configuration includes drainage of the posterior intercostal veins, vertebral vein, esophageal veins, HAV, and AHAV to an unpaired right-side AV at the level of the 8th/9th thoracic vertebra. The reported incidence of AHAV draining directly into the left brachiocephalic vein is 1-2%. METHODS: An adult formalin-fixed 70-year-old female cadaver was dissected as part of a medical gross anatomy elective course. RESULTS: Gross documentation of a direct connection of the HAV to the AHAV with the AHAV draining into the left brachiocephalic vein. CONCLUSION: It is important to note the variations of the azygos system to avoid confusion with a potential pathology such as mediastinal masses. Understanding of the rare variant reported here could be useful in the prevention of iatrogenic bleeding from the misplacement of venous catheters and help facilitate radiological diagnosis in the incidence of venous clot formation.

Inferior vena cava thrombosis-rope ladder sign.

Congenital heart disease comprises one of the largest groups of congenital defects, affecting approximately 1% of births. Advances in pre- and postoperative critical care treatment as well as surgery and interventional procedures have improved survival rates, but treatment and long-term care of children with complex congenital heart disease remains challenging, and is associated with a number of complications.Here, we report on a 17-month-old infant with congenital univentricular heart disease who devloped post-operatively inferior vena cava (IVC) thrombosis. IVC thrombosis was confirmed by a bedside contrast media study (X-ray) demonstrating collateral paravertebral circulation along the paravertebral sinuses bilaterally into the azygos and hemiazygos vein ("rope ladder sign"), with no contrast media detected in the IVC. The infant was subsequently started on aspirin and clopidogrel.

Azygos Vein Central Venous Access in a Patient with Thoracic Central Venous Obstruction.

This is a report of a 45-year-old female with thoracic central venous obstruction (TCVO) and alpha-1 antitrypsin deficiency requiring an implanted port for infusions. The azygos vein was used for catheter access in the setting of an occluded right internal jugular vein, bilateral innominate, and superior vena cava. A literature review examines the etiology of TCVO and superior vena cava syndrome (SVC), as well as the potential benefits and complications for using the azygos vein in patients with TCVO requiring port or catheter venous access.

Intrapulmonary course of superior caval vein associated with azygos lobe.

We report a case of a 4-month-old boy with tetralogy of Fallot where computed tomography angiography incidentally revealed the presence of a unique extra-mediastinal and intrapulmonary course of the superior caval vein within the anterior portion of the azygos fissure.

Staged approach for correction of anomalous venous return to the azygos vein.

Partial anomalous pulmonary venous return into the azygous vein is a rare pathological finding. We describe the case of a 28-year-old girl who had a successful staged approach to treat this rare congenital heart disease. To avoid potential connection of a systemic venous return to the left atrium, the proximal part of the azygous vein was occluded with a percutaneous approach, then the azygous vein flow was redirected into the left atrium with a surgical procedure.

Thoracoscopic AF ablation in situs inversus dextrocardia with interrupted inferior vena cava continuation in azygos vein.

INTRODUCTION: Situs inversus totalis, dextrocardia with interrupted inferior vena cava, and azygos vein continuation concomitant with symptomatic atrial fibrillation requiring ablation. This case was deemed not suitable for percutaneous ablation due to anatomic variations and the lack of case reports in the literature. METHODS AND RESULTS: We performed bilateral thoracoscopic epicardial ablation and epicardial left atrial appendage exclusion. The direct vision allowed for a complete box lesion set with bipolar radiofrequency device. Patient remained in sinus rhythm at the 12-months follow-up. CONCLUSION: Surgical thoracoscopic epicardial ablation is safe and effective also in congenital defects. Multidisciplinary expertise can offer minimally invasive ablation treatments.

Balloon atrial septostomy through azygos vein in two cases of D-TGA with left atrial isomerism.

Balloon atrial septostomy is a palliative procedure that is performed in D-transposition of great arteries when surgery is not immediately available. Although D-TGA and left isomerism association are rare, it is an important condition as the BAS procedure approach is unique. In this case report, we present two cases of D-TGA with left isomerism where BAS was performed due to restrictive atrial septal defect and lack of immediate availability of the paediatric cardiac surgeon.

