Outcomes of the Conversion of the Fontan-Kreutzer Operation to a Total Cavopulmonary Connection for the Failing Univentricular Circulation

Abstract

Background:

The Fontan-Kreutzer procedure (FK) was widely performed in the past, but in the long-term generated many complications resulting in univentricular circulation failure. The conversion to total cavopulmonary connection (TCPC) is one of the options for treatment.

Objective:

To evaluate the results of conversion from FK to TCPC.

Methods:

A retrospective review of medical records for patients who underwent the conversion of FK to TCPC in the period of 1985 to 2016. Significance p < 0,05.

Results:

Fontan-type operations were performed in 420 patients during this period: TCPC was performed in 320, lateral tunnel technique in 82, and FK in 18. Ten cases from the FK group were elected to conversion to TCPC. All patients submitted to Fontan Conversion were included in this study. In nine patients the indication was due to uncontrolled arrhythmia and in one, due to protein-losing enteropathy. Death was observed in the first two cases. The average intensive care unit (ICU) length of stay (LOS) was 13 days, and the average hospital LOS was 37 days. A functional class by New York Heart Association (NYHA) improvement was observed in 80% of the patients in NYHA I or II. Fifty-seven percent of conversions due to arrhythmias had improvement of arrhythmias; four cases are cured.

Conclusions:

The conversion is a complex procedure and requires an experienced tertiary hospital to be performed. The conversion has improved the NYHA functional class despite an unsatisfactory resolution of the arrhythmia.

Keywords:
Heart Defects Congenital/surgery; Arrihythmias, Cardiac/surgery; Fontan Procedure; Mortality; Fontan-Kreutzer Prodedure

Resumo

Fundamento:

O procedimento de Fontan-Kreutzer (FK) foi amplamente realizado no passado, mas a longo prazo gerou muitas complicações, resultando em falha na circulação univentricular. A conversão para conexão cavopulmonar total (CCPT) é uma das opções de tratamento.

Objetivo:

Avaliar os resultados da conversão de FK para CCPT.

Métodos:

Revisão retrospectiva de prontuários de pacientes submetidos à conversão de FK para CCPT no período de 1985 a 2016. Significância p < 0,05.

Resultados:

Operações do tipo Fontan foram realizadas em 420 pacientes durante este período: CCPT foi realizada em 320, técnica de túnel lateral em 82 e FK em 18. Dez casos do grupo FK foram eleitos para conversão em CCPT. Todos os pacientes submetidos à conversão de Fontan foram incluídos neste estudo. Em nove pacientes, a indicação deveu-se a arritmia não controlada e em um devido à enteropatia perdedora de proteínas. A morte foi observada nos dois primeiros casos. O tempo médio de internação na unidade de terapia intensiva (UTI) foi de 13 dias e o tempo médio de internação hospitalar foi de 37 dias. Uma classe funcional pela melhora da New York Heart Association (NYHA) foi observada em 80% dos pacientes em NYHA I ou II. Cinquenta e sete por cento das conversões devido a arritmias tiveram melhora das arritmias; quatro casos foram curados.

Conclusões:

A conversão é um procedimento complexo e requer que um hospital terciário experiente seja realizado. A conversão melhorou a classe funcional da NYHA, apesar de uma resolução insatisfatória da arritmia.

Palavras-chave:
Cardiopatias Congênitas/cirurgia; Arritmias Cardíacas/cirurgia; Técnica de Fontan; Mortalidade; Procedimento de Fontan-Kreutzer

Introduction

The Fontan operation (FO) is an important landmark in the history of congenital heart diseases because it increased the life expectancy of children with single-ventricle hearts.^1,2 After the development of the superior cavopulmonary connection (Glenn operation), the survival rate in univentricular hearts increased leading to the development of FO. The first description by Fontan and Baudet,³ was depicted as a right-heart bypass in patients with tricuspid atresia to improve the basal saturation and consequently improve their quality of life and life expectancy while avoiding the complications of chronic hypoxia. These and other techniques that use atrial as a conduit are called atrium-pulmonary connections. Many other techniques and strategies for Fontan operation have been developed since it´s description.

