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Ivor Lewis Esophagectomy in a Patient With Enlarged Azygos Vein: A Lesson to Learn

2007; Elsevier BV; Volume: 85; Issue: 1 Linguagem: Inglês

10.1016/j.athoracsur.2007.06.039

1552-6259

Antonio Martín‐Malagón, Alberto Bravo, Iván Arteaga, Lucrecia Rodríguez, Fernando Díaz Estévez, Antonio Alarcó,

Cardiac Arrhythmias and Treatments

We report the case of a 62-year-old patient with congenital interruption of the inferior vena cava and azygos continuation who required transthoracic esophagectomy to remove a tumor in the middle esophagus. The consequences of dividing an enlarged azygos vein in this kind of patient are reported and discussed. We report the case of a 62-year-old patient with congenital interruption of the inferior vena cava and azygos continuation who required transthoracic esophagectomy to remove a tumor in the middle esophagus. The consequences of dividing an enlarged azygos vein in this kind of patient are reported and discussed. Anomalies in the development of the vena cava are rare and present with multiple variants. One of the most common is inferior vena cava (IVC) interruption with azygos vein continuation. In this variation of normal anatomy, venous return from the lower limbs passes through the azygos vein, which is usually greatly enlarged in size. Given the low frequency of this disorder, little is known about the effects of surgery on the organism’s hemodynamics in the event that this vein is sectioned during a particular surgical procedure.We report the case of a 62-year-old man who was admitted to our service for dysphagia. An epidermoid carcinoma of the middle esophagus was diagnosed after gastroscopy. Staging a thoracic-abdominal computed tomographic scan revealed increased thickness of the middle esophagus wall and adenopathies around the left gastric artery without hepatic metastases. An enlarged azygos vein was also detected with no retrohepatic vena cava. Neoadjuvant radio-chemotherapy resulted in partial response, after which Ivor Lewis esophagectomy was deemed necessary to remove the tumor.We commenced with a midline laparotomy. Abdominal time was performed as per Nichols and colleagues [1Nichols 3rd, F.C. Allen M.S. Deschamps C. Cassivi S.D. Pairolero P.C. Ivor Lewis esophagogastrectomy.Surg Clin North Am. 2005; 85: 583-592Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] and without incidences. The adenopathies of the lesser curve were removed and the gastric tube was constructed. After that we placed the patient in the left lateral decubitus position, collapsed the right lung, and performed a right thoracotomy through the fifth intercostal space.During thoracotomy we observed a greatly enlarged azygos vein with a diameter of 2 to 3 cm, which crossed from the posterior mediastinum to join the superior vena cava anterior to the tumor. The tumor was located in the middle esophagus posterior to the right bronchi. We decided to divide the enlarged azygos vein to gain proper access to the tumor as described in classical Ivor Lewis esophagectomy [1Nichols 3rd, F.C. Allen M.S. Deschamps C. Cassivi S.D. Pairolero P.C. Ivor Lewis esophagogastrectomy.Surg Clin North Am. 2005; 85: 583-592Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar], after which we dissected the tumor from the right bronchi, freed the high thoracic esophagus, and divided it above the azygos vein. Finally an esophago-gastric anastomosis was performed and the thoracotomy wound was closed.After azygos vein transection, the patient suffered severe hypotension that failed to respond to fluid administration. Ionotropic amines were administered to maintain proper arterial pressure during the procedure.The general condition of the patient worsened in the first hours after intervention, with anuria that barely responded to fluid infusion and diuretics. Due to persistent hypotension, ionotropic agents to maintain blood pressure were necessary. Inferior vena cava syndrome with a large edema progressively developed in the patient, with pain in the lower limbs and increased intrabdominal pressure. Acute interruption of venous drainage from the mid-lower part of the body after azygos division was suspected. A preoperative computed tomographic scan was reviewed, and anomalous systemic venous return was confirmed with interruption of the inferior vena cava and with azygos continuation and absence of the retrohepatic segment of the vena cava. Reintervention was indicated to restore normal venous drainage of the lower body, normal systolic volume, and renal perfusion.A