Prenatal diagnosis of hepatic interruption of the inferior vena cava with azygos/hemiazygos continuation without structural heart defects: A case series.

OBJECTIVES: To describe fetal spectrum and echocardiographic characteristics of interrupted inferior vena cava (IIVC) with azygos/hemiazygous continuation without other structural heart defects and to evaluate its association with visceral heterotaxy and isomerism, extracardiac and genetic anomalies, and to review neonatal outcome. METHODS: This was a retrospective study of 14 fetuses with a confirmed diagnosis of IIVC with normal intracardiac anatomy. The following variables were collected; indication for referral, gestational age at diagnosis; associated isomerism and visceral heterotaxy, heart rhythm, genetic and extracardiac abnormalities, and fetal/neonatal outcome. RESULTS: Among 36 fetuses with IIVC, 14 cases (38.8%) had normal intracardiac anatomy. These IIVC cases correspond to 0.19% (14/7250) of all fetal cardiac examinations, and to 1.5% (14/922) of all cardiac abnormalities. Six patients had visceral abnormalities. Atrial appendage morphology was clearly depicted in three fetuses, both appendages were left. One fetus had bradyarrhythmia revealing atrial ectopic rhythm. Six fetuses did not have any concomitant cardiac or visceral abnormalities, therefore regarded as isolated. All babies were delivered at term with a good prognosis. CONCLUSION: Our study has shown that almost half of the IIVC cases without intracardiac structural anomalies displayed other findings of isomerism while the other half was isolated benign vascular variant. Therefore, prenatal diagnosis of IIVC should prompt a comprehensive evaluation for cardiac, situs, and visceral anomalies. The outcome is favorable.

Refractory Chylothorax Secondary to Sizeable Azygos Vein Hemangioma: Tailored Multimodal Treatment of a Challenging Case Report.

BACKGROUND: Mediastinal hemangiomas are rare, and their etiology remains unclear. Most patients affected have no pathognomonic clinical symptoms, and the diagnosis is often incidental. Due to the paucity of the available literature regarding the management of this disease, the choice and timing of treatment remains controversial. CASE PRESENTATION: Herein, we report the case of a hemangioma of the azygos vein arch in a 66-year-old woman who presented with dyspnea, chest discomfort, dysphagia, and weight loss. A simultaneous right chylothorax refractory to conservative management was found. A CT-guided biopsy of the mass was performed, and it confirmed the vascular nature of the lesion. Therefore, the patient underwent an angiography followed by endo-vascular embolization. Three days later, thoracoscopic surgical resection of the mass and the repair of the chyle leakage were performed safely. The patient was discharged uneventfully on postoperative day seven, with complete resolution of all the presenting symptoms. CONCLUSIONS: Treatment of symptomatic mediastinal hemangiomas could be mandatory, but a thorough multidisciplinary approach to these rare malformations is essential. Despite the risk of intraoperative bleeding, selective endovascular embolization followed by thoracoscopic surgery allowed for a complete and safe resection with a good outcome.

An inferior vena cava discontinuity with an hepato-renal accessory vein development: A radio-anatomical morphometric case study.

PURPOSE: Inferior vena cava (IVC) agenesis is an uncommon congenital vascular anomaly stemming from aberrant development during embryogenesis. It results from the failure of one or more of the supracardinal veins, subcardinal veins, vitelline veins or postcardinal veins to connect. The symptomatology resulting from this vascular malformation can be either absent or extremely rich and varied. METHODS: Thoracoabdominal-pelvic CT scan projections following iodine-based contrast product injection were analyzed and a three-dimensional model of vascularization constructed. RESULTS: Herein, an asymptomatic case of IVC agenesis with absence of the suprarenal and renal segments, with azygos continuation, presenting an accessory hepatorenal vein is reported. The presence of this type of accessory vein has never been described in the literature to date. The etiology of this case of IVC agenesis is explored in depth. We also analyzed the morphometric parameters of the IVC remnant segments and the azygos vein in order to quantify the dilatation of the collateral venous pathway overdeveloped to handle blood return. CONCLUSION: Using the findings from this case and those reported in the literature, we provide general recommendations that should be taken into account before managing a patient, symptomatic or asymptomatic, admitted to the hospital with IVC agenesis.