A few years after the first description, in 1973, this technique was modified by Kreutzer,⁴ where the right atrial appendage was connected directly to the trunk of the pulmonary artery with a shorter surgical time than Fontan's previous description. The Fontan-Kreutzer technique (FK) was widely performed and diffused at the beginning, but complications were observed in the long range, such as enlarged atrium, atrial arrhythmias, stasis intracavitary thrombosis and compression of pulmonary veins.^5-9 These complications are difficult to treat leading to worsening functional class by New York Heart Association (NYHA) and often evolving to ventricular dysfunction and failure of the univentricular circulation.

The next technique, described by de Leval in 1988,¹⁰, was the cavopulmonary connection using intra-atrial lateral tunnel. In 1990, Marcelletti et al.¹¹ described the total cavopulmonary connection (TCPC) using extra-cardiac tube. In subsequent studies it was observed that the TCPC presented better results than the previous techniques.^2,12-16

Nowadays the TCPC is the most used, however, many patients in whom the old techniques, such as FK, were performed survived and it was possible to observe long-term complications. A treatment option for these patients was to perform a conversion of the FK to TCPC. The removal of the atrium from the pulmonary circulation would decrease the volumetric overload reducing atrial dimensions and consequently lessening secondary outcomes.^17-26

Objective

The aim of this study is to evaluate the results of the conversion of FK to TCPC in patients with signs of univentricular circulation failure.

Methods

A retrospective review of medical records, in-hospital and outpatient notes, was performed for patients who underwent a Fontan conversion (FC). The inclusive criteria consisted of the conversion of FK to TCPC in the period of 1985 to 2016 regardless of their underlying pathology. This was a single center study performed in the Heart Institute (INCOR - HCFMUSP), São Paulo, Brazil. We reviewed all surgical records comprising age at procedure, ventricle morphology, indications for conversion, mortality, the presence of arrhythmias, functional class and the presence of comorbidities after correction.

We excluded the patients in whom FC was indicated but the death occurred before the surgical procedure or intraoperatively, or in whom the procedure was not accepted by the patient or their surrogate decision maker.

This study has been approved by the ethics committee of this Institution by the number CAAE 56617216.6.0000.0068. As the study is retrospective in nature, there was no need for the elaboration of a consent term.

Statiscal analysis

We used the Kolmogorov-Smirnov test to compare and chooose the sample of the study. Descriptive analysis was performed, including clinical and surgical characteristics. Continuous numerical variables were presented as median and interquartile range (IQR; 25th-75th percentile). Categorical variables were presented as frequencies, absolute number and percentages. Variables with normal distribution were presented average and standard deviation. Estimated actuarial survival were determined using the Kaplan-Meier method. Statistical analysis was performed with SPSS 23.0 for Windows (IBM Corp. Released 2015, IBM SPSS Statistics for Windows, Version 22.0, Armonk, NY: IBM Corp).

Results

The total number and type of FO performed are shown in Table 1. Of the 18 FK cases, 10 were elected for the conversion to the TCPC due to signs of Fontan circulation failure. All 10 patients previous FK were submitted to a FC procedure and all 10 were included in this study.

Table 1
Fontan operation performed between years 1995-2016

Fontan Type	Number of patients
Fontan-Kreutzer	18 (4.3%)
Lateral Tunnel	82 (19.5%)
TCPC with extra cardiac tube	320 (76.2%)
Total	420 (100%)

• TCPC: total cavo-pulmonary connection.

The FK were conducted in the beginning of our experience, all were performed before the year 2004, most of them before the year 1999. Only 29 surgeries of lateral tunnels were performed after 2004 and after this year the most performed surgery was the TCPC with extra cardiac tube.