second right thoracotomy was performed. Direct anastomosis of both azygos vein edges was not possible due to interposition of the gastric tube, so a prosthetic polytetrafluoroethylene graft was necessary for termino-terminal reconstruction of the vein. Unfortunately the patient’s condition deteriorated due to acute graft thrombosis, which led to death 1 day later.CommentAzygos vein enlargement is a rare condition that may be detected in certain clinical situations such as congestive heart failure, portal hypertension, inferior vena cava thrombosis, right atrial mural thrombosis, pulmonary embolism, arteriovenous fistula, and congenital interruption of the IVC [2Shin M.S. Ho K.J. Clinical significance of azygos vein enlargement: radiographic recognition and etiologic analysis.Clin Imaging. 1999; 23: 236-240Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar]. Our patient was asymptomatic before intervention and had no previous medical history. After revision of the computed tomography, we confirmed that enlargement was due to a congenital interruption of the IVC.Anatomical anomalies of the vena cava are rare but have been previously reported [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. There are many types, but one of the most frequently reported is interruption of the IVC with azygos continuation and an estimated prevalence of 0.15% [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar].In this congenital anomaly there is no retrohepatic portion of the vena cava; the IVC is interrupted above the renal veins and continues with an enlarged azygos. A large proportion of venous return from the lower part of the body is through the azygos vein into the superior vena cava, and the suprahepatic veins drain directly into the right auricle. Association with other congenital anomalies has been reported [4Matsuoka T. Kimura F. Sugiyama K. Nagata N. Takatani O. Anomalous inferior vena cava with azygos continuation, dysgenesis of lung, and clinically suspected absence of left pericardium.Chest. 1990; 97: 747-749Crossref PubMed Scopus (19) Google Scholar] (Fig 1, Fig 2, Fig 3, Fig 4).Fig 2Interruption of inferior vena cava above renal veins (arrow).View Large Image Figure ViewerDownload (PPT)Fig 3Continuation of inferior vena cava with azygos vein and absence of retrohepatic vena cava (arrow).View Large Image Figure ViewerDownload (PPT)Fig 4Enlarged azygos vein (arrow).View Large Image Figure ViewerDownload (PPT)If the azygos vein is well developed, the patient is usually asymptomatic, and if not, venous drainage of the lower extremities occurs through collateral veins associated with problems of deep venous thrombosis, pulmonary embolism, varicose veins, and venous aneurysm [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. If the azygos vein is well developed it may be misdiagnosed after an x-ray film indicates it as a mediastinic mass or tumor, and computed tomography is necessary for differential diagnosis [5Martinez Garcia M.A. Pastor A. Ferrando D. Nieto M.L. Casual recognition of an azygos continuation of the inferior vena cava in a patient with lung cancer.Respiration. 1999; 66: 66-68Crossref PubMed Scopus (9) Google Scholar].When this anomaly is asymptomatic it does not require treatment but must be taken into account if diagnostic or therapeutic maneuvers are necessary, as reported by cardiologists when access to the right ventricle is gained through transfemoral and IVC routes [6Vijayvergiya R. Bhat M.N. Kumar R.M. Vivekanand S.G. Grover A. Azygos continuation of interrupted inferior vena cava in association with sick sinus syndrome.Heart. 2005; 91Crossref PubMed Scopus (30) Google Scholar].A section of the azygos vein is a well-described surgical procedure in Ivor Lewis esophagectomy that allows better access to the tumor when it is located in the middle thoracic esophagus, making it possible to free enough length of high thoracic esophagus for an easy anastomotic reconstruction and facilitating optimal oncological resection. Strangulation of the reconstructed gastric tube by the azygos arch has been described, and dividing the azygos arch is routinely recommended by some authors if high thoracic anastomosis is needed [7Lin F.C. Russell H. Ferguson M.K. Strangulation of the reconstructive gastric tube by the azygos arch.Ann Thorac Surg. 2006; 82: e8-e10Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar]. Normal azygos transection during transthoracic esophagectomy has no effect on venous return, but the effects of transection have not been previously reported when this vein is enlarged due