Improving Image Quality and Reducing Radiation Dose for Pediatric CT by Using Deep Learning Reconstruction.

Background CT deep learning reconstruction (DLR) algorithms have been developed to remove image noise. How the DLR affects image quality and radiation dose reduction has yet to be fully investigated. Purpose To investigate a DLR algorithm's dose reduction and image quality improvement for pediatric CT. Materials and Methods DLR was compared with filtered back projection (FBP), statistical-based iterative reconstruction (SBIR), and model-based iterative reconstruction (MBIR) in a retrospective study by using data from CT examinations of pediatric patients (February to December 2018). A comparison of object detectability for 15 objects (diameter, 0.5-10 mm) at four contrast difference levels (50, 150, 250, and 350 HU) was performed by using a non-prewhitening-matched mathematical observer model with eye filter (d'NPWE), task transfer function, and noise power spectrum analysis. Object detectability was assessed by using area under the curve analysis. Three pediatric radiologists performed an observer study to assess anatomic structures with low object-to-background signal and contrast to noise in the azygos vein, right hepatic vein, common bile duct, and superior mesenteric artery. Observers rated from 1 to 10 (worst to best) for edge definition, quantum noise level, and object conspicuity. Analysis of variance and Tukey honest significant difference post hoc tests were used to analyze differences between reconstruction algorithms. Results Images from 19 patients (mean age, 11 years ± 5 [standard deviation]; 10 female patients) were evaluated. Compared with FBP, SBIR, and MBIR, DLR demonstrated improved object detectability by 51% (16.5 of 10.9), 18% (16.5 of 13.9), and 11% (16.5 of 14.8), respectively. DLR reduced image noise without noise texture effects seen with MBIR. Radiologist ratings were 7 ± 1 (DLR), 6.2 ± 1 (MBIR), 6.2 ± 1 (SBIR), and 4.6 ± 1 (FBP); two-way analysis of variance showed a difference on the basis of reconstruction type (P < .001). Radiologists consistently preferred DLR images (intraclass correlation coefficient, 0.89; 95% CI: 0.83, 0.93). DLR demonstrated 52% (1 of 2.1) greater dose reduction than SBIR. Conclusion The DLR algorithm improved image quality and dose reduction without sacrificing noise texture and spatial resolution. © RSNA, 2020 Online supplemental material is available for this article.

Modified (Bai-Jiang style) vagus nerve-preserving versus conventional laparoscopic splenectomy and azygoportal disconnection: a randomized clinical trial.

BACKGROUND: Digestive system complications are among the most important causes of postoperative poor quality of life after open and conventional laparoscopic splenectomy and azygoportal disconnection (CLSD). We firstly developed a modified vagus nerve-preserving laparoscopic splenectomy and azygoportal disconnection (MVLSD). In this study, we aimed to evaluate whether MVLSD is feasible and safe and to determine whether MVLSD can effectively eliminate postoperative digestive system complications, in comparison with CLSD. METHOD: In this randomized controlled single-center study, 60 patients with cirrhosis were randomly assigned to undergo either CLSD (n = 30) or MVLSD (n = 30) between April and December 2018. The primary outcome was delayed gastric emptying (DGE). Endoscopic physicians were blinded to group assignments. RESULTS: One patient who received MVLSD withdrew from the study. There were no significant differences in intraoperative blood loss, incidence of blood transfusion, time to off-bed activity, time to first flatus, and postoperative hospital stay between the two groups. Compared with CLSD, operation time and incidences of DGE, diarrhea, epigastric fullness, and overall postoperative complications were all significantly reduced in the MVLSD group (all P < 0.05). Compared with CLSD, MVLSD was associated with significantly increased weight and albumin levels at 1, 6, and 12 months postoperatively versus preoperative values (all P < 0.05). The curative effect of resolving gastroesophageal variceal bleeding was similar between the groups. CONCLUSION: MVLSD is not only a technically feasible and safe procedure, it is also succinct and convenient. Furthermore, MVLSD effectively reduces postoperative digestive system complications, contributing to improved quality of life.

