The azygos vein can be formed as a single root, two roots, and three roots, namely lateral, intermediate and the medial roots respectively. The hemiazygos vein and the accessory hemiazygos vein are the tributaries of azygos vein rather than its left side equivalents. Its variations, especially in young persons without any relevant risk factors, may result in thromboembolic illness. This study aimed to describe the morphological and morphometric variations of azygos system of veins. The present study was conducted on thirty formalin fixed adult human cadavers by dissecting azygos vein from formation to termination and variations were noted. The azygos vein was formed by a single root in 56.7%, by two roots: the lateral root and intermediate root in 36.7% cases and by the lateral root and medial root in 6.6%. The vertebral level of termination of azygos vein was seen at the level of T4 vertebrae in 70% cases, at the level of T3 vertebrae in 20% of cases and at the level of T5 vertebrae in 10% cases. The course of azygos vein was varying in 13.3%. These morphological variations can be useful while performing mediastinal surgery, mediastinoscopy, surgery of the deformations of the vertebral column, neurovascular surgeries of the retroperitoneal organs, disc herniation and fracture of thoracic vertebrae.

This study aimed to validate and compare the anatomical variations of the superior intercostal veins, focusing on their origin, course, anastomoses, and destination. In addition, the results were compared with findings from other relevant studies. Fifty Korean and 16 Chinese adult cadavers were dissected for this study. The superior intercostal veins were dissected and measured. In our study of 66 specimens, the right superior intercostal vein was observed in 92.3% of cases, while the left superior intercostal vein was observed in 50%. The right superior intercostal vein was subdivided into six types based on its composition, which mainly drained the second and third right posterior intercostal veins. Similarly, the left superior intercostal vein was subdivided into eight types, primarily involving the second to fourth left posterior intercostal veins. This detailed anatomical study successfully identified and classified the various morphologic types of the superior intercostal vein and reviewed the clinical significance of this vein. The findings of this study can offer valuable anatomical evidence to physicians, aiding in their understanding and utilization of the superior intercostal vein.

Esophagogastric variceal bleeding is the most common lethal factor for patients with cirrhotic portal hypertension. We firstly developed a laparoscopic splenectomy and azygoportal disconnection (LSD) with intraoperative endoscopic variceal ligation (LSDL) technique. In this study, we aimed to evaluate whether LSDL is feasible and safe and whether LSDL can effectively prevent esophagogastric variceal re-bleeding (EVR), as compared with single LSD.
In this randomized controlled single-center study, 88 patients with cirrhosis who had esophagogastric variceal bleeding and hypersplenism were randomly assigned to receive either LSD (n = 44) or LSDL (n = 44) between January 2020 and December 2021. The primary outcome was EVR.
No patients withdrew from the study. There were no significant differences in estimated blood loss, incidence of blood transfusion, time to first flatus and off-bed activity, or postoperative hospital stay between the two groups. Compared with that in the LSD group, operation time was significantly longer in the LSDL group (138.5 ± 19.4 min vs. 150.3 ± 19.0 min, P < 0.05); however, LSDL was associated with a significantly decreased EVR rate at 1-year follow-up (8/44 vs. 1/44, P < 0.05). Univariate analysis and multivariate logistic regression revealed that LSDL was a significant independent protective factor against EVR in comparison with LSD (relative risk: 0.105, 95% confidence interval 0.012-0.877; P = 0.037).
Our newly developed LSDL procedure is not only technically feasible and safe; it also contributed to lowering the EVR risk more so than single LSD.
We registered our research at https://www.
gov/ . The name of research registered is \"Laparoscopic Splenectomy and Azygoportal Disconnection with Intraoperative Endoscopic Variceal Ligation.\" The trial registration identifier at clinicaltrials.gov is NCT04244487.

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.

UNASSIGNED: To evaluate the short-term efficacy of azygos arch-sparing McKeown minimally invasive esophagectomy (McKeown-MIE).
UNASSIGNED: We retrospectively analyzed the clinical data of 221 patients with thoracic esophageal squamous cell carcinoma who underwent McKeown-MIE at the Department of Thoracic Surgery of Gaozhou People\'s Hospital from August 1, 2017 to September 30, 2019. According to whether the azygos arch was preserved or not, the patients were assigned to one of two groups: the preservation group (40 cases) and the ligation group (181 cases). Within 3 months of the operation, the perioperative outcomes and the postoperative short-term efficacy of the two groups were compared.
UNASSIGNED: After propensity score (PS) matching, 40 pairs of patients were matched successfully. Between the two groups, there were no statistical difference in intraoperative blood loss, the number of lymph nodes dissected, thoracic drainage duration, fasting time, postoperative hospital stay time, and major postoperative complications (P>0.05). Compared with the ligation group, patients in the preservation group had a shorter intensive care unit (ICU) stay time, a shorter operative time, a lower volume of postoperative thoracic drainage (both the first 3 days and overall) following surgery, a tubular stomach that had a smaller caliber, and a lower incidence of tubular gastric malpositioning (P<0.05).
UNASSIGNED: Preserving the azygos arch during a McKeown-MIE is safe and feasible. Doing so, not only effectively restricts the expansion of the gastric conduit, leading to a lower incidence of malpositioning, but also dramatically reduces postoperative thoracic drainage, and ICU stay time.