to an anomalous development of the IVC.After azygos transection, changes in normal hemodynamics of the patient were evident, but we considered that collateral veins could supply venous return and this situation would be temporary. Many patients with IVC interruption and without an enlarged azygos vein who survive are reported [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. In these patients, venous return is exclusively by the collateral veins, although thrombotic complications are described [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. Compensatory venous return by collateral veins was not sufficient in our patient probably because collateral circulation was limited and did not have enough time to develop. Although the enlargement of the azygos vein was evident in the preoperative computed tomographic scan, we did not consider it particularly relevant, probably because of our limited experience in vascular thoracic anomalies. This situation may be fatal if the question of venous return is overlooked in cases with this anomaly.We have not found any similar case reported in the literature probably because it is a very rare coincidence that a patient with this anomaly requires a procedure where section of the azygos vein is necessary. Haraguchi and colleagues [8Haraguchi S. Hioki M. Hisayoshi T. et al.Enucleation of esophageal leiomyoma with azygos continuation of the inferior vena cava: report of a case.Surg Today. 2006; 36: 722-726Crossref PubMed Scopus (5) Google Scholar] reported the enucleation of a leiomyoma of the middle esophagus in a patient with azygos continuation of the vena cava. They achieved proper access to the tumor by dividing the right superior intercostal vein, thus avoiding transection of the azygos. We think that this maneuver in our patient would not have allowed proper access to the tumor due to the magnitude of azygos enlargement.We decided on venous reconstruction to restore normal hemodynamics of the patient. Although venous reconstruction is rarely performed, good results have been reported. Direct reconstruction was not possible due to the interposition of the gastric tube between the edges of the azygos vein and we considered a termino-terminal reconstruction with a prosthetic polytetrafluoroethylene graft the best option. An azygos vein to the right atrium bypass graft has also been reported as successful in a patient with idiopathic fibrosing mediastinitis [9Kakkis J.L. Sicklick J.K. Gomes A. Cohen B. Quinones-Baldrich W.J. Azygous vein to right atrium bypass graft in a patient with idiopathic fibrosing mediastinitis and symptomatic superior and inferior vena cava obstructions.J Vasc Surg. 2002; 36: 1071-1075Abstract Full Text PDF PubMed Scopus (3) Google Scholar], but we ruled out this option given its technical complexity. Acute graft thrombosis probably occurred because of excessive delay in reintervention and general deterioration of the patient at that moment.Inferior vena cava interruption with azygos continuation is a rare vascular anomaly that must be taken into account if transthoracic esophagectomy is necessary. Azygos division must be avoided if tumor size and localization allows it. If not, immediate reconstruction of the enlarged azygos vein must be performed using a graft for termino-terminal anastomosis or a bypass graft to the right atrium to prevent fatal changes in patient hemodynamics. High technical skills and great experience are necessary to carry out this kind of surgery and it should only be attempted by a multidisciplinary team of general, thoracic, and vascular surgeons. Anomalies in the development of the vena cava are rare and present with multiple variants. One of the most common is inferior vena cava (IVC) interruption with azygos vein continuation. In this variation of normal anatomy, venous return from the lower limbs passes through the azygos vein, which is usually greatly enlarged in size. Given the low frequency of this disorder, little is known about the effects of surgery on the organism’s hemodynamics in the event that this vein is sectioned during a particular surgical procedure. We report the case of a 62-year-old man who was admitted to our service for dysphagia. An epidermoid carcinoma of the middle esophagus was diagnosed after gastroscopy. Staging a thoracic-abdominal computed tomographic scan revealed increased thickness of the middle esophagus wall and adenopathies around the left gastric artery without hepatic metastases. An enlarged azygos vein was also detected with no retrohepatic vena cava. Neoadjuvant radio-chemotherapy