A mortality of 11% (7,9% early deaths and 3,1% of late deaths) was observed for the FO procedure performed in this period. Regarding the ventricle morphology, we observed that 318 cases (75,7%) were classified as left ventricle, 57 (13,6%) as right ventricle, 40 (9,5%) had both ventricles and five (1,2%) had undefined ventricle.

Analyzing the population of the converted, we observed that 40% of the patients were male and 60% female. The youngest patient who underwent conversion was 11 years old and the oldest patient was 42 years old, with the mean average of 23.2 years old.

In nine cases (90%) the surgery was indicated for uncontrolled arrhythmia and one case was indicated by protein-losing enteropathy. In three cases, surgical cryoablation was performed in the same operative time. Before conversion three patients were in functional class I, four in functional class II and three in functional class III.

We observed two deaths in the period, an early death (on the second postoperative day) due to significant bleeding and coagulopathy, and a late death (38th postoperative day) due to multiple sepsis and stroke. Both occurred during hospitalization in a postoperative intensive care unit (ICU). The actuarial survival of 5 and 10 years was 80%, as shown in Figure 1.

Figure 1
Survival curve of patients submitted to FK conversion to TCPC.

After conversion, 80% of the patients who were in functional class II or higher evolved with functional class improvement. Currently, six patients are in functional class I (75%), one patient is in functional class II (12.5%) and one patient is in functional class III (12.5%).

Regarding cardiac arrhythmias, 44% of conversions indicated by arrhythmias had improvements after conversion. Four cases were cured with no need of specialist follow-up and three cases had an arrhythmic condition that needed specialist flow-up.

Before conversion, ventricular dysfunction was present in five patients. One of them evolved to death, and all the others had an improvement in their function in relation to the preoperative period, three of which currently have preserved function and one that had had moderate dysfunction previously, and now presents a slight dysfunction. These variables can be visualized on Table 2.

Table 2
Clinical improvements after conversion to TCPC

Variables	Before convertion (n = 10)	After convertion (n = 8)
Middly disfuction	2 (20%)	1 (12.5%)
Moderate disfunction	3 (30%)	0 (0%)
Arrhythmias	9 (90%)	4 (44%)
NYHA Functional class I	3 (30%)	6 (75%)
NYHA Functional class II	4 (40%)	1 (12.5%)
NYHA Functional class III	3 (30%)	1 (12.5%)

• TCPC: total cavo-pulmonary connection; NYHA: New York Heart Association.

For three of the cases in which surgical cryoablation was performed, one evolved to death despite of the arrhythmia. The other two cases had episodes of arrhythmia after conversion, one of which evolved to bradyarrhythmia requiring a pacemaker, and currently this patient is being evaluated for heart transplantation.

The mean ICU length of stay (LOS) was 13 days, the shortest time was 2 days and the highest 38 days. The average total hospital LOS was 37 days, the shortest being 17 days and the highest 59 days.

As complications, two patients presented bleeding, one pericarditis, one ischemic stroke, one presented convulsive seizures, one presented ventricular dysfunction and one presented bradyarrhythmia. Currently, eight patients are undergoing an outpatient clinic and one patient is being evaluated for heart transplantation.

Discussion

Fontan-Kreutzer conversion to TCPC is not a simple procedure. Despite a small sample size, we observed a 20% mortality in our experience. The prolonged hospitalization time, average of 37 days, also demonstrates the problems in the management of these patients in the postoperative period. In 25% of the patients evaluated, some types of complications were observed in the postoperative period, where most of them were resolved clinically without the need for new surgical procedures. These facts indicate that ideally this type of surgery should be performed in specialized tertiary centers with the availability of a multidisciplinary team for the best care of the patients.

Caneo et al.² showed a total mortality of 11% for all FO conducted in our Institution, the majority of the death cases were observed in the first period of the study (between years 1984-1994). All atriopulmonary Fontan were performed in the first and second periods (between years 1984-2004), 23,9% of them was elected for conversion years after, and all of these Fontan procedures were performed in the first period. A similar finding was observed in our study, where mortality occurred in the beginning of the experience by the years 1996 and 2000, our first two cases of conversion. It is possible that these two cases have evolved to an unfavorable outcome due to the unavailability of technological resources presented at that time.

