MAMC Journal of Medical Sciences

: 2017  |  Volume : 3  |  Issue : 1  |  Page : 28--30

Complete Thrombosis of the Conduit and Inferior Vena-cava Early After Extracardiac Fontan Operation

Nayem Raja1, Saket Agarwal1, Akhilesh S Tomar2, Muhammad A Geelani1, Swarnika Srivastava1,  
1 Department of Cardiothoracic & Vascular Surgery, G. B. Pant Institute of Postgraduate Medical Education and Research, New Delhi, Delhi, India
2 Department of Cardiac Anesthesiology, G. B. Pant Institute of Postgraduate Medical Education and Research, New Delhi, Delhi, India

Correspondence Address:
Nayem Raja
Department of Cardiothoracic & Vascular Surgery, G. B. Pant Institute of Postgraduate Medical Education and Research, J.L.N. Marg, New Delhi - 110 002, Delhi


Conduit thrombosis is a rare catastrophic complication of Fontan procedure. We report a case wherein the entire conduit and most of the inferior vena-cava got thrombosed within 8 days of the Fontan procedure. The patient was successfully managed by a surgical thrombectomy and Fontan takedown.

How to cite this article:
Raja N, Agarwal S, Tomar AS, Geelani MA, Srivastava S. Complete Thrombosis of the Conduit and Inferior Vena-cava Early After Extracardiac Fontan Operation.MAMC J Med Sci 2017;3:28-30

How to cite this URL:
Raja N, Agarwal S, Tomar AS, Geelani MA, Srivastava S. Complete Thrombosis of the Conduit and Inferior Vena-cava Early After Extracardiac Fontan Operation. MAMC J Med Sci [serial online] 2017 [cited 2020 May 28 ];3:28-30
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Full Text


Fontan procedure is the final common pathway for many complex congenital heart diseases, including single ventricle physiology. Thromboembolic events account for significant morbidity and mortality post-Fontan procedure, and there always remains a dilemma regarding their management, as no definite guidelines are available. The incidence rates of venous thromboembolic events after Fontan operation range from 3 to 16%.[1],[2] Obstruction of the Fontan circuit is a life-threatening condition and requires immediate intervention. Complete thrombosis of the Fontan circuit along with inferior venacava (IVC) is very rare and almost always fatal.[3] We report a case of fenestrated Fontan procedure complicated by complete early thrombosis of the extracardiac conduit and the IVC, which was successfully managed by surgical thrombectomy.

 Case Report

An 8-year-old boy underwent a completion-Fontan operation for tricuspid atresia with hypoplastic right ventricle after a prior bidirectional (BD) Glenn performed at the age of 2 years. His preoperative angiogram revealed slightly borderline pulmonary arteries (PAs) with patent Glenn flow. PA pressures were 14/10 mmHg with a mean of 12 mmHg. Extracardiac Fontan was performed using a 22 mm polyethylene terephthalate (PETE) conduit with a fenestration of 4 mm between the conduit and the right atrium. Heparin infusion at 8–10 units/kg/h was started in the postoperative period (4 h postsurgery) and oral anticoagulants were started from the postoperative day 1 and activated coagulation time (ACT) was maintained in between 150 and 180 s and an international normalized ratio (INR) between 1.5 and 2.0. Heparin infusion was stopped after 48 h.

The postoperative period was complicated by raised Fontan pressure (15–20 mm Hg) with features of ascites, pedal edema, and scrotal edema. However, echocardiogram revealed normal Fontan flow. The pedal and scrotal edema gradually decreased, but he developed hepatomegaly and dilated superficial abdominal veins. The patient had an episode of hemoptysis on 7th postoperative day for which a computerized tomographic (CT) scan of chest was performed. It showed complete thrombosis of the Fontan circuit [Figure 1] and [Figure 2] with one small area of lung infarct. A cardiac catheter angiogram revealed complete thrombosis of the Fontan circuit and suprahepatic IVC [Figure 3] and partial thrombosis of the infrahepatic IVC. Dye was flowing freely through the superior vena-cava (SVC) into the PAs, with no dye flowing through the Fontan circuit into the conduit or the IVC. INR on postoperative day 7 was 1.9. Owing to excessive thrombosis, the patient was not considered for thrombolysis.{Figure 1}{Figure 2}{Figure 3}