resulted in partial response, after which Ivor Lewis esophagectomy was deemed necessary to remove the tumor. We commenced with a midline laparotomy. Abdominal time was performed as per Nichols and colleagues [1Nichols 3rd, F.C. Allen M.S. Deschamps C. Cassivi S.D. Pairolero P.C. Ivor Lewis esophagogastrectomy.Surg Clin North Am. 2005; 85: 583-592Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar] and without incidences. The adenopathies of the lesser curve were removed and the gastric tube was constructed. After that we placed the patient in the left lateral decubitus position, collapsed the right lung, and performed a right thoracotomy through the fifth intercostal space. During thoracotomy we observed a greatly enlarged azygos vein with a diameter of 2 to 3 cm, which crossed from the posterior mediastinum to join the superior vena cava anterior to the tumor. The tumor was located in the middle esophagus posterior to the right bronchi. We decided to divide the enlarged azygos vein to gain proper access to the tumor as described in classical Ivor Lewis esophagectomy [1Nichols 3rd, F.C. Allen M.S. Deschamps C. Cassivi S.D. Pairolero P.C. Ivor Lewis esophagogastrectomy.Surg Clin North Am. 2005; 85: 583-592Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar], after which we dissected the tumor from the right bronchi, freed the high thoracic esophagus, and divided it above the azygos vein. Finally an esophago-gastric anastomosis was performed and the thoracotomy wound was closed. After azygos vein transection, the patient suffered severe hypotension that failed to respond to fluid administration. Ionotropic amines were administered to maintain proper arterial pressure during the procedure. The general condition of the patient worsened in the first hours after intervention, with anuria that barely responded to fluid infusion and diuretics. Due to persistent hypotension, ionotropic agents to maintain blood pressure were necessary. Inferior vena cava syndrome with a large edema progressively developed in the patient, with pain in the lower limbs and increased intrabdominal pressure. Acute interruption of venous drainage from the mid-lower part of the body after azygos division was suspected. A preoperative computed tomographic scan was reviewed, and anomalous systemic venous return was confirmed with interruption of the inferior vena cava and with azygos continuation and absence of the retrohepatic segment of the vena cava. Reintervention was indicated to restore normal venous drainage of the lower body, normal systolic volume, and renal perfusion. A second right thoracotomy was performed. Direct anastomosis of both azygos vein edges was not possible due to interposition of the gastric tube, so a prosthetic polytetrafluoroethylene graft was necessary for termino-terminal reconstruction of the vein. Unfortunately the patient’s condition deteriorated due to acute graft thrombosis, which led to death 1 day later. CommentAzygos vein enlargement is a rare condition that may be detected in certain clinical situations such as congestive heart failure, portal hypertension, inferior vena cava thrombosis, right atrial mural thrombosis, pulmonary embolism, arteriovenous fistula, and congenital interruption of the IVC [2Shin M.S. Ho K.J. Clinical significance of azygos vein enlargement: radiographic recognition and etiologic analysis.Clin Imaging. 1999; 23: 236-240Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar]. Our patient was asymptomatic before intervention and had no previous medical history. After revision of the computed tomography, we confirmed that enlargement was due to a congenital interruption of the IVC.Anatomical anomalies of the vena cava are rare but have been previously reported [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. There are many types, but one of the most frequently reported is interruption of the IVC with azygos continuation and an estimated prevalence of 0.15% [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar].In this congenital anomaly there is no retrohepatic portion of the vena cava; the IVC is interrupted above the renal veins and continues with an enlarged azygos. A large proportion of venous return from the lower part of the body is through the azygos vein into the superior vena cava, and the suprahepatic veins drain directly into the right auricle. Association with other congenital anomalies has been reported [4Matsuoka T. Kimura F. Sugiyama K. Nagata N. Takatani O. Anomalous inferior vena cava with azygos continuation, dysgenesis of lung, and clinically suspected absence of left pericardium.Chest. 