Atrial arrhythmias were the main indications of conversion because the modifications performed by Kreutzer resulted in large atrial dilations generating many disorders of the atrial rhythm, which complicated ventricular dysfunction and worsened symptomatology. We obtained an unsatisfactory rate of resolution of these arrhythmias (only 57% of cases indicated by arrhythmia). In cases in which surgical cryoablation was performed (three cases), the outcomes were not favorable: one case evolved to death in the recent postoperative period (due to bleeding and coagulopathy), one arrhythmia was not resolved, and one case progressed with total atrioventricular block, needing definitive pacemaker implantation. This patient evolved with dysfunctions and is currently in line for cardiac transplantation due to significant worsening of functional class and ventricular function. Although most studies suggest a benefit performing cryoablation,^24,26-31 our findings suggest that surgical cryoablation should not be performed routinely in conversion to TCPC surgery, despite our small sample size.

Studies from South Korea and Japan^32,33 have reported security and improvement in clinical outcomes by implanting permanent pacemaker in Fontan conversion. However, our only case with pacemaker implantation had unfavorable outcome, and is now in line for heart transplantation. Takeuchi et al.³⁴ showed favorable outcomes combining FC with resynchronization, but none of our patients were elected for resynchronization.

The presence of ventricular dysfunction before the FC procedure was found in five cases. All cases were elected to conversion by arrhythmia, one of them died and all the survivors had improved ventricular functions. Therefore, we conclude that the procedure presented a satisfactory result in improving the ventricular function. However, we observed no improvement of the arrhythmia in two cases of the survivors who presented preoperative dysfunction.

There was a significant improvement in functional class and quality of life of these patients after conversion, and therefore, our results demonstrate the importance and necessity of converting selected cases. These findings motivated us to perform this surgery in more cases after our first two cases that evolved to death. Currently, we have only a few cases of FK alive being followed in our ambulatory.

A review by Brida et al.³⁵ analyzed 1182 patients from 37 studies and concluded that conversion had substantial mortality risk. However, the results vary between centers and lower early mortality was associated with earlier age and with treatment being performed at high experienced centers.

Conclusions

The conversion of atrial-pulmonary anastomosis (Fontan-Kreutezer) to TCPC is a complex procedure with high mortality and morbidity justifying a prolonged hospitalization time, so this surgery needs to be performed in experienced tertiary hospitals. The conversion of atrial-pulmonary anastomosis to TCPC has, in our experience, improved the functional class and consequently the patients' quality of life despite an unsatisfactory resolution of the arrhythmia.

• Sources of Funding
  There were no external funding sources for this study.
• Study Association
  This study is not associated with any thesis or dissertation work.
• Ethics approval and consent to participate
  This article does not contain any studies with human participants or animals performed by any of the authors.

