<% 'if (Session("Type") <> 1 and Session("Type") <> 5 and Session("Type") <> 28) then Response.Redirect "../Msg.asp?Messaggio1=Restricted access area!!!&Messaggio2=Return to HomePage" 'if Session("UserCount") = "" then Response.Redirect "../Msg.asp?Messaggio1=Error while initialising the quiz!!!&Messaggio2=Return to HomePage" a_capo = chr(13) + chr(10) NumQuestions = 3 RightAnswer1 = "a" RightAnswer2 = "a" RightAnswer3 = "d" currentID = Request("currentID") if currentID = "" then currentID = 1 Answer1 = Request("Question1") if Request("Answer1") <> "" then Answer1 = Request("Answer1") Answer2 = Request("Question2") if Request("Answer2") <> "" then Answer2 = Request("Answer2") Answer3 = Request("Question3") if Request("Answer3") <> "" then Answer3 = Request("Answer3") Answer4 = Request("Question4") if Request("Answer4") <> "" then Answer4 = Request("Answer4") Answer5 = Request("Question5") if Request("Answer5") <> "" then Answer5 = Request("Answer5") if currentID = 11 or currentID = 22 or currentID = 33 or currentID = 44 then Label = "Continue" elseif currentID = 55 then Label = "Continue" else Label = "Evaluate" end if %> D. Rossi - Case study




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

Corresponding author:
Davide Rossi, MD
S.C. Nefrologia e Dialisi
Ospedale Silvestrini
Azienda Ospedaliera di Perugia
S.Andrea delle Fratte
06100 Perugia, Italy
Tel: +39 0755782268
Fax: +39 0755782558
E- mail: rossidav72@virgilio.it


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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.

In consideration of the presence of fluid retention and severe kidney failure, hemodialysis treatment was begun, after the insertion of a venous catheter as temporary vascular access.


  1. Schneider B, Hofmann T, Justen MH, Meinertz T. Chiari's network: normal anatomic variant or risk factor for arterial embolic events? J Am Coll Cardiol 1995; 26(1):203-10.
  2. Goldschlager A, Goldschlager N, Brewster H, Kaplan J. Catheter entrapment in a Chiari network involving an atrial septal defect. Chest 1972;62(3):345-6.
  3. Chiari H. Über netzbildungen im rechten vorhof des herzens. Beitr Pathol Anat 1897; 22: 1- 10.
  4. Yater WM. Variations and anomalies of the venous valves of the right atrium of the human heart. Arch Pathol 1929; 7: 418-41.
  5. McMahon CJ, Nihill MR, Kovalchin JP, Lewin MB. Echocardiographic features of Chiari's network in association with tricuspid atresia. Tex Heart Inst J 2000: 27(3): 312-3.
  6. Werner JA, Cheitlin MD, Gross BW, Speck SM, Ivey TD. Echocardiographic appearance of the Chiari network: differentiation from right-heart pathology. Circulation 1981; 63: 1104-9.
  7. Alborilas ET, Edwards WD, Driscoll DJ, Seward JB. Cor triatriatum dexter: two- dimensional echocardiographic diagnosis. J Am Coll Cardiol 1987; 9: 334-7.
  8. Helwig FC. The frequency of anomalous reticula in the right atrium of the human heart "Chiari network". Report of eight cases. Am J Pathol 1932; 8: 73-9.

Acknowledgments. The authors would like to thank Mrs Gina Danon for language revision.

Conflict of interest statement.
The authors had no involvements that may raise the question of bias in the work reported or in the conclusions, implications, or opinions stated.
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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
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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.
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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).

This anatomical condition is considered as a congenital remnant of the right valve of the sinus venosus and can be found in up to 4% of autopsy studies. It is generally believed to be of poor clinical significance1, but a mild intra-atrium flow obstruction was shown in our patient by two-dimensional echo and color-Doppler. A transesophageal echocardiography was subsequently done, confirming the presence of Chiari's network, excluding a prominent Eustachian valve or cor triatriatum (Figure 2).

Moreover, transesophageal approach excluded a thrombus over the membranous network and a contrast echocardiography showed the persistence of a patent foramen ovale.

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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
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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)
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<%end if if currentID = 3 or currentID = 33then%> In consideration of the echocardiographic diagnosis and the color-doppler result, we decided to use a tunneled femoral catheter as vascular access for chronic hemodialytic treatment, waiting for the construction of an arterio-venous fistula. The patient died from an ischemic stroke three months later; nonetheless she was on anticoagulant treatment. <%if currentID = 33 then%> <%end if%>

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
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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).

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 %>

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