1990; 97: 747-749Crossref PubMed Scopus (19) Google Scholar] (Fig 1, Fig 2, Fig 3, Fig 4).Fig 3Continuation of inferior vena cava with azygos vein and absence of retrohepatic vena cava (arrow).View Large Image Figure ViewerDownload (PPT)Fig 4Enlarged azygos vein (arrow).View Large Image Figure ViewerDownload (PPT)If the azygos vein is well developed, the patient is usually asymptomatic, and if not, venous drainage of the lower extremities occurs through collateral veins associated with problems of deep venous thrombosis, pulmonary embolism, varicose veins, and venous aneurysm [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. If the azygos vein is well developed it may be misdiagnosed after an x-ray film indicates it as a mediastinic mass or tumor, and computed tomography is necessary for differential diagnosis [5Martinez Garcia M.A. Pastor A. Ferrando D. Nieto M.L. Casual recognition of an azygos continuation of the inferior vena cava in a patient with lung cancer.Respiration. 1999; 66: 66-68Crossref PubMed Scopus (9) Google Scholar].When this anomaly is asymptomatic it does not require treatment but must be taken into account if diagnostic or therapeutic maneuvers are necessary, as reported by cardiologists when access to the right ventricle is gained through transfemoral and IVC routes [6Vijayvergiya R. Bhat M.N. Kumar R.M. Vivekanand S.G. Grover A. Azygos continuation of interrupted inferior vena cava in association with sick sinus syndrome.Heart. 2005; 91Crossref PubMed Scopus (30) Google Scholar].A section of the azygos vein is a well-described surgical procedure in Ivor Lewis esophagectomy that allows better access to the tumor when it is located in the middle thoracic esophagus, making it possible to free enough length of high thoracic esophagus for an easy anastomotic reconstruction and facilitating optimal oncological resection. Strangulation of the reconstructed gastric tube by the azygos arch has been described, and dividing the azygos arch is routinely recommended by some authors if high thoracic anastomosis is needed [7Lin F.C. Russell H. Ferguson M.K. Strangulation of the reconstructive gastric tube by the azygos arch.Ann Thorac Surg. 2006; 82: e8-e10Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar]. Normal azygos transection during transthoracic esophagectomy has no effect on venous return, but the effects of transection have not been previously reported when this vein is enlarged due to an anomalous development of the IVC.After azygos transection, changes in normal hemodynamics of the patient were evident, but we considered that collateral veins could supply venous return and this situation would be temporary. Many patients with IVC interruption and without an enlarged azygos vein who survive are reported [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. In these patients, venous return is exclusively by the collateral veins, although thrombotic complications are described [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. Compensatory venous return by collateral veins was not sufficient in our patient probably because collateral circulation was limited and did not have enough time to develop. Although the enlargement of the azygos vein was evident in the preoperative computed tomographic scan, we did not consider it particularly relevant, probably because of our limited experience in vascular thoracic anomalies. This situation may be fatal if the question of venous return is overlooked in cases with this anomaly.We have not found any similar case reported in the literature probably because it is a very rare coincidence that a patient with this anomaly requires a procedure where section of the azygos vein is necessary. Haraguchi and colleagues [8Haraguchi S. Hioki M. Hisayoshi T. et al.Enucleation of esophageal leiomyoma with azygos continuation of the inferior vena cava: report of a case.Surg Today. 