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Journal of the Anatomical Society of India

A Rare Presentation of Double Inferior Vena Cava with Anomalous Pattern Of Azygos And Hemiazygos Venous Systems : A Case Report

Author(s): Palit, S., Deb, S.

Vol. 51, No. 1 (2002-01 - 2002-06)

Department of Anatomy, North Bengal Medical College, Sushrutanagar, Darjeeling, W.B. INDIA.

Abstract

On dissection of an adult male cadaver, presence of double inferior vena cava with anomalous pattern of azygos and hemiazygos venous systems was found. The purpose of this study was to understand the actual nature of these congenital malformations and to correlate with the preexisting works of other authors both in respect of morbid anatomy and vascular surgery. In the abdomen the right sided IVC was normal but on the left side an anomalous venous channel connecting the left renal vein with left common iliac vein was found; (probably the left IVC). The testicular vein and suprarenal vein opening into left renal vein were found normal. In the thorax on the right side azygos vein started as a continuation of lumbar azygos vein into which joined subcostal vein. two 11th intercostal veins (10th being absent posteriorly) and lower 9th intercostal vein, in an arched manner. On the left side, the inferior hemiazygos vein begins as the union of subostal, two 11th intercostal, 10th and 9th intercostal veins in a similar arched pattern. The superior hemiazgos drains intercostal veins till 8th spaces, joins to from a common trunk with inferior hemiazygos, which joins the azygos vein at the level of T 9 vertebra. Moreover at the renal hilum, the artery is placed in front of vein,the renal artery giving off segmental branches on both sides before hilum, on the right side the lowest may be an accessory renal artery.

The right IVC being normal, the left IVC is probably due to persistence of left supracardinal vein (infra renal segment,) which normally disappears. The ascending lumbar vein in absent, instead the lumbar azygos vein, which contributes to the anomalous origin of azygos vein, is found coincidentally.

The work of previous authors have highlighted the incidence of venacaval duplication and related surgical implications, but here we present a unique case of double IVC combined with anomalous pattern of azygos and hemiazygos venous drainage and bilateral renal artery abnormalities. The conglomeration of such vascular malformations is of immense surgical importance, specially during surgery of abdominal aorta (aneurysm) or during renal transplantation, and is indicative of a grossly defective angiogenesis. Though the etiology may be unknown yet there may be the role of certain teratogenic agents on angiogenic cell clusters (differentiated from mesoderm of the wall of the yolk sac at the beginning of 3rd week of intrauterine life.

Key words: Inferior Vena Caval duplication; Supra Cardinal Vein, azygous vein, hemiazygos vein.

Introduction:

Congenital anomalies of the inferior vena cava are a relatively rare pathology, usually with an asymptomatic iter. They are usually diagnosed by chance during surgery on the aorta or retroperitoneal structures. From bioptic material their incidence has been estimated to be 2-3% and the percentage of intraoperative findings varies in different series between 0.2-0.6% of various kinds of anomalies, caval duplication and a left positioned vena cava are the most commonly found. (Cossu et al, 2000).

Usually associated with this condition were horseshoe kidney, diagnosed by USG and CT (Kehagias et al, 1999) or continuation by a left inferior hemiazygous vein and retro aortic left renal vein (Larde et al, 1981).

Duplicated inferior vena cave was found unexpectedly at the time of resection of abdominal aortic aneurysm (Hans & Gordon, 1985) or in patients investigated by venography for a clinically proven varicocele (as a probable cause of infertility or incidental finding on CT scan for diagnosis of Hodgkin’s lymphoma (Koch et al, 1986) Peroperatively found left IVC, was encountered in patients with Leriche’s syndrome (aortoiliac occlusive disease involving the infrarenal aorta with intermittent claudication requiring aortobifemoral bypass surgery. (Rispoli et al, 2001).

Here we present a case of venacaval duplication (left sided IVC probably due to a persistent left supracardinal vein) with anomalous pattern of azygos and hemiazygos veins and bilateral renal artery abnormalities.

Materials & methods:

During routine dissection of an adult male cadaver in the Department of Anatomy, N. B. M. C., the right IVC was found to be normal and the left IVC was probably due to the persistent infrarenal segment of left supracardinal vein. The anomalous pattern of origin of azygos and hemiazygos veins was also found together with bilateral abnormalities of renal arteries.

Observations & results:

In the abdomen, an abnormal venous channel was found on the left side connecting renal veins with left common iliac vein, the testicular vein and suprarenal vein joining the left renal vein as usual. This channel was taken as the persistent infrarenal segment of left IVC, which normally disappears; the right IVC was normal [Vide : Photo-I]. Apart from this, at the renal hilum, the renal artery was placed in front of the vein, the artery dividing into segmental branches much before reaching hilum, three on the left and 4 on the right, the lowest one might be an accessory renal artery [Vide : Photo-2]. Such anomaly was found at the time of donor nephrectomy where congenital anomalies of the IVC with reversal of location of renal artery and veins was found at the renal hilum in a 56 yr. old woman with no preoperative anomalies.

In the thorax, the ascending lumbar vein being absent, the azygos vein was arising as a combination of lumbar azygos vein into which joined the subcostal vein, two 11th intercostal, lower 9th intertcostal vein (10th being absent posteriorly) in a peculiar arched pattern. Rest of the azygos vein was normal till it opened into the SVC (Vide : Phote-3]

On the left side inferior hemiazygos was similarly formed by joining the subcostal, 11th, 10th & 9th intercostal veins in an arched manner. The superior hemiazygos drained intercostal veins upto 8th spaces, both of these joined to form a common trunk which drained into the azygos vein crossing behind the aorta at the lower border of T9 vertebra [Vide : Photo-4].