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).
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.
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.
Azygos vein level PNB did not significantly affect the incidence of ISP after VATS.

OBJECTIVE: To evaluate the feasibility of thoracoscopic placement of three vascular attenuation devices by using the azygos vein as a model for portoazygos (PA) shunts and to describe the approach for thoracoscopic placement of these attenuation devices in small breed dogs.
METHODS: Randomized, prospective, cadaveric study.
METHODS: Cadavers of 10 adult small breed dogs.
METHODS: Cadavers were placed in sternal recumbency with left dorsolateral obliquity, and three thoracoscopic ports were established in the right hemithorax at the mid-10th intercostal space and dorsal third of the ninth and 11th intercostal spaces. The caudal azygos vein was thoracoscopically isolated along three adjacent segments bordered by four intercostal arteries, beginning just cranial to the first intercostal artery visualized cranial to the diaphragm. Three attenuation devices including coated cellophane, uncoated cellophane, and a 5-mm ameroid constrictor were thoracoscopically placed around one segment in each dog. Minor port access modifications were required to improve working space and triangulation in three dogs. Ability to successfully place the device, time required for placement, endoscopic clip configuration, and complications associated with placement were recorded.
RESULTS: Median dog weight was 7.7 kg (range, 1.8-11). All attenuation devices were successfully placed thoracoscopically in all cadavers. No difference was detected in time required for placement between the ameroid constrictor and coated and uncoated cellophane (range, 2.3-33.8 minutes, P = .8).
CONCLUSIONS: Ameroid constrictors and thin film bands were consistently placed via thoracoscopy around the caudal azygos vein of small breed dogs.
CONCLUSIONS: These results justify further investigation of thoracoscopic PA shunt attenuation in affected dogs.

OBJECTIVE: The study highlights azygos vein (AV) topography, arrangement and confluence morphometry in dyspnoea and tachycardia patients of extrapulmonary and extracardiac aetiology.
METHODS: Computed-tomography angiography of 25 male and 26 female patients (mean age 66.5 years) were studied for: thoracic vertebral (T) height of AV- superior vena cava-SVC confluence, AV course and deviations from vertebral column (VC) midline, AV and SVC diameters, distance (AV arch- lower border of carina) and gender and age impact.
RESULTS: Commonest heights of the AV-SVC confluence were T5 (56.9%), T4 (31.4%), T6 (9.8%) and T3 (2%). The AV terminated into SVC after crossing the left side of VC midline in 56.9%, slightly deviated right of the midline in 37.3% and coursed right of VC in 5.9%. Mean AV and SVC diameters were 0.96 ± 0.18 cm and 1.86 ± 0.27 cm. Male predominance in AV and SVC diameters and a slight AV diameter significant increase with the age were found. The (AV highest point-lower border of carina) mean distance was 2.05 ± 0.44 cm and male predominance existed.
CONCLUSIONS: The commonest termination height of the AV was T5, while T3 was the rarest one. Aging induces the AV leftward displacement, while gender had no impact. AV and SVC diameters had higher significant values in males, while ageing had a significant impact only in AV diameter. The AV higher diameters will be used as predictors for higher values of SVC diameter and mediastinum pathology. Such findings can be useful in mediastinal surgery, mediastinoscopy and surgery of VC deformations, neurovascular surgery of retroperitoneal organs, disc herniation and T fractures.

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.
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.
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.
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.

OBJECTIVE: Anterior surgical approaches to the thoracic spine are common procedures for the treatment of many diseases of the thoracic spine. Purpose of this anatomic study is to investigate the course of the segmental vessels of the thoracic spine for the anterior and lateral transthoracic approach from the right side.
METHODS: 26 formalin-fixed human cadavers (20 femaless/6 male) with an average age of 84.9 ± 8.3 (range 67-97) were included. The segmental arteries and veins of the right thoracic cavity coursing between the third and twelfth thoracic vertebral body have been investigated. To define the localization of the vessels in accordance with the associated vertebral bodies, the distance between the endplates and vessels was measured in the ventral, middle and dorsal parts.
RESULTS: The results of the study reveal that not only one, but also two segmental arteries and veins may course over the right hemi-vertebral body, especially in the upper and middle thoracic spine. Furthermore, in the middle and lower thoracic spine (T7-T12) the vessels course over the middle and lower third of the craniocaudal extent of the vertebral body. On the contrary, in the upper thoracic spine (T3-T6), the vessels may course over the entire extent of the vertebral body.
CONCLUSIONS: Due to these common anatomic variations and variability of the course of the segmental vessels, spinal surgeons should remain careful in the identification of the segmental vessels in order to minimize risk of vascular injury in case of right-sided anterior and lateral approach to the thoracic spine.