2006; 36: 722-726Crossref PubMed Scopus (5) Google Scholar] reported the enucleation of a leiomyoma of the middle esophagus in a patient with azygos continuation of the vena cava. They achieved proper access to the tumor by dividing the right superior intercostal vein, thus avoiding transection of the azygos. We think that this maneuver in our patient would not have allowed proper access to the tumor due to the magnitude of azygos enlargement.We decided on venous reconstruction to restore normal hemodynamics of the patient. Although venous reconstruction is rarely performed, good results have been reported. Direct reconstruction was not possible due to the interposition of the gastric tube between the edges of the azygos vein and we considered a termino-terminal reconstruction with a prosthetic polytetrafluoroethylene graft the best option. An azygos vein to the right atrium bypass graft has also been reported as successful in a patient with idiopathic fibrosing mediastinitis [9Kakkis J.L. Sicklick J.K. Gomes A. Cohen B. Quinones-Baldrich W.J. Azygous vein to right atrium bypass graft in a patient with idiopathic fibrosing mediastinitis and symptomatic superior and inferior vena cava obstructions.J Vasc Surg. 2002; 36: 1071-1075Abstract Full Text PDF PubMed Scopus (3) Google Scholar], but we ruled out this option given its technical complexity. Acute graft thrombosis probably occurred because of excessive delay in reintervention and general deterioration of the patient at that moment.Inferior vena cava interruption with azygos continuation is a rare vascular anomaly that must be taken into account if transthoracic esophagectomy is necessary. Azygos division must be avoided if tumor size and localization allows it. If not, immediate reconstruction of the enlarged azygos vein must be performed using a graft for termino-terminal anastomosis or a bypass graft to the right atrium to prevent fatal changes in patient hemodynamics. High technical skills and great experience are necessary to carry out this kind of surgery and it should only be attempted by a multidisciplinary team of general, thoracic, and vascular surgeons. Azygos vein enlargement is a rare condition that may be detected in certain clinical situations such as congestive heart failure, portal hypertension, inferior vena cava thrombosis, right atrial mural thrombosis, pulmonary embolism, arteriovenous fistula, and congenital interruption of the IVC [2Shin M.S. Ho K.J. Clinical significance of azygos vein enlargement: radiographic recognition and etiologic analysis.Clin Imaging. 1999; 23: 236-240Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar]. Our patient was asymptomatic before intervention and had no previous medical history. After revision of the computed tomography, we confirmed that enlargement was due to a congenital interruption of the IVC. Anatomical anomalies of the vena cava are rare but have been previously reported [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. There are many types, but one of the most frequently reported is interruption of the IVC with azygos continuation and an estimated prevalence of 0.15% [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. In this congenital anomaly there is no retrohepatic portion of the vena cava; the IVC is interrupted above the renal veins and continues with an enlarged azygos. A large proportion of venous return from the lower part of the body is through the azygos vein into the superior vena cava, and the suprahepatic veins drain directly into the right auricle. Association with other congenital anomalies has been reported [4Matsuoka T. Kimura F. Sugiyama K. Nagata N. Takatani O. Anomalous inferior vena cava with azygos continuation, dysgenesis of lung, and clinically suspected absence of left pericardium.Chest. 1990; 97: 747-749Crossref PubMed Scopus (19) Google Scholar] (Fig 1, Fig 2, Fig 3, Fig 4). If the azygos vein is well developed, the patient is usually asymptomatic, and if not, venous drainage of the lower extremities occurs through collateral veins associated with problems of deep venous thrombosis, pulmonary embolism, varicose veins, and venous aneurysm [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. If the azygos vein is well developed it may be misdiagnosed after an x-ray film indicates it as a mediastinic mass or tumor, and computed tomography is necessary for differential diagnosis [5Martinez Garcia M.A. Pastor A. Ferrando D. Nieto M.L. Casual recognition of an azygos continuation of the inferior vena cava in a patient with lung cancer.Respiration. 1999; 66: 66-68Crossref PubMed Scopus (9) Google Scholar]. When this anomaly is asymptomatic it does not require treatment but must be taken into account if diagnostic or therapeutic maneuvers are necessary, as reported by cardiologists when access to the right ventricle is gained through transfemoral and IVC routes [6Vijayvergiya R. Bhat M.N. Kumar R.M. Vivekanand S.G. Grover A. Azygos continuation of interrupted inferior vena cava in association with sick sinus syndrome.Heart. 