WANDERING EDEMA, CENTRAL VENOUS CATHETERISM AND GUIDELINES

by Davide Rossi, Daniela Ricciardi, Ketty Savino* and Riccardo M. Fagugli
Nephrology and Dialysis Department, Silvestrini Hospital, Perugia, Italy
* Cardiology and cardiovascular pathophysiology, Silvestrini Hospital, Perugia, Italy

Case Report:
A 80-year-old Caucasian female, with a past medical history of chronic kidney failure, diffuse atherosclerosis, multiple myeloma and breast cancer surgically treated, was admitted to the hospital because of remarkable volume overload and worsening renal function within three months. On examination, there was lower limbs edema and a characteristic wandering edema of the arms and of the upper trunk; a grade 2-3/6 cardiac systolic ejection murmur was present. The laboratory tests revealed the presence of severe kidney failure and her 24 h urine volume was below 300 ml, although high diuretics dose. The patient denied to have taken potential neprhotoxic drugs (i.e. NSADs), the urine colture was negative and the renal ultrasound showed no hydronephrosis and a significant length reduction of both kidneys.

Question 1) - According to the NKF-K/DOQI Guidelines 2000, which insertion site for temporary vascular access should not be used in a patient with end-stage renal disease? (Only ONE answer is correct)
>	a) subclavian vein
>	b) internal jugular vein
>	c) femoral vein
<% if Answer1 = RightAnswer1 then Response.Write " Answer to question n. 1 is right! " else Response.Write " Answer to question n. 1 is wrong! " Response.Write " The right answer is the checked one! " end if %> The correct answer is "1". Subclavian vein catheterization is associated with central venous stenosis, which could generally preclude the use of the entire ipsilateral arm for vascular access (Schwab SJ et: Hemodialysis-associated subclavian vein stenosis. Kidney Int 33:1156-1159, 1988; Barrett N et al: Subclavian stenosis: A major complication of subclavian dialysis catheters. Nephrol Dial Transplant 3:423-425, 1988; Spinowitz BS et al: Subclavian vein stenosis as a complication of subclavian catheterization for hemodialysis. Arch Intern Med 147:305-307, 1987). Therefore, DOQI guidelines recommend not to use subclavian vein catheterization in patients who may need permanent vascular access. <% newID = 2 else newID = 11 %>

Subclavian access was avoided because of the risk of central venous stenosis in a patient with end-stage renal failure and a future need for artero-venous fistula. The femoral vein catheterization was initially judged as secondary option, because of an increased deep vein thrombosis risk by patient immobilization. Therefore, a jugular catheter placement was considered, but before its insertion, a transthoracic echocardiography was performed in order to rule out the occurrence of atrium or central veins thrombosis in a patient with upper trunk and arms edema. Unexpectedly, the exam revealed the presence of a membrane from middle lateral right atrium to atrial septum, interpreted as a Chiari's network (Figure 1).

Question 2) - What is the risk of cardiac catheterization in a patient with Chiari's network? (Only ONE answer is correct)
>	a) cardiac entrapment
>	b) vein thrombosis
>	c) catheter infection
<% if Answer2 = RightAnswer2 then Response.Write " Answer to question n. 2 is right! " else Response.Write " Answer to question n. 2 is wrong! " Response.Write " The right answer is the checked one! " end if %> The correct answer is "1". Goldschlager et al described the case of a patient with cardiac catheter entrapment in the membranous structure of Chiari's web. Although, it is an unusual complication of cardiac catheterization, it may occur and makes cardiac catheterization not recommended(2) <% newID = 3 else newID = 22 %>

Question 3) - Which one of the following conditions is associated with Chiari's network? (Only ONE answer is correct)
>	a) paradoxic embolism
>	b) interatrial communication
>	c) thrombus within the network
>	d) all of the above
<% if Answer3 = RightAnswer3 then Response.Write " Answer to question n. 3 is right! " else Response.Write " Answer to question n. 3 is wrong! " Response.Write " The right answer is the checked one! " end if %> The correct answer is "4". The finding of a patent foramen ovale associated with Chiari's network is quite common, being present in up to 83% of patients with this condition1. In fact, a flow pattern within the right atrium may in part be present in adult life and if the blood flow is preferentially directed from the inferior vena cava toward the fossa ovalis, a patent foramen ovale may persists and the development of an atrial aneurysm may occur1. This association is clinically relevant because of the risk of paradoxic embolism, occurring even in the absence of an apparent peripheral venous source: Chiari's web itself may be the site of thrombosis, by either primary thrombus formation or by entrapment of emboli from peripheral veins1. In our case, we cannot exclude an ischemic stroke by arterial embolism (being not done autopsy study). Conclusions Chiari's network was first described in 1897 by Hans Chiari who observed 11 cases in which a network of threads and fibers was found in the right atrium. This network was connected with the Eustachian and Thebesian valves at the orifice of the inferior vena cava and the coronary sinus with wide attachments to the upper region of the right atrium near the crista terminalis, to the interatrial septum or to the tuberculum of Lower1-3. In early cardiac development, two venous valves guard the right horn of the sinus venosus, which serves, during the embryonic life, to direct the blood flow from the inferior vena cava through the fossa ovalis into the left atrium. The smaller left valve is incorporated into the septum secundum, while the right valve divides the right atrium1-5. In normal development, the right valve regresses, its cephalic portion remaining as the crista terminalis and its caudal part dividing to form the Eustachian and Thebesian valves. Chiari's network represents the congenital remnant of the right valve of the sinus venosus, resulting from incomplete resorption of this structure during the embryonic development2, 3, 5, 6. This condition must be differentiated from a prominent eustachian valve1, 5 and from the condition known as "cor triatriatum dextrum", which derives from the persistence of the entire valve and usually is associated with cyanosis1, 4, 5, 7. The Chiari's web prevalence has been reported to range from 1.3% to 4% in autopsies studies1, 4, 8, often being an incidental finding at cardiac surgery or post-mortem examination. It is in fact generally not hemodinamically significant in terms of right atrial obstruction and has been regarded a normal anatomic variant that is seldom of clinical importance1. We suggest that in the case of our patient, this cardiac anomaly was hemodinamically significant, causing a transient obstruction of the right atrium or of the orifice of the inferior vena cava and therefore representing an obstacle to the blood flow into the right atrium. The volume overload of the patient might be a promoter factor causing a higher blood flow coming back to the heart. The position and the wandering feature of the edema might be explained by the highly mobility of the network, with a changeable grade of obstruction of the inferior vena cava orifice or of the right atrium. In our patient, the presence of Chiari's network was not initially suspected, and was an incidental echocardiographic diagnosis performed in order to exclude central venous obstruction. Nephrologists must be aware of this condition in patients with end-stage renal failure requiring a temporary and urgent vascular access and presenting edema of the upper trunk and of the arms. <% newID = 4 else newID = 33 %>