[Multiorgan malfunction after Fontan operation in adult patients].

UNLABELLED

Although 85% of patients with univentricular heart after Fontan procedure survive twenty years after operation, the procedure alone seems to be an inadequate treatment as a permanent clinical solution. Patients with a "Fontan physiology" additionally have to face a various extra-cardiac complications, including thyroid, liver and kidney dysfunction, which are not only potentially life-threatening, but also can potentiate the circulatory insufficiency.

AIM

The aim of the study was to assess a multiorgan dysfunction in adult patients after Fontan operation in long term follow-up and compare to healthy controls.

MATERIALS AND METHODS

54 patients after Fontan procedure (age=25.1±7 years, time after operation =19.8±6.3 years, age at the time of the procedure =5.3±4.3 years) and 30 controls (26.2±5.8 years) were included to the study. Clinical and laboratory examinations were performed including: hematologic, hepatic, renal and thyroid function tests. The following laboratory tests were performed: red blood cell counts (RBC), hematocrit (Ht), hemoglobin (Hb), platelets count, red blood cell distribution width (RDW), iron level; Btype natriuretic peptide (NT-proBNP), proteinogram blood test, alanine aminotransferase (ALT), aspartate aminotransferase (AST), gammaglutamyl transpeptidase (GGTP), alkaline phosphatase (ALP), total bilirubin, alpha fetoprotein (AFP) level. Furthermore creatinine level; cystatin C, urine albumin to creatynine ratio (ACR) and urinalysis were assessed. To assess a thyroid function free triiodothyronine (fT3), free thyroxine (fT4) and thyroid stimulating hormone (TSH) were measured. Furthermore an abdomen ultrasonography was performed.

RESULTS

In terms of the hematological disorders Fontan patients had a statistically significant higher level of RBC (5.6±0,8 vs 4.8±0.4 109/μl; p<0,001), Hb (16.5±2.8 vs 14.2±1.2 g/dl; p<0,001), HCT (48.7±8.1 vs 42.1±3 %; p<0,001), RDW (14±2.6 vs 12.8±0.5 %; p=0.001), as compared to control group, while PLT level was statistically lower in Fontan group (156.2±61.4 vs 224.2±48 103/μl; p<0,0001). Hepatic parameters in Fontan patients were statistically significant higher, as depicted by the level of: ALT (28.5±10.5 vs 21.5±6 U/l, p<0,001), GGTP (85.6±48.8 vs 19.3±9 U/ l, p<0,001), total bilirubin (26.6±24.8 vs 8.9±4.7 μmol/l; p<0,001), ALP (82.4±31.5 vs 51.2±16 U/l; p<0,001) and INR (1.21±0.3 vs 0.98±0.2; p<0,001). Other parameters such as: AFP, total protein and albumin level did not statistically significantly differ. Additionally five patients (9%) according to clinical symptoms and serum albumin level were diagnosed protein-losing enteropathy (PLE). There was no difference in serum creatinine level between Fontan patients and control group (79.6±23.6 vs 75.9±18.9 μmol/l; p=0.8) as well as in uric acid level (342.7±102 vs 303±105 μmol/l; p=0.2). Cystatin C level was significantly higher in Fontan group in comparison to controls (1.1±0.6 vs 0.8±0.1 ng/ml; p=0,05). Furthermore four Fontan patients (7%) had abnormal microalbumin/creatynine ratio. Urine testing preformed in 30 Fontan patients pointed to 7 cases (23%) where hematuria was observed, while proteinuria was detected in 4 cases (13%) and urobilinogen in 2 (7%). Dysfunction of the thyroid gland was found in 30% of patients after Fontan operation (7% in the control group, p=0,034). Among disorders of the thyroid gland: 13% of patients were diagnosed with hyperthyroidism, 54% diagnosed with subclinical hypothyroidism, and the remaining 33% with hypothyroidism.

CONCLUSIONS

Our study show that adult patients after Fontan procedure in long-term follow are exposed to multiorgan complications including hematological, liver, kidney and thyroid dysfunction.