Discussions:

A complex process of embryogenesis forms the IVC during 6th - 10th week of gestation. Improper completion of the process may result in 4 anatomic anomalies :- duplication of IVC, transposition of left sided IVC, retroaortic left renal vein and circumaortic left renal vein. The first two anomalies can be diagnosed by sonography and all 4 anomalies can be seen on CT scan of abdomen. Duplication and transportation of IVC should be further delineated by preoperative phlebography. Preoperative diagnosis of the anomalies shown reduce the complication rate of abdominal aortic operations (Giordano & Trout, 1986).

The IVC develops from persistent caudal part of posterior cardinal vein, supracardinal vein, supra- sub cardinal anastomosis receiving gonadal veins, upper part of right subcardinal vein receiving both renal & suprarenal veins, common hepatic vein and a communicating channel between common hepatic vein and right subcardinal vein. Due to regression of the left lobe of liver, cranial part of subcardinal vein forms suprarenal vein and rest of it forms left renal vein. The persistent left supra cardinal vein (infrarenal segment) forms left sided IVC in this case, which normally disappears (Williams, et al, 1995).

The azygos venous line right medial sympathetic line vein forms vertical part of azygos vein whereas the arch is formed by remnant of cephalic part of posterior cardinal vien. The left azygos venous line forms superior and inferior hemiazygos veins. sometimes of precostal or lumbocostal venous line may be traced which forms the ascending lumbar vein which is absent here. Usually the azygos vein arises by joining an ascending lumbar & subcostal veins but here the anomalous origin is due to the presence of lumbar azygos vein in which drains a common channel formed by subcostal two, 11th intercostal & lower 9th intercostal veins. Diagnostic and therapeutic indications have increased the need for ready access to IVC. Correct placement of a Greenfield filter in left IVC requires recognition of this anomaly. Placement through right internal jugular vein; otherwise left femoral vein is used. Because of incidence of anomalous IVC, routine inferior venacavography is recommended when an intracaval device is to the placed. (Sardi & Minken 1987) The works of previous authors have highlighted the incidence of venacaval duplication and related surgical implications. But here we present a unique case of double IVC combined with anomalous pattern of azygos and hemiazygos venous drainage and bilateral renal artery abnormalities. The conglomeration of such vascular malformations is of immense surgical importance, specially during surgery of abdominal aortic aneurysm or during renal transplantation and is indicative of a grossly defective angiogenesis.

Though the etiology may be unknown yet there may be the role of certain teratogenic agents or angiogenic cell clusters (differentiated from visceral mesoderm of the wall of the yolk sac) at the beginning of 3rd week of intrauterine life.

References:

  1. Cossu, M.L; Ruggiiu,M: Fais, E; Sparta, C; Dettori, G; Noya, G; (2000): Title not available Minerva Chir 55 (10) : 703- 8. (Article In Italian)
  2. Giordano, J.M; Trout, H.H; (1986): Anomalies of inferior venacava; Journal of Vascular Surgery. 3 (6) : 924-8
  3. Hans, S.S; Gordon, M ; (1989): Double inferior venacava & abdominal aortic aneurysm, Journal of Cardiovascular Surgery. 26 (I): 76-8.
  4. Kehagias, D.T; Gouliamos, A.d; Vlahos, L.J; (1999): Horseshoe kidney associated with anomalous inferior venacava; European Radiology. 9 (5): 935-6.
  5. Koch, F.R; Bouwer, A.J; Bornman, M.S; DU Plessis, D.J; (1986): Anomalies of inferior vena cava South African Medical Journal. 69 (I): 69-70.
  6. Larde, D; Frijol, J; Belloir, C; Meunier, S; Vasile, N; (1981): Contribution of computed tomography to the exploration of congenital anomalies of inferior venacava; Journal of Radiology 62 (6-7); 363 -7.
  7. Rispoli, P; Conforti, M; Cassatella, R; Varetto, G; Melloni, C.D; Raso, A.M; (2001): Left sided inferior venacava in patients submitted to aortoiliac surgery, our experience & review of literature; Journal of Cardiovascular Surgery (Torino) 42 (2) :249- 55
  8. Sardi, A; Minken, S.L; (1987): The placement of intracaval filters in an anomalous (Left. Sided) venacava; Journal of Vascular Surgery 6 (1) : 84-6.
  9. Uwatoko, N; Asano, T; Hayakawa, M; Ikeda, Y; Miyajima, A; Nakajima, F; Nakamura, H; (1999): [A patient with successful renal transplantation using donor kidney with congenital abnormalities of inferior venacava- article in japanese] Nippon hinyokika Gakkai zaasshi 90 (1) : 57- 60.
  10. Williams, P.L; Bannister, H; Berry, M.M; Collins, P; Dyson, M; Dussek, J.E., Fergusson, M.W.J.; Gray’s Anatomy In: Embryology and Development. 38th Edn, Churchill Livingstone. London: 324-5 (1995).

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Photo 1. Anomalous venous channel (Lt. IVC) Connecting left renal vein with left common iliac vein,right being normal.

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Photo-2. Renal artery shows segmental branches before hilum (bilateral); artery being in front of vein.

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Photo-3. Azygos vein starting as lumbar azygos vein which joins subcostal, to 11th, lower 9th inter costal veins in an arched manner (Rt. Side)

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Photo-4 Inferior hemiazygos vein starts by joining, two 11th, 10th, 9th intercostal veins in a similar arched manner, joined by superior hemiazygos,vein at the level of T9 Vertebra (Lt. Side).

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