2005; 91Crossref PubMed Scopus (30) Google Scholar]. A section of the azygos vein is a well-described surgical procedure in Ivor Lewis esophagectomy that allows better access to the tumor when it is located in the middle thoracic esophagus, making it possible to free enough length of high thoracic esophagus for an easy anastomotic reconstruction and facilitating optimal oncological resection. Strangulation of the reconstructed gastric tube by the azygos arch has been described, and dividing the azygos arch is routinely recommended by some authors if high thoracic anastomosis is needed [7Lin F.C. Russell H. Ferguson M.K. Strangulation of the reconstructive gastric tube by the azygos arch.Ann Thorac Surg. 2006; 82: e8-e10Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar]. Normal azygos transection during transthoracic esophagectomy has no effect on venous return, but the effects of transection have not been previously reported when this vein is enlarged due to an anomalous development of the IVC. After azygos transection, changes in normal hemodynamics of the patient were evident, but we considered that collateral veins could supply venous return and this situation would be temporary. Many patients with IVC interruption and without an enlarged azygos vein who survive are reported [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. In these patients, venous return is exclusively by the collateral veins, although thrombotic complications are described [3Koc Z. Oguzkurt L. Interruption or congenital stenosis of the inferior vena cava: prevalence, imaging, and clinical findings.Eur J Radiol. 2007; 62 (Epub 2006 Dec 11): 257-266Abstract Full Text Full Text PDF PubMed Scopus (108) Google Scholar]. Compensatory venous return by collateral veins was not sufficient in our patient probably because collateral circulation was limited and did not have enough time to develop. Although the enlargement of the azygos vein was evident in the preoperative computed tomographic scan, we did not consider it particularly relevant, probably because of our limited experience in vascular thoracic anomalies. This situation may be fatal if the question of venous return is overlooked in cases with this anomaly. We have not found any similar case reported in the literature probably because it is a very rare coincidence that a patient with this anomaly requires a procedure where section of the azygos vein is necessary. Haraguchi and colleagues [8Haraguchi S. Hioki M. Hisayoshi T. et al.Enucleation of esophageal leiomyoma with azygos continuation of the inferior vena cava: report of a case.Surg Today. 2006; 36: 722-726Crossref PubMed Scopus (5) Google Scholar] reported the enucleation of a leiomyoma of the middle esophagus in a patient with azygos continuation of the vena cava. They achieved proper access to the tumor by dividing the right superior intercostal vein, thus avoiding transection of the azygos. We think that this maneuver in our patient would not have allowed proper access to the tumor due to the magnitude of azygos enlargement. We decided on venous reconstruction to restore normal hemodynamics of the patient. Although venous reconstruction is rarely performed, good results have been reported. Direct reconstruction was not possible due to the interposition of the gastric tube between the edges of the azygos vein and we considered a termino-terminal reconstruction with a prosthetic polytetrafluoroethylene graft the best option. An azygos vein to the right atrium bypass graft has also been reported as successful in a patient with idiopathic fibrosing mediastinitis [9Kakkis J.L. Sicklick J.K. Gomes A. Cohen B. Quinones-Baldrich W.J. Azygous vein to right atrium bypass graft in a patient with idiopathic fibrosing mediastinitis and symptomatic superior and inferior vena cava obstructions.J Vasc Surg. 2002; 36: 1071-1075Abstract Full Text PDF PubMed Scopus (3) Google Scholar], but we ruled out this option given its technical complexity. Acute graft thrombosis probably occurred because of excessive delay in reintervention and general deterioration of the patient at that moment. Inferior vena cava interruption with azygos continuation is a rare vascular anomaly that must be taken into account if transthoracic esophagectomy is necessary. Azygos division must be avoided if tumor size and localization allows it. If not, immediate reconstruction of the enlarged azygos vein must be performed using a graft for termino-terminal anastomosis or a bypass graft to the right atrium to prevent fatal changes in patient hemodynamics. High technical skills and great experience are necessary to carry out this kind of surgery and it should only be attempted by a multidisciplinary team of general, thoracic, and vascular surgeons.