References

• ¹
  Caneo LF, Neirotti RA, Turquetto ALR, Jatene MB: A operação de Fontan não é o destino final. Arq Bras Cardiol. 2016;106(2):162-5.
• ²
  Caneo LF, Turquetto ALR, Neirotti RA, Binotto MA, Miana LA, Tanamati C, et al. Lessons Learned From a Critical Analysis of the Fontan Operation Over Three Decades in a Single Institution. World J Pediatr Cong Heart Surg. 2017; 8(3):376-84.
• ³
  Fontan F, Baudet E: Surgical repair of tricuspid atresia. Thorax. 1971;26(3):240-8.
• ⁴
  Kreutzer J, Keane F, Lock JE,Walsh EP, Jonas RA, Castaneda AR, et aI. Conversion of modified Fontan procedure to lateral atrial tunnel cavopulmonary anastomosis. J Thorac Cardiovasc Surg. 1996;111(6):1169-76.
• ⁵
  Kreutzer C, Kreutzer J, Kreutzer GO: Five decades of the Fontan Kreutzer procedure. Front Pediatr. 2013 Dec 18;1:45.
• ⁶
  Miura T. Hiramatsu T, Forbess JM, Marver JE Jr. Effects of elevated coronary sinus pressure on coronary blood flow and left ventricular function: Implications after the Fontan operation. Circulation.1995;92(9 Suppl):II298-303.
• ⁷
  Poh CL, Zannino D, Weintraub RG, Winlaw DS, Grigg LE, Cordina R, et al. Three decades later: The fate of the population of patients who underwent the Atriopulmonary Fontan procedure. Int J Cardiol. 2017; 231:99-104.
• ⁸
  Izumi G, Senzaki H, Takeda A, Yamazawa H, Takei K, Furukawa T, et al. Significance of right atrial tension for the development of complications in patients after atriopulmonary connection Fontan procedure: potential indicator for Fontan conversion. Heart Vessels. 2017;32(7):850-5.
• ⁹
  Park HK, Shin HJ, Park YH. Outcomes of Fontan conversion for failing Fontan circulation: mid-term results. Interact Cardiovasc Thorac Surg. 2016;23(1):14-7.
• ¹⁰
  De Leval MR, Kilner P, Gewillig M, Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations: experimental studies and early clinical experience. J Thorac Cardiovasc Surg. 1988;96(5):682-95.
• ¹¹
  Marcelletti C, Corno A, Giannico S,Marino B. Inferior vena cava-pulmonary artery extracardiac conduit: a new form of right heart bypass. J Thorac Cardiovasc Surg. 1990;100(2):228-32.
• ¹²
  Mastalir ET, Kalil RA, Horowitz ES, Wender O, Sant'Anna JR, Prates PR, et al. Late clinical outcomes of the fontan operation in patients with tricuspid atresia. Arq Bras Cardiol. 2002;79(1):56-60.
• ¹³
  Henaine R, Raisky O, Chavanis N, Aubert S, Di Filippo S, Ninet J. Evolution of the Fontan operation and results in patients with single ventricles or mixed congenital malformations. Arch Mal Coeur Vaiss. 2005;98(1):13-9.
• ¹⁴
  Rodefeld MD, Frankel SH, Giridharan GA. Cavopulmonary assist: (em)powering the univentricular fontan circulation. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2011;14(1):45-54.
• ¹⁵
  Wilder TJ, Ziemer G, Hickey EJ, Gruber PJ,Karamlou T, Kirshbom PM,et al. Surgical management of competing pulmonary blood flow affects survival before Fontan/Kreutzer completion in patients with tricuspid atresia type I. J Thorac Cardiovasc Surg 2015;150(15):1222-30.e7.
• ¹⁶
  Backer CL, Costello JM, Deal BJ. Fontan conversion: guidelines from Down Under. Eur J Cardiothorac Surg. 2016;49(2):536-7.
• ¹⁷
  Mavroudis C, Deal BJ. Fontan Conversion: Literature Review and Lessons Learned Over 20 Years. World J Pediatr Congenit Heart Surg. 2016;7(2):192-8.
• ¹⁸
  Backer CL. Rescuing the Late Failing Fontan: Focus on Surgical Treatment of Dysrhythmias. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2017 Jan;20:33-7.
• ¹⁹
