Left-sided Inferior Vena Cava and Aortoiliac Surgery
Article Outline
Congenital anomalies of the inferior vena cava vein are rare but may cause serious complications during abdominal aortic surgery. We present two patients with left-sided inferior vena cava: one with an abdominal aortic aneurysm and another with aortoiliac occlusive disease. The preoperative detection of such anomalies helps with operative planning, facilitates the surgical technique and may reduce the risk of severe venous haemorrhage.
Keywords: Inferior vena cava, Venous congenital anomalies, Aortoiliac surgery, Abdominal aortic aneurysm, Aortobifemoral bypass, Left sided vena cava
Introduction
The prevalence of major venous anomalies related to the abdominal aorta and iliac arteries detected by CT scan is 5.65%.1, 2 The most common variations are duplicate inferior vena cava (IVC), retroaortic left renal vein and circumaortic venous rings. Left-sided IVC occurs in 0.17–0.5% of the general population.1, 2, 3
The presence of vascular anatomical anomalies can create technical difficulties during aortoiliac surgery. We report successful repair of an aortoiliac aneurysm and the interposition of an aortobifemoral bypass graft for aortoiliac occlusive disease in two patients, both with a left-sided IVC. The embriology, diagnosis and management are discussed.
Case Reports
Case 1: A 74-year-old man was admitted with a periumbilical pulsatile mass. He had hypertension, chronic obstructive pulmonary disease (COPD) and dislipemia. A right carotid endarterectomy was done ten years previously. A CT scan showed an 5
cm abdominal aortic aneurysm (AAA) and a 3cm right common iliac aneurysm. A left-sided IVC was seen that began from the confluence of the left and right common iliac veins until it crossed anterior to the aorta, after receiving the left renal vein, to continue as a normal right-sided suprarenal IVC (Fig. 1). We performed a midline laparotomy. A left-sided IVC crossing the aorta on the aneurysmal neck was confirmed. The neck of the aneurysm was visualized by mobilising the vena cava superiorly. The aneurysm was resected and a bifurcated prosthesis was implanted. The postoperative course was uneventful and the patient was discharged on postoperative day 10. The patient continues to do well after a year follow up.
Fig. 1
Case no. 1: (A) The infrarenal left-sided IVC is showed in the CT (arrow), note the abdominal aortic aneurysm (sloping arrow). (B) The left-sided IVC (arrow), and the aortoiliac aneurysm (sloping arrows) are also showed in the angioCT.
Case 2: A 55-year-old man was admitted with a two day history of intense pain, paresthesia and coldness in the left leg. He was a heavy smoker, was hypertensive, hypercholesterolaemic and had a long history of intermittent claudication. The left limb appeared pale and cold on examination. The superficial veins were completely collapsed. No peripheral pulses were palpable in either leg. An angiogram showed an occlusion of the left iliac artery with filling of the common femoral artery through collaterals, and a severe right iliac stenosis (Fig. 2A), The patient was planned for surgery the following day. At operation, while dissecting the aorta, a left-sided IVC was found. The left sided IVC was mobilised to permit the proximal anastomosis and an aortobifemoral graft was inserted (Fig. 2B). The patient continues to do well alter 6 months.
Fig. 2
Case no. 2: (A) Angiography: left iliac artery occlusion and right aorta displacement (arrow). (B) Surgery field: proximal aortobifemoral anastomosis and left-sided IVC crossing anterior the aorta. (C) Embryologic origin: 1, hepatic cava (hepatic sinusoids and vitelline vein); 2, suprarenal cava (right subcardinal vein); 3, renal cava (intersubcardinal and suprasubcardinal anastomosis); 4, left renal vein (ventral limb of renal collar); 5, infrarenal cava (left supracardinal vein instead of the right one); 6, iliac veins (postcardinal veins).
Discussion
The IVC develops as a result of a complex embryologic process between the sixth and eighth week of gestation. Three pairs of primitive veins: the postcardinal, subcardinal, and supracardinal veins, appear in this order and form the four segments of the adult IVC: hepatic, suprarenal, renal and infrarenal.2 Anomalies of the IVC result from failures of regression during embryogenesis. The normal infrarenal IVC originates from the right supracardinal vein, whereas the left infrarenal IVC develops from the persistence of the left instead of the right supracardinal vein (Fig. 2C).1, 2, 3, 4 A left sided IVC is usually asymptomatic. However, an association with deep venous thrombosis and right isomerism with asplenia has been described.2
Since CT is routinely performed for the elective repair of AAA, this venous anomaly is usually easily detected and the risk of the operation is minimised, like in our first case.3 CT has proven to be superior to ultrasound and venogram for detecting IVC anomalies. Magnetic resonance imaging can be as effective as CT and avoids the risks of contrast nephropathy.4 A the left-sided infrarenal IVC typically joins the left renal vein, before it crosses the aorta to form a normal right-sided suprarenal IVC. It crosses usually anterior but rarely posterior. A complete transposition of the IVC to the left with hemiazygous continuation is extremely rare.2, 5 A preoperative CT scan is not routinely performed for aortoiliac occlusive disease like in our second case, therefore one needs to recognize this anomaly during surgery to prevent venous injury.4
Some authors prefer a right or left retroperitoneal approach in case of a left-sided IVC, which may be safer when preparing the perirenal aorta. A transperitoneal approach with division of the aberrant IVC as it crosses the aorta with subsequent anastomosis also has been suggested.3, 4 Nevertheless, an adequate control of the aneurysmal neck can be achieved through a midline transperitoneal approach with sufficient cava mobilization,4 like in our two cases. In emergency surgery for a ruptured AAA, diagnosed by ultrasound alone, abnormal IVC may be injured during surgery resulting in serious bleeding. In case of a ruptured AAA a CT could be useful to detect vascular anomalies and to avoid severe injuries. Patients with this IVC anomaly and an inflammatory AAA are at particularly high risk and could be candidates for endovascular procedures. Successful repair of a thoracoabdominal aortic aneurysm along with left-sided IVC, and of an AAA along with left-sided IVC and horseshoe kidney have been reported.3 Finally, this congenital anomaly may impose technicals difficulties to place a cava filter a pacemarker or during a right heart catheterization.5
Conclusion
The left-sided IVC is rarely encountered in patients undergoing aortoiliac surgery. Preoperative assessment and intraoperative awareness are important to prevent unexpected venous injuries and subsequent excessive bleeding. If the venous anomalies are recognized and treated correctly, serious injuries can be prevented and the outcome should not be affected.
Acknowledgments
We are grateful to PhD. Redondo for the review of this manuscript.
References
- . Incidence of major venous and renal anomalies relevant to aortoiliac surgery as demonstrated by computed tomography. Ann Vasc Surg. 2001;15:615–618
- . Congenital anomalies of the vena cavae: embryological origin, imaging features and report of three new variants. Eur Radiol. 2002;12:2040–2055
- . Repair of a thoracoabdominal aortic aneurysm in the presence of a left-sided inferior vena cava. J Vasc Surg. 2004;40(1):161–163
- Abdominal aortic aneurysm with left-sided inferior vena cava. Report of a case. Int Angiol. 2004;23(4):400–402
- . Left-sided or transposed inferior vena cava ascending as hemiazygos vein and draining into the coronary sinus via persistent left superior vena cava: case report. Int J Cardiol. 2004;93:293–295
PII: S1533-3167(07)00037-4
doi:10.1016/j.ejvsextra.2007.09.006
© 2007 European Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Refers to article:
- Left-sided Inferior Vena Cava and Aortoiliac Surgery , 03 January 2008