Phrenic Nerve Block at the Azygos Vein Level Versus Sham Block for Ipsilateral Shoulder Pain After Video-Assisted Thoracoscopic Surgery: A Randomized Controlled Trial.

BACKGROUND: Ipsilateral shoulder pain (ISP) is a common problem after pulmonary surgery. We hypothesized that phrenic nerve block (PNB) at the azygos vein level, near the location of the surgical operation, would be effective for reducing ISP. Our primary aim was to assess the effect of PNB on postoperative ISP, following video-assisted thoracic surgery (VATS). METHODS: This prospective, randomized, patient-blinded, single-institution trial was registered at the University Hospital Medical Information Network (UMIN000030464). Enrolled patients had been scheduled for VATS under general anesthesia with epidural analgesia. Patients were randomly allocated to receive infiltration of the ipsilateral phrenic nerve at the azygos vein level with either 10 mL of 0.375% ropivacaine (PNB group) or 0.9% saline (control group) before chest closure. Postoperative ISP was assessed using a numerical rating scale (NRS, 0-10) at rest at 2, 4, 8, 16, and 24 hours. The incidence of ISP was defined as the proportion of patients who reported an NRS score of ≥1 at least once within 24 hours after surgery. In the primary analysis, the proportion of patients with ISP was compared between PNB and control groups using the χ2 test. NRS values of ISP and postoperative incision pain within 24 hours were investigated, as was the frequency of postoperative analgesic use. Incision pain was assessed using an NRS at the time of ISP assessment. Finally, the incidence of postoperative nausea and vomiting and shoulder movement disorders were also evaluated. RESULTS: Eighty-five patients were included, and their data were analyzed. These patients were randomly assigned to either PNB group (n = 42) or control group (n = 43). There were no clinically relevant differences in demographic and surgical profiles between the groups. There was no significant difference in the incidence of ISP (the control group 20/43 [46.5%] versus the PNB group 14/42 [33.3%]; P = .215). The severity of ISP was lower in the PNB group than in the control group (linear mixed-effects model, the main effect of treatment [groups]: P < .001). There were no significant differences between groups in terms of postoperative incision pain. The frequency of postoperative analgesic use was significantly higher in the control group (Wilcoxon rank sum test, P < .001). Postoperative nausea and vomiting did not significantly differ between the 2 groups. There were no changes in the range of shoulder joint movement. CONCLUSIONS: Azygos vein level PNB did not significantly affect the incidence of ISP after VATS.

Clinical characteristics of 50 children with azygos lobe: a retrospective study.

An azygos lobe is a rare anatomic variant of the lung which may be misdiagnosed as other pathological conditions. There is a dearth of information on the clinical characteristics of children with azygos lobe. This study aims to summarize the clinical features of children with azygos lobe, which may be helpful to improve recognition and clinical care of those patients. Clinical findings of the children with imaging findings of azygos lobe were collected and analyzed. In this study, 50 children with azygos lobe were included. A total of 28% cases were found to have azygos lobe incidentally. The remaining 72% cases were diagnosed when they presented with respiratory symptoms including cough (36%), fever (34%), wheezing (18%), dyspnea (14%), and cyanosis (8%). Congenital heart disease, Down syndrome, and other respiratory malformations were also found in a small proportion of these patients. Only 7 (14%) patients suffered from azygos lobe infection and were clinically cured after reasonable anti-infective treatment. Compared with the non-infected group, no valuable risk factors were found to be related to azygos lobe infection. All children who had azygos lobe infections responded to appropriate antibiotics therapy. There was no evidence that an azygos lobe was associated with recurrent infections.Conclusion: The clinical characteristics of children with azygos lobe are nonspecific and diagnosis relies on chest imaging. Some congenital abnormalities may be complicated with azygos lobe. It is reasonable to keep watch over those patients without symptoms. What is Known: • An azygos lobe is a congenital variation of the lung. • Azygos lobe can mimic various pathological conditions leading to misdiagnosis and inappropriate treatment in adults, which presents challenges during thoracic surgical interventions. What is New: • Azygos lobe in children may be complicated with other congenital abnormalities. • There is no evidence that azygos lobe is associated with recurrent infections. • After appropriate anti-infective treatment, those children with azygos lobe infections could be clinically cured.