  van Melle JP, Wolff D, Hörer J, Belli E, Meyns B, Padalino M, et al. Surgical options after Fontan failure. Heart. 2016; 102(14):1127-33.
• ²⁰
  Sharma V, Burkhart HM, Cetta F, Hagler DJ, Phillips SD, Dearani JA. Fontan conversion to one and one half ventricle repair. Ann Thorac Surg. 2012;94(4):1269-74; discussion 1274.
• ²¹
  Coats L, Crossland D, Hudson M, O'Sullivan J, Hasan A. Fontan conversion is a dated approach to the failing Fontan. Heart. 2016;102(20):1692.
• ²²
  Egbe AC, Connolly HM, Dearani JA, Bonnichsen CR, Niaz T, Allison TG, et al. When is the right time for Fontan conversion? The role of cardiopulmonary exercise test. Int J Cardiol. 2016 Oct 1; 220:564-8.
• ²³
  Higashida A, Hoashi T, Kagisaki K, Shimada M, Ohuchi H, Shiraishi I,et al. Can Fontan Conversion for Patients Without Late Fontan Complications be Justified? Ann Thorac Surg. 2017103(6):1963-8.
• ²⁴
  Ono M, Cleuziou J, Kasnar-Samprec J, Burri M, Hepp V, Vogt M, et al. Conversion to Total Cavopulmonary Connection Improves Functional Status Even in Older Patients with Failing Fontan Circulation. Thorac Cardiovasc Surg. 2015; 63(5):380-7.
• ²⁵
  Said SM, Burkhart HM, Schaff HV, Cetta F, Driscoll DJ, Li Z, et al. Fontan conversion: identifying the high-risk patient. Ann Thorac Surg. 2014;97(6):2115-21; discussion 2121-2.
• ²⁶
  Poh CL, Cochrane A, Galati JC, Bullock A, Celermajer DS, Gentles T, et al. Ten-year outcomes of Fontan conversion in Australia and New Zealand demonstrate the superiority of a strategy of early conversion. Eur J Cardiothorac Surg. 2016;49(2):530-5; discussion 535.
• ²⁷
  Balaji S, Gewilling M, Bull C, de Leval MR, Deanfield JF. Arrhythmias after the Fontan procedure. Comparison of total cavopulmonary connection and atriopulmonary connection. 1991 Nov;84(5 Suppl):III162-7.
• ²⁸
  Backer CL. 12th Annual C. Walton Lillehei Memorial Lecture in Cardiovascular Surgery: Fontan conversion--the Chicago experience. Cardiol Young. 2011; 21(Suppl 2):169-76.
• ²⁹
  Deal BJ, Costello JM, Webster G, Tsao S, Backer CL, Mavroudis C. Intermediate-Term Outcome of 140 Consecutive Fontan Conversions with Arrhythmia Operations. Ann Thorac Surg. 2016; 101(2):717-24.
• ³⁰
  Sridhar A, Giamberti A, Foresti S, Cappato R, García CR, Cabrera ND, et al. Fontan conversion with concomitant arrhythmia surgery for the failing atriopulmonary connections: mid-term results from a single centre. Cardiol Young. 2011;21(6):665-9.
• ³¹
  Agnoletti G, Borghi A, Vignati G, Crupi GC. Fontan conversion to total cavopulmonary connection and arrhythmia ablation: clinical and functional results. Heart. 2003;89(2):193-8.
• ³²
  Jang WS, Kim WH, Choi K, Nam J, Choi ES, Lee JR, et al. The mid-term surgical results of Fontan conversion with antiarrhythmia surgery. Eur J Cardiothorac Surg. 2014;45(5):922-7.
• ³³
  Hiramatsu T, Iwata Y, Matsumura G, Konuma T, Yamazaki K. Impact of Fontan conversion with arrhythmia surgery and pacemaker therapy. Eur J Cardiothorac Surg. 2011;40(4):1007-10.
• ³⁴
  Takeuchi D, Asagai S, Ishihara K, Nakanishi T. Successful Fontan conversion combined with cardiac resynchronization therapy for a case of failing Fontan circulation with ventricular dysfunction. Eur J Cardiothorac Surg. 2014;46(5):913-5.
• ³⁵
  Brida M, Baumgartner H, Gatzoulis MA, Diller GP. Early mortality and concomitant procedures related to Fontan conversion: Quantitative analysis. Int J Cardiol. 2017 Jun 1;236:132-7.

Publication Dates

• Publication in this collection
  Feb 2019

History

• Received
  20 Mar 2018
• Reviewed
  23 July 2018
• Accepted
  23 July 2018