The patient was taken up for urgent surgery on the 9th postoperative day. The patient was placed on bypass via aortic and SVC cannulation, which achieved almost full flows. The conduit was incised near the PA end, which revealed complete thrombosis of the PETE conduit [Figure 4]. It was taken down with a rim of PETE tube left behind on the PA end. All thrombi were removed from the PA and a 4Fr Fogarty catheter was used to remove small thrombi from branch PAs. The rim of the conduit at the PA was closed by suturing it. Aortic cross clamp was applied and cardioplegia was administered. The right atrium was opened around the fenestration and conduit was detached from the IVC end. Thrombus was removed from the IVC using 10F Foley’s catheter. The IVC return was managed by a pump sucker. The patient was very sick and the PAs were of borderline size; so it was decided to take down the Fontan and convert him to a BD Glenn. Total circulatory arrest (TCA) was established at a temperature of 24°C and a bovine pericardial conduit was anastomosed to the IVC stump. Circulation was established and the upper end of the tube was anastomosed to the right atrium. TCA time was 10 min. The patient was gradually weaned off cardiopulmonary bypass (CPB). Aortic cross clamp time was 20 min and CPB time was 40 min. The patient had an uneventful postoperative course and was discharged on postoperative day 16 on aspirin and anticoagulant.{Figure 4}

The patient will be followed up in the outpatient department to consider him for possible completion-Fontan procedure in the future, using a bovine pericardial conduit or a polytetrafluoroethylene (PTFE) conduit, which is believed to be less thrombogenic as they have a smoother surface as compared to a PETE conduit.


Fontan operation is indicated for a variety of complex congenital heart lesions. However, studies indicate that there is a substantial morbidity post-Fontan procedure from perioperative and long-term complications. Thromboembolic events are one of the important complications, which sometimes require intervention and finally a reoperation.[2] Complete thrombosis is nearly always fatal. The cause of thromboembolism after the Fontan procedure may be attributed to low flow states, stasis in the venous pathways, right to-left shunts, prosthetic materials, atrial arrhythmias, and hypercoagulable states.[4] In our patient, coagulation tests were within the normal range and no episode of arrythmia was present in the postoperative period.

Thromboembolic events can occur from as early as 6 days to many years after a Fontan procedure.[3] The pulmonary blood flow after the Fontan operation is passive and is dependent on the transpulmonary gradient between the left atrium and the PA. Factors like a decrease in the size of the pulmonary vessels, increased pulmonary vascular resistance, or systemic ventricular failure, which reduces pulmonary blood flow, can lead to increased central venous pressure and eventually to sluggish venous blood flow, thus producing a risk factor for thrombosis or thromboembolism.[3],[5] The use of PETE graft in this case may also be a contributing factor for thrombosis. PETE graft (available in our hospital supply) was used rather than a PTFE graft due to the unavailability of PTFE grafts in our hospital and the patient being from a lower socioeconomic class. Anticoagulation prophylaxis for thromboembolism after Fontan surgery is usually started, but there is no consensus concerning the postoperative mode and duration of anticoagulation prophylaxis. In the present patient, heparin infusion was started with maintenance of ACT in between 150 and 180 s. This was subsequently changed to oral warfarin tablet and INR was maintained between 1.5 and 2.0.

The outcome after Fontan operation has been reported to be poor with scarce management. Reports show complete resolution of thrombosis, obtained in 48% of cases with anticoagulation and death occurred in 25%.[2],[4] There has been no study which report the use of thrombolysis in thrombosis of the Fontan circuit. However, in hemodynamically stable patients initially, there is an option of use of thrombolysis and anticoagulant therapies, but these treatment strategies need at least 12–24 h to be effective. In an acute thromboembolic event such as the present one with complete thrombosis of the conduit along with IVC (large thrombus load), medical treatment in the form of thrombolytics (reteplase) may cause complications which can further delay surgical treatment. Therefore, we preferred to perform an urgent surgical thrombectomy with Fontan takedown, which improved the patient’s condition considerably. Redo Fontan operation was not performed in the same setting, as it was an emergency life-saving procedure and the patient was having borderline hemodynamics. The patient was to be followed up for a possible Fontan operation in the future.


Thromboembolism is an infrequently reported complication in the immediate postoperative period after the Fontan procedure, and complete thrombosis of the Fontan conduit along with IVC is a very rare event. An emergency surgical thrombectomy should be considered for patients with acute clinical deterioration after acute thrombosis of the conduit.

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Conflicts of interest

There are no conflicts of interest.


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